From 38b1d3a4e38dce903541ef48f30842b1b5e72e3d Mon Sep 17 00:00:00 2001 From: "Paul W." Date: Tue, 13 Feb 2024 18:07:22 -0500 Subject: [PATCH] init Signed-off-by: Paul W. --- Makefile | 106 + README | 6 + doc/contents.html | 678 ++ doc/index.css | 21 + doc/logo.gif | Bin 0 -> 9893 bytes doc/lua.1 | 155 + doc/lua.css | 161 + doc/luac.1 | 118 + doc/manual.css | 21 + doc/manual.html | 12046 ++++++++++++++++++++++++++++++++++ doc/osi-certified-72x60.png | Bin 0 -> 3774 bytes doc/readme.html | 337 + src/Makefile | 225 + src/lapi.c | 1463 +++++ src/lapi.h | 52 + src/lauxlib.c | 1112 ++++ src/lauxlib.h | 301 + src/lbaselib.c | 549 ++ src/lcode.c | 1871 ++++++ src/lcode.h | 104 + src/lcorolib.c | 210 + src/lctype.c | 64 + src/lctype.h | 101 + src/ldblib.c | 483 ++ src/ldebug.c | 924 +++ src/ldebug.h | 63 + src/ldo.c | 1024 +++ src/ldo.h | 88 + src/ldump.c | 230 + src/lfunc.c | 294 + src/lfunc.h | 64 + src/lgc.c | 1739 +++++ src/lgc.h | 202 + src/linit.c | 65 + src/liolib.c | 828 +++ src/ljumptab.h | 112 + src/llex.c | 581 ++ src/llex.h | 91 + src/llimits.h | 380 ++ src/lmathlib.c | 764 +++ src/lmem.c | 215 + src/lmem.h | 93 + src/loadlib.c | 767 +++ src/lobject.c | 602 ++ src/lobject.h | 815 +++ src/lopcodes.c | 104 + src/lopcodes.h | 405 ++ src/lopnames.h | 103 + src/loslib.c | 428 ++ src/lparser.c | 1967 ++++++ src/lparser.h | 171 + src/lprefix.h | 45 + src/lstate.c | 445 ++ src/lstate.h | 409 ++ src/lstring.c | 273 + src/lstring.h | 57 + src/lstrlib.c | 1874 ++++++ src/ltable.c | 980 +++ src/ltable.h | 65 + src/ltablib.c | 430 ++ src/ltm.c | 271 + src/ltm.h | 104 + src/lua.c | 679 ++ src/lua.h | 523 ++ src/lua.hpp | 9 + src/luac.c | 723 ++ src/luaconf.h | 793 +++ src/lualib.h | 52 + src/lundump.c | 335 + src/lundump.h | 36 + src/lutf8lib.c | 291 + src/lvm.c | 1901 ++++++ src/lvm.h | 141 + src/lzio.c | 68 + src/lzio.h | 66 + 75 files changed, 43873 insertions(+) create mode 100644 Makefile create mode 100644 README create mode 100644 doc/contents.html create mode 100644 doc/index.css create mode 100644 doc/logo.gif create mode 100644 doc/lua.1 create mode 100644 doc/lua.css create mode 100644 doc/luac.1 create mode 100644 doc/manual.css create mode 100644 doc/manual.html create mode 100644 doc/osi-certified-72x60.png create mode 100644 doc/readme.html create mode 100644 src/Makefile create mode 100644 src/lapi.c create mode 100644 src/lapi.h create mode 100644 src/lauxlib.c create mode 100644 src/lauxlib.h create mode 100644 src/lbaselib.c create mode 100644 src/lcode.c create mode 100644 src/lcode.h create mode 100644 src/lcorolib.c create mode 100644 src/lctype.c create mode 100644 src/lctype.h create mode 100644 src/ldblib.c create mode 100644 src/ldebug.c create mode 100644 src/ldebug.h create mode 100644 src/ldo.c create mode 100644 src/ldo.h create mode 100644 src/ldump.c create mode 100644 src/lfunc.c create mode 100644 src/lfunc.h create mode 100644 src/lgc.c create mode 100644 src/lgc.h create mode 100644 src/linit.c create mode 100644 src/liolib.c create mode 100644 src/ljumptab.h create mode 100644 src/llex.c create mode 100644 src/llex.h create mode 100644 src/llimits.h create mode 100644 src/lmathlib.c create mode 100644 src/lmem.c create mode 100644 src/lmem.h create mode 100644 src/loadlib.c create mode 100644 src/lobject.c create mode 100644 src/lobject.h create mode 100644 src/lopcodes.c create mode 100644 src/lopcodes.h create mode 100644 src/lopnames.h create mode 100644 src/loslib.c create mode 100644 src/lparser.c create mode 100644 src/lparser.h create mode 100644 src/lprefix.h create mode 100644 src/lstate.c create mode 100644 src/lstate.h create mode 100644 src/lstring.c create mode 100644 src/lstring.h create mode 100644 src/lstrlib.c create mode 100644 src/ltable.c create mode 100644 src/ltable.h create mode 100644 src/ltablib.c create mode 100644 src/ltm.c create mode 100644 src/ltm.h create mode 100644 src/lua.c create mode 100644 src/lua.h create mode 100644 src/lua.hpp create mode 100644 src/luac.c create mode 100644 src/luaconf.h create mode 100644 src/lualib.h create mode 100644 src/lundump.c create mode 100644 src/lundump.h create mode 100644 src/lutf8lib.c create mode 100644 src/lvm.c create mode 100644 src/lvm.h create mode 100644 src/lzio.c create mode 100644 src/lzio.h diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..8efa2eb --- /dev/null +++ b/Makefile @@ -0,0 +1,106 @@ +# Makefile for installing Lua +# See doc/readme.html for installation and customization instructions. + +# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT ======================= + +# Your platform. See PLATS for possible values. +PLAT= guess + +# Where to install. The installation starts in the src and doc directories, +# so take care if INSTALL_TOP is not an absolute path. See the local target. +# You may want to make INSTALL_LMOD and INSTALL_CMOD consistent with +# LUA_ROOT, LUA_LDIR, and LUA_CDIR in luaconf.h. +INSTALL_TOP= /usr/local +INSTALL_BIN= $(INSTALL_TOP)/bin +INSTALL_INC= $(INSTALL_TOP)/include +INSTALL_LIB= $(INSTALL_TOP)/lib +INSTALL_MAN= $(INSTALL_TOP)/man/man1 +INSTALL_LMOD= $(INSTALL_TOP)/share/lua/$V +INSTALL_CMOD= $(INSTALL_TOP)/lib/lua/$V + +# How to install. If your install program does not support "-p", then +# you may have to run ranlib on the installed liblua.a. +INSTALL= install -p +INSTALL_EXEC= $(INSTALL) -m 0755 +INSTALL_DATA= $(INSTALL) -m 0644 +# +# If you don't have "install" you can use "cp" instead. +# INSTALL= cp -p +# INSTALL_EXEC= $(INSTALL) +# INSTALL_DATA= $(INSTALL) + +# Other utilities. +MKDIR= mkdir -p +RM= rm -f + +# == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE ======= + +# Convenience platforms targets. +PLATS= guess aix bsd c89 freebsd generic ios linux linux-readline macosx mingw posix solaris + +# What to install. +TO_BIN= lua luac +TO_INC= lua.h luaconf.h lualib.h lauxlib.h lua.hpp +TO_LIB= liblua.a +TO_MAN= lua.1 luac.1 + +# Lua version and release. +V= 5.4 +R= $V.6 + +# Targets start here. +all: $(PLAT) + +$(PLATS) help test clean: + @cd src && $(MAKE) $@ + +install: dummy + cd src && $(MKDIR) $(INSTALL_BIN) $(INSTALL_INC) $(INSTALL_LIB) $(INSTALL_MAN) $(INSTALL_LMOD) $(INSTALL_CMOD) + cd src && $(INSTALL_EXEC) $(TO_BIN) $(INSTALL_BIN) + cd src && $(INSTALL_DATA) $(TO_INC) $(INSTALL_INC) + cd src && $(INSTALL_DATA) $(TO_LIB) $(INSTALL_LIB) + cd doc && $(INSTALL_DATA) $(TO_MAN) $(INSTALL_MAN) + +uninstall: + cd src && cd $(INSTALL_BIN) && $(RM) $(TO_BIN) + cd src && cd $(INSTALL_INC) && $(RM) $(TO_INC) + cd src && cd $(INSTALL_LIB) && $(RM) $(TO_LIB) + cd doc && cd $(INSTALL_MAN) && $(RM) $(TO_MAN) + +local: + $(MAKE) install INSTALL_TOP=../install + +# make may get confused with install/ if it does not support .PHONY. +dummy: + +# Echo config parameters. +echo: + @cd src && $(MAKE) -s echo + @echo "PLAT= $(PLAT)" + @echo "V= $V" + @echo "R= $R" + @echo "TO_BIN= $(TO_BIN)" + @echo "TO_INC= $(TO_INC)" + @echo "TO_LIB= $(TO_LIB)" + @echo "TO_MAN= $(TO_MAN)" + @echo "INSTALL_TOP= $(INSTALL_TOP)" + @echo "INSTALL_BIN= $(INSTALL_BIN)" + @echo "INSTALL_INC= $(INSTALL_INC)" + @echo "INSTALL_LIB= $(INSTALL_LIB)" + @echo "INSTALL_MAN= $(INSTALL_MAN)" + @echo "INSTALL_LMOD= $(INSTALL_LMOD)" + @echo "INSTALL_CMOD= $(INSTALL_CMOD)" + @echo "INSTALL_EXEC= $(INSTALL_EXEC)" + @echo "INSTALL_DATA= $(INSTALL_DATA)" + +# Echo pkg-config data. +pc: + @echo "version=$R" + @echo "prefix=$(INSTALL_TOP)" + @echo "libdir=$(INSTALL_LIB)" + @echo "includedir=$(INSTALL_INC)" + +# Targets that do not create files (not all makes understand .PHONY). +.PHONY: all $(PLATS) help test clean install uninstall local dummy echo pc + +# (end of Makefile) diff --git a/README b/README new file mode 100644 index 0000000..1ae9716 --- /dev/null +++ b/README @@ -0,0 +1,6 @@ + +This is Lua 5.4.6, released on 02 May 2023. + +For installation instructions, license details, and +further information about Lua, see doc/readme.html. + diff --git a/doc/contents.html b/doc/contents.html new file mode 100644 index 0000000..1231e6d --- /dev/null +++ b/doc/contents.html @@ -0,0 +1,678 @@ + + + +Lua 5.4 Reference Manual - contents + + + + + + + +

+Lua +Lua 5.4 Reference Manual +

+ +

+The reference manual is the official definition of the Lua language. +
+For a complete introduction to Lua programming, see the book +Programming in Lua. + +

+start +· +contents +· +index +· +other versions +
+ +

+ +Copyright © 2020–2023 Lua.org, PUC-Rio. +Freely available under the terms of the +Lua license. + + +

Contents

+ + +

Index

+ + + + + + + +
+

Lua functions

+

+basic
+_G
+_VERSION
+assert
+collectgarbage
+dofile
+error
+getmetatable
+ipairs
+load
+loadfile
+next
+pairs
+pcall
+print
+rawequal
+rawget
+rawlen
+rawset
+require
+select
+setmetatable
+tonumber
+tostring
+type
+warn
+xpcall
+ +

+coroutine
+coroutine.close
+coroutine.create
+coroutine.isyieldable
+coroutine.resume
+coroutine.running
+coroutine.status
+coroutine.wrap
+coroutine.yield
+ +

+debug
+debug.debug
+debug.gethook
+debug.getinfo
+debug.getlocal
+debug.getmetatable
+debug.getregistry
+debug.getupvalue
+debug.getuservalue
+debug.sethook
+debug.setlocal
+debug.setmetatable
+debug.setupvalue
+debug.setuservalue
+debug.traceback
+debug.upvalueid
+debug.upvaluejoin
+ +

+io
+io.close
+io.flush
+io.input
+io.lines
+io.open
+io.output
+io.popen
+io.read
+io.stderr
+io.stdin
+io.stdout
+io.tmpfile
+io.type
+io.write
+ +file:close
+file:flush
+file:lines
+file:read
+file:seek
+file:setvbuf
+file:write
+ +

 +

 

+

+math
+math.abs
+math.acos
+math.asin
+math.atan
+math.ceil
+math.cos
+math.deg
+math.exp
+math.floor
+math.fmod
+math.huge
+math.log
+math.max
+math.maxinteger
+math.min
+math.mininteger
+math.modf
+math.pi
+math.rad
+math.random
+math.randomseed
+math.sin
+math.sqrt
+math.tan
+math.tointeger
+math.type
+math.ult
+ +

+os
+os.clock
+os.date
+os.difftime
+os.execute
+os.exit
+os.getenv
+os.remove
+os.rename
+os.setlocale
+os.time
+os.tmpname
+ +

+package
+package.config
+package.cpath
+package.loaded
+package.loadlib
+package.path
+package.preload
+package.searchers
+package.searchpath
+ +

+string
+string.byte
+string.char
+string.dump
+string.find
+string.format
+string.gmatch
+string.gsub
+string.len
+string.lower
+string.match
+string.pack
+string.packsize
+string.rep
+string.reverse
+string.sub
+string.unpack
+string.upper
+ +

+table
+table.concat
+table.insert
+table.move
+table.pack
+table.remove
+table.sort
+table.unpack
+ +

+utf8
+utf8.char
+utf8.charpattern
+utf8.codepoint
+utf8.codes
+utf8.len
+utf8.offset
+ +

metamethods

+

+__add
+__band
+__bnot
+__bor
+__bxor
+__call
+__close
+__concat
+__div
+__eq
+__gc
+__idiv
+__index
+__le
+__len
+__lt
+__metatable
+__mod
+__mode
+__mul
+__name
+__newindex
+__pairs
+__pow
+__shl
+__shr
+__sub
+__tostring
+__unm
+ +

environment
variables

+

+LUA_CPATH
+LUA_CPATH_5_4
+LUA_INIT
+LUA_INIT_5_4
+LUA_PATH
+LUA_PATH_5_4
+ +

 +

C API

+

+lua_Alloc
+lua_CFunction
+lua_Debug
+lua_Hook
+lua_Integer
+lua_KContext
+lua_KFunction
+lua_Number
+lua_Reader
+lua_State
+lua_Unsigned
+lua_WarnFunction
+lua_Writer
+ +

+lua_absindex
+lua_arith
+lua_atpanic
+lua_call
+lua_callk
+lua_checkstack
+lua_close
+lua_closeslot
+lua_compare
+lua_concat
+lua_copy
+lua_createtable
+lua_dump
+lua_error
+lua_gc
+lua_getallocf
+lua_getextraspace
+lua_getfield
+lua_getglobal
+lua_gethook
+lua_gethookcount
+lua_gethookmask
+lua_geti
+lua_getinfo
+lua_getiuservalue
+lua_getlocal
+lua_getmetatable
+lua_getstack
+lua_gettable
+lua_gettop
+lua_getupvalue
+lua_insert
+lua_isboolean
+lua_iscfunction
+lua_isfunction
+lua_isinteger
+lua_islightuserdata
+lua_isnil
+lua_isnone
+lua_isnoneornil
+lua_isnumber
+lua_isstring
+lua_istable
+lua_isthread
+lua_isuserdata
+lua_isyieldable
+lua_len
+lua_load
+lua_newstate
+lua_newtable
+lua_newthread
+lua_newuserdatauv
+lua_next
+lua_numbertointeger
+lua_pcall
+lua_pcallk
+lua_pop
+lua_pushboolean
+lua_pushcclosure
+lua_pushcfunction
+lua_pushfstring
+lua_pushglobaltable
+lua_pushinteger
+lua_pushlightuserdata
+lua_pushliteral
+lua_pushlstring
+lua_pushnil
+lua_pushnumber
+lua_pushstring
+lua_pushthread
+lua_pushvalue
+lua_pushvfstring
+lua_rawequal
+lua_rawget
+lua_rawgeti
+lua_rawgetp
+lua_rawlen
+lua_rawset
+lua_rawseti
+lua_rawsetp
+lua_register
+lua_remove
+lua_replace
+lua_resetthread
+lua_resume
+lua_rotate
+lua_setallocf
+lua_setfield
+lua_setglobal
+lua_sethook
+lua_seti
+lua_setiuservalue
+lua_setlocal
+lua_setmetatable
+lua_settable
+lua_settop
+lua_setupvalue
+lua_setwarnf
+lua_status
+lua_stringtonumber
+lua_toboolean
+lua_tocfunction
+lua_toclose
+lua_tointeger
+lua_tointegerx
+lua_tolstring
+lua_tonumber
+lua_tonumberx
+lua_topointer
+lua_tostring
+lua_tothread
+lua_touserdata
+lua_type
+lua_typename
+lua_upvalueid
+lua_upvalueindex
+lua_upvaluejoin
+lua_version
+lua_warning
+lua_xmove
+lua_yield
+lua_yieldk
+ +

 +

auxiliary library

+

+luaL_Buffer
+luaL_Reg
+luaL_Stream
+ +

+luaL_addchar
+luaL_addgsub
+luaL_addlstring
+luaL_addsize
+luaL_addstring
+luaL_addvalue
+luaL_argcheck
+luaL_argerror
+luaL_argexpected
+luaL_buffaddr
+luaL_buffinit
+luaL_buffinitsize
+luaL_bufflen
+luaL_buffsub
+luaL_callmeta
+luaL_checkany
+luaL_checkinteger
+luaL_checklstring
+luaL_checknumber
+luaL_checkoption
+luaL_checkstack
+luaL_checkstring
+luaL_checktype
+luaL_checkudata
+luaL_checkversion
+luaL_dofile
+luaL_dostring
+luaL_error
+luaL_execresult
+luaL_fileresult
+luaL_getmetafield
+luaL_getmetatable
+luaL_getsubtable
+luaL_gsub
+luaL_len
+luaL_loadbuffer
+luaL_loadbufferx
+luaL_loadfile
+luaL_loadfilex
+luaL_loadstring
+luaL_newlib
+luaL_newlibtable
+luaL_newmetatable
+luaL_newstate
+luaL_openlibs
+luaL_opt
+luaL_optinteger
+luaL_optlstring
+luaL_optnumber
+luaL_optstring
+luaL_prepbuffer
+luaL_prepbuffsize
+luaL_pushfail
+luaL_pushresult
+luaL_pushresultsize
+luaL_ref
+luaL_requiref
+luaL_setfuncs
+luaL_setmetatable
+luaL_testudata
+luaL_tolstring
+luaL_traceback
+luaL_typeerror
+luaL_typename
+luaL_unref
+luaL_where
+ +

standard library

+

+luaopen_base
+luaopen_coroutine
+luaopen_debug
+luaopen_io
+luaopen_math
+luaopen_os
+luaopen_package
+luaopen_string
+luaopen_table
+luaopen_utf8
+ +

constants

+

+LUA_ERRERR
+LUA_ERRFILE
+LUA_ERRMEM
+LUA_ERRRUN
+LUA_ERRSYNTAX
+LUA_HOOKCALL
+LUA_HOOKCOUNT
+LUA_HOOKLINE
+LUA_HOOKRET
+LUA_HOOKTAILCALL
+LUA_LOADED_TABLE
+LUA_MASKCALL
+LUA_MASKCOUNT
+LUA_MASKLINE
+LUA_MASKRET
+LUA_MAXINTEGER
+LUA_MININTEGER
+LUA_MINSTACK
+LUA_MULTRET
+LUA_NOREF
+LUA_OK
+LUA_OPADD
+LUA_OPBAND
+LUA_OPBNOT
+LUA_OPBOR
+LUA_OPBXOR
+LUA_OPDIV
+LUA_OPEQ
+LUA_OPIDIV
+LUA_OPLE
+LUA_OPLT
+LUA_OPMOD
+LUA_OPMUL
+LUA_OPPOW
+LUA_OPSHL
+LUA_OPSHR
+LUA_OPSUB
+LUA_OPUNM
+LUA_PRELOAD_TABLE
+LUA_REFNIL
+LUA_REGISTRYINDEX
+LUA_RIDX_GLOBALS
+LUA_RIDX_MAINTHREAD
+LUA_TBOOLEAN
+LUA_TFUNCTION
+LUA_TLIGHTUSERDATA
+LUA_TNIL
+LUA_TNONE
+LUA_TNUMBER
+LUA_TSTRING
+LUA_TTABLE
+LUA_TTHREAD
+LUA_TUSERDATA
+LUA_USE_APICHECK
+LUA_YIELD
+LUAL_BUFFERSIZE
+ +

+ +

+Last update: +Sat Apr 1 17:57:05 UTC 2023 +

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textual source form or +in precompiled binary form. +(Precompiled binaries are output by +.BR luac , +the Lua compiler.) +.B lua +can be used as a batch interpreter and also interactively. +.LP +After handling the +.IR options , +the Lua program in file +.I script +is loaded and executed. +The +.I args +are available to +.I script +as strings in a global table named +.B arg +and also as arguments to its main function. +When called without arguments, +.B lua +behaves as +.B "lua \-v \-i" +if the standard input is a terminal, +and as +.B "lua \-" +otherwise. +.LP +In interactive mode, +.B lua +prompts the user, +reads lines from the standard input, +and executes them as they are read. +If the line contains an expression, +then the line is evaluated and the result is printed. +If a line does not contain a complete statement, +then a secondary prompt is displayed and +lines are read until a complete statement is formed or +a syntax error is found. +.LP +Before handling command line options and scripts, +.B lua +checks the contents of the environment variables +.B LUA_INIT_5_4 +and +.BR LUA_INIT , +in that order. +If the contents are of the form +.RI '@ filename ', +then +.I filename +is executed. +Otherwise, the contents are assumed to be a Lua statement and is executed. +When +.B LUA_INIT_5_4 +is defined, +.B LUA_INIT +is ignored. +.SH OPTIONS +.TP +.BI \-e " stat" +execute statement +.IR stat . +.TP +.B \-i +enter interactive mode after executing +.IR script . +.TP +.BI \-l " mod" +require library +.I mod +into global +.IR mod . +.TP +.BI \-l " g=mod" +require library +.I mod +into global +.IR g . +.TP +.B \-v +show version information. +.TP +.B \-E +ignore environment variables. +.TP +.B \-W +turn warnings on. +.TP +.B \-\- +stop handling options. +.TP +.B \- +stop handling options and execute the standard input as a file. +.SH ENVIRONMENT VARIABLES +The following environment variables affect the execution of +.BR lua . +When defined, +the version-specific variants take priority +and the version-neutral variants are ignored. +.TP +.B LUA_INIT, LUA_INIT_5_4 +Code to be executed before command line options and scripts. +.TP +.B LUA_PATH, LUA_PATH_5_4 +Initial value of package.cpath, +the path used by require to search for Lua loaders. +.TP +.B LUA_CPATH, LUA_CPATH_5_4 +Initial value of package.cpath, +the path used by require to search for C loaders. +.SH EXIT STATUS +If a script calls os.exit, +then +.B lua +exits with the given exit status. +Otherwise, +.B lua +exits +with EXIT_SUCCESS (0 on POSIX systems) if there were no errors +and +with EXIT_FAILURE (1 on POSIX systems) if there were errors. +Errors raised in interactive mode do not cause exits. +.SH DIAGNOSTICS +Error messages should be self explanatory. +.SH "SEE ALSO" +.BR luac (1) +.br +The documentation at lua.org, +especially section 7 of the reference manual. +.SH AUTHORS +R. Ierusalimschy, +L. H. de Figueiredo, +W. Celes +.\" EOF diff --git a/doc/lua.css b/doc/lua.css new file mode 100644 index 0000000..cbd0799 --- /dev/null +++ b/doc/lua.css @@ -0,0 +1,161 @@ +html { + background-color: #F8F8F8 ; +} + +body { + background-color: #FFFFFF ; + color: #000000 ; + font-family: Helvetica, Arial, sans-serif ; + text-align: justify ; + line-height: 1.25 ; + margin: 16px auto ; + padding: 32px ; + border: solid #ccc 1px ; + border-radius: 20px ; + max-width: 70em ; + width: 90% ; +} + +h1, h2, h3, h4 { + color: #000080 ; + font-family: Verdana, Geneva, sans-serif ; + font-weight: normal ; + font-style: normal ; + text-align: left ; +} + +h1 { + font-size: 28pt ; +} + +h1 img { + vertical-align: text-bottom ; +} + +h2:before { + content: "\2756" ; + padding-right: 0.5em ; +} + +a { + text-decoration: none ; +} + +a:link { + color: #000080 ; +} + +a:link:hover, a:visited:hover { + background-color: #D0D0FF ; + color: #000080 ; + border-radius: 4px ; +} + +a:link:active, a:visited:active { + color: #FF0000 ; +} + +div.menubar { + padding-bottom: 0.5em ; +} + +p.menubar { + margin-left: 2.5em ; +} + +.menubar a:hover { + margin: -3px -3px -3px -3px ; + padding: 3px 3px 3px 3px ; + border-radius: 4px ; +} + +:target { + background-color: #F0F0F0 ; + margin: -8px ; + padding: 8px ; + border-radius: 8px ; + outline: none ; +} + +hr { + display: none ; +} + +table hr { + background-color: #a0a0a0 ; + color: #a0a0a0 ; + border: 0 ; + height: 1px ; + display: block ; +} + +.footer { + color: gray ; + font-size: x-small ; + text-transform: lowercase ; +} + +input[type=text] { + border: solid #a0a0a0 2px ; + border-radius: 2em ; + background-image: url('images/search.png') ; + background-repeat: no-repeat ; + background-position: 4px center ; + padding-left: 20px ; + height: 2em ; +} + +pre.session { + background-color: #F8F8F8 ; + padding: 1em ; + border-radius: 8px ; +} + +table { + border: none ; + border-spacing: 0 ; + border-collapse: collapse ; +} + +td { + padding: 0 ; + margin: 0 ; +} + +td.gutter { + width: 4% ; +} + +table.columns td { + vertical-align: top ; + padding-bottom: 1em ; + text-align: justify ; + line-height: 1.25 ; +} + +table.book td { + vertical-align: top ; +} + +table.book td.cover { + padding-right: 1em ; +} + +table.book img { + border: solid #000080 1px ; +} + +table.book span { + font-size: small ; + text-align: left ; + display: block ; + margin-top: 0.25em ; +} + +p.logos a:link:hover, p.logos a:visited:hover { + background-color: inherit ; +} + +img { + background-color: white ; +} diff --git a/doc/luac.1 b/doc/luac.1 new file mode 100644 index 0000000..33a4ed0 --- /dev/null +++ b/doc/luac.1 @@ -0,0 +1,118 @@ +.\" $Id: luac.man,v 1.29 2011/11/16 13:53:40 lhf Exp $ +.TH LUAC 1 "$Date: 2011/11/16 13:53:40 $" +.SH NAME +luac \- Lua compiler +.SH SYNOPSIS +.B luac +[ +.I options +] [ +.I filenames +] +.SH DESCRIPTION +.B luac +is the Lua compiler. +It translates programs written in the Lua programming language +into binary files containing precompiled chunks +that can be later loaded and executed. +.LP +The main advantages of precompiling chunks are: +faster loading, +protecting source code from accidental user changes, +and +off-line syntax checking. +Precompiling does not imply faster execution +because in Lua chunks are always compiled into bytecodes before being executed. +.B luac +simply allows those bytecodes to be saved in a file for later execution. +Precompiled chunks are not necessarily smaller than the corresponding source. +The main goal in precompiling is faster loading. +.LP +In the command line, +you can mix +text files containing Lua source and +binary files containing precompiled chunks. +.B luac +produces a single output file containing the combined bytecodes +for all files given. +Executing the combined file is equivalent to executing the given files. +By default, +the output file is named +.BR luac.out , +but you can change this with the +.B \-o +option. +.LP +Precompiled chunks are +.I not +portable across different architectures. +Moreover, +the internal format of precompiled chunks +is likely to change when a new version of Lua is released. +Make sure you save the source files of all Lua programs that you precompile. +.LP +.SH OPTIONS +.TP +.B \-l +produce a listing of the compiled bytecode for Lua's virtual machine. +Listing bytecodes is useful to learn about Lua's virtual machine. +If no files are given, then +.B luac +loads +.B luac.out +and lists its contents. +Use +.B \-l \-l +for a full listing. +.TP +.BI \-o " file" +output to +.IR file , +instead of the default +.BR luac.out . +(You can use +.B "'\-'" +for standard output, +but not on platforms that open standard output in text mode.) +The output file may be one of the given files because +all files are loaded before the output file is written. +Be careful not to overwrite precious files. +.TP +.B \-p +load files but do not generate any output file. +Used mainly for syntax checking and for testing precompiled chunks: +corrupted files will probably generate errors when loaded. +If no files are given, then +.B luac +loads +.B luac.out +and tests its contents. +No messages are displayed if the file loads without errors. +.TP +.B \-s +strip debug information before writing the output file. +This saves some space in very large chunks, +but if errors occur when running a stripped chunk, +then the error messages may not contain the full information they usually do. +In particular, +line numbers and names of local variables are lost. +.TP +.B \-v +show version information. +.TP +.B \-\- +stop handling options. +.TP +.B \- +stop handling options and process standard input. +.SH "SEE ALSO" +.BR lua (1) +.br +The documentation at lua.org. +.SH DIAGNOSTICS +Error messages should be self explanatory. +.SH AUTHORS +R. Ierusalimschy, +L. H. de Figueiredo, +W. Celes +.\" EOF diff --git a/doc/manual.css b/doc/manual.css new file mode 100644 index 0000000..aa0e677 --- /dev/null +++ b/doc/manual.css @@ -0,0 +1,21 @@ +h3 code { + font-family: inherit ; + font-size: inherit ; +} + +pre, code { + font-size: 12pt ; +} + +span.apii { + color: gray ; + float: right ; + font-family: inherit ; + font-style: normal ; + font-size: small ; +} + +h2:before { + content: "" ; + padding-right: 0em ; +} diff --git a/doc/manual.html b/doc/manual.html new file mode 100644 index 0000000..0af688b --- /dev/null +++ b/doc/manual.html @@ -0,0 +1,12046 @@ + + + +Lua 5.4 Reference Manual + + + + + + + +

+Lua +Lua 5.4 Reference Manual +

+ +

+by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes + +

+ +Copyright © 2020–2023 Lua.org, PUC-Rio. +Freely available under the terms of the +Lua license. + + +

+contents +· +index +· +other versions +
+ + +

+ + + + + + +

1 – Introduction

+ +

+Lua is a powerful, efficient, lightweight, embeddable scripting language. +It supports procedural programming, +object-oriented programming, functional programming, +data-driven programming, and data description. + + +

+Lua combines simple procedural syntax with powerful data description +constructs based on associative arrays and extensible semantics. +Lua is dynamically typed, +runs by interpreting bytecode with a register-based +virtual machine, +and has automatic memory management with +a generational garbage collection, +making it ideal for configuration, scripting, +and rapid prototyping. + + +

+Lua is implemented as a library, written in clean C, +the common subset of standard C and C++. +The Lua distribution includes a host program called lua, +which uses the Lua library to offer a complete, +standalone Lua interpreter, +for interactive or batch use. +Lua is intended to be used both as a powerful, lightweight, +embeddable scripting language for any program that needs one, +and as a powerful but lightweight and efficient stand-alone language. + + +

+As an extension language, Lua has no notion of a "main" program: +it works embedded in a host client, +called the embedding program or simply the host. +(Frequently, this host is the stand-alone lua program.) +The host program can invoke functions to execute a piece of Lua code, +can write and read Lua variables, +and can register C functions to be called by Lua code. +Through the use of C functions, Lua can be augmented to cope with +a wide range of different domains, +thus creating customized programming languages sharing a syntactical framework. + + +

+Lua is free software, +and is provided as usual with no guarantees, +as stated in its license. +The implementation described in this manual is available +at Lua's official web site, www.lua.org. + + +

+Like any other reference manual, +this document is dry in places. +For a discussion of the decisions behind the design of Lua, +see the technical papers available at Lua's web site. +For a detailed introduction to programming in Lua, +see Roberto's book, Programming in Lua. + + + +

2 – Basic Concepts

+ + + +

+This section describes the basic concepts of the language. + + + + + +

2.1 – Values and Types

+ +

+Lua is a dynamically typed language. +This means that +variables do not have types; only values do. +There are no type definitions in the language. +All values carry their own type. + + +

+All values in Lua are first-class values. +This means that all values can be stored in variables, +passed as arguments to other functions, and returned as results. + + +

+There are eight basic types in Lua: +nil, boolean, number, +string, function, userdata, +thread, and table. +The type nil has one single value, nil, +whose main property is to be different from any other value; +it often represents the absence of a useful value. +The type boolean has two values, false and true. +Both nil and false make a condition false; +they are collectively called false values. +Any other value makes a condition true. +Despite its name, +false is frequently used as an alternative to nil, +with the key difference that false behaves +like a regular value in a table, +while a nil in a table represents an absent key. + + +

+The type number represents both +integer numbers and real (floating-point) numbers, +using two subtypes: integer and float. +Standard Lua uses 64-bit integers and double-precision (64-bit) floats, +but you can also compile Lua so that it +uses 32-bit integers and/or single-precision (32-bit) floats. +The option with 32 bits for both integers and floats +is particularly attractive +for small machines and embedded systems. +(See macro LUA_32BITS in file luaconf.h.) + + +

+Unless stated otherwise, +any overflow when manipulating integer values wrap around, +according to the usual rules of two-complement arithmetic. +(In other words, +the actual result is the unique representable integer +that is equal modulo 2n to the mathematical result, +where n is the number of bits of the integer type.) + + +

+Lua has explicit rules about when each subtype is used, +but it also converts between them automatically as needed (see §3.4.3). +Therefore, +the programmer may choose to mostly ignore the difference +between integers and floats +or to assume complete control over the representation of each number. + + +

+The type string represents immutable sequences of bytes. + +Lua is 8-bit clean: +strings can contain any 8-bit value, +including embedded zeros ('\0'). +Lua is also encoding-agnostic; +it makes no assumptions about the contents of a string. +The length of any string in Lua must fit in a Lua integer. + + +

+Lua can call (and manipulate) functions written in Lua and +functions written in C (see §3.4.10). +Both are represented by the type function. + + +

+The type userdata is provided to allow arbitrary C data to +be stored in Lua variables. +A userdata value represents a block of raw memory. +There are two kinds of userdata: +full userdata, +which is an object with a block of memory managed by Lua, +and light userdata, +which is simply a C pointer value. +Userdata has no predefined operations in Lua, +except assignment and identity test. +By using metatables, +the programmer can define operations for full userdata values +(see §2.4). +Userdata values cannot be created or modified in Lua, +only through the C API. +This guarantees the integrity of data owned by +the host program and C libraries. + + +

+The type thread represents independent threads of execution +and it is used to implement coroutines (see §2.6). +Lua threads are not related to operating-system threads. +Lua supports coroutines on all systems, +even those that do not support threads natively. + + +

+The type table implements associative arrays, +that is, arrays that can have as indices not only numbers, +but any Lua value except nil and NaN. +(Not a Number is a special floating-point value +used by the IEEE 754 standard to represent +undefined numerical results, such as 0/0.) +Tables can be heterogeneous; +that is, they can contain values of all types (except nil). +Any key associated to the value nil is not considered part of the table. +Conversely, any key that is not part of a table has +an associated value nil. + + +

+Tables are the sole data-structuring mechanism in Lua; +they can be used to represent ordinary arrays, lists, +symbol tables, sets, records, graphs, trees, etc. +To represent records, Lua uses the field name as an index. +The language supports this representation by +providing a.name as syntactic sugar for a["name"]. +There are several convenient ways to create tables in Lua +(see §3.4.9). + + +

+Like indices, +the values of table fields can be of any type. +In particular, +because functions are first-class values, +table fields can contain functions. +Thus tables can also carry methods (see §3.4.11). + + +

+The indexing of tables follows +the definition of raw equality in the language. +The expressions a[i] and a[j] +denote the same table element +if and only if i and j are raw equal +(that is, equal without metamethods). +In particular, floats with integral values +are equal to their respective integers +(e.g., 1.0 == 1). +To avoid ambiguities, +any float used as a key that is equal to an integer +is converted to that integer. +For instance, if you write a[2.0] = true, +the actual key inserted into the table will be the integer 2. + + +

+Tables, functions, threads, and (full) userdata values are objects: +variables do not actually contain these values, +only references to them. +Assignment, parameter passing, and function returns +always manipulate references to such values; +these operations do not imply any kind of copy. + + +

+The library function type returns a string describing the type +of a given value (see type). + + + + + +

2.2 – Environments and the Global Environment

+ +

+As we will discuss further in §3.2 and §3.3.3, +any reference to a free name +(that is, a name not bound to any declaration) var +is syntactically translated to _ENV.var. +Moreover, every chunk is compiled in the scope of +an external local variable named _ENV (see §3.3.2), +so _ENV itself is never a free name in a chunk. + + +

+Despite the existence of this external _ENV variable and +the translation of free names, +_ENV is a completely regular name. +In particular, +you can define new variables and parameters with that name. +Each reference to a free name uses the _ENV that is +visible at that point in the program, +following the usual visibility rules of Lua (see §3.5). + + +

+Any table used as the value of _ENV is called an environment. + + +

+Lua keeps a distinguished environment called the global environment. +This value is kept at a special index in the C registry (see §4.3). +In Lua, the global variable _G is initialized with this same value. +(_G is never used internally, +so changing its value will affect only your own code.) + + +

+When Lua loads a chunk, +the default value for its _ENV variable +is the global environment (see load). +Therefore, by default, +free names in Lua code refer to entries in the global environment +and, therefore, they are also called global variables. +Moreover, all standard libraries are loaded in the global environment +and some functions there operate on that environment. +You can use load (or loadfile) +to load a chunk with a different environment. +(In C, you have to load the chunk and then change the value +of its first upvalue; see lua_setupvalue.) + + + + + +

2.3 – Error Handling

+ +

+Several operations in Lua can raise an error. +An error interrupts the normal flow of the program, +which can continue by catching the error. + + +

+Lua code can explicitly raise an error by calling the +error function. +(This function never returns.) + + +

+To catch errors in Lua, +you can do a protected call, +using pcall (or xpcall). +The function pcall calls a given function in protected mode. +Any error while running the function stops its execution, +and control returns immediately to pcall, +which returns a status code. + + +

+Because Lua is an embedded extension language, +Lua code starts running by a call +from C code in the host program. +(When you use Lua standalone, +the lua application is the host program.) +Usually, this call is protected; +so, when an otherwise unprotected error occurs during +the compilation or execution of a Lua chunk, +control returns to the host, +which can take appropriate measures, +such as printing an error message. + + +

+Whenever there is an error, +an error object +is propagated with information about the error. +Lua itself only generates errors whose error object is a string, +but programs may generate errors with +any value as the error object. +It is up to the Lua program or its host to handle such error objects. +For historical reasons, +an error object is often called an error message, +even though it does not have to be a string. + + +

+When you use xpcall (or lua_pcall, in C) +you may give a message handler +to be called in case of errors. +This function is called with the original error object +and returns a new error object. +It is called before the error unwinds the stack, +so that it can gather more information about the error, +for instance by inspecting the stack and creating a stack traceback. +This message handler is still protected by the protected call; +so, an error inside the message handler +will call the message handler again. +If this loop goes on for too long, +Lua breaks it and returns an appropriate message. +The message handler is called only for regular runtime errors. +It is not called for memory-allocation errors +nor for errors while running finalizers or other message handlers. + + +

+Lua also offers a system of warnings (see warn). +Unlike errors, warnings do not interfere +in any way with program execution. +They typically only generate a message to the user, +although this behavior can be adapted from C (see lua_setwarnf). + + + + + +

2.4 – Metatables and Metamethods

+ +

+Every value in Lua can have a metatable. +This metatable is an ordinary Lua table +that defines the behavior of the original value +under certain events. +You can change several aspects of the behavior +of a value by setting specific fields in its metatable. +For instance, when a non-numeric value is the operand of an addition, +Lua checks for a function in the field __add of the value's metatable. +If it finds one, +Lua calls this function to perform the addition. + + +

+The key for each event in a metatable is a string +with the event name prefixed by two underscores; +the corresponding value is called a metavalue. +For most events, the metavalue must be a function, +which is then called a metamethod. +In the previous example, the key is the string "__add" +and the metamethod is the function that performs the addition. +Unless stated otherwise, +a metamethod may in fact be any callable value, +which is either a function or a value with a __call metamethod. + + +

+You can query the metatable of any value +using the getmetatable function. +Lua queries metamethods in metatables using a raw access (see rawget). + + +

+You can replace the metatable of tables +using the setmetatable function. +You cannot change the metatable of other types from Lua code, +except by using the debug library (§6.10). + + +

+Tables and full userdata have individual metatables, +although multiple tables and userdata can share their metatables. +Values of all other types share one single metatable per type; +that is, there is one single metatable for all numbers, +one for all strings, etc. +By default, a value has no metatable, +but the string library sets a metatable for the string type (see §6.4). + + +

+A detailed list of operations controlled by metatables is given next. +Each event is identified by its corresponding key. +By convention, all metatable keys used by Lua are composed by +two underscores followed by lowercase Latin letters. + + + +

    + +
  • __add: +the addition (+) operation. +If any operand for an addition is not a number, +Lua will try to call a metamethod. +It starts by checking the first operand (even if it is a number); +if that operand does not define a metamethod for __add, +then Lua will check the second operand. +If Lua can find a metamethod, +it calls the metamethod with the two operands as arguments, +and the result of the call +(adjusted to one value) +is the result of the operation. +Otherwise, if no metamethod is found, +Lua raises an error. +
    • + +
  • __sub: +the subtraction (-) operation. +Behavior similar to the addition operation. +
    • + +
  • __mul: +the multiplication (*) operation. +Behavior similar to the addition operation. +
    • + +
  • __div: +the division (/) operation. +Behavior similar to the addition operation. +
    • + +
  • __mod: +the modulo (%) operation. +Behavior similar to the addition operation. +
    • + +
  • __pow: +the exponentiation (^) operation. +Behavior similar to the addition operation. +
    • + +
  • __unm: +the negation (unary -) operation. +Behavior similar to the addition operation. +
    • + +
  • __idiv: +the floor division (//) operation. +Behavior similar to the addition operation. +
    • + +
  • __band: +the bitwise AND (&) operation. +Behavior similar to the addition operation, +except that Lua will try a metamethod +if any operand is neither an integer +nor a float coercible to an integer (see §3.4.3). +
    • + +
  • __bor: +the bitwise OR (|) operation. +Behavior similar to the bitwise AND operation. +
    • + +
  • __bxor: +the bitwise exclusive OR (binary ~) operation. +Behavior similar to the bitwise AND operation. +
    • + +
  • __bnot: +the bitwise NOT (unary ~) operation. +Behavior similar to the bitwise AND operation. +
    • + +
  • __shl: +the bitwise left shift (<<) operation. +Behavior similar to the bitwise AND operation. +
    • + +
  • __shr: +the bitwise right shift (>>) operation. +Behavior similar to the bitwise AND operation. +
    • + +
  • __concat: +the concatenation (..) operation. +Behavior similar to the addition operation, +except that Lua will try a metamethod +if any operand is neither a string nor a number +(which is always coercible to a string). +
    • + +
  • __len: +the length (#) operation. +If the object is not a string, +Lua will try its metamethod. +If there is a metamethod, +Lua calls it with the object as argument, +and the result of the call +(always adjusted to one value) +is the result of the operation. +If there is no metamethod but the object is a table, +then Lua uses the table length operation (see §3.4.7). +Otherwise, Lua raises an error. +
    • + +
  • __eq: +the equal (==) operation. +Behavior similar to the addition operation, +except that Lua will try a metamethod only when the values +being compared are either both tables or both full userdata +and they are not primitively equal. +The result of the call is always converted to a boolean. +
    • + +
  • __lt: +the less than (<) operation. +Behavior similar to the addition operation, +except that Lua will try a metamethod only when the values +being compared are neither both numbers nor both strings. +Moreover, the result of the call is always converted to a boolean. +
    • + +
  • __le: +the less equal (<=) operation. +Behavior similar to the less than operation. +
    • + +
  • __index: +The indexing access operation table[key]. +This event happens when table is not a table or +when key is not present in table. +The metavalue is looked up in the metatable of table. + + +

    +The metavalue for this event can be either a function, a table, +or any value with an __index metavalue. +If it is a function, +it is called with table and key as arguments, +and the result of the call +(adjusted to one value) +is the result of the operation. +Otherwise, +the final result is the result of indexing this metavalue with key. +This indexing is regular, not raw, +and therefore can trigger another __index metavalue. +

    • + +
  • __newindex: +The indexing assignment table[key] = value. +Like the index event, +this event happens when table is not a table or +when key is not present in table. +The metavalue is looked up in the metatable of table. + + +

    +Like with indexing, +the metavalue for this event can be either a function, a table, +or any value with an __newindex metavalue. +If it is a function, +it is called with table, key, and value as arguments. +Otherwise, +Lua repeats the indexing assignment over this metavalue +with the same key and value. +This assignment is regular, not raw, +and therefore can trigger another __newindex metavalue. + + +

    +Whenever a __newindex metavalue is invoked, +Lua does not perform the primitive assignment. +If needed, +the metamethod itself can call rawset +to do the assignment. +

    • + +
  • __call: +The call operation func(args). +This event happens when Lua tries to call a non-function value +(that is, func is not a function). +The metamethod is looked up in func. +If present, +the metamethod is called with func as its first argument, +followed by the arguments of the original call (args). +All results of the call +are the results of the operation. +This is the only metamethod that allows multiple results. +
    • + +
+ +

+In addition to the previous list, +the interpreter also respects the following keys in metatables: +__gc (see §2.5.3), +__close (see §3.3.8), +__mode (see §2.5.4), +and __name. +(The entry __name, +when it contains a string, +may be used by tostring and in error messages.) + + +

+For the unary operators (negation, length, and bitwise NOT), +the metamethod is computed and called with a dummy second operand, +equal to the first one. +This extra operand is only to simplify Lua's internals +(by making these operators behave like a binary operation) +and may be removed in future versions. +For most uses this extra operand is irrelevant. + + +

+Because metatables are regular tables, +they can contain arbitrary fields, +not only the event names defined above. +Some functions in the standard library +(e.g., tostring) +use other fields in metatables for their own purposes. + + +

+It is a good practice to add all needed metamethods to a table +before setting it as a metatable of some object. +In particular, the __gc metamethod works only when this order +is followed (see §2.5.3). +It is also a good practice to set the metatable of an object +right after its creation. + + + + + +

2.5 – Garbage Collection

+ + + +

+Lua performs automatic memory management. +This means that +you do not have to worry about allocating memory for new objects +or freeing it when the objects are no longer needed. +Lua manages memory automatically by running +a garbage collector to collect all dead objects. +All memory used by Lua is subject to automatic management: +strings, tables, userdata, functions, threads, internal structures, etc. + + +

+An object is considered dead +as soon as the collector can be sure the object +will not be accessed again in the normal execution of the program. +("Normal execution" here excludes finalizers, +which can resurrect dead objects (see §2.5.3), +and excludes also operations using the debug library.) +Note that the time when the collector can be sure that an object +is dead may not coincide with the programmer's expectations. +The only guarantees are that Lua will not collect an object +that may still be accessed in the normal execution of the program, +and it will eventually collect an object +that is inaccessible from Lua. +(Here, +inaccessible from Lua means that neither a variable nor +another live object refer to the object.) +Because Lua has no knowledge about C code, +it never collects objects accessible through the registry (see §4.3), +which includes the global environment (see §2.2). + + +

+The garbage collector (GC) in Lua can work in two modes: +incremental and generational. + + +

+The default GC mode with the default parameters +are adequate for most uses. +However, programs that waste a large proportion of their time +allocating and freeing memory can benefit from other settings. +Keep in mind that the GC behavior is non-portable +both across platforms and across different Lua releases; +therefore, optimal settings are also non-portable. + + +

+You can change the GC mode and parameters by calling +lua_gc in C +or collectgarbage in Lua. +You can also use these functions to control +the collector directly (e.g., to stop and restart it). + + + + + +

2.5.1 – Incremental Garbage Collection

+ +

+In incremental mode, +each GC cycle performs a mark-and-sweep collection in small steps +interleaved with the program's execution. +In this mode, +the collector uses three numbers to control its garbage-collection cycles: +the garbage-collector pause, +the garbage-collector step multiplier, +and the garbage-collector step size. + + +

+The garbage-collector pause +controls how long the collector waits before starting a new cycle. +The collector starts a new cycle when the use of memory +hits n% of the use after the previous collection. +Larger values make the collector less aggressive. +Values equal to or less than 100 mean the collector will not wait to +start a new cycle. +A value of 200 means that the collector waits for the total memory in use +to double before starting a new cycle. +The default value is 200; the maximum value is 1000. + + +

+The garbage-collector step multiplier +controls the speed of the collector relative to +memory allocation, +that is, +how many elements it marks or sweeps for each +kilobyte of memory allocated. +Larger values make the collector more aggressive but also increase +the size of each incremental step. +You should not use values less than 100, +because they make the collector too slow and +can result in the collector never finishing a cycle. +The default value is 100; the maximum value is 1000. + + +

+The garbage-collector step size controls the +size of each incremental step, +specifically how many bytes the interpreter allocates +before performing a step. +This parameter is logarithmic: +A value of n means the interpreter will allocate 2n +bytes between steps and perform equivalent work during the step. +A large value (e.g., 60) makes the collector a stop-the-world +(non-incremental) collector. +The default value is 13, +which means steps of approximately 8 Kbytes. + + + + + +

2.5.2 – Generational Garbage Collection

+ +

+In generational mode, +the collector does frequent minor collections, +which traverses only objects recently created. +If after a minor collection the use of memory is still above a limit, +the collector does a stop-the-world major collection, +which traverses all objects. +The generational mode uses two parameters: +the minor multiplier and the the major multiplier. + + +

+The minor multiplier controls the frequency of minor collections. +For a minor multiplier x, +a new minor collection will be done when memory +grows x% larger than the memory in use after the previous major +collection. +For instance, for a multiplier of 20, +the collector will do a minor collection when the use of memory +gets 20% larger than the use after the previous major collection. +The default value is 20; the maximum value is 200. + + +

+The major multiplier controls the frequency of major collections. +For a major multiplier x, +a new major collection will be done when memory +grows x% larger than the memory in use after the previous major +collection. +For instance, for a multiplier of 100, +the collector will do a major collection when the use of memory +gets larger than twice the use after the previous collection. +The default value is 100; the maximum value is 1000. + + + + + +

2.5.3 – Garbage-Collection Metamethods

+ +

+You can set garbage-collector metamethods for tables +and, using the C API, +for full userdata (see §2.4). +These metamethods, called finalizers, +are called when the garbage collector detects that the +corresponding table or userdata is dead. +Finalizers allow you to coordinate Lua's garbage collection +with external resource management such as closing files, +network or database connections, +or freeing your own memory. + + +

+For an object (table or userdata) to be finalized when collected, +you must mark it for finalization. + +You mark an object for finalization when you set its metatable +and the metatable has a __gc metamethod. +Note that if you set a metatable without a __gc field +and later create that field in the metatable, +the object will not be marked for finalization. + + +

+When a marked object becomes dead, +it is not collected immediately by the garbage collector. +Instead, Lua puts it in a list. +After the collection, +Lua goes through that list. +For each object in the list, +it checks the object's __gc metamethod: +If it is present, +Lua calls it with the object as its single argument. + + +

+At the end of each garbage-collection cycle, +the finalizers are called in +the reverse order that the objects were marked for finalization, +among those collected in that cycle; +that is, the first finalizer to be called is the one associated +with the object marked last in the program. +The execution of each finalizer may occur at any point during +the execution of the regular code. + + +

+Because the object being collected must still be used by the finalizer, +that object (and other objects accessible only through it) +must be resurrected by Lua. +Usually, this resurrection is transient, +and the object memory is freed in the next garbage-collection cycle. +However, if the finalizer stores the object in some global place +(e.g., a global variable), +then the resurrection is permanent. +Moreover, if the finalizer marks a finalizing object for finalization again, +its finalizer will be called again in the next cycle where the +object is dead. +In any case, +the object memory is freed only in a GC cycle where +the object is dead and not marked for finalization. + + +

+When you close a state (see lua_close), +Lua calls the finalizers of all objects marked for finalization, +following the reverse order that they were marked. +If any finalizer marks objects for collection during that phase, +these marks have no effect. + + +

+Finalizers cannot yield nor run the garbage collector. +Because they can run in unpredictable times, +it is good practice to restrict each finalizer +to the minimum necessary to properly release +its associated resource. + + +

+Any error while running a finalizer generates a warning; +the error is not propagated. + + + + + +

2.5.4 – Weak Tables

+ +

+A weak table is a table whose elements are +weak references. +A weak reference is ignored by the garbage collector. +In other words, +if the only references to an object are weak references, +then the garbage collector will collect that object. + + +

+A weak table can have weak keys, weak values, or both. +A table with weak values allows the collection of its values, +but prevents the collection of its keys. +A table with both weak keys and weak values allows the collection of +both keys and values. +In any case, if either the key or the value is collected, +the whole pair is removed from the table. +The weakness of a table is controlled by the +__mode field of its metatable. +This metavalue, if present, must be one of the following strings: +"k", for a table with weak keys; +"v", for a table with weak values; +or "kv", for a table with both weak keys and values. + + +

+A table with weak keys and strong values +is also called an ephemeron table. +In an ephemeron table, +a value is considered reachable only if its key is reachable. +In particular, +if the only reference to a key comes through its value, +the pair is removed. + + +

+Any change in the weakness of a table may take effect only +at the next collect cycle. +In particular, if you change the weakness to a stronger mode, +Lua may still collect some items from that table +before the change takes effect. + + +

+Only objects that have an explicit construction +are removed from weak tables. +Values, such as numbers and light C functions, +are not subject to garbage collection, +and therefore are not removed from weak tables +(unless their associated values are collected). +Although strings are subject to garbage collection, +they do not have an explicit construction and +their equality is by value; +they behave more like values than like objects. +Therefore, they are not removed from weak tables. + + +

+Resurrected objects +(that is, objects being finalized +and objects accessible only through objects being finalized) +have a special behavior in weak tables. +They are removed from weak values before running their finalizers, +but are removed from weak keys only in the next collection +after running their finalizers, when such objects are actually freed. +This behavior allows the finalizer to access properties +associated with the object through weak tables. + + +

+If a weak table is among the resurrected objects in a collection cycle, +it may not be properly cleared until the next cycle. + + + + + + + +

2.6 – Coroutines

+ +

+Lua supports coroutines, +also called collaborative multithreading. +A coroutine in Lua represents an independent thread of execution. +Unlike threads in multithread systems, however, +a coroutine only suspends its execution by explicitly calling +a yield function. + + +

+You create a coroutine by calling coroutine.create. +Its sole argument is a function +that is the main function of the coroutine. +The create function only creates a new coroutine and +returns a handle to it (an object of type thread); +it does not start the coroutine. + + +

+You execute a coroutine by calling coroutine.resume. +When you first call coroutine.resume, +passing as its first argument +a thread returned by coroutine.create, +the coroutine starts its execution by +calling its main function. +Extra arguments passed to coroutine.resume are passed +as arguments to that function. +After the coroutine starts running, +it runs until it terminates or yields. + + +

+A coroutine can terminate its execution in two ways: +normally, when its main function returns +(explicitly or implicitly, after the last instruction); +and abnormally, if there is an unprotected error. +In case of normal termination, +coroutine.resume returns true, +plus any values returned by the coroutine main function. +In case of errors, coroutine.resume returns false +plus the error object. +In this case, the coroutine does not unwind its stack, +so that it is possible to inspect it after the error +with the debug API. + + +

+A coroutine yields by calling coroutine.yield. +When a coroutine yields, +the corresponding coroutine.resume returns immediately, +even if the yield happens inside nested function calls +(that is, not in the main function, +but in a function directly or indirectly called by the main function). +In the case of a yield, coroutine.resume also returns true, +plus any values passed to coroutine.yield. +The next time you resume the same coroutine, +it continues its execution from the point where it yielded, +with the call to coroutine.yield returning any extra +arguments passed to coroutine.resume. + + +

+Like coroutine.create, +the coroutine.wrap function also creates a coroutine, +but instead of returning the coroutine itself, +it returns a function that, when called, resumes the coroutine. +Any arguments passed to this function +go as extra arguments to coroutine.resume. +coroutine.wrap returns all the values returned by coroutine.resume, +except the first one (the boolean error code). +Unlike coroutine.resume, +the function created by coroutine.wrap +propagates any error to the caller. +In this case, +the function also closes the coroutine (see coroutine.close). + + +

+As an example of how coroutines work, +consider the following code: + +

+     function foo (a)
+       print("foo", a)
+       return coroutine.yield(2*a)
+     end
+     
+     co = coroutine.create(function (a,b)
+           print("co-body", a, b)
+           local r = foo(a+1)
+           print("co-body", r)
+           local r, s = coroutine.yield(a+b, a-b)
+           print("co-body", r, s)
+           return b, "end"
+     end)
+     
+     print("main", coroutine.resume(co, 1, 10))
+     print("main", coroutine.resume(co, "r"))
+     print("main", coroutine.resume(co, "x", "y"))
+     print("main", coroutine.resume(co, "x", "y"))
+

+When you run it, it produces the following output: + +

+     co-body 1       10
+     foo     2
+     main    true    4
+     co-body r
+     main    true    11      -9
+     co-body x       y
+     main    true    10      end
+     main    false   cannot resume dead coroutine
+
+ +

+You can also create and manipulate coroutines through the C API: +see functions lua_newthread, lua_resume, +and lua_yield. + + + + + +

3 – The Language

+ + + +

+This section describes the lexis, the syntax, and the semantics of Lua. +In other words, +this section describes +which tokens are valid, +how they can be combined, +and what their combinations mean. + + +

+Language constructs will be explained using the usual extended BNF notation, +in which +{a} means 0 or more a's, and +[a] means an optional a. +Non-terminals are shown like non-terminal, +keywords are shown like kword, +and other terminal symbols are shown like ‘=’. +The complete syntax of Lua can be found in §9 +at the end of this manual. + + + + + +

3.1 – Lexical Conventions

+ +

+Lua is a free-form language. +It ignores spaces and comments between lexical elements (tokens), +except as delimiters between two tokens. +In source code, +Lua recognizes as spaces the standard ASCII whitespace +characters space, form feed, newline, +carriage return, horizontal tab, and vertical tab. + + +

+Names +(also called identifiers) +in Lua can be any string of Latin letters, +Arabic-Indic digits, and underscores, +not beginning with a digit and +not being a reserved word. +Identifiers are used to name variables, table fields, and labels. + + +

+The following keywords are reserved +and cannot be used as names: + + +

+     and       break     do        else      elseif    end
+     false     for       function  goto      if        in
+     local     nil       not       or        repeat    return
+     then      true      until     while
+
+ +

+Lua is a case-sensitive language: +and is a reserved word, but And and AND +are two different, valid names. +As a convention, +programs should avoid creating +names that start with an underscore followed by +one or more uppercase letters (such as _VERSION). + + +

+The following strings denote other tokens: + +

+     +     -     *     /     %     ^     #
+     &     ~     |     <<    >>    //
+     ==    ~=    <=    >=    <     >     =
+     (     )     {     }     [     ]     ::
+     ;     :     ,     .     ..    ...
+
+ +

+A short literal string +can be delimited by matching single or double quotes, +and can contain the following C-like escape sequences: +'\a' (bell), +'\b' (backspace), +'\f' (form feed), +'\n' (newline), +'\r' (carriage return), +'\t' (horizontal tab), +'\v' (vertical tab), +'\\' (backslash), +'\"' (quotation mark [double quote]), +and '\'' (apostrophe [single quote]). +A backslash followed by a line break +results in a newline in the string. +The escape sequence '\z' skips the following span +of whitespace characters, +including line breaks; +it is particularly useful to break and indent a long literal string +into multiple lines without adding the newlines and spaces +into the string contents. +A short literal string cannot contain unescaped line breaks +nor escapes not forming a valid escape sequence. + + +

+We can specify any byte in a short literal string, +including embedded zeros, +by its numeric value. +This can be done +with the escape sequence \xXX, +where XX is a sequence of exactly two hexadecimal digits, +or with the escape sequence \ddd, +where ddd is a sequence of up to three decimal digits. +(Note that if a decimal escape sequence is to be followed by a digit, +it must be expressed using exactly three digits.) + + +

+The UTF-8 encoding of a Unicode character +can be inserted in a literal string with +the escape sequence \u{XXX} +(with mandatory enclosing braces), +where XXX is a sequence of one or more hexadecimal digits +representing the character code point. +This code point can be any value less than 231. +(Lua uses the original UTF-8 specification here, +which is not restricted to valid Unicode code points.) + + +

+Literal strings can also be defined using a long format +enclosed by long brackets. +We define an opening long bracket of level n as an opening +square bracket followed by n equal signs followed by another +opening square bracket. +So, an opening long bracket of level 0 is written as [[, +an opening long bracket of level 1 is written as [=[, +and so on. +A closing long bracket is defined similarly; +for instance, +a closing long bracket of level 4 is written as ]====]. +A long literal starts with an opening long bracket of any level and +ends at the first closing long bracket of the same level. +It can contain any text except a closing bracket of the same level. +Literals in this bracketed form can run for several lines, +do not interpret any escape sequences, +and ignore long brackets of any other level. +Any kind of end-of-line sequence +(carriage return, newline, carriage return followed by newline, +or newline followed by carriage return) +is converted to a simple newline. +When the opening long bracket is immediately followed by a newline, +the newline is not included in the string. + + +

+As an example, in a system using ASCII +(in which 'a' is coded as 97, +newline is coded as 10, and '1' is coded as 49), +the five literal strings below denote the same string: + +

+     a = 'alo\n123"'
+     a = "alo\n123\""
+     a = '\97lo\10\04923"'
+     a = [[alo
+     123"]]
+     a = [==[
+     alo
+     123"]==]
+
+ +

+Any byte in a literal string not +explicitly affected by the previous rules represents itself. +However, Lua opens files for parsing in text mode, +and the system's file functions may have problems with +some control characters. +So, it is safer to represent +binary data as a quoted literal with +explicit escape sequences for the non-text characters. + + +

+A numeric constant (or numeral) +can be written with an optional fractional part +and an optional decimal exponent, +marked by a letter 'e' or 'E'. +Lua also accepts hexadecimal constants, +which start with 0x or 0X. +Hexadecimal constants also accept an optional fractional part +plus an optional binary exponent, +marked by a letter 'p' or 'P' and written in decimal. +(For instance, 0x1.fp10 denotes 1984, +which is 0x1f / 16 multiplied by 210.) + + +

+A numeric constant with a radix point or an exponent +denotes a float; +otherwise, +if its value fits in an integer or it is a hexadecimal constant, +it denotes an integer; +otherwise (that is, a decimal integer numeral that overflows), +it denotes a float. +Hexadecimal numerals with neither a radix point nor an exponent +always denote an integer value; +if the value overflows, it wraps around +to fit into a valid integer. + + +

+Examples of valid integer constants are + +

+     3   345   0xff   0xBEBADA
+

+Examples of valid float constants are + +

+     3.0     3.1416     314.16e-2     0.31416E1     34e1
+     0x0.1E  0xA23p-4   0X1.921FB54442D18P+1
+
+ +

+A comment starts with a double hyphen (--) +anywhere outside a string. +If the text immediately after -- is not an opening long bracket, +the comment is a short comment, +which runs until the end of the line. +Otherwise, it is a long comment, +which runs until the corresponding closing long bracket. + + + + + +

3.2 – Variables

+ +

+Variables are places that store values. +There are three kinds of variables in Lua: +global variables, local variables, and table fields. + + +

+A single name can denote a global variable or a local variable +(or a function's formal parameter, +which is a particular kind of local variable): + +

+	var ::= Name
+

+Name denotes identifiers (see §3.1). + + +

+Any variable name is assumed to be global unless explicitly declared +as a local (see §3.3.7). +Local variables are lexically scoped: +local variables can be freely accessed by functions +defined inside their scope (see §3.5). + + +

+Before the first assignment to a variable, its value is nil. + + +

+Square brackets are used to index a table: + +

+	var ::= prefixexp ‘[’ exp ‘]’
+

+The meaning of accesses to table fields can be changed via metatables +(see §2.4). + + +

+The syntax var.Name is just syntactic sugar for +var["Name"]: + +

+	var ::= prefixexp ‘.’ Name
+
+ +

+An access to a global variable x +is equivalent to _ENV.x. +Due to the way that chunks are compiled, +the variable _ENV itself is never global (see §2.2). + + + + + +

3.3 – Statements

+ + + +

+Lua supports an almost conventional set of statements, +similar to those in other conventional languages. +This set includes +blocks, assignments, control structures, function calls, +and variable declarations. + + + + + +

3.3.1 – Blocks

+ +

+A block is a list of statements, +which are executed sequentially: + +

+	block ::= {stat}
+

+Lua has empty statements +that allow you to separate statements with semicolons, +start a block with a semicolon +or write two semicolons in sequence: + +

+	stat ::= ‘;’
+
+ +

+Both function calls and assignments +can start with an open parenthesis. +This possibility leads to an ambiguity in Lua's grammar. +Consider the following fragment: + +

+     a = b + c
+     (print or io.write)('done')
+

+The grammar could see this fragment in two ways: + +

+     a = b + c(print or io.write)('done')
+     
+     a = b + c; (print or io.write)('done')
+

+The current parser always sees such constructions +in the first way, +interpreting the open parenthesis +as the start of the arguments to a call. +To avoid this ambiguity, +it is a good practice to always precede with a semicolon +statements that start with a parenthesis: + +

+     ;(print or io.write)('done')
+
+ +

+A block can be explicitly delimited to produce a single statement: + +

+	stat ::= do block end
+

+Explicit blocks are useful +to control the scope of variable declarations. +Explicit blocks are also sometimes used to +add a return statement in the middle +of another block (see §3.3.4). + + + + + +

3.3.2 – Chunks

+ +

+The unit of compilation of Lua is called a chunk. +Syntactically, +a chunk is simply a block: + +

+	chunk ::= block
+
+ +

+Lua handles a chunk as the body of an anonymous function +with a variable number of arguments +(see §3.4.11). +As such, chunks can define local variables, +receive arguments, and return values. +Moreover, such anonymous function is compiled as in the +scope of an external local variable called _ENV (see §2.2). +The resulting function always has _ENV as its only external variable, +even if it does not use that variable. + + +

+A chunk can be stored in a file or in a string inside the host program. +To execute a chunk, +Lua first loads it, +precompiling the chunk's code into instructions for a virtual machine, +and then Lua executes the compiled code +with an interpreter for the virtual machine. + + +

+Chunks can also be precompiled into binary form; +see the program luac and the function string.dump for details. +Programs in source and compiled forms are interchangeable; +Lua automatically detects the file type and acts accordingly (see load). + + + + + +

3.3.3 – Assignment

+ +

+Lua allows multiple assignments. +Therefore, the syntax for assignment +defines a list of variables on the left side +and a list of expressions on the right side. +The elements in both lists are separated by commas: + +

+	stat ::= varlist ‘=’ explist
+	varlist ::= var {‘,’ var}
+	explist ::= exp {‘,’ exp}
+

+Expressions are discussed in §3.4. + + +

+Before the assignment, +the list of values is adjusted to the length of +the list of variables (see §3.4.12). + + +

+If a variable is both assigned and read +inside a multiple assignment, +Lua ensures that all reads get the value of the variable +before the assignment. +Thus the code + +

+     i = 3
+     i, a[i] = i+1, 20
+

+sets a[3] to 20, without affecting a[4] +because the i in a[i] is evaluated (to 3) +before it is assigned 4. +Similarly, the line + +

+     x, y = y, x
+

+exchanges the values of x and y, +and + +

+     x, y, z = y, z, x
+

+cyclically permutes the values of x, y, and z. + + +

+Note that this guarantee covers only accesses +syntactically inside the assignment statement. +If a function or a metamethod called during the assignment +changes the value of a variable, +Lua gives no guarantees about the order of that access. + + +

+An assignment to a global name x = val +is equivalent to the assignment +_ENV.x = val (see §2.2). + + +

+The meaning of assignments to table fields and +global variables (which are actually table fields, too) +can be changed via metatables (see §2.4). + + + + + +

3.3.4 – Control Structures

+The control structures +if, while, and repeat have the usual meaning and +familiar syntax: + + + + +

+	stat ::= while exp do block end
+	stat ::= repeat block until exp
+	stat ::= if exp then block {elseif exp then block} [else block] end
+

+Lua also has a for statement, in two flavors (see §3.3.5). + + +

+The condition expression of a +control structure can return any value. +Both false and nil test false. +All values different from nil and false test true. +In particular, the number 0 and the empty string also test true. + + +

+In the repeat–until loop, +the inner block does not end at the until keyword, +but only after the condition. +So, the condition can refer to local variables +declared inside the loop block. + + +

+The goto statement transfers the program control to a label. +For syntactical reasons, +labels in Lua are considered statements too: + + + +

+	stat ::= goto Name
+	stat ::= label
+	label ::= ‘::’ Name ‘::’
+
+ +

+A label is visible in the entire block where it is defined, +except inside nested functions. +A goto may jump to any visible label as long as it does not +enter into the scope of a local variable. +A label should not be declared +where a label with the same name is visible, +even if this other label has been declared in an enclosing block. + + +

+The break statement terminates the execution of a +while, repeat, or for loop, +skipping to the next statement after the loop: + + +

+	stat ::= break
+

+A break ends the innermost enclosing loop. + + +

+The return statement is used to return values +from a function or a chunk +(which is handled as an anonymous function). + +Functions can return more than one value, +so the syntax for the return statement is + +

+	stat ::= return [explist] [‘;’]
+
+ +

+The return statement can only be written +as the last statement of a block. +If it is necessary to return in the middle of a block, +then an explicit inner block can be used, +as in the idiom do return end, +because now return is the last statement in its (inner) block. + + + + + +

3.3.5 – For Statement

+ +

+ +The for statement has two forms: +one numerical and one generic. + + + +

The numerical for loop

+ +

+The numerical for loop repeats a block of code while a +control variable goes through an arithmetic progression. +It has the following syntax: + +

+	stat ::= for Name ‘=’ exp ‘,’ exp [‘,’ exp] do block end
+

+The given identifier (Name) defines the control variable, +which is a new variable local to the loop body (block). + + +

+The loop starts by evaluating once the three control expressions. +Their values are called respectively +the initial value, the limit, and the step. +If the step is absent, it defaults to 1. + + +

+If both the initial value and the step are integers, +the loop is done with integers; +note that the limit may not be an integer. +Otherwise, the three values are converted to +floats and the loop is done with floats. +Beware of floating-point accuracy in this case. + + +

+After that initialization, +the loop body is repeated with the value of the control variable +going through an arithmetic progression, +starting at the initial value, +with a common difference given by the step. +A negative step makes a decreasing sequence; +a step equal to zero raises an error. +The loop continues while the value is less than +or equal to the limit +(greater than or equal to for a negative step). +If the initial value is already greater than the limit +(or less than, if the step is negative), +the body is not executed. + + +

+For integer loops, +the control variable never wraps around; +instead, the loop ends in case of an overflow. + + +

+You should not change the value of the control variable +during the loop. +If you need its value after the loop, +assign it to another variable before exiting the loop. + + + + + +

The generic for loop

+ +

+The generic for statement works over functions, +called iterators. +On each iteration, the iterator function is called to produce a new value, +stopping when this new value is nil. +The generic for loop has the following syntax: + +

+	stat ::= for namelist in explist do block end
+	namelist ::= Name {‘,’ Name}
+

+A for statement like + +

+     for var_1, ···, var_n in explist do body end
+

+works as follows. + + +

+The names var_i declare loop variables local to the loop body. +The first of these variables is the control variable. + + +

+The loop starts by evaluating explist +to produce four values: +an iterator function, +a state, +an initial value for the control variable, +and a closing value. + + +

+Then, at each iteration, +Lua calls the iterator function with two arguments: +the state and the control variable. +The results from this call are then assigned to the loop variables, +following the rules of multiple assignments (see §3.3.3). +If the control variable becomes nil, +the loop terminates. +Otherwise, the body is executed and the loop goes +to the next iteration. + + +

+The closing value behaves like a +to-be-closed variable (see §3.3.8), +which can be used to release resources when the loop ends. +Otherwise, it does not interfere with the loop. + + +

+You should not change the value of the control variable +during the loop. + + + + + + + +

3.3.6 – Function Calls as Statements

+To allow possible side-effects, +function calls can be executed as statements: + +

+	stat ::= functioncall
+

+In this case, all returned values are thrown away. +Function calls are explained in §3.4.10. + + + + + +

3.3.7 – Local Declarations

+Local variables can be declared anywhere inside a block. +The declaration can include an initialization: + +

+	stat ::= local attnamelist [‘=’ explist]
+	attnamelist ::=  Name attrib {‘,’ Name attrib}
+

+If present, an initial assignment has the same semantics +of a multiple assignment (see §3.3.3). +Otherwise, all variables are initialized with nil. + + +

+Each variable name may be postfixed by an attribute +(a name between angle brackets): + +

+	attrib ::= [‘<’ Name ‘>’]
+

+There are two possible attributes: +const, which declares a constant variable, +that is, a variable that cannot be assigned to +after its initialization; +and close, which declares a to-be-closed variable (see §3.3.8). +A list of variables can contain at most one to-be-closed variable. + + +

+A chunk is also a block (see §3.3.2), +and so local variables can be declared in a chunk outside any explicit block. + + +

+The visibility rules for local variables are explained in §3.5. + + + + + +

3.3.8 – To-be-closed Variables

+ +

+A to-be-closed variable behaves like a constant local variable, +except that its value is closed whenever the variable +goes out of scope, including normal block termination, +exiting its block by break/goto/return, +or exiting by an error. + + +

+Here, to close a value means +to call its __close metamethod. +When calling the metamethod, +the value itself is passed as the first argument +and the error object that caused the exit (if any) +is passed as a second argument; +if there was no error, the second argument is nil. + + +

+The value assigned to a to-be-closed variable +must have a __close metamethod +or be a false value. +(nil and false are ignored as to-be-closed values.) + + +

+If several to-be-closed variables go out of scope at the same event, +they are closed in the reverse order that they were declared. + + +

+If there is any error while running a closing method, +that error is handled like an error in the regular code +where the variable was defined. +After an error, +the other pending closing methods will still be called. + + +

+If a coroutine yields and is never resumed again, +some variables may never go out of scope, +and therefore they will never be closed. +(These variables are the ones created inside the coroutine +and in scope at the point where the coroutine yielded.) +Similarly, if a coroutine ends with an error, +it does not unwind its stack, +so it does not close any variable. +In both cases, +you can either use finalizers +or call coroutine.close to close the variables. +However, if the coroutine was created +through coroutine.wrap, +then its corresponding function will close the coroutine +in case of errors. + + + + + + + +

3.4 – Expressions

+ + + +

+The basic expressions in Lua are the following: + +

+	exp ::= prefixexp
+	exp ::= nil | false | true
+	exp ::= Numeral
+	exp ::= LiteralString
+	exp ::= functiondef
+	exp ::= tableconstructor
+	exp ::= ‘...’
+	exp ::= exp binop exp
+	exp ::= unop exp
+	prefixexp ::= var | functioncall | ‘(’ exp ‘)’
+
+ +

+Numerals and literal strings are explained in §3.1; +variables are explained in §3.2; +function definitions are explained in §3.4.11; +function calls are explained in §3.4.10; +table constructors are explained in §3.4.9. +Vararg expressions, +denoted by three dots ('...'), can only be used when +directly inside a variadic function; +they are explained in §3.4.11. + + +

+Binary operators comprise arithmetic operators (see §3.4.1), +bitwise operators (see §3.4.2), +relational operators (see §3.4.4), logical operators (see §3.4.5), +and the concatenation operator (see §3.4.6). +Unary operators comprise the unary minus (see §3.4.1), +the unary bitwise NOT (see §3.4.2), +the unary logical not (see §3.4.5), +and the unary length operator (see §3.4.7). + + + + + +

3.4.1 – Arithmetic Operators

+Lua supports the following arithmetic operators: + +

    +
  • +: addition
    • +
  • -: subtraction
    • +
  • *: multiplication
    • +
  • /: float division
    • +
  • //: floor division
    • +
  • %: modulo
    • +
  • ^: exponentiation
    • +
  • -: unary minus
    • +
+ +

+With the exception of exponentiation and float division, +the arithmetic operators work as follows: +If both operands are integers, +the operation is performed over integers and the result is an integer. +Otherwise, if both operands are numbers, +then they are converted to floats, +the operation is performed following the machine's rules +for floating-point arithmetic +(usually the IEEE 754 standard), +and the result is a float. +(The string library coerces strings to numbers in +arithmetic operations; see §3.4.3 for details.) + + +

+Exponentiation and float division (/) +always convert their operands to floats +and the result is always a float. +Exponentiation uses the ISO C function pow, +so that it works for non-integer exponents too. + + +

+Floor division (//) is a division +that rounds the quotient towards minus infinity, +resulting in the floor of the division of its operands. + + +

+Modulo is defined as the remainder of a division +that rounds the quotient towards minus infinity (floor division). + + +

+In case of overflows in integer arithmetic, +all operations wrap around. + + + +

3.4.2 – Bitwise Operators

+Lua supports the following bitwise operators: + +

    +
  • &: bitwise AND
    • +
  • |: bitwise OR
    • +
  • ~: bitwise exclusive OR
    • +
  • >>: right shift
    • +
  • <<: left shift
    • +
  • ~: unary bitwise NOT
    • +
+ +

+All bitwise operations convert its operands to integers +(see §3.4.3), +operate on all bits of those integers, +and result in an integer. + + +

+Both right and left shifts fill the vacant bits with zeros. +Negative displacements shift to the other direction; +displacements with absolute values equal to or higher than +the number of bits in an integer +result in zero (as all bits are shifted out). + + + + + +

3.4.3 – Coercions and Conversions

+Lua provides some automatic conversions between some +types and representations at run time. +Bitwise operators always convert float operands to integers. +Exponentiation and float division +always convert integer operands to floats. +All other arithmetic operations applied to mixed numbers +(integers and floats) convert the integer operand to a float. +The C API also converts both integers to floats and +floats to integers, as needed. +Moreover, string concatenation accepts numbers as arguments, +besides strings. + + +

+In a conversion from integer to float, +if the integer value has an exact representation as a float, +that is the result. +Otherwise, +the conversion gets the nearest higher or +the nearest lower representable value. +This kind of conversion never fails. + + +

+The conversion from float to integer +checks whether the float has an exact representation as an integer +(that is, the float has an integral value and +it is in the range of integer representation). +If it does, that representation is the result. +Otherwise, the conversion fails. + + +

+Several places in Lua coerce strings to numbers when necessary. +In particular, +the string library sets metamethods that try to coerce +strings to numbers in all arithmetic operations. +If the conversion fails, +the library calls the metamethod of the other operand +(if present) or it raises an error. +Note that bitwise operators do not do this coercion. + + +

+It is always a good practice not to rely on the +implicit coercions from strings to numbers, +as they are not always applied; +in particular, "1"==1 is false and "1"<1 raises an error +(see §3.4.4). +These coercions exist mainly for compatibility and may be removed +in future versions of the language. + + +

+A string is converted to an integer or a float +following its syntax and the rules of the Lua lexer. +The string may have also leading and trailing whitespaces and a sign. +All conversions from strings to numbers +accept both a dot and the current locale mark +as the radix character. +(The Lua lexer, however, accepts only a dot.) +If the string is not a valid numeral, +the conversion fails. +If necessary, the result of this first step is then converted +to a specific number subtype following the previous rules +for conversions between floats and integers. + + +

+The conversion from numbers to strings uses a +non-specified human-readable format. +To convert numbers to strings in any specific way, +use the function string.format. + + + + + +

3.4.4 – Relational Operators

+Lua supports the following relational operators: + +

    +
  • ==: equality
    • +
  • ~=: inequality
    • +
  • <: less than
    • +
  • >: greater than
    • +
  • <=: less or equal
    • +
  • >=: greater or equal
    • +

+These operators always result in false or true. + + +

+Equality (==) first compares the type of its operands. +If the types are different, then the result is false. +Otherwise, the values of the operands are compared. +Strings are equal if they have the same byte content. +Numbers are equal if they denote the same mathematical value. + + +

+Tables, userdata, and threads +are compared by reference: +two objects are considered equal only if they are the same object. +Every time you create a new object +(a table, a userdata, or a thread), +this new object is different from any previously existing object. +A function is always equal to itself. +Functions with any detectable difference +(different behavior, different definition) are always different. +Functions created at different times but with no detectable differences +may be classified as equal or not +(depending on internal caching details). + + +

+You can change the way that Lua compares tables and userdata +by using the __eq metamethod (see §2.4). + + +

+Equality comparisons do not convert strings to numbers +or vice versa. +Thus, "0"==0 evaluates to false, +and t[0] and t["0"] denote different +entries in a table. + + +

+The operator ~= is exactly the negation of equality (==). + + +

+The order operators work as follows. +If both arguments are numbers, +then they are compared according to their mathematical values, +regardless of their subtypes. +Otherwise, if both arguments are strings, +then their values are compared according to the current locale. +Otherwise, Lua tries to call the __lt or the __le +metamethod (see §2.4). +A comparison a > b is translated to b < a +and a >= b is translated to b <= a. + + +

+Following the IEEE 754 standard, +the special value NaN is considered neither less than, +nor equal to, nor greater than any value, including itself. + + + + + +

3.4.5 – Logical Operators

+The logical operators in Lua are +and, or, and not. +Like the control structures (see §3.3.4), +all logical operators consider both false and nil as false +and anything else as true. + + +

+The negation operator not always returns false or true. +The conjunction operator and returns its first argument +if this value is false or nil; +otherwise, and returns its second argument. +The disjunction operator or returns its first argument +if this value is different from nil and false; +otherwise, or returns its second argument. +Both and and or use short-circuit evaluation; +that is, +the second operand is evaluated only if necessary. +Here are some examples: + +

+     10 or 20            --> 10
+     10 or error()       --> 10
+     nil or "a"          --> "a"
+     nil and 10          --> nil
+     false and error()   --> false
+     false and nil       --> false
+     false or nil        --> nil
+     10 and 20           --> 20
+
+ + + + +

3.4.6 – Concatenation

+The string concatenation operator in Lua is +denoted by two dots ('..'). +If both operands are strings or numbers, +then the numbers are converted to strings +in a non-specified format (see §3.4.3). +Otherwise, the __concat metamethod is called (see §2.4). + + + + + +

3.4.7 – The Length Operator

+ +

+The length operator is denoted by the unary prefix operator #. + + +

+The length of a string is its number of bytes. +(That is the usual meaning of string length when each +character is one byte.) + + +

+The length operator applied on a table +returns a border in that table. +A border in a table t is any non-negative integer +that satisfies the following condition: + +

+     (border == 0 or t[border] ~= nil) and
+     (t[border + 1] == nil or border == math.maxinteger)
+

+In words, +a border is any positive integer index present in the table +that is followed by an absent index, +plus two limit cases: +zero, when index 1 is absent; +and the maximum value for an integer, when that index is present. +Note that keys that are not positive integers +do not interfere with borders. + + +

+A table with exactly one border is called a sequence. +For instance, the table {10, 20, 30, 40, 50} is a sequence, +as it has only one border (5). +The table {10, 20, 30, nil, 50} has two borders (3 and 5), +and therefore it is not a sequence. +(The nil at index 4 is called a hole.) +The table {nil, 20, 30, nil, nil, 60, nil} +has three borders (0, 3, and 6), +so it is not a sequence, too. +The table {} is a sequence with border 0. + + +

+When t is a sequence, +#t returns its only border, +which corresponds to the intuitive notion of the length of the sequence. +When t is not a sequence, +#t can return any of its borders. +(The exact one depends on details of +the internal representation of the table, +which in turn can depend on how the table was populated and +the memory addresses of its non-numeric keys.) + + +

+The computation of the length of a table +has a guaranteed worst time of O(log n), +where n is the largest integer key in the table. + + +

+A program can modify the behavior of the length operator for +any value but strings through the __len metamethod (see §2.4). + + + + + +

3.4.8 – Precedence

+Operator precedence in Lua follows the table below, +from lower to higher priority: + +

+     or
+     and
+     <     >     <=    >=    ~=    ==
+     |
+     ~
+     &
+     <<    >>
+     ..
+     +     -
+     *     /     //    %
+     unary operators (not   #     -     ~)
+     ^
+

+As usual, +you can use parentheses to change the precedences of an expression. +The concatenation ('..') and exponentiation ('^') +operators are right associative. +All other binary operators are left associative. + + + + + +

3.4.9 – Table Constructors

+Table constructors are expressions that create tables. +Every time a constructor is evaluated, a new table is created. +A constructor can be used to create an empty table +or to create a table and initialize some of its fields. +The general syntax for constructors is + +

+	tableconstructor ::= ‘{’ [fieldlist] ‘}’
+	fieldlist ::= field {fieldsep field} [fieldsep]
+	field ::= ‘[’ exp ‘]’ ‘=’ exp | Name ‘=’ exp | exp
+	fieldsep ::= ‘,’ | ‘;’
+
+ +

+Each field of the form [exp1] = exp2 adds to the new table an entry +with key exp1 and value exp2. +A field of the form name = exp is equivalent to +["name"] = exp. +Fields of the form exp are equivalent to +[i] = exp, where i are consecutive integers +starting with 1; +fields in the other formats do not affect this counting. +For example, + +

+     a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
+

+is equivalent to + +

+     do
+       local t = {}
+       t[f(1)] = g
+       t[1] = "x"         -- 1st exp
+       t[2] = "y"         -- 2nd exp
+       t.x = 1            -- t["x"] = 1
+       t[3] = f(x)        -- 3rd exp
+       t[30] = 23
+       t[4] = 45          -- 4th exp
+       a = t
+     end
+
+ +

+The order of the assignments in a constructor is undefined. +(This order would be relevant only when there are repeated keys.) + + +

+If the last field in the list has the form exp +and the expression is a multires expression, +then all values returned by this expression enter the list consecutively +(see §3.4.12). + + +

+The field list can have an optional trailing separator, +as a convenience for machine-generated code. + + + + + +

3.4.10 – Function Calls

+A function call in Lua has the following syntax: + +

+	functioncall ::= prefixexp args
+

+In a function call, +first prefixexp and args are evaluated. +If the value of prefixexp has type function, +then this function is called +with the given arguments. +Otherwise, if present, +the prefixexp __call metamethod is called: +its first argument is the value of prefixexp, +followed by the original call arguments +(see §2.4). + + +

+The form + +

+	functioncall ::= prefixexp ‘:’ Name args
+

+can be used to emulate methods. +A call v:name(args) +is syntactic sugar for v.name(v,args), +except that v is evaluated only once. + + +

+Arguments have the following syntax: + +

+	args ::= ‘(’ [explist] ‘)’
+	args ::= tableconstructor
+	args ::= LiteralString
+

+All argument expressions are evaluated before the call. +A call of the form f{fields} is +syntactic sugar for f({fields}); +that is, the argument list is a single new table. +A call of the form f'string' +(or f"string" or f[[string]]) +is syntactic sugar for f('string'); +that is, the argument list is a single literal string. + + +

+A call of the form return functioncall not in the +scope of a to-be-closed variable is called a tail call. +Lua implements proper tail calls +(or proper tail recursion): +In a tail call, +the called function reuses the stack entry of the calling function. +Therefore, there is no limit on the number of nested tail calls that +a program can execute. +However, a tail call erases any debug information about the +calling function. +Note that a tail call only happens with a particular syntax, +where the return has one single function call as argument, +and it is outside the scope of any to-be-closed variable. +This syntax makes the calling function return exactly +the returns of the called function, +without any intervening action. +So, none of the following examples are tail calls: + +

+     return (f(x))        -- results adjusted to 1
+     return 2 * f(x)      -- result multiplied by 2
+     return x, f(x)       -- additional results
+     f(x); return         -- results discarded
+     return x or f(x)     -- results adjusted to 1
+
+ + + + +

3.4.11 – Function Definitions

+ +

+The syntax for function definition is + +

+	functiondef ::= function funcbody
+	funcbody ::= ‘(’ [parlist] ‘)’ block end
+
+ +

+The following syntactic sugar simplifies function definitions: + +

+	stat ::= function funcname funcbody
+	stat ::= local function Name funcbody
+	funcname ::= Name {‘.’ Name} [‘:’ Name]
+

+The statement + +

+     function f () body end
+

+translates to + +

+     f = function () body end
+

+The statement + +

+     function t.a.b.c.f () body end
+

+translates to + +

+     t.a.b.c.f = function () body end
+

+The statement + +

+     local function f () body end
+

+translates to + +

+     local f; f = function () body end
+

+not to + +

+     local f = function () body end
+

+(This only makes a difference when the body of the function +contains references to f.) + + +

+A function definition is an executable expression, +whose value has type function. +When Lua precompiles a chunk, +all its function bodies are precompiled too, +but they are not created yet. +Then, whenever Lua executes the function definition, +the function is instantiated (or closed). +This function instance, or closure, +is the final value of the expression. + + +

+Parameters act as local variables that are +initialized with the argument values: + +

+	parlist ::= namelist [‘,’ ‘...’] | ‘...’
+

+When a Lua function is called, +it adjusts its list of arguments to +the length of its list of parameters (see §3.4.12), +unless the function is a variadic function, +which is indicated by three dots ('...') +at the end of its parameter list. +A variadic function does not adjust its argument list; +instead, it collects all extra arguments and supplies them +to the function through a vararg expression, +which is also written as three dots. +The value of this expression is a list of all actual extra arguments, +similar to a function with multiple results (see §3.4.12). + + +

+As an example, consider the following definitions: + +

+     function f(a, b) end
+     function g(a, b, ...) end
+     function r() return 1,2,3 end
+

+Then, we have the following mapping from arguments to parameters and +to the vararg expression: + +

+     CALL             PARAMETERS
+     
+     f(3)             a=3, b=nil
+     f(3, 4)          a=3, b=4
+     f(3, 4, 5)       a=3, b=4
+     f(r(), 10)       a=1, b=10
+     f(r())           a=1, b=2
+     
+     g(3)             a=3, b=nil, ... -->  (nothing)
+     g(3, 4)          a=3, b=4,   ... -->  (nothing)
+     g(3, 4, 5, 8)    a=3, b=4,   ... -->  5  8
+     g(5, r())        a=5, b=1,   ... -->  2  3
+
+ +

+Results are returned using the return statement (see §3.3.4). +If control reaches the end of a function +without encountering a return statement, +then the function returns with no results. + + +

+ +There is a system-dependent limit on the number of values +that a function may return. +This limit is guaranteed to be greater than 1000. + + +

+The colon syntax +is used to emulate methods, +adding an implicit extra parameter self to the function. +Thus, the statement + +

+     function t.a.b.c:f (params) body end
+

+is syntactic sugar for + +

+     t.a.b.c.f = function (self, params) body end
+
+ + + + +

3.4.12 – Lists of expressions, multiple results, +and adjustment

+ +

+Both function calls and vararg expressions can result in multiple values. +These expressions are called multires expressions. + + +

+When a multires expression is used as the last element +of a list of expressions, +all results from the expression are added to the +list of values produced by the list of expressions. +Note that a single expression +in a place that expects a list of expressions +is the last expression in that (singleton) list. + + +

+These are the places where Lua expects a list of expressions: + +

    + +
  • A return statement, +for instance return e1, e2, e3 (see §3.3.4).
    • + +
  • A table constructor, +for instance {e1, e2, e3} (see §3.4.9).
    • + +
  • The arguments of a function call, +for instance foo(e1, e2, e3) (see §3.4.10).
    • + +
  • A multiple assignment, +for instance a , b, c = e1, e2, e3 (see §3.3.3).
    • + +
  • A local declaration, +for instance local a , b, c = e1, e2, e3 (see §3.3.7).
    • + +
  • The initial values in a generic for loop, +for instance for k in e1, e2, e3 do ... end (see §3.3.5).
    • + +

+In the last four cases, +the list of values from the list of expressions +must be adjusted to a specific length: +the number of parameters in a call to a non-variadic function +(see §3.4.11), +the number of variables in a multiple assignment or +a local declaration, +and exactly four values for a generic for loop. +The adjustment follows these rules: +If there are more values than needed, +the extra values are thrown away; +if there are fewer values than needed, +the list is extended with nil's. +When the list of expressions ends with a multires expression, +all results from that expression enter the list of values +before the adjustment. + + +

+When a multires expression is used +in a list of expressions without being the last element, +or in a place where the syntax expects a single expression, +Lua adjusts the result list of that expression to one element. +As a particular case, +the syntax expects a single expression inside a parenthesized expression; +therefore, adding parentheses around a multires expression +forces it to produce exactly one result. + + +

+We seldom need to use a vararg expression in a place +where the syntax expects a single expression. +(Usually it is simpler to add a regular parameter before +the variadic part and use that parameter.) +When there is such a need, +we recommend assigning the vararg expression +to a single variable and using that variable +in its place. + + +

+Here are some examples of uses of mutlres expressions. +In all cases, when the construction needs +"the n-th result" and there is no such result, +it uses a nil. + +

+     print(x, f())      -- prints x and all results from f().
+     print(x, (f()))    -- prints x and the first result from f().
+     print(f(), x)      -- prints the first result from f() and x.
+     print(1 + f())     -- prints 1 added to the first result from f().
+     local x = ...      -- x gets the first vararg argument.
+     x,y = ...          -- x gets the first vararg argument,
+                        -- y gets the second vararg argument.
+     x,y,z = w, f()     -- x gets w, y gets the first result from f(),
+                        -- z gets the second result from f().
+     x,y,z = f()        -- x gets the first result from f(),
+                        -- y gets the second result from f(),
+                        -- z gets the third result from f().
+     x,y,z = f(), g()   -- x gets the first result from f(),
+                        -- y gets the first result from g(),
+                        -- z gets the second result from g().
+     x,y,z = (f())      -- x gets the first result from f(), y and z get nil.
+     return f()         -- returns all results from f().
+     return x, ...      -- returns x and all received vararg arguments.
+     return x,y,f()     -- returns x, y, and all results from f().
+     {f()}              -- creates a list with all results from f().
+     {...}              -- creates a list with all vararg arguments.
+     {f(), 5}           -- creates a list with the first result from f() and 5.
+
+ + + + + + +

3.5 – Visibility Rules

+ +

+ +Lua is a lexically scoped language. +The scope of a local variable begins at the first statement after +its declaration and lasts until the last non-void statement +of the innermost block that includes the declaration. +(Void statements are labels and empty statements.) +Consider the following example: + +

+     x = 10                -- global variable
+     do                    -- new block
+       local x = x         -- new 'x', with value 10
+       print(x)            --> 10
+       x = x+1
+       do                  -- another block
+         local x = x+1     -- another 'x'
+         print(x)          --> 12
+       end
+       print(x)            --> 11
+     end
+     print(x)              --> 10  (the global one)
+
+ +

+Notice that, in a declaration like local x = x, +the new x being declared is not in scope yet, +and so the second x refers to the outside variable. + + +

+Because of the lexical scoping rules, +local variables can be freely accessed by functions +defined inside their scope. +A local variable used by an inner function is called an upvalue +(or external local variable, or simply external variable) +inside the inner function. + + +

+Notice that each execution of a local statement +defines new local variables. +Consider the following example: + +

+     a = {}
+     local x = 20
+     for i = 1, 10 do
+       local y = 0
+       a[i] = function () y = y + 1; return x + y end
+     end
+

+The loop creates ten closures +(that is, ten instances of the anonymous function). +Each of these closures uses a different y variable, +while all of them share the same x. + + + + + +

4 – The Application Program Interface

+ + + +

+ +This section describes the C API for Lua, that is, +the set of C functions available to the host program to communicate +with Lua. +All API functions and related types and constants +are declared in the header file lua.h. + + +

+Even when we use the term "function", +any facility in the API may be provided as a macro instead. +Except where stated otherwise, +all such macros use each of their arguments exactly once +(except for the first argument, which is always a Lua state), +and so do not generate any hidden side-effects. + + +

+As in most C libraries, +the Lua API functions do not check their arguments +for validity or consistency. +However, you can change this behavior by compiling Lua +with the macro LUA_USE_APICHECK defined. + + +

+The Lua library is fully reentrant: +it has no global variables. +It keeps all information it needs in a dynamic structure, +called the Lua state. + + +

+Each Lua state has one or more threads, +which correspond to independent, cooperative lines of execution. +The type lua_State (despite its name) refers to a thread. +(Indirectly, through the thread, it also refers to the +Lua state associated to the thread.) + + +

+A pointer to a thread must be passed as the first argument to +every function in the library, except to lua_newstate, +which creates a Lua state from scratch and returns a pointer +to the main thread in the new state. + + + + + +

4.1 – The Stack

+ + + +

+Lua uses a virtual stack to pass values to and from C. +Each element in this stack represents a Lua value +(nil, number, string, etc.). +Functions in the API can access this stack through the +Lua state parameter that they receive. + + +

+Whenever Lua calls C, the called function gets a new stack, +which is independent of previous stacks and of stacks of +C functions that are still active. +This stack initially contains any arguments to the C function +and it is where the C function can store temporary +Lua values and must push its results +to be returned to the caller (see lua_CFunction). + + +

+For convenience, +most query operations in the API do not follow a strict stack discipline. +Instead, they can refer to any element in the stack +by using an index: +A positive index represents an absolute stack position, +starting at 1 as the bottom of the stack; +a negative index represents an offset relative to the top of the stack. +More specifically, if the stack has n elements, +then index 1 represents the first element +(that is, the element that was pushed onto the stack first) +and +index n represents the last element; +index -1 also represents the last element +(that is, the element at the top) +and index -n represents the first element. + + + + + +

4.1.1 – Stack Size

+ +

+When you interact with the Lua API, +you are responsible for ensuring consistency. +In particular, +you are responsible for controlling stack overflow. +When you call any API function, +you must ensure the stack has enough room to accommodate the results. + + +

+There is one exception to the above rule: +When you call a Lua function +without a fixed number of results (see lua_call), +Lua ensures that the stack has enough space for all results. +However, it does not ensure any extra space. +So, before pushing anything on the stack after such a call +you should use lua_checkstack. + + +

+Whenever Lua calls C, +it ensures that the stack has space for +at least LUA_MINSTACK extra elements; +that is, you can safely push up to LUA_MINSTACK values into it. +LUA_MINSTACK is defined as 20, +so that usually you do not have to worry about stack space +unless your code has loops pushing elements onto the stack. +Whenever necessary, +you can use the function lua_checkstack +to ensure that the stack has enough space for pushing new elements. + + + + + +

4.1.2 – Valid and Acceptable Indices

+ +

+Any function in the API that receives stack indices +works only with valid indices or acceptable indices. + + +

+A valid index is an index that refers to a +position that stores a modifiable Lua value. +It comprises stack indices between 1 and the stack top +(1 ≤ abs(index) ≤ top) + +plus pseudo-indices, +which represent some positions that are accessible to C code +but that are not in the stack. +Pseudo-indices are used to access the registry (see §4.3) +and the upvalues of a C function (see §4.2). + + +

+Functions that do not need a specific mutable position, +but only a value (e.g., query functions), +can be called with acceptable indices. +An acceptable index can be any valid index, +but it also can be any positive index after the stack top +within the space allocated for the stack, +that is, indices up to the stack size. +(Note that 0 is never an acceptable index.) +Indices to upvalues (see §4.2) greater than the real number +of upvalues in the current C function are also acceptable (but invalid). +Except when noted otherwise, +functions in the API work with acceptable indices. + + +

+Acceptable indices serve to avoid extra tests +against the stack top when querying the stack. +For instance, a C function can query its third argument +without the need to check whether there is a third argument, +that is, without the need to check whether 3 is a valid index. + + +

+For functions that can be called with acceptable indices, +any non-valid index is treated as if it +contains a value of a virtual type LUA_TNONE, +which behaves like a nil value. + + + + + +

4.1.3 – Pointers to strings

+ +

+Several functions in the API return pointers (const char*) +to Lua strings in the stack. +(See lua_pushfstring, lua_pushlstring, +lua_pushstring, and lua_tolstring. +See also luaL_checklstring, luaL_checkstring, +and luaL_tolstring in the auxiliary library.) + + +

+In general, +Lua's garbage collection can free or move internal memory +and then invalidate pointers to internal strings. +To allow a safe use of these pointers, +the API guarantees that any pointer to a string in a stack index +is valid while the string value at that index is not removed from the stack. +(It can be moved to another index, though.) +When the index is a pseudo-index (referring to an upvalue), +the pointer is valid while the corresponding call is active and +the corresponding upvalue is not modified. + + +

+Some functions in the debug interface +also return pointers to strings, +namely lua_getlocal, lua_getupvalue, +lua_setlocal, and lua_setupvalue. +For these functions, the pointer is guaranteed to +be valid while the caller function is active and +the given closure (if one was given) is in the stack. + + +

+Except for these guarantees, +the garbage collector is free to invalidate +any pointer to internal strings. + + + + + + + +

4.2 – C Closures

+ +

+When a C function is created, +it is possible to associate some values with it, +thus creating a C closure +(see lua_pushcclosure); +these values are called upvalues and are +accessible to the function whenever it is called. + + +

+Whenever a C function is called, +its upvalues are located at specific pseudo-indices. +These pseudo-indices are produced by the macro +lua_upvalueindex. +The first upvalue associated with a function is at index +lua_upvalueindex(1), and so on. +Any access to lua_upvalueindex(n), +where n is greater than the number of upvalues of the +current function +(but not greater than 256, +which is one plus the maximum number of upvalues in a closure), +produces an acceptable but invalid index. + + +

+A C closure can also change the values +of its corresponding upvalues. + + + + + +

4.3 – Registry

+ +

+Lua provides a registry, +a predefined table that can be used by any C code to +store whatever Lua values it needs to store. +The registry table is always accessible at pseudo-index +LUA_REGISTRYINDEX. +Any C library can store data into this table, +but it must take care to choose keys +that are different from those used +by other libraries, to avoid collisions. +Typically, you should use as key a string containing your library name, +or a light userdata with the address of a C object in your code, +or any Lua object created by your code. +As with variable names, +string keys starting with an underscore followed by +uppercase letters are reserved for Lua. + + +

+The integer keys in the registry are used +by the reference mechanism (see luaL_ref) +and by some predefined values. +Therefore, integer keys in the registry +must not be used for other purposes. + + +

+When you create a new Lua state, +its registry comes with some predefined values. +These predefined values are indexed with integer keys +defined as constants in lua.h. +The following constants are defined: + +

    +
  • LUA_RIDX_MAINTHREAD: At this index the registry has +the main thread of the state. +(The main thread is the one created together with the state.) +
    • + +
  • LUA_RIDX_GLOBALS: At this index the registry has +the global environment. +
    • +
+ + + + +

4.4 – Error Handling in C

+ + + +

+Internally, Lua uses the C longjmp facility to handle errors. +(Lua will use exceptions if you compile it as C++; +search for LUAI_THROW in the source code for details.) +When Lua faces any error, +such as a memory allocation error or a type error, +it raises an error; +that is, it does a long jump. +A protected environment uses setjmp +to set a recovery point; +any error jumps to the most recent active recovery point. + + +

+Inside a C function you can raise an error explicitly +by calling lua_error. + + +

+Most functions in the API can raise an error, +for instance due to a memory allocation error. +The documentation for each function indicates whether +it can raise errors. + + +

+If an error happens outside any protected environment, +Lua calls a panic function (see lua_atpanic) +and then calls abort, +thus exiting the host application. +Your panic function can avoid this exit by +never returning +(e.g., doing a long jump to your own recovery point outside Lua). + + +

+The panic function, +as its name implies, +is a mechanism of last resort. +Programs should avoid it. +As a general rule, +when a C function is called by Lua with a Lua state, +it can do whatever it wants on that Lua state, +as it should be already protected. +However, +when C code operates on other Lua states +(e.g., a Lua-state argument to the function, +a Lua state stored in the registry, or +the result of lua_newthread), +it should use them only in API calls that cannot raise errors. + + +

+The panic function runs as if it were a message handler (see §2.3); +in particular, the error object is on the top of the stack. +However, there is no guarantee about stack space. +To push anything on the stack, +the panic function must first check the available space (see §4.1.1). + + + + + +

4.4.1 – Status Codes

+ +

+Several functions that report errors in the API use the following +status codes to indicate different kinds of errors or other conditions: + +

    + +
  • LUA_OK (0): no errors.
    • + +
  • LUA_ERRRUN: a runtime error.
    • + +
  • LUA_ERRMEM: +memory allocation error. +For such errors, Lua does not call the message handler. +
    • + +
  • LUA_ERRERR: error while running the message handler.
    • + +
  • LUA_ERRSYNTAX: syntax error during precompilation.
    • + +
  • LUA_YIELD: the thread (coroutine) yields.
    • + +
  • LUA_ERRFILE: a file-related error; +e.g., it cannot open or read the file.
    • + +

+These constants are defined in the header file lua.h. + + + + + + + +

4.5 – Handling Yields in C

+ +

+Internally, Lua uses the C longjmp facility to yield a coroutine. +Therefore, if a C function foo calls an API function +and this API function yields +(directly or indirectly by calling another function that yields), +Lua cannot return to foo any more, +because the longjmp removes its frame from the C stack. + + +

+To avoid this kind of problem, +Lua raises an error whenever it tries to yield across an API call, +except for three functions: +lua_yieldk, lua_callk, and lua_pcallk. +All those functions receive a continuation function +(as a parameter named k) to continue execution after a yield. + + +

+We need to set some terminology to explain continuations. +We have a C function called from Lua which we will call +the original function. +This original function then calls one of those three functions in the C API, +which we will call the callee function, +that then yields the current thread. +This can happen when the callee function is lua_yieldk, +or when the callee function is either lua_callk or lua_pcallk +and the function called by them yields. + + +

+Suppose the running thread yields while executing the callee function. +After the thread resumes, +it eventually will finish running the callee function. +However, +the callee function cannot return to the original function, +because its frame in the C stack was destroyed by the yield. +Instead, Lua calls a continuation function, +which was given as an argument to the callee function. +As the name implies, +the continuation function should continue the task +of the original function. + + +

+As an illustration, consider the following function: + +

+     int original_function (lua_State *L) {
+       ...     /* code 1 */
+       status = lua_pcall(L, n, m, h);  /* calls Lua */
+       ...     /* code 2 */
+     }
+

+Now we want to allow +the Lua code being run by lua_pcall to yield. +First, we can rewrite our function like here: + +

+     int k (lua_State *L, int status, lua_KContext ctx) {
+       ...  /* code 2 */
+     }
+     
+     int original_function (lua_State *L) {
+       ...     /* code 1 */
+       return k(L, lua_pcall(L, n, m, h), ctx);
+     }
+

+In the above code, +the new function k is a +continuation function (with type lua_KFunction), +which should do all the work that the original function +was doing after calling lua_pcall. +Now, we must inform Lua that it must call k if the Lua code +being executed by lua_pcall gets interrupted in some way +(errors or yielding), +so we rewrite the code as here, +replacing lua_pcall by lua_pcallk: + +

+     int original_function (lua_State *L) {
+       ...     /* code 1 */
+       return k(L, lua_pcallk(L, n, m, h, ctx2, k), ctx1);
+     }
+

+Note the external, explicit call to the continuation: +Lua will call the continuation only if needed, that is, +in case of errors or resuming after a yield. +If the called function returns normally without ever yielding, +lua_pcallk (and lua_callk) will also return normally. +(Of course, instead of calling the continuation in that case, +you can do the equivalent work directly inside the original function.) + + +

+Besides the Lua state, +the continuation function has two other parameters: +the final status of the call and the context value (ctx) that +was passed originally to lua_pcallk. +Lua does not use this context value; +it only passes this value from the original function to the +continuation function. +For lua_pcallk, +the status is the same value that would be returned by lua_pcallk, +except that it is LUA_YIELD when being executed after a yield +(instead of LUA_OK). +For lua_yieldk and lua_callk, +the status is always LUA_YIELD when Lua calls the continuation. +(For these two functions, +Lua will not call the continuation in case of errors, +because they do not handle errors.) +Similarly, when using lua_callk, +you should call the continuation function +with LUA_OK as the status. +(For lua_yieldk, there is not much point in calling +directly the continuation function, +because lua_yieldk usually does not return.) + + +

+Lua treats the continuation function as if it were the original function. +The continuation function receives the same Lua stack +from the original function, +in the same state it would be if the callee function had returned. +(For instance, +after a lua_callk the function and its arguments are +removed from the stack and replaced by the results from the call.) +It also has the same upvalues. +Whatever it returns is handled by Lua as if it were the return +of the original function. + + + + + +

4.6 – Functions and Types

+ +

+Here we list all functions and types from the C API in +alphabetical order. +Each function has an indicator like this: +[-o, +p, x] + + +

+The first field, o, +is how many elements the function pops from the stack. +The second field, p, +is how many elements the function pushes onto the stack. +(Any function always pushes its results after popping its arguments.) +A field in the form x|y means the function can push (or pop) +x or y elements, +depending on the situation; +an interrogation mark '?' means that +we cannot know how many elements the function pops/pushes +by looking only at its arguments. +(For instance, they may depend on what is in the stack.) +The third field, x, +tells whether the function may raise errors: +'-' means the function never raises any error; +'m' means the function may raise only out-of-memory errors; +'v' means the function may raise the errors explained in the text; +'e' means the function can run arbitrary Lua code, +either directly or through metamethods, +and therefore may raise any errors. + + + +

lua_absindex

+[-0, +0, –] +

int lua_absindex (lua_State *L, int idx);
+ +

+Converts the acceptable index idx +into an equivalent absolute index +(that is, one that does not depend on the stack size). + + + + + +

lua_Alloc

+
typedef void * (*lua_Alloc) (void *ud,
+                             void *ptr,
+                             size_t osize,
+                             size_t nsize);
+ +

+The type of the memory-allocation function used by Lua states. +The allocator function must provide a +functionality similar to realloc, +but not exactly the same. +Its arguments are +ud, an opaque pointer passed to lua_newstate; +ptr, a pointer to the block being allocated/reallocated/freed; +osize, the original size of the block or some code about what +is being allocated; +and nsize, the new size of the block. + + +

+When ptr is not NULL, +osize is the size of the block pointed by ptr, +that is, the size given when it was allocated or reallocated. + + +

+When ptr is NULL, +osize encodes the kind of object that Lua is allocating. +osize is any of +LUA_TSTRING, LUA_TTABLE, LUA_TFUNCTION, +LUA_TUSERDATA, or LUA_TTHREAD when (and only when) +Lua is creating a new object of that type. +When osize is some other value, +Lua is allocating memory for something else. + + +

+Lua assumes the following behavior from the allocator function: + + +

+When nsize is zero, +the allocator must behave like free +and then return NULL. + + +

+When nsize is not zero, +the allocator must behave like realloc. +In particular, the allocator returns NULL +if and only if it cannot fulfill the request. + + +

+Here is a simple implementation for the allocator function. +It is used in the auxiliary library by luaL_newstate. + +

+     static void *l_alloc (void *ud, void *ptr, size_t osize,
+                                                size_t nsize) {
+       (void)ud;  (void)osize;  /* not used */
+       if (nsize == 0) {
+         free(ptr);
+         return NULL;
+       }
+       else
+         return realloc(ptr, nsize);
+     }
+

+Note that ISO C ensures +that free(NULL) has no effect and that +realloc(NULL,size) is equivalent to malloc(size). + + + + + +

lua_arith

+[-(2|1), +1, e] +

void lua_arith (lua_State *L, int op);
+ +

+Performs an arithmetic or bitwise operation over the two values +(or one, in the case of negations) +at the top of the stack, +with the value on the top being the second operand, +pops these values, and pushes the result of the operation. +The function follows the semantics of the corresponding Lua operator +(that is, it may call metamethods). + + +

+The value of op must be one of the following constants: + +

+ + + + +

lua_atpanic

+[-0, +0, –] +

lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);
+ +

+Sets a new panic function and returns the old one (see §4.4). + + + + + +

lua_call

+[-(nargs+1), +nresults, e] +

void lua_call (lua_State *L, int nargs, int nresults);
+ +

+Calls a function. +Like regular Lua calls, +lua_call respects the __call metamethod. +So, here the word "function" +means any callable value. + + +

+To do a call you must use the following protocol: +first, the function to be called is pushed onto the stack; +then, the arguments to the call are pushed +in direct order; +that is, the first argument is pushed first. +Finally you call lua_call; +nargs is the number of arguments that you pushed onto the stack. +When the function returns, +all arguments and the function value are popped +and the call results are pushed onto the stack. +The number of results is adjusted to nresults, +unless nresults is LUA_MULTRET. +In this case, all results from the function are pushed; +Lua takes care that the returned values fit into the stack space, +but it does not ensure any extra space in the stack. +The function results are pushed onto the stack in direct order +(the first result is pushed first), +so that after the call the last result is on the top of the stack. + + +

+Any error while calling and running the function is propagated upwards +(with a longjmp). + + +

+The following example shows how the host program can do the +equivalent to this Lua code: + +

+     a = f("how", t.x, 14)
+

+Here it is in C: + +

+     lua_getglobal(L, "f");                  /* function to be called */
+     lua_pushliteral(L, "how");                       /* 1st argument */
+     lua_getglobal(L, "t");                    /* table to be indexed */
+     lua_getfield(L, -1, "x");        /* push result of t.x (2nd arg) */
+     lua_remove(L, -2);                  /* remove 't' from the stack */
+     lua_pushinteger(L, 14);                          /* 3rd argument */
+     lua_call(L, 3, 1);     /* call 'f' with 3 arguments and 1 result */
+     lua_setglobal(L, "a");                         /* set global 'a' */
+

+Note that the code above is balanced: +at its end, the stack is back to its original configuration. +This is considered good programming practice. + + + + + +

lua_callk

+[-(nargs + 1), +nresults, e] +

void lua_callk (lua_State *L,
+                int nargs,
+                int nresults,
+                lua_KContext ctx,
+                lua_KFunction k);
+ +

+This function behaves exactly like lua_call, +but allows the called function to yield (see §4.5). + + + + + +

lua_CFunction

+
typedef int (*lua_CFunction) (lua_State *L);
+ +

+Type for C functions. + + +

+In order to communicate properly with Lua, +a C function must use the following protocol, +which defines the way parameters and results are passed: +a C function receives its arguments from Lua in its stack +in direct order (the first argument is pushed first). +So, when the function starts, +lua_gettop(L) returns the number of arguments received by the function. +The first argument (if any) is at index 1 +and its last argument is at index lua_gettop(L). +To return values to Lua, a C function just pushes them onto the stack, +in direct order (the first result is pushed first), +and returns in C the number of results. +Any other value in the stack below the results will be properly +discarded by Lua. +Like a Lua function, a C function called by Lua can also return +many results. + + +

+As an example, the following function receives a variable number +of numeric arguments and returns their average and their sum: + +

+     static int foo (lua_State *L) {
+       int n = lua_gettop(L);    /* number of arguments */
+       lua_Number sum = 0.0;
+       int i;
+       for (i = 1; i <= n; i++) {
+         if (!lua_isnumber(L, i)) {
+           lua_pushliteral(L, "incorrect argument");
+           lua_error(L);
+         }
+         sum += lua_tonumber(L, i);
+       }
+       lua_pushnumber(L, sum/n);        /* first result */
+       lua_pushnumber(L, sum);         /* second result */
+       return 2;                   /* number of results */
+     }
+
+ + + + +

lua_checkstack

+[-0, +0, –] +

int lua_checkstack (lua_State *L, int n);
+ +

+Ensures that the stack has space for at least n extra elements, +that is, that you can safely push up to n values into it. +It returns false if it cannot fulfill the request, +either because it would cause the stack +to be greater than a fixed maximum size +(typically at least several thousand elements) or +because it cannot allocate memory for the extra space. +This function never shrinks the stack; +if the stack already has space for the extra elements, +it is left unchanged. + + + + + +

lua_close

+[-0, +0, –] +

void lua_close (lua_State *L);
+ +

+Close all active to-be-closed variables in the main thread, +release all objects in the given Lua state +(calling the corresponding garbage-collection metamethods, if any), +and frees all dynamic memory used by this state. + + +

+On several platforms, you may not need to call this function, +because all resources are naturally released when the host program ends. +On the other hand, long-running programs that create multiple states, +such as daemons or web servers, +will probably need to close states as soon as they are not needed. + + + + + +

lua_closeslot

+[-0, +0, e] +

void lua_closeslot (lua_State *L, int index);
+ +

+Close the to-be-closed slot at the given index and set its value to nil. +The index must be the last index previously marked to be closed +(see lua_toclose) that is still active (that is, not closed yet). + + +

+A __close metamethod cannot yield +when called through this function. + + +

+(This function was introduced in release 5.4.3.) + + + + + +

lua_closethread

+[-0, +?, –] +

int lua_closethread (lua_State *L, lua_State *from);
+ +

+Resets a thread, cleaning its call stack and closing all pending +to-be-closed variables. +Returns a status code: +LUA_OK for no errors in the thread +(either the original error that stopped the thread or +errors in closing methods), +or an error status otherwise. +In case of error, +leaves the error object on the top of the stack. + + +

+The parameter from represents the coroutine that is resetting L. +If there is no such coroutine, +this parameter can be NULL. + + +

+(This function was introduced in release 5.4.6.) + + + + + +

lua_compare

+[-0, +0, e] +

int lua_compare (lua_State *L, int index1, int index2, int op);
+ +

+Compares two Lua values. +Returns 1 if the value at index index1 satisfies op +when compared with the value at index index2, +following the semantics of the corresponding Lua operator +(that is, it may call metamethods). +Otherwise returns 0. +Also returns 0 if any of the indices is not valid. + + +

+The value of op must be one of the following constants: + +

    + +
  • LUA_OPEQ: compares for equality (==)
    • +
  • LUA_OPLT: compares for less than (<)
    • +
  • LUA_OPLE: compares for less or equal (<=)
    • + +
+ + + + +

lua_concat

+[-n, +1, e] +

void lua_concat (lua_State *L, int n);
+ +

+Concatenates the n values at the top of the stack, +pops them, and leaves the result on the top. +If n is 1, the result is the single value on the stack +(that is, the function does nothing); +if n is 0, the result is the empty string. +Concatenation is performed following the usual semantics of Lua +(see §3.4.6). + + + + + +

lua_copy

+[-0, +0, –] +

void lua_copy (lua_State *L, int fromidx, int toidx);
+ +

+Copies the element at index fromidx +into the valid index toidx, +replacing the value at that position. +Values at other positions are not affected. + + + + + +

lua_createtable

+[-0, +1, m] +

void lua_createtable (lua_State *L, int narr, int nrec);
+ +

+Creates a new empty table and pushes it onto the stack. +Parameter narr is a hint for how many elements the table +will have as a sequence; +parameter nrec is a hint for how many other elements +the table will have. +Lua may use these hints to preallocate memory for the new table. +This preallocation may help performance when you know in advance +how many elements the table will have. +Otherwise you can use the function lua_newtable. + + + + + +

lua_dump

+[-0, +0, –] +

int lua_dump (lua_State *L,
+                        lua_Writer writer,
+                        void *data,
+                        int strip);
+ +

+Dumps a function as a binary chunk. +Receives a Lua function on the top of the stack +and produces a binary chunk that, +if loaded again, +results in a function equivalent to the one dumped. +As it produces parts of the chunk, +lua_dump calls function writer (see lua_Writer) +with the given data +to write them. + + +

+If strip is true, +the binary representation may not include all debug information +about the function, +to save space. + + +

+The value returned is the error code returned by the last +call to the writer; +0 means no errors. + + +

+This function does not pop the Lua function from the stack. + + + + + +

lua_error

+[-1, +0, v] +

int lua_error (lua_State *L);
+ +

+Raises a Lua error, +using the value on the top of the stack as the error object. +This function does a long jump, +and therefore never returns +(see luaL_error). + + + + + +

lua_gc

+[-0, +0, –] +

int lua_gc (lua_State *L, int what, ...);
+ +

+Controls the garbage collector. + + +

+This function performs several tasks, +according to the value of the parameter what. +For options that need extra arguments, +they are listed after the option. + +

    + +
  • LUA_GCCOLLECT: +Performs a full garbage-collection cycle. +
    • + +
  • LUA_GCSTOP: +Stops the garbage collector. +
    • + +
  • LUA_GCRESTART: +Restarts the garbage collector. +
    • + +
  • LUA_GCCOUNT: +Returns the current amount of memory (in Kbytes) in use by Lua. +
    • + +
  • LUA_GCCOUNTB: +Returns the remainder of dividing the current amount of bytes of +memory in use by Lua by 1024. +
    • + +
  • LUA_GCSTEP (int stepsize): +Performs an incremental step of garbage collection, +corresponding to the allocation of stepsize Kbytes. +
    • + +
  • LUA_GCISRUNNING: +Returns a boolean that tells whether the collector is running +(i.e., not stopped). +
    • + +
  • LUA_GCINC (int pause, int stepmul, stepsize): +Changes the collector to incremental mode +with the given parameters (see §2.5.1). +Returns the previous mode (LUA_GCGEN or LUA_GCINC). +
    • + +
  • LUA_GCGEN (int minormul, int majormul): +Changes the collector to generational mode +with the given parameters (see §2.5.2). +Returns the previous mode (LUA_GCGEN or LUA_GCINC). +
    • + +

+For more details about these options, +see collectgarbage. + + +

+This function should not be called by a finalizer. + + + + + +

lua_getallocf

+[-0, +0, –] +

lua_Alloc lua_getallocf (lua_State *L, void **ud);
+ +

+Returns the memory-allocation function of a given state. +If ud is not NULL, Lua stores in *ud the +opaque pointer given when the memory-allocator function was set. + + + + + +

lua_getfield

+[-0, +1, e] +

int lua_getfield (lua_State *L, int index, const char *k);
+ +

+Pushes onto the stack the value t[k], +where t is the value at the given index. +As in Lua, this function may trigger a metamethod +for the "index" event (see §2.4). + + +

+Returns the type of the pushed value. + + + + + +

lua_getextraspace

+[-0, +0, –] +

void *lua_getextraspace (lua_State *L);
+ +

+Returns a pointer to a raw memory area associated with the +given Lua state. +The application can use this area for any purpose; +Lua does not use it for anything. + + +

+Each new thread has this area initialized with a copy +of the area of the main thread. + + +

+By default, this area has the size of a pointer to void, +but you can recompile Lua with a different size for this area. +(See LUA_EXTRASPACE in luaconf.h.) + + + + + +

lua_getglobal

+[-0, +1, e] +

int lua_getglobal (lua_State *L, const char *name);
+ +

+Pushes onto the stack the value of the global name. +Returns the type of that value. + + + + + +

lua_geti

+[-0, +1, e] +

int lua_geti (lua_State *L, int index, lua_Integer i);
+ +

+Pushes onto the stack the value t[i], +where t is the value at the given index. +As in Lua, this function may trigger a metamethod +for the "index" event (see §2.4). + + +

+Returns the type of the pushed value. + + + + + +

lua_getmetatable

+[-0, +(0|1), –] +

int lua_getmetatable (lua_State *L, int index);
+ +

+If the value at the given index has a metatable, +the function pushes that metatable onto the stack and returns 1. +Otherwise, +the function returns 0 and pushes nothing on the stack. + + + + + +

lua_gettable

+[-1, +1, e] +

int lua_gettable (lua_State *L, int index);
+ +

+Pushes onto the stack the value t[k], +where t is the value at the given index +and k is the value on the top of the stack. + + +

+This function pops the key from the stack, +pushing the resulting value in its place. +As in Lua, this function may trigger a metamethod +for the "index" event (see §2.4). + + +

+Returns the type of the pushed value. + + + + + +

lua_gettop

+[-0, +0, –] +

int lua_gettop (lua_State *L);
+ +

+Returns the index of the top element in the stack. +Because indices start at 1, +this result is equal to the number of elements in the stack; +in particular, 0 means an empty stack. + + + + + +

lua_getiuservalue

+[-0, +1, –] +

int lua_getiuservalue (lua_State *L, int index, int n);
+ +

+Pushes onto the stack the n-th user value associated with the +full userdata at the given index and +returns the type of the pushed value. + + +

+If the userdata does not have that value, +pushes nil and returns LUA_TNONE. + + + + + +

lua_insert

+[-1, +1, –] +

void lua_insert (lua_State *L, int index);
+ +

+Moves the top element into the given valid index, +shifting up the elements above this index to open space. +This function cannot be called with a pseudo-index, +because a pseudo-index is not an actual stack position. + + + + + +

lua_Integer

+
typedef ... lua_Integer;
+ +

+The type of integers in Lua. + + +

+By default this type is long long, +(usually a 64-bit two-complement integer), +but that can be changed to long or int +(usually a 32-bit two-complement integer). +(See LUA_INT_TYPE in luaconf.h.) + + +

+Lua also defines the constants +LUA_MININTEGER and LUA_MAXINTEGER, +with the minimum and the maximum values that fit in this type. + + + + + +

lua_isboolean

+[-0, +0, –] +

int lua_isboolean (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a boolean, +and 0 otherwise. + + + + + +

lua_iscfunction

+[-0, +0, –] +

int lua_iscfunction (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a C function, +and 0 otherwise. + + + + + +

lua_isfunction

+[-0, +0, –] +

int lua_isfunction (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a function +(either C or Lua), and 0 otherwise. + + + + + +

lua_isinteger

+[-0, +0, –] +

int lua_isinteger (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is an integer +(that is, the value is a number and is represented as an integer), +and 0 otherwise. + + + + + +

lua_islightuserdata

+[-0, +0, –] +

int lua_islightuserdata (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a light userdata, +and 0 otherwise. + + + + + +

lua_isnil

+[-0, +0, –] +

int lua_isnil (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is nil, +and 0 otherwise. + + + + + +

lua_isnone

+[-0, +0, –] +

int lua_isnone (lua_State *L, int index);
+ +

+Returns 1 if the given index is not valid, +and 0 otherwise. + + + + + +

lua_isnoneornil

+[-0, +0, –] +

int lua_isnoneornil (lua_State *L, int index);
+ +

+Returns 1 if the given index is not valid +or if the value at this index is nil, +and 0 otherwise. + + + + + +

lua_isnumber

+[-0, +0, –] +

int lua_isnumber (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a number +or a string convertible to a number, +and 0 otherwise. + + + + + +

lua_isstring

+[-0, +0, –] +

int lua_isstring (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a string +or a number (which is always convertible to a string), +and 0 otherwise. + + + + + +

lua_istable

+[-0, +0, –] +

int lua_istable (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a table, +and 0 otherwise. + + + + + +

lua_isthread

+[-0, +0, –] +

int lua_isthread (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a thread, +and 0 otherwise. + + + + + +

lua_isuserdata

+[-0, +0, –] +

int lua_isuserdata (lua_State *L, int index);
+ +

+Returns 1 if the value at the given index is a userdata +(either full or light), and 0 otherwise. + + + + + +

lua_isyieldable

+[-0, +0, –] +

int lua_isyieldable (lua_State *L);
+ +

+Returns 1 if the given coroutine can yield, +and 0 otherwise. + + + + + +

lua_KContext

+
typedef ... lua_KContext;
+ +

+The type for continuation-function contexts. +It must be a numeric type. +This type is defined as intptr_t +when intptr_t is available, +so that it can store pointers too. +Otherwise, it is defined as ptrdiff_t. + + + + + +

lua_KFunction

+
typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx);
+ +

+Type for continuation functions (see §4.5). + + + + + +

lua_len

+[-0, +1, e] +

void lua_len (lua_State *L, int index);
+ +

+Returns the length of the value at the given index. +It is equivalent to the '#' operator in Lua (see §3.4.7) and +may trigger a metamethod for the "length" event (see §2.4). +The result is pushed on the stack. + + + + + +

lua_load

+[-0, +1, –] +

int lua_load (lua_State *L,
+              lua_Reader reader,
+              void *data,
+              const char *chunkname,
+              const char *mode);
+ +

+Loads a Lua chunk without running it. +If there are no errors, +lua_load pushes the compiled chunk as a Lua +function on top of the stack. +Otherwise, it pushes an error message. + + +

+The lua_load function uses a user-supplied reader function +to read the chunk (see lua_Reader). +The data argument is an opaque value passed to the reader function. + + +

+The chunkname argument gives a name to the chunk, +which is used for error messages and in debug information (see §4.7). + + +

+lua_load automatically detects whether the chunk is text or binary +and loads it accordingly (see program luac). +The string mode works as in function load, +with the addition that +a NULL value is equivalent to the string "bt". + + +

+lua_load uses the stack internally, +so the reader function must always leave the stack +unmodified when returning. + + +

+lua_load can return +LUA_OK, LUA_ERRSYNTAX, or LUA_ERRMEM. +The function may also return other values corresponding to +errors raised by the read function (see §4.4.1). + + +

+If the resulting function has upvalues, +its first upvalue is set to the value of the global environment +stored at index LUA_RIDX_GLOBALS in the registry (see §4.3). +When loading main chunks, +this upvalue will be the _ENV variable (see §2.2). +Other upvalues are initialized with nil. + + + + + +

lua_newstate

+[-0, +0, –] +

lua_State *lua_newstate (lua_Alloc f, void *ud);
+ +

+Creates a new independent state and returns its main thread. +Returns NULL if it cannot create the state +(due to lack of memory). +The argument f is the allocator function; +Lua will do all memory allocation for this state +through this function (see lua_Alloc). +The second argument, ud, is an opaque pointer that Lua +passes to the allocator in every call. + + + + + +

lua_newtable

+[-0, +1, m] +

void lua_newtable (lua_State *L);
+ +

+Creates a new empty table and pushes it onto the stack. +It is equivalent to lua_createtable(L, 0, 0). + + + + + +

lua_newthread

+[-0, +1, m] +

lua_State *lua_newthread (lua_State *L);
+ +

+Creates a new thread, pushes it on the stack, +and returns a pointer to a lua_State that represents this new thread. +The new thread returned by this function shares with the original thread +its global environment, +but has an independent execution stack. + + +

+Threads are subject to garbage collection, +like any Lua object. + + + + + +

lua_newuserdatauv

+[-0, +1, m] +

void *lua_newuserdatauv (lua_State *L, size_t size, int nuvalue);
+ +

+This function creates and pushes on the stack a new full userdata, +with nuvalue associated Lua values, called user values, +plus an associated block of raw memory with size bytes. +(The user values can be set and read with the functions +lua_setiuservalue and lua_getiuservalue.) + + +

+The function returns the address of the block of memory. +Lua ensures that this address is valid as long as +the corresponding userdata is alive (see §2.5). +Moreover, if the userdata is marked for finalization (see §2.5.3), +its address is valid at least until the call to its finalizer. + + + + + +

lua_next

+[-1, +(2|0), v] +

int lua_next (lua_State *L, int index);
+ +

+Pops a key from the stack, +and pushes a key–value pair from the table at the given index, +the "next" pair after the given key. +If there are no more elements in the table, +then lua_next returns 0 and pushes nothing. + + +

+A typical table traversal looks like this: + +

+     /* table is in the stack at index 't' */
+     lua_pushnil(L);  /* first key */
+     while (lua_next(L, t) != 0) {
+       /* uses 'key' (at index -2) and 'value' (at index -1) */
+       printf("%s - %s\n",
+              lua_typename(L, lua_type(L, -2)),
+              lua_typename(L, lua_type(L, -1)));
+       /* removes 'value'; keeps 'key' for next iteration */
+       lua_pop(L, 1);
+     }
+
+ +

+While traversing a table, +avoid calling lua_tolstring directly on a key, +unless you know that the key is actually a string. +Recall that lua_tolstring may change +the value at the given index; +this confuses the next call to lua_next. + + +

+This function may raise an error if the given key +is neither nil nor present in the table. +See function next for the caveats of modifying +the table during its traversal. + + + + + +

lua_Number

+
typedef ... lua_Number;
+ +

+The type of floats in Lua. + + +

+By default this type is double, +but that can be changed to a single float or a long double. +(See LUA_FLOAT_TYPE in luaconf.h.) + + + + + +

lua_numbertointeger

+
int lua_numbertointeger (lua_Number n, lua_Integer *p);
+ +

+Tries to convert a Lua float to a Lua integer; +the float n must have an integral value. +If that value is within the range of Lua integers, +it is converted to an integer and assigned to *p. +The macro results in a boolean indicating whether the +conversion was successful. +(Note that this range test can be tricky to do +correctly without this macro, due to rounding.) + + +

+This macro may evaluate its arguments more than once. + + + + + +

lua_pcall

+[-(nargs + 1), +(nresults|1), –] +

int lua_pcall (lua_State *L, int nargs, int nresults, int msgh);
+ +

+Calls a function (or a callable object) in protected mode. + + +

+Both nargs and nresults have the same meaning as +in lua_call. +If there are no errors during the call, +lua_pcall behaves exactly like lua_call. +However, if there is any error, +lua_pcall catches it, +pushes a single value on the stack (the error object), +and returns an error code. +Like lua_call, +lua_pcall always removes the function +and its arguments from the stack. + + +

+If msgh is 0, +then the error object returned on the stack +is exactly the original error object. +Otherwise, msgh is the stack index of a +message handler. +(This index cannot be a pseudo-index.) +In case of runtime errors, +this handler will be called with the error object +and its return value will be the object +returned on the stack by lua_pcall. + + +

+Typically, the message handler is used to add more debug +information to the error object, such as a stack traceback. +Such information cannot be gathered after the return of lua_pcall, +since by then the stack has unwound. + + +

+The lua_pcall function returns one of the following status codes: +LUA_OK, LUA_ERRRUN, LUA_ERRMEM, or LUA_ERRERR. + + + + + +

lua_pcallk

+[-(nargs + 1), +(nresults|1), –] +

int lua_pcallk (lua_State *L,
+                int nargs,
+                int nresults,
+                int msgh,
+                lua_KContext ctx,
+                lua_KFunction k);
+ +

+This function behaves exactly like lua_pcall, +except that it allows the called function to yield (see §4.5). + + + + + +

lua_pop

+[-n, +0, e] +

void lua_pop (lua_State *L, int n);
+ +

+Pops n elements from the stack. +It is implemented as a macro over lua_settop. + + + + + +

lua_pushboolean

+[-0, +1, –] +

void lua_pushboolean (lua_State *L, int b);
+ +

+Pushes a boolean value with value b onto the stack. + + + + + +

lua_pushcclosure

+[-n, +1, m] +

void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);
+ +

+Pushes a new C closure onto the stack. +This function receives a pointer to a C function +and pushes onto the stack a Lua value of type function that, +when called, invokes the corresponding C function. +The parameter n tells how many upvalues this function will have +(see §4.2). + + +

+Any function to be callable by Lua must +follow the correct protocol to receive its parameters +and return its results (see lua_CFunction). + + +

+When a C function is created, +it is possible to associate some values with it, +the so called upvalues; +these upvalues are then accessible to the function whenever it is called. +This association is called a C closure (see §4.2). +To create a C closure, +first the initial values for its upvalues must be pushed onto the stack. +(When there are multiple upvalues, the first value is pushed first.) +Then lua_pushcclosure +is called to create and push the C function onto the stack, +with the argument n telling how many values will be +associated with the function. +lua_pushcclosure also pops these values from the stack. + + +

+The maximum value for n is 255. + + +

+When n is zero, +this function creates a light C function, +which is just a pointer to the C function. +In that case, it never raises a memory error. + + + + + +

lua_pushcfunction

+[-0, +1, –] +

void lua_pushcfunction (lua_State *L, lua_CFunction f);
+ +

+Pushes a C function onto the stack. +This function is equivalent to lua_pushcclosure with no upvalues. + + + + + +

lua_pushfstring

+[-0, +1, v] +

const char *lua_pushfstring (lua_State *L, const char *fmt, ...);
+ +

+Pushes onto the stack a formatted string +and returns a pointer to this string (see §4.1.3). +It is similar to the ISO C function sprintf, +but has two important differences. +First, +you do not have to allocate space for the result; +the result is a Lua string and Lua takes care of memory allocation +(and deallocation, through garbage collection). +Second, +the conversion specifiers are quite restricted. +There are no flags, widths, or precisions. +The conversion specifiers can only be +'%%' (inserts the character '%'), +'%s' (inserts a zero-terminated string, with no size restrictions), +'%f' (inserts a lua_Number), +'%I' (inserts a lua_Integer), +'%p' (inserts a pointer), +'%d' (inserts an int), +'%c' (inserts an int as a one-byte character), and +'%U' (inserts a long int as a UTF-8 byte sequence). + + +

+This function may raise errors due to memory overflow +or an invalid conversion specifier. + + + + + +

lua_pushglobaltable

+[-0, +1, –] +

void lua_pushglobaltable (lua_State *L);
+ +

+Pushes the global environment onto the stack. + + + + + +

lua_pushinteger

+[-0, +1, –] +

void lua_pushinteger (lua_State *L, lua_Integer n);
+ +

+Pushes an integer with value n onto the stack. + + + + + +

lua_pushlightuserdata

+[-0, +1, –] +

void lua_pushlightuserdata (lua_State *L, void *p);
+ +

+Pushes a light userdata onto the stack. + + +

+Userdata represent C values in Lua. +A light userdata represents a pointer, a void*. +It is a value (like a number): +you do not create it, it has no individual metatable, +and it is not collected (as it was never created). +A light userdata is equal to "any" +light userdata with the same C address. + + + + + +

lua_pushliteral

+[-0, +1, m] +

const char *lua_pushliteral (lua_State *L, const char *s);
+ +

+This macro is equivalent to lua_pushstring, +but should be used only when s is a literal string. +(Lua may optimize this case.) + + + + + +

lua_pushlstring

+[-0, +1, m] +

const char *lua_pushlstring (lua_State *L, const char *s, size_t len);
+ +

+Pushes the string pointed to by s with size len +onto the stack. +Lua will make or reuse an internal copy of the given string, +so the memory at s can be freed or reused immediately after +the function returns. +The string can contain any binary data, +including embedded zeros. + + +

+Returns a pointer to the internal copy of the string (see §4.1.3). + + + + + +

lua_pushnil

+[-0, +1, –] +

void lua_pushnil (lua_State *L);
+ +

+Pushes a nil value onto the stack. + + + + + +

lua_pushnumber

+[-0, +1, –] +

void lua_pushnumber (lua_State *L, lua_Number n);
+ +

+Pushes a float with value n onto the stack. + + + + + +

lua_pushstring

+[-0, +1, m] +

const char *lua_pushstring (lua_State *L, const char *s);
+ +

+Pushes the zero-terminated string pointed to by s +onto the stack. +Lua will make or reuse an internal copy of the given string, +so the memory at s can be freed or reused immediately after +the function returns. + + +

+Returns a pointer to the internal copy of the string (see §4.1.3). + + +

+If s is NULL, pushes nil and returns NULL. + + + + + +

lua_pushthread

+[-0, +1, –] +

int lua_pushthread (lua_State *L);
+ +

+Pushes the thread represented by L onto the stack. +Returns 1 if this thread is the main thread of its state. + + + + + +

lua_pushvalue

+[-0, +1, –] +

void lua_pushvalue (lua_State *L, int index);
+ +

+Pushes a copy of the element at the given index +onto the stack. + + + + + +

lua_pushvfstring

+[-0, +1, v] +

const char *lua_pushvfstring (lua_State *L,
+                              const char *fmt,
+                              va_list argp);
+ +

+Equivalent to lua_pushfstring, except that it receives a va_list +instead of a variable number of arguments. + + + + + +

lua_rawequal

+[-0, +0, –] +

int lua_rawequal (lua_State *L, int index1, int index2);
+ +

+Returns 1 if the two values in indices index1 and +index2 are primitively equal +(that is, equal without calling the __eq metamethod). +Otherwise returns 0. +Also returns 0 if any of the indices are not valid. + + + + + +

lua_rawget

+[-1, +1, –] +

int lua_rawget (lua_State *L, int index);
+ +

+Similar to lua_gettable, but does a raw access +(i.e., without metamethods). +The value at index must be a table. + + + + + +

lua_rawgeti

+[-0, +1, –] +

int lua_rawgeti (lua_State *L, int index, lua_Integer n);
+ +

+Pushes onto the stack the value t[n], +where t is the table at the given index. +The access is raw, +that is, it does not use the __index metavalue. + + +

+Returns the type of the pushed value. + + + + + +

lua_rawgetp

+[-0, +1, –] +

int lua_rawgetp (lua_State *L, int index, const void *p);
+ +

+Pushes onto the stack the value t[k], +where t is the table at the given index and +k is the pointer p represented as a light userdata. +The access is raw; +that is, it does not use the __index metavalue. + + +

+Returns the type of the pushed value. + + + + + +

lua_rawlen

+[-0, +0, –] +

lua_Unsigned lua_rawlen (lua_State *L, int index);
+ +

+Returns the raw "length" of the value at the given index: +for strings, this is the string length; +for tables, this is the result of the length operator ('#') +with no metamethods; +for userdata, this is the size of the block of memory allocated +for the userdata. +For other values, this call returns 0. + + + + + +

lua_rawset

+[-2, +0, m] +

void lua_rawset (lua_State *L, int index);
+ +

+Similar to lua_settable, but does a raw assignment +(i.e., without metamethods). +The value at index must be a table. + + + + + +

lua_rawseti

+[-1, +0, m] +

void lua_rawseti (lua_State *L, int index, lua_Integer i);
+ +

+Does the equivalent of t[i] = v, +where t is the table at the given index +and v is the value on the top of the stack. + + +

+This function pops the value from the stack. +The assignment is raw, +that is, it does not use the __newindex metavalue. + + + + + +

lua_rawsetp

+[-1, +0, m] +

void lua_rawsetp (lua_State *L, int index, const void *p);
+ +

+Does the equivalent of t[p] = v, +where t is the table at the given index, +p is encoded as a light userdata, +and v is the value on the top of the stack. + + +

+This function pops the value from the stack. +The assignment is raw, +that is, it does not use the __newindex metavalue. + + + + + +

lua_Reader

+
typedef const char * (*lua_Reader) (lua_State *L,
+                                    void *data,
+                                    size_t *size);
+ +

+The reader function used by lua_load. +Every time lua_load needs another piece of the chunk, +it calls the reader, +passing along its data parameter. +The reader must return a pointer to a block of memory +with a new piece of the chunk +and set size to the block size. +The block must exist until the reader function is called again. +To signal the end of the chunk, +the reader must return NULL or set size to zero. +The reader function may return pieces of any size greater than zero. + + + + + +

lua_register

+[-0, +0, e] +

void lua_register (lua_State *L, const char *name, lua_CFunction f);
+ +

+Sets the C function f as the new value of global name. +It is defined as a macro: + +

+     #define lua_register(L,n,f) \
+            (lua_pushcfunction(L, f), lua_setglobal(L, n))
+
+ + + + +

lua_remove

+[-1, +0, –] +

void lua_remove (lua_State *L, int index);
+ +

+Removes the element at the given valid index, +shifting down the elements above this index to fill the gap. +This function cannot be called with a pseudo-index, +because a pseudo-index is not an actual stack position. + + + + + +

lua_replace

+[-1, +0, –] +

void lua_replace (lua_State *L, int index);
+ +

+Moves the top element into the given valid index +without shifting any element +(therefore replacing the value at that given index), +and then pops the top element. + + + + + +

lua_resetthread

+[-0, +?, –] +

int lua_resetthread (lua_State *L);
+ +

+This function is deprecated; +it is equivalent to lua_closethread with +from being NULL. + + + + + +

lua_resume

+[-?, +?, –] +

int lua_resume (lua_State *L, lua_State *from, int nargs,
+                          int *nresults);
+ +

+Starts and resumes a coroutine in the given thread L. + + +

+To start a coroutine, +you push the main function plus any arguments +onto the empty stack of the thread. +then you call lua_resume, +with nargs being the number of arguments. +This call returns when the coroutine suspends or finishes its execution. +When it returns, +*nresults is updated and +the top of the stack contains +the *nresults values passed to lua_yield +or returned by the body function. +lua_resume returns +LUA_YIELD if the coroutine yields, +LUA_OK if the coroutine finishes its execution +without errors, +or an error code in case of errors (see §4.4.1). +In case of errors, +the error object is on the top of the stack. + + +

+To resume a coroutine, +you remove the *nresults yielded values from its stack, +push the values to be passed as results from yield, +and then call lua_resume. + + +

+The parameter from represents the coroutine that is resuming L. +If there is no such coroutine, +this parameter can be NULL. + + + + + +

lua_rotate

+[-0, +0, –] +

void lua_rotate (lua_State *L, int idx, int n);
+ +

+Rotates the stack elements between the valid index idx +and the top of the stack. +The elements are rotated n positions in the direction of the top, +for a positive n, +or -n positions in the direction of the bottom, +for a negative n. +The absolute value of n must not be greater than the size +of the slice being rotated. +This function cannot be called with a pseudo-index, +because a pseudo-index is not an actual stack position. + + + + + +

lua_setallocf

+[-0, +0, –] +

void lua_setallocf (lua_State *L, lua_Alloc f, void *ud);
+ +

+Changes the allocator function of a given state to f +with user data ud. + + + + + +

lua_setfield

+[-1, +0, e] +

void lua_setfield (lua_State *L, int index, const char *k);
+ +

+Does the equivalent to t[k] = v, +where t is the value at the given index +and v is the value on the top of the stack. + + +

+This function pops the value from the stack. +As in Lua, this function may trigger a metamethod +for the "newindex" event (see §2.4). + + + + + +

lua_setglobal

+[-1, +0, e] +

void lua_setglobal (lua_State *L, const char *name);
+ +

+Pops a value from the stack and +sets it as the new value of global name. + + + + + +

lua_seti

+[-1, +0, e] +

void lua_seti (lua_State *L, int index, lua_Integer n);
+ +

+Does the equivalent to t[n] = v, +where t is the value at the given index +and v is the value on the top of the stack. + + +

+This function pops the value from the stack. +As in Lua, this function may trigger a metamethod +for the "newindex" event (see §2.4). + + + + + +

lua_setiuservalue

+[-1, +0, –] +

int lua_setiuservalue (lua_State *L, int index, int n);
+ +

+Pops a value from the stack and sets it as +the new n-th user value associated to the +full userdata at the given index. +Returns 0 if the userdata does not have that value. + + + + + +

lua_setmetatable

+[-1, +0, –] +

int lua_setmetatable (lua_State *L, int index);
+ +

+Pops a table or nil from the stack and +sets that value as the new metatable for the value at the given index. +(nil means no metatable.) + + +

+(For historical reasons, this function returns an int, +which now is always 1.) + + + + + +

lua_settable

+[-2, +0, e] +

void lua_settable (lua_State *L, int index);
+ +

+Does the equivalent to t[k] = v, +where t is the value at the given index, +v is the value on the top of the stack, +and k is the value just below the top. + + +

+This function pops both the key and the value from the stack. +As in Lua, this function may trigger a metamethod +for the "newindex" event (see §2.4). + + + + + +

lua_settop

+[-?, +?, e] +

void lua_settop (lua_State *L, int index);
+ +

+Accepts any index, or 0, +and sets the stack top to this index. +If the new top is greater than the old one, +then the new elements are filled with nil. +If index is 0, then all stack elements are removed. + + +

+This function can run arbitrary code when removing an index +marked as to-be-closed from the stack. + + + + + +

lua_setwarnf

+[-0, +0, –] +

void lua_setwarnf (lua_State *L, lua_WarnFunction f, void *ud);
+ +

+Sets the warning function to be used by Lua to emit warnings +(see lua_WarnFunction). +The ud parameter sets the value ud passed to +the warning function. + + + + + +

lua_State

+
typedef struct lua_State lua_State;
+ +

+An opaque structure that points to a thread and indirectly +(through the thread) to the whole state of a Lua interpreter. +The Lua library is fully reentrant: +it has no global variables. +All information about a state is accessible through this structure. + + +

+A pointer to this structure must be passed as the first argument to +every function in the library, except to lua_newstate, +which creates a Lua state from scratch. + + + + + +

lua_status

+[-0, +0, –] +

int lua_status (lua_State *L);
+ +

+Returns the status of the thread L. + + +

+The status can be LUA_OK for a normal thread, +an error code if the thread finished the execution +of a lua_resume with an error, +or LUA_YIELD if the thread is suspended. + + +

+You can call functions only in threads with status LUA_OK. +You can resume threads with status LUA_OK +(to start a new coroutine) or LUA_YIELD +(to resume a coroutine). + + + + + +

lua_stringtonumber

+[-0, +1, –] +

size_t lua_stringtonumber (lua_State *L, const char *s);
+ +

+Converts the zero-terminated string s to a number, +pushes that number into the stack, +and returns the total size of the string, +that is, its length plus one. +The conversion can result in an integer or a float, +according to the lexical conventions of Lua (see §3.1). +The string may have leading and trailing whitespaces and a sign. +If the string is not a valid numeral, +returns 0 and pushes nothing. +(Note that the result can be used as a boolean, +true if the conversion succeeds.) + + + + + +

lua_toboolean

+[-0, +0, –] +

int lua_toboolean (lua_State *L, int index);
+ +

+Converts the Lua value at the given index to a C boolean +value (0 or 1). +Like all tests in Lua, +lua_toboolean returns true for any Lua value +different from false and nil; +otherwise it returns false. +(If you want to accept only actual boolean values, +use lua_isboolean to test the value's type.) + + + + + +

lua_tocfunction

+[-0, +0, –] +

lua_CFunction lua_tocfunction (lua_State *L, int index);
+ +

+Converts a value at the given index to a C function. +That value must be a C function; +otherwise, returns NULL. + + + + + +

lua_toclose

+[-0, +0, m] +

void lua_toclose (lua_State *L, int index);
+ +

+Marks the given index in the stack as a +to-be-closed slot (see §3.3.8). +Like a to-be-closed variable in Lua, +the value at that slot in the stack will be closed +when it goes out of scope. +Here, in the context of a C function, +to go out of scope means that the running function returns to Lua, +or there is an error, +or the slot is removed from the stack through +lua_settop or lua_pop, +or there is a call to lua_closeslot. +A slot marked as to-be-closed should not be removed from the stack +by any other function in the API except lua_settop or lua_pop, +unless previously deactivated by lua_closeslot. + + +

+This function should not be called for an index +that is equal to or below an active to-be-closed slot. + + +

+Note that, both in case of errors and of a regular return, +by the time the __close metamethod runs, +the C stack was already unwound, +so that any automatic C variable declared in the calling function +(e.g., a buffer) will be out of scope. + + + + + +

lua_tointeger

+[-0, +0, –] +

lua_Integer lua_tointeger (lua_State *L, int index);
+ +

+Equivalent to lua_tointegerx with isnum equal to NULL. + + + + + +

lua_tointegerx

+[-0, +0, –] +

lua_Integer lua_tointegerx (lua_State *L, int index, int *isnum);
+ +

+Converts the Lua value at the given index +to the signed integral type lua_Integer. +The Lua value must be an integer, +or a number or string convertible to an integer (see §3.4.3); +otherwise, lua_tointegerx returns 0. + + +

+If isnum is not NULL, +its referent is assigned a boolean value that +indicates whether the operation succeeded. + + + + + +

lua_tolstring

+[-0, +0, m] +

const char *lua_tolstring (lua_State *L, int index, size_t *len);
+ +

+Converts the Lua value at the given index to a C string. +If len is not NULL, +it sets *len with the string length. +The Lua value must be a string or a number; +otherwise, the function returns NULL. +If the value is a number, +then lua_tolstring also +changes the actual value in the stack to a string. +(This change confuses lua_next +when lua_tolstring is applied to keys during a table traversal.) + + +

+lua_tolstring returns a pointer +to a string inside the Lua state (see §4.1.3). +This string always has a zero ('\0') +after its last character (as in C), +but can contain other zeros in its body. + + + + + +

lua_tonumber

+[-0, +0, –] +

lua_Number lua_tonumber (lua_State *L, int index);
+ +

+Equivalent to lua_tonumberx with isnum equal to NULL. + + + + + +

lua_tonumberx

+[-0, +0, –] +

lua_Number lua_tonumberx (lua_State *L, int index, int *isnum);
+ +

+Converts the Lua value at the given index +to the C type lua_Number (see lua_Number). +The Lua value must be a number or a string convertible to a number +(see §3.4.3); +otherwise, lua_tonumberx returns 0. + + +

+If isnum is not NULL, +its referent is assigned a boolean value that +indicates whether the operation succeeded. + + + + + +

lua_topointer

+[-0, +0, –] +

const void *lua_topointer (lua_State *L, int index);
+ +

+Converts the value at the given index to a generic +C pointer (void*). +The value can be a userdata, a table, a thread, a string, or a function; +otherwise, lua_topointer returns NULL. +Different objects will give different pointers. +There is no way to convert the pointer back to its original value. + + +

+Typically this function is used only for hashing and debug information. + + + + + +

lua_tostring

+[-0, +0, m] +

const char *lua_tostring (lua_State *L, int index);
+ +

+Equivalent to lua_tolstring with len equal to NULL. + + + + + +

lua_tothread

+[-0, +0, –] +

lua_State *lua_tothread (lua_State *L, int index);
+ +

+Converts the value at the given index to a Lua thread +(represented as lua_State*). +This value must be a thread; +otherwise, the function returns NULL. + + + + + +

lua_touserdata

+[-0, +0, –] +

void *lua_touserdata (lua_State *L, int index);
+ +

+If the value at the given index is a full userdata, +returns its memory-block address. +If the value is a light userdata, +returns its value (a pointer). +Otherwise, returns NULL. + + + + + +

lua_type

+[-0, +0, –] +

int lua_type (lua_State *L, int index);
+ +

+Returns the type of the value in the given valid index, +or LUA_TNONE for a non-valid but acceptable index. +The types returned by lua_type are coded by the following constants +defined in lua.h: +LUA_TNIL, +LUA_TNUMBER, +LUA_TBOOLEAN, +LUA_TSTRING, +LUA_TTABLE, +LUA_TFUNCTION, +LUA_TUSERDATA, +LUA_TTHREAD, +and +LUA_TLIGHTUSERDATA. + + + + + +

lua_typename

+[-0, +0, –] +

const char *lua_typename (lua_State *L, int tp);
+ +

+Returns the name of the type encoded by the value tp, +which must be one the values returned by lua_type. + + + + + +

lua_Unsigned

+
typedef ... lua_Unsigned;
+ +

+The unsigned version of lua_Integer. + + + + + +

lua_upvalueindex

+[-0, +0, –] +

int lua_upvalueindex (int i);
+ +

+Returns the pseudo-index that represents the i-th upvalue of +the running function (see §4.2). +i must be in the range [1,256]. + + + + + +

lua_version

+[-0, +0, –] +

lua_Number lua_version (lua_State *L);
+ +

+Returns the version number of this core. + + + + + +

lua_WarnFunction

+
typedef void (*lua_WarnFunction) (void *ud, const char *msg, int tocont);
+ +

+The type of warning functions, called by Lua to emit warnings. +The first parameter is an opaque pointer +set by lua_setwarnf. +The second parameter is the warning message. +The third parameter is a boolean that +indicates whether the message is +to be continued by the message in the next call. + + +

+See warn for more details about warnings. + + + + + +

lua_warning

+[-0, +0, –] +

void lua_warning (lua_State *L, const char *msg, int tocont);
+ +

+Emits a warning with the given message. +A message in a call with tocont true should be +continued in another call to this function. + + +

+See warn for more details about warnings. + + + + + +

lua_Writer

+
typedef int (*lua_Writer) (lua_State *L,
+                           const void* p,
+                           size_t sz,
+                           void* ud);
+ +

+The type of the writer function used by lua_dump. +Every time lua_dump produces another piece of chunk, +it calls the writer, +passing along the buffer to be written (p), +its size (sz), +and the ud parameter supplied to lua_dump. + + +

+The writer returns an error code: +0 means no errors; +any other value means an error and stops lua_dump from +calling the writer again. + + + + + +

lua_xmove

+[-?, +?, –] +

void lua_xmove (lua_State *from, lua_State *to, int n);
+ +

+Exchange values between different threads of the same state. + + +

+This function pops n values from the stack from, +and pushes them onto the stack to. + + + + + +

lua_yield

+[-?, +?, v] +

int lua_yield (lua_State *L, int nresults);
+ +

+This function is equivalent to lua_yieldk, +but it has no continuation (see §4.5). +Therefore, when the thread resumes, +it continues the function that called +the function calling lua_yield. +To avoid surprises, +this function should be called only in a tail call. + + + + + +

lua_yieldk

+[-?, +?, v] +

int lua_yieldk (lua_State *L,
+                int nresults,
+                lua_KContext ctx,
+                lua_KFunction k);
+ +

+Yields a coroutine (thread). + + +

+When a C function calls lua_yieldk, +the running coroutine suspends its execution, +and the call to lua_resume that started this coroutine returns. +The parameter nresults is the number of values from the stack +that will be passed as results to lua_resume. + + +

+When the coroutine is resumed again, +Lua calls the given continuation function k to continue +the execution of the C function that yielded (see §4.5). +This continuation function receives the same stack +from the previous function, +with the n results removed and +replaced by the arguments passed to lua_resume. +Moreover, +the continuation function receives the value ctx +that was passed to lua_yieldk. + + +

+Usually, this function does not return; +when the coroutine eventually resumes, +it continues executing the continuation function. +However, there is one special case, +which is when this function is called +from inside a line or a count hook (see §4.7). +In that case, lua_yieldk should be called with no continuation +(probably in the form of lua_yield) and no results, +and the hook should return immediately after the call. +Lua will yield and, +when the coroutine resumes again, +it will continue the normal execution +of the (Lua) function that triggered the hook. + + +

+This function can raise an error if it is called from a thread +with a pending C call with no continuation function +(what is called a C-call boundary), +or it is called from a thread that is not running inside a resume +(typically the main thread). + + + + + + + +

4.7 – The Debug Interface

+ +

+Lua has no built-in debugging facilities. +Instead, it offers a special interface +by means of functions and hooks. +This interface allows the construction of different +kinds of debuggers, profilers, and other tools +that need "inside information" from the interpreter. + + + +

lua_Debug

+
typedef struct lua_Debug {
+  int event;
+  const char *name;           /* (n) */
+  const char *namewhat;       /* (n) */
+  const char *what;           /* (S) */
+  const char *source;         /* (S) */
+  size_t srclen;              /* (S) */
+  int currentline;            /* (l) */
+  int linedefined;            /* (S) */
+  int lastlinedefined;        /* (S) */
+  unsigned char nups;         /* (u) number of upvalues */
+  unsigned char nparams;      /* (u) number of parameters */
+  char isvararg;              /* (u) */
+  char istailcall;            /* (t) */
+  unsigned short ftransfer;   /* (r) index of first value transferred */
+  unsigned short ntransfer;   /* (r) number of transferred values */
+  char short_src[LUA_IDSIZE]; /* (S) */
+  /* private part */
+  other fields
+} lua_Debug;
+ +

+A structure used to carry different pieces of +information about a function or an activation record. +lua_getstack fills only the private part +of this structure, for later use. +To fill the other fields of lua_Debug with useful information, +you must call lua_getinfo with an appropriate parameter. +(Specifically, to get a field, +you must add the letter between parentheses in the field's comment +to the parameter what of lua_getinfo.) + + +

+The fields of lua_Debug have the following meaning: + +

    + +
  • source: +the source of the chunk that created the function. +If source starts with a '@', +it means that the function was defined in a file where +the file name follows the '@'. +If source starts with a '=', +the remainder of its contents describes the source in a user-dependent manner. +Otherwise, +the function was defined in a string where +source is that string. +
    • + +
  • srclen: +The length of the string source. +
    • + +
  • short_src: +a "printable" version of source, to be used in error messages. +
    • + +
  • linedefined: +the line number where the definition of the function starts. +
    • + +
  • lastlinedefined: +the line number where the definition of the function ends. +
    • + +
  • what: +the string "Lua" if the function is a Lua function, +"C" if it is a C function, +"main" if it is the main part of a chunk. +
    • + +
  • currentline: +the current line where the given function is executing. +When no line information is available, +currentline is set to -1. +
    • + +
  • name: +a reasonable name for the given function. +Because functions in Lua are first-class values, +they do not have a fixed name: +some functions can be the value of multiple global variables, +while others can be stored only in a table field. +The lua_getinfo function checks how the function was +called to find a suitable name. +If it cannot find a name, +then name is set to NULL. +
    • + +
  • namewhat: +explains the name field. +The value of namewhat can be +"global", "local", "method", +"field", "upvalue", or "" (the empty string), +according to how the function was called. +(Lua uses the empty string when no other option seems to apply.) +
    • + +
  • istailcall: +true if this function invocation was called by a tail call. +In this case, the caller of this level is not in the stack. +
    • + +
  • nups: +the number of upvalues of the function. +
    • + +
  • nparams: +the number of parameters of the function +(always 0 for C functions). +
    • + +
  • isvararg: +true if the function is a variadic function +(always true for C functions). +
    • + +
  • ftransfer: +the index in the stack of the first value being "transferred", +that is, parameters in a call or return values in a return. +(The other values are in consecutive indices.) +Using this index, you can access and modify these values +through lua_getlocal and lua_setlocal. +This field is only meaningful during a +call hook, denoting the first parameter, +or a return hook, denoting the first value being returned. +(For call hooks, this value is always 1.) +
    • + +
  • ntransfer: +The number of values being transferred (see previous item). +(For calls of Lua functions, +this value is always equal to nparams.) +
    • + +
+ + + + +

lua_gethook

+[-0, +0, –] +

lua_Hook lua_gethook (lua_State *L);
+ +

+Returns the current hook function. + + + + + +

lua_gethookcount

+[-0, +0, –] +

int lua_gethookcount (lua_State *L);
+ +

+Returns the current hook count. + + + + + +

lua_gethookmask

+[-0, +0, –] +

int lua_gethookmask (lua_State *L);
+ +

+Returns the current hook mask. + + + + + +

lua_getinfo

+[-(0|1), +(0|1|2), m] +

int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);
+ +

+Gets information about a specific function or function invocation. + + +

+To get information about a function invocation, +the parameter ar must be a valid activation record that was +filled by a previous call to lua_getstack or +given as argument to a hook (see lua_Hook). + + +

+To get information about a function, you push it onto the stack +and start the what string with the character '>'. +(In that case, +lua_getinfo pops the function from the top of the stack.) +For instance, to know in which line a function f was defined, +you can write the following code: + +

+     lua_Debug ar;
+     lua_getglobal(L, "f");  /* get global 'f' */
+     lua_getinfo(L, ">S", &ar);
+     printf("%d\n", ar.linedefined);
+
+ +

+Each character in the string what +selects some fields of the structure ar to be filled or +a value to be pushed on the stack. +(These characters are also documented in the declaration of +the structure lua_Debug, +between parentheses in the comments following each field.) + +

    + +
  • 'f': +pushes onto the stack the function that is +running at the given level; +
    • + +
  • 'l': fills in the field currentline; +
    • + +
  • 'n': fills in the fields name and namewhat; +
    • + +
  • 'r': fills in the fields ftransfer and ntransfer; +
    • + +
  • 'S': +fills in the fields source, short_src, +linedefined, lastlinedefined, and what; +
    • + +
  • 't': fills in the field istailcall; +
    • + +
  • 'u': fills in the fields +nups, nparams, and isvararg; +
    • + +
  • 'L': +pushes onto the stack a table whose indices are +the lines on the function with some associated code, +that is, the lines where you can put a break point. +(Lines with no code include empty lines and comments.) +If this option is given together with option 'f', +its table is pushed after the function. +This is the only option that can raise a memory error. +
    • + +
+ +

+This function returns 0 to signal an invalid option in what; +even then the valid options are handled correctly. + + + + + +

lua_getlocal

+[-0, +(0|1), –] +

const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);
+ +

+Gets information about a local variable or a temporary value +of a given activation record or a given function. + + +

+In the first case, +the parameter ar must be a valid activation record that was +filled by a previous call to lua_getstack or +given as argument to a hook (see lua_Hook). +The index n selects which local variable to inspect; +see debug.getlocal for details about variable indices +and names. + + +

+lua_getlocal pushes the variable's value onto the stack +and returns its name. + + +

+In the second case, ar must be NULL and the function +to be inspected must be on the top of the stack. +In this case, only parameters of Lua functions are visible +(as there is no information about what variables are active) +and no values are pushed onto the stack. + + +

+Returns NULL (and pushes nothing) +when the index is greater than +the number of active local variables. + + + + + +

lua_getstack

+[-0, +0, –] +

int lua_getstack (lua_State *L, int level, lua_Debug *ar);
+ +

+Gets information about the interpreter runtime stack. + + +

+This function fills parts of a lua_Debug structure with +an identification of the activation record +of the function executing at a given level. +Level 0 is the current running function, +whereas level n+1 is the function that has called level n +(except for tail calls, which do not count in the stack). +When called with a level greater than the stack depth, +lua_getstack returns 0; +otherwise it returns 1. + + + + + +

lua_getupvalue

+[-0, +(0|1), –] +

const char *lua_getupvalue (lua_State *L, int funcindex, int n);
+ +

+Gets information about the n-th upvalue +of the closure at index funcindex. +It pushes the upvalue's value onto the stack +and returns its name. +Returns NULL (and pushes nothing) +when the index n is greater than the number of upvalues. + + +

+See debug.getupvalue for more information about upvalues. + + + + + +

lua_Hook

+
typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
+ +

+Type for debugging hook functions. + + +

+Whenever a hook is called, its ar argument has its field +event set to the specific event that triggered the hook. +Lua identifies these events with the following constants: +LUA_HOOKCALL, LUA_HOOKRET, +LUA_HOOKTAILCALL, LUA_HOOKLINE, +and LUA_HOOKCOUNT. +Moreover, for line events, the field currentline is also set. +To get the value of any other field in ar, +the hook must call lua_getinfo. + + +

+For call events, event can be LUA_HOOKCALL, +the normal value, or LUA_HOOKTAILCALL, for a tail call; +in this case, there will be no corresponding return event. + + +

+While Lua is running a hook, it disables other calls to hooks. +Therefore, if a hook calls back Lua to execute a function or a chunk, +this execution occurs without any calls to hooks. + + +

+Hook functions cannot have continuations, +that is, they cannot call lua_yieldk, +lua_pcallk, or lua_callk with a non-null k. + + +

+Hook functions can yield under the following conditions: +Only count and line events can yield; +to yield, a hook function must finish its execution +calling lua_yield with nresults equal to zero +(that is, with no values). + + + + + +

lua_sethook

+[-0, +0, –] +

void lua_sethook (lua_State *L, lua_Hook f, int mask, int count);
+ +

+Sets the debugging hook function. + + +

+Argument f is the hook function. +mask specifies on which events the hook will be called: +it is formed by a bitwise OR of the constants +LUA_MASKCALL, +LUA_MASKRET, +LUA_MASKLINE, +and LUA_MASKCOUNT. +The count argument is only meaningful when the mask +includes LUA_MASKCOUNT. +For each event, the hook is called as explained below: + +

    + +
  • The call hook: is called when the interpreter calls a function. +The hook is called just after Lua enters the new function. +
    • + +
  • The return hook: is called when the interpreter returns from a function. +The hook is called just before Lua leaves the function. +
    • + +
  • The line hook: is called when the interpreter is about to +start the execution of a new line of code, +or when it jumps back in the code (even to the same line). +This event only happens while Lua is executing a Lua function. +
    • + +
  • The count hook: is called after the interpreter executes every +count instructions. +This event only happens while Lua is executing a Lua function. +
    • + +
+ +

+Hooks are disabled by setting mask to zero. + + + + + +

lua_setlocal

+[-(0|1), +0, –] +

const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);
+ +

+Sets the value of a local variable of a given activation record. +It assigns the value on the top of the stack +to the variable and returns its name. +It also pops the value from the stack. + + +

+Returns NULL (and pops nothing) +when the index is greater than +the number of active local variables. + + +

+Parameters ar and n are as in the function lua_getlocal. + + + + + +

lua_setupvalue

+[-(0|1), +0, –] +

const char *lua_setupvalue (lua_State *L, int funcindex, int n);
+ +

+Sets the value of a closure's upvalue. +It assigns the value on the top of the stack +to the upvalue and returns its name. +It also pops the value from the stack. + + +

+Returns NULL (and pops nothing) +when the index n is greater than the number of upvalues. + + +

+Parameters funcindex and n are as in +the function lua_getupvalue. + + + + + +

lua_upvalueid

+[-0, +0, –] +

void *lua_upvalueid (lua_State *L, int funcindex, int n);
+ +

+Returns a unique identifier for the upvalue numbered n +from the closure at index funcindex. + + +

+These unique identifiers allow a program to check whether different +closures share upvalues. +Lua closures that share an upvalue +(that is, that access a same external local variable) +will return identical ids for those upvalue indices. + + +

+Parameters funcindex and n are as in +the function lua_getupvalue, +but n cannot be greater than the number of upvalues. + + + + + +

lua_upvaluejoin

+[-0, +0, –] +

void lua_upvaluejoin (lua_State *L, int funcindex1, int n1,
+                                    int funcindex2, int n2);
+ +

+Make the n1-th upvalue of the Lua closure at index funcindex1 +refer to the n2-th upvalue of the Lua closure at index funcindex2. + + + + + + + +

5 – The Auxiliary Library

+ + + +

+ +The auxiliary library provides several convenient functions +to interface C with Lua. +While the basic API provides the primitive functions for all +interactions between C and Lua, +the auxiliary library provides higher-level functions for some +common tasks. + + +

+All functions and types from the auxiliary library +are defined in header file lauxlib.h and +have a prefix luaL_. + + +

+All functions in the auxiliary library are built on +top of the basic API, +and so they provide nothing that cannot be done with that API. +Nevertheless, the use of the auxiliary library ensures +more consistency to your code. + + +

+Several functions in the auxiliary library use internally some +extra stack slots. +When a function in the auxiliary library uses less than five slots, +it does not check the stack size; +it simply assumes that there are enough slots. + + +

+Several functions in the auxiliary library are used to +check C function arguments. +Because the error message is formatted for arguments +(e.g., "bad argument #1"), +you should not use these functions for other stack values. + + +

+Functions called luaL_check* +always raise an error if the check is not satisfied. + + + + + +

5.1 – Functions and Types

+ +

+Here we list all functions and types from the auxiliary library +in alphabetical order. + + + +

luaL_addchar

+[-?, +?, m] +

void luaL_addchar (luaL_Buffer *B, char c);
+ +

+Adds the byte c to the buffer B +(see luaL_Buffer). + + + + + +

luaL_addgsub

+[-?, +?, m] +

const void luaL_addgsub (luaL_Buffer *B, const char *s,
+                         const char *p, const char *r);
+ +

+Adds a copy of the string s to the buffer B (see luaL_Buffer), +replacing any occurrence of the string p +with the string r. + + + + + +

luaL_addlstring

+[-?, +?, m] +

void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l);
+ +

+Adds the string pointed to by s with length l to +the buffer B +(see luaL_Buffer). +The string can contain embedded zeros. + + + + + +

luaL_addsize

+[-?, +?, –] +

void luaL_addsize (luaL_Buffer *B, size_t n);
+ +

+Adds to the buffer B +a string of length n previously copied to the +buffer area (see luaL_prepbuffer). + + + + + +

luaL_addstring

+[-?, +?, m] +

void luaL_addstring (luaL_Buffer *B, const char *s);
+ +

+Adds the zero-terminated string pointed to by s +to the buffer B +(see luaL_Buffer). + + + + + +

luaL_addvalue

+[-?, +?, m] +

void luaL_addvalue (luaL_Buffer *B);
+ +

+Adds the value on the top of the stack +to the buffer B +(see luaL_Buffer). +Pops the value. + + +

+This is the only function on string buffers that can (and must) +be called with an extra element on the stack, +which is the value to be added to the buffer. + + + + + +

luaL_argcheck

+[-0, +0, v] +

void luaL_argcheck (lua_State *L,
+                    int cond,
+                    int arg,
+                    const char *extramsg);
+ +

+Checks whether cond is true. +If it is not, raises an error with a standard message (see luaL_argerror). + + + + + +

luaL_argerror

+[-0, +0, v] +

int luaL_argerror (lua_State *L, int arg, const char *extramsg);
+ +

+Raises an error reporting a problem with argument arg +of the C function that called it, +using a standard message +that includes extramsg as a comment: + +

+     bad argument #arg to 'funcname' (extramsg)
+

+This function never returns. + + + + + +

luaL_argexpected

+[-0, +0, v] +

void luaL_argexpected (lua_State *L,
+                       int cond,
+                       int arg,
+                       const char *tname);
+ +

+Checks whether cond is true. +If it is not, raises an error about the type of the argument arg +with a standard message (see luaL_typeerror). + + + + + +

luaL_Buffer

+
typedef struct luaL_Buffer luaL_Buffer;
+ +

+Type for a string buffer. + + +

+A string buffer allows C code to build Lua strings piecemeal. +Its pattern of use is as follows: + +

    + +
  • First declare a variable b of type luaL_Buffer.
    • + +
  • Then initialize it with a call luaL_buffinit(L, &b).
    • + +
  • +Then add string pieces to the buffer calling any of +the luaL_add* functions. +
    • + +
  • +Finish by calling luaL_pushresult(&b). +This call leaves the final string on the top of the stack. +
    • + +
+ +

+If you know beforehand the maximum size of the resulting string, +you can use the buffer like this: + +

    + +
  • First declare a variable b of type luaL_Buffer.
    • + +
  • Then initialize it and preallocate a space of +size sz with a call luaL_buffinitsize(L, &b, sz).
    • + +
  • Then produce the string into that space.
    • + +
  • +Finish by calling luaL_pushresultsize(&b, sz), +where sz is the total size of the resulting string +copied into that space (which may be less than or +equal to the preallocated size). +
    • + +
+ +

+During its normal operation, +a string buffer uses a variable number of stack slots. +So, while using a buffer, you cannot assume that you know where +the top of the stack is. +You can use the stack between successive calls to buffer operations +as long as that use is balanced; +that is, +when you call a buffer operation, +the stack is at the same level +it was immediately after the previous buffer operation. +(The only exception to this rule is luaL_addvalue.) +After calling luaL_pushresult, +the stack is back to its level when the buffer was initialized, +plus the final string on its top. + + + + + +

luaL_buffaddr

+[-0, +0, –] +

char *luaL_buffaddr (luaL_Buffer *B);
+ +

+Returns the address of the current content of buffer B +(see luaL_Buffer). +Note that any addition to the buffer may invalidate this address. + + + + + +

luaL_buffinit

+[-0, +?, –] +

void luaL_buffinit (lua_State *L, luaL_Buffer *B);
+ +

+Initializes a buffer B +(see luaL_Buffer). +This function does not allocate any space; +the buffer must be declared as a variable. + + + + + +

luaL_bufflen

+[-0, +0, –] +

size_t luaL_bufflen (luaL_Buffer *B);
+ +

+Returns the length of the current content of buffer B +(see luaL_Buffer). + + + + + +

luaL_buffinitsize

+[-?, +?, m] +

char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz);
+ +

+Equivalent to the sequence +luaL_buffinit, luaL_prepbuffsize. + + + + + +

luaL_buffsub

+[-?, +?, –] +

void luaL_buffsub (luaL_Buffer *B, int n);
+ +

+Removes n bytes from the buffer B +(see luaL_Buffer). +The buffer must have at least that many bytes. + + + + + +

luaL_callmeta

+[-0, +(0|1), e] +

int luaL_callmeta (lua_State *L, int obj, const char *e);
+ +

+Calls a metamethod. + + +

+If the object at index obj has a metatable and this +metatable has a field e, +this function calls this field passing the object as its only argument. +In this case this function returns true and pushes onto the +stack the value returned by the call. +If there is no metatable or no metamethod, +this function returns false without pushing any value on the stack. + + + + + +

luaL_checkany

+[-0, +0, v] +

void luaL_checkany (lua_State *L, int arg);
+ +

+Checks whether the function has an argument +of any type (including nil) at position arg. + + + + + +

luaL_checkinteger

+[-0, +0, v] +

lua_Integer luaL_checkinteger (lua_State *L, int arg);
+ +

+Checks whether the function argument arg is an integer +(or can be converted to an integer) +and returns this integer. + + + + + +

luaL_checklstring

+[-0, +0, v] +

const char *luaL_checklstring (lua_State *L, int arg, size_t *l);
+ +

+Checks whether the function argument arg is a string +and returns this string; +if l is not NULL fills its referent +with the string's length. + + +

+This function uses lua_tolstring to get its result, +so all conversions and caveats of that function apply here. + + + + + +

luaL_checknumber

+[-0, +0, v] +

lua_Number luaL_checknumber (lua_State *L, int arg);
+ +

+Checks whether the function argument arg is a number +and returns this number converted to a lua_Number. + + + + + +

luaL_checkoption

+[-0, +0, v] +

int luaL_checkoption (lua_State *L,
+                      int arg,
+                      const char *def,
+                      const char *const lst[]);
+ +

+Checks whether the function argument arg is a string and +searches for this string in the array lst +(which must be NULL-terminated). +Returns the index in the array where the string was found. +Raises an error if the argument is not a string or +if the string cannot be found. + + +

+If def is not NULL, +the function uses def as a default value when +there is no argument arg or when this argument is nil. + + +

+This is a useful function for mapping strings to C enums. +(The usual convention in Lua libraries is +to use strings instead of numbers to select options.) + + + + + +

luaL_checkstack

+[-0, +0, v] +

void luaL_checkstack (lua_State *L, int sz, const char *msg);
+ +

+Grows the stack size to top + sz elements, +raising an error if the stack cannot grow to that size. +msg is an additional text to go into the error message +(or NULL for no additional text). + + + + + +

luaL_checkstring

+[-0, +0, v] +

const char *luaL_checkstring (lua_State *L, int arg);
+ +

+Checks whether the function argument arg is a string +and returns this string. + + +

+This function uses lua_tolstring to get its result, +so all conversions and caveats of that function apply here. + + + + + +

luaL_checktype

+[-0, +0, v] +

void luaL_checktype (lua_State *L, int arg, int t);
+ +

+Checks whether the function argument arg has type t. +See lua_type for the encoding of types for t. + + + + + +

luaL_checkudata

+[-0, +0, v] +

void *luaL_checkudata (lua_State *L, int arg, const char *tname);
+ +

+Checks whether the function argument arg is a userdata +of the type tname (see luaL_newmetatable) and +returns the userdata's memory-block address (see lua_touserdata). + + + + + +

luaL_checkversion

+[-0, +0, v] +

void luaL_checkversion (lua_State *L);
+ +

+Checks whether the code making the call and the Lua library being called +are using the same version of Lua and the same numeric types. + + + + + +

luaL_dofile

+[-0, +?, m] +

int luaL_dofile (lua_State *L, const char *filename);
+ +

+Loads and runs the given file. +It is defined as the following macro: + +

+     (luaL_loadfile(L, filename) || lua_pcall(L, 0, LUA_MULTRET, 0))
+

+It returns 0 (LUA_OK) if there are no errors, +or 1 in case of errors. + + + + + +

luaL_dostring

+[-0, +?, –] +

int luaL_dostring (lua_State *L, const char *str);
+ +

+Loads and runs the given string. +It is defined as the following macro: + +

+     (luaL_loadstring(L, str) || lua_pcall(L, 0, LUA_MULTRET, 0))
+

+It returns 0 (LUA_OK) if there are no errors, +or 1 in case of errors. + + + + + +

luaL_error

+[-0, +0, v] +

int luaL_error (lua_State *L, const char *fmt, ...);
+ +

+Raises an error. +The error message format is given by fmt +plus any extra arguments, +following the same rules of lua_pushfstring. +It also adds at the beginning of the message the file name and +the line number where the error occurred, +if this information is available. + + +

+This function never returns, +but it is an idiom to use it in C functions +as return luaL_error(args). + + + + + +

luaL_execresult

+[-0, +3, m] +

int luaL_execresult (lua_State *L, int stat);
+ +

+This function produces the return values for +process-related functions in the standard library +(os.execute and io.close). + + + + + +

luaL_fileresult

+[-0, +(1|3), m] +

int luaL_fileresult (lua_State *L, int stat, const char *fname);
+ +

+This function produces the return values for +file-related functions in the standard library +(io.open, os.rename, file:seek, etc.). + + + + + +

luaL_getmetafield

+[-0, +(0|1), m] +

int luaL_getmetafield (lua_State *L, int obj, const char *e);
+ +

+Pushes onto the stack the field e from the metatable +of the object at index obj and returns the type of the pushed value. +If the object does not have a metatable, +or if the metatable does not have this field, +pushes nothing and returns LUA_TNIL. + + + + + +

luaL_getmetatable

+[-0, +1, m] +

int luaL_getmetatable (lua_State *L, const char *tname);
+ +

+Pushes onto the stack the metatable associated with the name tname +in the registry (see luaL_newmetatable), +or nil if there is no metatable associated with that name. +Returns the type of the pushed value. + + + + + +

luaL_getsubtable

+[-0, +1, e] +

int luaL_getsubtable (lua_State *L, int idx, const char *fname);
+ +

+Ensures that the value t[fname], +where t is the value at index idx, +is a table, +and pushes that table onto the stack. +Returns true if it finds a previous table there +and false if it creates a new table. + + + + + +

luaL_gsub

+[-0, +1, m] +

const char *luaL_gsub (lua_State *L,
+                       const char *s,
+                       const char *p,
+                       const char *r);
+ +

+Creates a copy of string s, +replacing any occurrence of the string p +with the string r. +Pushes the resulting string on the stack and returns it. + + + + + +

luaL_len

+[-0, +0, e] +

lua_Integer luaL_len (lua_State *L, int index);
+ +

+Returns the "length" of the value at the given index +as a number; +it is equivalent to the '#' operator in Lua (see §3.4.7). +Raises an error if the result of the operation is not an integer. +(This case can only happen through metamethods.) + + + + + +

luaL_loadbuffer

+[-0, +1, –] +

int luaL_loadbuffer (lua_State *L,
+                     const char *buff,
+                     size_t sz,
+                     const char *name);
+ +

+Equivalent to luaL_loadbufferx with mode equal to NULL. + + + + + +

luaL_loadbufferx

+[-0, +1, –] +

int luaL_loadbufferx (lua_State *L,
+                      const char *buff,
+                      size_t sz,
+                      const char *name,
+                      const char *mode);
+ +

+Loads a buffer as a Lua chunk. +This function uses lua_load to load the chunk in the +buffer pointed to by buff with size sz. + + +

+This function returns the same results as lua_load. +name is the chunk name, +used for debug information and error messages. +The string mode works as in the function lua_load. + + + + + +

luaL_loadfile

+[-0, +1, m] +

int luaL_loadfile (lua_State *L, const char *filename);
+ +

+Equivalent to luaL_loadfilex with mode equal to NULL. + + + + + +

luaL_loadfilex

+[-0, +1, m] +

int luaL_loadfilex (lua_State *L, const char *filename,
+                                            const char *mode);
+ +

+Loads a file as a Lua chunk. +This function uses lua_load to load the chunk in the file +named filename. +If filename is NULL, +then it loads from the standard input. +The first line in the file is ignored if it starts with a #. + + +

+The string mode works as in the function lua_load. + + +

+This function returns the same results as lua_load +or LUA_ERRFILE for file-related errors. + + +

+As lua_load, this function only loads the chunk; +it does not run it. + + + + + +

luaL_loadstring

+[-0, +1, –] +

int luaL_loadstring (lua_State *L, const char *s);
+ +

+Loads a string as a Lua chunk. +This function uses lua_load to load the chunk in +the zero-terminated string s. + + +

+This function returns the same results as lua_load. + + +

+Also as lua_load, this function only loads the chunk; +it does not run it. + + + + + +

luaL_newlib

+[-0, +1, m] +

void luaL_newlib (lua_State *L, const luaL_Reg l[]);
+ +

+Creates a new table and registers there +the functions in the list l. + + +

+It is implemented as the following macro: + +

+     (luaL_newlibtable(L,l), luaL_setfuncs(L,l,0))
+

+The array l must be the actual array, +not a pointer to it. + + + + + +

luaL_newlibtable

+[-0, +1, m] +

void luaL_newlibtable (lua_State *L, const luaL_Reg l[]);
+ +

+Creates a new table with a size optimized +to store all entries in the array l +(but does not actually store them). +It is intended to be used in conjunction with luaL_setfuncs +(see luaL_newlib). + + +

+It is implemented as a macro. +The array l must be the actual array, +not a pointer to it. + + + + + +

luaL_newmetatable

+[-0, +1, m] +

int luaL_newmetatable (lua_State *L, const char *tname);
+ +

+If the registry already has the key tname, +returns 0. +Otherwise, +creates a new table to be used as a metatable for userdata, +adds to this new table the pair __name = tname, +adds to the registry the pair [tname] = new table, +and returns 1. + + +

+In both cases, +the function pushes onto the stack the final value associated +with tname in the registry. + + + + + +

luaL_newstate

+[-0, +0, –] +

lua_State *luaL_newstate (void);
+ +

+Creates a new Lua state. +It calls lua_newstate with an +allocator based on the ISO C allocation functions +and then sets a warning function and a panic function (see §4.4) +that print messages to the standard error output. + + +

+Returns the new state, +or NULL if there is a memory allocation error. + + + + + +

luaL_openlibs

+[-0, +0, e] +

void luaL_openlibs (lua_State *L);
+ +

+Opens all standard Lua libraries into the given state. + + + + + +

luaL_opt

+[-0, +0, –] +

T luaL_opt (L, func, arg, dflt);
+ +

+This macro is defined as follows: + +

+     (lua_isnoneornil(L,(arg)) ? (dflt) : func(L,(arg)))
+

+In words, if the argument arg is nil or absent, +the macro results in the default dflt. +Otherwise, it results in the result of calling func +with the state L and the argument index arg as +arguments. +Note that it evaluates the expression dflt only if needed. + + + + + +

luaL_optinteger

+[-0, +0, v] +

lua_Integer luaL_optinteger (lua_State *L,
+                             int arg,
+                             lua_Integer d);
+ +

+If the function argument arg is an integer +(or it is convertible to an integer), +returns this integer. +If this argument is absent or is nil, +returns d. +Otherwise, raises an error. + + + + + +

luaL_optlstring

+[-0, +0, v] +

const char *luaL_optlstring (lua_State *L,
+                             int arg,
+                             const char *d,
+                             size_t *l);
+ +

+If the function argument arg is a string, +returns this string. +If this argument is absent or is nil, +returns d. +Otherwise, raises an error. + + +

+If l is not NULL, +fills its referent with the result's length. +If the result is NULL +(only possible when returning d and d == NULL), +its length is considered zero. + + +

+This function uses lua_tolstring to get its result, +so all conversions and caveats of that function apply here. + + + + + +

luaL_optnumber

+[-0, +0, v] +

lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number d);
+ +

+If the function argument arg is a number, +returns this number as a lua_Number. +If this argument is absent or is nil, +returns d. +Otherwise, raises an error. + + + + + +

luaL_optstring

+[-0, +0, v] +

const char *luaL_optstring (lua_State *L,
+                            int arg,
+                            const char *d);
+ +

+If the function argument arg is a string, +returns this string. +If this argument is absent or is nil, +returns d. +Otherwise, raises an error. + + + + + +

luaL_prepbuffer

+[-?, +?, m] +

char *luaL_prepbuffer (luaL_Buffer *B);
+ +

+Equivalent to luaL_prepbuffsize +with the predefined size LUAL_BUFFERSIZE. + + + + + +

luaL_prepbuffsize

+[-?, +?, m] +

char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz);
+ +

+Returns an address to a space of size sz +where you can copy a string to be added to buffer B +(see luaL_Buffer). +After copying the string into this space you must call +luaL_addsize with the size of the string to actually add +it to the buffer. + + + + + +

luaL_pushfail

+[-0, +1, –] +

void luaL_pushfail (lua_State *L);
+ +

+Pushes the fail value onto the stack (see §6). + + + + + +

luaL_pushresult

+[-?, +1, m] +

void luaL_pushresult (luaL_Buffer *B);
+ +

+Finishes the use of buffer B leaving the final string on +the top of the stack. + + + + + +

luaL_pushresultsize

+[-?, +1, m] +

void luaL_pushresultsize (luaL_Buffer *B, size_t sz);
+ +

+Equivalent to the sequence luaL_addsize, luaL_pushresult. + + + + + +

luaL_ref

+[-1, +0, m] +

int luaL_ref (lua_State *L, int t);
+ +

+Creates and returns a reference, +in the table at index t, +for the object on the top of the stack (and pops the object). + + +

+A reference is a unique integer key. +As long as you do not manually add integer keys into the table t, +luaL_ref ensures the uniqueness of the key it returns. +You can retrieve an object referred by the reference r +by calling lua_rawgeti(L, t, r). +The function luaL_unref frees a reference. + + +

+If the object on the top of the stack is nil, +luaL_ref returns the constant LUA_REFNIL. +The constant LUA_NOREF is guaranteed to be different +from any reference returned by luaL_ref. + + + + + +

luaL_Reg

+
typedef struct luaL_Reg {
+  const char *name;
+  lua_CFunction func;
+} luaL_Reg;
+ +

+Type for arrays of functions to be registered by +luaL_setfuncs. +name is the function name and func is a pointer to +the function. +Any array of luaL_Reg must end with a sentinel entry +in which both name and func are NULL. + + + + + +

luaL_requiref

+[-0, +1, e] +

void luaL_requiref (lua_State *L, const char *modname,
+                    lua_CFunction openf, int glb);
+ +

+If package.loaded[modname] is not true, +calls the function openf with the string modname as an argument +and sets the call result to package.loaded[modname], +as if that function has been called through require. + + +

+If glb is true, +also stores the module into the global modname. + + +

+Leaves a copy of the module on the stack. + + + + + +

luaL_setfuncs

+[-nup, +0, m] +

void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);
+ +

+Registers all functions in the array l +(see luaL_Reg) into the table on the top of the stack +(below optional upvalues, see next). + + +

+When nup is not zero, +all functions are created with nup upvalues, +initialized with copies of the nup values +previously pushed on the stack +on top of the library table. +These values are popped from the stack after the registration. + + +

+A function with a NULL value represents a placeholder, +which is filled with false. + + + + + +

luaL_setmetatable

+[-0, +0, –] +

void luaL_setmetatable (lua_State *L, const char *tname);
+ +

+Sets the metatable of the object on the top of the stack +as the metatable associated with name tname +in the registry (see luaL_newmetatable). + + + + + +

luaL_Stream

+
typedef struct luaL_Stream {
+  FILE *f;
+  lua_CFunction closef;
+} luaL_Stream;
+ +

+The standard representation for file handles +used by the standard I/O library. + + +

+A file handle is implemented as a full userdata, +with a metatable called LUA_FILEHANDLE +(where LUA_FILEHANDLE is a macro with the actual metatable's name). +The metatable is created by the I/O library +(see luaL_newmetatable). + + +

+This userdata must start with the structure luaL_Stream; +it can contain other data after this initial structure. +The field f points to the corresponding C stream +(or it can be NULL to indicate an incompletely created handle). +The field closef points to a Lua function +that will be called to close the stream +when the handle is closed or collected; +this function receives the file handle as its sole argument and +must return either a true value, in case of success, +or a false value plus an error message, in case of error. +Once Lua calls this field, +it changes the field value to NULL +to signal that the handle is closed. + + + + + +

luaL_testudata

+[-0, +0, m] +

void *luaL_testudata (lua_State *L, int arg, const char *tname);
+ +

+This function works like luaL_checkudata, +except that, when the test fails, +it returns NULL instead of raising an error. + + + + + +

luaL_tolstring

+[-0, +1, e] +

const char *luaL_tolstring (lua_State *L, int idx, size_t *len);
+ +

+Converts any Lua value at the given index to a C string +in a reasonable format. +The resulting string is pushed onto the stack and also +returned by the function (see §4.1.3). +If len is not NULL, +the function also sets *len with the string length. + + +

+If the value has a metatable with a __tostring field, +then luaL_tolstring calls the corresponding metamethod +with the value as argument, +and uses the result of the call as its result. + + + + + +

luaL_traceback

+[-0, +1, m] +

void luaL_traceback (lua_State *L, lua_State *L1, const char *msg,
+                     int level);
+ +

+Creates and pushes a traceback of the stack L1. +If msg is not NULL, it is appended +at the beginning of the traceback. +The level parameter tells at which level +to start the traceback. + + + + + +

luaL_typeerror

+[-0, +0, v] +

int luaL_typeerror (lua_State *L, int arg, const char *tname);
+ +

+Raises a type error for the argument arg +of the C function that called it, +using a standard message; +tname is a "name" for the expected type. +This function never returns. + + + + + +

luaL_typename

+[-0, +0, –] +

const char *luaL_typename (lua_State *L, int index);
+ +

+Returns the name of the type of the value at the given index. + + + + + +

luaL_unref

+[-0, +0, –] +

void luaL_unref (lua_State *L, int t, int ref);
+ +

+Releases the reference ref from the table at index t +(see luaL_ref). +The entry is removed from the table, +so that the referred object can be collected. +The reference ref is also freed to be used again. + + +

+If ref is LUA_NOREF or LUA_REFNIL, +luaL_unref does nothing. + + + + + +

luaL_where

+[-0, +1, m] +

void luaL_where (lua_State *L, int lvl);
+ +

+Pushes onto the stack a string identifying the current position +of the control at level lvl in the call stack. +Typically this string has the following format: + +

+     chunkname:currentline:
+

+Level 0 is the running function, +level 1 is the function that called the running function, +etc. + + +

+This function is used to build a prefix for error messages. + + + + + + + +

6 – The Standard Libraries

+ + + +

+The standard Lua libraries provide useful functions +that are implemented in C through the C API. +Some of these functions provide essential services to the language +(e.g., type and getmetatable); +others provide access to outside services (e.g., I/O); +and others could be implemented in Lua itself, +but that for different reasons +deserve an implementation in C (e.g., table.sort). + + +

+All libraries are implemented through the official C API +and are provided as separate C modules. +Unless otherwise noted, +these library functions do not adjust its number of arguments +to its expected parameters. +For instance, a function documented as foo(arg) +should not be called without an argument. + + +

+The notation fail means a false value representing +some kind of failure. +(Currently, fail is equal to nil, +but that may change in future versions. +The recommendation is to always test the success of these functions +with (not status), instead of (status == nil).) + + +

+Currently, Lua has the following standard libraries: + +

    + +
  • basic library (§6.1);
    • + +
  • coroutine library (§6.2);
    • + +
  • package library (§6.3);
    • + +
  • string manipulation (§6.4);
    • + +
  • basic UTF-8 support (§6.5);
    • + +
  • table manipulation (§6.6);
    • + +
  • mathematical functions (§6.7) (sin, log, etc.);
    • + +
  • input and output (§6.8);
    • + +
  • operating system facilities (§6.9);
    • + +
  • debug facilities (§6.10).
    • + +

+Except for the basic and the package libraries, +each library provides all its functions as fields of a global table +or as methods of its objects. + + +

+To have access to these libraries, +the C host program should call the luaL_openlibs function, +which opens all standard libraries. +Alternatively, +the host program can open them individually by using +luaL_requiref to call +luaopen_base (for the basic library), +luaopen_package (for the package library), +luaopen_coroutine (for the coroutine library), +luaopen_string (for the string library), +luaopen_utf8 (for the UTF-8 library), +luaopen_table (for the table library), +luaopen_math (for the mathematical library), +luaopen_io (for the I/O library), +luaopen_os (for the operating system library), +and luaopen_debug (for the debug library). +These functions are declared in lualib.h. + + + + + +

6.1 – Basic Functions

+ +

+The basic library provides core functions to Lua. +If you do not include this library in your application, +you should check carefully whether you need to provide +implementations for some of its facilities. + + +

+

assert (v [, message])

+ + +

+Raises an error if +the value of its argument v is false (i.e., nil or false); +otherwise, returns all its arguments. +In case of error, +message is the error object; +when absent, it defaults to "assertion failed!" + + + + +

+

collectgarbage ([opt [, arg]])

+ + +

+This function is a generic interface to the garbage collector. +It performs different functions according to its first argument, opt: + +

    + +
  • "collect": +Performs a full garbage-collection cycle. +This is the default option. +
    • + +
  • "stop": +Stops automatic execution of the garbage collector. +The collector will run only when explicitly invoked, +until a call to restart it. +
    • + +
  • "restart": +Restarts automatic execution of the garbage collector. +
    • + +
  • "count": +Returns the total memory in use by Lua in Kbytes. +The value has a fractional part, +so that it multiplied by 1024 +gives the exact number of bytes in use by Lua. +
    • + +
  • "step": +Performs a garbage-collection step. +The step "size" is controlled by arg. +With a zero value, +the collector will perform one basic (indivisible) step. +For non-zero values, +the collector will perform as if that amount of memory +(in Kbytes) had been allocated by Lua. +Returns true if the step finished a collection cycle. +
    • + +
  • "isrunning": +Returns a boolean that tells whether the collector is running +(i.e., not stopped). +
    • + +
  • "incremental": +Change the collector mode to incremental. +This option can be followed by three numbers: +the garbage-collector pause, +the step multiplier, +and the step size (see §2.5.1). +A zero means to not change that value. +
    • + +
  • "generational": +Change the collector mode to generational. +This option can be followed by two numbers: +the garbage-collector minor multiplier +and the major multiplier (see §2.5.2). +A zero means to not change that value. +
    • + +

+See §2.5 for more details about garbage collection +and some of these options. + + +

+This function should not be called by a finalizer. + + + + +

+

dofile ([filename])

+Opens the named file and executes its content as a Lua chunk. +When called without arguments, +dofile executes the content of the standard input (stdin). +Returns all values returned by the chunk. +In case of errors, dofile propagates the error +to its caller. +(That is, dofile does not run in protected mode.) + + + + +

+

error (message [, level])

+Raises an error (see §2.3) with message as the error object. +This function never returns. + + +

+Usually, error adds some information about the error position +at the beginning of the message, if the message is a string. +The level argument specifies how to get the error position. +With level 1 (the default), the error position is where the +error function was called. +Level 2 points the error to where the function +that called error was called; and so on. +Passing a level 0 avoids the addition of error position information +to the message. + + + + +

+

_G

+A global variable (not a function) that +holds the global environment (see §2.2). +Lua itself does not use this variable; +changing its value does not affect any environment, +nor vice versa. + + + + +

+

getmetatable (object)

+ + +

+If object does not have a metatable, returns nil. +Otherwise, +if the object's metatable has a __metatable field, +returns the associated value. +Otherwise, returns the metatable of the given object. + + + + +

+

ipairs (t)

+ + +

+Returns three values (an iterator function, the table t, and 0) +so that the construction + +

+     for i,v in ipairs(t) do body end
+

+will iterate over the key–value pairs +(1,t[1]), (2,t[2]), ..., +up to the first absent index. + + + + +

+

load (chunk [, chunkname [, mode [, env]]])

+ + +

+Loads a chunk. + + +

+If chunk is a string, the chunk is this string. +If chunk is a function, +load calls it repeatedly to get the chunk pieces. +Each call to chunk must return a string that concatenates +with previous results. +A return of an empty string, nil, or no value signals the end of the chunk. + + +

+If there are no syntactic errors, +load returns the compiled chunk as a function; +otherwise, it returns fail plus the error message. + + +

+When you load a main chunk, +the resulting function will always have exactly one upvalue, +the _ENV variable (see §2.2). +However, +when you load a binary chunk created from a function (see string.dump), +the resulting function can have an arbitrary number of upvalues, +and there is no guarantee that its first upvalue will be +the _ENV variable. +(A non-main function may not even have an _ENV upvalue.) + + +

+Regardless, if the resulting function has any upvalues, +its first upvalue is set to the value of env, +if that parameter is given, +or to the value of the global environment. +Other upvalues are initialized with nil. +All upvalues are fresh, that is, +they are not shared with any other function. + + +

+chunkname is used as the name of the chunk for error messages +and debug information (see §4.7). +When absent, +it defaults to chunk, if chunk is a string, +or to "=(load)" otherwise. + + +

+The string mode controls whether the chunk can be text or binary +(that is, a precompiled chunk). +It may be the string "b" (only binary chunks), +"t" (only text chunks), +or "bt" (both binary and text). +The default is "bt". + + +

+It is safe to load malformed binary chunks; +load signals an appropriate error. +However, +Lua does not check the consistency of the code inside binary chunks; +running maliciously crafted bytecode can crash the interpreter. + + + + +

+

loadfile ([filename [, mode [, env]]])

+ + +

+Similar to load, +but gets the chunk from file filename +or from the standard input, +if no file name is given. + + + + +

+

next (table [, index])

+ + +

+Allows a program to traverse all fields of a table. +Its first argument is a table and its second argument +is an index in this table. +A call to next returns the next index of the table +and its associated value. +When called with nil as its second argument, +next returns an initial index +and its associated value. +When called with the last index, +or with nil in an empty table, +next returns nil. +If the second argument is absent, then it is interpreted as nil. +In particular, +you can use next(t) to check whether a table is empty. + + +

+The order in which the indices are enumerated is not specified, +even for numeric indices. +(To traverse a table in numerical order, +use a numerical for.) + + +

+You should not assign any value to a non-existent field in a table +during its traversal. +You may however modify existing fields. +In particular, you may set existing fields to nil. + + + + +

+

pairs (t)

+ + +

+If t has a metamethod __pairs, +calls it with t as argument and returns the first three +results from the call. + + +

+Otherwise, +returns three values: the next function, the table t, and nil, +so that the construction + +

+     for k,v in pairs(t) do body end
+

+will iterate over all key–value pairs of table t. + + +

+See function next for the caveats of modifying +the table during its traversal. + + + + +

+

pcall (f [, arg1, ···])

+ + +

+Calls the function f with +the given arguments in protected mode. +This means that any error inside f is not propagated; +instead, pcall catches the error +and returns a status code. +Its first result is the status code (a boolean), +which is true if the call succeeds without errors. +In such case, pcall also returns all results from the call, +after this first result. +In case of any error, pcall returns false plus the error object. +Note that errors caught by pcall do not call a message handler. + + + + +

+

print (···)

+Receives any number of arguments +and prints their values to stdout, +converting each argument to a string +following the same rules of tostring. + + +

+The function print is not intended for formatted output, +but only as a quick way to show a value, +for instance for debugging. +For complete control over the output, +use string.format and io.write. + + + + +

+

rawequal (v1, v2)

+Checks whether v1 is equal to v2, +without invoking the __eq metamethod. +Returns a boolean. + + + + +

+

rawget (table, index)

+Gets the real value of table[index], +without using the __index metavalue. +table must be a table; +index may be any value. + + + + +

+

rawlen (v)

+Returns the length of the object v, +which must be a table or a string, +without invoking the __len metamethod. +Returns an integer. + + + + +

+

rawset (table, index, value)

+Sets the real value of table[index] to value, +without using the __newindex metavalue. +table must be a table, +index any value different from nil and NaN, +and value any Lua value. + + +

+This function returns table. + + + + +

+

select (index, ···)

+ + +

+If index is a number, +returns all arguments after argument number index; +a negative number indexes from the end (-1 is the last argument). +Otherwise, index must be the string "#", +and select returns the total number of extra arguments it received. + + + + +

+

setmetatable (table, metatable)

+ + +

+Sets the metatable for the given table. +If metatable is nil, +removes the metatable of the given table. +If the original metatable has a __metatable field, +raises an error. + + +

+This function returns table. + + +

+To change the metatable of other types from Lua code, +you must use the debug library (§6.10). + + + + +

+

tonumber (e [, base])

+ + +

+When called with no base, +tonumber tries to convert its argument to a number. +If the argument is already a number or +a string convertible to a number, +then tonumber returns this number; +otherwise, it returns fail. + + +

+The conversion of strings can result in integers or floats, +according to the lexical conventions of Lua (see §3.1). +The string may have leading and trailing spaces and a sign. + + +

+When called with base, +then e must be a string to be interpreted as +an integer numeral in that base. +The base may be any integer between 2 and 36, inclusive. +In bases above 10, the letter 'A' (in either upper or lower case) +represents 10, 'B' represents 11, and so forth, +with 'Z' representing 35. +If the string e is not a valid numeral in the given base, +the function returns fail. + + + + +

+

tostring (v)

+ + +

+Receives a value of any type and +converts it to a string in a human-readable format. + + +

+If the metatable of v has a __tostring field, +then tostring calls the corresponding value +with v as argument, +and uses the result of the call as its result. +Otherwise, if the metatable of v has a __name field +with a string value, +tostring may use that string in its final result. + + +

+For complete control of how numbers are converted, +use string.format. + + + + +

+

type (v)

+ + +

+Returns the type of its only argument, coded as a string. +The possible results of this function are +"nil" (a string, not the value nil), +"number", +"string", +"boolean", +"table", +"function", +"thread", +and "userdata". + + + + +

+

_VERSION

+ + +

+A global variable (not a function) that +holds a string containing the running Lua version. +The current value of this variable is "Lua 5.4". + + + + +

+

warn (msg1, ···)

+ + +

+Emits a warning with a message composed by the concatenation +of all its arguments (which should be strings). + + +

+By convention, +a one-piece message starting with '@' +is intended to be a control message, +which is a message to the warning system itself. +In particular, the standard warning function in Lua +recognizes the control messages "@off", +to stop the emission of warnings, +and "@on", to (re)start the emission; +it ignores unknown control messages. + + + + +

+

xpcall (f, msgh [, arg1, ···])

+ + +

+This function is similar to pcall, +except that it sets a new message handler msgh. + + + + + + + +

6.2 – Coroutine Manipulation

+ +

+This library comprises the operations to manipulate coroutines, +which come inside the table coroutine. +See §2.6 for a general description of coroutines. + + +

+

coroutine.close (co)

+ + +

+Closes coroutine co, +that is, +closes all its pending to-be-closed variables +and puts the coroutine in a dead state. +The given coroutine must be dead or suspended. +In case of error +(either the original error that stopped the coroutine or +errors in closing methods), +returns false plus the error object; +otherwise returns true. + + + + +

+

coroutine.create (f)

+ + +

+Creates a new coroutine, with body f. +f must be a function. +Returns this new coroutine, +an object with type "thread". + + + + +

+

coroutine.isyieldable ([co])

+ + +

+Returns true when the coroutine co can yield. +The default for co is the running coroutine. + + +

+A coroutine is yieldable if it is not the main thread and +it is not inside a non-yieldable C function. + + + + +

+

coroutine.resume (co [, val1, ···])

+ + +

+Starts or continues the execution of coroutine co. +The first time you resume a coroutine, +it starts running its body. +The values val1, ... are passed +as the arguments to the body function. +If the coroutine has yielded, +resume restarts it; +the values val1, ... are passed +as the results from the yield. + + +

+If the coroutine runs without any errors, +resume returns true plus any values passed to yield +(when the coroutine yields) or any values returned by the body function +(when the coroutine terminates). +If there is any error, +resume returns false plus the error message. + + + + +

+

coroutine.running ()

+ + +

+Returns the running coroutine plus a boolean, +true when the running coroutine is the main one. + + + + +

+

coroutine.status (co)

+ + +

+Returns the status of the coroutine co, as a string: +"running", +if the coroutine is running +(that is, it is the one that called status); +"suspended", if the coroutine is suspended in a call to yield, +or if it has not started running yet; +"normal" if the coroutine is active but not running +(that is, it has resumed another coroutine); +and "dead" if the coroutine has finished its body function, +or if it has stopped with an error. + + + + +

+

coroutine.wrap (f)

+ + +

+Creates a new coroutine, with body f; +f must be a function. +Returns a function that resumes the coroutine each time it is called. +Any arguments passed to this function behave as the +extra arguments to resume. +The function returns the same values returned by resume, +except the first boolean. +In case of error, +the function closes the coroutine and propagates the error. + + + + +

+

coroutine.yield (···)

+ + +

+Suspends the execution of the calling coroutine. +Any arguments to yield are passed as extra results to resume. + + + + + + + +

6.3 – Modules

+ +

+The package library provides basic +facilities for loading modules in Lua. +It exports one function directly in the global environment: +require. +Everything else is exported in the table package. + + +

+

require (modname)

+ + +

+Loads the given module. +The function starts by looking into the package.loaded table +to determine whether modname is already loaded. +If it is, then require returns the value stored +at package.loaded[modname]. +(The absence of a second result in this case +signals that this call did not have to load the module.) +Otherwise, it tries to find a loader for the module. + + +

+To find a loader, +require is guided by the table package.searchers. +Each item in this table is a search function, +that searches for the module in a particular way. +By changing this table, +we can change how require looks for a module. +The following explanation is based on the default configuration +for package.searchers. + + +

+First require queries package.preload[modname]. +If it has a value, +this value (which must be a function) is the loader. +Otherwise require searches for a Lua loader using the +path stored in package.path. +If that also fails, it searches for a C loader using the +path stored in package.cpath. +If that also fails, +it tries an all-in-one loader (see package.searchers). + + +

+Once a loader is found, +require calls the loader with two arguments: +modname and an extra value, +a loader data, +also returned by the searcher. +The loader data can be any value useful to the module; +for the default searchers, +it indicates where the loader was found. +(For instance, if the loader came from a file, +this extra value is the file path.) +If the loader returns any non-nil value, +require assigns the returned value to package.loaded[modname]. +If the loader does not return a non-nil value and +has not assigned any value to package.loaded[modname], +then require assigns true to this entry. +In any case, require returns the +final value of package.loaded[modname]. +Besides that value, require also returns as a second result +the loader data returned by the searcher, +which indicates how require found the module. + + +

+If there is any error loading or running the module, +or if it cannot find any loader for the module, +then require raises an error. + + + + +

+

package.config

+ + +

+A string describing some compile-time configurations for packages. +This string is a sequence of lines: + +

    + +
  • The first line is the directory separator string. +Default is '\' for Windows and '/' for all other systems.
    • + +
  • The second line is the character that separates templates in a path. +Default is ';'.
    • + +
  • The third line is the string that marks the +substitution points in a template. +Default is '?'.
    • + +
  • The fourth line is a string that, in a path in Windows, +is replaced by the executable's directory. +Default is '!'.
    • + +
  • The fifth line is a mark to ignore all text after it +when building the luaopen_ function name. +Default is '-'.
    • + +
+ + + +

+

package.cpath

+ + +

+A string with the path used by require +to search for a C loader. + + +

+Lua initializes the C path package.cpath in the same way +it initializes the Lua path package.path, +using the environment variable LUA_CPATH_5_4, +or the environment variable LUA_CPATH, +or a default path defined in luaconf.h. + + + + +

+

package.loaded

+ + +

+A table used by require to control which +modules are already loaded. +When you require a module modname and +package.loaded[modname] is not false, +require simply returns the value stored there. + + +

+This variable is only a reference to the real table; +assignments to this variable do not change the +table used by require. +The real table is stored in the C registry (see §4.3), +indexed by the key LUA_LOADED_TABLE, a string. + + + + +

+

package.loadlib (libname, funcname)

+ + +

+Dynamically links the host program with the C library libname. + + +

+If funcname is "*", +then it only links with the library, +making the symbols exported by the library +available to other dynamically linked libraries. +Otherwise, +it looks for a function funcname inside the library +and returns this function as a C function. +So, funcname must follow the lua_CFunction prototype +(see lua_CFunction). + + +

+This is a low-level function. +It completely bypasses the package and module system. +Unlike require, +it does not perform any path searching and +does not automatically adds extensions. +libname must be the complete file name of the C library, +including if necessary a path and an extension. +funcname must be the exact name exported by the C library +(which may depend on the C compiler and linker used). + + +

+This functionality is not supported by ISO C. +As such, it is only available on some platforms +(Windows, Linux, Mac OS X, Solaris, BSD, +plus other Unix systems that support the dlfcn standard). + + +

+This function is inherently insecure, +as it allows Lua to call any function in any readable dynamic +library in the system. +(Lua calls any function assuming the function +has a proper prototype and respects a proper protocol +(see lua_CFunction). +Therefore, +calling an arbitrary function in an arbitrary dynamic library +more often than not results in an access violation.) + + + + +

+

package.path

+ + +

+A string with the path used by require +to search for a Lua loader. + + +

+At start-up, Lua initializes this variable with +the value of the environment variable LUA_PATH_5_4 or +the environment variable LUA_PATH or +with a default path defined in luaconf.h, +if those environment variables are not defined. +A ";;" in the value of the environment variable +is replaced by the default path. + + + + +

+

package.preload

+ + +

+A table to store loaders for specific modules +(see require). + + +

+This variable is only a reference to the real table; +assignments to this variable do not change the +table used by require. +The real table is stored in the C registry (see §4.3), +indexed by the key LUA_PRELOAD_TABLE, a string. + + + + +

+

package.searchers

+ + +

+A table used by require to control how to find modules. + + +

+Each entry in this table is a searcher function. +When looking for a module, +require calls each of these searchers in ascending order, +with the module name (the argument given to require) as its +sole argument. +If the searcher finds the module, +it returns another function, the module loader, +plus an extra value, a loader data, +that will be passed to that loader and +returned as a second result by require. +If it cannot find the module, +it returns a string explaining why +(or nil if it has nothing to say). + + +

+Lua initializes this table with four searcher functions. + + +

+The first searcher simply looks for a loader in the +package.preload table. + + +

+The second searcher looks for a loader as a Lua library, +using the path stored at package.path. +The search is done as described in function package.searchpath. + + +

+The third searcher looks for a loader as a C library, +using the path given by the variable package.cpath. +Again, +the search is done as described in function package.searchpath. +For instance, +if the C path is the string + +

+     "./?.so;./?.dll;/usr/local/?/init.so"
+

+the searcher for module foo +will try to open the files ./foo.so, ./foo.dll, +and /usr/local/foo/init.so, in that order. +Once it finds a C library, +this searcher first uses a dynamic link facility to link the +application with the library. +Then it tries to find a C function inside the library to +be used as the loader. +The name of this C function is the string "luaopen_" +concatenated with a copy of the module name where each dot +is replaced by an underscore. +Moreover, if the module name has a hyphen, +its suffix after (and including) the first hyphen is removed. +For instance, if the module name is a.b.c-v2.1, +the function name will be luaopen_a_b_c. + + +

+The fourth searcher tries an all-in-one loader. +It searches the C path for a library for +the root name of the given module. +For instance, when requiring a.b.c, +it will search for a C library for a. +If found, it looks into it for an open function for +the submodule; +in our example, that would be luaopen_a_b_c. +With this facility, a package can pack several C submodules +into one single library, +with each submodule keeping its original open function. + + +

+All searchers except the first one (preload) return as the extra value +the file path where the module was found, +as returned by package.searchpath. +The first searcher always returns the string ":preload:". + + +

+Searchers should raise no errors and have no side effects in Lua. +(They may have side effects in C, +for instance by linking the application with a library.) + + + + +

+

package.searchpath (name, path [, sep [, rep]])

+ + +

+Searches for the given name in the given path. + + +

+A path is a string containing a sequence of +templates separated by semicolons. +For each template, +the function replaces each interrogation mark (if any) +in the template with a copy of name +wherein all occurrences of sep +(a dot, by default) +were replaced by rep +(the system's directory separator, by default), +and then tries to open the resulting file name. + + +

+For instance, if the path is the string + +

+     "./?.lua;./?.lc;/usr/local/?/init.lua"
+

+the search for the name foo.a +will try to open the files +./foo/a.lua, ./foo/a.lc, and +/usr/local/foo/a/init.lua, in that order. + + +

+Returns the resulting name of the first file that it can +open in read mode (after closing the file), +or fail plus an error message if none succeeds. +(This error message lists all file names it tried to open.) + + + + + + + +

6.4 – String Manipulation

+ + + +

+This library provides generic functions for string manipulation, +such as finding and extracting substrings, and pattern matching. +When indexing a string in Lua, the first character is at position 1 +(not at 0, as in C). +Indices are allowed to be negative and are interpreted as indexing backwards, +from the end of the string. +Thus, the last character is at position -1, and so on. + + +

+The string library provides all its functions inside the table +string. +It also sets a metatable for strings +where the __index field points to the string table. +Therefore, you can use the string functions in object-oriented style. +For instance, string.byte(s,i) +can be written as s:byte(i). + + +

+The string library assumes one-byte character encodings. + + +

+

string.byte (s [, i [, j]])

+Returns the internal numeric codes of the characters s[i], +s[i+1], ..., s[j]. +The default value for i is 1; +the default value for j is i. +These indices are corrected +following the same rules of function string.sub. + + +

+Numeric codes are not necessarily portable across platforms. + + + + +

+

string.char (···)

+Receives zero or more integers. +Returns a string with length equal to the number of arguments, +in which each character has the internal numeric code equal +to its corresponding argument. + + +

+Numeric codes are not necessarily portable across platforms. + + + + +

+

string.dump (function [, strip])

+ + +

+Returns a string containing a binary representation +(a binary chunk) +of the given function, +so that a later load on this string returns +a copy of the function (but with new upvalues). +If strip is a true value, +the binary representation may not include all debug information +about the function, +to save space. + + +

+Functions with upvalues have only their number of upvalues saved. +When (re)loaded, +those upvalues receive fresh instances. +(See the load function for details about +how these upvalues are initialized. +You can use the debug library to serialize +and reload the upvalues of a function +in a way adequate to your needs.) + + + + +

+

string.find (s, pattern [, init [, plain]])

+ + +

+Looks for the first match of +pattern (see §6.4.1) in the string s. +If it finds a match, then find returns the indices of s +where this occurrence starts and ends; +otherwise, it returns fail. +A third, optional numeric argument init specifies +where to start the search; +its default value is 1 and can be negative. +A true as a fourth, optional argument plain +turns off the pattern matching facilities, +so the function does a plain "find substring" operation, +with no characters in pattern being considered magic. + + +

+If the pattern has captures, +then in a successful match +the captured values are also returned, +after the two indices. + + + + +

+

string.format (formatstring, ···)

+ + +

+Returns a formatted version of its variable number of arguments +following the description given in its first argument, +which must be a string. +The format string follows the same rules as the ISO C function sprintf. +The only differences are that the conversion specifiers and modifiers +F, n, *, h, L, and l are not supported +and that there is an extra specifier, q. +Both width and precision, when present, +are limited to two digits. + + +

+The specifier q formats booleans, nil, numbers, and strings +in a way that the result is a valid constant in Lua source code. +Booleans and nil are written in the obvious way +(true, false, nil). +Floats are written in hexadecimal, +to preserve full precision. +A string is written between double quotes, +using escape sequences when necessary to ensure that +it can safely be read back by the Lua interpreter. +For instance, the call + +

+     string.format('%q', 'a string with "quotes" and \n new line')
+

+may produce the string: + +

+     "a string with \"quotes\" and \
+      new line"
+

+This specifier does not support modifiers (flags, width, precision). + + +

+The conversion specifiers +A, a, E, e, f, +G, and g all expect a number as argument. +The specifiers c, d, +i, o, u, X, and x +expect an integer. +When Lua is compiled with a C89 compiler, +the specifiers A and a (hexadecimal floats) +do not support modifiers. + + +

+The specifier s expects a string; +if its argument is not a string, +it is converted to one following the same rules of tostring. +If the specifier has any modifier, +the corresponding string argument should not contain embedded zeros. + + +

+The specifier p formats the pointer +returned by lua_topointer. +That gives a unique string identifier for tables, userdata, +threads, strings, and functions. +For other values (numbers, nil, booleans), +this specifier results in a string representing +the pointer NULL. + + + + +

+

string.gmatch (s, pattern [, init])

+Returns an iterator function that, +each time it is called, +returns the next captures from pattern (see §6.4.1) +over the string s. +If pattern specifies no captures, +then the whole match is produced in each call. +A third, optional numeric argument init specifies +where to start the search; +its default value is 1 and can be negative. + + +

+As an example, the following loop +will iterate over all the words from string s, +printing one per line: + +

+     s = "hello world from Lua"
+     for w in string.gmatch(s, "%a+") do
+       print(w)
+     end
+

+The next example collects all pairs key=value from the +given string into a table: + +

+     t = {}
+     s = "from=world, to=Lua"
+     for k, v in string.gmatch(s, "(%w+)=(%w+)") do
+       t[k] = v
+     end
+
+ +

+For this function, a caret '^' at the start of a pattern does not +work as an anchor, as this would prevent the iteration. + + + + +

+

string.gsub (s, pattern, repl [, n])

+Returns a copy of s +in which all (or the first n, if given) +occurrences of the pattern (see §6.4.1) have been +replaced by a replacement string specified by repl, +which can be a string, a table, or a function. +gsub also returns, as its second value, +the total number of matches that occurred. +The name gsub comes from Global SUBstitution. + + +

+If repl is a string, then its value is used for replacement. +The character % works as an escape character: +any sequence in repl of the form %d, +with d between 1 and 9, +stands for the value of the d-th captured substring; +the sequence %0 stands for the whole match; +the sequence %% stands for a single %. + + +

+If repl is a table, then the table is queried for every match, +using the first capture as the key. + + +

+If repl is a function, then this function is called every time a +match occurs, with all captured substrings passed as arguments, +in order. + + +

+In any case, +if the pattern specifies no captures, +then it behaves as if the whole pattern was inside a capture. + + +

+If the value returned by the table query or by the function call +is a string or a number, +then it is used as the replacement string; +otherwise, if it is false or nil, +then there is no replacement +(that is, the original match is kept in the string). + + +

+Here are some examples: + +

+     x = string.gsub("hello world", "(%w+)", "%1 %1")
+     --> x="hello hello world world"
+     
+     x = string.gsub("hello world", "%w+", "%0 %0", 1)
+     --> x="hello hello world"
+     
+     x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
+     --> x="world hello Lua from"
+     
+     x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
+     --> x="home = /home/roberto, user = roberto"
+     
+     x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
+           return load(s)()
+         end)
+     --> x="4+5 = 9"
+     
+     local t = {name="lua", version="5.4"}
+     x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t)
+     --> x="lua-5.4.tar.gz"
+
+ + + +

+

string.len (s)

+ + +

+Receives a string and returns its length. +The empty string "" has length 0. +Embedded zeros are counted, +so "a\000bc\000" has length 5. + + + + +

+

string.lower (s)

+ + +

+Receives a string and returns a copy of this string with all +uppercase letters changed to lowercase. +All other characters are left unchanged. +The definition of what an uppercase letter is depends on the current locale. + + + + +

+

string.match (s, pattern [, init])

+ + +

+Looks for the first match of +the pattern (see §6.4.1) in the string s. +If it finds one, then match returns +the captures from the pattern; +otherwise it returns fail. +If pattern specifies no captures, +then the whole match is returned. +A third, optional numeric argument init specifies +where to start the search; +its default value is 1 and can be negative. + + + + +

+

string.pack (fmt, v1, v2, ···)

+ + +

+Returns a binary string containing the values v1, v2, etc. +serialized in binary form (packed) +according to the format string fmt (see §6.4.2). + + + + +

+

string.packsize (fmt)

+ + +

+Returns the length of a string resulting from string.pack +with the given format. +The format string cannot have the variable-length options +'s' or 'z' (see §6.4.2). + + + + +

+

string.rep (s, n [, sep])

+ + +

+Returns a string that is the concatenation of n copies of +the string s separated by the string sep. +The default value for sep is the empty string +(that is, no separator). +Returns the empty string if n is not positive. + + +

+(Note that it is very easy to exhaust the memory of your machine +with a single call to this function.) + + + + +

+

string.reverse (s)

+ + +

+Returns a string that is the string s reversed. + + + + +

+

string.sub (s, i [, j])

+ + +

+Returns the substring of s that +starts at i and continues until j; +i and j can be negative. +If j is absent, then it is assumed to be equal to -1 +(which is the same as the string length). +In particular, +the call string.sub(s,1,j) returns a prefix of s +with length j, +and string.sub(s, -i) (for a positive i) +returns a suffix of s +with length i. + + +

+If, after the translation of negative indices, +i is less than 1, +it is corrected to 1. +If j is greater than the string length, +it is corrected to that length. +If, after these corrections, +i is greater than j, +the function returns the empty string. + + + + +

+

string.unpack (fmt, s [, pos])

+ + +

+Returns the values packed in string s (see string.pack) +according to the format string fmt (see §6.4.2). +An optional pos marks where +to start reading in s (default is 1). +After the read values, +this function also returns the index of the first unread byte in s. + + + + +

+

string.upper (s)

+ + +

+Receives a string and returns a copy of this string with all +lowercase letters changed to uppercase. +All other characters are left unchanged. +The definition of what a lowercase letter is depends on the current locale. + + + + + + + +

6.4.1 – Patterns

+ + + +

+Patterns in Lua are described by regular strings, +which are interpreted as patterns by the pattern-matching functions +string.find, +string.gmatch, +string.gsub, +and string.match. +This section describes the syntax and the meaning +(that is, what they match) of these strings. + + + + + +

Character Class:

+A character class is used to represent a set of characters. +The following combinations are allowed in describing a character class: + +

    + +
  • x: +(where x is not one of the magic characters +^$()%.[]*+-?) +represents the character x itself. +
    • + +
  • .: (a dot) represents all characters.
    • + +
  • %a: represents all letters.
    • + +
  • %c: represents all control characters.
    • + +
  • %d: represents all digits.
    • + +
  • %g: represents all printable characters except space.
    • + +
  • %l: represents all lowercase letters.
    • + +
  • %p: represents all punctuation characters.
    • + +
  • %s: represents all space characters.
    • + +
  • %u: represents all uppercase letters.
    • + +
  • %w: represents all alphanumeric characters.
    • + +
  • %x: represents all hexadecimal digits.
    • + +
  • %x: (where x is any non-alphanumeric character) +represents the character x. +This is the standard way to escape the magic characters. +Any non-alphanumeric character +(including all punctuation characters, even the non-magical) +can be preceded by a '%' to represent itself in a pattern. +
    • + +
  • [set]: +represents the class which is the union of all +characters in set. +A range of characters can be specified by +separating the end characters of the range, +in ascending order, with a '-'. +All classes %x described above can also be used as +components in set. +All other characters in set represent themselves. +For example, [%w_] (or [_%w]) +represents all alphanumeric characters plus the underscore, +[0-7] represents the octal digits, +and [0-7%l%-] represents the octal digits plus +the lowercase letters plus the '-' character. + + +

    +You can put a closing square bracket in a set +by positioning it as the first character in the set. +You can put a hyphen in a set +by positioning it as the first or the last character in the set. +(You can also use an escape for both cases.) + + +

    +The interaction between ranges and classes is not defined. +Therefore, patterns like [%a-z] or [a-%%] +have no meaning. +

    • + +
  • [^set]: +represents the complement of set, +where set is interpreted as above. +
    • + +

+For all classes represented by single letters (%a, %c, etc.), +the corresponding uppercase letter represents the complement of the class. +For instance, %S represents all non-space characters. + + +

+The definitions of letter, space, and other character groups +depend on the current locale. +In particular, the class [a-z] may not be equivalent to %l. + + + + + +

Pattern Item:

+A pattern item can be + +

    + +
  • +a single character class, +which matches any single character in the class; +
    • + +
  • +a single character class followed by '*', +which matches sequences of zero or more characters in the class. +These repetition items will always match the longest possible sequence; +
    • + +
  • +a single character class followed by '+', +which matches sequences of one or more characters in the class. +These repetition items will always match the longest possible sequence; +
    • + +
  • +a single character class followed by '-', +which also matches sequences of zero or more characters in the class. +Unlike '*', +these repetition items will always match the shortest possible sequence; +
    • + +
  • +a single character class followed by '?', +which matches zero or one occurrence of a character in the class. +It always matches one occurrence if possible; +
    • + +
  • +%n, for n between 1 and 9; +such item matches a substring equal to the n-th captured string +(see below); +
    • + +
  • +%bxy, where x and y are two distinct characters; +such item matches strings that start with x, end with y, +and where the x and y are balanced. +This means that, if one reads the string from left to right, +counting +1 for an x and -1 for a y, +the ending y is the first y where the count reaches 0. +For instance, the item %b() matches expressions with +balanced parentheses. +
    • + +
  • +%f[set], a frontier pattern; +such item matches an empty string at any position such that +the next character belongs to set +and the previous character does not belong to set. +The set set is interpreted as previously described. +The beginning and the end of the subject are handled as if +they were the character '\0'. +
    • + +
+ + + + +

Pattern:

+A pattern is a sequence of pattern items. +A caret '^' at the beginning of a pattern anchors the match at the +beginning of the subject string. +A '$' at the end of a pattern anchors the match at the +end of the subject string. +At other positions, +'^' and '$' have no special meaning and represent themselves. + + + + + +

Captures:

+A pattern can contain sub-patterns enclosed in parentheses; +they describe captures. +When a match succeeds, the substrings of the subject string +that match captures are stored (captured) for future use. +Captures are numbered according to their left parentheses. +For instance, in the pattern "(a*(.)%w(%s*))", +the part of the string matching "a*(.)%w(%s*)" is +stored as the first capture, and therefore has number 1; +the character matching "." is captured with number 2, +and the part matching "%s*" has number 3. + + +

+As a special case, the capture () captures +the current string position (a number). +For instance, if we apply the pattern "()aa()" on the +string "flaaap", there will be two captures: 3 and 5. + + + + + +

Multiple matches:

+The function string.gsub and the iterator string.gmatch +match multiple occurrences of the given pattern in the subject. +For these functions, +a new match is considered valid only +if it ends at least one byte after the end of the previous match. +In other words, the pattern machine never accepts the +empty string as a match immediately after another match. +As an example, +consider the results of the following code: + +

+     > string.gsub("abc", "()a*()", print);
+     --> 1   2
+     --> 3   3
+     --> 4   4
+

+The second and third results come from Lua matching an empty +string after 'b' and another one after 'c'. +Lua does not match an empty string after 'a', +because it would end at the same position of the previous match. + + + + + + + +

6.4.2 – Format Strings for Pack and Unpack

+ +

+The first argument to string.pack, +string.packsize, and string.unpack +is a format string, +which describes the layout of the structure being created or read. + + +

+A format string is a sequence of conversion options. +The conversion options are as follows: + +

    +
  • <: sets little endian
    • +
  • >: sets big endian
    • +
  • =: sets native endian
    • +
  • ![n]: sets maximum alignment to n +(default is native alignment)
    • +
  • b: a signed byte (char)
    • +
  • B: an unsigned byte (char)
    • +
  • h: a signed short (native size)
    • +
  • H: an unsigned short (native size)
    • +
  • l: a signed long (native size)
    • +
  • L: an unsigned long (native size)
    • +
  • j: a lua_Integer
    • +
  • J: a lua_Unsigned
    • +
  • T: a size_t (native size)
    • +
  • i[n]: a signed int with n bytes +(default is native size)
    • +
  • I[n]: an unsigned int with n bytes +(default is native size)
    • +
  • f: a float (native size)
    • +
  • d: a double (native size)
    • +
  • n: a lua_Number
    • +
  • cn: a fixed-sized string with n bytes
    • +
  • z: a zero-terminated string
    • +
  • s[n]: a string preceded by its length +coded as an unsigned integer with n bytes +(default is a size_t)
    • +
  • x: one byte of padding
    • +
  • Xop: an empty item that aligns +according to option op +(which is otherwise ignored)
    • +
  • ' ': (space) ignored
    • +

+(A "[n]" means an optional integral numeral.) +Except for padding, spaces, and configurations +(options "xX <=>!"), +each option corresponds to an argument in string.pack +or a result in string.unpack. + + +

+For options "!n", "sn", "in", and "In", +n can be any integer between 1 and 16. +All integral options check overflows; +string.pack checks whether the given value fits in the given size; +string.unpack checks whether the read value fits in a Lua integer. +For the unsigned options, +Lua integers are treated as unsigned values too. + + +

+Any format string starts as if prefixed by "!1=", +that is, +with maximum alignment of 1 (no alignment) +and native endianness. + + +

+Native endianness assumes that the whole system is +either big or little endian. +The packing functions will not emulate correctly the behavior +of mixed-endian formats. + + +

+Alignment works as follows: +For each option, +the format gets extra padding until the data starts +at an offset that is a multiple of the minimum between the +option size and the maximum alignment; +this minimum must be a power of 2. +Options "c" and "z" are not aligned; +option "s" follows the alignment of its starting integer. + + +

+All padding is filled with zeros by string.pack +and ignored by string.unpack. + + + + + + + +

6.5 – UTF-8 Support

+ +

+This library provides basic support for UTF-8 encoding. +It provides all its functions inside the table utf8. +This library does not provide any support for Unicode other +than the handling of the encoding. +Any operation that needs the meaning of a character, +such as character classification, is outside its scope. + + +

+Unless stated otherwise, +all functions that expect a byte position as a parameter +assume that the given position is either the start of a byte sequence +or one plus the length of the subject string. +As in the string library, +negative indices count from the end of the string. + + +

+Functions that create byte sequences +accept all values up to 0x7FFFFFFF, +as defined in the original UTF-8 specification; +that implies byte sequences of up to six bytes. + + +

+Functions that interpret byte sequences only accept +valid sequences (well formed and not overlong). +By default, they only accept byte sequences +that result in valid Unicode code points, +rejecting values greater than 10FFFF and surrogates. +A boolean argument lax, when available, +lifts these checks, +so that all values up to 0x7FFFFFFF are accepted. +(Not well formed and overlong sequences are still rejected.) + + +

+

utf8.char (···)

+ + +

+Receives zero or more integers, +converts each one to its corresponding UTF-8 byte sequence +and returns a string with the concatenation of all these sequences. + + + + +

+

utf8.charpattern

+ + +

+The pattern (a string, not a function) "[\0-\x7F\xC2-\xFD][\x80-\xBF]*" +(see §6.4.1), +which matches exactly one UTF-8 byte sequence, +assuming that the subject is a valid UTF-8 string. + + + + +

+

utf8.codes (s [, lax])

+ + +

+Returns values so that the construction + +

+     for p, c in utf8.codes(s) do body end
+

+will iterate over all UTF-8 characters in string s, +with p being the position (in bytes) and c the code point +of each character. +It raises an error if it meets any invalid byte sequence. + + + + +

+

utf8.codepoint (s [, i [, j [, lax]]])

+ + +

+Returns the code points (as integers) from all characters in s +that start between byte position i and j (both included). +The default for i is 1 and for j is i. +It raises an error if it meets any invalid byte sequence. + + + + +

+

utf8.len (s [, i [, j [, lax]]])

+ + +

+Returns the number of UTF-8 characters in string s +that start between positions i and j (both inclusive). +The default for i is 1 and for j is -1. +If it finds any invalid byte sequence, +returns fail plus the position of the first invalid byte. + + + + +

+

utf8.offset (s, n [, i])

+ + +

+Returns the position (in bytes) where the encoding of the +n-th character of s +(counting from position i) starts. +A negative n gets characters before position i. +The default for i is 1 when n is non-negative +and #s + 1 otherwise, +so that utf8.offset(s, -n) gets the offset of the +n-th character from the end of the string. +If the specified character is neither in the subject +nor right after its end, +the function returns fail. + + +

+As a special case, +when n is 0 the function returns the start of the encoding +of the character that contains the i-th byte of s. + + +

+This function assumes that s is a valid UTF-8 string. + + + + + + + +

6.6 – Table Manipulation

+ +

+This library provides generic functions for table manipulation. +It provides all its functions inside the table table. + + +

+Remember that, whenever an operation needs the length of a table, +all caveats about the length operator apply (see §3.4.7). +All functions ignore non-numeric keys +in the tables given as arguments. + + +

+

table.concat (list [, sep [, i [, j]]])

+ + +

+Given a list where all elements are strings or numbers, +returns the string list[i]..sep..list[i+1] ··· sep..list[j]. +The default value for sep is the empty string, +the default for i is 1, +and the default for j is #list. +If i is greater than j, returns the empty string. + + + + +

+

table.insert (list, [pos,] value)

+ + +

+Inserts element value at position pos in list, +shifting up the elements +list[pos], list[pos+1], ···, list[#list]. +The default value for pos is #list+1, +so that a call table.insert(t,x) inserts x at the end +of the list t. + + + + +

+

table.move (a1, f, e, t [,a2])

+ + +

+Moves elements from the table a1 to the table a2, +performing the equivalent to the following +multiple assignment: +a2[t],··· = a1[f],···,a1[e]. +The default for a2 is a1. +The destination range can overlap with the source range. +The number of elements to be moved must fit in a Lua integer. + + +

+Returns the destination table a2. + + + + +

+

table.pack (···)

+ + +

+Returns a new table with all arguments stored into keys 1, 2, etc. +and with a field "n" with the total number of arguments. +Note that the resulting table may not be a sequence, +if some arguments are nil. + + + + +

+

table.remove (list [, pos])

+ + +

+Removes from list the element at position pos, +returning the value of the removed element. +When pos is an integer between 1 and #list, +it shifts down the elements +list[pos+1], list[pos+2], ···, list[#list] +and erases element list[#list]; +The index pos can also be 0 when #list is 0, +or #list + 1. + + +

+The default value for pos is #list, +so that a call table.remove(l) removes the last element +of the list l. + + + + +

+

table.sort (list [, comp])

+ + +

+Sorts the list elements in a given order, in-place, +from list[1] to list[#list]. +If comp is given, +then it must be a function that receives two list elements +and returns true when the first element must come +before the second in the final order, +so that, after the sort, +i <= j implies not comp(list[j],list[i]). +If comp is not given, +then the standard Lua operator < is used instead. + + +

+The comp function must define a consistent order; +more formally, the function must define a strict weak order. +(A weak order is similar to a total order, +but it can equate different elements for comparison purposes.) + + +

+The sort algorithm is not stable: +Different elements considered equal by the given order +may have their relative positions changed by the sort. + + + + +

+

table.unpack (list [, i [, j]])

+ + +

+Returns the elements from the given list. +This function is equivalent to + +

+     return list[i], list[i+1], ···, list[j]
+

+By default, i is 1 and j is #list. + + + + + + + +

6.7 – Mathematical Functions

+ +

+This library provides basic mathematical functions. +It provides all its functions and constants inside the table math. +Functions with the annotation "integer/float" give +integer results for integer arguments +and float results for non-integer arguments. +The rounding functions +math.ceil, math.floor, and math.modf +return an integer when the result fits in the range of an integer, +or a float otherwise. + + +

+

math.abs (x)

+ + +

+Returns the maximum value between x and -x. (integer/float) + + + + +

+

math.acos (x)

+ + +

+Returns the arc cosine of x (in radians). + + + + +

+

math.asin (x)

+ + +

+Returns the arc sine of x (in radians). + + + + +

+

math.atan (y [, x])

+ + +

+ +Returns the arc tangent of y/x (in radians), +using the signs of both arguments to find the +quadrant of the result. +It also handles correctly the case of x being zero. + + +

+The default value for x is 1, +so that the call math.atan(y) +returns the arc tangent of y. + + + + +

+

math.ceil (x)

+ + +

+Returns the smallest integral value greater than or equal to x. + + + + +

+

math.cos (x)

+ + +

+Returns the cosine of x (assumed to be in radians). + + + + +

+

math.deg (x)

+ + +

+Converts the angle x from radians to degrees. + + + + +

+

math.exp (x)

+ + +

+Returns the value ex +(where e is the base of natural logarithms). + + + + +

+

math.floor (x)

+ + +

+Returns the largest integral value less than or equal to x. + + + + +

+

math.fmod (x, y)

+ + +

+Returns the remainder of the division of x by y +that rounds the quotient towards zero. (integer/float) + + + + +

+

math.huge

+ + +

+The float value HUGE_VAL, +a value greater than any other numeric value. + + + + +

+

math.log (x [, base])

+ + +

+Returns the logarithm of x in the given base. +The default for base is e +(so that the function returns the natural logarithm of x). + + + + +

+

math.max (x, ···)

+ + +

+Returns the argument with the maximum value, +according to the Lua operator <. + + + + +

+

math.maxinteger

+An integer with the maximum value for an integer. + + + + +

+

math.min (x, ···)

+ + +

+Returns the argument with the minimum value, +according to the Lua operator <. + + + + +

+

math.mininteger

+An integer with the minimum value for an integer. + + + + +

+

math.modf (x)

+ + +

+Returns the integral part of x and the fractional part of x. +Its second result is always a float. + + + + +

+

math.pi

+ + +

+The value of π. + + + + +

+

math.rad (x)

+ + +

+Converts the angle x from degrees to radians. + + + + +

+

math.random ([m [, n]])

+ + +

+When called without arguments, +returns a pseudo-random float with uniform distribution +in the range [0,1). +When called with two integers m and n, +math.random returns a pseudo-random integer +with uniform distribution in the range [m, n]. +The call math.random(n), for a positive n, +is equivalent to math.random(1,n). +The call math.random(0) produces an integer with +all bits (pseudo)random. + + +

+This function uses the xoshiro256** algorithm to produce +pseudo-random 64-bit integers, +which are the results of calls with argument 0. +Other results (ranges and floats) +are unbiased extracted from these integers. + + +

+Lua initializes its pseudo-random generator with the equivalent of +a call to math.randomseed with no arguments, +so that math.random should generate +different sequences of results each time the program runs. + + + + +

+

math.randomseed ([x [, y]])

+ + +

+When called with at least one argument, +the integer parameters x and y are +joined into a 128-bit seed that +is used to reinitialize the pseudo-random generator; +equal seeds produce equal sequences of numbers. +The default for y is zero. + + +

+When called with no arguments, +Lua generates a seed with +a weak attempt for randomness. + + +

+This function returns the two seed components +that were effectively used, +so that setting them again repeats the sequence. + + +

+To ensure a required level of randomness to the initial state +(or contrarily, to have a deterministic sequence, +for instance when debugging a program), +you should call math.randomseed with explicit arguments. + + + + +

+

math.sin (x)

+ + +

+Returns the sine of x (assumed to be in radians). + + + + +

+

math.sqrt (x)

+ + +

+Returns the square root of x. +(You can also use the expression x^0.5 to compute this value.) + + + + +

+

math.tan (x)

+ + +

+Returns the tangent of x (assumed to be in radians). + + + + +

+

math.tointeger (x)

+ + +

+If the value x is convertible to an integer, +returns that integer. +Otherwise, returns fail. + + + + +

+

math.type (x)

+ + +

+Returns "integer" if x is an integer, +"float" if it is a float, +or fail if x is not a number. + + + + +

+

math.ult (m, n)

+ + +

+Returns a boolean, +true if and only if integer m is below integer n when +they are compared as unsigned integers. + + + + + + + +

6.8 – Input and Output Facilities

+ +

+The I/O library provides two different styles for file manipulation. +The first one uses implicit file handles; +that is, there are operations to set a default input file and a +default output file, +and all input/output operations are done over these default files. +The second style uses explicit file handles. + + +

+When using implicit file handles, +all operations are supplied by table io. +When using explicit file handles, +the operation io.open returns a file handle +and then all operations are supplied as methods of the file handle. + + +

+The metatable for file handles provides metamethods +for __gc and __close that try +to close the file when called. + + +

+The table io also provides +three predefined file handles with their usual meanings from C: +io.stdin, io.stdout, and io.stderr. +The I/O library never closes these files. + + +

+Unless otherwise stated, +all I/O functions return fail on failure, +plus an error message as a second result and +a system-dependent error code as a third result, +and some non-false value on success. +On non-POSIX systems, +the computation of the error message and error code +in case of errors +may be not thread safe, +because they rely on the global C variable errno. + + +

+

io.close ([file])

+ + +

+Equivalent to file:close(). +Without a file, closes the default output file. + + + + +

+

io.flush ()

+ + +

+Equivalent to io.output():flush(). + + + + +

+

io.input ([file])

+ + +

+When called with a file name, it opens the named file (in text mode), +and sets its handle as the default input file. +When called with a file handle, +it simply sets this file handle as the default input file. +When called without arguments, +it returns the current default input file. + + +

+In case of errors this function raises the error, +instead of returning an error code. + + + + +

+

io.lines ([filename, ···])

+ + +

+Opens the given file name in read mode +and returns an iterator function that +works like file:lines(···) over the opened file. +When the iterator function fails to read any value, +it automatically closes the file. +Besides the iterator function, +io.lines returns three other values: +two nil values as placeholders, +plus the created file handle. +Therefore, when used in a generic for loop, +the file is closed also if the loop is interrupted by an +error or a break. + + +

+The call io.lines() (with no file name) is equivalent +to io.input():lines("l"); +that is, it iterates over the lines of the default input file. +In this case, the iterator does not close the file when the loop ends. + + +

+In case of errors opening the file, +this function raises the error, +instead of returning an error code. + + + + +

+

io.open (filename [, mode])

+ + +

+This function opens a file, +in the mode specified in the string mode. +In case of success, +it returns a new file handle. + + +

+The mode string can be any of the following: + +

    +
  • "r": read mode (the default);
    • +
  • "w": write mode;
    • +
  • "a": append mode;
    • +
  • "r+": update mode, all previous data is preserved;
    • +
  • "w+": update mode, all previous data is erased;
    • +
  • "a+": append update mode, previous data is preserved, + writing is only allowed at the end of file.
    • +

+The mode string can also have a 'b' at the end, +which is needed in some systems to open the file in binary mode. + + + + +

+

io.output ([file])

+ + +

+Similar to io.input, but operates over the default output file. + + + + +

+

io.popen (prog [, mode])

+ + +

+This function is system dependent and is not available +on all platforms. + + +

+Starts the program prog in a separated process and returns +a file handle that you can use to read data from this program +(if mode is "r", the default) +or to write data to this program +(if mode is "w"). + + + + +

+

io.read (···)

+ + +

+Equivalent to io.input():read(···). + + + + +

+

io.tmpfile ()

+ + +

+In case of success, +returns a handle for a temporary file. +This file is opened in update mode +and it is automatically removed when the program ends. + + + + +

+

io.type (obj)

+ + +

+Checks whether obj is a valid file handle. +Returns the string "file" if obj is an open file handle, +"closed file" if obj is a closed file handle, +or fail if obj is not a file handle. + + + + +

+

io.write (···)

+ + +

+Equivalent to io.output():write(···). + + + + +

+

file:close ()

+ + +

+Closes file. +Note that files are automatically closed when +their handles are garbage collected, +but that takes an unpredictable amount of time to happen. + + +

+When closing a file handle created with io.popen, +file:close returns the same values +returned by os.execute. + + + + +

+

file:flush ()

+ + +

+Saves any written data to file. + + + + +

+

file:lines (···)

+ + +

+Returns an iterator function that, +each time it is called, +reads the file according to the given formats. +When no format is given, +uses "l" as a default. +As an example, the construction + +

+     for c in file:lines(1) do body end
+

+will iterate over all characters of the file, +starting at the current position. +Unlike io.lines, this function does not close the file +when the loop ends. + + + + +

+

file:read (···)

+ + +

+Reads the file file, +according to the given formats, which specify what to read. +For each format, +the function returns a string or a number with the characters read, +or fail if it cannot read data with the specified format. +(In this latter case, +the function does not read subsequent formats.) +When called without arguments, +it uses a default format that reads the next line +(see below). + + +

+The available formats are + +

    + +
  • "n": +reads a numeral and returns it as a float or an integer, +following the lexical conventions of Lua. +(The numeral may have leading whitespaces and a sign.) +This format always reads the longest input sequence that +is a valid prefix for a numeral; +if that prefix does not form a valid numeral +(e.g., an empty string, "0x", or "3.4e-") +or it is too long (more than 200 characters), +it is discarded and the format returns fail. +
    • + +
  • "a": +reads the whole file, starting at the current position. +On end of file, it returns the empty string; +this format never fails. +
    • + +
  • "l": +reads the next line skipping the end of line, +returning fail on end of file. +This is the default format. +
    • + +
  • "L": +reads the next line keeping the end-of-line character (if present), +returning fail on end of file. +
    • + +
  • number: +reads a string with up to this number of bytes, +returning fail on end of file. +If number is zero, +it reads nothing and returns an empty string, +or fail on end of file. +
    • + +

+The formats "l" and "L" should be used only for text files. + + + + +

+

file:seek ([whence [, offset]])

+ + +

+Sets and gets the file position, +measured from the beginning of the file, +to the position given by offset plus a base +specified by the string whence, as follows: + +

    +
  • "set": base is position 0 (beginning of the file);
    • +
  • "cur": base is current position;
    • +
  • "end": base is end of file;
    • +

+In case of success, seek returns the final file position, +measured in bytes from the beginning of the file. +If seek fails, it returns fail, +plus a string describing the error. + + +

+The default value for whence is "cur", +and for offset is 0. +Therefore, the call file:seek() returns the current +file position, without changing it; +the call file:seek("set") sets the position to the +beginning of the file (and returns 0); +and the call file:seek("end") sets the position to the +end of the file, and returns its size. + + + + +

+

file:setvbuf (mode [, size])

+ + +

+Sets the buffering mode for a file. +There are three available modes: + +

    +
  • "no": no buffering.
    • +
  • "full": full buffering.
    • +
  • "line": line buffering.
    • +
+ +

+For the last two cases, +size is a hint for the size of the buffer, in bytes. +The default is an appropriate size. + + +

+The specific behavior of each mode is non portable; +check the underlying ISO C function setvbuf in your platform for +more details. + + + + +

+

file:write (···)

+ + +

+Writes the value of each of its arguments to file. +The arguments must be strings or numbers. + + +

+In case of success, this function returns file. + + + + + + + +

6.9 – Operating System Facilities

+ +

+This library is implemented through table os. + + +

+

os.clock ()

+ + +

+Returns an approximation of the amount in seconds of CPU time +used by the program, +as returned by the underlying ISO C function clock. + + + + +

+

os.date ([format [, time]])

+ + +

+Returns a string or a table containing date and time, +formatted according to the given string format. + + +

+If the time argument is present, +this is the time to be formatted +(see the os.time function for a description of this value). +Otherwise, date formats the current time. + + +

+If format starts with '!', +then the date is formatted in Coordinated Universal Time. +After this optional character, +if format is the string "*t", +then date returns a table with the following fields: +year, month (1–12), day (1–31), +hour (0–23), min (0–59), +sec (0–61, due to leap seconds), +wday (weekday, 1–7, Sunday is 1), +yday (day of the year, 1–366), +and isdst (daylight saving flag, a boolean). +This last field may be absent +if the information is not available. + + +

+If format is not "*t", +then date returns the date as a string, +formatted according to the same rules as the ISO C function strftime. + + +

+If format is absent, it defaults to "%c", +which gives a human-readable date and time representation +using the current locale. + + +

+On non-POSIX systems, +this function may be not thread safe +because of its reliance on C function gmtime and C function localtime. + + + + +

+

os.difftime (t2, t1)

+ + +

+Returns the difference, in seconds, +from time t1 to time t2 +(where the times are values returned by os.time). +In POSIX, Windows, and some other systems, +this value is exactly t2-t1. + + + + +

+

os.execute ([command])

+ + +

+This function is equivalent to the ISO C function system. +It passes command to be executed by an operating system shell. +Its first result is true +if the command terminated successfully, +or fail otherwise. +After this first result +the function returns a string plus a number, +as follows: + +

    + +
  • "exit": +the command terminated normally; +the following number is the exit status of the command. +
    • + +
  • "signal": +the command was terminated by a signal; +the following number is the signal that terminated the command. +
    • + +
+ +

+When called without a command, +os.execute returns a boolean that is true if a shell is available. + + + + +

+

os.exit ([code [, close]])

+ + +

+Calls the ISO C function exit to terminate the host program. +If code is true, +the returned status is EXIT_SUCCESS; +if code is false, +the returned status is EXIT_FAILURE; +if code is a number, +the returned status is this number. +The default value for code is true. + + +

+If the optional second argument close is true, +the function closes the Lua state before exiting (see lua_close). + + + + +

+

os.getenv (varname)

+ + +

+Returns the value of the process environment variable varname +or fail if the variable is not defined. + + + + +

+

os.remove (filename)

+ + +

+Deletes the file (or empty directory, on POSIX systems) +with the given name. +If this function fails, it returns fail +plus a string describing the error and the error code. +Otherwise, it returns true. + + + + +

+

os.rename (oldname, newname)

+ + +

+Renames the file or directory named oldname to newname. +If this function fails, it returns fail, +plus a string describing the error and the error code. +Otherwise, it returns true. + + + + +

+

os.setlocale (locale [, category])

+ + +

+Sets the current locale of the program. +locale is a system-dependent string specifying a locale; +category is an optional string describing which category to change: +"all", "collate", "ctype", +"monetary", "numeric", or "time"; +the default category is "all". +The function returns the name of the new locale, +or fail if the request cannot be honored. + + +

+If locale is the empty string, +the current locale is set to an implementation-defined native locale. +If locale is the string "C", +the current locale is set to the standard C locale. + + +

+When called with nil as the first argument, +this function only returns the name of the current locale +for the given category. + + +

+This function may be not thread safe +because of its reliance on C function setlocale. + + + + +

+

os.time ([table])

+ + +

+Returns the current time when called without arguments, +or a time representing the local date and time specified by the given table. +This table must have fields year, month, and day, +and may have fields +hour (default is 12), +min (default is 0), +sec (default is 0), +and isdst (default is nil). +Other fields are ignored. +For a description of these fields, see the os.date function. + + +

+When the function is called, +the values in these fields do not need to be inside their valid ranges. +For instance, if sec is -10, +it means 10 seconds before the time specified by the other fields; +if hour is 1000, +it means 1000 hours after the time specified by the other fields. + + +

+The returned value is a number, whose meaning depends on your system. +In POSIX, Windows, and some other systems, +this number counts the number +of seconds since some given start time (the "epoch"). +In other systems, the meaning is not specified, +and the number returned by time can be used only as an argument to +os.date and os.difftime. + + +

+When called with a table, +os.time also normalizes all the fields +documented in the os.date function, +so that they represent the same time as before the call +but with values inside their valid ranges. + + + + +

+

os.tmpname ()

+ + +

+Returns a string with a file name that can +be used for a temporary file. +The file must be explicitly opened before its use +and explicitly removed when no longer needed. + + +

+In POSIX systems, +this function also creates a file with that name, +to avoid security risks. +(Someone else might create the file with wrong permissions +in the time between getting the name and creating the file.) +You still have to open the file to use it +and to remove it (even if you do not use it). + + +

+When possible, +you may prefer to use io.tmpfile, +which automatically removes the file when the program ends. + + + + + + + +

6.10 – The Debug Library

+ +

+This library provides +the functionality of the debug interface (§4.7) to Lua programs. +You should exert care when using this library. +Several of its functions +violate basic assumptions about Lua code +(e.g., that variables local to a function +cannot be accessed from outside; +that userdata metatables cannot be changed by Lua code; +that Lua programs do not crash) +and therefore can compromise otherwise secure code. +Moreover, some functions in this library may be slow. + + +

+All functions in this library are provided +inside the debug table. +All functions that operate over a thread +have an optional first argument which is the +thread to operate over. +The default is always the current thread. + + +

+

debug.debug ()

+ + +

+Enters an interactive mode with the user, +running each string that the user enters. +Using simple commands and other debug facilities, +the user can inspect global and local variables, +change their values, evaluate expressions, and so on. +A line containing only the word cont finishes this function, +so that the caller continues its execution. + + +

+Note that commands for debug.debug are not lexically nested +within any function and so have no direct access to local variables. + + + + +

+

debug.gethook ([thread])

+ + +

+Returns the current hook settings of the thread, as three values: +the current hook function, the current hook mask, +and the current hook count, +as set by the debug.sethook function. + + +

+Returns fail if there is no active hook. + + + + +

+

debug.getinfo ([thread,] f [, what])

+ + +

+Returns a table with information about a function. +You can give the function directly +or you can give a number as the value of f, +which means the function running at level f of the call stack +of the given thread: +level 0 is the current function (getinfo itself); +level 1 is the function that called getinfo +(except for tail calls, which do not count in the stack); +and so on. +If f is a number greater than the number of active functions, +then getinfo returns fail. + + +

+The returned table can contain all the fields returned by lua_getinfo, +with the string what describing which fields to fill in. +The default for what is to get all information available, +except the table of valid lines. +If present, +the option 'f' +adds a field named func with the function itself. +If present, +the option 'L' +adds a field named activelines with the table of +valid lines. + + +

+For instance, the expression debug.getinfo(1,"n").name returns +a name for the current function, +if a reasonable name can be found, +and the expression debug.getinfo(print) +returns a table with all available information +about the print function. + + + + +

+

debug.getlocal ([thread,] f, local)

+ + +

+This function returns the name and the value of the local variable +with index local of the function at level f of the stack. +This function accesses not only explicit local variables, +but also parameters and temporary values. + + +

+The first parameter or local variable has index 1, and so on, +following the order that they are declared in the code, +counting only the variables that are active +in the current scope of the function. +Compile-time constants may not appear in this listing, +if they were optimized away by the compiler. +Negative indices refer to vararg arguments; +-1 is the first vararg argument. +The function returns fail +if there is no variable with the given index, +and raises an error when called with a level out of range. +(You can call debug.getinfo to check whether the level is valid.) + + +

+Variable names starting with '(' (open parenthesis) +represent variables with no known names +(internal variables such as loop control variables, +and variables from chunks saved without debug information). + + +

+The parameter f may also be a function. +In that case, getlocal returns only the name of function parameters. + + + + +

+

debug.getmetatable (value)

+ + +

+Returns the metatable of the given value +or nil if it does not have a metatable. + + + + +

+

debug.getregistry ()

+ + +

+Returns the registry table (see §4.3). + + + + +

+

debug.getupvalue (f, up)

+ + +

+This function returns the name and the value of the upvalue +with index up of the function f. +The function returns fail +if there is no upvalue with the given index. + + +

+(For Lua functions, +upvalues are the external local variables that the function uses, +and that are consequently included in its closure.) + + +

+For C functions, this function uses the empty string "" +as a name for all upvalues. + + +

+Variable name '?' (interrogation mark) +represents variables with no known names +(variables from chunks saved without debug information). + + + + +

+

debug.getuservalue (u, n)

+ + +

+Returns the n-th user value associated +to the userdata u plus a boolean, +false if the userdata does not have that value. + + + + +

+

debug.sethook ([thread,] hook, mask [, count])

+ + +

+Sets the given function as the debug hook. +The string mask and the number count describe +when the hook will be called. +The string mask may have any combination of the following characters, +with the given meaning: + +

    +
  • 'c': the hook is called every time Lua calls a function;
    • +
  • 'r': the hook is called every time Lua returns from a function;
    • +
  • 'l': the hook is called every time Lua enters a new line of code.
    • +

+Moreover, +with a count different from zero, +the hook is called also after every count instructions. + + +

+When called without arguments, +debug.sethook turns off the hook. + + +

+When the hook is called, its first parameter is a string +describing the event that has triggered its call: +"call", "tail call", "return", +"line", and "count". +For line events, +the hook also gets the new line number as its second parameter. +Inside a hook, +you can call getinfo with level 2 to get more information about +the running function. +(Level 0 is the getinfo function, +and level 1 is the hook function.) + + + + +

+

debug.setlocal ([thread,] level, local, value)

+ + +

+This function assigns the value value to the local variable +with index local of the function at level level of the stack. +The function returns fail if there is no local +variable with the given index, +and raises an error when called with a level out of range. +(You can call getinfo to check whether the level is valid.) +Otherwise, it returns the name of the local variable. + + +

+See debug.getlocal for more information about +variable indices and names. + + + + +

+

debug.setmetatable (value, table)

+ + +

+Sets the metatable for the given value to the given table +(which can be nil). +Returns value. + + + + +

+

debug.setupvalue (f, up, value)

+ + +

+This function assigns the value value to the upvalue +with index up of the function f. +The function returns fail if there is no upvalue +with the given index. +Otherwise, it returns the name of the upvalue. + + +

+See debug.getupvalue for more information about upvalues. + + + + +

+

debug.setuservalue (udata, value, n)

+ + +

+Sets the given value as +the n-th user value associated to the given udata. +udata must be a full userdata. + + +

+Returns udata, +or fail if the userdata does not have that value. + + + + +

+

debug.traceback ([thread,] [message [, level]])

+ + +

+If message is present but is neither a string nor nil, +this function returns message without further processing. +Otherwise, +it returns a string with a traceback of the call stack. +The optional message string is appended +at the beginning of the traceback. +An optional level number tells at which level +to start the traceback +(default is 1, the function calling traceback). + + + + +

+

debug.upvalueid (f, n)

+ + +

+Returns a unique identifier (as a light userdata) +for the upvalue numbered n +from the given function. + + +

+These unique identifiers allow a program to check whether different +closures share upvalues. +Lua closures that share an upvalue +(that is, that access a same external local variable) +will return identical ids for those upvalue indices. + + + + +

+

debug.upvaluejoin (f1, n1, f2, n2)

+ + +

+Make the n1-th upvalue of the Lua closure f1 +refer to the n2-th upvalue of the Lua closure f2. + + + + + + + +

7 – Lua Standalone

+ +

+Although Lua has been designed as an extension language, +to be embedded in a host C program, +it is also frequently used as a standalone language. +An interpreter for Lua as a standalone language, +called simply lua, +is provided with the standard distribution. +The standalone interpreter includes +all standard libraries. +Its usage is: + +

+     lua [options] [script [args]]
+

+The options are: + +

    +
  • -e stat: execute string stat;
    • +
  • -i: enter interactive mode after running script;
    • +
  • -l mod: "require" mod and assign the + result to global mod;
    • +
  • -l g=mod: "require" mod and assign the + result to global g;
    • +
  • -v: print version information;
    • +
  • -E: ignore environment variables;
    • +
  • -W: turn warnings on;
    • +
  • --: stop handling options;
    • +
  • -: execute stdin as a file and stop handling options.
    • +

+(The form -l g=mod was introduced in release 5.4.4.) + + +

+After handling its options, lua runs the given script. +When called without arguments, +lua behaves as lua -v -i +when the standard input (stdin) is a terminal, +and as lua - otherwise. + + +

+When called without the option -E, +the interpreter checks for an environment variable LUA_INIT_5_4 +(or LUA_INIT if the versioned name is not defined) +before running any argument. +If the variable content has the format @filename, +then lua executes the file. +Otherwise, lua executes the string itself. + + +

+When called with the option -E, +Lua does not consult any environment variables. +In particular, +the values of package.path and package.cpath +are set with the default paths defined in luaconf.h. + + +

+The options -e, -l, and -W are handled in +the order they appear. +For instance, an invocation like + +

+     $ lua -e 'a=1' -llib1 script.lua
+

+will first set a to 1, then require the library lib1, +and finally run the file script.lua with no arguments. +(Here $ is the shell prompt. Your prompt may be different.) + + +

+Before running any code, +lua collects all command-line arguments +in a global table called arg. +The script name goes to index 0, +the first argument after the script name goes to index 1, +and so on. +Any arguments before the script name +(that is, the interpreter name plus its options) +go to negative indices. +For instance, in the call + +

+     $ lua -la b.lua t1 t2
+

+the table is like this: + +

+     arg = { [-2] = "lua", [-1] = "-la",
+             [0] = "b.lua",
+             [1] = "t1", [2] = "t2" }
+

+If there is no script in the call, +the interpreter name goes to index 0, +followed by the other arguments. +For instance, the call + +

+     $ lua -e "print(arg[1])"
+

+will print "-e". +If there is a script, +the script is called with arguments +arg[1], ···, arg[#arg]. +Like all chunks in Lua, +the script is compiled as a variadic function. + + +

+In interactive mode, +Lua repeatedly prompts and waits for a line. +After reading a line, +Lua first try to interpret the line as an expression. +If it succeeds, it prints its value. +Otherwise, it interprets the line as a statement. +If you write an incomplete statement, +the interpreter waits for its completion +by issuing a different prompt. + + +

+If the global variable _PROMPT contains a string, +then its value is used as the prompt. +Similarly, if the global variable _PROMPT2 contains a string, +its value is used as the secondary prompt +(issued during incomplete statements). + + +

+In case of unprotected errors in the script, +the interpreter reports the error to the standard error stream. +If the error object is not a string but +has a metamethod __tostring, +the interpreter calls this metamethod to produce the final message. +Otherwise, the interpreter converts the error object to a string +and adds a stack traceback to it. +When warnings are on, +they are simply printed in the standard error output. + + +

+When finishing normally, +the interpreter closes its main Lua state +(see lua_close). +The script can avoid this step by +calling os.exit to terminate. + + +

+To allow the use of Lua as a +script interpreter in Unix systems, +Lua skips the first line of a file chunk if it starts with #. +Therefore, Lua scripts can be made into executable programs +by using chmod +x and the #! form, +as in + +

+     #!/usr/local/bin/lua
+

+Of course, +the location of the Lua interpreter may be different in your machine. +If lua is in your PATH, +then + +

+     #!/usr/bin/env lua
+

+is a more portable solution. + + + +

8 – Incompatibilities with the Previous Version

+ + + +

+Here we list the incompatibilities that you may find when moving a program +from Lua 5.3 to Lua 5.4. + + +

+You can avoid some incompatibilities by compiling Lua with +appropriate options (see file luaconf.h). +However, +all these compatibility options will be removed in the future. +More often than not, +compatibility issues arise when these compatibility options +are removed. +So, whenever you have the chance, +you should try to test your code with a version of Lua compiled +with all compatibility options turned off. +That will ease transitions to newer versions of Lua. + + +

+Lua versions can always change the C API in ways that +do not imply source-code changes in a program, +such as the numeric values for constants +or the implementation of functions as macros. +Therefore, +you should never assume that binaries are compatible between +different Lua versions. +Always recompile clients of the Lua API when +using a new version. + + +

+Similarly, Lua versions can always change the internal representation +of precompiled chunks; +precompiled chunks are not compatible between different Lua versions. + + +

+The standard paths in the official distribution may +change between versions. + + + + + +

8.1 – Incompatibilities in the Language

+
    + +
  • +The coercion of strings to numbers in +arithmetic and bitwise operations +has been removed from the core language. +The string library does a similar job +for arithmetic (but not for bitwise) operations +using the string metamethods. +However, unlike in previous versions, +the new implementation preserves the implicit type of the numeral +in the string. +For instance, the result of "1" + "2" now is an integer, +not a float. +
    • + +
  • +Literal decimal integer constants that overflow are read as floats, +instead of wrapping around. +You can use hexadecimal notation for such constants if you +want the old behavior +(reading them as integers with wrap around). +
    • + +
  • +The use of the __lt metamethod to emulate __le +has been removed. +When needed, this metamethod must be explicitly defined. +
    • + +
  • +The semantics of the numerical for loop +over integers changed in some details. +In particular, the control variable never wraps around. +
    • + +
  • +A label for a goto cannot be declared where a label with the same +name is visible, even if this other label is declared in an enclosing +block. +
    • + +
  • +When finalizing an object, +Lua does not ignore __gc metamethods that are not functions. +Any value will be called, if present. +(Non-callable values will generate a warning, +like any other error when calling a finalizer.) +
    • + +
+ + + + +

8.2 – Incompatibilities in the Libraries

+
    + +
  • +The function print does not call tostring +to format its arguments; +instead, it has this functionality hardwired. +You should use __tostring to modify how values are printed. +
    • + +
  • +The pseudo-random number generator used by the function math.random +now starts with a somewhat random seed. +Moreover, it uses a different algorithm. +
    • + +
  • +By default, the decoding functions in the utf8 library +do not accept surrogates as valid code points. +An extra parameter in these functions makes them more permissive. +
    • + +
  • +The options "setpause" and "setstepmul" +of the function collectgarbage are deprecated. +You should use the new option "incremental" to set them. +
    • + +
  • +The function io.lines now returns four values, +instead of just one. +That can be a problem when it is used as the sole +argument to another function that has optional parameters, +such as in load(io.lines(filename, "L")). +To fix that issue, +you can wrap the call into parentheses, +to adjust its number of results to one. +
    • + +
+ + + + +

8.3 – Incompatibilities in the API

+ + +
    + +
  • +Full userdata now has an arbitrary number of associated user values. +Therefore, the functions lua_newuserdata, +lua_setuservalue, and lua_getuservalue were +replaced by lua_newuserdatauv, +lua_setiuservalue, and lua_getiuservalue, +which have an extra argument. + + +

    +For compatibility, the old names still work as macros assuming +one single user value. +Note, however, that userdata with zero user values +are more efficient memory-wise. +

    • + +
  • +The function lua_resume has an extra parameter. +This out parameter returns the number of values on +the top of the stack that were yielded or returned by the coroutine. +(In previous versions, +those values were the entire stack.) +
    • + +
  • +The function lua_version returns the version number, +instead of an address of the version number. +The Lua core should work correctly with libraries using their +own static copies of the same core, +so there is no need to check whether they are using the same +address space. +
    • + +
  • +The constant LUA_ERRGCMM was removed. +Errors in finalizers are never propagated; +instead, they generate a warning. +
    • + +
  • +The options LUA_GCSETPAUSE and LUA_GCSETSTEPMUL +of the function lua_gc are deprecated. +You should use the new option LUA_GCINC to set them. +
    • + +
+ + + + +

9 – The Complete Syntax of Lua

+ +

+Here is the complete syntax of Lua in extended BNF. +As usual in extended BNF, +{A} means 0 or more As, +and [A] means an optional A. +(For operator precedences, see §3.4.8; +for a description of the terminals +Name, Numeral, +and LiteralString, see §3.1.) + + + + +

+
+	chunk ::= block
+
+	block ::= {stat} [retstat]
+
+	stat ::=  ‘;’ | 
+		 varlist ‘=’ explist | 
+		 functioncall | 
+		 label | 
+		 break | 
+		 goto Name | 
+		 do block end | 
+		 while exp do block end | 
+		 repeat block until exp | 
+		 if exp then block {elseif exp then block} [else block] end | 
+		 for Name ‘=’ exp ‘,’ exp [‘,’ exp] do block end | 
+		 for namelist in explist do block end | 
+		 function funcname funcbody | 
+		 local function Name funcbody | 
+		 local attnamelist [‘=’ explist] 
+
+	attnamelist ::=  Name attrib {‘,’ Name attrib}
+
+	attrib ::= [‘<’ Name ‘>’]
+
+	retstat ::= return [explist] [‘;’]
+
+	label ::= ‘::’ Name ‘::’
+
+	funcname ::= Name {‘.’ Name} [‘:’ Name]
+
+	varlist ::= var {‘,’ var}
+
+	var ::=  Name | prefixexp ‘[’ exp ‘]’ | prefixexp ‘.’ Name 
+
+	namelist ::= Name {‘,’ Name}
+
+	explist ::= exp {‘,’ exp}
+
+	exp ::=  nil | false | true | Numeral | LiteralString | ‘...’ | functiondef | 
+		 prefixexp | tableconstructor | exp binop exp | unop exp 
+
+	prefixexp ::= var | functioncall | ‘(’ exp ‘)’
+
+	functioncall ::=  prefixexp args | prefixexp ‘:’ Name args 
+
+	args ::=  ‘(’ [explist] ‘)’ | tableconstructor | LiteralString 
+
+	functiondef ::= function funcbody
+
+	funcbody ::= ‘(’ [parlist] ‘)’ block end
+
+	parlist ::= namelist [‘,’ ‘...’] | ‘...’
+
+	tableconstructor ::= ‘{’ [fieldlist] ‘}’
+
+	fieldlist ::= field {fieldsep field} [fieldsep]
+
+	field ::= ‘[’ exp ‘]’ ‘=’ exp | Name ‘=’ exp | exp
+
+	fieldsep ::= ‘,’ | ‘;’
+
+	binop ::=  ‘+’ | ‘-’ | ‘*’ | ‘/’ | ‘//’ | ‘^’ | ‘%’ | 
+		 ‘&’ | ‘~’ | ‘|’ | ‘>>’ | ‘<<’ | ‘..’ | 
+		 ‘<’ | ‘<=’ | ‘>’ | ‘>=’ | ‘==’ | ‘~=’ | 
+		 and | or
+
+	unop ::= ‘-’ | not | ‘#’ | ‘~’
+
+
+ +

+ + + + + + + +

+Last update: +Tue May 2 20:09:38 UTC 2023 +

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+Lua +Welcome to Lua 5.4 +

+ +
+about +· +installation +· +changes +· +license +· +reference manual +
+ +

About Lua

+

+Lua is a powerful, efficient, lightweight, embeddable scripting language +developed by a +team +at +PUC-Rio, +the Pontifical Catholic University of Rio de Janeiro in Brazil. +Lua is +free software +used in +many products and projects +around the world. + +

+Lua's +official web site +provides complete information +about Lua, +including +an +executive summary +and +updated +documentation, +especially the +reference manual, +which may differ slightly from the +local copy +distributed in this package. + +

Installing Lua

+

+Lua is distributed in +source +form. +You need to build it before using it. +Building Lua should be straightforward +because +Lua is implemented in pure ANSI C and compiles unmodified in all known +platforms that have an ANSI C compiler. +Lua also compiles unmodified as C++. +The instructions given below for building Lua are for Unix-like platforms, +such as Linux and Mac OS X. +See also +instructions for other systems +and +customization options. + +

+If you don't have the time or the inclination to compile Lua yourself, +get a binary from +LuaBinaries. + +

Building Lua

+

+In most common Unix-like platforms, simply do "make". +Here are the details. + +

    +
  1. +Open a terminal window and move to +the top-level directory, which is named lua-5.4.6. +The Makefile there controls both the build process and the installation process. +

    +

  2. + Do "make". The Makefile will guess your platform and build Lua for it. +

    +

  3. + If the guess failed, do "make help" and see if your platform is listed. + The platforms currently supported are: +

    +

    + guess aix bsd c89 freebsd generic ios linux linux-readline macosx mingw posix solaris +

    +

    + If your platform is listed, just do "make xxx", where xxx + is your platform name. +

    + If your platform is not listed, try the closest one or posix, generic, + c89, in this order. +

    +

  4. +The compilation takes only a few moments +and produces three files in the src directory: +lua (the interpreter), +luac (the compiler), +and liblua.a (the library). +

    +

  5. + To check that Lua has been built correctly, do "make test" + after building Lua. This will run the interpreter and print its version. +
+

+If you're running Linux, try "make linux-readline" to build the interactive Lua interpreter with handy line-editing and history capabilities. +If you get compilation errors, +make sure you have installed the readline development package +(which is probably named libreadline-dev or readline-devel). +If you get link errors after that, +then try "make linux-readline MYLIBS=-ltermcap". + +

Installing Lua

+

+ Once you have built Lua, you may want to install it in an official + place in your system. In this case, do "make install". The official + place and the way to install files are defined in the Makefile. You'll + probably need the right permissions to install files, and so may need to do "sudo make install". + +

+ To build and install Lua in one step, do "make all install", + or "make xxx install", + where xxx is your platform name. + +

+ To install Lua locally after building it, do "make local". + This will create a directory install with subdirectories + bin, include, lib, man, share, + and install Lua as listed below. + + To install Lua locally, but in some other directory, do + "make install INSTALL_TOP=xxx", where xxx is your chosen directory. + The installation starts in the src and doc directories, + so take care if INSTALL_TOP is not an absolute path. + +

+
+ bin: +
+ lua luac +
+ include: +
+ lua.h luaconf.h lualib.h lauxlib.h lua.hpp +
+ lib: +
+ liblua.a +
+ man/man1: +
+ lua.1 luac.1 +
+ +

+ These are the only directories you need for development. + If you only want to run Lua programs, + you only need the files in bin and man. + The files in include and lib are needed for + embedding Lua in C or C++ programs. + +

Customization

+

+ Three kinds of things can be customized by editing a file: +

    +
  • Where and how to install Lua — edit Makefile. +
  • How to build Lua — edit src/Makefile. +
  • Lua features — edit src/luaconf.h. +
+ +

+ You don't actually need to edit the Makefiles because you may set the + relevant variables in the command line when invoking make. + Nevertheless, it's probably best to edit and save the Makefiles to + record the changes you've made. + +

+ On the other hand, if you need to customize some Lua features, you'll need + to edit src/luaconf.h before building and installing Lua. + The edited file will be the one installed, and + it will be used by any Lua clients that you build, to ensure consistency. + Further customization is available to experts by editing the Lua sources. + +

Building Lua on other systems

+

+ If you're not using the usual Unix tools, then the instructions for + building Lua depend on the compiler you use. You'll need to create + projects (or whatever your compiler uses) for building the library, + the interpreter, and the compiler, as follows: + +

+
+library: +
+lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c ltable.c ltm.c lundump.c lvm.c lzio.c +lauxlib.c lbaselib.c lcorolib.c ldblib.c liolib.c lmathlib.c loadlib.c loslib.c lstrlib.c ltablib.c lutf8lib.c linit.c +
+interpreter: +
+ library, lua.c +
+compiler: +
+ library, luac.c +
+ +

+ To use Lua as a library in your own programs, you'll need to know how to + create and use libraries with your compiler. Moreover, to dynamically load + C libraries for Lua, you'll need to know how to create dynamic libraries + and you'll need to make sure that the Lua API functions are accessible to + those dynamic libraries — but don't link the Lua library + into each dynamic library. For Unix, we recommend that the Lua library + be linked statically into the host program and its symbols exported for + dynamic linking; src/Makefile does this for the Lua interpreter. + For Windows, we recommend that the Lua library be a DLL. + In all cases, the compiler luac should be linked statically. + +

+ As mentioned above, you may edit src/luaconf.h to customize + some features before building Lua. + +

Changes since Lua 5.3

+

+Here are the main changes introduced in Lua 5.4. +The +reference manual +lists the +incompatibilities that had to be introduced. + +

Main changes

+
    +
  • new generational mode for garbage collection +
  • to-be-closed variables +
  • const variables +
  • userdata can have multiple user values +
  • new implementation for math.random +
  • warning system +
  • debug information about function arguments and returns +
  • new semantics for the integer 'for' loop +
  • optional 'init' argument to 'string.gmatch' +
  • new functions 'lua_resetthread' and 'coroutine.close' +
  • string-to-number coercions moved to the string library +
  • allocation function allowed to fail when shrinking a memory block +
  • new format '%p' in 'string.format' +
  • utf8 library accepts codepoints up to 2^31 +
+ +

License

+

+ +[osi certified] + +Lua is free software distributed under the terms of the +MIT license +reproduced below; +it may be used for any purpose, including commercial purposes, +at absolutely no cost without having to ask us. + +The only requirement is that if you do use Lua, +then you should give us credit by including the appropriate copyright notice somewhere in your product or its documentation. + +For details, see +this. + +

+Copyright © 1994–2023 Lua.org, PUC-Rio. + +

+Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +

+The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +

+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. +

+

+ +

+Last update: +Tue May 2 20:08:55 UTC 2023 +

+ + + + diff --git a/src/Makefile b/src/Makefile new file mode 100644 index 0000000..b771196 --- /dev/null +++ b/src/Makefile @@ -0,0 +1,225 @@ +# Makefile for building Lua +# See ../doc/readme.html for installation and customization instructions. + +# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT ======================= + +# Your platform. See PLATS for possible values. +PLAT= guess + +CC= gcc -std=gnu99 +CFLAGS= -O2 -Wall -Wextra -DLUA_COMPAT_5_3 $(SYSCFLAGS) $(MYCFLAGS) +LDFLAGS= $(SYSLDFLAGS) $(MYLDFLAGS) +LIBS= -lm $(SYSLIBS) $(MYLIBS) + +AR= ar rcu +RANLIB= ranlib +RM= rm -f +UNAME= uname + +SYSCFLAGS= +SYSLDFLAGS= +SYSLIBS= + +MYCFLAGS= +MYLDFLAGS= +MYLIBS= +MYOBJS= + +# Special flags for compiler modules; -Os reduces code size. +CMCFLAGS= + +# == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE ======= + +PLATS= guess aix bsd c89 freebsd generic ios linux linux-readline macosx mingw posix solaris + +LUA_A= liblua.a +CORE_O= lapi.o lcode.o lctype.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o +LIB_O= lauxlib.o lbaselib.o lcorolib.o ldblib.o liolib.o lmathlib.o loadlib.o loslib.o lstrlib.o ltablib.o lutf8lib.o linit.o +BASE_O= $(CORE_O) $(LIB_O) $(MYOBJS) + +LUA_T= lua +LUA_O= lua.o + +LUAC_T= luac +LUAC_O= luac.o + +ALL_O= $(BASE_O) $(LUA_O) $(LUAC_O) +ALL_T= $(LUA_A) $(LUA_T) $(LUAC_T) +ALL_A= $(LUA_A) + +# Targets start here. +default: $(PLAT) + +all: $(ALL_T) + +o: $(ALL_O) + +a: $(ALL_A) + +$(LUA_A): $(BASE_O) + $(AR) $@ $(BASE_O) + $(RANLIB) $@ + +$(LUA_T): $(LUA_O) $(LUA_A) + $(CC) -o $@ $(LDFLAGS) $(LUA_O) $(LUA_A) $(LIBS) + +$(LUAC_T): $(LUAC_O) $(LUA_A) + $(CC) -o $@ $(LDFLAGS) $(LUAC_O) $(LUA_A) $(LIBS) + +test: + ./$(LUA_T) -v + +clean: + $(RM) $(ALL_T) $(ALL_O) + +depend: + @$(CC) $(CFLAGS) -MM l*.c + +echo: + @echo "PLAT= $(PLAT)" + @echo "CC= $(CC)" + @echo "CFLAGS= $(CFLAGS)" + @echo "LDFLAGS= $(LDFLAGS)" + @echo "LIBS= $(LIBS)" + @echo "AR= $(AR)" + @echo "RANLIB= $(RANLIB)" + @echo "RM= $(RM)" + @echo "UNAME= $(UNAME)" + +# Convenience targets for popular platforms. +ALL= all + +help: + @echo "Do 'make PLATFORM' where PLATFORM is one of these:" + @echo " $(PLATS)" + @echo "See doc/readme.html for complete instructions." + +guess: + @echo Guessing `$(UNAME)` + @$(MAKE) `$(UNAME)` + +AIX aix: + $(MAKE) $(ALL) CC="xlc" CFLAGS="-O2 -DLUA_USE_POSIX -DLUA_USE_DLOPEN" SYSLIBS="-ldl" SYSLDFLAGS="-brtl -bexpall" + +bsd: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX -DLUA_USE_DLOPEN" SYSLIBS="-Wl,-E" + +c89: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_C89" CC="gcc -std=c89" + @echo '' + @echo '*** C89 does not guarantee 64-bit integers for Lua.' + @echo '*** Make sure to compile all external Lua libraries' + @echo '*** with LUA_USE_C89 to ensure consistency' + @echo '' + +FreeBSD NetBSD OpenBSD freebsd: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX -DLUA_USE_READLINE -I/usr/include/edit" SYSLIBS="-Wl,-E -ledit" CC="cc" + +generic: $(ALL) + +ios: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_IOS" + +Linux linux: linux-noreadline + +linux-noreadline: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX" SYSLIBS="-Wl,-E -ldl" + +linux-readline: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX -DLUA_USE_READLINE" SYSLIBS="-Wl,-E -ldl -lreadline" + +Darwin macos macosx: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_MACOSX -DLUA_USE_READLINE" SYSLIBS="-lreadline" + +mingw: + $(MAKE) "LUA_A=lua54.dll" "LUA_T=lua.exe" \ + "AR=$(CC) -shared -o" "RANLIB=strip --strip-unneeded" \ + "SYSCFLAGS=-DLUA_BUILD_AS_DLL" "SYSLIBS=" "SYSLDFLAGS=-s" lua.exe + $(MAKE) "LUAC_T=luac.exe" luac.exe + +posix: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX" + +SunOS solaris: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX -DLUA_USE_DLOPEN -D_REENTRANT" SYSLIBS="-ldl" + +# Targets that do not create files (not all makes understand .PHONY). +.PHONY: all $(PLATS) help test clean default o a depend echo + +# Compiler modules may use special flags. +llex.o: + $(CC) $(CFLAGS) $(CMCFLAGS) -c llex.c + +lparser.o: + $(CC) $(CFLAGS) $(CMCFLAGS) -c lparser.c + +lcode.o: + $(CC) $(CFLAGS) $(CMCFLAGS) -c lcode.c + +# DO NOT DELETE + +lapi.o: lapi.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h lstring.h \ + ltable.h lundump.h lvm.h +lauxlib.o: lauxlib.c lprefix.h lua.h luaconf.h lauxlib.h +lbaselib.o: lbaselib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lcode.o: lcode.c lprefix.h lua.h luaconf.h lcode.h llex.h lobject.h \ + llimits.h lzio.h lmem.h lopcodes.h lparser.h ldebug.h lstate.h ltm.h \ + ldo.h lgc.h lstring.h ltable.h lvm.h +lcorolib.o: lcorolib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lctype.o: lctype.c lprefix.h lctype.h lua.h luaconf.h llimits.h +ldblib.o: ldblib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +ldebug.o: ldebug.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h lcode.h llex.h lopcodes.h lparser.h \ + ldebug.h ldo.h lfunc.h lstring.h lgc.h ltable.h lvm.h +ldo.o: ldo.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h lopcodes.h \ + lparser.h lstring.h ltable.h lundump.h lvm.h +ldump.o: ldump.c lprefix.h lua.h luaconf.h lobject.h llimits.h lstate.h \ + ltm.h lzio.h lmem.h lundump.h +lfunc.o: lfunc.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h +lgc.o: lgc.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h lstring.h ltable.h +linit.o: linit.c lprefix.h lua.h luaconf.h lualib.h lauxlib.h +liolib.o: liolib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +llex.o: llex.c lprefix.h lua.h luaconf.h lctype.h llimits.h ldebug.h \ + lstate.h lobject.h ltm.h lzio.h lmem.h ldo.h lgc.h llex.h lparser.h \ + lstring.h ltable.h +lmathlib.o: lmathlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lmem.o: lmem.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h +loadlib.o: loadlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lobject.o: lobject.c lprefix.h lua.h luaconf.h lctype.h llimits.h \ + ldebug.h lstate.h lobject.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h \ + lvm.h +lopcodes.o: lopcodes.c lprefix.h lopcodes.h llimits.h lua.h luaconf.h +loslib.o: loslib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lparser.o: lparser.c lprefix.h lua.h luaconf.h lcode.h llex.h lobject.h \ + llimits.h lzio.h lmem.h lopcodes.h lparser.h ldebug.h lstate.h ltm.h \ + ldo.h lfunc.h lstring.h lgc.h ltable.h +lstate.o: lstate.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h llex.h \ + lstring.h ltable.h +lstring.o: lstring.c lprefix.h lua.h luaconf.h ldebug.h lstate.h \ + lobject.h llimits.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h +lstrlib.o: lstrlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +ltable.o: ltable.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h lstring.h ltable.h lvm.h +ltablib.o: ltablib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +ltm.o: ltm.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h lstring.h ltable.h lvm.h +lua.o: lua.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +luac.o: luac.c lprefix.h lua.h luaconf.h lauxlib.h ldebug.h lstate.h \ + lobject.h llimits.h ltm.h lzio.h lmem.h lopcodes.h lopnames.h lundump.h +lundump.o: lundump.c lprefix.h lua.h luaconf.h ldebug.h lstate.h \ + lobject.h llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lstring.h lgc.h \ + lundump.h +lutf8lib.o: lutf8lib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lvm.o: lvm.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h lopcodes.h lstring.h \ + ltable.h lvm.h ljumptab.h +lzio.o: lzio.c lprefix.h lua.h luaconf.h llimits.h lmem.h lstate.h \ + lobject.h ltm.h lzio.h + +# (end of Makefile) diff --git a/src/lapi.c b/src/lapi.c new file mode 100644 index 0000000..34e64af --- /dev/null +++ b/src/lapi.c @@ -0,0 +1,1463 @@ +/* +** $Id: lapi.c $ +** Lua API +** See Copyright Notice in lua.h +*/ + +#define lapi_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lundump.h" +#include "lvm.h" + + + +const char lua_ident[] = + "$LuaVersion: " LUA_COPYRIGHT " $" + "$LuaAuthors: " LUA_AUTHORS " $"; + + + +/* +** Test for a valid index (one that is not the 'nilvalue'). +** '!ttisnil(o)' implies 'o != &G(L)->nilvalue', so it is not needed. +** However, it covers the most common cases in a faster way. +*/ +#define isvalid(L, o) (!ttisnil(o) || o != &G(L)->nilvalue) + + +/* test for pseudo index */ +#define ispseudo(i) ((i) <= LUA_REGISTRYINDEX) + +/* test for upvalue */ +#define isupvalue(i) ((i) < LUA_REGISTRYINDEX) + + +/* +** Convert an acceptable index to a pointer to its respective value. +** Non-valid indices return the special nil value 'G(L)->nilvalue'. +*/ +static TValue *index2value (lua_State *L, int idx) { + CallInfo *ci = L->ci; + if (idx > 0) { + StkId o = ci->func.p + idx; + api_check(L, idx <= ci->top.p - (ci->func.p + 1), "unacceptable index"); + if (o >= L->top.p) return &G(L)->nilvalue; + else return s2v(o); + } + else if (!ispseudo(idx)) { /* negative index */ + api_check(L, idx != 0 && -idx <= L->top.p - (ci->func.p + 1), + "invalid index"); + return s2v(L->top.p + idx); + } + else if (idx == LUA_REGISTRYINDEX) + return &G(L)->l_registry; + else { /* upvalues */ + idx = LUA_REGISTRYINDEX - idx; + api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large"); + if (ttisCclosure(s2v(ci->func.p))) { /* C closure? */ + CClosure *func = clCvalue(s2v(ci->func.p)); + return (idx <= func->nupvalues) ? &func->upvalue[idx-1] + : &G(L)->nilvalue; + } + else { /* light C function or Lua function (through a hook)?) */ + api_check(L, ttislcf(s2v(ci->func.p)), "caller not a C function"); + return &G(L)->nilvalue; /* no upvalues */ + } + } +} + + + +/* +** Convert a valid actual index (not a pseudo-index) to its address. +*/ +l_sinline StkId index2stack (lua_State *L, int idx) { + CallInfo *ci = L->ci; + if (idx > 0) { + StkId o = ci->func.p + idx; + api_check(L, o < L->top.p, "invalid index"); + return o; + } + else { /* non-positive index */ + api_check(L, idx != 0 && -idx <= L->top.p - (ci->func.p + 1), + "invalid index"); + api_check(L, !ispseudo(idx), "invalid index"); + return L->top.p + idx; + } +} + + +LUA_API int lua_checkstack (lua_State *L, int n) { + int res; + CallInfo *ci; + lua_lock(L); + ci = L->ci; + api_check(L, n >= 0, "negative 'n'"); + if (L->stack_last.p - L->top.p > n) /* stack large enough? */ + res = 1; /* yes; check is OK */ + else /* need to grow stack */ + res = luaD_growstack(L, n, 0); + if (res && ci->top.p < L->top.p + n) + ci->top.p = L->top.p + n; /* adjust frame top */ + lua_unlock(L); + return res; +} + + +LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) { + int i; + if (from == to) return; + lua_lock(to); + api_checknelems(from, n); + api_check(from, G(from) == G(to), "moving among independent states"); + api_check(from, to->ci->top.p - to->top.p >= n, "stack overflow"); + from->top.p -= n; + for (i = 0; i < n; i++) { + setobjs2s(to, to->top.p, from->top.p + i); + to->top.p++; /* stack already checked by previous 'api_check' */ + } + lua_unlock(to); +} + + +LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) { + lua_CFunction old; + lua_lock(L); + old = G(L)->panic; + G(L)->panic = panicf; + lua_unlock(L); + return old; +} + + +LUA_API lua_Number lua_version (lua_State *L) { + UNUSED(L); + return LUA_VERSION_NUM; +} + + + +/* +** basic stack manipulation +*/ + + +/* +** convert an acceptable stack index into an absolute index +*/ +LUA_API int lua_absindex (lua_State *L, int idx) { + return (idx > 0 || ispseudo(idx)) + ? idx + : cast_int(L->top.p - L->ci->func.p) + idx; +} + + +LUA_API int lua_gettop (lua_State *L) { + return cast_int(L->top.p - (L->ci->func.p + 1)); +} + + +LUA_API void lua_settop (lua_State *L, int idx) { + CallInfo *ci; + StkId func, newtop; + ptrdiff_t diff; /* difference for new top */ + lua_lock(L); + ci = L->ci; + func = ci->func.p; + if (idx >= 0) { + api_check(L, idx <= ci->top.p - (func + 1), "new top too large"); + diff = ((func + 1) + idx) - L->top.p; + for (; diff > 0; diff--) + setnilvalue(s2v(L->top.p++)); /* clear new slots */ + } + else { + api_check(L, -(idx+1) <= (L->top.p - (func + 1)), "invalid new top"); + diff = idx + 1; /* will "subtract" index (as it is negative) */ + } + api_check(L, L->tbclist.p < L->top.p, "previous pop of an unclosed slot"); + newtop = L->top.p + diff; + if (diff < 0 && L->tbclist.p >= newtop) { + lua_assert(hastocloseCfunc(ci->nresults)); + newtop = luaF_close(L, newtop, CLOSEKTOP, 0); + } + L->top.p = newtop; /* correct top only after closing any upvalue */ + lua_unlock(L); +} + + +LUA_API void lua_closeslot (lua_State *L, int idx) { + StkId level; + lua_lock(L); + level = index2stack(L, idx); + api_check(L, hastocloseCfunc(L->ci->nresults) && L->tbclist.p == level, + "no variable to close at given level"); + level = luaF_close(L, level, CLOSEKTOP, 0); + setnilvalue(s2v(level)); + lua_unlock(L); +} + + +/* +** Reverse the stack segment from 'from' to 'to' +** (auxiliary to 'lua_rotate') +** Note that we move(copy) only the value inside the stack. +** (We do not move additional fields that may exist.) +*/ +l_sinline void reverse (lua_State *L, StkId from, StkId to) { + for (; from < to; from++, to--) { + TValue temp; + setobj(L, &temp, s2v(from)); + setobjs2s(L, from, to); + setobj2s(L, to, &temp); + } +} + + +/* +** Let x = AB, where A is a prefix of length 'n'. Then, +** rotate x n == BA. But BA == (A^r . B^r)^r. +*/ +LUA_API void lua_rotate (lua_State *L, int idx, int n) { + StkId p, t, m; + lua_lock(L); + t = L->top.p - 1; /* end of stack segment being rotated */ + p = index2stack(L, idx); /* start of segment */ + api_check(L, (n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'"); + m = (n >= 0 ? t - n : p - n - 1); /* end of prefix */ + reverse(L, p, m); /* reverse the prefix with length 'n' */ + reverse(L, m + 1, t); /* reverse the suffix */ + reverse(L, p, t); /* reverse the entire segment */ + lua_unlock(L); +} + + +LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) { + TValue *fr, *to; + lua_lock(L); + fr = index2value(L, fromidx); + to = index2value(L, toidx); + api_check(L, isvalid(L, to), "invalid index"); + setobj(L, to, fr); + if (isupvalue(toidx)) /* function upvalue? */ + luaC_barrier(L, clCvalue(s2v(L->ci->func.p)), fr); + /* LUA_REGISTRYINDEX does not need gc barrier + (collector revisits it before finishing collection) */ + lua_unlock(L); +} + + +LUA_API void lua_pushvalue (lua_State *L, int idx) { + lua_lock(L); + setobj2s(L, L->top.p, index2value(L, idx)); + api_incr_top(L); + lua_unlock(L); +} + + + +/* +** access functions (stack -> C) +*/ + + +LUA_API int lua_type (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return (isvalid(L, o) ? ttype(o) : LUA_TNONE); +} + + +LUA_API const char *lua_typename (lua_State *L, int t) { + UNUSED(L); + api_check(L, LUA_TNONE <= t && t < LUA_NUMTYPES, "invalid type"); + return ttypename(t); +} + + +LUA_API int lua_iscfunction (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return (ttislcf(o) || (ttisCclosure(o))); +} + + +LUA_API int lua_isinteger (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return ttisinteger(o); +} + + +LUA_API int lua_isnumber (lua_State *L, int idx) { + lua_Number n; + const TValue *o = index2value(L, idx); + return tonumber(o, &n); +} + + +LUA_API int lua_isstring (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return (ttisstring(o) || cvt2str(o)); +} + + +LUA_API int lua_isuserdata (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return (ttisfulluserdata(o) || ttislightuserdata(o)); +} + + +LUA_API int lua_rawequal (lua_State *L, int index1, int index2) { + const TValue *o1 = index2value(L, index1); + const TValue *o2 = index2value(L, index2); + return (isvalid(L, o1) && isvalid(L, o2)) ? luaV_rawequalobj(o1, o2) : 0; +} + + +LUA_API void lua_arith (lua_State *L, int op) { + lua_lock(L); + if (op != LUA_OPUNM && op != LUA_OPBNOT) + api_checknelems(L, 2); /* all other operations expect two operands */ + else { /* for unary operations, add fake 2nd operand */ + api_checknelems(L, 1); + setobjs2s(L, L->top.p, L->top.p - 1); + api_incr_top(L); + } + /* first operand at top - 2, second at top - 1; result go to top - 2 */ + luaO_arith(L, op, s2v(L->top.p - 2), s2v(L->top.p - 1), L->top.p - 2); + L->top.p--; /* remove second operand */ + lua_unlock(L); +} + + +LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) { + const TValue *o1; + const TValue *o2; + int i = 0; + lua_lock(L); /* may call tag method */ + o1 = index2value(L, index1); + o2 = index2value(L, index2); + if (isvalid(L, o1) && isvalid(L, o2)) { + switch (op) { + case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break; + case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break; + case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break; + default: api_check(L, 0, "invalid option"); + } + } + lua_unlock(L); + return i; +} + + +LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) { + size_t sz = luaO_str2num(s, s2v(L->top.p)); + if (sz != 0) + api_incr_top(L); + return sz; +} + + +LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) { + lua_Number n = 0; + const TValue *o = index2value(L, idx); + int isnum = tonumber(o, &n); + if (pisnum) + *pisnum = isnum; + return n; +} + + +LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum) { + lua_Integer res = 0; + const TValue *o = index2value(L, idx); + int isnum = tointeger(o, &res); + if (pisnum) + *pisnum = isnum; + return res; +} + + +LUA_API int lua_toboolean (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return !l_isfalse(o); +} + + +LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) { + TValue *o; + lua_lock(L); + o = index2value(L, idx); + if (!ttisstring(o)) { + if (!cvt2str(o)) { /* not convertible? */ + if (len != NULL) *len = 0; + lua_unlock(L); + return NULL; + } + luaO_tostring(L, o); + luaC_checkGC(L); + o = index2value(L, idx); /* previous call may reallocate the stack */ + } + if (len != NULL) + *len = vslen(o); + lua_unlock(L); + return svalue(o); +} + + +LUA_API lua_Unsigned lua_rawlen (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + switch (ttypetag(o)) { + case LUA_VSHRSTR: return tsvalue(o)->shrlen; + case LUA_VLNGSTR: return tsvalue(o)->u.lnglen; + case LUA_VUSERDATA: return uvalue(o)->len; + case LUA_VTABLE: return luaH_getn(hvalue(o)); + default: return 0; + } +} + + +LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + if (ttislcf(o)) return fvalue(o); + else if (ttisCclosure(o)) + return clCvalue(o)->f; + else return NULL; /* not a C function */ +} + + +l_sinline void *touserdata (const TValue *o) { + switch (ttype(o)) { + case LUA_TUSERDATA: return getudatamem(uvalue(o)); + case LUA_TLIGHTUSERDATA: return pvalue(o); + default: return NULL; + } +} + + +LUA_API void *lua_touserdata (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return touserdata(o); +} + + +LUA_API lua_State *lua_tothread (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + return (!ttisthread(o)) ? NULL : thvalue(o); +} + + +/* +** Returns a pointer to the internal representation of an object. +** Note that ANSI C does not allow the conversion of a pointer to +** function to a 'void*', so the conversion here goes through +** a 'size_t'. (As the returned pointer is only informative, this +** conversion should not be a problem.) +*/ +LUA_API const void *lua_topointer (lua_State *L, int idx) { + const TValue *o = index2value(L, idx); + switch (ttypetag(o)) { + case LUA_VLCF: return cast_voidp(cast_sizet(fvalue(o))); + case LUA_VUSERDATA: case LUA_VLIGHTUSERDATA: + return touserdata(o); + default: { + if (iscollectable(o)) + return gcvalue(o); + else + return NULL; + } + } +} + + + +/* +** push functions (C -> stack) +*/ + + +LUA_API void lua_pushnil (lua_State *L) { + lua_lock(L); + setnilvalue(s2v(L->top.p)); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushnumber (lua_State *L, lua_Number n) { + lua_lock(L); + setfltvalue(s2v(L->top.p), n); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) { + lua_lock(L); + setivalue(s2v(L->top.p), n); + api_incr_top(L); + lua_unlock(L); +} + + +/* +** Pushes on the stack a string with given length. Avoid using 's' when +** 'len' == 0 (as 's' can be NULL in that case), due to later use of +** 'memcmp' and 'memcpy'. +*/ +LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) { + TString *ts; + lua_lock(L); + ts = (len == 0) ? luaS_new(L, "") : luaS_newlstr(L, s, len); + setsvalue2s(L, L->top.p, ts); + api_incr_top(L); + luaC_checkGC(L); + lua_unlock(L); + return getstr(ts); +} + + +LUA_API const char *lua_pushstring (lua_State *L, const char *s) { + lua_lock(L); + if (s == NULL) + setnilvalue(s2v(L->top.p)); + else { + TString *ts; + ts = luaS_new(L, s); + setsvalue2s(L, L->top.p, ts); + s = getstr(ts); /* internal copy's address */ + } + api_incr_top(L); + luaC_checkGC(L); + lua_unlock(L); + return s; +} + + +LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt, + va_list argp) { + const char *ret; + lua_lock(L); + ret = luaO_pushvfstring(L, fmt, argp); + luaC_checkGC(L); + lua_unlock(L); + return ret; +} + + +LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) { + const char *ret; + va_list argp; + lua_lock(L); + va_start(argp, fmt); + ret = luaO_pushvfstring(L, fmt, argp); + va_end(argp); + luaC_checkGC(L); + lua_unlock(L); + return ret; +} + + +LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) { + lua_lock(L); + if (n == 0) { + setfvalue(s2v(L->top.p), fn); + api_incr_top(L); + } + else { + CClosure *cl; + api_checknelems(L, n); + api_check(L, n <= MAXUPVAL, "upvalue index too large"); + cl = luaF_newCclosure(L, n); + cl->f = fn; + L->top.p -= n; + while (n--) { + setobj2n(L, &cl->upvalue[n], s2v(L->top.p + n)); + /* does not need barrier because closure is white */ + lua_assert(iswhite(cl)); + } + setclCvalue(L, s2v(L->top.p), cl); + api_incr_top(L); + luaC_checkGC(L); + } + lua_unlock(L); +} + + +LUA_API void lua_pushboolean (lua_State *L, int b) { + lua_lock(L); + if (b) + setbtvalue(s2v(L->top.p)); + else + setbfvalue(s2v(L->top.p)); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushlightuserdata (lua_State *L, void *p) { + lua_lock(L); + setpvalue(s2v(L->top.p), p); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API int lua_pushthread (lua_State *L) { + lua_lock(L); + setthvalue(L, s2v(L->top.p), L); + api_incr_top(L); + lua_unlock(L); + return (G(L)->mainthread == L); +} + + + +/* +** get functions (Lua -> stack) +*/ + + +l_sinline int auxgetstr (lua_State *L, const TValue *t, const char *k) { + const TValue *slot; + TString *str = luaS_new(L, k); + if (luaV_fastget(L, t, str, slot, luaH_getstr)) { + setobj2s(L, L->top.p, slot); + api_incr_top(L); + } + else { + setsvalue2s(L, L->top.p, str); + api_incr_top(L); + luaV_finishget(L, t, s2v(L->top.p - 1), L->top.p - 1, slot); + } + lua_unlock(L); + return ttype(s2v(L->top.p - 1)); +} + + +/* +** Get the global table in the registry. Since all predefined +** indices in the registry were inserted right when the registry +** was created and never removed, they must always be in the array +** part of the registry. +*/ +#define getGtable(L) \ + (&hvalue(&G(L)->l_registry)->array[LUA_RIDX_GLOBALS - 1]) + + +LUA_API int lua_getglobal (lua_State *L, const char *name) { + const TValue *G; + lua_lock(L); + G = getGtable(L); + return auxgetstr(L, G, name); +} + + +LUA_API int lua_gettable (lua_State *L, int idx) { + const TValue *slot; + TValue *t; + lua_lock(L); + t = index2value(L, idx); + if (luaV_fastget(L, t, s2v(L->top.p - 1), slot, luaH_get)) { + setobj2s(L, L->top.p - 1, slot); + } + else + luaV_finishget(L, t, s2v(L->top.p - 1), L->top.p - 1, slot); + lua_unlock(L); + return ttype(s2v(L->top.p - 1)); +} + + +LUA_API int lua_getfield (lua_State *L, int idx, const char *k) { + lua_lock(L); + return auxgetstr(L, index2value(L, idx), k); +} + + +LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) { + TValue *t; + const TValue *slot; + lua_lock(L); + t = index2value(L, idx); + if (luaV_fastgeti(L, t, n, slot)) { + setobj2s(L, L->top.p, slot); + } + else { + TValue aux; + setivalue(&aux, n); + luaV_finishget(L, t, &aux, L->top.p, slot); + } + api_incr_top(L); + lua_unlock(L); + return ttype(s2v(L->top.p - 1)); +} + + +l_sinline int finishrawget (lua_State *L, const TValue *val) { + if (isempty(val)) /* avoid copying empty items to the stack */ + setnilvalue(s2v(L->top.p)); + else + setobj2s(L, L->top.p, val); + api_incr_top(L); + lua_unlock(L); + return ttype(s2v(L->top.p - 1)); +} + + +static Table *gettable (lua_State *L, int idx) { + TValue *t = index2value(L, idx); + api_check(L, ttistable(t), "table expected"); + return hvalue(t); +} + + +LUA_API int lua_rawget (lua_State *L, int idx) { + Table *t; + const TValue *val; + lua_lock(L); + api_checknelems(L, 1); + t = gettable(L, idx); + val = luaH_get(t, s2v(L->top.p - 1)); + L->top.p--; /* remove key */ + return finishrawget(L, val); +} + + +LUA_API int lua_rawgeti (lua_State *L, int idx, lua_Integer n) { + Table *t; + lua_lock(L); + t = gettable(L, idx); + return finishrawget(L, luaH_getint(t, n)); +} + + +LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) { + Table *t; + TValue k; + lua_lock(L); + t = gettable(L, idx); + setpvalue(&k, cast_voidp(p)); + return finishrawget(L, luaH_get(t, &k)); +} + + +LUA_API void lua_createtable (lua_State *L, int narray, int nrec) { + Table *t; + lua_lock(L); + t = luaH_new(L); + sethvalue2s(L, L->top.p, t); + api_incr_top(L); + if (narray > 0 || nrec > 0) + luaH_resize(L, t, narray, nrec); + luaC_checkGC(L); + lua_unlock(L); +} + + +LUA_API int lua_getmetatable (lua_State *L, int objindex) { + const TValue *obj; + Table *mt; + int res = 0; + lua_lock(L); + obj = index2value(L, objindex); + switch (ttype(obj)) { + case LUA_TTABLE: + mt = hvalue(obj)->metatable; + break; + case LUA_TUSERDATA: + mt = uvalue(obj)->metatable; + break; + default: + mt = G(L)->mt[ttype(obj)]; + break; + } + if (mt != NULL) { + sethvalue2s(L, L->top.p, mt); + api_incr_top(L); + res = 1; + } + lua_unlock(L); + return res; +} + + +LUA_API int lua_getiuservalue (lua_State *L, int idx, int n) { + TValue *o; + int t; + lua_lock(L); + o = index2value(L, idx); + api_check(L, ttisfulluserdata(o), "full userdata expected"); + if (n <= 0 || n > uvalue(o)->nuvalue) { + setnilvalue(s2v(L->top.p)); + t = LUA_TNONE; + } + else { + setobj2s(L, L->top.p, &uvalue(o)->uv[n - 1].uv); + t = ttype(s2v(L->top.p)); + } + api_incr_top(L); + lua_unlock(L); + return t; +} + + +/* +** set functions (stack -> Lua) +*/ + +/* +** t[k] = value at the top of the stack (where 'k' is a string) +*/ +static void auxsetstr (lua_State *L, const TValue *t, const char *k) { + const TValue *slot; + TString *str = luaS_new(L, k); + api_checknelems(L, 1); + if (luaV_fastget(L, t, str, slot, luaH_getstr)) { + luaV_finishfastset(L, t, slot, s2v(L->top.p - 1)); + L->top.p--; /* pop value */ + } + else { + setsvalue2s(L, L->top.p, str); /* push 'str' (to make it a TValue) */ + api_incr_top(L); + luaV_finishset(L, t, s2v(L->top.p - 1), s2v(L->top.p - 2), slot); + L->top.p -= 2; /* pop value and key */ + } + lua_unlock(L); /* lock done by caller */ +} + + +LUA_API void lua_setglobal (lua_State *L, const char *name) { + const TValue *G; + lua_lock(L); /* unlock done in 'auxsetstr' */ + G = getGtable(L); + auxsetstr(L, G, name); +} + + +LUA_API void lua_settable (lua_State *L, int idx) { + TValue *t; + const TValue *slot; + lua_lock(L); + api_checknelems(L, 2); + t = index2value(L, idx); + if (luaV_fastget(L, t, s2v(L->top.p - 2), slot, luaH_get)) { + luaV_finishfastset(L, t, slot, s2v(L->top.p - 1)); + } + else + luaV_finishset(L, t, s2v(L->top.p - 2), s2v(L->top.p - 1), slot); + L->top.p -= 2; /* pop index and value */ + lua_unlock(L); +} + + +LUA_API void lua_setfield (lua_State *L, int idx, const char *k) { + lua_lock(L); /* unlock done in 'auxsetstr' */ + auxsetstr(L, index2value(L, idx), k); +} + + +LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) { + TValue *t; + const TValue *slot; + lua_lock(L); + api_checknelems(L, 1); + t = index2value(L, idx); + if (luaV_fastgeti(L, t, n, slot)) { + luaV_finishfastset(L, t, slot, s2v(L->top.p - 1)); + } + else { + TValue aux; + setivalue(&aux, n); + luaV_finishset(L, t, &aux, s2v(L->top.p - 1), slot); + } + L->top.p--; /* pop value */ + lua_unlock(L); +} + + +static void aux_rawset (lua_State *L, int idx, TValue *key, int n) { + Table *t; + lua_lock(L); + api_checknelems(L, n); + t = gettable(L, idx); + luaH_set(L, t, key, s2v(L->top.p - 1)); + invalidateTMcache(t); + luaC_barrierback(L, obj2gco(t), s2v(L->top.p - 1)); + L->top.p -= n; + lua_unlock(L); +} + + +LUA_API void lua_rawset (lua_State *L, int idx) { + aux_rawset(L, idx, s2v(L->top.p - 2), 2); +} + + +LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) { + TValue k; + setpvalue(&k, cast_voidp(p)); + aux_rawset(L, idx, &k, 1); +} + + +LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) { + Table *t; + lua_lock(L); + api_checknelems(L, 1); + t = gettable(L, idx); + luaH_setint(L, t, n, s2v(L->top.p - 1)); + luaC_barrierback(L, obj2gco(t), s2v(L->top.p - 1)); + L->top.p--; + lua_unlock(L); +} + + +LUA_API int lua_setmetatable (lua_State *L, int objindex) { + TValue *obj; + Table *mt; + lua_lock(L); + api_checknelems(L, 1); + obj = index2value(L, objindex); + if (ttisnil(s2v(L->top.p - 1))) + mt = NULL; + else { + api_check(L, ttistable(s2v(L->top.p - 1)), "table expected"); + mt = hvalue(s2v(L->top.p - 1)); + } + switch (ttype(obj)) { + case LUA_TTABLE: { + hvalue(obj)->metatable = mt; + if (mt) { + luaC_objbarrier(L, gcvalue(obj), mt); + luaC_checkfinalizer(L, gcvalue(obj), mt); + } + break; + } + case LUA_TUSERDATA: { + uvalue(obj)->metatable = mt; + if (mt) { + luaC_objbarrier(L, uvalue(obj), mt); + luaC_checkfinalizer(L, gcvalue(obj), mt); + } + break; + } + default: { + G(L)->mt[ttype(obj)] = mt; + break; + } + } + L->top.p--; + lua_unlock(L); + return 1; +} + + +LUA_API int lua_setiuservalue (lua_State *L, int idx, int n) { + TValue *o; + int res; + lua_lock(L); + api_checknelems(L, 1); + o = index2value(L, idx); + api_check(L, ttisfulluserdata(o), "full userdata expected"); + if (!(cast_uint(n) - 1u < cast_uint(uvalue(o)->nuvalue))) + res = 0; /* 'n' not in [1, uvalue(o)->nuvalue] */ + else { + setobj(L, &uvalue(o)->uv[n - 1].uv, s2v(L->top.p - 1)); + luaC_barrierback(L, gcvalue(o), s2v(L->top.p - 1)); + res = 1; + } + L->top.p--; + lua_unlock(L); + return res; +} + + +/* +** 'load' and 'call' functions (run Lua code) +*/ + + +#define checkresults(L,na,nr) \ + api_check(L, (nr) == LUA_MULTRET \ + || (L->ci->top.p - L->top.p >= (nr) - (na)), \ + "results from function overflow current stack size") + + +LUA_API void lua_callk (lua_State *L, int nargs, int nresults, + lua_KContext ctx, lua_KFunction k) { + StkId func; + lua_lock(L); + api_check(L, k == NULL || !isLua(L->ci), + "cannot use continuations inside hooks"); + api_checknelems(L, nargs+1); + api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread"); + checkresults(L, nargs, nresults); + func = L->top.p - (nargs+1); + if (k != NULL && yieldable(L)) { /* need to prepare continuation? */ + L->ci->u.c.k = k; /* save continuation */ + L->ci->u.c.ctx = ctx; /* save context */ + luaD_call(L, func, nresults); /* do the call */ + } + else /* no continuation or no yieldable */ + luaD_callnoyield(L, func, nresults); /* just do the call */ + adjustresults(L, nresults); + lua_unlock(L); +} + + + +/* +** Execute a protected call. +*/ +struct CallS { /* data to 'f_call' */ + StkId func; + int nresults; +}; + + +static void f_call (lua_State *L, void *ud) { + struct CallS *c = cast(struct CallS *, ud); + luaD_callnoyield(L, c->func, c->nresults); +} + + + +LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc, + lua_KContext ctx, lua_KFunction k) { + struct CallS c; + int status; + ptrdiff_t func; + lua_lock(L); + api_check(L, k == NULL || !isLua(L->ci), + "cannot use continuations inside hooks"); + api_checknelems(L, nargs+1); + api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread"); + checkresults(L, nargs, nresults); + if (errfunc == 0) + func = 0; + else { + StkId o = index2stack(L, errfunc); + api_check(L, ttisfunction(s2v(o)), "error handler must be a function"); + func = savestack(L, o); + } + c.func = L->top.p - (nargs+1); /* function to be called */ + if (k == NULL || !yieldable(L)) { /* no continuation or no yieldable? */ + c.nresults = nresults; /* do a 'conventional' protected call */ + status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func); + } + else { /* prepare continuation (call is already protected by 'resume') */ + CallInfo *ci = L->ci; + ci->u.c.k = k; /* save continuation */ + ci->u.c.ctx = ctx; /* save context */ + /* save information for error recovery */ + ci->u2.funcidx = cast_int(savestack(L, c.func)); + ci->u.c.old_errfunc = L->errfunc; + L->errfunc = func; + setoah(ci->callstatus, L->allowhook); /* save value of 'allowhook' */ + ci->callstatus |= CIST_YPCALL; /* function can do error recovery */ + luaD_call(L, c.func, nresults); /* do the call */ + ci->callstatus &= ~CIST_YPCALL; + L->errfunc = ci->u.c.old_errfunc; + status = LUA_OK; /* if it is here, there were no errors */ + } + adjustresults(L, nresults); + lua_unlock(L); + return status; +} + + +LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data, + const char *chunkname, const char *mode) { + ZIO z; + int status; + lua_lock(L); + if (!chunkname) chunkname = "?"; + luaZ_init(L, &z, reader, data); + status = luaD_protectedparser(L, &z, chunkname, mode); + if (status == LUA_OK) { /* no errors? */ + LClosure *f = clLvalue(s2v(L->top.p - 1)); /* get new function */ + if (f->nupvalues >= 1) { /* does it have an upvalue? */ + /* get global table from registry */ + const TValue *gt = getGtable(L); + /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */ + setobj(L, f->upvals[0]->v.p, gt); + luaC_barrier(L, f->upvals[0], gt); + } + } + lua_unlock(L); + return status; +} + + +LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) { + int status; + TValue *o; + lua_lock(L); + api_checknelems(L, 1); + o = s2v(L->top.p - 1); + if (isLfunction(o)) + status = luaU_dump(L, getproto(o), writer, data, strip); + else + status = 1; + lua_unlock(L); + return status; +} + + +LUA_API int lua_status (lua_State *L) { + return L->status; +} + + +/* +** Garbage-collection function +*/ +LUA_API int lua_gc (lua_State *L, int what, ...) { + va_list argp; + int res = 0; + global_State *g = G(L); + if (g->gcstp & GCSTPGC) /* internal stop? */ + return -1; /* all options are invalid when stopped */ + lua_lock(L); + va_start(argp, what); + switch (what) { + case LUA_GCSTOP: { + g->gcstp = GCSTPUSR; /* stopped by the user */ + break; + } + case LUA_GCRESTART: { + luaE_setdebt(g, 0); + g->gcstp = 0; /* (GCSTPGC must be already zero here) */ + break; + } + case LUA_GCCOLLECT: { + luaC_fullgc(L, 0); + break; + } + case LUA_GCCOUNT: { + /* GC values are expressed in Kbytes: #bytes/2^10 */ + res = cast_int(gettotalbytes(g) >> 10); + break; + } + case LUA_GCCOUNTB: { + res = cast_int(gettotalbytes(g) & 0x3ff); + break; + } + case LUA_GCSTEP: { + int data = va_arg(argp, int); + l_mem debt = 1; /* =1 to signal that it did an actual step */ + lu_byte oldstp = g->gcstp; + g->gcstp = 0; /* allow GC to run (GCSTPGC must be zero here) */ + if (data == 0) { + luaE_setdebt(g, 0); /* do a basic step */ + luaC_step(L); + } + else { /* add 'data' to total debt */ + debt = cast(l_mem, data) * 1024 + g->GCdebt; + luaE_setdebt(g, debt); + luaC_checkGC(L); + } + g->gcstp = oldstp; /* restore previous state */ + if (debt > 0 && g->gcstate == GCSpause) /* end of cycle? */ + res = 1; /* signal it */ + break; + } + case LUA_GCSETPAUSE: { + int data = va_arg(argp, int); + res = getgcparam(g->gcpause); + setgcparam(g->gcpause, data); + break; + } + case LUA_GCSETSTEPMUL: { + int data = va_arg(argp, int); + res = getgcparam(g->gcstepmul); + setgcparam(g->gcstepmul, data); + break; + } + case LUA_GCISRUNNING: { + res = gcrunning(g); + break; + } + case LUA_GCGEN: { + int minormul = va_arg(argp, int); + int majormul = va_arg(argp, int); + res = isdecGCmodegen(g) ? LUA_GCGEN : LUA_GCINC; + if (minormul != 0) + g->genminormul = minormul; + if (majormul != 0) + setgcparam(g->genmajormul, majormul); + luaC_changemode(L, KGC_GEN); + break; + } + case LUA_GCINC: { + int pause = va_arg(argp, int); + int stepmul = va_arg(argp, int); + int stepsize = va_arg(argp, int); + res = isdecGCmodegen(g) ? LUA_GCGEN : LUA_GCINC; + if (pause != 0) + setgcparam(g->gcpause, pause); + if (stepmul != 0) + setgcparam(g->gcstepmul, stepmul); + if (stepsize != 0) + g->gcstepsize = stepsize; + luaC_changemode(L, KGC_INC); + break; + } + default: res = -1; /* invalid option */ + } + va_end(argp); + lua_unlock(L); + return res; +} + + + +/* +** miscellaneous functions +*/ + + +LUA_API int lua_error (lua_State *L) { + TValue *errobj; + lua_lock(L); + errobj = s2v(L->top.p - 1); + api_checknelems(L, 1); + /* error object is the memory error message? */ + if (ttisshrstring(errobj) && eqshrstr(tsvalue(errobj), G(L)->memerrmsg)) + luaM_error(L); /* raise a memory error */ + else + luaG_errormsg(L); /* raise a regular error */ + /* code unreachable; will unlock when control actually leaves the kernel */ + return 0; /* to avoid warnings */ +} + + +LUA_API int lua_next (lua_State *L, int idx) { + Table *t; + int more; + lua_lock(L); + api_checknelems(L, 1); + t = gettable(L, idx); + more = luaH_next(L, t, L->top.p - 1); + if (more) { + api_incr_top(L); + } + else /* no more elements */ + L->top.p -= 1; /* remove key */ + lua_unlock(L); + return more; +} + + +LUA_API void lua_toclose (lua_State *L, int idx) { + int nresults; + StkId o; + lua_lock(L); + o = index2stack(L, idx); + nresults = L->ci->nresults; + api_check(L, L->tbclist.p < o, "given index below or equal a marked one"); + luaF_newtbcupval(L, o); /* create new to-be-closed upvalue */ + if (!hastocloseCfunc(nresults)) /* function not marked yet? */ + L->ci->nresults = codeNresults(nresults); /* mark it */ + lua_assert(hastocloseCfunc(L->ci->nresults)); + lua_unlock(L); +} + + +LUA_API void lua_concat (lua_State *L, int n) { + lua_lock(L); + api_checknelems(L, n); + if (n > 0) + luaV_concat(L, n); + else { /* nothing to concatenate */ + setsvalue2s(L, L->top.p, luaS_newlstr(L, "", 0)); /* push empty string */ + api_incr_top(L); + } + luaC_checkGC(L); + lua_unlock(L); +} + + +LUA_API void lua_len (lua_State *L, int idx) { + TValue *t; + lua_lock(L); + t = index2value(L, idx); + luaV_objlen(L, L->top.p, t); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) { + lua_Alloc f; + lua_lock(L); + if (ud) *ud = G(L)->ud; + f = G(L)->frealloc; + lua_unlock(L); + return f; +} + + +LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) { + lua_lock(L); + G(L)->ud = ud; + G(L)->frealloc = f; + lua_unlock(L); +} + + +void lua_setwarnf (lua_State *L, lua_WarnFunction f, void *ud) { + lua_lock(L); + G(L)->ud_warn = ud; + G(L)->warnf = f; + lua_unlock(L); +} + + +void lua_warning (lua_State *L, const char *msg, int tocont) { + lua_lock(L); + luaE_warning(L, msg, tocont); + lua_unlock(L); +} + + + +LUA_API void *lua_newuserdatauv (lua_State *L, size_t size, int nuvalue) { + Udata *u; + lua_lock(L); + api_check(L, 0 <= nuvalue && nuvalue < USHRT_MAX, "invalid value"); + u = luaS_newudata(L, size, nuvalue); + setuvalue(L, s2v(L->top.p), u); + api_incr_top(L); + luaC_checkGC(L); + lua_unlock(L); + return getudatamem(u); +} + + + +static const char *aux_upvalue (TValue *fi, int n, TValue **val, + GCObject **owner) { + switch (ttypetag(fi)) { + case LUA_VCCL: { /* C closure */ + CClosure *f = clCvalue(fi); + if (!(cast_uint(n) - 1u < cast_uint(f->nupvalues))) + return NULL; /* 'n' not in [1, f->nupvalues] */ + *val = &f->upvalue[n-1]; + if (owner) *owner = obj2gco(f); + return ""; + } + case LUA_VLCL: { /* Lua closure */ + LClosure *f = clLvalue(fi); + TString *name; + Proto *p = f->p; + if (!(cast_uint(n) - 1u < cast_uint(p->sizeupvalues))) + return NULL; /* 'n' not in [1, p->sizeupvalues] */ + *val = f->upvals[n-1]->v.p; + if (owner) *owner = obj2gco(f->upvals[n - 1]); + name = p->upvalues[n-1].name; + return (name == NULL) ? "(no name)" : getstr(name); + } + default: return NULL; /* not a closure */ + } +} + + +LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) { + const char *name; + TValue *val = NULL; /* to avoid warnings */ + lua_lock(L); + name = aux_upvalue(index2value(L, funcindex), n, &val, NULL); + if (name) { + setobj2s(L, L->top.p, val); + api_incr_top(L); + } + lua_unlock(L); + return name; +} + + +LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) { + const char *name; + TValue *val = NULL; /* to avoid warnings */ + GCObject *owner = NULL; /* to avoid warnings */ + TValue *fi; + lua_lock(L); + fi = index2value(L, funcindex); + api_checknelems(L, 1); + name = aux_upvalue(fi, n, &val, &owner); + if (name) { + L->top.p--; + setobj(L, val, s2v(L->top.p)); + luaC_barrier(L, owner, val); + } + lua_unlock(L); + return name; +} + + +static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) { + static const UpVal *const nullup = NULL; + LClosure *f; + TValue *fi = index2value(L, fidx); + api_check(L, ttisLclosure(fi), "Lua function expected"); + f = clLvalue(fi); + if (pf) *pf = f; + if (1 <= n && n <= f->p->sizeupvalues) + return &f->upvals[n - 1]; /* get its upvalue pointer */ + else + return (UpVal**)&nullup; +} + + +LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) { + TValue *fi = index2value(L, fidx); + switch (ttypetag(fi)) { + case LUA_VLCL: { /* lua closure */ + return *getupvalref(L, fidx, n, NULL); + } + case LUA_VCCL: { /* C closure */ + CClosure *f = clCvalue(fi); + if (1 <= n && n <= f->nupvalues) + return &f->upvalue[n - 1]; + /* else */ + } /* FALLTHROUGH */ + case LUA_VLCF: + return NULL; /* light C functions have no upvalues */ + default: { + api_check(L, 0, "function expected"); + return NULL; + } + } +} + + +LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1, + int fidx2, int n2) { + LClosure *f1; + UpVal **up1 = getupvalref(L, fidx1, n1, &f1); + UpVal **up2 = getupvalref(L, fidx2, n2, NULL); + api_check(L, *up1 != NULL && *up2 != NULL, "invalid upvalue index"); + *up1 = *up2; + luaC_objbarrier(L, f1, *up1); +} + + diff --git a/src/lapi.h b/src/lapi.h new file mode 100644 index 0000000..a742427 --- /dev/null +++ b/src/lapi.h @@ -0,0 +1,52 @@ +/* +** $Id: lapi.h $ +** Auxiliary functions from Lua API +** See Copyright Notice in lua.h +*/ + +#ifndef lapi_h +#define lapi_h + + +#include "llimits.h" +#include "lstate.h" + + +/* Increments 'L->top.p', checking for stack overflows */ +#define api_incr_top(L) {L->top.p++; \ + api_check(L, L->top.p <= L->ci->top.p, \ + "stack overflow");} + + +/* +** If a call returns too many multiple returns, the callee may not have +** stack space to accommodate all results. In this case, this macro +** increases its stack space ('L->ci->top.p'). +*/ +#define adjustresults(L,nres) \ + { if ((nres) <= LUA_MULTRET && L->ci->top.p < L->top.p) \ + L->ci->top.p = L->top.p; } + + +/* Ensure the stack has at least 'n' elements */ +#define api_checknelems(L,n) \ + api_check(L, (n) < (L->top.p - L->ci->func.p), \ + "not enough elements in the stack") + + +/* +** To reduce the overhead of returning from C functions, the presence of +** to-be-closed variables in these functions is coded in the CallInfo's +** field 'nresults', in a way that functions with no to-be-closed variables +** with zero, one, or "all" wanted results have no overhead. Functions +** with other number of wanted results, as well as functions with +** variables to be closed, have an extra check. +*/ + +#define hastocloseCfunc(n) ((n) < LUA_MULTRET) + +/* Map [-1, inf) (range of 'nresults') into (-inf, -2] */ +#define codeNresults(n) (-(n) - 3) +#define decodeNresults(n) (-(n) - 3) + +#endif diff --git a/src/lauxlib.c b/src/lauxlib.c new file mode 100644 index 0000000..4ca6c65 --- /dev/null +++ b/src/lauxlib.c @@ -0,0 +1,1112 @@ +/* +** $Id: lauxlib.c $ +** Auxiliary functions for building Lua libraries +** See Copyright Notice in lua.h +*/ + +#define lauxlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include +#include + + +/* +** This file uses only the official API of Lua. +** Any function declared here could be written as an application function. +*/ + +#include "lua.h" + +#include "lauxlib.h" + + +#if !defined(MAX_SIZET) +/* maximum value for size_t */ +#define MAX_SIZET ((size_t)(~(size_t)0)) +#endif + + +/* +** {====================================================== +** Traceback +** ======================================================= +*/ + + +#define LEVELS1 10 /* size of the first part of the stack */ +#define LEVELS2 11 /* size of the second part of the stack */ + + + +/* +** Search for 'objidx' in table at index -1. ('objidx' must be an +** absolute index.) Return 1 + string at top if it found a good name. +*/ +static int findfield (lua_State *L, int objidx, int level) { + if (level == 0 || !lua_istable(L, -1)) + return 0; /* not found */ + lua_pushnil(L); /* start 'next' loop */ + while (lua_next(L, -2)) { /* for each pair in table */ + if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */ + if (lua_rawequal(L, objidx, -1)) { /* found object? */ + lua_pop(L, 1); /* remove value (but keep name) */ + return 1; + } + else if (findfield(L, objidx, level - 1)) { /* try recursively */ + /* stack: lib_name, lib_table, field_name (top) */ + lua_pushliteral(L, "."); /* place '.' between the two names */ + lua_replace(L, -3); /* (in the slot occupied by table) */ + lua_concat(L, 3); /* lib_name.field_name */ + return 1; + } + } + lua_pop(L, 1); /* remove value */ + } + return 0; /* not found */ +} + + +/* +** Search for a name for a function in all loaded modules +*/ +static int pushglobalfuncname (lua_State *L, lua_Debug *ar) { + int top = lua_gettop(L); + lua_getinfo(L, "f", ar); /* push function */ + lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); + if (findfield(L, top + 1, 2)) { + const char *name = lua_tostring(L, -1); + if (strncmp(name, LUA_GNAME ".", 3) == 0) { /* name start with '_G.'? */ + lua_pushstring(L, name + 3); /* push name without prefix */ + lua_remove(L, -2); /* remove original name */ + } + lua_copy(L, -1, top + 1); /* copy name to proper place */ + lua_settop(L, top + 1); /* remove table "loaded" and name copy */ + return 1; + } + else { + lua_settop(L, top); /* remove function and global table */ + return 0; + } +} + + +static void pushfuncname (lua_State *L, lua_Debug *ar) { + if (pushglobalfuncname(L, ar)) { /* try first a global name */ + lua_pushfstring(L, "function '%s'", lua_tostring(L, -1)); + lua_remove(L, -2); /* remove name */ + } + else if (*ar->namewhat != '\0') /* is there a name from code? */ + lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name); /* use it */ + else if (*ar->what == 'm') /* main? */ + lua_pushliteral(L, "main chunk"); + else if (*ar->what != 'C') /* for Lua functions, use */ + lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined); + else /* nothing left... */ + lua_pushliteral(L, "?"); +} + + +static int lastlevel (lua_State *L) { + lua_Debug ar; + int li = 1, le = 1; + /* find an upper bound */ + while (lua_getstack(L, le, &ar)) { li = le; le *= 2; } + /* do a binary search */ + while (li < le) { + int m = (li + le)/2; + if (lua_getstack(L, m, &ar)) li = m + 1; + else le = m; + } + return le - 1; +} + + +LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, + const char *msg, int level) { + luaL_Buffer b; + lua_Debug ar; + int last = lastlevel(L1); + int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1; + luaL_buffinit(L, &b); + if (msg) { + luaL_addstring(&b, msg); + luaL_addchar(&b, '\n'); + } + luaL_addstring(&b, "stack traceback:"); + while (lua_getstack(L1, level++, &ar)) { + if (limit2show-- == 0) { /* too many levels? */ + int n = last - level - LEVELS2 + 1; /* number of levels to skip */ + lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n); + luaL_addvalue(&b); /* add warning about skip */ + level += n; /* and skip to last levels */ + } + else { + lua_getinfo(L1, "Slnt", &ar); + if (ar.currentline <= 0) + lua_pushfstring(L, "\n\t%s: in ", ar.short_src); + else + lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline); + luaL_addvalue(&b); + pushfuncname(L, &ar); + luaL_addvalue(&b); + if (ar.istailcall) + luaL_addstring(&b, "\n\t(...tail calls...)"); + } + } + luaL_pushresult(&b); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Error-report functions +** ======================================================= +*/ + +LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) { + lua_Debug ar; + if (!lua_getstack(L, 0, &ar)) /* no stack frame? */ + return luaL_error(L, "bad argument #%d (%s)", arg, extramsg); + lua_getinfo(L, "n", &ar); + if (strcmp(ar.namewhat, "method") == 0) { + arg--; /* do not count 'self' */ + if (arg == 0) /* error is in the self argument itself? */ + return luaL_error(L, "calling '%s' on bad self (%s)", + ar.name, extramsg); + } + if (ar.name == NULL) + ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?"; + return luaL_error(L, "bad argument #%d to '%s' (%s)", + arg, ar.name, extramsg); +} + + +LUALIB_API int luaL_typeerror (lua_State *L, int arg, const char *tname) { + const char *msg; + const char *typearg; /* name for the type of the actual argument */ + if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING) + typearg = lua_tostring(L, -1); /* use the given type name */ + else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA) + typearg = "light userdata"; /* special name for messages */ + else + typearg = luaL_typename(L, arg); /* standard name */ + msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg); + return luaL_argerror(L, arg, msg); +} + + +static void tag_error (lua_State *L, int arg, int tag) { + luaL_typeerror(L, arg, lua_typename(L, tag)); +} + + +/* +** The use of 'lua_pushfstring' ensures this function does not +** need reserved stack space when called. +*/ +LUALIB_API void luaL_where (lua_State *L, int level) { + lua_Debug ar; + if (lua_getstack(L, level, &ar)) { /* check function at level */ + lua_getinfo(L, "Sl", &ar); /* get info about it */ + if (ar.currentline > 0) { /* is there info? */ + lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline); + return; + } + } + lua_pushfstring(L, ""); /* else, no information available... */ +} + + +/* +** Again, the use of 'lua_pushvfstring' ensures this function does +** not need reserved stack space when called. (At worst, it generates +** an error with "stack overflow" instead of the given message.) +*/ +LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) { + va_list argp; + va_start(argp, fmt); + luaL_where(L, 1); + lua_pushvfstring(L, fmt, argp); + va_end(argp); + lua_concat(L, 2); + return lua_error(L); +} + + +LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) { + int en = errno; /* calls to Lua API may change this value */ + if (stat) { + lua_pushboolean(L, 1); + return 1; + } + else { + luaL_pushfail(L); + if (fname) + lua_pushfstring(L, "%s: %s", fname, strerror(en)); + else + lua_pushstring(L, strerror(en)); + lua_pushinteger(L, en); + return 3; + } +} + + +#if !defined(l_inspectstat) /* { */ + +#if defined(LUA_USE_POSIX) + +#include + +/* +** use appropriate macros to interpret 'pclose' return status +*/ +#define l_inspectstat(stat,what) \ + if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \ + else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; } + +#else + +#define l_inspectstat(stat,what) /* no op */ + +#endif + +#endif /* } */ + + +LUALIB_API int luaL_execresult (lua_State *L, int stat) { + if (stat != 0 && errno != 0) /* error with an 'errno'? */ + return luaL_fileresult(L, 0, NULL); + else { + const char *what = "exit"; /* type of termination */ + l_inspectstat(stat, what); /* interpret result */ + if (*what == 'e' && stat == 0) /* successful termination? */ + lua_pushboolean(L, 1); + else + luaL_pushfail(L); + lua_pushstring(L, what); + lua_pushinteger(L, stat); + return 3; /* return true/fail,what,code */ + } +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** Userdata's metatable manipulation +** ======================================================= +*/ + +LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { + if (luaL_getmetatable(L, tname) != LUA_TNIL) /* name already in use? */ + return 0; /* leave previous value on top, but return 0 */ + lua_pop(L, 1); + lua_createtable(L, 0, 2); /* create metatable */ + lua_pushstring(L, tname); + lua_setfield(L, -2, "__name"); /* metatable.__name = tname */ + lua_pushvalue(L, -1); + lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */ + return 1; +} + + +LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) { + luaL_getmetatable(L, tname); + lua_setmetatable(L, -2); +} + + +LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) { + void *p = lua_touserdata(L, ud); + if (p != NULL) { /* value is a userdata? */ + if (lua_getmetatable(L, ud)) { /* does it have a metatable? */ + luaL_getmetatable(L, tname); /* get correct metatable */ + if (!lua_rawequal(L, -1, -2)) /* not the same? */ + p = NULL; /* value is a userdata with wrong metatable */ + lua_pop(L, 2); /* remove both metatables */ + return p; + } + } + return NULL; /* value is not a userdata with a metatable */ +} + + +LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { + void *p = luaL_testudata(L, ud, tname); + luaL_argexpected(L, p != NULL, ud, tname); + return p; +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Argument check functions +** ======================================================= +*/ + +LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def, + const char *const lst[]) { + const char *name = (def) ? luaL_optstring(L, arg, def) : + luaL_checkstring(L, arg); + int i; + for (i=0; lst[i]; i++) + if (strcmp(lst[i], name) == 0) + return i; + return luaL_argerror(L, arg, + lua_pushfstring(L, "invalid option '%s'", name)); +} + + +/* +** Ensures the stack has at least 'space' extra slots, raising an error +** if it cannot fulfill the request. (The error handling needs a few +** extra slots to format the error message. In case of an error without +** this extra space, Lua will generate the same 'stack overflow' error, +** but without 'msg'.) +*/ +LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) { + if (l_unlikely(!lua_checkstack(L, space))) { + if (msg) + luaL_error(L, "stack overflow (%s)", msg); + else + luaL_error(L, "stack overflow"); + } +} + + +LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) { + if (l_unlikely(lua_type(L, arg) != t)) + tag_error(L, arg, t); +} + + +LUALIB_API void luaL_checkany (lua_State *L, int arg) { + if (l_unlikely(lua_type(L, arg) == LUA_TNONE)) + luaL_argerror(L, arg, "value expected"); +} + + +LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) { + const char *s = lua_tolstring(L, arg, len); + if (l_unlikely(!s)) tag_error(L, arg, LUA_TSTRING); + return s; +} + + +LUALIB_API const char *luaL_optlstring (lua_State *L, int arg, + const char *def, size_t *len) { + if (lua_isnoneornil(L, arg)) { + if (len) + *len = (def ? strlen(def) : 0); + return def; + } + else return luaL_checklstring(L, arg, len); +} + + +LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) { + int isnum; + lua_Number d = lua_tonumberx(L, arg, &isnum); + if (l_unlikely(!isnum)) + tag_error(L, arg, LUA_TNUMBER); + return d; +} + + +LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) { + return luaL_opt(L, luaL_checknumber, arg, def); +} + + +static void interror (lua_State *L, int arg) { + if (lua_isnumber(L, arg)) + luaL_argerror(L, arg, "number has no integer representation"); + else + tag_error(L, arg, LUA_TNUMBER); +} + + +LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) { + int isnum; + lua_Integer d = lua_tointegerx(L, arg, &isnum); + if (l_unlikely(!isnum)) { + interror(L, arg); + } + return d; +} + + +LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg, + lua_Integer def) { + return luaL_opt(L, luaL_checkinteger, arg, def); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Generic Buffer manipulation +** ======================================================= +*/ + +/* userdata to box arbitrary data */ +typedef struct UBox { + void *box; + size_t bsize; +} UBox; + + +static void *resizebox (lua_State *L, int idx, size_t newsize) { + void *ud; + lua_Alloc allocf = lua_getallocf(L, &ud); + UBox *box = (UBox *)lua_touserdata(L, idx); + void *temp = allocf(ud, box->box, box->bsize, newsize); + if (l_unlikely(temp == NULL && newsize > 0)) { /* allocation error? */ + lua_pushliteral(L, "not enough memory"); + lua_error(L); /* raise a memory error */ + } + box->box = temp; + box->bsize = newsize; + return temp; +} + + +static int boxgc (lua_State *L) { + resizebox(L, 1, 0); + return 0; +} + + +static const luaL_Reg boxmt[] = { /* box metamethods */ + {"__gc", boxgc}, + {"__close", boxgc}, + {NULL, NULL} +}; + + +static void newbox (lua_State *L) { + UBox *box = (UBox *)lua_newuserdatauv(L, sizeof(UBox), 0); + box->box = NULL; + box->bsize = 0; + if (luaL_newmetatable(L, "_UBOX*")) /* creating metatable? */ + luaL_setfuncs(L, boxmt, 0); /* set its metamethods */ + lua_setmetatable(L, -2); +} + + +/* +** check whether buffer is using a userdata on the stack as a temporary +** buffer +*/ +#define buffonstack(B) ((B)->b != (B)->init.b) + + +/* +** Whenever buffer is accessed, slot 'idx' must either be a box (which +** cannot be NULL) or it is a placeholder for the buffer. +*/ +#define checkbufferlevel(B,idx) \ + lua_assert(buffonstack(B) ? lua_touserdata(B->L, idx) != NULL \ + : lua_touserdata(B->L, idx) == (void*)B) + + +/* +** Compute new size for buffer 'B', enough to accommodate extra 'sz' +** bytes. (The test for "not big enough" also gets the case when the +** computation of 'newsize' overflows.) +*/ +static size_t newbuffsize (luaL_Buffer *B, size_t sz) { + size_t newsize = (B->size / 2) * 3; /* buffer size * 1.5 */ + if (l_unlikely(MAX_SIZET - sz < B->n)) /* overflow in (B->n + sz)? */ + return luaL_error(B->L, "buffer too large"); + if (newsize < B->n + sz) /* not big enough? */ + newsize = B->n + sz; + return newsize; +} + + +/* +** Returns a pointer to a free area with at least 'sz' bytes in buffer +** 'B'. 'boxidx' is the relative position in the stack where is the +** buffer's box or its placeholder. +*/ +static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) { + checkbufferlevel(B, boxidx); + if (B->size - B->n >= sz) /* enough space? */ + return B->b + B->n; + else { + lua_State *L = B->L; + char *newbuff; + size_t newsize = newbuffsize(B, sz); + /* create larger buffer */ + if (buffonstack(B)) /* buffer already has a box? */ + newbuff = (char *)resizebox(L, boxidx, newsize); /* resize it */ + else { /* no box yet */ + lua_remove(L, boxidx); /* remove placeholder */ + newbox(L); /* create a new box */ + lua_insert(L, boxidx); /* move box to its intended position */ + lua_toclose(L, boxidx); + newbuff = (char *)resizebox(L, boxidx, newsize); + memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */ + } + B->b = newbuff; + B->size = newsize; + return newbuff + B->n; + } +} + +/* +** returns a pointer to a free area with at least 'sz' bytes +*/ +LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) { + return prepbuffsize(B, sz, -1); +} + + +LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { + if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */ + char *b = prepbuffsize(B, l, -1); + memcpy(b, s, l * sizeof(char)); + luaL_addsize(B, l); + } +} + + +LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) { + luaL_addlstring(B, s, strlen(s)); +} + + +LUALIB_API void luaL_pushresult (luaL_Buffer *B) { + lua_State *L = B->L; + checkbufferlevel(B, -1); + lua_pushlstring(L, B->b, B->n); + if (buffonstack(B)) + lua_closeslot(L, -2); /* close the box */ + lua_remove(L, -2); /* remove box or placeholder from the stack */ +} + + +LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) { + luaL_addsize(B, sz); + luaL_pushresult(B); +} + + +/* +** 'luaL_addvalue' is the only function in the Buffer system where the +** box (if existent) is not on the top of the stack. So, instead of +** calling 'luaL_addlstring', it replicates the code using -2 as the +** last argument to 'prepbuffsize', signaling that the box is (or will +** be) below the string being added to the buffer. (Box creation can +** trigger an emergency GC, so we should not remove the string from the +** stack before we have the space guaranteed.) +*/ +LUALIB_API void luaL_addvalue (luaL_Buffer *B) { + lua_State *L = B->L; + size_t len; + const char *s = lua_tolstring(L, -1, &len); + char *b = prepbuffsize(B, len, -2); + memcpy(b, s, len * sizeof(char)); + luaL_addsize(B, len); + lua_pop(L, 1); /* pop string */ +} + + +LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { + B->L = L; + B->b = B->init.b; + B->n = 0; + B->size = LUAL_BUFFERSIZE; + lua_pushlightuserdata(L, (void*)B); /* push placeholder */ +} + + +LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) { + luaL_buffinit(L, B); + return prepbuffsize(B, sz, -1); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Reference system +** ======================================================= +*/ + +/* index of free-list header (after the predefined values) */ +#define freelist (LUA_RIDX_LAST + 1) + +/* +** The previously freed references form a linked list: +** t[freelist] is the index of a first free index, or zero if list is +** empty; t[t[freelist]] is the index of the second element; etc. +*/ +LUALIB_API int luaL_ref (lua_State *L, int t) { + int ref; + if (lua_isnil(L, -1)) { + lua_pop(L, 1); /* remove from stack */ + return LUA_REFNIL; /* 'nil' has a unique fixed reference */ + } + t = lua_absindex(L, t); + if (lua_rawgeti(L, t, freelist) == LUA_TNIL) { /* first access? */ + ref = 0; /* list is empty */ + lua_pushinteger(L, 0); /* initialize as an empty list */ + lua_rawseti(L, t, freelist); /* ref = t[freelist] = 0 */ + } + else { /* already initialized */ + lua_assert(lua_isinteger(L, -1)); + ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */ + } + lua_pop(L, 1); /* remove element from stack */ + if (ref != 0) { /* any free element? */ + lua_rawgeti(L, t, ref); /* remove it from list */ + lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */ + } + else /* no free elements */ + ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */ + lua_rawseti(L, t, ref); + return ref; +} + + +LUALIB_API void luaL_unref (lua_State *L, int t, int ref) { + if (ref >= 0) { + t = lua_absindex(L, t); + lua_rawgeti(L, t, freelist); + lua_assert(lua_isinteger(L, -1)); + lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */ + lua_pushinteger(L, ref); + lua_rawseti(L, t, freelist); /* t[freelist] = ref */ + } +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Load functions +** ======================================================= +*/ + +typedef struct LoadF { + int n; /* number of pre-read characters */ + FILE *f; /* file being read */ + char buff[BUFSIZ]; /* area for reading file */ +} LoadF; + + +static const char *getF (lua_State *L, void *ud, size_t *size) { + LoadF *lf = (LoadF *)ud; + (void)L; /* not used */ + if (lf->n > 0) { /* are there pre-read characters to be read? */ + *size = lf->n; /* return them (chars already in buffer) */ + lf->n = 0; /* no more pre-read characters */ + } + else { /* read a block from file */ + /* 'fread' can return > 0 *and* set the EOF flag. If next call to + 'getF' called 'fread', it might still wait for user input. + The next check avoids this problem. */ + if (feof(lf->f)) return NULL; + *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */ + } + return lf->buff; +} + + +static int errfile (lua_State *L, const char *what, int fnameindex) { + const char *serr = strerror(errno); + const char *filename = lua_tostring(L, fnameindex) + 1; + lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr); + lua_remove(L, fnameindex); + return LUA_ERRFILE; +} + + +/* +** Skip an optional BOM at the start of a stream. If there is an +** incomplete BOM (the first character is correct but the rest is +** not), returns the first character anyway to force an error +** (as no chunk can start with 0xEF). +*/ +static int skipBOM (FILE *f) { + int c = getc(f); /* read first character */ + if (c == 0xEF && getc(f) == 0xBB && getc(f) == 0xBF) /* correct BOM? */ + return getc(f); /* ignore BOM and return next char */ + else /* no (valid) BOM */ + return c; /* return first character */ +} + + +/* +** reads the first character of file 'f' and skips an optional BOM mark +** in its beginning plus its first line if it starts with '#'. Returns +** true if it skipped the first line. In any case, '*cp' has the +** first "valid" character of the file (after the optional BOM and +** a first-line comment). +*/ +static int skipcomment (FILE *f, int *cp) { + int c = *cp = skipBOM(f); + if (c == '#') { /* first line is a comment (Unix exec. file)? */ + do { /* skip first line */ + c = getc(f); + } while (c != EOF && c != '\n'); + *cp = getc(f); /* next character after comment, if present */ + return 1; /* there was a comment */ + } + else return 0; /* no comment */ +} + + +LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename, + const char *mode) { + LoadF lf; + int status, readstatus; + int c; + int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */ + if (filename == NULL) { + lua_pushliteral(L, "=stdin"); + lf.f = stdin; + } + else { + lua_pushfstring(L, "@%s", filename); + lf.f = fopen(filename, "r"); + if (lf.f == NULL) return errfile(L, "open", fnameindex); + } + lf.n = 0; + if (skipcomment(lf.f, &c)) /* read initial portion */ + lf.buff[lf.n++] = '\n'; /* add newline to correct line numbers */ + if (c == LUA_SIGNATURE[0]) { /* binary file? */ + lf.n = 0; /* remove possible newline */ + if (filename) { /* "real" file? */ + lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */ + if (lf.f == NULL) return errfile(L, "reopen", fnameindex); + skipcomment(lf.f, &c); /* re-read initial portion */ + } + } + if (c != EOF) + lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */ + status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode); + readstatus = ferror(lf.f); + if (filename) fclose(lf.f); /* close file (even in case of errors) */ + if (readstatus) { + lua_settop(L, fnameindex); /* ignore results from 'lua_load' */ + return errfile(L, "read", fnameindex); + } + lua_remove(L, fnameindex); + return status; +} + + +typedef struct LoadS { + const char *s; + size_t size; +} LoadS; + + +static const char *getS (lua_State *L, void *ud, size_t *size) { + LoadS *ls = (LoadS *)ud; + (void)L; /* not used */ + if (ls->size == 0) return NULL; + *size = ls->size; + ls->size = 0; + return ls->s; +} + + +LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size, + const char *name, const char *mode) { + LoadS ls; + ls.s = buff; + ls.size = size; + return lua_load(L, getS, &ls, name, mode); +} + + +LUALIB_API int luaL_loadstring (lua_State *L, const char *s) { + return luaL_loadbuffer(L, s, strlen(s), s); +} + +/* }====================================================== */ + + + +LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) { + if (!lua_getmetatable(L, obj)) /* no metatable? */ + return LUA_TNIL; + else { + int tt; + lua_pushstring(L, event); + tt = lua_rawget(L, -2); + if (tt == LUA_TNIL) /* is metafield nil? */ + lua_pop(L, 2); /* remove metatable and metafield */ + else + lua_remove(L, -2); /* remove only metatable */ + return tt; /* return metafield type */ + } +} + + +LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) { + obj = lua_absindex(L, obj); + if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */ + return 0; + lua_pushvalue(L, obj); + lua_call(L, 1, 1); + return 1; +} + + +LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) { + lua_Integer l; + int isnum; + lua_len(L, idx); + l = lua_tointegerx(L, -1, &isnum); + if (l_unlikely(!isnum)) + luaL_error(L, "object length is not an integer"); + lua_pop(L, 1); /* remove object */ + return l; +} + + +LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) { + idx = lua_absindex(L,idx); + if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */ + if (!lua_isstring(L, -1)) + luaL_error(L, "'__tostring' must return a string"); + } + else { + switch (lua_type(L, idx)) { + case LUA_TNUMBER: { + if (lua_isinteger(L, idx)) + lua_pushfstring(L, "%I", (LUAI_UACINT)lua_tointeger(L, idx)); + else + lua_pushfstring(L, "%f", (LUAI_UACNUMBER)lua_tonumber(L, idx)); + break; + } + case LUA_TSTRING: + lua_pushvalue(L, idx); + break; + case LUA_TBOOLEAN: + lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false")); + break; + case LUA_TNIL: + lua_pushliteral(L, "nil"); + break; + default: { + int tt = luaL_getmetafield(L, idx, "__name"); /* try name */ + const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) : + luaL_typename(L, idx); + lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx)); + if (tt != LUA_TNIL) + lua_remove(L, -2); /* remove '__name' */ + break; + } + } + } + return lua_tolstring(L, -1, len); +} + + +/* +** set functions from list 'l' into table at top - 'nup'; each +** function gets the 'nup' elements at the top as upvalues. +** Returns with only the table at the stack. +*/ +LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) { + luaL_checkstack(L, nup, "too many upvalues"); + for (; l->name != NULL; l++) { /* fill the table with given functions */ + if (l->func == NULL) /* place holder? */ + lua_pushboolean(L, 0); + else { + int i; + for (i = 0; i < nup; i++) /* copy upvalues to the top */ + lua_pushvalue(L, -nup); + lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */ + } + lua_setfield(L, -(nup + 2), l->name); + } + lua_pop(L, nup); /* remove upvalues */ +} + + +/* +** ensure that stack[idx][fname] has a table and push that table +** into the stack +*/ +LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) { + if (lua_getfield(L, idx, fname) == LUA_TTABLE) + return 1; /* table already there */ + else { + lua_pop(L, 1); /* remove previous result */ + idx = lua_absindex(L, idx); + lua_newtable(L); + lua_pushvalue(L, -1); /* copy to be left at top */ + lua_setfield(L, idx, fname); /* assign new table to field */ + return 0; /* false, because did not find table there */ + } +} + + +/* +** Stripped-down 'require': After checking "loaded" table, calls 'openf' +** to open a module, registers the result in 'package.loaded' table and, +** if 'glb' is true, also registers the result in the global table. +** Leaves resulting module on the top. +*/ +LUALIB_API void luaL_requiref (lua_State *L, const char *modname, + lua_CFunction openf, int glb) { + luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); + lua_getfield(L, -1, modname); /* LOADED[modname] */ + if (!lua_toboolean(L, -1)) { /* package not already loaded? */ + lua_pop(L, 1); /* remove field */ + lua_pushcfunction(L, openf); + lua_pushstring(L, modname); /* argument to open function */ + lua_call(L, 1, 1); /* call 'openf' to open module */ + lua_pushvalue(L, -1); /* make copy of module (call result) */ + lua_setfield(L, -3, modname); /* LOADED[modname] = module */ + } + lua_remove(L, -2); /* remove LOADED table */ + if (glb) { + lua_pushvalue(L, -1); /* copy of module */ + lua_setglobal(L, modname); /* _G[modname] = module */ + } +} + + +LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s, + const char *p, const char *r) { + const char *wild; + size_t l = strlen(p); + while ((wild = strstr(s, p)) != NULL) { + luaL_addlstring(b, s, wild - s); /* push prefix */ + luaL_addstring(b, r); /* push replacement in place of pattern */ + s = wild + l; /* continue after 'p' */ + } + luaL_addstring(b, s); /* push last suffix */ +} + + +LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, + const char *p, const char *r) { + luaL_Buffer b; + luaL_buffinit(L, &b); + luaL_addgsub(&b, s, p, r); + luaL_pushresult(&b); + return lua_tostring(L, -1); +} + + +static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) { + (void)ud; (void)osize; /* not used */ + if (nsize == 0) { + free(ptr); + return NULL; + } + else + return realloc(ptr, nsize); +} + + +static int panic (lua_State *L) { + const char *msg = lua_tostring(L, -1); + if (msg == NULL) msg = "error object is not a string"; + lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n", + msg); + return 0; /* return to Lua to abort */ +} + + +/* +** Warning functions: +** warnfoff: warning system is off +** warnfon: ready to start a new message +** warnfcont: previous message is to be continued +*/ +static void warnfoff (void *ud, const char *message, int tocont); +static void warnfon (void *ud, const char *message, int tocont); +static void warnfcont (void *ud, const char *message, int tocont); + + +/* +** Check whether message is a control message. If so, execute the +** control or ignore it if unknown. +*/ +static int checkcontrol (lua_State *L, const char *message, int tocont) { + if (tocont || *(message++) != '@') /* not a control message? */ + return 0; + else { + if (strcmp(message, "off") == 0) + lua_setwarnf(L, warnfoff, L); /* turn warnings off */ + else if (strcmp(message, "on") == 0) + lua_setwarnf(L, warnfon, L); /* turn warnings on */ + return 1; /* it was a control message */ + } +} + + +static void warnfoff (void *ud, const char *message, int tocont) { + checkcontrol((lua_State *)ud, message, tocont); +} + + +/* +** Writes the message and handle 'tocont', finishing the message +** if needed and setting the next warn function. +*/ +static void warnfcont (void *ud, const char *message, int tocont) { + lua_State *L = (lua_State *)ud; + lua_writestringerror("%s", message); /* write message */ + if (tocont) /* not the last part? */ + lua_setwarnf(L, warnfcont, L); /* to be continued */ + else { /* last part */ + lua_writestringerror("%s", "\n"); /* finish message with end-of-line */ + lua_setwarnf(L, warnfon, L); /* next call is a new message */ + } +} + + +static void warnfon (void *ud, const char *message, int tocont) { + if (checkcontrol((lua_State *)ud, message, tocont)) /* control message? */ + return; /* nothing else to be done */ + lua_writestringerror("%s", "Lua warning: "); /* start a new warning */ + warnfcont(ud, message, tocont); /* finish processing */ +} + + +LUALIB_API lua_State *luaL_newstate (void) { + lua_State *L = lua_newstate(l_alloc, NULL); + if (l_likely(L)) { + lua_atpanic(L, &panic); + lua_setwarnf(L, warnfoff, L); /* default is warnings off */ + } + return L; +} + + +LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) { + lua_Number v = lua_version(L); + if (sz != LUAL_NUMSIZES) /* check numeric types */ + luaL_error(L, "core and library have incompatible numeric types"); + else if (v != ver) + luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f", + (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)v); +} + diff --git a/src/lauxlib.h b/src/lauxlib.h new file mode 100644 index 0000000..5b977e2 --- /dev/null +++ b/src/lauxlib.h @@ -0,0 +1,301 @@ +/* +** $Id: lauxlib.h $ +** Auxiliary functions for building Lua libraries +** See Copyright Notice in lua.h +*/ + + +#ifndef lauxlib_h +#define lauxlib_h + + +#include +#include + +#include "luaconf.h" +#include "lua.h" + + +/* global table */ +#define LUA_GNAME "_G" + + +typedef struct luaL_Buffer luaL_Buffer; + + +/* extra error code for 'luaL_loadfilex' */ +#define LUA_ERRFILE (LUA_ERRERR+1) + + +/* key, in the registry, for table of loaded modules */ +#define LUA_LOADED_TABLE "_LOADED" + + +/* key, in the registry, for table of preloaded loaders */ +#define LUA_PRELOAD_TABLE "_PRELOAD" + + +typedef struct luaL_Reg { + const char *name; + lua_CFunction func; +} luaL_Reg; + + +#define LUAL_NUMSIZES (sizeof(lua_Integer)*16 + sizeof(lua_Number)) + +LUALIB_API void (luaL_checkversion_) (lua_State *L, lua_Number ver, size_t sz); +#define luaL_checkversion(L) \ + luaL_checkversion_(L, LUA_VERSION_NUM, LUAL_NUMSIZES) + +LUALIB_API int (luaL_getmetafield) (lua_State *L, int obj, const char *e); +LUALIB_API int (luaL_callmeta) (lua_State *L, int obj, const char *e); +LUALIB_API const char *(luaL_tolstring) (lua_State *L, int idx, size_t *len); +LUALIB_API int (luaL_argerror) (lua_State *L, int arg, const char *extramsg); +LUALIB_API int (luaL_typeerror) (lua_State *L, int arg, const char *tname); +LUALIB_API const char *(luaL_checklstring) (lua_State *L, int arg, + size_t *l); +LUALIB_API const char *(luaL_optlstring) (lua_State *L, int arg, + const char *def, size_t *l); +LUALIB_API lua_Number (luaL_checknumber) (lua_State *L, int arg); +LUALIB_API lua_Number (luaL_optnumber) (lua_State *L, int arg, lua_Number def); + +LUALIB_API lua_Integer (luaL_checkinteger) (lua_State *L, int arg); +LUALIB_API lua_Integer (luaL_optinteger) (lua_State *L, int arg, + lua_Integer def); + +LUALIB_API void (luaL_checkstack) (lua_State *L, int sz, const char *msg); +LUALIB_API void (luaL_checktype) (lua_State *L, int arg, int t); +LUALIB_API void (luaL_checkany) (lua_State *L, int arg); + +LUALIB_API int (luaL_newmetatable) (lua_State *L, const char *tname); +LUALIB_API void (luaL_setmetatable) (lua_State *L, const char *tname); +LUALIB_API void *(luaL_testudata) (lua_State *L, int ud, const char *tname); +LUALIB_API void *(luaL_checkudata) (lua_State *L, int ud, const char *tname); + +LUALIB_API void (luaL_where) (lua_State *L, int lvl); +LUALIB_API int (luaL_error) (lua_State *L, const char *fmt, ...); + +LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def, + const char *const lst[]); + +LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname); +LUALIB_API int (luaL_execresult) (lua_State *L, int stat); + + +/* predefined references */ +#define LUA_NOREF (-2) +#define LUA_REFNIL (-1) + +LUALIB_API int (luaL_ref) (lua_State *L, int t); +LUALIB_API void (luaL_unref) (lua_State *L, int t, int ref); + +LUALIB_API int (luaL_loadfilex) (lua_State *L, const char *filename, + const char *mode); + +#define luaL_loadfile(L,f) luaL_loadfilex(L,f,NULL) + +LUALIB_API int (luaL_loadbufferx) (lua_State *L, const char *buff, size_t sz, + const char *name, const char *mode); +LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s); + +LUALIB_API lua_State *(luaL_newstate) (void); + +LUALIB_API lua_Integer (luaL_len) (lua_State *L, int idx); + +LUALIB_API void (luaL_addgsub) (luaL_Buffer *b, const char *s, + const char *p, const char *r); +LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s, + const char *p, const char *r); + +LUALIB_API void (luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup); + +LUALIB_API int (luaL_getsubtable) (lua_State *L, int idx, const char *fname); + +LUALIB_API void (luaL_traceback) (lua_State *L, lua_State *L1, + const char *msg, int level); + +LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname, + lua_CFunction openf, int glb); + +/* +** =============================================================== +** some useful macros +** =============================================================== +*/ + + +#define luaL_newlibtable(L,l) \ + lua_createtable(L, 0, sizeof(l)/sizeof((l)[0]) - 1) + +#define luaL_newlib(L,l) \ + (luaL_checkversion(L), luaL_newlibtable(L,l), luaL_setfuncs(L,l,0)) + +#define luaL_argcheck(L, cond,arg,extramsg) \ + ((void)(luai_likely(cond) || luaL_argerror(L, (arg), (extramsg)))) + +#define luaL_argexpected(L,cond,arg,tname) \ + ((void)(luai_likely(cond) || luaL_typeerror(L, (arg), (tname)))) + +#define luaL_checkstring(L,n) (luaL_checklstring(L, (n), NULL)) +#define luaL_optstring(L,n,d) (luaL_optlstring(L, (n), (d), NULL)) + +#define luaL_typename(L,i) lua_typename(L, lua_type(L,(i))) + +#define luaL_dofile(L, fn) \ + (luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0)) + +#define luaL_dostring(L, s) \ + (luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0)) + +#define luaL_getmetatable(L,n) (lua_getfield(L, LUA_REGISTRYINDEX, (n))) + +#define luaL_opt(L,f,n,d) (lua_isnoneornil(L,(n)) ? (d) : f(L,(n))) + +#define luaL_loadbuffer(L,s,sz,n) luaL_loadbufferx(L,s,sz,n,NULL) + + +/* +** Perform arithmetic operations on lua_Integer values with wrap-around +** semantics, as the Lua core does. +*/ +#define luaL_intop(op,v1,v2) \ + ((lua_Integer)((lua_Unsigned)(v1) op (lua_Unsigned)(v2))) + + +/* push the value used to represent failure/error */ +#define luaL_pushfail(L) lua_pushnil(L) + + +/* +** Internal assertions for in-house debugging +*/ +#if !defined(lua_assert) + +#if defined LUAI_ASSERT + #include + #define lua_assert(c) assert(c) +#else + #define lua_assert(c) ((void)0) +#endif + +#endif + + + +/* +** {====================================================== +** Generic Buffer manipulation +** ======================================================= +*/ + +struct luaL_Buffer { + char *b; /* buffer address */ + size_t size; /* buffer size */ + size_t n; /* number of characters in buffer */ + lua_State *L; + union { + LUAI_MAXALIGN; /* ensure maximum alignment for buffer */ + char b[LUAL_BUFFERSIZE]; /* initial buffer */ + } init; +}; + + +#define luaL_bufflen(bf) ((bf)->n) +#define luaL_buffaddr(bf) ((bf)->b) + + +#define luaL_addchar(B,c) \ + ((void)((B)->n < (B)->size || luaL_prepbuffsize((B), 1)), \ + ((B)->b[(B)->n++] = (c))) + +#define luaL_addsize(B,s) ((B)->n += (s)) + +#define luaL_buffsub(B,s) ((B)->n -= (s)) + +LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B); +LUALIB_API char *(luaL_prepbuffsize) (luaL_Buffer *B, size_t sz); +LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l); +LUALIB_API void (luaL_addstring) (luaL_Buffer *B, const char *s); +LUALIB_API void (luaL_addvalue) (luaL_Buffer *B); +LUALIB_API void (luaL_pushresult) (luaL_Buffer *B); +LUALIB_API void (luaL_pushresultsize) (luaL_Buffer *B, size_t sz); +LUALIB_API char *(luaL_buffinitsize) (lua_State *L, luaL_Buffer *B, size_t sz); + +#define luaL_prepbuffer(B) luaL_prepbuffsize(B, LUAL_BUFFERSIZE) + +/* }====================================================== */ + + + +/* +** {====================================================== +** File handles for IO library +** ======================================================= +*/ + +/* +** A file handle is a userdata with metatable 'LUA_FILEHANDLE' and +** initial structure 'luaL_Stream' (it may contain other fields +** after that initial structure). +*/ + +#define LUA_FILEHANDLE "FILE*" + + +typedef struct luaL_Stream { + FILE *f; /* stream (NULL for incompletely created streams) */ + lua_CFunction closef; /* to close stream (NULL for closed streams) */ +} luaL_Stream; + +/* }====================================================== */ + +/* +** {================================================================== +** "Abstraction Layer" for basic report of messages and errors +** =================================================================== +*/ + +/* print a string */ +#if !defined(lua_writestring) +#define lua_writestring(s,l) fwrite((s), sizeof(char), (l), stdout) +#endif + +/* print a newline and flush the output */ +#if !defined(lua_writeline) +#define lua_writeline() (lua_writestring("\n", 1), fflush(stdout)) +#endif + +/* print an error message */ +#if !defined(lua_writestringerror) +#define lua_writestringerror(s,p) \ + (fprintf(stderr, (s), (p)), fflush(stderr)) +#endif + +/* }================================================================== */ + + +/* +** {============================================================ +** Compatibility with deprecated conversions +** ============================================================= +*/ +#if defined(LUA_COMPAT_APIINTCASTS) + +#define luaL_checkunsigned(L,a) ((lua_Unsigned)luaL_checkinteger(L,a)) +#define luaL_optunsigned(L,a,d) \ + ((lua_Unsigned)luaL_optinteger(L,a,(lua_Integer)(d))) + +#define luaL_checkint(L,n) ((int)luaL_checkinteger(L, (n))) +#define luaL_optint(L,n,d) ((int)luaL_optinteger(L, (n), (d))) + +#define luaL_checklong(L,n) ((long)luaL_checkinteger(L, (n))) +#define luaL_optlong(L,n,d) ((long)luaL_optinteger(L, (n), (d))) + +#endif +/* }============================================================ */ + + + +#endif + + diff --git a/src/lbaselib.c b/src/lbaselib.c new file mode 100644 index 0000000..1d60c9d --- /dev/null +++ b/src/lbaselib.c @@ -0,0 +1,549 @@ +/* +** $Id: lbaselib.c $ +** Basic library +** See Copyright Notice in lua.h +*/ + +#define lbaselib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +static int luaB_print (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int i; + for (i = 1; i <= n; i++) { /* for each argument */ + size_t l; + const char *s = luaL_tolstring(L, i, &l); /* convert it to string */ + if (i > 1) /* not the first element? */ + lua_writestring("\t", 1); /* add a tab before it */ + lua_writestring(s, l); /* print it */ + lua_pop(L, 1); /* pop result */ + } + lua_writeline(); + return 0; +} + + +/* +** Creates a warning with all given arguments. +** Check first for errors; otherwise an error may interrupt +** the composition of a warning, leaving it unfinished. +*/ +static int luaB_warn (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int i; + luaL_checkstring(L, 1); /* at least one argument */ + for (i = 2; i <= n; i++) + luaL_checkstring(L, i); /* make sure all arguments are strings */ + for (i = 1; i < n; i++) /* compose warning */ + lua_warning(L, lua_tostring(L, i), 1); + lua_warning(L, lua_tostring(L, n), 0); /* close warning */ + return 0; +} + + +#define SPACECHARS " \f\n\r\t\v" + +static const char *b_str2int (const char *s, int base, lua_Integer *pn) { + lua_Unsigned n = 0; + int neg = 0; + s += strspn(s, SPACECHARS); /* skip initial spaces */ + if (*s == '-') { s++; neg = 1; } /* handle sign */ + else if (*s == '+') s++; + if (!isalnum((unsigned char)*s)) /* no digit? */ + return NULL; + do { + int digit = (isdigit((unsigned char)*s)) ? *s - '0' + : (toupper((unsigned char)*s) - 'A') + 10; + if (digit >= base) return NULL; /* invalid numeral */ + n = n * base + digit; + s++; + } while (isalnum((unsigned char)*s)); + s += strspn(s, SPACECHARS); /* skip trailing spaces */ + *pn = (lua_Integer)((neg) ? (0u - n) : n); + return s; +} + + +static int luaB_tonumber (lua_State *L) { + if (lua_isnoneornil(L, 2)) { /* standard conversion? */ + if (lua_type(L, 1) == LUA_TNUMBER) { /* already a number? */ + lua_settop(L, 1); /* yes; return it */ + return 1; + } + else { + size_t l; + const char *s = lua_tolstring(L, 1, &l); + if (s != NULL && lua_stringtonumber(L, s) == l + 1) + return 1; /* successful conversion to number */ + /* else not a number */ + luaL_checkany(L, 1); /* (but there must be some parameter) */ + } + } + else { + size_t l; + const char *s; + lua_Integer n = 0; /* to avoid warnings */ + lua_Integer base = luaL_checkinteger(L, 2); + luaL_checktype(L, 1, LUA_TSTRING); /* no numbers as strings */ + s = lua_tolstring(L, 1, &l); + luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range"); + if (b_str2int(s, (int)base, &n) == s + l) { + lua_pushinteger(L, n); + return 1; + } /* else not a number */ + } /* else not a number */ + luaL_pushfail(L); /* not a number */ + return 1; +} + + +static int luaB_error (lua_State *L) { + int level = (int)luaL_optinteger(L, 2, 1); + lua_settop(L, 1); + if (lua_type(L, 1) == LUA_TSTRING && level > 0) { + luaL_where(L, level); /* add extra information */ + lua_pushvalue(L, 1); + lua_concat(L, 2); + } + return lua_error(L); +} + + +static int luaB_getmetatable (lua_State *L) { + luaL_checkany(L, 1); + if (!lua_getmetatable(L, 1)) { + lua_pushnil(L); + return 1; /* no metatable */ + } + luaL_getmetafield(L, 1, "__metatable"); + return 1; /* returns either __metatable field (if present) or metatable */ +} + + +static int luaB_setmetatable (lua_State *L) { + int t = lua_type(L, 2); + luaL_checktype(L, 1, LUA_TTABLE); + luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table"); + if (l_unlikely(luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)) + return luaL_error(L, "cannot change a protected metatable"); + lua_settop(L, 2); + lua_setmetatable(L, 1); + return 1; +} + + +static int luaB_rawequal (lua_State *L) { + luaL_checkany(L, 1); + luaL_checkany(L, 2); + lua_pushboolean(L, lua_rawequal(L, 1, 2)); + return 1; +} + + +static int luaB_rawlen (lua_State *L) { + int t = lua_type(L, 1); + luaL_argexpected(L, t == LUA_TTABLE || t == LUA_TSTRING, 1, + "table or string"); + lua_pushinteger(L, lua_rawlen(L, 1)); + return 1; +} + + +static int luaB_rawget (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + luaL_checkany(L, 2); + lua_settop(L, 2); + lua_rawget(L, 1); + return 1; +} + +static int luaB_rawset (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + luaL_checkany(L, 2); + luaL_checkany(L, 3); + lua_settop(L, 3); + lua_rawset(L, 1); + return 1; +} + + +static int pushmode (lua_State *L, int oldmode) { + if (oldmode == -1) + luaL_pushfail(L); /* invalid call to 'lua_gc' */ + else + lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental" + : "generational"); + return 1; +} + + +/* +** check whether call to 'lua_gc' was valid (not inside a finalizer) +*/ +#define checkvalres(res) { if (res == -1) break; } + +static int luaB_collectgarbage (lua_State *L) { + static const char *const opts[] = {"stop", "restart", "collect", + "count", "step", "setpause", "setstepmul", + "isrunning", "generational", "incremental", NULL}; + static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT, + LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL, + LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC}; + int o = optsnum[luaL_checkoption(L, 1, "collect", opts)]; + switch (o) { + case LUA_GCCOUNT: { + int k = lua_gc(L, o); + int b = lua_gc(L, LUA_GCCOUNTB); + checkvalres(k); + lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024)); + return 1; + } + case LUA_GCSTEP: { + int step = (int)luaL_optinteger(L, 2, 0); + int res = lua_gc(L, o, step); + checkvalres(res); + lua_pushboolean(L, res); + return 1; + } + case LUA_GCSETPAUSE: + case LUA_GCSETSTEPMUL: { + int p = (int)luaL_optinteger(L, 2, 0); + int previous = lua_gc(L, o, p); + checkvalres(previous); + lua_pushinteger(L, previous); + return 1; + } + case LUA_GCISRUNNING: { + int res = lua_gc(L, o); + checkvalres(res); + lua_pushboolean(L, res); + return 1; + } + case LUA_GCGEN: { + int minormul = (int)luaL_optinteger(L, 2, 0); + int majormul = (int)luaL_optinteger(L, 3, 0); + return pushmode(L, lua_gc(L, o, minormul, majormul)); + } + case LUA_GCINC: { + int pause = (int)luaL_optinteger(L, 2, 0); + int stepmul = (int)luaL_optinteger(L, 3, 0); + int stepsize = (int)luaL_optinteger(L, 4, 0); + return pushmode(L, lua_gc(L, o, pause, stepmul, stepsize)); + } + default: { + int res = lua_gc(L, o); + checkvalres(res); + lua_pushinteger(L, res); + return 1; + } + } + luaL_pushfail(L); /* invalid call (inside a finalizer) */ + return 1; +} + + +static int luaB_type (lua_State *L) { + int t = lua_type(L, 1); + luaL_argcheck(L, t != LUA_TNONE, 1, "value expected"); + lua_pushstring(L, lua_typename(L, t)); + return 1; +} + + +static int luaB_next (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + lua_settop(L, 2); /* create a 2nd argument if there isn't one */ + if (lua_next(L, 1)) + return 2; + else { + lua_pushnil(L); + return 1; + } +} + + +static int pairscont (lua_State *L, int status, lua_KContext k) { + (void)L; (void)status; (void)k; /* unused */ + return 3; +} + +static int luaB_pairs (lua_State *L) { + luaL_checkany(L, 1); + if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) { /* no metamethod? */ + lua_pushcfunction(L, luaB_next); /* will return generator, */ + lua_pushvalue(L, 1); /* state, */ + lua_pushnil(L); /* and initial value */ + } + else { + lua_pushvalue(L, 1); /* argument 'self' to metamethod */ + lua_callk(L, 1, 3, 0, pairscont); /* get 3 values from metamethod */ + } + return 3; +} + + +/* +** Traversal function for 'ipairs' +*/ +static int ipairsaux (lua_State *L) { + lua_Integer i = luaL_checkinteger(L, 2); + i = luaL_intop(+, i, 1); + lua_pushinteger(L, i); + return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2; +} + + +/* +** 'ipairs' function. Returns 'ipairsaux', given "table", 0. +** (The given "table" may not be a table.) +*/ +static int luaB_ipairs (lua_State *L) { + luaL_checkany(L, 1); + lua_pushcfunction(L, ipairsaux); /* iteration function */ + lua_pushvalue(L, 1); /* state */ + lua_pushinteger(L, 0); /* initial value */ + return 3; +} + + +static int load_aux (lua_State *L, int status, int envidx) { + if (l_likely(status == LUA_OK)) { + if (envidx != 0) { /* 'env' parameter? */ + lua_pushvalue(L, envidx); /* environment for loaded function */ + if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */ + lua_pop(L, 1); /* remove 'env' if not used by previous call */ + } + return 1; + } + else { /* error (message is on top of the stack) */ + luaL_pushfail(L); + lua_insert(L, -2); /* put before error message */ + return 2; /* return fail plus error message */ + } +} + + +static int luaB_loadfile (lua_State *L) { + const char *fname = luaL_optstring(L, 1, NULL); + const char *mode = luaL_optstring(L, 2, NULL); + int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */ + int status = luaL_loadfilex(L, fname, mode); + return load_aux(L, status, env); +} + + +/* +** {====================================================== +** Generic Read function +** ======================================================= +*/ + + +/* +** reserved slot, above all arguments, to hold a copy of the returned +** string to avoid it being collected while parsed. 'load' has four +** optional arguments (chunk, source name, mode, and environment). +*/ +#define RESERVEDSLOT 5 + + +/* +** Reader for generic 'load' function: 'lua_load' uses the +** stack for internal stuff, so the reader cannot change the +** stack top. Instead, it keeps its resulting string in a +** reserved slot inside the stack. +*/ +static const char *generic_reader (lua_State *L, void *ud, size_t *size) { + (void)(ud); /* not used */ + luaL_checkstack(L, 2, "too many nested functions"); + lua_pushvalue(L, 1); /* get function */ + lua_call(L, 0, 1); /* call it */ + if (lua_isnil(L, -1)) { + lua_pop(L, 1); /* pop result */ + *size = 0; + return NULL; + } + else if (l_unlikely(!lua_isstring(L, -1))) + luaL_error(L, "reader function must return a string"); + lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */ + return lua_tolstring(L, RESERVEDSLOT, size); +} + + +static int luaB_load (lua_State *L) { + int status; + size_t l; + const char *s = lua_tolstring(L, 1, &l); + const char *mode = luaL_optstring(L, 3, "bt"); + int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */ + if (s != NULL) { /* loading a string? */ + const char *chunkname = luaL_optstring(L, 2, s); + status = luaL_loadbufferx(L, s, l, chunkname, mode); + } + else { /* loading from a reader function */ + const char *chunkname = luaL_optstring(L, 2, "=(load)"); + luaL_checktype(L, 1, LUA_TFUNCTION); + lua_settop(L, RESERVEDSLOT); /* create reserved slot */ + status = lua_load(L, generic_reader, NULL, chunkname, mode); + } + return load_aux(L, status, env); +} + +/* }====================================================== */ + + +static int dofilecont (lua_State *L, int d1, lua_KContext d2) { + (void)d1; (void)d2; /* only to match 'lua_Kfunction' prototype */ + return lua_gettop(L) - 1; +} + + +static int luaB_dofile (lua_State *L) { + const char *fname = luaL_optstring(L, 1, NULL); + lua_settop(L, 1); + if (l_unlikely(luaL_loadfile(L, fname) != LUA_OK)) + return lua_error(L); + lua_callk(L, 0, LUA_MULTRET, 0, dofilecont); + return dofilecont(L, 0, 0); +} + + +static int luaB_assert (lua_State *L) { + if (l_likely(lua_toboolean(L, 1))) /* condition is true? */ + return lua_gettop(L); /* return all arguments */ + else { /* error */ + luaL_checkany(L, 1); /* there must be a condition */ + lua_remove(L, 1); /* remove it */ + lua_pushliteral(L, "assertion failed!"); /* default message */ + lua_settop(L, 1); /* leave only message (default if no other one) */ + return luaB_error(L); /* call 'error' */ + } +} + + +static int luaB_select (lua_State *L) { + int n = lua_gettop(L); + if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') { + lua_pushinteger(L, n-1); + return 1; + } + else { + lua_Integer i = luaL_checkinteger(L, 1); + if (i < 0) i = n + i; + else if (i > n) i = n; + luaL_argcheck(L, 1 <= i, 1, "index out of range"); + return n - (int)i; + } +} + + +/* +** Continuation function for 'pcall' and 'xpcall'. Both functions +** already pushed a 'true' before doing the call, so in case of success +** 'finishpcall' only has to return everything in the stack minus +** 'extra' values (where 'extra' is exactly the number of items to be +** ignored). +*/ +static int finishpcall (lua_State *L, int status, lua_KContext extra) { + if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) { /* error? */ + lua_pushboolean(L, 0); /* first result (false) */ + lua_pushvalue(L, -2); /* error message */ + return 2; /* return false, msg */ + } + else + return lua_gettop(L) - (int)extra; /* return all results */ +} + + +static int luaB_pcall (lua_State *L) { + int status; + luaL_checkany(L, 1); + lua_pushboolean(L, 1); /* first result if no errors */ + lua_insert(L, 1); /* put it in place */ + status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall); + return finishpcall(L, status, 0); +} + + +/* +** Do a protected call with error handling. After 'lua_rotate', the +** stack will have ; so, the function passes +** 2 to 'finishpcall' to skip the 2 first values when returning results. +*/ +static int luaB_xpcall (lua_State *L) { + int status; + int n = lua_gettop(L); + luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */ + lua_pushboolean(L, 1); /* first result */ + lua_pushvalue(L, 1); /* function */ + lua_rotate(L, 3, 2); /* move them below function's arguments */ + status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall); + return finishpcall(L, status, 2); +} + + +static int luaB_tostring (lua_State *L) { + luaL_checkany(L, 1); + luaL_tolstring(L, 1, NULL); + return 1; +} + + +static const luaL_Reg base_funcs[] = { + {"assert", luaB_assert}, + {"collectgarbage", luaB_collectgarbage}, + {"dofile", luaB_dofile}, + {"error", luaB_error}, + {"getmetatable", luaB_getmetatable}, + {"ipairs", luaB_ipairs}, + {"loadfile", luaB_loadfile}, + {"load", luaB_load}, + {"next", luaB_next}, + {"pairs", luaB_pairs}, + {"pcall", luaB_pcall}, + {"print", luaB_print}, + {"warn", luaB_warn}, + {"rawequal", luaB_rawequal}, + {"rawlen", luaB_rawlen}, + {"rawget", luaB_rawget}, + {"rawset", luaB_rawset}, + {"select", luaB_select}, + {"setmetatable", luaB_setmetatable}, + {"tonumber", luaB_tonumber}, + {"tostring", luaB_tostring}, + {"type", luaB_type}, + {"xpcall", luaB_xpcall}, + /* placeholders */ + {LUA_GNAME, NULL}, + {"_VERSION", NULL}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_base (lua_State *L) { + /* open lib into global table */ + lua_pushglobaltable(L); + luaL_setfuncs(L, base_funcs, 0); + /* set global _G */ + lua_pushvalue(L, -1); + lua_setfield(L, -2, LUA_GNAME); + /* set global _VERSION */ + lua_pushliteral(L, LUA_VERSION); + lua_setfield(L, -2, "_VERSION"); + return 1; +} + diff --git a/src/lcode.c b/src/lcode.c new file mode 100644 index 0000000..1a371ca --- /dev/null +++ b/src/lcode.c @@ -0,0 +1,1871 @@ +/* +** $Id: lcode.c $ +** Code generator for Lua +** See Copyright Notice in lua.h +*/ + +#define lcode_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include +#include +#include + +#include "lua.h" + +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "llex.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstring.h" +#include "ltable.h" +#include "lvm.h" + + +/* Maximum number of registers in a Lua function (must fit in 8 bits) */ +#define MAXREGS 255 + + +#define hasjumps(e) ((e)->t != (e)->f) + + +static int codesJ (FuncState *fs, OpCode o, int sj, int k); + + + +/* semantic error */ +l_noret luaK_semerror (LexState *ls, const char *msg) { + ls->t.token = 0; /* remove "near " from final message */ + luaX_syntaxerror(ls, msg); +} + + +/* +** If expression is a numeric constant, fills 'v' with its value +** and returns 1. Otherwise, returns 0. +*/ +static int tonumeral (const expdesc *e, TValue *v) { + if (hasjumps(e)) + return 0; /* not a numeral */ + switch (e->k) { + case VKINT: + if (v) setivalue(v, e->u.ival); + return 1; + case VKFLT: + if (v) setfltvalue(v, e->u.nval); + return 1; + default: return 0; + } +} + + +/* +** Get the constant value from a constant expression +*/ +static TValue *const2val (FuncState *fs, const expdesc *e) { + lua_assert(e->k == VCONST); + return &fs->ls->dyd->actvar.arr[e->u.info].k; +} + + +/* +** If expression is a constant, fills 'v' with its value +** and returns 1. Otherwise, returns 0. +*/ +int luaK_exp2const (FuncState *fs, const expdesc *e, TValue *v) { + if (hasjumps(e)) + return 0; /* not a constant */ + switch (e->k) { + case VFALSE: + setbfvalue(v); + return 1; + case VTRUE: + setbtvalue(v); + return 1; + case VNIL: + setnilvalue(v); + return 1; + case VKSTR: { + setsvalue(fs->ls->L, v, e->u.strval); + return 1; + } + case VCONST: { + setobj(fs->ls->L, v, const2val(fs, e)); + return 1; + } + default: return tonumeral(e, v); + } +} + + +/* +** Return the previous instruction of the current code. If there +** may be a jump target between the current instruction and the +** previous one, return an invalid instruction (to avoid wrong +** optimizations). +*/ +static Instruction *previousinstruction (FuncState *fs) { + static const Instruction invalidinstruction = ~(Instruction)0; + if (fs->pc > fs->lasttarget) + return &fs->f->code[fs->pc - 1]; /* previous instruction */ + else + return cast(Instruction*, &invalidinstruction); +} + + +/* +** Create a OP_LOADNIL instruction, but try to optimize: if the previous +** instruction is also OP_LOADNIL and ranges are compatible, adjust +** range of previous instruction instead of emitting a new one. (For +** instance, 'local a; local b' will generate a single opcode.) +*/ +void luaK_nil (FuncState *fs, int from, int n) { + int l = from + n - 1; /* last register to set nil */ + Instruction *previous = previousinstruction(fs); + if (GET_OPCODE(*previous) == OP_LOADNIL) { /* previous is LOADNIL? */ + int pfrom = GETARG_A(*previous); /* get previous range */ + int pl = pfrom + GETARG_B(*previous); + if ((pfrom <= from && from <= pl + 1) || + (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */ + if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */ + if (pl > l) l = pl; /* l = max(l, pl) */ + SETARG_A(*previous, from); + SETARG_B(*previous, l - from); + return; + } /* else go through */ + } + luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */ +} + + +/* +** Gets the destination address of a jump instruction. Used to traverse +** a list of jumps. +*/ +static int getjump (FuncState *fs, int pc) { + int offset = GETARG_sJ(fs->f->code[pc]); + if (offset == NO_JUMP) /* point to itself represents end of list */ + return NO_JUMP; /* end of list */ + else + return (pc+1)+offset; /* turn offset into absolute position */ +} + + +/* +** Fix jump instruction at position 'pc' to jump to 'dest'. +** (Jump addresses are relative in Lua) +*/ +static void fixjump (FuncState *fs, int pc, int dest) { + Instruction *jmp = &fs->f->code[pc]; + int offset = dest - (pc + 1); + lua_assert(dest != NO_JUMP); + if (!(-OFFSET_sJ <= offset && offset <= MAXARG_sJ - OFFSET_sJ)) + luaX_syntaxerror(fs->ls, "control structure too long"); + lua_assert(GET_OPCODE(*jmp) == OP_JMP); + SETARG_sJ(*jmp, offset); +} + + +/* +** Concatenate jump-list 'l2' into jump-list 'l1' +*/ +void luaK_concat (FuncState *fs, int *l1, int l2) { + if (l2 == NO_JUMP) return; /* nothing to concatenate? */ + else if (*l1 == NO_JUMP) /* no original list? */ + *l1 = l2; /* 'l1' points to 'l2' */ + else { + int list = *l1; + int next; + while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */ + list = next; + fixjump(fs, list, l2); /* last element links to 'l2' */ + } +} + + +/* +** Create a jump instruction and return its position, so its destination +** can be fixed later (with 'fixjump'). +*/ +int luaK_jump (FuncState *fs) { + return codesJ(fs, OP_JMP, NO_JUMP, 0); +} + + +/* +** Code a 'return' instruction +*/ +void luaK_ret (FuncState *fs, int first, int nret) { + OpCode op; + switch (nret) { + case 0: op = OP_RETURN0; break; + case 1: op = OP_RETURN1; break; + default: op = OP_RETURN; break; + } + luaK_codeABC(fs, op, first, nret + 1, 0); +} + + +/* +** Code a "conditional jump", that is, a test or comparison opcode +** followed by a jump. Return jump position. +*/ +static int condjump (FuncState *fs, OpCode op, int A, int B, int C, int k) { + luaK_codeABCk(fs, op, A, B, C, k); + return luaK_jump(fs); +} + + +/* +** returns current 'pc' and marks it as a jump target (to avoid wrong +** optimizations with consecutive instructions not in the same basic block). +*/ +int luaK_getlabel (FuncState *fs) { + fs->lasttarget = fs->pc; + return fs->pc; +} + + +/* +** Returns the position of the instruction "controlling" a given +** jump (that is, its condition), or the jump itself if it is +** unconditional. +*/ +static Instruction *getjumpcontrol (FuncState *fs, int pc) { + Instruction *pi = &fs->f->code[pc]; + if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1)))) + return pi-1; + else + return pi; +} + + +/* +** Patch destination register for a TESTSET instruction. +** If instruction in position 'node' is not a TESTSET, return 0 ("fails"). +** Otherwise, if 'reg' is not 'NO_REG', set it as the destination +** register. Otherwise, change instruction to a simple 'TEST' (produces +** no register value) +*/ +static int patchtestreg (FuncState *fs, int node, int reg) { + Instruction *i = getjumpcontrol(fs, node); + if (GET_OPCODE(*i) != OP_TESTSET) + return 0; /* cannot patch other instructions */ + if (reg != NO_REG && reg != GETARG_B(*i)) + SETARG_A(*i, reg); + else { + /* no register to put value or register already has the value; + change instruction to simple test */ + *i = CREATE_ABCk(OP_TEST, GETARG_B(*i), 0, 0, GETARG_k(*i)); + } + return 1; +} + + +/* +** Traverse a list of tests ensuring no one produces a value +*/ +static void removevalues (FuncState *fs, int list) { + for (; list != NO_JUMP; list = getjump(fs, list)) + patchtestreg(fs, list, NO_REG); +} + + +/* +** Traverse a list of tests, patching their destination address and +** registers: tests producing values jump to 'vtarget' (and put their +** values in 'reg'), other tests jump to 'dtarget'. +*/ +static void patchlistaux (FuncState *fs, int list, int vtarget, int reg, + int dtarget) { + while (list != NO_JUMP) { + int next = getjump(fs, list); + if (patchtestreg(fs, list, reg)) + fixjump(fs, list, vtarget); + else + fixjump(fs, list, dtarget); /* jump to default target */ + list = next; + } +} + + +/* +** Path all jumps in 'list' to jump to 'target'. +** (The assert means that we cannot fix a jump to a forward address +** because we only know addresses once code is generated.) +*/ +void luaK_patchlist (FuncState *fs, int list, int target) { + lua_assert(target <= fs->pc); + patchlistaux(fs, list, target, NO_REG, target); +} + + +void luaK_patchtohere (FuncState *fs, int list) { + int hr = luaK_getlabel(fs); /* mark "here" as a jump target */ + luaK_patchlist(fs, list, hr); +} + + +/* limit for difference between lines in relative line info. */ +#define LIMLINEDIFF 0x80 + + +/* +** Save line info for a new instruction. If difference from last line +** does not fit in a byte, of after that many instructions, save a new +** absolute line info; (in that case, the special value 'ABSLINEINFO' +** in 'lineinfo' signals the existence of this absolute information.) +** Otherwise, store the difference from last line in 'lineinfo'. +*/ +static void savelineinfo (FuncState *fs, Proto *f, int line) { + int linedif = line - fs->previousline; + int pc = fs->pc - 1; /* last instruction coded */ + if (abs(linedif) >= LIMLINEDIFF || fs->iwthabs++ >= MAXIWTHABS) { + luaM_growvector(fs->ls->L, f->abslineinfo, fs->nabslineinfo, + f->sizeabslineinfo, AbsLineInfo, MAX_INT, "lines"); + f->abslineinfo[fs->nabslineinfo].pc = pc; + f->abslineinfo[fs->nabslineinfo++].line = line; + linedif = ABSLINEINFO; /* signal that there is absolute information */ + fs->iwthabs = 1; /* restart counter */ + } + luaM_growvector(fs->ls->L, f->lineinfo, pc, f->sizelineinfo, ls_byte, + MAX_INT, "opcodes"); + f->lineinfo[pc] = linedif; + fs->previousline = line; /* last line saved */ +} + + +/* +** Remove line information from the last instruction. +** If line information for that instruction is absolute, set 'iwthabs' +** above its max to force the new (replacing) instruction to have +** absolute line info, too. +*/ +static void removelastlineinfo (FuncState *fs) { + Proto *f = fs->f; + int pc = fs->pc - 1; /* last instruction coded */ + if (f->lineinfo[pc] != ABSLINEINFO) { /* relative line info? */ + fs->previousline -= f->lineinfo[pc]; /* correct last line saved */ + fs->iwthabs--; /* undo previous increment */ + } + else { /* absolute line information */ + lua_assert(f->abslineinfo[fs->nabslineinfo - 1].pc == pc); + fs->nabslineinfo--; /* remove it */ + fs->iwthabs = MAXIWTHABS + 1; /* force next line info to be absolute */ + } +} + + +/* +** Remove the last instruction created, correcting line information +** accordingly. +*/ +static void removelastinstruction (FuncState *fs) { + removelastlineinfo(fs); + fs->pc--; +} + + +/* +** Emit instruction 'i', checking for array sizes and saving also its +** line information. Return 'i' position. +*/ +int luaK_code (FuncState *fs, Instruction i) { + Proto *f = fs->f; + /* put new instruction in code array */ + luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction, + MAX_INT, "opcodes"); + f->code[fs->pc++] = i; + savelineinfo(fs, f, fs->ls->lastline); + return fs->pc - 1; /* index of new instruction */ +} + + +/* +** Format and emit an 'iABC' instruction. (Assertions check consistency +** of parameters versus opcode.) +*/ +int luaK_codeABCk (FuncState *fs, OpCode o, int a, int b, int c, int k) { + lua_assert(getOpMode(o) == iABC); + lua_assert(a <= MAXARG_A && b <= MAXARG_B && + c <= MAXARG_C && (k & ~1) == 0); + return luaK_code(fs, CREATE_ABCk(o, a, b, c, k)); +} + + +/* +** Format and emit an 'iABx' instruction. +*/ +int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) { + lua_assert(getOpMode(o) == iABx); + lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx); + return luaK_code(fs, CREATE_ABx(o, a, bc)); +} + + +/* +** Format and emit an 'iAsBx' instruction. +*/ +int luaK_codeAsBx (FuncState *fs, OpCode o, int a, int bc) { + unsigned int b = bc + OFFSET_sBx; + lua_assert(getOpMode(o) == iAsBx); + lua_assert(a <= MAXARG_A && b <= MAXARG_Bx); + return luaK_code(fs, CREATE_ABx(o, a, b)); +} + + +/* +** Format and emit an 'isJ' instruction. +*/ +static int codesJ (FuncState *fs, OpCode o, int sj, int k) { + unsigned int j = sj + OFFSET_sJ; + lua_assert(getOpMode(o) == isJ); + lua_assert(j <= MAXARG_sJ && (k & ~1) == 0); + return luaK_code(fs, CREATE_sJ(o, j, k)); +} + + +/* +** Emit an "extra argument" instruction (format 'iAx') +*/ +static int codeextraarg (FuncState *fs, int a) { + lua_assert(a <= MAXARG_Ax); + return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a)); +} + + +/* +** Emit a "load constant" instruction, using either 'OP_LOADK' +** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX' +** instruction with "extra argument". +*/ +static int luaK_codek (FuncState *fs, int reg, int k) { + if (k <= MAXARG_Bx) + return luaK_codeABx(fs, OP_LOADK, reg, k); + else { + int p = luaK_codeABx(fs, OP_LOADKX, reg, 0); + codeextraarg(fs, k); + return p; + } +} + + +/* +** Check register-stack level, keeping track of its maximum size +** in field 'maxstacksize' +*/ +void luaK_checkstack (FuncState *fs, int n) { + int newstack = fs->freereg + n; + if (newstack > fs->f->maxstacksize) { + if (newstack >= MAXREGS) + luaX_syntaxerror(fs->ls, + "function or expression needs too many registers"); + fs->f->maxstacksize = cast_byte(newstack); + } +} + + +/* +** Reserve 'n' registers in register stack +*/ +void luaK_reserveregs (FuncState *fs, int n) { + luaK_checkstack(fs, n); + fs->freereg += n; +} + + +/* +** Free register 'reg', if it is neither a constant index nor +** a local variable. +) +*/ +static void freereg (FuncState *fs, int reg) { + if (reg >= luaY_nvarstack(fs)) { + fs->freereg--; + lua_assert(reg == fs->freereg); + } +} + + +/* +** Free two registers in proper order +*/ +static void freeregs (FuncState *fs, int r1, int r2) { + if (r1 > r2) { + freereg(fs, r1); + freereg(fs, r2); + } + else { + freereg(fs, r2); + freereg(fs, r1); + } +} + + +/* +** Free register used by expression 'e' (if any) +*/ +static void freeexp (FuncState *fs, expdesc *e) { + if (e->k == VNONRELOC) + freereg(fs, e->u.info); +} + + +/* +** Free registers used by expressions 'e1' and 'e2' (if any) in proper +** order. +*/ +static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) { + int r1 = (e1->k == VNONRELOC) ? e1->u.info : -1; + int r2 = (e2->k == VNONRELOC) ? e2->u.info : -1; + freeregs(fs, r1, r2); +} + + +/* +** Add constant 'v' to prototype's list of constants (field 'k'). +** Use scanner's table to cache position of constants in constant list +** and try to reuse constants. Because some values should not be used +** as keys (nil cannot be a key, integer keys can collapse with float +** keys), the caller must provide a useful 'key' for indexing the cache. +** Note that all functions share the same table, so entering or exiting +** a function can make some indices wrong. +*/ +static int addk (FuncState *fs, TValue *key, TValue *v) { + TValue val; + lua_State *L = fs->ls->L; + Proto *f = fs->f; + const TValue *idx = luaH_get(fs->ls->h, key); /* query scanner table */ + int k, oldsize; + if (ttisinteger(idx)) { /* is there an index there? */ + k = cast_int(ivalue(idx)); + /* correct value? (warning: must distinguish floats from integers!) */ + if (k < fs->nk && ttypetag(&f->k[k]) == ttypetag(v) && + luaV_rawequalobj(&f->k[k], v)) + return k; /* reuse index */ + } + /* constant not found; create a new entry */ + oldsize = f->sizek; + k = fs->nk; + /* numerical value does not need GC barrier; + table has no metatable, so it does not need to invalidate cache */ + setivalue(&val, k); + luaH_finishset(L, fs->ls->h, key, idx, &val); + luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants"); + while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]); + setobj(L, &f->k[k], v); + fs->nk++; + luaC_barrier(L, f, v); + return k; +} + + +/* +** Add a string to list of constants and return its index. +*/ +static int stringK (FuncState *fs, TString *s) { + TValue o; + setsvalue(fs->ls->L, &o, s); + return addk(fs, &o, &o); /* use string itself as key */ +} + + +/* +** Add an integer to list of constants and return its index. +*/ +static int luaK_intK (FuncState *fs, lua_Integer n) { + TValue o; + setivalue(&o, n); + return addk(fs, &o, &o); /* use integer itself as key */ +} + +/* +** Add a float to list of constants and return its index. Floats +** with integral values need a different key, to avoid collision +** with actual integers. To that, we add to the number its smaller +** power-of-two fraction that is still significant in its scale. +** For doubles, that would be 1/2^52. +** (This method is not bulletproof: there may be another float +** with that value, and for floats larger than 2^53 the result is +** still an integer. At worst, this only wastes an entry with +** a duplicate.) +*/ +static int luaK_numberK (FuncState *fs, lua_Number r) { + TValue o; + lua_Integer ik; + setfltvalue(&o, r); + if (!luaV_flttointeger(r, &ik, F2Ieq)) /* not an integral value? */ + return addk(fs, &o, &o); /* use number itself as key */ + else { /* must build an alternative key */ + const int nbm = l_floatatt(MANT_DIG); + const lua_Number q = l_mathop(ldexp)(l_mathop(1.0), -nbm + 1); + const lua_Number k = (ik == 0) ? q : r + r*q; /* new key */ + TValue kv; + setfltvalue(&kv, k); + /* result is not an integral value, unless value is too large */ + lua_assert(!luaV_flttointeger(k, &ik, F2Ieq) || + l_mathop(fabs)(r) >= l_mathop(1e6)); + return addk(fs, &kv, &o); + } +} + + +/* +** Add a false to list of constants and return its index. +*/ +static int boolF (FuncState *fs) { + TValue o; + setbfvalue(&o); + return addk(fs, &o, &o); /* use boolean itself as key */ +} + + +/* +** Add a true to list of constants and return its index. +*/ +static int boolT (FuncState *fs) { + TValue o; + setbtvalue(&o); + return addk(fs, &o, &o); /* use boolean itself as key */ +} + + +/* +** Add nil to list of constants and return its index. +*/ +static int nilK (FuncState *fs) { + TValue k, v; + setnilvalue(&v); + /* cannot use nil as key; instead use table itself to represent nil */ + sethvalue(fs->ls->L, &k, fs->ls->h); + return addk(fs, &k, &v); +} + + +/* +** Check whether 'i' can be stored in an 'sC' operand. Equivalent to +** (0 <= int2sC(i) && int2sC(i) <= MAXARG_C) but without risk of +** overflows in the hidden addition inside 'int2sC'. +*/ +static int fitsC (lua_Integer i) { + return (l_castS2U(i) + OFFSET_sC <= cast_uint(MAXARG_C)); +} + + +/* +** Check whether 'i' can be stored in an 'sBx' operand. +*/ +static int fitsBx (lua_Integer i) { + return (-OFFSET_sBx <= i && i <= MAXARG_Bx - OFFSET_sBx); +} + + +void luaK_int (FuncState *fs, int reg, lua_Integer i) { + if (fitsBx(i)) + luaK_codeAsBx(fs, OP_LOADI, reg, cast_int(i)); + else + luaK_codek(fs, reg, luaK_intK(fs, i)); +} + + +static void luaK_float (FuncState *fs, int reg, lua_Number f) { + lua_Integer fi; + if (luaV_flttointeger(f, &fi, F2Ieq) && fitsBx(fi)) + luaK_codeAsBx(fs, OP_LOADF, reg, cast_int(fi)); + else + luaK_codek(fs, reg, luaK_numberK(fs, f)); +} + + +/* +** Convert a constant in 'v' into an expression description 'e' +*/ +static void const2exp (TValue *v, expdesc *e) { + switch (ttypetag(v)) { + case LUA_VNUMINT: + e->k = VKINT; e->u.ival = ivalue(v); + break; + case LUA_VNUMFLT: + e->k = VKFLT; e->u.nval = fltvalue(v); + break; + case LUA_VFALSE: + e->k = VFALSE; + break; + case LUA_VTRUE: + e->k = VTRUE; + break; + case LUA_VNIL: + e->k = VNIL; + break; + case LUA_VSHRSTR: case LUA_VLNGSTR: + e->k = VKSTR; e->u.strval = tsvalue(v); + break; + default: lua_assert(0); + } +} + + +/* +** Fix an expression to return the number of results 'nresults'. +** 'e' must be a multi-ret expression (function call or vararg). +*/ +void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) { + Instruction *pc = &getinstruction(fs, e); + if (e->k == VCALL) /* expression is an open function call? */ + SETARG_C(*pc, nresults + 1); + else { + lua_assert(e->k == VVARARG); + SETARG_C(*pc, nresults + 1); + SETARG_A(*pc, fs->freereg); + luaK_reserveregs(fs, 1); + } +} + + +/* +** Convert a VKSTR to a VK +*/ +static void str2K (FuncState *fs, expdesc *e) { + lua_assert(e->k == VKSTR); + e->u.info = stringK(fs, e->u.strval); + e->k = VK; +} + + +/* +** Fix an expression to return one result. +** If expression is not a multi-ret expression (function call or +** vararg), it already returns one result, so nothing needs to be done. +** Function calls become VNONRELOC expressions (as its result comes +** fixed in the base register of the call), while vararg expressions +** become VRELOC (as OP_VARARG puts its results where it wants). +** (Calls are created returning one result, so that does not need +** to be fixed.) +*/ +void luaK_setoneret (FuncState *fs, expdesc *e) { + if (e->k == VCALL) { /* expression is an open function call? */ + /* already returns 1 value */ + lua_assert(GETARG_C(getinstruction(fs, e)) == 2); + e->k = VNONRELOC; /* result has fixed position */ + e->u.info = GETARG_A(getinstruction(fs, e)); + } + else if (e->k == VVARARG) { + SETARG_C(getinstruction(fs, e), 2); + e->k = VRELOC; /* can relocate its simple result */ + } +} + + +/* +** Ensure that expression 'e' is not a variable (nor a ). +** (Expression still may have jump lists.) +*/ +void luaK_dischargevars (FuncState *fs, expdesc *e) { + switch (e->k) { + case VCONST: { + const2exp(const2val(fs, e), e); + break; + } + case VLOCAL: { /* already in a register */ + e->u.info = e->u.var.ridx; + e->k = VNONRELOC; /* becomes a non-relocatable value */ + break; + } + case VUPVAL: { /* move value to some (pending) register */ + e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0); + e->k = VRELOC; + break; + } + case VINDEXUP: { + e->u.info = luaK_codeABC(fs, OP_GETTABUP, 0, e->u.ind.t, e->u.ind.idx); + e->k = VRELOC; + break; + } + case VINDEXI: { + freereg(fs, e->u.ind.t); + e->u.info = luaK_codeABC(fs, OP_GETI, 0, e->u.ind.t, e->u.ind.idx); + e->k = VRELOC; + break; + } + case VINDEXSTR: { + freereg(fs, e->u.ind.t); + e->u.info = luaK_codeABC(fs, OP_GETFIELD, 0, e->u.ind.t, e->u.ind.idx); + e->k = VRELOC; + break; + } + case VINDEXED: { + freeregs(fs, e->u.ind.t, e->u.ind.idx); + e->u.info = luaK_codeABC(fs, OP_GETTABLE, 0, e->u.ind.t, e->u.ind.idx); + e->k = VRELOC; + break; + } + case VVARARG: case VCALL: { + luaK_setoneret(fs, e); + break; + } + default: break; /* there is one value available (somewhere) */ + } +} + + +/* +** Ensure expression value is in register 'reg', making 'e' a +** non-relocatable expression. +** (Expression still may have jump lists.) +*/ +static void discharge2reg (FuncState *fs, expdesc *e, int reg) { + luaK_dischargevars(fs, e); + switch (e->k) { + case VNIL: { + luaK_nil(fs, reg, 1); + break; + } + case VFALSE: { + luaK_codeABC(fs, OP_LOADFALSE, reg, 0, 0); + break; + } + case VTRUE: { + luaK_codeABC(fs, OP_LOADTRUE, reg, 0, 0); + break; + } + case VKSTR: { + str2K(fs, e); + } /* FALLTHROUGH */ + case VK: { + luaK_codek(fs, reg, e->u.info); + break; + } + case VKFLT: { + luaK_float(fs, reg, e->u.nval); + break; + } + case VKINT: { + luaK_int(fs, reg, e->u.ival); + break; + } + case VRELOC: { + Instruction *pc = &getinstruction(fs, e); + SETARG_A(*pc, reg); /* instruction will put result in 'reg' */ + break; + } + case VNONRELOC: { + if (reg != e->u.info) + luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0); + break; + } + default: { + lua_assert(e->k == VJMP); + return; /* nothing to do... */ + } + } + e->u.info = reg; + e->k = VNONRELOC; +} + + +/* +** Ensure expression value is in a register, making 'e' a +** non-relocatable expression. +** (Expression still may have jump lists.) +*/ +static void discharge2anyreg (FuncState *fs, expdesc *e) { + if (e->k != VNONRELOC) { /* no fixed register yet? */ + luaK_reserveregs(fs, 1); /* get a register */ + discharge2reg(fs, e, fs->freereg-1); /* put value there */ + } +} + + +static int code_loadbool (FuncState *fs, int A, OpCode op) { + luaK_getlabel(fs); /* those instructions may be jump targets */ + return luaK_codeABC(fs, op, A, 0, 0); +} + + +/* +** check whether list has any jump that do not produce a value +** or produce an inverted value +*/ +static int need_value (FuncState *fs, int list) { + for (; list != NO_JUMP; list = getjump(fs, list)) { + Instruction i = *getjumpcontrol(fs, list); + if (GET_OPCODE(i) != OP_TESTSET) return 1; + } + return 0; /* not found */ +} + + +/* +** Ensures final expression result (which includes results from its +** jump lists) is in register 'reg'. +** If expression has jumps, need to patch these jumps either to +** its final position or to "load" instructions (for those tests +** that do not produce values). +*/ +static void exp2reg (FuncState *fs, expdesc *e, int reg) { + discharge2reg(fs, e, reg); + if (e->k == VJMP) /* expression itself is a test? */ + luaK_concat(fs, &e->t, e->u.info); /* put this jump in 't' list */ + if (hasjumps(e)) { + int final; /* position after whole expression */ + int p_f = NO_JUMP; /* position of an eventual LOAD false */ + int p_t = NO_JUMP; /* position of an eventual LOAD true */ + if (need_value(fs, e->t) || need_value(fs, e->f)) { + int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs); + p_f = code_loadbool(fs, reg, OP_LFALSESKIP); /* skip next inst. */ + p_t = code_loadbool(fs, reg, OP_LOADTRUE); + /* jump around these booleans if 'e' is not a test */ + luaK_patchtohere(fs, fj); + } + final = luaK_getlabel(fs); + patchlistaux(fs, e->f, final, reg, p_f); + patchlistaux(fs, e->t, final, reg, p_t); + } + e->f = e->t = NO_JUMP; + e->u.info = reg; + e->k = VNONRELOC; +} + + +/* +** Ensures final expression result is in next available register. +*/ +void luaK_exp2nextreg (FuncState *fs, expdesc *e) { + luaK_dischargevars(fs, e); + freeexp(fs, e); + luaK_reserveregs(fs, 1); + exp2reg(fs, e, fs->freereg - 1); +} + + +/* +** Ensures final expression result is in some (any) register +** and return that register. +*/ +int luaK_exp2anyreg (FuncState *fs, expdesc *e) { + luaK_dischargevars(fs, e); + if (e->k == VNONRELOC) { /* expression already has a register? */ + if (!hasjumps(e)) /* no jumps? */ + return e->u.info; /* result is already in a register */ + if (e->u.info >= luaY_nvarstack(fs)) { /* reg. is not a local? */ + exp2reg(fs, e, e->u.info); /* put final result in it */ + return e->u.info; + } + /* else expression has jumps and cannot change its register + to hold the jump values, because it is a local variable. + Go through to the default case. */ + } + luaK_exp2nextreg(fs, e); /* default: use next available register */ + return e->u.info; +} + + +/* +** Ensures final expression result is either in a register +** or in an upvalue. +*/ +void luaK_exp2anyregup (FuncState *fs, expdesc *e) { + if (e->k != VUPVAL || hasjumps(e)) + luaK_exp2anyreg(fs, e); +} + + +/* +** Ensures final expression result is either in a register +** or it is a constant. +*/ +void luaK_exp2val (FuncState *fs, expdesc *e) { + if (hasjumps(e)) + luaK_exp2anyreg(fs, e); + else + luaK_dischargevars(fs, e); +} + + +/* +** Try to make 'e' a K expression with an index in the range of R/K +** indices. Return true iff succeeded. +*/ +static int luaK_exp2K (FuncState *fs, expdesc *e) { + if (!hasjumps(e)) { + int info; + switch (e->k) { /* move constants to 'k' */ + case VTRUE: info = boolT(fs); break; + case VFALSE: info = boolF(fs); break; + case VNIL: info = nilK(fs); break; + case VKINT: info = luaK_intK(fs, e->u.ival); break; + case VKFLT: info = luaK_numberK(fs, e->u.nval); break; + case VKSTR: info = stringK(fs, e->u.strval); break; + case VK: info = e->u.info; break; + default: return 0; /* not a constant */ + } + if (info <= MAXINDEXRK) { /* does constant fit in 'argC'? */ + e->k = VK; /* make expression a 'K' expression */ + e->u.info = info; + return 1; + } + } + /* else, expression doesn't fit; leave it unchanged */ + return 0; +} + + +/* +** Ensures final expression result is in a valid R/K index +** (that is, it is either in a register or in 'k' with an index +** in the range of R/K indices). +** Returns 1 iff expression is K. +*/ +int luaK_exp2RK (FuncState *fs, expdesc *e) { + if (luaK_exp2K(fs, e)) + return 1; + else { /* not a constant in the right range: put it in a register */ + luaK_exp2anyreg(fs, e); + return 0; + } +} + + +static void codeABRK (FuncState *fs, OpCode o, int a, int b, + expdesc *ec) { + int k = luaK_exp2RK(fs, ec); + luaK_codeABCk(fs, o, a, b, ec->u.info, k); +} + + +/* +** Generate code to store result of expression 'ex' into variable 'var'. +*/ +void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) { + switch (var->k) { + case VLOCAL: { + freeexp(fs, ex); + exp2reg(fs, ex, var->u.var.ridx); /* compute 'ex' into proper place */ + return; + } + case VUPVAL: { + int e = luaK_exp2anyreg(fs, ex); + luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0); + break; + } + case VINDEXUP: { + codeABRK(fs, OP_SETTABUP, var->u.ind.t, var->u.ind.idx, ex); + break; + } + case VINDEXI: { + codeABRK(fs, OP_SETI, var->u.ind.t, var->u.ind.idx, ex); + break; + } + case VINDEXSTR: { + codeABRK(fs, OP_SETFIELD, var->u.ind.t, var->u.ind.idx, ex); + break; + } + case VINDEXED: { + codeABRK(fs, OP_SETTABLE, var->u.ind.t, var->u.ind.idx, ex); + break; + } + default: lua_assert(0); /* invalid var kind to store */ + } + freeexp(fs, ex); +} + + +/* +** Emit SELF instruction (convert expression 'e' into 'e:key(e,'). +*/ +void luaK_self (FuncState *fs, expdesc *e, expdesc *key) { + int ereg; + luaK_exp2anyreg(fs, e); + ereg = e->u.info; /* register where 'e' was placed */ + freeexp(fs, e); + e->u.info = fs->freereg; /* base register for op_self */ + e->k = VNONRELOC; /* self expression has a fixed register */ + luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */ + codeABRK(fs, OP_SELF, e->u.info, ereg, key); + freeexp(fs, key); +} + + +/* +** Negate condition 'e' (where 'e' is a comparison). +*/ +static void negatecondition (FuncState *fs, expdesc *e) { + Instruction *pc = getjumpcontrol(fs, e->u.info); + lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET && + GET_OPCODE(*pc) != OP_TEST); + SETARG_k(*pc, (GETARG_k(*pc) ^ 1)); +} + + +/* +** Emit instruction to jump if 'e' is 'cond' (that is, if 'cond' +** is true, code will jump if 'e' is true.) Return jump position. +** Optimize when 'e' is 'not' something, inverting the condition +** and removing the 'not'. +*/ +static int jumponcond (FuncState *fs, expdesc *e, int cond) { + if (e->k == VRELOC) { + Instruction ie = getinstruction(fs, e); + if (GET_OPCODE(ie) == OP_NOT) { + removelastinstruction(fs); /* remove previous OP_NOT */ + return condjump(fs, OP_TEST, GETARG_B(ie), 0, 0, !cond); + } + /* else go through */ + } + discharge2anyreg(fs, e); + freeexp(fs, e); + return condjump(fs, OP_TESTSET, NO_REG, e->u.info, 0, cond); +} + + +/* +** Emit code to go through if 'e' is true, jump otherwise. +*/ +void luaK_goiftrue (FuncState *fs, expdesc *e) { + int pc; /* pc of new jump */ + luaK_dischargevars(fs, e); + switch (e->k) { + case VJMP: { /* condition? */ + negatecondition(fs, e); /* jump when it is false */ + pc = e->u.info; /* save jump position */ + break; + } + case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: { + pc = NO_JUMP; /* always true; do nothing */ + break; + } + default: { + pc = jumponcond(fs, e, 0); /* jump when false */ + break; + } + } + luaK_concat(fs, &e->f, pc); /* insert new jump in false list */ + luaK_patchtohere(fs, e->t); /* true list jumps to here (to go through) */ + e->t = NO_JUMP; +} + + +/* +** Emit code to go through if 'e' is false, jump otherwise. +*/ +void luaK_goiffalse (FuncState *fs, expdesc *e) { + int pc; /* pc of new jump */ + luaK_dischargevars(fs, e); + switch (e->k) { + case VJMP: { + pc = e->u.info; /* already jump if true */ + break; + } + case VNIL: case VFALSE: { + pc = NO_JUMP; /* always false; do nothing */ + break; + } + default: { + pc = jumponcond(fs, e, 1); /* jump if true */ + break; + } + } + luaK_concat(fs, &e->t, pc); /* insert new jump in 't' list */ + luaK_patchtohere(fs, e->f); /* false list jumps to here (to go through) */ + e->f = NO_JUMP; +} + + +/* +** Code 'not e', doing constant folding. +*/ +static void codenot (FuncState *fs, expdesc *e) { + switch (e->k) { + case VNIL: case VFALSE: { + e->k = VTRUE; /* true == not nil == not false */ + break; + } + case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: { + e->k = VFALSE; /* false == not "x" == not 0.5 == not 1 == not true */ + break; + } + case VJMP: { + negatecondition(fs, e); + break; + } + case VRELOC: + case VNONRELOC: { + discharge2anyreg(fs, e); + freeexp(fs, e); + e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0); + e->k = VRELOC; + break; + } + default: lua_assert(0); /* cannot happen */ + } + /* interchange true and false lists */ + { int temp = e->f; e->f = e->t; e->t = temp; } + removevalues(fs, e->f); /* values are useless when negated */ + removevalues(fs, e->t); +} + + +/* +** Check whether expression 'e' is a small literal string +*/ +static int isKstr (FuncState *fs, expdesc *e) { + return (e->k == VK && !hasjumps(e) && e->u.info <= MAXARG_B && + ttisshrstring(&fs->f->k[e->u.info])); +} + +/* +** Check whether expression 'e' is a literal integer. +*/ +int luaK_isKint (expdesc *e) { + return (e->k == VKINT && !hasjumps(e)); +} + + +/* +** Check whether expression 'e' is a literal integer in +** proper range to fit in register C +*/ +static int isCint (expdesc *e) { + return luaK_isKint(e) && (l_castS2U(e->u.ival) <= l_castS2U(MAXARG_C)); +} + + +/* +** Check whether expression 'e' is a literal integer in +** proper range to fit in register sC +*/ +static int isSCint (expdesc *e) { + return luaK_isKint(e) && fitsC(e->u.ival); +} + + +/* +** Check whether expression 'e' is a literal integer or float in +** proper range to fit in a register (sB or sC). +*/ +static int isSCnumber (expdesc *e, int *pi, int *isfloat) { + lua_Integer i; + if (e->k == VKINT) + i = e->u.ival; + else if (e->k == VKFLT && luaV_flttointeger(e->u.nval, &i, F2Ieq)) + *isfloat = 1; + else + return 0; /* not a number */ + if (!hasjumps(e) && fitsC(i)) { + *pi = int2sC(cast_int(i)); + return 1; + } + else + return 0; +} + + +/* +** Create expression 't[k]'. 't' must have its final result already in a +** register or upvalue. Upvalues can only be indexed by literal strings. +** Keys can be literal strings in the constant table or arbitrary +** values in registers. +*/ +void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) { + if (k->k == VKSTR) + str2K(fs, k); + lua_assert(!hasjumps(t) && + (t->k == VLOCAL || t->k == VNONRELOC || t->k == VUPVAL)); + if (t->k == VUPVAL && !isKstr(fs, k)) /* upvalue indexed by non 'Kstr'? */ + luaK_exp2anyreg(fs, t); /* put it in a register */ + if (t->k == VUPVAL) { + t->u.ind.t = t->u.info; /* upvalue index */ + t->u.ind.idx = k->u.info; /* literal string */ + t->k = VINDEXUP; + } + else { + /* register index of the table */ + t->u.ind.t = (t->k == VLOCAL) ? t->u.var.ridx: t->u.info; + if (isKstr(fs, k)) { + t->u.ind.idx = k->u.info; /* literal string */ + t->k = VINDEXSTR; + } + else if (isCint(k)) { + t->u.ind.idx = cast_int(k->u.ival); /* int. constant in proper range */ + t->k = VINDEXI; + } + else { + t->u.ind.idx = luaK_exp2anyreg(fs, k); /* register */ + t->k = VINDEXED; + } + } +} + + +/* +** Return false if folding can raise an error. +** Bitwise operations need operands convertible to integers; division +** operations cannot have 0 as divisor. +*/ +static int validop (int op, TValue *v1, TValue *v2) { + switch (op) { + case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: + case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: { /* conversion errors */ + lua_Integer i; + return (luaV_tointegerns(v1, &i, LUA_FLOORN2I) && + luaV_tointegerns(v2, &i, LUA_FLOORN2I)); + } + case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD: /* division by 0 */ + return (nvalue(v2) != 0); + default: return 1; /* everything else is valid */ + } +} + + +/* +** Try to "constant-fold" an operation; return 1 iff successful. +** (In this case, 'e1' has the final result.) +*/ +static int constfolding (FuncState *fs, int op, expdesc *e1, + const expdesc *e2) { + TValue v1, v2, res; + if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2)) + return 0; /* non-numeric operands or not safe to fold */ + luaO_rawarith(fs->ls->L, op, &v1, &v2, &res); /* does operation */ + if (ttisinteger(&res)) { + e1->k = VKINT; + e1->u.ival = ivalue(&res); + } + else { /* folds neither NaN nor 0.0 (to avoid problems with -0.0) */ + lua_Number n = fltvalue(&res); + if (luai_numisnan(n) || n == 0) + return 0; + e1->k = VKFLT; + e1->u.nval = n; + } + return 1; +} + + +/* +** Convert a BinOpr to an OpCode (ORDER OPR - ORDER OP) +*/ +l_sinline OpCode binopr2op (BinOpr opr, BinOpr baser, OpCode base) { + lua_assert(baser <= opr && + ((baser == OPR_ADD && opr <= OPR_SHR) || + (baser == OPR_LT && opr <= OPR_LE))); + return cast(OpCode, (cast_int(opr) - cast_int(baser)) + cast_int(base)); +} + + +/* +** Convert a UnOpr to an OpCode (ORDER OPR - ORDER OP) +*/ +l_sinline OpCode unopr2op (UnOpr opr) { + return cast(OpCode, (cast_int(opr) - cast_int(OPR_MINUS)) + + cast_int(OP_UNM)); +} + + +/* +** Convert a BinOpr to a tag method (ORDER OPR - ORDER TM) +*/ +l_sinline TMS binopr2TM (BinOpr opr) { + lua_assert(OPR_ADD <= opr && opr <= OPR_SHR); + return cast(TMS, (cast_int(opr) - cast_int(OPR_ADD)) + cast_int(TM_ADD)); +} + + +/* +** Emit code for unary expressions that "produce values" +** (everything but 'not'). +** Expression to produce final result will be encoded in 'e'. +*/ +static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) { + int r = luaK_exp2anyreg(fs, e); /* opcodes operate only on registers */ + freeexp(fs, e); + e->u.info = luaK_codeABC(fs, op, 0, r, 0); /* generate opcode */ + e->k = VRELOC; /* all those operations are relocatable */ + luaK_fixline(fs, line); +} + + +/* +** Emit code for binary expressions that "produce values" +** (everything but logical operators 'and'/'or' and comparison +** operators). +** Expression to produce final result will be encoded in 'e1'. +*/ +static void finishbinexpval (FuncState *fs, expdesc *e1, expdesc *e2, + OpCode op, int v2, int flip, int line, + OpCode mmop, TMS event) { + int v1 = luaK_exp2anyreg(fs, e1); + int pc = luaK_codeABCk(fs, op, 0, v1, v2, 0); + freeexps(fs, e1, e2); + e1->u.info = pc; + e1->k = VRELOC; /* all those operations are relocatable */ + luaK_fixline(fs, line); + luaK_codeABCk(fs, mmop, v1, v2, event, flip); /* to call metamethod */ + luaK_fixline(fs, line); +} + + +/* +** Emit code for binary expressions that "produce values" over +** two registers. +*/ +static void codebinexpval (FuncState *fs, BinOpr opr, + expdesc *e1, expdesc *e2, int line) { + OpCode op = binopr2op(opr, OPR_ADD, OP_ADD); + int v2 = luaK_exp2anyreg(fs, e2); /* make sure 'e2' is in a register */ + /* 'e1' must be already in a register or it is a constant */ + lua_assert((VNIL <= e1->k && e1->k <= VKSTR) || + e1->k == VNONRELOC || e1->k == VRELOC); + lua_assert(OP_ADD <= op && op <= OP_SHR); + finishbinexpval(fs, e1, e2, op, v2, 0, line, OP_MMBIN, binopr2TM(opr)); +} + + +/* +** Code binary operators with immediate operands. +*/ +static void codebini (FuncState *fs, OpCode op, + expdesc *e1, expdesc *e2, int flip, int line, + TMS event) { + int v2 = int2sC(cast_int(e2->u.ival)); /* immediate operand */ + lua_assert(e2->k == VKINT); + finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINI, event); +} + + +/* +** Code binary operators with K operand. +*/ +static void codebinK (FuncState *fs, BinOpr opr, + expdesc *e1, expdesc *e2, int flip, int line) { + TMS event = binopr2TM(opr); + int v2 = e2->u.info; /* K index */ + OpCode op = binopr2op(opr, OPR_ADD, OP_ADDK); + finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINK, event); +} + + +/* Try to code a binary operator negating its second operand. +** For the metamethod, 2nd operand must keep its original value. +*/ +static int finishbinexpneg (FuncState *fs, expdesc *e1, expdesc *e2, + OpCode op, int line, TMS event) { + if (!luaK_isKint(e2)) + return 0; /* not an integer constant */ + else { + lua_Integer i2 = e2->u.ival; + if (!(fitsC(i2) && fitsC(-i2))) + return 0; /* not in the proper range */ + else { /* operating a small integer constant */ + int v2 = cast_int(i2); + finishbinexpval(fs, e1, e2, op, int2sC(-v2), 0, line, OP_MMBINI, event); + /* correct metamethod argument */ + SETARG_B(fs->f->code[fs->pc - 1], int2sC(v2)); + return 1; /* successfully coded */ + } + } +} + + +static void swapexps (expdesc *e1, expdesc *e2) { + expdesc temp = *e1; *e1 = *e2; *e2 = temp; /* swap 'e1' and 'e2' */ +} + + +/* +** Code binary operators with no constant operand. +*/ +static void codebinNoK (FuncState *fs, BinOpr opr, + expdesc *e1, expdesc *e2, int flip, int line) { + if (flip) + swapexps(e1, e2); /* back to original order */ + codebinexpval(fs, opr, e1, e2, line); /* use standard operators */ +} + + +/* +** Code arithmetic operators ('+', '-', ...). If second operand is a +** constant in the proper range, use variant opcodes with K operands. +*/ +static void codearith (FuncState *fs, BinOpr opr, + expdesc *e1, expdesc *e2, int flip, int line) { + if (tonumeral(e2, NULL) && luaK_exp2K(fs, e2)) /* K operand? */ + codebinK(fs, opr, e1, e2, flip, line); + else /* 'e2' is neither an immediate nor a K operand */ + codebinNoK(fs, opr, e1, e2, flip, line); +} + + +/* +** Code commutative operators ('+', '*'). If first operand is a +** numeric constant, change order of operands to try to use an +** immediate or K operator. +*/ +static void codecommutative (FuncState *fs, BinOpr op, + expdesc *e1, expdesc *e2, int line) { + int flip = 0; + if (tonumeral(e1, NULL)) { /* is first operand a numeric constant? */ + swapexps(e1, e2); /* change order */ + flip = 1; + } + if (op == OPR_ADD && isSCint(e2)) /* immediate operand? */ + codebini(fs, OP_ADDI, e1, e2, flip, line, TM_ADD); + else + codearith(fs, op, e1, e2, flip, line); +} + + +/* +** Code bitwise operations; they are all commutative, so the function +** tries to put an integer constant as the 2nd operand (a K operand). +*/ +static void codebitwise (FuncState *fs, BinOpr opr, + expdesc *e1, expdesc *e2, int line) { + int flip = 0; + if (e1->k == VKINT) { + swapexps(e1, e2); /* 'e2' will be the constant operand */ + flip = 1; + } + if (e2->k == VKINT && luaK_exp2K(fs, e2)) /* K operand? */ + codebinK(fs, opr, e1, e2, flip, line); + else /* no constants */ + codebinNoK(fs, opr, e1, e2, flip, line); +} + + +/* +** Emit code for order comparisons. When using an immediate operand, +** 'isfloat' tells whether the original value was a float. +*/ +static void codeorder (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) { + int r1, r2; + int im; + int isfloat = 0; + OpCode op; + if (isSCnumber(e2, &im, &isfloat)) { + /* use immediate operand */ + r1 = luaK_exp2anyreg(fs, e1); + r2 = im; + op = binopr2op(opr, OPR_LT, OP_LTI); + } + else if (isSCnumber(e1, &im, &isfloat)) { + /* transform (A < B) to (B > A) and (A <= B) to (B >= A) */ + r1 = luaK_exp2anyreg(fs, e2); + r2 = im; + op = binopr2op(opr, OPR_LT, OP_GTI); + } + else { /* regular case, compare two registers */ + r1 = luaK_exp2anyreg(fs, e1); + r2 = luaK_exp2anyreg(fs, e2); + op = binopr2op(opr, OPR_LT, OP_LT); + } + freeexps(fs, e1, e2); + e1->u.info = condjump(fs, op, r1, r2, isfloat, 1); + e1->k = VJMP; +} + + +/* +** Emit code for equality comparisons ('==', '~='). +** 'e1' was already put as RK by 'luaK_infix'. +*/ +static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) { + int r1, r2; + int im; + int isfloat = 0; /* not needed here, but kept for symmetry */ + OpCode op; + if (e1->k != VNONRELOC) { + lua_assert(e1->k == VK || e1->k == VKINT || e1->k == VKFLT); + swapexps(e1, e2); + } + r1 = luaK_exp2anyreg(fs, e1); /* 1st expression must be in register */ + if (isSCnumber(e2, &im, &isfloat)) { + op = OP_EQI; + r2 = im; /* immediate operand */ + } + else if (luaK_exp2RK(fs, e2)) { /* 2nd expression is constant? */ + op = OP_EQK; + r2 = e2->u.info; /* constant index */ + } + else { + op = OP_EQ; /* will compare two registers */ + r2 = luaK_exp2anyreg(fs, e2); + } + freeexps(fs, e1, e2); + e1->u.info = condjump(fs, op, r1, r2, isfloat, (opr == OPR_EQ)); + e1->k = VJMP; +} + + +/* +** Apply prefix operation 'op' to expression 'e'. +*/ +void luaK_prefix (FuncState *fs, UnOpr opr, expdesc *e, int line) { + static const expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP}; + luaK_dischargevars(fs, e); + switch (opr) { + case OPR_MINUS: case OPR_BNOT: /* use 'ef' as fake 2nd operand */ + if (constfolding(fs, opr + LUA_OPUNM, e, &ef)) + break; + /* else */ /* FALLTHROUGH */ + case OPR_LEN: + codeunexpval(fs, unopr2op(opr), e, line); + break; + case OPR_NOT: codenot(fs, e); break; + default: lua_assert(0); + } +} + + +/* +** Process 1st operand 'v' of binary operation 'op' before reading +** 2nd operand. +*/ +void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) { + luaK_dischargevars(fs, v); + switch (op) { + case OPR_AND: { + luaK_goiftrue(fs, v); /* go ahead only if 'v' is true */ + break; + } + case OPR_OR: { + luaK_goiffalse(fs, v); /* go ahead only if 'v' is false */ + break; + } + case OPR_CONCAT: { + luaK_exp2nextreg(fs, v); /* operand must be on the stack */ + break; + } + case OPR_ADD: case OPR_SUB: + case OPR_MUL: case OPR_DIV: case OPR_IDIV: + case OPR_MOD: case OPR_POW: + case OPR_BAND: case OPR_BOR: case OPR_BXOR: + case OPR_SHL: case OPR_SHR: { + if (!tonumeral(v, NULL)) + luaK_exp2anyreg(fs, v); + /* else keep numeral, which may be folded or used as an immediate + operand */ + break; + } + case OPR_EQ: case OPR_NE: { + if (!tonumeral(v, NULL)) + luaK_exp2RK(fs, v); + /* else keep numeral, which may be an immediate operand */ + break; + } + case OPR_LT: case OPR_LE: + case OPR_GT: case OPR_GE: { + int dummy, dummy2; + if (!isSCnumber(v, &dummy, &dummy2)) + luaK_exp2anyreg(fs, v); + /* else keep numeral, which may be an immediate operand */ + break; + } + default: lua_assert(0); + } +} + +/* +** Create code for '(e1 .. e2)'. +** For '(e1 .. e2.1 .. e2.2)' (which is '(e1 .. (e2.1 .. e2.2))', +** because concatenation is right associative), merge both CONCATs. +*/ +static void codeconcat (FuncState *fs, expdesc *e1, expdesc *e2, int line) { + Instruction *ie2 = previousinstruction(fs); + if (GET_OPCODE(*ie2) == OP_CONCAT) { /* is 'e2' a concatenation? */ + int n = GETARG_B(*ie2); /* # of elements concatenated in 'e2' */ + lua_assert(e1->u.info + 1 == GETARG_A(*ie2)); + freeexp(fs, e2); + SETARG_A(*ie2, e1->u.info); /* correct first element ('e1') */ + SETARG_B(*ie2, n + 1); /* will concatenate one more element */ + } + else { /* 'e2' is not a concatenation */ + luaK_codeABC(fs, OP_CONCAT, e1->u.info, 2, 0); /* new concat opcode */ + freeexp(fs, e2); + luaK_fixline(fs, line); + } +} + + +/* +** Finalize code for binary operation, after reading 2nd operand. +*/ +void luaK_posfix (FuncState *fs, BinOpr opr, + expdesc *e1, expdesc *e2, int line) { + luaK_dischargevars(fs, e2); + if (foldbinop(opr) && constfolding(fs, opr + LUA_OPADD, e1, e2)) + return; /* done by folding */ + switch (opr) { + case OPR_AND: { + lua_assert(e1->t == NO_JUMP); /* list closed by 'luaK_infix' */ + luaK_concat(fs, &e2->f, e1->f); + *e1 = *e2; + break; + } + case OPR_OR: { + lua_assert(e1->f == NO_JUMP); /* list closed by 'luaK_infix' */ + luaK_concat(fs, &e2->t, e1->t); + *e1 = *e2; + break; + } + case OPR_CONCAT: { /* e1 .. e2 */ + luaK_exp2nextreg(fs, e2); + codeconcat(fs, e1, e2, line); + break; + } + case OPR_ADD: case OPR_MUL: { + codecommutative(fs, opr, e1, e2, line); + break; + } + case OPR_SUB: { + if (finishbinexpneg(fs, e1, e2, OP_ADDI, line, TM_SUB)) + break; /* coded as (r1 + -I) */ + /* ELSE */ + } /* FALLTHROUGH */ + case OPR_DIV: case OPR_IDIV: case OPR_MOD: case OPR_POW: { + codearith(fs, opr, e1, e2, 0, line); + break; + } + case OPR_BAND: case OPR_BOR: case OPR_BXOR: { + codebitwise(fs, opr, e1, e2, line); + break; + } + case OPR_SHL: { + if (isSCint(e1)) { + swapexps(e1, e2); + codebini(fs, OP_SHLI, e1, e2, 1, line, TM_SHL); /* I << r2 */ + } + else if (finishbinexpneg(fs, e1, e2, OP_SHRI, line, TM_SHL)) { + /* coded as (r1 >> -I) */; + } + else /* regular case (two registers) */ + codebinexpval(fs, opr, e1, e2, line); + break; + } + case OPR_SHR: { + if (isSCint(e2)) + codebini(fs, OP_SHRI, e1, e2, 0, line, TM_SHR); /* r1 >> I */ + else /* regular case (two registers) */ + codebinexpval(fs, opr, e1, e2, line); + break; + } + case OPR_EQ: case OPR_NE: { + codeeq(fs, opr, e1, e2); + break; + } + case OPR_GT: case OPR_GE: { + /* '(a > b)' <=> '(b < a)'; '(a >= b)' <=> '(b <= a)' */ + swapexps(e1, e2); + opr = cast(BinOpr, (opr - OPR_GT) + OPR_LT); + } /* FALLTHROUGH */ + case OPR_LT: case OPR_LE: { + codeorder(fs, opr, e1, e2); + break; + } + default: lua_assert(0); + } +} + + +/* +** Change line information associated with current position, by removing +** previous info and adding it again with new line. +*/ +void luaK_fixline (FuncState *fs, int line) { + removelastlineinfo(fs); + savelineinfo(fs, fs->f, line); +} + + +void luaK_settablesize (FuncState *fs, int pc, int ra, int asize, int hsize) { + Instruction *inst = &fs->f->code[pc]; + int rb = (hsize != 0) ? luaO_ceillog2(hsize) + 1 : 0; /* hash size */ + int extra = asize / (MAXARG_C + 1); /* higher bits of array size */ + int rc = asize % (MAXARG_C + 1); /* lower bits of array size */ + int k = (extra > 0); /* true iff needs extra argument */ + *inst = CREATE_ABCk(OP_NEWTABLE, ra, rb, rc, k); + *(inst + 1) = CREATE_Ax(OP_EXTRAARG, extra); +} + + +/* +** Emit a SETLIST instruction. +** 'base' is register that keeps table; +** 'nelems' is #table plus those to be stored now; +** 'tostore' is number of values (in registers 'base + 1',...) to add to +** table (or LUA_MULTRET to add up to stack top). +*/ +void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) { + lua_assert(tostore != 0 && tostore <= LFIELDS_PER_FLUSH); + if (tostore == LUA_MULTRET) + tostore = 0; + if (nelems <= MAXARG_C) + luaK_codeABC(fs, OP_SETLIST, base, tostore, nelems); + else { + int extra = nelems / (MAXARG_C + 1); + nelems %= (MAXARG_C + 1); + luaK_codeABCk(fs, OP_SETLIST, base, tostore, nelems, 1); + codeextraarg(fs, extra); + } + fs->freereg = base + 1; /* free registers with list values */ +} + + +/* +** return the final target of a jump (skipping jumps to jumps) +*/ +static int finaltarget (Instruction *code, int i) { + int count; + for (count = 0; count < 100; count++) { /* avoid infinite loops */ + Instruction pc = code[i]; + if (GET_OPCODE(pc) != OP_JMP) + break; + else + i += GETARG_sJ(pc) + 1; + } + return i; +} + + +/* +** Do a final pass over the code of a function, doing small peephole +** optimizations and adjustments. +*/ +void luaK_finish (FuncState *fs) { + int i; + Proto *p = fs->f; + for (i = 0; i < fs->pc; i++) { + Instruction *pc = &p->code[i]; + lua_assert(i == 0 || isOT(*(pc - 1)) == isIT(*pc)); + switch (GET_OPCODE(*pc)) { + case OP_RETURN0: case OP_RETURN1: { + if (!(fs->needclose || p->is_vararg)) + break; /* no extra work */ + /* else use OP_RETURN to do the extra work */ + SET_OPCODE(*pc, OP_RETURN); + } /* FALLTHROUGH */ + case OP_RETURN: case OP_TAILCALL: { + if (fs->needclose) + SETARG_k(*pc, 1); /* signal that it needs to close */ + if (p->is_vararg) + SETARG_C(*pc, p->numparams + 1); /* signal that it is vararg */ + break; + } + case OP_JMP: { + int target = finaltarget(p->code, i); + fixjump(fs, i, target); + break; + } + default: break; + } + } +} diff --git a/src/lcode.h b/src/lcode.h new file mode 100644 index 0000000..3265824 --- /dev/null +++ b/src/lcode.h @@ -0,0 +1,104 @@ +/* +** $Id: lcode.h $ +** Code generator for Lua +** See Copyright Notice in lua.h +*/ + +#ifndef lcode_h +#define lcode_h + +#include "llex.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" + + +/* +** Marks the end of a patch list. It is an invalid value both as an absolute +** address, and as a list link (would link an element to itself). +*/ +#define NO_JUMP (-1) + + +/* +** grep "ORDER OPR" if you change these enums (ORDER OP) +*/ +typedef enum BinOpr { + /* arithmetic operators */ + OPR_ADD, OPR_SUB, OPR_MUL, OPR_MOD, OPR_POW, + OPR_DIV, OPR_IDIV, + /* bitwise operators */ + OPR_BAND, OPR_BOR, OPR_BXOR, + OPR_SHL, OPR_SHR, + /* string operator */ + OPR_CONCAT, + /* comparison operators */ + OPR_EQ, OPR_LT, OPR_LE, + OPR_NE, OPR_GT, OPR_GE, + /* logical operators */ + OPR_AND, OPR_OR, + OPR_NOBINOPR +} BinOpr; + + +/* true if operation is foldable (that is, it is arithmetic or bitwise) */ +#define foldbinop(op) ((op) <= OPR_SHR) + + +#define luaK_codeABC(fs,o,a,b,c) luaK_codeABCk(fs,o,a,b,c,0) + + +typedef enum UnOpr { OPR_MINUS, OPR_BNOT, OPR_NOT, OPR_LEN, OPR_NOUNOPR } UnOpr; + + +/* get (pointer to) instruction of given 'expdesc' */ +#define getinstruction(fs,e) ((fs)->f->code[(e)->u.info]) + + +#define luaK_setmultret(fs,e) luaK_setreturns(fs, e, LUA_MULTRET) + +#define luaK_jumpto(fs,t) luaK_patchlist(fs, luaK_jump(fs), t) + +LUAI_FUNC int luaK_code (FuncState *fs, Instruction i); +LUAI_FUNC int luaK_codeABx (FuncState *fs, OpCode o, int A, unsigned int Bx); +LUAI_FUNC int luaK_codeAsBx (FuncState *fs, OpCode o, int A, int Bx); +LUAI_FUNC int luaK_codeABCk (FuncState *fs, OpCode o, int A, + int B, int C, int k); +LUAI_FUNC int luaK_isKint (expdesc *e); +LUAI_FUNC int luaK_exp2const (FuncState *fs, const expdesc *e, TValue *v); +LUAI_FUNC void luaK_fixline (FuncState *fs, int line); +LUAI_FUNC void luaK_nil (FuncState *fs, int from, int n); +LUAI_FUNC void luaK_reserveregs (FuncState *fs, int n); +LUAI_FUNC void luaK_checkstack (FuncState *fs, int n); +LUAI_FUNC void luaK_int (FuncState *fs, int reg, lua_Integer n); +LUAI_FUNC void luaK_dischargevars (FuncState *fs, expdesc *e); +LUAI_FUNC int luaK_exp2anyreg (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_exp2anyregup (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_exp2nextreg (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_exp2val (FuncState *fs, expdesc *e); +LUAI_FUNC int luaK_exp2RK (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_self (FuncState *fs, expdesc *e, expdesc *key); +LUAI_FUNC void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k); +LUAI_FUNC void luaK_goiftrue (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_goiffalse (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_storevar (FuncState *fs, expdesc *var, expdesc *e); +LUAI_FUNC void luaK_setreturns (FuncState *fs, expdesc *e, int nresults); +LUAI_FUNC void luaK_setoneret (FuncState *fs, expdesc *e); +LUAI_FUNC int luaK_jump (FuncState *fs); +LUAI_FUNC void luaK_ret (FuncState *fs, int first, int nret); +LUAI_FUNC void luaK_patchlist (FuncState *fs, int list, int target); +LUAI_FUNC void luaK_patchtohere (FuncState *fs, int list); +LUAI_FUNC void luaK_concat (FuncState *fs, int *l1, int l2); +LUAI_FUNC int luaK_getlabel (FuncState *fs); +LUAI_FUNC void luaK_prefix (FuncState *fs, UnOpr op, expdesc *v, int line); +LUAI_FUNC void luaK_infix (FuncState *fs, BinOpr op, expdesc *v); +LUAI_FUNC void luaK_posfix (FuncState *fs, BinOpr op, expdesc *v1, + expdesc *v2, int line); +LUAI_FUNC void luaK_settablesize (FuncState *fs, int pc, + int ra, int asize, int hsize); +LUAI_FUNC void luaK_setlist (FuncState *fs, int base, int nelems, int tostore); +LUAI_FUNC void luaK_finish (FuncState *fs); +LUAI_FUNC l_noret luaK_semerror (LexState *ls, const char *msg); + + +#endif diff --git a/src/lcorolib.c b/src/lcorolib.c new file mode 100644 index 0000000..c64adf0 --- /dev/null +++ b/src/lcorolib.c @@ -0,0 +1,210 @@ +/* +** $Id: lcorolib.c $ +** Coroutine Library +** See Copyright Notice in lua.h +*/ + +#define lcorolib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +static lua_State *getco (lua_State *L) { + lua_State *co = lua_tothread(L, 1); + luaL_argexpected(L, co, 1, "thread"); + return co; +} + + +/* +** Resumes a coroutine. Returns the number of results for non-error +** cases or -1 for errors. +*/ +static int auxresume (lua_State *L, lua_State *co, int narg) { + int status, nres; + if (l_unlikely(!lua_checkstack(co, narg))) { + lua_pushliteral(L, "too many arguments to resume"); + return -1; /* error flag */ + } + lua_xmove(L, co, narg); + status = lua_resume(co, L, narg, &nres); + if (l_likely(status == LUA_OK || status == LUA_YIELD)) { + if (l_unlikely(!lua_checkstack(L, nres + 1))) { + lua_pop(co, nres); /* remove results anyway */ + lua_pushliteral(L, "too many results to resume"); + return -1; /* error flag */ + } + lua_xmove(co, L, nres); /* move yielded values */ + return nres; + } + else { + lua_xmove(co, L, 1); /* move error message */ + return -1; /* error flag */ + } +} + + +static int luaB_coresume (lua_State *L) { + lua_State *co = getco(L); + int r; + r = auxresume(L, co, lua_gettop(L) - 1); + if (l_unlikely(r < 0)) { + lua_pushboolean(L, 0); + lua_insert(L, -2); + return 2; /* return false + error message */ + } + else { + lua_pushboolean(L, 1); + lua_insert(L, -(r + 1)); + return r + 1; /* return true + 'resume' returns */ + } +} + + +static int luaB_auxwrap (lua_State *L) { + lua_State *co = lua_tothread(L, lua_upvalueindex(1)); + int r = auxresume(L, co, lua_gettop(L)); + if (l_unlikely(r < 0)) { /* error? */ + int stat = lua_status(co); + if (stat != LUA_OK && stat != LUA_YIELD) { /* error in the coroutine? */ + stat = lua_closethread(co, L); /* close its tbc variables */ + lua_assert(stat != LUA_OK); + lua_xmove(co, L, 1); /* move error message to the caller */ + } + if (stat != LUA_ERRMEM && /* not a memory error and ... */ + lua_type(L, -1) == LUA_TSTRING) { /* ... error object is a string? */ + luaL_where(L, 1); /* add extra info, if available */ + lua_insert(L, -2); + lua_concat(L, 2); + } + return lua_error(L); /* propagate error */ + } + return r; +} + + +static int luaB_cocreate (lua_State *L) { + lua_State *NL; + luaL_checktype(L, 1, LUA_TFUNCTION); + NL = lua_newthread(L); + lua_pushvalue(L, 1); /* move function to top */ + lua_xmove(L, NL, 1); /* move function from L to NL */ + return 1; +} + + +static int luaB_cowrap (lua_State *L) { + luaB_cocreate(L); + lua_pushcclosure(L, luaB_auxwrap, 1); + return 1; +} + + +static int luaB_yield (lua_State *L) { + return lua_yield(L, lua_gettop(L)); +} + + +#define COS_RUN 0 +#define COS_DEAD 1 +#define COS_YIELD 2 +#define COS_NORM 3 + + +static const char *const statname[] = + {"running", "dead", "suspended", "normal"}; + + +static int auxstatus (lua_State *L, lua_State *co) { + if (L == co) return COS_RUN; + else { + switch (lua_status(co)) { + case LUA_YIELD: + return COS_YIELD; + case LUA_OK: { + lua_Debug ar; + if (lua_getstack(co, 0, &ar)) /* does it have frames? */ + return COS_NORM; /* it is running */ + else if (lua_gettop(co) == 0) + return COS_DEAD; + else + return COS_YIELD; /* initial state */ + } + default: /* some error occurred */ + return COS_DEAD; + } + } +} + + +static int luaB_costatus (lua_State *L) { + lua_State *co = getco(L); + lua_pushstring(L, statname[auxstatus(L, co)]); + return 1; +} + + +static int luaB_yieldable (lua_State *L) { + lua_State *co = lua_isnone(L, 1) ? L : getco(L); + lua_pushboolean(L, lua_isyieldable(co)); + return 1; +} + + +static int luaB_corunning (lua_State *L) { + int ismain = lua_pushthread(L); + lua_pushboolean(L, ismain); + return 2; +} + + +static int luaB_close (lua_State *L) { + lua_State *co = getco(L); + int status = auxstatus(L, co); + switch (status) { + case COS_DEAD: case COS_YIELD: { + status = lua_closethread(co, L); + if (status == LUA_OK) { + lua_pushboolean(L, 1); + return 1; + } + else { + lua_pushboolean(L, 0); + lua_xmove(co, L, 1); /* move error message */ + return 2; + } + } + default: /* normal or running coroutine */ + return luaL_error(L, "cannot close a %s coroutine", statname[status]); + } +} + + +static const luaL_Reg co_funcs[] = { + {"create", luaB_cocreate}, + {"resume", luaB_coresume}, + {"running", luaB_corunning}, + {"status", luaB_costatus}, + {"wrap", luaB_cowrap}, + {"yield", luaB_yield}, + {"isyieldable", luaB_yieldable}, + {"close", luaB_close}, + {NULL, NULL} +}; + + + +LUAMOD_API int luaopen_coroutine (lua_State *L) { + luaL_newlib(L, co_funcs); + return 1; +} + diff --git a/src/lctype.c b/src/lctype.c new file mode 100644 index 0000000..9542280 --- /dev/null +++ b/src/lctype.c @@ -0,0 +1,64 @@ +/* +** $Id: lctype.c $ +** 'ctype' functions for Lua +** See Copyright Notice in lua.h +*/ + +#define lctype_c +#define LUA_CORE + +#include "lprefix.h" + + +#include "lctype.h" + +#if !LUA_USE_CTYPE /* { */ + +#include + + +#if defined (LUA_UCID) /* accept UniCode IDentifiers? */ +/* consider all non-ascii codepoints to be alphabetic */ +#define NONA 0x01 +#else +#define NONA 0x00 /* default */ +#endif + + +LUAI_DDEF const lu_byte luai_ctype_[UCHAR_MAX + 2] = { + 0x00, /* EOZ */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0. */ + 0x00, 0x08, 0x08, 0x08, 0x08, 0x08, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 1. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x0c, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, /* 2. */ + 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, + 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, /* 3. */ + 0x16, 0x16, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, + 0x04, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x05, /* 4. */ + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, /* 5. */ + 0x05, 0x05, 0x05, 0x04, 0x04, 0x04, 0x04, 0x05, + 0x04, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x05, /* 6. */ + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, /* 7. */ + 0x05, 0x05, 0x05, 0x04, 0x04, 0x04, 0x04, 0x00, + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, /* 8. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, /* 9. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, /* a. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, /* b. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + 0x00, 0x00, NONA, NONA, NONA, NONA, NONA, NONA, /* c. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, /* d. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, /* e. */ + NONA, NONA, NONA, NONA, NONA, NONA, NONA, NONA, + NONA, NONA, NONA, NONA, NONA, 0x00, 0x00, 0x00, /* f. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 +}; + +#endif /* } */ diff --git a/src/lctype.h b/src/lctype.h new file mode 100644 index 0000000..864e190 --- /dev/null +++ b/src/lctype.h @@ -0,0 +1,101 @@ +/* +** $Id: lctype.h $ +** 'ctype' functions for Lua +** See Copyright Notice in lua.h +*/ + +#ifndef lctype_h +#define lctype_h + +#include "lua.h" + + +/* +** WARNING: the functions defined here do not necessarily correspond +** to the similar functions in the standard C ctype.h. They are +** optimized for the specific needs of Lua. +*/ + +#if !defined(LUA_USE_CTYPE) + +#if 'A' == 65 && '0' == 48 +/* ASCII case: can use its own tables; faster and fixed */ +#define LUA_USE_CTYPE 0 +#else +/* must use standard C ctype */ +#define LUA_USE_CTYPE 1 +#endif + +#endif + + +#if !LUA_USE_CTYPE /* { */ + +#include + +#include "llimits.h" + + +#define ALPHABIT 0 +#define DIGITBIT 1 +#define PRINTBIT 2 +#define SPACEBIT 3 +#define XDIGITBIT 4 + + +#define MASK(B) (1 << (B)) + + +/* +** add 1 to char to allow index -1 (EOZ) +*/ +#define testprop(c,p) (luai_ctype_[(c)+1] & (p)) + +/* +** 'lalpha' (Lua alphabetic) and 'lalnum' (Lua alphanumeric) both include '_' +*/ +#define lislalpha(c) testprop(c, MASK(ALPHABIT)) +#define lislalnum(c) testprop(c, (MASK(ALPHABIT) | MASK(DIGITBIT))) +#define lisdigit(c) testprop(c, MASK(DIGITBIT)) +#define lisspace(c) testprop(c, MASK(SPACEBIT)) +#define lisprint(c) testprop(c, MASK(PRINTBIT)) +#define lisxdigit(c) testprop(c, MASK(XDIGITBIT)) + + +/* +** In ASCII, this 'ltolower' is correct for alphabetic characters and +** for '.'. That is enough for Lua needs. ('check_exp' ensures that +** the character either is an upper-case letter or is unchanged by +** the transformation, which holds for lower-case letters and '.'.) +*/ +#define ltolower(c) \ + check_exp(('A' <= (c) && (c) <= 'Z') || (c) == ((c) | ('A' ^ 'a')), \ + (c) | ('A' ^ 'a')) + + +/* one entry for each character and for -1 (EOZ) */ +LUAI_DDEC(const lu_byte luai_ctype_[UCHAR_MAX + 2];) + + +#else /* }{ */ + +/* +** use standard C ctypes +*/ + +#include + + +#define lislalpha(c) (isalpha(c) || (c) == '_') +#define lislalnum(c) (isalnum(c) || (c) == '_') +#define lisdigit(c) (isdigit(c)) +#define lisspace(c) (isspace(c)) +#define lisprint(c) (isprint(c)) +#define lisxdigit(c) (isxdigit(c)) + +#define ltolower(c) (tolower(c)) + +#endif /* } */ + +#endif + diff --git a/src/ldblib.c b/src/ldblib.c new file mode 100644 index 0000000..6dcbaa9 --- /dev/null +++ b/src/ldblib.c @@ -0,0 +1,483 @@ +/* +** $Id: ldblib.c $ +** Interface from Lua to its debug API +** See Copyright Notice in lua.h +*/ + +#define ldblib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** The hook table at registry[HOOKKEY] maps threads to their current +** hook function. +*/ +static const char *const HOOKKEY = "_HOOKKEY"; + + +/* +** If L1 != L, L1 can be in any state, and therefore there are no +** guarantees about its stack space; any push in L1 must be +** checked. +*/ +static void checkstack (lua_State *L, lua_State *L1, int n) { + if (l_unlikely(L != L1 && !lua_checkstack(L1, n))) + luaL_error(L, "stack overflow"); +} + + +static int db_getregistry (lua_State *L) { + lua_pushvalue(L, LUA_REGISTRYINDEX); + return 1; +} + + +static int db_getmetatable (lua_State *L) { + luaL_checkany(L, 1); + if (!lua_getmetatable(L, 1)) { + lua_pushnil(L); /* no metatable */ + } + return 1; +} + + +static int db_setmetatable (lua_State *L) { + int t = lua_type(L, 2); + luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table"); + lua_settop(L, 2); + lua_setmetatable(L, 1); + return 1; /* return 1st argument */ +} + + +static int db_getuservalue (lua_State *L) { + int n = (int)luaL_optinteger(L, 2, 1); + if (lua_type(L, 1) != LUA_TUSERDATA) + luaL_pushfail(L); + else if (lua_getiuservalue(L, 1, n) != LUA_TNONE) { + lua_pushboolean(L, 1); + return 2; + } + return 1; +} + + +static int db_setuservalue (lua_State *L) { + int n = (int)luaL_optinteger(L, 3, 1); + luaL_checktype(L, 1, LUA_TUSERDATA); + luaL_checkany(L, 2); + lua_settop(L, 2); + if (!lua_setiuservalue(L, 1, n)) + luaL_pushfail(L); + return 1; +} + + +/* +** Auxiliary function used by several library functions: check for +** an optional thread as function's first argument and set 'arg' with +** 1 if this argument is present (so that functions can skip it to +** access their other arguments) +*/ +static lua_State *getthread (lua_State *L, int *arg) { + if (lua_isthread(L, 1)) { + *arg = 1; + return lua_tothread(L, 1); + } + else { + *arg = 0; + return L; /* function will operate over current thread */ + } +} + + +/* +** Variations of 'lua_settable', used by 'db_getinfo' to put results +** from 'lua_getinfo' into result table. Key is always a string; +** value can be a string, an int, or a boolean. +*/ +static void settabss (lua_State *L, const char *k, const char *v) { + lua_pushstring(L, v); + lua_setfield(L, -2, k); +} + +static void settabsi (lua_State *L, const char *k, int v) { + lua_pushinteger(L, v); + lua_setfield(L, -2, k); +} + +static void settabsb (lua_State *L, const char *k, int v) { + lua_pushboolean(L, v); + lua_setfield(L, -2, k); +} + + +/* +** In function 'db_getinfo', the call to 'lua_getinfo' may push +** results on the stack; later it creates the result table to put +** these objects. Function 'treatstackoption' puts the result from +** 'lua_getinfo' on top of the result table so that it can call +** 'lua_setfield'. +*/ +static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) { + if (L == L1) + lua_rotate(L, -2, 1); /* exchange object and table */ + else + lua_xmove(L1, L, 1); /* move object to the "main" stack */ + lua_setfield(L, -2, fname); /* put object into table */ +} + + +/* +** Calls 'lua_getinfo' and collects all results in a new table. +** L1 needs stack space for an optional input (function) plus +** two optional outputs (function and line table) from function +** 'lua_getinfo'. +*/ +static int db_getinfo (lua_State *L) { + lua_Debug ar; + int arg; + lua_State *L1 = getthread(L, &arg); + const char *options = luaL_optstring(L, arg+2, "flnSrtu"); + checkstack(L, L1, 3); + luaL_argcheck(L, options[0] != '>', arg + 2, "invalid option '>'"); + if (lua_isfunction(L, arg + 1)) { /* info about a function? */ + options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */ + lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */ + lua_xmove(L, L1, 1); + } + else { /* stack level */ + if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) { + luaL_pushfail(L); /* level out of range */ + return 1; + } + } + if (!lua_getinfo(L1, options, &ar)) + return luaL_argerror(L, arg+2, "invalid option"); + lua_newtable(L); /* table to collect results */ + if (strchr(options, 'S')) { + lua_pushlstring(L, ar.source, ar.srclen); + lua_setfield(L, -2, "source"); + settabss(L, "short_src", ar.short_src); + settabsi(L, "linedefined", ar.linedefined); + settabsi(L, "lastlinedefined", ar.lastlinedefined); + settabss(L, "what", ar.what); + } + if (strchr(options, 'l')) + settabsi(L, "currentline", ar.currentline); + if (strchr(options, 'u')) { + settabsi(L, "nups", ar.nups); + settabsi(L, "nparams", ar.nparams); + settabsb(L, "isvararg", ar.isvararg); + } + if (strchr(options, 'n')) { + settabss(L, "name", ar.name); + settabss(L, "namewhat", ar.namewhat); + } + if (strchr(options, 'r')) { + settabsi(L, "ftransfer", ar.ftransfer); + settabsi(L, "ntransfer", ar.ntransfer); + } + if (strchr(options, 't')) + settabsb(L, "istailcall", ar.istailcall); + if (strchr(options, 'L')) + treatstackoption(L, L1, "activelines"); + if (strchr(options, 'f')) + treatstackoption(L, L1, "func"); + return 1; /* return table */ +} + + +static int db_getlocal (lua_State *L) { + int arg; + lua_State *L1 = getthread(L, &arg); + int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */ + if (lua_isfunction(L, arg + 1)) { /* function argument? */ + lua_pushvalue(L, arg + 1); /* push function */ + lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */ + return 1; /* return only name (there is no value) */ + } + else { /* stack-level argument */ + lua_Debug ar; + const char *name; + int level = (int)luaL_checkinteger(L, arg + 1); + if (l_unlikely(!lua_getstack(L1, level, &ar))) /* out of range? */ + return luaL_argerror(L, arg+1, "level out of range"); + checkstack(L, L1, 1); + name = lua_getlocal(L1, &ar, nvar); + if (name) { + lua_xmove(L1, L, 1); /* move local value */ + lua_pushstring(L, name); /* push name */ + lua_rotate(L, -2, 1); /* re-order */ + return 2; + } + else { + luaL_pushfail(L); /* no name (nor value) */ + return 1; + } + } +} + + +static int db_setlocal (lua_State *L) { + int arg; + const char *name; + lua_State *L1 = getthread(L, &arg); + lua_Debug ar; + int level = (int)luaL_checkinteger(L, arg + 1); + int nvar = (int)luaL_checkinteger(L, arg + 2); + if (l_unlikely(!lua_getstack(L1, level, &ar))) /* out of range? */ + return luaL_argerror(L, arg+1, "level out of range"); + luaL_checkany(L, arg+3); + lua_settop(L, arg+3); + checkstack(L, L1, 1); + lua_xmove(L, L1, 1); + name = lua_setlocal(L1, &ar, nvar); + if (name == NULL) + lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */ + lua_pushstring(L, name); + return 1; +} + + +/* +** get (if 'get' is true) or set an upvalue from a closure +*/ +static int auxupvalue (lua_State *L, int get) { + const char *name; + int n = (int)luaL_checkinteger(L, 2); /* upvalue index */ + luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */ + name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n); + if (name == NULL) return 0; + lua_pushstring(L, name); + lua_insert(L, -(get+1)); /* no-op if get is false */ + return get + 1; +} + + +static int db_getupvalue (lua_State *L) { + return auxupvalue(L, 1); +} + + +static int db_setupvalue (lua_State *L) { + luaL_checkany(L, 3); + return auxupvalue(L, 0); +} + + +/* +** Check whether a given upvalue from a given closure exists and +** returns its index +*/ +static void *checkupval (lua_State *L, int argf, int argnup, int *pnup) { + void *id; + int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */ + luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */ + id = lua_upvalueid(L, argf, nup); + if (pnup) { + luaL_argcheck(L, id != NULL, argnup, "invalid upvalue index"); + *pnup = nup; + } + return id; +} + + +static int db_upvalueid (lua_State *L) { + void *id = checkupval(L, 1, 2, NULL); + if (id != NULL) + lua_pushlightuserdata(L, id); + else + luaL_pushfail(L); + return 1; +} + + +static int db_upvaluejoin (lua_State *L) { + int n1, n2; + checkupval(L, 1, 2, &n1); + checkupval(L, 3, 4, &n2); + luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected"); + luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected"); + lua_upvaluejoin(L, 1, n1, 3, n2); + return 0; +} + + +/* +** Call hook function registered at hook table for the current +** thread (if there is one) +*/ +static void hookf (lua_State *L, lua_Debug *ar) { + static const char *const hooknames[] = + {"call", "return", "line", "count", "tail call"}; + lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY); + lua_pushthread(L); + if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */ + lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */ + if (ar->currentline >= 0) + lua_pushinteger(L, ar->currentline); /* push current line */ + else lua_pushnil(L); + lua_assert(lua_getinfo(L, "lS", ar)); + lua_call(L, 2, 0); /* call hook function */ + } +} + + +/* +** Convert a string mask (for 'sethook') into a bit mask +*/ +static int makemask (const char *smask, int count) { + int mask = 0; + if (strchr(smask, 'c')) mask |= LUA_MASKCALL; + if (strchr(smask, 'r')) mask |= LUA_MASKRET; + if (strchr(smask, 'l')) mask |= LUA_MASKLINE; + if (count > 0) mask |= LUA_MASKCOUNT; + return mask; +} + + +/* +** Convert a bit mask (for 'gethook') into a string mask +*/ +static char *unmakemask (int mask, char *smask) { + int i = 0; + if (mask & LUA_MASKCALL) smask[i++] = 'c'; + if (mask & LUA_MASKRET) smask[i++] = 'r'; + if (mask & LUA_MASKLINE) smask[i++] = 'l'; + smask[i] = '\0'; + return smask; +} + + +static int db_sethook (lua_State *L) { + int arg, mask, count; + lua_Hook func; + lua_State *L1 = getthread(L, &arg); + if (lua_isnoneornil(L, arg+1)) { /* no hook? */ + lua_settop(L, arg+1); + func = NULL; mask = 0; count = 0; /* turn off hooks */ + } + else { + const char *smask = luaL_checkstring(L, arg+2); + luaL_checktype(L, arg+1, LUA_TFUNCTION); + count = (int)luaL_optinteger(L, arg + 3, 0); + func = hookf; mask = makemask(smask, count); + } + if (!luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)) { + /* table just created; initialize it */ + lua_pushliteral(L, "k"); + lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */ + lua_pushvalue(L, -1); + lua_setmetatable(L, -2); /* metatable(hooktable) = hooktable */ + } + checkstack(L, L1, 1); + lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */ + lua_pushvalue(L, arg + 1); /* value (hook function) */ + lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */ + lua_sethook(L1, func, mask, count); + return 0; +} + + +static int db_gethook (lua_State *L) { + int arg; + lua_State *L1 = getthread(L, &arg); + char buff[5]; + int mask = lua_gethookmask(L1); + lua_Hook hook = lua_gethook(L1); + if (hook == NULL) { /* no hook? */ + luaL_pushfail(L); + return 1; + } + else if (hook != hookf) /* external hook? */ + lua_pushliteral(L, "external hook"); + else { /* hook table must exist */ + lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY); + checkstack(L, L1, 1); + lua_pushthread(L1); lua_xmove(L1, L, 1); + lua_rawget(L, -2); /* 1st result = hooktable[L1] */ + lua_remove(L, -2); /* remove hook table */ + } + lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */ + lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */ + return 3; +} + + +static int db_debug (lua_State *L) { + for (;;) { + char buffer[250]; + lua_writestringerror("%s", "lua_debug> "); + if (fgets(buffer, sizeof(buffer), stdin) == NULL || + strcmp(buffer, "cont\n") == 0) + return 0; + if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") || + lua_pcall(L, 0, 0, 0)) + lua_writestringerror("%s\n", luaL_tolstring(L, -1, NULL)); + lua_settop(L, 0); /* remove eventual returns */ + } +} + + +static int db_traceback (lua_State *L) { + int arg; + lua_State *L1 = getthread(L, &arg); + const char *msg = lua_tostring(L, arg + 1); + if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */ + lua_pushvalue(L, arg + 1); /* return it untouched */ + else { + int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0); + luaL_traceback(L, L1, msg, level); + } + return 1; +} + + +static int db_setcstacklimit (lua_State *L) { + int limit = (int)luaL_checkinteger(L, 1); + int res = lua_setcstacklimit(L, limit); + lua_pushinteger(L, res); + return 1; +} + + +static const luaL_Reg dblib[] = { + {"debug", db_debug}, + {"getuservalue", db_getuservalue}, + {"gethook", db_gethook}, + {"getinfo", db_getinfo}, + {"getlocal", db_getlocal}, + {"getregistry", db_getregistry}, + {"getmetatable", db_getmetatable}, + {"getupvalue", db_getupvalue}, + {"upvaluejoin", db_upvaluejoin}, + {"upvalueid", db_upvalueid}, + {"setuservalue", db_setuservalue}, + {"sethook", db_sethook}, + {"setlocal", db_setlocal}, + {"setmetatable", db_setmetatable}, + {"setupvalue", db_setupvalue}, + {"traceback", db_traceback}, + {"setcstacklimit", db_setcstacklimit}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_debug (lua_State *L) { + luaL_newlib(L, dblib); + return 1; +} + diff --git a/src/ldebug.c b/src/ldebug.c new file mode 100644 index 0000000..28b1caa --- /dev/null +++ b/src/ldebug.c @@ -0,0 +1,924 @@ +/* +** $Id: ldebug.c $ +** Debug Interface +** See Copyright Notice in lua.h +*/ + +#define ldebug_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lapi.h" +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + + +#define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_VCCL) + + +static const char *funcnamefromcall (lua_State *L, CallInfo *ci, + const char **name); + + +static int currentpc (CallInfo *ci) { + lua_assert(isLua(ci)); + return pcRel(ci->u.l.savedpc, ci_func(ci)->p); +} + + +/* +** Get a "base line" to find the line corresponding to an instruction. +** Base lines are regularly placed at MAXIWTHABS intervals, so usually +** an integer division gets the right place. When the source file has +** large sequences of empty/comment lines, it may need extra entries, +** so the original estimate needs a correction. +** If the original estimate is -1, the initial 'if' ensures that the +** 'while' will run at least once. +** The assertion that the estimate is a lower bound for the correct base +** is valid as long as the debug info has been generated with the same +** value for MAXIWTHABS or smaller. (Previous releases use a little +** smaller value.) +*/ +static int getbaseline (const Proto *f, int pc, int *basepc) { + if (f->sizeabslineinfo == 0 || pc < f->abslineinfo[0].pc) { + *basepc = -1; /* start from the beginning */ + return f->linedefined; + } + else { + int i = cast_uint(pc) / MAXIWTHABS - 1; /* get an estimate */ + /* estimate must be a lower bound of the correct base */ + lua_assert(i < 0 || + (i < f->sizeabslineinfo && f->abslineinfo[i].pc <= pc)); + while (i + 1 < f->sizeabslineinfo && pc >= f->abslineinfo[i + 1].pc) + i++; /* low estimate; adjust it */ + *basepc = f->abslineinfo[i].pc; + return f->abslineinfo[i].line; + } +} + + +/* +** Get the line corresponding to instruction 'pc' in function 'f'; +** first gets a base line and from there does the increments until +** the desired instruction. +*/ +int luaG_getfuncline (const Proto *f, int pc) { + if (f->lineinfo == NULL) /* no debug information? */ + return -1; + else { + int basepc; + int baseline = getbaseline(f, pc, &basepc); + while (basepc++ < pc) { /* walk until given instruction */ + lua_assert(f->lineinfo[basepc] != ABSLINEINFO); + baseline += f->lineinfo[basepc]; /* correct line */ + } + return baseline; + } +} + + +static int getcurrentline (CallInfo *ci) { + return luaG_getfuncline(ci_func(ci)->p, currentpc(ci)); +} + + +/* +** Set 'trap' for all active Lua frames. +** This function can be called during a signal, under "reasonable" +** assumptions. A new 'ci' is completely linked in the list before it +** becomes part of the "active" list, and we assume that pointers are +** atomic; see comment in next function. +** (A compiler doing interprocedural optimizations could, theoretically, +** reorder memory writes in such a way that the list could be +** temporarily broken while inserting a new element. We simply assume it +** has no good reasons to do that.) +*/ +static void settraps (CallInfo *ci) { + for (; ci != NULL; ci = ci->previous) + if (isLua(ci)) + ci->u.l.trap = 1; +} + + +/* +** This function can be called during a signal, under "reasonable" +** assumptions. +** Fields 'basehookcount' and 'hookcount' (set by 'resethookcount') +** are for debug only, and it is no problem if they get arbitrary +** values (causes at most one wrong hook call). 'hookmask' is an atomic +** value. We assume that pointers are atomic too (e.g., gcc ensures that +** for all platforms where it runs). Moreover, 'hook' is always checked +** before being called (see 'luaD_hook'). +*/ +LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) { + if (func == NULL || mask == 0) { /* turn off hooks? */ + mask = 0; + func = NULL; + } + L->hook = func; + L->basehookcount = count; + resethookcount(L); + L->hookmask = cast_byte(mask); + if (mask) + settraps(L->ci); /* to trace inside 'luaV_execute' */ +} + + +LUA_API lua_Hook lua_gethook (lua_State *L) { + return L->hook; +} + + +LUA_API int lua_gethookmask (lua_State *L) { + return L->hookmask; +} + + +LUA_API int lua_gethookcount (lua_State *L) { + return L->basehookcount; +} + + +LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) { + int status; + CallInfo *ci; + if (level < 0) return 0; /* invalid (negative) level */ + lua_lock(L); + for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous) + level--; + if (level == 0 && ci != &L->base_ci) { /* level found? */ + status = 1; + ar->i_ci = ci; + } + else status = 0; /* no such level */ + lua_unlock(L); + return status; +} + + +static const char *upvalname (const Proto *p, int uv) { + TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name); + if (s == NULL) return "?"; + else return getstr(s); +} + + +static const char *findvararg (CallInfo *ci, int n, StkId *pos) { + if (clLvalue(s2v(ci->func.p))->p->is_vararg) { + int nextra = ci->u.l.nextraargs; + if (n >= -nextra) { /* 'n' is negative */ + *pos = ci->func.p - nextra - (n + 1); + return "(vararg)"; /* generic name for any vararg */ + } + } + return NULL; /* no such vararg */ +} + + +const char *luaG_findlocal (lua_State *L, CallInfo *ci, int n, StkId *pos) { + StkId base = ci->func.p + 1; + const char *name = NULL; + if (isLua(ci)) { + if (n < 0) /* access to vararg values? */ + return findvararg(ci, n, pos); + else + name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci)); + } + if (name == NULL) { /* no 'standard' name? */ + StkId limit = (ci == L->ci) ? L->top.p : ci->next->func.p; + if (limit - base >= n && n > 0) { /* is 'n' inside 'ci' stack? */ + /* generic name for any valid slot */ + name = isLua(ci) ? "(temporary)" : "(C temporary)"; + } + else + return NULL; /* no name */ + } + if (pos) + *pos = base + (n - 1); + return name; +} + + +LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) { + const char *name; + lua_lock(L); + if (ar == NULL) { /* information about non-active function? */ + if (!isLfunction(s2v(L->top.p - 1))) /* not a Lua function? */ + name = NULL; + else /* consider live variables at function start (parameters) */ + name = luaF_getlocalname(clLvalue(s2v(L->top.p - 1))->p, n, 0); + } + else { /* active function; get information through 'ar' */ + StkId pos = NULL; /* to avoid warnings */ + name = luaG_findlocal(L, ar->i_ci, n, &pos); + if (name) { + setobjs2s(L, L->top.p, pos); + api_incr_top(L); + } + } + lua_unlock(L); + return name; +} + + +LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) { + StkId pos = NULL; /* to avoid warnings */ + const char *name; + lua_lock(L); + name = luaG_findlocal(L, ar->i_ci, n, &pos); + if (name) { + setobjs2s(L, pos, L->top.p - 1); + L->top.p--; /* pop value */ + } + lua_unlock(L); + return name; +} + + +static void funcinfo (lua_Debug *ar, Closure *cl) { + if (noLuaClosure(cl)) { + ar->source = "=[C]"; + ar->srclen = LL("=[C]"); + ar->linedefined = -1; + ar->lastlinedefined = -1; + ar->what = "C"; + } + else { + const Proto *p = cl->l.p; + if (p->source) { + ar->source = getstr(p->source); + ar->srclen = tsslen(p->source); + } + else { + ar->source = "=?"; + ar->srclen = LL("=?"); + } + ar->linedefined = p->linedefined; + ar->lastlinedefined = p->lastlinedefined; + ar->what = (ar->linedefined == 0) ? "main" : "Lua"; + } + luaO_chunkid(ar->short_src, ar->source, ar->srclen); +} + + +static int nextline (const Proto *p, int currentline, int pc) { + if (p->lineinfo[pc] != ABSLINEINFO) + return currentline + p->lineinfo[pc]; + else + return luaG_getfuncline(p, pc); +} + + +static void collectvalidlines (lua_State *L, Closure *f) { + if (noLuaClosure(f)) { + setnilvalue(s2v(L->top.p)); + api_incr_top(L); + } + else { + int i; + TValue v; + const Proto *p = f->l.p; + int currentline = p->linedefined; + Table *t = luaH_new(L); /* new table to store active lines */ + sethvalue2s(L, L->top.p, t); /* push it on stack */ + api_incr_top(L); + setbtvalue(&v); /* boolean 'true' to be the value of all indices */ + if (!p->is_vararg) /* regular function? */ + i = 0; /* consider all instructions */ + else { /* vararg function */ + lua_assert(GET_OPCODE(p->code[0]) == OP_VARARGPREP); + currentline = nextline(p, currentline, 0); + i = 1; /* skip first instruction (OP_VARARGPREP) */ + } + for (; i < p->sizelineinfo; i++) { /* for each instruction */ + currentline = nextline(p, currentline, i); /* get its line */ + luaH_setint(L, t, currentline, &v); /* table[line] = true */ + } + } +} + + +static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { + /* calling function is a known function? */ + if (ci != NULL && !(ci->callstatus & CIST_TAIL)) + return funcnamefromcall(L, ci->previous, name); + else return NULL; /* no way to find a name */ +} + + +static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar, + Closure *f, CallInfo *ci) { + int status = 1; + for (; *what; what++) { + switch (*what) { + case 'S': { + funcinfo(ar, f); + break; + } + case 'l': { + ar->currentline = (ci && isLua(ci)) ? getcurrentline(ci) : -1; + break; + } + case 'u': { + ar->nups = (f == NULL) ? 0 : f->c.nupvalues; + if (noLuaClosure(f)) { + ar->isvararg = 1; + ar->nparams = 0; + } + else { + ar->isvararg = f->l.p->is_vararg; + ar->nparams = f->l.p->numparams; + } + break; + } + case 't': { + ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0; + break; + } + case 'n': { + ar->namewhat = getfuncname(L, ci, &ar->name); + if (ar->namewhat == NULL) { + ar->namewhat = ""; /* not found */ + ar->name = NULL; + } + break; + } + case 'r': { + if (ci == NULL || !(ci->callstatus & CIST_TRAN)) + ar->ftransfer = ar->ntransfer = 0; + else { + ar->ftransfer = ci->u2.transferinfo.ftransfer; + ar->ntransfer = ci->u2.transferinfo.ntransfer; + } + break; + } + case 'L': + case 'f': /* handled by lua_getinfo */ + break; + default: status = 0; /* invalid option */ + } + } + return status; +} + + +LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) { + int status; + Closure *cl; + CallInfo *ci; + TValue *func; + lua_lock(L); + if (*what == '>') { + ci = NULL; + func = s2v(L->top.p - 1); + api_check(L, ttisfunction(func), "function expected"); + what++; /* skip the '>' */ + L->top.p--; /* pop function */ + } + else { + ci = ar->i_ci; + func = s2v(ci->func.p); + lua_assert(ttisfunction(func)); + } + cl = ttisclosure(func) ? clvalue(func) : NULL; + status = auxgetinfo(L, what, ar, cl, ci); + if (strchr(what, 'f')) { + setobj2s(L, L->top.p, func); + api_incr_top(L); + } + if (strchr(what, 'L')) + collectvalidlines(L, cl); + lua_unlock(L); + return status; +} + + +/* +** {====================================================== +** Symbolic Execution +** ======================================================= +*/ + +static const char *getobjname (const Proto *p, int lastpc, int reg, + const char **name); + + +/* +** Find a "name" for the constant 'c'. +*/ +static void kname (const Proto *p, int c, const char **name) { + TValue *kvalue = &p->k[c]; + *name = (ttisstring(kvalue)) ? svalue(kvalue) : "?"; +} + + +/* +** Find a "name" for the register 'c'. +*/ +static void rname (const Proto *p, int pc, int c, const char **name) { + const char *what = getobjname(p, pc, c, name); /* search for 'c' */ + if (!(what && *what == 'c')) /* did not find a constant name? */ + *name = "?"; +} + + +/* +** Find a "name" for a 'C' value in an RK instruction. +*/ +static void rkname (const Proto *p, int pc, Instruction i, const char **name) { + int c = GETARG_C(i); /* key index */ + if (GETARG_k(i)) /* is 'c' a constant? */ + kname(p, c, name); + else /* 'c' is a register */ + rname(p, pc, c, name); +} + + +static int filterpc (int pc, int jmptarget) { + if (pc < jmptarget) /* is code conditional (inside a jump)? */ + return -1; /* cannot know who sets that register */ + else return pc; /* current position sets that register */ +} + + +/* +** Try to find last instruction before 'lastpc' that modified register 'reg'. +*/ +static int findsetreg (const Proto *p, int lastpc, int reg) { + int pc; + int setreg = -1; /* keep last instruction that changed 'reg' */ + int jmptarget = 0; /* any code before this address is conditional */ + if (testMMMode(GET_OPCODE(p->code[lastpc]))) + lastpc--; /* previous instruction was not actually executed */ + for (pc = 0; pc < lastpc; pc++) { + Instruction i = p->code[pc]; + OpCode op = GET_OPCODE(i); + int a = GETARG_A(i); + int change; /* true if current instruction changed 'reg' */ + switch (op) { + case OP_LOADNIL: { /* set registers from 'a' to 'a+b' */ + int b = GETARG_B(i); + change = (a <= reg && reg <= a + b); + break; + } + case OP_TFORCALL: { /* affect all regs above its base */ + change = (reg >= a + 2); + break; + } + case OP_CALL: + case OP_TAILCALL: { /* affect all registers above base */ + change = (reg >= a); + break; + } + case OP_JMP: { /* doesn't change registers, but changes 'jmptarget' */ + int b = GETARG_sJ(i); + int dest = pc + 1 + b; + /* jump does not skip 'lastpc' and is larger than current one? */ + if (dest <= lastpc && dest > jmptarget) + jmptarget = dest; /* update 'jmptarget' */ + change = 0; + break; + } + default: /* any instruction that sets A */ + change = (testAMode(op) && reg == a); + break; + } + if (change) + setreg = filterpc(pc, jmptarget); + } + return setreg; +} + + +/* +** Check whether table being indexed by instruction 'i' is the +** environment '_ENV' +*/ +static const char *gxf (const Proto *p, int pc, Instruction i, int isup) { + int t = GETARG_B(i); /* table index */ + const char *name; /* name of indexed variable */ + if (isup) /* is an upvalue? */ + name = upvalname(p, t); + else + getobjname(p, pc, t, &name); + return (name && strcmp(name, LUA_ENV) == 0) ? "global" : "field"; +} + + +static const char *getobjname (const Proto *p, int lastpc, int reg, + const char **name) { + int pc; + *name = luaF_getlocalname(p, reg + 1, lastpc); + if (*name) /* is a local? */ + return "local"; + /* else try symbolic execution */ + pc = findsetreg(p, lastpc, reg); + if (pc != -1) { /* could find instruction? */ + Instruction i = p->code[pc]; + OpCode op = GET_OPCODE(i); + switch (op) { + case OP_MOVE: { + int b = GETARG_B(i); /* move from 'b' to 'a' */ + if (b < GETARG_A(i)) + return getobjname(p, pc, b, name); /* get name for 'b' */ + break; + } + case OP_GETTABUP: { + int k = GETARG_C(i); /* key index */ + kname(p, k, name); + return gxf(p, pc, i, 1); + } + case OP_GETTABLE: { + int k = GETARG_C(i); /* key index */ + rname(p, pc, k, name); + return gxf(p, pc, i, 0); + } + case OP_GETI: { + *name = "integer index"; + return "field"; + } + case OP_GETFIELD: { + int k = GETARG_C(i); /* key index */ + kname(p, k, name); + return gxf(p, pc, i, 0); + } + case OP_GETUPVAL: { + *name = upvalname(p, GETARG_B(i)); + return "upvalue"; + } + case OP_LOADK: + case OP_LOADKX: { + int b = (op == OP_LOADK) ? GETARG_Bx(i) + : GETARG_Ax(p->code[pc + 1]); + if (ttisstring(&p->k[b])) { + *name = svalue(&p->k[b]); + return "constant"; + } + break; + } + case OP_SELF: { + rkname(p, pc, i, name); + return "method"; + } + default: break; /* go through to return NULL */ + } + } + return NULL; /* could not find reasonable name */ +} + + +/* +** Try to find a name for a function based on the code that called it. +** (Only works when function was called by a Lua function.) +** Returns what the name is (e.g., "for iterator", "method", +** "metamethod") and sets '*name' to point to the name. +*/ +static const char *funcnamefromcode (lua_State *L, const Proto *p, + int pc, const char **name) { + TMS tm = (TMS)0; /* (initial value avoids warnings) */ + Instruction i = p->code[pc]; /* calling instruction */ + switch (GET_OPCODE(i)) { + case OP_CALL: + case OP_TAILCALL: + return getobjname(p, pc, GETARG_A(i), name); /* get function name */ + case OP_TFORCALL: { /* for iterator */ + *name = "for iterator"; + return "for iterator"; + } + /* other instructions can do calls through metamethods */ + case OP_SELF: case OP_GETTABUP: case OP_GETTABLE: + case OP_GETI: case OP_GETFIELD: + tm = TM_INDEX; + break; + case OP_SETTABUP: case OP_SETTABLE: case OP_SETI: case OP_SETFIELD: + tm = TM_NEWINDEX; + break; + case OP_MMBIN: case OP_MMBINI: case OP_MMBINK: { + tm = cast(TMS, GETARG_C(i)); + break; + } + case OP_UNM: tm = TM_UNM; break; + case OP_BNOT: tm = TM_BNOT; break; + case OP_LEN: tm = TM_LEN; break; + case OP_CONCAT: tm = TM_CONCAT; break; + case OP_EQ: tm = TM_EQ; break; + /* no cases for OP_EQI and OP_EQK, as they don't call metamethods */ + case OP_LT: case OP_LTI: case OP_GTI: tm = TM_LT; break; + case OP_LE: case OP_LEI: case OP_GEI: tm = TM_LE; break; + case OP_CLOSE: case OP_RETURN: tm = TM_CLOSE; break; + default: + return NULL; /* cannot find a reasonable name */ + } + *name = getstr(G(L)->tmname[tm]) + 2; + return "metamethod"; +} + + +/* +** Try to find a name for a function based on how it was called. +*/ +static const char *funcnamefromcall (lua_State *L, CallInfo *ci, + const char **name) { + if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */ + *name = "?"; + return "hook"; + } + else if (ci->callstatus & CIST_FIN) { /* was it called as a finalizer? */ + *name = "__gc"; + return "metamethod"; /* report it as such */ + } + else if (isLua(ci)) + return funcnamefromcode(L, ci_func(ci)->p, currentpc(ci), name); + else + return NULL; +} + +/* }====================================================== */ + + + +/* +** Check whether pointer 'o' points to some value in the stack frame of +** the current function and, if so, returns its index. Because 'o' may +** not point to a value in this stack, we cannot compare it with the +** region boundaries (undefined behavior in ISO C). +*/ +static int instack (CallInfo *ci, const TValue *o) { + int pos; + StkId base = ci->func.p + 1; + for (pos = 0; base + pos < ci->top.p; pos++) { + if (o == s2v(base + pos)) + return pos; + } + return -1; /* not found */ +} + + +/* +** Checks whether value 'o' came from an upvalue. (That can only happen +** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on +** upvalues.) +*/ +static const char *getupvalname (CallInfo *ci, const TValue *o, + const char **name) { + LClosure *c = ci_func(ci); + int i; + for (i = 0; i < c->nupvalues; i++) { + if (c->upvals[i]->v.p == o) { + *name = upvalname(c->p, i); + return "upvalue"; + } + } + return NULL; +} + + +static const char *formatvarinfo (lua_State *L, const char *kind, + const char *name) { + if (kind == NULL) + return ""; /* no information */ + else + return luaO_pushfstring(L, " (%s '%s')", kind, name); +} + +/* +** Build a string with a "description" for the value 'o', such as +** "variable 'x'" or "upvalue 'y'". +*/ +static const char *varinfo (lua_State *L, const TValue *o) { + CallInfo *ci = L->ci; + const char *name = NULL; /* to avoid warnings */ + const char *kind = NULL; + if (isLua(ci)) { + kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */ + if (!kind) { /* not an upvalue? */ + int reg = instack(ci, o); /* try a register */ + if (reg >= 0) /* is 'o' a register? */ + kind = getobjname(ci_func(ci)->p, currentpc(ci), reg, &name); + } + } + return formatvarinfo(L, kind, name); +} + + +/* +** Raise a type error +*/ +static l_noret typeerror (lua_State *L, const TValue *o, const char *op, + const char *extra) { + const char *t = luaT_objtypename(L, o); + luaG_runerror(L, "attempt to %s a %s value%s", op, t, extra); +} + + +/* +** Raise a type error with "standard" information about the faulty +** object 'o' (using 'varinfo'). +*/ +l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) { + typeerror(L, o, op, varinfo(L, o)); +} + + +/* +** Raise an error for calling a non-callable object. Try to find a name +** for the object based on how it was called ('funcnamefromcall'); if it +** cannot get a name there, try 'varinfo'. +*/ +l_noret luaG_callerror (lua_State *L, const TValue *o) { + CallInfo *ci = L->ci; + const char *name = NULL; /* to avoid warnings */ + const char *kind = funcnamefromcall(L, ci, &name); + const char *extra = kind ? formatvarinfo(L, kind, name) : varinfo(L, o); + typeerror(L, o, "call", extra); +} + + +l_noret luaG_forerror (lua_State *L, const TValue *o, const char *what) { + luaG_runerror(L, "bad 'for' %s (number expected, got %s)", + what, luaT_objtypename(L, o)); +} + + +l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) { + if (ttisstring(p1) || cvt2str(p1)) p1 = p2; + luaG_typeerror(L, p1, "concatenate"); +} + + +l_noret luaG_opinterror (lua_State *L, const TValue *p1, + const TValue *p2, const char *msg) { + if (!ttisnumber(p1)) /* first operand is wrong? */ + p2 = p1; /* now second is wrong */ + luaG_typeerror(L, p2, msg); +} + + +/* +** Error when both values are convertible to numbers, but not to integers +*/ +l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) { + lua_Integer temp; + if (!luaV_tointegerns(p1, &temp, LUA_FLOORN2I)) + p2 = p1; + luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2)); +} + + +l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { + const char *t1 = luaT_objtypename(L, p1); + const char *t2 = luaT_objtypename(L, p2); + if (strcmp(t1, t2) == 0) + luaG_runerror(L, "attempt to compare two %s values", t1); + else + luaG_runerror(L, "attempt to compare %s with %s", t1, t2); +} + + +/* add src:line information to 'msg' */ +const char *luaG_addinfo (lua_State *L, const char *msg, TString *src, + int line) { + char buff[LUA_IDSIZE]; + if (src) + luaO_chunkid(buff, getstr(src), tsslen(src)); + else { /* no source available; use "?" instead */ + buff[0] = '?'; buff[1] = '\0'; + } + return luaO_pushfstring(L, "%s:%d: %s", buff, line, msg); +} + + +l_noret luaG_errormsg (lua_State *L) { + if (L->errfunc != 0) { /* is there an error handling function? */ + StkId errfunc = restorestack(L, L->errfunc); + lua_assert(ttisfunction(s2v(errfunc))); + setobjs2s(L, L->top.p, L->top.p - 1); /* move argument */ + setobjs2s(L, L->top.p - 1, errfunc); /* push function */ + L->top.p++; /* assume EXTRA_STACK */ + luaD_callnoyield(L, L->top.p - 2, 1); /* call it */ + } + luaD_throw(L, LUA_ERRRUN); +} + + +l_noret luaG_runerror (lua_State *L, const char *fmt, ...) { + CallInfo *ci = L->ci; + const char *msg; + va_list argp; + luaC_checkGC(L); /* error message uses memory */ + va_start(argp, fmt); + msg = luaO_pushvfstring(L, fmt, argp); /* format message */ + va_end(argp); + if (isLua(ci)) { /* if Lua function, add source:line information */ + luaG_addinfo(L, msg, ci_func(ci)->p->source, getcurrentline(ci)); + setobjs2s(L, L->top.p - 2, L->top.p - 1); /* remove 'msg' */ + L->top.p--; + } + luaG_errormsg(L); +} + + +/* +** Check whether new instruction 'newpc' is in a different line from +** previous instruction 'oldpc'. More often than not, 'newpc' is only +** one or a few instructions after 'oldpc' (it must be after, see +** caller), so try to avoid calling 'luaG_getfuncline'. If they are +** too far apart, there is a good chance of a ABSLINEINFO in the way, +** so it goes directly to 'luaG_getfuncline'. +*/ +static int changedline (const Proto *p, int oldpc, int newpc) { + if (p->lineinfo == NULL) /* no debug information? */ + return 0; + if (newpc - oldpc < MAXIWTHABS / 2) { /* not too far apart? */ + int delta = 0; /* line difference */ + int pc = oldpc; + for (;;) { + int lineinfo = p->lineinfo[++pc]; + if (lineinfo == ABSLINEINFO) + break; /* cannot compute delta; fall through */ + delta += lineinfo; + if (pc == newpc) + return (delta != 0); /* delta computed successfully */ + } + } + /* either instructions are too far apart or there is an absolute line + info in the way; compute line difference explicitly */ + return (luaG_getfuncline(p, oldpc) != luaG_getfuncline(p, newpc)); +} + + +/* +** Traces the execution of a Lua function. Called before the execution +** of each opcode, when debug is on. 'L->oldpc' stores the last +** instruction traced, to detect line changes. When entering a new +** function, 'npci' will be zero and will test as a new line whatever +** the value of 'oldpc'. Some exceptional conditions may return to +** a function without setting 'oldpc'. In that case, 'oldpc' may be +** invalid; if so, use zero as a valid value. (A wrong but valid 'oldpc' +** at most causes an extra call to a line hook.) +** This function is not "Protected" when called, so it should correct +** 'L->top.p' before calling anything that can run the GC. +*/ +int luaG_traceexec (lua_State *L, const Instruction *pc) { + CallInfo *ci = L->ci; + lu_byte mask = L->hookmask; + const Proto *p = ci_func(ci)->p; + int counthook; + if (!(mask & (LUA_MASKLINE | LUA_MASKCOUNT))) { /* no hooks? */ + ci->u.l.trap = 0; /* don't need to stop again */ + return 0; /* turn off 'trap' */ + } + pc++; /* reference is always next instruction */ + ci->u.l.savedpc = pc; /* save 'pc' */ + counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT)); + if (counthook) + resethookcount(L); /* reset count */ + else if (!(mask & LUA_MASKLINE)) + return 1; /* no line hook and count != 0; nothing to be done now */ + if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */ + ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ + return 1; /* do not call hook again (VM yielded, so it did not move) */ + } + if (!isIT(*(ci->u.l.savedpc - 1))) /* top not being used? */ + L->top.p = ci->top.p; /* correct top */ + if (counthook) + luaD_hook(L, LUA_HOOKCOUNT, -1, 0, 0); /* call count hook */ + if (mask & LUA_MASKLINE) { + /* 'L->oldpc' may be invalid; use zero in this case */ + int oldpc = (L->oldpc < p->sizecode) ? L->oldpc : 0; + int npci = pcRel(pc, p); + if (npci <= oldpc || /* call hook when jump back (loop), */ + changedline(p, oldpc, npci)) { /* or when enter new line */ + int newline = luaG_getfuncline(p, npci); + luaD_hook(L, LUA_HOOKLINE, newline, 0, 0); /* call line hook */ + } + L->oldpc = npci; /* 'pc' of last call to line hook */ + } + if (L->status == LUA_YIELD) { /* did hook yield? */ + if (counthook) + L->hookcount = 1; /* undo decrement to zero */ + ci->u.l.savedpc--; /* undo increment (resume will increment it again) */ + ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ + luaD_throw(L, LUA_YIELD); + } + return 1; /* keep 'trap' on */ +} + diff --git a/src/ldebug.h b/src/ldebug.h new file mode 100644 index 0000000..2c3074c --- /dev/null +++ b/src/ldebug.h @@ -0,0 +1,63 @@ +/* +** $Id: ldebug.h $ +** Auxiliary functions from Debug Interface module +** See Copyright Notice in lua.h +*/ + +#ifndef ldebug_h +#define ldebug_h + + +#include "lstate.h" + + +#define pcRel(pc, p) (cast_int((pc) - (p)->code) - 1) + + +/* Active Lua function (given call info) */ +#define ci_func(ci) (clLvalue(s2v((ci)->func.p))) + + +#define resethookcount(L) (L->hookcount = L->basehookcount) + +/* +** mark for entries in 'lineinfo' array that has absolute information in +** 'abslineinfo' array +*/ +#define ABSLINEINFO (-0x80) + + +/* +** MAXimum number of successive Instructions WiTHout ABSolute line +** information. (A power of two allows fast divisions.) +*/ +#if !defined(MAXIWTHABS) +#define MAXIWTHABS 128 +#endif + + +LUAI_FUNC int luaG_getfuncline (const Proto *f, int pc); +LUAI_FUNC const char *luaG_findlocal (lua_State *L, CallInfo *ci, int n, + StkId *pos); +LUAI_FUNC l_noret luaG_typeerror (lua_State *L, const TValue *o, + const char *opname); +LUAI_FUNC l_noret luaG_callerror (lua_State *L, const TValue *o); +LUAI_FUNC l_noret luaG_forerror (lua_State *L, const TValue *o, + const char *what); +LUAI_FUNC l_noret luaG_concaterror (lua_State *L, const TValue *p1, + const TValue *p2); +LUAI_FUNC l_noret luaG_opinterror (lua_State *L, const TValue *p1, + const TValue *p2, + const char *msg); +LUAI_FUNC l_noret luaG_tointerror (lua_State *L, const TValue *p1, + const TValue *p2); +LUAI_FUNC l_noret luaG_ordererror (lua_State *L, const TValue *p1, + const TValue *p2); +LUAI_FUNC l_noret luaG_runerror (lua_State *L, const char *fmt, ...); +LUAI_FUNC const char *luaG_addinfo (lua_State *L, const char *msg, + TString *src, int line); +LUAI_FUNC l_noret luaG_errormsg (lua_State *L); +LUAI_FUNC int luaG_traceexec (lua_State *L, const Instruction *pc); + + +#endif diff --git a/src/ldo.c b/src/ldo.c new file mode 100644 index 0000000..2a0017c --- /dev/null +++ b/src/ldo.c @@ -0,0 +1,1024 @@ +/* +** $Id: ldo.c $ +** Stack and Call structure of Lua +** See Copyright Notice in lua.h +*/ + +#define ldo_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lundump.h" +#include "lvm.h" +#include "lzio.h" + + + +#define errorstatus(s) ((s) > LUA_YIELD) + + +/* +** {====================================================== +** Error-recovery functions +** ======================================================= +*/ + +/* +** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By +** default, Lua handles errors with exceptions when compiling as +** C++ code, with _longjmp/_setjmp when asked to use them, and with +** longjmp/setjmp otherwise. +*/ +#if !defined(LUAI_THROW) /* { */ + +#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) /* { */ + +/* C++ exceptions */ +#define LUAI_THROW(L,c) throw(c) +#define LUAI_TRY(L,c,a) \ + try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; } +#define luai_jmpbuf int /* dummy variable */ + +#elif defined(LUA_USE_POSIX) /* }{ */ + +/* in POSIX, try _longjmp/_setjmp (more efficient) */ +#define LUAI_THROW(L,c) _longjmp((c)->b, 1) +#define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a } +#define luai_jmpbuf jmp_buf + +#else /* }{ */ + +/* ISO C handling with long jumps */ +#define LUAI_THROW(L,c) longjmp((c)->b, 1) +#define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a } +#define luai_jmpbuf jmp_buf + +#endif /* } */ + +#endif /* } */ + + + +/* chain list of long jump buffers */ +struct lua_longjmp { + struct lua_longjmp *previous; + luai_jmpbuf b; + volatile int status; /* error code */ +}; + + +void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) { + switch (errcode) { + case LUA_ERRMEM: { /* memory error? */ + setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */ + break; + } + case LUA_ERRERR: { + setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); + break; + } + case LUA_OK: { /* special case only for closing upvalues */ + setnilvalue(s2v(oldtop)); /* no error message */ + break; + } + default: { + lua_assert(errorstatus(errcode)); /* real error */ + setobjs2s(L, oldtop, L->top.p - 1); /* error message on current top */ + break; + } + } + L->top.p = oldtop + 1; +} + + +l_noret luaD_throw (lua_State *L, int errcode) { + if (L->errorJmp) { /* thread has an error handler? */ + L->errorJmp->status = errcode; /* set status */ + LUAI_THROW(L, L->errorJmp); /* jump to it */ + } + else { /* thread has no error handler */ + global_State *g = G(L); + errcode = luaE_resetthread(L, errcode); /* close all upvalues */ + if (g->mainthread->errorJmp) { /* main thread has a handler? */ + setobjs2s(L, g->mainthread->top.p++, L->top.p - 1); /* copy error obj. */ + luaD_throw(g->mainthread, errcode); /* re-throw in main thread */ + } + else { /* no handler at all; abort */ + if (g->panic) { /* panic function? */ + lua_unlock(L); + g->panic(L); /* call panic function (last chance to jump out) */ + } + abort(); + } + } +} + + +int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { + l_uint32 oldnCcalls = L->nCcalls; + struct lua_longjmp lj; + lj.status = LUA_OK; + lj.previous = L->errorJmp; /* chain new error handler */ + L->errorJmp = &lj; + LUAI_TRY(L, &lj, + (*f)(L, ud); + ); + L->errorJmp = lj.previous; /* restore old error handler */ + L->nCcalls = oldnCcalls; + return lj.status; +} + +/* }====================================================== */ + + +/* +** {================================================================== +** Stack reallocation +** =================================================================== +*/ + + +/* +** Change all pointers to the stack into offsets. +*/ +static void relstack (lua_State *L) { + CallInfo *ci; + UpVal *up; + L->top.offset = savestack(L, L->top.p); + L->tbclist.offset = savestack(L, L->tbclist.p); + for (up = L->openupval; up != NULL; up = up->u.open.next) + up->v.offset = savestack(L, uplevel(up)); + for (ci = L->ci; ci != NULL; ci = ci->previous) { + ci->top.offset = savestack(L, ci->top.p); + ci->func.offset = savestack(L, ci->func.p); + } +} + + +/* +** Change back all offsets into pointers. +*/ +static void correctstack (lua_State *L) { + CallInfo *ci; + UpVal *up; + L->top.p = restorestack(L, L->top.offset); + L->tbclist.p = restorestack(L, L->tbclist.offset); + for (up = L->openupval; up != NULL; up = up->u.open.next) + up->v.p = s2v(restorestack(L, up->v.offset)); + for (ci = L->ci; ci != NULL; ci = ci->previous) { + ci->top.p = restorestack(L, ci->top.offset); + ci->func.p = restorestack(L, ci->func.offset); + if (isLua(ci)) + ci->u.l.trap = 1; /* signal to update 'trap' in 'luaV_execute' */ + } +} + + +/* some space for error handling */ +#define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) + +/* +** Reallocate the stack to a new size, correcting all pointers into it. +** In ISO C, any pointer use after the pointer has been deallocated is +** undefined behavior. So, before the reallocation, all pointers are +** changed to offsets, and after the reallocation they are changed back +** to pointers. As during the reallocation the pointers are invalid, the +** reallocation cannot run emergency collections. +** +** In case of allocation error, raise an error or return false according +** to 'raiseerror'. +*/ +int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) { + int oldsize = stacksize(L); + int i; + StkId newstack; + int oldgcstop = G(L)->gcstopem; + lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE); + relstack(L); /* change pointers to offsets */ + G(L)->gcstopem = 1; /* stop emergency collection */ + newstack = luaM_reallocvector(L, L->stack.p, oldsize + EXTRA_STACK, + newsize + EXTRA_STACK, StackValue); + G(L)->gcstopem = oldgcstop; /* restore emergency collection */ + if (l_unlikely(newstack == NULL)) { /* reallocation failed? */ + correctstack(L); /* change offsets back to pointers */ + if (raiseerror) + luaM_error(L); + else return 0; /* do not raise an error */ + } + L->stack.p = newstack; + correctstack(L); /* change offsets back to pointers */ + L->stack_last.p = L->stack.p + newsize; + for (i = oldsize + EXTRA_STACK; i < newsize + EXTRA_STACK; i++) + setnilvalue(s2v(newstack + i)); /* erase new segment */ + return 1; +} + + +/* +** Try to grow the stack by at least 'n' elements. When 'raiseerror' +** is true, raises any error; otherwise, return 0 in case of errors. +*/ +int luaD_growstack (lua_State *L, int n, int raiseerror) { + int size = stacksize(L); + if (l_unlikely(size > LUAI_MAXSTACK)) { + /* if stack is larger than maximum, thread is already using the + extra space reserved for errors, that is, thread is handling + a stack error; cannot grow further than that. */ + lua_assert(stacksize(L) == ERRORSTACKSIZE); + if (raiseerror) + luaD_throw(L, LUA_ERRERR); /* error inside message handler */ + return 0; /* if not 'raiseerror', just signal it */ + } + else if (n < LUAI_MAXSTACK) { /* avoids arithmetic overflows */ + int newsize = 2 * size; /* tentative new size */ + int needed = cast_int(L->top.p - L->stack.p) + n; + if (newsize > LUAI_MAXSTACK) /* cannot cross the limit */ + newsize = LUAI_MAXSTACK; + if (newsize < needed) /* but must respect what was asked for */ + newsize = needed; + if (l_likely(newsize <= LUAI_MAXSTACK)) + return luaD_reallocstack(L, newsize, raiseerror); + } + /* else stack overflow */ + /* add extra size to be able to handle the error message */ + luaD_reallocstack(L, ERRORSTACKSIZE, raiseerror); + if (raiseerror) + luaG_runerror(L, "stack overflow"); + return 0; +} + + +/* +** Compute how much of the stack is being used, by computing the +** maximum top of all call frames in the stack and the current top. +*/ +static int stackinuse (lua_State *L) { + CallInfo *ci; + int res; + StkId lim = L->top.p; + for (ci = L->ci; ci != NULL; ci = ci->previous) { + if (lim < ci->top.p) lim = ci->top.p; + } + lua_assert(lim <= L->stack_last.p + EXTRA_STACK); + res = cast_int(lim - L->stack.p) + 1; /* part of stack in use */ + if (res < LUA_MINSTACK) + res = LUA_MINSTACK; /* ensure a minimum size */ + return res; +} + + +/* +** If stack size is more than 3 times the current use, reduce that size +** to twice the current use. (So, the final stack size is at most 2/3 the +** previous size, and half of its entries are empty.) +** As a particular case, if stack was handling a stack overflow and now +** it is not, 'max' (limited by LUAI_MAXSTACK) will be smaller than +** stacksize (equal to ERRORSTACKSIZE in this case), and so the stack +** will be reduced to a "regular" size. +*/ +void luaD_shrinkstack (lua_State *L) { + int inuse = stackinuse(L); + int max = (inuse > LUAI_MAXSTACK / 3) ? LUAI_MAXSTACK : inuse * 3; + /* if thread is currently not handling a stack overflow and its + size is larger than maximum "reasonable" size, shrink it */ + if (inuse <= LUAI_MAXSTACK && stacksize(L) > max) { + int nsize = (inuse > LUAI_MAXSTACK / 2) ? LUAI_MAXSTACK : inuse * 2; + luaD_reallocstack(L, nsize, 0); /* ok if that fails */ + } + else /* don't change stack */ + condmovestack(L,{},{}); /* (change only for debugging) */ + luaE_shrinkCI(L); /* shrink CI list */ +} + + +void luaD_inctop (lua_State *L) { + luaD_checkstack(L, 1); + L->top.p++; +} + +/* }================================================================== */ + + +/* +** Call a hook for the given event. Make sure there is a hook to be +** called. (Both 'L->hook' and 'L->hookmask', which trigger this +** function, can be changed asynchronously by signals.) +*/ +void luaD_hook (lua_State *L, int event, int line, + int ftransfer, int ntransfer) { + lua_Hook hook = L->hook; + if (hook && L->allowhook) { /* make sure there is a hook */ + int mask = CIST_HOOKED; + CallInfo *ci = L->ci; + ptrdiff_t top = savestack(L, L->top.p); /* preserve original 'top' */ + ptrdiff_t ci_top = savestack(L, ci->top.p); /* idem for 'ci->top' */ + lua_Debug ar; + ar.event = event; + ar.currentline = line; + ar.i_ci = ci; + if (ntransfer != 0) { + mask |= CIST_TRAN; /* 'ci' has transfer information */ + ci->u2.transferinfo.ftransfer = ftransfer; + ci->u2.transferinfo.ntransfer = ntransfer; + } + if (isLua(ci) && L->top.p < ci->top.p) + L->top.p = ci->top.p; /* protect entire activation register */ + luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ + if (ci->top.p < L->top.p + LUA_MINSTACK) + ci->top.p = L->top.p + LUA_MINSTACK; + L->allowhook = 0; /* cannot call hooks inside a hook */ + ci->callstatus |= mask; + lua_unlock(L); + (*hook)(L, &ar); + lua_lock(L); + lua_assert(!L->allowhook); + L->allowhook = 1; + ci->top.p = restorestack(L, ci_top); + L->top.p = restorestack(L, top); + ci->callstatus &= ~mask; + } +} + + +/* +** Executes a call hook for Lua functions. This function is called +** whenever 'hookmask' is not zero, so it checks whether call hooks are +** active. +*/ +void luaD_hookcall (lua_State *L, CallInfo *ci) { + L->oldpc = 0; /* set 'oldpc' for new function */ + if (L->hookmask & LUA_MASKCALL) { /* is call hook on? */ + int event = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL + : LUA_HOOKCALL; + Proto *p = ci_func(ci)->p; + ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ + luaD_hook(L, event, -1, 1, p->numparams); + ci->u.l.savedpc--; /* correct 'pc' */ + } +} + + +/* +** Executes a return hook for Lua and C functions and sets/corrects +** 'oldpc'. (Note that this correction is needed by the line hook, so it +** is done even when return hooks are off.) +*/ +static void rethook (lua_State *L, CallInfo *ci, int nres) { + if (L->hookmask & LUA_MASKRET) { /* is return hook on? */ + StkId firstres = L->top.p - nres; /* index of first result */ + int delta = 0; /* correction for vararg functions */ + int ftransfer; + if (isLua(ci)) { + Proto *p = ci_func(ci)->p; + if (p->is_vararg) + delta = ci->u.l.nextraargs + p->numparams + 1; + } + ci->func.p += delta; /* if vararg, back to virtual 'func' */ + ftransfer = cast(unsigned short, firstres - ci->func.p); + luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres); /* call it */ + ci->func.p -= delta; + } + if (isLua(ci = ci->previous)) + L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p); /* set 'oldpc' */ +} + + +/* +** Check whether 'func' has a '__call' metafield. If so, put it in the +** stack, below original 'func', so that 'luaD_precall' can call it. Raise +** an error if there is no '__call' metafield. +*/ +StkId luaD_tryfuncTM (lua_State *L, StkId func) { + const TValue *tm; + StkId p; + checkstackGCp(L, 1, func); /* space for metamethod */ + tm = luaT_gettmbyobj(L, s2v(func), TM_CALL); /* (after previous GC) */ + if (l_unlikely(ttisnil(tm))) + luaG_callerror(L, s2v(func)); /* nothing to call */ + for (p = L->top.p; p > func; p--) /* open space for metamethod */ + setobjs2s(L, p, p-1); + L->top.p++; /* stack space pre-allocated by the caller */ + setobj2s(L, func, tm); /* metamethod is the new function to be called */ + return func; +} + + +/* +** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'. +** Handle most typical cases (zero results for commands, one result for +** expressions, multiple results for tail calls/single parameters) +** separated. +*/ +l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) { + StkId firstresult; + int i; + switch (wanted) { /* handle typical cases separately */ + case 0: /* no values needed */ + L->top.p = res; + return; + case 1: /* one value needed */ + if (nres == 0) /* no results? */ + setnilvalue(s2v(res)); /* adjust with nil */ + else /* at least one result */ + setobjs2s(L, res, L->top.p - nres); /* move it to proper place */ + L->top.p = res + 1; + return; + case LUA_MULTRET: + wanted = nres; /* we want all results */ + break; + default: /* two/more results and/or to-be-closed variables */ + if (hastocloseCfunc(wanted)) { /* to-be-closed variables? */ + L->ci->callstatus |= CIST_CLSRET; /* in case of yields */ + L->ci->u2.nres = nres; + res = luaF_close(L, res, CLOSEKTOP, 1); + L->ci->callstatus &= ~CIST_CLSRET; + if (L->hookmask) { /* if needed, call hook after '__close's */ + ptrdiff_t savedres = savestack(L, res); + rethook(L, L->ci, nres); + res = restorestack(L, savedres); /* hook can move stack */ + } + wanted = decodeNresults(wanted); + if (wanted == LUA_MULTRET) + wanted = nres; /* we want all results */ + } + break; + } + /* generic case */ + firstresult = L->top.p - nres; /* index of first result */ + if (nres > wanted) /* extra results? */ + nres = wanted; /* don't need them */ + for (i = 0; i < nres; i++) /* move all results to correct place */ + setobjs2s(L, res + i, firstresult + i); + for (; i < wanted; i++) /* complete wanted number of results */ + setnilvalue(s2v(res + i)); + L->top.p = res + wanted; /* top points after the last result */ +} + + +/* +** Finishes a function call: calls hook if necessary, moves current +** number of results to proper place, and returns to previous call +** info. If function has to close variables, hook must be called after +** that. +*/ +void luaD_poscall (lua_State *L, CallInfo *ci, int nres) { + int wanted = ci->nresults; + if (l_unlikely(L->hookmask && !hastocloseCfunc(wanted))) + rethook(L, ci, nres); + /* move results to proper place */ + moveresults(L, ci->func.p, nres, wanted); + /* function cannot be in any of these cases when returning */ + lua_assert(!(ci->callstatus & + (CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_TRAN | CIST_CLSRET))); + L->ci = ci->previous; /* back to caller (after closing variables) */ +} + + + +#define next_ci(L) (L->ci->next ? L->ci->next : luaE_extendCI(L)) + + +l_sinline CallInfo *prepCallInfo (lua_State *L, StkId func, int nret, + int mask, StkId top) { + CallInfo *ci = L->ci = next_ci(L); /* new frame */ + ci->func.p = func; + ci->nresults = nret; + ci->callstatus = mask; + ci->top.p = top; + return ci; +} + + +/* +** precall for C functions +*/ +l_sinline int precallC (lua_State *L, StkId func, int nresults, + lua_CFunction f) { + int n; /* number of returns */ + CallInfo *ci; + checkstackGCp(L, LUA_MINSTACK, func); /* ensure minimum stack size */ + L->ci = ci = prepCallInfo(L, func, nresults, CIST_C, + L->top.p + LUA_MINSTACK); + lua_assert(ci->top.p <= L->stack_last.p); + if (l_unlikely(L->hookmask & LUA_MASKCALL)) { + int narg = cast_int(L->top.p - func) - 1; + luaD_hook(L, LUA_HOOKCALL, -1, 1, narg); + } + lua_unlock(L); + n = (*f)(L); /* do the actual call */ + lua_lock(L); + api_checknelems(L, n); + luaD_poscall(L, ci, n); + return n; +} + + +/* +** Prepare a function for a tail call, building its call info on top +** of the current call info. 'narg1' is the number of arguments plus 1 +** (so that it includes the function itself). Return the number of +** results, if it was a C function, or -1 for a Lua function. +*/ +int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, + int narg1, int delta) { + retry: + switch (ttypetag(s2v(func))) { + case LUA_VCCL: /* C closure */ + return precallC(L, func, LUA_MULTRET, clCvalue(s2v(func))->f); + case LUA_VLCF: /* light C function */ + return precallC(L, func, LUA_MULTRET, fvalue(s2v(func))); + case LUA_VLCL: { /* Lua function */ + Proto *p = clLvalue(s2v(func))->p; + int fsize = p->maxstacksize; /* frame size */ + int nfixparams = p->numparams; + int i; + checkstackGCp(L, fsize - delta, func); + ci->func.p -= delta; /* restore 'func' (if vararg) */ + for (i = 0; i < narg1; i++) /* move down function and arguments */ + setobjs2s(L, ci->func.p + i, func + i); + func = ci->func.p; /* moved-down function */ + for (; narg1 <= nfixparams; narg1++) + setnilvalue(s2v(func + narg1)); /* complete missing arguments */ + ci->top.p = func + 1 + fsize; /* top for new function */ + lua_assert(ci->top.p <= L->stack_last.p); + ci->u.l.savedpc = p->code; /* starting point */ + ci->callstatus |= CIST_TAIL; + L->top.p = func + narg1; /* set top */ + return -1; + } + default: { /* not a function */ + func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ + /* return luaD_pretailcall(L, ci, func, narg1 + 1, delta); */ + narg1++; + goto retry; /* try again */ + } + } +} + + +/* +** Prepares the call to a function (C or Lua). For C functions, also do +** the call. The function to be called is at '*func'. The arguments +** are on the stack, right after the function. Returns the CallInfo +** to be executed, if it was a Lua function. Otherwise (a C function) +** returns NULL, with all the results on the stack, starting at the +** original function position. +*/ +CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) { + retry: + switch (ttypetag(s2v(func))) { + case LUA_VCCL: /* C closure */ + precallC(L, func, nresults, clCvalue(s2v(func))->f); + return NULL; + case LUA_VLCF: /* light C function */ + precallC(L, func, nresults, fvalue(s2v(func))); + return NULL; + case LUA_VLCL: { /* Lua function */ + CallInfo *ci; + Proto *p = clLvalue(s2v(func))->p; + int narg = cast_int(L->top.p - func) - 1; /* number of real arguments */ + int nfixparams = p->numparams; + int fsize = p->maxstacksize; /* frame size */ + checkstackGCp(L, fsize, func); + L->ci = ci = prepCallInfo(L, func, nresults, 0, func + 1 + fsize); + ci->u.l.savedpc = p->code; /* starting point */ + for (; narg < nfixparams; narg++) + setnilvalue(s2v(L->top.p++)); /* complete missing arguments */ + lua_assert(ci->top.p <= L->stack_last.p); + return ci; + } + default: { /* not a function */ + func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ + /* return luaD_precall(L, func, nresults); */ + goto retry; /* try again with metamethod */ + } + } +} + + +/* +** Call a function (C or Lua) through C. 'inc' can be 1 (increment +** number of recursive invocations in the C stack) or nyci (the same +** plus increment number of non-yieldable calls). +** This function can be called with some use of EXTRA_STACK, so it should +** check the stack before doing anything else. 'luaD_precall' already +** does that. +*/ +l_sinline void ccall (lua_State *L, StkId func, int nResults, l_uint32 inc) { + CallInfo *ci; + L->nCcalls += inc; + if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS)) { + checkstackp(L, 0, func); /* free any use of EXTRA_STACK */ + luaE_checkcstack(L); + } + if ((ci = luaD_precall(L, func, nResults)) != NULL) { /* Lua function? */ + ci->callstatus = CIST_FRESH; /* mark that it is a "fresh" execute */ + luaV_execute(L, ci); /* call it */ + } + L->nCcalls -= inc; +} + + +/* +** External interface for 'ccall' +*/ +void luaD_call (lua_State *L, StkId func, int nResults) { + ccall(L, func, nResults, 1); +} + + +/* +** Similar to 'luaD_call', but does not allow yields during the call. +*/ +void luaD_callnoyield (lua_State *L, StkId func, int nResults) { + ccall(L, func, nResults, nyci); +} + + +/* +** Finish the job of 'lua_pcallk' after it was interrupted by an yield. +** (The caller, 'finishCcall', does the final call to 'adjustresults'.) +** The main job is to complete the 'luaD_pcall' called by 'lua_pcallk'. +** If a '__close' method yields here, eventually control will be back +** to 'finishCcall' (when that '__close' method finally returns) and +** 'finishpcallk' will run again and close any still pending '__close' +** methods. Similarly, if a '__close' method errs, 'precover' calls +** 'unroll' which calls ''finishCcall' and we are back here again, to +** close any pending '__close' methods. +** Note that, up to the call to 'luaF_close', the corresponding +** 'CallInfo' is not modified, so that this repeated run works like the +** first one (except that it has at least one less '__close' to do). In +** particular, field CIST_RECST preserves the error status across these +** multiple runs, changing only if there is a new error. +*/ +static int finishpcallk (lua_State *L, CallInfo *ci) { + int status = getcistrecst(ci); /* get original status */ + if (l_likely(status == LUA_OK)) /* no error? */ + status = LUA_YIELD; /* was interrupted by an yield */ + else { /* error */ + StkId func = restorestack(L, ci->u2.funcidx); + L->allowhook = getoah(ci->callstatus); /* restore 'allowhook' */ + func = luaF_close(L, func, status, 1); /* can yield or raise an error */ + luaD_seterrorobj(L, status, func); + luaD_shrinkstack(L); /* restore stack size in case of overflow */ + setcistrecst(ci, LUA_OK); /* clear original status */ + } + ci->callstatus &= ~CIST_YPCALL; + L->errfunc = ci->u.c.old_errfunc; + /* if it is here, there were errors or yields; unlike 'lua_pcallk', + do not change status */ + return status; +} + + +/* +** Completes the execution of a C function interrupted by an yield. +** The interruption must have happened while the function was either +** closing its tbc variables in 'moveresults' or executing +** 'lua_callk'/'lua_pcallk'. In the first case, it just redoes +** 'luaD_poscall'. In the second case, the call to 'finishpcallk' +** finishes the interrupted execution of 'lua_pcallk'. After that, it +** calls the continuation of the interrupted function and finally it +** completes the job of the 'luaD_call' that called the function. In +** the call to 'adjustresults', we do not know the number of results +** of the function called by 'lua_callk'/'lua_pcallk', so we are +** conservative and use LUA_MULTRET (always adjust). +*/ +static void finishCcall (lua_State *L, CallInfo *ci) { + int n; /* actual number of results from C function */ + if (ci->callstatus & CIST_CLSRET) { /* was returning? */ + lua_assert(hastocloseCfunc(ci->nresults)); + n = ci->u2.nres; /* just redo 'luaD_poscall' */ + /* don't need to reset CIST_CLSRET, as it will be set again anyway */ + } + else { + int status = LUA_YIELD; /* default if there were no errors */ + /* must have a continuation and must be able to call it */ + lua_assert(ci->u.c.k != NULL && yieldable(L)); + if (ci->callstatus & CIST_YPCALL) /* was inside a 'lua_pcallk'? */ + status = finishpcallk(L, ci); /* finish it */ + adjustresults(L, LUA_MULTRET); /* finish 'lua_callk' */ + lua_unlock(L); + n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation */ + lua_lock(L); + api_checknelems(L, n); + } + luaD_poscall(L, ci, n); /* finish 'luaD_call' */ +} + + +/* +** Executes "full continuation" (everything in the stack) of a +** previously interrupted coroutine until the stack is empty (or another +** interruption long-jumps out of the loop). +*/ +static void unroll (lua_State *L, void *ud) { + CallInfo *ci; + UNUSED(ud); + while ((ci = L->ci) != &L->base_ci) { /* something in the stack */ + if (!isLua(ci)) /* C function? */ + finishCcall(L, ci); /* complete its execution */ + else { /* Lua function */ + luaV_finishOp(L); /* finish interrupted instruction */ + luaV_execute(L, ci); /* execute down to higher C 'boundary' */ + } + } +} + + +/* +** Try to find a suspended protected call (a "recover point") for the +** given thread. +*/ +static CallInfo *findpcall (lua_State *L) { + CallInfo *ci; + for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */ + if (ci->callstatus & CIST_YPCALL) + return ci; + } + return NULL; /* no pending pcall */ +} + + +/* +** Signal an error in the call to 'lua_resume', not in the execution +** of the coroutine itself. (Such errors should not be handled by any +** coroutine error handler and should not kill the coroutine.) +*/ +static int resume_error (lua_State *L, const char *msg, int narg) { + L->top.p -= narg; /* remove args from the stack */ + setsvalue2s(L, L->top.p, luaS_new(L, msg)); /* push error message */ + api_incr_top(L); + lua_unlock(L); + return LUA_ERRRUN; +} + + +/* +** Do the work for 'lua_resume' in protected mode. Most of the work +** depends on the status of the coroutine: initial state, suspended +** inside a hook, or regularly suspended (optionally with a continuation +** function), plus erroneous cases: non-suspended coroutine or dead +** coroutine. +*/ +static void resume (lua_State *L, void *ud) { + int n = *(cast(int*, ud)); /* number of arguments */ + StkId firstArg = L->top.p - n; /* first argument */ + CallInfo *ci = L->ci; + if (L->status == LUA_OK) /* starting a coroutine? */ + ccall(L, firstArg - 1, LUA_MULTRET, 0); /* just call its body */ + else { /* resuming from previous yield */ + lua_assert(L->status == LUA_YIELD); + L->status = LUA_OK; /* mark that it is running (again) */ + if (isLua(ci)) { /* yielded inside a hook? */ + L->top.p = firstArg; /* discard arguments */ + luaV_execute(L, ci); /* just continue running Lua code */ + } + else { /* 'common' yield */ + if (ci->u.c.k != NULL) { /* does it have a continuation function? */ + lua_unlock(L); + n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */ + lua_lock(L); + api_checknelems(L, n); + } + luaD_poscall(L, ci, n); /* finish 'luaD_call' */ + } + unroll(L, NULL); /* run continuation */ + } +} + + +/* +** Unrolls a coroutine in protected mode while there are recoverable +** errors, that is, errors inside a protected call. (Any error +** interrupts 'unroll', and this loop protects it again so it can +** continue.) Stops with a normal end (status == LUA_OK), an yield +** (status == LUA_YIELD), or an unprotected error ('findpcall' doesn't +** find a recover point). +*/ +static int precover (lua_State *L, int status) { + CallInfo *ci; + while (errorstatus(status) && (ci = findpcall(L)) != NULL) { + L->ci = ci; /* go down to recovery functions */ + setcistrecst(ci, status); /* status to finish 'pcall' */ + status = luaD_rawrunprotected(L, unroll, NULL); + } + return status; +} + + +LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs, + int *nresults) { + int status; + lua_lock(L); + if (L->status == LUA_OK) { /* may be starting a coroutine */ + if (L->ci != &L->base_ci) /* not in base level? */ + return resume_error(L, "cannot resume non-suspended coroutine", nargs); + else if (L->top.p - (L->ci->func.p + 1) == nargs) /* no function? */ + return resume_error(L, "cannot resume dead coroutine", nargs); + } + else if (L->status != LUA_YIELD) /* ended with errors? */ + return resume_error(L, "cannot resume dead coroutine", nargs); + L->nCcalls = (from) ? getCcalls(from) : 0; + if (getCcalls(L) >= LUAI_MAXCCALLS) + return resume_error(L, "C stack overflow", nargs); + L->nCcalls++; + luai_userstateresume(L, nargs); + api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs); + status = luaD_rawrunprotected(L, resume, &nargs); + /* continue running after recoverable errors */ + status = precover(L, status); + if (l_likely(!errorstatus(status))) + lua_assert(status == L->status); /* normal end or yield */ + else { /* unrecoverable error */ + L->status = cast_byte(status); /* mark thread as 'dead' */ + luaD_seterrorobj(L, status, L->top.p); /* push error message */ + L->ci->top.p = L->top.p; + } + *nresults = (status == LUA_YIELD) ? L->ci->u2.nyield + : cast_int(L->top.p - (L->ci->func.p + 1)); + lua_unlock(L); + return status; +} + + +LUA_API int lua_isyieldable (lua_State *L) { + return yieldable(L); +} + + +LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, + lua_KFunction k) { + CallInfo *ci; + luai_userstateyield(L, nresults); + lua_lock(L); + ci = L->ci; + api_checknelems(L, nresults); + if (l_unlikely(!yieldable(L))) { + if (L != G(L)->mainthread) + luaG_runerror(L, "attempt to yield across a C-call boundary"); + else + luaG_runerror(L, "attempt to yield from outside a coroutine"); + } + L->status = LUA_YIELD; + ci->u2.nyield = nresults; /* save number of results */ + if (isLua(ci)) { /* inside a hook? */ + lua_assert(!isLuacode(ci)); + api_check(L, nresults == 0, "hooks cannot yield values"); + api_check(L, k == NULL, "hooks cannot continue after yielding"); + } + else { + if ((ci->u.c.k = k) != NULL) /* is there a continuation? */ + ci->u.c.ctx = ctx; /* save context */ + luaD_throw(L, LUA_YIELD); + } + lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */ + lua_unlock(L); + return 0; /* return to 'luaD_hook' */ +} + + +/* +** Auxiliary structure to call 'luaF_close' in protected mode. +*/ +struct CloseP { + StkId level; + int status; +}; + + +/* +** Auxiliary function to call 'luaF_close' in protected mode. +*/ +static void closepaux (lua_State *L, void *ud) { + struct CloseP *pcl = cast(struct CloseP *, ud); + luaF_close(L, pcl->level, pcl->status, 0); +} + + +/* +** Calls 'luaF_close' in protected mode. Return the original status +** or, in case of errors, the new status. +*/ +int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status) { + CallInfo *old_ci = L->ci; + lu_byte old_allowhooks = L->allowhook; + for (;;) { /* keep closing upvalues until no more errors */ + struct CloseP pcl; + pcl.level = restorestack(L, level); pcl.status = status; + status = luaD_rawrunprotected(L, &closepaux, &pcl); + if (l_likely(status == LUA_OK)) /* no more errors? */ + return pcl.status; + else { /* an error occurred; restore saved state and repeat */ + L->ci = old_ci; + L->allowhook = old_allowhooks; + } + } +} + + +/* +** Call the C function 'func' in protected mode, restoring basic +** thread information ('allowhook', etc.) and in particular +** its stack level in case of errors. +*/ +int luaD_pcall (lua_State *L, Pfunc func, void *u, + ptrdiff_t old_top, ptrdiff_t ef) { + int status; + CallInfo *old_ci = L->ci; + lu_byte old_allowhooks = L->allowhook; + ptrdiff_t old_errfunc = L->errfunc; + L->errfunc = ef; + status = luaD_rawrunprotected(L, func, u); + if (l_unlikely(status != LUA_OK)) { /* an error occurred? */ + L->ci = old_ci; + L->allowhook = old_allowhooks; + status = luaD_closeprotected(L, old_top, status); + luaD_seterrorobj(L, status, restorestack(L, old_top)); + luaD_shrinkstack(L); /* restore stack size in case of overflow */ + } + L->errfunc = old_errfunc; + return status; +} + + + +/* +** Execute a protected parser. +*/ +struct SParser { /* data to 'f_parser' */ + ZIO *z; + Mbuffer buff; /* dynamic structure used by the scanner */ + Dyndata dyd; /* dynamic structures used by the parser */ + const char *mode; + const char *name; +}; + + +static void checkmode (lua_State *L, const char *mode, const char *x) { + if (mode && strchr(mode, x[0]) == NULL) { + luaO_pushfstring(L, + "attempt to load a %s chunk (mode is '%s')", x, mode); + luaD_throw(L, LUA_ERRSYNTAX); + } +} + + +static void f_parser (lua_State *L, void *ud) { + LClosure *cl; + struct SParser *p = cast(struct SParser *, ud); + int c = zgetc(p->z); /* read first character */ + if (c == LUA_SIGNATURE[0]) { + checkmode(L, p->mode, "binary"); + cl = luaU_undump(L, p->z, p->name); + } + else { + checkmode(L, p->mode, "text"); + cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c); + } + lua_assert(cl->nupvalues == cl->p->sizeupvalues); + luaF_initupvals(L, cl); +} + + +int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, + const char *mode) { + struct SParser p; + int status; + incnny(L); /* cannot yield during parsing */ + p.z = z; p.name = name; p.mode = mode; + p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0; + p.dyd.gt.arr = NULL; p.dyd.gt.size = 0; + p.dyd.label.arr = NULL; p.dyd.label.size = 0; + luaZ_initbuffer(L, &p.buff); + status = luaD_pcall(L, f_parser, &p, savestack(L, L->top.p), L->errfunc); + luaZ_freebuffer(L, &p.buff); + luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size); + luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size); + luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size); + decnny(L); + return status; +} + + diff --git a/src/ldo.h b/src/ldo.h new file mode 100644 index 0000000..1aa446a --- /dev/null +++ b/src/ldo.h @@ -0,0 +1,88 @@ +/* +** $Id: ldo.h $ +** Stack and Call structure of Lua +** See Copyright Notice in lua.h +*/ + +#ifndef ldo_h +#define ldo_h + + +#include "llimits.h" +#include "lobject.h" +#include "lstate.h" +#include "lzio.h" + + +/* +** Macro to check stack size and grow stack if needed. Parameters +** 'pre'/'pos' allow the macro to preserve a pointer into the +** stack across reallocations, doing the work only when needed. +** It also allows the running of one GC step when the stack is +** reallocated. +** 'condmovestack' is used in heavy tests to force a stack reallocation +** at every check. +*/ +#define luaD_checkstackaux(L,n,pre,pos) \ + if (l_unlikely(L->stack_last.p - L->top.p <= (n))) \ + { pre; luaD_growstack(L, n, 1); pos; } \ + else { condmovestack(L,pre,pos); } + +/* In general, 'pre'/'pos' are empty (nothing to save) */ +#define luaD_checkstack(L,n) luaD_checkstackaux(L,n,(void)0,(void)0) + + + +#define savestack(L,pt) (cast_charp(pt) - cast_charp(L->stack.p)) +#define restorestack(L,n) cast(StkId, cast_charp(L->stack.p) + (n)) + + +/* macro to check stack size, preserving 'p' */ +#define checkstackp(L,n,p) \ + luaD_checkstackaux(L, n, \ + ptrdiff_t t__ = savestack(L, p), /* save 'p' */ \ + p = restorestack(L, t__)) /* 'pos' part: restore 'p' */ + + +/* macro to check stack size and GC, preserving 'p' */ +#define checkstackGCp(L,n,p) \ + luaD_checkstackaux(L, n, \ + ptrdiff_t t__ = savestack(L, p); /* save 'p' */ \ + luaC_checkGC(L), /* stack grow uses memory */ \ + p = restorestack(L, t__)) /* 'pos' part: restore 'p' */ + + +/* macro to check stack size and GC */ +#define checkstackGC(L,fsize) \ + luaD_checkstackaux(L, (fsize), luaC_checkGC(L), (void)0) + + +/* type of protected functions, to be ran by 'runprotected' */ +typedef void (*Pfunc) (lua_State *L, void *ud); + +LUAI_FUNC void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop); +LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, + const char *mode); +LUAI_FUNC void luaD_hook (lua_State *L, int event, int line, + int fTransfer, int nTransfer); +LUAI_FUNC void luaD_hookcall (lua_State *L, CallInfo *ci); +LUAI_FUNC int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, + int narg1, int delta); +LUAI_FUNC CallInfo *luaD_precall (lua_State *L, StkId func, int nResults); +LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults); +LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults); +LUAI_FUNC StkId luaD_tryfuncTM (lua_State *L, StkId func); +LUAI_FUNC int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status); +LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u, + ptrdiff_t oldtop, ptrdiff_t ef); +LUAI_FUNC void luaD_poscall (lua_State *L, CallInfo *ci, int nres); +LUAI_FUNC int luaD_reallocstack (lua_State *L, int newsize, int raiseerror); +LUAI_FUNC int luaD_growstack (lua_State *L, int n, int raiseerror); +LUAI_FUNC void luaD_shrinkstack (lua_State *L); +LUAI_FUNC void luaD_inctop (lua_State *L); + +LUAI_FUNC l_noret luaD_throw (lua_State *L, int errcode); +LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud); + +#endif + diff --git a/src/ldump.c b/src/ldump.c new file mode 100644 index 0000000..f231691 --- /dev/null +++ b/src/ldump.c @@ -0,0 +1,230 @@ +/* +** $Id: ldump.c $ +** save precompiled Lua chunks +** See Copyright Notice in lua.h +*/ + +#define ldump_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include + +#include "lua.h" + +#include "lobject.h" +#include "lstate.h" +#include "lundump.h" + + +typedef struct { + lua_State *L; + lua_Writer writer; + void *data; + int strip; + int status; +} DumpState; + + +/* +** All high-level dumps go through dumpVector; you can change it to +** change the endianness of the result +*/ +#define dumpVector(D,v,n) dumpBlock(D,v,(n)*sizeof((v)[0])) + +#define dumpLiteral(D, s) dumpBlock(D,s,sizeof(s) - sizeof(char)) + + +static void dumpBlock (DumpState *D, const void *b, size_t size) { + if (D->status == 0 && size > 0) { + lua_unlock(D->L); + D->status = (*D->writer)(D->L, b, size, D->data); + lua_lock(D->L); + } +} + + +#define dumpVar(D,x) dumpVector(D,&x,1) + + +static void dumpByte (DumpState *D, int y) { + lu_byte x = (lu_byte)y; + dumpVar(D, x); +} + + +/* +** 'dumpSize' buffer size: each byte can store up to 7 bits. (The "+6" +** rounds up the division.) +*/ +#define DIBS ((sizeof(size_t) * CHAR_BIT + 6) / 7) + +static void dumpSize (DumpState *D, size_t x) { + lu_byte buff[DIBS]; + int n = 0; + do { + buff[DIBS - (++n)] = x & 0x7f; /* fill buffer in reverse order */ + x >>= 7; + } while (x != 0); + buff[DIBS - 1] |= 0x80; /* mark last byte */ + dumpVector(D, buff + DIBS - n, n); +} + + +static void dumpInt (DumpState *D, int x) { + dumpSize(D, x); +} + + +static void dumpNumber (DumpState *D, lua_Number x) { + dumpVar(D, x); +} + + +static void dumpInteger (DumpState *D, lua_Integer x) { + dumpVar(D, x); +} + + +static void dumpString (DumpState *D, const TString *s) { + if (s == NULL) + dumpSize(D, 0); + else { + size_t size = tsslen(s); + const char *str = getstr(s); + dumpSize(D, size + 1); + dumpVector(D, str, size); + } +} + + +static void dumpCode (DumpState *D, const Proto *f) { + dumpInt(D, f->sizecode); + dumpVector(D, f->code, f->sizecode); +} + + +static void dumpFunction(DumpState *D, const Proto *f, TString *psource); + +static void dumpConstants (DumpState *D, const Proto *f) { + int i; + int n = f->sizek; + dumpInt(D, n); + for (i = 0; i < n; i++) { + const TValue *o = &f->k[i]; + int tt = ttypetag(o); + dumpByte(D, tt); + switch (tt) { + case LUA_VNUMFLT: + dumpNumber(D, fltvalue(o)); + break; + case LUA_VNUMINT: + dumpInteger(D, ivalue(o)); + break; + case LUA_VSHRSTR: + case LUA_VLNGSTR: + dumpString(D, tsvalue(o)); + break; + default: + lua_assert(tt == LUA_VNIL || tt == LUA_VFALSE || tt == LUA_VTRUE); + } + } +} + + +static void dumpProtos (DumpState *D, const Proto *f) { + int i; + int n = f->sizep; + dumpInt(D, n); + for (i = 0; i < n; i++) + dumpFunction(D, f->p[i], f->source); +} + + +static void dumpUpvalues (DumpState *D, const Proto *f) { + int i, n = f->sizeupvalues; + dumpInt(D, n); + for (i = 0; i < n; i++) { + dumpByte(D, f->upvalues[i].instack); + dumpByte(D, f->upvalues[i].idx); + dumpByte(D, f->upvalues[i].kind); + } +} + + +static void dumpDebug (DumpState *D, const Proto *f) { + int i, n; + n = (D->strip) ? 0 : f->sizelineinfo; + dumpInt(D, n); + dumpVector(D, f->lineinfo, n); + n = (D->strip) ? 0 : f->sizeabslineinfo; + dumpInt(D, n); + for (i = 0; i < n; i++) { + dumpInt(D, f->abslineinfo[i].pc); + dumpInt(D, f->abslineinfo[i].line); + } + n = (D->strip) ? 0 : f->sizelocvars; + dumpInt(D, n); + for (i = 0; i < n; i++) { + dumpString(D, f->locvars[i].varname); + dumpInt(D, f->locvars[i].startpc); + dumpInt(D, f->locvars[i].endpc); + } + n = (D->strip) ? 0 : f->sizeupvalues; + dumpInt(D, n); + for (i = 0; i < n; i++) + dumpString(D, f->upvalues[i].name); +} + + +static void dumpFunction (DumpState *D, const Proto *f, TString *psource) { + if (D->strip || f->source == psource) + dumpString(D, NULL); /* no debug info or same source as its parent */ + else + dumpString(D, f->source); + dumpInt(D, f->linedefined); + dumpInt(D, f->lastlinedefined); + dumpByte(D, f->numparams); + dumpByte(D, f->is_vararg); + dumpByte(D, f->maxstacksize); + dumpCode(D, f); + dumpConstants(D, f); + dumpUpvalues(D, f); + dumpProtos(D, f); + dumpDebug(D, f); +} + + +static void dumpHeader (DumpState *D) { + dumpLiteral(D, LUA_SIGNATURE); + dumpByte(D, LUAC_VERSION); + dumpByte(D, LUAC_FORMAT); + dumpLiteral(D, LUAC_DATA); + dumpByte(D, sizeof(Instruction)); + dumpByte(D, sizeof(lua_Integer)); + dumpByte(D, sizeof(lua_Number)); + dumpInteger(D, LUAC_INT); + dumpNumber(D, LUAC_NUM); +} + + +/* +** dump Lua function as precompiled chunk +*/ +int luaU_dump(lua_State *L, const Proto *f, lua_Writer w, void *data, + int strip) { + DumpState D; + D.L = L; + D.writer = w; + D.data = data; + D.strip = strip; + D.status = 0; + dumpHeader(&D); + dumpByte(&D, f->sizeupvalues); + dumpFunction(&D, f, NULL); + return D.status; +} + diff --git a/src/lfunc.c b/src/lfunc.c new file mode 100644 index 0000000..0945f24 --- /dev/null +++ b/src/lfunc.c @@ -0,0 +1,294 @@ +/* +** $Id: lfunc.c $ +** Auxiliary functions to manipulate prototypes and closures +** See Copyright Notice in lua.h +*/ + +#define lfunc_c +#define LUA_CORE + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" + + + +CClosure *luaF_newCclosure (lua_State *L, int nupvals) { + GCObject *o = luaC_newobj(L, LUA_VCCL, sizeCclosure(nupvals)); + CClosure *c = gco2ccl(o); + c->nupvalues = cast_byte(nupvals); + return c; +} + + +LClosure *luaF_newLclosure (lua_State *L, int nupvals) { + GCObject *o = luaC_newobj(L, LUA_VLCL, sizeLclosure(nupvals)); + LClosure *c = gco2lcl(o); + c->p = NULL; + c->nupvalues = cast_byte(nupvals); + while (nupvals--) c->upvals[nupvals] = NULL; + return c; +} + + +/* +** fill a closure with new closed upvalues +*/ +void luaF_initupvals (lua_State *L, LClosure *cl) { + int i; + for (i = 0; i < cl->nupvalues; i++) { + GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal)); + UpVal *uv = gco2upv(o); + uv->v.p = &uv->u.value; /* make it closed */ + setnilvalue(uv->v.p); + cl->upvals[i] = uv; + luaC_objbarrier(L, cl, uv); + } +} + + +/* +** Create a new upvalue at the given level, and link it to the list of +** open upvalues of 'L' after entry 'prev'. +**/ +static UpVal *newupval (lua_State *L, StkId level, UpVal **prev) { + GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal)); + UpVal *uv = gco2upv(o); + UpVal *next = *prev; + uv->v.p = s2v(level); /* current value lives in the stack */ + uv->u.open.next = next; /* link it to list of open upvalues */ + uv->u.open.previous = prev; + if (next) + next->u.open.previous = &uv->u.open.next; + *prev = uv; + if (!isintwups(L)) { /* thread not in list of threads with upvalues? */ + L->twups = G(L)->twups; /* link it to the list */ + G(L)->twups = L; + } + return uv; +} + + +/* +** Find and reuse, or create if it does not exist, an upvalue +** at the given level. +*/ +UpVal *luaF_findupval (lua_State *L, StkId level) { + UpVal **pp = &L->openupval; + UpVal *p; + lua_assert(isintwups(L) || L->openupval == NULL); + while ((p = *pp) != NULL && uplevel(p) >= level) { /* search for it */ + lua_assert(!isdead(G(L), p)); + if (uplevel(p) == level) /* corresponding upvalue? */ + return p; /* return it */ + pp = &p->u.open.next; + } + /* not found: create a new upvalue after 'pp' */ + return newupval(L, level, pp); +} + + +/* +** Call closing method for object 'obj' with error message 'err'. The +** boolean 'yy' controls whether the call is yieldable. +** (This function assumes EXTRA_STACK.) +*/ +static void callclosemethod (lua_State *L, TValue *obj, TValue *err, int yy) { + StkId top = L->top.p; + const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE); + setobj2s(L, top, tm); /* will call metamethod... */ + setobj2s(L, top + 1, obj); /* with 'self' as the 1st argument */ + setobj2s(L, top + 2, err); /* and error msg. as 2nd argument */ + L->top.p = top + 3; /* add function and arguments */ + if (yy) + luaD_call(L, top, 0); + else + luaD_callnoyield(L, top, 0); +} + + +/* +** Check whether object at given level has a close metamethod and raise +** an error if not. +*/ +static void checkclosemth (lua_State *L, StkId level) { + const TValue *tm = luaT_gettmbyobj(L, s2v(level), TM_CLOSE); + if (ttisnil(tm)) { /* no metamethod? */ + int idx = cast_int(level - L->ci->func.p); /* variable index */ + const char *vname = luaG_findlocal(L, L->ci, idx, NULL); + if (vname == NULL) vname = "?"; + luaG_runerror(L, "variable '%s' got a non-closable value", vname); + } +} + + +/* +** Prepare and call a closing method. +** If status is CLOSEKTOP, the call to the closing method will be pushed +** at the top of the stack. Otherwise, values can be pushed right after +** the 'level' of the upvalue being closed, as everything after that +** won't be used again. +*/ +static void prepcallclosemth (lua_State *L, StkId level, int status, int yy) { + TValue *uv = s2v(level); /* value being closed */ + TValue *errobj; + if (status == CLOSEKTOP) + errobj = &G(L)->nilvalue; /* error object is nil */ + else { /* 'luaD_seterrorobj' will set top to level + 2 */ + errobj = s2v(level + 1); /* error object goes after 'uv' */ + luaD_seterrorobj(L, status, level + 1); /* set error object */ + } + callclosemethod(L, uv, errobj, yy); +} + + +/* +** Maximum value for deltas in 'tbclist', dependent on the type +** of delta. (This macro assumes that an 'L' is in scope where it +** is used.) +*/ +#define MAXDELTA \ + ((256ul << ((sizeof(L->stack.p->tbclist.delta) - 1) * 8)) - 1) + + +/* +** Insert a variable in the list of to-be-closed variables. +*/ +void luaF_newtbcupval (lua_State *L, StkId level) { + lua_assert(level > L->tbclist.p); + if (l_isfalse(s2v(level))) + return; /* false doesn't need to be closed */ + checkclosemth(L, level); /* value must have a close method */ + while (cast_uint(level - L->tbclist.p) > MAXDELTA) { + L->tbclist.p += MAXDELTA; /* create a dummy node at maximum delta */ + L->tbclist.p->tbclist.delta = 0; + } + level->tbclist.delta = cast(unsigned short, level - L->tbclist.p); + L->tbclist.p = level; +} + + +void luaF_unlinkupval (UpVal *uv) { + lua_assert(upisopen(uv)); + *uv->u.open.previous = uv->u.open.next; + if (uv->u.open.next) + uv->u.open.next->u.open.previous = uv->u.open.previous; +} + + +/* +** Close all upvalues up to the given stack level. +*/ +void luaF_closeupval (lua_State *L, StkId level) { + UpVal *uv; + StkId upl; /* stack index pointed by 'uv' */ + while ((uv = L->openupval) != NULL && (upl = uplevel(uv)) >= level) { + TValue *slot = &uv->u.value; /* new position for value */ + lua_assert(uplevel(uv) < L->top.p); + luaF_unlinkupval(uv); /* remove upvalue from 'openupval' list */ + setobj(L, slot, uv->v.p); /* move value to upvalue slot */ + uv->v.p = slot; /* now current value lives here */ + if (!iswhite(uv)) { /* neither white nor dead? */ + nw2black(uv); /* closed upvalues cannot be gray */ + luaC_barrier(L, uv, slot); + } + } +} + + +/* +** Remove first element from the tbclist plus its dummy nodes. +*/ +static void poptbclist (lua_State *L) { + StkId tbc = L->tbclist.p; + lua_assert(tbc->tbclist.delta > 0); /* first element cannot be dummy */ + tbc -= tbc->tbclist.delta; + while (tbc > L->stack.p && tbc->tbclist.delta == 0) + tbc -= MAXDELTA; /* remove dummy nodes */ + L->tbclist.p = tbc; +} + + +/* +** Close all upvalues and to-be-closed variables up to the given stack +** level. Return restored 'level'. +*/ +StkId luaF_close (lua_State *L, StkId level, int status, int yy) { + ptrdiff_t levelrel = savestack(L, level); + luaF_closeupval(L, level); /* first, close the upvalues */ + while (L->tbclist.p >= level) { /* traverse tbc's down to that level */ + StkId tbc = L->tbclist.p; /* get variable index */ + poptbclist(L); /* remove it from list */ + prepcallclosemth(L, tbc, status, yy); /* close variable */ + level = restorestack(L, levelrel); + } + return level; +} + + +Proto *luaF_newproto (lua_State *L) { + GCObject *o = luaC_newobj(L, LUA_VPROTO, sizeof(Proto)); + Proto *f = gco2p(o); + f->k = NULL; + f->sizek = 0; + f->p = NULL; + f->sizep = 0; + f->code = NULL; + f->sizecode = 0; + f->lineinfo = NULL; + f->sizelineinfo = 0; + f->abslineinfo = NULL; + f->sizeabslineinfo = 0; + f->upvalues = NULL; + f->sizeupvalues = 0; + f->numparams = 0; + f->is_vararg = 0; + f->maxstacksize = 0; + f->locvars = NULL; + f->sizelocvars = 0; + f->linedefined = 0; + f->lastlinedefined = 0; + f->source = NULL; + return f; +} + + +void luaF_freeproto (lua_State *L, Proto *f) { + luaM_freearray(L, f->code, f->sizecode); + luaM_freearray(L, f->p, f->sizep); + luaM_freearray(L, f->k, f->sizek); + luaM_freearray(L, f->lineinfo, f->sizelineinfo); + luaM_freearray(L, f->abslineinfo, f->sizeabslineinfo); + luaM_freearray(L, f->locvars, f->sizelocvars); + luaM_freearray(L, f->upvalues, f->sizeupvalues); + luaM_free(L, f); +} + + +/* +** Look for n-th local variable at line 'line' in function 'func'. +** Returns NULL if not found. +*/ +const char *luaF_getlocalname (const Proto *f, int local_number, int pc) { + int i; + for (i = 0; isizelocvars && f->locvars[i].startpc <= pc; i++) { + if (pc < f->locvars[i].endpc) { /* is variable active? */ + local_number--; + if (local_number == 0) + return getstr(f->locvars[i].varname); + } + } + return NULL; /* not found */ +} + diff --git a/src/lfunc.h b/src/lfunc.h new file mode 100644 index 0000000..3be265e --- /dev/null +++ b/src/lfunc.h @@ -0,0 +1,64 @@ +/* +** $Id: lfunc.h $ +** Auxiliary functions to manipulate prototypes and closures +** See Copyright Notice in lua.h +*/ + +#ifndef lfunc_h +#define lfunc_h + + +#include "lobject.h" + + +#define sizeCclosure(n) (cast_int(offsetof(CClosure, upvalue)) + \ + cast_int(sizeof(TValue)) * (n)) + +#define sizeLclosure(n) (cast_int(offsetof(LClosure, upvals)) + \ + cast_int(sizeof(TValue *)) * (n)) + + +/* test whether thread is in 'twups' list */ +#define isintwups(L) (L->twups != L) + + +/* +** maximum number of upvalues in a closure (both C and Lua). (Value +** must fit in a VM register.) +*/ +#define MAXUPVAL 255 + + +#define upisopen(up) ((up)->v.p != &(up)->u.value) + + +#define uplevel(up) check_exp(upisopen(up), cast(StkId, (up)->v.p)) + + +/* +** maximum number of misses before giving up the cache of closures +** in prototypes +*/ +#define MAXMISS 10 + + + +/* special status to close upvalues preserving the top of the stack */ +#define CLOSEKTOP (-1) + + +LUAI_FUNC Proto *luaF_newproto (lua_State *L); +LUAI_FUNC CClosure *luaF_newCclosure (lua_State *L, int nupvals); +LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nupvals); +LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl); +LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level); +LUAI_FUNC void luaF_newtbcupval (lua_State *L, StkId level); +LUAI_FUNC void luaF_closeupval (lua_State *L, StkId level); +LUAI_FUNC StkId luaF_close (lua_State *L, StkId level, int status, int yy); +LUAI_FUNC void luaF_unlinkupval (UpVal *uv); +LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f); +LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number, + int pc); + + +#endif diff --git a/src/lgc.c b/src/lgc.c new file mode 100644 index 0000000..a3094ff --- /dev/null +++ b/src/lgc.c @@ -0,0 +1,1739 @@ +/* +** $Id: lgc.c $ +** Garbage Collector +** See Copyright Notice in lua.h +*/ + +#define lgc_c +#define LUA_CORE + +#include "lprefix.h" + +#include +#include + + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" + + +/* +** Maximum number of elements to sweep in each single step. +** (Large enough to dissipate fixed overheads but small enough +** to allow small steps for the collector.) +*/ +#define GCSWEEPMAX 100 + +/* +** Maximum number of finalizers to call in each single step. +*/ +#define GCFINMAX 10 + + +/* +** Cost of calling one finalizer. +*/ +#define GCFINALIZECOST 50 + + +/* +** The equivalent, in bytes, of one unit of "work" (visiting a slot, +** sweeping an object, etc.) +*/ +#define WORK2MEM sizeof(TValue) + + +/* +** macro to adjust 'pause': 'pause' is actually used like +** 'pause / PAUSEADJ' (value chosen by tests) +*/ +#define PAUSEADJ 100 + + +/* mask with all color bits */ +#define maskcolors (bitmask(BLACKBIT) | WHITEBITS) + +/* mask with all GC bits */ +#define maskgcbits (maskcolors | AGEBITS) + + +/* macro to erase all color bits then set only the current white bit */ +#define makewhite(g,x) \ + (x->marked = cast_byte((x->marked & ~maskcolors) | luaC_white(g))) + +/* make an object gray (neither white nor black) */ +#define set2gray(x) resetbits(x->marked, maskcolors) + + +/* make an object black (coming from any color) */ +#define set2black(x) \ + (x->marked = cast_byte((x->marked & ~WHITEBITS) | bitmask(BLACKBIT))) + + +#define valiswhite(x) (iscollectable(x) && iswhite(gcvalue(x))) + +#define keyiswhite(n) (keyiscollectable(n) && iswhite(gckey(n))) + + +/* +** Protected access to objects in values +*/ +#define gcvalueN(o) (iscollectable(o) ? gcvalue(o) : NULL) + + +#define markvalue(g,o) { checkliveness(g->mainthread,o); \ + if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); } + +#define markkey(g, n) { if keyiswhite(n) reallymarkobject(g,gckey(n)); } + +#define markobject(g,t) { if (iswhite(t)) reallymarkobject(g, obj2gco(t)); } + +/* +** mark an object that can be NULL (either because it is really optional, +** or it was stripped as debug info, or inside an uncompleted structure) +*/ +#define markobjectN(g,t) { if (t) markobject(g,t); } + +static void reallymarkobject (global_State *g, GCObject *o); +static lu_mem atomic (lua_State *L); +static void entersweep (lua_State *L); + + +/* +** {====================================================== +** Generic functions +** ======================================================= +*/ + + +/* +** one after last element in a hash array +*/ +#define gnodelast(h) gnode(h, cast_sizet(sizenode(h))) + + +static GCObject **getgclist (GCObject *o) { + switch (o->tt) { + case LUA_VTABLE: return &gco2t(o)->gclist; + case LUA_VLCL: return &gco2lcl(o)->gclist; + case LUA_VCCL: return &gco2ccl(o)->gclist; + case LUA_VTHREAD: return &gco2th(o)->gclist; + case LUA_VPROTO: return &gco2p(o)->gclist; + case LUA_VUSERDATA: { + Udata *u = gco2u(o); + lua_assert(u->nuvalue > 0); + return &u->gclist; + } + default: lua_assert(0); return 0; + } +} + + +/* +** Link a collectable object 'o' with a known type into the list 'p'. +** (Must be a macro to access the 'gclist' field in different types.) +*/ +#define linkgclist(o,p) linkgclist_(obj2gco(o), &(o)->gclist, &(p)) + +static void linkgclist_ (GCObject *o, GCObject **pnext, GCObject **list) { + lua_assert(!isgray(o)); /* cannot be in a gray list */ + *pnext = *list; + *list = o; + set2gray(o); /* now it is */ +} + + +/* +** Link a generic collectable object 'o' into the list 'p'. +*/ +#define linkobjgclist(o,p) linkgclist_(obj2gco(o), getgclist(o), &(p)) + + + +/* +** Clear keys for empty entries in tables. If entry is empty, mark its +** entry as dead. This allows the collection of the key, but keeps its +** entry in the table: its removal could break a chain and could break +** a table traversal. Other places never manipulate dead keys, because +** its associated empty value is enough to signal that the entry is +** logically empty. +*/ +static void clearkey (Node *n) { + lua_assert(isempty(gval(n))); + if (keyiscollectable(n)) + setdeadkey(n); /* unused key; remove it */ +} + + +/* +** tells whether a key or value can be cleared from a weak +** table. Non-collectable objects are never removed from weak +** tables. Strings behave as 'values', so are never removed too. for +** other objects: if really collected, cannot keep them; for objects +** being finalized, keep them in keys, but not in values +*/ +static int iscleared (global_State *g, const GCObject *o) { + if (o == NULL) return 0; /* non-collectable value */ + else if (novariant(o->tt) == LUA_TSTRING) { + markobject(g, o); /* strings are 'values', so are never weak */ + return 0; + } + else return iswhite(o); +} + + +/* +** Barrier that moves collector forward, that is, marks the white object +** 'v' being pointed by the black object 'o'. In the generational +** mode, 'v' must also become old, if 'o' is old; however, it cannot +** be changed directly to OLD, because it may still point to non-old +** objects. So, it is marked as OLD0. In the next cycle it will become +** OLD1, and in the next it will finally become OLD (regular old). By +** then, any object it points to will also be old. If called in the +** incremental sweep phase, it clears the black object to white (sweep +** it) to avoid other barrier calls for this same object. (That cannot +** be done is generational mode, as its sweep does not distinguish +** whites from deads.) +*/ +void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) { + global_State *g = G(L); + lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o)); + if (keepinvariant(g)) { /* must keep invariant? */ + reallymarkobject(g, v); /* restore invariant */ + if (isold(o)) { + lua_assert(!isold(v)); /* white object could not be old */ + setage(v, G_OLD0); /* restore generational invariant */ + } + } + else { /* sweep phase */ + lua_assert(issweepphase(g)); + if (g->gckind == KGC_INC) /* incremental mode? */ + makewhite(g, o); /* mark 'o' as white to avoid other barriers */ + } +} + + +/* +** barrier that moves collector backward, that is, mark the black object +** pointing to a white object as gray again. +*/ +void luaC_barrierback_ (lua_State *L, GCObject *o) { + global_State *g = G(L); + lua_assert(isblack(o) && !isdead(g, o)); + lua_assert((g->gckind == KGC_GEN) == (isold(o) && getage(o) != G_TOUCHED1)); + if (getage(o) == G_TOUCHED2) /* already in gray list? */ + set2gray(o); /* make it gray to become touched1 */ + else /* link it in 'grayagain' and paint it gray */ + linkobjgclist(o, g->grayagain); + if (isold(o)) /* generational mode? */ + setage(o, G_TOUCHED1); /* touched in current cycle */ +} + + +void luaC_fix (lua_State *L, GCObject *o) { + global_State *g = G(L); + lua_assert(g->allgc == o); /* object must be 1st in 'allgc' list! */ + set2gray(o); /* they will be gray forever */ + setage(o, G_OLD); /* and old forever */ + g->allgc = o->next; /* remove object from 'allgc' list */ + o->next = g->fixedgc; /* link it to 'fixedgc' list */ + g->fixedgc = o; +} + + +/* +** create a new collectable object (with given type, size, and offset) +** and link it to 'allgc' list. +*/ +GCObject *luaC_newobjdt (lua_State *L, int tt, size_t sz, size_t offset) { + global_State *g = G(L); + char *p = cast_charp(luaM_newobject(L, novariant(tt), sz)); + GCObject *o = cast(GCObject *, p + offset); + o->marked = luaC_white(g); + o->tt = tt; + o->next = g->allgc; + g->allgc = o; + return o; +} + + +GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) { + return luaC_newobjdt(L, tt, sz, 0); +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** Mark functions +** ======================================================= +*/ + + +/* +** Mark an object. Userdata with no user values, strings, and closed +** upvalues are visited and turned black here. Open upvalues are +** already indirectly linked through their respective threads in the +** 'twups' list, so they don't go to the gray list; nevertheless, they +** are kept gray to avoid barriers, as their values will be revisited +** by the thread or by 'remarkupvals'. Other objects are added to the +** gray list to be visited (and turned black) later. Both userdata and +** upvalues can call this function recursively, but this recursion goes +** for at most two levels: An upvalue cannot refer to another upvalue +** (only closures can), and a userdata's metatable must be a table. +*/ +static void reallymarkobject (global_State *g, GCObject *o) { + switch (o->tt) { + case LUA_VSHRSTR: + case LUA_VLNGSTR: { + set2black(o); /* nothing to visit */ + break; + } + case LUA_VUPVAL: { + UpVal *uv = gco2upv(o); + if (upisopen(uv)) + set2gray(uv); /* open upvalues are kept gray */ + else + set2black(uv); /* closed upvalues are visited here */ + markvalue(g, uv->v.p); /* mark its content */ + break; + } + case LUA_VUSERDATA: { + Udata *u = gco2u(o); + if (u->nuvalue == 0) { /* no user values? */ + markobjectN(g, u->metatable); /* mark its metatable */ + set2black(u); /* nothing else to mark */ + break; + } + /* else... */ + } /* FALLTHROUGH */ + case LUA_VLCL: case LUA_VCCL: case LUA_VTABLE: + case LUA_VTHREAD: case LUA_VPROTO: { + linkobjgclist(o, g->gray); /* to be visited later */ + break; + } + default: lua_assert(0); break; + } +} + + +/* +** mark metamethods for basic types +*/ +static void markmt (global_State *g) { + int i; + for (i=0; i < LUA_NUMTAGS; i++) + markobjectN(g, g->mt[i]); +} + + +/* +** mark all objects in list of being-finalized +*/ +static lu_mem markbeingfnz (global_State *g) { + GCObject *o; + lu_mem count = 0; + for (o = g->tobefnz; o != NULL; o = o->next) { + count++; + markobject(g, o); + } + return count; +} + + +/* +** For each non-marked thread, simulates a barrier between each open +** upvalue and its value. (If the thread is collected, the value will be +** assigned to the upvalue, but then it can be too late for the barrier +** to act. The "barrier" does not need to check colors: A non-marked +** thread must be young; upvalues cannot be older than their threads; so +** any visited upvalue must be young too.) Also removes the thread from +** the list, as it was already visited. Removes also threads with no +** upvalues, as they have nothing to be checked. (If the thread gets an +** upvalue later, it will be linked in the list again.) +*/ +static int remarkupvals (global_State *g) { + lua_State *thread; + lua_State **p = &g->twups; + int work = 0; /* estimate of how much work was done here */ + while ((thread = *p) != NULL) { + work++; + if (!iswhite(thread) && thread->openupval != NULL) + p = &thread->twups; /* keep marked thread with upvalues in the list */ + else { /* thread is not marked or without upvalues */ + UpVal *uv; + lua_assert(!isold(thread) || thread->openupval == NULL); + *p = thread->twups; /* remove thread from the list */ + thread->twups = thread; /* mark that it is out of list */ + for (uv = thread->openupval; uv != NULL; uv = uv->u.open.next) { + lua_assert(getage(uv) <= getage(thread)); + work++; + if (!iswhite(uv)) { /* upvalue already visited? */ + lua_assert(upisopen(uv) && isgray(uv)); + markvalue(g, uv->v.p); /* mark its value */ + } + } + } + } + return work; +} + + +static void cleargraylists (global_State *g) { + g->gray = g->grayagain = NULL; + g->weak = g->allweak = g->ephemeron = NULL; +} + + +/* +** mark root set and reset all gray lists, to start a new collection +*/ +static void restartcollection (global_State *g) { + cleargraylists(g); + markobject(g, g->mainthread); + markvalue(g, &g->l_registry); + markmt(g); + markbeingfnz(g); /* mark any finalizing object left from previous cycle */ +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Traverse functions +** ======================================================= +*/ + + +/* +** Check whether object 'o' should be kept in the 'grayagain' list for +** post-processing by 'correctgraylist'. (It could put all old objects +** in the list and leave all the work to 'correctgraylist', but it is +** more efficient to avoid adding elements that will be removed.) Only +** TOUCHED1 objects need to be in the list. TOUCHED2 doesn't need to go +** back to a gray list, but then it must become OLD. (That is what +** 'correctgraylist' does when it finds a TOUCHED2 object.) +*/ +static void genlink (global_State *g, GCObject *o) { + lua_assert(isblack(o)); + if (getage(o) == G_TOUCHED1) { /* touched in this cycle? */ + linkobjgclist(o, g->grayagain); /* link it back in 'grayagain' */ + } /* everything else do not need to be linked back */ + else if (getage(o) == G_TOUCHED2) + changeage(o, G_TOUCHED2, G_OLD); /* advance age */ +} + + +/* +** Traverse a table with weak values and link it to proper list. During +** propagate phase, keep it in 'grayagain' list, to be revisited in the +** atomic phase. In the atomic phase, if table has any white value, +** put it in 'weak' list, to be cleared. +*/ +static void traverseweakvalue (global_State *g, Table *h) { + Node *n, *limit = gnodelast(h); + /* if there is array part, assume it may have white values (it is not + worth traversing it now just to check) */ + int hasclears = (h->alimit > 0); + for (n = gnode(h, 0); n < limit; n++) { /* traverse hash part */ + if (isempty(gval(n))) /* entry is empty? */ + clearkey(n); /* clear its key */ + else { + lua_assert(!keyisnil(n)); + markkey(g, n); + if (!hasclears && iscleared(g, gcvalueN(gval(n)))) /* a white value? */ + hasclears = 1; /* table will have to be cleared */ + } + } + if (g->gcstate == GCSatomic && hasclears) + linkgclist(h, g->weak); /* has to be cleared later */ + else + linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */ +} + + +/* +** Traverse an ephemeron table and link it to proper list. Returns true +** iff any object was marked during this traversal (which implies that +** convergence has to continue). During propagation phase, keep table +** in 'grayagain' list, to be visited again in the atomic phase. In +** the atomic phase, if table has any white->white entry, it has to +** be revisited during ephemeron convergence (as that key may turn +** black). Otherwise, if it has any white key, table has to be cleared +** (in the atomic phase). In generational mode, some tables +** must be kept in some gray list for post-processing; this is done +** by 'genlink'. +*/ +static int traverseephemeron (global_State *g, Table *h, int inv) { + int marked = 0; /* true if an object is marked in this traversal */ + int hasclears = 0; /* true if table has white keys */ + int hasww = 0; /* true if table has entry "white-key -> white-value" */ + unsigned int i; + unsigned int asize = luaH_realasize(h); + unsigned int nsize = sizenode(h); + /* traverse array part */ + for (i = 0; i < asize; i++) { + if (valiswhite(&h->array[i])) { + marked = 1; + reallymarkobject(g, gcvalue(&h->array[i])); + } + } + /* traverse hash part; if 'inv', traverse descending + (see 'convergeephemerons') */ + for (i = 0; i < nsize; i++) { + Node *n = inv ? gnode(h, nsize - 1 - i) : gnode(h, i); + if (isempty(gval(n))) /* entry is empty? */ + clearkey(n); /* clear its key */ + else if (iscleared(g, gckeyN(n))) { /* key is not marked (yet)? */ + hasclears = 1; /* table must be cleared */ + if (valiswhite(gval(n))) /* value not marked yet? */ + hasww = 1; /* white-white entry */ + } + else if (valiswhite(gval(n))) { /* value not marked yet? */ + marked = 1; + reallymarkobject(g, gcvalue(gval(n))); /* mark it now */ + } + } + /* link table into proper list */ + if (g->gcstate == GCSpropagate) + linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */ + else if (hasww) /* table has white->white entries? */ + linkgclist(h, g->ephemeron); /* have to propagate again */ + else if (hasclears) /* table has white keys? */ + linkgclist(h, g->allweak); /* may have to clean white keys */ + else + genlink(g, obj2gco(h)); /* check whether collector still needs to see it */ + return marked; +} + + +static void traversestrongtable (global_State *g, Table *h) { + Node *n, *limit = gnodelast(h); + unsigned int i; + unsigned int asize = luaH_realasize(h); + for (i = 0; i < asize; i++) /* traverse array part */ + markvalue(g, &h->array[i]); + for (n = gnode(h, 0); n < limit; n++) { /* traverse hash part */ + if (isempty(gval(n))) /* entry is empty? */ + clearkey(n); /* clear its key */ + else { + lua_assert(!keyisnil(n)); + markkey(g, n); + markvalue(g, gval(n)); + } + } + genlink(g, obj2gco(h)); +} + + +static lu_mem traversetable (global_State *g, Table *h) { + const char *weakkey, *weakvalue; + const TValue *mode = gfasttm(g, h->metatable, TM_MODE); + markobjectN(g, h->metatable); + if (mode && ttisstring(mode) && /* is there a weak mode? */ + (cast_void(weakkey = strchr(svalue(mode), 'k')), + cast_void(weakvalue = strchr(svalue(mode), 'v')), + (weakkey || weakvalue))) { /* is really weak? */ + if (!weakkey) /* strong keys? */ + traverseweakvalue(g, h); + else if (!weakvalue) /* strong values? */ + traverseephemeron(g, h, 0); + else /* all weak */ + linkgclist(h, g->allweak); /* nothing to traverse now */ + } + else /* not weak */ + traversestrongtable(g, h); + return 1 + h->alimit + 2 * allocsizenode(h); +} + + +static int traverseudata (global_State *g, Udata *u) { + int i; + markobjectN(g, u->metatable); /* mark its metatable */ + for (i = 0; i < u->nuvalue; i++) + markvalue(g, &u->uv[i].uv); + genlink(g, obj2gco(u)); + return 1 + u->nuvalue; +} + + +/* +** Traverse a prototype. (While a prototype is being build, its +** arrays can be larger than needed; the extra slots are filled with +** NULL, so the use of 'markobjectN') +*/ +static int traverseproto (global_State *g, Proto *f) { + int i; + markobjectN(g, f->source); + for (i = 0; i < f->sizek; i++) /* mark literals */ + markvalue(g, &f->k[i]); + for (i = 0; i < f->sizeupvalues; i++) /* mark upvalue names */ + markobjectN(g, f->upvalues[i].name); + for (i = 0; i < f->sizep; i++) /* mark nested protos */ + markobjectN(g, f->p[i]); + for (i = 0; i < f->sizelocvars; i++) /* mark local-variable names */ + markobjectN(g, f->locvars[i].varname); + return 1 + f->sizek + f->sizeupvalues + f->sizep + f->sizelocvars; +} + + +static int traverseCclosure (global_State *g, CClosure *cl) { + int i; + for (i = 0; i < cl->nupvalues; i++) /* mark its upvalues */ + markvalue(g, &cl->upvalue[i]); + return 1 + cl->nupvalues; +} + +/* +** Traverse a Lua closure, marking its prototype and its upvalues. +** (Both can be NULL while closure is being created.) +*/ +static int traverseLclosure (global_State *g, LClosure *cl) { + int i; + markobjectN(g, cl->p); /* mark its prototype */ + for (i = 0; i < cl->nupvalues; i++) { /* visit its upvalues */ + UpVal *uv = cl->upvals[i]; + markobjectN(g, uv); /* mark upvalue */ + } + return 1 + cl->nupvalues; +} + + +/* +** Traverse a thread, marking the elements in the stack up to its top +** and cleaning the rest of the stack in the final traversal. That +** ensures that the entire stack have valid (non-dead) objects. +** Threads have no barriers. In gen. mode, old threads must be visited +** at every cycle, because they might point to young objects. In inc. +** mode, the thread can still be modified before the end of the cycle, +** and therefore it must be visited again in the atomic phase. To ensure +** these visits, threads must return to a gray list if they are not new +** (which can only happen in generational mode) or if the traverse is in +** the propagate phase (which can only happen in incremental mode). +*/ +static int traversethread (global_State *g, lua_State *th) { + UpVal *uv; + StkId o = th->stack.p; + if (isold(th) || g->gcstate == GCSpropagate) + linkgclist(th, g->grayagain); /* insert into 'grayagain' list */ + if (o == NULL) + return 1; /* stack not completely built yet */ + lua_assert(g->gcstate == GCSatomic || + th->openupval == NULL || isintwups(th)); + for (; o < th->top.p; o++) /* mark live elements in the stack */ + markvalue(g, s2v(o)); + for (uv = th->openupval; uv != NULL; uv = uv->u.open.next) + markobject(g, uv); /* open upvalues cannot be collected */ + if (g->gcstate == GCSatomic) { /* final traversal? */ + for (; o < th->stack_last.p + EXTRA_STACK; o++) + setnilvalue(s2v(o)); /* clear dead stack slice */ + /* 'remarkupvals' may have removed thread from 'twups' list */ + if (!isintwups(th) && th->openupval != NULL) { + th->twups = g->twups; /* link it back to the list */ + g->twups = th; + } + } + else if (!g->gcemergency) + luaD_shrinkstack(th); /* do not change stack in emergency cycle */ + return 1 + stacksize(th); +} + + +/* +** traverse one gray object, turning it to black. +*/ +static lu_mem propagatemark (global_State *g) { + GCObject *o = g->gray; + nw2black(o); + g->gray = *getgclist(o); /* remove from 'gray' list */ + switch (o->tt) { + case LUA_VTABLE: return traversetable(g, gco2t(o)); + case LUA_VUSERDATA: return traverseudata(g, gco2u(o)); + case LUA_VLCL: return traverseLclosure(g, gco2lcl(o)); + case LUA_VCCL: return traverseCclosure(g, gco2ccl(o)); + case LUA_VPROTO: return traverseproto(g, gco2p(o)); + case LUA_VTHREAD: return traversethread(g, gco2th(o)); + default: lua_assert(0); return 0; + } +} + + +static lu_mem propagateall (global_State *g) { + lu_mem tot = 0; + while (g->gray) + tot += propagatemark(g); + return tot; +} + + +/* +** Traverse all ephemeron tables propagating marks from keys to values. +** Repeat until it converges, that is, nothing new is marked. 'dir' +** inverts the direction of the traversals, trying to speed up +** convergence on chains in the same table. +** +*/ +static void convergeephemerons (global_State *g) { + int changed; + int dir = 0; + do { + GCObject *w; + GCObject *next = g->ephemeron; /* get ephemeron list */ + g->ephemeron = NULL; /* tables may return to this list when traversed */ + changed = 0; + while ((w = next) != NULL) { /* for each ephemeron table */ + Table *h = gco2t(w); + next = h->gclist; /* list is rebuilt during loop */ + nw2black(h); /* out of the list (for now) */ + if (traverseephemeron(g, h, dir)) { /* marked some value? */ + propagateall(g); /* propagate changes */ + changed = 1; /* will have to revisit all ephemeron tables */ + } + } + dir = !dir; /* invert direction next time */ + } while (changed); /* repeat until no more changes */ +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Sweep Functions +** ======================================================= +*/ + + +/* +** clear entries with unmarked keys from all weaktables in list 'l' +*/ +static void clearbykeys (global_State *g, GCObject *l) { + for (; l; l = gco2t(l)->gclist) { + Table *h = gco2t(l); + Node *limit = gnodelast(h); + Node *n; + for (n = gnode(h, 0); n < limit; n++) { + if (iscleared(g, gckeyN(n))) /* unmarked key? */ + setempty(gval(n)); /* remove entry */ + if (isempty(gval(n))) /* is entry empty? */ + clearkey(n); /* clear its key */ + } + } +} + + +/* +** clear entries with unmarked values from all weaktables in list 'l' up +** to element 'f' +*/ +static void clearbyvalues (global_State *g, GCObject *l, GCObject *f) { + for (; l != f; l = gco2t(l)->gclist) { + Table *h = gco2t(l); + Node *n, *limit = gnodelast(h); + unsigned int i; + unsigned int asize = luaH_realasize(h); + for (i = 0; i < asize; i++) { + TValue *o = &h->array[i]; + if (iscleared(g, gcvalueN(o))) /* value was collected? */ + setempty(o); /* remove entry */ + } + for (n = gnode(h, 0); n < limit; n++) { + if (iscleared(g, gcvalueN(gval(n)))) /* unmarked value? */ + setempty(gval(n)); /* remove entry */ + if (isempty(gval(n))) /* is entry empty? */ + clearkey(n); /* clear its key */ + } + } +} + + +static void freeupval (lua_State *L, UpVal *uv) { + if (upisopen(uv)) + luaF_unlinkupval(uv); + luaM_free(L, uv); +} + + +static void freeobj (lua_State *L, GCObject *o) { + switch (o->tt) { + case LUA_VPROTO: + luaF_freeproto(L, gco2p(o)); + break; + case LUA_VUPVAL: + freeupval(L, gco2upv(o)); + break; + case LUA_VLCL: { + LClosure *cl = gco2lcl(o); + luaM_freemem(L, cl, sizeLclosure(cl->nupvalues)); + break; + } + case LUA_VCCL: { + CClosure *cl = gco2ccl(o); + luaM_freemem(L, cl, sizeCclosure(cl->nupvalues)); + break; + } + case LUA_VTABLE: + luaH_free(L, gco2t(o)); + break; + case LUA_VTHREAD: + luaE_freethread(L, gco2th(o)); + break; + case LUA_VUSERDATA: { + Udata *u = gco2u(o); + luaM_freemem(L, o, sizeudata(u->nuvalue, u->len)); + break; + } + case LUA_VSHRSTR: { + TString *ts = gco2ts(o); + luaS_remove(L, ts); /* remove it from hash table */ + luaM_freemem(L, ts, sizelstring(ts->shrlen)); + break; + } + case LUA_VLNGSTR: { + TString *ts = gco2ts(o); + luaM_freemem(L, ts, sizelstring(ts->u.lnglen)); + break; + } + default: lua_assert(0); + } +} + + +/* +** sweep at most 'countin' elements from a list of GCObjects erasing dead +** objects, where a dead object is one marked with the old (non current) +** white; change all non-dead objects back to white, preparing for next +** collection cycle. Return where to continue the traversal or NULL if +** list is finished. ('*countout' gets the number of elements traversed.) +*/ +static GCObject **sweeplist (lua_State *L, GCObject **p, int countin, + int *countout) { + global_State *g = G(L); + int ow = otherwhite(g); + int i; + int white = luaC_white(g); /* current white */ + for (i = 0; *p != NULL && i < countin; i++) { + GCObject *curr = *p; + int marked = curr->marked; + if (isdeadm(ow, marked)) { /* is 'curr' dead? */ + *p = curr->next; /* remove 'curr' from list */ + freeobj(L, curr); /* erase 'curr' */ + } + else { /* change mark to 'white' */ + curr->marked = cast_byte((marked & ~maskgcbits) | white); + p = &curr->next; /* go to next element */ + } + } + if (countout) + *countout = i; /* number of elements traversed */ + return (*p == NULL) ? NULL : p; +} + + +/* +** sweep a list until a live object (or end of list) +*/ +static GCObject **sweeptolive (lua_State *L, GCObject **p) { + GCObject **old = p; + do { + p = sweeplist(L, p, 1, NULL); + } while (p == old); + return p; +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Finalization +** ======================================================= +*/ + +/* +** If possible, shrink string table. +*/ +static void checkSizes (lua_State *L, global_State *g) { + if (!g->gcemergency) { + if (g->strt.nuse < g->strt.size / 4) { /* string table too big? */ + l_mem olddebt = g->GCdebt; + luaS_resize(L, g->strt.size / 2); + g->GCestimate += g->GCdebt - olddebt; /* correct estimate */ + } + } +} + + +/* +** Get the next udata to be finalized from the 'tobefnz' list, and +** link it back into the 'allgc' list. +*/ +static GCObject *udata2finalize (global_State *g) { + GCObject *o = g->tobefnz; /* get first element */ + lua_assert(tofinalize(o)); + g->tobefnz = o->next; /* remove it from 'tobefnz' list */ + o->next = g->allgc; /* return it to 'allgc' list */ + g->allgc = o; + resetbit(o->marked, FINALIZEDBIT); /* object is "normal" again */ + if (issweepphase(g)) + makewhite(g, o); /* "sweep" object */ + else if (getage(o) == G_OLD1) + g->firstold1 = o; /* it is the first OLD1 object in the list */ + return o; +} + + +static void dothecall (lua_State *L, void *ud) { + UNUSED(ud); + luaD_callnoyield(L, L->top.p - 2, 0); +} + + +static void GCTM (lua_State *L) { + global_State *g = G(L); + const TValue *tm; + TValue v; + lua_assert(!g->gcemergency); + setgcovalue(L, &v, udata2finalize(g)); + tm = luaT_gettmbyobj(L, &v, TM_GC); + if (!notm(tm)) { /* is there a finalizer? */ + int status; + lu_byte oldah = L->allowhook; + int oldgcstp = g->gcstp; + g->gcstp |= GCSTPGC; /* avoid GC steps */ + L->allowhook = 0; /* stop debug hooks during GC metamethod */ + setobj2s(L, L->top.p++, tm); /* push finalizer... */ + setobj2s(L, L->top.p++, &v); /* ... and its argument */ + L->ci->callstatus |= CIST_FIN; /* will run a finalizer */ + status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top.p - 2), 0); + L->ci->callstatus &= ~CIST_FIN; /* not running a finalizer anymore */ + L->allowhook = oldah; /* restore hooks */ + g->gcstp = oldgcstp; /* restore state */ + if (l_unlikely(status != LUA_OK)) { /* error while running __gc? */ + luaE_warnerror(L, "__gc"); + L->top.p--; /* pops error object */ + } + } +} + + +/* +** Call a few finalizers +*/ +static int runafewfinalizers (lua_State *L, int n) { + global_State *g = G(L); + int i; + for (i = 0; i < n && g->tobefnz; i++) + GCTM(L); /* call one finalizer */ + return i; +} + + +/* +** call all pending finalizers +*/ +static void callallpendingfinalizers (lua_State *L) { + global_State *g = G(L); + while (g->tobefnz) + GCTM(L); +} + + +/* +** find last 'next' field in list 'p' list (to add elements in its end) +*/ +static GCObject **findlast (GCObject **p) { + while (*p != NULL) + p = &(*p)->next; + return p; +} + + +/* +** Move all unreachable objects (or 'all' objects) that need +** finalization from list 'finobj' to list 'tobefnz' (to be finalized). +** (Note that objects after 'finobjold1' cannot be white, so they +** don't need to be traversed. In incremental mode, 'finobjold1' is NULL, +** so the whole list is traversed.) +*/ +static void separatetobefnz (global_State *g, int all) { + GCObject *curr; + GCObject **p = &g->finobj; + GCObject **lastnext = findlast(&g->tobefnz); + while ((curr = *p) != g->finobjold1) { /* traverse all finalizable objects */ + lua_assert(tofinalize(curr)); + if (!(iswhite(curr) || all)) /* not being collected? */ + p = &curr->next; /* don't bother with it */ + else { + if (curr == g->finobjsur) /* removing 'finobjsur'? */ + g->finobjsur = curr->next; /* correct it */ + *p = curr->next; /* remove 'curr' from 'finobj' list */ + curr->next = *lastnext; /* link at the end of 'tobefnz' list */ + *lastnext = curr; + lastnext = &curr->next; + } + } +} + + +/* +** If pointer 'p' points to 'o', move it to the next element. +*/ +static void checkpointer (GCObject **p, GCObject *o) { + if (o == *p) + *p = o->next; +} + + +/* +** Correct pointers to objects inside 'allgc' list when +** object 'o' is being removed from the list. +*/ +static void correctpointers (global_State *g, GCObject *o) { + checkpointer(&g->survival, o); + checkpointer(&g->old1, o); + checkpointer(&g->reallyold, o); + checkpointer(&g->firstold1, o); +} + + +/* +** if object 'o' has a finalizer, remove it from 'allgc' list (must +** search the list to find it) and link it in 'finobj' list. +*/ +void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) { + global_State *g = G(L); + if (tofinalize(o) || /* obj. is already marked... */ + gfasttm(g, mt, TM_GC) == NULL || /* or has no finalizer... */ + (g->gcstp & GCSTPCLS)) /* or closing state? */ + return; /* nothing to be done */ + else { /* move 'o' to 'finobj' list */ + GCObject **p; + if (issweepphase(g)) { + makewhite(g, o); /* "sweep" object 'o' */ + if (g->sweepgc == &o->next) /* should not remove 'sweepgc' object */ + g->sweepgc = sweeptolive(L, g->sweepgc); /* change 'sweepgc' */ + } + else + correctpointers(g, o); + /* search for pointer pointing to 'o' */ + for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ } + *p = o->next; /* remove 'o' from 'allgc' list */ + o->next = g->finobj; /* link it in 'finobj' list */ + g->finobj = o; + l_setbit(o->marked, FINALIZEDBIT); /* mark it as such */ + } +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Generational Collector +** ======================================================= +*/ + + +/* +** Set the "time" to wait before starting a new GC cycle; cycle will +** start when memory use hits the threshold of ('estimate' * pause / +** PAUSEADJ). (Division by 'estimate' should be OK: it cannot be zero, +** because Lua cannot even start with less than PAUSEADJ bytes). +*/ +static void setpause (global_State *g) { + l_mem threshold, debt; + int pause = getgcparam(g->gcpause); + l_mem estimate = g->GCestimate / PAUSEADJ; /* adjust 'estimate' */ + lua_assert(estimate > 0); + threshold = (pause < MAX_LMEM / estimate) /* overflow? */ + ? estimate * pause /* no overflow */ + : MAX_LMEM; /* overflow; truncate to maximum */ + debt = gettotalbytes(g) - threshold; + if (debt > 0) debt = 0; + luaE_setdebt(g, debt); +} + + +/* +** Sweep a list of objects to enter generational mode. Deletes dead +** objects and turns the non dead to old. All non-dead threads---which +** are now old---must be in a gray list. Everything else is not in a +** gray list. Open upvalues are also kept gray. +*/ +static void sweep2old (lua_State *L, GCObject **p) { + GCObject *curr; + global_State *g = G(L); + while ((curr = *p) != NULL) { + if (iswhite(curr)) { /* is 'curr' dead? */ + lua_assert(isdead(g, curr)); + *p = curr->next; /* remove 'curr' from list */ + freeobj(L, curr); /* erase 'curr' */ + } + else { /* all surviving objects become old */ + setage(curr, G_OLD); + if (curr->tt == LUA_VTHREAD) { /* threads must be watched */ + lua_State *th = gco2th(curr); + linkgclist(th, g->grayagain); /* insert into 'grayagain' list */ + } + else if (curr->tt == LUA_VUPVAL && upisopen(gco2upv(curr))) + set2gray(curr); /* open upvalues are always gray */ + else /* everything else is black */ + nw2black(curr); + p = &curr->next; /* go to next element */ + } + } +} + + +/* +** Sweep for generational mode. Delete dead objects. (Because the +** collection is not incremental, there are no "new white" objects +** during the sweep. So, any white object must be dead.) For +** non-dead objects, advance their ages and clear the color of +** new objects. (Old objects keep their colors.) +** The ages of G_TOUCHED1 and G_TOUCHED2 objects cannot be advanced +** here, because these old-generation objects are usually not swept +** here. They will all be advanced in 'correctgraylist'. That function +** will also remove objects turned white here from any gray list. +*/ +static GCObject **sweepgen (lua_State *L, global_State *g, GCObject **p, + GCObject *limit, GCObject **pfirstold1) { + static const lu_byte nextage[] = { + G_SURVIVAL, /* from G_NEW */ + G_OLD1, /* from G_SURVIVAL */ + G_OLD1, /* from G_OLD0 */ + G_OLD, /* from G_OLD1 */ + G_OLD, /* from G_OLD (do not change) */ + G_TOUCHED1, /* from G_TOUCHED1 (do not change) */ + G_TOUCHED2 /* from G_TOUCHED2 (do not change) */ + }; + int white = luaC_white(g); + GCObject *curr; + while ((curr = *p) != limit) { + if (iswhite(curr)) { /* is 'curr' dead? */ + lua_assert(!isold(curr) && isdead(g, curr)); + *p = curr->next; /* remove 'curr' from list */ + freeobj(L, curr); /* erase 'curr' */ + } + else { /* correct mark and age */ + if (getage(curr) == G_NEW) { /* new objects go back to white */ + int marked = curr->marked & ~maskgcbits; /* erase GC bits */ + curr->marked = cast_byte(marked | G_SURVIVAL | white); + } + else { /* all other objects will be old, and so keep their color */ + setage(curr, nextage[getage(curr)]); + if (getage(curr) == G_OLD1 && *pfirstold1 == NULL) + *pfirstold1 = curr; /* first OLD1 object in the list */ + } + p = &curr->next; /* go to next element */ + } + } + return p; +} + + +/* +** Traverse a list making all its elements white and clearing their +** age. In incremental mode, all objects are 'new' all the time, +** except for fixed strings (which are always old). +*/ +static void whitelist (global_State *g, GCObject *p) { + int white = luaC_white(g); + for (; p != NULL; p = p->next) + p->marked = cast_byte((p->marked & ~maskgcbits) | white); +} + + +/* +** Correct a list of gray objects. Return pointer to where rest of the +** list should be linked. +** Because this correction is done after sweeping, young objects might +** be turned white and still be in the list. They are only removed. +** 'TOUCHED1' objects are advanced to 'TOUCHED2' and remain on the list; +** Non-white threads also remain on the list; 'TOUCHED2' objects become +** regular old; they and anything else are removed from the list. +*/ +static GCObject **correctgraylist (GCObject **p) { + GCObject *curr; + while ((curr = *p) != NULL) { + GCObject **next = getgclist(curr); + if (iswhite(curr)) + goto remove; /* remove all white objects */ + else if (getage(curr) == G_TOUCHED1) { /* touched in this cycle? */ + lua_assert(isgray(curr)); + nw2black(curr); /* make it black, for next barrier */ + changeage(curr, G_TOUCHED1, G_TOUCHED2); + goto remain; /* keep it in the list and go to next element */ + } + else if (curr->tt == LUA_VTHREAD) { + lua_assert(isgray(curr)); + goto remain; /* keep non-white threads on the list */ + } + else { /* everything else is removed */ + lua_assert(isold(curr)); /* young objects should be white here */ + if (getage(curr) == G_TOUCHED2) /* advance from TOUCHED2... */ + changeage(curr, G_TOUCHED2, G_OLD); /* ... to OLD */ + nw2black(curr); /* make object black (to be removed) */ + goto remove; + } + remove: *p = *next; continue; + remain: p = next; continue; + } + return p; +} + + +/* +** Correct all gray lists, coalescing them into 'grayagain'. +*/ +static void correctgraylists (global_State *g) { + GCObject **list = correctgraylist(&g->grayagain); + *list = g->weak; g->weak = NULL; + list = correctgraylist(list); + *list = g->allweak; g->allweak = NULL; + list = correctgraylist(list); + *list = g->ephemeron; g->ephemeron = NULL; + correctgraylist(list); +} + + +/* +** Mark black 'OLD1' objects when starting a new young collection. +** Gray objects are already in some gray list, and so will be visited +** in the atomic step. +*/ +static void markold (global_State *g, GCObject *from, GCObject *to) { + GCObject *p; + for (p = from; p != to; p = p->next) { + if (getage(p) == G_OLD1) { + lua_assert(!iswhite(p)); + changeage(p, G_OLD1, G_OLD); /* now they are old */ + if (isblack(p)) + reallymarkobject(g, p); + } + } +} + + +/* +** Finish a young-generation collection. +*/ +static void finishgencycle (lua_State *L, global_State *g) { + correctgraylists(g); + checkSizes(L, g); + g->gcstate = GCSpropagate; /* skip restart */ + if (!g->gcemergency) + callallpendingfinalizers(L); +} + + +/* +** Does a young collection. First, mark 'OLD1' objects. Then does the +** atomic step. Then, sweep all lists and advance pointers. Finally, +** finish the collection. +*/ +static void youngcollection (lua_State *L, global_State *g) { + GCObject **psurvival; /* to point to first non-dead survival object */ + GCObject *dummy; /* dummy out parameter to 'sweepgen' */ + lua_assert(g->gcstate == GCSpropagate); + if (g->firstold1) { /* are there regular OLD1 objects? */ + markold(g, g->firstold1, g->reallyold); /* mark them */ + g->firstold1 = NULL; /* no more OLD1 objects (for now) */ + } + markold(g, g->finobj, g->finobjrold); + markold(g, g->tobefnz, NULL); + atomic(L); + + /* sweep nursery and get a pointer to its last live element */ + g->gcstate = GCSswpallgc; + psurvival = sweepgen(L, g, &g->allgc, g->survival, &g->firstold1); + /* sweep 'survival' */ + sweepgen(L, g, psurvival, g->old1, &g->firstold1); + g->reallyold = g->old1; + g->old1 = *psurvival; /* 'survival' survivals are old now */ + g->survival = g->allgc; /* all news are survivals */ + + /* repeat for 'finobj' lists */ + dummy = NULL; /* no 'firstold1' optimization for 'finobj' lists */ + psurvival = sweepgen(L, g, &g->finobj, g->finobjsur, &dummy); + /* sweep 'survival' */ + sweepgen(L, g, psurvival, g->finobjold1, &dummy); + g->finobjrold = g->finobjold1; + g->finobjold1 = *psurvival; /* 'survival' survivals are old now */ + g->finobjsur = g->finobj; /* all news are survivals */ + + sweepgen(L, g, &g->tobefnz, NULL, &dummy); + finishgencycle(L, g); +} + + +/* +** Clears all gray lists, sweeps objects, and prepare sublists to enter +** generational mode. The sweeps remove dead objects and turn all +** surviving objects to old. Threads go back to 'grayagain'; everything +** else is turned black (not in any gray list). +*/ +static void atomic2gen (lua_State *L, global_State *g) { + cleargraylists(g); + /* sweep all elements making them old */ + g->gcstate = GCSswpallgc; + sweep2old(L, &g->allgc); + /* everything alive now is old */ + g->reallyold = g->old1 = g->survival = g->allgc; + g->firstold1 = NULL; /* there are no OLD1 objects anywhere */ + + /* repeat for 'finobj' lists */ + sweep2old(L, &g->finobj); + g->finobjrold = g->finobjold1 = g->finobjsur = g->finobj; + + sweep2old(L, &g->tobefnz); + + g->gckind = KGC_GEN; + g->lastatomic = 0; + g->GCestimate = gettotalbytes(g); /* base for memory control */ + finishgencycle(L, g); +} + + +/* +** Set debt for the next minor collection, which will happen when +** memory grows 'genminormul'%. +*/ +static void setminordebt (global_State *g) { + luaE_setdebt(g, -(cast(l_mem, (gettotalbytes(g) / 100)) * g->genminormul)); +} + + +/* +** Enter generational mode. Must go until the end of an atomic cycle +** to ensure that all objects are correctly marked and weak tables +** are cleared. Then, turn all objects into old and finishes the +** collection. +*/ +static lu_mem entergen (lua_State *L, global_State *g) { + lu_mem numobjs; + luaC_runtilstate(L, bitmask(GCSpause)); /* prepare to start a new cycle */ + luaC_runtilstate(L, bitmask(GCSpropagate)); /* start new cycle */ + numobjs = atomic(L); /* propagates all and then do the atomic stuff */ + atomic2gen(L, g); + setminordebt(g); /* set debt assuming next cycle will be minor */ + return numobjs; +} + + +/* +** Enter incremental mode. Turn all objects white, make all +** intermediate lists point to NULL (to avoid invalid pointers), +** and go to the pause state. +*/ +static void enterinc (global_State *g) { + whitelist(g, g->allgc); + g->reallyold = g->old1 = g->survival = NULL; + whitelist(g, g->finobj); + whitelist(g, g->tobefnz); + g->finobjrold = g->finobjold1 = g->finobjsur = NULL; + g->gcstate = GCSpause; + g->gckind = KGC_INC; + g->lastatomic = 0; +} + + +/* +** Change collector mode to 'newmode'. +*/ +void luaC_changemode (lua_State *L, int newmode) { + global_State *g = G(L); + if (newmode != g->gckind) { + if (newmode == KGC_GEN) /* entering generational mode? */ + entergen(L, g); + else + enterinc(g); /* entering incremental mode */ + } + g->lastatomic = 0; +} + + +/* +** Does a full collection in generational mode. +*/ +static lu_mem fullgen (lua_State *L, global_State *g) { + enterinc(g); + return entergen(L, g); +} + + +/* +** Does a major collection after last collection was a "bad collection". +** +** When the program is building a big structure, it allocates lots of +** memory but generates very little garbage. In those scenarios, +** the generational mode just wastes time doing small collections, and +** major collections are frequently what we call a "bad collection", a +** collection that frees too few objects. To avoid the cost of switching +** between generational mode and the incremental mode needed for full +** (major) collections, the collector tries to stay in incremental mode +** after a bad collection, and to switch back to generational mode only +** after a "good" collection (one that traverses less than 9/8 objects +** of the previous one). +** The collector must choose whether to stay in incremental mode or to +** switch back to generational mode before sweeping. At this point, it +** does not know the real memory in use, so it cannot use memory to +** decide whether to return to generational mode. Instead, it uses the +** number of objects traversed (returned by 'atomic') as a proxy. The +** field 'g->lastatomic' keeps this count from the last collection. +** ('g->lastatomic != 0' also means that the last collection was bad.) +*/ +static void stepgenfull (lua_State *L, global_State *g) { + lu_mem newatomic; /* count of traversed objects */ + lu_mem lastatomic = g->lastatomic; /* count from last collection */ + if (g->gckind == KGC_GEN) /* still in generational mode? */ + enterinc(g); /* enter incremental mode */ + luaC_runtilstate(L, bitmask(GCSpropagate)); /* start new cycle */ + newatomic = atomic(L); /* mark everybody */ + if (newatomic < lastatomic + (lastatomic >> 3)) { /* good collection? */ + atomic2gen(L, g); /* return to generational mode */ + setminordebt(g); + } + else { /* another bad collection; stay in incremental mode */ + g->GCestimate = gettotalbytes(g); /* first estimate */; + entersweep(L); + luaC_runtilstate(L, bitmask(GCSpause)); /* finish collection */ + setpause(g); + g->lastatomic = newatomic; + } +} + + +/* +** Does a generational "step". +** Usually, this means doing a minor collection and setting the debt to +** make another collection when memory grows 'genminormul'% larger. +** +** However, there are exceptions. If memory grows 'genmajormul'% +** larger than it was at the end of the last major collection (kept +** in 'g->GCestimate'), the function does a major collection. At the +** end, it checks whether the major collection was able to free a +** decent amount of memory (at least half the growth in memory since +** previous major collection). If so, the collector keeps its state, +** and the next collection will probably be minor again. Otherwise, +** we have what we call a "bad collection". In that case, set the field +** 'g->lastatomic' to signal that fact, so that the next collection will +** go to 'stepgenfull'. +** +** 'GCdebt <= 0' means an explicit call to GC step with "size" zero; +** in that case, do a minor collection. +*/ +static void genstep (lua_State *L, global_State *g) { + if (g->lastatomic != 0) /* last collection was a bad one? */ + stepgenfull(L, g); /* do a full step */ + else { + lu_mem majorbase = g->GCestimate; /* memory after last major collection */ + lu_mem majorinc = (majorbase / 100) * getgcparam(g->genmajormul); + if (g->GCdebt > 0 && gettotalbytes(g) > majorbase + majorinc) { + lu_mem numobjs = fullgen(L, g); /* do a major collection */ + if (gettotalbytes(g) < majorbase + (majorinc / 2)) { + /* collected at least half of memory growth since last major + collection; keep doing minor collections. */ + lua_assert(g->lastatomic == 0); + } + else { /* bad collection */ + g->lastatomic = numobjs; /* signal that last collection was bad */ + setpause(g); /* do a long wait for next (major) collection */ + } + } + else { /* regular case; do a minor collection */ + youngcollection(L, g); + setminordebt(g); + g->GCestimate = majorbase; /* preserve base value */ + } + } + lua_assert(isdecGCmodegen(g)); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** GC control +** ======================================================= +*/ + + +/* +** Enter first sweep phase. +** The call to 'sweeptolive' makes the pointer point to an object +** inside the list (instead of to the header), so that the real sweep do +** not need to skip objects created between "now" and the start of the +** real sweep. +*/ +static void entersweep (lua_State *L) { + global_State *g = G(L); + g->gcstate = GCSswpallgc; + lua_assert(g->sweepgc == NULL); + g->sweepgc = sweeptolive(L, &g->allgc); +} + + +/* +** Delete all objects in list 'p' until (but not including) object +** 'limit'. +*/ +static void deletelist (lua_State *L, GCObject *p, GCObject *limit) { + while (p != limit) { + GCObject *next = p->next; + freeobj(L, p); + p = next; + } +} + + +/* +** Call all finalizers of the objects in the given Lua state, and +** then free all objects, except for the main thread. +*/ +void luaC_freeallobjects (lua_State *L) { + global_State *g = G(L); + g->gcstp = GCSTPCLS; /* no extra finalizers after here */ + luaC_changemode(L, KGC_INC); + separatetobefnz(g, 1); /* separate all objects with finalizers */ + lua_assert(g->finobj == NULL); + callallpendingfinalizers(L); + deletelist(L, g->allgc, obj2gco(g->mainthread)); + lua_assert(g->finobj == NULL); /* no new finalizers */ + deletelist(L, g->fixedgc, NULL); /* collect fixed objects */ + lua_assert(g->strt.nuse == 0); +} + + +static lu_mem atomic (lua_State *L) { + global_State *g = G(L); + lu_mem work = 0; + GCObject *origweak, *origall; + GCObject *grayagain = g->grayagain; /* save original list */ + g->grayagain = NULL; + lua_assert(g->ephemeron == NULL && g->weak == NULL); + lua_assert(!iswhite(g->mainthread)); + g->gcstate = GCSatomic; + markobject(g, L); /* mark running thread */ + /* registry and global metatables may be changed by API */ + markvalue(g, &g->l_registry); + markmt(g); /* mark global metatables */ + work += propagateall(g); /* empties 'gray' list */ + /* remark occasional upvalues of (maybe) dead threads */ + work += remarkupvals(g); + work += propagateall(g); /* propagate changes */ + g->gray = grayagain; + work += propagateall(g); /* traverse 'grayagain' list */ + convergeephemerons(g); + /* at this point, all strongly accessible objects are marked. */ + /* Clear values from weak tables, before checking finalizers */ + clearbyvalues(g, g->weak, NULL); + clearbyvalues(g, g->allweak, NULL); + origweak = g->weak; origall = g->allweak; + separatetobefnz(g, 0); /* separate objects to be finalized */ + work += markbeingfnz(g); /* mark objects that will be finalized */ + work += propagateall(g); /* remark, to propagate 'resurrection' */ + convergeephemerons(g); + /* at this point, all resurrected objects are marked. */ + /* remove dead objects from weak tables */ + clearbykeys(g, g->ephemeron); /* clear keys from all ephemeron tables */ + clearbykeys(g, g->allweak); /* clear keys from all 'allweak' tables */ + /* clear values from resurrected weak tables */ + clearbyvalues(g, g->weak, origweak); + clearbyvalues(g, g->allweak, origall); + luaS_clearcache(g); + g->currentwhite = cast_byte(otherwhite(g)); /* flip current white */ + lua_assert(g->gray == NULL); + return work; /* estimate of slots marked by 'atomic' */ +} + + +static int sweepstep (lua_State *L, global_State *g, + int nextstate, GCObject **nextlist) { + if (g->sweepgc) { + l_mem olddebt = g->GCdebt; + int count; + g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX, &count); + g->GCestimate += g->GCdebt - olddebt; /* update estimate */ + return count; + } + else { /* enter next state */ + g->gcstate = nextstate; + g->sweepgc = nextlist; + return 0; /* no work done */ + } +} + + +static lu_mem singlestep (lua_State *L) { + global_State *g = G(L); + lu_mem work; + lua_assert(!g->gcstopem); /* collector is not reentrant */ + g->gcstopem = 1; /* no emergency collections while collecting */ + switch (g->gcstate) { + case GCSpause: { + restartcollection(g); + g->gcstate = GCSpropagate; + work = 1; + break; + } + case GCSpropagate: { + if (g->gray == NULL) { /* no more gray objects? */ + g->gcstate = GCSenteratomic; /* finish propagate phase */ + work = 0; + } + else + work = propagatemark(g); /* traverse one gray object */ + break; + } + case GCSenteratomic: { + work = atomic(L); /* work is what was traversed by 'atomic' */ + entersweep(L); + g->GCestimate = gettotalbytes(g); /* first estimate */; + break; + } + case GCSswpallgc: { /* sweep "regular" objects */ + work = sweepstep(L, g, GCSswpfinobj, &g->finobj); + break; + } + case GCSswpfinobj: { /* sweep objects with finalizers */ + work = sweepstep(L, g, GCSswptobefnz, &g->tobefnz); + break; + } + case GCSswptobefnz: { /* sweep objects to be finalized */ + work = sweepstep(L, g, GCSswpend, NULL); + break; + } + case GCSswpend: { /* finish sweeps */ + checkSizes(L, g); + g->gcstate = GCScallfin; + work = 0; + break; + } + case GCScallfin: { /* call remaining finalizers */ + if (g->tobefnz && !g->gcemergency) { + g->gcstopem = 0; /* ok collections during finalizers */ + work = runafewfinalizers(L, GCFINMAX) * GCFINALIZECOST; + } + else { /* emergency mode or no more finalizers */ + g->gcstate = GCSpause; /* finish collection */ + work = 0; + } + break; + } + default: lua_assert(0); return 0; + } + g->gcstopem = 0; + return work; +} + + +/* +** advances the garbage collector until it reaches a state allowed +** by 'statemask' +*/ +void luaC_runtilstate (lua_State *L, int statesmask) { + global_State *g = G(L); + while (!testbit(statesmask, g->gcstate)) + singlestep(L); +} + + + +/* +** Performs a basic incremental step. The debt and step size are +** converted from bytes to "units of work"; then the function loops +** running single steps until adding that many units of work or +** finishing a cycle (pause state). Finally, it sets the debt that +** controls when next step will be performed. +*/ +static void incstep (lua_State *L, global_State *g) { + int stepmul = (getgcparam(g->gcstepmul) | 1); /* avoid division by 0 */ + l_mem debt = (g->GCdebt / WORK2MEM) * stepmul; + l_mem stepsize = (g->gcstepsize <= log2maxs(l_mem)) + ? ((cast(l_mem, 1) << g->gcstepsize) / WORK2MEM) * stepmul + : MAX_LMEM; /* overflow; keep maximum value */ + do { /* repeat until pause or enough "credit" (negative debt) */ + lu_mem work = singlestep(L); /* perform one single step */ + debt -= work; + } while (debt > -stepsize && g->gcstate != GCSpause); + if (g->gcstate == GCSpause) + setpause(g); /* pause until next cycle */ + else { + debt = (debt / stepmul) * WORK2MEM; /* convert 'work units' to bytes */ + luaE_setdebt(g, debt); + } +} + +/* +** Performs a basic GC step if collector is running. (If collector is +** not running, set a reasonable debt to avoid it being called at +** every single check.) +*/ +void luaC_step (lua_State *L) { + global_State *g = G(L); + if (!gcrunning(g)) /* not running? */ + luaE_setdebt(g, -2000); + else { + if(isdecGCmodegen(g)) + genstep(L, g); + else + incstep(L, g); + } +} + + +/* +** Perform a full collection in incremental mode. +** Before running the collection, check 'keepinvariant'; if it is true, +** there may be some objects marked as black, so the collector has +** to sweep all objects to turn them back to white (as white has not +** changed, nothing will be collected). +*/ +static void fullinc (lua_State *L, global_State *g) { + if (keepinvariant(g)) /* black objects? */ + entersweep(L); /* sweep everything to turn them back to white */ + /* finish any pending sweep phase to start a new cycle */ + luaC_runtilstate(L, bitmask(GCSpause)); + luaC_runtilstate(L, bitmask(GCScallfin)); /* run up to finalizers */ + /* estimate must be correct after a full GC cycle */ + lua_assert(g->GCestimate == gettotalbytes(g)); + luaC_runtilstate(L, bitmask(GCSpause)); /* finish collection */ + setpause(g); +} + + +/* +** Performs a full GC cycle; if 'isemergency', set a flag to avoid +** some operations which could change the interpreter state in some +** unexpected ways (running finalizers and shrinking some structures). +*/ +void luaC_fullgc (lua_State *L, int isemergency) { + global_State *g = G(L); + lua_assert(!g->gcemergency); + g->gcemergency = isemergency; /* set flag */ + if (g->gckind == KGC_INC) + fullinc(L, g); + else + fullgen(L, g); + g->gcemergency = 0; +} + +/* }====================================================== */ + + diff --git a/src/lgc.h b/src/lgc.h new file mode 100644 index 0000000..538f6ed --- /dev/null +++ b/src/lgc.h @@ -0,0 +1,202 @@ +/* +** $Id: lgc.h $ +** Garbage Collector +** See Copyright Notice in lua.h +*/ + +#ifndef lgc_h +#define lgc_h + + +#include "lobject.h" +#include "lstate.h" + +/* +** Collectable objects may have one of three colors: white, which means +** the object is not marked; gray, which means the object is marked, but +** its references may be not marked; and black, which means that the +** object and all its references are marked. The main invariant of the +** garbage collector, while marking objects, is that a black object can +** never point to a white one. Moreover, any gray object must be in a +** "gray list" (gray, grayagain, weak, allweak, ephemeron) so that it +** can be visited again before finishing the collection cycle. (Open +** upvalues are an exception to this rule.) These lists have no meaning +** when the invariant is not being enforced (e.g., sweep phase). +*/ + + +/* +** Possible states of the Garbage Collector +*/ +#define GCSpropagate 0 +#define GCSenteratomic 1 +#define GCSatomic 2 +#define GCSswpallgc 3 +#define GCSswpfinobj 4 +#define GCSswptobefnz 5 +#define GCSswpend 6 +#define GCScallfin 7 +#define GCSpause 8 + + +#define issweepphase(g) \ + (GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend) + + +/* +** macro to tell when main invariant (white objects cannot point to black +** ones) must be kept. During a collection, the sweep +** phase may break the invariant, as objects turned white may point to +** still-black objects. The invariant is restored when sweep ends and +** all objects are white again. +*/ + +#define keepinvariant(g) ((g)->gcstate <= GCSatomic) + + +/* +** some useful bit tricks +*/ +#define resetbits(x,m) ((x) &= cast_byte(~(m))) +#define setbits(x,m) ((x) |= (m)) +#define testbits(x,m) ((x) & (m)) +#define bitmask(b) (1<<(b)) +#define bit2mask(b1,b2) (bitmask(b1) | bitmask(b2)) +#define l_setbit(x,b) setbits(x, bitmask(b)) +#define resetbit(x,b) resetbits(x, bitmask(b)) +#define testbit(x,b) testbits(x, bitmask(b)) + + +/* +** Layout for bit use in 'marked' field. First three bits are +** used for object "age" in generational mode. Last bit is used +** by tests. +*/ +#define WHITE0BIT 3 /* object is white (type 0) */ +#define WHITE1BIT 4 /* object is white (type 1) */ +#define BLACKBIT 5 /* object is black */ +#define FINALIZEDBIT 6 /* object has been marked for finalization */ + +#define TESTBIT 7 + + + +#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT) + + +#define iswhite(x) testbits((x)->marked, WHITEBITS) +#define isblack(x) testbit((x)->marked, BLACKBIT) +#define isgray(x) /* neither white nor black */ \ + (!testbits((x)->marked, WHITEBITS | bitmask(BLACKBIT))) + +#define tofinalize(x) testbit((x)->marked, FINALIZEDBIT) + +#define otherwhite(g) ((g)->currentwhite ^ WHITEBITS) +#define isdeadm(ow,m) ((m) & (ow)) +#define isdead(g,v) isdeadm(otherwhite(g), (v)->marked) + +#define changewhite(x) ((x)->marked ^= WHITEBITS) +#define nw2black(x) \ + check_exp(!iswhite(x), l_setbit((x)->marked, BLACKBIT)) + +#define luaC_white(g) cast_byte((g)->currentwhite & WHITEBITS) + + +/* object age in generational mode */ +#define G_NEW 0 /* created in current cycle */ +#define G_SURVIVAL 1 /* created in previous cycle */ +#define G_OLD0 2 /* marked old by frw. barrier in this cycle */ +#define G_OLD1 3 /* first full cycle as old */ +#define G_OLD 4 /* really old object (not to be visited) */ +#define G_TOUCHED1 5 /* old object touched this cycle */ +#define G_TOUCHED2 6 /* old object touched in previous cycle */ + +#define AGEBITS 7 /* all age bits (111) */ + +#define getage(o) ((o)->marked & AGEBITS) +#define setage(o,a) ((o)->marked = cast_byte(((o)->marked & (~AGEBITS)) | a)) +#define isold(o) (getage(o) > G_SURVIVAL) + +#define changeage(o,f,t) \ + check_exp(getage(o) == (f), (o)->marked ^= ((f)^(t))) + + +/* Default Values for GC parameters */ +#define LUAI_GENMAJORMUL 100 +#define LUAI_GENMINORMUL 20 + +/* wait memory to double before starting new cycle */ +#define LUAI_GCPAUSE 200 + +/* +** some gc parameters are stored divided by 4 to allow a maximum value +** up to 1023 in a 'lu_byte'. +*/ +#define getgcparam(p) ((p) * 4) +#define setgcparam(p,v) ((p) = (v) / 4) + +#define LUAI_GCMUL 100 + +/* how much to allocate before next GC step (log2) */ +#define LUAI_GCSTEPSIZE 13 /* 8 KB */ + + +/* +** Check whether the declared GC mode is generational. While in +** generational mode, the collector can go temporarily to incremental +** mode to improve performance. This is signaled by 'g->lastatomic != 0'. +*/ +#define isdecGCmodegen(g) (g->gckind == KGC_GEN || g->lastatomic != 0) + + +/* +** Control when GC is running: +*/ +#define GCSTPUSR 1 /* bit true when GC stopped by user */ +#define GCSTPGC 2 /* bit true when GC stopped by itself */ +#define GCSTPCLS 4 /* bit true when closing Lua state */ +#define gcrunning(g) ((g)->gcstp == 0) + + +/* +** Does one step of collection when debt becomes positive. 'pre'/'pos' +** allows some adjustments to be done only when needed. macro +** 'condchangemem' is used only for heavy tests (forcing a full +** GC cycle on every opportunity) +*/ +#define luaC_condGC(L,pre,pos) \ + { if (G(L)->GCdebt > 0) { pre; luaC_step(L); pos;}; \ + condchangemem(L,pre,pos); } + +/* more often than not, 'pre'/'pos' are empty */ +#define luaC_checkGC(L) luaC_condGC(L,(void)0,(void)0) + + +#define luaC_objbarrier(L,p,o) ( \ + (isblack(p) && iswhite(o)) ? \ + luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0)) + +#define luaC_barrier(L,p,v) ( \ + iscollectable(v) ? luaC_objbarrier(L,p,gcvalue(v)) : cast_void(0)) + +#define luaC_objbarrierback(L,p,o) ( \ + (isblack(p) && iswhite(o)) ? luaC_barrierback_(L,p) : cast_void(0)) + +#define luaC_barrierback(L,p,v) ( \ + iscollectable(v) ? luaC_objbarrierback(L, p, gcvalue(v)) : cast_void(0)) + +LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o); +LUAI_FUNC void luaC_freeallobjects (lua_State *L); +LUAI_FUNC void luaC_step (lua_State *L); +LUAI_FUNC void luaC_runtilstate (lua_State *L, int statesmask); +LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency); +LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz); +LUAI_FUNC GCObject *luaC_newobjdt (lua_State *L, int tt, size_t sz, + size_t offset); +LUAI_FUNC void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v); +LUAI_FUNC void luaC_barrierback_ (lua_State *L, GCObject *o); +LUAI_FUNC void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt); +LUAI_FUNC void luaC_changemode (lua_State *L, int newmode); + + +#endif diff --git a/src/linit.c b/src/linit.c new file mode 100644 index 0000000..69808f8 --- /dev/null +++ b/src/linit.c @@ -0,0 +1,65 @@ +/* +** $Id: linit.c $ +** Initialization of libraries for lua.c and other clients +** See Copyright Notice in lua.h +*/ + + +#define linit_c +#define LUA_LIB + +/* +** If you embed Lua in your program and need to open the standard +** libraries, call luaL_openlibs in your program. If you need a +** different set of libraries, copy this file to your project and edit +** it to suit your needs. +** +** You can also *preload* libraries, so that a later 'require' can +** open the library, which is already linked to the application. +** For that, do the following code: +** +** luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE); +** lua_pushcfunction(L, luaopen_modname); +** lua_setfield(L, -2, modname); +** lua_pop(L, 1); // remove PRELOAD table +*/ + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "lualib.h" +#include "lauxlib.h" + + +/* +** these libs are loaded by lua.c and are readily available to any Lua +** program +*/ +static const luaL_Reg loadedlibs[] = { + {LUA_GNAME, luaopen_base}, + {LUA_LOADLIBNAME, luaopen_package}, + {LUA_COLIBNAME, luaopen_coroutine}, + {LUA_TABLIBNAME, luaopen_table}, + {LUA_IOLIBNAME, luaopen_io}, + {LUA_OSLIBNAME, luaopen_os}, + {LUA_STRLIBNAME, luaopen_string}, + {LUA_MATHLIBNAME, luaopen_math}, + {LUA_UTF8LIBNAME, luaopen_utf8}, + {LUA_DBLIBNAME, luaopen_debug}, + {NULL, NULL} +}; + + +LUALIB_API void luaL_openlibs (lua_State *L) { + const luaL_Reg *lib; + /* "require" functions from 'loadedlibs' and set results to global table */ + for (lib = loadedlibs; lib->func; lib++) { + luaL_requiref(L, lib->name, lib->func, 1); + lua_pop(L, 1); /* remove lib */ + } +} + diff --git a/src/liolib.c b/src/liolib.c new file mode 100644 index 0000000..b08397d --- /dev/null +++ b/src/liolib.c @@ -0,0 +1,828 @@ +/* +** $Id: liolib.c $ +** Standard I/O (and system) library +** See Copyright Notice in lua.h +*/ + +#define liolib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + + + +/* +** Change this macro to accept other modes for 'fopen' besides +** the standard ones. +*/ +#if !defined(l_checkmode) + +/* accepted extensions to 'mode' in 'fopen' */ +#if !defined(L_MODEEXT) +#define L_MODEEXT "b" +#endif + +/* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */ +static int l_checkmode (const char *mode) { + return (*mode != '\0' && strchr("rwa", *(mode++)) != NULL && + (*mode != '+' || ((void)(++mode), 1)) && /* skip if char is '+' */ + (strspn(mode, L_MODEEXT) == strlen(mode))); /* check extensions */ +} + +#endif + +/* +** {====================================================== +** l_popen spawns a new process connected to the current +** one through the file streams. +** ======================================================= +*/ + +#if !defined(l_popen) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#define l_popen(L,c,m) (fflush(NULL), popen(c,m)) +#define l_pclose(L,file) (pclose(file)) + +#elif defined(LUA_USE_WINDOWS) /* }{ */ + +#define l_popen(L,c,m) (_popen(c,m)) +#define l_pclose(L,file) (_pclose(file)) + +#if !defined(l_checkmodep) +/* Windows accepts "[rw][bt]?" as valid modes */ +#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && \ + (m[1] == '\0' || ((m[1] == 'b' || m[1] == 't') && m[2] == '\0'))) +#endif + +#else /* }{ */ + +/* ISO C definitions */ +#define l_popen(L,c,m) \ + ((void)c, (void)m, \ + luaL_error(L, "'popen' not supported"), \ + (FILE*)0) +#define l_pclose(L,file) ((void)L, (void)file, -1) + +#endif /* } */ + +#endif /* } */ + + +#if !defined(l_checkmodep) +/* By default, Lua accepts only "r" or "w" as valid modes */ +#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0') +#endif + +/* }====================================================== */ + + +#if !defined(l_getc) /* { */ + +#if defined(LUA_USE_POSIX) +#define l_getc(f) getc_unlocked(f) +#define l_lockfile(f) flockfile(f) +#define l_unlockfile(f) funlockfile(f) +#else +#define l_getc(f) getc(f) +#define l_lockfile(f) ((void)0) +#define l_unlockfile(f) ((void)0) +#endif + +#endif /* } */ + + +/* +** {====================================================== +** l_fseek: configuration for longer offsets +** ======================================================= +*/ + +#if !defined(l_fseek) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#include + +#define l_fseek(f,o,w) fseeko(f,o,w) +#define l_ftell(f) ftello(f) +#define l_seeknum off_t + +#elif defined(LUA_USE_WINDOWS) && !defined(_CRTIMP_TYPEINFO) \ + && defined(_MSC_VER) && (_MSC_VER >= 1400) /* }{ */ + +/* Windows (but not DDK) and Visual C++ 2005 or higher */ +#define l_fseek(f,o,w) _fseeki64(f,o,w) +#define l_ftell(f) _ftelli64(f) +#define l_seeknum __int64 + +#else /* }{ */ + +/* ISO C definitions */ +#define l_fseek(f,o,w) fseek(f,o,w) +#define l_ftell(f) ftell(f) +#define l_seeknum long + +#endif /* } */ + +#endif /* } */ + +/* }====================================================== */ + + + +#define IO_PREFIX "_IO_" +#define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1) +#define IO_INPUT (IO_PREFIX "input") +#define IO_OUTPUT (IO_PREFIX "output") + + +typedef luaL_Stream LStream; + + +#define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE)) + +#define isclosed(p) ((p)->closef == NULL) + + +static int io_type (lua_State *L) { + LStream *p; + luaL_checkany(L, 1); + p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE); + if (p == NULL) + luaL_pushfail(L); /* not a file */ + else if (isclosed(p)) + lua_pushliteral(L, "closed file"); + else + lua_pushliteral(L, "file"); + return 1; +} + + +static int f_tostring (lua_State *L) { + LStream *p = tolstream(L); + if (isclosed(p)) + lua_pushliteral(L, "file (closed)"); + else + lua_pushfstring(L, "file (%p)", p->f); + return 1; +} + + +static FILE *tofile (lua_State *L) { + LStream *p = tolstream(L); + if (l_unlikely(isclosed(p))) + luaL_error(L, "attempt to use a closed file"); + lua_assert(p->f); + return p->f; +} + + +/* +** When creating file handles, always creates a 'closed' file handle +** before opening the actual file; so, if there is a memory error, the +** handle is in a consistent state. +*/ +static LStream *newprefile (lua_State *L) { + LStream *p = (LStream *)lua_newuserdatauv(L, sizeof(LStream), 0); + p->closef = NULL; /* mark file handle as 'closed' */ + luaL_setmetatable(L, LUA_FILEHANDLE); + return p; +} + + +/* +** Calls the 'close' function from a file handle. The 'volatile' avoids +** a bug in some versions of the Clang compiler (e.g., clang 3.0 for +** 32 bits). +*/ +static int aux_close (lua_State *L) { + LStream *p = tolstream(L); + volatile lua_CFunction cf = p->closef; + p->closef = NULL; /* mark stream as closed */ + return (*cf)(L); /* close it */ +} + + +static int f_close (lua_State *L) { + tofile(L); /* make sure argument is an open stream */ + return aux_close(L); +} + + +static int io_close (lua_State *L) { + if (lua_isnone(L, 1)) /* no argument? */ + lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use default output */ + return f_close(L); +} + + +static int f_gc (lua_State *L) { + LStream *p = tolstream(L); + if (!isclosed(p) && p->f != NULL) + aux_close(L); /* ignore closed and incompletely open files */ + return 0; +} + + +/* +** function to close regular files +*/ +static int io_fclose (lua_State *L) { + LStream *p = tolstream(L); + int res = fclose(p->f); + return luaL_fileresult(L, (res == 0), NULL); +} + + +static LStream *newfile (lua_State *L) { + LStream *p = newprefile(L); + p->f = NULL; + p->closef = &io_fclose; + return p; +} + + +static void opencheck (lua_State *L, const char *fname, const char *mode) { + LStream *p = newfile(L); + p->f = fopen(fname, mode); + if (l_unlikely(p->f == NULL)) + luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno)); +} + + +static int io_open (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + const char *mode = luaL_optstring(L, 2, "r"); + LStream *p = newfile(L); + const char *md = mode; /* to traverse/check mode */ + luaL_argcheck(L, l_checkmode(md), 2, "invalid mode"); + p->f = fopen(filename, mode); + return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; +} + + +/* +** function to close 'popen' files +*/ +static int io_pclose (lua_State *L) { + LStream *p = tolstream(L); + errno = 0; + return luaL_execresult(L, l_pclose(L, p->f)); +} + + +static int io_popen (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + const char *mode = luaL_optstring(L, 2, "r"); + LStream *p = newprefile(L); + luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode"); + p->f = l_popen(L, filename, mode); + p->closef = &io_pclose; + return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; +} + + +static int io_tmpfile (lua_State *L) { + LStream *p = newfile(L); + p->f = tmpfile(); + return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; +} + + +static FILE *getiofile (lua_State *L, const char *findex) { + LStream *p; + lua_getfield(L, LUA_REGISTRYINDEX, findex); + p = (LStream *)lua_touserdata(L, -1); + if (l_unlikely(isclosed(p))) + luaL_error(L, "default %s file is closed", findex + IOPREF_LEN); + return p->f; +} + + +static int g_iofile (lua_State *L, const char *f, const char *mode) { + if (!lua_isnoneornil(L, 1)) { + const char *filename = lua_tostring(L, 1); + if (filename) + opencheck(L, filename, mode); + else { + tofile(L); /* check that it's a valid file handle */ + lua_pushvalue(L, 1); + } + lua_setfield(L, LUA_REGISTRYINDEX, f); + } + /* return current value */ + lua_getfield(L, LUA_REGISTRYINDEX, f); + return 1; +} + + +static int io_input (lua_State *L) { + return g_iofile(L, IO_INPUT, "r"); +} + + +static int io_output (lua_State *L) { + return g_iofile(L, IO_OUTPUT, "w"); +} + + +static int io_readline (lua_State *L); + + +/* +** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit +** in the limit for upvalues of a closure) +*/ +#define MAXARGLINE 250 + +/* +** Auxiliary function to create the iteration function for 'lines'. +** The iteration function is a closure over 'io_readline', with +** the following upvalues: +** 1) The file being read (first value in the stack) +** 2) the number of arguments to read +** 3) a boolean, true iff file has to be closed when finished ('toclose') +** *) a variable number of format arguments (rest of the stack) +*/ +static void aux_lines (lua_State *L, int toclose) { + int n = lua_gettop(L) - 1; /* number of arguments to read */ + luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments"); + lua_pushvalue(L, 1); /* file */ + lua_pushinteger(L, n); /* number of arguments to read */ + lua_pushboolean(L, toclose); /* close/not close file when finished */ + lua_rotate(L, 2, 3); /* move the three values to their positions */ + lua_pushcclosure(L, io_readline, 3 + n); +} + + +static int f_lines (lua_State *L) { + tofile(L); /* check that it's a valid file handle */ + aux_lines(L, 0); + return 1; +} + + +/* +** Return an iteration function for 'io.lines'. If file has to be +** closed, also returns the file itself as a second result (to be +** closed as the state at the exit of a generic for). +*/ +static int io_lines (lua_State *L) { + int toclose; + if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */ + if (lua_isnil(L, 1)) { /* no file name? */ + lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */ + lua_replace(L, 1); /* put it at index 1 */ + tofile(L); /* check that it's a valid file handle */ + toclose = 0; /* do not close it after iteration */ + } + else { /* open a new file */ + const char *filename = luaL_checkstring(L, 1); + opencheck(L, filename, "r"); + lua_replace(L, 1); /* put file at index 1 */ + toclose = 1; /* close it after iteration */ + } + aux_lines(L, toclose); /* push iteration function */ + if (toclose) { + lua_pushnil(L); /* state */ + lua_pushnil(L); /* control */ + lua_pushvalue(L, 1); /* file is the to-be-closed variable (4th result) */ + return 4; + } + else + return 1; +} + + +/* +** {====================================================== +** READ +** ======================================================= +*/ + + +/* maximum length of a numeral */ +#if !defined (L_MAXLENNUM) +#define L_MAXLENNUM 200 +#endif + + +/* auxiliary structure used by 'read_number' */ +typedef struct { + FILE *f; /* file being read */ + int c; /* current character (look ahead) */ + int n; /* number of elements in buffer 'buff' */ + char buff[L_MAXLENNUM + 1]; /* +1 for ending '\0' */ +} RN; + + +/* +** Add current char to buffer (if not out of space) and read next one +*/ +static int nextc (RN *rn) { + if (l_unlikely(rn->n >= L_MAXLENNUM)) { /* buffer overflow? */ + rn->buff[0] = '\0'; /* invalidate result */ + return 0; /* fail */ + } + else { + rn->buff[rn->n++] = rn->c; /* save current char */ + rn->c = l_getc(rn->f); /* read next one */ + return 1; + } +} + + +/* +** Accept current char if it is in 'set' (of size 2) +*/ +static int test2 (RN *rn, const char *set) { + if (rn->c == set[0] || rn->c == set[1]) + return nextc(rn); + else return 0; +} + + +/* +** Read a sequence of (hex)digits +*/ +static int readdigits (RN *rn, int hex) { + int count = 0; + while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn)) + count++; + return count; +} + + +/* +** Read a number: first reads a valid prefix of a numeral into a buffer. +** Then it calls 'lua_stringtonumber' to check whether the format is +** correct and to convert it to a Lua number. +*/ +static int read_number (lua_State *L, FILE *f) { + RN rn; + int count = 0; + int hex = 0; + char decp[2]; + rn.f = f; rn.n = 0; + decp[0] = lua_getlocaledecpoint(); /* get decimal point from locale */ + decp[1] = '.'; /* always accept a dot */ + l_lockfile(rn.f); + do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */ + test2(&rn, "-+"); /* optional sign */ + if (test2(&rn, "00")) { + if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */ + else count = 1; /* count initial '0' as a valid digit */ + } + count += readdigits(&rn, hex); /* integral part */ + if (test2(&rn, decp)) /* decimal point? */ + count += readdigits(&rn, hex); /* fractional part */ + if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */ + test2(&rn, "-+"); /* exponent sign */ + readdigits(&rn, 0); /* exponent digits */ + } + ungetc(rn.c, rn.f); /* unread look-ahead char */ + l_unlockfile(rn.f); + rn.buff[rn.n] = '\0'; /* finish string */ + if (l_likely(lua_stringtonumber(L, rn.buff))) + return 1; /* ok, it is a valid number */ + else { /* invalid format */ + lua_pushnil(L); /* "result" to be removed */ + return 0; /* read fails */ + } +} + + +static int test_eof (lua_State *L, FILE *f) { + int c = getc(f); + ungetc(c, f); /* no-op when c == EOF */ + lua_pushliteral(L, ""); + return (c != EOF); +} + + +static int read_line (lua_State *L, FILE *f, int chop) { + luaL_Buffer b; + int c; + luaL_buffinit(L, &b); + do { /* may need to read several chunks to get whole line */ + char *buff = luaL_prepbuffer(&b); /* preallocate buffer space */ + int i = 0; + l_lockfile(f); /* no memory errors can happen inside the lock */ + while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n') + buff[i++] = c; /* read up to end of line or buffer limit */ + l_unlockfile(f); + luaL_addsize(&b, i); + } while (c != EOF && c != '\n'); /* repeat until end of line */ + if (!chop && c == '\n') /* want a newline and have one? */ + luaL_addchar(&b, c); /* add ending newline to result */ + luaL_pushresult(&b); /* close buffer */ + /* return ok if read something (either a newline or something else) */ + return (c == '\n' || lua_rawlen(L, -1) > 0); +} + + +static void read_all (lua_State *L, FILE *f) { + size_t nr; + luaL_Buffer b; + luaL_buffinit(L, &b); + do { /* read file in chunks of LUAL_BUFFERSIZE bytes */ + char *p = luaL_prepbuffer(&b); + nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f); + luaL_addsize(&b, nr); + } while (nr == LUAL_BUFFERSIZE); + luaL_pushresult(&b); /* close buffer */ +} + + +static int read_chars (lua_State *L, FILE *f, size_t n) { + size_t nr; /* number of chars actually read */ + char *p; + luaL_Buffer b; + luaL_buffinit(L, &b); + p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */ + nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */ + luaL_addsize(&b, nr); + luaL_pushresult(&b); /* close buffer */ + return (nr > 0); /* true iff read something */ +} + + +static int g_read (lua_State *L, FILE *f, int first) { + int nargs = lua_gettop(L) - 1; + int n, success; + clearerr(f); + if (nargs == 0) { /* no arguments? */ + success = read_line(L, f, 1); + n = first + 1; /* to return 1 result */ + } + else { + /* ensure stack space for all results and for auxlib's buffer */ + luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); + success = 1; + for (n = first; nargs-- && success; n++) { + if (lua_type(L, n) == LUA_TNUMBER) { + size_t l = (size_t)luaL_checkinteger(L, n); + success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); + } + else { + const char *p = luaL_checkstring(L, n); + if (*p == '*') p++; /* skip optional '*' (for compatibility) */ + switch (*p) { + case 'n': /* number */ + success = read_number(L, f); + break; + case 'l': /* line */ + success = read_line(L, f, 1); + break; + case 'L': /* line with end-of-line */ + success = read_line(L, f, 0); + break; + case 'a': /* file */ + read_all(L, f); /* read entire file */ + success = 1; /* always success */ + break; + default: + return luaL_argerror(L, n, "invalid format"); + } + } + } + } + if (ferror(f)) + return luaL_fileresult(L, 0, NULL); + if (!success) { + lua_pop(L, 1); /* remove last result */ + luaL_pushfail(L); /* push nil instead */ + } + return n - first; +} + + +static int io_read (lua_State *L) { + return g_read(L, getiofile(L, IO_INPUT), 1); +} + + +static int f_read (lua_State *L) { + return g_read(L, tofile(L), 2); +} + + +/* +** Iteration function for 'lines'. +*/ +static int io_readline (lua_State *L) { + LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1)); + int i; + int n = (int)lua_tointeger(L, lua_upvalueindex(2)); + if (isclosed(p)) /* file is already closed? */ + return luaL_error(L, "file is already closed"); + lua_settop(L , 1); + luaL_checkstack(L, n, "too many arguments"); + for (i = 1; i <= n; i++) /* push arguments to 'g_read' */ + lua_pushvalue(L, lua_upvalueindex(3 + i)); + n = g_read(L, p->f, 2); /* 'n' is number of results */ + lua_assert(n > 0); /* should return at least a nil */ + if (lua_toboolean(L, -n)) /* read at least one value? */ + return n; /* return them */ + else { /* first result is false: EOF or error */ + if (n > 1) { /* is there error information? */ + /* 2nd result is error message */ + return luaL_error(L, "%s", lua_tostring(L, -n + 1)); + } + if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */ + lua_settop(L, 0); /* clear stack */ + lua_pushvalue(L, lua_upvalueindex(1)); /* push file at index 1 */ + aux_close(L); /* close it */ + } + return 0; + } +} + +/* }====================================================== */ + + +static int g_write (lua_State *L, FILE *f, int arg) { + int nargs = lua_gettop(L) - arg; + int status = 1; + for (; nargs--; arg++) { + if (lua_type(L, arg) == LUA_TNUMBER) { + /* optimization: could be done exactly as for strings */ + int len = lua_isinteger(L, arg) + ? fprintf(f, LUA_INTEGER_FMT, + (LUAI_UACINT)lua_tointeger(L, arg)) + : fprintf(f, LUA_NUMBER_FMT, + (LUAI_UACNUMBER)lua_tonumber(L, arg)); + status = status && (len > 0); + } + else { + size_t l; + const char *s = luaL_checklstring(L, arg, &l); + status = status && (fwrite(s, sizeof(char), l, f) == l); + } + } + if (l_likely(status)) + return 1; /* file handle already on stack top */ + else return luaL_fileresult(L, status, NULL); +} + + +static int io_write (lua_State *L) { + return g_write(L, getiofile(L, IO_OUTPUT), 1); +} + + +static int f_write (lua_State *L) { + FILE *f = tofile(L); + lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */ + return g_write(L, f, 2); +} + + +static int f_seek (lua_State *L) { + static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; + static const char *const modenames[] = {"set", "cur", "end", NULL}; + FILE *f = tofile(L); + int op = luaL_checkoption(L, 2, "cur", modenames); + lua_Integer p3 = luaL_optinteger(L, 3, 0); + l_seeknum offset = (l_seeknum)p3; + luaL_argcheck(L, (lua_Integer)offset == p3, 3, + "not an integer in proper range"); + op = l_fseek(f, offset, mode[op]); + if (l_unlikely(op)) + return luaL_fileresult(L, 0, NULL); /* error */ + else { + lua_pushinteger(L, (lua_Integer)l_ftell(f)); + return 1; + } +} + + +static int f_setvbuf (lua_State *L) { + static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; + static const char *const modenames[] = {"no", "full", "line", NULL}; + FILE *f = tofile(L); + int op = luaL_checkoption(L, 2, NULL, modenames); + lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); + int res = setvbuf(f, NULL, mode[op], (size_t)sz); + return luaL_fileresult(L, res == 0, NULL); +} + + + +static int io_flush (lua_State *L) { + return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); +} + + +static int f_flush (lua_State *L) { + return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL); +} + + +/* +** functions for 'io' library +*/ +static const luaL_Reg iolib[] = { + {"close", io_close}, + {"flush", io_flush}, + {"input", io_input}, + {"lines", io_lines}, + {"open", io_open}, + {"output", io_output}, + {"popen", io_popen}, + {"read", io_read}, + {"tmpfile", io_tmpfile}, + {"type", io_type}, + {"write", io_write}, + {NULL, NULL} +}; + + +/* +** methods for file handles +*/ +static const luaL_Reg meth[] = { + {"read", f_read}, + {"write", f_write}, + {"lines", f_lines}, + {"flush", f_flush}, + {"seek", f_seek}, + {"close", f_close}, + {"setvbuf", f_setvbuf}, + {NULL, NULL} +}; + + +/* +** metamethods for file handles +*/ +static const luaL_Reg metameth[] = { + {"__index", NULL}, /* place holder */ + {"__gc", f_gc}, + {"__close", f_gc}, + {"__tostring", f_tostring}, + {NULL, NULL} +}; + + +static void createmeta (lua_State *L) { + luaL_newmetatable(L, LUA_FILEHANDLE); /* metatable for file handles */ + luaL_setfuncs(L, metameth, 0); /* add metamethods to new metatable */ + luaL_newlibtable(L, meth); /* create method table */ + luaL_setfuncs(L, meth, 0); /* add file methods to method table */ + lua_setfield(L, -2, "__index"); /* metatable.__index = method table */ + lua_pop(L, 1); /* pop metatable */ +} + + +/* +** function to (not) close the standard files stdin, stdout, and stderr +*/ +static int io_noclose (lua_State *L) { + LStream *p = tolstream(L); + p->closef = &io_noclose; /* keep file opened */ + luaL_pushfail(L); + lua_pushliteral(L, "cannot close standard file"); + return 2; +} + + +static void createstdfile (lua_State *L, FILE *f, const char *k, + const char *fname) { + LStream *p = newprefile(L); + p->f = f; + p->closef = &io_noclose; + if (k != NULL) { + lua_pushvalue(L, -1); + lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */ + } + lua_setfield(L, -2, fname); /* add file to module */ +} + + +LUAMOD_API int luaopen_io (lua_State *L) { + luaL_newlib(L, iolib); /* new module */ + createmeta(L); + /* create (and set) default files */ + createstdfile(L, stdin, IO_INPUT, "stdin"); + createstdfile(L, stdout, IO_OUTPUT, "stdout"); + createstdfile(L, stderr, NULL, "stderr"); + return 1; +} + diff --git a/src/ljumptab.h b/src/ljumptab.h new file mode 100644 index 0000000..8306f25 --- /dev/null +++ b/src/ljumptab.h @@ -0,0 +1,112 @@ +/* +** $Id: ljumptab.h $ +** Jump Table for the Lua interpreter +** See Copyright Notice in lua.h +*/ + + +#undef vmdispatch +#undef vmcase +#undef vmbreak + +#define vmdispatch(x) goto *disptab[x]; + +#define vmcase(l) L_##l: + +#define vmbreak vmfetch(); vmdispatch(GET_OPCODE(i)); + + +static const void *const disptab[NUM_OPCODES] = { + +#if 0 +** you can update the following list with this command: +** +** sed -n '/^OP_/\!d; s/OP_/\&\&L_OP_/ ; s/,.*/,/ ; s/\/.*// ; p' lopcodes.h +** +#endif + +&&L_OP_MOVE, +&&L_OP_LOADI, +&&L_OP_LOADF, +&&L_OP_LOADK, +&&L_OP_LOADKX, +&&L_OP_LOADFALSE, +&&L_OP_LFALSESKIP, +&&L_OP_LOADTRUE, +&&L_OP_LOADNIL, +&&L_OP_GETUPVAL, +&&L_OP_SETUPVAL, +&&L_OP_GETTABUP, +&&L_OP_GETTABLE, +&&L_OP_GETI, +&&L_OP_GETFIELD, +&&L_OP_SETTABUP, +&&L_OP_SETTABLE, +&&L_OP_SETI, +&&L_OP_SETFIELD, +&&L_OP_NEWTABLE, +&&L_OP_SELF, +&&L_OP_ADDI, +&&L_OP_ADDK, +&&L_OP_SUBK, +&&L_OP_MULK, +&&L_OP_MODK, +&&L_OP_POWK, +&&L_OP_DIVK, +&&L_OP_IDIVK, +&&L_OP_BANDK, +&&L_OP_BORK, +&&L_OP_BXORK, +&&L_OP_SHRI, +&&L_OP_SHLI, +&&L_OP_ADD, +&&L_OP_SUB, +&&L_OP_MUL, +&&L_OP_MOD, +&&L_OP_POW, +&&L_OP_DIV, +&&L_OP_IDIV, +&&L_OP_BAND, +&&L_OP_BOR, +&&L_OP_BXOR, +&&L_OP_SHL, +&&L_OP_SHR, +&&L_OP_MMBIN, +&&L_OP_MMBINI, +&&L_OP_MMBINK, +&&L_OP_UNM, +&&L_OP_BNOT, +&&L_OP_NOT, +&&L_OP_LEN, +&&L_OP_CONCAT, +&&L_OP_CLOSE, +&&L_OP_TBC, +&&L_OP_JMP, +&&L_OP_EQ, +&&L_OP_LT, +&&L_OP_LE, +&&L_OP_EQK, +&&L_OP_EQI, +&&L_OP_LTI, +&&L_OP_LEI, +&&L_OP_GTI, +&&L_OP_GEI, +&&L_OP_TEST, +&&L_OP_TESTSET, +&&L_OP_CALL, +&&L_OP_TAILCALL, +&&L_OP_RETURN, +&&L_OP_RETURN0, +&&L_OP_RETURN1, +&&L_OP_FORLOOP, +&&L_OP_FORPREP, +&&L_OP_TFORPREP, +&&L_OP_TFORCALL, +&&L_OP_TFORLOOP, +&&L_OP_SETLIST, +&&L_OP_CLOSURE, +&&L_OP_VARARG, +&&L_OP_VARARGPREP, +&&L_OP_EXTRAARG + +}; diff --git a/src/llex.c b/src/llex.c new file mode 100644 index 0000000..5fc39a5 --- /dev/null +++ b/src/llex.c @@ -0,0 +1,581 @@ +/* +** $Id: llex.c $ +** Lexical Analyzer +** See Copyright Notice in lua.h +*/ + +#define llex_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include + +#include "lua.h" + +#include "lctype.h" +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "llex.h" +#include "lobject.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "lzio.h" + + + +#define next(ls) (ls->current = zgetc(ls->z)) + + + +#define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r') + + +/* ORDER RESERVED */ +static const char *const luaX_tokens [] = { + "and", "break", "do", "else", "elseif", + "end", "false", "for", "function", "goto", "if", + "in", "local", "nil", "not", "or", "repeat", + "return", "then", "true", "until", "while", + "//", "..", "...", "==", ">=", "<=", "~=", + "<<", ">>", "::", "", + "", "", "", "" +}; + + +#define save_and_next(ls) (save(ls, ls->current), next(ls)) + + +static l_noret lexerror (LexState *ls, const char *msg, int token); + + +static void save (LexState *ls, int c) { + Mbuffer *b = ls->buff; + if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) { + size_t newsize; + if (luaZ_sizebuffer(b) >= MAX_SIZE/2) + lexerror(ls, "lexical element too long", 0); + newsize = luaZ_sizebuffer(b) * 2; + luaZ_resizebuffer(ls->L, b, newsize); + } + b->buffer[luaZ_bufflen(b)++] = cast_char(c); +} + + +void luaX_init (lua_State *L) { + int i; + TString *e = luaS_newliteral(L, LUA_ENV); /* create env name */ + luaC_fix(L, obj2gco(e)); /* never collect this name */ + for (i=0; iextra = cast_byte(i+1); /* reserved word */ + } +} + + +const char *luaX_token2str (LexState *ls, int token) { + if (token < FIRST_RESERVED) { /* single-byte symbols? */ + if (lisprint(token)) + return luaO_pushfstring(ls->L, "'%c'", token); + else /* control character */ + return luaO_pushfstring(ls->L, "'<\\%d>'", token); + } + else { + const char *s = luaX_tokens[token - FIRST_RESERVED]; + if (token < TK_EOS) /* fixed format (symbols and reserved words)? */ + return luaO_pushfstring(ls->L, "'%s'", s); + else /* names, strings, and numerals */ + return s; + } +} + + +static const char *txtToken (LexState *ls, int token) { + switch (token) { + case TK_NAME: case TK_STRING: + case TK_FLT: case TK_INT: + save(ls, '\0'); + return luaO_pushfstring(ls->L, "'%s'", luaZ_buffer(ls->buff)); + default: + return luaX_token2str(ls, token); + } +} + + +static l_noret lexerror (LexState *ls, const char *msg, int token) { + msg = luaG_addinfo(ls->L, msg, ls->source, ls->linenumber); + if (token) + luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token)); + luaD_throw(ls->L, LUA_ERRSYNTAX); +} + + +l_noret luaX_syntaxerror (LexState *ls, const char *msg) { + lexerror(ls, msg, ls->t.token); +} + + +/* +** Creates a new string and anchors it in scanner's table so that it +** will not be collected until the end of the compilation; by that time +** it should be anchored somewhere. It also internalizes long strings, +** ensuring there is only one copy of each unique string. The table +** here is used as a set: the string enters as the key, while its value +** is irrelevant. We use the string itself as the value only because it +** is a TValue readily available. Later, the code generation can change +** this value. +*/ +TString *luaX_newstring (LexState *ls, const char *str, size_t l) { + lua_State *L = ls->L; + TString *ts = luaS_newlstr(L, str, l); /* create new string */ + const TValue *o = luaH_getstr(ls->h, ts); + if (!ttisnil(o)) /* string already present? */ + ts = keystrval(nodefromval(o)); /* get saved copy */ + else { /* not in use yet */ + TValue *stv = s2v(L->top.p++); /* reserve stack space for string */ + setsvalue(L, stv, ts); /* temporarily anchor the string */ + luaH_finishset(L, ls->h, stv, o, stv); /* t[string] = string */ + /* table is not a metatable, so it does not need to invalidate cache */ + luaC_checkGC(L); + L->top.p--; /* remove string from stack */ + } + return ts; +} + + +/* +** increment line number and skips newline sequence (any of +** \n, \r, \n\r, or \r\n) +*/ +static void inclinenumber (LexState *ls) { + int old = ls->current; + lua_assert(currIsNewline(ls)); + next(ls); /* skip '\n' or '\r' */ + if (currIsNewline(ls) && ls->current != old) + next(ls); /* skip '\n\r' or '\r\n' */ + if (++ls->linenumber >= MAX_INT) + lexerror(ls, "chunk has too many lines", 0); +} + + +void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source, + int firstchar) { + ls->t.token = 0; + ls->L = L; + ls->current = firstchar; + ls->lookahead.token = TK_EOS; /* no look-ahead token */ + ls->z = z; + ls->fs = NULL; + ls->linenumber = 1; + ls->lastline = 1; + ls->source = source; + ls->envn = luaS_newliteral(L, LUA_ENV); /* get env name */ + luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER); /* initialize buffer */ +} + + + +/* +** ======================================================= +** LEXICAL ANALYZER +** ======================================================= +*/ + + +static int check_next1 (LexState *ls, int c) { + if (ls->current == c) { + next(ls); + return 1; + } + else return 0; +} + + +/* +** Check whether current char is in set 'set' (with two chars) and +** saves it +*/ +static int check_next2 (LexState *ls, const char *set) { + lua_assert(set[2] == '\0'); + if (ls->current == set[0] || ls->current == set[1]) { + save_and_next(ls); + return 1; + } + else return 0; +} + + +/* LUA_NUMBER */ +/* +** This function is quite liberal in what it accepts, as 'luaO_str2num' +** will reject ill-formed numerals. Roughly, it accepts the following +** pattern: +** +** %d(%x|%.|([Ee][+-]?))* | 0[Xx](%x|%.|([Pp][+-]?))* +** +** The only tricky part is to accept [+-] only after a valid exponent +** mark, to avoid reading '3-4' or '0xe+1' as a single number. +** +** The caller might have already read an initial dot. +*/ +static int read_numeral (LexState *ls, SemInfo *seminfo) { + TValue obj; + const char *expo = "Ee"; + int first = ls->current; + lua_assert(lisdigit(ls->current)); + save_and_next(ls); + if (first == '0' && check_next2(ls, "xX")) /* hexadecimal? */ + expo = "Pp"; + for (;;) { + if (check_next2(ls, expo)) /* exponent mark? */ + check_next2(ls, "-+"); /* optional exponent sign */ + else if (lisxdigit(ls->current) || ls->current == '.') /* '%x|%.' */ + save_and_next(ls); + else break; + } + if (lislalpha(ls->current)) /* is numeral touching a letter? */ + save_and_next(ls); /* force an error */ + save(ls, '\0'); + if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0) /* format error? */ + lexerror(ls, "malformed number", TK_FLT); + if (ttisinteger(&obj)) { + seminfo->i = ivalue(&obj); + return TK_INT; + } + else { + lua_assert(ttisfloat(&obj)); + seminfo->r = fltvalue(&obj); + return TK_FLT; + } +} + + +/* +** read a sequence '[=*[' or ']=*]', leaving the last bracket. If +** sequence is well formed, return its number of '='s + 2; otherwise, +** return 1 if it is a single bracket (no '='s and no 2nd bracket); +** otherwise (an unfinished '[==...') return 0. +*/ +static size_t skip_sep (LexState *ls) { + size_t count = 0; + int s = ls->current; + lua_assert(s == '[' || s == ']'); + save_and_next(ls); + while (ls->current == '=') { + save_and_next(ls); + count++; + } + return (ls->current == s) ? count + 2 + : (count == 0) ? 1 + : 0; +} + + +static void read_long_string (LexState *ls, SemInfo *seminfo, size_t sep) { + int line = ls->linenumber; /* initial line (for error message) */ + save_and_next(ls); /* skip 2nd '[' */ + if (currIsNewline(ls)) /* string starts with a newline? */ + inclinenumber(ls); /* skip it */ + for (;;) { + switch (ls->current) { + case EOZ: { /* error */ + const char *what = (seminfo ? "string" : "comment"); + const char *msg = luaO_pushfstring(ls->L, + "unfinished long %s (starting at line %d)", what, line); + lexerror(ls, msg, TK_EOS); + break; /* to avoid warnings */ + } + case ']': { + if (skip_sep(ls) == sep) { + save_and_next(ls); /* skip 2nd ']' */ + goto endloop; + } + break; + } + case '\n': case '\r': { + save(ls, '\n'); + inclinenumber(ls); + if (!seminfo) luaZ_resetbuffer(ls->buff); /* avoid wasting space */ + break; + } + default: { + if (seminfo) save_and_next(ls); + else next(ls); + } + } + } endloop: + if (seminfo) + seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + sep, + luaZ_bufflen(ls->buff) - 2 * sep); +} + + +static void esccheck (LexState *ls, int c, const char *msg) { + if (!c) { + if (ls->current != EOZ) + save_and_next(ls); /* add current to buffer for error message */ + lexerror(ls, msg, TK_STRING); + } +} + + +static int gethexa (LexState *ls) { + save_and_next(ls); + esccheck (ls, lisxdigit(ls->current), "hexadecimal digit expected"); + return luaO_hexavalue(ls->current); +} + + +static int readhexaesc (LexState *ls) { + int r = gethexa(ls); + r = (r << 4) + gethexa(ls); + luaZ_buffremove(ls->buff, 2); /* remove saved chars from buffer */ + return r; +} + + +static unsigned long readutf8esc (LexState *ls) { + unsigned long r; + int i = 4; /* chars to be removed: '\', 'u', '{', and first digit */ + save_and_next(ls); /* skip 'u' */ + esccheck(ls, ls->current == '{', "missing '{'"); + r = gethexa(ls); /* must have at least one digit */ + while (cast_void(save_and_next(ls)), lisxdigit(ls->current)) { + i++; + esccheck(ls, r <= (0x7FFFFFFFu >> 4), "UTF-8 value too large"); + r = (r << 4) + luaO_hexavalue(ls->current); + } + esccheck(ls, ls->current == '}', "missing '}'"); + next(ls); /* skip '}' */ + luaZ_buffremove(ls->buff, i); /* remove saved chars from buffer */ + return r; +} + + +static void utf8esc (LexState *ls) { + char buff[UTF8BUFFSZ]; + int n = luaO_utf8esc(buff, readutf8esc(ls)); + for (; n > 0; n--) /* add 'buff' to string */ + save(ls, buff[UTF8BUFFSZ - n]); +} + + +static int readdecesc (LexState *ls) { + int i; + int r = 0; /* result accumulator */ + for (i = 0; i < 3 && lisdigit(ls->current); i++) { /* read up to 3 digits */ + r = 10*r + ls->current - '0'; + save_and_next(ls); + } + esccheck(ls, r <= UCHAR_MAX, "decimal escape too large"); + luaZ_buffremove(ls->buff, i); /* remove read digits from buffer */ + return r; +} + + +static void read_string (LexState *ls, int del, SemInfo *seminfo) { + save_and_next(ls); /* keep delimiter (for error messages) */ + while (ls->current != del) { + switch (ls->current) { + case EOZ: + lexerror(ls, "unfinished string", TK_EOS); + break; /* to avoid warnings */ + case '\n': + case '\r': + lexerror(ls, "unfinished string", TK_STRING); + break; /* to avoid warnings */ + case '\\': { /* escape sequences */ + int c; /* final character to be saved */ + save_and_next(ls); /* keep '\\' for error messages */ + switch (ls->current) { + case 'a': c = '\a'; goto read_save; + case 'b': c = '\b'; goto read_save; + case 'f': c = '\f'; goto read_save; + case 'n': c = '\n'; goto read_save; + case 'r': c = '\r'; goto read_save; + case 't': c = '\t'; goto read_save; + case 'v': c = '\v'; goto read_save; + case 'x': c = readhexaesc(ls); goto read_save; + case 'u': utf8esc(ls); goto no_save; + case '\n': case '\r': + inclinenumber(ls); c = '\n'; goto only_save; + case '\\': case '\"': case '\'': + c = ls->current; goto read_save; + case EOZ: goto no_save; /* will raise an error next loop */ + case 'z': { /* zap following span of spaces */ + luaZ_buffremove(ls->buff, 1); /* remove '\\' */ + next(ls); /* skip the 'z' */ + while (lisspace(ls->current)) { + if (currIsNewline(ls)) inclinenumber(ls); + else next(ls); + } + goto no_save; + } + default: { + esccheck(ls, lisdigit(ls->current), "invalid escape sequence"); + c = readdecesc(ls); /* digital escape '\ddd' */ + goto only_save; + } + } + read_save: + next(ls); + /* go through */ + only_save: + luaZ_buffremove(ls->buff, 1); /* remove '\\' */ + save(ls, c); + /* go through */ + no_save: break; + } + default: + save_and_next(ls); + } + } + save_and_next(ls); /* skip delimiter */ + seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1, + luaZ_bufflen(ls->buff) - 2); +} + + +static int llex (LexState *ls, SemInfo *seminfo) { + luaZ_resetbuffer(ls->buff); + for (;;) { + switch (ls->current) { + case '\n': case '\r': { /* line breaks */ + inclinenumber(ls); + break; + } + case ' ': case '\f': case '\t': case '\v': { /* spaces */ + next(ls); + break; + } + case '-': { /* '-' or '--' (comment) */ + next(ls); + if (ls->current != '-') return '-'; + /* else is a comment */ + next(ls); + if (ls->current == '[') { /* long comment? */ + size_t sep = skip_sep(ls); + luaZ_resetbuffer(ls->buff); /* 'skip_sep' may dirty the buffer */ + if (sep >= 2) { + read_long_string(ls, NULL, sep); /* skip long comment */ + luaZ_resetbuffer(ls->buff); /* previous call may dirty the buff. */ + break; + } + } + /* else short comment */ + while (!currIsNewline(ls) && ls->current != EOZ) + next(ls); /* skip until end of line (or end of file) */ + break; + } + case '[': { /* long string or simply '[' */ + size_t sep = skip_sep(ls); + if (sep >= 2) { + read_long_string(ls, seminfo, sep); + return TK_STRING; + } + else if (sep == 0) /* '[=...' missing second bracket? */ + lexerror(ls, "invalid long string delimiter", TK_STRING); + return '['; + } + case '=': { + next(ls); + if (check_next1(ls, '=')) return TK_EQ; /* '==' */ + else return '='; + } + case '<': { + next(ls); + if (check_next1(ls, '=')) return TK_LE; /* '<=' */ + else if (check_next1(ls, '<')) return TK_SHL; /* '<<' */ + else return '<'; + } + case '>': { + next(ls); + if (check_next1(ls, '=')) return TK_GE; /* '>=' */ + else if (check_next1(ls, '>')) return TK_SHR; /* '>>' */ + else return '>'; + } + case '/': { + next(ls); + if (check_next1(ls, '/')) return TK_IDIV; /* '//' */ + else return '/'; + } + case '~': { + next(ls); + if (check_next1(ls, '=')) return TK_NE; /* '~=' */ + else return '~'; + } + case ':': { + next(ls); + if (check_next1(ls, ':')) return TK_DBCOLON; /* '::' */ + else return ':'; + } + case '"': case '\'': { /* short literal strings */ + read_string(ls, ls->current, seminfo); + return TK_STRING; + } + case '.': { /* '.', '..', '...', or number */ + save_and_next(ls); + if (check_next1(ls, '.')) { + if (check_next1(ls, '.')) + return TK_DOTS; /* '...' */ + else return TK_CONCAT; /* '..' */ + } + else if (!lisdigit(ls->current)) return '.'; + else return read_numeral(ls, seminfo); + } + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': { + return read_numeral(ls, seminfo); + } + case EOZ: { + return TK_EOS; + } + default: { + if (lislalpha(ls->current)) { /* identifier or reserved word? */ + TString *ts; + do { + save_and_next(ls); + } while (lislalnum(ls->current)); + ts = luaX_newstring(ls, luaZ_buffer(ls->buff), + luaZ_bufflen(ls->buff)); + seminfo->ts = ts; + if (isreserved(ts)) /* reserved word? */ + return ts->extra - 1 + FIRST_RESERVED; + else { + return TK_NAME; + } + } + else { /* single-char tokens ('+', '*', '%', '{', '}', ...) */ + int c = ls->current; + next(ls); + return c; + } + } + } + } +} + + +void luaX_next (LexState *ls) { + ls->lastline = ls->linenumber; + if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */ + ls->t = ls->lookahead; /* use this one */ + ls->lookahead.token = TK_EOS; /* and discharge it */ + } + else + ls->t.token = llex(ls, &ls->t.seminfo); /* read next token */ +} + + +int luaX_lookahead (LexState *ls) { + lua_assert(ls->lookahead.token == TK_EOS); + ls->lookahead.token = llex(ls, &ls->lookahead.seminfo); + return ls->lookahead.token; +} + diff --git a/src/llex.h b/src/llex.h new file mode 100644 index 0000000..389d2f8 --- /dev/null +++ b/src/llex.h @@ -0,0 +1,91 @@ +/* +** $Id: llex.h $ +** Lexical Analyzer +** See Copyright Notice in lua.h +*/ + +#ifndef llex_h +#define llex_h + +#include + +#include "lobject.h" +#include "lzio.h" + + +/* +** Single-char tokens (terminal symbols) are represented by their own +** numeric code. Other tokens start at the following value. +*/ +#define FIRST_RESERVED (UCHAR_MAX + 1) + + +#if !defined(LUA_ENV) +#define LUA_ENV "_ENV" +#endif + + +/* +* WARNING: if you change the order of this enumeration, +* grep "ORDER RESERVED" +*/ +enum RESERVED { + /* terminal symbols denoted by reserved words */ + TK_AND = FIRST_RESERVED, TK_BREAK, + TK_DO, TK_ELSE, TK_ELSEIF, TK_END, TK_FALSE, TK_FOR, TK_FUNCTION, + TK_GOTO, TK_IF, TK_IN, TK_LOCAL, TK_NIL, TK_NOT, TK_OR, TK_REPEAT, + TK_RETURN, TK_THEN, TK_TRUE, TK_UNTIL, TK_WHILE, + /* other terminal symbols */ + TK_IDIV, TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE, + TK_SHL, TK_SHR, + TK_DBCOLON, TK_EOS, + TK_FLT, TK_INT, TK_NAME, TK_STRING +}; + +/* number of reserved words */ +#define NUM_RESERVED (cast_int(TK_WHILE-FIRST_RESERVED + 1)) + + +typedef union { + lua_Number r; + lua_Integer i; + TString *ts; +} SemInfo; /* semantics information */ + + +typedef struct Token { + int token; + SemInfo seminfo; +} Token; + + +/* state of the lexer plus state of the parser when shared by all + functions */ +typedef struct LexState { + int current; /* current character (charint) */ + int linenumber; /* input line counter */ + int lastline; /* line of last token 'consumed' */ + Token t; /* current token */ + Token lookahead; /* look ahead token */ + struct FuncState *fs; /* current function (parser) */ + struct lua_State *L; + ZIO *z; /* input stream */ + Mbuffer *buff; /* buffer for tokens */ + Table *h; /* to avoid collection/reuse strings */ + struct Dyndata *dyd; /* dynamic structures used by the parser */ + TString *source; /* current source name */ + TString *envn; /* environment variable name */ +} LexState; + + +LUAI_FUNC void luaX_init (lua_State *L); +LUAI_FUNC void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, + TString *source, int firstchar); +LUAI_FUNC TString *luaX_newstring (LexState *ls, const char *str, size_t l); +LUAI_FUNC void luaX_next (LexState *ls); +LUAI_FUNC int luaX_lookahead (LexState *ls); +LUAI_FUNC l_noret luaX_syntaxerror (LexState *ls, const char *s); +LUAI_FUNC const char *luaX_token2str (LexState *ls, int token); + + +#endif diff --git a/src/llimits.h b/src/llimits.h new file mode 100644 index 0000000..1c826f7 --- /dev/null +++ b/src/llimits.h @@ -0,0 +1,380 @@ +/* +** $Id: llimits.h $ +** Limits, basic types, and some other 'installation-dependent' definitions +** See Copyright Notice in lua.h +*/ + +#ifndef llimits_h +#define llimits_h + + +#include +#include + + +#include "lua.h" + + +/* +** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count +** the total memory used by Lua (in bytes). Usually, 'size_t' and +** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines. +*/ +#if defined(LUAI_MEM) /* { external definitions? */ +typedef LUAI_UMEM lu_mem; +typedef LUAI_MEM l_mem; +#elif LUAI_IS32INT /* }{ */ +typedef size_t lu_mem; +typedef ptrdiff_t l_mem; +#else /* 16-bit ints */ /* }{ */ +typedef unsigned long lu_mem; +typedef long l_mem; +#endif /* } */ + + +/* chars used as small naturals (so that 'char' is reserved for characters) */ +typedef unsigned char lu_byte; +typedef signed char ls_byte; + + +/* maximum value for size_t */ +#define MAX_SIZET ((size_t)(~(size_t)0)) + +/* maximum size visible for Lua (must be representable in a lua_Integer) */ +#define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ + : (size_t)(LUA_MAXINTEGER)) + + +#define MAX_LUMEM ((lu_mem)(~(lu_mem)0)) + +#define MAX_LMEM ((l_mem)(MAX_LUMEM >> 1)) + + +#define MAX_INT INT_MAX /* maximum value of an int */ + + +/* +** floor of the log2 of the maximum signed value for integral type 't'. +** (That is, maximum 'n' such that '2^n' fits in the given signed type.) +*/ +#define log2maxs(t) (sizeof(t) * 8 - 2) + + +/* +** test whether an unsigned value is a power of 2 (or zero) +*/ +#define ispow2(x) (((x) & ((x) - 1)) == 0) + + +/* number of chars of a literal string without the ending \0 */ +#define LL(x) (sizeof(x)/sizeof(char) - 1) + + +/* +** conversion of pointer to unsigned integer: this is for hashing only; +** there is no problem if the integer cannot hold the whole pointer +** value. (In strict ISO C this may cause undefined behavior, but no +** actual machine seems to bother.) +*/ +#if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \ + __STDC_VERSION__ >= 199901L +#include +#if defined(UINTPTR_MAX) /* even in C99 this type is optional */ +#define L_P2I uintptr_t +#else /* no 'intptr'? */ +#define L_P2I uintmax_t /* use the largest available integer */ +#endif +#else /* C89 option */ +#define L_P2I size_t +#endif + +#define point2uint(p) ((unsigned int)((L_P2I)(p) & UINT_MAX)) + + + +/* types of 'usual argument conversions' for lua_Number and lua_Integer */ +typedef LUAI_UACNUMBER l_uacNumber; +typedef LUAI_UACINT l_uacInt; + + +/* +** Internal assertions for in-house debugging +*/ +#if defined LUAI_ASSERT +#undef NDEBUG +#include +#define lua_assert(c) assert(c) +#endif + +#if defined(lua_assert) +#define check_exp(c,e) (lua_assert(c), (e)) +/* to avoid problems with conditions too long */ +#define lua_longassert(c) ((c) ? (void)0 : lua_assert(0)) +#else +#define lua_assert(c) ((void)0) +#define check_exp(c,e) (e) +#define lua_longassert(c) ((void)0) +#endif + +/* +** assertion for checking API calls +*/ +#if !defined(luai_apicheck) +#define luai_apicheck(l,e) ((void)l, lua_assert(e)) +#endif + +#define api_check(l,e,msg) luai_apicheck(l,(e) && msg) + + +/* macro to avoid warnings about unused variables */ +#if !defined(UNUSED) +#define UNUSED(x) ((void)(x)) +#endif + + +/* type casts (a macro highlights casts in the code) */ +#define cast(t, exp) ((t)(exp)) + +#define cast_void(i) cast(void, (i)) +#define cast_voidp(i) cast(void *, (i)) +#define cast_num(i) cast(lua_Number, (i)) +#define cast_int(i) cast(int, (i)) +#define cast_uint(i) cast(unsigned int, (i)) +#define cast_byte(i) cast(lu_byte, (i)) +#define cast_uchar(i) cast(unsigned char, (i)) +#define cast_char(i) cast(char, (i)) +#define cast_charp(i) cast(char *, (i)) +#define cast_sizet(i) cast(size_t, (i)) + + +/* cast a signed lua_Integer to lua_Unsigned */ +#if !defined(l_castS2U) +#define l_castS2U(i) ((lua_Unsigned)(i)) +#endif + +/* +** cast a lua_Unsigned to a signed lua_Integer; this cast is +** not strict ISO C, but two-complement architectures should +** work fine. +*/ +#if !defined(l_castU2S) +#define l_castU2S(i) ((lua_Integer)(i)) +#endif + + +/* +** non-return type +*/ +#if !defined(l_noret) + +#if defined(__GNUC__) +#define l_noret void __attribute__((noreturn)) +#elif defined(_MSC_VER) && _MSC_VER >= 1200 +#define l_noret void __declspec(noreturn) +#else +#define l_noret void +#endif + +#endif + + +/* +** Inline functions +*/ +#if !defined(LUA_USE_C89) +#define l_inline inline +#elif defined(__GNUC__) +#define l_inline __inline__ +#else +#define l_inline /* empty */ +#endif + +#define l_sinline static l_inline + + +/* +** type for virtual-machine instructions; +** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) +*/ +#if LUAI_IS32INT +typedef unsigned int l_uint32; +#else +typedef unsigned long l_uint32; +#endif + +typedef l_uint32 Instruction; + + + +/* +** Maximum length for short strings, that is, strings that are +** internalized. (Cannot be smaller than reserved words or tags for +** metamethods, as these strings must be internalized; +** #("function") = 8, #("__newindex") = 10.) +*/ +#if !defined(LUAI_MAXSHORTLEN) +#define LUAI_MAXSHORTLEN 40 +#endif + + +/* +** Initial size for the string table (must be power of 2). +** The Lua core alone registers ~50 strings (reserved words + +** metaevent keys + a few others). Libraries would typically add +** a few dozens more. +*/ +#if !defined(MINSTRTABSIZE) +#define MINSTRTABSIZE 128 +#endif + + +/* +** Size of cache for strings in the API. 'N' is the number of +** sets (better be a prime) and "M" is the size of each set (M == 1 +** makes a direct cache.) +*/ +#if !defined(STRCACHE_N) +#define STRCACHE_N 53 +#define STRCACHE_M 2 +#endif + + +/* minimum size for string buffer */ +#if !defined(LUA_MINBUFFER) +#define LUA_MINBUFFER 32 +#endif + + +/* +** Maximum depth for nested C calls, syntactical nested non-terminals, +** and other features implemented through recursion in C. (Value must +** fit in a 16-bit unsigned integer. It must also be compatible with +** the size of the C stack.) +*/ +#if !defined(LUAI_MAXCCALLS) +#define LUAI_MAXCCALLS 200 +#endif + + +/* +** macros that are executed whenever program enters the Lua core +** ('lua_lock') and leaves the core ('lua_unlock') +*/ +#if !defined(lua_lock) +#define lua_lock(L) ((void) 0) +#define lua_unlock(L) ((void) 0) +#endif + +/* +** macro executed during Lua functions at points where the +** function can yield. +*/ +#if !defined(luai_threadyield) +#define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} +#endif + + +/* +** these macros allow user-specific actions when a thread is +** created/deleted/resumed/yielded. +*/ +#if !defined(luai_userstateopen) +#define luai_userstateopen(L) ((void)L) +#endif + +#if !defined(luai_userstateclose) +#define luai_userstateclose(L) ((void)L) +#endif + +#if !defined(luai_userstatethread) +#define luai_userstatethread(L,L1) ((void)L) +#endif + +#if !defined(luai_userstatefree) +#define luai_userstatefree(L,L1) ((void)L) +#endif + +#if !defined(luai_userstateresume) +#define luai_userstateresume(L,n) ((void)L) +#endif + +#if !defined(luai_userstateyield) +#define luai_userstateyield(L,n) ((void)L) +#endif + + + +/* +** The luai_num* macros define the primitive operations over numbers. +*/ + +/* floor division (defined as 'floor(a/b)') */ +#if !defined(luai_numidiv) +#define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) +#endif + +/* float division */ +#if !defined(luai_numdiv) +#define luai_numdiv(L,a,b) ((a)/(b)) +#endif + +/* +** modulo: defined as 'a - floor(a/b)*b'; the direct computation +** using this definition has several problems with rounding errors, +** so it is better to use 'fmod'. 'fmod' gives the result of +** 'a - trunc(a/b)*b', and therefore must be corrected when +** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a +** non-integer negative result: non-integer result is equivalent to +** a non-zero remainder 'm'; negative result is equivalent to 'a' and +** 'b' with different signs, or 'm' and 'b' with different signs +** (as the result 'm' of 'fmod' has the same sign of 'a'). +*/ +#if !defined(luai_nummod) +#define luai_nummod(L,a,b,m) \ + { (void)L; (m) = l_mathop(fmod)(a,b); \ + if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); } +#endif + +/* exponentiation */ +#if !defined(luai_numpow) +#define luai_numpow(L,a,b) \ + ((void)L, (b == 2) ? (a)*(a) : l_mathop(pow)(a,b)) +#endif + +/* the others are quite standard operations */ +#if !defined(luai_numadd) +#define luai_numadd(L,a,b) ((a)+(b)) +#define luai_numsub(L,a,b) ((a)-(b)) +#define luai_nummul(L,a,b) ((a)*(b)) +#define luai_numunm(L,a) (-(a)) +#define luai_numeq(a,b) ((a)==(b)) +#define luai_numlt(a,b) ((a)<(b)) +#define luai_numle(a,b) ((a)<=(b)) +#define luai_numgt(a,b) ((a)>(b)) +#define luai_numge(a,b) ((a)>=(b)) +#define luai_numisnan(a) (!luai_numeq((a), (a))) +#endif + + + + + +/* +** macro to control inclusion of some hard tests on stack reallocation +*/ +#if !defined(HARDSTACKTESTS) +#define condmovestack(L,pre,pos) ((void)0) +#else +/* realloc stack keeping its size */ +#define condmovestack(L,pre,pos) \ + { int sz_ = stacksize(L); pre; luaD_reallocstack((L), sz_, 0); pos; } +#endif + +#if !defined(HARDMEMTESTS) +#define condchangemem(L,pre,pos) ((void)0) +#else +#define condchangemem(L,pre,pos) \ + { if (gcrunning(G(L))) { pre; luaC_fullgc(L, 0); pos; } } +#endif + +#endif diff --git a/src/lmathlib.c b/src/lmathlib.c new file mode 100644 index 0000000..d0b1e1e --- /dev/null +++ b/src/lmathlib.c @@ -0,0 +1,764 @@ +/* +** $Id: lmathlib.c $ +** Standard mathematical library +** See Copyright Notice in lua.h +*/ + +#define lmathlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#undef PI +#define PI (l_mathop(3.141592653589793238462643383279502884)) + + +static int math_abs (lua_State *L) { + if (lua_isinteger(L, 1)) { + lua_Integer n = lua_tointeger(L, 1); + if (n < 0) n = (lua_Integer)(0u - (lua_Unsigned)n); + lua_pushinteger(L, n); + } + else + lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_sin (lua_State *L) { + lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_cos (lua_State *L) { + lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_tan (lua_State *L) { + lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_asin (lua_State *L) { + lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_acos (lua_State *L) { + lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_atan (lua_State *L) { + lua_Number y = luaL_checknumber(L, 1); + lua_Number x = luaL_optnumber(L, 2, 1); + lua_pushnumber(L, l_mathop(atan2)(y, x)); + return 1; +} + + +static int math_toint (lua_State *L) { + int valid; + lua_Integer n = lua_tointegerx(L, 1, &valid); + if (l_likely(valid)) + lua_pushinteger(L, n); + else { + luaL_checkany(L, 1); + luaL_pushfail(L); /* value is not convertible to integer */ + } + return 1; +} + + +static void pushnumint (lua_State *L, lua_Number d) { + lua_Integer n; + if (lua_numbertointeger(d, &n)) /* does 'd' fit in an integer? */ + lua_pushinteger(L, n); /* result is integer */ + else + lua_pushnumber(L, d); /* result is float */ +} + + +static int math_floor (lua_State *L) { + if (lua_isinteger(L, 1)) + lua_settop(L, 1); /* integer is its own floor */ + else { + lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1)); + pushnumint(L, d); + } + return 1; +} + + +static int math_ceil (lua_State *L) { + if (lua_isinteger(L, 1)) + lua_settop(L, 1); /* integer is its own ceil */ + else { + lua_Number d = l_mathop(ceil)(luaL_checknumber(L, 1)); + pushnumint(L, d); + } + return 1; +} + + +static int math_fmod (lua_State *L) { + if (lua_isinteger(L, 1) && lua_isinteger(L, 2)) { + lua_Integer d = lua_tointeger(L, 2); + if ((lua_Unsigned)d + 1u <= 1u) { /* special cases: -1 or 0 */ + luaL_argcheck(L, d != 0, 2, "zero"); + lua_pushinteger(L, 0); /* avoid overflow with 0x80000... / -1 */ + } + else + lua_pushinteger(L, lua_tointeger(L, 1) % d); + } + else + lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1), + luaL_checknumber(L, 2))); + return 1; +} + + +/* +** next function does not use 'modf', avoiding problems with 'double*' +** (which is not compatible with 'float*') when lua_Number is not +** 'double'. +*/ +static int math_modf (lua_State *L) { + if (lua_isinteger(L ,1)) { + lua_settop(L, 1); /* number is its own integer part */ + lua_pushnumber(L, 0); /* no fractional part */ + } + else { + lua_Number n = luaL_checknumber(L, 1); + /* integer part (rounds toward zero) */ + lua_Number ip = (n < 0) ? l_mathop(ceil)(n) : l_mathop(floor)(n); + pushnumint(L, ip); + /* fractional part (test needed for inf/-inf) */ + lua_pushnumber(L, (n == ip) ? l_mathop(0.0) : (n - ip)); + } + return 2; +} + + +static int math_sqrt (lua_State *L) { + lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1))); + return 1; +} + + +static int math_ult (lua_State *L) { + lua_Integer a = luaL_checkinteger(L, 1); + lua_Integer b = luaL_checkinteger(L, 2); + lua_pushboolean(L, (lua_Unsigned)a < (lua_Unsigned)b); + return 1; +} + +static int math_log (lua_State *L) { + lua_Number x = luaL_checknumber(L, 1); + lua_Number res; + if (lua_isnoneornil(L, 2)) + res = l_mathop(log)(x); + else { + lua_Number base = luaL_checknumber(L, 2); +#if !defined(LUA_USE_C89) + if (base == l_mathop(2.0)) + res = l_mathop(log2)(x); + else +#endif + if (base == l_mathop(10.0)) + res = l_mathop(log10)(x); + else + res = l_mathop(log)(x)/l_mathop(log)(base); + } + lua_pushnumber(L, res); + return 1; +} + +static int math_exp (lua_State *L) { + lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_deg (lua_State *L) { + lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI)); + return 1; +} + +static int math_rad (lua_State *L) { + lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0))); + return 1; +} + + +static int math_min (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int imin = 1; /* index of current minimum value */ + int i; + luaL_argcheck(L, n >= 1, 1, "value expected"); + for (i = 2; i <= n; i++) { + if (lua_compare(L, i, imin, LUA_OPLT)) + imin = i; + } + lua_pushvalue(L, imin); + return 1; +} + + +static int math_max (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int imax = 1; /* index of current maximum value */ + int i; + luaL_argcheck(L, n >= 1, 1, "value expected"); + for (i = 2; i <= n; i++) { + if (lua_compare(L, imax, i, LUA_OPLT)) + imax = i; + } + lua_pushvalue(L, imax); + return 1; +} + + +static int math_type (lua_State *L) { + if (lua_type(L, 1) == LUA_TNUMBER) + lua_pushstring(L, (lua_isinteger(L, 1)) ? "integer" : "float"); + else { + luaL_checkany(L, 1); + luaL_pushfail(L); + } + return 1; +} + + + +/* +** {================================================================== +** Pseudo-Random Number Generator based on 'xoshiro256**'. +** =================================================================== +*/ + +/* number of binary digits in the mantissa of a float */ +#define FIGS l_floatatt(MANT_DIG) + +#if FIGS > 64 +/* there are only 64 random bits; use them all */ +#undef FIGS +#define FIGS 64 +#endif + + +/* +** LUA_RAND32 forces the use of 32-bit integers in the implementation +** of the PRN generator (mainly for testing). +*/ +#if !defined(LUA_RAND32) && !defined(Rand64) + +/* try to find an integer type with at least 64 bits */ + +#if ((ULONG_MAX >> 31) >> 31) >= 3 + +/* 'long' has at least 64 bits */ +#define Rand64 unsigned long + +#elif !defined(LUA_USE_C89) && defined(LLONG_MAX) + +/* there is a 'long long' type (which must have at least 64 bits) */ +#define Rand64 unsigned long long + +#elif ((LUA_MAXUNSIGNED >> 31) >> 31) >= 3 + +/* 'lua_Unsigned' has at least 64 bits */ +#define Rand64 lua_Unsigned + +#endif + +#endif + + +#if defined(Rand64) /* { */ + +/* +** Standard implementation, using 64-bit integers. +** If 'Rand64' has more than 64 bits, the extra bits do not interfere +** with the 64 initial bits, except in a right shift. Moreover, the +** final result has to discard the extra bits. +*/ + +/* avoid using extra bits when needed */ +#define trim64(x) ((x) & 0xffffffffffffffffu) + + +/* rotate left 'x' by 'n' bits */ +static Rand64 rotl (Rand64 x, int n) { + return (x << n) | (trim64(x) >> (64 - n)); +} + +static Rand64 nextrand (Rand64 *state) { + Rand64 state0 = state[0]; + Rand64 state1 = state[1]; + Rand64 state2 = state[2] ^ state0; + Rand64 state3 = state[3] ^ state1; + Rand64 res = rotl(state1 * 5, 7) * 9; + state[0] = state0 ^ state3; + state[1] = state1 ^ state2; + state[2] = state2 ^ (state1 << 17); + state[3] = rotl(state3, 45); + return res; +} + + +/* must take care to not shift stuff by more than 63 slots */ + + +/* +** Convert bits from a random integer into a float in the +** interval [0,1), getting the higher FIG bits from the +** random unsigned integer and converting that to a float. +*/ + +/* must throw out the extra (64 - FIGS) bits */ +#define shift64_FIG (64 - FIGS) + +/* to scale to [0, 1), multiply by scaleFIG = 2^(-FIGS) */ +#define scaleFIG (l_mathop(0.5) / ((Rand64)1 << (FIGS - 1))) + +static lua_Number I2d (Rand64 x) { + return (lua_Number)(trim64(x) >> shift64_FIG) * scaleFIG; +} + +/* convert a 'Rand64' to a 'lua_Unsigned' */ +#define I2UInt(x) ((lua_Unsigned)trim64(x)) + +/* convert a 'lua_Unsigned' to a 'Rand64' */ +#define Int2I(x) ((Rand64)(x)) + + +#else /* no 'Rand64' }{ */ + +/* get an integer with at least 32 bits */ +#if LUAI_IS32INT +typedef unsigned int lu_int32; +#else +typedef unsigned long lu_int32; +#endif + + +/* +** Use two 32-bit integers to represent a 64-bit quantity. +*/ +typedef struct Rand64 { + lu_int32 h; /* higher half */ + lu_int32 l; /* lower half */ +} Rand64; + + +/* +** If 'lu_int32' has more than 32 bits, the extra bits do not interfere +** with the 32 initial bits, except in a right shift and comparisons. +** Moreover, the final result has to discard the extra bits. +*/ + +/* avoid using extra bits when needed */ +#define trim32(x) ((x) & 0xffffffffu) + + +/* +** basic operations on 'Rand64' values +*/ + +/* build a new Rand64 value */ +static Rand64 packI (lu_int32 h, lu_int32 l) { + Rand64 result; + result.h = h; + result.l = l; + return result; +} + +/* return i << n */ +static Rand64 Ishl (Rand64 i, int n) { + lua_assert(n > 0 && n < 32); + return packI((i.h << n) | (trim32(i.l) >> (32 - n)), i.l << n); +} + +/* i1 ^= i2 */ +static void Ixor (Rand64 *i1, Rand64 i2) { + i1->h ^= i2.h; + i1->l ^= i2.l; +} + +/* return i1 + i2 */ +static Rand64 Iadd (Rand64 i1, Rand64 i2) { + Rand64 result = packI(i1.h + i2.h, i1.l + i2.l); + if (trim32(result.l) < trim32(i1.l)) /* carry? */ + result.h++; + return result; +} + +/* return i * 5 */ +static Rand64 times5 (Rand64 i) { + return Iadd(Ishl(i, 2), i); /* i * 5 == (i << 2) + i */ +} + +/* return i * 9 */ +static Rand64 times9 (Rand64 i) { + return Iadd(Ishl(i, 3), i); /* i * 9 == (i << 3) + i */ +} + +/* return 'i' rotated left 'n' bits */ +static Rand64 rotl (Rand64 i, int n) { + lua_assert(n > 0 && n < 32); + return packI((i.h << n) | (trim32(i.l) >> (32 - n)), + (trim32(i.h) >> (32 - n)) | (i.l << n)); +} + +/* for offsets larger than 32, rotate right by 64 - offset */ +static Rand64 rotl1 (Rand64 i, int n) { + lua_assert(n > 32 && n < 64); + n = 64 - n; + return packI((trim32(i.h) >> n) | (i.l << (32 - n)), + (i.h << (32 - n)) | (trim32(i.l) >> n)); +} + +/* +** implementation of 'xoshiro256**' algorithm on 'Rand64' values +*/ +static Rand64 nextrand (Rand64 *state) { + Rand64 res = times9(rotl(times5(state[1]), 7)); + Rand64 t = Ishl(state[1], 17); + Ixor(&state[2], state[0]); + Ixor(&state[3], state[1]); + Ixor(&state[1], state[2]); + Ixor(&state[0], state[3]); + Ixor(&state[2], t); + state[3] = rotl1(state[3], 45); + return res; +} + + +/* +** Converts a 'Rand64' into a float. +*/ + +/* an unsigned 1 with proper type */ +#define UONE ((lu_int32)1) + + +#if FIGS <= 32 + +/* 2^(-FIGS) */ +#define scaleFIG (l_mathop(0.5) / (UONE << (FIGS - 1))) + +/* +** get up to 32 bits from higher half, shifting right to +** throw out the extra bits. +*/ +static lua_Number I2d (Rand64 x) { + lua_Number h = (lua_Number)(trim32(x.h) >> (32 - FIGS)); + return h * scaleFIG; +} + +#else /* 32 < FIGS <= 64 */ + +/* must take care to not shift stuff by more than 31 slots */ + +/* 2^(-FIGS) = 1.0 / 2^30 / 2^3 / 2^(FIGS-33) */ +#define scaleFIG \ + (l_mathop(1.0) / (UONE << 30) / l_mathop(8.0) / (UONE << (FIGS - 33))) + +/* +** use FIGS - 32 bits from lower half, throwing out the other +** (32 - (FIGS - 32)) = (64 - FIGS) bits +*/ +#define shiftLOW (64 - FIGS) + +/* +** higher 32 bits go after those (FIGS - 32) bits: shiftHI = 2^(FIGS - 32) +*/ +#define shiftHI ((lua_Number)(UONE << (FIGS - 33)) * l_mathop(2.0)) + + +static lua_Number I2d (Rand64 x) { + lua_Number h = (lua_Number)trim32(x.h) * shiftHI; + lua_Number l = (lua_Number)(trim32(x.l) >> shiftLOW); + return (h + l) * scaleFIG; +} + +#endif + + +/* convert a 'Rand64' to a 'lua_Unsigned' */ +static lua_Unsigned I2UInt (Rand64 x) { + return (((lua_Unsigned)trim32(x.h) << 31) << 1) | (lua_Unsigned)trim32(x.l); +} + +/* convert a 'lua_Unsigned' to a 'Rand64' */ +static Rand64 Int2I (lua_Unsigned n) { + return packI((lu_int32)((n >> 31) >> 1), (lu_int32)n); +} + +#endif /* } */ + + +/* +** A state uses four 'Rand64' values. +*/ +typedef struct { + Rand64 s[4]; +} RanState; + + +/* +** Project the random integer 'ran' into the interval [0, n]. +** Because 'ran' has 2^B possible values, the projection can only be +** uniform when the size of the interval is a power of 2 (exact +** division). Otherwise, to get a uniform projection into [0, n], we +** first compute 'lim', the smallest Mersenne number not smaller than +** 'n'. We then project 'ran' into the interval [0, lim]. If the result +** is inside [0, n], we are done. Otherwise, we try with another 'ran', +** until we have a result inside the interval. +*/ +static lua_Unsigned project (lua_Unsigned ran, lua_Unsigned n, + RanState *state) { + if ((n & (n + 1)) == 0) /* is 'n + 1' a power of 2? */ + return ran & n; /* no bias */ + else { + lua_Unsigned lim = n; + /* compute the smallest (2^b - 1) not smaller than 'n' */ + lim |= (lim >> 1); + lim |= (lim >> 2); + lim |= (lim >> 4); + lim |= (lim >> 8); + lim |= (lim >> 16); +#if (LUA_MAXUNSIGNED >> 31) >= 3 + lim |= (lim >> 32); /* integer type has more than 32 bits */ +#endif + lua_assert((lim & (lim + 1)) == 0 /* 'lim + 1' is a power of 2, */ + && lim >= n /* not smaller than 'n', */ + && (lim >> 1) < n); /* and it is the smallest one */ + while ((ran &= lim) > n) /* project 'ran' into [0..lim] */ + ran = I2UInt(nextrand(state->s)); /* not inside [0..n]? try again */ + return ran; + } +} + + +static int math_random (lua_State *L) { + lua_Integer low, up; + lua_Unsigned p; + RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1)); + Rand64 rv = nextrand(state->s); /* next pseudo-random value */ + switch (lua_gettop(L)) { /* check number of arguments */ + case 0: { /* no arguments */ + lua_pushnumber(L, I2d(rv)); /* float between 0 and 1 */ + return 1; + } + case 1: { /* only upper limit */ + low = 1; + up = luaL_checkinteger(L, 1); + if (up == 0) { /* single 0 as argument? */ + lua_pushinteger(L, I2UInt(rv)); /* full random integer */ + return 1; + } + break; + } + case 2: { /* lower and upper limits */ + low = luaL_checkinteger(L, 1); + up = luaL_checkinteger(L, 2); + break; + } + default: return luaL_error(L, "wrong number of arguments"); + } + /* random integer in the interval [low, up] */ + luaL_argcheck(L, low <= up, 1, "interval is empty"); + /* project random integer into the interval [0, up - low] */ + p = project(I2UInt(rv), (lua_Unsigned)up - (lua_Unsigned)low, state); + lua_pushinteger(L, p + (lua_Unsigned)low); + return 1; +} + + +static void setseed (lua_State *L, Rand64 *state, + lua_Unsigned n1, lua_Unsigned n2) { + int i; + state[0] = Int2I(n1); + state[1] = Int2I(0xff); /* avoid a zero state */ + state[2] = Int2I(n2); + state[3] = Int2I(0); + for (i = 0; i < 16; i++) + nextrand(state); /* discard initial values to "spread" seed */ + lua_pushinteger(L, n1); + lua_pushinteger(L, n2); +} + + +/* +** Set a "random" seed. To get some randomness, use the current time +** and the address of 'L' (in case the machine does address space layout +** randomization). +*/ +static void randseed (lua_State *L, RanState *state) { + lua_Unsigned seed1 = (lua_Unsigned)time(NULL); + lua_Unsigned seed2 = (lua_Unsigned)(size_t)L; + setseed(L, state->s, seed1, seed2); +} + + +static int math_randomseed (lua_State *L) { + RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1)); + if (lua_isnone(L, 1)) { + randseed(L, state); + } + else { + lua_Integer n1 = luaL_checkinteger(L, 1); + lua_Integer n2 = luaL_optinteger(L, 2, 0); + setseed(L, state->s, n1, n2); + } + return 2; /* return seeds */ +} + + +static const luaL_Reg randfuncs[] = { + {"random", math_random}, + {"randomseed", math_randomseed}, + {NULL, NULL} +}; + + +/* +** Register the random functions and initialize their state. +*/ +static void setrandfunc (lua_State *L) { + RanState *state = (RanState *)lua_newuserdatauv(L, sizeof(RanState), 0); + randseed(L, state); /* initialize with a "random" seed */ + lua_pop(L, 2); /* remove pushed seeds */ + luaL_setfuncs(L, randfuncs, 1); +} + +/* }================================================================== */ + + +/* +** {================================================================== +** Deprecated functions (for compatibility only) +** =================================================================== +*/ +#if defined(LUA_COMPAT_MATHLIB) + +static int math_cosh (lua_State *L) { + lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_sinh (lua_State *L) { + lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_tanh (lua_State *L) { + lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_pow (lua_State *L) { + lua_Number x = luaL_checknumber(L, 1); + lua_Number y = luaL_checknumber(L, 2); + lua_pushnumber(L, l_mathop(pow)(x, y)); + return 1; +} + +static int math_frexp (lua_State *L) { + int e; + lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e)); + lua_pushinteger(L, e); + return 2; +} + +static int math_ldexp (lua_State *L) { + lua_Number x = luaL_checknumber(L, 1); + int ep = (int)luaL_checkinteger(L, 2); + lua_pushnumber(L, l_mathop(ldexp)(x, ep)); + return 1; +} + +static int math_log10 (lua_State *L) { + lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1))); + return 1; +} + +#endif +/* }================================================================== */ + + + +static const luaL_Reg mathlib[] = { + {"abs", math_abs}, + {"acos", math_acos}, + {"asin", math_asin}, + {"atan", math_atan}, + {"ceil", math_ceil}, + {"cos", math_cos}, + {"deg", math_deg}, + {"exp", math_exp}, + {"tointeger", math_toint}, + {"floor", math_floor}, + {"fmod", math_fmod}, + {"ult", math_ult}, + {"log", math_log}, + {"max", math_max}, + {"min", math_min}, + {"modf", math_modf}, + {"rad", math_rad}, + {"sin", math_sin}, + {"sqrt", math_sqrt}, + {"tan", math_tan}, + {"type", math_type}, +#if defined(LUA_COMPAT_MATHLIB) + {"atan2", math_atan}, + {"cosh", math_cosh}, + {"sinh", math_sinh}, + {"tanh", math_tanh}, + {"pow", math_pow}, + {"frexp", math_frexp}, + {"ldexp", math_ldexp}, + {"log10", math_log10}, +#endif + /* placeholders */ + {"random", NULL}, + {"randomseed", NULL}, + {"pi", NULL}, + {"huge", NULL}, + {"maxinteger", NULL}, + {"mininteger", NULL}, + {NULL, NULL} +}; + + +/* +** Open math library +*/ +LUAMOD_API int luaopen_math (lua_State *L) { + luaL_newlib(L, mathlib); + lua_pushnumber(L, PI); + lua_setfield(L, -2, "pi"); + lua_pushnumber(L, (lua_Number)HUGE_VAL); + lua_setfield(L, -2, "huge"); + lua_pushinteger(L, LUA_MAXINTEGER); + lua_setfield(L, -2, "maxinteger"); + lua_pushinteger(L, LUA_MININTEGER); + lua_setfield(L, -2, "mininteger"); + setrandfunc(L); + return 1; +} + diff --git a/src/lmem.c b/src/lmem.c new file mode 100644 index 0000000..9800a86 --- /dev/null +++ b/src/lmem.c @@ -0,0 +1,215 @@ +/* +** $Id: lmem.c $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + +#define lmem_c +#define LUA_CORE + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" + + + +/* +** About the realloc function: +** void *frealloc (void *ud, void *ptr, size_t osize, size_t nsize); +** ('osize' is the old size, 'nsize' is the new size) +** +** - frealloc(ud, p, x, 0) frees the block 'p' and returns NULL. +** Particularly, frealloc(ud, NULL, 0, 0) does nothing, +** which is equivalent to free(NULL) in ISO C. +** +** - frealloc(ud, NULL, x, s) creates a new block of size 's' +** (no matter 'x'). Returns NULL if it cannot create the new block. +** +** - otherwise, frealloc(ud, b, x, y) reallocates the block 'b' from +** size 'x' to size 'y'. Returns NULL if it cannot reallocate the +** block to the new size. +*/ + + +/* +** Macro to call the allocation function. +*/ +#define callfrealloc(g,block,os,ns) ((*g->frealloc)(g->ud, block, os, ns)) + + +/* +** When an allocation fails, it will try again after an emergency +** collection, except when it cannot run a collection. The GC should +** not be called while the state is not fully built, as the collector +** is not yet fully initialized. Also, it should not be called when +** 'gcstopem' is true, because then the interpreter is in the middle of +** a collection step. +*/ +#define cantryagain(g) (completestate(g) && !g->gcstopem) + + + + +#if defined(EMERGENCYGCTESTS) +/* +** First allocation will fail except when freeing a block (frees never +** fail) and when it cannot try again; this fail will trigger 'tryagain' +** and a full GC cycle at every allocation. +*/ +static void *firsttry (global_State *g, void *block, size_t os, size_t ns) { + if (ns > 0 && cantryagain(g)) + return NULL; /* fail */ + else /* normal allocation */ + return callfrealloc(g, block, os, ns); +} +#else +#define firsttry(g,block,os,ns) callfrealloc(g, block, os, ns) +#endif + + + + + +/* +** {================================================================== +** Functions to allocate/deallocate arrays for the Parser +** =================================================================== +*/ + +/* +** Minimum size for arrays during parsing, to avoid overhead of +** reallocating to size 1, then 2, and then 4. All these arrays +** will be reallocated to exact sizes or erased when parsing ends. +*/ +#define MINSIZEARRAY 4 + + +void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize, + int size_elems, int limit, const char *what) { + void *newblock; + int size = *psize; + if (nelems + 1 <= size) /* does one extra element still fit? */ + return block; /* nothing to be done */ + if (size >= limit / 2) { /* cannot double it? */ + if (l_unlikely(size >= limit)) /* cannot grow even a little? */ + luaG_runerror(L, "too many %s (limit is %d)", what, limit); + size = limit; /* still have at least one free place */ + } + else { + size *= 2; + if (size < MINSIZEARRAY) + size = MINSIZEARRAY; /* minimum size */ + } + lua_assert(nelems + 1 <= size && size <= limit); + /* 'limit' ensures that multiplication will not overflow */ + newblock = luaM_saferealloc_(L, block, cast_sizet(*psize) * size_elems, + cast_sizet(size) * size_elems); + *psize = size; /* update only when everything else is OK */ + return newblock; +} + + +/* +** In prototypes, the size of the array is also its number of +** elements (to save memory). So, if it cannot shrink an array +** to its number of elements, the only option is to raise an +** error. +*/ +void *luaM_shrinkvector_ (lua_State *L, void *block, int *size, + int final_n, int size_elem) { + void *newblock; + size_t oldsize = cast_sizet((*size) * size_elem); + size_t newsize = cast_sizet(final_n * size_elem); + lua_assert(newsize <= oldsize); + newblock = luaM_saferealloc_(L, block, oldsize, newsize); + *size = final_n; + return newblock; +} + +/* }================================================================== */ + + +l_noret luaM_toobig (lua_State *L) { + luaG_runerror(L, "memory allocation error: block too big"); +} + + +/* +** Free memory +*/ +void luaM_free_ (lua_State *L, void *block, size_t osize) { + global_State *g = G(L); + lua_assert((osize == 0) == (block == NULL)); + callfrealloc(g, block, osize, 0); + g->GCdebt -= osize; +} + + +/* +** In case of allocation fail, this function will do an emergency +** collection to free some memory and then try the allocation again. +*/ +static void *tryagain (lua_State *L, void *block, + size_t osize, size_t nsize) { + global_State *g = G(L); + if (cantryagain(g)) { + luaC_fullgc(L, 1); /* try to free some memory... */ + return callfrealloc(g, block, osize, nsize); /* try again */ + } + else return NULL; /* cannot run an emergency collection */ +} + + +/* +** Generic allocation routine. +*/ +void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) { + void *newblock; + global_State *g = G(L); + lua_assert((osize == 0) == (block == NULL)); + newblock = firsttry(g, block, osize, nsize); + if (l_unlikely(newblock == NULL && nsize > 0)) { + newblock = tryagain(L, block, osize, nsize); + if (newblock == NULL) /* still no memory? */ + return NULL; /* do not update 'GCdebt' */ + } + lua_assert((nsize == 0) == (newblock == NULL)); + g->GCdebt = (g->GCdebt + nsize) - osize; + return newblock; +} + + +void *luaM_saferealloc_ (lua_State *L, void *block, size_t osize, + size_t nsize) { + void *newblock = luaM_realloc_(L, block, osize, nsize); + if (l_unlikely(newblock == NULL && nsize > 0)) /* allocation failed? */ + luaM_error(L); + return newblock; +} + + +void *luaM_malloc_ (lua_State *L, size_t size, int tag) { + if (size == 0) + return NULL; /* that's all */ + else { + global_State *g = G(L); + void *newblock = firsttry(g, NULL, tag, size); + if (l_unlikely(newblock == NULL)) { + newblock = tryagain(L, NULL, tag, size); + if (newblock == NULL) + luaM_error(L); + } + g->GCdebt += size; + return newblock; + } +} diff --git a/src/lmem.h b/src/lmem.h new file mode 100644 index 0000000..8c75a44 --- /dev/null +++ b/src/lmem.h @@ -0,0 +1,93 @@ +/* +** $Id: lmem.h $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + +#ifndef lmem_h +#define lmem_h + + +#include + +#include "llimits.h" +#include "lua.h" + + +#define luaM_error(L) luaD_throw(L, LUA_ERRMEM) + + +/* +** This macro tests whether it is safe to multiply 'n' by the size of +** type 't' without overflows. Because 'e' is always constant, it avoids +** the runtime division MAX_SIZET/(e). +** (The macro is somewhat complex to avoid warnings: The 'sizeof' +** comparison avoids a runtime comparison when overflow cannot occur. +** The compiler should be able to optimize the real test by itself, but +** when it does it, it may give a warning about "comparison is always +** false due to limited range of data type"; the +1 tricks the compiler, +** avoiding this warning but also this optimization.) +*/ +#define luaM_testsize(n,e) \ + (sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e)) + +#define luaM_checksize(L,n,e) \ + (luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0)) + + +/* +** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that +** the result is not larger than 'n' and cannot overflow a 'size_t' +** when multiplied by the size of type 't'. (Assumes that 'n' is an +** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.) +*/ +#define luaM_limitN(n,t) \ + ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) : \ + cast_uint((MAX_SIZET/sizeof(t)))) + + +/* +** Arrays of chars do not need any test +*/ +#define luaM_reallocvchar(L,b,on,n) \ + cast_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char))) + +#define luaM_freemem(L, b, s) luaM_free_(L, (b), (s)) +#define luaM_free(L, b) luaM_free_(L, (b), sizeof(*(b))) +#define luaM_freearray(L, b, n) luaM_free_(L, (b), (n)*sizeof(*(b))) + +#define luaM_new(L,t) cast(t*, luaM_malloc_(L, sizeof(t), 0)) +#define luaM_newvector(L,n,t) cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0)) +#define luaM_newvectorchecked(L,n,t) \ + (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t)) + +#define luaM_newobject(L,tag,s) luaM_malloc_(L, (s), tag) + +#define luaM_growvector(L,v,nelems,size,t,limit,e) \ + ((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t), \ + luaM_limitN(limit,t),e))) + +#define luaM_reallocvector(L, v,oldn,n,t) \ + (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \ + cast_sizet(n) * sizeof(t)))) + +#define luaM_shrinkvector(L,v,size,fs,t) \ + ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, sizeof(t)))) + +LUAI_FUNC l_noret luaM_toobig (lua_State *L); + +/* not to be called directly */ +LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize, + size_t size); +LUAI_FUNC void *luaM_saferealloc_ (lua_State *L, void *block, size_t oldsize, + size_t size); +LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize); +LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems, + int *size, int size_elem, int limit, + const char *what); +LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem, + int final_n, int size_elem); +LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag); + +#endif + diff --git a/src/loadlib.c b/src/loadlib.c new file mode 100644 index 0000000..d792dff --- /dev/null +++ b/src/loadlib.c @@ -0,0 +1,767 @@ +/* +** $Id: loadlib.c $ +** Dynamic library loader for Lua +** See Copyright Notice in lua.h +** +** This module contains an implementation of loadlib for Unix systems +** that have dlfcn, an implementation for Windows, and a stub for other +** systems. +*/ + +#define loadlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** LUA_IGMARK is a mark to ignore all before it when building the +** luaopen_ function name. +*/ +#if !defined (LUA_IGMARK) +#define LUA_IGMARK "-" +#endif + + +/* +** LUA_CSUBSEP is the character that replaces dots in submodule names +** when searching for a C loader. +** LUA_LSUBSEP is the character that replaces dots in submodule names +** when searching for a Lua loader. +*/ +#if !defined(LUA_CSUBSEP) +#define LUA_CSUBSEP LUA_DIRSEP +#endif + +#if !defined(LUA_LSUBSEP) +#define LUA_LSUBSEP LUA_DIRSEP +#endif + + +/* prefix for open functions in C libraries */ +#define LUA_POF "luaopen_" + +/* separator for open functions in C libraries */ +#define LUA_OFSEP "_" + + +/* +** key for table in the registry that keeps handles +** for all loaded C libraries +*/ +static const char *const CLIBS = "_CLIBS"; + +#define LIB_FAIL "open" + + +#define setprogdir(L) ((void)0) + + +/* +** Special type equivalent to '(void*)' for functions in gcc +** (to suppress warnings when converting function pointers) +*/ +typedef void (*voidf)(void); + + +/* +** system-dependent functions +*/ + +/* +** unload library 'lib' +*/ +static void lsys_unloadlib (void *lib); + +/* +** load C library in file 'path'. If 'seeglb', load with all names in +** the library global. +** Returns the library; in case of error, returns NULL plus an +** error string in the stack. +*/ +static void *lsys_load (lua_State *L, const char *path, int seeglb); + +/* +** Try to find a function named 'sym' in library 'lib'. +** Returns the function; in case of error, returns NULL plus an +** error string in the stack. +*/ +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym); + + + + +#if defined(LUA_USE_DLOPEN) /* { */ +/* +** {======================================================================== +** This is an implementation of loadlib based on the dlfcn interface. +** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD, +** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least +** as an emulation layer on top of native functions. +** ========================================================================= +*/ + +#include + +/* +** Macro to convert pointer-to-void* to pointer-to-function. This cast +** is undefined according to ISO C, but POSIX assumes that it works. +** (The '__extension__' in gnu compilers is only to avoid warnings.) +*/ +#if defined(__GNUC__) +#define cast_func(p) (__extension__ (lua_CFunction)(p)) +#else +#define cast_func(p) ((lua_CFunction)(p)) +#endif + + +static void lsys_unloadlib (void *lib) { + dlclose(lib); +} + + +static void *lsys_load (lua_State *L, const char *path, int seeglb) { + void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL)); + if (l_unlikely(lib == NULL)) + lua_pushstring(L, dlerror()); + return lib; +} + + +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { + lua_CFunction f = cast_func(dlsym(lib, sym)); + if (l_unlikely(f == NULL)) + lua_pushstring(L, dlerror()); + return f; +} + +/* }====================================================== */ + + + +#elif defined(LUA_DL_DLL) /* }{ */ +/* +** {====================================================================== +** This is an implementation of loadlib for Windows using native functions. +** ======================================================================= +*/ + +#include + + +/* +** optional flags for LoadLibraryEx +*/ +#if !defined(LUA_LLE_FLAGS) +#define LUA_LLE_FLAGS 0 +#endif + + +#undef setprogdir + + +/* +** Replace in the path (on the top of the stack) any occurrence +** of LUA_EXEC_DIR with the executable's path. +*/ +static void setprogdir (lua_State *L) { + char buff[MAX_PATH + 1]; + char *lb; + DWORD nsize = sizeof(buff)/sizeof(char); + DWORD n = GetModuleFileNameA(NULL, buff, nsize); /* get exec. name */ + if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL) + luaL_error(L, "unable to get ModuleFileName"); + else { + *lb = '\0'; /* cut name on the last '\\' to get the path */ + luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff); + lua_remove(L, -2); /* remove original string */ + } +} + + + + +static void pusherror (lua_State *L) { + int error = GetLastError(); + char buffer[128]; + if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM, + NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL)) + lua_pushstring(L, buffer); + else + lua_pushfstring(L, "system error %d\n", error); +} + +static void lsys_unloadlib (void *lib) { + FreeLibrary((HMODULE)lib); +} + + +static void *lsys_load (lua_State *L, const char *path, int seeglb) { + HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS); + (void)(seeglb); /* not used: symbols are 'global' by default */ + if (lib == NULL) pusherror(L); + return lib; +} + + +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { + lua_CFunction f = (lua_CFunction)(voidf)GetProcAddress((HMODULE)lib, sym); + if (f == NULL) pusherror(L); + return f; +} + +/* }====================================================== */ + + +#else /* }{ */ +/* +** {====================================================== +** Fallback for other systems +** ======================================================= +*/ + +#undef LIB_FAIL +#define LIB_FAIL "absent" + + +#define DLMSG "dynamic libraries not enabled; check your Lua installation" + + +static void lsys_unloadlib (void *lib) { + (void)(lib); /* not used */ +} + + +static void *lsys_load (lua_State *L, const char *path, int seeglb) { + (void)(path); (void)(seeglb); /* not used */ + lua_pushliteral(L, DLMSG); + return NULL; +} + + +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { + (void)(lib); (void)(sym); /* not used */ + lua_pushliteral(L, DLMSG); + return NULL; +} + +/* }====================================================== */ +#endif /* } */ + + +/* +** {================================================================== +** Set Paths +** =================================================================== +*/ + +/* +** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment +** variables that Lua check to set its paths. +*/ +#if !defined(LUA_PATH_VAR) +#define LUA_PATH_VAR "LUA_PATH" +#endif + +#if !defined(LUA_CPATH_VAR) +#define LUA_CPATH_VAR "LUA_CPATH" +#endif + + + +/* +** return registry.LUA_NOENV as a boolean +*/ +static int noenv (lua_State *L) { + int b; + lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); + b = lua_toboolean(L, -1); + lua_pop(L, 1); /* remove value */ + return b; +} + + +/* +** Set a path +*/ +static void setpath (lua_State *L, const char *fieldname, + const char *envname, + const char *dft) { + const char *dftmark; + const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX); + const char *path = getenv(nver); /* try versioned name */ + if (path == NULL) /* no versioned environment variable? */ + path = getenv(envname); /* try unversioned name */ + if (path == NULL || noenv(L)) /* no environment variable? */ + lua_pushstring(L, dft); /* use default */ + else if ((dftmark = strstr(path, LUA_PATH_SEP LUA_PATH_SEP)) == NULL) + lua_pushstring(L, path); /* nothing to change */ + else { /* path contains a ";;": insert default path in its place */ + size_t len = strlen(path); + luaL_Buffer b; + luaL_buffinit(L, &b); + if (path < dftmark) { /* is there a prefix before ';;'? */ + luaL_addlstring(&b, path, dftmark - path); /* add it */ + luaL_addchar(&b, *LUA_PATH_SEP); + } + luaL_addstring(&b, dft); /* add default */ + if (dftmark < path + len - 2) { /* is there a suffix after ';;'? */ + luaL_addchar(&b, *LUA_PATH_SEP); + luaL_addlstring(&b, dftmark + 2, (path + len - 2) - dftmark); + } + luaL_pushresult(&b); + } + setprogdir(L); + lua_setfield(L, -3, fieldname); /* package[fieldname] = path value */ + lua_pop(L, 1); /* pop versioned variable name ('nver') */ +} + +/* }================================================================== */ + + +/* +** return registry.CLIBS[path] +*/ +static void *checkclib (lua_State *L, const char *path) { + void *plib; + lua_getfield(L, LUA_REGISTRYINDEX, CLIBS); + lua_getfield(L, -1, path); + plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */ + lua_pop(L, 2); /* pop CLIBS table and 'plib' */ + return plib; +} + + +/* +** registry.CLIBS[path] = plib -- for queries +** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries +*/ +static void addtoclib (lua_State *L, const char *path, void *plib) { + lua_getfield(L, LUA_REGISTRYINDEX, CLIBS); + lua_pushlightuserdata(L, plib); + lua_pushvalue(L, -1); + lua_setfield(L, -3, path); /* CLIBS[path] = plib */ + lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */ + lua_pop(L, 1); /* pop CLIBS table */ +} + + +/* +** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib +** handles in list CLIBS +*/ +static int gctm (lua_State *L) { + lua_Integer n = luaL_len(L, 1); + for (; n >= 1; n--) { /* for each handle, in reverse order */ + lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */ + lsys_unloadlib(lua_touserdata(L, -1)); + lua_pop(L, 1); /* pop handle */ + } + return 0; +} + + + +/* error codes for 'lookforfunc' */ +#define ERRLIB 1 +#define ERRFUNC 2 + +/* +** Look for a C function named 'sym' in a dynamically loaded library +** 'path'. +** First, check whether the library is already loaded; if not, try +** to load it. +** Then, if 'sym' is '*', return true (as library has been loaded). +** Otherwise, look for symbol 'sym' in the library and push a +** C function with that symbol. +** Return 0 and 'true' or a function in the stack; in case of +** errors, return an error code and an error message in the stack. +*/ +static int lookforfunc (lua_State *L, const char *path, const char *sym) { + void *reg = checkclib(L, path); /* check loaded C libraries */ + if (reg == NULL) { /* must load library? */ + reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */ + if (reg == NULL) return ERRLIB; /* unable to load library */ + addtoclib(L, path, reg); + } + if (*sym == '*') { /* loading only library (no function)? */ + lua_pushboolean(L, 1); /* return 'true' */ + return 0; /* no errors */ + } + else { + lua_CFunction f = lsys_sym(L, reg, sym); + if (f == NULL) + return ERRFUNC; /* unable to find function */ + lua_pushcfunction(L, f); /* else create new function */ + return 0; /* no errors */ + } +} + + +static int ll_loadlib (lua_State *L) { + const char *path = luaL_checkstring(L, 1); + const char *init = luaL_checkstring(L, 2); + int stat = lookforfunc(L, path, init); + if (l_likely(stat == 0)) /* no errors? */ + return 1; /* return the loaded function */ + else { /* error; error message is on stack top */ + luaL_pushfail(L); + lua_insert(L, -2); + lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init"); + return 3; /* return fail, error message, and where */ + } +} + + + +/* +** {====================================================== +** 'require' function +** ======================================================= +*/ + + +static int readable (const char *filename) { + FILE *f = fopen(filename, "r"); /* try to open file */ + if (f == NULL) return 0; /* open failed */ + fclose(f); + return 1; +} + + +/* +** Get the next name in '*path' = 'name1;name2;name3;...', changing +** the ending ';' to '\0' to create a zero-terminated string. Return +** NULL when list ends. +*/ +static const char *getnextfilename (char **path, char *end) { + char *sep; + char *name = *path; + if (name == end) + return NULL; /* no more names */ + else if (*name == '\0') { /* from previous iteration? */ + *name = *LUA_PATH_SEP; /* restore separator */ + name++; /* skip it */ + } + sep = strchr(name, *LUA_PATH_SEP); /* find next separator */ + if (sep == NULL) /* separator not found? */ + sep = end; /* name goes until the end */ + *sep = '\0'; /* finish file name */ + *path = sep; /* will start next search from here */ + return name; +} + + +/* +** Given a path such as ";blabla.so;blublu.so", pushes the string +** +** no file 'blabla.so' +** no file 'blublu.so' +*/ +static void pusherrornotfound (lua_State *L, const char *path) { + luaL_Buffer b; + luaL_buffinit(L, &b); + luaL_addstring(&b, "no file '"); + luaL_addgsub(&b, path, LUA_PATH_SEP, "'\n\tno file '"); + luaL_addstring(&b, "'"); + luaL_pushresult(&b); +} + + +static const char *searchpath (lua_State *L, const char *name, + const char *path, + const char *sep, + const char *dirsep) { + luaL_Buffer buff; + char *pathname; /* path with name inserted */ + char *endpathname; /* its end */ + const char *filename; + /* separator is non-empty and appears in 'name'? */ + if (*sep != '\0' && strchr(name, *sep) != NULL) + name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */ + luaL_buffinit(L, &buff); + /* add path to the buffer, replacing marks ('?') with the file name */ + luaL_addgsub(&buff, path, LUA_PATH_MARK, name); + luaL_addchar(&buff, '\0'); + pathname = luaL_buffaddr(&buff); /* writable list of file names */ + endpathname = pathname + luaL_bufflen(&buff) - 1; + while ((filename = getnextfilename(&pathname, endpathname)) != NULL) { + if (readable(filename)) /* does file exist and is readable? */ + return lua_pushstring(L, filename); /* save and return name */ + } + luaL_pushresult(&buff); /* push path to create error message */ + pusherrornotfound(L, lua_tostring(L, -1)); /* create error message */ + return NULL; /* not found */ +} + + +static int ll_searchpath (lua_State *L) { + const char *f = searchpath(L, luaL_checkstring(L, 1), + luaL_checkstring(L, 2), + luaL_optstring(L, 3, "."), + luaL_optstring(L, 4, LUA_DIRSEP)); + if (f != NULL) return 1; + else { /* error message is on top of the stack */ + luaL_pushfail(L); + lua_insert(L, -2); + return 2; /* return fail + error message */ + } +} + + +static const char *findfile (lua_State *L, const char *name, + const char *pname, + const char *dirsep) { + const char *path; + lua_getfield(L, lua_upvalueindex(1), pname); + path = lua_tostring(L, -1); + if (l_unlikely(path == NULL)) + luaL_error(L, "'package.%s' must be a string", pname); + return searchpath(L, name, path, ".", dirsep); +} + + +static int checkload (lua_State *L, int stat, const char *filename) { + if (l_likely(stat)) { /* module loaded successfully? */ + lua_pushstring(L, filename); /* will be 2nd argument to module */ + return 2; /* return open function and file name */ + } + else + return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s", + lua_tostring(L, 1), filename, lua_tostring(L, -1)); +} + + +static int searcher_Lua (lua_State *L) { + const char *filename; + const char *name = luaL_checkstring(L, 1); + filename = findfile(L, name, "path", LUA_LSUBSEP); + if (filename == NULL) return 1; /* module not found in this path */ + return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename); +} + + +/* +** Try to find a load function for module 'modname' at file 'filename'. +** First, change '.' to '_' in 'modname'; then, if 'modname' has +** the form X-Y (that is, it has an "ignore mark"), build a function +** name "luaopen_X" and look for it. (For compatibility, if that +** fails, it also tries "luaopen_Y".) If there is no ignore mark, +** look for a function named "luaopen_modname". +*/ +static int loadfunc (lua_State *L, const char *filename, const char *modname) { + const char *openfunc; + const char *mark; + modname = luaL_gsub(L, modname, ".", LUA_OFSEP); + mark = strchr(modname, *LUA_IGMARK); + if (mark) { + int stat; + openfunc = lua_pushlstring(L, modname, mark - modname); + openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc); + stat = lookforfunc(L, filename, openfunc); + if (stat != ERRFUNC) return stat; + modname = mark + 1; /* else go ahead and try old-style name */ + } + openfunc = lua_pushfstring(L, LUA_POF"%s", modname); + return lookforfunc(L, filename, openfunc); +} + + +static int searcher_C (lua_State *L) { + const char *name = luaL_checkstring(L, 1); + const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP); + if (filename == NULL) return 1; /* module not found in this path */ + return checkload(L, (loadfunc(L, filename, name) == 0), filename); +} + + +static int searcher_Croot (lua_State *L) { + const char *filename; + const char *name = luaL_checkstring(L, 1); + const char *p = strchr(name, '.'); + int stat; + if (p == NULL) return 0; /* is root */ + lua_pushlstring(L, name, p - name); + filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP); + if (filename == NULL) return 1; /* root not found */ + if ((stat = loadfunc(L, filename, name)) != 0) { + if (stat != ERRFUNC) + return checkload(L, 0, filename); /* real error */ + else { /* open function not found */ + lua_pushfstring(L, "no module '%s' in file '%s'", name, filename); + return 1; + } + } + lua_pushstring(L, filename); /* will be 2nd argument to module */ + return 2; +} + + +static int searcher_preload (lua_State *L) { + const char *name = luaL_checkstring(L, 1); + lua_getfield(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE); + if (lua_getfield(L, -1, name) == LUA_TNIL) { /* not found? */ + lua_pushfstring(L, "no field package.preload['%s']", name); + return 1; + } + else { + lua_pushliteral(L, ":preload:"); + return 2; + } +} + + +static void findloader (lua_State *L, const char *name) { + int i; + luaL_Buffer msg; /* to build error message */ + /* push 'package.searchers' to index 3 in the stack */ + if (l_unlikely(lua_getfield(L, lua_upvalueindex(1), "searchers") + != LUA_TTABLE)) + luaL_error(L, "'package.searchers' must be a table"); + luaL_buffinit(L, &msg); + /* iterate over available searchers to find a loader */ + for (i = 1; ; i++) { + luaL_addstring(&msg, "\n\t"); /* error-message prefix */ + if (l_unlikely(lua_rawgeti(L, 3, i) == LUA_TNIL)) { /* no more searchers? */ + lua_pop(L, 1); /* remove nil */ + luaL_buffsub(&msg, 2); /* remove prefix */ + luaL_pushresult(&msg); /* create error message */ + luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1)); + } + lua_pushstring(L, name); + lua_call(L, 1, 2); /* call it */ + if (lua_isfunction(L, -2)) /* did it find a loader? */ + return; /* module loader found */ + else if (lua_isstring(L, -2)) { /* searcher returned error message? */ + lua_pop(L, 1); /* remove extra return */ + luaL_addvalue(&msg); /* concatenate error message */ + } + else { /* no error message */ + lua_pop(L, 2); /* remove both returns */ + luaL_buffsub(&msg, 2); /* remove prefix */ + } + } +} + + +static int ll_require (lua_State *L) { + const char *name = luaL_checkstring(L, 1); + lua_settop(L, 1); /* LOADED table will be at index 2 */ + lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); + lua_getfield(L, 2, name); /* LOADED[name] */ + if (lua_toboolean(L, -1)) /* is it there? */ + return 1; /* package is already loaded */ + /* else must load package */ + lua_pop(L, 1); /* remove 'getfield' result */ + findloader(L, name); + lua_rotate(L, -2, 1); /* function <-> loader data */ + lua_pushvalue(L, 1); /* name is 1st argument to module loader */ + lua_pushvalue(L, -3); /* loader data is 2nd argument */ + /* stack: ...; loader data; loader function; mod. name; loader data */ + lua_call(L, 2, 1); /* run loader to load module */ + /* stack: ...; loader data; result from loader */ + if (!lua_isnil(L, -1)) /* non-nil return? */ + lua_setfield(L, 2, name); /* LOADED[name] = returned value */ + else + lua_pop(L, 1); /* pop nil */ + if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */ + lua_pushboolean(L, 1); /* use true as result */ + lua_copy(L, -1, -2); /* replace loader result */ + lua_setfield(L, 2, name); /* LOADED[name] = true */ + } + lua_rotate(L, -2, 1); /* loader data <-> module result */ + return 2; /* return module result and loader data */ +} + +/* }====================================================== */ + + + + +static const luaL_Reg pk_funcs[] = { + {"loadlib", ll_loadlib}, + {"searchpath", ll_searchpath}, + /* placeholders */ + {"preload", NULL}, + {"cpath", NULL}, + {"path", NULL}, + {"searchers", NULL}, + {"loaded", NULL}, + {NULL, NULL} +}; + + +static const luaL_Reg ll_funcs[] = { + {"require", ll_require}, + {NULL, NULL} +}; + + +static void createsearcherstable (lua_State *L) { + static const lua_CFunction searchers[] = { + searcher_preload, + searcher_Lua, + searcher_C, + searcher_Croot, + NULL + }; + int i; + /* create 'searchers' table */ + lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0); + /* fill it with predefined searchers */ + for (i=0; searchers[i] != NULL; i++) { + lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */ + lua_pushcclosure(L, searchers[i], 1); + lua_rawseti(L, -2, i+1); + } + lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */ +} + + +/* +** create table CLIBS to keep track of loaded C libraries, +** setting a finalizer to close all libraries when closing state. +*/ +static void createclibstable (lua_State *L) { + luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS); /* create CLIBS table */ + lua_createtable(L, 0, 1); /* create metatable for CLIBS */ + lua_pushcfunction(L, gctm); + lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */ + lua_setmetatable(L, -2); +} + + +LUAMOD_API int luaopen_package (lua_State *L) { + createclibstable(L); + luaL_newlib(L, pk_funcs); /* create 'package' table */ + createsearcherstable(L); + /* set paths */ + setpath(L, "path", LUA_PATH_VAR, LUA_PATH_DEFAULT); + setpath(L, "cpath", LUA_CPATH_VAR, LUA_CPATH_DEFAULT); + /* store config information */ + lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n" + LUA_EXEC_DIR "\n" LUA_IGMARK "\n"); + lua_setfield(L, -2, "config"); + /* set field 'loaded' */ + luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); + lua_setfield(L, -2, "loaded"); + /* set field 'preload' */ + luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE); + lua_setfield(L, -2, "preload"); + lua_pushglobaltable(L); + lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */ + luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */ + lua_pop(L, 1); /* pop global table */ + return 1; /* return 'package' table */ +} + diff --git a/src/lobject.c b/src/lobject.c new file mode 100644 index 0000000..f73ffc6 --- /dev/null +++ b/src/lobject.c @@ -0,0 +1,602 @@ +/* +** $Id: lobject.c $ +** Some generic functions over Lua objects +** See Copyright Notice in lua.h +*/ + +#define lobject_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include +#include +#include +#include +#include + +#include "lua.h" + +#include "lctype.h" +#include "ldebug.h" +#include "ldo.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "lvm.h" + + +/* +** Computes ceil(log2(x)) +*/ +int luaO_ceillog2 (unsigned int x) { + static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */ + 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, + 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8 + }; + int l = 0; + x--; + while (x >= 256) { l += 8; x >>= 8; } + return l + log_2[x]; +} + + +static lua_Integer intarith (lua_State *L, int op, lua_Integer v1, + lua_Integer v2) { + switch (op) { + case LUA_OPADD: return intop(+, v1, v2); + case LUA_OPSUB:return intop(-, v1, v2); + case LUA_OPMUL:return intop(*, v1, v2); + case LUA_OPMOD: return luaV_mod(L, v1, v2); + case LUA_OPIDIV: return luaV_idiv(L, v1, v2); + case LUA_OPBAND: return intop(&, v1, v2); + case LUA_OPBOR: return intop(|, v1, v2); + case LUA_OPBXOR: return intop(^, v1, v2); + case LUA_OPSHL: return luaV_shiftl(v1, v2); + case LUA_OPSHR: return luaV_shiftr(v1, v2); + case LUA_OPUNM: return intop(-, 0, v1); + case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1); + default: lua_assert(0); return 0; + } +} + + +static lua_Number numarith (lua_State *L, int op, lua_Number v1, + lua_Number v2) { + switch (op) { + case LUA_OPADD: return luai_numadd(L, v1, v2); + case LUA_OPSUB: return luai_numsub(L, v1, v2); + case LUA_OPMUL: return luai_nummul(L, v1, v2); + case LUA_OPDIV: return luai_numdiv(L, v1, v2); + case LUA_OPPOW: return luai_numpow(L, v1, v2); + case LUA_OPIDIV: return luai_numidiv(L, v1, v2); + case LUA_OPUNM: return luai_numunm(L, v1); + case LUA_OPMOD: return luaV_modf(L, v1, v2); + default: lua_assert(0); return 0; + } +} + + +int luaO_rawarith (lua_State *L, int op, const TValue *p1, const TValue *p2, + TValue *res) { + switch (op) { + case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: + case LUA_OPSHL: case LUA_OPSHR: + case LUA_OPBNOT: { /* operate only on integers */ + lua_Integer i1; lua_Integer i2; + if (tointegerns(p1, &i1) && tointegerns(p2, &i2)) { + setivalue(res, intarith(L, op, i1, i2)); + return 1; + } + else return 0; /* fail */ + } + case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */ + lua_Number n1; lua_Number n2; + if (tonumberns(p1, n1) && tonumberns(p2, n2)) { + setfltvalue(res, numarith(L, op, n1, n2)); + return 1; + } + else return 0; /* fail */ + } + default: { /* other operations */ + lua_Number n1; lua_Number n2; + if (ttisinteger(p1) && ttisinteger(p2)) { + setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2))); + return 1; + } + else if (tonumberns(p1, n1) && tonumberns(p2, n2)) { + setfltvalue(res, numarith(L, op, n1, n2)); + return 1; + } + else return 0; /* fail */ + } + } +} + + +void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2, + StkId res) { + if (!luaO_rawarith(L, op, p1, p2, s2v(res))) { + /* could not perform raw operation; try metamethod */ + luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD)); + } +} + + +int luaO_hexavalue (int c) { + if (lisdigit(c)) return c - '0'; + else return (ltolower(c) - 'a') + 10; +} + + +static int isneg (const char **s) { + if (**s == '-') { (*s)++; return 1; } + else if (**s == '+') (*s)++; + return 0; +} + + + +/* +** {================================================================== +** Lua's implementation for 'lua_strx2number' +** =================================================================== +*/ + +#if !defined(lua_strx2number) + +/* maximum number of significant digits to read (to avoid overflows + even with single floats) */ +#define MAXSIGDIG 30 + +/* +** convert a hexadecimal numeric string to a number, following +** C99 specification for 'strtod' +*/ +static lua_Number lua_strx2number (const char *s, char **endptr) { + int dot = lua_getlocaledecpoint(); + lua_Number r = l_mathop(0.0); /* result (accumulator) */ + int sigdig = 0; /* number of significant digits */ + int nosigdig = 0; /* number of non-significant digits */ + int e = 0; /* exponent correction */ + int neg; /* 1 if number is negative */ + int hasdot = 0; /* true after seen a dot */ + *endptr = cast_charp(s); /* nothing is valid yet */ + while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ + neg = isneg(&s); /* check sign */ + if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */ + return l_mathop(0.0); /* invalid format (no '0x') */ + for (s += 2; ; s++) { /* skip '0x' and read numeral */ + if (*s == dot) { + if (hasdot) break; /* second dot? stop loop */ + else hasdot = 1; + } + else if (lisxdigit(cast_uchar(*s))) { + if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */ + nosigdig++; + else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */ + r = (r * l_mathop(16.0)) + luaO_hexavalue(*s); + else e++; /* too many digits; ignore, but still count for exponent */ + if (hasdot) e--; /* decimal digit? correct exponent */ + } + else break; /* neither a dot nor a digit */ + } + if (nosigdig + sigdig == 0) /* no digits? */ + return l_mathop(0.0); /* invalid format */ + *endptr = cast_charp(s); /* valid up to here */ + e *= 4; /* each digit multiplies/divides value by 2^4 */ + if (*s == 'p' || *s == 'P') { /* exponent part? */ + int exp1 = 0; /* exponent value */ + int neg1; /* exponent sign */ + s++; /* skip 'p' */ + neg1 = isneg(&s); /* sign */ + if (!lisdigit(cast_uchar(*s))) + return l_mathop(0.0); /* invalid; must have at least one digit */ + while (lisdigit(cast_uchar(*s))) /* read exponent */ + exp1 = exp1 * 10 + *(s++) - '0'; + if (neg1) exp1 = -exp1; + e += exp1; + *endptr = cast_charp(s); /* valid up to here */ + } + if (neg) r = -r; + return l_mathop(ldexp)(r, e); +} + +#endif +/* }====================================================== */ + + +/* maximum length of a numeral to be converted to a number */ +#if !defined (L_MAXLENNUM) +#define L_MAXLENNUM 200 +#endif + +/* +** Convert string 's' to a Lua number (put in 'result'). Return NULL on +** fail or the address of the ending '\0' on success. ('mode' == 'x') +** means a hexadecimal numeral. +*/ +static const char *l_str2dloc (const char *s, lua_Number *result, int mode) { + char *endptr; + *result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */ + : lua_str2number(s, &endptr); + if (endptr == s) return NULL; /* nothing recognized? */ + while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */ + return (*endptr == '\0') ? endptr : NULL; /* OK iff no trailing chars */ +} + + +/* +** Convert string 's' to a Lua number (put in 'result') handling the +** current locale. +** This function accepts both the current locale or a dot as the radix +** mark. If the conversion fails, it may mean number has a dot but +** locale accepts something else. In that case, the code copies 's' +** to a buffer (because 's' is read-only), changes the dot to the +** current locale radix mark, and tries to convert again. +** The variable 'mode' checks for special characters in the string: +** - 'n' means 'inf' or 'nan' (which should be rejected) +** - 'x' means a hexadecimal numeral +** - '.' just optimizes the search for the common case (no special chars) +*/ +static const char *l_str2d (const char *s, lua_Number *result) { + const char *endptr; + const char *pmode = strpbrk(s, ".xXnN"); /* look for special chars */ + int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0; + if (mode == 'n') /* reject 'inf' and 'nan' */ + return NULL; + endptr = l_str2dloc(s, result, mode); /* try to convert */ + if (endptr == NULL) { /* failed? may be a different locale */ + char buff[L_MAXLENNUM + 1]; + const char *pdot = strchr(s, '.'); + if (pdot == NULL || strlen(s) > L_MAXLENNUM) + return NULL; /* string too long or no dot; fail */ + strcpy(buff, s); /* copy string to buffer */ + buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */ + endptr = l_str2dloc(buff, result, mode); /* try again */ + if (endptr != NULL) + endptr = s + (endptr - buff); /* make relative to 's' */ + } + return endptr; +} + + +#define MAXBY10 cast(lua_Unsigned, LUA_MAXINTEGER / 10) +#define MAXLASTD cast_int(LUA_MAXINTEGER % 10) + +static const char *l_str2int (const char *s, lua_Integer *result) { + lua_Unsigned a = 0; + int empty = 1; + int neg; + while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ + neg = isneg(&s); + if (s[0] == '0' && + (s[1] == 'x' || s[1] == 'X')) { /* hex? */ + s += 2; /* skip '0x' */ + for (; lisxdigit(cast_uchar(*s)); s++) { + a = a * 16 + luaO_hexavalue(*s); + empty = 0; + } + } + else { /* decimal */ + for (; lisdigit(cast_uchar(*s)); s++) { + int d = *s - '0'; + if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */ + return NULL; /* do not accept it (as integer) */ + a = a * 10 + d; + empty = 0; + } + } + while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */ + if (empty || *s != '\0') return NULL; /* something wrong in the numeral */ + else { + *result = l_castU2S((neg) ? 0u - a : a); + return s; + } +} + + +size_t luaO_str2num (const char *s, TValue *o) { + lua_Integer i; lua_Number n; + const char *e; + if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */ + setivalue(o, i); + } + else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */ + setfltvalue(o, n); + } + else + return 0; /* conversion failed */ + return (e - s) + 1; /* success; return string size */ +} + + +int luaO_utf8esc (char *buff, unsigned long x) { + int n = 1; /* number of bytes put in buffer (backwards) */ + lua_assert(x <= 0x7FFFFFFFu); + if (x < 0x80) /* ascii? */ + buff[UTF8BUFFSZ - 1] = cast_char(x); + else { /* need continuation bytes */ + unsigned int mfb = 0x3f; /* maximum that fits in first byte */ + do { /* add continuation bytes */ + buff[UTF8BUFFSZ - (n++)] = cast_char(0x80 | (x & 0x3f)); + x >>= 6; /* remove added bits */ + mfb >>= 1; /* now there is one less bit available in first byte */ + } while (x > mfb); /* still needs continuation byte? */ + buff[UTF8BUFFSZ - n] = cast_char((~mfb << 1) | x); /* add first byte */ + } + return n; +} + + +/* +** Maximum length of the conversion of a number to a string. Must be +** enough to accommodate both LUA_INTEGER_FMT and LUA_NUMBER_FMT. +** (For a long long int, this is 19 digits plus a sign and a final '\0', +** adding to 21. For a long double, it can go to a sign, 33 digits, +** the dot, an exponent letter, an exponent sign, 5 exponent digits, +** and a final '\0', adding to 43.) +*/ +#define MAXNUMBER2STR 44 + + +/* +** Convert a number object to a string, adding it to a buffer +*/ +static int tostringbuff (TValue *obj, char *buff) { + int len; + lua_assert(ttisnumber(obj)); + if (ttisinteger(obj)) + len = lua_integer2str(buff, MAXNUMBER2STR, ivalue(obj)); + else { + len = lua_number2str(buff, MAXNUMBER2STR, fltvalue(obj)); + if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */ + buff[len++] = lua_getlocaledecpoint(); + buff[len++] = '0'; /* adds '.0' to result */ + } + } + return len; +} + + +/* +** Convert a number object to a Lua string, replacing the value at 'obj' +*/ +void luaO_tostring (lua_State *L, TValue *obj) { + char buff[MAXNUMBER2STR]; + int len = tostringbuff(obj, buff); + setsvalue(L, obj, luaS_newlstr(L, buff, len)); +} + + + + +/* +** {================================================================== +** 'luaO_pushvfstring' +** =================================================================== +*/ + +/* +** Size for buffer space used by 'luaO_pushvfstring'. It should be +** (LUA_IDSIZE + MAXNUMBER2STR) + a minimal space for basic messages, +** so that 'luaG_addinfo' can work directly on the buffer. +*/ +#define BUFVFS (LUA_IDSIZE + MAXNUMBER2STR + 95) + +/* buffer used by 'luaO_pushvfstring' */ +typedef struct BuffFS { + lua_State *L; + int pushed; /* true if there is a part of the result on the stack */ + int blen; /* length of partial string in 'space' */ + char space[BUFVFS]; /* holds last part of the result */ +} BuffFS; + + +/* +** Push given string to the stack, as part of the result, and +** join it to previous partial result if there is one. +** It may call 'luaV_concat' while using one slot from EXTRA_STACK. +** This call cannot invoke metamethods, as both operands must be +** strings. It can, however, raise an error if the result is too +** long. In that case, 'luaV_concat' frees the extra slot before +** raising the error. +*/ +static void pushstr (BuffFS *buff, const char *str, size_t lstr) { + lua_State *L = buff->L; + setsvalue2s(L, L->top.p, luaS_newlstr(L, str, lstr)); + L->top.p++; /* may use one slot from EXTRA_STACK */ + if (!buff->pushed) /* no previous string on the stack? */ + buff->pushed = 1; /* now there is one */ + else /* join previous string with new one */ + luaV_concat(L, 2); +} + + +/* +** empty the buffer space into the stack +*/ +static void clearbuff (BuffFS *buff) { + pushstr(buff, buff->space, buff->blen); /* push buffer contents */ + buff->blen = 0; /* space now is empty */ +} + + +/* +** Get a space of size 'sz' in the buffer. If buffer has not enough +** space, empty it. 'sz' must fit in an empty buffer. +*/ +static char *getbuff (BuffFS *buff, int sz) { + lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS); + if (sz > BUFVFS - buff->blen) /* not enough space? */ + clearbuff(buff); + return buff->space + buff->blen; +} + + +#define addsize(b,sz) ((b)->blen += (sz)) + + +/* +** Add 'str' to the buffer. If string is larger than the buffer space, +** push the string directly to the stack. +*/ +static void addstr2buff (BuffFS *buff, const char *str, size_t slen) { + if (slen <= BUFVFS) { /* does string fit into buffer? */ + char *bf = getbuff(buff, cast_int(slen)); + memcpy(bf, str, slen); /* add string to buffer */ + addsize(buff, cast_int(slen)); + } + else { /* string larger than buffer */ + clearbuff(buff); /* string comes after buffer's content */ + pushstr(buff, str, slen); /* push string */ + } +} + + +/* +** Add a numeral to the buffer. +*/ +static void addnum2buff (BuffFS *buff, TValue *num) { + char *numbuff = getbuff(buff, MAXNUMBER2STR); + int len = tostringbuff(num, numbuff); /* format number into 'numbuff' */ + addsize(buff, len); +} + + +/* +** this function handles only '%d', '%c', '%f', '%p', '%s', and '%%' + conventional formats, plus Lua-specific '%I' and '%U' +*/ +const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) { + BuffFS buff; /* holds last part of the result */ + const char *e; /* points to next '%' */ + buff.pushed = buff.blen = 0; + buff.L = L; + while ((e = strchr(fmt, '%')) != NULL) { + addstr2buff(&buff, fmt, e - fmt); /* add 'fmt' up to '%' */ + switch (*(e + 1)) { /* conversion specifier */ + case 's': { /* zero-terminated string */ + const char *s = va_arg(argp, char *); + if (s == NULL) s = "(null)"; + addstr2buff(&buff, s, strlen(s)); + break; + } + case 'c': { /* an 'int' as a character */ + char c = cast_uchar(va_arg(argp, int)); + addstr2buff(&buff, &c, sizeof(char)); + break; + } + case 'd': { /* an 'int' */ + TValue num; + setivalue(&num, va_arg(argp, int)); + addnum2buff(&buff, &num); + break; + } + case 'I': { /* a 'lua_Integer' */ + TValue num; + setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt))); + addnum2buff(&buff, &num); + break; + } + case 'f': { /* a 'lua_Number' */ + TValue num; + setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber))); + addnum2buff(&buff, &num); + break; + } + case 'p': { /* a pointer */ + const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */ + char *bf = getbuff(&buff, sz); + void *p = va_arg(argp, void *); + int len = lua_pointer2str(bf, sz, p); + addsize(&buff, len); + break; + } + case 'U': { /* a 'long' as a UTF-8 sequence */ + char bf[UTF8BUFFSZ]; + int len = luaO_utf8esc(bf, va_arg(argp, long)); + addstr2buff(&buff, bf + UTF8BUFFSZ - len, len); + break; + } + case '%': { + addstr2buff(&buff, "%", 1); + break; + } + default: { + luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'", + *(e + 1)); + } + } + fmt = e + 2; /* skip '%' and the specifier */ + } + addstr2buff(&buff, fmt, strlen(fmt)); /* rest of 'fmt' */ + clearbuff(&buff); /* empty buffer into the stack */ + lua_assert(buff.pushed == 1); + return svalue(s2v(L->top.p - 1)); +} + + +const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) { + const char *msg; + va_list argp; + va_start(argp, fmt); + msg = luaO_pushvfstring(L, fmt, argp); + va_end(argp); + return msg; +} + +/* }================================================================== */ + + +#define RETS "..." +#define PRE "[string \"" +#define POS "\"]" + +#define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) ) + +void luaO_chunkid (char *out, const char *source, size_t srclen) { + size_t bufflen = LUA_IDSIZE; /* free space in buffer */ + if (*source == '=') { /* 'literal' source */ + if (srclen <= bufflen) /* small enough? */ + memcpy(out, source + 1, srclen * sizeof(char)); + else { /* truncate it */ + addstr(out, source + 1, bufflen - 1); + *out = '\0'; + } + } + else if (*source == '@') { /* file name */ + if (srclen <= bufflen) /* small enough? */ + memcpy(out, source + 1, srclen * sizeof(char)); + else { /* add '...' before rest of name */ + addstr(out, RETS, LL(RETS)); + bufflen -= LL(RETS); + memcpy(out, source + 1 + srclen - bufflen, bufflen * sizeof(char)); + } + } + else { /* string; format as [string "source"] */ + const char *nl = strchr(source, '\n'); /* find first new line (if any) */ + addstr(out, PRE, LL(PRE)); /* add prefix */ + bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */ + if (srclen < bufflen && nl == NULL) { /* small one-line source? */ + addstr(out, source, srclen); /* keep it */ + } + else { + if (nl != NULL) srclen = nl - source; /* stop at first newline */ + if (srclen > bufflen) srclen = bufflen; + addstr(out, source, srclen); + addstr(out, RETS, LL(RETS)); + } + memcpy(out, POS, (LL(POS) + 1) * sizeof(char)); + } +} + diff --git a/src/lobject.h b/src/lobject.h new file mode 100644 index 0000000..556608e --- /dev/null +++ b/src/lobject.h @@ -0,0 +1,815 @@ +/* +** $Id: lobject.h $ +** Type definitions for Lua objects +** See Copyright Notice in lua.h +*/ + + +#ifndef lobject_h +#define lobject_h + + +#include + + +#include "llimits.h" +#include "lua.h" + + +/* +** Extra types for collectable non-values +*/ +#define LUA_TUPVAL LUA_NUMTYPES /* upvalues */ +#define LUA_TPROTO (LUA_NUMTYPES+1) /* function prototypes */ +#define LUA_TDEADKEY (LUA_NUMTYPES+2) /* removed keys in tables */ + + + +/* +** number of all possible types (including LUA_TNONE but excluding DEADKEY) +*/ +#define LUA_TOTALTYPES (LUA_TPROTO + 2) + + +/* +** tags for Tagged Values have the following use of bits: +** bits 0-3: actual tag (a LUA_T* constant) +** bits 4-5: variant bits +** bit 6: whether value is collectable +*/ + +/* add variant bits to a type */ +#define makevariant(t,v) ((t) | ((v) << 4)) + + + +/* +** Union of all Lua values +*/ +typedef union Value { + struct GCObject *gc; /* collectable objects */ + void *p; /* light userdata */ + lua_CFunction f; /* light C functions */ + lua_Integer i; /* integer numbers */ + lua_Number n; /* float numbers */ + /* not used, but may avoid warnings for uninitialized value */ + lu_byte ub; +} Value; + + +/* +** Tagged Values. This is the basic representation of values in Lua: +** an actual value plus a tag with its type. +*/ + +#define TValuefields Value value_; lu_byte tt_ + +typedef struct TValue { + TValuefields; +} TValue; + + +#define val_(o) ((o)->value_) +#define valraw(o) (val_(o)) + + +/* raw type tag of a TValue */ +#define rawtt(o) ((o)->tt_) + +/* tag with no variants (bits 0-3) */ +#define novariant(t) ((t) & 0x0F) + +/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */ +#define withvariant(t) ((t) & 0x3F) +#define ttypetag(o) withvariant(rawtt(o)) + +/* type of a TValue */ +#define ttype(o) (novariant(rawtt(o))) + + +/* Macros to test type */ +#define checktag(o,t) (rawtt(o) == (t)) +#define checktype(o,t) (ttype(o) == (t)) + + +/* Macros for internal tests */ + +/* collectable object has the same tag as the original value */ +#define righttt(obj) (ttypetag(obj) == gcvalue(obj)->tt) + +/* +** Any value being manipulated by the program either is non +** collectable, or the collectable object has the right tag +** and it is not dead. The option 'L == NULL' allows other +** macros using this one to be used where L is not available. +*/ +#define checkliveness(L,obj) \ + ((void)L, lua_longassert(!iscollectable(obj) || \ + (righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj)))))) + + +/* Macros to set values */ + +/* set a value's tag */ +#define settt_(o,t) ((o)->tt_=(t)) + + +/* main macro to copy values (from 'obj2' to 'obj1') */ +#define setobj(L,obj1,obj2) \ + { TValue *io1=(obj1); const TValue *io2=(obj2); \ + io1->value_ = io2->value_; settt_(io1, io2->tt_); \ + checkliveness(L,io1); lua_assert(!isnonstrictnil(io1)); } + +/* +** Different types of assignments, according to source and destination. +** (They are mostly equal now, but may be different in the future.) +*/ + +/* from stack to stack */ +#define setobjs2s(L,o1,o2) setobj(L,s2v(o1),s2v(o2)) +/* to stack (not from same stack) */ +#define setobj2s(L,o1,o2) setobj(L,s2v(o1),o2) +/* from table to same table */ +#define setobjt2t setobj +/* to new object */ +#define setobj2n setobj +/* to table */ +#define setobj2t setobj + + +/* +** Entries in a Lua stack. Field 'tbclist' forms a list of all +** to-be-closed variables active in this stack. Dummy entries are +** used when the distance between two tbc variables does not fit +** in an unsigned short. They are represented by delta==0, and +** their real delta is always the maximum value that fits in +** that field. +*/ +typedef union StackValue { + TValue val; + struct { + TValuefields; + unsigned short delta; + } tbclist; +} StackValue; + + +/* index to stack elements */ +typedef StackValue *StkId; + + +/* +** When reallocating the stack, change all pointers to the stack into +** proper offsets. +*/ +typedef union { + StkId p; /* actual pointer */ + ptrdiff_t offset; /* used while the stack is being reallocated */ +} StkIdRel; + + +/* convert a 'StackValue' to a 'TValue' */ +#define s2v(o) (&(o)->val) + + + +/* +** {================================================================== +** Nil +** =================================================================== +*/ + +/* Standard nil */ +#define LUA_VNIL makevariant(LUA_TNIL, 0) + +/* Empty slot (which might be different from a slot containing nil) */ +#define LUA_VEMPTY makevariant(LUA_TNIL, 1) + +/* Value returned for a key not found in a table (absent key) */ +#define LUA_VABSTKEY makevariant(LUA_TNIL, 2) + + +/* macro to test for (any kind of) nil */ +#define ttisnil(v) checktype((v), LUA_TNIL) + + +/* macro to test for a standard nil */ +#define ttisstrictnil(o) checktag((o), LUA_VNIL) + + +#define setnilvalue(obj) settt_(obj, LUA_VNIL) + + +#define isabstkey(v) checktag((v), LUA_VABSTKEY) + + +/* +** macro to detect non-standard nils (used only in assertions) +*/ +#define isnonstrictnil(v) (ttisnil(v) && !ttisstrictnil(v)) + + +/* +** By default, entries with any kind of nil are considered empty. +** (In any definition, values associated with absent keys must also +** be accepted as empty.) +*/ +#define isempty(v) ttisnil(v) + + +/* macro defining a value corresponding to an absent key */ +#define ABSTKEYCONSTANT {NULL}, LUA_VABSTKEY + + +/* mark an entry as empty */ +#define setempty(v) settt_(v, LUA_VEMPTY) + + + +/* }================================================================== */ + + +/* +** {================================================================== +** Booleans +** =================================================================== +*/ + + +#define LUA_VFALSE makevariant(LUA_TBOOLEAN, 0) +#define LUA_VTRUE makevariant(LUA_TBOOLEAN, 1) + +#define ttisboolean(o) checktype((o), LUA_TBOOLEAN) +#define ttisfalse(o) checktag((o), LUA_VFALSE) +#define ttistrue(o) checktag((o), LUA_VTRUE) + + +#define l_isfalse(o) (ttisfalse(o) || ttisnil(o)) + + +#define setbfvalue(obj) settt_(obj, LUA_VFALSE) +#define setbtvalue(obj) settt_(obj, LUA_VTRUE) + +/* }================================================================== */ + + +/* +** {================================================================== +** Threads +** =================================================================== +*/ + +#define LUA_VTHREAD makevariant(LUA_TTHREAD, 0) + +#define ttisthread(o) checktag((o), ctb(LUA_VTHREAD)) + +#define thvalue(o) check_exp(ttisthread(o), gco2th(val_(o).gc)) + +#define setthvalue(L,obj,x) \ + { TValue *io = (obj); lua_State *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTHREAD)); \ + checkliveness(L,io); } + +#define setthvalue2s(L,o,t) setthvalue(L,s2v(o),t) + +/* }================================================================== */ + + +/* +** {================================================================== +** Collectable Objects +** =================================================================== +*/ + +/* +** Common Header for all collectable objects (in macro form, to be +** included in other objects) +*/ +#define CommonHeader struct GCObject *next; lu_byte tt; lu_byte marked + + +/* Common type for all collectable objects */ +typedef struct GCObject { + CommonHeader; +} GCObject; + + +/* Bit mark for collectable types */ +#define BIT_ISCOLLECTABLE (1 << 6) + +#define iscollectable(o) (rawtt(o) & BIT_ISCOLLECTABLE) + +/* mark a tag as collectable */ +#define ctb(t) ((t) | BIT_ISCOLLECTABLE) + +#define gcvalue(o) check_exp(iscollectable(o), val_(o).gc) + +#define gcvalueraw(v) ((v).gc) + +#define setgcovalue(L,obj,x) \ + { TValue *io = (obj); GCObject *i_g=(x); \ + val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); } + +/* }================================================================== */ + + +/* +** {================================================================== +** Numbers +** =================================================================== +*/ + +/* Variant tags for numbers */ +#define LUA_VNUMINT makevariant(LUA_TNUMBER, 0) /* integer numbers */ +#define LUA_VNUMFLT makevariant(LUA_TNUMBER, 1) /* float numbers */ + +#define ttisnumber(o) checktype((o), LUA_TNUMBER) +#define ttisfloat(o) checktag((o), LUA_VNUMFLT) +#define ttisinteger(o) checktag((o), LUA_VNUMINT) + +#define nvalue(o) check_exp(ttisnumber(o), \ + (ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o))) +#define fltvalue(o) check_exp(ttisfloat(o), val_(o).n) +#define ivalue(o) check_exp(ttisinteger(o), val_(o).i) + +#define fltvalueraw(v) ((v).n) +#define ivalueraw(v) ((v).i) + +#define setfltvalue(obj,x) \ + { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_VNUMFLT); } + +#define chgfltvalue(obj,x) \ + { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); } + +#define setivalue(obj,x) \ + { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_VNUMINT); } + +#define chgivalue(obj,x) \ + { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); } + +/* }================================================================== */ + + +/* +** {================================================================== +** Strings +** =================================================================== +*/ + +/* Variant tags for strings */ +#define LUA_VSHRSTR makevariant(LUA_TSTRING, 0) /* short strings */ +#define LUA_VLNGSTR makevariant(LUA_TSTRING, 1) /* long strings */ + +#define ttisstring(o) checktype((o), LUA_TSTRING) +#define ttisshrstring(o) checktag((o), ctb(LUA_VSHRSTR)) +#define ttislngstring(o) checktag((o), ctb(LUA_VLNGSTR)) + +#define tsvalueraw(v) (gco2ts((v).gc)) + +#define tsvalue(o) check_exp(ttisstring(o), gco2ts(val_(o).gc)) + +#define setsvalue(L,obj,x) \ + { TValue *io = (obj); TString *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \ + checkliveness(L,io); } + +/* set a string to the stack */ +#define setsvalue2s(L,o,s) setsvalue(L,s2v(o),s) + +/* set a string to a new object */ +#define setsvalue2n setsvalue + + +/* +** Header for a string value. +*/ +typedef struct TString { + CommonHeader; + lu_byte extra; /* reserved words for short strings; "has hash" for longs */ + lu_byte shrlen; /* length for short strings */ + unsigned int hash; + union { + size_t lnglen; /* length for long strings */ + struct TString *hnext; /* linked list for hash table */ + } u; + char contents[1]; +} TString; + + + +/* +** Get the actual string (array of bytes) from a 'TString'. +*/ +#define getstr(ts) ((ts)->contents) + + +/* get the actual string (array of bytes) from a Lua value */ +#define svalue(o) getstr(tsvalue(o)) + +/* get string length from 'TString *s' */ +#define tsslen(s) ((s)->tt == LUA_VSHRSTR ? (s)->shrlen : (s)->u.lnglen) + +/* get string length from 'TValue *o' */ +#define vslen(o) tsslen(tsvalue(o)) + +/* }================================================================== */ + + +/* +** {================================================================== +** Userdata +** =================================================================== +*/ + + +/* +** Light userdata should be a variant of userdata, but for compatibility +** reasons they are also different types. +*/ +#define LUA_VLIGHTUSERDATA makevariant(LUA_TLIGHTUSERDATA, 0) + +#define LUA_VUSERDATA makevariant(LUA_TUSERDATA, 0) + +#define ttislightuserdata(o) checktag((o), LUA_VLIGHTUSERDATA) +#define ttisfulluserdata(o) checktag((o), ctb(LUA_VUSERDATA)) + +#define pvalue(o) check_exp(ttislightuserdata(o), val_(o).p) +#define uvalue(o) check_exp(ttisfulluserdata(o), gco2u(val_(o).gc)) + +#define pvalueraw(v) ((v).p) + +#define setpvalue(obj,x) \ + { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_VLIGHTUSERDATA); } + +#define setuvalue(L,obj,x) \ + { TValue *io = (obj); Udata *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VUSERDATA)); \ + checkliveness(L,io); } + + +/* Ensures that addresses after this type are always fully aligned. */ +typedef union UValue { + TValue uv; + LUAI_MAXALIGN; /* ensures maximum alignment for udata bytes */ +} UValue; + + +/* +** Header for userdata with user values; +** memory area follows the end of this structure. +*/ +typedef struct Udata { + CommonHeader; + unsigned short nuvalue; /* number of user values */ + size_t len; /* number of bytes */ + struct Table *metatable; + GCObject *gclist; + UValue uv[1]; /* user values */ +} Udata; + + +/* +** Header for userdata with no user values. These userdata do not need +** to be gray during GC, and therefore do not need a 'gclist' field. +** To simplify, the code always use 'Udata' for both kinds of userdata, +** making sure it never accesses 'gclist' on userdata with no user values. +** This structure here is used only to compute the correct size for +** this representation. (The 'bindata' field in its end ensures correct +** alignment for binary data following this header.) +*/ +typedef struct Udata0 { + CommonHeader; + unsigned short nuvalue; /* number of user values */ + size_t len; /* number of bytes */ + struct Table *metatable; + union {LUAI_MAXALIGN;} bindata; +} Udata0; + + +/* compute the offset of the memory area of a userdata */ +#define udatamemoffset(nuv) \ + ((nuv) == 0 ? offsetof(Udata0, bindata) \ + : offsetof(Udata, uv) + (sizeof(UValue) * (nuv))) + +/* get the address of the memory block inside 'Udata' */ +#define getudatamem(u) (cast_charp(u) + udatamemoffset((u)->nuvalue)) + +/* compute the size of a userdata */ +#define sizeudata(nuv,nb) (udatamemoffset(nuv) + (nb)) + +/* }================================================================== */ + + +/* +** {================================================================== +** Prototypes +** =================================================================== +*/ + +#define LUA_VPROTO makevariant(LUA_TPROTO, 0) + + +/* +** Description of an upvalue for function prototypes +*/ +typedef struct Upvaldesc { + TString *name; /* upvalue name (for debug information) */ + lu_byte instack; /* whether it is in stack (register) */ + lu_byte idx; /* index of upvalue (in stack or in outer function's list) */ + lu_byte kind; /* kind of corresponding variable */ +} Upvaldesc; + + +/* +** Description of a local variable for function prototypes +** (used for debug information) +*/ +typedef struct LocVar { + TString *varname; + int startpc; /* first point where variable is active */ + int endpc; /* first point where variable is dead */ +} LocVar; + + +/* +** Associates the absolute line source for a given instruction ('pc'). +** The array 'lineinfo' gives, for each instruction, the difference in +** lines from the previous instruction. When that difference does not +** fit into a byte, Lua saves the absolute line for that instruction. +** (Lua also saves the absolute line periodically, to speed up the +** computation of a line number: we can use binary search in the +** absolute-line array, but we must traverse the 'lineinfo' array +** linearly to compute a line.) +*/ +typedef struct AbsLineInfo { + int pc; + int line; +} AbsLineInfo; + +/* +** Function Prototypes +*/ +typedef struct Proto { + CommonHeader; + lu_byte numparams; /* number of fixed (named) parameters */ + lu_byte is_vararg; + lu_byte maxstacksize; /* number of registers needed by this function */ + int sizeupvalues; /* size of 'upvalues' */ + int sizek; /* size of 'k' */ + int sizecode; + int sizelineinfo; + int sizep; /* size of 'p' */ + int sizelocvars; + int sizeabslineinfo; /* size of 'abslineinfo' */ + int linedefined; /* debug information */ + int lastlinedefined; /* debug information */ + TValue *k; /* constants used by the function */ + Instruction *code; /* opcodes */ + struct Proto **p; /* functions defined inside the function */ + Upvaldesc *upvalues; /* upvalue information */ + ls_byte *lineinfo; /* information about source lines (debug information) */ + AbsLineInfo *abslineinfo; /* idem */ + LocVar *locvars; /* information about local variables (debug information) */ + TString *source; /* used for debug information */ + GCObject *gclist; +} Proto; + +/* }================================================================== */ + + +/* +** {================================================================== +** Functions +** =================================================================== +*/ + +#define LUA_VUPVAL makevariant(LUA_TUPVAL, 0) + + +/* Variant tags for functions */ +#define LUA_VLCL makevariant(LUA_TFUNCTION, 0) /* Lua closure */ +#define LUA_VLCF makevariant(LUA_TFUNCTION, 1) /* light C function */ +#define LUA_VCCL makevariant(LUA_TFUNCTION, 2) /* C closure */ + +#define ttisfunction(o) checktype(o, LUA_TFUNCTION) +#define ttisLclosure(o) checktag((o), ctb(LUA_VLCL)) +#define ttislcf(o) checktag((o), LUA_VLCF) +#define ttisCclosure(o) checktag((o), ctb(LUA_VCCL)) +#define ttisclosure(o) (ttisLclosure(o) || ttisCclosure(o)) + + +#define isLfunction(o) ttisLclosure(o) + +#define clvalue(o) check_exp(ttisclosure(o), gco2cl(val_(o).gc)) +#define clLvalue(o) check_exp(ttisLclosure(o), gco2lcl(val_(o).gc)) +#define fvalue(o) check_exp(ttislcf(o), val_(o).f) +#define clCvalue(o) check_exp(ttisCclosure(o), gco2ccl(val_(o).gc)) + +#define fvalueraw(v) ((v).f) + +#define setclLvalue(L,obj,x) \ + { TValue *io = (obj); LClosure *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VLCL)); \ + checkliveness(L,io); } + +#define setclLvalue2s(L,o,cl) setclLvalue(L,s2v(o),cl) + +#define setfvalue(obj,x) \ + { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_VLCF); } + +#define setclCvalue(L,obj,x) \ + { TValue *io = (obj); CClosure *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VCCL)); \ + checkliveness(L,io); } + + +/* +** Upvalues for Lua closures +*/ +typedef struct UpVal { + CommonHeader; + union { + TValue *p; /* points to stack or to its own value */ + ptrdiff_t offset; /* used while the stack is being reallocated */ + } v; + union { + struct { /* (when open) */ + struct UpVal *next; /* linked list */ + struct UpVal **previous; + } open; + TValue value; /* the value (when closed) */ + } u; +} UpVal; + + + +#define ClosureHeader \ + CommonHeader; lu_byte nupvalues; GCObject *gclist + +typedef struct CClosure { + ClosureHeader; + lua_CFunction f; + TValue upvalue[1]; /* list of upvalues */ +} CClosure; + + +typedef struct LClosure { + ClosureHeader; + struct Proto *p; + UpVal *upvals[1]; /* list of upvalues */ +} LClosure; + + +typedef union Closure { + CClosure c; + LClosure l; +} Closure; + + +#define getproto(o) (clLvalue(o)->p) + +/* }================================================================== */ + + +/* +** {================================================================== +** Tables +** =================================================================== +*/ + +#define LUA_VTABLE makevariant(LUA_TTABLE, 0) + +#define ttistable(o) checktag((o), ctb(LUA_VTABLE)) + +#define hvalue(o) check_exp(ttistable(o), gco2t(val_(o).gc)) + +#define sethvalue(L,obj,x) \ + { TValue *io = (obj); Table *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTABLE)); \ + checkliveness(L,io); } + +#define sethvalue2s(L,o,h) sethvalue(L,s2v(o),h) + + +/* +** Nodes for Hash tables: A pack of two TValue's (key-value pairs) +** plus a 'next' field to link colliding entries. The distribution +** of the key's fields ('key_tt' and 'key_val') not forming a proper +** 'TValue' allows for a smaller size for 'Node' both in 4-byte +** and 8-byte alignments. +*/ +typedef union Node { + struct NodeKey { + TValuefields; /* fields for value */ + lu_byte key_tt; /* key type */ + int next; /* for chaining */ + Value key_val; /* key value */ + } u; + TValue i_val; /* direct access to node's value as a proper 'TValue' */ +} Node; + + +/* copy a value into a key */ +#define setnodekey(L,node,obj) \ + { Node *n_=(node); const TValue *io_=(obj); \ + n_->u.key_val = io_->value_; n_->u.key_tt = io_->tt_; \ + checkliveness(L,io_); } + + +/* copy a value from a key */ +#define getnodekey(L,obj,node) \ + { TValue *io_=(obj); const Node *n_=(node); \ + io_->value_ = n_->u.key_val; io_->tt_ = n_->u.key_tt; \ + checkliveness(L,io_); } + + +/* +** About 'alimit': if 'isrealasize(t)' is true, then 'alimit' is the +** real size of 'array'. Otherwise, the real size of 'array' is the +** smallest power of two not smaller than 'alimit' (or zero iff 'alimit' +** is zero); 'alimit' is then used as a hint for #t. +*/ + +#define BITRAS (1 << 7) +#define isrealasize(t) (!((t)->flags & BITRAS)) +#define setrealasize(t) ((t)->flags &= cast_byte(~BITRAS)) +#define setnorealasize(t) ((t)->flags |= BITRAS) + + +typedef struct Table { + CommonHeader; + lu_byte flags; /* 1<

u.key_tt) +#define keyval(node) ((node)->u.key_val) + +#define keyisnil(node) (keytt(node) == LUA_TNIL) +#define keyisinteger(node) (keytt(node) == LUA_VNUMINT) +#define keyival(node) (keyval(node).i) +#define keyisshrstr(node) (keytt(node) == ctb(LUA_VSHRSTR)) +#define keystrval(node) (gco2ts(keyval(node).gc)) + +#define setnilkey(node) (keytt(node) = LUA_TNIL) + +#define keyiscollectable(n) (keytt(n) & BIT_ISCOLLECTABLE) + +#define gckey(n) (keyval(n).gc) +#define gckeyN(n) (keyiscollectable(n) ? gckey(n) : NULL) + + +/* +** Dead keys in tables have the tag DEADKEY but keep their original +** gcvalue. This distinguishes them from regular keys but allows them to +** be found when searched in a special way. ('next' needs that to find +** keys removed from a table during a traversal.) +*/ +#define setdeadkey(node) (keytt(node) = LUA_TDEADKEY) +#define keyisdead(node) (keytt(node) == LUA_TDEADKEY) + +/* }================================================================== */ + + + +/* +** 'module' operation for hashing (size is always a power of 2) +*/ +#define lmod(s,size) \ + (check_exp((size&(size-1))==0, (cast_int((s) & ((size)-1))))) + + +#define twoto(x) (1<<(x)) +#define sizenode(t) (twoto((t)->lsizenode)) + + +/* size of buffer for 'luaO_utf8esc' function */ +#define UTF8BUFFSZ 8 + +LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x); +LUAI_FUNC int luaO_ceillog2 (unsigned int x); +LUAI_FUNC int luaO_rawarith (lua_State *L, int op, const TValue *p1, + const TValue *p2, TValue *res); +LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1, + const TValue *p2, StkId res); +LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o); +LUAI_FUNC int luaO_hexavalue (int c); +LUAI_FUNC void luaO_tostring (lua_State *L, TValue *obj); +LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt, + va_list argp); +LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...); +LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t srclen); + + +#endif + diff --git a/src/lopcodes.c b/src/lopcodes.c new file mode 100644 index 0000000..c67aa22 --- /dev/null +++ b/src/lopcodes.c @@ -0,0 +1,104 @@ +/* +** $Id: lopcodes.c $ +** Opcodes for Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#define lopcodes_c +#define LUA_CORE + +#include "lprefix.h" + + +#include "lopcodes.h" + + +/* ORDER OP */ + +LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = { +/* MM OT IT T A mode opcode */ + opmode(0, 0, 0, 0, 1, iABC) /* OP_MOVE */ + ,opmode(0, 0, 0, 0, 1, iAsBx) /* OP_LOADI */ + ,opmode(0, 0, 0, 0, 1, iAsBx) /* OP_LOADF */ + ,opmode(0, 0, 0, 0, 1, iABx) /* OP_LOADK */ + ,opmode(0, 0, 0, 0, 1, iABx) /* OP_LOADKX */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_LOADFALSE */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_LFALSESKIP */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_LOADTRUE */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_LOADNIL */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_GETUPVAL */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_SETUPVAL */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_GETTABUP */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_GETTABLE */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_GETI */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_GETFIELD */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_SETTABUP */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_SETTABLE */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_SETI */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_SETFIELD */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_NEWTABLE */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SELF */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_ADDI */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_ADDK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SUBK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_MULK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_MODK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_POWK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_DIVK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_IDIVK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BANDK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BORK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BXORK */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SHRI */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SHLI */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_ADD */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SUB */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_MUL */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_MOD */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_POW */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_DIV */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_IDIV */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BAND */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BOR */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BXOR */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SHL */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_SHR */ + ,opmode(1, 0, 0, 0, 0, iABC) /* OP_MMBIN */ + ,opmode(1, 0, 0, 0, 0, iABC) /* OP_MMBINI*/ + ,opmode(1, 0, 0, 0, 0, iABC) /* OP_MMBINK*/ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_UNM */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_BNOT */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_NOT */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_LEN */ + ,opmode(0, 0, 0, 0, 1, iABC) /* OP_CONCAT */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_CLOSE */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_TBC */ + ,opmode(0, 0, 0, 0, 0, isJ) /* OP_JMP */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_EQ */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_LT */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_LE */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_EQK */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_EQI */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_LTI */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_LEI */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_GTI */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_GEI */ + ,opmode(0, 0, 0, 1, 0, iABC) /* OP_TEST */ + ,opmode(0, 0, 0, 1, 1, iABC) /* OP_TESTSET */ + ,opmode(0, 1, 1, 0, 1, iABC) /* OP_CALL */ + ,opmode(0, 1, 1, 0, 1, iABC) /* OP_TAILCALL */ + ,opmode(0, 0, 1, 0, 0, iABC) /* OP_RETURN */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_RETURN0 */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_RETURN1 */ + ,opmode(0, 0, 0, 0, 1, iABx) /* OP_FORLOOP */ + ,opmode(0, 0, 0, 0, 1, iABx) /* OP_FORPREP */ + ,opmode(0, 0, 0, 0, 0, iABx) /* OP_TFORPREP */ + ,opmode(0, 0, 0, 0, 0, iABC) /* OP_TFORCALL */ + ,opmode(0, 0, 0, 0, 1, iABx) /* OP_TFORLOOP */ + ,opmode(0, 0, 1, 0, 0, iABC) /* OP_SETLIST */ + ,opmode(0, 0, 0, 0, 1, iABx) /* OP_CLOSURE */ + ,opmode(0, 1, 0, 0, 1, iABC) /* OP_VARARG */ + ,opmode(0, 0, 1, 0, 1, iABC) /* OP_VARARGPREP */ + ,opmode(0, 0, 0, 0, 0, iAx) /* OP_EXTRAARG */ +}; + diff --git a/src/lopcodes.h b/src/lopcodes.h new file mode 100644 index 0000000..4c55145 --- /dev/null +++ b/src/lopcodes.h @@ -0,0 +1,405 @@ +/* +** $Id: lopcodes.h $ +** Opcodes for Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#ifndef lopcodes_h +#define lopcodes_h + +#include "llimits.h" + + +/*=========================================================================== + We assume that instructions are unsigned 32-bit integers. + All instructions have an opcode in the first 7 bits. + Instructions can have the following formats: + + 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 + 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 +iABC C(8) | B(8) |k| A(8) | Op(7) | +iABx Bx(17) | A(8) | Op(7) | +iAsBx sBx (signed)(17) | A(8) | Op(7) | +iAx Ax(25) | Op(7) | +isJ sJ (signed)(25) | Op(7) | + + A signed argument is represented in excess K: the represented value is + the written unsigned value minus K, where K is half the maximum for the + corresponding unsigned argument. +===========================================================================*/ + + +enum OpMode {iABC, iABx, iAsBx, iAx, isJ}; /* basic instruction formats */ + + +/* +** size and position of opcode arguments. +*/ +#define SIZE_C 8 +#define SIZE_B 8 +#define SIZE_Bx (SIZE_C + SIZE_B + 1) +#define SIZE_A 8 +#define SIZE_Ax (SIZE_Bx + SIZE_A) +#define SIZE_sJ (SIZE_Bx + SIZE_A) + +#define SIZE_OP 7 + +#define POS_OP 0 + +#define POS_A (POS_OP + SIZE_OP) +#define POS_k (POS_A + SIZE_A) +#define POS_B (POS_k + 1) +#define POS_C (POS_B + SIZE_B) + +#define POS_Bx POS_k + +#define POS_Ax POS_A + +#define POS_sJ POS_A + + +/* +** limits for opcode arguments. +** we use (signed) 'int' to manipulate most arguments, +** so they must fit in ints. +*/ + +/* Check whether type 'int' has at least 'b' bits ('b' < 32) */ +#define L_INTHASBITS(b) ((UINT_MAX >> ((b) - 1)) >= 1) + + +#if L_INTHASBITS(SIZE_Bx) +#define MAXARG_Bx ((1<>1) /* 'sBx' is signed */ + + +#if L_INTHASBITS(SIZE_Ax) +#define MAXARG_Ax ((1<> 1) + + +#define MAXARG_A ((1<> 1) + +#define int2sC(i) ((i) + OFFSET_sC) +#define sC2int(i) ((i) - OFFSET_sC) + + +/* creates a mask with 'n' 1 bits at position 'p' */ +#define MASK1(n,p) ((~((~(Instruction)0)<<(n)))<<(p)) + +/* creates a mask with 'n' 0 bits at position 'p' */ +#define MASK0(n,p) (~MASK1(n,p)) + +/* +** the following macros help to manipulate instructions +*/ + +#define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) +#define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ + ((cast(Instruction, o)<>(pos)) & MASK1(size,0))) +#define setarg(i,v,pos,size) ((i) = (((i)&MASK0(size,pos)) | \ + ((cast(Instruction, v)<> sC */ +OP_SHLI,/* A B sC R[A] := sC << R[B] */ + +OP_ADD,/* A B C R[A] := R[B] + R[C] */ +OP_SUB,/* A B C R[A] := R[B] - R[C] */ +OP_MUL,/* A B C R[A] := R[B] * R[C] */ +OP_MOD,/* A B C R[A] := R[B] % R[C] */ +OP_POW,/* A B C R[A] := R[B] ^ R[C] */ +OP_DIV,/* A B C R[A] := R[B] / R[C] */ +OP_IDIV,/* A B C R[A] := R[B] // R[C] */ + +OP_BAND,/* A B C R[A] := R[B] & R[C] */ +OP_BOR,/* A B C R[A] := R[B] | R[C] */ +OP_BXOR,/* A B C R[A] := R[B] ~ R[C] */ +OP_SHL,/* A B C R[A] := R[B] << R[C] */ +OP_SHR,/* A B C R[A] := R[B] >> R[C] */ + +OP_MMBIN,/* A B C call C metamethod over R[A] and R[B] (*) */ +OP_MMBINI,/* A sB C k call C metamethod over R[A] and sB */ +OP_MMBINK,/* A B C k call C metamethod over R[A] and K[B] */ + +OP_UNM,/* A B R[A] := -R[B] */ +OP_BNOT,/* A B R[A] := ~R[B] */ +OP_NOT,/* A B R[A] := not R[B] */ +OP_LEN,/* A B R[A] := #R[B] (length operator) */ + +OP_CONCAT,/* A B R[A] := R[A].. ... ..R[A + B - 1] */ + +OP_CLOSE,/* A close all upvalues >= R[A] */ +OP_TBC,/* A mark variable A "to be closed" */ +OP_JMP,/* sJ pc += sJ */ +OP_EQ,/* A B k if ((R[A] == R[B]) ~= k) then pc++ */ +OP_LT,/* A B k if ((R[A] < R[B]) ~= k) then pc++ */ +OP_LE,/* A B k if ((R[A] <= R[B]) ~= k) then pc++ */ + +OP_EQK,/* A B k if ((R[A] == K[B]) ~= k) then pc++ */ +OP_EQI,/* A sB k if ((R[A] == sB) ~= k) then pc++ */ +OP_LTI,/* A sB k if ((R[A] < sB) ~= k) then pc++ */ +OP_LEI,/* A sB k if ((R[A] <= sB) ~= k) then pc++ */ +OP_GTI,/* A sB k if ((R[A] > sB) ~= k) then pc++ */ +OP_GEI,/* A sB k if ((R[A] >= sB) ~= k) then pc++ */ + +OP_TEST,/* A k if (not R[A] == k) then pc++ */ +OP_TESTSET,/* A B k if (not R[B] == k) then pc++ else R[A] := R[B] (*) */ + +OP_CALL,/* A B C R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */ +OP_TAILCALL,/* A B C k return R[A](R[A+1], ... ,R[A+B-1]) */ + +OP_RETURN,/* A B C k return R[A], ... ,R[A+B-2] (see note) */ +OP_RETURN0,/* return */ +OP_RETURN1,/* A return R[A] */ + +OP_FORLOOP,/* A Bx update counters; if loop continues then pc-=Bx; */ +OP_FORPREP,/* A Bx ; + if not to run then pc+=Bx+1; */ + +OP_TFORPREP,/* A Bx create upvalue for R[A + 3]; pc+=Bx */ +OP_TFORCALL,/* A C R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2]); */ +OP_TFORLOOP,/* A Bx if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx } */ + +OP_SETLIST,/* A B C k R[A][C+i] := R[A+i], 1 <= i <= B */ + +OP_CLOSURE,/* A Bx R[A] := closure(KPROTO[Bx]) */ + +OP_VARARG,/* A C R[A], R[A+1], ..., R[A+C-2] = vararg */ + +OP_VARARGPREP,/*A (adjust vararg parameters) */ + +OP_EXTRAARG/* Ax extra (larger) argument for previous opcode */ +} OpCode; + + +#define NUM_OPCODES ((int)(OP_EXTRAARG) + 1) + + + +/*=========================================================================== + Notes: + + (*) Opcode OP_LFALSESKIP is used to convert a condition to a boolean + value, in a code equivalent to (not cond ? false : true). (It + produces false and skips the next instruction producing true.) + + (*) Opcodes OP_MMBIN and variants follow each arithmetic and + bitwise opcode. If the operation succeeds, it skips this next + opcode. Otherwise, this opcode calls the corresponding metamethod. + + (*) Opcode OP_TESTSET is used in short-circuit expressions that need + both to jump and to produce a value, such as (a = b or c). + + (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then + 'top' is set to last_result+1, so next open instruction (OP_CALL, + OP_RETURN*, OP_SETLIST) may use 'top'. + + (*) In OP_VARARG, if (C == 0) then use actual number of varargs and + set top (like in OP_CALL with C == 0). + + (*) In OP_RETURN, if (B == 0) then return up to 'top'. + + (*) In OP_LOADKX and OP_NEWTABLE, the next instruction is always + OP_EXTRAARG. + + (*) In OP_SETLIST, if (B == 0) then real B = 'top'; if k, then + real C = EXTRAARG _ C (the bits of EXTRAARG concatenated with the + bits of C). + + (*) In OP_NEWTABLE, B is log2 of the hash size (which is always a + power of 2) plus 1, or zero for size zero. If not k, the array size + is C. Otherwise, the array size is EXTRAARG _ C. + + (*) For comparisons, k specifies what condition the test should accept + (true or false). + + (*) In OP_MMBINI/OP_MMBINK, k means the arguments were flipped + (the constant is the first operand). + + (*) All 'skips' (pc++) assume that next instruction is a jump. + + (*) In instructions OP_RETURN/OP_TAILCALL, 'k' specifies that the + function builds upvalues, which may need to be closed. C > 0 means + the function is vararg, so that its 'func' must be corrected before + returning; in this case, (C - 1) is its number of fixed parameters. + + (*) In comparisons with an immediate operand, C signals whether the + original operand was a float. (It must be corrected in case of + metamethods.) + +===========================================================================*/ + + +/* +** masks for instruction properties. The format is: +** bits 0-2: op mode +** bit 3: instruction set register A +** bit 4: operator is a test (next instruction must be a jump) +** bit 5: instruction uses 'L->top' set by previous instruction (when B == 0) +** bit 6: instruction sets 'L->top' for next instruction (when C == 0) +** bit 7: instruction is an MM instruction (call a metamethod) +*/ + +LUAI_DDEC(const lu_byte luaP_opmodes[NUM_OPCODES];) + +#define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 7)) +#define testAMode(m) (luaP_opmodes[m] & (1 << 3)) +#define testTMode(m) (luaP_opmodes[m] & (1 << 4)) +#define testITMode(m) (luaP_opmodes[m] & (1 << 5)) +#define testOTMode(m) (luaP_opmodes[m] & (1 << 6)) +#define testMMMode(m) (luaP_opmodes[m] & (1 << 7)) + +/* "out top" (set top for next instruction) */ +#define isOT(i) \ + ((testOTMode(GET_OPCODE(i)) && GETARG_C(i) == 0) || \ + GET_OPCODE(i) == OP_TAILCALL) + +/* "in top" (uses top from previous instruction) */ +#define isIT(i) (testITMode(GET_OPCODE(i)) && GETARG_B(i) == 0) + +#define opmode(mm,ot,it,t,a,m) \ + (((mm) << 7) | ((ot) << 6) | ((it) << 5) | ((t) << 4) | ((a) << 3) | (m)) + + +/* number of list items to accumulate before a SETLIST instruction */ +#define LFIELDS_PER_FLUSH 50 + +#endif diff --git a/src/lopnames.h b/src/lopnames.h new file mode 100644 index 0000000..965cec9 --- /dev/null +++ b/src/lopnames.h @@ -0,0 +1,103 @@ +/* +** $Id: lopnames.h $ +** Opcode names +** See Copyright Notice in lua.h +*/ + +#if !defined(lopnames_h) +#define lopnames_h + +#include + + +/* ORDER OP */ + +static const char *const opnames[] = { + "MOVE", + "LOADI", + "LOADF", + "LOADK", + "LOADKX", + "LOADFALSE", + "LFALSESKIP", + "LOADTRUE", + "LOADNIL", + "GETUPVAL", + "SETUPVAL", + "GETTABUP", + "GETTABLE", + "GETI", + "GETFIELD", + "SETTABUP", + "SETTABLE", + "SETI", + "SETFIELD", + "NEWTABLE", + "SELF", + "ADDI", + "ADDK", + "SUBK", + "MULK", + "MODK", + "POWK", + "DIVK", + "IDIVK", + "BANDK", + "BORK", + "BXORK", + "SHRI", + "SHLI", + "ADD", + "SUB", + "MUL", + "MOD", + "POW", + "DIV", + "IDIV", + "BAND", + "BOR", + "BXOR", + "SHL", + "SHR", + "MMBIN", + "MMBINI", + "MMBINK", + "UNM", + "BNOT", + "NOT", + "LEN", + "CONCAT", + "CLOSE", + "TBC", + "JMP", + "EQ", + "LT", + "LE", + "EQK", + "EQI", + "LTI", + "LEI", + "GTI", + "GEI", + "TEST", + "TESTSET", + "CALL", + "TAILCALL", + "RETURN", + "RETURN0", + "RETURN1", + "FORLOOP", + "FORPREP", + "TFORPREP", + "TFORCALL", + "TFORLOOP", + "SETLIST", + "CLOSURE", + "VARARG", + "VARARGPREP", + "EXTRAARG", + NULL +}; + +#endif + diff --git a/src/loslib.c b/src/loslib.c new file mode 100644 index 0000000..ad5a927 --- /dev/null +++ b/src/loslib.c @@ -0,0 +1,428 @@ +/* +** $Id: loslib.c $ +** Standard Operating System library +** See Copyright Notice in lua.h +*/ + +#define loslib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** {================================================================== +** List of valid conversion specifiers for the 'strftime' function; +** options are grouped by length; group of length 2 start with '||'. +** =================================================================== +*/ +#if !defined(LUA_STRFTIMEOPTIONS) /* { */ + +#if defined(LUA_USE_WINDOWS) +#define LUA_STRFTIMEOPTIONS "aAbBcdHIjmMpSUwWxXyYzZ%" \ + "||" "#c#x#d#H#I#j#m#M#S#U#w#W#y#Y" /* two-char options */ +#elif defined(LUA_USE_C89) /* ANSI C 89 (only 1-char options) */ +#define LUA_STRFTIMEOPTIONS "aAbBcdHIjmMpSUwWxXyYZ%" +#else /* C99 specification */ +#define LUA_STRFTIMEOPTIONS "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%" \ + "||" "EcECExEXEyEY" "OdOeOHOIOmOMOSOuOUOVOwOWOy" /* two-char options */ +#endif + +#endif /* } */ +/* }================================================================== */ + + +/* +** {================================================================== +** Configuration for time-related stuff +** =================================================================== +*/ + +/* +** type to represent time_t in Lua +*/ +#if !defined(LUA_NUMTIME) /* { */ + +#define l_timet lua_Integer +#define l_pushtime(L,t) lua_pushinteger(L,(lua_Integer)(t)) +#define l_gettime(L,arg) luaL_checkinteger(L, arg) + +#else /* }{ */ + +#define l_timet lua_Number +#define l_pushtime(L,t) lua_pushnumber(L,(lua_Number)(t)) +#define l_gettime(L,arg) luaL_checknumber(L, arg) + +#endif /* } */ + + +#if !defined(l_gmtime) /* { */ +/* +** By default, Lua uses gmtime/localtime, except when POSIX is available, +** where it uses gmtime_r/localtime_r +*/ + +#if defined(LUA_USE_POSIX) /* { */ + +#define l_gmtime(t,r) gmtime_r(t,r) +#define l_localtime(t,r) localtime_r(t,r) + +#else /* }{ */ + +/* ISO C definitions */ +#define l_gmtime(t,r) ((void)(r)->tm_sec, gmtime(t)) +#define l_localtime(t,r) ((void)(r)->tm_sec, localtime(t)) + +#endif /* } */ + +#endif /* } */ + +/* }================================================================== */ + + +/* +** {================================================================== +** Configuration for 'tmpnam': +** By default, Lua uses tmpnam except when POSIX is available, where +** it uses mkstemp. +** =================================================================== +*/ +#if !defined(lua_tmpnam) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#include + +#define LUA_TMPNAMBUFSIZE 32 + +#if !defined(LUA_TMPNAMTEMPLATE) +#define LUA_TMPNAMTEMPLATE "/tmp/lua_XXXXXX" +#endif + +#define lua_tmpnam(b,e) { \ + strcpy(b, LUA_TMPNAMTEMPLATE); \ + e = mkstemp(b); \ + if (e != -1) close(e); \ + e = (e == -1); } + +#else /* }{ */ + +/* ISO C definitions */ +#define LUA_TMPNAMBUFSIZE L_tmpnam +#define lua_tmpnam(b,e) { e = (tmpnam(b) == NULL); } + +#endif /* } */ + +#endif /* } */ +/* }================================================================== */ + + +#if !defined(l_system) +#if defined(LUA_USE_IOS) +/* Despite claiming to be ISO C, iOS does not implement 'system'. */ +#define l_system(cmd) ((cmd) == NULL ? 0 : -1) +#else +#define l_system(cmd) system(cmd) /* default definition */ +#endif +#endif + + +static int os_execute (lua_State *L) { + const char *cmd = luaL_optstring(L, 1, NULL); + int stat; + errno = 0; + stat = l_system(cmd); + if (cmd != NULL) + return luaL_execresult(L, stat); + else { + lua_pushboolean(L, stat); /* true if there is a shell */ + return 1; + } +} + + +static int os_remove (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + return luaL_fileresult(L, remove(filename) == 0, filename); +} + + +static int os_rename (lua_State *L) { + const char *fromname = luaL_checkstring(L, 1); + const char *toname = luaL_checkstring(L, 2); + return luaL_fileresult(L, rename(fromname, toname) == 0, NULL); +} + + +static int os_tmpname (lua_State *L) { + char buff[LUA_TMPNAMBUFSIZE]; + int err; + lua_tmpnam(buff, err); + if (l_unlikely(err)) + return luaL_error(L, "unable to generate a unique filename"); + lua_pushstring(L, buff); + return 1; +} + + +static int os_getenv (lua_State *L) { + lua_pushstring(L, getenv(luaL_checkstring(L, 1))); /* if NULL push nil */ + return 1; +} + + +static int os_clock (lua_State *L) { + lua_pushnumber(L, ((lua_Number)clock())/(lua_Number)CLOCKS_PER_SEC); + return 1; +} + + +/* +** {====================================================== +** Time/Date operations +** { year=%Y, month=%m, day=%d, hour=%H, min=%M, sec=%S, +** wday=%w+1, yday=%j, isdst=? } +** ======================================================= +*/ + +/* +** About the overflow check: an overflow cannot occur when time +** is represented by a lua_Integer, because either lua_Integer is +** large enough to represent all int fields or it is not large enough +** to represent a time that cause a field to overflow. However, if +** times are represented as doubles and lua_Integer is int, then the +** time 0x1.e1853b0d184f6p+55 would cause an overflow when adding 1900 +** to compute the year. +*/ +static void setfield (lua_State *L, const char *key, int value, int delta) { + #if (defined(LUA_NUMTIME) && LUA_MAXINTEGER <= INT_MAX) + if (l_unlikely(value > LUA_MAXINTEGER - delta)) + luaL_error(L, "field '%s' is out-of-bound", key); + #endif + lua_pushinteger(L, (lua_Integer)value + delta); + lua_setfield(L, -2, key); +} + + +static void setboolfield (lua_State *L, const char *key, int value) { + if (value < 0) /* undefined? */ + return; /* does not set field */ + lua_pushboolean(L, value); + lua_setfield(L, -2, key); +} + + +/* +** Set all fields from structure 'tm' in the table on top of the stack +*/ +static void setallfields (lua_State *L, struct tm *stm) { + setfield(L, "year", stm->tm_year, 1900); + setfield(L, "month", stm->tm_mon, 1); + setfield(L, "day", stm->tm_mday, 0); + setfield(L, "hour", stm->tm_hour, 0); + setfield(L, "min", stm->tm_min, 0); + setfield(L, "sec", stm->tm_sec, 0); + setfield(L, "yday", stm->tm_yday, 1); + setfield(L, "wday", stm->tm_wday, 1); + setboolfield(L, "isdst", stm->tm_isdst); +} + + +static int getboolfield (lua_State *L, const char *key) { + int res; + res = (lua_getfield(L, -1, key) == LUA_TNIL) ? -1 : lua_toboolean(L, -1); + lua_pop(L, 1); + return res; +} + + +static int getfield (lua_State *L, const char *key, int d, int delta) { + int isnum; + int t = lua_getfield(L, -1, key); /* get field and its type */ + lua_Integer res = lua_tointegerx(L, -1, &isnum); + if (!isnum) { /* field is not an integer? */ + if (l_unlikely(t != LUA_TNIL)) /* some other value? */ + return luaL_error(L, "field '%s' is not an integer", key); + else if (l_unlikely(d < 0)) /* absent field; no default? */ + return luaL_error(L, "field '%s' missing in date table", key); + res = d; + } + else { + if (!(res >= 0 ? res - delta <= INT_MAX : INT_MIN + delta <= res)) + return luaL_error(L, "field '%s' is out-of-bound", key); + res -= delta; + } + lua_pop(L, 1); + return (int)res; +} + + +static const char *checkoption (lua_State *L, const char *conv, + ptrdiff_t convlen, char *buff) { + const char *option = LUA_STRFTIMEOPTIONS; + int oplen = 1; /* length of options being checked */ + for (; *option != '\0' && oplen <= convlen; option += oplen) { + if (*option == '|') /* next block? */ + oplen++; /* will check options with next length (+1) */ + else if (memcmp(conv, option, oplen) == 0) { /* match? */ + memcpy(buff, conv, oplen); /* copy valid option to buffer */ + buff[oplen] = '\0'; + return conv + oplen; /* return next item */ + } + } + luaL_argerror(L, 1, + lua_pushfstring(L, "invalid conversion specifier '%%%s'", conv)); + return conv; /* to avoid warnings */ +} + + +static time_t l_checktime (lua_State *L, int arg) { + l_timet t = l_gettime(L, arg); + luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds"); + return (time_t)t; +} + + +/* maximum size for an individual 'strftime' item */ +#define SIZETIMEFMT 250 + + +static int os_date (lua_State *L) { + size_t slen; + const char *s = luaL_optlstring(L, 1, "%c", &slen); + time_t t = luaL_opt(L, l_checktime, 2, time(NULL)); + const char *se = s + slen; /* 's' end */ + struct tm tmr, *stm; + if (*s == '!') { /* UTC? */ + stm = l_gmtime(&t, &tmr); + s++; /* skip '!' */ + } + else + stm = l_localtime(&t, &tmr); + if (stm == NULL) /* invalid date? */ + return luaL_error(L, + "date result cannot be represented in this installation"); + if (strcmp(s, "*t") == 0) { + lua_createtable(L, 0, 9); /* 9 = number of fields */ + setallfields(L, stm); + } + else { + char cc[4]; /* buffer for individual conversion specifiers */ + luaL_Buffer b; + cc[0] = '%'; + luaL_buffinit(L, &b); + while (s < se) { + if (*s != '%') /* not a conversion specifier? */ + luaL_addchar(&b, *s++); + else { + size_t reslen; + char *buff = luaL_prepbuffsize(&b, SIZETIMEFMT); + s++; /* skip '%' */ + s = checkoption(L, s, se - s, cc + 1); /* copy specifier to 'cc' */ + reslen = strftime(buff, SIZETIMEFMT, cc, stm); + luaL_addsize(&b, reslen); + } + } + luaL_pushresult(&b); + } + return 1; +} + + +static int os_time (lua_State *L) { + time_t t; + if (lua_isnoneornil(L, 1)) /* called without args? */ + t = time(NULL); /* get current time */ + else { + struct tm ts; + luaL_checktype(L, 1, LUA_TTABLE); + lua_settop(L, 1); /* make sure table is at the top */ + ts.tm_year = getfield(L, "year", -1, 1900); + ts.tm_mon = getfield(L, "month", -1, 1); + ts.tm_mday = getfield(L, "day", -1, 0); + ts.tm_hour = getfield(L, "hour", 12, 0); + ts.tm_min = getfield(L, "min", 0, 0); + ts.tm_sec = getfield(L, "sec", 0, 0); + ts.tm_isdst = getboolfield(L, "isdst"); + t = mktime(&ts); + setallfields(L, &ts); /* update fields with normalized values */ + } + if (t != (time_t)(l_timet)t || t == (time_t)(-1)) + return luaL_error(L, + "time result cannot be represented in this installation"); + l_pushtime(L, t); + return 1; +} + + +static int os_difftime (lua_State *L) { + time_t t1 = l_checktime(L, 1); + time_t t2 = l_checktime(L, 2); + lua_pushnumber(L, (lua_Number)difftime(t1, t2)); + return 1; +} + +/* }====================================================== */ + + +static int os_setlocale (lua_State *L) { + static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY, + LC_NUMERIC, LC_TIME}; + static const char *const catnames[] = {"all", "collate", "ctype", "monetary", + "numeric", "time", NULL}; + const char *l = luaL_optstring(L, 1, NULL); + int op = luaL_checkoption(L, 2, "all", catnames); + lua_pushstring(L, setlocale(cat[op], l)); + return 1; +} + + +static int os_exit (lua_State *L) { + int status; + if (lua_isboolean(L, 1)) + status = (lua_toboolean(L, 1) ? EXIT_SUCCESS : EXIT_FAILURE); + else + status = (int)luaL_optinteger(L, 1, EXIT_SUCCESS); + if (lua_toboolean(L, 2)) + lua_close(L); + if (L) exit(status); /* 'if' to avoid warnings for unreachable 'return' */ + return 0; +} + + +static const luaL_Reg syslib[] = { + {"clock", os_clock}, + {"date", os_date}, + {"difftime", os_difftime}, + {"execute", os_execute}, + {"exit", os_exit}, + {"getenv", os_getenv}, + {"remove", os_remove}, + {"rename", os_rename}, + {"setlocale", os_setlocale}, + {"time", os_time}, + {"tmpname", os_tmpname}, + {NULL, NULL} +}; + +/* }====================================================== */ + + + +LUAMOD_API int luaopen_os (lua_State *L) { + luaL_newlib(L, syslib); + return 1; +} + diff --git a/src/lparser.c b/src/lparser.c new file mode 100644 index 0000000..b745f23 --- /dev/null +++ b/src/lparser.c @@ -0,0 +1,1967 @@ +/* +** $Id: lparser.c $ +** Lua Parser +** See Copyright Notice in lua.h +*/ + +#define lparser_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include + +#include "lua.h" + +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "llex.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" + + + +/* maximum number of local variables per function (must be smaller + than 250, due to the bytecode format) */ +#define MAXVARS 200 + + +#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) + + +/* because all strings are unified by the scanner, the parser + can use pointer equality for string equality */ +#define eqstr(a,b) ((a) == (b)) + + +/* +** nodes for block list (list of active blocks) +*/ +typedef struct BlockCnt { + struct BlockCnt *previous; /* chain */ + int firstlabel; /* index of first label in this block */ + int firstgoto; /* index of first pending goto in this block */ + lu_byte nactvar; /* # active locals outside the block */ + lu_byte upval; /* true if some variable in the block is an upvalue */ + lu_byte isloop; /* true if 'block' is a loop */ + lu_byte insidetbc; /* true if inside the scope of a to-be-closed var. */ +} BlockCnt; + + + +/* +** prototypes for recursive non-terminal functions +*/ +static void statement (LexState *ls); +static void expr (LexState *ls, expdesc *v); + + +static l_noret error_expected (LexState *ls, int token) { + luaX_syntaxerror(ls, + luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token))); +} + + +static l_noret errorlimit (FuncState *fs, int limit, const char *what) { + lua_State *L = fs->ls->L; + const char *msg; + int line = fs->f->linedefined; + const char *where = (line == 0) + ? "main function" + : luaO_pushfstring(L, "function at line %d", line); + msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s", + what, limit, where); + luaX_syntaxerror(fs->ls, msg); +} + + +static void checklimit (FuncState *fs, int v, int l, const char *what) { + if (v > l) errorlimit(fs, l, what); +} + + +/* +** Test whether next token is 'c'; if so, skip it. +*/ +static int testnext (LexState *ls, int c) { + if (ls->t.token == c) { + luaX_next(ls); + return 1; + } + else return 0; +} + + +/* +** Check that next token is 'c'. +*/ +static void check (LexState *ls, int c) { + if (ls->t.token != c) + error_expected(ls, c); +} + + +/* +** Check that next token is 'c' and skip it. +*/ +static void checknext (LexState *ls, int c) { + check(ls, c); + luaX_next(ls); +} + + +#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } + + +/* +** Check that next token is 'what' and skip it. In case of error, +** raise an error that the expected 'what' should match a 'who' +** in line 'where' (if that is not the current line). +*/ +static void check_match (LexState *ls, int what, int who, int where) { + if (l_unlikely(!testnext(ls, what))) { + if (where == ls->linenumber) /* all in the same line? */ + error_expected(ls, what); /* do not need a complex message */ + else { + luaX_syntaxerror(ls, luaO_pushfstring(ls->L, + "%s expected (to close %s at line %d)", + luaX_token2str(ls, what), luaX_token2str(ls, who), where)); + } + } +} + + +static TString *str_checkname (LexState *ls) { + TString *ts; + check(ls, TK_NAME); + ts = ls->t.seminfo.ts; + luaX_next(ls); + return ts; +} + + +static void init_exp (expdesc *e, expkind k, int i) { + e->f = e->t = NO_JUMP; + e->k = k; + e->u.info = i; +} + + +static void codestring (expdesc *e, TString *s) { + e->f = e->t = NO_JUMP; + e->k = VKSTR; + e->u.strval = s; +} + + +static void codename (LexState *ls, expdesc *e) { + codestring(e, str_checkname(ls)); +} + + +/* +** Register a new local variable in the active 'Proto' (for debug +** information). +*/ +static int registerlocalvar (LexState *ls, FuncState *fs, TString *varname) { + Proto *f = fs->f; + int oldsize = f->sizelocvars; + luaM_growvector(ls->L, f->locvars, fs->ndebugvars, f->sizelocvars, + LocVar, SHRT_MAX, "local variables"); + while (oldsize < f->sizelocvars) + f->locvars[oldsize++].varname = NULL; + f->locvars[fs->ndebugvars].varname = varname; + f->locvars[fs->ndebugvars].startpc = fs->pc; + luaC_objbarrier(ls->L, f, varname); + return fs->ndebugvars++; +} + + +/* +** Create a new local variable with the given 'name'. Return its index +** in the function. +*/ +static int new_localvar (LexState *ls, TString *name) { + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Dyndata *dyd = ls->dyd; + Vardesc *var; + checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal, + MAXVARS, "local variables"); + luaM_growvector(L, dyd->actvar.arr, dyd->actvar.n + 1, + dyd->actvar.size, Vardesc, USHRT_MAX, "local variables"); + var = &dyd->actvar.arr[dyd->actvar.n++]; + var->vd.kind = VDKREG; /* default */ + var->vd.name = name; + return dyd->actvar.n - 1 - fs->firstlocal; +} + +#define new_localvarliteral(ls,v) \ + new_localvar(ls, \ + luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char)) - 1)); + + + +/* +** Return the "variable description" (Vardesc) of a given variable. +** (Unless noted otherwise, all variables are referred to by their +** compiler indices.) +*/ +static Vardesc *getlocalvardesc (FuncState *fs, int vidx) { + return &fs->ls->dyd->actvar.arr[fs->firstlocal + vidx]; +} + + +/* +** Convert 'nvar', a compiler index level, to its corresponding +** register. For that, search for the highest variable below that level +** that is in a register and uses its register index ('ridx') plus one. +*/ +static int reglevel (FuncState *fs, int nvar) { + while (nvar-- > 0) { + Vardesc *vd = getlocalvardesc(fs, nvar); /* get previous variable */ + if (vd->vd.kind != RDKCTC) /* is in a register? */ + return vd->vd.ridx + 1; + } + return 0; /* no variables in registers */ +} + + +/* +** Return the number of variables in the register stack for the given +** function. +*/ +int luaY_nvarstack (FuncState *fs) { + return reglevel(fs, fs->nactvar); +} + + +/* +** Get the debug-information entry for current variable 'vidx'. +*/ +static LocVar *localdebuginfo (FuncState *fs, int vidx) { + Vardesc *vd = getlocalvardesc(fs, vidx); + if (vd->vd.kind == RDKCTC) + return NULL; /* no debug info. for constants */ + else { + int idx = vd->vd.pidx; + lua_assert(idx < fs->ndebugvars); + return &fs->f->locvars[idx]; + } +} + + +/* +** Create an expression representing variable 'vidx' +*/ +static void init_var (FuncState *fs, expdesc *e, int vidx) { + e->f = e->t = NO_JUMP; + e->k = VLOCAL; + e->u.var.vidx = vidx; + e->u.var.ridx = getlocalvardesc(fs, vidx)->vd.ridx; +} + + +/* +** Raises an error if variable described by 'e' is read only +*/ +static void check_readonly (LexState *ls, expdesc *e) { + FuncState *fs = ls->fs; + TString *varname = NULL; /* to be set if variable is const */ + switch (e->k) { + case VCONST: { + varname = ls->dyd->actvar.arr[e->u.info].vd.name; + break; + } + case VLOCAL: { + Vardesc *vardesc = getlocalvardesc(fs, e->u.var.vidx); + if (vardesc->vd.kind != VDKREG) /* not a regular variable? */ + varname = vardesc->vd.name; + break; + } + case VUPVAL: { + Upvaldesc *up = &fs->f->upvalues[e->u.info]; + if (up->kind != VDKREG) + varname = up->name; + break; + } + default: + return; /* other cases cannot be read-only */ + } + if (varname) { + const char *msg = luaO_pushfstring(ls->L, + "attempt to assign to const variable '%s'", getstr(varname)); + luaK_semerror(ls, msg); /* error */ + } +} + + +/* +** Start the scope for the last 'nvars' created variables. +*/ +static void adjustlocalvars (LexState *ls, int nvars) { + FuncState *fs = ls->fs; + int reglevel = luaY_nvarstack(fs); + int i; + for (i = 0; i < nvars; i++) { + int vidx = fs->nactvar++; + Vardesc *var = getlocalvardesc(fs, vidx); + var->vd.ridx = reglevel++; + var->vd.pidx = registerlocalvar(ls, fs, var->vd.name); + } +} + + +/* +** Close the scope for all variables up to level 'tolevel'. +** (debug info.) +*/ +static void removevars (FuncState *fs, int tolevel) { + fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel); + while (fs->nactvar > tolevel) { + LocVar *var = localdebuginfo(fs, --fs->nactvar); + if (var) /* does it have debug information? */ + var->endpc = fs->pc; + } +} + + +/* +** Search the upvalues of the function 'fs' for one +** with the given 'name'. +*/ +static int searchupvalue (FuncState *fs, TString *name) { + int i; + Upvaldesc *up = fs->f->upvalues; + for (i = 0; i < fs->nups; i++) { + if (eqstr(up[i].name, name)) return i; + } + return -1; /* not found */ +} + + +static Upvaldesc *allocupvalue (FuncState *fs) { + Proto *f = fs->f; + int oldsize = f->sizeupvalues; + checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues"); + luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues, + Upvaldesc, MAXUPVAL, "upvalues"); + while (oldsize < f->sizeupvalues) + f->upvalues[oldsize++].name = NULL; + return &f->upvalues[fs->nups++]; +} + + +static int newupvalue (FuncState *fs, TString *name, expdesc *v) { + Upvaldesc *up = allocupvalue(fs); + FuncState *prev = fs->prev; + if (v->k == VLOCAL) { + up->instack = 1; + up->idx = v->u.var.ridx; + up->kind = getlocalvardesc(prev, v->u.var.vidx)->vd.kind; + lua_assert(eqstr(name, getlocalvardesc(prev, v->u.var.vidx)->vd.name)); + } + else { + up->instack = 0; + up->idx = cast_byte(v->u.info); + up->kind = prev->f->upvalues[v->u.info].kind; + lua_assert(eqstr(name, prev->f->upvalues[v->u.info].name)); + } + up->name = name; + luaC_objbarrier(fs->ls->L, fs->f, name); + return fs->nups - 1; +} + + +/* +** Look for an active local variable with the name 'n' in the +** function 'fs'. If found, initialize 'var' with it and return +** its expression kind; otherwise return -1. +*/ +static int searchvar (FuncState *fs, TString *n, expdesc *var) { + int i; + for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) { + Vardesc *vd = getlocalvardesc(fs, i); + if (eqstr(n, vd->vd.name)) { /* found? */ + if (vd->vd.kind == RDKCTC) /* compile-time constant? */ + init_exp(var, VCONST, fs->firstlocal + i); + else /* real variable */ + init_var(fs, var, i); + return var->k; + } + } + return -1; /* not found */ +} + + +/* +** Mark block where variable at given level was defined +** (to emit close instructions later). +*/ +static void markupval (FuncState *fs, int level) { + BlockCnt *bl = fs->bl; + while (bl->nactvar > level) + bl = bl->previous; + bl->upval = 1; + fs->needclose = 1; +} + + +/* +** Mark that current block has a to-be-closed variable. +*/ +static void marktobeclosed (FuncState *fs) { + BlockCnt *bl = fs->bl; + bl->upval = 1; + bl->insidetbc = 1; + fs->needclose = 1; +} + + +/* +** Find a variable with the given name 'n'. If it is an upvalue, add +** this upvalue into all intermediate functions. If it is a global, set +** 'var' as 'void' as a flag. +*/ +static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { + if (fs == NULL) /* no more levels? */ + init_exp(var, VVOID, 0); /* default is global */ + else { + int v = searchvar(fs, n, var); /* look up locals at current level */ + if (v >= 0) { /* found? */ + if (v == VLOCAL && !base) + markupval(fs, var->u.var.vidx); /* local will be used as an upval */ + } + else { /* not found as local at current level; try upvalues */ + int idx = searchupvalue(fs, n); /* try existing upvalues */ + if (idx < 0) { /* not found? */ + singlevaraux(fs->prev, n, var, 0); /* try upper levels */ + if (var->k == VLOCAL || var->k == VUPVAL) /* local or upvalue? */ + idx = newupvalue(fs, n, var); /* will be a new upvalue */ + else /* it is a global or a constant */ + return; /* don't need to do anything at this level */ + } + init_exp(var, VUPVAL, idx); /* new or old upvalue */ + } + } +} + + +/* +** Find a variable with the given name 'n', handling global variables +** too. +*/ +static void singlevar (LexState *ls, expdesc *var) { + TString *varname = str_checkname(ls); + FuncState *fs = ls->fs; + singlevaraux(fs, varname, var, 1); + if (var->k == VVOID) { /* global name? */ + expdesc key; + singlevaraux(fs, ls->envn, var, 1); /* get environment variable */ + lua_assert(var->k != VVOID); /* this one must exist */ + luaK_exp2anyregup(fs, var); /* but could be a constant */ + codestring(&key, varname); /* key is variable name */ + luaK_indexed(fs, var, &key); /* env[varname] */ + } +} + + +/* +** Adjust the number of results from an expression list 'e' with 'nexps' +** expressions to 'nvars' values. +*/ +static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { + FuncState *fs = ls->fs; + int needed = nvars - nexps; /* extra values needed */ + if (hasmultret(e->k)) { /* last expression has multiple returns? */ + int extra = needed + 1; /* discount last expression itself */ + if (extra < 0) + extra = 0; + luaK_setreturns(fs, e, extra); /* last exp. provides the difference */ + } + else { + if (e->k != VVOID) /* at least one expression? */ + luaK_exp2nextreg(fs, e); /* close last expression */ + if (needed > 0) /* missing values? */ + luaK_nil(fs, fs->freereg, needed); /* complete with nils */ + } + if (needed > 0) + luaK_reserveregs(fs, needed); /* registers for extra values */ + else /* adding 'needed' is actually a subtraction */ + fs->freereg += needed; /* remove extra values */ +} + + +#define enterlevel(ls) luaE_incCstack(ls->L) + + +#define leavelevel(ls) ((ls)->L->nCcalls--) + + +/* +** Generates an error that a goto jumps into the scope of some +** local variable. +*/ +static l_noret jumpscopeerror (LexState *ls, Labeldesc *gt) { + const char *varname = getstr(getlocalvardesc(ls->fs, gt->nactvar)->vd.name); + const char *msg = " at line %d jumps into the scope of local '%s'"; + msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line, varname); + luaK_semerror(ls, msg); /* raise the error */ +} + + +/* +** Solves the goto at index 'g' to given 'label' and removes it +** from the list of pending gotos. +** If it jumps into the scope of some variable, raises an error. +*/ +static void solvegoto (LexState *ls, int g, Labeldesc *label) { + int i; + Labellist *gl = &ls->dyd->gt; /* list of gotos */ + Labeldesc *gt = &gl->arr[g]; /* goto to be resolved */ + lua_assert(eqstr(gt->name, label->name)); + if (l_unlikely(gt->nactvar < label->nactvar)) /* enter some scope? */ + jumpscopeerror(ls, gt); + luaK_patchlist(ls->fs, gt->pc, label->pc); + for (i = g; i < gl->n - 1; i++) /* remove goto from pending list */ + gl->arr[i] = gl->arr[i + 1]; + gl->n--; +} + + +/* +** Search for an active label with the given name. +*/ +static Labeldesc *findlabel (LexState *ls, TString *name) { + int i; + Dyndata *dyd = ls->dyd; + /* check labels in current function for a match */ + for (i = ls->fs->firstlabel; i < dyd->label.n; i++) { + Labeldesc *lb = &dyd->label.arr[i]; + if (eqstr(lb->name, name)) /* correct label? */ + return lb; + } + return NULL; /* label not found */ +} + + +/* +** Adds a new label/goto in the corresponding list. +*/ +static int newlabelentry (LexState *ls, Labellist *l, TString *name, + int line, int pc) { + int n = l->n; + luaM_growvector(ls->L, l->arr, n, l->size, + Labeldesc, SHRT_MAX, "labels/gotos"); + l->arr[n].name = name; + l->arr[n].line = line; + l->arr[n].nactvar = ls->fs->nactvar; + l->arr[n].close = 0; + l->arr[n].pc = pc; + l->n = n + 1; + return n; +} + + +static int newgotoentry (LexState *ls, TString *name, int line, int pc) { + return newlabelentry(ls, &ls->dyd->gt, name, line, pc); +} + + +/* +** Solves forward jumps. Check whether new label 'lb' matches any +** pending gotos in current block and solves them. Return true +** if any of the gotos need to close upvalues. +*/ +static int solvegotos (LexState *ls, Labeldesc *lb) { + Labellist *gl = &ls->dyd->gt; + int i = ls->fs->bl->firstgoto; + int needsclose = 0; + while (i < gl->n) { + if (eqstr(gl->arr[i].name, lb->name)) { + needsclose |= gl->arr[i].close; + solvegoto(ls, i, lb); /* will remove 'i' from the list */ + } + else + i++; + } + return needsclose; +} + + +/* +** Create a new label with the given 'name' at the given 'line'. +** 'last' tells whether label is the last non-op statement in its +** block. Solves all pending gotos to this new label and adds +** a close instruction if necessary. +** Returns true iff it added a close instruction. +*/ +static int createlabel (LexState *ls, TString *name, int line, + int last) { + FuncState *fs = ls->fs; + Labellist *ll = &ls->dyd->label; + int l = newlabelentry(ls, ll, name, line, luaK_getlabel(fs)); + if (last) { /* label is last no-op statement in the block? */ + /* assume that locals are already out of scope */ + ll->arr[l].nactvar = fs->bl->nactvar; + } + if (solvegotos(ls, &ll->arr[l])) { /* need close? */ + luaK_codeABC(fs, OP_CLOSE, luaY_nvarstack(fs), 0, 0); + return 1; + } + return 0; +} + + +/* +** Adjust pending gotos to outer level of a block. +*/ +static void movegotosout (FuncState *fs, BlockCnt *bl) { + int i; + Labellist *gl = &fs->ls->dyd->gt; + /* correct pending gotos to current block */ + for (i = bl->firstgoto; i < gl->n; i++) { /* for each pending goto */ + Labeldesc *gt = &gl->arr[i]; + /* leaving a variable scope? */ + if (reglevel(fs, gt->nactvar) > reglevel(fs, bl->nactvar)) + gt->close |= bl->upval; /* jump may need a close */ + gt->nactvar = bl->nactvar; /* update goto level */ + } +} + + +static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) { + bl->isloop = isloop; + bl->nactvar = fs->nactvar; + bl->firstlabel = fs->ls->dyd->label.n; + bl->firstgoto = fs->ls->dyd->gt.n; + bl->upval = 0; + bl->insidetbc = (fs->bl != NULL && fs->bl->insidetbc); + bl->previous = fs->bl; + fs->bl = bl; + lua_assert(fs->freereg == luaY_nvarstack(fs)); +} + + +/* +** generates an error for an undefined 'goto'. +*/ +static l_noret undefgoto (LexState *ls, Labeldesc *gt) { + const char *msg; + if (eqstr(gt->name, luaS_newliteral(ls->L, "break"))) { + msg = "break outside loop at line %d"; + msg = luaO_pushfstring(ls->L, msg, gt->line); + } + else { + msg = "no visible label '%s' for at line %d"; + msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line); + } + luaK_semerror(ls, msg); +} + + +static void leaveblock (FuncState *fs) { + BlockCnt *bl = fs->bl; + LexState *ls = fs->ls; + int hasclose = 0; + int stklevel = reglevel(fs, bl->nactvar); /* level outside the block */ + removevars(fs, bl->nactvar); /* remove block locals */ + lua_assert(bl->nactvar == fs->nactvar); /* back to level on entry */ + if (bl->isloop) /* has to fix pending breaks? */ + hasclose = createlabel(ls, luaS_newliteral(ls->L, "break"), 0, 0); + if (!hasclose && bl->previous && bl->upval) /* still need a 'close'? */ + luaK_codeABC(fs, OP_CLOSE, stklevel, 0, 0); + fs->freereg = stklevel; /* free registers */ + ls->dyd->label.n = bl->firstlabel; /* remove local labels */ + fs->bl = bl->previous; /* current block now is previous one */ + if (bl->previous) /* was it a nested block? */ + movegotosout(fs, bl); /* update pending gotos to enclosing block */ + else { + if (bl->firstgoto < ls->dyd->gt.n) /* still pending gotos? */ + undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */ + } +} + + +/* +** adds a new prototype into list of prototypes +*/ +static Proto *addprototype (LexState *ls) { + Proto *clp; + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Proto *f = fs->f; /* prototype of current function */ + if (fs->np >= f->sizep) { + int oldsize = f->sizep; + luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions"); + while (oldsize < f->sizep) + f->p[oldsize++] = NULL; + } + f->p[fs->np++] = clp = luaF_newproto(L); + luaC_objbarrier(L, f, clp); + return clp; +} + + +/* +** codes instruction to create new closure in parent function. +** The OP_CLOSURE instruction uses the last available register, +** so that, if it invokes the GC, the GC knows which registers +** are in use at that time. + +*/ +static void codeclosure (LexState *ls, expdesc *v) { + FuncState *fs = ls->fs->prev; + init_exp(v, VRELOC, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1)); + luaK_exp2nextreg(fs, v); /* fix it at the last register */ +} + + +static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) { + Proto *f = fs->f; + fs->prev = ls->fs; /* linked list of funcstates */ + fs->ls = ls; + ls->fs = fs; + fs->pc = 0; + fs->previousline = f->linedefined; + fs->iwthabs = 0; + fs->lasttarget = 0; + fs->freereg = 0; + fs->nk = 0; + fs->nabslineinfo = 0; + fs->np = 0; + fs->nups = 0; + fs->ndebugvars = 0; + fs->nactvar = 0; + fs->needclose = 0; + fs->firstlocal = ls->dyd->actvar.n; + fs->firstlabel = ls->dyd->label.n; + fs->bl = NULL; + f->source = ls->source; + luaC_objbarrier(ls->L, f, f->source); + f->maxstacksize = 2; /* registers 0/1 are always valid */ + enterblock(fs, bl, 0); +} + + +static void close_func (LexState *ls) { + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Proto *f = fs->f; + luaK_ret(fs, luaY_nvarstack(fs), 0); /* final return */ + leaveblock(fs); + lua_assert(fs->bl == NULL); + luaK_finish(fs); + luaM_shrinkvector(L, f->code, f->sizecode, fs->pc, Instruction); + luaM_shrinkvector(L, f->lineinfo, f->sizelineinfo, fs->pc, ls_byte); + luaM_shrinkvector(L, f->abslineinfo, f->sizeabslineinfo, + fs->nabslineinfo, AbsLineInfo); + luaM_shrinkvector(L, f->k, f->sizek, fs->nk, TValue); + luaM_shrinkvector(L, f->p, f->sizep, fs->np, Proto *); + luaM_shrinkvector(L, f->locvars, f->sizelocvars, fs->ndebugvars, LocVar); + luaM_shrinkvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc); + ls->fs = fs->prev; + luaC_checkGC(L); +} + + + +/*============================================================*/ +/* GRAMMAR RULES */ +/*============================================================*/ + + +/* +** check whether current token is in the follow set of a block. +** 'until' closes syntactical blocks, but do not close scope, +** so it is handled in separate. +*/ +static int block_follow (LexState *ls, int withuntil) { + switch (ls->t.token) { + case TK_ELSE: case TK_ELSEIF: + case TK_END: case TK_EOS: + return 1; + case TK_UNTIL: return withuntil; + default: return 0; + } +} + + +static void statlist (LexState *ls) { + /* statlist -> { stat [';'] } */ + while (!block_follow(ls, 1)) { + if (ls->t.token == TK_RETURN) { + statement(ls); + return; /* 'return' must be last statement */ + } + statement(ls); + } +} + + +static void fieldsel (LexState *ls, expdesc *v) { + /* fieldsel -> ['.' | ':'] NAME */ + FuncState *fs = ls->fs; + expdesc key; + luaK_exp2anyregup(fs, v); + luaX_next(ls); /* skip the dot or colon */ + codename(ls, &key); + luaK_indexed(fs, v, &key); +} + + +static void yindex (LexState *ls, expdesc *v) { + /* index -> '[' expr ']' */ + luaX_next(ls); /* skip the '[' */ + expr(ls, v); + luaK_exp2val(ls->fs, v); + checknext(ls, ']'); +} + + +/* +** {====================================================================== +** Rules for Constructors +** ======================================================================= +*/ + + +typedef struct ConsControl { + expdesc v; /* last list item read */ + expdesc *t; /* table descriptor */ + int nh; /* total number of 'record' elements */ + int na; /* number of array elements already stored */ + int tostore; /* number of array elements pending to be stored */ +} ConsControl; + + +static void recfield (LexState *ls, ConsControl *cc) { + /* recfield -> (NAME | '['exp']') = exp */ + FuncState *fs = ls->fs; + int reg = ls->fs->freereg; + expdesc tab, key, val; + if (ls->t.token == TK_NAME) { + checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); + codename(ls, &key); + } + else /* ls->t.token == '[' */ + yindex(ls, &key); + cc->nh++; + checknext(ls, '='); + tab = *cc->t; + luaK_indexed(fs, &tab, &key); + expr(ls, &val); + luaK_storevar(fs, &tab, &val); + fs->freereg = reg; /* free registers */ +} + + +static void closelistfield (FuncState *fs, ConsControl *cc) { + if (cc->v.k == VVOID) return; /* there is no list item */ + luaK_exp2nextreg(fs, &cc->v); + cc->v.k = VVOID; + if (cc->tostore == LFIELDS_PER_FLUSH) { + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */ + cc->na += cc->tostore; + cc->tostore = 0; /* no more items pending */ + } +} + + +static void lastlistfield (FuncState *fs, ConsControl *cc) { + if (cc->tostore == 0) return; + if (hasmultret(cc->v.k)) { + luaK_setmultret(fs, &cc->v); + luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET); + cc->na--; /* do not count last expression (unknown number of elements) */ + } + else { + if (cc->v.k != VVOID) + luaK_exp2nextreg(fs, &cc->v); + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); + } + cc->na += cc->tostore; +} + + +static void listfield (LexState *ls, ConsControl *cc) { + /* listfield -> exp */ + expr(ls, &cc->v); + cc->tostore++; +} + + +static void field (LexState *ls, ConsControl *cc) { + /* field -> listfield | recfield */ + switch(ls->t.token) { + case TK_NAME: { /* may be 'listfield' or 'recfield' */ + if (luaX_lookahead(ls) != '=') /* expression? */ + listfield(ls, cc); + else + recfield(ls, cc); + break; + } + case '[': { + recfield(ls, cc); + break; + } + default: { + listfield(ls, cc); + break; + } + } +} + + +static void constructor (LexState *ls, expdesc *t) { + /* constructor -> '{' [ field { sep field } [sep] ] '}' + sep -> ',' | ';' */ + FuncState *fs = ls->fs; + int line = ls->linenumber; + int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); + ConsControl cc; + luaK_code(fs, 0); /* space for extra arg. */ + cc.na = cc.nh = cc.tostore = 0; + cc.t = t; + init_exp(t, VNONRELOC, fs->freereg); /* table will be at stack top */ + luaK_reserveregs(fs, 1); + init_exp(&cc.v, VVOID, 0); /* no value (yet) */ + checknext(ls, '{'); + do { + lua_assert(cc.v.k == VVOID || cc.tostore > 0); + if (ls->t.token == '}') break; + closelistfield(fs, &cc); + field(ls, &cc); + } while (testnext(ls, ',') || testnext(ls, ';')); + check_match(ls, '}', '{', line); + lastlistfield(fs, &cc); + luaK_settablesize(fs, pc, t->u.info, cc.na, cc.nh); +} + +/* }====================================================================== */ + + +static void setvararg (FuncState *fs, int nparams) { + fs->f->is_vararg = 1; + luaK_codeABC(fs, OP_VARARGPREP, nparams, 0, 0); +} + + +static void parlist (LexState *ls) { + /* parlist -> [ {NAME ','} (NAME | '...') ] */ + FuncState *fs = ls->fs; + Proto *f = fs->f; + int nparams = 0; + int isvararg = 0; + if (ls->t.token != ')') { /* is 'parlist' not empty? */ + do { + switch (ls->t.token) { + case TK_NAME: { + new_localvar(ls, str_checkname(ls)); + nparams++; + break; + } + case TK_DOTS: { + luaX_next(ls); + isvararg = 1; + break; + } + default: luaX_syntaxerror(ls, " or '...' expected"); + } + } while (!isvararg && testnext(ls, ',')); + } + adjustlocalvars(ls, nparams); + f->numparams = cast_byte(fs->nactvar); + if (isvararg) + setvararg(fs, f->numparams); /* declared vararg */ + luaK_reserveregs(fs, fs->nactvar); /* reserve registers for parameters */ +} + + +static void body (LexState *ls, expdesc *e, int ismethod, int line) { + /* body -> '(' parlist ')' block END */ + FuncState new_fs; + BlockCnt bl; + new_fs.f = addprototype(ls); + new_fs.f->linedefined = line; + open_func(ls, &new_fs, &bl); + checknext(ls, '('); + if (ismethod) { + new_localvarliteral(ls, "self"); /* create 'self' parameter */ + adjustlocalvars(ls, 1); + } + parlist(ls); + checknext(ls, ')'); + statlist(ls); + new_fs.f->lastlinedefined = ls->linenumber; + check_match(ls, TK_END, TK_FUNCTION, line); + codeclosure(ls, e); + close_func(ls); +} + + +static int explist (LexState *ls, expdesc *v) { + /* explist -> expr { ',' expr } */ + int n = 1; /* at least one expression */ + expr(ls, v); + while (testnext(ls, ',')) { + luaK_exp2nextreg(ls->fs, v); + expr(ls, v); + n++; + } + return n; +} + + +static void funcargs (LexState *ls, expdesc *f, int line) { + FuncState *fs = ls->fs; + expdesc args; + int base, nparams; + switch (ls->t.token) { + case '(': { /* funcargs -> '(' [ explist ] ')' */ + luaX_next(ls); + if (ls->t.token == ')') /* arg list is empty? */ + args.k = VVOID; + else { + explist(ls, &args); + if (hasmultret(args.k)) + luaK_setmultret(fs, &args); + } + check_match(ls, ')', '(', line); + break; + } + case '{': { /* funcargs -> constructor */ + constructor(ls, &args); + break; + } + case TK_STRING: { /* funcargs -> STRING */ + codestring(&args, ls->t.seminfo.ts); + luaX_next(ls); /* must use 'seminfo' before 'next' */ + break; + } + default: { + luaX_syntaxerror(ls, "function arguments expected"); + } + } + lua_assert(f->k == VNONRELOC); + base = f->u.info; /* base register for call */ + if (hasmultret(args.k)) + nparams = LUA_MULTRET; /* open call */ + else { + if (args.k != VVOID) + luaK_exp2nextreg(fs, &args); /* close last argument */ + nparams = fs->freereg - (base+1); + } + init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); + luaK_fixline(fs, line); + fs->freereg = base+1; /* call remove function and arguments and leaves + (unless changed) one result */ +} + + + + +/* +** {====================================================================== +** Expression parsing +** ======================================================================= +*/ + + +static void primaryexp (LexState *ls, expdesc *v) { + /* primaryexp -> NAME | '(' expr ')' */ + switch (ls->t.token) { + case '(': { + int line = ls->linenumber; + luaX_next(ls); + expr(ls, v); + check_match(ls, ')', '(', line); + luaK_dischargevars(ls->fs, v); + return; + } + case TK_NAME: { + singlevar(ls, v); + return; + } + default: { + luaX_syntaxerror(ls, "unexpected symbol"); + } + } +} + + +static void suffixedexp (LexState *ls, expdesc *v) { + /* suffixedexp -> + primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */ + FuncState *fs = ls->fs; + int line = ls->linenumber; + primaryexp(ls, v); + for (;;) { + switch (ls->t.token) { + case '.': { /* fieldsel */ + fieldsel(ls, v); + break; + } + case '[': { /* '[' exp ']' */ + expdesc key; + luaK_exp2anyregup(fs, v); + yindex(ls, &key); + luaK_indexed(fs, v, &key); + break; + } + case ':': { /* ':' NAME funcargs */ + expdesc key; + luaX_next(ls); + codename(ls, &key); + luaK_self(fs, v, &key); + funcargs(ls, v, line); + break; + } + case '(': case TK_STRING: case '{': { /* funcargs */ + luaK_exp2nextreg(fs, v); + funcargs(ls, v, line); + break; + } + default: return; + } + } +} + + +static void simpleexp (LexState *ls, expdesc *v) { + /* simpleexp -> FLT | INT | STRING | NIL | TRUE | FALSE | ... | + constructor | FUNCTION body | suffixedexp */ + switch (ls->t.token) { + case TK_FLT: { + init_exp(v, VKFLT, 0); + v->u.nval = ls->t.seminfo.r; + break; + } + case TK_INT: { + init_exp(v, VKINT, 0); + v->u.ival = ls->t.seminfo.i; + break; + } + case TK_STRING: { + codestring(v, ls->t.seminfo.ts); + break; + } + case TK_NIL: { + init_exp(v, VNIL, 0); + break; + } + case TK_TRUE: { + init_exp(v, VTRUE, 0); + break; + } + case TK_FALSE: { + init_exp(v, VFALSE, 0); + break; + } + case TK_DOTS: { /* vararg */ + FuncState *fs = ls->fs; + check_condition(ls, fs->f->is_vararg, + "cannot use '...' outside a vararg function"); + init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 0, 1)); + break; + } + case '{': { /* constructor */ + constructor(ls, v); + return; + } + case TK_FUNCTION: { + luaX_next(ls); + body(ls, v, 0, ls->linenumber); + return; + } + default: { + suffixedexp(ls, v); + return; + } + } + luaX_next(ls); +} + + +static UnOpr getunopr (int op) { + switch (op) { + case TK_NOT: return OPR_NOT; + case '-': return OPR_MINUS; + case '~': return OPR_BNOT; + case '#': return OPR_LEN; + default: return OPR_NOUNOPR; + } +} + + +static BinOpr getbinopr (int op) { + switch (op) { + case '+': return OPR_ADD; + case '-': return OPR_SUB; + case '*': return OPR_MUL; + case '%': return OPR_MOD; + case '^': return OPR_POW; + case '/': return OPR_DIV; + case TK_IDIV: return OPR_IDIV; + case '&': return OPR_BAND; + case '|': return OPR_BOR; + case '~': return OPR_BXOR; + case TK_SHL: return OPR_SHL; + case TK_SHR: return OPR_SHR; + case TK_CONCAT: return OPR_CONCAT; + case TK_NE: return OPR_NE; + case TK_EQ: return OPR_EQ; + case '<': return OPR_LT; + case TK_LE: return OPR_LE; + case '>': return OPR_GT; + case TK_GE: return OPR_GE; + case TK_AND: return OPR_AND; + case TK_OR: return OPR_OR; + default: return OPR_NOBINOPR; + } +} + + +/* +** Priority table for binary operators. +*/ +static const struct { + lu_byte left; /* left priority for each binary operator */ + lu_byte right; /* right priority */ +} priority[] = { /* ORDER OPR */ + {10, 10}, {10, 10}, /* '+' '-' */ + {11, 11}, {11, 11}, /* '*' '%' */ + {14, 13}, /* '^' (right associative) */ + {11, 11}, {11, 11}, /* '/' '//' */ + {6, 6}, {4, 4}, {5, 5}, /* '&' '|' '~' */ + {7, 7}, {7, 7}, /* '<<' '>>' */ + {9, 8}, /* '..' (right associative) */ + {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */ + {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */ + {2, 2}, {1, 1} /* and, or */ +}; + +#define UNARY_PRIORITY 12 /* priority for unary operators */ + + +/* +** subexpr -> (simpleexp | unop subexpr) { binop subexpr } +** where 'binop' is any binary operator with a priority higher than 'limit' +*/ +static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { + BinOpr op; + UnOpr uop; + enterlevel(ls); + uop = getunopr(ls->t.token); + if (uop != OPR_NOUNOPR) { /* prefix (unary) operator? */ + int line = ls->linenumber; + luaX_next(ls); /* skip operator */ + subexpr(ls, v, UNARY_PRIORITY); + luaK_prefix(ls->fs, uop, v, line); + } + else simpleexp(ls, v); + /* expand while operators have priorities higher than 'limit' */ + op = getbinopr(ls->t.token); + while (op != OPR_NOBINOPR && priority[op].left > limit) { + expdesc v2; + BinOpr nextop; + int line = ls->linenumber; + luaX_next(ls); /* skip operator */ + luaK_infix(ls->fs, op, v); + /* read sub-expression with higher priority */ + nextop = subexpr(ls, &v2, priority[op].right); + luaK_posfix(ls->fs, op, v, &v2, line); + op = nextop; + } + leavelevel(ls); + return op; /* return first untreated operator */ +} + + +static void expr (LexState *ls, expdesc *v) { + subexpr(ls, v, 0); +} + +/* }==================================================================== */ + + + +/* +** {====================================================================== +** Rules for Statements +** ======================================================================= +*/ + + +static void block (LexState *ls) { + /* block -> statlist */ + FuncState *fs = ls->fs; + BlockCnt bl; + enterblock(fs, &bl, 0); + statlist(ls); + leaveblock(fs); +} + + +/* +** structure to chain all variables in the left-hand side of an +** assignment +*/ +struct LHS_assign { + struct LHS_assign *prev; + expdesc v; /* variable (global, local, upvalue, or indexed) */ +}; + + +/* +** check whether, in an assignment to an upvalue/local variable, the +** upvalue/local variable is begin used in a previous assignment to a +** table. If so, save original upvalue/local value in a safe place and +** use this safe copy in the previous assignment. +*/ +static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { + FuncState *fs = ls->fs; + int extra = fs->freereg; /* eventual position to save local variable */ + int conflict = 0; + for (; lh; lh = lh->prev) { /* check all previous assignments */ + if (vkisindexed(lh->v.k)) { /* assignment to table field? */ + if (lh->v.k == VINDEXUP) { /* is table an upvalue? */ + if (v->k == VUPVAL && lh->v.u.ind.t == v->u.info) { + conflict = 1; /* table is the upvalue being assigned now */ + lh->v.k = VINDEXSTR; + lh->v.u.ind.t = extra; /* assignment will use safe copy */ + } + } + else { /* table is a register */ + if (v->k == VLOCAL && lh->v.u.ind.t == v->u.var.ridx) { + conflict = 1; /* table is the local being assigned now */ + lh->v.u.ind.t = extra; /* assignment will use safe copy */ + } + /* is index the local being assigned? */ + if (lh->v.k == VINDEXED && v->k == VLOCAL && + lh->v.u.ind.idx == v->u.var.ridx) { + conflict = 1; + lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */ + } + } + } + } + if (conflict) { + /* copy upvalue/local value to a temporary (in position 'extra') */ + if (v->k == VLOCAL) + luaK_codeABC(fs, OP_MOVE, extra, v->u.var.ridx, 0); + else + luaK_codeABC(fs, OP_GETUPVAL, extra, v->u.info, 0); + luaK_reserveregs(fs, 1); + } +} + +/* +** Parse and compile a multiple assignment. The first "variable" +** (a 'suffixedexp') was already read by the caller. +** +** assignment -> suffixedexp restassign +** restassign -> ',' suffixedexp restassign | '=' explist +*/ +static void restassign (LexState *ls, struct LHS_assign *lh, int nvars) { + expdesc e; + check_condition(ls, vkisvar(lh->v.k), "syntax error"); + check_readonly(ls, &lh->v); + if (testnext(ls, ',')) { /* restassign -> ',' suffixedexp restassign */ + struct LHS_assign nv; + nv.prev = lh; + suffixedexp(ls, &nv.v); + if (!vkisindexed(nv.v.k)) + check_conflict(ls, lh, &nv.v); + enterlevel(ls); /* control recursion depth */ + restassign(ls, &nv, nvars+1); + leavelevel(ls); + } + else { /* restassign -> '=' explist */ + int nexps; + checknext(ls, '='); + nexps = explist(ls, &e); + if (nexps != nvars) + adjust_assign(ls, nvars, nexps, &e); + else { + luaK_setoneret(ls->fs, &e); /* close last expression */ + luaK_storevar(ls->fs, &lh->v, &e); + return; /* avoid default */ + } + } + init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ + luaK_storevar(ls->fs, &lh->v, &e); +} + + +static int cond (LexState *ls) { + /* cond -> exp */ + expdesc v; + expr(ls, &v); /* read condition */ + if (v.k == VNIL) v.k = VFALSE; /* 'falses' are all equal here */ + luaK_goiftrue(ls->fs, &v); + return v.f; +} + + +static void gotostat (LexState *ls) { + FuncState *fs = ls->fs; + int line = ls->linenumber; + TString *name = str_checkname(ls); /* label's name */ + Labeldesc *lb = findlabel(ls, name); + if (lb == NULL) /* no label? */ + /* forward jump; will be resolved when the label is declared */ + newgotoentry(ls, name, line, luaK_jump(fs)); + else { /* found a label */ + /* backward jump; will be resolved here */ + int lblevel = reglevel(fs, lb->nactvar); /* label level */ + if (luaY_nvarstack(fs) > lblevel) /* leaving the scope of a variable? */ + luaK_codeABC(fs, OP_CLOSE, lblevel, 0, 0); + /* create jump and link it to the label */ + luaK_patchlist(fs, luaK_jump(fs), lb->pc); + } +} + + +/* +** Break statement. Semantically equivalent to "goto break". +*/ +static void breakstat (LexState *ls) { + int line = ls->linenumber; + luaX_next(ls); /* skip break */ + newgotoentry(ls, luaS_newliteral(ls->L, "break"), line, luaK_jump(ls->fs)); +} + + +/* +** Check whether there is already a label with the given 'name'. +*/ +static void checkrepeated (LexState *ls, TString *name) { + Labeldesc *lb = findlabel(ls, name); + if (l_unlikely(lb != NULL)) { /* already defined? */ + const char *msg = "label '%s' already defined on line %d"; + msg = luaO_pushfstring(ls->L, msg, getstr(name), lb->line); + luaK_semerror(ls, msg); /* error */ + } +} + + +static void labelstat (LexState *ls, TString *name, int line) { + /* label -> '::' NAME '::' */ + checknext(ls, TK_DBCOLON); /* skip double colon */ + while (ls->t.token == ';' || ls->t.token == TK_DBCOLON) + statement(ls); /* skip other no-op statements */ + checkrepeated(ls, name); /* check for repeated labels */ + createlabel(ls, name, line, block_follow(ls, 0)); +} + + +static void whilestat (LexState *ls, int line) { + /* whilestat -> WHILE cond DO block END */ + FuncState *fs = ls->fs; + int whileinit; + int condexit; + BlockCnt bl; + luaX_next(ls); /* skip WHILE */ + whileinit = luaK_getlabel(fs); + condexit = cond(ls); + enterblock(fs, &bl, 1); + checknext(ls, TK_DO); + block(ls); + luaK_jumpto(fs, whileinit); + check_match(ls, TK_END, TK_WHILE, line); + leaveblock(fs); + luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ +} + + +static void repeatstat (LexState *ls, int line) { + /* repeatstat -> REPEAT block UNTIL cond */ + int condexit; + FuncState *fs = ls->fs; + int repeat_init = luaK_getlabel(fs); + BlockCnt bl1, bl2; + enterblock(fs, &bl1, 1); /* loop block */ + enterblock(fs, &bl2, 0); /* scope block */ + luaX_next(ls); /* skip REPEAT */ + statlist(ls); + check_match(ls, TK_UNTIL, TK_REPEAT, line); + condexit = cond(ls); /* read condition (inside scope block) */ + leaveblock(fs); /* finish scope */ + if (bl2.upval) { /* upvalues? */ + int exit = luaK_jump(fs); /* normal exit must jump over fix */ + luaK_patchtohere(fs, condexit); /* repetition must close upvalues */ + luaK_codeABC(fs, OP_CLOSE, reglevel(fs, bl2.nactvar), 0, 0); + condexit = luaK_jump(fs); /* repeat after closing upvalues */ + luaK_patchtohere(fs, exit); /* normal exit comes to here */ + } + luaK_patchlist(fs, condexit, repeat_init); /* close the loop */ + leaveblock(fs); /* finish loop */ +} + + +/* +** Read an expression and generate code to put its results in next +** stack slot. +** +*/ +static void exp1 (LexState *ls) { + expdesc e; + expr(ls, &e); + luaK_exp2nextreg(ls->fs, &e); + lua_assert(e.k == VNONRELOC); +} + + +/* +** Fix for instruction at position 'pc' to jump to 'dest'. +** (Jump addresses are relative in Lua). 'back' true means +** a back jump. +*/ +static void fixforjump (FuncState *fs, int pc, int dest, int back) { + Instruction *jmp = &fs->f->code[pc]; + int offset = dest - (pc + 1); + if (back) + offset = -offset; + if (l_unlikely(offset > MAXARG_Bx)) + luaX_syntaxerror(fs->ls, "control structure too long"); + SETARG_Bx(*jmp, offset); +} + + +/* +** Generate code for a 'for' loop. +*/ +static void forbody (LexState *ls, int base, int line, int nvars, int isgen) { + /* forbody -> DO block */ + static const OpCode forprep[2] = {OP_FORPREP, OP_TFORPREP}; + static const OpCode forloop[2] = {OP_FORLOOP, OP_TFORLOOP}; + BlockCnt bl; + FuncState *fs = ls->fs; + int prep, endfor; + checknext(ls, TK_DO); + prep = luaK_codeABx(fs, forprep[isgen], base, 0); + enterblock(fs, &bl, 0); /* scope for declared variables */ + adjustlocalvars(ls, nvars); + luaK_reserveregs(fs, nvars); + block(ls); + leaveblock(fs); /* end of scope for declared variables */ + fixforjump(fs, prep, luaK_getlabel(fs), 0); + if (isgen) { /* generic for? */ + luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars); + luaK_fixline(fs, line); + } + endfor = luaK_codeABx(fs, forloop[isgen], base, 0); + fixforjump(fs, endfor, prep + 1, 1); + luaK_fixline(fs, line); +} + + +static void fornum (LexState *ls, TString *varname, int line) { + /* fornum -> NAME = exp,exp[,exp] forbody */ + FuncState *fs = ls->fs; + int base = fs->freereg; + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for state)"); + new_localvar(ls, varname); + checknext(ls, '='); + exp1(ls); /* initial value */ + checknext(ls, ','); + exp1(ls); /* limit */ + if (testnext(ls, ',')) + exp1(ls); /* optional step */ + else { /* default step = 1 */ + luaK_int(fs, fs->freereg, 1); + luaK_reserveregs(fs, 1); + } + adjustlocalvars(ls, 3); /* control variables */ + forbody(ls, base, line, 1, 0); +} + + +static void forlist (LexState *ls, TString *indexname) { + /* forlist -> NAME {,NAME} IN explist forbody */ + FuncState *fs = ls->fs; + expdesc e; + int nvars = 5; /* gen, state, control, toclose, 'indexname' */ + int line; + int base = fs->freereg; + /* create control variables */ + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for state)"); + /* create declared variables */ + new_localvar(ls, indexname); + while (testnext(ls, ',')) { + new_localvar(ls, str_checkname(ls)); + nvars++; + } + checknext(ls, TK_IN); + line = ls->linenumber; + adjust_assign(ls, 4, explist(ls, &e), &e); + adjustlocalvars(ls, 4); /* control variables */ + marktobeclosed(fs); /* last control var. must be closed */ + luaK_checkstack(fs, 3); /* extra space to call generator */ + forbody(ls, base, line, nvars - 4, 1); +} + + +static void forstat (LexState *ls, int line) { + /* forstat -> FOR (fornum | forlist) END */ + FuncState *fs = ls->fs; + TString *varname; + BlockCnt bl; + enterblock(fs, &bl, 1); /* scope for loop and control variables */ + luaX_next(ls); /* skip 'for' */ + varname = str_checkname(ls); /* first variable name */ + switch (ls->t.token) { + case '=': fornum(ls, varname, line); break; + case ',': case TK_IN: forlist(ls, varname); break; + default: luaX_syntaxerror(ls, "'=' or 'in' expected"); + } + check_match(ls, TK_END, TK_FOR, line); + leaveblock(fs); /* loop scope ('break' jumps to this point) */ +} + + +static void test_then_block (LexState *ls, int *escapelist) { + /* test_then_block -> [IF | ELSEIF] cond THEN block */ + BlockCnt bl; + FuncState *fs = ls->fs; + expdesc v; + int jf; /* instruction to skip 'then' code (if condition is false) */ + luaX_next(ls); /* skip IF or ELSEIF */ + expr(ls, &v); /* read condition */ + checknext(ls, TK_THEN); + if (ls->t.token == TK_BREAK) { /* 'if x then break' ? */ + int line = ls->linenumber; + luaK_goiffalse(ls->fs, &v); /* will jump if condition is true */ + luaX_next(ls); /* skip 'break' */ + enterblock(fs, &bl, 0); /* must enter block before 'goto' */ + newgotoentry(ls, luaS_newliteral(ls->L, "break"), line, v.t); + while (testnext(ls, ';')) {} /* skip semicolons */ + if (block_follow(ls, 0)) { /* jump is the entire block? */ + leaveblock(fs); + return; /* and that is it */ + } + else /* must skip over 'then' part if condition is false */ + jf = luaK_jump(fs); + } + else { /* regular case (not a break) */ + luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ + enterblock(fs, &bl, 0); + jf = v.f; + } + statlist(ls); /* 'then' part */ + leaveblock(fs); + if (ls->t.token == TK_ELSE || + ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ + luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ + luaK_patchtohere(fs, jf); +} + + +static void ifstat (LexState *ls, int line) { + /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ + FuncState *fs = ls->fs; + int escapelist = NO_JUMP; /* exit list for finished parts */ + test_then_block(ls, &escapelist); /* IF cond THEN block */ + while (ls->t.token == TK_ELSEIF) + test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */ + if (testnext(ls, TK_ELSE)) + block(ls); /* 'else' part */ + check_match(ls, TK_END, TK_IF, line); + luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */ +} + + +static void localfunc (LexState *ls) { + expdesc b; + FuncState *fs = ls->fs; + int fvar = fs->nactvar; /* function's variable index */ + new_localvar(ls, str_checkname(ls)); /* new local variable */ + adjustlocalvars(ls, 1); /* enter its scope */ + body(ls, &b, 0, ls->linenumber); /* function created in next register */ + /* debug information will only see the variable after this point! */ + localdebuginfo(fs, fvar)->startpc = fs->pc; +} + + +static int getlocalattribute (LexState *ls) { + /* ATTRIB -> ['<' Name '>'] */ + if (testnext(ls, '<')) { + const char *attr = getstr(str_checkname(ls)); + checknext(ls, '>'); + if (strcmp(attr, "const") == 0) + return RDKCONST; /* read-only variable */ + else if (strcmp(attr, "close") == 0) + return RDKTOCLOSE; /* to-be-closed variable */ + else + luaK_semerror(ls, + luaO_pushfstring(ls->L, "unknown attribute '%s'", attr)); + } + return VDKREG; /* regular variable */ +} + + +static void checktoclose (FuncState *fs, int level) { + if (level != -1) { /* is there a to-be-closed variable? */ + marktobeclosed(fs); + luaK_codeABC(fs, OP_TBC, reglevel(fs, level), 0, 0); + } +} + + +static void localstat (LexState *ls) { + /* stat -> LOCAL NAME ATTRIB { ',' NAME ATTRIB } ['=' explist] */ + FuncState *fs = ls->fs; + int toclose = -1; /* index of to-be-closed variable (if any) */ + Vardesc *var; /* last variable */ + int vidx, kind; /* index and kind of last variable */ + int nvars = 0; + int nexps; + expdesc e; + do { + vidx = new_localvar(ls, str_checkname(ls)); + kind = getlocalattribute(ls); + getlocalvardesc(fs, vidx)->vd.kind = kind; + if (kind == RDKTOCLOSE) { /* to-be-closed? */ + if (toclose != -1) /* one already present? */ + luaK_semerror(ls, "multiple to-be-closed variables in local list"); + toclose = fs->nactvar + nvars; + } + nvars++; + } while (testnext(ls, ',')); + if (testnext(ls, '=')) + nexps = explist(ls, &e); + else { + e.k = VVOID; + nexps = 0; + } + var = getlocalvardesc(fs, vidx); /* get last variable */ + if (nvars == nexps && /* no adjustments? */ + var->vd.kind == RDKCONST && /* last variable is const? */ + luaK_exp2const(fs, &e, &var->k)) { /* compile-time constant? */ + var->vd.kind = RDKCTC; /* variable is a compile-time constant */ + adjustlocalvars(ls, nvars - 1); /* exclude last variable */ + fs->nactvar++; /* but count it */ + } + else { + adjust_assign(ls, nvars, nexps, &e); + adjustlocalvars(ls, nvars); + } + checktoclose(fs, toclose); +} + + +static int funcname (LexState *ls, expdesc *v) { + /* funcname -> NAME {fieldsel} [':' NAME] */ + int ismethod = 0; + singlevar(ls, v); + while (ls->t.token == '.') + fieldsel(ls, v); + if (ls->t.token == ':') { + ismethod = 1; + fieldsel(ls, v); + } + return ismethod; +} + + +static void funcstat (LexState *ls, int line) { + /* funcstat -> FUNCTION funcname body */ + int ismethod; + expdesc v, b; + luaX_next(ls); /* skip FUNCTION */ + ismethod = funcname(ls, &v); + body(ls, &b, ismethod, line); + check_readonly(ls, &v); + luaK_storevar(ls->fs, &v, &b); + luaK_fixline(ls->fs, line); /* definition "happens" in the first line */ +} + + +static void exprstat (LexState *ls) { + /* stat -> func | assignment */ + FuncState *fs = ls->fs; + struct LHS_assign v; + suffixedexp(ls, &v.v); + if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */ + v.prev = NULL; + restassign(ls, &v, 1); + } + else { /* stat -> func */ + Instruction *inst; + check_condition(ls, v.v.k == VCALL, "syntax error"); + inst = &getinstruction(fs, &v.v); + SETARG_C(*inst, 1); /* call statement uses no results */ + } +} + + +static void retstat (LexState *ls) { + /* stat -> RETURN [explist] [';'] */ + FuncState *fs = ls->fs; + expdesc e; + int nret; /* number of values being returned */ + int first = luaY_nvarstack(fs); /* first slot to be returned */ + if (block_follow(ls, 1) || ls->t.token == ';') + nret = 0; /* return no values */ + else { + nret = explist(ls, &e); /* optional return values */ + if (hasmultret(e.k)) { + luaK_setmultret(fs, &e); + if (e.k == VCALL && nret == 1 && !fs->bl->insidetbc) { /* tail call? */ + SET_OPCODE(getinstruction(fs,&e), OP_TAILCALL); + lua_assert(GETARG_A(getinstruction(fs,&e)) == luaY_nvarstack(fs)); + } + nret = LUA_MULTRET; /* return all values */ + } + else { + if (nret == 1) /* only one single value? */ + first = luaK_exp2anyreg(fs, &e); /* can use original slot */ + else { /* values must go to the top of the stack */ + luaK_exp2nextreg(fs, &e); + lua_assert(nret == fs->freereg - first); + } + } + } + luaK_ret(fs, first, nret); + testnext(ls, ';'); /* skip optional semicolon */ +} + + +static void statement (LexState *ls) { + int line = ls->linenumber; /* may be needed for error messages */ + enterlevel(ls); + switch (ls->t.token) { + case ';': { /* stat -> ';' (empty statement) */ + luaX_next(ls); /* skip ';' */ + break; + } + case TK_IF: { /* stat -> ifstat */ + ifstat(ls, line); + break; + } + case TK_WHILE: { /* stat -> whilestat */ + whilestat(ls, line); + break; + } + case TK_DO: { /* stat -> DO block END */ + luaX_next(ls); /* skip DO */ + block(ls); + check_match(ls, TK_END, TK_DO, line); + break; + } + case TK_FOR: { /* stat -> forstat */ + forstat(ls, line); + break; + } + case TK_REPEAT: { /* stat -> repeatstat */ + repeatstat(ls, line); + break; + } + case TK_FUNCTION: { /* stat -> funcstat */ + funcstat(ls, line); + break; + } + case TK_LOCAL: { /* stat -> localstat */ + luaX_next(ls); /* skip LOCAL */ + if (testnext(ls, TK_FUNCTION)) /* local function? */ + localfunc(ls); + else + localstat(ls); + break; + } + case TK_DBCOLON: { /* stat -> label */ + luaX_next(ls); /* skip double colon */ + labelstat(ls, str_checkname(ls), line); + break; + } + case TK_RETURN: { /* stat -> retstat */ + luaX_next(ls); /* skip RETURN */ + retstat(ls); + break; + } + case TK_BREAK: { /* stat -> breakstat */ + breakstat(ls); + break; + } + case TK_GOTO: { /* stat -> 'goto' NAME */ + luaX_next(ls); /* skip 'goto' */ + gotostat(ls); + break; + } + default: { /* stat -> func | assignment */ + exprstat(ls); + break; + } + } + lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg && + ls->fs->freereg >= luaY_nvarstack(ls->fs)); + ls->fs->freereg = luaY_nvarstack(ls->fs); /* free registers */ + leavelevel(ls); +} + +/* }====================================================================== */ + + +/* +** compiles the main function, which is a regular vararg function with an +** upvalue named LUA_ENV +*/ +static void mainfunc (LexState *ls, FuncState *fs) { + BlockCnt bl; + Upvaldesc *env; + open_func(ls, fs, &bl); + setvararg(fs, 0); /* main function is always declared vararg */ + env = allocupvalue(fs); /* ...set environment upvalue */ + env->instack = 1; + env->idx = 0; + env->kind = VDKREG; + env->name = ls->envn; + luaC_objbarrier(ls->L, fs->f, env->name); + luaX_next(ls); /* read first token */ + statlist(ls); /* parse main body */ + check(ls, TK_EOS); + close_func(ls); +} + + +LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, + Dyndata *dyd, const char *name, int firstchar) { + LexState lexstate; + FuncState funcstate; + LClosure *cl = luaF_newLclosure(L, 1); /* create main closure */ + setclLvalue2s(L, L->top.p, cl); /* anchor it (to avoid being collected) */ + luaD_inctop(L); + lexstate.h = luaH_new(L); /* create table for scanner */ + sethvalue2s(L, L->top.p, lexstate.h); /* anchor it */ + luaD_inctop(L); + funcstate.f = cl->p = luaF_newproto(L); + luaC_objbarrier(L, cl, cl->p); + funcstate.f->source = luaS_new(L, name); /* create and anchor TString */ + luaC_objbarrier(L, funcstate.f, funcstate.f->source); + lexstate.buff = buff; + lexstate.dyd = dyd; + dyd->actvar.n = dyd->gt.n = dyd->label.n = 0; + luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar); + mainfunc(&lexstate, &funcstate); + lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs); + /* all scopes should be correctly finished */ + lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0); + L->top.p--; /* remove scanner's table */ + return cl; /* closure is on the stack, too */ +} + diff --git a/src/lparser.h b/src/lparser.h new file mode 100644 index 0000000..5e4500f --- /dev/null +++ b/src/lparser.h @@ -0,0 +1,171 @@ +/* +** $Id: lparser.h $ +** Lua Parser +** See Copyright Notice in lua.h +*/ + +#ifndef lparser_h +#define lparser_h + +#include "llimits.h" +#include "lobject.h" +#include "lzio.h" + + +/* +** Expression and variable descriptor. +** Code generation for variables and expressions can be delayed to allow +** optimizations; An 'expdesc' structure describes a potentially-delayed +** variable/expression. It has a description of its "main" value plus a +** list of conditional jumps that can also produce its value (generated +** by short-circuit operators 'and'/'or'). +*/ + +/* kinds of variables/expressions */ +typedef enum { + VVOID, /* when 'expdesc' describes the last expression of a list, + this kind means an empty list (so, no expression) */ + VNIL, /* constant nil */ + VTRUE, /* constant true */ + VFALSE, /* constant false */ + VK, /* constant in 'k'; info = index of constant in 'k' */ + VKFLT, /* floating constant; nval = numerical float value */ + VKINT, /* integer constant; ival = numerical integer value */ + VKSTR, /* string constant; strval = TString address; + (string is fixed by the lexer) */ + VNONRELOC, /* expression has its value in a fixed register; + info = result register */ + VLOCAL, /* local variable; var.ridx = register index; + var.vidx = relative index in 'actvar.arr' */ + VUPVAL, /* upvalue variable; info = index of upvalue in 'upvalues' */ + VCONST, /* compile-time variable; + info = absolute index in 'actvar.arr' */ + VINDEXED, /* indexed variable; + ind.t = table register; + ind.idx = key's R index */ + VINDEXUP, /* indexed upvalue; + ind.t = table upvalue; + ind.idx = key's K index */ + VINDEXI, /* indexed variable with constant integer; + ind.t = table register; + ind.idx = key's value */ + VINDEXSTR, /* indexed variable with literal string; + ind.t = table register; + ind.idx = key's K index */ + VJMP, /* expression is a test/comparison; + info = pc of corresponding jump instruction */ + VRELOC, /* expression can put result in any register; + info = instruction pc */ + VCALL, /* expression is a function call; info = instruction pc */ + VVARARG /* vararg expression; info = instruction pc */ +} expkind; + + +#define vkisvar(k) (VLOCAL <= (k) && (k) <= VINDEXSTR) +#define vkisindexed(k) (VINDEXED <= (k) && (k) <= VINDEXSTR) + + +typedef struct expdesc { + expkind k; + union { + lua_Integer ival; /* for VKINT */ + lua_Number nval; /* for VKFLT */ + TString *strval; /* for VKSTR */ + int info; /* for generic use */ + struct { /* for indexed variables */ + short idx; /* index (R or "long" K) */ + lu_byte t; /* table (register or upvalue) */ + } ind; + struct { /* for local variables */ + lu_byte ridx; /* register holding the variable */ + unsigned short vidx; /* compiler index (in 'actvar.arr') */ + } var; + } u; + int t; /* patch list of 'exit when true' */ + int f; /* patch list of 'exit when false' */ +} expdesc; + + +/* kinds of variables */ +#define VDKREG 0 /* regular */ +#define RDKCONST 1 /* constant */ +#define RDKTOCLOSE 2 /* to-be-closed */ +#define RDKCTC 3 /* compile-time constant */ + +/* description of an active local variable */ +typedef union Vardesc { + struct { + TValuefields; /* constant value (if it is a compile-time constant) */ + lu_byte kind; + lu_byte ridx; /* register holding the variable */ + short pidx; /* index of the variable in the Proto's 'locvars' array */ + TString *name; /* variable name */ + } vd; + TValue k; /* constant value (if any) */ +} Vardesc; + + + +/* description of pending goto statements and label statements */ +typedef struct Labeldesc { + TString *name; /* label identifier */ + int pc; /* position in code */ + int line; /* line where it appeared */ + lu_byte nactvar; /* number of active variables in that position */ + lu_byte close; /* goto that escapes upvalues */ +} Labeldesc; + + +/* list of labels or gotos */ +typedef struct Labellist { + Labeldesc *arr; /* array */ + int n; /* number of entries in use */ + int size; /* array size */ +} Labellist; + + +/* dynamic structures used by the parser */ +typedef struct Dyndata { + struct { /* list of all active local variables */ + Vardesc *arr; + int n; + int size; + } actvar; + Labellist gt; /* list of pending gotos */ + Labellist label; /* list of active labels */ +} Dyndata; + + +/* control of blocks */ +struct BlockCnt; /* defined in lparser.c */ + + +/* state needed to generate code for a given function */ +typedef struct FuncState { + Proto *f; /* current function header */ + struct FuncState *prev; /* enclosing function */ + struct LexState *ls; /* lexical state */ + struct BlockCnt *bl; /* chain of current blocks */ + int pc; /* next position to code (equivalent to 'ncode') */ + int lasttarget; /* 'label' of last 'jump label' */ + int previousline; /* last line that was saved in 'lineinfo' */ + int nk; /* number of elements in 'k' */ + int np; /* number of elements in 'p' */ + int nabslineinfo; /* number of elements in 'abslineinfo' */ + int firstlocal; /* index of first local var (in Dyndata array) */ + int firstlabel; /* index of first label (in 'dyd->label->arr') */ + short ndebugvars; /* number of elements in 'f->locvars' */ + lu_byte nactvar; /* number of active local variables */ + lu_byte nups; /* number of upvalues */ + lu_byte freereg; /* first free register */ + lu_byte iwthabs; /* instructions issued since last absolute line info */ + lu_byte needclose; /* function needs to close upvalues when returning */ +} FuncState; + + +LUAI_FUNC int luaY_nvarstack (FuncState *fs); +LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, + Dyndata *dyd, const char *name, int firstchar); + + +#endif diff --git a/src/lprefix.h b/src/lprefix.h new file mode 100644 index 0000000..484f2ad --- /dev/null +++ b/src/lprefix.h @@ -0,0 +1,45 @@ +/* +** $Id: lprefix.h $ +** Definitions for Lua code that must come before any other header file +** See Copyright Notice in lua.h +*/ + +#ifndef lprefix_h +#define lprefix_h + + +/* +** Allows POSIX/XSI stuff +*/ +#if !defined(LUA_USE_C89) /* { */ + +#if !defined(_XOPEN_SOURCE) +#define _XOPEN_SOURCE 600 +#elif _XOPEN_SOURCE == 0 +#undef _XOPEN_SOURCE /* use -D_XOPEN_SOURCE=0 to undefine it */ +#endif + +/* +** Allows manipulation of large files in gcc and some other compilers +*/ +#if !defined(LUA_32BITS) && !defined(_FILE_OFFSET_BITS) +#define _LARGEFILE_SOURCE 1 +#define _FILE_OFFSET_BITS 64 +#endif + +#endif /* } */ + + +/* +** Windows stuff +*/ +#if defined(_WIN32) /* { */ + +#if !defined(_CRT_SECURE_NO_WARNINGS) +#define _CRT_SECURE_NO_WARNINGS /* avoid warnings about ISO C functions */ +#endif + +#endif /* } */ + +#endif + diff --git a/src/lstate.c b/src/lstate.c new file mode 100644 index 0000000..1e925e5 --- /dev/null +++ b/src/lstate.c @@ -0,0 +1,445 @@ +/* +** $Id: lstate.c $ +** Global State +** See Copyright Notice in lua.h +*/ + +#define lstate_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "llex.h" +#include "lmem.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" + + + +/* +** thread state + extra space +*/ +typedef struct LX { + lu_byte extra_[LUA_EXTRASPACE]; + lua_State l; +} LX; + + +/* +** Main thread combines a thread state and the global state +*/ +typedef struct LG { + LX l; + global_State g; +} LG; + + + +#define fromstate(L) (cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l))) + + +/* +** A macro to create a "random" seed when a state is created; +** the seed is used to randomize string hashes. +*/ +#if !defined(luai_makeseed) + +#include + +/* +** Compute an initial seed with some level of randomness. +** Rely on Address Space Layout Randomization (if present) and +** current time. +*/ +#define addbuff(b,p,e) \ + { size_t t = cast_sizet(e); \ + memcpy(b + p, &t, sizeof(t)); p += sizeof(t); } + +static unsigned int luai_makeseed (lua_State *L) { + char buff[3 * sizeof(size_t)]; + unsigned int h = cast_uint(time(NULL)); + int p = 0; + addbuff(buff, p, L); /* heap variable */ + addbuff(buff, p, &h); /* local variable */ + addbuff(buff, p, &lua_newstate); /* public function */ + lua_assert(p == sizeof(buff)); + return luaS_hash(buff, p, h); +} + +#endif + + +/* +** set GCdebt to a new value keeping the value (totalbytes + GCdebt) +** invariant (and avoiding underflows in 'totalbytes') +*/ +void luaE_setdebt (global_State *g, l_mem debt) { + l_mem tb = gettotalbytes(g); + lua_assert(tb > 0); + if (debt < tb - MAX_LMEM) + debt = tb - MAX_LMEM; /* will make 'totalbytes == MAX_LMEM' */ + g->totalbytes = tb - debt; + g->GCdebt = debt; +} + + +LUA_API int lua_setcstacklimit (lua_State *L, unsigned int limit) { + UNUSED(L); UNUSED(limit); + return LUAI_MAXCCALLS; /* warning?? */ +} + + +CallInfo *luaE_extendCI (lua_State *L) { + CallInfo *ci; + lua_assert(L->ci->next == NULL); + ci = luaM_new(L, CallInfo); + lua_assert(L->ci->next == NULL); + L->ci->next = ci; + ci->previous = L->ci; + ci->next = NULL; + ci->u.l.trap = 0; + L->nci++; + return ci; +} + + +/* +** free all CallInfo structures not in use by a thread +*/ +void luaE_freeCI (lua_State *L) { + CallInfo *ci = L->ci; + CallInfo *next = ci->next; + ci->next = NULL; + while ((ci = next) != NULL) { + next = ci->next; + luaM_free(L, ci); + L->nci--; + } +} + + +/* +** free half of the CallInfo structures not in use by a thread, +** keeping the first one. +*/ +void luaE_shrinkCI (lua_State *L) { + CallInfo *ci = L->ci->next; /* first free CallInfo */ + CallInfo *next; + if (ci == NULL) + return; /* no extra elements */ + while ((next = ci->next) != NULL) { /* two extra elements? */ + CallInfo *next2 = next->next; /* next's next */ + ci->next = next2; /* remove next from the list */ + L->nci--; + luaM_free(L, next); /* free next */ + if (next2 == NULL) + break; /* no more elements */ + else { + next2->previous = ci; + ci = next2; /* continue */ + } + } +} + + +/* +** Called when 'getCcalls(L)' larger or equal to LUAI_MAXCCALLS. +** If equal, raises an overflow error. If value is larger than +** LUAI_MAXCCALLS (which means it is handling an overflow) but +** not much larger, does not report an error (to allow overflow +** handling to work). +*/ +void luaE_checkcstack (lua_State *L) { + if (getCcalls(L) == LUAI_MAXCCALLS) + luaG_runerror(L, "C stack overflow"); + else if (getCcalls(L) >= (LUAI_MAXCCALLS / 10 * 11)) + luaD_throw(L, LUA_ERRERR); /* error while handling stack error */ +} + + +LUAI_FUNC void luaE_incCstack (lua_State *L) { + L->nCcalls++; + if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS)) + luaE_checkcstack(L); +} + + +static void stack_init (lua_State *L1, lua_State *L) { + int i; CallInfo *ci; + /* initialize stack array */ + L1->stack.p = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, StackValue); + L1->tbclist.p = L1->stack.p; + for (i = 0; i < BASIC_STACK_SIZE + EXTRA_STACK; i++) + setnilvalue(s2v(L1->stack.p + i)); /* erase new stack */ + L1->top.p = L1->stack.p; + L1->stack_last.p = L1->stack.p + BASIC_STACK_SIZE; + /* initialize first ci */ + ci = &L1->base_ci; + ci->next = ci->previous = NULL; + ci->callstatus = CIST_C; + ci->func.p = L1->top.p; + ci->u.c.k = NULL; + ci->nresults = 0; + setnilvalue(s2v(L1->top.p)); /* 'function' entry for this 'ci' */ + L1->top.p++; + ci->top.p = L1->top.p + LUA_MINSTACK; + L1->ci = ci; +} + + +static void freestack (lua_State *L) { + if (L->stack.p == NULL) + return; /* stack not completely built yet */ + L->ci = &L->base_ci; /* free the entire 'ci' list */ + luaE_freeCI(L); + lua_assert(L->nci == 0); + luaM_freearray(L, L->stack.p, stacksize(L) + EXTRA_STACK); /* free stack */ +} + + +/* +** Create registry table and its predefined values +*/ +static void init_registry (lua_State *L, global_State *g) { + /* create registry */ + Table *registry = luaH_new(L); + sethvalue(L, &g->l_registry, registry); + luaH_resize(L, registry, LUA_RIDX_LAST, 0); + /* registry[LUA_RIDX_MAINTHREAD] = L */ + setthvalue(L, ®istry->array[LUA_RIDX_MAINTHREAD - 1], L); + /* registry[LUA_RIDX_GLOBALS] = new table (table of globals) */ + sethvalue(L, ®istry->array[LUA_RIDX_GLOBALS - 1], luaH_new(L)); +} + + +/* +** open parts of the state that may cause memory-allocation errors. +*/ +static void f_luaopen (lua_State *L, void *ud) { + global_State *g = G(L); + UNUSED(ud); + stack_init(L, L); /* init stack */ + init_registry(L, g); + luaS_init(L); + luaT_init(L); + luaX_init(L); + g->gcstp = 0; /* allow gc */ + setnilvalue(&g->nilvalue); /* now state is complete */ + luai_userstateopen(L); +} + + +/* +** preinitialize a thread with consistent values without allocating +** any memory (to avoid errors) +*/ +static void preinit_thread (lua_State *L, global_State *g) { + G(L) = g; + L->stack.p = NULL; + L->ci = NULL; + L->nci = 0; + L->twups = L; /* thread has no upvalues */ + L->nCcalls = 0; + L->errorJmp = NULL; + L->hook = NULL; + L->hookmask = 0; + L->basehookcount = 0; + L->allowhook = 1; + resethookcount(L); + L->openupval = NULL; + L->status = LUA_OK; + L->errfunc = 0; + L->oldpc = 0; +} + + +static void close_state (lua_State *L) { + global_State *g = G(L); + if (!completestate(g)) /* closing a partially built state? */ + luaC_freeallobjects(L); /* just collect its objects */ + else { /* closing a fully built state */ + L->ci = &L->base_ci; /* unwind CallInfo list */ + luaD_closeprotected(L, 1, LUA_OK); /* close all upvalues */ + luaC_freeallobjects(L); /* collect all objects */ + luai_userstateclose(L); + } + luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size); + freestack(L); + lua_assert(gettotalbytes(g) == sizeof(LG)); + (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0); /* free main block */ +} + + +LUA_API lua_State *lua_newthread (lua_State *L) { + global_State *g = G(L); + GCObject *o; + lua_State *L1; + lua_lock(L); + luaC_checkGC(L); + /* create new thread */ + o = luaC_newobjdt(L, LUA_TTHREAD, sizeof(LX), offsetof(LX, l)); + L1 = gco2th(o); + /* anchor it on L stack */ + setthvalue2s(L, L->top.p, L1); + api_incr_top(L); + preinit_thread(L1, g); + L1->hookmask = L->hookmask; + L1->basehookcount = L->basehookcount; + L1->hook = L->hook; + resethookcount(L1); + /* initialize L1 extra space */ + memcpy(lua_getextraspace(L1), lua_getextraspace(g->mainthread), + LUA_EXTRASPACE); + luai_userstatethread(L, L1); + stack_init(L1, L); /* init stack */ + lua_unlock(L); + return L1; +} + + +void luaE_freethread (lua_State *L, lua_State *L1) { + LX *l = fromstate(L1); + luaF_closeupval(L1, L1->stack.p); /* close all upvalues */ + lua_assert(L1->openupval == NULL); + luai_userstatefree(L, L1); + freestack(L1); + luaM_free(L, l); +} + + +int luaE_resetthread (lua_State *L, int status) { + CallInfo *ci = L->ci = &L->base_ci; /* unwind CallInfo list */ + setnilvalue(s2v(L->stack.p)); /* 'function' entry for basic 'ci' */ + ci->func.p = L->stack.p; + ci->callstatus = CIST_C; + if (status == LUA_YIELD) + status = LUA_OK; + L->status = LUA_OK; /* so it can run __close metamethods */ + status = luaD_closeprotected(L, 1, status); + if (status != LUA_OK) /* errors? */ + luaD_seterrorobj(L, status, L->stack.p + 1); + else + L->top.p = L->stack.p + 1; + ci->top.p = L->top.p + LUA_MINSTACK; + luaD_reallocstack(L, cast_int(ci->top.p - L->stack.p), 0); + return status; +} + + +LUA_API int lua_closethread (lua_State *L, lua_State *from) { + int status; + lua_lock(L); + L->nCcalls = (from) ? getCcalls(from) : 0; + status = luaE_resetthread(L, L->status); + lua_unlock(L); + return status; +} + + +/* +** Deprecated! Use 'lua_closethread' instead. +*/ +LUA_API int lua_resetthread (lua_State *L) { + return lua_closethread(L, NULL); +} + + +LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) { + int i; + lua_State *L; + global_State *g; + LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG))); + if (l == NULL) return NULL; + L = &l->l.l; + g = &l->g; + L->tt = LUA_VTHREAD; + g->currentwhite = bitmask(WHITE0BIT); + L->marked = luaC_white(g); + preinit_thread(L, g); + g->allgc = obj2gco(L); /* by now, only object is the main thread */ + L->next = NULL; + incnny(L); /* main thread is always non yieldable */ + g->frealloc = f; + g->ud = ud; + g->warnf = NULL; + g->ud_warn = NULL; + g->mainthread = L; + g->seed = luai_makeseed(L); + g->gcstp = GCSTPGC; /* no GC while building state */ + g->strt.size = g->strt.nuse = 0; + g->strt.hash = NULL; + setnilvalue(&g->l_registry); + g->panic = NULL; + g->gcstate = GCSpause; + g->gckind = KGC_INC; + g->gcstopem = 0; + g->gcemergency = 0; + g->finobj = g->tobefnz = g->fixedgc = NULL; + g->firstold1 = g->survival = g->old1 = g->reallyold = NULL; + g->finobjsur = g->finobjold1 = g->finobjrold = NULL; + g->sweepgc = NULL; + g->gray = g->grayagain = NULL; + g->weak = g->ephemeron = g->allweak = NULL; + g->twups = NULL; + g->totalbytes = sizeof(LG); + g->GCdebt = 0; + g->lastatomic = 0; + setivalue(&g->nilvalue, 0); /* to signal that state is not yet built */ + setgcparam(g->gcpause, LUAI_GCPAUSE); + setgcparam(g->gcstepmul, LUAI_GCMUL); + g->gcstepsize = LUAI_GCSTEPSIZE; + setgcparam(g->genmajormul, LUAI_GENMAJORMUL); + g->genminormul = LUAI_GENMINORMUL; + for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL; + if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) { + /* memory allocation error: free partial state */ + close_state(L); + L = NULL; + } + return L; +} + + +LUA_API void lua_close (lua_State *L) { + lua_lock(L); + L = G(L)->mainthread; /* only the main thread can be closed */ + close_state(L); +} + + +void luaE_warning (lua_State *L, const char *msg, int tocont) { + lua_WarnFunction wf = G(L)->warnf; + if (wf != NULL) + wf(G(L)->ud_warn, msg, tocont); +} + + +/* +** Generate a warning from an error message +*/ +void luaE_warnerror (lua_State *L, const char *where) { + TValue *errobj = s2v(L->top.p - 1); /* error object */ + const char *msg = (ttisstring(errobj)) + ? svalue(errobj) + : "error object is not a string"; + /* produce warning "error in %s (%s)" (where, msg) */ + luaE_warning(L, "error in ", 1); + luaE_warning(L, where, 1); + luaE_warning(L, " (", 1); + luaE_warning(L, msg, 1); + luaE_warning(L, ")", 0); +} + diff --git a/src/lstate.h b/src/lstate.h new file mode 100644 index 0000000..8bf6600 --- /dev/null +++ b/src/lstate.h @@ -0,0 +1,409 @@ +/* +** $Id: lstate.h $ +** Global State +** See Copyright Notice in lua.h +*/ + +#ifndef lstate_h +#define lstate_h + +#include "lua.h" + + +/* Some header files included here need this definition */ +typedef struct CallInfo CallInfo; + + +#include "lobject.h" +#include "ltm.h" +#include "lzio.h" + + +/* +** Some notes about garbage-collected objects: All objects in Lua must +** be kept somehow accessible until being freed, so all objects always +** belong to one (and only one) of these lists, using field 'next' of +** the 'CommonHeader' for the link: +** +** 'allgc': all objects not marked for finalization; +** 'finobj': all objects marked for finalization; +** 'tobefnz': all objects ready to be finalized; +** 'fixedgc': all objects that are not to be collected (currently +** only small strings, such as reserved words). +** +** For the generational collector, some of these lists have marks for +** generations. Each mark points to the first element in the list for +** that particular generation; that generation goes until the next mark. +** +** 'allgc' -> 'survival': new objects; +** 'survival' -> 'old': objects that survived one collection; +** 'old1' -> 'reallyold': objects that became old in last collection; +** 'reallyold' -> NULL: objects old for more than one cycle. +** +** 'finobj' -> 'finobjsur': new objects marked for finalization; +** 'finobjsur' -> 'finobjold1': survived """"; +** 'finobjold1' -> 'finobjrold': just old """"; +** 'finobjrold' -> NULL: really old """". +** +** All lists can contain elements older than their main ages, due +** to 'luaC_checkfinalizer' and 'udata2finalize', which move +** objects between the normal lists and the "marked for finalization" +** lists. Moreover, barriers can age young objects in young lists as +** OLD0, which then become OLD1. However, a list never contains +** elements younger than their main ages. +** +** The generational collector also uses a pointer 'firstold1', which +** points to the first OLD1 object in the list. It is used to optimize +** 'markold'. (Potentially OLD1 objects can be anywhere between 'allgc' +** and 'reallyold', but often the list has no OLD1 objects or they are +** after 'old1'.) Note the difference between it and 'old1': +** 'firstold1': no OLD1 objects before this point; there can be all +** ages after it. +** 'old1': no objects younger than OLD1 after this point. +*/ + +/* +** Moreover, there is another set of lists that control gray objects. +** These lists are linked by fields 'gclist'. (All objects that +** can become gray have such a field. The field is not the same +** in all objects, but it always has this name.) Any gray object +** must belong to one of these lists, and all objects in these lists +** must be gray (with two exceptions explained below): +** +** 'gray': regular gray objects, still waiting to be visited. +** 'grayagain': objects that must be revisited at the atomic phase. +** That includes +** - black objects got in a write barrier; +** - all kinds of weak tables during propagation phase; +** - all threads. +** 'weak': tables with weak values to be cleared; +** 'ephemeron': ephemeron tables with white->white entries; +** 'allweak': tables with weak keys and/or weak values to be cleared. +** +** The exceptions to that "gray rule" are: +** - TOUCHED2 objects in generational mode stay in a gray list (because +** they must be visited again at the end of the cycle), but they are +** marked black because assignments to them must activate barriers (to +** move them back to TOUCHED1). +** - Open upvales are kept gray to avoid barriers, but they stay out +** of gray lists. (They don't even have a 'gclist' field.) +*/ + + + +/* +** About 'nCcalls': This count has two parts: the lower 16 bits counts +** the number of recursive invocations in the C stack; the higher +** 16 bits counts the number of non-yieldable calls in the stack. +** (They are together so that we can change and save both with one +** instruction.) +*/ + + +/* true if this thread does not have non-yieldable calls in the stack */ +#define yieldable(L) (((L)->nCcalls & 0xffff0000) == 0) + +/* real number of C calls */ +#define getCcalls(L) ((L)->nCcalls & 0xffff) + + +/* Increment the number of non-yieldable calls */ +#define incnny(L) ((L)->nCcalls += 0x10000) + +/* Decrement the number of non-yieldable calls */ +#define decnny(L) ((L)->nCcalls -= 0x10000) + +/* Non-yieldable call increment */ +#define nyci (0x10000 | 1) + + + + +struct lua_longjmp; /* defined in ldo.c */ + + +/* +** Atomic type (relative to signals) to better ensure that 'lua_sethook' +** is thread safe +*/ +#if !defined(l_signalT) +#include +#define l_signalT sig_atomic_t +#endif + + +/* +** Extra stack space to handle TM calls and some other extras. This +** space is not included in 'stack_last'. It is used only to avoid stack +** checks, either because the element will be promptly popped or because +** there will be a stack check soon after the push. Function frames +** never use this extra space, so it does not need to be kept clean. +*/ +#define EXTRA_STACK 5 + + +#define BASIC_STACK_SIZE (2*LUA_MINSTACK) + +#define stacksize(th) cast_int((th)->stack_last.p - (th)->stack.p) + + +/* kinds of Garbage Collection */ +#define KGC_INC 0 /* incremental gc */ +#define KGC_GEN 1 /* generational gc */ + + +typedef struct stringtable { + TString **hash; + int nuse; /* number of elements */ + int size; +} stringtable; + + +/* +** Information about a call. +** About union 'u': +** - field 'l' is used only for Lua functions; +** - field 'c' is used only for C functions. +** About union 'u2': +** - field 'funcidx' is used only by C functions while doing a +** protected call; +** - field 'nyield' is used only while a function is "doing" an +** yield (from the yield until the next resume); +** - field 'nres' is used only while closing tbc variables when +** returning from a function; +** - field 'transferinfo' is used only during call/returnhooks, +** before the function starts or after it ends. +*/ +struct CallInfo { + StkIdRel func; /* function index in the stack */ + StkIdRel top; /* top for this function */ + struct CallInfo *previous, *next; /* dynamic call link */ + union { + struct { /* only for Lua functions */ + const Instruction *savedpc; + volatile l_signalT trap; + int nextraargs; /* # of extra arguments in vararg functions */ + } l; + struct { /* only for C functions */ + lua_KFunction k; /* continuation in case of yields */ + ptrdiff_t old_errfunc; + lua_KContext ctx; /* context info. in case of yields */ + } c; + } u; + union { + int funcidx; /* called-function index */ + int nyield; /* number of values yielded */ + int nres; /* number of values returned */ + struct { /* info about transferred values (for call/return hooks) */ + unsigned short ftransfer; /* offset of first value transferred */ + unsigned short ntransfer; /* number of values transferred */ + } transferinfo; + } u2; + short nresults; /* expected number of results from this function */ + unsigned short callstatus; +}; + + +/* +** Bits in CallInfo status +*/ +#define CIST_OAH (1<<0) /* original value of 'allowhook' */ +#define CIST_C (1<<1) /* call is running a C function */ +#define CIST_FRESH (1<<2) /* call is on a fresh "luaV_execute" frame */ +#define CIST_HOOKED (1<<3) /* call is running a debug hook */ +#define CIST_YPCALL (1<<4) /* doing a yieldable protected call */ +#define CIST_TAIL (1<<5) /* call was tail called */ +#define CIST_HOOKYIELD (1<<6) /* last hook called yielded */ +#define CIST_FIN (1<<7) /* function "called" a finalizer */ +#define CIST_TRAN (1<<8) /* 'ci' has transfer information */ +#define CIST_CLSRET (1<<9) /* function is closing tbc variables */ +/* Bits 10-12 are used for CIST_RECST (see below) */ +#define CIST_RECST 10 +#if defined(LUA_COMPAT_LT_LE) +#define CIST_LEQ (1<<13) /* using __lt for __le */ +#endif + + +/* +** Field CIST_RECST stores the "recover status", used to keep the error +** status while closing to-be-closed variables in coroutines, so that +** Lua can correctly resume after an yield from a __close method called +** because of an error. (Three bits are enough for error status.) +*/ +#define getcistrecst(ci) (((ci)->callstatus >> CIST_RECST) & 7) +#define setcistrecst(ci,st) \ + check_exp(((st) & 7) == (st), /* status must fit in three bits */ \ + ((ci)->callstatus = ((ci)->callstatus & ~(7 << CIST_RECST)) \ + | ((st) << CIST_RECST))) + + +/* active function is a Lua function */ +#define isLua(ci) (!((ci)->callstatus & CIST_C)) + +/* call is running Lua code (not a hook) */ +#define isLuacode(ci) (!((ci)->callstatus & (CIST_C | CIST_HOOKED))) + +/* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */ +#define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v)) +#define getoah(st) ((st) & CIST_OAH) + + +/* +** 'global state', shared by all threads of this state +*/ +typedef struct global_State { + lua_Alloc frealloc; /* function to reallocate memory */ + void *ud; /* auxiliary data to 'frealloc' */ + l_mem totalbytes; /* number of bytes currently allocated - GCdebt */ + l_mem GCdebt; /* bytes allocated not yet compensated by the collector */ + lu_mem GCestimate; /* an estimate of the non-garbage memory in use */ + lu_mem lastatomic; /* see function 'genstep' in file 'lgc.c' */ + stringtable strt; /* hash table for strings */ + TValue l_registry; + TValue nilvalue; /* a nil value */ + unsigned int seed; /* randomized seed for hashes */ + lu_byte currentwhite; + lu_byte gcstate; /* state of garbage collector */ + lu_byte gckind; /* kind of GC running */ + lu_byte gcstopem; /* stops emergency collections */ + lu_byte genminormul; /* control for minor generational collections */ + lu_byte genmajormul; /* control for major generational collections */ + lu_byte gcstp; /* control whether GC is running */ + lu_byte gcemergency; /* true if this is an emergency collection */ + lu_byte gcpause; /* size of pause between successive GCs */ + lu_byte gcstepmul; /* GC "speed" */ + lu_byte gcstepsize; /* (log2 of) GC granularity */ + GCObject *allgc; /* list of all collectable objects */ + GCObject **sweepgc; /* current position of sweep in list */ + GCObject *finobj; /* list of collectable objects with finalizers */ + GCObject *gray; /* list of gray objects */ + GCObject *grayagain; /* list of objects to be traversed atomically */ + GCObject *weak; /* list of tables with weak values */ + GCObject *ephemeron; /* list of ephemeron tables (weak keys) */ + GCObject *allweak; /* list of all-weak tables */ + GCObject *tobefnz; /* list of userdata to be GC */ + GCObject *fixedgc; /* list of objects not to be collected */ + /* fields for generational collector */ + GCObject *survival; /* start of objects that survived one GC cycle */ + GCObject *old1; /* start of old1 objects */ + GCObject *reallyold; /* objects more than one cycle old ("really old") */ + GCObject *firstold1; /* first OLD1 object in the list (if any) */ + GCObject *finobjsur; /* list of survival objects with finalizers */ + GCObject *finobjold1; /* list of old1 objects with finalizers */ + GCObject *finobjrold; /* list of really old objects with finalizers */ + struct lua_State *twups; /* list of threads with open upvalues */ + lua_CFunction panic; /* to be called in unprotected errors */ + struct lua_State *mainthread; + TString *memerrmsg; /* message for memory-allocation errors */ + TString *tmname[TM_N]; /* array with tag-method names */ + struct Table *mt[LUA_NUMTYPES]; /* metatables for basic types */ + TString *strcache[STRCACHE_N][STRCACHE_M]; /* cache for strings in API */ + lua_WarnFunction warnf; /* warning function */ + void *ud_warn; /* auxiliary data to 'warnf' */ +} global_State; + + +/* +** 'per thread' state +*/ +struct lua_State { + CommonHeader; + lu_byte status; + lu_byte allowhook; + unsigned short nci; /* number of items in 'ci' list */ + StkIdRel top; /* first free slot in the stack */ + global_State *l_G; + CallInfo *ci; /* call info for current function */ + StkIdRel stack_last; /* end of stack (last element + 1) */ + StkIdRel stack; /* stack base */ + UpVal *openupval; /* list of open upvalues in this stack */ + StkIdRel tbclist; /* list of to-be-closed variables */ + GCObject *gclist; + struct lua_State *twups; /* list of threads with open upvalues */ + struct lua_longjmp *errorJmp; /* current error recover point */ + CallInfo base_ci; /* CallInfo for first level (C calling Lua) */ + volatile lua_Hook hook; + ptrdiff_t errfunc; /* current error handling function (stack index) */ + l_uint32 nCcalls; /* number of nested (non-yieldable | C) calls */ + int oldpc; /* last pc traced */ + int basehookcount; + int hookcount; + volatile l_signalT hookmask; +}; + + +#define G(L) (L->l_G) + +/* +** 'g->nilvalue' being a nil value flags that the state was completely +** build. +*/ +#define completestate(g) ttisnil(&g->nilvalue) + + +/* +** Union of all collectable objects (only for conversions) +** ISO C99, 6.5.2.3 p.5: +** "if a union contains several structures that share a common initial +** sequence [...], and if the union object currently contains one +** of these structures, it is permitted to inspect the common initial +** part of any of them anywhere that a declaration of the complete type +** of the union is visible." +*/ +union GCUnion { + GCObject gc; /* common header */ + struct TString ts; + struct Udata u; + union Closure cl; + struct Table h; + struct Proto p; + struct lua_State th; /* thread */ + struct UpVal upv; +}; + + +/* +** ISO C99, 6.7.2.1 p.14: +** "A pointer to a union object, suitably converted, points to each of +** its members [...], and vice versa." +*/ +#define cast_u(o) cast(union GCUnion *, (o)) + +/* macros to convert a GCObject into a specific value */ +#define gco2ts(o) \ + check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts)) +#define gco2u(o) check_exp((o)->tt == LUA_VUSERDATA, &((cast_u(o))->u)) +#define gco2lcl(o) check_exp((o)->tt == LUA_VLCL, &((cast_u(o))->cl.l)) +#define gco2ccl(o) check_exp((o)->tt == LUA_VCCL, &((cast_u(o))->cl.c)) +#define gco2cl(o) \ + check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl)) +#define gco2t(o) check_exp((o)->tt == LUA_VTABLE, &((cast_u(o))->h)) +#define gco2p(o) check_exp((o)->tt == LUA_VPROTO, &((cast_u(o))->p)) +#define gco2th(o) check_exp((o)->tt == LUA_VTHREAD, &((cast_u(o))->th)) +#define gco2upv(o) check_exp((o)->tt == LUA_VUPVAL, &((cast_u(o))->upv)) + + +/* +** macro to convert a Lua object into a GCObject +** (The access to 'tt' tries to ensure that 'v' is actually a Lua object.) +*/ +#define obj2gco(v) check_exp((v)->tt >= LUA_TSTRING, &(cast_u(v)->gc)) + + +/* actual number of total bytes allocated */ +#define gettotalbytes(g) cast(lu_mem, (g)->totalbytes + (g)->GCdebt) + +LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt); +LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1); +LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L); +LUAI_FUNC void luaE_freeCI (lua_State *L); +LUAI_FUNC void luaE_shrinkCI (lua_State *L); +LUAI_FUNC void luaE_checkcstack (lua_State *L); +LUAI_FUNC void luaE_incCstack (lua_State *L); +LUAI_FUNC void luaE_warning (lua_State *L, const char *msg, int tocont); +LUAI_FUNC void luaE_warnerror (lua_State *L, const char *where); +LUAI_FUNC int luaE_resetthread (lua_State *L, int status); + + +#endif + diff --git a/src/lstring.c b/src/lstring.c new file mode 100644 index 0000000..13dcaf4 --- /dev/null +++ b/src/lstring.c @@ -0,0 +1,273 @@ +/* +** $Id: lstring.c $ +** String table (keeps all strings handled by Lua) +** See Copyright Notice in lua.h +*/ + +#define lstring_c +#define LUA_CORE + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" + + +/* +** Maximum size for string table. +*/ +#define MAXSTRTB cast_int(luaM_limitN(MAX_INT, TString*)) + + +/* +** equality for long strings +*/ +int luaS_eqlngstr (TString *a, TString *b) { + size_t len = a->u.lnglen; + lua_assert(a->tt == LUA_VLNGSTR && b->tt == LUA_VLNGSTR); + return (a == b) || /* same instance or... */ + ((len == b->u.lnglen) && /* equal length and ... */ + (memcmp(getstr(a), getstr(b), len) == 0)); /* equal contents */ +} + + +unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) { + unsigned int h = seed ^ cast_uint(l); + for (; l > 0; l--) + h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1])); + return h; +} + + +unsigned int luaS_hashlongstr (TString *ts) { + lua_assert(ts->tt == LUA_VLNGSTR); + if (ts->extra == 0) { /* no hash? */ + size_t len = ts->u.lnglen; + ts->hash = luaS_hash(getstr(ts), len, ts->hash); + ts->extra = 1; /* now it has its hash */ + } + return ts->hash; +} + + +static void tablerehash (TString **vect, int osize, int nsize) { + int i; + for (i = osize; i < nsize; i++) /* clear new elements */ + vect[i] = NULL; + for (i = 0; i < osize; i++) { /* rehash old part of the array */ + TString *p = vect[i]; + vect[i] = NULL; + while (p) { /* for each string in the list */ + TString *hnext = p->u.hnext; /* save next */ + unsigned int h = lmod(p->hash, nsize); /* new position */ + p->u.hnext = vect[h]; /* chain it into array */ + vect[h] = p; + p = hnext; + } + } +} + + +/* +** Resize the string table. If allocation fails, keep the current size. +** (This can degrade performance, but any non-zero size should work +** correctly.) +*/ +void luaS_resize (lua_State *L, int nsize) { + stringtable *tb = &G(L)->strt; + int osize = tb->size; + TString **newvect; + if (nsize < osize) /* shrinking table? */ + tablerehash(tb->hash, osize, nsize); /* depopulate shrinking part */ + newvect = luaM_reallocvector(L, tb->hash, osize, nsize, TString*); + if (l_unlikely(newvect == NULL)) { /* reallocation failed? */ + if (nsize < osize) /* was it shrinking table? */ + tablerehash(tb->hash, nsize, osize); /* restore to original size */ + /* leave table as it was */ + } + else { /* allocation succeeded */ + tb->hash = newvect; + tb->size = nsize; + if (nsize > osize) + tablerehash(newvect, osize, nsize); /* rehash for new size */ + } +} + + +/* +** Clear API string cache. (Entries cannot be empty, so fill them with +** a non-collectable string.) +*/ +void luaS_clearcache (global_State *g) { + int i, j; + for (i = 0; i < STRCACHE_N; i++) + for (j = 0; j < STRCACHE_M; j++) { + if (iswhite(g->strcache[i][j])) /* will entry be collected? */ + g->strcache[i][j] = g->memerrmsg; /* replace it with something fixed */ + } +} + + +/* +** Initialize the string table and the string cache +*/ +void luaS_init (lua_State *L) { + global_State *g = G(L); + int i, j; + stringtable *tb = &G(L)->strt; + tb->hash = luaM_newvector(L, MINSTRTABSIZE, TString*); + tablerehash(tb->hash, 0, MINSTRTABSIZE); /* clear array */ + tb->size = MINSTRTABSIZE; + /* pre-create memory-error message */ + g->memerrmsg = luaS_newliteral(L, MEMERRMSG); + luaC_fix(L, obj2gco(g->memerrmsg)); /* it should never be collected */ + for (i = 0; i < STRCACHE_N; i++) /* fill cache with valid strings */ + for (j = 0; j < STRCACHE_M; j++) + g->strcache[i][j] = g->memerrmsg; +} + + + +/* +** creates a new string object +*/ +static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) { + TString *ts; + GCObject *o; + size_t totalsize; /* total size of TString object */ + totalsize = sizelstring(l); + o = luaC_newobj(L, tag, totalsize); + ts = gco2ts(o); + ts->hash = h; + ts->extra = 0; + getstr(ts)[l] = '\0'; /* ending 0 */ + return ts; +} + + +TString *luaS_createlngstrobj (lua_State *L, size_t l) { + TString *ts = createstrobj(L, l, LUA_VLNGSTR, G(L)->seed); + ts->u.lnglen = l; + return ts; +} + + +void luaS_remove (lua_State *L, TString *ts) { + stringtable *tb = &G(L)->strt; + TString **p = &tb->hash[lmod(ts->hash, tb->size)]; + while (*p != ts) /* find previous element */ + p = &(*p)->u.hnext; + *p = (*p)->u.hnext; /* remove element from its list */ + tb->nuse--; +} + + +static void growstrtab (lua_State *L, stringtable *tb) { + if (l_unlikely(tb->nuse == MAX_INT)) { /* too many strings? */ + luaC_fullgc(L, 1); /* try to free some... */ + if (tb->nuse == MAX_INT) /* still too many? */ + luaM_error(L); /* cannot even create a message... */ + } + if (tb->size <= MAXSTRTB / 2) /* can grow string table? */ + luaS_resize(L, tb->size * 2); +} + + +/* +** Checks whether short string exists and reuses it or creates a new one. +*/ +static TString *internshrstr (lua_State *L, const char *str, size_t l) { + TString *ts; + global_State *g = G(L); + stringtable *tb = &g->strt; + unsigned int h = luaS_hash(str, l, g->seed); + TString **list = &tb->hash[lmod(h, tb->size)]; + lua_assert(str != NULL); /* otherwise 'memcmp'/'memcpy' are undefined */ + for (ts = *list; ts != NULL; ts = ts->u.hnext) { + if (l == ts->shrlen && (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) { + /* found! */ + if (isdead(g, ts)) /* dead (but not collected yet)? */ + changewhite(ts); /* resurrect it */ + return ts; + } + } + /* else must create a new string */ + if (tb->nuse >= tb->size) { /* need to grow string table? */ + growstrtab(L, tb); + list = &tb->hash[lmod(h, tb->size)]; /* rehash with new size */ + } + ts = createstrobj(L, l, LUA_VSHRSTR, h); + memcpy(getstr(ts), str, l * sizeof(char)); + ts->shrlen = cast_byte(l); + ts->u.hnext = *list; + *list = ts; + tb->nuse++; + return ts; +} + + +/* +** new string (with explicit length) +*/ +TString *luaS_newlstr (lua_State *L, const char *str, size_t l) { + if (l <= LUAI_MAXSHORTLEN) /* short string? */ + return internshrstr(L, str, l); + else { + TString *ts; + if (l_unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char))) + luaM_toobig(L); + ts = luaS_createlngstrobj(L, l); + memcpy(getstr(ts), str, l * sizeof(char)); + return ts; + } +} + + +/* +** Create or reuse a zero-terminated string, first checking in the +** cache (using the string address as a key). The cache can contain +** only zero-terminated strings, so it is safe to use 'strcmp' to +** check hits. +*/ +TString *luaS_new (lua_State *L, const char *str) { + unsigned int i = point2uint(str) % STRCACHE_N; /* hash */ + int j; + TString **p = G(L)->strcache[i]; + for (j = 0; j < STRCACHE_M; j++) { + if (strcmp(str, getstr(p[j])) == 0) /* hit? */ + return p[j]; /* that is it */ + } + /* normal route */ + for (j = STRCACHE_M - 1; j > 0; j--) + p[j] = p[j - 1]; /* move out last element */ + /* new element is first in the list */ + p[0] = luaS_newlstr(L, str, strlen(str)); + return p[0]; +} + + +Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue) { + Udata *u; + int i; + GCObject *o; + if (l_unlikely(s > MAX_SIZE - udatamemoffset(nuvalue))) + luaM_toobig(L); + o = luaC_newobj(L, LUA_VUSERDATA, sizeudata(nuvalue, s)); + u = gco2u(o); + u->len = s; + u->nuvalue = nuvalue; + u->metatable = NULL; + for (i = 0; i < nuvalue; i++) + setnilvalue(&u->uv[i].uv); + return u; +} + diff --git a/src/lstring.h b/src/lstring.h new file mode 100644 index 0000000..450c239 --- /dev/null +++ b/src/lstring.h @@ -0,0 +1,57 @@ +/* +** $Id: lstring.h $ +** String table (keep all strings handled by Lua) +** See Copyright Notice in lua.h +*/ + +#ifndef lstring_h +#define lstring_h + +#include "lgc.h" +#include "lobject.h" +#include "lstate.h" + + +/* +** Memory-allocation error message must be preallocated (it cannot +** be created after memory is exhausted) +*/ +#define MEMERRMSG "not enough memory" + + +/* +** Size of a TString: Size of the header plus space for the string +** itself (including final '\0'). +*/ +#define sizelstring(l) (offsetof(TString, contents) + ((l) + 1) * sizeof(char)) + +#define luaS_newliteral(L, s) (luaS_newlstr(L, "" s, \ + (sizeof(s)/sizeof(char))-1)) + + +/* +** test whether a string is a reserved word +*/ +#define isreserved(s) ((s)->tt == LUA_VSHRSTR && (s)->extra > 0) + + +/* +** equality for short strings, which are always internalized +*/ +#define eqshrstr(a,b) check_exp((a)->tt == LUA_VSHRSTR, (a) == (b)) + + +LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l, unsigned int seed); +LUAI_FUNC unsigned int luaS_hashlongstr (TString *ts); +LUAI_FUNC int luaS_eqlngstr (TString *a, TString *b); +LUAI_FUNC void luaS_resize (lua_State *L, int newsize); +LUAI_FUNC void luaS_clearcache (global_State *g); +LUAI_FUNC void luaS_init (lua_State *L); +LUAI_FUNC void luaS_remove (lua_State *L, TString *ts); +LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue); +LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l); +LUAI_FUNC TString *luaS_new (lua_State *L, const char *str); +LUAI_FUNC TString *luaS_createlngstrobj (lua_State *L, size_t l); + + +#endif diff --git a/src/lstrlib.c b/src/lstrlib.c new file mode 100644 index 0000000..0316716 --- /dev/null +++ b/src/lstrlib.c @@ -0,0 +1,1874 @@ +/* +** $Id: lstrlib.c $ +** Standard library for string operations and pattern-matching +** See Copyright Notice in lua.h +*/ + +#define lstrlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** maximum number of captures that a pattern can do during +** pattern-matching. This limit is arbitrary, but must fit in +** an unsigned char. +*/ +#if !defined(LUA_MAXCAPTURES) +#define LUA_MAXCAPTURES 32 +#endif + + +/* macro to 'unsign' a character */ +#define uchar(c) ((unsigned char)(c)) + + +/* +** Some sizes are better limited to fit in 'int', but must also fit in +** 'size_t'. (We assume that 'lua_Integer' cannot be smaller than 'int'.) +*/ +#define MAX_SIZET ((size_t)(~(size_t)0)) + +#define MAXSIZE \ + (sizeof(size_t) < sizeof(int) ? MAX_SIZET : (size_t)(INT_MAX)) + + + + +static int str_len (lua_State *L) { + size_t l; + luaL_checklstring(L, 1, &l); + lua_pushinteger(L, (lua_Integer)l); + return 1; +} + + +/* +** translate a relative initial string position +** (negative means back from end): clip result to [1, inf). +** The length of any string in Lua must fit in a lua_Integer, +** so there are no overflows in the casts. +** The inverted comparison avoids a possible overflow +** computing '-pos'. +*/ +static size_t posrelatI (lua_Integer pos, size_t len) { + if (pos > 0) + return (size_t)pos; + else if (pos == 0) + return 1; + else if (pos < -(lua_Integer)len) /* inverted comparison */ + return 1; /* clip to 1 */ + else return len + (size_t)pos + 1; +} + + +/* +** Gets an optional ending string position from argument 'arg', +** with default value 'def'. +** Negative means back from end: clip result to [0, len] +*/ +static size_t getendpos (lua_State *L, int arg, lua_Integer def, + size_t len) { + lua_Integer pos = luaL_optinteger(L, arg, def); + if (pos > (lua_Integer)len) + return len; + else if (pos >= 0) + return (size_t)pos; + else if (pos < -(lua_Integer)len) + return 0; + else return len + (size_t)pos + 1; +} + + +static int str_sub (lua_State *L) { + size_t l; + const char *s = luaL_checklstring(L, 1, &l); + size_t start = posrelatI(luaL_checkinteger(L, 2), l); + size_t end = getendpos(L, 3, -1, l); + if (start <= end) + lua_pushlstring(L, s + start - 1, (end - start) + 1); + else lua_pushliteral(L, ""); + return 1; +} + + +static int str_reverse (lua_State *L) { + size_t l, i; + luaL_Buffer b; + const char *s = luaL_checklstring(L, 1, &l); + char *p = luaL_buffinitsize(L, &b, l); + for (i = 0; i < l; i++) + p[i] = s[l - i - 1]; + luaL_pushresultsize(&b, l); + return 1; +} + + +static int str_lower (lua_State *L) { + size_t l; + size_t i; + luaL_Buffer b; + const char *s = luaL_checklstring(L, 1, &l); + char *p = luaL_buffinitsize(L, &b, l); + for (i=0; i MAXSIZE / n)) + return luaL_error(L, "resulting string too large"); + else { + size_t totallen = (size_t)n * l + (size_t)(n - 1) * lsep; + luaL_Buffer b; + char *p = luaL_buffinitsize(L, &b, totallen); + while (n-- > 1) { /* first n-1 copies (followed by separator) */ + memcpy(p, s, l * sizeof(char)); p += l; + if (lsep > 0) { /* empty 'memcpy' is not that cheap */ + memcpy(p, sep, lsep * sizeof(char)); + p += lsep; + } + } + memcpy(p, s, l * sizeof(char)); /* last copy (not followed by separator) */ + luaL_pushresultsize(&b, totallen); + } + return 1; +} + + +static int str_byte (lua_State *L) { + size_t l; + const char *s = luaL_checklstring(L, 1, &l); + lua_Integer pi = luaL_optinteger(L, 2, 1); + size_t posi = posrelatI(pi, l); + size_t pose = getendpos(L, 3, pi, l); + int n, i; + if (posi > pose) return 0; /* empty interval; return no values */ + if (l_unlikely(pose - posi >= (size_t)INT_MAX)) /* arithmetic overflow? */ + return luaL_error(L, "string slice too long"); + n = (int)(pose - posi) + 1; + luaL_checkstack(L, n, "string slice too long"); + for (i=0; iinit) { + state->init = 1; + luaL_buffinit(L, &state->B); + } + luaL_addlstring(&state->B, (const char *)b, size); + return 0; +} + + +static int str_dump (lua_State *L) { + struct str_Writer state; + int strip = lua_toboolean(L, 2); + luaL_checktype(L, 1, LUA_TFUNCTION); + lua_settop(L, 1); /* ensure function is on the top of the stack */ + state.init = 0; + if (l_unlikely(lua_dump(L, writer, &state, strip) != 0)) + return luaL_error(L, "unable to dump given function"); + luaL_pushresult(&state.B); + return 1; +} + + + +/* +** {====================================================== +** METAMETHODS +** ======================================================= +*/ + +#if defined(LUA_NOCVTS2N) /* { */ + +/* no coercion from strings to numbers */ + +static const luaL_Reg stringmetamethods[] = { + {"__index", NULL}, /* placeholder */ + {NULL, NULL} +}; + +#else /* }{ */ + +static int tonum (lua_State *L, int arg) { + if (lua_type(L, arg) == LUA_TNUMBER) { /* already a number? */ + lua_pushvalue(L, arg); + return 1; + } + else { /* check whether it is a numerical string */ + size_t len; + const char *s = lua_tolstring(L, arg, &len); + return (s != NULL && lua_stringtonumber(L, s) == len + 1); + } +} + + +static void trymt (lua_State *L, const char *mtname) { + lua_settop(L, 2); /* back to the original arguments */ + if (l_unlikely(lua_type(L, 2) == LUA_TSTRING || + !luaL_getmetafield(L, 2, mtname))) + luaL_error(L, "attempt to %s a '%s' with a '%s'", mtname + 2, + luaL_typename(L, -2), luaL_typename(L, -1)); + lua_insert(L, -3); /* put metamethod before arguments */ + lua_call(L, 2, 1); /* call metamethod */ +} + + +static int arith (lua_State *L, int op, const char *mtname) { + if (tonum(L, 1) && tonum(L, 2)) + lua_arith(L, op); /* result will be on the top */ + else + trymt(L, mtname); + return 1; +} + + +static int arith_add (lua_State *L) { + return arith(L, LUA_OPADD, "__add"); +} + +static int arith_sub (lua_State *L) { + return arith(L, LUA_OPSUB, "__sub"); +} + +static int arith_mul (lua_State *L) { + return arith(L, LUA_OPMUL, "__mul"); +} + +static int arith_mod (lua_State *L) { + return arith(L, LUA_OPMOD, "__mod"); +} + +static int arith_pow (lua_State *L) { + return arith(L, LUA_OPPOW, "__pow"); +} + +static int arith_div (lua_State *L) { + return arith(L, LUA_OPDIV, "__div"); +} + +static int arith_idiv (lua_State *L) { + return arith(L, LUA_OPIDIV, "__idiv"); +} + +static int arith_unm (lua_State *L) { + return arith(L, LUA_OPUNM, "__unm"); +} + + +static const luaL_Reg stringmetamethods[] = { + {"__add", arith_add}, + {"__sub", arith_sub}, + {"__mul", arith_mul}, + {"__mod", arith_mod}, + {"__pow", arith_pow}, + {"__div", arith_div}, + {"__idiv", arith_idiv}, + {"__unm", arith_unm}, + {"__index", NULL}, /* placeholder */ + {NULL, NULL} +}; + +#endif /* } */ + +/* }====================================================== */ + +/* +** {====================================================== +** PATTERN MATCHING +** ======================================================= +*/ + + +#define CAP_UNFINISHED (-1) +#define CAP_POSITION (-2) + + +typedef struct MatchState { + const char *src_init; /* init of source string */ + const char *src_end; /* end ('\0') of source string */ + const char *p_end; /* end ('\0') of pattern */ + lua_State *L; + int matchdepth; /* control for recursive depth (to avoid C stack overflow) */ + unsigned char level; /* total number of captures (finished or unfinished) */ + struct { + const char *init; + ptrdiff_t len; + } capture[LUA_MAXCAPTURES]; +} MatchState; + + +/* recursive function */ +static const char *match (MatchState *ms, const char *s, const char *p); + + +/* maximum recursion depth for 'match' */ +#if !defined(MAXCCALLS) +#define MAXCCALLS 200 +#endif + + +#define L_ESC '%' +#define SPECIALS "^$*+?.([%-" + + +static int check_capture (MatchState *ms, int l) { + l -= '1'; + if (l_unlikely(l < 0 || l >= ms->level || + ms->capture[l].len == CAP_UNFINISHED)) + return luaL_error(ms->L, "invalid capture index %%%d", l + 1); + return l; +} + + +static int capture_to_close (MatchState *ms) { + int level = ms->level; + for (level--; level>=0; level--) + if (ms->capture[level].len == CAP_UNFINISHED) return level; + return luaL_error(ms->L, "invalid pattern capture"); +} + + +static const char *classend (MatchState *ms, const char *p) { + switch (*p++) { + case L_ESC: { + if (l_unlikely(p == ms->p_end)) + luaL_error(ms->L, "malformed pattern (ends with '%%')"); + return p+1; + } + case '[': { + if (*p == '^') p++; + do { /* look for a ']' */ + if (l_unlikely(p == ms->p_end)) + luaL_error(ms->L, "malformed pattern (missing ']')"); + if (*(p++) == L_ESC && p < ms->p_end) + p++; /* skip escapes (e.g. '%]') */ + } while (*p != ']'); + return p+1; + } + default: { + return p; + } + } +} + + +static int match_class (int c, int cl) { + int res; + switch (tolower(cl)) { + case 'a' : res = isalpha(c); break; + case 'c' : res = iscntrl(c); break; + case 'd' : res = isdigit(c); break; + case 'g' : res = isgraph(c); break; + case 'l' : res = islower(c); break; + case 'p' : res = ispunct(c); break; + case 's' : res = isspace(c); break; + case 'u' : res = isupper(c); break; + case 'w' : res = isalnum(c); break; + case 'x' : res = isxdigit(c); break; + case 'z' : res = (c == 0); break; /* deprecated option */ + default: return (cl == c); + } + return (islower(cl) ? res : !res); +} + + +static int matchbracketclass (int c, const char *p, const char *ec) { + int sig = 1; + if (*(p+1) == '^') { + sig = 0; + p++; /* skip the '^' */ + } + while (++p < ec) { + if (*p == L_ESC) { + p++; + if (match_class(c, uchar(*p))) + return sig; + } + else if ((*(p+1) == '-') && (p+2 < ec)) { + p+=2; + if (uchar(*(p-2)) <= c && c <= uchar(*p)) + return sig; + } + else if (uchar(*p) == c) return sig; + } + return !sig; +} + + +static int singlematch (MatchState *ms, const char *s, const char *p, + const char *ep) { + if (s >= ms->src_end) + return 0; + else { + int c = uchar(*s); + switch (*p) { + case '.': return 1; /* matches any char */ + case L_ESC: return match_class(c, uchar(*(p+1))); + case '[': return matchbracketclass(c, p, ep-1); + default: return (uchar(*p) == c); + } + } +} + + +static const char *matchbalance (MatchState *ms, const char *s, + const char *p) { + if (l_unlikely(p >= ms->p_end - 1)) + luaL_error(ms->L, "malformed pattern (missing arguments to '%%b')"); + if (*s != *p) return NULL; + else { + int b = *p; + int e = *(p+1); + int cont = 1; + while (++s < ms->src_end) { + if (*s == e) { + if (--cont == 0) return s+1; + } + else if (*s == b) cont++; + } + } + return NULL; /* string ends out of balance */ +} + + +static const char *max_expand (MatchState *ms, const char *s, + const char *p, const char *ep) { + ptrdiff_t i = 0; /* counts maximum expand for item */ + while (singlematch(ms, s + i, p, ep)) + i++; + /* keeps trying to match with the maximum repetitions */ + while (i>=0) { + const char *res = match(ms, (s+i), ep+1); + if (res) return res; + i--; /* else didn't match; reduce 1 repetition to try again */ + } + return NULL; +} + + +static const char *min_expand (MatchState *ms, const char *s, + const char *p, const char *ep) { + for (;;) { + const char *res = match(ms, s, ep+1); + if (res != NULL) + return res; + else if (singlematch(ms, s, p, ep)) + s++; /* try with one more repetition */ + else return NULL; + } +} + + +static const char *start_capture (MatchState *ms, const char *s, + const char *p, int what) { + const char *res; + int level = ms->level; + if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures"); + ms->capture[level].init = s; + ms->capture[level].len = what; + ms->level = level+1; + if ((res=match(ms, s, p)) == NULL) /* match failed? */ + ms->level--; /* undo capture */ + return res; +} + + +static const char *end_capture (MatchState *ms, const char *s, + const char *p) { + int l = capture_to_close(ms); + const char *res; + ms->capture[l].len = s - ms->capture[l].init; /* close capture */ + if ((res = match(ms, s, p)) == NULL) /* match failed? */ + ms->capture[l].len = CAP_UNFINISHED; /* undo capture */ + return res; +} + + +static const char *match_capture (MatchState *ms, const char *s, int l) { + size_t len; + l = check_capture(ms, l); + len = ms->capture[l].len; + if ((size_t)(ms->src_end-s) >= len && + memcmp(ms->capture[l].init, s, len) == 0) + return s+len; + else return NULL; +} + + +static const char *match (MatchState *ms, const char *s, const char *p) { + if (l_unlikely(ms->matchdepth-- == 0)) + luaL_error(ms->L, "pattern too complex"); + init: /* using goto to optimize tail recursion */ + if (p != ms->p_end) { /* end of pattern? */ + switch (*p) { + case '(': { /* start capture */ + if (*(p + 1) == ')') /* position capture? */ + s = start_capture(ms, s, p + 2, CAP_POSITION); + else + s = start_capture(ms, s, p + 1, CAP_UNFINISHED); + break; + } + case ')': { /* end capture */ + s = end_capture(ms, s, p + 1); + break; + } + case '$': { + if ((p + 1) != ms->p_end) /* is the '$' the last char in pattern? */ + goto dflt; /* no; go to default */ + s = (s == ms->src_end) ? s : NULL; /* check end of string */ + break; + } + case L_ESC: { /* escaped sequences not in the format class[*+?-]? */ + switch (*(p + 1)) { + case 'b': { /* balanced string? */ + s = matchbalance(ms, s, p + 2); + if (s != NULL) { + p += 4; goto init; /* return match(ms, s, p + 4); */ + } /* else fail (s == NULL) */ + break; + } + case 'f': { /* frontier? */ + const char *ep; char previous; + p += 2; + if (l_unlikely(*p != '[')) + luaL_error(ms->L, "missing '[' after '%%f' in pattern"); + ep = classend(ms, p); /* points to what is next */ + previous = (s == ms->src_init) ? '\0' : *(s - 1); + if (!matchbracketclass(uchar(previous), p, ep - 1) && + matchbracketclass(uchar(*s), p, ep - 1)) { + p = ep; goto init; /* return match(ms, s, ep); */ + } + s = NULL; /* match failed */ + break; + } + case '0': case '1': case '2': case '3': + case '4': case '5': case '6': case '7': + case '8': case '9': { /* capture results (%0-%9)? */ + s = match_capture(ms, s, uchar(*(p + 1))); + if (s != NULL) { + p += 2; goto init; /* return match(ms, s, p + 2) */ + } + break; + } + default: goto dflt; + } + break; + } + default: dflt: { /* pattern class plus optional suffix */ + const char *ep = classend(ms, p); /* points to optional suffix */ + /* does not match at least once? */ + if (!singlematch(ms, s, p, ep)) { + if (*ep == '*' || *ep == '?' || *ep == '-') { /* accept empty? */ + p = ep + 1; goto init; /* return match(ms, s, ep + 1); */ + } + else /* '+' or no suffix */ + s = NULL; /* fail */ + } + else { /* matched once */ + switch (*ep) { /* handle optional suffix */ + case '?': { /* optional */ + const char *res; + if ((res = match(ms, s + 1, ep + 1)) != NULL) + s = res; + else { + p = ep + 1; goto init; /* else return match(ms, s, ep + 1); */ + } + break; + } + case '+': /* 1 or more repetitions */ + s++; /* 1 match already done */ + /* FALLTHROUGH */ + case '*': /* 0 or more repetitions */ + s = max_expand(ms, s, p, ep); + break; + case '-': /* 0 or more repetitions (minimum) */ + s = min_expand(ms, s, p, ep); + break; + default: /* no suffix */ + s++; p = ep; goto init; /* return match(ms, s + 1, ep); */ + } + } + break; + } + } + } + ms->matchdepth++; + return s; +} + + + +static const char *lmemfind (const char *s1, size_t l1, + const char *s2, size_t l2) { + if (l2 == 0) return s1; /* empty strings are everywhere */ + else if (l2 > l1) return NULL; /* avoids a negative 'l1' */ + else { + const char *init; /* to search for a '*s2' inside 's1' */ + l2--; /* 1st char will be checked by 'memchr' */ + l1 = l1-l2; /* 's2' cannot be found after that */ + while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) { + init++; /* 1st char is already checked */ + if (memcmp(init, s2+1, l2) == 0) + return init-1; + else { /* correct 'l1' and 's1' to try again */ + l1 -= init-s1; + s1 = init; + } + } + return NULL; /* not found */ + } +} + + +/* +** get information about the i-th capture. If there are no captures +** and 'i==0', return information about the whole match, which +** is the range 's'..'e'. If the capture is a string, return +** its length and put its address in '*cap'. If it is an integer +** (a position), push it on the stack and return CAP_POSITION. +*/ +static size_t get_onecapture (MatchState *ms, int i, const char *s, + const char *e, const char **cap) { + if (i >= ms->level) { + if (l_unlikely(i != 0)) + luaL_error(ms->L, "invalid capture index %%%d", i + 1); + *cap = s; + return e - s; + } + else { + ptrdiff_t capl = ms->capture[i].len; + *cap = ms->capture[i].init; + if (l_unlikely(capl == CAP_UNFINISHED)) + luaL_error(ms->L, "unfinished capture"); + else if (capl == CAP_POSITION) + lua_pushinteger(ms->L, (ms->capture[i].init - ms->src_init) + 1); + return capl; + } +} + + +/* +** Push the i-th capture on the stack. +*/ +static void push_onecapture (MatchState *ms, int i, const char *s, + const char *e) { + const char *cap; + ptrdiff_t l = get_onecapture(ms, i, s, e, &cap); + if (l != CAP_POSITION) + lua_pushlstring(ms->L, cap, l); + /* else position was already pushed */ +} + + +static int push_captures (MatchState *ms, const char *s, const char *e) { + int i; + int nlevels = (ms->level == 0 && s) ? 1 : ms->level; + luaL_checkstack(ms->L, nlevels, "too many captures"); + for (i = 0; i < nlevels; i++) + push_onecapture(ms, i, s, e); + return nlevels; /* number of strings pushed */ +} + + +/* check whether pattern has no special characters */ +static int nospecials (const char *p, size_t l) { + size_t upto = 0; + do { + if (strpbrk(p + upto, SPECIALS)) + return 0; /* pattern has a special character */ + upto += strlen(p + upto) + 1; /* may have more after \0 */ + } while (upto <= l); + return 1; /* no special chars found */ +} + + +static void prepstate (MatchState *ms, lua_State *L, + const char *s, size_t ls, const char *p, size_t lp) { + ms->L = L; + ms->matchdepth = MAXCCALLS; + ms->src_init = s; + ms->src_end = s + ls; + ms->p_end = p + lp; +} + + +static void reprepstate (MatchState *ms) { + ms->level = 0; + lua_assert(ms->matchdepth == MAXCCALLS); +} + + +static int str_find_aux (lua_State *L, int find) { + size_t ls, lp; + const char *s = luaL_checklstring(L, 1, &ls); + const char *p = luaL_checklstring(L, 2, &lp); + size_t init = posrelatI(luaL_optinteger(L, 3, 1), ls) - 1; + if (init > ls) { /* start after string's end? */ + luaL_pushfail(L); /* cannot find anything */ + return 1; + } + /* explicit request or no special characters? */ + if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) { + /* do a plain search */ + const char *s2 = lmemfind(s + init, ls - init, p, lp); + if (s2) { + lua_pushinteger(L, (s2 - s) + 1); + lua_pushinteger(L, (s2 - s) + lp); + return 2; + } + } + else { + MatchState ms; + const char *s1 = s + init; + int anchor = (*p == '^'); + if (anchor) { + p++; lp--; /* skip anchor character */ + } + prepstate(&ms, L, s, ls, p, lp); + do { + const char *res; + reprepstate(&ms); + if ((res=match(&ms, s1, p)) != NULL) { + if (find) { + lua_pushinteger(L, (s1 - s) + 1); /* start */ + lua_pushinteger(L, res - s); /* end */ + return push_captures(&ms, NULL, 0) + 2; + } + else + return push_captures(&ms, s1, res); + } + } while (s1++ < ms.src_end && !anchor); + } + luaL_pushfail(L); /* not found */ + return 1; +} + + +static int str_find (lua_State *L) { + return str_find_aux(L, 1); +} + + +static int str_match (lua_State *L) { + return str_find_aux(L, 0); +} + + +/* state for 'gmatch' */ +typedef struct GMatchState { + const char *src; /* current position */ + const char *p; /* pattern */ + const char *lastmatch; /* end of last match */ + MatchState ms; /* match state */ +} GMatchState; + + +static int gmatch_aux (lua_State *L) { + GMatchState *gm = (GMatchState *)lua_touserdata(L, lua_upvalueindex(3)); + const char *src; + gm->ms.L = L; + for (src = gm->src; src <= gm->ms.src_end; src++) { + const char *e; + reprepstate(&gm->ms); + if ((e = match(&gm->ms, src, gm->p)) != NULL && e != gm->lastmatch) { + gm->src = gm->lastmatch = e; + return push_captures(&gm->ms, src, e); + } + } + return 0; /* not found */ +} + + +static int gmatch (lua_State *L) { + size_t ls, lp; + const char *s = luaL_checklstring(L, 1, &ls); + const char *p = luaL_checklstring(L, 2, &lp); + size_t init = posrelatI(luaL_optinteger(L, 3, 1), ls) - 1; + GMatchState *gm; + lua_settop(L, 2); /* keep strings on closure to avoid being collected */ + gm = (GMatchState *)lua_newuserdatauv(L, sizeof(GMatchState), 0); + if (init > ls) /* start after string's end? */ + init = ls + 1; /* avoid overflows in 's + init' */ + prepstate(&gm->ms, L, s, ls, p, lp); + gm->src = s + init; gm->p = p; gm->lastmatch = NULL; + lua_pushcclosure(L, gmatch_aux, 3); + return 1; +} + + +static void add_s (MatchState *ms, luaL_Buffer *b, const char *s, + const char *e) { + size_t l; + lua_State *L = ms->L; + const char *news = lua_tolstring(L, 3, &l); + const char *p; + while ((p = (char *)memchr(news, L_ESC, l)) != NULL) { + luaL_addlstring(b, news, p - news); + p++; /* skip ESC */ + if (*p == L_ESC) /* '%%' */ + luaL_addchar(b, *p); + else if (*p == '0') /* '%0' */ + luaL_addlstring(b, s, e - s); + else if (isdigit(uchar(*p))) { /* '%n' */ + const char *cap; + ptrdiff_t resl = get_onecapture(ms, *p - '1', s, e, &cap); + if (resl == CAP_POSITION) + luaL_addvalue(b); /* add position to accumulated result */ + else + luaL_addlstring(b, cap, resl); + } + else + luaL_error(L, "invalid use of '%c' in replacement string", L_ESC); + l -= p + 1 - news; + news = p + 1; + } + luaL_addlstring(b, news, l); +} + + +/* +** Add the replacement value to the string buffer 'b'. +** Return true if the original string was changed. (Function calls and +** table indexing resulting in nil or false do not change the subject.) +*/ +static int add_value (MatchState *ms, luaL_Buffer *b, const char *s, + const char *e, int tr) { + lua_State *L = ms->L; + switch (tr) { + case LUA_TFUNCTION: { /* call the function */ + int n; + lua_pushvalue(L, 3); /* push the function */ + n = push_captures(ms, s, e); /* all captures as arguments */ + lua_call(L, n, 1); /* call it */ + break; + } + case LUA_TTABLE: { /* index the table */ + push_onecapture(ms, 0, s, e); /* first capture is the index */ + lua_gettable(L, 3); + break; + } + default: { /* LUA_TNUMBER or LUA_TSTRING */ + add_s(ms, b, s, e); /* add value to the buffer */ + return 1; /* something changed */ + } + } + if (!lua_toboolean(L, -1)) { /* nil or false? */ + lua_pop(L, 1); /* remove value */ + luaL_addlstring(b, s, e - s); /* keep original text */ + return 0; /* no changes */ + } + else if (l_unlikely(!lua_isstring(L, -1))) + return luaL_error(L, "invalid replacement value (a %s)", + luaL_typename(L, -1)); + else { + luaL_addvalue(b); /* add result to accumulator */ + return 1; /* something changed */ + } +} + + +static int str_gsub (lua_State *L) { + size_t srcl, lp; + const char *src = luaL_checklstring(L, 1, &srcl); /* subject */ + const char *p = luaL_checklstring(L, 2, &lp); /* pattern */ + const char *lastmatch = NULL; /* end of last match */ + int tr = lua_type(L, 3); /* replacement type */ + lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1); /* max replacements */ + int anchor = (*p == '^'); + lua_Integer n = 0; /* replacement count */ + int changed = 0; /* change flag */ + MatchState ms; + luaL_Buffer b; + luaL_argexpected(L, tr == LUA_TNUMBER || tr == LUA_TSTRING || + tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3, + "string/function/table"); + luaL_buffinit(L, &b); + if (anchor) { + p++; lp--; /* skip anchor character */ + } + prepstate(&ms, L, src, srcl, p, lp); + while (n < max_s) { + const char *e; + reprepstate(&ms); /* (re)prepare state for new match */ + if ((e = match(&ms, src, p)) != NULL && e != lastmatch) { /* match? */ + n++; + changed = add_value(&ms, &b, src, e, tr) | changed; + src = lastmatch = e; + } + else if (src < ms.src_end) /* otherwise, skip one character */ + luaL_addchar(&b, *src++); + else break; /* end of subject */ + if (anchor) break; + } + if (!changed) /* no changes? */ + lua_pushvalue(L, 1); /* return original string */ + else { /* something changed */ + luaL_addlstring(&b, src, ms.src_end-src); + luaL_pushresult(&b); /* create and return new string */ + } + lua_pushinteger(L, n); /* number of substitutions */ + return 2; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** STRING FORMAT +** ======================================================= +*/ + +#if !defined(lua_number2strx) /* { */ + +/* +** Hexadecimal floating-point formatter +*/ + +#define SIZELENMOD (sizeof(LUA_NUMBER_FRMLEN)/sizeof(char)) + + +/* +** Number of bits that goes into the first digit. It can be any value +** between 1 and 4; the following definition tries to align the number +** to nibble boundaries by making what is left after that first digit a +** multiple of 4. +*/ +#define L_NBFD ((l_floatatt(MANT_DIG) - 1)%4 + 1) + + +/* +** Add integer part of 'x' to buffer and return new 'x' +*/ +static lua_Number adddigit (char *buff, int n, lua_Number x) { + lua_Number dd = l_mathop(floor)(x); /* get integer part from 'x' */ + int d = (int)dd; + buff[n] = (d < 10 ? d + '0' : d - 10 + 'a'); /* add to buffer */ + return x - dd; /* return what is left */ +} + + +static int num2straux (char *buff, int sz, lua_Number x) { + /* if 'inf' or 'NaN', format it like '%g' */ + if (x != x || x == (lua_Number)HUGE_VAL || x == -(lua_Number)HUGE_VAL) + return l_sprintf(buff, sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)x); + else if (x == 0) { /* can be -0... */ + /* create "0" or "-0" followed by exponent */ + return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", (LUAI_UACNUMBER)x); + } + else { + int e; + lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */ + int n = 0; /* character count */ + if (m < 0) { /* is number negative? */ + buff[n++] = '-'; /* add sign */ + m = -m; /* make it positive */ + } + buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */ + m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */ + e -= L_NBFD; /* this digit goes before the radix point */ + if (m > 0) { /* more digits? */ + buff[n++] = lua_getlocaledecpoint(); /* add radix point */ + do { /* add as many digits as needed */ + m = adddigit(buff, n++, m * 16); + } while (m > 0); + } + n += l_sprintf(buff + n, sz - n, "p%+d", e); /* add exponent */ + lua_assert(n < sz); + return n; + } +} + + +static int lua_number2strx (lua_State *L, char *buff, int sz, + const char *fmt, lua_Number x) { + int n = num2straux(buff, sz, x); + if (fmt[SIZELENMOD] == 'A') { + int i; + for (i = 0; i < n; i++) + buff[i] = toupper(uchar(buff[i])); + } + else if (l_unlikely(fmt[SIZELENMOD] != 'a')) + return luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented"); + return n; +} + +#endif /* } */ + + +/* +** Maximum size for items formatted with '%f'. This size is produced +** by format('%.99f', -maxfloat), and is equal to 99 + 3 ('-', '.', +** and '\0') + number of decimal digits to represent maxfloat (which +** is maximum exponent + 1). (99+3+1, adding some extra, 110) +*/ +#define MAX_ITEMF (110 + l_floatatt(MAX_10_EXP)) + + +/* +** All formats except '%f' do not need that large limit. The other +** float formats use exponents, so that they fit in the 99 limit for +** significant digits; 's' for large strings and 'q' add items directly +** to the buffer; all integer formats also fit in the 99 limit. The +** worst case are floats: they may need 99 significant digits, plus +** '0x', '-', '.', 'e+XXXX', and '\0'. Adding some extra, 120. +*/ +#define MAX_ITEM 120 + + +/* valid flags in a format specification */ +#if !defined(L_FMTFLAGSF) + +/* valid flags for a, A, e, E, f, F, g, and G conversions */ +#define L_FMTFLAGSF "-+#0 " + +/* valid flags for o, x, and X conversions */ +#define L_FMTFLAGSX "-#0" + +/* valid flags for d and i conversions */ +#define L_FMTFLAGSI "-+0 " + +/* valid flags for u conversions */ +#define L_FMTFLAGSU "-0" + +/* valid flags for c, p, and s conversions */ +#define L_FMTFLAGSC "-" + +#endif + + +/* +** Maximum size of each format specification (such as "%-099.99d"): +** Initial '%', flags (up to 5), width (2), period, precision (2), +** length modifier (8), conversion specifier, and final '\0', plus some +** extra. +*/ +#define MAX_FORMAT 32 + + +static void addquoted (luaL_Buffer *b, const char *s, size_t len) { + luaL_addchar(b, '"'); + while (len--) { + if (*s == '"' || *s == '\\' || *s == '\n') { + luaL_addchar(b, '\\'); + luaL_addchar(b, *s); + } + else if (iscntrl(uchar(*s))) { + char buff[10]; + if (!isdigit(uchar(*(s+1)))) + l_sprintf(buff, sizeof(buff), "\\%d", (int)uchar(*s)); + else + l_sprintf(buff, sizeof(buff), "\\%03d", (int)uchar(*s)); + luaL_addstring(b, buff); + } + else + luaL_addchar(b, *s); + s++; + } + luaL_addchar(b, '"'); +} + + +/* +** Serialize a floating-point number in such a way that it can be +** scanned back by Lua. Use hexadecimal format for "common" numbers +** (to preserve precision); inf, -inf, and NaN are handled separately. +** (NaN cannot be expressed as a numeral, so we write '(0/0)' for it.) +*/ +static int quotefloat (lua_State *L, char *buff, lua_Number n) { + const char *s; /* for the fixed representations */ + if (n == (lua_Number)HUGE_VAL) /* inf? */ + s = "1e9999"; + else if (n == -(lua_Number)HUGE_VAL) /* -inf? */ + s = "-1e9999"; + else if (n != n) /* NaN? */ + s = "(0/0)"; + else { /* format number as hexadecimal */ + int nb = lua_number2strx(L, buff, MAX_ITEM, + "%" LUA_NUMBER_FRMLEN "a", n); + /* ensures that 'buff' string uses a dot as the radix character */ + if (memchr(buff, '.', nb) == NULL) { /* no dot? */ + char point = lua_getlocaledecpoint(); /* try locale point */ + char *ppoint = (char *)memchr(buff, point, nb); + if (ppoint) *ppoint = '.'; /* change it to a dot */ + } + return nb; + } + /* for the fixed representations */ + return l_sprintf(buff, MAX_ITEM, "%s", s); +} + + +static void addliteral (lua_State *L, luaL_Buffer *b, int arg) { + switch (lua_type(L, arg)) { + case LUA_TSTRING: { + size_t len; + const char *s = lua_tolstring(L, arg, &len); + addquoted(b, s, len); + break; + } + case LUA_TNUMBER: { + char *buff = luaL_prepbuffsize(b, MAX_ITEM); + int nb; + if (!lua_isinteger(L, arg)) /* float? */ + nb = quotefloat(L, buff, lua_tonumber(L, arg)); + else { /* integers */ + lua_Integer n = lua_tointeger(L, arg); + const char *format = (n == LUA_MININTEGER) /* corner case? */ + ? "0x%" LUA_INTEGER_FRMLEN "x" /* use hex */ + : LUA_INTEGER_FMT; /* else use default format */ + nb = l_sprintf(buff, MAX_ITEM, format, (LUAI_UACINT)n); + } + luaL_addsize(b, nb); + break; + } + case LUA_TNIL: case LUA_TBOOLEAN: { + luaL_tolstring(L, arg, NULL); + luaL_addvalue(b); + break; + } + default: { + luaL_argerror(L, arg, "value has no literal form"); + } + } +} + + +static const char *get2digits (const char *s) { + if (isdigit(uchar(*s))) { + s++; + if (isdigit(uchar(*s))) s++; /* (2 digits at most) */ + } + return s; +} + + +/* +** Check whether a conversion specification is valid. When called, +** first character in 'form' must be '%' and last character must +** be a valid conversion specifier. 'flags' are the accepted flags; +** 'precision' signals whether to accept a precision. +*/ +static void checkformat (lua_State *L, const char *form, const char *flags, + int precision) { + const char *spec = form + 1; /* skip '%' */ + spec += strspn(spec, flags); /* skip flags */ + if (*spec != '0') { /* a width cannot start with '0' */ + spec = get2digits(spec); /* skip width */ + if (*spec == '.' && precision) { + spec++; + spec = get2digits(spec); /* skip precision */ + } + } + if (!isalpha(uchar(*spec))) /* did not go to the end? */ + luaL_error(L, "invalid conversion specification: '%s'", form); +} + + +/* +** Get a conversion specification and copy it to 'form'. +** Return the address of its last character. +*/ +static const char *getformat (lua_State *L, const char *strfrmt, + char *form) { + /* spans flags, width, and precision ('0' is included as a flag) */ + size_t len = strspn(strfrmt, L_FMTFLAGSF "123456789."); + len++; /* adds following character (should be the specifier) */ + /* still needs space for '%', '\0', plus a length modifier */ + if (len >= MAX_FORMAT - 10) + luaL_error(L, "invalid format (too long)"); + *(form++) = '%'; + memcpy(form, strfrmt, len * sizeof(char)); + *(form + len) = '\0'; + return strfrmt + len - 1; +} + + +/* +** add length modifier into formats +*/ +static void addlenmod (char *form, const char *lenmod) { + size_t l = strlen(form); + size_t lm = strlen(lenmod); + char spec = form[l - 1]; + strcpy(form + l - 1, lenmod); + form[l + lm - 1] = spec; + form[l + lm] = '\0'; +} + + +static int str_format (lua_State *L) { + int top = lua_gettop(L); + int arg = 1; + size_t sfl; + const char *strfrmt = luaL_checklstring(L, arg, &sfl); + const char *strfrmt_end = strfrmt+sfl; + const char *flags; + luaL_Buffer b; + luaL_buffinit(L, &b); + while (strfrmt < strfrmt_end) { + if (*strfrmt != L_ESC) + luaL_addchar(&b, *strfrmt++); + else if (*++strfrmt == L_ESC) + luaL_addchar(&b, *strfrmt++); /* %% */ + else { /* format item */ + char form[MAX_FORMAT]; /* to store the format ('%...') */ + int maxitem = MAX_ITEM; /* maximum length for the result */ + char *buff = luaL_prepbuffsize(&b, maxitem); /* to put result */ + int nb = 0; /* number of bytes in result */ + if (++arg > top) + return luaL_argerror(L, arg, "no value"); + strfrmt = getformat(L, strfrmt, form); + switch (*strfrmt++) { + case 'c': { + checkformat(L, form, L_FMTFLAGSC, 0); + nb = l_sprintf(buff, maxitem, form, (int)luaL_checkinteger(L, arg)); + break; + } + case 'd': case 'i': + flags = L_FMTFLAGSI; + goto intcase; + case 'u': + flags = L_FMTFLAGSU; + goto intcase; + case 'o': case 'x': case 'X': + flags = L_FMTFLAGSX; + intcase: { + lua_Integer n = luaL_checkinteger(L, arg); + checkformat(L, form, flags, 1); + addlenmod(form, LUA_INTEGER_FRMLEN); + nb = l_sprintf(buff, maxitem, form, (LUAI_UACINT)n); + break; + } + case 'a': case 'A': + checkformat(L, form, L_FMTFLAGSF, 1); + addlenmod(form, LUA_NUMBER_FRMLEN); + nb = lua_number2strx(L, buff, maxitem, form, + luaL_checknumber(L, arg)); + break; + case 'f': + maxitem = MAX_ITEMF; /* extra space for '%f' */ + buff = luaL_prepbuffsize(&b, maxitem); + /* FALLTHROUGH */ + case 'e': case 'E': case 'g': case 'G': { + lua_Number n = luaL_checknumber(L, arg); + checkformat(L, form, L_FMTFLAGSF, 1); + addlenmod(form, LUA_NUMBER_FRMLEN); + nb = l_sprintf(buff, maxitem, form, (LUAI_UACNUMBER)n); + break; + } + case 'p': { + const void *p = lua_topointer(L, arg); + checkformat(L, form, L_FMTFLAGSC, 0); + if (p == NULL) { /* avoid calling 'printf' with argument NULL */ + p = "(null)"; /* result */ + form[strlen(form) - 1] = 's'; /* format it as a string */ + } + nb = l_sprintf(buff, maxitem, form, p); + break; + } + case 'q': { + if (form[2] != '\0') /* modifiers? */ + return luaL_error(L, "specifier '%%q' cannot have modifiers"); + addliteral(L, &b, arg); + break; + } + case 's': { + size_t l; + const char *s = luaL_tolstring(L, arg, &l); + if (form[2] == '\0') /* no modifiers? */ + luaL_addvalue(&b); /* keep entire string */ + else { + luaL_argcheck(L, l == strlen(s), arg, "string contains zeros"); + checkformat(L, form, L_FMTFLAGSC, 1); + if (strchr(form, '.') == NULL && l >= 100) { + /* no precision and string is too long to be formatted */ + luaL_addvalue(&b); /* keep entire string */ + } + else { /* format the string into 'buff' */ + nb = l_sprintf(buff, maxitem, form, s); + lua_pop(L, 1); /* remove result from 'luaL_tolstring' */ + } + } + break; + } + default: { /* also treat cases 'pnLlh' */ + return luaL_error(L, "invalid conversion '%s' to 'format'", form); + } + } + lua_assert(nb < maxitem); + luaL_addsize(&b, nb); + } + } + luaL_pushresult(&b); + return 1; +} + +/* }====================================================== */ + + +/* +** {====================================================== +** PACK/UNPACK +** ======================================================= +*/ + + +/* value used for padding */ +#if !defined(LUAL_PACKPADBYTE) +#define LUAL_PACKPADBYTE 0x00 +#endif + +/* maximum size for the binary representation of an integer */ +#define MAXINTSIZE 16 + +/* number of bits in a character */ +#define NB CHAR_BIT + +/* mask for one character (NB 1's) */ +#define MC ((1 << NB) - 1) + +/* size of a lua_Integer */ +#define SZINT ((int)sizeof(lua_Integer)) + + +/* dummy union to get native endianness */ +static const union { + int dummy; + char little; /* true iff machine is little endian */ +} nativeendian = {1}; + + +/* +** information to pack/unpack stuff +*/ +typedef struct Header { + lua_State *L; + int islittle; + int maxalign; +} Header; + + +/* +** options for pack/unpack +*/ +typedef enum KOption { + Kint, /* signed integers */ + Kuint, /* unsigned integers */ + Kfloat, /* single-precision floating-point numbers */ + Knumber, /* Lua "native" floating-point numbers */ + Kdouble, /* double-precision floating-point numbers */ + Kchar, /* fixed-length strings */ + Kstring, /* strings with prefixed length */ + Kzstr, /* zero-terminated strings */ + Kpadding, /* padding */ + Kpaddalign, /* padding for alignment */ + Knop /* no-op (configuration or spaces) */ +} KOption; + + +/* +** Read an integer numeral from string 'fmt' or return 'df' if +** there is no numeral +*/ +static int digit (int c) { return '0' <= c && c <= '9'; } + +static int getnum (const char **fmt, int df) { + if (!digit(**fmt)) /* no number? */ + return df; /* return default value */ + else { + int a = 0; + do { + a = a*10 + (*((*fmt)++) - '0'); + } while (digit(**fmt) && a <= ((int)MAXSIZE - 9)/10); + return a; + } +} + + +/* +** Read an integer numeral and raises an error if it is larger +** than the maximum size for integers. +*/ +static int getnumlimit (Header *h, const char **fmt, int df) { + int sz = getnum(fmt, df); + if (l_unlikely(sz > MAXINTSIZE || sz <= 0)) + return luaL_error(h->L, "integral size (%d) out of limits [1,%d]", + sz, MAXINTSIZE); + return sz; +} + + +/* +** Initialize Header +*/ +static void initheader (lua_State *L, Header *h) { + h->L = L; + h->islittle = nativeendian.little; + h->maxalign = 1; +} + + +/* +** Read and classify next option. 'size' is filled with option's size. +*/ +static KOption getoption (Header *h, const char **fmt, int *size) { + /* dummy structure to get native alignment requirements */ + struct cD { char c; union { LUAI_MAXALIGN; } u; }; + int opt = *((*fmt)++); + *size = 0; /* default */ + switch (opt) { + case 'b': *size = sizeof(char); return Kint; + case 'B': *size = sizeof(char); return Kuint; + case 'h': *size = sizeof(short); return Kint; + case 'H': *size = sizeof(short); return Kuint; + case 'l': *size = sizeof(long); return Kint; + case 'L': *size = sizeof(long); return Kuint; + case 'j': *size = sizeof(lua_Integer); return Kint; + case 'J': *size = sizeof(lua_Integer); return Kuint; + case 'T': *size = sizeof(size_t); return Kuint; + case 'f': *size = sizeof(float); return Kfloat; + case 'n': *size = sizeof(lua_Number); return Knumber; + case 'd': *size = sizeof(double); return Kdouble; + case 'i': *size = getnumlimit(h, fmt, sizeof(int)); return Kint; + case 'I': *size = getnumlimit(h, fmt, sizeof(int)); return Kuint; + case 's': *size = getnumlimit(h, fmt, sizeof(size_t)); return Kstring; + case 'c': + *size = getnum(fmt, -1); + if (l_unlikely(*size == -1)) + luaL_error(h->L, "missing size for format option 'c'"); + return Kchar; + case 'z': return Kzstr; + case 'x': *size = 1; return Kpadding; + case 'X': return Kpaddalign; + case ' ': break; + case '<': h->islittle = 1; break; + case '>': h->islittle = 0; break; + case '=': h->islittle = nativeendian.little; break; + case '!': { + const int maxalign = offsetof(struct cD, u); + h->maxalign = getnumlimit(h, fmt, maxalign); + break; + } + default: luaL_error(h->L, "invalid format option '%c'", opt); + } + return Knop; +} + + +/* +** Read, classify, and fill other details about the next option. +** 'psize' is filled with option's size, 'notoalign' with its +** alignment requirements. +** Local variable 'size' gets the size to be aligned. (Kpadal option +** always gets its full alignment, other options are limited by +** the maximum alignment ('maxalign'). Kchar option needs no alignment +** despite its size. +*/ +static KOption getdetails (Header *h, size_t totalsize, + const char **fmt, int *psize, int *ntoalign) { + KOption opt = getoption(h, fmt, psize); + int align = *psize; /* usually, alignment follows size */ + if (opt == Kpaddalign) { /* 'X' gets alignment from following option */ + if (**fmt == '\0' || getoption(h, fmt, &align) == Kchar || align == 0) + luaL_argerror(h->L, 1, "invalid next option for option 'X'"); + } + if (align <= 1 || opt == Kchar) /* need no alignment? */ + *ntoalign = 0; + else { + if (align > h->maxalign) /* enforce maximum alignment */ + align = h->maxalign; + if (l_unlikely((align & (align - 1)) != 0)) /* not a power of 2? */ + luaL_argerror(h->L, 1, "format asks for alignment not power of 2"); + *ntoalign = (align - (int)(totalsize & (align - 1))) & (align - 1); + } + return opt; +} + + +/* +** Pack integer 'n' with 'size' bytes and 'islittle' endianness. +** The final 'if' handles the case when 'size' is larger than +** the size of a Lua integer, correcting the extra sign-extension +** bytes if necessary (by default they would be zeros). +*/ +static void packint (luaL_Buffer *b, lua_Unsigned n, + int islittle, int size, int neg) { + char *buff = luaL_prepbuffsize(b, size); + int i; + buff[islittle ? 0 : size - 1] = (char)(n & MC); /* first byte */ + for (i = 1; i < size; i++) { + n >>= NB; + buff[islittle ? i : size - 1 - i] = (char)(n & MC); + } + if (neg && size > SZINT) { /* negative number need sign extension? */ + for (i = SZINT; i < size; i++) /* correct extra bytes */ + buff[islittle ? i : size - 1 - i] = (char)MC; + } + luaL_addsize(b, size); /* add result to buffer */ +} + + +/* +** Copy 'size' bytes from 'src' to 'dest', correcting endianness if +** given 'islittle' is different from native endianness. +*/ +static void copywithendian (char *dest, const char *src, + int size, int islittle) { + if (islittle == nativeendian.little) + memcpy(dest, src, size); + else { + dest += size - 1; + while (size-- != 0) + *(dest--) = *(src++); + } +} + + +static int str_pack (lua_State *L) { + luaL_Buffer b; + Header h; + const char *fmt = luaL_checkstring(L, 1); /* format string */ + int arg = 1; /* current argument to pack */ + size_t totalsize = 0; /* accumulate total size of result */ + initheader(L, &h); + lua_pushnil(L); /* mark to separate arguments from string buffer */ + luaL_buffinit(L, &b); + while (*fmt != '\0') { + int size, ntoalign; + KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign); + totalsize += ntoalign + size; + while (ntoalign-- > 0) + luaL_addchar(&b, LUAL_PACKPADBYTE); /* fill alignment */ + arg++; + switch (opt) { + case Kint: { /* signed integers */ + lua_Integer n = luaL_checkinteger(L, arg); + if (size < SZINT) { /* need overflow check? */ + lua_Integer lim = (lua_Integer)1 << ((size * NB) - 1); + luaL_argcheck(L, -lim <= n && n < lim, arg, "integer overflow"); + } + packint(&b, (lua_Unsigned)n, h.islittle, size, (n < 0)); + break; + } + case Kuint: { /* unsigned integers */ + lua_Integer n = luaL_checkinteger(L, arg); + if (size < SZINT) /* need overflow check? */ + luaL_argcheck(L, (lua_Unsigned)n < ((lua_Unsigned)1 << (size * NB)), + arg, "unsigned overflow"); + packint(&b, (lua_Unsigned)n, h.islittle, size, 0); + break; + } + case Kfloat: { /* C float */ + float f = (float)luaL_checknumber(L, arg); /* get argument */ + char *buff = luaL_prepbuffsize(&b, sizeof(f)); + /* move 'f' to final result, correcting endianness if needed */ + copywithendian(buff, (char *)&f, sizeof(f), h.islittle); + luaL_addsize(&b, size); + break; + } + case Knumber: { /* Lua float */ + lua_Number f = luaL_checknumber(L, arg); /* get argument */ + char *buff = luaL_prepbuffsize(&b, sizeof(f)); + /* move 'f' to final result, correcting endianness if needed */ + copywithendian(buff, (char *)&f, sizeof(f), h.islittle); + luaL_addsize(&b, size); + break; + } + case Kdouble: { /* C double */ + double f = (double)luaL_checknumber(L, arg); /* get argument */ + char *buff = luaL_prepbuffsize(&b, sizeof(f)); + /* move 'f' to final result, correcting endianness if needed */ + copywithendian(buff, (char *)&f, sizeof(f), h.islittle); + luaL_addsize(&b, size); + break; + } + case Kchar: { /* fixed-size string */ + size_t len; + const char *s = luaL_checklstring(L, arg, &len); + luaL_argcheck(L, len <= (size_t)size, arg, + "string longer than given size"); + luaL_addlstring(&b, s, len); /* add string */ + while (len++ < (size_t)size) /* pad extra space */ + luaL_addchar(&b, LUAL_PACKPADBYTE); + break; + } + case Kstring: { /* strings with length count */ + size_t len; + const char *s = luaL_checklstring(L, arg, &len); + luaL_argcheck(L, size >= (int)sizeof(size_t) || + len < ((size_t)1 << (size * NB)), + arg, "string length does not fit in given size"); + packint(&b, (lua_Unsigned)len, h.islittle, size, 0); /* pack length */ + luaL_addlstring(&b, s, len); + totalsize += len; + break; + } + case Kzstr: { /* zero-terminated string */ + size_t len; + const char *s = luaL_checklstring(L, arg, &len); + luaL_argcheck(L, strlen(s) == len, arg, "string contains zeros"); + luaL_addlstring(&b, s, len); + luaL_addchar(&b, '\0'); /* add zero at the end */ + totalsize += len + 1; + break; + } + case Kpadding: luaL_addchar(&b, LUAL_PACKPADBYTE); /* FALLTHROUGH */ + case Kpaddalign: case Knop: + arg--; /* undo increment */ + break; + } + } + luaL_pushresult(&b); + return 1; +} + + +static int str_packsize (lua_State *L) { + Header h; + const char *fmt = luaL_checkstring(L, 1); /* format string */ + size_t totalsize = 0; /* accumulate total size of result */ + initheader(L, &h); + while (*fmt != '\0') { + int size, ntoalign; + KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign); + luaL_argcheck(L, opt != Kstring && opt != Kzstr, 1, + "variable-length format"); + size += ntoalign; /* total space used by option */ + luaL_argcheck(L, totalsize <= MAXSIZE - size, 1, + "format result too large"); + totalsize += size; + } + lua_pushinteger(L, (lua_Integer)totalsize); + return 1; +} + + +/* +** Unpack an integer with 'size' bytes and 'islittle' endianness. +** If size is smaller than the size of a Lua integer and integer +** is signed, must do sign extension (propagating the sign to the +** higher bits); if size is larger than the size of a Lua integer, +** it must check the unread bytes to see whether they do not cause an +** overflow. +*/ +static lua_Integer unpackint (lua_State *L, const char *str, + int islittle, int size, int issigned) { + lua_Unsigned res = 0; + int i; + int limit = (size <= SZINT) ? size : SZINT; + for (i = limit - 1; i >= 0; i--) { + res <<= NB; + res |= (lua_Unsigned)(unsigned char)str[islittle ? i : size - 1 - i]; + } + if (size < SZINT) { /* real size smaller than lua_Integer? */ + if (issigned) { /* needs sign extension? */ + lua_Unsigned mask = (lua_Unsigned)1 << (size*NB - 1); + res = ((res ^ mask) - mask); /* do sign extension */ + } + } + else if (size > SZINT) { /* must check unread bytes */ + int mask = (!issigned || (lua_Integer)res >= 0) ? 0 : MC; + for (i = limit; i < size; i++) { + if (l_unlikely((unsigned char)str[islittle ? i : size - 1 - i] != mask)) + luaL_error(L, "%d-byte integer does not fit into Lua Integer", size); + } + } + return (lua_Integer)res; +} + + +static int str_unpack (lua_State *L) { + Header h; + const char *fmt = luaL_checkstring(L, 1); + size_t ld; + const char *data = luaL_checklstring(L, 2, &ld); + size_t pos = posrelatI(luaL_optinteger(L, 3, 1), ld) - 1; + int n = 0; /* number of results */ + luaL_argcheck(L, pos <= ld, 3, "initial position out of string"); + initheader(L, &h); + while (*fmt != '\0') { + int size, ntoalign; + KOption opt = getdetails(&h, pos, &fmt, &size, &ntoalign); + luaL_argcheck(L, (size_t)ntoalign + size <= ld - pos, 2, + "data string too short"); + pos += ntoalign; /* skip alignment */ + /* stack space for item + next position */ + luaL_checkstack(L, 2, "too many results"); + n++; + switch (opt) { + case Kint: + case Kuint: { + lua_Integer res = unpackint(L, data + pos, h.islittle, size, + (opt == Kint)); + lua_pushinteger(L, res); + break; + } + case Kfloat: { + float f; + copywithendian((char *)&f, data + pos, sizeof(f), h.islittle); + lua_pushnumber(L, (lua_Number)f); + break; + } + case Knumber: { + lua_Number f; + copywithendian((char *)&f, data + pos, sizeof(f), h.islittle); + lua_pushnumber(L, f); + break; + } + case Kdouble: { + double f; + copywithendian((char *)&f, data + pos, sizeof(f), h.islittle); + lua_pushnumber(L, (lua_Number)f); + break; + } + case Kchar: { + lua_pushlstring(L, data + pos, size); + break; + } + case Kstring: { + size_t len = (size_t)unpackint(L, data + pos, h.islittle, size, 0); + luaL_argcheck(L, len <= ld - pos - size, 2, "data string too short"); + lua_pushlstring(L, data + pos + size, len); + pos += len; /* skip string */ + break; + } + case Kzstr: { + size_t len = strlen(data + pos); + luaL_argcheck(L, pos + len < ld, 2, + "unfinished string for format 'z'"); + lua_pushlstring(L, data + pos, len); + pos += len + 1; /* skip string plus final '\0' */ + break; + } + case Kpaddalign: case Kpadding: case Knop: + n--; /* undo increment */ + break; + } + pos += size; + } + lua_pushinteger(L, pos + 1); /* next position */ + return n + 1; +} + +/* }====================================================== */ + + +static const luaL_Reg strlib[] = { + {"byte", str_byte}, + {"char", str_char}, + {"dump", str_dump}, + {"find", str_find}, + {"format", str_format}, + {"gmatch", gmatch}, + {"gsub", str_gsub}, + {"len", str_len}, + {"lower", str_lower}, + {"match", str_match}, + {"rep", str_rep}, + {"reverse", str_reverse}, + {"sub", str_sub}, + {"upper", str_upper}, + {"pack", str_pack}, + {"packsize", str_packsize}, + {"unpack", str_unpack}, + {NULL, NULL} +}; + + +static void createmetatable (lua_State *L) { + /* table to be metatable for strings */ + luaL_newlibtable(L, stringmetamethods); + luaL_setfuncs(L, stringmetamethods, 0); + lua_pushliteral(L, ""); /* dummy string */ + lua_pushvalue(L, -2); /* copy table */ + lua_setmetatable(L, -2); /* set table as metatable for strings */ + lua_pop(L, 1); /* pop dummy string */ + lua_pushvalue(L, -2); /* get string library */ + lua_setfield(L, -2, "__index"); /* metatable.__index = string */ + lua_pop(L, 1); /* pop metatable */ +} + + +/* +** Open string library +*/ +LUAMOD_API int luaopen_string (lua_State *L) { + luaL_newlib(L, strlib); + createmetatable(L); + return 1; +} + diff --git a/src/ltable.c b/src/ltable.c new file mode 100644 index 0000000..3c690c5 --- /dev/null +++ b/src/ltable.c @@ -0,0 +1,980 @@ +/* +** $Id: ltable.c $ +** Lua tables (hash) +** See Copyright Notice in lua.h +*/ + +#define ltable_c +#define LUA_CORE + +#include "lprefix.h" + + +/* +** Implementation of tables (aka arrays, objects, or hash tables). +** Tables keep its elements in two parts: an array part and a hash part. +** Non-negative integer keys are all candidates to be kept in the array +** part. The actual size of the array is the largest 'n' such that +** more than half the slots between 1 and n are in use. +** Hash uses a mix of chained scatter table with Brent's variation. +** A main invariant of these tables is that, if an element is not +** in its main position (i.e. the 'original' position that its hash gives +** to it), then the colliding element is in its own main position. +** Hence even when the load factor reaches 100%, performance remains good. +*/ + +#include +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "lvm.h" + + +/* +** MAXABITS is the largest integer such that MAXASIZE fits in an +** unsigned int. +*/ +#define MAXABITS cast_int(sizeof(int) * CHAR_BIT - 1) + + +/* +** MAXASIZE is the maximum size of the array part. It is the minimum +** between 2^MAXABITS and the maximum size that, measured in bytes, +** fits in a 'size_t'. +*/ +#define MAXASIZE luaM_limitN(1u << MAXABITS, TValue) + +/* +** MAXHBITS is the largest integer such that 2^MAXHBITS fits in a +** signed int. +*/ +#define MAXHBITS (MAXABITS - 1) + + +/* +** MAXHSIZE is the maximum size of the hash part. It is the minimum +** between 2^MAXHBITS and the maximum size such that, measured in bytes, +** it fits in a 'size_t'. +*/ +#define MAXHSIZE luaM_limitN(1u << MAXHBITS, Node) + + +/* +** When the original hash value is good, hashing by a power of 2 +** avoids the cost of '%'. +*/ +#define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t)))) + +/* +** for other types, it is better to avoid modulo by power of 2, as +** they can have many 2 factors. +*/ +#define hashmod(t,n) (gnode(t, ((n) % ((sizenode(t)-1)|1)))) + + +#define hashstr(t,str) hashpow2(t, (str)->hash) +#define hashboolean(t,p) hashpow2(t, p) + + +#define hashpointer(t,p) hashmod(t, point2uint(p)) + + +#define dummynode (&dummynode_) + +static const Node dummynode_ = { + {{NULL}, LUA_VEMPTY, /* value's value and type */ + LUA_VNIL, 0, {NULL}} /* key type, next, and key value */ +}; + + +static const TValue absentkey = {ABSTKEYCONSTANT}; + + +/* +** Hash for integers. To allow a good hash, use the remainder operator +** ('%'). If integer fits as a non-negative int, compute an int +** remainder, which is faster. Otherwise, use an unsigned-integer +** remainder, which uses all bits and ensures a non-negative result. +*/ +static Node *hashint (const Table *t, lua_Integer i) { + lua_Unsigned ui = l_castS2U(i); + if (ui <= cast_uint(INT_MAX)) + return hashmod(t, cast_int(ui)); + else + return hashmod(t, ui); +} + + +/* +** Hash for floating-point numbers. +** The main computation should be just +** n = frexp(n, &i); return (n * INT_MAX) + i +** but there are some numerical subtleties. +** In a two-complement representation, INT_MAX does not has an exact +** representation as a float, but INT_MIN does; because the absolute +** value of 'frexp' is smaller than 1 (unless 'n' is inf/NaN), the +** absolute value of the product 'frexp * -INT_MIN' is smaller or equal +** to INT_MAX. Next, the use of 'unsigned int' avoids overflows when +** adding 'i'; the use of '~u' (instead of '-u') avoids problems with +** INT_MIN. +*/ +#if !defined(l_hashfloat) +static int l_hashfloat (lua_Number n) { + int i; + lua_Integer ni; + n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN); + if (!lua_numbertointeger(n, &ni)) { /* is 'n' inf/-inf/NaN? */ + lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL)); + return 0; + } + else { /* normal case */ + unsigned int u = cast_uint(i) + cast_uint(ni); + return cast_int(u <= cast_uint(INT_MAX) ? u : ~u); + } +} +#endif + + +/* +** returns the 'main' position of an element in a table (that is, +** the index of its hash value). +*/ +static Node *mainpositionTV (const Table *t, const TValue *key) { + switch (ttypetag(key)) { + case LUA_VNUMINT: { + lua_Integer i = ivalue(key); + return hashint(t, i); + } + case LUA_VNUMFLT: { + lua_Number n = fltvalue(key); + return hashmod(t, l_hashfloat(n)); + } + case LUA_VSHRSTR: { + TString *ts = tsvalue(key); + return hashstr(t, ts); + } + case LUA_VLNGSTR: { + TString *ts = tsvalue(key); + return hashpow2(t, luaS_hashlongstr(ts)); + } + case LUA_VFALSE: + return hashboolean(t, 0); + case LUA_VTRUE: + return hashboolean(t, 1); + case LUA_VLIGHTUSERDATA: { + void *p = pvalue(key); + return hashpointer(t, p); + } + case LUA_VLCF: { + lua_CFunction f = fvalue(key); + return hashpointer(t, f); + } + default: { + GCObject *o = gcvalue(key); + return hashpointer(t, o); + } + } +} + + +l_sinline Node *mainpositionfromnode (const Table *t, Node *nd) { + TValue key; + getnodekey(cast(lua_State *, NULL), &key, nd); + return mainpositionTV(t, &key); +} + + +/* +** Check whether key 'k1' is equal to the key in node 'n2'. This +** equality is raw, so there are no metamethods. Floats with integer +** values have been normalized, so integers cannot be equal to +** floats. It is assumed that 'eqshrstr' is simply pointer equality, so +** that short strings are handled in the default case. +** A true 'deadok' means to accept dead keys as equal to their original +** values. All dead keys are compared in the default case, by pointer +** identity. (Only collectable objects can produce dead keys.) Note that +** dead long strings are also compared by identity. +** Once a key is dead, its corresponding value may be collected, and +** then another value can be created with the same address. If this +** other value is given to 'next', 'equalkey' will signal a false +** positive. In a regular traversal, this situation should never happen, +** as all keys given to 'next' came from the table itself, and therefore +** could not have been collected. Outside a regular traversal, we +** have garbage in, garbage out. What is relevant is that this false +** positive does not break anything. (In particular, 'next' will return +** some other valid item on the table or nil.) +*/ +static int equalkey (const TValue *k1, const Node *n2, int deadok) { + if ((rawtt(k1) != keytt(n2)) && /* not the same variants? */ + !(deadok && keyisdead(n2) && iscollectable(k1))) + return 0; /* cannot be same key */ + switch (keytt(n2)) { + case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE: + return 1; + case LUA_VNUMINT: + return (ivalue(k1) == keyival(n2)); + case LUA_VNUMFLT: + return luai_numeq(fltvalue(k1), fltvalueraw(keyval(n2))); + case LUA_VLIGHTUSERDATA: + return pvalue(k1) == pvalueraw(keyval(n2)); + case LUA_VLCF: + return fvalue(k1) == fvalueraw(keyval(n2)); + case ctb(LUA_VLNGSTR): + return luaS_eqlngstr(tsvalue(k1), keystrval(n2)); + default: + return gcvalue(k1) == gcvalueraw(keyval(n2)); + } +} + + +/* +** True if value of 'alimit' is equal to the real size of the array +** part of table 't'. (Otherwise, the array part must be larger than +** 'alimit'.) +*/ +#define limitequalsasize(t) (isrealasize(t) || ispow2((t)->alimit)) + + +/* +** Returns the real size of the 'array' array +*/ +LUAI_FUNC unsigned int luaH_realasize (const Table *t) { + if (limitequalsasize(t)) + return t->alimit; /* this is the size */ + else { + unsigned int size = t->alimit; + /* compute the smallest power of 2 not smaller than 'n' */ + size |= (size >> 1); + size |= (size >> 2); + size |= (size >> 4); + size |= (size >> 8); +#if (UINT_MAX >> 14) > 3 /* unsigned int has more than 16 bits */ + size |= (size >> 16); +#if (UINT_MAX >> 30) > 3 + size |= (size >> 32); /* unsigned int has more than 32 bits */ +#endif +#endif + size++; + lua_assert(ispow2(size) && size/2 < t->alimit && t->alimit < size); + return size; + } +} + + +/* +** Check whether real size of the array is a power of 2. +** (If it is not, 'alimit' cannot be changed to any other value +** without changing the real size.) +*/ +static int ispow2realasize (const Table *t) { + return (!isrealasize(t) || ispow2(t->alimit)); +} + + +static unsigned int setlimittosize (Table *t) { + t->alimit = luaH_realasize(t); + setrealasize(t); + return t->alimit; +} + + +#define limitasasize(t) check_exp(isrealasize(t), t->alimit) + + + +/* +** "Generic" get version. (Not that generic: not valid for integers, +** which may be in array part, nor for floats with integral values.) +** See explanation about 'deadok' in function 'equalkey'. +*/ +static const TValue *getgeneric (Table *t, const TValue *key, int deadok) { + Node *n = mainpositionTV(t, key); + for (;;) { /* check whether 'key' is somewhere in the chain */ + if (equalkey(key, n, deadok)) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) + return &absentkey; /* not found */ + n += nx; + } + } +} + + +/* +** returns the index for 'k' if 'k' is an appropriate key to live in +** the array part of a table, 0 otherwise. +*/ +static unsigned int arrayindex (lua_Integer k) { + if (l_castS2U(k) - 1u < MAXASIZE) /* 'k' in [1, MAXASIZE]? */ + return cast_uint(k); /* 'key' is an appropriate array index */ + else + return 0; +} + + +/* +** returns the index of a 'key' for table traversals. First goes all +** elements in the array part, then elements in the hash part. The +** beginning of a traversal is signaled by 0. +*/ +static unsigned int findindex (lua_State *L, Table *t, TValue *key, + unsigned int asize) { + unsigned int i; + if (ttisnil(key)) return 0; /* first iteration */ + i = ttisinteger(key) ? arrayindex(ivalue(key)) : 0; + if (i - 1u < asize) /* is 'key' inside array part? */ + return i; /* yes; that's the index */ + else { + const TValue *n = getgeneric(t, key, 1); + if (l_unlikely(isabstkey(n))) + luaG_runerror(L, "invalid key to 'next'"); /* key not found */ + i = cast_int(nodefromval(n) - gnode(t, 0)); /* key index in hash table */ + /* hash elements are numbered after array ones */ + return (i + 1) + asize; + } +} + + +int luaH_next (lua_State *L, Table *t, StkId key) { + unsigned int asize = luaH_realasize(t); + unsigned int i = findindex(L, t, s2v(key), asize); /* find original key */ + for (; i < asize; i++) { /* try first array part */ + if (!isempty(&t->array[i])) { /* a non-empty entry? */ + setivalue(s2v(key), i + 1); + setobj2s(L, key + 1, &t->array[i]); + return 1; + } + } + for (i -= asize; cast_int(i) < sizenode(t); i++) { /* hash part */ + if (!isempty(gval(gnode(t, i)))) { /* a non-empty entry? */ + Node *n = gnode(t, i); + getnodekey(L, s2v(key), n); + setobj2s(L, key + 1, gval(n)); + return 1; + } + } + return 0; /* no more elements */ +} + + +static void freehash (lua_State *L, Table *t) { + if (!isdummy(t)) + luaM_freearray(L, t->node, cast_sizet(sizenode(t))); +} + + +/* +** {============================================================= +** Rehash +** ============================================================== +*/ + +/* +** Compute the optimal size for the array part of table 't'. 'nums' is a +** "count array" where 'nums[i]' is the number of integers in the table +** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of +** integer keys in the table and leaves with the number of keys that +** will go to the array part; return the optimal size. (The condition +** 'twotoi > 0' in the for loop stops the loop if 'twotoi' overflows.) +*/ +static unsigned int computesizes (unsigned int nums[], unsigned int *pna) { + int i; + unsigned int twotoi; /* 2^i (candidate for optimal size) */ + unsigned int a = 0; /* number of elements smaller than 2^i */ + unsigned int na = 0; /* number of elements to go to array part */ + unsigned int optimal = 0; /* optimal size for array part */ + /* loop while keys can fill more than half of total size */ + for (i = 0, twotoi = 1; + twotoi > 0 && *pna > twotoi / 2; + i++, twotoi *= 2) { + a += nums[i]; + if (a > twotoi/2) { /* more than half elements present? */ + optimal = twotoi; /* optimal size (till now) */ + na = a; /* all elements up to 'optimal' will go to array part */ + } + } + lua_assert((optimal == 0 || optimal / 2 < na) && na <= optimal); + *pna = na; + return optimal; +} + + +static int countint (lua_Integer key, unsigned int *nums) { + unsigned int k = arrayindex(key); + if (k != 0) { /* is 'key' an appropriate array index? */ + nums[luaO_ceillog2(k)]++; /* count as such */ + return 1; + } + else + return 0; +} + + +/* +** Count keys in array part of table 't': Fill 'nums[i]' with +** number of keys that will go into corresponding slice and return +** total number of non-nil keys. +*/ +static unsigned int numusearray (const Table *t, unsigned int *nums) { + int lg; + unsigned int ttlg; /* 2^lg */ + unsigned int ause = 0; /* summation of 'nums' */ + unsigned int i = 1; /* count to traverse all array keys */ + unsigned int asize = limitasasize(t); /* real array size */ + /* traverse each slice */ + for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) { + unsigned int lc = 0; /* counter */ + unsigned int lim = ttlg; + if (lim > asize) { + lim = asize; /* adjust upper limit */ + if (i > lim) + break; /* no more elements to count */ + } + /* count elements in range (2^(lg - 1), 2^lg] */ + for (; i <= lim; i++) { + if (!isempty(&t->array[i-1])) + lc++; + } + nums[lg] += lc; + ause += lc; + } + return ause; +} + + +static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) { + int totaluse = 0; /* total number of elements */ + int ause = 0; /* elements added to 'nums' (can go to array part) */ + int i = sizenode(t); + while (i--) { + Node *n = &t->node[i]; + if (!isempty(gval(n))) { + if (keyisinteger(n)) + ause += countint(keyival(n), nums); + totaluse++; + } + } + *pna += ause; + return totaluse; +} + + +/* +** Creates an array for the hash part of a table with the given +** size, or reuses the dummy node if size is zero. +** The computation for size overflow is in two steps: the first +** comparison ensures that the shift in the second one does not +** overflow. +*/ +static void setnodevector (lua_State *L, Table *t, unsigned int size) { + if (size == 0) { /* no elements to hash part? */ + t->node = cast(Node *, dummynode); /* use common 'dummynode' */ + t->lsizenode = 0; + t->lastfree = NULL; /* signal that it is using dummy node */ + } + else { + int i; + int lsize = luaO_ceillog2(size); + if (lsize > MAXHBITS || (1u << lsize) > MAXHSIZE) + luaG_runerror(L, "table overflow"); + size = twoto(lsize); + t->node = luaM_newvector(L, size, Node); + for (i = 0; i < cast_int(size); i++) { + Node *n = gnode(t, i); + gnext(n) = 0; + setnilkey(n); + setempty(gval(n)); + } + t->lsizenode = cast_byte(lsize); + t->lastfree = gnode(t, size); /* all positions are free */ + } +} + + +/* +** (Re)insert all elements from the hash part of 'ot' into table 't'. +*/ +static void reinsert (lua_State *L, Table *ot, Table *t) { + int j; + int size = sizenode(ot); + for (j = 0; j < size; j++) { + Node *old = gnode(ot, j); + if (!isempty(gval(old))) { + /* doesn't need barrier/invalidate cache, as entry was + already present in the table */ + TValue k; + getnodekey(L, &k, old); + luaH_set(L, t, &k, gval(old)); + } + } +} + + +/* +** Exchange the hash part of 't1' and 't2'. +*/ +static void exchangehashpart (Table *t1, Table *t2) { + lu_byte lsizenode = t1->lsizenode; + Node *node = t1->node; + Node *lastfree = t1->lastfree; + t1->lsizenode = t2->lsizenode; + t1->node = t2->node; + t1->lastfree = t2->lastfree; + t2->lsizenode = lsizenode; + t2->node = node; + t2->lastfree = lastfree; +} + + +/* +** Resize table 't' for the new given sizes. Both allocations (for +** the hash part and for the array part) can fail, which creates some +** subtleties. If the first allocation, for the hash part, fails, an +** error is raised and that is it. Otherwise, it copies the elements from +** the shrinking part of the array (if it is shrinking) into the new +** hash. Then it reallocates the array part. If that fails, the table +** is in its original state; the function frees the new hash part and then +** raises the allocation error. Otherwise, it sets the new hash part +** into the table, initializes the new part of the array (if any) with +** nils and reinserts the elements of the old hash back into the new +** parts of the table. +*/ +void luaH_resize (lua_State *L, Table *t, unsigned int newasize, + unsigned int nhsize) { + unsigned int i; + Table newt; /* to keep the new hash part */ + unsigned int oldasize = setlimittosize(t); + TValue *newarray; + /* create new hash part with appropriate size into 'newt' */ + setnodevector(L, &newt, nhsize); + if (newasize < oldasize) { /* will array shrink? */ + t->alimit = newasize; /* pretend array has new size... */ + exchangehashpart(t, &newt); /* and new hash */ + /* re-insert into the new hash the elements from vanishing slice */ + for (i = newasize; i < oldasize; i++) { + if (!isempty(&t->array[i])) + luaH_setint(L, t, i + 1, &t->array[i]); + } + t->alimit = oldasize; /* restore current size... */ + exchangehashpart(t, &newt); /* and hash (in case of errors) */ + } + /* allocate new array */ + newarray = luaM_reallocvector(L, t->array, oldasize, newasize, TValue); + if (l_unlikely(newarray == NULL && newasize > 0)) { /* allocation failed? */ + freehash(L, &newt); /* release new hash part */ + luaM_error(L); /* raise error (with array unchanged) */ + } + /* allocation ok; initialize new part of the array */ + exchangehashpart(t, &newt); /* 't' has the new hash ('newt' has the old) */ + t->array = newarray; /* set new array part */ + t->alimit = newasize; + for (i = oldasize; i < newasize; i++) /* clear new slice of the array */ + setempty(&t->array[i]); + /* re-insert elements from old hash part into new parts */ + reinsert(L, &newt, t); /* 'newt' now has the old hash */ + freehash(L, &newt); /* free old hash part */ +} + + +void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) { + int nsize = allocsizenode(t); + luaH_resize(L, t, nasize, nsize); +} + +/* +** nums[i] = number of keys 'k' where 2^(i - 1) < k <= 2^i +*/ +static void rehash (lua_State *L, Table *t, const TValue *ek) { + unsigned int asize; /* optimal size for array part */ + unsigned int na; /* number of keys in the array part */ + unsigned int nums[MAXABITS + 1]; + int i; + int totaluse; + for (i = 0; i <= MAXABITS; i++) nums[i] = 0; /* reset counts */ + setlimittosize(t); + na = numusearray(t, nums); /* count keys in array part */ + totaluse = na; /* all those keys are integer keys */ + totaluse += numusehash(t, nums, &na); /* count keys in hash part */ + /* count extra key */ + if (ttisinteger(ek)) + na += countint(ivalue(ek), nums); + totaluse++; + /* compute new size for array part */ + asize = computesizes(nums, &na); + /* resize the table to new computed sizes */ + luaH_resize(L, t, asize, totaluse - na); +} + + + +/* +** }============================================================= +*/ + + +Table *luaH_new (lua_State *L) { + GCObject *o = luaC_newobj(L, LUA_VTABLE, sizeof(Table)); + Table *t = gco2t(o); + t->metatable = NULL; + t->flags = cast_byte(maskflags); /* table has no metamethod fields */ + t->array = NULL; + t->alimit = 0; + setnodevector(L, t, 0); + return t; +} + + +void luaH_free (lua_State *L, Table *t) { + freehash(L, t); + luaM_freearray(L, t->array, luaH_realasize(t)); + luaM_free(L, t); +} + + +static Node *getfreepos (Table *t) { + if (!isdummy(t)) { + while (t->lastfree > t->node) { + t->lastfree--; + if (keyisnil(t->lastfree)) + return t->lastfree; + } + } + return NULL; /* could not find a free place */ +} + + + +/* +** inserts a new key into a hash table; first, check whether key's main +** position is free. If not, check whether colliding node is in its main +** position or not: if it is not, move colliding node to an empty place and +** put new key in its main position; otherwise (colliding node is in its main +** position), new key goes to an empty position. +*/ +void luaH_newkey (lua_State *L, Table *t, const TValue *key, TValue *value) { + Node *mp; + TValue aux; + if (l_unlikely(ttisnil(key))) + luaG_runerror(L, "table index is nil"); + else if (ttisfloat(key)) { + lua_Number f = fltvalue(key); + lua_Integer k; + if (luaV_flttointeger(f, &k, F2Ieq)) { /* does key fit in an integer? */ + setivalue(&aux, k); + key = &aux; /* insert it as an integer */ + } + else if (l_unlikely(luai_numisnan(f))) + luaG_runerror(L, "table index is NaN"); + } + if (ttisnil(value)) + return; /* do not insert nil values */ + mp = mainpositionTV(t, key); + if (!isempty(gval(mp)) || isdummy(t)) { /* main position is taken? */ + Node *othern; + Node *f = getfreepos(t); /* get a free place */ + if (f == NULL) { /* cannot find a free place? */ + rehash(L, t, key); /* grow table */ + /* whatever called 'newkey' takes care of TM cache */ + luaH_set(L, t, key, value); /* insert key into grown table */ + return; + } + lua_assert(!isdummy(t)); + othern = mainpositionfromnode(t, mp); + if (othern != mp) { /* is colliding node out of its main position? */ + /* yes; move colliding node into free position */ + while (othern + gnext(othern) != mp) /* find previous */ + othern += gnext(othern); + gnext(othern) = cast_int(f - othern); /* rechain to point to 'f' */ + *f = *mp; /* copy colliding node into free pos. (mp->next also goes) */ + if (gnext(mp) != 0) { + gnext(f) += cast_int(mp - f); /* correct 'next' */ + gnext(mp) = 0; /* now 'mp' is free */ + } + setempty(gval(mp)); + } + else { /* colliding node is in its own main position */ + /* new node will go into free position */ + if (gnext(mp) != 0) + gnext(f) = cast_int((mp + gnext(mp)) - f); /* chain new position */ + else lua_assert(gnext(f) == 0); + gnext(mp) = cast_int(f - mp); + mp = f; + } + } + setnodekey(L, mp, key); + luaC_barrierback(L, obj2gco(t), key); + lua_assert(isempty(gval(mp))); + setobj2t(L, gval(mp), value); +} + + +/* +** Search function for integers. If integer is inside 'alimit', get it +** directly from the array part. Otherwise, if 'alimit' is not equal to +** the real size of the array, key still can be in the array part. In +** this case, try to avoid a call to 'luaH_realasize' when key is just +** one more than the limit (so that it can be incremented without +** changing the real size of the array). +*/ +const TValue *luaH_getint (Table *t, lua_Integer key) { + if (l_castS2U(key) - 1u < t->alimit) /* 'key' in [1, t->alimit]? */ + return &t->array[key - 1]; + else if (!limitequalsasize(t) && /* key still may be in the array part? */ + (l_castS2U(key) == t->alimit + 1 || + l_castS2U(key) - 1u < luaH_realasize(t))) { + t->alimit = cast_uint(key); /* probably '#t' is here now */ + return &t->array[key - 1]; + } + else { + Node *n = hashint(t, key); + for (;;) { /* check whether 'key' is somewhere in the chain */ + if (keyisinteger(n) && keyival(n) == key) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) break; + n += nx; + } + } + return &absentkey; + } +} + + +/* +** search function for short strings +*/ +const TValue *luaH_getshortstr (Table *t, TString *key) { + Node *n = hashstr(t, key); + lua_assert(key->tt == LUA_VSHRSTR); + for (;;) { /* check whether 'key' is somewhere in the chain */ + if (keyisshrstr(n) && eqshrstr(keystrval(n), key)) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) + return &absentkey; /* not found */ + n += nx; + } + } +} + + +const TValue *luaH_getstr (Table *t, TString *key) { + if (key->tt == LUA_VSHRSTR) + return luaH_getshortstr(t, key); + else { /* for long strings, use generic case */ + TValue ko; + setsvalue(cast(lua_State *, NULL), &ko, key); + return getgeneric(t, &ko, 0); + } +} + + +/* +** main search function +*/ +const TValue *luaH_get (Table *t, const TValue *key) { + switch (ttypetag(key)) { + case LUA_VSHRSTR: return luaH_getshortstr(t, tsvalue(key)); + case LUA_VNUMINT: return luaH_getint(t, ivalue(key)); + case LUA_VNIL: return &absentkey; + case LUA_VNUMFLT: { + lua_Integer k; + if (luaV_flttointeger(fltvalue(key), &k, F2Ieq)) /* integral index? */ + return luaH_getint(t, k); /* use specialized version */ + /* else... */ + } /* FALLTHROUGH */ + default: + return getgeneric(t, key, 0); + } +} + + +/* +** Finish a raw "set table" operation, where 'slot' is where the value +** should have been (the result of a previous "get table"). +** Beware: when using this function you probably need to check a GC +** barrier and invalidate the TM cache. +*/ +void luaH_finishset (lua_State *L, Table *t, const TValue *key, + const TValue *slot, TValue *value) { + if (isabstkey(slot)) + luaH_newkey(L, t, key, value); + else + setobj2t(L, cast(TValue *, slot), value); +} + + +/* +** beware: when using this function you probably need to check a GC +** barrier and invalidate the TM cache. +*/ +void luaH_set (lua_State *L, Table *t, const TValue *key, TValue *value) { + const TValue *slot = luaH_get(t, key); + luaH_finishset(L, t, key, slot, value); +} + + +void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) { + const TValue *p = luaH_getint(t, key); + if (isabstkey(p)) { + TValue k; + setivalue(&k, key); + luaH_newkey(L, t, &k, value); + } + else + setobj2t(L, cast(TValue *, p), value); +} + + +/* +** Try to find a boundary in the hash part of table 't'. From the +** caller, we know that 'j' is zero or present and that 'j + 1' is +** present. We want to find a larger key that is absent from the +** table, so that we can do a binary search between the two keys to +** find a boundary. We keep doubling 'j' until we get an absent index. +** If the doubling would overflow, we try LUA_MAXINTEGER. If it is +** absent, we are ready for the binary search. ('j', being max integer, +** is larger or equal to 'i', but it cannot be equal because it is +** absent while 'i' is present; so 'j > i'.) Otherwise, 'j' is a +** boundary. ('j + 1' cannot be a present integer key because it is +** not a valid integer in Lua.) +*/ +static lua_Unsigned hash_search (Table *t, lua_Unsigned j) { + lua_Unsigned i; + if (j == 0) j++; /* the caller ensures 'j + 1' is present */ + do { + i = j; /* 'i' is a present index */ + if (j <= l_castS2U(LUA_MAXINTEGER) / 2) + j *= 2; + else { + j = LUA_MAXINTEGER; + if (isempty(luaH_getint(t, j))) /* t[j] not present? */ + break; /* 'j' now is an absent index */ + else /* weird case */ + return j; /* well, max integer is a boundary... */ + } + } while (!isempty(luaH_getint(t, j))); /* repeat until an absent t[j] */ + /* i < j && t[i] present && t[j] absent */ + while (j - i > 1u) { /* do a binary search between them */ + lua_Unsigned m = (i + j) / 2; + if (isempty(luaH_getint(t, m))) j = m; + else i = m; + } + return i; +} + + +static unsigned int binsearch (const TValue *array, unsigned int i, + unsigned int j) { + while (j - i > 1u) { /* binary search */ + unsigned int m = (i + j) / 2; + if (isempty(&array[m - 1])) j = m; + else i = m; + } + return i; +} + + +/* +** Try to find a boundary in table 't'. (A 'boundary' is an integer index +** such that t[i] is present and t[i+1] is absent, or 0 if t[1] is absent +** and 'maxinteger' if t[maxinteger] is present.) +** (In the next explanation, we use Lua indices, that is, with base 1. +** The code itself uses base 0 when indexing the array part of the table.) +** The code starts with 'limit = t->alimit', a position in the array +** part that may be a boundary. +** +** (1) If 't[limit]' is empty, there must be a boundary before it. +** As a common case (e.g., after 't[#t]=nil'), check whether 'limit-1' +** is present. If so, it is a boundary. Otherwise, do a binary search +** between 0 and limit to find a boundary. In both cases, try to +** use this boundary as the new 'alimit', as a hint for the next call. +** +** (2) If 't[limit]' is not empty and the array has more elements +** after 'limit', try to find a boundary there. Again, try first +** the special case (which should be quite frequent) where 'limit+1' +** is empty, so that 'limit' is a boundary. Otherwise, check the +** last element of the array part. If it is empty, there must be a +** boundary between the old limit (present) and the last element +** (absent), which is found with a binary search. (This boundary always +** can be a new limit.) +** +** (3) The last case is when there are no elements in the array part +** (limit == 0) or its last element (the new limit) is present. +** In this case, must check the hash part. If there is no hash part +** or 'limit+1' is absent, 'limit' is a boundary. Otherwise, call +** 'hash_search' to find a boundary in the hash part of the table. +** (In those cases, the boundary is not inside the array part, and +** therefore cannot be used as a new limit.) +*/ +lua_Unsigned luaH_getn (Table *t) { + unsigned int limit = t->alimit; + if (limit > 0 && isempty(&t->array[limit - 1])) { /* (1)? */ + /* there must be a boundary before 'limit' */ + if (limit >= 2 && !isempty(&t->array[limit - 2])) { + /* 'limit - 1' is a boundary; can it be a new limit? */ + if (ispow2realasize(t) && !ispow2(limit - 1)) { + t->alimit = limit - 1; + setnorealasize(t); /* now 'alimit' is not the real size */ + } + return limit - 1; + } + else { /* must search for a boundary in [0, limit] */ + unsigned int boundary = binsearch(t->array, 0, limit); + /* can this boundary represent the real size of the array? */ + if (ispow2realasize(t) && boundary > luaH_realasize(t) / 2) { + t->alimit = boundary; /* use it as the new limit */ + setnorealasize(t); + } + return boundary; + } + } + /* 'limit' is zero or present in table */ + if (!limitequalsasize(t)) { /* (2)? */ + /* 'limit' > 0 and array has more elements after 'limit' */ + if (isempty(&t->array[limit])) /* 'limit + 1' is empty? */ + return limit; /* this is the boundary */ + /* else, try last element in the array */ + limit = luaH_realasize(t); + if (isempty(&t->array[limit - 1])) { /* empty? */ + /* there must be a boundary in the array after old limit, + and it must be a valid new limit */ + unsigned int boundary = binsearch(t->array, t->alimit, limit); + t->alimit = boundary; + return boundary; + } + /* else, new limit is present in the table; check the hash part */ + } + /* (3) 'limit' is the last element and either is zero or present in table */ + lua_assert(limit == luaH_realasize(t) && + (limit == 0 || !isempty(&t->array[limit - 1]))); + if (isdummy(t) || isempty(luaH_getint(t, cast(lua_Integer, limit + 1)))) + return limit; /* 'limit + 1' is absent */ + else /* 'limit + 1' is also present */ + return hash_search(t, limit); +} + + + +#if defined(LUA_DEBUG) + +/* export these functions for the test library */ + +Node *luaH_mainposition (const Table *t, const TValue *key) { + return mainpositionTV(t, key); +} + +#endif diff --git a/src/ltable.h b/src/ltable.h new file mode 100644 index 0000000..75dd9e2 --- /dev/null +++ b/src/ltable.h @@ -0,0 +1,65 @@ +/* +** $Id: ltable.h $ +** Lua tables (hash) +** See Copyright Notice in lua.h +*/ + +#ifndef ltable_h +#define ltable_h + +#include "lobject.h" + + +#define gnode(t,i) (&(t)->node[i]) +#define gval(n) (&(n)->i_val) +#define gnext(n) ((n)->u.next) + + +/* +** Clear all bits of fast-access metamethods, which means that the table +** may have any of these metamethods. (First access that fails after the +** clearing will set the bit again.) +*/ +#define invalidateTMcache(t) ((t)->flags &= ~maskflags) + + +/* true when 't' is using 'dummynode' as its hash part */ +#define isdummy(t) ((t)->lastfree == NULL) + + +/* allocated size for hash nodes */ +#define allocsizenode(t) (isdummy(t) ? 0 : sizenode(t)) + + +/* returns the Node, given the value of a table entry */ +#define nodefromval(v) cast(Node *, (v)) + + +LUAI_FUNC const TValue *luaH_getint (Table *t, lua_Integer key); +LUAI_FUNC void luaH_setint (lua_State *L, Table *t, lua_Integer key, + TValue *value); +LUAI_FUNC const TValue *luaH_getshortstr (Table *t, TString *key); +LUAI_FUNC const TValue *luaH_getstr (Table *t, TString *key); +LUAI_FUNC const TValue *luaH_get (Table *t, const TValue *key); +LUAI_FUNC void luaH_newkey (lua_State *L, Table *t, const TValue *key, + TValue *value); +LUAI_FUNC void luaH_set (lua_State *L, Table *t, const TValue *key, + TValue *value); +LUAI_FUNC void luaH_finishset (lua_State *L, Table *t, const TValue *key, + const TValue *slot, TValue *value); +LUAI_FUNC Table *luaH_new (lua_State *L); +LUAI_FUNC void luaH_resize (lua_State *L, Table *t, unsigned int nasize, + unsigned int nhsize); +LUAI_FUNC void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize); +LUAI_FUNC void luaH_free (lua_State *L, Table *t); +LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key); +LUAI_FUNC lua_Unsigned luaH_getn (Table *t); +LUAI_FUNC unsigned int luaH_realasize (const Table *t); + + +#if defined(LUA_DEBUG) +LUAI_FUNC Node *luaH_mainposition (const Table *t, const TValue *key); +#endif + + +#endif diff --git a/src/ltablib.c b/src/ltablib.c new file mode 100644 index 0000000..e6bc4d0 --- /dev/null +++ b/src/ltablib.c @@ -0,0 +1,430 @@ +/* +** $Id: ltablib.c $ +** Library for Table Manipulation +** See Copyright Notice in lua.h +*/ + +#define ltablib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** Operations that an object must define to mimic a table +** (some functions only need some of them) +*/ +#define TAB_R 1 /* read */ +#define TAB_W 2 /* write */ +#define TAB_L 4 /* length */ +#define TAB_RW (TAB_R | TAB_W) /* read/write */ + + +#define aux_getn(L,n,w) (checktab(L, n, (w) | TAB_L), luaL_len(L, n)) + + +static int checkfield (lua_State *L, const char *key, int n) { + lua_pushstring(L, key); + return (lua_rawget(L, -n) != LUA_TNIL); +} + + +/* +** Check that 'arg' either is a table or can behave like one (that is, +** has a metatable with the required metamethods) +*/ +static void checktab (lua_State *L, int arg, int what) { + if (lua_type(L, arg) != LUA_TTABLE) { /* is it not a table? */ + int n = 1; /* number of elements to pop */ + if (lua_getmetatable(L, arg) && /* must have metatable */ + (!(what & TAB_R) || checkfield(L, "__index", ++n)) && + (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) && + (!(what & TAB_L) || checkfield(L, "__len", ++n))) { + lua_pop(L, n); /* pop metatable and tested metamethods */ + } + else + luaL_checktype(L, arg, LUA_TTABLE); /* force an error */ + } +} + + +static int tinsert (lua_State *L) { + lua_Integer pos; /* where to insert new element */ + lua_Integer e = aux_getn(L, 1, TAB_RW); + e = luaL_intop(+, e, 1); /* first empty element */ + switch (lua_gettop(L)) { + case 2: { /* called with only 2 arguments */ + pos = e; /* insert new element at the end */ + break; + } + case 3: { + lua_Integer i; + pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */ + /* check whether 'pos' is in [1, e] */ + luaL_argcheck(L, (lua_Unsigned)pos - 1u < (lua_Unsigned)e, 2, + "position out of bounds"); + for (i = e; i > pos; i--) { /* move up elements */ + lua_geti(L, 1, i - 1); + lua_seti(L, 1, i); /* t[i] = t[i - 1] */ + } + break; + } + default: { + return luaL_error(L, "wrong number of arguments to 'insert'"); + } + } + lua_seti(L, 1, pos); /* t[pos] = v */ + return 0; +} + + +static int tremove (lua_State *L) { + lua_Integer size = aux_getn(L, 1, TAB_RW); + lua_Integer pos = luaL_optinteger(L, 2, size); + if (pos != size) /* validate 'pos' if given */ + /* check whether 'pos' is in [1, size + 1] */ + luaL_argcheck(L, (lua_Unsigned)pos - 1u <= (lua_Unsigned)size, 2, + "position out of bounds"); + lua_geti(L, 1, pos); /* result = t[pos] */ + for ( ; pos < size; pos++) { + lua_geti(L, 1, pos + 1); + lua_seti(L, 1, pos); /* t[pos] = t[pos + 1] */ + } + lua_pushnil(L); + lua_seti(L, 1, pos); /* remove entry t[pos] */ + return 1; +} + + +/* +** Copy elements (1[f], ..., 1[e]) into (tt[t], tt[t+1], ...). Whenever +** possible, copy in increasing order, which is better for rehashing. +** "possible" means destination after original range, or smaller +** than origin, or copying to another table. +*/ +static int tmove (lua_State *L) { + lua_Integer f = luaL_checkinteger(L, 2); + lua_Integer e = luaL_checkinteger(L, 3); + lua_Integer t = luaL_checkinteger(L, 4); + int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */ + checktab(L, 1, TAB_R); + checktab(L, tt, TAB_W); + if (e >= f) { /* otherwise, nothing to move */ + lua_Integer n, i; + luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3, + "too many elements to move"); + n = e - f + 1; /* number of elements to move */ + luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4, + "destination wrap around"); + if (t > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) { + for (i = 0; i < n; i++) { + lua_geti(L, 1, f + i); + lua_seti(L, tt, t + i); + } + } + else { + for (i = n - 1; i >= 0; i--) { + lua_geti(L, 1, f + i); + lua_seti(L, tt, t + i); + } + } + } + lua_pushvalue(L, tt); /* return destination table */ + return 1; +} + + +static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) { + lua_geti(L, 1, i); + if (l_unlikely(!lua_isstring(L, -1))) + luaL_error(L, "invalid value (%s) at index %I in table for 'concat'", + luaL_typename(L, -1), (LUAI_UACINT)i); + luaL_addvalue(b); +} + + +static int tconcat (lua_State *L) { + luaL_Buffer b; + lua_Integer last = aux_getn(L, 1, TAB_R); + size_t lsep; + const char *sep = luaL_optlstring(L, 2, "", &lsep); + lua_Integer i = luaL_optinteger(L, 3, 1); + last = luaL_optinteger(L, 4, last); + luaL_buffinit(L, &b); + for (; i < last; i++) { + addfield(L, &b, i); + luaL_addlstring(&b, sep, lsep); + } + if (i == last) /* add last value (if interval was not empty) */ + addfield(L, &b, i); + luaL_pushresult(&b); + return 1; +} + + +/* +** {====================================================== +** Pack/unpack +** ======================================================= +*/ + +static int tpack (lua_State *L) { + int i; + int n = lua_gettop(L); /* number of elements to pack */ + lua_createtable(L, n, 1); /* create result table */ + lua_insert(L, 1); /* put it at index 1 */ + for (i = n; i >= 1; i--) /* assign elements */ + lua_seti(L, 1, i); + lua_pushinteger(L, n); + lua_setfield(L, 1, "n"); /* t.n = number of elements */ + return 1; /* return table */ +} + + +static int tunpack (lua_State *L) { + lua_Unsigned n; + lua_Integer i = luaL_optinteger(L, 2, 1); + lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1)); + if (i > e) return 0; /* empty range */ + n = (lua_Unsigned)e - i; /* number of elements minus 1 (avoid overflows) */ + if (l_unlikely(n >= (unsigned int)INT_MAX || + !lua_checkstack(L, (int)(++n)))) + return luaL_error(L, "too many results to unpack"); + for (; i < e; i++) { /* push arg[i..e - 1] (to avoid overflows) */ + lua_geti(L, 1, i); + } + lua_geti(L, 1, e); /* push last element */ + return (int)n; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** Quicksort +** (based on 'Algorithms in MODULA-3', Robert Sedgewick; +** Addison-Wesley, 1993.) +** ======================================================= +*/ + + +/* type for array indices */ +typedef unsigned int IdxT; + + +/* +** Produce a "random" 'unsigned int' to randomize pivot choice. This +** macro is used only when 'sort' detects a big imbalance in the result +** of a partition. (If you don't want/need this "randomness", ~0 is a +** good choice.) +*/ +#if !defined(l_randomizePivot) /* { */ + +#include + +/* size of 'e' measured in number of 'unsigned int's */ +#define sof(e) (sizeof(e) / sizeof(unsigned int)) + +/* +** Use 'time' and 'clock' as sources of "randomness". Because we don't +** know the types 'clock_t' and 'time_t', we cannot cast them to +** anything without risking overflows. A safe way to use their values +** is to copy them to an array of a known type and use the array values. +*/ +static unsigned int l_randomizePivot (void) { + clock_t c = clock(); + time_t t = time(NULL); + unsigned int buff[sof(c) + sof(t)]; + unsigned int i, rnd = 0; + memcpy(buff, &c, sof(c) * sizeof(unsigned int)); + memcpy(buff + sof(c), &t, sof(t) * sizeof(unsigned int)); + for (i = 0; i < sof(buff); i++) + rnd += buff[i]; + return rnd; +} + +#endif /* } */ + + +/* arrays larger than 'RANLIMIT' may use randomized pivots */ +#define RANLIMIT 100u + + +static void set2 (lua_State *L, IdxT i, IdxT j) { + lua_seti(L, 1, i); + lua_seti(L, 1, j); +} + + +/* +** Return true iff value at stack index 'a' is less than the value at +** index 'b' (according to the order of the sort). +*/ +static int sort_comp (lua_State *L, int a, int b) { + if (lua_isnil(L, 2)) /* no function? */ + return lua_compare(L, a, b, LUA_OPLT); /* a < b */ + else { /* function */ + int res; + lua_pushvalue(L, 2); /* push function */ + lua_pushvalue(L, a-1); /* -1 to compensate function */ + lua_pushvalue(L, b-2); /* -2 to compensate function and 'a' */ + lua_call(L, 2, 1); /* call function */ + res = lua_toboolean(L, -1); /* get result */ + lua_pop(L, 1); /* pop result */ + return res; + } +} + + +/* +** Does the partition: Pivot P is at the top of the stack. +** precondition: a[lo] <= P == a[up-1] <= a[up], +** so it only needs to do the partition from lo + 1 to up - 2. +** Pos-condition: a[lo .. i - 1] <= a[i] == P <= a[i + 1 .. up] +** returns 'i'. +*/ +static IdxT partition (lua_State *L, IdxT lo, IdxT up) { + IdxT i = lo; /* will be incremented before first use */ + IdxT j = up - 1; /* will be decremented before first use */ + /* loop invariant: a[lo .. i] <= P <= a[j .. up] */ + for (;;) { + /* next loop: repeat ++i while a[i] < P */ + while ((void)lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) { + if (l_unlikely(i == up - 1)) /* a[i] < P but a[up - 1] == P ?? */ + luaL_error(L, "invalid order function for sorting"); + lua_pop(L, 1); /* remove a[i] */ + } + /* after the loop, a[i] >= P and a[lo .. i - 1] < P */ + /* next loop: repeat --j while P < a[j] */ + while ((void)lua_geti(L, 1, --j), sort_comp(L, -3, -1)) { + if (l_unlikely(j < i)) /* j < i but a[j] > P ?? */ + luaL_error(L, "invalid order function for sorting"); + lua_pop(L, 1); /* remove a[j] */ + } + /* after the loop, a[j] <= P and a[j + 1 .. up] >= P */ + if (j < i) { /* no elements out of place? */ + /* a[lo .. i - 1] <= P <= a[j + 1 .. i .. up] */ + lua_pop(L, 1); /* pop a[j] */ + /* swap pivot (a[up - 1]) with a[i] to satisfy pos-condition */ + set2(L, up - 1, i); + return i; + } + /* otherwise, swap a[i] - a[j] to restore invariant and repeat */ + set2(L, i, j); + } +} + + +/* +** Choose an element in the middle (2nd-3th quarters) of [lo,up] +** "randomized" by 'rnd' +*/ +static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) { + IdxT r4 = (up - lo) / 4; /* range/4 */ + IdxT p = rnd % (r4 * 2) + (lo + r4); + lua_assert(lo + r4 <= p && p <= up - r4); + return p; +} + + +/* +** Quicksort algorithm (recursive function) +*/ +static void auxsort (lua_State *L, IdxT lo, IdxT up, + unsigned int rnd) { + while (lo < up) { /* loop for tail recursion */ + IdxT p; /* Pivot index */ + IdxT n; /* to be used later */ + /* sort elements 'lo', 'p', and 'up' */ + lua_geti(L, 1, lo); + lua_geti(L, 1, up); + if (sort_comp(L, -1, -2)) /* a[up] < a[lo]? */ + set2(L, lo, up); /* swap a[lo] - a[up] */ + else + lua_pop(L, 2); /* remove both values */ + if (up - lo == 1) /* only 2 elements? */ + return; /* already sorted */ + if (up - lo < RANLIMIT || rnd == 0) /* small interval or no randomize? */ + p = (lo + up)/2; /* middle element is a good pivot */ + else /* for larger intervals, it is worth a random pivot */ + p = choosePivot(lo, up, rnd); + lua_geti(L, 1, p); + lua_geti(L, 1, lo); + if (sort_comp(L, -2, -1)) /* a[p] < a[lo]? */ + set2(L, p, lo); /* swap a[p] - a[lo] */ + else { + lua_pop(L, 1); /* remove a[lo] */ + lua_geti(L, 1, up); + if (sort_comp(L, -1, -2)) /* a[up] < a[p]? */ + set2(L, p, up); /* swap a[up] - a[p] */ + else + lua_pop(L, 2); + } + if (up - lo == 2) /* only 3 elements? */ + return; /* already sorted */ + lua_geti(L, 1, p); /* get middle element (Pivot) */ + lua_pushvalue(L, -1); /* push Pivot */ + lua_geti(L, 1, up - 1); /* push a[up - 1] */ + set2(L, p, up - 1); /* swap Pivot (a[p]) with a[up - 1] */ + p = partition(L, lo, up); + /* a[lo .. p - 1] <= a[p] == P <= a[p + 1 .. up] */ + if (p - lo < up - p) { /* lower interval is smaller? */ + auxsort(L, lo, p - 1, rnd); /* call recursively for lower interval */ + n = p - lo; /* size of smaller interval */ + lo = p + 1; /* tail call for [p + 1 .. up] (upper interval) */ + } + else { + auxsort(L, p + 1, up, rnd); /* call recursively for upper interval */ + n = up - p; /* size of smaller interval */ + up = p - 1; /* tail call for [lo .. p - 1] (lower interval) */ + } + if ((up - lo) / 128 > n) /* partition too imbalanced? */ + rnd = l_randomizePivot(); /* try a new randomization */ + } /* tail call auxsort(L, lo, up, rnd) */ +} + + +static int sort (lua_State *L) { + lua_Integer n = aux_getn(L, 1, TAB_RW); + if (n > 1) { /* non-trivial interval? */ + luaL_argcheck(L, n < INT_MAX, 1, "array too big"); + if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ + luaL_checktype(L, 2, LUA_TFUNCTION); /* must be a function */ + lua_settop(L, 2); /* make sure there are two arguments */ + auxsort(L, 1, (IdxT)n, 0); + } + return 0; +} + +/* }====================================================== */ + + +static const luaL_Reg tab_funcs[] = { + {"concat", tconcat}, + {"insert", tinsert}, + {"pack", tpack}, + {"unpack", tunpack}, + {"remove", tremove}, + {"move", tmove}, + {"sort", sort}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_table (lua_State *L) { + luaL_newlib(L, tab_funcs); + return 1; +} + diff --git a/src/ltm.c b/src/ltm.c new file mode 100644 index 0000000..07a0608 --- /dev/null +++ b/src/ltm.c @@ -0,0 +1,271 @@ +/* +** $Id: ltm.c $ +** Tag methods +** See Copyright Notice in lua.h +*/ + +#define ltm_c +#define LUA_CORE + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + +static const char udatatypename[] = "userdata"; + +LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTYPES] = { + "no value", + "nil", "boolean", udatatypename, "number", + "string", "table", "function", udatatypename, "thread", + "upvalue", "proto" /* these last cases are used for tests only */ +}; + + +void luaT_init (lua_State *L) { + static const char *const luaT_eventname[] = { /* ORDER TM */ + "__index", "__newindex", + "__gc", "__mode", "__len", "__eq", + "__add", "__sub", "__mul", "__mod", "__pow", + "__div", "__idiv", + "__band", "__bor", "__bxor", "__shl", "__shr", + "__unm", "__bnot", "__lt", "__le", + "__concat", "__call", "__close" + }; + int i; + for (i=0; itmname[i] = luaS_new(L, luaT_eventname[i]); + luaC_fix(L, obj2gco(G(L)->tmname[i])); /* never collect these names */ + } +} + + +/* +** function to be used with macro "fasttm": optimized for absence of +** tag methods +*/ +const TValue *luaT_gettm (Table *events, TMS event, TString *ename) { + const TValue *tm = luaH_getshortstr(events, ename); + lua_assert(event <= TM_EQ); + if (notm(tm)) { /* no tag method? */ + events->flags |= cast_byte(1u<metatable; + break; + case LUA_TUSERDATA: + mt = uvalue(o)->metatable; + break; + default: + mt = G(L)->mt[ttype(o)]; + } + return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : &G(L)->nilvalue); +} + + +/* +** Return the name of the type of an object. For tables and userdata +** with metatable, use their '__name' metafield, if present. +*/ +const char *luaT_objtypename (lua_State *L, const TValue *o) { + Table *mt; + if ((ttistable(o) && (mt = hvalue(o)->metatable) != NULL) || + (ttisfulluserdata(o) && (mt = uvalue(o)->metatable) != NULL)) { + const TValue *name = luaH_getshortstr(mt, luaS_new(L, "__name")); + if (ttisstring(name)) /* is '__name' a string? */ + return getstr(tsvalue(name)); /* use it as type name */ + } + return ttypename(ttype(o)); /* else use standard type name */ +} + + +void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1, + const TValue *p2, const TValue *p3) { + StkId func = L->top.p; + setobj2s(L, func, f); /* push function (assume EXTRA_STACK) */ + setobj2s(L, func + 1, p1); /* 1st argument */ + setobj2s(L, func + 2, p2); /* 2nd argument */ + setobj2s(L, func + 3, p3); /* 3rd argument */ + L->top.p = func + 4; + /* metamethod may yield only when called from Lua code */ + if (isLuacode(L->ci)) + luaD_call(L, func, 0); + else + luaD_callnoyield(L, func, 0); +} + + +void luaT_callTMres (lua_State *L, const TValue *f, const TValue *p1, + const TValue *p2, StkId res) { + ptrdiff_t result = savestack(L, res); + StkId func = L->top.p; + setobj2s(L, func, f); /* push function (assume EXTRA_STACK) */ + setobj2s(L, func + 1, p1); /* 1st argument */ + setobj2s(L, func + 2, p2); /* 2nd argument */ + L->top.p += 3; + /* metamethod may yield only when called from Lua code */ + if (isLuacode(L->ci)) + luaD_call(L, func, 1); + else + luaD_callnoyield(L, func, 1); + res = restorestack(L, result); + setobjs2s(L, res, --L->top.p); /* move result to its place */ +} + + +static int callbinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event) { + const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */ + if (notm(tm)) + tm = luaT_gettmbyobj(L, p2, event); /* try second operand */ + if (notm(tm)) return 0; + luaT_callTMres(L, tm, p1, p2, res); + return 1; +} + + +void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event) { + if (l_unlikely(!callbinTM(L, p1, p2, res, event))) { + switch (event) { + case TM_BAND: case TM_BOR: case TM_BXOR: + case TM_SHL: case TM_SHR: case TM_BNOT: { + if (ttisnumber(p1) && ttisnumber(p2)) + luaG_tointerror(L, p1, p2); + else + luaG_opinterror(L, p1, p2, "perform bitwise operation on"); + } + /* calls never return, but to avoid warnings: *//* FALLTHROUGH */ + default: + luaG_opinterror(L, p1, p2, "perform arithmetic on"); + } + } +} + + +void luaT_tryconcatTM (lua_State *L) { + StkId top = L->top.p; + if (l_unlikely(!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2, + TM_CONCAT))) + luaG_concaterror(L, s2v(top - 2), s2v(top - 1)); +} + + +void luaT_trybinassocTM (lua_State *L, const TValue *p1, const TValue *p2, + int flip, StkId res, TMS event) { + if (flip) + luaT_trybinTM(L, p2, p1, res, event); + else + luaT_trybinTM(L, p1, p2, res, event); +} + + +void luaT_trybiniTM (lua_State *L, const TValue *p1, lua_Integer i2, + int flip, StkId res, TMS event) { + TValue aux; + setivalue(&aux, i2); + luaT_trybinassocTM(L, p1, &aux, flip, res, event); +} + + +/* +** Calls an order tag method. +** For lessequal, LUA_COMPAT_LT_LE keeps compatibility with old +** behavior: if there is no '__le', try '__lt', based on l <= r iff +** !(r < l) (assuming a total order). If the metamethod yields during +** this substitution, the continuation has to know about it (to negate +** the result of rtop.p, event)) /* try original event */ + return !l_isfalse(s2v(L->top.p)); +#if defined(LUA_COMPAT_LT_LE) + else if (event == TM_LE) { + /* try '!(p2 < p1)' for '(p1 <= p2)' */ + L->ci->callstatus |= CIST_LEQ; /* mark it is doing 'lt' for 'le' */ + if (callbinTM(L, p2, p1, L->top.p, TM_LT)) { + L->ci->callstatus ^= CIST_LEQ; /* clear mark */ + return l_isfalse(s2v(L->top.p)); + } + /* else error will remove this 'ci'; no need to clear mark */ + } +#endif + luaG_ordererror(L, p1, p2); /* no metamethod found */ + return 0; /* to avoid warnings */ +} + + +int luaT_callorderiTM (lua_State *L, const TValue *p1, int v2, + int flip, int isfloat, TMS event) { + TValue aux; const TValue *p2; + if (isfloat) { + setfltvalue(&aux, cast_num(v2)); + } + else + setivalue(&aux, v2); + if (flip) { /* arguments were exchanged? */ + p2 = p1; p1 = &aux; /* correct them */ + } + else + p2 = &aux; + return luaT_callorderTM(L, p1, p2, event); +} + + +void luaT_adjustvarargs (lua_State *L, int nfixparams, CallInfo *ci, + const Proto *p) { + int i; + int actual = cast_int(L->top.p - ci->func.p) - 1; /* number of arguments */ + int nextra = actual - nfixparams; /* number of extra arguments */ + ci->u.l.nextraargs = nextra; + luaD_checkstack(L, p->maxstacksize + 1); + /* copy function to the top of the stack */ + setobjs2s(L, L->top.p++, ci->func.p); + /* move fixed parameters to the top of the stack */ + for (i = 1; i <= nfixparams; i++) { + setobjs2s(L, L->top.p++, ci->func.p + i); + setnilvalue(s2v(ci->func.p + i)); /* erase original parameter (for GC) */ + } + ci->func.p += actual + 1; + ci->top.p += actual + 1; + lua_assert(L->top.p <= ci->top.p && ci->top.p <= L->stack_last.p); +} + + +void luaT_getvarargs (lua_State *L, CallInfo *ci, StkId where, int wanted) { + int i; + int nextra = ci->u.l.nextraargs; + if (wanted < 0) { + wanted = nextra; /* get all extra arguments available */ + checkstackGCp(L, nextra, where); /* ensure stack space */ + L->top.p = where + nextra; /* next instruction will need top */ + } + for (i = 0; i < wanted && i < nextra; i++) + setobjs2s(L, where + i, ci->func.p - nextra + i); + for (; i < wanted; i++) /* complete required results with nil */ + setnilvalue(s2v(where + i)); +} + diff --git a/src/ltm.h b/src/ltm.h new file mode 100644 index 0000000..c309e2a --- /dev/null +++ b/src/ltm.h @@ -0,0 +1,104 @@ +/* +** $Id: ltm.h $ +** Tag methods +** See Copyright Notice in lua.h +*/ + +#ifndef ltm_h +#define ltm_h + + +#include "lobject.h" +#include "lstate.h" + + +/* +* WARNING: if you change the order of this enumeration, +* grep "ORDER TM" and "ORDER OP" +*/ +typedef enum { + TM_INDEX, + TM_NEWINDEX, + TM_GC, + TM_MODE, + TM_LEN, + TM_EQ, /* last tag method with fast access */ + TM_ADD, + TM_SUB, + TM_MUL, + TM_MOD, + TM_POW, + TM_DIV, + TM_IDIV, + TM_BAND, + TM_BOR, + TM_BXOR, + TM_SHL, + TM_SHR, + TM_UNM, + TM_BNOT, + TM_LT, + TM_LE, + TM_CONCAT, + TM_CALL, + TM_CLOSE, + TM_N /* number of elements in the enum */ +} TMS; + + +/* +** Mask with 1 in all fast-access methods. A 1 in any of these bits +** in the flag of a (meta)table means the metatable does not have the +** corresponding metamethod field. (Bit 7 of the flag is used for +** 'isrealasize'.) +*/ +#define maskflags (~(~0u << (TM_EQ + 1))) + + +/* +** Test whether there is no tagmethod. +** (Because tagmethods use raw accesses, the result may be an "empty" nil.) +*/ +#define notm(tm) ttisnil(tm) + + +#define gfasttm(g,et,e) ((et) == NULL ? NULL : \ + ((et)->flags & (1u<<(e))) ? NULL : luaT_gettm(et, e, (g)->tmname[e])) + +#define fasttm(l,et,e) gfasttm(G(l), et, e) + +#define ttypename(x) luaT_typenames_[(x) + 1] + +LUAI_DDEC(const char *const luaT_typenames_[LUA_TOTALTYPES];) + + +LUAI_FUNC const char *luaT_objtypename (lua_State *L, const TValue *o); + +LUAI_FUNC const TValue *luaT_gettm (Table *events, TMS event, TString *ename); +LUAI_FUNC const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, + TMS event); +LUAI_FUNC void luaT_init (lua_State *L); + +LUAI_FUNC void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1, + const TValue *p2, const TValue *p3); +LUAI_FUNC void luaT_callTMres (lua_State *L, const TValue *f, + const TValue *p1, const TValue *p2, StkId p3); +LUAI_FUNC void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event); +LUAI_FUNC void luaT_tryconcatTM (lua_State *L); +LUAI_FUNC void luaT_trybinassocTM (lua_State *L, const TValue *p1, + const TValue *p2, int inv, StkId res, TMS event); +LUAI_FUNC void luaT_trybiniTM (lua_State *L, const TValue *p1, lua_Integer i2, + int inv, StkId res, TMS event); +LUAI_FUNC int luaT_callorderTM (lua_State *L, const TValue *p1, + const TValue *p2, TMS event); +LUAI_FUNC int luaT_callorderiTM (lua_State *L, const TValue *p1, int v2, + int inv, int isfloat, TMS event); + +LUAI_FUNC void luaT_adjustvarargs (lua_State *L, int nfixparams, + CallInfo *ci, const Proto *p); +LUAI_FUNC void luaT_getvarargs (lua_State *L, CallInfo *ci, + StkId where, int wanted); + + +#endif diff --git a/src/lua.c b/src/lua.c new file mode 100644 index 0000000..0ff8845 --- /dev/null +++ b/src/lua.c @@ -0,0 +1,679 @@ +/* +** $Id: lua.c $ +** Lua stand-alone interpreter +** See Copyright Notice in lua.h +*/ + +#define lua_c + +#include "lprefix.h" + + +#include +#include +#include + +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#if !defined(LUA_PROGNAME) +#define LUA_PROGNAME "lua" +#endif + +#if !defined(LUA_INIT_VAR) +#define LUA_INIT_VAR "LUA_INIT" +#endif + +#define LUA_INITVARVERSION LUA_INIT_VAR LUA_VERSUFFIX + + +static lua_State *globalL = NULL; + +static const char *progname = LUA_PROGNAME; + + +#if defined(LUA_USE_POSIX) /* { */ + +/* +** Use 'sigaction' when available. +*/ +static void setsignal (int sig, void (*handler)(int)) { + struct sigaction sa; + sa.sa_handler = handler; + sa.sa_flags = 0; + sigemptyset(&sa.sa_mask); /* do not mask any signal */ + sigaction(sig, &sa, NULL); +} + +#else /* }{ */ + +#define setsignal signal + +#endif /* } */ + + +/* +** Hook set by signal function to stop the interpreter. +*/ +static void lstop (lua_State *L, lua_Debug *ar) { + (void)ar; /* unused arg. */ + lua_sethook(L, NULL, 0, 0); /* reset hook */ + luaL_error(L, "interrupted!"); +} + + +/* +** Function to be called at a C signal. Because a C signal cannot +** just change a Lua state (as there is no proper synchronization), +** this function only sets a hook that, when called, will stop the +** interpreter. +*/ +static void laction (int i) { + int flag = LUA_MASKCALL | LUA_MASKRET | LUA_MASKLINE | LUA_MASKCOUNT; + setsignal(i, SIG_DFL); /* if another SIGINT happens, terminate process */ + lua_sethook(globalL, lstop, flag, 1); +} + + +static void print_usage (const char *badoption) { + lua_writestringerror("%s: ", progname); + if (badoption[1] == 'e' || badoption[1] == 'l') + lua_writestringerror("'%s' needs argument\n", badoption); + else + lua_writestringerror("unrecognized option '%s'\n", badoption); + lua_writestringerror( + "usage: %s [options] [script [args]]\n" + "Available options are:\n" + " -e stat execute string 'stat'\n" + " -i enter interactive mode after executing 'script'\n" + " -l mod require library 'mod' into global 'mod'\n" + " -l g=mod require library 'mod' into global 'g'\n" + " -v show version information\n" + " -E ignore environment variables\n" + " -W turn warnings on\n" + " -- stop handling options\n" + " - stop handling options and execute stdin\n" + , + progname); +} + + +/* +** Prints an error message, adding the program name in front of it +** (if present) +*/ +static void l_message (const char *pname, const char *msg) { + if (pname) lua_writestringerror("%s: ", pname); + lua_writestringerror("%s\n", msg); +} + + +/* +** Check whether 'status' is not OK and, if so, prints the error +** message on the top of the stack. It assumes that the error object +** is a string, as it was either generated by Lua or by 'msghandler'. +*/ +static int report (lua_State *L, int status) { + if (status != LUA_OK) { + const char *msg = lua_tostring(L, -1); + l_message(progname, msg); + lua_pop(L, 1); /* remove message */ + } + return status; +} + + +/* +** Message handler used to run all chunks +*/ +static int msghandler (lua_State *L) { + const char *msg = lua_tostring(L, 1); + if (msg == NULL) { /* is error object not a string? */ + if (luaL_callmeta(L, 1, "__tostring") && /* does it have a metamethod */ + lua_type(L, -1) == LUA_TSTRING) /* that produces a string? */ + return 1; /* that is the message */ + else + msg = lua_pushfstring(L, "(error object is a %s value)", + luaL_typename(L, 1)); + } + luaL_traceback(L, L, msg, 1); /* append a standard traceback */ + return 1; /* return the traceback */ +} + + +/* +** Interface to 'lua_pcall', which sets appropriate message function +** and C-signal handler. Used to run all chunks. +*/ +static int docall (lua_State *L, int narg, int nres) { + int status; + int base = lua_gettop(L) - narg; /* function index */ + lua_pushcfunction(L, msghandler); /* push message handler */ + lua_insert(L, base); /* put it under function and args */ + globalL = L; /* to be available to 'laction' */ + setsignal(SIGINT, laction); /* set C-signal handler */ + status = lua_pcall(L, narg, nres, base); + setsignal(SIGINT, SIG_DFL); /* reset C-signal handler */ + lua_remove(L, base); /* remove message handler from the stack */ + return status; +} + + +static void print_version (void) { + lua_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT)); + lua_writeline(); +} + + +/* +** Create the 'arg' table, which stores all arguments from the +** command line ('argv'). It should be aligned so that, at index 0, +** it has 'argv[script]', which is the script name. The arguments +** to the script (everything after 'script') go to positive indices; +** other arguments (before the script name) go to negative indices. +** If there is no script name, assume interpreter's name as base. +** (If there is no interpreter's name either, 'script' is -1, so +** table sizes are zero.) +*/ +static void createargtable (lua_State *L, char **argv, int argc, int script) { + int i, narg; + narg = argc - (script + 1); /* number of positive indices */ + lua_createtable(L, narg, script + 1); + for (i = 0; i < argc; i++) { + lua_pushstring(L, argv[i]); + lua_rawseti(L, -2, i - script); + } + lua_setglobal(L, "arg"); +} + + +static int dochunk (lua_State *L, int status) { + if (status == LUA_OK) status = docall(L, 0, 0); + return report(L, status); +} + + +static int dofile (lua_State *L, const char *name) { + return dochunk(L, luaL_loadfile(L, name)); +} + + +static int dostring (lua_State *L, const char *s, const char *name) { + return dochunk(L, luaL_loadbuffer(L, s, strlen(s), name)); +} + + +/* +** Receives 'globname[=modname]' and runs 'globname = require(modname)'. +*/ +static int dolibrary (lua_State *L, char *globname) { + int status; + char *modname = strchr(globname, '='); + if (modname == NULL) /* no explicit name? */ + modname = globname; /* module name is equal to global name */ + else { + *modname = '\0'; /* global name ends here */ + modname++; /* module name starts after the '=' */ + } + lua_getglobal(L, "require"); + lua_pushstring(L, modname); + status = docall(L, 1, 1); /* call 'require(modname)' */ + if (status == LUA_OK) + lua_setglobal(L, globname); /* globname = require(modname) */ + return report(L, status); +} + + +/* +** Push on the stack the contents of table 'arg' from 1 to #arg +*/ +static int pushargs (lua_State *L) { + int i, n; + if (lua_getglobal(L, "arg") != LUA_TTABLE) + luaL_error(L, "'arg' is not a table"); + n = (int)luaL_len(L, -1); + luaL_checkstack(L, n + 3, "too many arguments to script"); + for (i = 1; i <= n; i++) + lua_rawgeti(L, -i, i); + lua_remove(L, -i); /* remove table from the stack */ + return n; +} + + +static int handle_script (lua_State *L, char **argv) { + int status; + const char *fname = argv[0]; + if (strcmp(fname, "-") == 0 && strcmp(argv[-1], "--") != 0) + fname = NULL; /* stdin */ + status = luaL_loadfile(L, fname); + if (status == LUA_OK) { + int n = pushargs(L); /* push arguments to script */ + status = docall(L, n, LUA_MULTRET); + } + return report(L, status); +} + + +/* bits of various argument indicators in 'args' */ +#define has_error 1 /* bad option */ +#define has_i 2 /* -i */ +#define has_v 4 /* -v */ +#define has_e 8 /* -e */ +#define has_E 16 /* -E */ + + +/* +** Traverses all arguments from 'argv', returning a mask with those +** needed before running any Lua code or an error code if it finds any +** invalid argument. In case of error, 'first' is the index of the bad +** argument. Otherwise, 'first' is -1 if there is no program name, +** 0 if there is no script name, or the index of the script name. +*/ +static int collectargs (char **argv, int *first) { + int args = 0; + int i; + if (argv[0] != NULL) { /* is there a program name? */ + if (argv[0][0]) /* not empty? */ + progname = argv[0]; /* save it */ + } + else { /* no program name */ + *first = -1; + return 0; + } + for (i = 1; argv[i] != NULL; i++) { /* handle arguments */ + *first = i; + if (argv[i][0] != '-') /* not an option? */ + return args; /* stop handling options */ + switch (argv[i][1]) { /* else check option */ + case '-': /* '--' */ + if (argv[i][2] != '\0') /* extra characters after '--'? */ + return has_error; /* invalid option */ + *first = i + 1; + return args; + case '\0': /* '-' */ + return args; /* script "name" is '-' */ + case 'E': + if (argv[i][2] != '\0') /* extra characters? */ + return has_error; /* invalid option */ + args |= has_E; + break; + case 'W': + if (argv[i][2] != '\0') /* extra characters? */ + return has_error; /* invalid option */ + break; + case 'i': + args |= has_i; /* (-i implies -v) *//* FALLTHROUGH */ + case 'v': + if (argv[i][2] != '\0') /* extra characters? */ + return has_error; /* invalid option */ + args |= has_v; + break; + case 'e': + args |= has_e; /* FALLTHROUGH */ + case 'l': /* both options need an argument */ + if (argv[i][2] == '\0') { /* no concatenated argument? */ + i++; /* try next 'argv' */ + if (argv[i] == NULL || argv[i][0] == '-') + return has_error; /* no next argument or it is another option */ + } + break; + default: /* invalid option */ + return has_error; + } + } + *first = 0; /* no script name */ + return args; +} + + +/* +** Processes options 'e' and 'l', which involve running Lua code, and +** 'W', which also affects the state. +** Returns 0 if some code raises an error. +*/ +static int runargs (lua_State *L, char **argv, int n) { + int i; + for (i = 1; i < n; i++) { + int option = argv[i][1]; + lua_assert(argv[i][0] == '-'); /* already checked */ + switch (option) { + case 'e': case 'l': { + int status; + char *extra = argv[i] + 2; /* both options need an argument */ + if (*extra == '\0') extra = argv[++i]; + lua_assert(extra != NULL); + status = (option == 'e') + ? dostring(L, extra, "=(command line)") + : dolibrary(L, extra); + if (status != LUA_OK) return 0; + break; + } + case 'W': + lua_warning(L, "@on", 0); /* warnings on */ + break; + } + } + return 1; +} + + +static int handle_luainit (lua_State *L) { + const char *name = "=" LUA_INITVARVERSION; + const char *init = getenv(name + 1); + if (init == NULL) { + name = "=" LUA_INIT_VAR; + init = getenv(name + 1); /* try alternative name */ + } + if (init == NULL) return LUA_OK; + else if (init[0] == '@') + return dofile(L, init+1); + else + return dostring(L, init, name); +} + + +/* +** {================================================================== +** Read-Eval-Print Loop (REPL) +** =================================================================== +*/ + +#if !defined(LUA_PROMPT) +#define LUA_PROMPT "> " +#define LUA_PROMPT2 ">> " +#endif + +#if !defined(LUA_MAXINPUT) +#define LUA_MAXINPUT 512 +#endif + + +/* +** lua_stdin_is_tty detects whether the standard input is a 'tty' (that +** is, whether we're running lua interactively). +*/ +#if !defined(lua_stdin_is_tty) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#include +#define lua_stdin_is_tty() isatty(0) + +#elif defined(LUA_USE_WINDOWS) /* }{ */ + +#include +#include + +#define lua_stdin_is_tty() _isatty(_fileno(stdin)) + +#else /* }{ */ + +/* ISO C definition */ +#define lua_stdin_is_tty() 1 /* assume stdin is a tty */ + +#endif /* } */ + +#endif /* } */ + + +/* +** lua_readline defines how to show a prompt and then read a line from +** the standard input. +** lua_saveline defines how to "save" a read line in a "history". +** lua_freeline defines how to free a line read by lua_readline. +*/ +#if !defined(lua_readline) /* { */ + +#if defined(LUA_USE_READLINE) /* { */ + +#include +#include +#define lua_initreadline(L) ((void)L, rl_readline_name="lua") +#define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL) +#define lua_saveline(L,line) ((void)L, add_history(line)) +#define lua_freeline(L,b) ((void)L, free(b)) + +#else /* }{ */ + +#define lua_initreadline(L) ((void)L) +#define lua_readline(L,b,p) \ + ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \ + fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */ +#define lua_saveline(L,line) { (void)L; (void)line; } +#define lua_freeline(L,b) { (void)L; (void)b; } + +#endif /* } */ + +#endif /* } */ + + +/* +** Return the string to be used as a prompt by the interpreter. Leave +** the string (or nil, if using the default value) on the stack, to keep +** it anchored. +*/ +static const char *get_prompt (lua_State *L, int firstline) { + if (lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2") == LUA_TNIL) + return (firstline ? LUA_PROMPT : LUA_PROMPT2); /* use the default */ + else { /* apply 'tostring' over the value */ + const char *p = luaL_tolstring(L, -1, NULL); + lua_remove(L, -2); /* remove original value */ + return p; + } +} + +/* mark in error messages for incomplete statements */ +#define EOFMARK "" +#define marklen (sizeof(EOFMARK)/sizeof(char) - 1) + + +/* +** Check whether 'status' signals a syntax error and the error +** message at the top of the stack ends with the above mark for +** incomplete statements. +*/ +static int incomplete (lua_State *L, int status) { + if (status == LUA_ERRSYNTAX) { + size_t lmsg; + const char *msg = lua_tolstring(L, -1, &lmsg); + if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) { + lua_pop(L, 1); + return 1; + } + } + return 0; /* else... */ +} + + +/* +** Prompt the user, read a line, and push it into the Lua stack. +*/ +static int pushline (lua_State *L, int firstline) { + char buffer[LUA_MAXINPUT]; + char *b = buffer; + size_t l; + const char *prmt = get_prompt(L, firstline); + int readstatus = lua_readline(L, b, prmt); + if (readstatus == 0) + return 0; /* no input (prompt will be popped by caller) */ + lua_pop(L, 1); /* remove prompt */ + l = strlen(b); + if (l > 0 && b[l-1] == '\n') /* line ends with newline? */ + b[--l] = '\0'; /* remove it */ + if (firstline && b[0] == '=') /* for compatibility with 5.2, ... */ + lua_pushfstring(L, "return %s", b + 1); /* change '=' to 'return' */ + else + lua_pushlstring(L, b, l); + lua_freeline(L, b); + return 1; +} + + +/* +** Try to compile line on the stack as 'return ;'; on return, stack +** has either compiled chunk or original line (if compilation failed). +*/ +static int addreturn (lua_State *L) { + const char *line = lua_tostring(L, -1); /* original line */ + const char *retline = lua_pushfstring(L, "return %s;", line); + int status = luaL_loadbuffer(L, retline, strlen(retline), "=stdin"); + if (status == LUA_OK) { + lua_remove(L, -2); /* remove modified line */ + if (line[0] != '\0') /* non empty? */ + lua_saveline(L, line); /* keep history */ + } + else + lua_pop(L, 2); /* pop result from 'luaL_loadbuffer' and modified line */ + return status; +} + + +/* +** Read multiple lines until a complete Lua statement +*/ +static int multiline (lua_State *L) { + for (;;) { /* repeat until gets a complete statement */ + size_t len; + const char *line = lua_tolstring(L, 1, &len); /* get what it has */ + int status = luaL_loadbuffer(L, line, len, "=stdin"); /* try it */ + if (!incomplete(L, status) || !pushline(L, 0)) { + lua_saveline(L, line); /* keep history */ + return status; /* cannot or should not try to add continuation line */ + } + lua_pushliteral(L, "\n"); /* add newline... */ + lua_insert(L, -2); /* ...between the two lines */ + lua_concat(L, 3); /* join them */ + } +} + + +/* +** Read a line and try to load (compile) it first as an expression (by +** adding "return " in front of it) and second as a statement. Return +** the final status of load/call with the resulting function (if any) +** in the top of the stack. +*/ +static int loadline (lua_State *L) { + int status; + lua_settop(L, 0); + if (!pushline(L, 1)) + return -1; /* no input */ + if ((status = addreturn(L)) != LUA_OK) /* 'return ...' did not work? */ + status = multiline(L); /* try as command, maybe with continuation lines */ + lua_remove(L, 1); /* remove line from the stack */ + lua_assert(lua_gettop(L) == 1); + return status; +} + + +/* +** Prints (calling the Lua 'print' function) any values on the stack +*/ +static void l_print (lua_State *L) { + int n = lua_gettop(L); + if (n > 0) { /* any result to be printed? */ + luaL_checkstack(L, LUA_MINSTACK, "too many results to print"); + lua_getglobal(L, "print"); + lua_insert(L, 1); + if (lua_pcall(L, n, 0, 0) != LUA_OK) + l_message(progname, lua_pushfstring(L, "error calling 'print' (%s)", + lua_tostring(L, -1))); + } +} + + +/* +** Do the REPL: repeatedly read (load) a line, evaluate (call) it, and +** print any results. +*/ +static void doREPL (lua_State *L) { + int status; + const char *oldprogname = progname; + progname = NULL; /* no 'progname' on errors in interactive mode */ + lua_initreadline(L); + while ((status = loadline(L)) != -1) { + if (status == LUA_OK) + status = docall(L, 0, LUA_MULTRET); + if (status == LUA_OK) l_print(L); + else report(L, status); + } + lua_settop(L, 0); /* clear stack */ + lua_writeline(); + progname = oldprogname; +} + +/* }================================================================== */ + + +/* +** Main body of stand-alone interpreter (to be called in protected mode). +** Reads the options and handles them all. +*/ +static int pmain (lua_State *L) { + int argc = (int)lua_tointeger(L, 1); + char **argv = (char **)lua_touserdata(L, 2); + int script; + int args = collectargs(argv, &script); + int optlim = (script > 0) ? script : argc; /* first argv not an option */ + luaL_checkversion(L); /* check that interpreter has correct version */ + if (args == has_error) { /* bad arg? */ + print_usage(argv[script]); /* 'script' has index of bad arg. */ + return 0; + } + if (args & has_v) /* option '-v'? */ + print_version(); + if (args & has_E) { /* option '-E'? */ + lua_pushboolean(L, 1); /* signal for libraries to ignore env. vars. */ + lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); + } + luaL_openlibs(L); /* open standard libraries */ + createargtable(L, argv, argc, script); /* create table 'arg' */ + lua_gc(L, LUA_GCRESTART); /* start GC... */ + lua_gc(L, LUA_GCGEN, 0, 0); /* ...in generational mode */ + if (!(args & has_E)) { /* no option '-E'? */ + if (handle_luainit(L) != LUA_OK) /* run LUA_INIT */ + return 0; /* error running LUA_INIT */ + } + if (!runargs(L, argv, optlim)) /* execute arguments -e and -l */ + return 0; /* something failed */ + if (script > 0) { /* execute main script (if there is one) */ + if (handle_script(L, argv + script) != LUA_OK) + return 0; /* interrupt in case of error */ + } + if (args & has_i) /* -i option? */ + doREPL(L); /* do read-eval-print loop */ + else if (script < 1 && !(args & (has_e | has_v))) { /* no active option? */ + if (lua_stdin_is_tty()) { /* running in interactive mode? */ + print_version(); + doREPL(L); /* do read-eval-print loop */ + } + else dofile(L, NULL); /* executes stdin as a file */ + } + lua_pushboolean(L, 1); /* signal no errors */ + return 1; +} + + +int main (int argc, char **argv) { + int status, result; + lua_State *L = luaL_newstate(); /* create state */ + if (L == NULL) { + l_message(argv[0], "cannot create state: not enough memory"); + return EXIT_FAILURE; + } + lua_gc(L, LUA_GCSTOP); /* stop GC while building state */ + lua_pushcfunction(L, &pmain); /* to call 'pmain' in protected mode */ + lua_pushinteger(L, argc); /* 1st argument */ + lua_pushlightuserdata(L, argv); /* 2nd argument */ + status = lua_pcall(L, 2, 1, 0); /* do the call */ + result = lua_toboolean(L, -1); /* get result */ + report(L, status); + lua_close(L); + return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE; +} + diff --git a/src/lua.h b/src/lua.h new file mode 100644 index 0000000..fd16cf8 --- /dev/null +++ b/src/lua.h @@ -0,0 +1,523 @@ +/* +** $Id: lua.h $ +** Lua - A Scripting Language +** Lua.org, PUC-Rio, Brazil (http://www.lua.org) +** See Copyright Notice at the end of this file +*/ + + +#ifndef lua_h +#define lua_h + +#include +#include + + +#include "luaconf.h" + + +#define LUA_VERSION_MAJOR "5" +#define LUA_VERSION_MINOR "4" +#define LUA_VERSION_RELEASE "6" + +#define LUA_VERSION_NUM 504 +#define LUA_VERSION_RELEASE_NUM (LUA_VERSION_NUM * 100 + 6) + +#define LUA_VERSION "Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR +#define LUA_RELEASE LUA_VERSION "." LUA_VERSION_RELEASE +#define LUA_COPYRIGHT LUA_RELEASE " Copyright (C) 1994-2023 Lua.org, PUC-Rio" +#define LUA_AUTHORS "R. Ierusalimschy, L. H. de Figueiredo, W. Celes" + + +/* mark for precompiled code ('Lua') */ +#define LUA_SIGNATURE "\x1bLua" + +/* option for multiple returns in 'lua_pcall' and 'lua_call' */ +#define LUA_MULTRET (-1) + + +/* +** Pseudo-indices +** (-LUAI_MAXSTACK is the minimum valid index; we keep some free empty +** space after that to help overflow detection) +*/ +#define LUA_REGISTRYINDEX (-LUAI_MAXSTACK - 1000) +#define lua_upvalueindex(i) (LUA_REGISTRYINDEX - (i)) + + +/* thread status */ +#define LUA_OK 0 +#define LUA_YIELD 1 +#define LUA_ERRRUN 2 +#define LUA_ERRSYNTAX 3 +#define LUA_ERRMEM 4 +#define LUA_ERRERR 5 + + +typedef struct lua_State lua_State; + + +/* +** basic types +*/ +#define LUA_TNONE (-1) + +#define LUA_TNIL 0 +#define LUA_TBOOLEAN 1 +#define LUA_TLIGHTUSERDATA 2 +#define LUA_TNUMBER 3 +#define LUA_TSTRING 4 +#define LUA_TTABLE 5 +#define LUA_TFUNCTION 6 +#define LUA_TUSERDATA 7 +#define LUA_TTHREAD 8 + +#define LUA_NUMTYPES 9 + + + +/* minimum Lua stack available to a C function */ +#define LUA_MINSTACK 20 + + +/* predefined values in the registry */ +#define LUA_RIDX_MAINTHREAD 1 +#define LUA_RIDX_GLOBALS 2 +#define LUA_RIDX_LAST LUA_RIDX_GLOBALS + + +/* type of numbers in Lua */ +typedef LUA_NUMBER lua_Number; + + +/* type for integer functions */ +typedef LUA_INTEGER lua_Integer; + +/* unsigned integer type */ +typedef LUA_UNSIGNED lua_Unsigned; + +/* type for continuation-function contexts */ +typedef LUA_KCONTEXT lua_KContext; + + +/* +** Type for C functions registered with Lua +*/ +typedef int (*lua_CFunction) (lua_State *L); + +/* +** Type for continuation functions +*/ +typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx); + + +/* +** Type for functions that read/write blocks when loading/dumping Lua chunks +*/ +typedef const char * (*lua_Reader) (lua_State *L, void *ud, size_t *sz); + +typedef int (*lua_Writer) (lua_State *L, const void *p, size_t sz, void *ud); + + +/* +** Type for memory-allocation functions +*/ +typedef void * (*lua_Alloc) (void *ud, void *ptr, size_t osize, size_t nsize); + + +/* +** Type for warning functions +*/ +typedef void (*lua_WarnFunction) (void *ud, const char *msg, int tocont); + + +/* +** Type used by the debug API to collect debug information +*/ +typedef struct lua_Debug lua_Debug; + + +/* +** Functions to be called by the debugger in specific events +*/ +typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar); + + +/* +** generic extra include file +*/ +#if defined(LUA_USER_H) +#include LUA_USER_H +#endif + + +/* +** RCS ident string +*/ +extern const char lua_ident[]; + + +/* +** state manipulation +*/ +LUA_API lua_State *(lua_newstate) (lua_Alloc f, void *ud); +LUA_API void (lua_close) (lua_State *L); +LUA_API lua_State *(lua_newthread) (lua_State *L); +LUA_API int (lua_closethread) (lua_State *L, lua_State *from); +LUA_API int (lua_resetthread) (lua_State *L); /* Deprecated! */ + +LUA_API lua_CFunction (lua_atpanic) (lua_State *L, lua_CFunction panicf); + + +LUA_API lua_Number (lua_version) (lua_State *L); + + +/* +** basic stack manipulation +*/ +LUA_API int (lua_absindex) (lua_State *L, int idx); +LUA_API int (lua_gettop) (lua_State *L); +LUA_API void (lua_settop) (lua_State *L, int idx); +LUA_API void (lua_pushvalue) (lua_State *L, int idx); +LUA_API void (lua_rotate) (lua_State *L, int idx, int n); +LUA_API void (lua_copy) (lua_State *L, int fromidx, int toidx); +LUA_API int (lua_checkstack) (lua_State *L, int n); + +LUA_API void (lua_xmove) (lua_State *from, lua_State *to, int n); + + +/* +** access functions (stack -> C) +*/ + +LUA_API int (lua_isnumber) (lua_State *L, int idx); +LUA_API int (lua_isstring) (lua_State *L, int idx); +LUA_API int (lua_iscfunction) (lua_State *L, int idx); +LUA_API int (lua_isinteger) (lua_State *L, int idx); +LUA_API int (lua_isuserdata) (lua_State *L, int idx); +LUA_API int (lua_type) (lua_State *L, int idx); +LUA_API const char *(lua_typename) (lua_State *L, int tp); + +LUA_API lua_Number (lua_tonumberx) (lua_State *L, int idx, int *isnum); +LUA_API lua_Integer (lua_tointegerx) (lua_State *L, int idx, int *isnum); +LUA_API int (lua_toboolean) (lua_State *L, int idx); +LUA_API const char *(lua_tolstring) (lua_State *L, int idx, size_t *len); +LUA_API lua_Unsigned (lua_rawlen) (lua_State *L, int idx); +LUA_API lua_CFunction (lua_tocfunction) (lua_State *L, int idx); +LUA_API void *(lua_touserdata) (lua_State *L, int idx); +LUA_API lua_State *(lua_tothread) (lua_State *L, int idx); +LUA_API const void *(lua_topointer) (lua_State *L, int idx); + + +/* +** Comparison and arithmetic functions +*/ + +#define LUA_OPADD 0 /* ORDER TM, ORDER OP */ +#define LUA_OPSUB 1 +#define LUA_OPMUL 2 +#define LUA_OPMOD 3 +#define LUA_OPPOW 4 +#define LUA_OPDIV 5 +#define LUA_OPIDIV 6 +#define LUA_OPBAND 7 +#define LUA_OPBOR 8 +#define LUA_OPBXOR 9 +#define LUA_OPSHL 10 +#define LUA_OPSHR 11 +#define LUA_OPUNM 12 +#define LUA_OPBNOT 13 + +LUA_API void (lua_arith) (lua_State *L, int op); + +#define LUA_OPEQ 0 +#define LUA_OPLT 1 +#define LUA_OPLE 2 + +LUA_API int (lua_rawequal) (lua_State *L, int idx1, int idx2); +LUA_API int (lua_compare) (lua_State *L, int idx1, int idx2, int op); + + +/* +** push functions (C -> stack) +*/ +LUA_API void (lua_pushnil) (lua_State *L); +LUA_API void (lua_pushnumber) (lua_State *L, lua_Number n); +LUA_API void (lua_pushinteger) (lua_State *L, lua_Integer n); +LUA_API const char *(lua_pushlstring) (lua_State *L, const char *s, size_t len); +LUA_API const char *(lua_pushstring) (lua_State *L, const char *s); +LUA_API const char *(lua_pushvfstring) (lua_State *L, const char *fmt, + va_list argp); +LUA_API const char *(lua_pushfstring) (lua_State *L, const char *fmt, ...); +LUA_API void (lua_pushcclosure) (lua_State *L, lua_CFunction fn, int n); +LUA_API void (lua_pushboolean) (lua_State *L, int b); +LUA_API void (lua_pushlightuserdata) (lua_State *L, void *p); +LUA_API int (lua_pushthread) (lua_State *L); + + +/* +** get functions (Lua -> stack) +*/ +LUA_API int (lua_getglobal) (lua_State *L, const char *name); +LUA_API int (lua_gettable) (lua_State *L, int idx); +LUA_API int (lua_getfield) (lua_State *L, int idx, const char *k); +LUA_API int (lua_geti) (lua_State *L, int idx, lua_Integer n); +LUA_API int (lua_rawget) (lua_State *L, int idx); +LUA_API int (lua_rawgeti) (lua_State *L, int idx, lua_Integer n); +LUA_API int (lua_rawgetp) (lua_State *L, int idx, const void *p); + +LUA_API void (lua_createtable) (lua_State *L, int narr, int nrec); +LUA_API void *(lua_newuserdatauv) (lua_State *L, size_t sz, int nuvalue); +LUA_API int (lua_getmetatable) (lua_State *L, int objindex); +LUA_API int (lua_getiuservalue) (lua_State *L, int idx, int n); + + +/* +** set functions (stack -> Lua) +*/ +LUA_API void (lua_setglobal) (lua_State *L, const char *name); +LUA_API void (lua_settable) (lua_State *L, int idx); +LUA_API void (lua_setfield) (lua_State *L, int idx, const char *k); +LUA_API void (lua_seti) (lua_State *L, int idx, lua_Integer n); +LUA_API void (lua_rawset) (lua_State *L, int idx); +LUA_API void (lua_rawseti) (lua_State *L, int idx, lua_Integer n); +LUA_API void (lua_rawsetp) (lua_State *L, int idx, const void *p); +LUA_API int (lua_setmetatable) (lua_State *L, int objindex); +LUA_API int (lua_setiuservalue) (lua_State *L, int idx, int n); + + +/* +** 'load' and 'call' functions (load and run Lua code) +*/ +LUA_API void (lua_callk) (lua_State *L, int nargs, int nresults, + lua_KContext ctx, lua_KFunction k); +#define lua_call(L,n,r) lua_callk(L, (n), (r), 0, NULL) + +LUA_API int (lua_pcallk) (lua_State *L, int nargs, int nresults, int errfunc, + lua_KContext ctx, lua_KFunction k); +#define lua_pcall(L,n,r,f) lua_pcallk(L, (n), (r), (f), 0, NULL) + +LUA_API int (lua_load) (lua_State *L, lua_Reader reader, void *dt, + const char *chunkname, const char *mode); + +LUA_API int (lua_dump) (lua_State *L, lua_Writer writer, void *data, int strip); + + +/* +** coroutine functions +*/ +LUA_API int (lua_yieldk) (lua_State *L, int nresults, lua_KContext ctx, + lua_KFunction k); +LUA_API int (lua_resume) (lua_State *L, lua_State *from, int narg, + int *nres); +LUA_API int (lua_status) (lua_State *L); +LUA_API int (lua_isyieldable) (lua_State *L); + +#define lua_yield(L,n) lua_yieldk(L, (n), 0, NULL) + + +/* +** Warning-related functions +*/ +LUA_API void (lua_setwarnf) (lua_State *L, lua_WarnFunction f, void *ud); +LUA_API void (lua_warning) (lua_State *L, const char *msg, int tocont); + + +/* +** garbage-collection function and options +*/ + +#define LUA_GCSTOP 0 +#define LUA_GCRESTART 1 +#define LUA_GCCOLLECT 2 +#define LUA_GCCOUNT 3 +#define LUA_GCCOUNTB 4 +#define LUA_GCSTEP 5 +#define LUA_GCSETPAUSE 6 +#define LUA_GCSETSTEPMUL 7 +#define LUA_GCISRUNNING 9 +#define LUA_GCGEN 10 +#define LUA_GCINC 11 + +LUA_API int (lua_gc) (lua_State *L, int what, ...); + + +/* +** miscellaneous functions +*/ + +LUA_API int (lua_error) (lua_State *L); + +LUA_API int (lua_next) (lua_State *L, int idx); + +LUA_API void (lua_concat) (lua_State *L, int n); +LUA_API void (lua_len) (lua_State *L, int idx); + +LUA_API size_t (lua_stringtonumber) (lua_State *L, const char *s); + +LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud); +LUA_API void (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud); + +LUA_API void (lua_toclose) (lua_State *L, int idx); +LUA_API void (lua_closeslot) (lua_State *L, int idx); + + +/* +** {============================================================== +** some useful macros +** =============================================================== +*/ + +#define lua_getextraspace(L) ((void *)((char *)(L) - LUA_EXTRASPACE)) + +#define lua_tonumber(L,i) lua_tonumberx(L,(i),NULL) +#define lua_tointeger(L,i) lua_tointegerx(L,(i),NULL) + +#define lua_pop(L,n) lua_settop(L, -(n)-1) + +#define lua_newtable(L) lua_createtable(L, 0, 0) + +#define lua_register(L,n,f) (lua_pushcfunction(L, (f)), lua_setglobal(L, (n))) + +#define lua_pushcfunction(L,f) lua_pushcclosure(L, (f), 0) + +#define lua_isfunction(L,n) (lua_type(L, (n)) == LUA_TFUNCTION) +#define lua_istable(L,n) (lua_type(L, (n)) == LUA_TTABLE) +#define lua_islightuserdata(L,n) (lua_type(L, (n)) == LUA_TLIGHTUSERDATA) +#define lua_isnil(L,n) (lua_type(L, (n)) == LUA_TNIL) +#define lua_isboolean(L,n) (lua_type(L, (n)) == LUA_TBOOLEAN) +#define lua_isthread(L,n) (lua_type(L, (n)) == LUA_TTHREAD) +#define lua_isnone(L,n) (lua_type(L, (n)) == LUA_TNONE) +#define lua_isnoneornil(L, n) (lua_type(L, (n)) <= 0) + +#define lua_pushliteral(L, s) lua_pushstring(L, "" s) + +#define lua_pushglobaltable(L) \ + ((void)lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)) + +#define lua_tostring(L,i) lua_tolstring(L, (i), NULL) + + +#define lua_insert(L,idx) lua_rotate(L, (idx), 1) + +#define lua_remove(L,idx) (lua_rotate(L, (idx), -1), lua_pop(L, 1)) + +#define lua_replace(L,idx) (lua_copy(L, -1, (idx)), lua_pop(L, 1)) + +/* }============================================================== */ + + +/* +** {============================================================== +** compatibility macros +** =============================================================== +*/ +#if defined(LUA_COMPAT_APIINTCASTS) + +#define lua_pushunsigned(L,n) lua_pushinteger(L, (lua_Integer)(n)) +#define lua_tounsignedx(L,i,is) ((lua_Unsigned)lua_tointegerx(L,i,is)) +#define lua_tounsigned(L,i) lua_tounsignedx(L,(i),NULL) + +#endif + +#define lua_newuserdata(L,s) lua_newuserdatauv(L,s,1) +#define lua_getuservalue(L,idx) lua_getiuservalue(L,idx,1) +#define lua_setuservalue(L,idx) lua_setiuservalue(L,idx,1) + +#define LUA_NUMTAGS LUA_NUMTYPES + +/* }============================================================== */ + +/* +** {====================================================================== +** Debug API +** ======================================================================= +*/ + + +/* +** Event codes +*/ +#define LUA_HOOKCALL 0 +#define LUA_HOOKRET 1 +#define LUA_HOOKLINE 2 +#define LUA_HOOKCOUNT 3 +#define LUA_HOOKTAILCALL 4 + + +/* +** Event masks +*/ +#define LUA_MASKCALL (1 << LUA_HOOKCALL) +#define LUA_MASKRET (1 << LUA_HOOKRET) +#define LUA_MASKLINE (1 << LUA_HOOKLINE) +#define LUA_MASKCOUNT (1 << LUA_HOOKCOUNT) + + +LUA_API int (lua_getstack) (lua_State *L, int level, lua_Debug *ar); +LUA_API int (lua_getinfo) (lua_State *L, const char *what, lua_Debug *ar); +LUA_API const char *(lua_getlocal) (lua_State *L, const lua_Debug *ar, int n); +LUA_API const char *(lua_setlocal) (lua_State *L, const lua_Debug *ar, int n); +LUA_API const char *(lua_getupvalue) (lua_State *L, int funcindex, int n); +LUA_API const char *(lua_setupvalue) (lua_State *L, int funcindex, int n); + +LUA_API void *(lua_upvalueid) (lua_State *L, int fidx, int n); +LUA_API void (lua_upvaluejoin) (lua_State *L, int fidx1, int n1, + int fidx2, int n2); + +LUA_API void (lua_sethook) (lua_State *L, lua_Hook func, int mask, int count); +LUA_API lua_Hook (lua_gethook) (lua_State *L); +LUA_API int (lua_gethookmask) (lua_State *L); +LUA_API int (lua_gethookcount) (lua_State *L); + +LUA_API int (lua_setcstacklimit) (lua_State *L, unsigned int limit); + +struct lua_Debug { + int event; + const char *name; /* (n) */ + const char *namewhat; /* (n) 'global', 'local', 'field', 'method' */ + const char *what; /* (S) 'Lua', 'C', 'main', 'tail' */ + const char *source; /* (S) */ + size_t srclen; /* (S) */ + int currentline; /* (l) */ + int linedefined; /* (S) */ + int lastlinedefined; /* (S) */ + unsigned char nups; /* (u) number of upvalues */ + unsigned char nparams;/* (u) number of parameters */ + char isvararg; /* (u) */ + char istailcall; /* (t) */ + unsigned short ftransfer; /* (r) index of first value transferred */ + unsigned short ntransfer; /* (r) number of transferred values */ + char short_src[LUA_IDSIZE]; /* (S) */ + /* private part */ + struct CallInfo *i_ci; /* active function */ +}; + +/* }====================================================================== */ + + +/****************************************************************************** +* Copyright (C) 1994-2023 Lua.org, PUC-Rio. +* +* Permission is hereby granted, free of charge, to any person obtaining +* a copy of this software and associated documentation files (the +* "Software"), to deal in the Software without restriction, including +* without limitation the rights to use, copy, modify, merge, publish, +* distribute, sublicense, and/or sell copies of the Software, and to +* permit persons to whom the Software is furnished to do so, subject to +* the following conditions: +* +* The above copyright notice and this permission notice shall be +* included in all copies or substantial portions of the Software. +* +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +******************************************************************************/ + + +#endif diff --git a/src/lua.hpp b/src/lua.hpp new file mode 100644 index 0000000..ec417f5 --- /dev/null +++ b/src/lua.hpp @@ -0,0 +1,9 @@ +// lua.hpp +// Lua header files for C++ +// <> not supplied automatically because Lua also compiles as C++ + +extern "C" { +#include "lua.h" +#include "lualib.h" +#include "lauxlib.h" +} diff --git a/src/luac.c b/src/luac.c new file mode 100644 index 0000000..5f4a141 --- /dev/null +++ b/src/luac.c @@ -0,0 +1,723 @@ +/* +** $Id: luac.c $ +** Lua compiler (saves bytecodes to files; also lists bytecodes) +** See Copyright Notice in lua.h +*/ + +#define luac_c +#define LUA_CORE + +#include "lprefix.h" + +#include +#include +#include +#include +#include + +#include "lua.h" +#include "lauxlib.h" + +#include "ldebug.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lopnames.h" +#include "lstate.h" +#include "lundump.h" + +static void PrintFunction(const Proto* f, int full); +#define luaU_print PrintFunction + +#define PROGNAME "luac" /* default program name */ +#define OUTPUT PROGNAME ".out" /* default output file */ + +static int listing=0; /* list bytecodes? */ +static int dumping=1; /* dump bytecodes? */ +static int stripping=0; /* strip debug information? */ +static char Output[]={ OUTPUT }; /* default output file name */ +static const char* output=Output; /* actual output file name */ +static const char* progname=PROGNAME; /* actual program name */ +static TString **tmname; + +static void fatal(const char* message) +{ + fprintf(stderr,"%s: %s\n",progname,message); + exit(EXIT_FAILURE); +} + +static void cannot(const char* what) +{ + fprintf(stderr,"%s: cannot %s %s: %s\n",progname,what,output,strerror(errno)); + exit(EXIT_FAILURE); +} + +static void usage(const char* message) +{ + if (*message=='-') + fprintf(stderr,"%s: unrecognized option '%s'\n",progname,message); + else + fprintf(stderr,"%s: %s\n",progname,message); + fprintf(stderr, + "usage: %s [options] [filenames]\n" + "Available options are:\n" + " -l list (use -l -l for full listing)\n" + " -o name output to file 'name' (default is \"%s\")\n" + " -p parse only\n" + " -s strip debug information\n" + " -v show version information\n" + " -- stop handling options\n" + " - stop handling options and process stdin\n" + ,progname,Output); + exit(EXIT_FAILURE); +} + +#define IS(s) (strcmp(argv[i],s)==0) + +static int doargs(int argc, char* argv[]) +{ + int i; + int version=0; + if (argv[0]!=NULL && *argv[0]!=0) progname=argv[0]; + for (i=1; itop.p+(i))) + +static const Proto* combine(lua_State* L, int n) +{ + if (n==1) + return toproto(L,-1); + else + { + Proto* f; + int i=n; + if (lua_load(L,reader,&i,"=(" PROGNAME ")",NULL)!=LUA_OK) fatal(lua_tostring(L,-1)); + f=toproto(L,-1); + for (i=0; ip[i]=toproto(L,i-n-1); + if (f->p[i]->sizeupvalues>0) f->p[i]->upvalues[0].instack=0; + } + return f; + } +} + +static int writer(lua_State* L, const void* p, size_t size, void* u) +{ + UNUSED(L); + return (fwrite(p,size,1,(FILE*)u)!=1) && (size!=0); +} + +static int pmain(lua_State* L) +{ + int argc=(int)lua_tointeger(L,1); + char** argv=(char**)lua_touserdata(L,2); + const Proto* f; + int i; + tmname=G(L)->tmname; + if (!lua_checkstack(L,argc)) fatal("too many input files"); + for (i=0; i1); + if (dumping) + { + FILE* D= (output==NULL) ? stdout : fopen(output,"wb"); + if (D==NULL) cannot("open"); + lua_lock(L); + luaU_dump(L,f,writer,D,stripping); + lua_unlock(L); + if (ferror(D)) cannot("write"); + if (fclose(D)) cannot("close"); + } + return 0; +} + +int main(int argc, char* argv[]) +{ + lua_State* L; + int i=doargs(argc,argv); + argc-=i; argv+=i; + if (argc<=0) usage("no input files given"); + L=luaL_newstate(); + if (L==NULL) fatal("cannot create state: not enough memory"); + lua_pushcfunction(L,&pmain); + lua_pushinteger(L,argc); + lua_pushlightuserdata(L,argv); + if (lua_pcall(L,2,0,0)!=LUA_OK) fatal(lua_tostring(L,-1)); + lua_close(L); + return EXIT_SUCCESS; +} + +/* +** print bytecodes +*/ + +#define UPVALNAME(x) ((f->upvalues[x].name) ? getstr(f->upvalues[x].name) : "-") +#define VOID(p) ((const void*)(p)) +#define eventname(i) (getstr(tmname[i])) + +static void PrintString(const TString* ts) +{ + const char* s=getstr(ts); + size_t i,n=tsslen(ts); + printf("\""); + for (i=0; ik[i]; + switch (ttypetag(o)) + { + case LUA_VNIL: + printf("N"); + break; + case LUA_VFALSE: + case LUA_VTRUE: + printf("B"); + break; + case LUA_VNUMFLT: + printf("F"); + break; + case LUA_VNUMINT: + printf("I"); + break; + case LUA_VSHRSTR: + case LUA_VLNGSTR: + printf("S"); + break; + default: /* cannot happen */ + printf("?%d",ttypetag(o)); + break; + } + printf("\t"); +} + +static void PrintConstant(const Proto* f, int i) +{ + const TValue* o=&f->k[i]; + switch (ttypetag(o)) + { + case LUA_VNIL: + printf("nil"); + break; + case LUA_VFALSE: + printf("false"); + break; + case LUA_VTRUE: + printf("true"); + break; + case LUA_VNUMFLT: + { + char buff[100]; + sprintf(buff,LUA_NUMBER_FMT,fltvalue(o)); + printf("%s",buff); + if (buff[strspn(buff,"-0123456789")]=='\0') printf(".0"); + break; + } + case LUA_VNUMINT: + printf(LUA_INTEGER_FMT,ivalue(o)); + break; + case LUA_VSHRSTR: + case LUA_VLNGSTR: + PrintString(tsvalue(o)); + break; + default: /* cannot happen */ + printf("?%d",ttypetag(o)); + break; + } +} + +#define COMMENT "\t; " +#define EXTRAARG GETARG_Ax(code[pc+1]) +#define EXTRAARGC (EXTRAARG*(MAXARG_C+1)) +#define ISK (isk ? "k" : "") + +static void PrintCode(const Proto* f) +{ + const Instruction* code=f->code; + int pc,n=f->sizecode; + for (pc=0; pc0) printf("[%d]\t",line); else printf("[-]\t"); + printf("%-9s\t",opnames[o]); + switch (o) + { + case OP_MOVE: + printf("%d %d",a,b); + break; + case OP_LOADI: + printf("%d %d",a,sbx); + break; + case OP_LOADF: + printf("%d %d",a,sbx); + break; + case OP_LOADK: + printf("%d %d",a,bx); + printf(COMMENT); PrintConstant(f,bx); + break; + case OP_LOADKX: + printf("%d",a); + printf(COMMENT); PrintConstant(f,EXTRAARG); + break; + case OP_LOADFALSE: + printf("%d",a); + break; + case OP_LFALSESKIP: + printf("%d",a); + break; + case OP_LOADTRUE: + printf("%d",a); + break; + case OP_LOADNIL: + printf("%d %d",a,b); + printf(COMMENT "%d out",b+1); + break; + case OP_GETUPVAL: + printf("%d %d",a,b); + printf(COMMENT "%s",UPVALNAME(b)); + break; + case OP_SETUPVAL: + printf("%d %d",a,b); + printf(COMMENT "%s",UPVALNAME(b)); + break; + case OP_GETTABUP: + printf("%d %d %d",a,b,c); + printf(COMMENT "%s",UPVALNAME(b)); + printf(" "); PrintConstant(f,c); + break; + case OP_GETTABLE: + printf("%d %d %d",a,b,c); + break; + case OP_GETI: + printf("%d %d %d",a,b,c); + break; + case OP_GETFIELD: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_SETTABUP: + printf("%d %d %d%s",a,b,c,ISK); + printf(COMMENT "%s",UPVALNAME(a)); + printf(" "); PrintConstant(f,b); + if (isk) { printf(" "); PrintConstant(f,c); } + break; + case OP_SETTABLE: + printf("%d %d %d%s",a,b,c,ISK); + if (isk) { printf(COMMENT); PrintConstant(f,c); } + break; + case OP_SETI: + printf("%d %d %d%s",a,b,c,ISK); + if (isk) { printf(COMMENT); PrintConstant(f,c); } + break; + case OP_SETFIELD: + printf("%d %d %d%s",a,b,c,ISK); + printf(COMMENT); PrintConstant(f,b); + if (isk) { printf(" "); PrintConstant(f,c); } + break; + case OP_NEWTABLE: + printf("%d %d %d",a,b,c); + printf(COMMENT "%d",c+EXTRAARGC); + break; + case OP_SELF: + printf("%d %d %d%s",a,b,c,ISK); + if (isk) { printf(COMMENT); PrintConstant(f,c); } + break; + case OP_ADDI: + printf("%d %d %d",a,b,sc); + break; + case OP_ADDK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_SUBK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_MULK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_MODK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_POWK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_DIVK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_IDIVK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_BANDK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_BORK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_BXORK: + printf("%d %d %d",a,b,c); + printf(COMMENT); PrintConstant(f,c); + break; + case OP_SHRI: + printf("%d %d %d",a,b,sc); + break; + case OP_SHLI: + printf("%d %d %d",a,b,sc); + break; + case OP_ADD: + printf("%d %d %d",a,b,c); + break; + case OP_SUB: + printf("%d %d %d",a,b,c); + break; + case OP_MUL: + printf("%d %d %d",a,b,c); + break; + case OP_MOD: + printf("%d %d %d",a,b,c); + break; + case OP_POW: + printf("%d %d %d",a,b,c); + break; + case OP_DIV: + printf("%d %d %d",a,b,c); + break; + case OP_IDIV: + printf("%d %d %d",a,b,c); + break; + case OP_BAND: + printf("%d %d %d",a,b,c); + break; + case OP_BOR: + printf("%d %d %d",a,b,c); + break; + case OP_BXOR: + printf("%d %d %d",a,b,c); + break; + case OP_SHL: + printf("%d %d %d",a,b,c); + break; + case OP_SHR: + printf("%d %d %d",a,b,c); + break; + case OP_MMBIN: + printf("%d %d %d",a,b,c); + printf(COMMENT "%s",eventname(c)); + break; + case OP_MMBINI: + printf("%d %d %d %d",a,sb,c,isk); + printf(COMMENT "%s",eventname(c)); + if (isk) printf(" flip"); + break; + case OP_MMBINK: + printf("%d %d %d %d",a,b,c,isk); + printf(COMMENT "%s ",eventname(c)); PrintConstant(f,b); + if (isk) printf(" flip"); + break; + case OP_UNM: + printf("%d %d",a,b); + break; + case OP_BNOT: + printf("%d %d",a,b); + break; + case OP_NOT: + printf("%d %d",a,b); + break; + case OP_LEN: + printf("%d %d",a,b); + break; + case OP_CONCAT: + printf("%d %d",a,b); + break; + case OP_CLOSE: + printf("%d",a); + break; + case OP_TBC: + printf("%d",a); + break; + case OP_JMP: + printf("%d",GETARG_sJ(i)); + printf(COMMENT "to %d",GETARG_sJ(i)+pc+2); + break; + case OP_EQ: + printf("%d %d %d",a,b,isk); + break; + case OP_LT: + printf("%d %d %d",a,b,isk); + break; + case OP_LE: + printf("%d %d %d",a,b,isk); + break; + case OP_EQK: + printf("%d %d %d",a,b,isk); + printf(COMMENT); PrintConstant(f,b); + break; + case OP_EQI: + printf("%d %d %d",a,sb,isk); + break; + case OP_LTI: + printf("%d %d %d",a,sb,isk); + break; + case OP_LEI: + printf("%d %d %d",a,sb,isk); + break; + case OP_GTI: + printf("%d %d %d",a,sb,isk); + break; + case OP_GEI: + printf("%d %d %d",a,sb,isk); + break; + case OP_TEST: + printf("%d %d",a,isk); + break; + case OP_TESTSET: + printf("%d %d %d",a,b,isk); + break; + case OP_CALL: + printf("%d %d %d",a,b,c); + printf(COMMENT); + if (b==0) printf("all in "); else printf("%d in ",b-1); + if (c==0) printf("all out"); else printf("%d out",c-1); + break; + case OP_TAILCALL: + printf("%d %d %d%s",a,b,c,ISK); + printf(COMMENT "%d in",b-1); + break; + case OP_RETURN: + printf("%d %d %d%s",a,b,c,ISK); + printf(COMMENT); + if (b==0) printf("all out"); else printf("%d out",b-1); + break; + case OP_RETURN0: + break; + case OP_RETURN1: + printf("%d",a); + break; + case OP_FORLOOP: + printf("%d %d",a,bx); + printf(COMMENT "to %d",pc-bx+2); + break; + case OP_FORPREP: + printf("%d %d",a,bx); + printf(COMMENT "exit to %d",pc+bx+3); + break; + case OP_TFORPREP: + printf("%d %d",a,bx); + printf(COMMENT "to %d",pc+bx+2); + break; + case OP_TFORCALL: + printf("%d %d",a,c); + break; + case OP_TFORLOOP: + printf("%d %d",a,bx); + printf(COMMENT "to %d",pc-bx+2); + break; + case OP_SETLIST: + printf("%d %d %d",a,b,c); + if (isk) printf(COMMENT "%d",c+EXTRAARGC); + break; + case OP_CLOSURE: + printf("%d %d",a,bx); + printf(COMMENT "%p",VOID(f->p[bx])); + break; + case OP_VARARG: + printf("%d %d",a,c); + printf(COMMENT); + if (c==0) printf("all out"); else printf("%d out",c-1); + break; + case OP_VARARGPREP: + printf("%d",a); + break; + case OP_EXTRAARG: + printf("%d",ax); + break; +#if 0 + default: + printf("%d %d %d",a,b,c); + printf(COMMENT "not handled"); + break; +#endif + } + printf("\n"); + } +} + + +#define SS(x) ((x==1)?"":"s") +#define S(x) (int)(x),SS(x) + +static void PrintHeader(const Proto* f) +{ + const char* s=f->source ? getstr(f->source) : "=?"; + if (*s=='@' || *s=='=') + s++; + else if (*s==LUA_SIGNATURE[0]) + s="(bstring)"; + else + s="(string)"; + printf("\n%s <%s:%d,%d> (%d instruction%s at %p)\n", + (f->linedefined==0)?"main":"function",s, + f->linedefined,f->lastlinedefined, + S(f->sizecode),VOID(f)); + printf("%d%s param%s, %d slot%s, %d upvalue%s, ", + (int)(f->numparams),f->is_vararg?"+":"",SS(f->numparams), + S(f->maxstacksize),S(f->sizeupvalues)); + printf("%d local%s, %d constant%s, %d function%s\n", + S(f->sizelocvars),S(f->sizek),S(f->sizep)); +} + +static void PrintDebug(const Proto* f) +{ + int i,n; + n=f->sizek; + printf("constants (%d) for %p:\n",n,VOID(f)); + for (i=0; isizelocvars; + printf("locals (%d) for %p:\n",n,VOID(f)); + for (i=0; ilocvars[i].varname),f->locvars[i].startpc+1,f->locvars[i].endpc+1); + } + n=f->sizeupvalues; + printf("upvalues (%d) for %p:\n",n,VOID(f)); + for (i=0; iupvalues[i].instack,f->upvalues[i].idx); + } +} + +static void PrintFunction(const Proto* f, int full) +{ + int i,n=f->sizep; + PrintHeader(f); + PrintCode(f); + if (full) PrintDebug(f); + for (i=0; ip[i],full); +} diff --git a/src/luaconf.h b/src/luaconf.h new file mode 100644 index 0000000..137103e --- /dev/null +++ b/src/luaconf.h @@ -0,0 +1,793 @@ +/* +** $Id: luaconf.h $ +** Configuration file for Lua +** See Copyright Notice in lua.h +*/ + + +#ifndef luaconf_h +#define luaconf_h + +#include +#include + + +/* +** =================================================================== +** General Configuration File for Lua +** +** Some definitions here can be changed externally, through the compiler +** (e.g., with '-D' options): They are commented out or protected +** by '#if !defined' guards. However, several other definitions +** should be changed directly here, either because they affect the +** Lua ABI (by making the changes here, you ensure that all software +** connected to Lua, such as C libraries, will be compiled with the same +** configuration); or because they are seldom changed. +** +** Search for "@@" to find all configurable definitions. +** =================================================================== +*/ + + +/* +** {==================================================================== +** System Configuration: macros to adapt (if needed) Lua to some +** particular platform, for instance restricting it to C89. +** ===================================================================== +*/ + +/* +@@ LUA_USE_C89 controls the use of non-ISO-C89 features. +** Define it if you want Lua to avoid the use of a few C99 features +** or Windows-specific features on Windows. +*/ +/* #define LUA_USE_C89 */ + + +/* +** By default, Lua on Windows use (some) specific Windows features +*/ +#if !defined(LUA_USE_C89) && defined(_WIN32) && !defined(_WIN32_WCE) +#define LUA_USE_WINDOWS /* enable goodies for regular Windows */ +#endif + + +#if defined(LUA_USE_WINDOWS) +#define LUA_DL_DLL /* enable support for DLL */ +#define LUA_USE_C89 /* broadly, Windows is C89 */ +#endif + + +#if defined(LUA_USE_LINUX) +#define LUA_USE_POSIX +#define LUA_USE_DLOPEN /* needs an extra library: -ldl */ +#endif + + +#if defined(LUA_USE_MACOSX) +#define LUA_USE_POSIX +#define LUA_USE_DLOPEN /* MacOS does not need -ldl */ +#endif + + +#if defined(LUA_USE_IOS) +#define LUA_USE_POSIX +#define LUA_USE_DLOPEN +#endif + + +/* +@@ LUAI_IS32INT is true iff 'int' has (at least) 32 bits. +*/ +#define LUAI_IS32INT ((UINT_MAX >> 30) >= 3) + +/* }================================================================== */ + + + +/* +** {================================================================== +** Configuration for Number types. These options should not be +** set externally, because any other code connected to Lua must +** use the same configuration. +** =================================================================== +*/ + +/* +@@ LUA_INT_TYPE defines the type for Lua integers. +@@ LUA_FLOAT_TYPE defines the type for Lua floats. +** Lua should work fine with any mix of these options supported +** by your C compiler. The usual configurations are 64-bit integers +** and 'double' (the default), 32-bit integers and 'float' (for +** restricted platforms), and 'long'/'double' (for C compilers not +** compliant with C99, which may not have support for 'long long'). +*/ + +/* predefined options for LUA_INT_TYPE */ +#define LUA_INT_INT 1 +#define LUA_INT_LONG 2 +#define LUA_INT_LONGLONG 3 + +/* predefined options for LUA_FLOAT_TYPE */ +#define LUA_FLOAT_FLOAT 1 +#define LUA_FLOAT_DOUBLE 2 +#define LUA_FLOAT_LONGDOUBLE 3 + + +/* Default configuration ('long long' and 'double', for 64-bit Lua) */ +#define LUA_INT_DEFAULT LUA_INT_LONGLONG +#define LUA_FLOAT_DEFAULT LUA_FLOAT_DOUBLE + + +/* +@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats. +*/ +#define LUA_32BITS 0 + + +/* +@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for +** C89 ('long' and 'double'); Windows always has '__int64', so it does +** not need to use this case. +*/ +#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS) +#define LUA_C89_NUMBERS 1 +#else +#define LUA_C89_NUMBERS 0 +#endif + + +#if LUA_32BITS /* { */ +/* +** 32-bit integers and 'float' +*/ +#if LUAI_IS32INT /* use 'int' if big enough */ +#define LUA_INT_TYPE LUA_INT_INT +#else /* otherwise use 'long' */ +#define LUA_INT_TYPE LUA_INT_LONG +#endif +#define LUA_FLOAT_TYPE LUA_FLOAT_FLOAT + +#elif LUA_C89_NUMBERS /* }{ */ +/* +** largest types available for C89 ('long' and 'double') +*/ +#define LUA_INT_TYPE LUA_INT_LONG +#define LUA_FLOAT_TYPE LUA_FLOAT_DOUBLE + +#else /* }{ */ +/* use defaults */ + +#define LUA_INT_TYPE LUA_INT_DEFAULT +#define LUA_FLOAT_TYPE LUA_FLOAT_DEFAULT + +#endif /* } */ + + +/* }================================================================== */ + + + +/* +** {================================================================== +** Configuration for Paths. +** =================================================================== +*/ + +/* +** LUA_PATH_SEP is the character that separates templates in a path. +** LUA_PATH_MARK is the string that marks the substitution points in a +** template. +** LUA_EXEC_DIR in a Windows path is replaced by the executable's +** directory. +*/ +#define LUA_PATH_SEP ";" +#define LUA_PATH_MARK "?" +#define LUA_EXEC_DIR "!" + + +/* +@@ LUA_PATH_DEFAULT is the default path that Lua uses to look for +** Lua libraries. +@@ LUA_CPATH_DEFAULT is the default path that Lua uses to look for +** C libraries. +** CHANGE them if your machine has a non-conventional directory +** hierarchy or if you want to install your libraries in +** non-conventional directories. +*/ + +#define LUA_VDIR LUA_VERSION_MAJOR "." LUA_VERSION_MINOR +#if defined(_WIN32) /* { */ +/* +** In Windows, any exclamation mark ('!') in the path is replaced by the +** path of the directory of the executable file of the current process. +*/ +#define LUA_LDIR "!\\lua\\" +#define LUA_CDIR "!\\" +#define LUA_SHRDIR "!\\..\\share\\lua\\" LUA_VDIR "\\" + +#if !defined(LUA_PATH_DEFAULT) +#define LUA_PATH_DEFAULT \ + LUA_LDIR"?.lua;" LUA_LDIR"?\\init.lua;" \ + LUA_CDIR"?.lua;" LUA_CDIR"?\\init.lua;" \ + LUA_SHRDIR"?.lua;" LUA_SHRDIR"?\\init.lua;" \ + ".\\?.lua;" ".\\?\\init.lua" +#endif + +#if !defined(LUA_CPATH_DEFAULT) +#define LUA_CPATH_DEFAULT \ + LUA_CDIR"?.dll;" \ + LUA_CDIR"..\\lib\\lua\\" LUA_VDIR "\\?.dll;" \ + LUA_CDIR"loadall.dll;" ".\\?.dll" +#endif + +#else /* }{ */ + +#define LUA_ROOT "/usr/local/" +#define LUA_LDIR LUA_ROOT "share/lua/" LUA_VDIR "/" +#define LUA_CDIR LUA_ROOT "lib/lua/" LUA_VDIR "/" + +#if !defined(LUA_PATH_DEFAULT) +#define LUA_PATH_DEFAULT \ + LUA_LDIR"?.lua;" LUA_LDIR"?/init.lua;" \ + LUA_CDIR"?.lua;" LUA_CDIR"?/init.lua;" \ + "./?.lua;" "./?/init.lua" +#endif + +#if !defined(LUA_CPATH_DEFAULT) +#define LUA_CPATH_DEFAULT \ + LUA_CDIR"?.so;" LUA_CDIR"loadall.so;" "./?.so" +#endif + +#endif /* } */ + + +/* +@@ LUA_DIRSEP is the directory separator (for submodules). +** CHANGE it if your machine does not use "/" as the directory separator +** and is not Windows. (On Windows Lua automatically uses "\".) +*/ +#if !defined(LUA_DIRSEP) + +#if defined(_WIN32) +#define LUA_DIRSEP "\\" +#else +#define LUA_DIRSEP "/" +#endif + +#endif + +/* }================================================================== */ + + +/* +** {================================================================== +** Marks for exported symbols in the C code +** =================================================================== +*/ + +/* +@@ LUA_API is a mark for all core API functions. +@@ LUALIB_API is a mark for all auxiliary library functions. +@@ LUAMOD_API is a mark for all standard library opening functions. +** CHANGE them if you need to define those functions in some special way. +** For instance, if you want to create one Windows DLL with the core and +** the libraries, you may want to use the following definition (define +** LUA_BUILD_AS_DLL to get it). +*/ +#if defined(LUA_BUILD_AS_DLL) /* { */ + +#if defined(LUA_CORE) || defined(LUA_LIB) /* { */ +#define LUA_API __declspec(dllexport) +#else /* }{ */ +#define LUA_API __declspec(dllimport) +#endif /* } */ + +#else /* }{ */ + +#define LUA_API extern + +#endif /* } */ + + +/* +** More often than not the libs go together with the core. +*/ +#define LUALIB_API LUA_API +#define LUAMOD_API LUA_API + + +/* +@@ LUAI_FUNC is a mark for all extern functions that are not to be +** exported to outside modules. +@@ LUAI_DDEF and LUAI_DDEC are marks for all extern (const) variables, +** none of which to be exported to outside modules (LUAI_DDEF for +** definitions and LUAI_DDEC for declarations). +** CHANGE them if you need to mark them in some special way. Elf/gcc +** (versions 3.2 and later) mark them as "hidden" to optimize access +** when Lua is compiled as a shared library. Not all elf targets support +** this attribute. Unfortunately, gcc does not offer a way to check +** whether the target offers that support, and those without support +** give a warning about it. To avoid these warnings, change to the +** default definition. +*/ +#if defined(__GNUC__) && ((__GNUC__*100 + __GNUC_MINOR__) >= 302) && \ + defined(__ELF__) /* { */ +#define LUAI_FUNC __attribute__((visibility("internal"))) extern +#else /* }{ */ +#define LUAI_FUNC extern +#endif /* } */ + +#define LUAI_DDEC(dec) LUAI_FUNC dec +#define LUAI_DDEF /* empty */ + +/* }================================================================== */ + + +/* +** {================================================================== +** Compatibility with previous versions +** =================================================================== +*/ + +/* +@@ LUA_COMPAT_5_3 controls other macros for compatibility with Lua 5.3. +** You can define it to get all options, or change specific options +** to fit your specific needs. +*/ +#if defined(LUA_COMPAT_5_3) /* { */ + +/* +@@ LUA_COMPAT_MATHLIB controls the presence of several deprecated +** functions in the mathematical library. +** (These functions were already officially removed in 5.3; +** nevertheless they are still available here.) +*/ +#define LUA_COMPAT_MATHLIB + +/* +@@ LUA_COMPAT_APIINTCASTS controls the presence of macros for +** manipulating other integer types (lua_pushunsigned, lua_tounsigned, +** luaL_checkint, luaL_checklong, etc.) +** (These macros were also officially removed in 5.3, but they are still +** available here.) +*/ +#define LUA_COMPAT_APIINTCASTS + + +/* +@@ LUA_COMPAT_LT_LE controls the emulation of the '__le' metamethod +** using '__lt'. +*/ +#define LUA_COMPAT_LT_LE + + +/* +@@ The following macros supply trivial compatibility for some +** changes in the API. The macros themselves document how to +** change your code to avoid using them. +** (Once more, these macros were officially removed in 5.3, but they are +** still available here.) +*/ +#define lua_strlen(L,i) lua_rawlen(L, (i)) + +#define lua_objlen(L,i) lua_rawlen(L, (i)) + +#define lua_equal(L,idx1,idx2) lua_compare(L,(idx1),(idx2),LUA_OPEQ) +#define lua_lessthan(L,idx1,idx2) lua_compare(L,(idx1),(idx2),LUA_OPLT) + +#endif /* } */ + +/* }================================================================== */ + + + +/* +** {================================================================== +** Configuration for Numbers (low-level part). +** Change these definitions if no predefined LUA_FLOAT_* / LUA_INT_* +** satisfy your needs. +** =================================================================== +*/ + +/* +@@ LUAI_UACNUMBER is the result of a 'default argument promotion' +@@ over a floating number. +@@ l_floatatt(x) corrects float attribute 'x' to the proper float type +** by prefixing it with one of FLT/DBL/LDBL. +@@ LUA_NUMBER_FRMLEN is the length modifier for writing floats. +@@ LUA_NUMBER_FMT is the format for writing floats. +@@ lua_number2str converts a float to a string. +@@ l_mathop allows the addition of an 'l' or 'f' to all math operations. +@@ l_floor takes the floor of a float. +@@ lua_str2number converts a decimal numeral to a number. +*/ + + +/* The following definitions are good for most cases here */ + +#define l_floor(x) (l_mathop(floor)(x)) + +#define lua_number2str(s,sz,n) \ + l_sprintf((s), sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)(n)) + +/* +@@ lua_numbertointeger converts a float number with an integral value +** to an integer, or returns 0 if float is not within the range of +** a lua_Integer. (The range comparisons are tricky because of +** rounding. The tests here assume a two-complement representation, +** where MININTEGER always has an exact representation as a float; +** MAXINTEGER may not have one, and therefore its conversion to float +** may have an ill-defined value.) +*/ +#define lua_numbertointeger(n,p) \ + ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \ + (n) < -(LUA_NUMBER)(LUA_MININTEGER) && \ + (*(p) = (LUA_INTEGER)(n), 1)) + + +/* now the variable definitions */ + +#if LUA_FLOAT_TYPE == LUA_FLOAT_FLOAT /* { single float */ + +#define LUA_NUMBER float + +#define l_floatatt(n) (FLT_##n) + +#define LUAI_UACNUMBER double + +#define LUA_NUMBER_FRMLEN "" +#define LUA_NUMBER_FMT "%.7g" + +#define l_mathop(op) op##f + +#define lua_str2number(s,p) strtof((s), (p)) + + +#elif LUA_FLOAT_TYPE == LUA_FLOAT_LONGDOUBLE /* }{ long double */ + +#define LUA_NUMBER long double + +#define l_floatatt(n) (LDBL_##n) + +#define LUAI_UACNUMBER long double + +#define LUA_NUMBER_FRMLEN "L" +#define LUA_NUMBER_FMT "%.19Lg" + +#define l_mathop(op) op##l + +#define lua_str2number(s,p) strtold((s), (p)) + +#elif LUA_FLOAT_TYPE == LUA_FLOAT_DOUBLE /* }{ double */ + +#define LUA_NUMBER double + +#define l_floatatt(n) (DBL_##n) + +#define LUAI_UACNUMBER double + +#define LUA_NUMBER_FRMLEN "" +#define LUA_NUMBER_FMT "%.14g" + +#define l_mathop(op) op + +#define lua_str2number(s,p) strtod((s), (p)) + +#else /* }{ */ + +#error "numeric float type not defined" + +#endif /* } */ + + + +/* +@@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER. +@@ LUAI_UACINT is the result of a 'default argument promotion' +@@ over a LUA_INTEGER. +@@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers. +@@ LUA_INTEGER_FMT is the format for writing integers. +@@ LUA_MAXINTEGER is the maximum value for a LUA_INTEGER. +@@ LUA_MININTEGER is the minimum value for a LUA_INTEGER. +@@ LUA_MAXUNSIGNED is the maximum value for a LUA_UNSIGNED. +@@ lua_integer2str converts an integer to a string. +*/ + + +/* The following definitions are good for most cases here */ + +#define LUA_INTEGER_FMT "%" LUA_INTEGER_FRMLEN "d" + +#define LUAI_UACINT LUA_INTEGER + +#define lua_integer2str(s,sz,n) \ + l_sprintf((s), sz, LUA_INTEGER_FMT, (LUAI_UACINT)(n)) + +/* +** use LUAI_UACINT here to avoid problems with promotions (which +** can turn a comparison between unsigneds into a signed comparison) +*/ +#define LUA_UNSIGNED unsigned LUAI_UACINT + + +/* now the variable definitions */ + +#if LUA_INT_TYPE == LUA_INT_INT /* { int */ + +#define LUA_INTEGER int +#define LUA_INTEGER_FRMLEN "" + +#define LUA_MAXINTEGER INT_MAX +#define LUA_MININTEGER INT_MIN + +#define LUA_MAXUNSIGNED UINT_MAX + +#elif LUA_INT_TYPE == LUA_INT_LONG /* }{ long */ + +#define LUA_INTEGER long +#define LUA_INTEGER_FRMLEN "l" + +#define LUA_MAXINTEGER LONG_MAX +#define LUA_MININTEGER LONG_MIN + +#define LUA_MAXUNSIGNED ULONG_MAX + +#elif LUA_INT_TYPE == LUA_INT_LONGLONG /* }{ long long */ + +/* use presence of macro LLONG_MAX as proxy for C99 compliance */ +#if defined(LLONG_MAX) /* { */ +/* use ISO C99 stuff */ + +#define LUA_INTEGER long long +#define LUA_INTEGER_FRMLEN "ll" + +#define LUA_MAXINTEGER LLONG_MAX +#define LUA_MININTEGER LLONG_MIN + +#define LUA_MAXUNSIGNED ULLONG_MAX + +#elif defined(LUA_USE_WINDOWS) /* }{ */ +/* in Windows, can use specific Windows types */ + +#define LUA_INTEGER __int64 +#define LUA_INTEGER_FRMLEN "I64" + +#define LUA_MAXINTEGER _I64_MAX +#define LUA_MININTEGER _I64_MIN + +#define LUA_MAXUNSIGNED _UI64_MAX + +#else /* }{ */ + +#error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' \ + or '-DLUA_C89_NUMBERS' (see file 'luaconf.h' for details)" + +#endif /* } */ + +#else /* }{ */ + +#error "numeric integer type not defined" + +#endif /* } */ + +/* }================================================================== */ + + +/* +** {================================================================== +** Dependencies with C99 and other C details +** =================================================================== +*/ + +/* +@@ l_sprintf is equivalent to 'snprintf' or 'sprintf' in C89. +** (All uses in Lua have only one format item.) +*/ +#if !defined(LUA_USE_C89) +#define l_sprintf(s,sz,f,i) snprintf(s,sz,f,i) +#else +#define l_sprintf(s,sz,f,i) ((void)(sz), sprintf(s,f,i)) +#endif + + +/* +@@ lua_strx2number converts a hexadecimal numeral to a number. +** In C99, 'strtod' does that conversion. Otherwise, you can +** leave 'lua_strx2number' undefined and Lua will provide its own +** implementation. +*/ +#if !defined(LUA_USE_C89) +#define lua_strx2number(s,p) lua_str2number(s,p) +#endif + + +/* +@@ lua_pointer2str converts a pointer to a readable string in a +** non-specified way. +*/ +#define lua_pointer2str(buff,sz,p) l_sprintf(buff,sz,"%p",p) + + +/* +@@ lua_number2strx converts a float to a hexadecimal numeral. +** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that. +** Otherwise, you can leave 'lua_number2strx' undefined and Lua will +** provide its own implementation. +*/ +#if !defined(LUA_USE_C89) +#define lua_number2strx(L,b,sz,f,n) \ + ((void)L, l_sprintf(b,sz,f,(LUAI_UACNUMBER)(n))) +#endif + + +/* +** 'strtof' and 'opf' variants for math functions are not valid in +** C89. Otherwise, the macro 'HUGE_VALF' is a good proxy for testing the +** availability of these variants. ('math.h' is already included in +** all files that use these macros.) +*/ +#if defined(LUA_USE_C89) || (defined(HUGE_VAL) && !defined(HUGE_VALF)) +#undef l_mathop /* variants not available */ +#undef lua_str2number +#define l_mathop(op) (lua_Number)op /* no variant */ +#define lua_str2number(s,p) ((lua_Number)strtod((s), (p))) +#endif + + +/* +@@ LUA_KCONTEXT is the type of the context ('ctx') for continuation +** functions. It must be a numerical type; Lua will use 'intptr_t' if +** available, otherwise it will use 'ptrdiff_t' (the nearest thing to +** 'intptr_t' in C89) +*/ +#define LUA_KCONTEXT ptrdiff_t + +#if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \ + __STDC_VERSION__ >= 199901L +#include +#if defined(INTPTR_MAX) /* even in C99 this type is optional */ +#undef LUA_KCONTEXT +#define LUA_KCONTEXT intptr_t +#endif +#endif + + +/* +@@ lua_getlocaledecpoint gets the locale "radix character" (decimal point). +** Change that if you do not want to use C locales. (Code using this +** macro must include the header 'locale.h'.) +*/ +#if !defined(lua_getlocaledecpoint) +#define lua_getlocaledecpoint() (localeconv()->decimal_point[0]) +#endif + + +/* +** macros to improve jump prediction, used mostly for error handling +** and debug facilities. (Some macros in the Lua API use these macros. +** Define LUA_NOBUILTIN if you do not want '__builtin_expect' in your +** code.) +*/ +#if !defined(luai_likely) + +#if defined(__GNUC__) && !defined(LUA_NOBUILTIN) +#define luai_likely(x) (__builtin_expect(((x) != 0), 1)) +#define luai_unlikely(x) (__builtin_expect(((x) != 0), 0)) +#else +#define luai_likely(x) (x) +#define luai_unlikely(x) (x) +#endif + +#endif + + +#if defined(LUA_CORE) || defined(LUA_LIB) +/* shorter names for Lua's own use */ +#define l_likely(x) luai_likely(x) +#define l_unlikely(x) luai_unlikely(x) +#endif + + + +/* }================================================================== */ + + +/* +** {================================================================== +** Language Variations +** ===================================================================== +*/ + +/* +@@ LUA_NOCVTN2S/LUA_NOCVTS2N control how Lua performs some +** coercions. Define LUA_NOCVTN2S to turn off automatic coercion from +** numbers to strings. Define LUA_NOCVTS2N to turn off automatic +** coercion from strings to numbers. +*/ +/* #define LUA_NOCVTN2S */ +/* #define LUA_NOCVTS2N */ + + +/* +@@ LUA_USE_APICHECK turns on several consistency checks on the C API. +** Define it as a help when debugging C code. +*/ +#if defined(LUA_USE_APICHECK) +#include +#define luai_apicheck(l,e) assert(e) +#endif + +/* }================================================================== */ + + +/* +** {================================================================== +** Macros that affect the API and must be stable (that is, must be the +** same when you compile Lua and when you compile code that links to +** Lua). +** ===================================================================== +*/ + +/* +@@ LUAI_MAXSTACK limits the size of the Lua stack. +** CHANGE it if you need a different limit. This limit is arbitrary; +** its only purpose is to stop Lua from consuming unlimited stack +** space (and to reserve some numbers for pseudo-indices). +** (It must fit into max(size_t)/32 and max(int)/2.) +*/ +#if LUAI_IS32INT +#define LUAI_MAXSTACK 1000000 +#else +#define LUAI_MAXSTACK 15000 +#endif + + +/* +@@ LUA_EXTRASPACE defines the size of a raw memory area associated with +** a Lua state with very fast access. +** CHANGE it if you need a different size. +*/ +#define LUA_EXTRASPACE (sizeof(void *)) + + +/* +@@ LUA_IDSIZE gives the maximum size for the description of the source +** of a function in debug information. +** CHANGE it if you want a different size. +*/ +#define LUA_IDSIZE 60 + + +/* +@@ LUAL_BUFFERSIZE is the initial buffer size used by the lauxlib +** buffer system. +*/ +#define LUAL_BUFFERSIZE ((int)(16 * sizeof(void*) * sizeof(lua_Number))) + + +/* +@@ LUAI_MAXALIGN defines fields that, when used in a union, ensure +** maximum alignment for the other items in that union. +*/ +#define LUAI_MAXALIGN lua_Number n; double u; void *s; lua_Integer i; long l + +/* }================================================================== */ + + + + + +/* =================================================================== */ + +/* +** Local configuration. You can use this space to add your redefinitions +** without modifying the main part of the file. +*/ + + + + + +#endif + diff --git a/src/lualib.h b/src/lualib.h new file mode 100644 index 0000000..2625529 --- /dev/null +++ b/src/lualib.h @@ -0,0 +1,52 @@ +/* +** $Id: lualib.h $ +** Lua standard libraries +** See Copyright Notice in lua.h +*/ + + +#ifndef lualib_h +#define lualib_h + +#include "lua.h" + + +/* version suffix for environment variable names */ +#define LUA_VERSUFFIX "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR + + +LUAMOD_API int (luaopen_base) (lua_State *L); + +#define LUA_COLIBNAME "coroutine" +LUAMOD_API int (luaopen_coroutine) (lua_State *L); + +#define LUA_TABLIBNAME "table" +LUAMOD_API int (luaopen_table) (lua_State *L); + +#define LUA_IOLIBNAME "io" +LUAMOD_API int (luaopen_io) (lua_State *L); + +#define LUA_OSLIBNAME "os" +LUAMOD_API int (luaopen_os) (lua_State *L); + +#define LUA_STRLIBNAME "string" +LUAMOD_API int (luaopen_string) (lua_State *L); + +#define LUA_UTF8LIBNAME "utf8" +LUAMOD_API int (luaopen_utf8) (lua_State *L); + +#define LUA_MATHLIBNAME "math" +LUAMOD_API int (luaopen_math) (lua_State *L); + +#define LUA_DBLIBNAME "debug" +LUAMOD_API int (luaopen_debug) (lua_State *L); + +#define LUA_LOADLIBNAME "package" +LUAMOD_API int (luaopen_package) (lua_State *L); + + +/* open all previous libraries */ +LUALIB_API void (luaL_openlibs) (lua_State *L); + + +#endif diff --git a/src/lundump.c b/src/lundump.c new file mode 100644 index 0000000..02aed64 --- /dev/null +++ b/src/lundump.c @@ -0,0 +1,335 @@ +/* +** $Id: lundump.c $ +** load precompiled Lua chunks +** See Copyright Notice in lua.h +*/ + +#define lundump_c +#define LUA_CORE + +#include "lprefix.h" + + +#include +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstring.h" +#include "lundump.h" +#include "lzio.h" + + +#if !defined(luai_verifycode) +#define luai_verifycode(L,f) /* empty */ +#endif + + +typedef struct { + lua_State *L; + ZIO *Z; + const char *name; +} LoadState; + + +static l_noret error (LoadState *S, const char *why) { + luaO_pushfstring(S->L, "%s: bad binary format (%s)", S->name, why); + luaD_throw(S->L, LUA_ERRSYNTAX); +} + + +/* +** All high-level loads go through loadVector; you can change it to +** adapt to the endianness of the input +*/ +#define loadVector(S,b,n) loadBlock(S,b,(n)*sizeof((b)[0])) + +static void loadBlock (LoadState *S, void *b, size_t size) { + if (luaZ_read(S->Z, b, size) != 0) + error(S, "truncated chunk"); +} + + +#define loadVar(S,x) loadVector(S,&x,1) + + +static lu_byte loadByte (LoadState *S) { + int b = zgetc(S->Z); + if (b == EOZ) + error(S, "truncated chunk"); + return cast_byte(b); +} + + +static size_t loadUnsigned (LoadState *S, size_t limit) { + size_t x = 0; + int b; + limit >>= 7; + do { + b = loadByte(S); + if (x >= limit) + error(S, "integer overflow"); + x = (x << 7) | (b & 0x7f); + } while ((b & 0x80) == 0); + return x; +} + + +static size_t loadSize (LoadState *S) { + return loadUnsigned(S, ~(size_t)0); +} + + +static int loadInt (LoadState *S) { + return cast_int(loadUnsigned(S, INT_MAX)); +} + + +static lua_Number loadNumber (LoadState *S) { + lua_Number x; + loadVar(S, x); + return x; +} + + +static lua_Integer loadInteger (LoadState *S) { + lua_Integer x; + loadVar(S, x); + return x; +} + + +/* +** Load a nullable string into prototype 'p'. +*/ +static TString *loadStringN (LoadState *S, Proto *p) { + lua_State *L = S->L; + TString *ts; + size_t size = loadSize(S); + if (size == 0) /* no string? */ + return NULL; + else if (--size <= LUAI_MAXSHORTLEN) { /* short string? */ + char buff[LUAI_MAXSHORTLEN]; + loadVector(S, buff, size); /* load string into buffer */ + ts = luaS_newlstr(L, buff, size); /* create string */ + } + else { /* long string */ + ts = luaS_createlngstrobj(L, size); /* create string */ + setsvalue2s(L, L->top.p, ts); /* anchor it ('loadVector' can GC) */ + luaD_inctop(L); + loadVector(S, getstr(ts), size); /* load directly in final place */ + L->top.p--; /* pop string */ + } + luaC_objbarrier(L, p, ts); + return ts; +} + + +/* +** Load a non-nullable string into prototype 'p'. +*/ +static TString *loadString (LoadState *S, Proto *p) { + TString *st = loadStringN(S, p); + if (st == NULL) + error(S, "bad format for constant string"); + return st; +} + + +static void loadCode (LoadState *S, Proto *f) { + int n = loadInt(S); + f->code = luaM_newvectorchecked(S->L, n, Instruction); + f->sizecode = n; + loadVector(S, f->code, n); +} + + +static void loadFunction(LoadState *S, Proto *f, TString *psource); + + +static void loadConstants (LoadState *S, Proto *f) { + int i; + int n = loadInt(S); + f->k = luaM_newvectorchecked(S->L, n, TValue); + f->sizek = n; + for (i = 0; i < n; i++) + setnilvalue(&f->k[i]); + for (i = 0; i < n; i++) { + TValue *o = &f->k[i]; + int t = loadByte(S); + switch (t) { + case LUA_VNIL: + setnilvalue(o); + break; + case LUA_VFALSE: + setbfvalue(o); + break; + case LUA_VTRUE: + setbtvalue(o); + break; + case LUA_VNUMFLT: + setfltvalue(o, loadNumber(S)); + break; + case LUA_VNUMINT: + setivalue(o, loadInteger(S)); + break; + case LUA_VSHRSTR: + case LUA_VLNGSTR: + setsvalue2n(S->L, o, loadString(S, f)); + break; + default: lua_assert(0); + } + } +} + + +static void loadProtos (LoadState *S, Proto *f) { + int i; + int n = loadInt(S); + f->p = luaM_newvectorchecked(S->L, n, Proto *); + f->sizep = n; + for (i = 0; i < n; i++) + f->p[i] = NULL; + for (i = 0; i < n; i++) { + f->p[i] = luaF_newproto(S->L); + luaC_objbarrier(S->L, f, f->p[i]); + loadFunction(S, f->p[i], f->source); + } +} + + +/* +** Load the upvalues for a function. The names must be filled first, +** because the filling of the other fields can raise read errors and +** the creation of the error message can call an emergency collection; +** in that case all prototypes must be consistent for the GC. +*/ +static void loadUpvalues (LoadState *S, Proto *f) { + int i, n; + n = loadInt(S); + f->upvalues = luaM_newvectorchecked(S->L, n, Upvaldesc); + f->sizeupvalues = n; + for (i = 0; i < n; i++) /* make array valid for GC */ + f->upvalues[i].name = NULL; + for (i = 0; i < n; i++) { /* following calls can raise errors */ + f->upvalues[i].instack = loadByte(S); + f->upvalues[i].idx = loadByte(S); + f->upvalues[i].kind = loadByte(S); + } +} + + +static void loadDebug (LoadState *S, Proto *f) { + int i, n; + n = loadInt(S); + f->lineinfo = luaM_newvectorchecked(S->L, n, ls_byte); + f->sizelineinfo = n; + loadVector(S, f->lineinfo, n); + n = loadInt(S); + f->abslineinfo = luaM_newvectorchecked(S->L, n, AbsLineInfo); + f->sizeabslineinfo = n; + for (i = 0; i < n; i++) { + f->abslineinfo[i].pc = loadInt(S); + f->abslineinfo[i].line = loadInt(S); + } + n = loadInt(S); + f->locvars = luaM_newvectorchecked(S->L, n, LocVar); + f->sizelocvars = n; + for (i = 0; i < n; i++) + f->locvars[i].varname = NULL; + for (i = 0; i < n; i++) { + f->locvars[i].varname = loadStringN(S, f); + f->locvars[i].startpc = loadInt(S); + f->locvars[i].endpc = loadInt(S); + } + n = loadInt(S); + if (n != 0) /* does it have debug information? */ + n = f->sizeupvalues; /* must be this many */ + for (i = 0; i < n; i++) + f->upvalues[i].name = loadStringN(S, f); +} + + +static void loadFunction (LoadState *S, Proto *f, TString *psource) { + f->source = loadStringN(S, f); + if (f->source == NULL) /* no source in dump? */ + f->source = psource; /* reuse parent's source */ + f->linedefined = loadInt(S); + f->lastlinedefined = loadInt(S); + f->numparams = loadByte(S); + f->is_vararg = loadByte(S); + f->maxstacksize = loadByte(S); + loadCode(S, f); + loadConstants(S, f); + loadUpvalues(S, f); + loadProtos(S, f); + loadDebug(S, f); +} + + +static void checkliteral (LoadState *S, const char *s, const char *msg) { + char buff[sizeof(LUA_SIGNATURE) + sizeof(LUAC_DATA)]; /* larger than both */ + size_t len = strlen(s); + loadVector(S, buff, len); + if (memcmp(s, buff, len) != 0) + error(S, msg); +} + + +static void fchecksize (LoadState *S, size_t size, const char *tname) { + if (loadByte(S) != size) + error(S, luaO_pushfstring(S->L, "%s size mismatch", tname)); +} + + +#define checksize(S,t) fchecksize(S,sizeof(t),#t) + +static void checkHeader (LoadState *S) { + /* skip 1st char (already read and checked) */ + checkliteral(S, &LUA_SIGNATURE[1], "not a binary chunk"); + if (loadByte(S) != LUAC_VERSION) + error(S, "version mismatch"); + if (loadByte(S) != LUAC_FORMAT) + error(S, "format mismatch"); + checkliteral(S, LUAC_DATA, "corrupted chunk"); + checksize(S, Instruction); + checksize(S, lua_Integer); + checksize(S, lua_Number); + if (loadInteger(S) != LUAC_INT) + error(S, "integer format mismatch"); + if (loadNumber(S) != LUAC_NUM) + error(S, "float format mismatch"); +} + + +/* +** Load precompiled chunk. +*/ +LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) { + LoadState S; + LClosure *cl; + if (*name == '@' || *name == '=') + S.name = name + 1; + else if (*name == LUA_SIGNATURE[0]) + S.name = "binary string"; + else + S.name = name; + S.L = L; + S.Z = Z; + checkHeader(&S); + cl = luaF_newLclosure(L, loadByte(&S)); + setclLvalue2s(L, L->top.p, cl); + luaD_inctop(L); + cl->p = luaF_newproto(L); + luaC_objbarrier(L, cl, cl->p); + loadFunction(&S, cl->p, NULL); + lua_assert(cl->nupvalues == cl->p->sizeupvalues); + luai_verifycode(L, cl->p); + return cl; +} + diff --git a/src/lundump.h b/src/lundump.h new file mode 100644 index 0000000..f3748a9 --- /dev/null +++ b/src/lundump.h @@ -0,0 +1,36 @@ +/* +** $Id: lundump.h $ +** load precompiled Lua chunks +** See Copyright Notice in lua.h +*/ + +#ifndef lundump_h +#define lundump_h + +#include "llimits.h" +#include "lobject.h" +#include "lzio.h" + + +/* data to catch conversion errors */ +#define LUAC_DATA "\x19\x93\r\n\x1a\n" + +#define LUAC_INT 0x5678 +#define LUAC_NUM cast_num(370.5) + +/* +** Encode major-minor version in one byte, one nibble for each +*/ +#define MYINT(s) (s[0]-'0') /* assume one-digit numerals */ +#define LUAC_VERSION (MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR)) + +#define LUAC_FORMAT 0 /* this is the official format */ + +/* load one chunk; from lundump.c */ +LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, const char* name); + +/* dump one chunk; from ldump.c */ +LUAI_FUNC int luaU_dump (lua_State* L, const Proto* f, lua_Writer w, + void* data, int strip); + +#endif diff --git a/src/lutf8lib.c b/src/lutf8lib.c new file mode 100644 index 0000000..3a5b9bc --- /dev/null +++ b/src/lutf8lib.c @@ -0,0 +1,291 @@ +/* +** $Id: lutf8lib.c $ +** Standard library for UTF-8 manipulation +** See Copyright Notice in lua.h +*/ + +#define lutf8lib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#define MAXUNICODE 0x10FFFFu + +#define MAXUTF 0x7FFFFFFFu + + +#define MSGInvalid "invalid UTF-8 code" + +/* +** Integer type for decoded UTF-8 values; MAXUTF needs 31 bits. +*/ +#if (UINT_MAX >> 30) >= 1 +typedef unsigned int utfint; +#else +typedef unsigned long utfint; +#endif + + +#define iscont(c) (((c) & 0xC0) == 0x80) +#define iscontp(p) iscont(*(p)) + + +/* from strlib */ +/* translate a relative string position: negative means back from end */ +static lua_Integer u_posrelat (lua_Integer pos, size_t len) { + if (pos >= 0) return pos; + else if (0u - (size_t)pos > len) return 0; + else return (lua_Integer)len + pos + 1; +} + + +/* +** Decode one UTF-8 sequence, returning NULL if byte sequence is +** invalid. The array 'limits' stores the minimum value for each +** sequence length, to check for overlong representations. Its first +** entry forces an error for non-ascii bytes with no continuation +** bytes (count == 0). +*/ +static const char *utf8_decode (const char *s, utfint *val, int strict) { + static const utfint limits[] = + {~(utfint)0, 0x80, 0x800, 0x10000u, 0x200000u, 0x4000000u}; + unsigned int c = (unsigned char)s[0]; + utfint res = 0; /* final result */ + if (c < 0x80) /* ascii? */ + res = c; + else { + int count = 0; /* to count number of continuation bytes */ + for (; c & 0x40; c <<= 1) { /* while it needs continuation bytes... */ + unsigned int cc = (unsigned char)s[++count]; /* read next byte */ + if (!iscont(cc)) /* not a continuation byte? */ + return NULL; /* invalid byte sequence */ + res = (res << 6) | (cc & 0x3F); /* add lower 6 bits from cont. byte */ + } + res |= ((utfint)(c & 0x7F) << (count * 5)); /* add first byte */ + if (count > 5 || res > MAXUTF || res < limits[count]) + return NULL; /* invalid byte sequence */ + s += count; /* skip continuation bytes read */ + } + if (strict) { + /* check for invalid code points; too large or surrogates */ + if (res > MAXUNICODE || (0xD800u <= res && res <= 0xDFFFu)) + return NULL; + } + if (val) *val = res; + return s + 1; /* +1 to include first byte */ +} + + +/* +** utf8len(s [, i [, j [, lax]]]) --> number of characters that +** start in the range [i,j], or nil + current position if 's' is not +** well formed in that interval +*/ +static int utflen (lua_State *L) { + lua_Integer n = 0; /* counter for the number of characters */ + size_t len; /* string length in bytes */ + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len); + lua_Integer posj = u_posrelat(luaL_optinteger(L, 3, -1), len); + int lax = lua_toboolean(L, 4); + luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2, + "initial position out of bounds"); + luaL_argcheck(L, --posj < (lua_Integer)len, 3, + "final position out of bounds"); + while (posi <= posj) { + const char *s1 = utf8_decode(s + posi, NULL, !lax); + if (s1 == NULL) { /* conversion error? */ + luaL_pushfail(L); /* return fail ... */ + lua_pushinteger(L, posi + 1); /* ... and current position */ + return 2; + } + posi = s1 - s; + n++; + } + lua_pushinteger(L, n); + return 1; +} + + +/* +** codepoint(s, [i, [j [, lax]]]) -> returns codepoints for all +** characters that start in the range [i,j] +*/ +static int codepoint (lua_State *L) { + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len); + lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len); + int lax = lua_toboolean(L, 4); + int n; + const char *se; + luaL_argcheck(L, posi >= 1, 2, "out of bounds"); + luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of bounds"); + if (posi > pose) return 0; /* empty interval; return no values */ + if (pose - posi >= INT_MAX) /* (lua_Integer -> int) overflow? */ + return luaL_error(L, "string slice too long"); + n = (int)(pose - posi) + 1; /* upper bound for number of returns */ + luaL_checkstack(L, n, "string slice too long"); + n = 0; /* count the number of returns */ + se = s + pose; /* string end */ + for (s += posi - 1; s < se;) { + utfint code; + s = utf8_decode(s, &code, !lax); + if (s == NULL) + return luaL_error(L, MSGInvalid); + lua_pushinteger(L, code); + n++; + } + return n; +} + + +static void pushutfchar (lua_State *L, int arg) { + lua_Unsigned code = (lua_Unsigned)luaL_checkinteger(L, arg); + luaL_argcheck(L, code <= MAXUTF, arg, "value out of range"); + lua_pushfstring(L, "%U", (long)code); +} + + +/* +** utfchar(n1, n2, ...) -> char(n1)..char(n2)... +*/ +static int utfchar (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + if (n == 1) /* optimize common case of single char */ + pushutfchar(L, 1); + else { + int i; + luaL_Buffer b; + luaL_buffinit(L, &b); + for (i = 1; i <= n; i++) { + pushutfchar(L, i); + luaL_addvalue(&b); + } + luaL_pushresult(&b); + } + return 1; +} + + +/* +** offset(s, n, [i]) -> index where n-th character counting from +** position 'i' starts; 0 means character at 'i'. +*/ +static int byteoffset (lua_State *L) { + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer n = luaL_checkinteger(L, 2); + lua_Integer posi = (n >= 0) ? 1 : len + 1; + posi = u_posrelat(luaL_optinteger(L, 3, posi), len); + luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3, + "position out of bounds"); + if (n == 0) { + /* find beginning of current byte sequence */ + while (posi > 0 && iscontp(s + posi)) posi--; + } + else { + if (iscontp(s + posi)) + return luaL_error(L, "initial position is a continuation byte"); + if (n < 0) { + while (n < 0 && posi > 0) { /* move back */ + do { /* find beginning of previous character */ + posi--; + } while (posi > 0 && iscontp(s + posi)); + n++; + } + } + else { + n--; /* do not move for 1st character */ + while (n > 0 && posi < (lua_Integer)len) { + do { /* find beginning of next character */ + posi++; + } while (iscontp(s + posi)); /* (cannot pass final '\0') */ + n--; + } + } + } + if (n == 0) /* did it find given character? */ + lua_pushinteger(L, posi + 1); + else /* no such character */ + luaL_pushfail(L); + return 1; +} + + +static int iter_aux (lua_State *L, int strict) { + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Unsigned n = (lua_Unsigned)lua_tointeger(L, 2); + if (n < len) { + while (iscontp(s + n)) n++; /* go to next character */ + } + if (n >= len) /* (also handles original 'n' being negative) */ + return 0; /* no more codepoints */ + else { + utfint code; + const char *next = utf8_decode(s + n, &code, strict); + if (next == NULL || iscontp(next)) + return luaL_error(L, MSGInvalid); + lua_pushinteger(L, n + 1); + lua_pushinteger(L, code); + return 2; + } +} + + +static int iter_auxstrict (lua_State *L) { + return iter_aux(L, 1); +} + +static int iter_auxlax (lua_State *L) { + return iter_aux(L, 0); +} + + +static int iter_codes (lua_State *L) { + int lax = lua_toboolean(L, 2); + const char *s = luaL_checkstring(L, 1); + luaL_argcheck(L, !iscontp(s), 1, MSGInvalid); + lua_pushcfunction(L, lax ? iter_auxlax : iter_auxstrict); + lua_pushvalue(L, 1); + lua_pushinteger(L, 0); + return 3; +} + + +/* pattern to match a single UTF-8 character */ +#define UTF8PATT "[\0-\x7F\xC2-\xFD][\x80-\xBF]*" + + +static const luaL_Reg funcs[] = { + {"offset", byteoffset}, + {"codepoint", codepoint}, + {"char", utfchar}, + {"len", utflen}, + {"codes", iter_codes}, + /* placeholders */ + {"charpattern", NULL}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_utf8 (lua_State *L) { + luaL_newlib(L, funcs); + lua_pushlstring(L, UTF8PATT, sizeof(UTF8PATT)/sizeof(char) - 1); + lua_setfield(L, -2, "charpattern"); + return 1; +} + diff --git a/src/lvm.c b/src/lvm.c new file mode 100644 index 0000000..8493a77 --- /dev/null +++ b/src/lvm.c @@ -0,0 +1,1901 @@ +/* +** $Id: lvm.c $ +** Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#define lvm_c +#define LUA_CORE + +#include "lprefix.h" + +#include +#include +#include +#include +#include +#include + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + +/* +** By default, use jump tables in the main interpreter loop on gcc +** and compatible compilers. +*/ +#if !defined(LUA_USE_JUMPTABLE) +#if defined(__GNUC__) +#define LUA_USE_JUMPTABLE 1 +#else +#define LUA_USE_JUMPTABLE 0 +#endif +#endif + + + +/* limit for table tag-method chains (to avoid infinite loops) */ +#define MAXTAGLOOP 2000 + + +/* +** 'l_intfitsf' checks whether a given integer is in the range that +** can be converted to a float without rounding. Used in comparisons. +*/ + +/* number of bits in the mantissa of a float */ +#define NBM (l_floatatt(MANT_DIG)) + +/* +** Check whether some integers may not fit in a float, testing whether +** (maxinteger >> NBM) > 0. (That implies (1 << NBM) <= maxinteger.) +** (The shifts are done in parts, to avoid shifting by more than the size +** of an integer. In a worst case, NBM == 113 for long double and +** sizeof(long) == 32.) +*/ +#if ((((LUA_MAXINTEGER >> (NBM / 4)) >> (NBM / 4)) >> (NBM / 4)) \ + >> (NBM - (3 * (NBM / 4)))) > 0 + +/* limit for integers that fit in a float */ +#define MAXINTFITSF ((lua_Unsigned)1 << NBM) + +/* check whether 'i' is in the interval [-MAXINTFITSF, MAXINTFITSF] */ +#define l_intfitsf(i) ((MAXINTFITSF + l_castS2U(i)) <= (2 * MAXINTFITSF)) + +#else /* all integers fit in a float precisely */ + +#define l_intfitsf(i) 1 + +#endif + + +/* +** Try to convert a value from string to a number value. +** If the value is not a string or is a string not representing +** a valid numeral (or if coercions from strings to numbers +** are disabled via macro 'cvt2num'), do not modify 'result' +** and return 0. +*/ +static int l_strton (const TValue *obj, TValue *result) { + lua_assert(obj != result); + if (!cvt2num(obj)) /* is object not a string? */ + return 0; + else + return (luaO_str2num(svalue(obj), result) == vslen(obj) + 1); +} + + +/* +** Try to convert a value to a float. The float case is already handled +** by the macro 'tonumber'. +*/ +int luaV_tonumber_ (const TValue *obj, lua_Number *n) { + TValue v; + if (ttisinteger(obj)) { + *n = cast_num(ivalue(obj)); + return 1; + } + else if (l_strton(obj, &v)) { /* string coercible to number? */ + *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */ + return 1; + } + else + return 0; /* conversion failed */ +} + + +/* +** try to convert a float to an integer, rounding according to 'mode'. +*/ +int luaV_flttointeger (lua_Number n, lua_Integer *p, F2Imod mode) { + lua_Number f = l_floor(n); + if (n != f) { /* not an integral value? */ + if (mode == F2Ieq) return 0; /* fails if mode demands integral value */ + else if (mode == F2Iceil) /* needs ceil? */ + f += 1; /* convert floor to ceil (remember: n != f) */ + } + return lua_numbertointeger(f, p); +} + + +/* +** try to convert a value to an integer, rounding according to 'mode', +** without string coercion. +** ("Fast track" handled by macro 'tointegerns'.) +*/ +int luaV_tointegerns (const TValue *obj, lua_Integer *p, F2Imod mode) { + if (ttisfloat(obj)) + return luaV_flttointeger(fltvalue(obj), p, mode); + else if (ttisinteger(obj)) { + *p = ivalue(obj); + return 1; + } + else + return 0; +} + + +/* +** try to convert a value to an integer. +*/ +int luaV_tointeger (const TValue *obj, lua_Integer *p, F2Imod mode) { + TValue v; + if (l_strton(obj, &v)) /* does 'obj' point to a numerical string? */ + obj = &v; /* change it to point to its corresponding number */ + return luaV_tointegerns(obj, p, mode); +} + + +/* +** Try to convert a 'for' limit to an integer, preserving the semantics +** of the loop. Return true if the loop must not run; otherwise, '*p' +** gets the integer limit. +** (The following explanation assumes a positive step; it is valid for +** negative steps mutatis mutandis.) +** If the limit is an integer or can be converted to an integer, +** rounding down, that is the limit. +** Otherwise, check whether the limit can be converted to a float. If +** the float is too large, clip it to LUA_MAXINTEGER. If the float +** is too negative, the loop should not run, because any initial +** integer value is greater than such limit; so, the function returns +** true to signal that. (For this latter case, no integer limit would be +** correct; even a limit of LUA_MININTEGER would run the loop once for +** an initial value equal to LUA_MININTEGER.) +*/ +static int forlimit (lua_State *L, lua_Integer init, const TValue *lim, + lua_Integer *p, lua_Integer step) { + if (!luaV_tointeger(lim, p, (step < 0 ? F2Iceil : F2Ifloor))) { + /* not coercible to in integer */ + lua_Number flim; /* try to convert to float */ + if (!tonumber(lim, &flim)) /* cannot convert to float? */ + luaG_forerror(L, lim, "limit"); + /* else 'flim' is a float out of integer bounds */ + if (luai_numlt(0, flim)) { /* if it is positive, it is too large */ + if (step < 0) return 1; /* initial value must be less than it */ + *p = LUA_MAXINTEGER; /* truncate */ + } + else { /* it is less than min integer */ + if (step > 0) return 1; /* initial value must be greater than it */ + *p = LUA_MININTEGER; /* truncate */ + } + } + return (step > 0 ? init > *p : init < *p); /* not to run? */ +} + + +/* +** Prepare a numerical for loop (opcode OP_FORPREP). +** Return true to skip the loop. Otherwise, +** after preparation, stack will be as follows: +** ra : internal index (safe copy of the control variable) +** ra + 1 : loop counter (integer loops) or limit (float loops) +** ra + 2 : step +** ra + 3 : control variable +*/ +static int forprep (lua_State *L, StkId ra) { + TValue *pinit = s2v(ra); + TValue *plimit = s2v(ra + 1); + TValue *pstep = s2v(ra + 2); + if (ttisinteger(pinit) && ttisinteger(pstep)) { /* integer loop? */ + lua_Integer init = ivalue(pinit); + lua_Integer step = ivalue(pstep); + lua_Integer limit; + if (step == 0) + luaG_runerror(L, "'for' step is zero"); + setivalue(s2v(ra + 3), init); /* control variable */ + if (forlimit(L, init, plimit, &limit, step)) + return 1; /* skip the loop */ + else { /* prepare loop counter */ + lua_Unsigned count; + if (step > 0) { /* ascending loop? */ + count = l_castS2U(limit) - l_castS2U(init); + if (step != 1) /* avoid division in the too common case */ + count /= l_castS2U(step); + } + else { /* step < 0; descending loop */ + count = l_castS2U(init) - l_castS2U(limit); + /* 'step+1' avoids negating 'mininteger' */ + count /= l_castS2U(-(step + 1)) + 1u; + } + /* store the counter in place of the limit (which won't be + needed anymore) */ + setivalue(plimit, l_castU2S(count)); + } + } + else { /* try making all values floats */ + lua_Number init; lua_Number limit; lua_Number step; + if (l_unlikely(!tonumber(plimit, &limit))) + luaG_forerror(L, plimit, "limit"); + if (l_unlikely(!tonumber(pstep, &step))) + luaG_forerror(L, pstep, "step"); + if (l_unlikely(!tonumber(pinit, &init))) + luaG_forerror(L, pinit, "initial value"); + if (step == 0) + luaG_runerror(L, "'for' step is zero"); + if (luai_numlt(0, step) ? luai_numlt(limit, init) + : luai_numlt(init, limit)) + return 1; /* skip the loop */ + else { + /* make sure internal values are all floats */ + setfltvalue(plimit, limit); + setfltvalue(pstep, step); + setfltvalue(s2v(ra), init); /* internal index */ + setfltvalue(s2v(ra + 3), init); /* control variable */ + } + } + return 0; +} + + +/* +** Execute a step of a float numerical for loop, returning +** true iff the loop must continue. (The integer case is +** written online with opcode OP_FORLOOP, for performance.) +*/ +static int floatforloop (StkId ra) { + lua_Number step = fltvalue(s2v(ra + 2)); + lua_Number limit = fltvalue(s2v(ra + 1)); + lua_Number idx = fltvalue(s2v(ra)); /* internal index */ + idx = luai_numadd(L, idx, step); /* increment index */ + if (luai_numlt(0, step) ? luai_numle(idx, limit) + : luai_numle(limit, idx)) { + chgfltvalue(s2v(ra), idx); /* update internal index */ + setfltvalue(s2v(ra + 3), idx); /* and control variable */ + return 1; /* jump back */ + } + else + return 0; /* finish the loop */ +} + + +/* +** Finish the table access 'val = t[key]'. +** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to +** t[k] entry (which must be empty). +*/ +void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val, + const TValue *slot) { + int loop; /* counter to avoid infinite loops */ + const TValue *tm; /* metamethod */ + for (loop = 0; loop < MAXTAGLOOP; loop++) { + if (slot == NULL) { /* 't' is not a table? */ + lua_assert(!ttistable(t)); + tm = luaT_gettmbyobj(L, t, TM_INDEX); + if (l_unlikely(notm(tm))) + luaG_typeerror(L, t, "index"); /* no metamethod */ + /* else will try the metamethod */ + } + else { /* 't' is a table */ + lua_assert(isempty(slot)); + tm = fasttm(L, hvalue(t)->metatable, TM_INDEX); /* table's metamethod */ + if (tm == NULL) { /* no metamethod? */ + setnilvalue(s2v(val)); /* result is nil */ + return; + } + /* else will try the metamethod */ + } + if (ttisfunction(tm)) { /* is metamethod a function? */ + luaT_callTMres(L, tm, t, key, val); /* call it */ + return; + } + t = tm; /* else try to access 'tm[key]' */ + if (luaV_fastget(L, t, key, slot, luaH_get)) { /* fast track? */ + setobj2s(L, val, slot); /* done */ + return; + } + /* else repeat (tail call 'luaV_finishget') */ + } + luaG_runerror(L, "'__index' chain too long; possible loop"); +} + + +/* +** Finish a table assignment 't[key] = val'. +** If 'slot' is NULL, 't' is not a table. Otherwise, 'slot' points +** to the entry 't[key]', or to a value with an absent key if there +** is no such entry. (The value at 'slot' must be empty, otherwise +** 'luaV_fastget' would have done the job.) +*/ +void luaV_finishset (lua_State *L, const TValue *t, TValue *key, + TValue *val, const TValue *slot) { + int loop; /* counter to avoid infinite loops */ + for (loop = 0; loop < MAXTAGLOOP; loop++) { + const TValue *tm; /* '__newindex' metamethod */ + if (slot != NULL) { /* is 't' a table? */ + Table *h = hvalue(t); /* save 't' table */ + lua_assert(isempty(slot)); /* slot must be empty */ + tm = fasttm(L, h->metatable, TM_NEWINDEX); /* get metamethod */ + if (tm == NULL) { /* no metamethod? */ + luaH_finishset(L, h, key, slot, val); /* set new value */ + invalidateTMcache(h); + luaC_barrierback(L, obj2gco(h), val); + return; + } + /* else will try the metamethod */ + } + else { /* not a table; check metamethod */ + tm = luaT_gettmbyobj(L, t, TM_NEWINDEX); + if (l_unlikely(notm(tm))) + luaG_typeerror(L, t, "index"); + } + /* try the metamethod */ + if (ttisfunction(tm)) { + luaT_callTM(L, tm, t, key, val); + return; + } + t = tm; /* else repeat assignment over 'tm' */ + if (luaV_fastget(L, t, key, slot, luaH_get)) { + luaV_finishfastset(L, t, slot, val); + return; /* done */ + } + /* else 'return luaV_finishset(L, t, key, val, slot)' (loop) */ + } + luaG_runerror(L, "'__newindex' chain too long; possible loop"); +} + + +/* +** Compare two strings 'ls' x 'rs', returning an integer less-equal- +** -greater than zero if 'ls' is less-equal-greater than 'rs'. +** The code is a little tricky because it allows '\0' in the strings +** and it uses 'strcoll' (to respect locales) for each segments +** of the strings. +*/ +static int l_strcmp (const TString *ls, const TString *rs) { + const char *l = getstr(ls); + size_t ll = tsslen(ls); + const char *r = getstr(rs); + size_t lr = tsslen(rs); + for (;;) { /* for each segment */ + int temp = strcoll(l, r); + if (temp != 0) /* not equal? */ + return temp; /* done */ + else { /* strings are equal up to a '\0' */ + size_t len = strlen(l); /* index of first '\0' in both strings */ + if (len == lr) /* 'rs' is finished? */ + return (len == ll) ? 0 : 1; /* check 'ls' */ + else if (len == ll) /* 'ls' is finished? */ + return -1; /* 'ls' is less than 'rs' ('rs' is not finished) */ + /* both strings longer than 'len'; go on comparing after the '\0' */ + len++; + l += len; ll -= len; r += len; lr -= len; + } + } +} + + +/* +** Check whether integer 'i' is less than float 'f'. If 'i' has an +** exact representation as a float ('l_intfitsf'), compare numbers as +** floats. Otherwise, use the equivalence 'i < f <=> i < ceil(f)'. +** If 'ceil(f)' is out of integer range, either 'f' is greater than +** all integers or less than all integers. +** (The test with 'l_intfitsf' is only for performance; the else +** case is correct for all values, but it is slow due to the conversion +** from float to int.) +** When 'f' is NaN, comparisons must result in false. +*/ +l_sinline int LTintfloat (lua_Integer i, lua_Number f) { + if (l_intfitsf(i)) + return luai_numlt(cast_num(i), f); /* compare them as floats */ + else { /* i < f <=> i < ceil(f) */ + lua_Integer fi; + if (luaV_flttointeger(f, &fi, F2Iceil)) /* fi = ceil(f) */ + return i < fi; /* compare them as integers */ + else /* 'f' is either greater or less than all integers */ + return f > 0; /* greater? */ + } +} + + +/* +** Check whether integer 'i' is less than or equal to float 'f'. +** See comments on previous function. +*/ +l_sinline int LEintfloat (lua_Integer i, lua_Number f) { + if (l_intfitsf(i)) + return luai_numle(cast_num(i), f); /* compare them as floats */ + else { /* i <= f <=> i <= floor(f) */ + lua_Integer fi; + if (luaV_flttointeger(f, &fi, F2Ifloor)) /* fi = floor(f) */ + return i <= fi; /* compare them as integers */ + else /* 'f' is either greater or less than all integers */ + return f > 0; /* greater? */ + } +} + + +/* +** Check whether float 'f' is less than integer 'i'. +** See comments on previous function. +*/ +l_sinline int LTfloatint (lua_Number f, lua_Integer i) { + if (l_intfitsf(i)) + return luai_numlt(f, cast_num(i)); /* compare them as floats */ + else { /* f < i <=> floor(f) < i */ + lua_Integer fi; + if (luaV_flttointeger(f, &fi, F2Ifloor)) /* fi = floor(f) */ + return fi < i; /* compare them as integers */ + else /* 'f' is either greater or less than all integers */ + return f < 0; /* less? */ + } +} + + +/* +** Check whether float 'f' is less than or equal to integer 'i'. +** See comments on previous function. +*/ +l_sinline int LEfloatint (lua_Number f, lua_Integer i) { + if (l_intfitsf(i)) + return luai_numle(f, cast_num(i)); /* compare them as floats */ + else { /* f <= i <=> ceil(f) <= i */ + lua_Integer fi; + if (luaV_flttointeger(f, &fi, F2Iceil)) /* fi = ceil(f) */ + return fi <= i; /* compare them as integers */ + else /* 'f' is either greater or less than all integers */ + return f < 0; /* less? */ + } +} + + +/* +** Return 'l < r', for numbers. +*/ +l_sinline int LTnum (const TValue *l, const TValue *r) { + lua_assert(ttisnumber(l) && ttisnumber(r)); + if (ttisinteger(l)) { + lua_Integer li = ivalue(l); + if (ttisinteger(r)) + return li < ivalue(r); /* both are integers */ + else /* 'l' is int and 'r' is float */ + return LTintfloat(li, fltvalue(r)); /* l < r ? */ + } + else { + lua_Number lf = fltvalue(l); /* 'l' must be float */ + if (ttisfloat(r)) + return luai_numlt(lf, fltvalue(r)); /* both are float */ + else /* 'l' is float and 'r' is int */ + return LTfloatint(lf, ivalue(r)); + } +} + + +/* +** Return 'l <= r', for numbers. +*/ +l_sinline int LEnum (const TValue *l, const TValue *r) { + lua_assert(ttisnumber(l) && ttisnumber(r)); + if (ttisinteger(l)) { + lua_Integer li = ivalue(l); + if (ttisinteger(r)) + return li <= ivalue(r); /* both are integers */ + else /* 'l' is int and 'r' is float */ + return LEintfloat(li, fltvalue(r)); /* l <= r ? */ + } + else { + lua_Number lf = fltvalue(l); /* 'l' must be float */ + if (ttisfloat(r)) + return luai_numle(lf, fltvalue(r)); /* both are float */ + else /* 'l' is float and 'r' is int */ + return LEfloatint(lf, ivalue(r)); + } +} + + +/* +** return 'l < r' for non-numbers. +*/ +static int lessthanothers (lua_State *L, const TValue *l, const TValue *r) { + lua_assert(!ttisnumber(l) || !ttisnumber(r)); + if (ttisstring(l) && ttisstring(r)) /* both are strings? */ + return l_strcmp(tsvalue(l), tsvalue(r)) < 0; + else + return luaT_callorderTM(L, l, r, TM_LT); +} + + +/* +** Main operation less than; return 'l < r'. +*/ +int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { + if (ttisnumber(l) && ttisnumber(r)) /* both operands are numbers? */ + return LTnum(l, r); + else return lessthanothers(L, l, r); +} + + +/* +** return 'l <= r' for non-numbers. +*/ +static int lessequalothers (lua_State *L, const TValue *l, const TValue *r) { + lua_assert(!ttisnumber(l) || !ttisnumber(r)); + if (ttisstring(l) && ttisstring(r)) /* both are strings? */ + return l_strcmp(tsvalue(l), tsvalue(r)) <= 0; + else + return luaT_callorderTM(L, l, r, TM_LE); +} + + +/* +** Main operation less than or equal to; return 'l <= r'. +*/ +int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) { + if (ttisnumber(l) && ttisnumber(r)) /* both operands are numbers? */ + return LEnum(l, r); + else return lessequalothers(L, l, r); +} + + +/* +** Main operation for equality of Lua values; return 't1 == t2'. +** L == NULL means raw equality (no metamethods) +*/ +int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) { + const TValue *tm; + if (ttypetag(t1) != ttypetag(t2)) { /* not the same variant? */ + if (ttype(t1) != ttype(t2) || ttype(t1) != LUA_TNUMBER) + return 0; /* only numbers can be equal with different variants */ + else { /* two numbers with different variants */ + /* One of them is an integer. If the other does not have an + integer value, they cannot be equal; otherwise, compare their + integer values. */ + lua_Integer i1, i2; + return (luaV_tointegerns(t1, &i1, F2Ieq) && + luaV_tointegerns(t2, &i2, F2Ieq) && + i1 == i2); + } + } + /* values have same type and same variant */ + switch (ttypetag(t1)) { + case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE: return 1; + case LUA_VNUMINT: return (ivalue(t1) == ivalue(t2)); + case LUA_VNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2)); + case LUA_VLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); + case LUA_VLCF: return fvalue(t1) == fvalue(t2); + case LUA_VSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2)); + case LUA_VLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2)); + case LUA_VUSERDATA: { + if (uvalue(t1) == uvalue(t2)) return 1; + else if (L == NULL) return 0; + tm = fasttm(L, uvalue(t1)->metatable, TM_EQ); + if (tm == NULL) + tm = fasttm(L, uvalue(t2)->metatable, TM_EQ); + break; /* will try TM */ + } + case LUA_VTABLE: { + if (hvalue(t1) == hvalue(t2)) return 1; + else if (L == NULL) return 0; + tm = fasttm(L, hvalue(t1)->metatable, TM_EQ); + if (tm == NULL) + tm = fasttm(L, hvalue(t2)->metatable, TM_EQ); + break; /* will try TM */ + } + default: + return gcvalue(t1) == gcvalue(t2); + } + if (tm == NULL) /* no TM? */ + return 0; /* objects are different */ + else { + luaT_callTMres(L, tm, t1, t2, L->top.p); /* call TM */ + return !l_isfalse(s2v(L->top.p)); + } +} + + +/* macro used by 'luaV_concat' to ensure that element at 'o' is a string */ +#define tostring(L,o) \ + (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1))) + +#define isemptystr(o) (ttisshrstring(o) && tsvalue(o)->shrlen == 0) + +/* copy strings in stack from top - n up to top - 1 to buffer */ +static void copy2buff (StkId top, int n, char *buff) { + size_t tl = 0; /* size already copied */ + do { + size_t l = vslen(s2v(top - n)); /* length of string being copied */ + memcpy(buff + tl, svalue(s2v(top - n)), l * sizeof(char)); + tl += l; + } while (--n > 0); +} + + +/* +** Main operation for concatenation: concat 'total' values in the stack, +** from 'L->top.p - total' up to 'L->top.p - 1'. +*/ +void luaV_concat (lua_State *L, int total) { + if (total == 1) + return; /* "all" values already concatenated */ + do { + StkId top = L->top.p; + int n = 2; /* number of elements handled in this pass (at least 2) */ + if (!(ttisstring(s2v(top - 2)) || cvt2str(s2v(top - 2))) || + !tostring(L, s2v(top - 1))) + luaT_tryconcatTM(L); /* may invalidate 'top' */ + else if (isemptystr(s2v(top - 1))) /* second operand is empty? */ + cast_void(tostring(L, s2v(top - 2))); /* result is first operand */ + else if (isemptystr(s2v(top - 2))) { /* first operand is empty string? */ + setobjs2s(L, top - 2, top - 1); /* result is second op. */ + } + else { + /* at least two non-empty string values; get as many as possible */ + size_t tl = vslen(s2v(top - 1)); + TString *ts; + /* collect total length and number of strings */ + for (n = 1; n < total && tostring(L, s2v(top - n - 1)); n++) { + size_t l = vslen(s2v(top - n - 1)); + if (l_unlikely(l >= (MAX_SIZE/sizeof(char)) - tl)) { + L->top.p = top - total; /* pop strings to avoid wasting stack */ + luaG_runerror(L, "string length overflow"); + } + tl += l; + } + if (tl <= LUAI_MAXSHORTLEN) { /* is result a short string? */ + char buff[LUAI_MAXSHORTLEN]; + copy2buff(top, n, buff); /* copy strings to buffer */ + ts = luaS_newlstr(L, buff, tl); + } + else { /* long string; copy strings directly to final result */ + ts = luaS_createlngstrobj(L, tl); + copy2buff(top, n, getstr(ts)); + } + setsvalue2s(L, top - n, ts); /* create result */ + } + total -= n - 1; /* got 'n' strings to create one new */ + L->top.p -= n - 1; /* popped 'n' strings and pushed one */ + } while (total > 1); /* repeat until only 1 result left */ +} + + +/* +** Main operation 'ra = #rb'. +*/ +void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { + const TValue *tm; + switch (ttypetag(rb)) { + case LUA_VTABLE: { + Table *h = hvalue(rb); + tm = fasttm(L, h->metatable, TM_LEN); + if (tm) break; /* metamethod? break switch to call it */ + setivalue(s2v(ra), luaH_getn(h)); /* else primitive len */ + return; + } + case LUA_VSHRSTR: { + setivalue(s2v(ra), tsvalue(rb)->shrlen); + return; + } + case LUA_VLNGSTR: { + setivalue(s2v(ra), tsvalue(rb)->u.lnglen); + return; + } + default: { /* try metamethod */ + tm = luaT_gettmbyobj(L, rb, TM_LEN); + if (l_unlikely(notm(tm))) /* no metamethod? */ + luaG_typeerror(L, rb, "get length of"); + break; + } + } + luaT_callTMres(L, tm, rb, rb, ra); +} + + +/* +** Integer division; return 'm // n', that is, floor(m/n). +** C division truncates its result (rounds towards zero). +** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer, +** otherwise 'floor(q) == trunc(q) - 1'. +*/ +lua_Integer luaV_idiv (lua_State *L, lua_Integer m, lua_Integer n) { + if (l_unlikely(l_castS2U(n) + 1u <= 1u)) { /* special cases: -1 or 0 */ + if (n == 0) + luaG_runerror(L, "attempt to divide by zero"); + return intop(-, 0, m); /* n==-1; avoid overflow with 0x80000...//-1 */ + } + else { + lua_Integer q = m / n; /* perform C division */ + if ((m ^ n) < 0 && m % n != 0) /* 'm/n' would be negative non-integer? */ + q -= 1; /* correct result for different rounding */ + return q; + } +} + + +/* +** Integer modulus; return 'm % n'. (Assume that C '%' with +** negative operands follows C99 behavior. See previous comment +** about luaV_idiv.) +*/ +lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) { + if (l_unlikely(l_castS2U(n) + 1u <= 1u)) { /* special cases: -1 or 0 */ + if (n == 0) + luaG_runerror(L, "attempt to perform 'n%%0'"); + return 0; /* m % -1 == 0; avoid overflow with 0x80000...%-1 */ + } + else { + lua_Integer r = m % n; + if (r != 0 && (r ^ n) < 0) /* 'm/n' would be non-integer negative? */ + r += n; /* correct result for different rounding */ + return r; + } +} + + +/* +** Float modulus +*/ +lua_Number luaV_modf (lua_State *L, lua_Number m, lua_Number n) { + lua_Number r; + luai_nummod(L, m, n, r); + return r; +} + + +/* number of bits in an integer */ +#define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT) + + +/* +** Shift left operation. (Shift right just negates 'y'.) +*/ +lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) { + if (y < 0) { /* shift right? */ + if (y <= -NBITS) return 0; + else return intop(>>, x, -y); + } + else { /* shift left */ + if (y >= NBITS) return 0; + else return intop(<<, x, y); + } +} + + +/* +** create a new Lua closure, push it in the stack, and initialize +** its upvalues. +*/ +static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base, + StkId ra) { + int nup = p->sizeupvalues; + Upvaldesc *uv = p->upvalues; + int i; + LClosure *ncl = luaF_newLclosure(L, nup); + ncl->p = p; + setclLvalue2s(L, ra, ncl); /* anchor new closure in stack */ + for (i = 0; i < nup; i++) { /* fill in its upvalues */ + if (uv[i].instack) /* upvalue refers to local variable? */ + ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx); + else /* get upvalue from enclosing function */ + ncl->upvals[i] = encup[uv[i].idx]; + luaC_objbarrier(L, ncl, ncl->upvals[i]); + } +} + + +/* +** finish execution of an opcode interrupted by a yield +*/ +void luaV_finishOp (lua_State *L) { + CallInfo *ci = L->ci; + StkId base = ci->func.p + 1; + Instruction inst = *(ci->u.l.savedpc - 1); /* interrupted instruction */ + OpCode op = GET_OPCODE(inst); + switch (op) { /* finish its execution */ + case OP_MMBIN: case OP_MMBINI: case OP_MMBINK: { + setobjs2s(L, base + GETARG_A(*(ci->u.l.savedpc - 2)), --L->top.p); + break; + } + case OP_UNM: case OP_BNOT: case OP_LEN: + case OP_GETTABUP: case OP_GETTABLE: case OP_GETI: + case OP_GETFIELD: case OP_SELF: { + setobjs2s(L, base + GETARG_A(inst), --L->top.p); + break; + } + case OP_LT: case OP_LE: + case OP_LTI: case OP_LEI: + case OP_GTI: case OP_GEI: + case OP_EQ: { /* note that 'OP_EQI'/'OP_EQK' cannot yield */ + int res = !l_isfalse(s2v(L->top.p - 1)); + L->top.p--; +#if defined(LUA_COMPAT_LT_LE) + if (ci->callstatus & CIST_LEQ) { /* "<=" using "<" instead? */ + ci->callstatus ^= CIST_LEQ; /* clear mark */ + res = !res; /* negate result */ + } +#endif + lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP); + if (res != GETARG_k(inst)) /* condition failed? */ + ci->u.l.savedpc++; /* skip jump instruction */ + break; + } + case OP_CONCAT: { + StkId top = L->top.p - 1; /* top when 'luaT_tryconcatTM' was called */ + int a = GETARG_A(inst); /* first element to concatenate */ + int total = cast_int(top - 1 - (base + a)); /* yet to concatenate */ + setobjs2s(L, top - 2, top); /* put TM result in proper position */ + L->top.p = top - 1; /* top is one after last element (at top-2) */ + luaV_concat(L, total); /* concat them (may yield again) */ + break; + } + case OP_CLOSE: { /* yielded closing variables */ + ci->u.l.savedpc--; /* repeat instruction to close other vars. */ + break; + } + case OP_RETURN: { /* yielded closing variables */ + StkId ra = base + GETARG_A(inst); + /* adjust top to signal correct number of returns, in case the + return is "up to top" ('isIT') */ + L->top.p = ra + ci->u2.nres; + /* repeat instruction to close other vars. and complete the return */ + ci->u.l.savedpc--; + break; + } + default: { + /* only these other opcodes can yield */ + lua_assert(op == OP_TFORCALL || op == OP_CALL || + op == OP_TAILCALL || op == OP_SETTABUP || op == OP_SETTABLE || + op == OP_SETI || op == OP_SETFIELD); + break; + } + } +} + + + + +/* +** {================================================================== +** Macros for arithmetic/bitwise/comparison opcodes in 'luaV_execute' +** =================================================================== +*/ + +#define l_addi(L,a,b) intop(+, a, b) +#define l_subi(L,a,b) intop(-, a, b) +#define l_muli(L,a,b) intop(*, a, b) +#define l_band(a,b) intop(&, a, b) +#define l_bor(a,b) intop(|, a, b) +#define l_bxor(a,b) intop(^, a, b) + +#define l_lti(a,b) (a < b) +#define l_lei(a,b) (a <= b) +#define l_gti(a,b) (a > b) +#define l_gei(a,b) (a >= b) + + +/* +** Arithmetic operations with immediate operands. 'iop' is the integer +** operation, 'fop' is the float operation. +*/ +#define op_arithI(L,iop,fop) { \ + StkId ra = RA(i); \ + TValue *v1 = vRB(i); \ + int imm = GETARG_sC(i); \ + if (ttisinteger(v1)) { \ + lua_Integer iv1 = ivalue(v1); \ + pc++; setivalue(s2v(ra), iop(L, iv1, imm)); \ + } \ + else if (ttisfloat(v1)) { \ + lua_Number nb = fltvalue(v1); \ + lua_Number fimm = cast_num(imm); \ + pc++; setfltvalue(s2v(ra), fop(L, nb, fimm)); \ + }} + + +/* +** Auxiliary function for arithmetic operations over floats and others +** with two register operands. +*/ +#define op_arithf_aux(L,v1,v2,fop) { \ + lua_Number n1; lua_Number n2; \ + if (tonumberns(v1, n1) && tonumberns(v2, n2)) { \ + pc++; setfltvalue(s2v(ra), fop(L, n1, n2)); \ + }} + + +/* +** Arithmetic operations over floats and others with register operands. +*/ +#define op_arithf(L,fop) { \ + StkId ra = RA(i); \ + TValue *v1 = vRB(i); \ + TValue *v2 = vRC(i); \ + op_arithf_aux(L, v1, v2, fop); } + + +/* +** Arithmetic operations with K operands for floats. +*/ +#define op_arithfK(L,fop) { \ + StkId ra = RA(i); \ + TValue *v1 = vRB(i); \ + TValue *v2 = KC(i); lua_assert(ttisnumber(v2)); \ + op_arithf_aux(L, v1, v2, fop); } + + +/* +** Arithmetic operations over integers and floats. +*/ +#define op_arith_aux(L,v1,v2,iop,fop) { \ + StkId ra = RA(i); \ + if (ttisinteger(v1) && ttisinteger(v2)) { \ + lua_Integer i1 = ivalue(v1); lua_Integer i2 = ivalue(v2); \ + pc++; setivalue(s2v(ra), iop(L, i1, i2)); \ + } \ + else op_arithf_aux(L, v1, v2, fop); } + + +/* +** Arithmetic operations with register operands. +*/ +#define op_arith(L,iop,fop) { \ + TValue *v1 = vRB(i); \ + TValue *v2 = vRC(i); \ + op_arith_aux(L, v1, v2, iop, fop); } + + +/* +** Arithmetic operations with K operands. +*/ +#define op_arithK(L,iop,fop) { \ + TValue *v1 = vRB(i); \ + TValue *v2 = KC(i); lua_assert(ttisnumber(v2)); \ + op_arith_aux(L, v1, v2, iop, fop); } + + +/* +** Bitwise operations with constant operand. +*/ +#define op_bitwiseK(L,op) { \ + StkId ra = RA(i); \ + TValue *v1 = vRB(i); \ + TValue *v2 = KC(i); \ + lua_Integer i1; \ + lua_Integer i2 = ivalue(v2); \ + if (tointegerns(v1, &i1)) { \ + pc++; setivalue(s2v(ra), op(i1, i2)); \ + }} + + +/* +** Bitwise operations with register operands. +*/ +#define op_bitwise(L,op) { \ + StkId ra = RA(i); \ + TValue *v1 = vRB(i); \ + TValue *v2 = vRC(i); \ + lua_Integer i1; lua_Integer i2; \ + if (tointegerns(v1, &i1) && tointegerns(v2, &i2)) { \ + pc++; setivalue(s2v(ra), op(i1, i2)); \ + }} + + +/* +** Order operations with register operands. 'opn' actually works +** for all numbers, but the fast track improves performance for +** integers. +*/ +#define op_order(L,opi,opn,other) { \ + StkId ra = RA(i); \ + int cond; \ + TValue *rb = vRB(i); \ + if (ttisinteger(s2v(ra)) && ttisinteger(rb)) { \ + lua_Integer ia = ivalue(s2v(ra)); \ + lua_Integer ib = ivalue(rb); \ + cond = opi(ia, ib); \ + } \ + else if (ttisnumber(s2v(ra)) && ttisnumber(rb)) \ + cond = opn(s2v(ra), rb); \ + else \ + Protect(cond = other(L, s2v(ra), rb)); \ + docondjump(); } + + +/* +** Order operations with immediate operand. (Immediate operand is +** always small enough to have an exact representation as a float.) +*/ +#define op_orderI(L,opi,opf,inv,tm) { \ + StkId ra = RA(i); \ + int cond; \ + int im = GETARG_sB(i); \ + if (ttisinteger(s2v(ra))) \ + cond = opi(ivalue(s2v(ra)), im); \ + else if (ttisfloat(s2v(ra))) { \ + lua_Number fa = fltvalue(s2v(ra)); \ + lua_Number fim = cast_num(im); \ + cond = opf(fa, fim); \ + } \ + else { \ + int isf = GETARG_C(i); \ + Protect(cond = luaT_callorderiTM(L, s2v(ra), im, inv, isf, tm)); \ + } \ + docondjump(); } + +/* }================================================================== */ + + +/* +** {================================================================== +** Function 'luaV_execute': main interpreter loop +** =================================================================== +*/ + +/* +** some macros for common tasks in 'luaV_execute' +*/ + + +#define RA(i) (base+GETARG_A(i)) +#define RB(i) (base+GETARG_B(i)) +#define vRB(i) s2v(RB(i)) +#define KB(i) (k+GETARG_B(i)) +#define RC(i) (base+GETARG_C(i)) +#define vRC(i) s2v(RC(i)) +#define KC(i) (k+GETARG_C(i)) +#define RKC(i) ((TESTARG_k(i)) ? k + GETARG_C(i) : s2v(base + GETARG_C(i))) + + + +#define updatetrap(ci) (trap = ci->u.l.trap) + +#define updatebase(ci) (base = ci->func.p + 1) + + +#define updatestack(ci) \ + { if (l_unlikely(trap)) { updatebase(ci); ra = RA(i); } } + + +/* +** Execute a jump instruction. The 'updatetrap' allows signals to stop +** tight loops. (Without it, the local copy of 'trap' could never change.) +*/ +#define dojump(ci,i,e) { pc += GETARG_sJ(i) + e; updatetrap(ci); } + + +/* for test instructions, execute the jump instruction that follows it */ +#define donextjump(ci) { Instruction ni = *pc; dojump(ci, ni, 1); } + +/* +** do a conditional jump: skip next instruction if 'cond' is not what +** was expected (parameter 'k'), else do next instruction, which must +** be a jump. +*/ +#define docondjump() if (cond != GETARG_k(i)) pc++; else donextjump(ci); + + +/* +** Correct global 'pc'. +*/ +#define savepc(L) (ci->u.l.savedpc = pc) + + +/* +** Whenever code can raise errors, the global 'pc' and the global +** 'top' must be correct to report occasional errors. +*/ +#define savestate(L,ci) (savepc(L), L->top.p = ci->top.p) + + +/* +** Protect code that, in general, can raise errors, reallocate the +** stack, and change the hooks. +*/ +#define Protect(exp) (savestate(L,ci), (exp), updatetrap(ci)) + +/* special version that does not change the top */ +#define ProtectNT(exp) (savepc(L), (exp), updatetrap(ci)) + +/* +** Protect code that can only raise errors. (That is, it cannot change +** the stack or hooks.) +*/ +#define halfProtect(exp) (savestate(L,ci), (exp)) + +/* 'c' is the limit of live values in the stack */ +#define checkGC(L,c) \ + { luaC_condGC(L, (savepc(L), L->top.p = (c)), \ + updatetrap(ci)); \ + luai_threadyield(L); } + + +/* fetch an instruction and prepare its execution */ +#define vmfetch() { \ + if (l_unlikely(trap)) { /* stack reallocation or hooks? */ \ + trap = luaG_traceexec(L, pc); /* handle hooks */ \ + updatebase(ci); /* correct stack */ \ + } \ + i = *(pc++); \ +} + +#define vmdispatch(o) switch(o) +#define vmcase(l) case l: +#define vmbreak break + + +void luaV_execute (lua_State *L, CallInfo *ci) { + LClosure *cl; + TValue *k; + StkId base; + const Instruction *pc; + int trap; +#if LUA_USE_JUMPTABLE +#include "ljumptab.h" +#endif + startfunc: + trap = L->hookmask; + returning: /* trap already set */ + cl = clLvalue(s2v(ci->func.p)); + k = cl->p->k; + pc = ci->u.l.savedpc; + if (l_unlikely(trap)) { + if (pc == cl->p->code) { /* first instruction (not resuming)? */ + if (cl->p->is_vararg) + trap = 0; /* hooks will start after VARARGPREP instruction */ + else /* check 'call' hook */ + luaD_hookcall(L, ci); + } + ci->u.l.trap = 1; /* assume trap is on, for now */ + } + base = ci->func.p + 1; + /* main loop of interpreter */ + for (;;) { + Instruction i; /* instruction being executed */ + vmfetch(); + #if 0 + /* low-level line tracing for debugging Lua */ + printf("line: %d\n", luaG_getfuncline(cl->p, pcRel(pc, cl->p))); + #endif + lua_assert(base == ci->func.p + 1); + lua_assert(base <= L->top.p && L->top.p <= L->stack_last.p); + /* invalidate top for instructions not expecting it */ + lua_assert(isIT(i) || (cast_void(L->top.p = base), 1)); + vmdispatch (GET_OPCODE(i)) { + vmcase(OP_MOVE) { + StkId ra = RA(i); + setobjs2s(L, ra, RB(i)); + vmbreak; + } + vmcase(OP_LOADI) { + StkId ra = RA(i); + lua_Integer b = GETARG_sBx(i); + setivalue(s2v(ra), b); + vmbreak; + } + vmcase(OP_LOADF) { + StkId ra = RA(i); + int b = GETARG_sBx(i); + setfltvalue(s2v(ra), cast_num(b)); + vmbreak; + } + vmcase(OP_LOADK) { + StkId ra = RA(i); + TValue *rb = k + GETARG_Bx(i); + setobj2s(L, ra, rb); + vmbreak; + } + vmcase(OP_LOADKX) { + StkId ra = RA(i); + TValue *rb; + rb = k + GETARG_Ax(*pc); pc++; + setobj2s(L, ra, rb); + vmbreak; + } + vmcase(OP_LOADFALSE) { + StkId ra = RA(i); + setbfvalue(s2v(ra)); + vmbreak; + } + vmcase(OP_LFALSESKIP) { + StkId ra = RA(i); + setbfvalue(s2v(ra)); + pc++; /* skip next instruction */ + vmbreak; + } + vmcase(OP_LOADTRUE) { + StkId ra = RA(i); + setbtvalue(s2v(ra)); + vmbreak; + } + vmcase(OP_LOADNIL) { + StkId ra = RA(i); + int b = GETARG_B(i); + do { + setnilvalue(s2v(ra++)); + } while (b--); + vmbreak; + } + vmcase(OP_GETUPVAL) { + StkId ra = RA(i); + int b = GETARG_B(i); + setobj2s(L, ra, cl->upvals[b]->v.p); + vmbreak; + } + vmcase(OP_SETUPVAL) { + StkId ra = RA(i); + UpVal *uv = cl->upvals[GETARG_B(i)]; + setobj(L, uv->v.p, s2v(ra)); + luaC_barrier(L, uv, s2v(ra)); + vmbreak; + } + vmcase(OP_GETTABUP) { + StkId ra = RA(i); + const TValue *slot; + TValue *upval = cl->upvals[GETARG_B(i)]->v.p; + TValue *rc = KC(i); + TString *key = tsvalue(rc); /* key must be a string */ + if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) { + setobj2s(L, ra, slot); + } + else + Protect(luaV_finishget(L, upval, rc, ra, slot)); + vmbreak; + } + vmcase(OP_GETTABLE) { + StkId ra = RA(i); + const TValue *slot; + TValue *rb = vRB(i); + TValue *rc = vRC(i); + lua_Unsigned n; + if (ttisinteger(rc) /* fast track for integers? */ + ? (cast_void(n = ivalue(rc)), luaV_fastgeti(L, rb, n, slot)) + : luaV_fastget(L, rb, rc, slot, luaH_get)) { + setobj2s(L, ra, slot); + } + else + Protect(luaV_finishget(L, rb, rc, ra, slot)); + vmbreak; + } + vmcase(OP_GETI) { + StkId ra = RA(i); + const TValue *slot; + TValue *rb = vRB(i); + int c = GETARG_C(i); + if (luaV_fastgeti(L, rb, c, slot)) { + setobj2s(L, ra, slot); + } + else { + TValue key; + setivalue(&key, c); + Protect(luaV_finishget(L, rb, &key, ra, slot)); + } + vmbreak; + } + vmcase(OP_GETFIELD) { + StkId ra = RA(i); + const TValue *slot; + TValue *rb = vRB(i); + TValue *rc = KC(i); + TString *key = tsvalue(rc); /* key must be a string */ + if (luaV_fastget(L, rb, key, slot, luaH_getshortstr)) { + setobj2s(L, ra, slot); + } + else + Protect(luaV_finishget(L, rb, rc, ra, slot)); + vmbreak; + } + vmcase(OP_SETTABUP) { + const TValue *slot; + TValue *upval = cl->upvals[GETARG_A(i)]->v.p; + TValue *rb = KB(i); + TValue *rc = RKC(i); + TString *key = tsvalue(rb); /* key must be a string */ + if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) { + luaV_finishfastset(L, upval, slot, rc); + } + else + Protect(luaV_finishset(L, upval, rb, rc, slot)); + vmbreak; + } + vmcase(OP_SETTABLE) { + StkId ra = RA(i); + const TValue *slot; + TValue *rb = vRB(i); /* key (table is in 'ra') */ + TValue *rc = RKC(i); /* value */ + lua_Unsigned n; + if (ttisinteger(rb) /* fast track for integers? */ + ? (cast_void(n = ivalue(rb)), luaV_fastgeti(L, s2v(ra), n, slot)) + : luaV_fastget(L, s2v(ra), rb, slot, luaH_get)) { + luaV_finishfastset(L, s2v(ra), slot, rc); + } + else + Protect(luaV_finishset(L, s2v(ra), rb, rc, slot)); + vmbreak; + } + vmcase(OP_SETI) { + StkId ra = RA(i); + const TValue *slot; + int c = GETARG_B(i); + TValue *rc = RKC(i); + if (luaV_fastgeti(L, s2v(ra), c, slot)) { + luaV_finishfastset(L, s2v(ra), slot, rc); + } + else { + TValue key; + setivalue(&key, c); + Protect(luaV_finishset(L, s2v(ra), &key, rc, slot)); + } + vmbreak; + } + vmcase(OP_SETFIELD) { + StkId ra = RA(i); + const TValue *slot; + TValue *rb = KB(i); + TValue *rc = RKC(i); + TString *key = tsvalue(rb); /* key must be a string */ + if (luaV_fastget(L, s2v(ra), key, slot, luaH_getshortstr)) { + luaV_finishfastset(L, s2v(ra), slot, rc); + } + else + Protect(luaV_finishset(L, s2v(ra), rb, rc, slot)); + vmbreak; + } + vmcase(OP_NEWTABLE) { + StkId ra = RA(i); + int b = GETARG_B(i); /* log2(hash size) + 1 */ + int c = GETARG_C(i); /* array size */ + Table *t; + if (b > 0) + b = 1 << (b - 1); /* size is 2^(b - 1) */ + lua_assert((!TESTARG_k(i)) == (GETARG_Ax(*pc) == 0)); + if (TESTARG_k(i)) /* non-zero extra argument? */ + c += GETARG_Ax(*pc) * (MAXARG_C + 1); /* add it to size */ + pc++; /* skip extra argument */ + L->top.p = ra + 1; /* correct top in case of emergency GC */ + t = luaH_new(L); /* memory allocation */ + sethvalue2s(L, ra, t); + if (b != 0 || c != 0) + luaH_resize(L, t, c, b); /* idem */ + checkGC(L, ra + 1); + vmbreak; + } + vmcase(OP_SELF) { + StkId ra = RA(i); + const TValue *slot; + TValue *rb = vRB(i); + TValue *rc = RKC(i); + TString *key = tsvalue(rc); /* key must be a string */ + setobj2s(L, ra + 1, rb); + if (luaV_fastget(L, rb, key, slot, luaH_getstr)) { + setobj2s(L, ra, slot); + } + else + Protect(luaV_finishget(L, rb, rc, ra, slot)); + vmbreak; + } + vmcase(OP_ADDI) { + op_arithI(L, l_addi, luai_numadd); + vmbreak; + } + vmcase(OP_ADDK) { + op_arithK(L, l_addi, luai_numadd); + vmbreak; + } + vmcase(OP_SUBK) { + op_arithK(L, l_subi, luai_numsub); + vmbreak; + } + vmcase(OP_MULK) { + op_arithK(L, l_muli, luai_nummul); + vmbreak; + } + vmcase(OP_MODK) { + savestate(L, ci); /* in case of division by 0 */ + op_arithK(L, luaV_mod, luaV_modf); + vmbreak; + } + vmcase(OP_POWK) { + op_arithfK(L, luai_numpow); + vmbreak; + } + vmcase(OP_DIVK) { + op_arithfK(L, luai_numdiv); + vmbreak; + } + vmcase(OP_IDIVK) { + savestate(L, ci); /* in case of division by 0 */ + op_arithK(L, luaV_idiv, luai_numidiv); + vmbreak; + } + vmcase(OP_BANDK) { + op_bitwiseK(L, l_band); + vmbreak; + } + vmcase(OP_BORK) { + op_bitwiseK(L, l_bor); + vmbreak; + } + vmcase(OP_BXORK) { + op_bitwiseK(L, l_bxor); + vmbreak; + } + vmcase(OP_SHRI) { + StkId ra = RA(i); + TValue *rb = vRB(i); + int ic = GETARG_sC(i); + lua_Integer ib; + if (tointegerns(rb, &ib)) { + pc++; setivalue(s2v(ra), luaV_shiftl(ib, -ic)); + } + vmbreak; + } + vmcase(OP_SHLI) { + StkId ra = RA(i); + TValue *rb = vRB(i); + int ic = GETARG_sC(i); + lua_Integer ib; + if (tointegerns(rb, &ib)) { + pc++; setivalue(s2v(ra), luaV_shiftl(ic, ib)); + } + vmbreak; + } + vmcase(OP_ADD) { + op_arith(L, l_addi, luai_numadd); + vmbreak; + } + vmcase(OP_SUB) { + op_arith(L, l_subi, luai_numsub); + vmbreak; + } + vmcase(OP_MUL) { + op_arith(L, l_muli, luai_nummul); + vmbreak; + } + vmcase(OP_MOD) { + savestate(L, ci); /* in case of division by 0 */ + op_arith(L, luaV_mod, luaV_modf); + vmbreak; + } + vmcase(OP_POW) { + op_arithf(L, luai_numpow); + vmbreak; + } + vmcase(OP_DIV) { /* float division (always with floats) */ + op_arithf(L, luai_numdiv); + vmbreak; + } + vmcase(OP_IDIV) { /* floor division */ + savestate(L, ci); /* in case of division by 0 */ + op_arith(L, luaV_idiv, luai_numidiv); + vmbreak; + } + vmcase(OP_BAND) { + op_bitwise(L, l_band); + vmbreak; + } + vmcase(OP_BOR) { + op_bitwise(L, l_bor); + vmbreak; + } + vmcase(OP_BXOR) { + op_bitwise(L, l_bxor); + vmbreak; + } + vmcase(OP_SHR) { + op_bitwise(L, luaV_shiftr); + vmbreak; + } + vmcase(OP_SHL) { + op_bitwise(L, luaV_shiftl); + vmbreak; + } + vmcase(OP_MMBIN) { + StkId ra = RA(i); + Instruction pi = *(pc - 2); /* original arith. expression */ + TValue *rb = vRB(i); + TMS tm = (TMS)GETARG_C(i); + StkId result = RA(pi); + lua_assert(OP_ADD <= GET_OPCODE(pi) && GET_OPCODE(pi) <= OP_SHR); + Protect(luaT_trybinTM(L, s2v(ra), rb, result, tm)); + vmbreak; + } + vmcase(OP_MMBINI) { + StkId ra = RA(i); + Instruction pi = *(pc - 2); /* original arith. expression */ + int imm = GETARG_sB(i); + TMS tm = (TMS)GETARG_C(i); + int flip = GETARG_k(i); + StkId result = RA(pi); + Protect(luaT_trybiniTM(L, s2v(ra), imm, flip, result, tm)); + vmbreak; + } + vmcase(OP_MMBINK) { + StkId ra = RA(i); + Instruction pi = *(pc - 2); /* original arith. expression */ + TValue *imm = KB(i); + TMS tm = (TMS)GETARG_C(i); + int flip = GETARG_k(i); + StkId result = RA(pi); + Protect(luaT_trybinassocTM(L, s2v(ra), imm, flip, result, tm)); + vmbreak; + } + vmcase(OP_UNM) { + StkId ra = RA(i); + TValue *rb = vRB(i); + lua_Number nb; + if (ttisinteger(rb)) { + lua_Integer ib = ivalue(rb); + setivalue(s2v(ra), intop(-, 0, ib)); + } + else if (tonumberns(rb, nb)) { + setfltvalue(s2v(ra), luai_numunm(L, nb)); + } + else + Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM)); + vmbreak; + } + vmcase(OP_BNOT) { + StkId ra = RA(i); + TValue *rb = vRB(i); + lua_Integer ib; + if (tointegerns(rb, &ib)) { + setivalue(s2v(ra), intop(^, ~l_castS2U(0), ib)); + } + else + Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT)); + vmbreak; + } + vmcase(OP_NOT) { + StkId ra = RA(i); + TValue *rb = vRB(i); + if (l_isfalse(rb)) + setbtvalue(s2v(ra)); + else + setbfvalue(s2v(ra)); + vmbreak; + } + vmcase(OP_LEN) { + StkId ra = RA(i); + Protect(luaV_objlen(L, ra, vRB(i))); + vmbreak; + } + vmcase(OP_CONCAT) { + StkId ra = RA(i); + int n = GETARG_B(i); /* number of elements to concatenate */ + L->top.p = ra + n; /* mark the end of concat operands */ + ProtectNT(luaV_concat(L, n)); + checkGC(L, L->top.p); /* 'luaV_concat' ensures correct top */ + vmbreak; + } + vmcase(OP_CLOSE) { + StkId ra = RA(i); + Protect(luaF_close(L, ra, LUA_OK, 1)); + vmbreak; + } + vmcase(OP_TBC) { + StkId ra = RA(i); + /* create new to-be-closed upvalue */ + halfProtect(luaF_newtbcupval(L, ra)); + vmbreak; + } + vmcase(OP_JMP) { + dojump(ci, i, 0); + vmbreak; + } + vmcase(OP_EQ) { + StkId ra = RA(i); + int cond; + TValue *rb = vRB(i); + Protect(cond = luaV_equalobj(L, s2v(ra), rb)); + docondjump(); + vmbreak; + } + vmcase(OP_LT) { + op_order(L, l_lti, LTnum, lessthanothers); + vmbreak; + } + vmcase(OP_LE) { + op_order(L, l_lei, LEnum, lessequalothers); + vmbreak; + } + vmcase(OP_EQK) { + StkId ra = RA(i); + TValue *rb = KB(i); + /* basic types do not use '__eq'; we can use raw equality */ + int cond = luaV_rawequalobj(s2v(ra), rb); + docondjump(); + vmbreak; + } + vmcase(OP_EQI) { + StkId ra = RA(i); + int cond; + int im = GETARG_sB(i); + if (ttisinteger(s2v(ra))) + cond = (ivalue(s2v(ra)) == im); + else if (ttisfloat(s2v(ra))) + cond = luai_numeq(fltvalue(s2v(ra)), cast_num(im)); + else + cond = 0; /* other types cannot be equal to a number */ + docondjump(); + vmbreak; + } + vmcase(OP_LTI) { + op_orderI(L, l_lti, luai_numlt, 0, TM_LT); + vmbreak; + } + vmcase(OP_LEI) { + op_orderI(L, l_lei, luai_numle, 0, TM_LE); + vmbreak; + } + vmcase(OP_GTI) { + op_orderI(L, l_gti, luai_numgt, 1, TM_LT); + vmbreak; + } + vmcase(OP_GEI) { + op_orderI(L, l_gei, luai_numge, 1, TM_LE); + vmbreak; + } + vmcase(OP_TEST) { + StkId ra = RA(i); + int cond = !l_isfalse(s2v(ra)); + docondjump(); + vmbreak; + } + vmcase(OP_TESTSET) { + StkId ra = RA(i); + TValue *rb = vRB(i); + if (l_isfalse(rb) == GETARG_k(i)) + pc++; + else { + setobj2s(L, ra, rb); + donextjump(ci); + } + vmbreak; + } + vmcase(OP_CALL) { + StkId ra = RA(i); + CallInfo *newci; + int b = GETARG_B(i); + int nresults = GETARG_C(i) - 1; + if (b != 0) /* fixed number of arguments? */ + L->top.p = ra + b; /* top signals number of arguments */ + /* else previous instruction set top */ + savepc(L); /* in case of errors */ + if ((newci = luaD_precall(L, ra, nresults)) == NULL) + updatetrap(ci); /* C call; nothing else to be done */ + else { /* Lua call: run function in this same C frame */ + ci = newci; + goto startfunc; + } + vmbreak; + } + vmcase(OP_TAILCALL) { + StkId ra = RA(i); + int b = GETARG_B(i); /* number of arguments + 1 (function) */ + int n; /* number of results when calling a C function */ + int nparams1 = GETARG_C(i); + /* delta is virtual 'func' - real 'func' (vararg functions) */ + int delta = (nparams1) ? ci->u.l.nextraargs + nparams1 : 0; + if (b != 0) + L->top.p = ra + b; + else /* previous instruction set top */ + b = cast_int(L->top.p - ra); + savepc(ci); /* several calls here can raise errors */ + if (TESTARG_k(i)) { + luaF_closeupval(L, base); /* close upvalues from current call */ + lua_assert(L->tbclist.p < base); /* no pending tbc variables */ + lua_assert(base == ci->func.p + 1); + } + if ((n = luaD_pretailcall(L, ci, ra, b, delta)) < 0) /* Lua function? */ + goto startfunc; /* execute the callee */ + else { /* C function? */ + ci->func.p -= delta; /* restore 'func' (if vararg) */ + luaD_poscall(L, ci, n); /* finish caller */ + updatetrap(ci); /* 'luaD_poscall' can change hooks */ + goto ret; /* caller returns after the tail call */ + } + } + vmcase(OP_RETURN) { + StkId ra = RA(i); + int n = GETARG_B(i) - 1; /* number of results */ + int nparams1 = GETARG_C(i); + if (n < 0) /* not fixed? */ + n = cast_int(L->top.p - ra); /* get what is available */ + savepc(ci); + if (TESTARG_k(i)) { /* may there be open upvalues? */ + ci->u2.nres = n; /* save number of returns */ + if (L->top.p < ci->top.p) + L->top.p = ci->top.p; + luaF_close(L, base, CLOSEKTOP, 1); + updatetrap(ci); + updatestack(ci); + } + if (nparams1) /* vararg function? */ + ci->func.p -= ci->u.l.nextraargs + nparams1; + L->top.p = ra + n; /* set call for 'luaD_poscall' */ + luaD_poscall(L, ci, n); + updatetrap(ci); /* 'luaD_poscall' can change hooks */ + goto ret; + } + vmcase(OP_RETURN0) { + if (l_unlikely(L->hookmask)) { + StkId ra = RA(i); + L->top.p = ra; + savepc(ci); + luaD_poscall(L, ci, 0); /* no hurry... */ + trap = 1; + } + else { /* do the 'poscall' here */ + int nres; + L->ci = ci->previous; /* back to caller */ + L->top.p = base - 1; + for (nres = ci->nresults; l_unlikely(nres > 0); nres--) + setnilvalue(s2v(L->top.p++)); /* all results are nil */ + } + goto ret; + } + vmcase(OP_RETURN1) { + if (l_unlikely(L->hookmask)) { + StkId ra = RA(i); + L->top.p = ra + 1; + savepc(ci); + luaD_poscall(L, ci, 1); /* no hurry... */ + trap = 1; + } + else { /* do the 'poscall' here */ + int nres = ci->nresults; + L->ci = ci->previous; /* back to caller */ + if (nres == 0) + L->top.p = base - 1; /* asked for no results */ + else { + StkId ra = RA(i); + setobjs2s(L, base - 1, ra); /* at least this result */ + L->top.p = base; + for (; l_unlikely(nres > 1); nres--) + setnilvalue(s2v(L->top.p++)); /* complete missing results */ + } + } + ret: /* return from a Lua function */ + if (ci->callstatus & CIST_FRESH) + return; /* end this frame */ + else { + ci = ci->previous; + goto returning; /* continue running caller in this frame */ + } + } + vmcase(OP_FORLOOP) { + StkId ra = RA(i); + if (ttisinteger(s2v(ra + 2))) { /* integer loop? */ + lua_Unsigned count = l_castS2U(ivalue(s2v(ra + 1))); + if (count > 0) { /* still more iterations? */ + lua_Integer step = ivalue(s2v(ra + 2)); + lua_Integer idx = ivalue(s2v(ra)); /* internal index */ + chgivalue(s2v(ra + 1), count - 1); /* update counter */ + idx = intop(+, idx, step); /* add step to index */ + chgivalue(s2v(ra), idx); /* update internal index */ + setivalue(s2v(ra + 3), idx); /* and control variable */ + pc -= GETARG_Bx(i); /* jump back */ + } + } + else if (floatforloop(ra)) /* float loop */ + pc -= GETARG_Bx(i); /* jump back */ + updatetrap(ci); /* allows a signal to break the loop */ + vmbreak; + } + vmcase(OP_FORPREP) { + StkId ra = RA(i); + savestate(L, ci); /* in case of errors */ + if (forprep(L, ra)) + pc += GETARG_Bx(i) + 1; /* skip the loop */ + vmbreak; + } + vmcase(OP_TFORPREP) { + StkId ra = RA(i); + /* create to-be-closed upvalue (if needed) */ + halfProtect(luaF_newtbcupval(L, ra + 3)); + pc += GETARG_Bx(i); + i = *(pc++); /* go to next instruction */ + lua_assert(GET_OPCODE(i) == OP_TFORCALL && ra == RA(i)); + goto l_tforcall; + } + vmcase(OP_TFORCALL) { + l_tforcall: { + StkId ra = RA(i); + /* 'ra' has the iterator function, 'ra + 1' has the state, + 'ra + 2' has the control variable, and 'ra + 3' has the + to-be-closed variable. The call will use the stack after + these values (starting at 'ra + 4') + */ + /* push function, state, and control variable */ + memcpy(ra + 4, ra, 3 * sizeof(*ra)); + L->top.p = ra + 4 + 3; + ProtectNT(luaD_call(L, ra + 4, GETARG_C(i))); /* do the call */ + updatestack(ci); /* stack may have changed */ + i = *(pc++); /* go to next instruction */ + lua_assert(GET_OPCODE(i) == OP_TFORLOOP && ra == RA(i)); + goto l_tforloop; + }} + vmcase(OP_TFORLOOP) { + l_tforloop: { + StkId ra = RA(i); + if (!ttisnil(s2v(ra + 4))) { /* continue loop? */ + setobjs2s(L, ra + 2, ra + 4); /* save control variable */ + pc -= GETARG_Bx(i); /* jump back */ + } + vmbreak; + }} + vmcase(OP_SETLIST) { + StkId ra = RA(i); + int n = GETARG_B(i); + unsigned int last = GETARG_C(i); + Table *h = hvalue(s2v(ra)); + if (n == 0) + n = cast_int(L->top.p - ra) - 1; /* get up to the top */ + else + L->top.p = ci->top.p; /* correct top in case of emergency GC */ + last += n; + if (TESTARG_k(i)) { + last += GETARG_Ax(*pc) * (MAXARG_C + 1); + pc++; + } + if (last > luaH_realasize(h)) /* needs more space? */ + luaH_resizearray(L, h, last); /* preallocate it at once */ + for (; n > 0; n--) { + TValue *val = s2v(ra + n); + setobj2t(L, &h->array[last - 1], val); + last--; + luaC_barrierback(L, obj2gco(h), val); + } + vmbreak; + } + vmcase(OP_CLOSURE) { + StkId ra = RA(i); + Proto *p = cl->p->p[GETARG_Bx(i)]; + halfProtect(pushclosure(L, p, cl->upvals, base, ra)); + checkGC(L, ra + 1); + vmbreak; + } + vmcase(OP_VARARG) { + StkId ra = RA(i); + int n = GETARG_C(i) - 1; /* required results */ + Protect(luaT_getvarargs(L, ci, ra, n)); + vmbreak; + } + vmcase(OP_VARARGPREP) { + ProtectNT(luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p)); + if (l_unlikely(trap)) { /* previous "Protect" updated trap */ + luaD_hookcall(L, ci); + L->oldpc = 1; /* next opcode will be seen as a "new" line */ + } + updatebase(ci); /* function has new base after adjustment */ + vmbreak; + } + vmcase(OP_EXTRAARG) { + lua_assert(0); + vmbreak; + } + } + } +} + +/* }================================================================== */ diff --git a/src/lvm.h b/src/lvm.h new file mode 100644 index 0000000..dba1ad2 --- /dev/null +++ b/src/lvm.h @@ -0,0 +1,141 @@ +/* +** $Id: lvm.h $ +** Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#ifndef lvm_h +#define lvm_h + + +#include "ldo.h" +#include "lobject.h" +#include "ltm.h" + + +#if !defined(LUA_NOCVTN2S) +#define cvt2str(o) ttisnumber(o) +#else +#define cvt2str(o) 0 /* no conversion from numbers to strings */ +#endif + + +#if !defined(LUA_NOCVTS2N) +#define cvt2num(o) ttisstring(o) +#else +#define cvt2num(o) 0 /* no conversion from strings to numbers */ +#endif + + +/* +** You can define LUA_FLOORN2I if you want to convert floats to integers +** by flooring them (instead of raising an error if they are not +** integral values) +*/ +#if !defined(LUA_FLOORN2I) +#define LUA_FLOORN2I F2Ieq +#endif + + +/* +** Rounding modes for float->integer coercion + */ +typedef enum { + F2Ieq, /* no rounding; accepts only integral values */ + F2Ifloor, /* takes the floor of the number */ + F2Iceil /* takes the ceil of the number */ +} F2Imod; + + +/* convert an object to a float (including string coercion) */ +#define tonumber(o,n) \ + (ttisfloat(o) ? (*(n) = fltvalue(o), 1) : luaV_tonumber_(o,n)) + + +/* convert an object to a float (without string coercion) */ +#define tonumberns(o,n) \ + (ttisfloat(o) ? ((n) = fltvalue(o), 1) : \ + (ttisinteger(o) ? ((n) = cast_num(ivalue(o)), 1) : 0)) + + +/* convert an object to an integer (including string coercion) */ +#define tointeger(o,i) \ + (l_likely(ttisinteger(o)) ? (*(i) = ivalue(o), 1) \ + : luaV_tointeger(o,i,LUA_FLOORN2I)) + + +/* convert an object to an integer (without string coercion) */ +#define tointegerns(o,i) \ + (l_likely(ttisinteger(o)) ? (*(i) = ivalue(o), 1) \ + : luaV_tointegerns(o,i,LUA_FLOORN2I)) + + +#define intop(op,v1,v2) l_castU2S(l_castS2U(v1) op l_castS2U(v2)) + +#define luaV_rawequalobj(t1,t2) luaV_equalobj(NULL,t1,t2) + + +/* +** fast track for 'gettable': if 't' is a table and 't[k]' is present, +** return 1 with 'slot' pointing to 't[k]' (position of final result). +** Otherwise, return 0 (meaning it will have to check metamethod) +** with 'slot' pointing to an empty 't[k]' (if 't' is a table) or NULL +** (otherwise). 'f' is the raw get function to use. +*/ +#define luaV_fastget(L,t,k,slot,f) \ + (!ttistable(t) \ + ? (slot = NULL, 0) /* not a table; 'slot' is NULL and result is 0 */ \ + : (slot = f(hvalue(t), k), /* else, do raw access */ \ + !isempty(slot))) /* result not empty? */ + + +/* +** Special case of 'luaV_fastget' for integers, inlining the fast case +** of 'luaH_getint'. +*/ +#define luaV_fastgeti(L,t,k,slot) \ + (!ttistable(t) \ + ? (slot = NULL, 0) /* not a table; 'slot' is NULL and result is 0 */ \ + : (slot = (l_castS2U(k) - 1u < hvalue(t)->alimit) \ + ? &hvalue(t)->array[k - 1] : luaH_getint(hvalue(t), k), \ + !isempty(slot))) /* result not empty? */ + + +/* +** Finish a fast set operation (when fast get succeeds). In that case, +** 'slot' points to the place to put the value. +*/ +#define luaV_finishfastset(L,t,slot,v) \ + { setobj2t(L, cast(TValue *,slot), v); \ + luaC_barrierback(L, gcvalue(t), v); } + + +/* +** Shift right is the same as shift left with a negative 'y' +*/ +#define luaV_shiftr(x,y) luaV_shiftl(x,intop(-, 0, y)) + + + +LUAI_FUNC int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2); +LUAI_FUNC int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r); +LUAI_FUNC int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r); +LUAI_FUNC int luaV_tonumber_ (const TValue *obj, lua_Number *n); +LUAI_FUNC int luaV_tointeger (const TValue *obj, lua_Integer *p, F2Imod mode); +LUAI_FUNC int luaV_tointegerns (const TValue *obj, lua_Integer *p, + F2Imod mode); +LUAI_FUNC int luaV_flttointeger (lua_Number n, lua_Integer *p, F2Imod mode); +LUAI_FUNC void luaV_finishget (lua_State *L, const TValue *t, TValue *key, + StkId val, const TValue *slot); +LUAI_FUNC void luaV_finishset (lua_State *L, const TValue *t, TValue *key, + TValue *val, const TValue *slot); +LUAI_FUNC void luaV_finishOp (lua_State *L); +LUAI_FUNC void luaV_execute (lua_State *L, CallInfo *ci); +LUAI_FUNC void luaV_concat (lua_State *L, int total); +LUAI_FUNC lua_Integer luaV_idiv (lua_State *L, lua_Integer x, lua_Integer y); +LUAI_FUNC lua_Integer luaV_mod (lua_State *L, lua_Integer x, lua_Integer y); +LUAI_FUNC lua_Number luaV_modf (lua_State *L, lua_Number x, lua_Number y); +LUAI_FUNC lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y); +LUAI_FUNC void luaV_objlen (lua_State *L, StkId ra, const TValue *rb); + +#endif diff --git a/src/lzio.c b/src/lzio.c new file mode 100644 index 0000000..cd0a02d --- /dev/null +++ b/src/lzio.c @@ -0,0 +1,68 @@ +/* +** $Id: lzio.c $ +** Buffered streams +** See Copyright Notice in lua.h +*/ + +#define lzio_c +#define LUA_CORE + +#include "lprefix.h" + + +#include + +#include "lua.h" + +#include "llimits.h" +#include "lmem.h" +#include "lstate.h" +#include "lzio.h" + + +int luaZ_fill (ZIO *z) { + size_t size; + lua_State *L = z->L; + const char *buff; + lua_unlock(L); + buff = z->reader(L, z->data, &size); + lua_lock(L); + if (buff == NULL || size == 0) + return EOZ; + z->n = size - 1; /* discount char being returned */ + z->p = buff; + return cast_uchar(*(z->p++)); +} + + +void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) { + z->L = L; + z->reader = reader; + z->data = data; + z->n = 0; + z->p = NULL; +} + + +/* --------------------------------------------------------------- read --- */ +size_t luaZ_read (ZIO *z, void *b, size_t n) { + while (n) { + size_t m; + if (z->n == 0) { /* no bytes in buffer? */ + if (luaZ_fill(z) == EOZ) /* try to read more */ + return n; /* no more input; return number of missing bytes */ + else { + z->n++; /* luaZ_fill consumed first byte; put it back */ + z->p--; + } + } + m = (n <= z->n) ? n : z->n; /* min. between n and z->n */ + memcpy(b, z->p, m); + z->n -= m; + z->p += m; + b = (char *)b + m; + n -= m; + } + return 0; +} + diff --git a/src/lzio.h b/src/lzio.h new file mode 100644 index 0000000..38f397f --- /dev/null +++ b/src/lzio.h @@ -0,0 +1,66 @@ +/* +** $Id: lzio.h $ +** Buffered streams +** See Copyright Notice in lua.h +*/ + + +#ifndef lzio_h +#define lzio_h + +#include "lua.h" + +#include "lmem.h" + + +#define EOZ (-1) /* end of stream */ + +typedef struct Zio ZIO; + +#define zgetc(z) (((z)->n--)>0 ? cast_uchar(*(z)->p++) : luaZ_fill(z)) + + +typedef struct Mbuffer { + char *buffer; + size_t n; + size_t buffsize; +} Mbuffer; + +#define luaZ_initbuffer(L, buff) ((buff)->buffer = NULL, (buff)->buffsize = 0) + +#define luaZ_buffer(buff) ((buff)->buffer) +#define luaZ_sizebuffer(buff) ((buff)->buffsize) +#define luaZ_bufflen(buff) ((buff)->n) + +#define luaZ_buffremove(buff,i) ((buff)->n -= (i)) +#define luaZ_resetbuffer(buff) ((buff)->n = 0) + + +#define luaZ_resizebuffer(L, buff, size) \ + ((buff)->buffer = luaM_reallocvchar(L, (buff)->buffer, \ + (buff)->buffsize, size), \ + (buff)->buffsize = size) + +#define luaZ_freebuffer(L, buff) luaZ_resizebuffer(L, buff, 0) + + +LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, + void *data); +LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n); /* read next n bytes */ + + + +/* --------- Private Part ------------------ */ + +struct Zio { + size_t n; /* bytes still unread */ + const char *p; /* current position in buffer */ + lua_Reader reader; /* reader function */ + void *data; /* additional data */ + lua_State *L; /* Lua state (for reader) */ +}; + + +LUAI_FUNC int luaZ_fill (ZIO *z); + +#endif