mirror of
https://github.com/lua/lua
synced 2024-11-24 13:49:39 +03:00
55ac40f859
Several definitions that don't need to be "global" (that is, that concerns only specific parts of the code) moved out of llimits.h, to more appropriate places.
1048 lines
34 KiB
C
1048 lines
34 KiB
C
/*
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** $Id: ldo.c $
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** Stack and Call structure of Lua
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** See Copyright Notice in lua.h
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*/
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#define ldo_c
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#define LUA_CORE
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#include "lprefix.h"
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#include <setjmp.h>
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#include <stdlib.h>
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#include <string.h>
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#include "lua.h"
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#include "lapi.h"
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#include "ldebug.h"
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#include "ldo.h"
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#include "lfunc.h"
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#include "lgc.h"
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#include "lmem.h"
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#include "lobject.h"
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#include "lopcodes.h"
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#include "lparser.h"
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#include "lstate.h"
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#include "lstring.h"
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#include "ltable.h"
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#include "ltm.h"
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#include "lundump.h"
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#include "lvm.h"
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#include "lzio.h"
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#define errorstatus(s) ((s) > LUA_YIELD)
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/*
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** these macros allow user-specific actions when a thread is
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** resumed/yielded.
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*/
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#if !defined(luai_userstateresume)
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#define luai_userstateresume(L,n) ((void)L)
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#endif
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#if !defined(luai_userstateyield)
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#define luai_userstateyield(L,n) ((void)L)
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#endif
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/*
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** {======================================================
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** Error-recovery functions
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** =======================================================
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*/
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/*
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** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By
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** default, Lua handles errors with exceptions when compiling as
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** C++ code, with _longjmp/_setjmp when asked to use them, and with
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** longjmp/setjmp otherwise.
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*/
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#if !defined(LUAI_THROW) /* { */
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#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) /* { */
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/* C++ exceptions */
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#define LUAI_THROW(L,c) throw(c)
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#define LUAI_TRY(L,c,a) \
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try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; }
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#define luai_jmpbuf int /* dummy variable */
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#elif defined(LUA_USE_POSIX) /* }{ */
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/* in POSIX, try _longjmp/_setjmp (more efficient) */
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#define LUAI_THROW(L,c) _longjmp((c)->b, 1)
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#define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a }
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#define luai_jmpbuf jmp_buf
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#else /* }{ */
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/* ISO C handling with long jumps */
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#define LUAI_THROW(L,c) longjmp((c)->b, 1)
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#define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a }
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#define luai_jmpbuf jmp_buf
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#endif /* } */
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#endif /* } */
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/* chain list of long jump buffers */
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struct lua_longjmp {
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struct lua_longjmp *previous;
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luai_jmpbuf b;
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volatile int status; /* error code */
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};
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void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
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switch (errcode) {
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case LUA_ERRMEM: { /* memory error? */
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setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */
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break;
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}
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case LUA_ERRERR: {
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setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
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break;
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}
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case LUA_OK: { /* special case only for closing upvalues */
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setnilvalue(s2v(oldtop)); /* no error message */
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break;
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}
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default: {
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lua_assert(errorstatus(errcode)); /* real error */
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setobjs2s(L, oldtop, L->top.p - 1); /* error message on current top */
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break;
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}
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}
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L->top.p = oldtop + 1;
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}
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l_noret luaD_throw (lua_State *L, int errcode) {
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if (L->errorJmp) { /* thread has an error handler? */
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L->errorJmp->status = errcode; /* set status */
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LUAI_THROW(L, L->errorJmp); /* jump to it */
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}
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else { /* thread has no error handler */
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global_State *g = G(L);
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errcode = luaE_resetthread(L, errcode); /* close all upvalues */
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if (g->mainthread->errorJmp) { /* main thread has a handler? */
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setobjs2s(L, g->mainthread->top.p++, L->top.p - 1); /* copy error obj. */
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luaD_throw(g->mainthread, errcode); /* re-throw in main thread */
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}
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else { /* no handler at all; abort */
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if (g->panic) { /* panic function? */
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lua_unlock(L);
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g->panic(L); /* call panic function (last chance to jump out) */
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}
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abort();
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}
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}
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}
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int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
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l_uint32 oldnCcalls = L->nCcalls;
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struct lua_longjmp lj;
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lj.status = LUA_OK;
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lj.previous = L->errorJmp; /* chain new error handler */
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L->errorJmp = &lj;
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LUAI_TRY(L, &lj,
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(*f)(L, ud);
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);
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L->errorJmp = lj.previous; /* restore old error handler */
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L->nCcalls = oldnCcalls;
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return lj.status;
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}
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/* }====================================================== */
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/*
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** {==================================================================
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** Stack reallocation
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** ===================================================================
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*/
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/*
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** Change all pointers to the stack into offsets.
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*/
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static void relstack (lua_State *L) {
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CallInfo *ci;
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UpVal *up;
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L->top.offset = savestack(L, L->top.p);
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L->tbclist.offset = savestack(L, L->tbclist.p);
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for (up = L->openupval; up != NULL; up = up->u.open.next)
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up->v.offset = savestack(L, uplevel(up));
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for (ci = L->ci; ci != NULL; ci = ci->previous) {
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ci->top.offset = savestack(L, ci->top.p);
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ci->func.offset = savestack(L, ci->func.p);
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}
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}
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/*
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** Change back all offsets into pointers.
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*/
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static void correctstack (lua_State *L) {
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CallInfo *ci;
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UpVal *up;
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L->top.p = restorestack(L, L->top.offset);
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L->tbclist.p = restorestack(L, L->tbclist.offset);
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for (up = L->openupval; up != NULL; up = up->u.open.next)
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up->v.p = s2v(restorestack(L, up->v.offset));
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for (ci = L->ci; ci != NULL; ci = ci->previous) {
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ci->top.p = restorestack(L, ci->top.offset);
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ci->func.p = restorestack(L, ci->func.offset);
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if (isLua(ci))
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ci->u.l.trap = 1; /* signal to update 'trap' in 'luaV_execute' */
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}
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}
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/* some space for error handling */
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#define ERRORSTACKSIZE (LUAI_MAXSTACK + 200)
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/*
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** Reallocate the stack to a new size, correcting all pointers into it.
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** In ISO C, any pointer use after the pointer has been deallocated is
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** undefined behavior. So, before the reallocation, all pointers are
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** changed to offsets, and after the reallocation they are changed back
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** to pointers. As during the reallocation the pointers are invalid, the
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** reallocation cannot run emergency collections.
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**
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** In case of allocation error, raise an error or return false according
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** to 'raiseerror'.
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*/
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int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
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int oldsize = stacksize(L);
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int i;
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StkId newstack;
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int oldgcstop = G(L)->gcstopem;
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lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
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relstack(L); /* change pointers to offsets */
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G(L)->gcstopem = 1; /* stop emergency collection */
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newstack = luaM_reallocvector(L, L->stack.p, oldsize + EXTRA_STACK,
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newsize + EXTRA_STACK, StackValue);
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G(L)->gcstopem = oldgcstop; /* restore emergency collection */
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if (l_unlikely(newstack == NULL)) { /* reallocation failed? */
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correctstack(L); /* change offsets back to pointers */
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if (raiseerror)
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luaM_error(L);
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else return 0; /* do not raise an error */
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}
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L->stack.p = newstack;
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correctstack(L); /* change offsets back to pointers */
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L->stack_last.p = L->stack.p + newsize;
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for (i = oldsize + EXTRA_STACK; i < newsize + EXTRA_STACK; i++)
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setnilvalue(s2v(newstack + i)); /* erase new segment */
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return 1;
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}
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/*
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** Try to grow the stack by at least 'n' elements. When 'raiseerror'
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** is true, raises any error; otherwise, return 0 in case of errors.
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*/
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int luaD_growstack (lua_State *L, int n, int raiseerror) {
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int size = stacksize(L);
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if (l_unlikely(size > LUAI_MAXSTACK)) {
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/* if stack is larger than maximum, thread is already using the
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extra space reserved for errors, that is, thread is handling
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a stack error; cannot grow further than that. */
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lua_assert(stacksize(L) == ERRORSTACKSIZE);
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if (raiseerror)
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luaD_throw(L, LUA_ERRERR); /* error inside message handler */
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return 0; /* if not 'raiseerror', just signal it */
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}
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else if (n < LUAI_MAXSTACK) { /* avoids arithmetic overflows */
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int newsize = 2 * size; /* tentative new size */
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int needed = cast_int(L->top.p - L->stack.p) + n;
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if (newsize > LUAI_MAXSTACK) /* cannot cross the limit */
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newsize = LUAI_MAXSTACK;
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if (newsize < needed) /* but must respect what was asked for */
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newsize = needed;
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if (l_likely(newsize <= LUAI_MAXSTACK))
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return luaD_reallocstack(L, newsize, raiseerror);
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}
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/* else stack overflow */
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/* add extra size to be able to handle the error message */
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luaD_reallocstack(L, ERRORSTACKSIZE, raiseerror);
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if (raiseerror)
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luaG_runerror(L, "stack overflow");
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return 0;
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}
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/*
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** Compute how much of the stack is being used, by computing the
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** maximum top of all call frames in the stack and the current top.
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*/
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static int stackinuse (lua_State *L) {
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CallInfo *ci;
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int res;
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StkId lim = L->top.p;
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for (ci = L->ci; ci != NULL; ci = ci->previous) {
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if (lim < ci->top.p) lim = ci->top.p;
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}
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lua_assert(lim <= L->stack_last.p + EXTRA_STACK);
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res = cast_int(lim - L->stack.p) + 1; /* part of stack in use */
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if (res < LUA_MINSTACK)
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res = LUA_MINSTACK; /* ensure a minimum size */
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return res;
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}
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/*
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** If stack size is more than 3 times the current use, reduce that size
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** to twice the current use. (So, the final stack size is at most 2/3 the
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** previous size, and half of its entries are empty.)
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** As a particular case, if stack was handling a stack overflow and now
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** it is not, 'max' (limited by LUAI_MAXSTACK) will be smaller than
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** stacksize (equal to ERRORSTACKSIZE in this case), and so the stack
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** will be reduced to a "regular" size.
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*/
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void luaD_shrinkstack (lua_State *L) {
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int inuse = stackinuse(L);
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int max = (inuse > LUAI_MAXSTACK / 3) ? LUAI_MAXSTACK : inuse * 3;
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/* if thread is currently not handling a stack overflow and its
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size is larger than maximum "reasonable" size, shrink it */
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if (inuse <= LUAI_MAXSTACK && stacksize(L) > max) {
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int nsize = (inuse > LUAI_MAXSTACK / 2) ? LUAI_MAXSTACK : inuse * 2;
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luaD_reallocstack(L, nsize, 0); /* ok if that fails */
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}
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else /* don't change stack */
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condmovestack(L,{},{}); /* (change only for debugging) */
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luaE_shrinkCI(L); /* shrink CI list */
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}
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void luaD_inctop (lua_State *L) {
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luaD_checkstack(L, 1);
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L->top.p++;
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}
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/* }================================================================== */
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/*
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** Call a hook for the given event. Make sure there is a hook to be
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** called. (Both 'L->hook' and 'L->hookmask', which trigger this
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** function, can be changed asynchronously by signals.)
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*/
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void luaD_hook (lua_State *L, int event, int line,
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int ftransfer, int ntransfer) {
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lua_Hook hook = L->hook;
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if (hook && L->allowhook) { /* make sure there is a hook */
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int mask = CIST_HOOKED;
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CallInfo *ci = L->ci;
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ptrdiff_t top = savestack(L, L->top.p); /* preserve original 'top' */
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ptrdiff_t ci_top = savestack(L, ci->top.p); /* idem for 'ci->top' */
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lua_Debug ar;
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ar.event = event;
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ar.currentline = line;
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ar.i_ci = ci;
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if (ntransfer != 0) {
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mask |= CIST_TRAN; /* 'ci' has transfer information */
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ci->u2.transferinfo.ftransfer = ftransfer;
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ci->u2.transferinfo.ntransfer = ntransfer;
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}
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if (isLua(ci) && L->top.p < ci->top.p)
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L->top.p = ci->top.p; /* protect entire activation register */
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luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
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if (ci->top.p < L->top.p + LUA_MINSTACK)
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ci->top.p = L->top.p + LUA_MINSTACK;
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L->allowhook = 0; /* cannot call hooks inside a hook */
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ci->callstatus |= mask;
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lua_unlock(L);
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(*hook)(L, &ar);
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lua_lock(L);
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lua_assert(!L->allowhook);
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L->allowhook = 1;
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ci->top.p = restorestack(L, ci_top);
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L->top.p = restorestack(L, top);
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ci->callstatus &= ~mask;
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}
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}
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/*
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** Executes a call hook for Lua functions. This function is called
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** whenever 'hookmask' is not zero, so it checks whether call hooks are
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** active.
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*/
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void luaD_hookcall (lua_State *L, CallInfo *ci) {
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L->oldpc = 0; /* set 'oldpc' for new function */
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if (L->hookmask & LUA_MASKCALL) { /* is call hook on? */
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int event = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL
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: LUA_HOOKCALL;
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Proto *p = ci_func(ci)->p;
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ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
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luaD_hook(L, event, -1, 1, p->numparams);
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ci->u.l.savedpc--; /* correct 'pc' */
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}
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}
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/*
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** Executes a return hook for Lua and C functions and sets/corrects
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** 'oldpc'. (Note that this correction is needed by the line hook, so it
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** is done even when return hooks are off.)
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*/
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static void rethook (lua_State *L, CallInfo *ci, int nres) {
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if (L->hookmask & LUA_MASKRET) { /* is return hook on? */
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StkId firstres = L->top.p - nres; /* index of first result */
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int delta = 0; /* correction for vararg functions */
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int ftransfer;
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if (isLua(ci)) {
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Proto *p = ci_func(ci)->p;
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if (p->flag & PF_ISVARARG)
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delta = ci->u.l.nextraargs + p->numparams + 1;
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}
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ci->func.p += delta; /* if vararg, back to virtual 'func' */
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ftransfer = cast(unsigned short, firstres - ci->func.p);
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luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres); /* call it */
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ci->func.p -= delta;
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}
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if (isLua(ci = ci->previous))
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L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p); /* set 'oldpc' */
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}
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/*
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** Check whether 'func' has a '__call' metafield. If so, put it in the
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** stack, below original 'func', so that 'luaD_precall' can call it. Raise
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** an error if there is no '__call' metafield.
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*/
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static StkId tryfuncTM (lua_State *L, StkId func) {
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const TValue *tm;
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StkId p;
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checkstackp(L, 1, func); /* space for metamethod */
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tm = luaT_gettmbyobj(L, s2v(func), TM_CALL); /* (after previous GC) */
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if (l_unlikely(ttisnil(tm)))
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luaG_callerror(L, s2v(func)); /* nothing to call */
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for (p = L->top.p; p > func; p--) /* open space for metamethod */
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setobjs2s(L, p, p-1);
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L->top.p++; /* stack space pre-allocated by the caller */
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setobj2s(L, func, tm); /* metamethod is the new function to be called */
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return func;
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}
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/*
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** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'.
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** Handle most typical cases (zero results for commands, one result for
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** expressions, multiple results for tail calls/single parameters)
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** separated.
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*/
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l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) {
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StkId firstresult;
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int i;
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switch (wanted) { /* handle typical cases separately */
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case 0: /* no values needed */
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L->top.p = res;
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return;
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case 1: /* one value needed */
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if (nres == 0) /* no results? */
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setnilvalue(s2v(res)); /* adjust with nil */
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else /* at least one result */
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setobjs2s(L, res, L->top.p - nres); /* move it to proper place */
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L->top.p = res + 1;
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return;
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case LUA_MULTRET:
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wanted = nres; /* we want all results */
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break;
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default: /* two/more results and/or to-be-closed variables */
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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;
|
|
checkstackp(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;
|
|
checkstackp(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 = 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 */
|
|
checkstackp(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 = 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) {
|
|
api_checkpop(L, 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? */
|
|
/* undo increment made by 'luaG_traceexec': instruction was not
|
|
executed yet */
|
|
lua_assert(ci->callstatus & CIST_HOOKYIELD);
|
|
ci->u.l.savedpc--;
|
|
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_checkpop(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_checkpop(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 (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);
|
|
const char *mode = p->mode ? p->mode : "bt";
|
|
int c = zgetc(p->z); /* read first character */
|
|
if (c == LUA_SIGNATURE[0]) {
|
|
int fixed = 0;
|
|
if (strchr(mode, 'B') != NULL)
|
|
fixed = 1;
|
|
else
|
|
checkmode(L, mode, "binary");
|
|
cl = luaU_undump(L, p->z, p->name, fixed);
|
|
}
|
|
else {
|
|
checkmode(L, 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;
|
|
}
|
|
|
|
|