1 /* 2 ** $Id: ldo.c,v 2.108 2012/10/01 14:05:04 roberto Exp $ 3 ** Stack and Call structure of Lua 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #include <setjmp.h> 9 #include <stdlib.h> 10 #include <string.h> 11 12 #define ldo_c 13 #define LUA_CORE 14 15 #include "lua.h" 16 17 #include "lapi.h" 18 #include "ldebug.h" 19 #include "ldo.h" 20 #include "lfunc.h" 21 #include "lgc.h" 22 #include "lmem.h" 23 #include "lobject.h" 24 #include "lopcodes.h" 25 #include "lparser.h" 26 #include "lstate.h" 27 #include "lstring.h" 28 #include "ltable.h" 29 #include "ltm.h" 30 #include "lundump.h" 31 #include "lvm.h" 32 #include "lzio.h" 33 34 35 36 37 /* 38 ** {====================================================== 39 ** Error-recovery functions 40 ** ======================================================= 41 */ 42 43 /* 44 ** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By 45 ** default, Lua handles errors with exceptions when compiling as 46 ** C++ code, with _longjmp/_setjmp when asked to use them, and with 47 ** longjmp/setjmp otherwise. 48 */ 49 #if !defined(LUAI_THROW) 50 51 #if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) 52 /* C++ exceptions */ 53 #define LUAI_THROW(L,c) throw(c) 54 #define LUAI_TRY(L,c,a) \ 55 try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; } 56 #define luai_jmpbuf int /* dummy variable */ 57 58 #elif defined(LUA_USE_ULONGJMP) 59 /* in Unix, try _longjmp/_setjmp (more efficient) */ 60 #define LUAI_THROW(L,c) _longjmp((c)->b, 1) 61 #define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a } 62 #define luai_jmpbuf jmp_buf 63 64 #else 65 /* default handling with long jumps */ 66 #define LUAI_THROW(L,c) longjmp((c)->b, 1) 67 #define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a } 68 #define luai_jmpbuf jmp_buf 69 70 #endif 71 72 #endif 73 74 75 76 /* chain list of long jump buffers */ 77 struct lua_longjmp { 78 struct lua_longjmp *previous; 79 luai_jmpbuf b; 80 volatile int status; /* error code */ 81 }; 82 83 84 static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { 85 switch (errcode) { 86 case LUA_ERRMEM: { /* memory error? */ 87 setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */ 88 break; 89 } 90 case LUA_ERRERR: { 91 setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); 92 break; 93 } 94 default: { 95 setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ 96 break; 97 } 98 } 99 L->top = oldtop + 1; 100 } 101 102 103 l_noret luaD_throw (lua_State *L, int errcode) { 104 if (L->errorJmp) { /* thread has an error handler? */ 105 L->errorJmp->status = errcode; /* set status */ 106 LUAI_THROW(L, L->errorJmp); /* jump to it */ 107 } 108 else { /* thread has no error handler */ 109 L->status = cast_byte(errcode); /* mark it as dead */ 110 if (G(L)->mainthread->errorJmp) { /* main thread has a handler? */ 111 setobjs2s(L, G(L)->mainthread->top++, L->top - 1); /* copy error obj. */ 112 luaD_throw(G(L)->mainthread, errcode); /* re-throw in main thread */ 113 } 114 else { /* no handler at all; abort */ 115 if (G(L)->panic) { /* panic function? */ 116 lua_unlock(L); 117 G(L)->panic(L); /* call it (last chance to jump out) */ 118 } 119 abort(); 120 } 121 } 122 } 123 124 125 int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { 126 unsigned short oldnCcalls = L->nCcalls; 127 struct lua_longjmp lj; 128 lj.status = LUA_OK; 129 lj.previous = L->errorJmp; /* chain new error handler */ 130 L->errorJmp = &lj; 131 LUAI_TRY(L, &lj, 132 (*f)(L, ud); 133 ); 134 L->errorJmp = lj.previous; /* restore old error handler */ 135 L->nCcalls = oldnCcalls; 136 return lj.status; 137 } 138 139 /* }====================================================== */ 140 141 142 static void correctstack (lua_State *L, TValue *oldstack) { 143 CallInfo *ci; 144 GCObject *up; 145 L->top = (L->top - oldstack) + L->stack; 146 for (up = L->openupval; up != NULL; up = up->gch.next) 147 gco2uv(up)->v = (gco2uv(up)->v - oldstack) + L->stack; 148 for (ci = L->ci; ci != NULL; ci = ci->previous) { 149 ci->top = (ci->top - oldstack) + L->stack; 150 ci->func = (ci->func - oldstack) + L->stack; 151 if (isLua(ci)) 152 ci->u.l.base = (ci->u.l.base - oldstack) + L->stack; 153 } 154 } 155 156 157 /* some space for error handling */ 158 #define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) 159 160 161 void luaD_reallocstack (lua_State *L, int newsize) { 162 TValue *oldstack = L->stack; 163 int lim = L->stacksize; 164 lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE); 165 lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK); 166 luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue); 167 for (; lim < newsize; lim++) 168 setnilvalue(L->stack + lim); /* erase new segment */ 169 L->stacksize = newsize; 170 L->stack_last = L->stack + newsize - EXTRA_STACK; 171 correctstack(L, oldstack); 172 } 173 174 175 void luaD_growstack (lua_State *L, int n) { 176 int size = L->stacksize; 177 if (size > LUAI_MAXSTACK) /* error after extra size? */ 178 luaD_throw(L, LUA_ERRERR); 179 else { 180 int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK; 181 int newsize = 2 * size; 182 if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK; 183 if (newsize < needed) newsize = needed; 184 if (newsize > LUAI_MAXSTACK) { /* stack overflow? */ 185 luaD_reallocstack(L, ERRORSTACKSIZE); 186 luaG_runerror(L, "stack overflow"); 187 } 188 else 189 luaD_reallocstack(L, newsize); 190 } 191 } 192 193 194 static int stackinuse (lua_State *L) { 195 CallInfo *ci; 196 StkId lim = L->top; 197 for (ci = L->ci; ci != NULL; ci = ci->previous) { 198 lua_assert(ci->top <= L->stack_last); 199 if (lim < ci->top) lim = ci->top; 200 } 201 return cast_int(lim - L->stack) + 1; /* part of stack in use */ 202 } 203 204 205 void luaD_shrinkstack (lua_State *L) { 206 int inuse = stackinuse(L); 207 int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK; 208 if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK; 209 if (inuse > LUAI_MAXSTACK || /* handling stack overflow? */ 210 goodsize >= L->stacksize) /* would grow instead of shrink? */ 211 condmovestack(L); /* don't change stack (change only for debugging) */ 212 else 213 luaD_reallocstack(L, goodsize); /* shrink it */ 214 } 215 216 217 void luaD_hook (lua_State *L, int event, int line) { 218 lua_Hook hook = L->hook; 219 if (hook && L->allowhook) { 220 CallInfo *ci = L->ci; 221 ptrdiff_t top = savestack(L, L->top); 222 ptrdiff_t ci_top = savestack(L, ci->top); 223 lua_Debug ar; 224 ar.event = event; 225 ar.currentline = line; 226 ar.i_ci = ci; 227 luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ 228 ci->top = L->top + LUA_MINSTACK; 229 lua_assert(ci->top <= L->stack_last); 230 L->allowhook = 0; /* cannot call hooks inside a hook */ 231 ci->callstatus |= CIST_HOOKED; 232 lua_unlock(L); 233 (*hook)(L, &ar); 234 lua_lock(L); 235 lua_assert(!L->allowhook); 236 L->allowhook = 1; 237 ci->top = restorestack(L, ci_top); 238 L->top = restorestack(L, top); 239 ci->callstatus &= ~CIST_HOOKED; 240 } 241 } 242 243 244 static void callhook (lua_State *L, CallInfo *ci) { 245 int hook = LUA_HOOKCALL; 246 ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ 247 if (isLua(ci->previous) && 248 GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) { 249 ci->callstatus |= CIST_TAIL; 250 hook = LUA_HOOKTAILCALL; 251 } 252 luaD_hook(L, hook, -1); 253 ci->u.l.savedpc--; /* correct 'pc' */ 254 } 255 256 257 static StkId adjust_varargs (lua_State *L, Proto *p, int actual) { 258 int i; 259 int nfixargs = p->numparams; 260 StkId base, fixed; 261 lua_assert(actual >= nfixargs); 262 /* move fixed parameters to final position */ 263 fixed = L->top - actual; /* first fixed argument */ 264 base = L->top; /* final position of first argument */ 265 for (i=0; i<nfixargs; i++) { 266 setobjs2s(L, L->top++, fixed + i); 267 setnilvalue(fixed + i); 268 } 269 return base; 270 } 271 272 273 static StkId tryfuncTM (lua_State *L, StkId func) { 274 const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL); 275 StkId p; 276 ptrdiff_t funcr = savestack(L, func); 277 if (!ttisfunction(tm)) 278 luaG_typeerror(L, func, "call"); 279 /* Open a hole inside the stack at `func' */ 280 for (p = L->top; p > func; p--) setobjs2s(L, p, p-1); 281 incr_top(L); 282 func = restorestack(L, funcr); /* previous call may change stack */ 283 setobj2s(L, func, tm); /* tag method is the new function to be called */ 284 return func; 285 } 286 287 288 289 #define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L))) 290 291 292 /* 293 ** returns true if function has been executed (C function) 294 */ 295 int luaD_precall (lua_State *L, StkId func, int nresults) { 296 lua_CFunction f; 297 CallInfo *ci; 298 int n; /* number of arguments (Lua) or returns (C) */ 299 ptrdiff_t funcr = savestack(L, func); 300 switch (ttype(func)) { 301 case LUA_TLCF: /* light C function */ 302 f = fvalue(func); 303 goto Cfunc; 304 case LUA_TCCL: { /* C closure */ 305 f = clCvalue(func)->f; 306 Cfunc: 307 luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ 308 ci = next_ci(L); /* now 'enter' new function */ 309 ci->nresults = nresults; 310 ci->func = restorestack(L, funcr); 311 ci->top = L->top + LUA_MINSTACK; 312 lua_assert(ci->top <= L->stack_last); 313 ci->callstatus = 0; 314 luaC_checkGC(L); /* stack grow uses memory */ 315 if (L->hookmask & LUA_MASKCALL) 316 luaD_hook(L, LUA_HOOKCALL, -1); 317 lua_unlock(L); 318 n = (*f)(L); /* do the actual call */ 319 lua_lock(L); 320 api_checknelems(L, n); 321 luaD_poscall(L, L->top - n); 322 return 1; 323 } 324 case LUA_TLCL: { /* Lua function: prepare its call */ 325 StkId base; 326 Proto *p = clLvalue(func)->p; 327 luaD_checkstack(L, p->maxstacksize); 328 func = restorestack(L, funcr); 329 n = cast_int(L->top - func) - 1; /* number of real arguments */ 330 for (; n < p->numparams; n++) 331 setnilvalue(L->top++); /* complete missing arguments */ 332 base = (!p->is_vararg) ? func + 1 : adjust_varargs(L, p, n); 333 ci = next_ci(L); /* now 'enter' new function */ 334 ci->nresults = nresults; 335 ci->func = func; 336 ci->u.l.base = base; 337 ci->top = base + p->maxstacksize; 338 lua_assert(ci->top <= L->stack_last); 339 ci->u.l.savedpc = p->code; /* starting point */ 340 ci->callstatus = CIST_LUA; 341 L->top = ci->top; 342 luaC_checkGC(L); /* stack grow uses memory */ 343 if (L->hookmask & LUA_MASKCALL) 344 callhook(L, ci); 345 return 0; 346 } 347 default: { /* not a function */ 348 func = tryfuncTM(L, func); /* retry with 'function' tag method */ 349 return luaD_precall(L, func, nresults); /* now it must be a function */ 350 } 351 } 352 } 353 354 355 int luaD_poscall (lua_State *L, StkId firstResult) { 356 StkId res; 357 int wanted, i; 358 CallInfo *ci = L->ci; 359 if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) { 360 if (L->hookmask & LUA_MASKRET) { 361 ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */ 362 luaD_hook(L, LUA_HOOKRET, -1); 363 firstResult = restorestack(L, fr); 364 } 365 L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */ 366 } 367 res = ci->func; /* res == final position of 1st result */ 368 wanted = ci->nresults; 369 L->ci = ci = ci->previous; /* back to caller */ 370 /* move results to correct place */ 371 for (i = wanted; i != 0 && firstResult < L->top; i--) 372 setobjs2s(L, res++, firstResult++); 373 while (i-- > 0) 374 setnilvalue(res++); 375 L->top = res; 376 return (wanted - LUA_MULTRET); /* 0 iff wanted == LUA_MULTRET */ 377 } 378 379 380 /* 381 ** Call a function (C or Lua). The function to be called is at *func. 382 ** The arguments are on the stack, right after the function. 383 ** When returns, all the results are on the stack, starting at the original 384 ** function position. 385 */ 386 void luaD_call (lua_State *L, StkId func, int nResults, int allowyield) { 387 if (++L->nCcalls >= LUAI_MAXCCALLS) { 388 if (L->nCcalls == LUAI_MAXCCALLS) 389 luaG_runerror(L, "C stack overflow"); 390 else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3))) 391 luaD_throw(L, LUA_ERRERR); /* error while handing stack error */ 392 } 393 if (!allowyield) L->nny++; 394 if (!luaD_precall(L, func, nResults)) /* is a Lua function? */ 395 luaV_execute(L); /* call it */ 396 if (!allowyield) L->nny--; 397 L->nCcalls--; 398 } 399 400 401 static void finishCcall (lua_State *L) { 402 CallInfo *ci = L->ci; 403 int n; 404 lua_assert(ci->u.c.k != NULL); /* must have a continuation */ 405 lua_assert(L->nny == 0); 406 if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */ 407 ci->callstatus &= ~CIST_YPCALL; /* finish 'lua_pcall' */ 408 L->errfunc = ci->u.c.old_errfunc; 409 } 410 /* finish 'lua_callk'/'lua_pcall' */ 411 adjustresults(L, ci->nresults); 412 /* call continuation function */ 413 if (!(ci->callstatus & CIST_STAT)) /* no call status? */ 414 ci->u.c.status = LUA_YIELD; /* 'default' status */ 415 lua_assert(ci->u.c.status != LUA_OK); 416 ci->callstatus = (ci->callstatus & ~(CIST_YPCALL | CIST_STAT)) | CIST_YIELDED; 417 lua_unlock(L); 418 n = (*ci->u.c.k)(L); 419 lua_lock(L); 420 api_checknelems(L, n); 421 /* finish 'luaD_precall' */ 422 luaD_poscall(L, L->top - n); 423 } 424 425 426 static void unroll (lua_State *L, void *ud) { 427 UNUSED(ud); 428 for (;;) { 429 if (L->ci == &L->base_ci) /* stack is empty? */ 430 return; /* coroutine finished normally */ 431 if (!isLua(L->ci)) /* C function? */ 432 finishCcall(L); 433 else { /* Lua function */ 434 luaV_finishOp(L); /* finish interrupted instruction */ 435 luaV_execute(L); /* execute down to higher C 'boundary' */ 436 } 437 } 438 } 439 440 441 /* 442 ** check whether thread has a suspended protected call 443 */ 444 static CallInfo *findpcall (lua_State *L) { 445 CallInfo *ci; 446 for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */ 447 if (ci->callstatus & CIST_YPCALL) 448 return ci; 449 } 450 return NULL; /* no pending pcall */ 451 } 452 453 454 static int recover (lua_State *L, int status) { 455 StkId oldtop; 456 CallInfo *ci = findpcall(L); 457 if (ci == NULL) return 0; /* no recovery point */ 458 /* "finish" luaD_pcall */ 459 oldtop = restorestack(L, ci->extra); 460 luaF_close(L, oldtop); 461 seterrorobj(L, status, oldtop); 462 L->ci = ci; 463 L->allowhook = ci->u.c.old_allowhook; 464 L->nny = 0; /* should be zero to be yieldable */ 465 luaD_shrinkstack(L); 466 L->errfunc = ci->u.c.old_errfunc; 467 ci->callstatus |= CIST_STAT; /* call has error status */ 468 ci->u.c.status = status; /* (here it is) */ 469 return 1; /* continue running the coroutine */ 470 } 471 472 473 /* 474 ** signal an error in the call to 'resume', not in the execution of the 475 ** coroutine itself. (Such errors should not be handled by any coroutine 476 ** error handler and should not kill the coroutine.) 477 */ 478 static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) { 479 L->top = firstArg; /* remove args from the stack */ 480 setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */ 481 api_incr_top(L); 482 luaD_throw(L, -1); /* jump back to 'lua_resume' */ 483 } 484 485 486 /* 487 ** do the work for 'lua_resume' in protected mode 488 */ 489 static void resume (lua_State *L, void *ud) { 490 int nCcalls = L->nCcalls; 491 StkId firstArg = cast(StkId, ud); 492 CallInfo *ci = L->ci; 493 if (nCcalls >= LUAI_MAXCCALLS) 494 resume_error(L, "C stack overflow", firstArg); 495 if (L->status == LUA_OK) { /* may be starting a coroutine */ 496 if (ci != &L->base_ci) /* not in base level? */ 497 resume_error(L, "cannot resume non-suspended coroutine", firstArg); 498 /* coroutine is in base level; start running it */ 499 if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */ 500 luaV_execute(L); /* call it */ 501 } 502 else if (L->status != LUA_YIELD) 503 resume_error(L, "cannot resume dead coroutine", firstArg); 504 else { /* resuming from previous yield */ 505 L->status = LUA_OK; 506 ci->func = restorestack(L, ci->extra); 507 if (isLua(ci)) /* yielded inside a hook? */ 508 luaV_execute(L); /* just continue running Lua code */ 509 else { /* 'common' yield */ 510 if (ci->u.c.k != NULL) { /* does it have a continuation? */ 511 int n; 512 ci->u.c.status = LUA_YIELD; /* 'default' status */ 513 ci->callstatus |= CIST_YIELDED; 514 lua_unlock(L); 515 n = (*ci->u.c.k)(L); /* call continuation */ 516 lua_lock(L); 517 api_checknelems(L, n); 518 firstArg = L->top - n; /* yield results come from continuation */ 519 } 520 luaD_poscall(L, firstArg); /* finish 'luaD_precall' */ 521 } 522 unroll(L, NULL); 523 } 524 lua_assert(nCcalls == L->nCcalls); 525 } 526 527 528 LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) { 529 int status; 530 lua_lock(L); 531 luai_userstateresume(L, nargs); 532 L->nCcalls = (from) ? from->nCcalls + 1 : 1; 533 L->nny = 0; /* allow yields */ 534 api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs); 535 status = luaD_rawrunprotected(L, resume, L->top - nargs); 536 if (status == -1) /* error calling 'lua_resume'? */ 537 status = LUA_ERRRUN; 538 else { /* yield or regular error */ 539 while (status != LUA_OK && status != LUA_YIELD) { /* error? */ 540 if (recover(L, status)) /* recover point? */ 541 status = luaD_rawrunprotected(L, unroll, NULL); /* run continuation */ 542 else { /* unrecoverable error */ 543 L->status = cast_byte(status); /* mark thread as `dead' */ 544 seterrorobj(L, status, L->top); 545 L->ci->top = L->top; 546 break; 547 } 548 } 549 lua_assert(status == L->status); 550 } 551 L->nny = 1; /* do not allow yields */ 552 L->nCcalls--; 553 lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0)); 554 lua_unlock(L); 555 return status; 556 } 557 558 559 LUA_API int lua_yieldk (lua_State *L, int nresults, int ctx, lua_CFunction k) { 560 CallInfo *ci = L->ci; 561 luai_userstateyield(L, nresults); 562 lua_lock(L); 563 api_checknelems(L, nresults); 564 if (L->nny > 0) { 565 if (L != G(L)->mainthread) 566 luaG_runerror(L, "attempt to yield across a C-call boundary"); 567 else 568 luaG_runerror(L, "attempt to yield from outside a coroutine"); 569 } 570 L->status = LUA_YIELD; 571 ci->extra = savestack(L, ci->func); /* save current 'func' */ 572 if (isLua(ci)) { /* inside a hook? */ 573 api_check(L, k == NULL, "hooks cannot continue after yielding"); 574 } 575 else { 576 if ((ci->u.c.k = k) != NULL) /* is there a continuation? */ 577 ci->u.c.ctx = ctx; /* save context */ 578 ci->func = L->top - nresults - 1; /* protect stack below results */ 579 luaD_throw(L, LUA_YIELD); 580 } 581 lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */ 582 lua_unlock(L); 583 return 0; /* return to 'luaD_hook' */ 584 } 585 586 587 int luaD_pcall (lua_State *L, Pfunc func, void *u, 588 ptrdiff_t old_top, ptrdiff_t ef) { 589 int status; 590 CallInfo *old_ci = L->ci; 591 lu_byte old_allowhooks = L->allowhook; 592 unsigned short old_nny = L->nny; 593 ptrdiff_t old_errfunc = L->errfunc; 594 L->errfunc = ef; 595 status = luaD_rawrunprotected(L, func, u); 596 if (status != LUA_OK) { /* an error occurred? */ 597 StkId oldtop = restorestack(L, old_top); 598 luaF_close(L, oldtop); /* close possible pending closures */ 599 seterrorobj(L, status, oldtop); 600 L->ci = old_ci; 601 L->allowhook = old_allowhooks; 602 L->nny = old_nny; 603 luaD_shrinkstack(L); 604 } 605 L->errfunc = old_errfunc; 606 return status; 607 } 608 609 610 611 /* 612 ** Execute a protected parser. 613 */ 614 struct SParser { /* data to `f_parser' */ 615 ZIO *z; 616 Mbuffer buff; /* dynamic structure used by the scanner */ 617 Dyndata dyd; /* dynamic structures used by the parser */ 618 const char *mode; 619 const char *name; 620 }; 621 622 623 static void checkmode (lua_State *L, const char *mode, const char *x) { 624 if (mode && strchr(mode, x[0]) == NULL) { 625 luaO_pushfstring(L, 626 "attempt to load a %s chunk (mode is " LUA_QS ")", x, mode); 627 luaD_throw(L, LUA_ERRSYNTAX); 628 } 629 } 630 631 632 static void f_parser (lua_State *L, void *ud) { 633 int i; 634 Closure *cl; 635 struct SParser *p = cast(struct SParser *, ud); 636 int c = zgetc(p->z); /* read first character */ 637 if (c == LUA_SIGNATURE[0]) { 638 checkmode(L, p->mode, "binary"); 639 cl = luaU_undump(L, p->z, &p->buff, p->name); 640 } 641 else { 642 checkmode(L, p->mode, "text"); 643 cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c); 644 } 645 lua_assert(cl->l.nupvalues == cl->l.p->sizeupvalues); 646 for (i = 0; i < cl->l.nupvalues; i++) { /* initialize upvalues */ 647 UpVal *up = luaF_newupval(L); 648 cl->l.upvals[i] = up; 649 luaC_objbarrier(L, cl, up); 650 } 651 } 652 653 654 int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, 655 const char *mode) { 656 struct SParser p; 657 int status; 658 L->nny++; /* cannot yield during parsing */ 659 p.z = z; p.name = name; p.mode = mode; 660 p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0; 661 p.dyd.gt.arr = NULL; p.dyd.gt.size = 0; 662 p.dyd.label.arr = NULL; p.dyd.label.size = 0; 663 luaZ_initbuffer(L, &p.buff); 664 status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc); 665 luaZ_freebuffer(L, &p.buff); 666 luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size); 667 luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size); 668 luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size); 669 L->nny--; 670 return status; 671 } 672 673 674
