/* ** $Id: ldo.c,v 2.157 2016/12/13 15:52:21 roberto Exp $ ** 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 */ }; static void 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; } default: { setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ break; } } L->top = 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); L->status = cast_byte(errcode); /* mark it as dead */ if (g->mainthread->errorJmp) { /* main thread has a handler? */ setobjs2s(L, g->mainthread->top++, L->top - 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? */ seterrorobj(L, errcode, L->top); /* assume EXTRA_STACK */ if (L->ci->top < L->top) L->ci->top = L->top; /* pushing msg. can break this invariant */ 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) { unsigned short 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 ** =================================================================== */ static void correctstack (lua_State *L, TValue *oldstack) { CallInfo *ci; UpVal *up; L->top = (L->top - oldstack) + L->stack; for (up = L->openupval; up != NULL; up = up->u.open.next) up->v = (up->v - oldstack) + L->stack; for (ci = L->ci; ci != NULL; ci = ci->previous) { ci->top = (ci->top - oldstack) + L->stack; ci->func = (ci->func - oldstack) + L->stack; if (isLua(ci)) ci->u.l.base = (ci->u.l.base - oldstack) + L->stack; } } /* some space for error handling */ #define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) void luaD_reallocstack (lua_State *L, int newsize) { TValue *oldstack = L->stack; int lim = L->stacksize; lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE); lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK); luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue); for (; lim < newsize; lim++) setnilvalue(L->stack + lim); /* erase new segment */ L->stacksize = newsize; L->stack_last = L->stack + newsize - EXTRA_STACK; correctstack(L, oldstack); } void luaD_growstack (lua_State *L, int n) { int size = L->stacksize; if (size > LUAI_MAXSTACK) /* error after extra size? */ luaD_throw(L, LUA_ERRERR); else { int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK; int newsize = 2 * size; if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK; if (newsize < needed) newsize = needed; if (newsize > LUAI_MAXSTACK) { /* stack overflow? */ luaD_reallocstack(L, ERRORSTACKSIZE); luaG_runerror(L, "stack overflow"); } else luaD_reallocstack(L, newsize); } } static int stackinuse (lua_State *L) { CallInfo *ci; StkId lim = L->top; for (ci = L->ci; ci != NULL; ci = ci->previous) { if (lim < ci->top) lim = ci->top; } lua_assert(lim <= L->stack_last); return cast_int(lim - L->stack) + 1; /* part of stack in use */ } void luaD_shrinkstack (lua_State *L) { int inuse = stackinuse(L); int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK; if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK; /* respect stack limit */ if (L->stacksize > LUAI_MAXSTACK) /* had been handling stack overflow? */ luaE_freeCI(L); /* free all CIs (list grew because of an error) */ else luaE_shrinkCI(L); /* shrink list */ /* if thread is currently not handling a stack overflow and its good size is smaller than current size, shrink its stack */ if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) && goodsize < L->stacksize) luaD_reallocstack(L, goodsize); else /* don't change stack */ condmovestack(L,{},{}); /* (change only for debugging) */ } void luaD_inctop (lua_State *L) { luaD_checkstack(L, 1); L->top++; } /* }================================================================== */ /* ** Call a hook for the given event. Make sure there is a hook to be ** called. (Both 'L->hook' and 'L->hookmask', which triggers this ** function, can be changed asynchronously by signals.) */ void luaD_hook (lua_State *L, int event, int line) { lua_Hook hook = L->hook; if (hook && L->allowhook) { /* make sure there is a hook */ CallInfo *ci = L->ci; ptrdiff_t top = savestack(L, L->top); ptrdiff_t ci_top = savestack(L, ci->top); lua_Debug ar; ar.event = event; ar.currentline = line; ar.i_ci = ci; luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ ci->top = L->top + LUA_MINSTACK; lua_assert(ci->top <= L->stack_last); L->allowhook = 0; /* cannot call hooks inside a hook */ ci->callstatus |= CIST_HOOKED; lua_unlock(L); (*hook)(L, &ar); lua_lock(L); lua_assert(!L->allowhook); L->allowhook = 1; ci->top = restorestack(L, ci_top); L->top = restorestack(L, top); ci->callstatus &= ~CIST_HOOKED; } } static void callhook (lua_State *L, CallInfo *ci) { int hook = LUA_HOOKCALL; ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ if (isLua(ci->previous) && GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) { ci->callstatus |= CIST_TAIL; hook = LUA_HOOKTAILCALL; } luaD_hook(L, hook, -1); ci->u.l.savedpc--; /* correct 'pc' */ } static StkId adjust_varargs (lua_State *L, Proto *p, int actual) { int i; int nfixargs = p->numparams; StkId base, fixed; /* move fixed parameters to final position */ fixed = L->top - actual; /* first fixed argument */ base = L->top; /* final position of first argument */ for (i = 0; i < nfixargs && i < actual; i++) { setobjs2s(L, L->top++, fixed + i); setnilvalue(fixed + i); /* erase original copy (for GC) */ } for (; i < nfixargs; i++) setnilvalue(L->top++); /* complete missing arguments */ return base; } /* ** Check whether __call metafield of 'func' is a function. If so, put ** it in stack below original 'func' so that 'luaD_precall' can call ** it. Raise an error if __call metafield is not a function. */ static void tryfuncTM (lua_State *L, StkId func) { const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL); StkId p; if (!ttisfunction(tm)) luaG_typeerror(L, func, "call"); /* Open a hole inside the stack at 'func' */ for (p = L->top; p > func; p--) setobjs2s(L, p, p-1); L->top++; /* slot ensured by caller */ setobj2s(L, func, tm); /* tag method is the new function to be called */ } /* ** 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. */ static int moveresults (lua_State *L, const TValue *firstResult, StkId res, int nres, int wanted) { switch (wanted) { /* handle typical cases separately */ case 0: break; /* nothing to move */ case 1: { /* one result needed */ if (nres == 0) /* no results? */ firstResult = luaO_nilobject; /* adjust with nil */ setobjs2s(L, res, firstResult); /* move it to proper place */ break; } case LUA_MULTRET: { int i; for (i = 0; i < nres; i++) /* move all results to correct place */ setobjs2s(L, res + i, firstResult + i); L->top = res + nres; return 0; /* wanted == LUA_MULTRET */ } default: { int i; if (wanted <= nres) { /* enough results? */ for (i = 0; i < wanted; i++) /* move wanted results to correct place */ setobjs2s(L, res + i, firstResult + i); } else { /* not enough results; use all of them plus nils */ 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(res + i); } break; } } L->top = res + wanted; /* top points after the last result */ return 1; } /* ** Finishes a function call: calls hook if necessary, removes CallInfo, ** moves current number of results to proper place; returns 0 iff call ** wanted multiple (variable number of) results. */ int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) { StkId res; int wanted = ci->nresults; if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) { if (L->hookmask & LUA_MASKRET) { ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */ luaD_hook(L, LUA_HOOKRET, -1); firstResult = restorestack(L, fr); } L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */ } res = ci->func; /* res == final position of 1st result */ L->ci = ci->previous; /* back to caller */ /* move results to proper place */ return moveresults(L, firstResult, res, nres, wanted); } #define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L))) /* macro to check stack size, preserving 'p' */ #define checkstackp(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' */ /* ** Prepares a function call: checks the stack, creates a new CallInfo ** entry, fills in the relevant information, calls hook if needed. ** If function is a C function, does the call, too. (Otherwise, leave ** the execution ('luaV_execute') to the caller, to allow stackless ** calls.) Returns true iff function has been executed (C function). */ int luaD_precall (lua_State *L, StkId func, int nresults) { lua_CFunction f; CallInfo *ci; switch (ttype(func)) { case LUA_TCCL: /* C closure */ f = clCvalue(func)->f; goto Cfunc; case LUA_TLCF: /* light C function */ f = fvalue(func); Cfunc: { int n; /* number of returns */ checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */ ci = next_ci(L); /* now 'enter' new function */ ci->nresults = nresults; ci->func = func; ci->top = L->top + LUA_MINSTACK; lua_assert(ci->top <= L->stack_last); ci->callstatus = 0; if (L->hookmask & LUA_MASKCALL) luaD_hook(L, LUA_HOOKCALL, -1); lua_unlock(L); n = (*f)(L); /* do the actual call */ lua_lock(L); api_checknelems(L, n); luaD_poscall(L, ci, L->top - n, n); return 1; } case LUA_TLCL: { /* Lua function: prepare its call */ StkId base; Proto *p = clLvalue(func)->p; int n = cast_int(L->top - func) - 1; /* number of real arguments */ int fsize = p->maxstacksize; /* frame size */ checkstackp(L, fsize, func); if (p->is_vararg) base = adjust_varargs(L, p, n); else { /* non vararg function */ for (; n < p->numparams; n++) setnilvalue(L->top++); /* complete missing arguments */ base = func + 1; } ci = next_ci(L); /* now 'enter' new function */ ci->nresults = nresults; ci->func = func; ci->u.l.base = base; L->top = ci->top = base + fsize; lua_assert(ci->top <= L->stack_last); ci->u.l.savedpc = p->code; /* starting point */ ci->callstatus = CIST_LUA; if (L->hookmask & LUA_MASKCALL) callhook(L, ci); return 0; } default: { /* not a function */ checkstackp(L, 1, func); /* ensure space for metamethod */ tryfuncTM(L, func); /* try to get '__call' metamethod */ return luaD_precall(L, func, nresults); /* now it must be a function */ } } } /* ** Check appropriate error for stack overflow ("regular" overflow or ** overflow while handling stack overflow). If 'nCalls' is larger than ** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but ** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to ** allow overflow handling to work) */ static void stackerror (lua_State *L) { if (L->nCcalls == LUAI_MAXCCALLS) luaG_runerror(L, "C stack overflow"); else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3))) luaD_throw(L, LUA_ERRERR); /* error while handing stack error */ } /* ** Call a function (C or Lua). The function to be called is at *func. ** The arguments are on the stack, right after the function. ** When returns, all the results are on the stack, starting at the original ** function position. */ void luaD_call (lua_State *L, StkId func, int nResults) { if (++L->nCcalls >= LUAI_MAXCCALLS) stackerror(L); if (!luaD_precall(L, func, nResults)) /* is a Lua function? */ luaV_execute(L); /* call it */ L->nCcalls--; } /* ** Similar to 'luaD_call', but does not allow yields during the call */ void luaD_callnoyield (lua_State *L, StkId func, int nResults) { L->nny++; luaD_call(L, func, nResults); L->nny--; } /* ** Completes the execution of an interrupted C function, calling its ** continuation function. */ static void finishCcall (lua_State *L, int status) { CallInfo *ci = L->ci; int n; /* must have a continuation and must be able to call it */ lua_assert(ci->u.c.k != NULL && L->nny == 0); /* error status can only happen in a protected call */ lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD); if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */ ci->callstatus &= ~CIST_YPCALL; /* continuation is also inside it */ L->errfunc = ci->u.c.old_errfunc; /* with the same error function */ } /* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already handled */ adjustresults(L, ci->nresults); lua_unlock(L); n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation function */ lua_lock(L); api_checknelems(L, n); luaD_poscall(L, ci, L->top - n, n); /* finish 'luaD_precall' */ } /* ** 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). If the coroutine is ** recovering from an error, 'ud' points to the error status, which must ** be passed to the first continuation function (otherwise the default ** status is LUA_YIELD). */ static void unroll (lua_State *L, void *ud) { if (ud != NULL) /* error status? */ finishCcall(L, *(int *)ud); /* finish 'lua_pcallk' callee */ while (L->ci != &L->base_ci) { /* something in the stack */ if (!isLua(L->ci)) /* C function? */ finishCcall(L, LUA_YIELD); /* complete its execution */ else { /* Lua function */ luaV_finishOp(L); /* finish interrupted instruction */ luaV_execute(L); /* 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 */ } /* ** Recovers from an error in a coroutine. Finds a recover point (if ** there is one) and completes the execution of the interrupted ** 'luaD_pcall'. If there is no recover point, returns zero. */ static int recover (lua_State *L, int status) { StkId oldtop; CallInfo *ci = findpcall(L); if (ci == NULL) return 0; /* no recovery point */ /* "finish" luaD_pcall */ oldtop = restorestack(L, ci->extra); luaF_close(L, oldtop); seterrorobj(L, status, oldtop); L->ci = ci; L->allowhook = getoah(ci->callstatus); /* restore original 'allowhook' */ L->nny = 0; /* should be zero to be yieldable */ luaD_shrinkstack(L); L->errfunc = ci->u.c.old_errfunc; return 1; /* continue running the coroutine */ } /* ** 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 -= narg; /* remove args from the stack */ setsvalue2s(L, L->top, 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 - n; /* first argument */ CallInfo *ci = L->ci; if (L->status == LUA_OK) { /* starting a coroutine? */ if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */ luaV_execute(L); /* call it */ } else { /* resuming from previous yield */ lua_assert(L->status == LUA_YIELD); L->status = LUA_OK; /* mark that it is running (again) */ ci->func = restorestack(L, ci->extra); if (isLua(ci)) /* yielded inside a hook? */ luaV_execute(L); /* 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); firstArg = L->top - n; /* yield results come from continuation */ } luaD_poscall(L, ci, firstArg, n); /* finish 'luaD_precall' */ } unroll(L, NULL); /* run continuation */ } } LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) { int status; unsigned short oldnny = L->nny; /* save "number of non-yieldable" calls */ 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->status != LUA_YIELD) return resume_error(L, "cannot resume dead coroutine", nargs); L->nCcalls = (from) ? from->nCcalls + 1 : 1; if (L->nCcalls >= LUAI_MAXCCALLS) return resume_error(L, "C stack overflow", nargs); luai_userstateresume(L, nargs); L->nny = 0; /* allow yields */ api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs); status = luaD_rawrunprotected(L, resume, &nargs); if (status == -1) /* error calling 'lua_resume'? */ status = LUA_ERRRUN; else { /* continue running after recoverable errors */ while (errorstatus(status) && recover(L, status)) { /* unroll continuation */ status = luaD_rawrunprotected(L, unroll, &status); } if (errorstatus(status)) { /* unrecoverable error? */ L->status = cast_byte(status); /* mark thread as 'dead' */ seterrorobj(L, status, L->top); /* push error message */ L->ci->top = L->top; } else lua_assert(status == L->status); /* normal end or yield */ } L->nny = oldnny; /* restore 'nny' */ L->nCcalls--; lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0)); lua_unlock(L); return status; } LUA_API int lua_isyieldable (lua_State *L) { return (L->nny == 0); } LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, lua_KFunction k) { CallInfo *ci = L->ci; luai_userstateyield(L, nresults); lua_lock(L); api_checknelems(L, nresults); if (L->nny > 0) { 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->extra = savestack(L, ci->func); /* save current 'func' */ if (isLua(ci)) { /* inside a hook? */ 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 */ ci->func = L->top - nresults - 1; /* protect stack below results */ 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' */ } 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; unsigned short old_nny = L->nny; ptrdiff_t old_errfunc = L->errfunc; L->errfunc = ef; status = luaD_rawrunprotected(L, func, u); if (status != LUA_OK) { /* an error occurred? */ StkId oldtop = restorestack(L, old_top); luaF_close(L, oldtop); /* close possible pending closures */ seterrorobj(L, status, oldtop); L->ci = old_ci; L->allowhook = old_allowhooks; L->nny = old_nny; luaD_shrinkstack(L); } 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; L->nny++; /* 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), 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); L->nny--; return status; }