ldo.c 20 KB

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  1. /*
  2. ** $Id: ldo.c,v 2.115 2014/03/21 13:52:33 roberto Exp roberto $
  3. ** Stack and Call structure of Lua
  4. ** See Copyright Notice in lua.h
  5. */
  6. #include <setjmp.h>
  7. #include <stdlib.h>
  8. #include <string.h>
  9. #define ldo_c
  10. #define LUA_CORE
  11. #include "lua.h"
  12. #include "lapi.h"
  13. #include "ldebug.h"
  14. #include "ldo.h"
  15. #include "lfunc.h"
  16. #include "lgc.h"
  17. #include "lmem.h"
  18. #include "lobject.h"
  19. #include "lopcodes.h"
  20. #include "lparser.h"
  21. #include "lstate.h"
  22. #include "lstring.h"
  23. #include "ltable.h"
  24. #include "ltm.h"
  25. #include "lundump.h"
  26. #include "lvm.h"
  27. #include "lzio.h"
  28. /*
  29. ** {======================================================
  30. ** Error-recovery functions
  31. ** =======================================================
  32. */
  33. /*
  34. ** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By
  35. ** default, Lua handles errors with exceptions when compiling as
  36. ** C++ code, with _longjmp/_setjmp when asked to use them, and with
  37. ** longjmp/setjmp otherwise.
  38. */
  39. #if !defined(LUAI_THROW) /* { */
  40. #if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) /* { */
  41. /* C++ exceptions */
  42. #define LUAI_THROW(L,c) throw(c)
  43. #define LUAI_TRY(L,c,a) \
  44. try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; }
  45. #define luai_jmpbuf int /* dummy variable */
  46. #elif defined(LUA_USE_POSIX) /* }{ */
  47. /* in POSIX, try _longjmp/_setjmp (more efficient) */
  48. #define LUAI_THROW(L,c) _longjmp((c)->b, 1)
  49. #define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a }
  50. #define luai_jmpbuf jmp_buf
  51. #else /* }{ */
  52. /* ANSI handling with long jumps */
  53. #define LUAI_THROW(L,c) longjmp((c)->b, 1)
  54. #define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a }
  55. #define luai_jmpbuf jmp_buf
  56. #endif /* } */
  57. #endif /* } */
  58. /* chain list of long jump buffers */
  59. struct lua_longjmp {
  60. struct lua_longjmp *previous;
  61. luai_jmpbuf b;
  62. volatile int status; /* error code */
  63. };
  64. static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
  65. switch (errcode) {
  66. case LUA_ERRMEM: { /* memory error? */
  67. setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */
  68. break;
  69. }
  70. case LUA_ERRERR: {
  71. setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
  72. break;
  73. }
  74. default: {
  75. setobjs2s(L, oldtop, L->top - 1); /* error message on current top */
  76. break;
  77. }
  78. }
  79. L->top = oldtop + 1;
  80. }
  81. l_noret luaD_throw (lua_State *L, int errcode) {
  82. if (L->errorJmp) { /* thread has an error handler? */
  83. L->errorJmp->status = errcode; /* set status */
  84. LUAI_THROW(L, L->errorJmp); /* jump to it */
  85. }
  86. else { /* thread has no error handler */
  87. L->status = cast_byte(errcode); /* mark it as dead */
  88. if (G(L)->mainthread->errorJmp) { /* main thread has a handler? */
  89. setobjs2s(L, G(L)->mainthread->top++, L->top - 1); /* copy error obj. */
  90. luaD_throw(G(L)->mainthread, errcode); /* re-throw in main thread */
  91. }
  92. else { /* no handler at all; abort */
  93. if (G(L)->panic) { /* panic function? */
  94. lua_unlock(L);
  95. G(L)->panic(L); /* call it (last chance to jump out) */
  96. }
  97. abort();
  98. }
  99. }
  100. }
  101. int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
  102. unsigned short oldnCcalls = L->nCcalls;
  103. struct lua_longjmp lj;
  104. lj.status = LUA_OK;
  105. lj.previous = L->errorJmp; /* chain new error handler */
  106. L->errorJmp = &lj;
  107. LUAI_TRY(L, &lj,
  108. (*f)(L, ud);
  109. );
  110. L->errorJmp = lj.previous; /* restore old error handler */
  111. L->nCcalls = oldnCcalls;
  112. return lj.status;
  113. }
  114. /* }====================================================== */
  115. static void correctstack (lua_State *L, TValue *oldstack) {
  116. CallInfo *ci;
  117. UpVal *up;
  118. L->top = (L->top - oldstack) + L->stack;
  119. for (up = L->openupval; up != NULL; up = up->u.open.next)
  120. up->v = (up->v - oldstack) + L->stack;
  121. for (ci = L->ci; ci != NULL; ci = ci->previous) {
  122. ci->top = (ci->top - oldstack) + L->stack;
  123. ci->func = (ci->func - oldstack) + L->stack;
  124. if (isLua(ci))
  125. ci->u.l.base = (ci->u.l.base - oldstack) + L->stack;
  126. }
  127. }
  128. /* some space for error handling */
  129. #define ERRORSTACKSIZE (LUAI_MAXSTACK + 200)
  130. void luaD_reallocstack (lua_State *L, int newsize) {
  131. TValue *oldstack = L->stack;
  132. int lim = L->stacksize;
  133. lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
  134. lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK);
  135. luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue);
  136. for (; lim < newsize; lim++)
  137. setnilvalue(L->stack + lim); /* erase new segment */
  138. L->stacksize = newsize;
  139. L->stack_last = L->stack + newsize - EXTRA_STACK;
  140. correctstack(L, oldstack);
  141. }
  142. void luaD_growstack (lua_State *L, int n) {
  143. int size = L->stacksize;
  144. if (size > LUAI_MAXSTACK) /* error after extra size? */
  145. luaD_throw(L, LUA_ERRERR);
  146. else {
  147. int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK;
  148. int newsize = 2 * size;
  149. if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK;
  150. if (newsize < needed) newsize = needed;
  151. if (newsize > LUAI_MAXSTACK) { /* stack overflow? */
  152. luaD_reallocstack(L, ERRORSTACKSIZE);
  153. luaG_runerror(L, "stack overflow");
  154. }
  155. else
  156. luaD_reallocstack(L, newsize);
  157. }
  158. }
  159. static int stackinuse (lua_State *L) {
  160. CallInfo *ci;
  161. StkId lim = L->top;
  162. for (ci = L->ci; ci != NULL; ci = ci->previous) {
  163. lua_assert(ci->top <= L->stack_last);
  164. if (lim < ci->top) lim = ci->top;
  165. }
  166. return cast_int(lim - L->stack) + 1; /* part of stack in use */
  167. }
  168. void luaD_shrinkstack (lua_State *L) {
  169. int inuse = stackinuse(L);
  170. int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
  171. if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK;
  172. if (L->stacksize > LUAI_MAXSTACK) /* was handling stack overflow? */
  173. luaE_freeCI(L); /* free all CIs (list grew because of an error) */
  174. else
  175. luaE_shrinkCI(L); /* shrink list */
  176. if (inuse > LUAI_MAXSTACK || /* still handling stack overflow? */
  177. goodsize >= L->stacksize) /* would grow instead of shrink? */
  178. condmovestack(L); /* don't change stack (change only for debugging) */
  179. else
  180. luaD_reallocstack(L, goodsize); /* shrink it */
  181. }
  182. void luaD_hook (lua_State *L, int event, int line) {
  183. lua_Hook hook = L->hook;
  184. if (hook && L->allowhook) {
  185. CallInfo *ci = L->ci;
  186. ptrdiff_t top = savestack(L, L->top);
  187. ptrdiff_t ci_top = savestack(L, ci->top);
  188. lua_Debug ar;
  189. ar.event = event;
  190. ar.currentline = line;
  191. ar.i_ci = ci;
  192. luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
  193. ci->top = L->top + LUA_MINSTACK;
  194. lua_assert(ci->top <= L->stack_last);
  195. L->allowhook = 0; /* cannot call hooks inside a hook */
  196. ci->callstatus |= CIST_HOOKED;
  197. lua_unlock(L);
  198. (*hook)(L, &ar);
  199. lua_lock(L);
  200. lua_assert(!L->allowhook);
  201. L->allowhook = 1;
  202. ci->top = restorestack(L, ci_top);
  203. L->top = restorestack(L, top);
  204. ci->callstatus &= ~CIST_HOOKED;
  205. }
  206. }
  207. static void callhook (lua_State *L, CallInfo *ci) {
  208. int hook = LUA_HOOKCALL;
  209. ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
  210. if (isLua(ci->previous) &&
  211. GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
  212. ci->callstatus |= CIST_TAIL;
  213. hook = LUA_HOOKTAILCALL;
  214. }
  215. luaD_hook(L, hook, -1);
  216. ci->u.l.savedpc--; /* correct 'pc' */
  217. }
  218. static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
  219. int i;
  220. int nfixargs = p->numparams;
  221. StkId base, fixed;
  222. lua_assert(actual >= nfixargs);
  223. /* move fixed parameters to final position */
  224. luaD_checkstack(L, p->maxstacksize); /* check again for new 'base' */
  225. fixed = L->top - actual; /* first fixed argument */
  226. base = L->top; /* final position of first argument */
  227. for (i=0; i<nfixargs; i++) {
  228. setobjs2s(L, L->top++, fixed + i);
  229. setnilvalue(fixed + i);
  230. }
  231. return base;
  232. }
  233. static StkId tryfuncTM (lua_State *L, StkId func) {
  234. const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL);
  235. StkId p;
  236. ptrdiff_t funcr = savestack(L, func);
  237. if (!ttisfunction(tm))
  238. luaG_typeerror(L, func, "call");
  239. /* Open a hole inside the stack at `func' */
  240. for (p = L->top; p > func; p--) setobjs2s(L, p, p-1);
  241. incr_top(L);
  242. func = restorestack(L, funcr); /* previous call may change stack */
  243. setobj2s(L, func, tm); /* tag method is the new function to be called */
  244. return func;
  245. }
  246. #define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
  247. /*
  248. ** returns true if function has been executed (C function)
  249. */
  250. int luaD_precall (lua_State *L, StkId func, int nresults) {
  251. lua_CFunction f;
  252. CallInfo *ci;
  253. int n; /* number of arguments (Lua) or returns (C) */
  254. ptrdiff_t funcr = savestack(L, func);
  255. switch (ttype(func)) {
  256. case LUA_TLCF: /* light C function */
  257. f = fvalue(func);
  258. goto Cfunc;
  259. case LUA_TCCL: { /* C closure */
  260. f = clCvalue(func)->f;
  261. Cfunc:
  262. luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
  263. ci = next_ci(L); /* now 'enter' new function */
  264. ci->nresults = nresults;
  265. ci->func = restorestack(L, funcr);
  266. ci->top = L->top + LUA_MINSTACK;
  267. lua_assert(ci->top <= L->stack_last);
  268. ci->callstatus = 0;
  269. luaC_checkGC(L); /* stack grow uses memory */
  270. if (L->hookmask & LUA_MASKCALL)
  271. luaD_hook(L, LUA_HOOKCALL, -1);
  272. lua_unlock(L);
  273. n = (*f)(L); /* do the actual call */
  274. lua_lock(L);
  275. api_checknelems(L, n);
  276. luaD_poscall(L, L->top - n);
  277. return 1;
  278. }
  279. case LUA_TLCL: { /* Lua function: prepare its call */
  280. StkId base;
  281. Proto *p = clLvalue(func)->p;
  282. n = cast_int(L->top - func) - 1; /* number of real arguments */
  283. luaD_checkstack(L, p->maxstacksize);
  284. for (; n < p->numparams; n++)
  285. setnilvalue(L->top++); /* complete missing arguments */
  286. if (!p->is_vararg) {
  287. func = restorestack(L, funcr);
  288. base = func + 1;
  289. }
  290. else {
  291. base = adjust_varargs(L, p, n);
  292. func = restorestack(L, funcr); /* previous call can change stack */
  293. }
  294. ci = next_ci(L); /* now 'enter' new function */
  295. ci->nresults = nresults;
  296. ci->func = func;
  297. ci->u.l.base = base;
  298. ci->top = base + p->maxstacksize;
  299. lua_assert(ci->top <= L->stack_last);
  300. ci->u.l.savedpc = p->code; /* starting point */
  301. ci->callstatus = CIST_LUA;
  302. L->top = ci->top;
  303. luaC_checkGC(L); /* stack grow uses memory */
  304. if (L->hookmask & LUA_MASKCALL)
  305. callhook(L, ci);
  306. return 0;
  307. }
  308. default: { /* not a function */
  309. func = tryfuncTM(L, func); /* retry with 'function' tag method */
  310. return luaD_precall(L, func, nresults); /* now it must be a function */
  311. }
  312. }
  313. }
  314. int luaD_poscall (lua_State *L, StkId firstResult) {
  315. StkId res;
  316. int wanted, i;
  317. CallInfo *ci = L->ci;
  318. if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
  319. if (L->hookmask & LUA_MASKRET) {
  320. ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
  321. luaD_hook(L, LUA_HOOKRET, -1);
  322. firstResult = restorestack(L, fr);
  323. }
  324. L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */
  325. }
  326. res = ci->func; /* res == final position of 1st result */
  327. wanted = ci->nresults;
  328. L->ci = ci = ci->previous; /* back to caller */
  329. /* move results to correct place */
  330. for (i = wanted; i != 0 && firstResult < L->top; i--)
  331. setobjs2s(L, res++, firstResult++);
  332. while (i-- > 0)
  333. setnilvalue(res++);
  334. L->top = res;
  335. return (wanted - LUA_MULTRET); /* 0 iff wanted == LUA_MULTRET */
  336. }
  337. /*
  338. ** Call a function (C or Lua). The function to be called is at *func.
  339. ** The arguments are on the stack, right after the function.
  340. ** When returns, all the results are on the stack, starting at the original
  341. ** function position.
  342. */
  343. void luaD_call (lua_State *L, StkId func, int nResults, int allowyield) {
  344. if (++L->nCcalls >= LUAI_MAXCCALLS) {
  345. if (L->nCcalls == LUAI_MAXCCALLS)
  346. luaG_runerror(L, "C stack overflow");
  347. else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3)))
  348. luaD_throw(L, LUA_ERRERR); /* error while handing stack error */
  349. }
  350. if (!allowyield) L->nny++;
  351. if (!luaD_precall(L, func, nResults)) /* is a Lua function? */
  352. luaV_execute(L); /* call it */
  353. if (!allowyield) L->nny--;
  354. L->nCcalls--;
  355. }
  356. static void finishCcall (lua_State *L) {
  357. CallInfo *ci = L->ci;
  358. int n;
  359. lua_assert(ci->u.c.k != NULL); /* must have a continuation */
  360. lua_assert(L->nny == 0);
  361. if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */
  362. ci->callstatus &= ~CIST_YPCALL; /* finish 'lua_pcall' */
  363. L->errfunc = ci->u.c.old_errfunc;
  364. }
  365. /* finish 'lua_callk'/'lua_pcall' */
  366. adjustresults(L, ci->nresults);
  367. /* call continuation function */
  368. if (!(ci->callstatus & CIST_STAT)) /* no call status? */
  369. ci->u.c.status = LUA_YIELD; /* 'default' status */
  370. lua_assert(ci->u.c.status != LUA_OK);
  371. ci->callstatus = (ci->callstatus & ~(CIST_YPCALL | CIST_STAT)) | CIST_YIELDED;
  372. lua_unlock(L);
  373. n = (*ci->u.c.k)(L);
  374. lua_lock(L);
  375. api_checknelems(L, n);
  376. /* finish 'luaD_precall' */
  377. luaD_poscall(L, L->top - n);
  378. }
  379. static void unroll (lua_State *L, void *ud) {
  380. UNUSED(ud);
  381. for (;;) {
  382. if (L->ci == &L->base_ci) /* stack is empty? */
  383. return; /* coroutine finished normally */
  384. if (!isLua(L->ci)) /* C function? */
  385. finishCcall(L);
  386. else { /* Lua function */
  387. luaV_finishOp(L); /* finish interrupted instruction */
  388. luaV_execute(L); /* execute down to higher C 'boundary' */
  389. }
  390. }
  391. }
  392. /*
  393. ** check whether thread has a suspended protected call
  394. */
  395. static CallInfo *findpcall (lua_State *L) {
  396. CallInfo *ci;
  397. for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */
  398. if (ci->callstatus & CIST_YPCALL)
  399. return ci;
  400. }
  401. return NULL; /* no pending pcall */
  402. }
  403. static int recover (lua_State *L, int status) {
  404. StkId oldtop;
  405. CallInfo *ci = findpcall(L);
  406. if (ci == NULL) return 0; /* no recovery point */
  407. /* "finish" luaD_pcall */
  408. oldtop = restorestack(L, ci->extra);
  409. luaF_close(L, oldtop);
  410. seterrorobj(L, status, oldtop);
  411. L->ci = ci;
  412. L->allowhook = ci->u.c.old_allowhook;
  413. L->nny = 0; /* should be zero to be yieldable */
  414. luaD_shrinkstack(L);
  415. L->errfunc = ci->u.c.old_errfunc;
  416. ci->callstatus |= CIST_STAT; /* call has error status */
  417. ci->u.c.status = status; /* (here it is) */
  418. return 1; /* continue running the coroutine */
  419. }
  420. /*
  421. ** signal an error in the call to 'resume', not in the execution of the
  422. ** coroutine itself. (Such errors should not be handled by any coroutine
  423. ** error handler and should not kill the coroutine.)
  424. */
  425. static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
  426. L->top = firstArg; /* remove args from the stack */
  427. setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */
  428. api_incr_top(L);
  429. luaD_throw(L, -1); /* jump back to 'lua_resume' */
  430. }
  431. /*
  432. ** do the work for 'lua_resume' in protected mode
  433. */
  434. static void resume (lua_State *L, void *ud) {
  435. int nCcalls = L->nCcalls;
  436. StkId firstArg = cast(StkId, ud);
  437. CallInfo *ci = L->ci;
  438. if (nCcalls >= LUAI_MAXCCALLS)
  439. resume_error(L, "C stack overflow", firstArg);
  440. if (L->status == LUA_OK) { /* may be starting a coroutine */
  441. if (ci != &L->base_ci) /* not in base level? */
  442. resume_error(L, "cannot resume non-suspended coroutine", firstArg);
  443. /* coroutine is in base level; start running it */
  444. if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */
  445. luaV_execute(L); /* call it */
  446. }
  447. else if (L->status != LUA_YIELD)
  448. resume_error(L, "cannot resume dead coroutine", firstArg);
  449. else { /* resuming from previous yield */
  450. L->status = LUA_OK;
  451. ci->func = restorestack(L, ci->extra);
  452. if (isLua(ci)) /* yielded inside a hook? */
  453. luaV_execute(L); /* just continue running Lua code */
  454. else { /* 'common' yield */
  455. if (ci->u.c.k != NULL) { /* does it have a continuation? */
  456. int n;
  457. ci->u.c.status = LUA_YIELD; /* 'default' status */
  458. ci->callstatus |= CIST_YIELDED;
  459. lua_unlock(L);
  460. n = (*ci->u.c.k)(L); /* call continuation */
  461. lua_lock(L);
  462. api_checknelems(L, n);
  463. firstArg = L->top - n; /* yield results come from continuation */
  464. }
  465. luaD_poscall(L, firstArg); /* finish 'luaD_precall' */
  466. }
  467. unroll(L, NULL);
  468. }
  469. lua_assert(nCcalls == L->nCcalls);
  470. }
  471. LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
  472. int status;
  473. int oldnny = L->nny; /* save 'nny' */
  474. lua_lock(L);
  475. luai_userstateresume(L, nargs);
  476. L->nCcalls = (from) ? from->nCcalls + 1 : 1;
  477. L->nny = 0; /* allow yields */
  478. api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
  479. status = luaD_rawrunprotected(L, resume, L->top - nargs);
  480. if (status == -1) /* error calling 'lua_resume'? */
  481. status = LUA_ERRRUN;
  482. else { /* yield or regular error */
  483. while (status != LUA_OK && status != LUA_YIELD) { /* error? */
  484. if (recover(L, status)) /* recover point? */
  485. status = luaD_rawrunprotected(L, unroll, NULL); /* run continuation */
  486. else { /* unrecoverable error */
  487. L->status = cast_byte(status); /* mark thread as `dead' */
  488. seterrorobj(L, status, L->top);
  489. L->ci->top = L->top;
  490. break;
  491. }
  492. }
  493. lua_assert(status == L->status);
  494. }
  495. L->nny = oldnny; /* restore 'nny' */
  496. L->nCcalls--;
  497. lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
  498. lua_unlock(L);
  499. return status;
  500. }
  501. LUA_API int lua_isyieldable (lua_State *L) {
  502. return (L->nny == 0);
  503. }
  504. LUA_API int lua_yieldk (lua_State *L, int nresults, int ctx, lua_CFunction k) {
  505. CallInfo *ci = L->ci;
  506. luai_userstateyield(L, nresults);
  507. lua_lock(L);
  508. api_checknelems(L, nresults);
  509. if (L->nny > 0) {
  510. if (L != G(L)->mainthread)
  511. luaG_runerror(L, "attempt to yield across a C-call boundary");
  512. else
  513. luaG_runerror(L, "attempt to yield from outside a coroutine");
  514. }
  515. L->status = LUA_YIELD;
  516. ci->extra = savestack(L, ci->func); /* save current 'func' */
  517. if (isLua(ci)) { /* inside a hook? */
  518. api_check(L, k == NULL, "hooks cannot continue after yielding");
  519. }
  520. else {
  521. if ((ci->u.c.k = k) != NULL) /* is there a continuation? */
  522. ci->u.c.ctx = ctx; /* save context */
  523. ci->func = L->top - nresults - 1; /* protect stack below results */
  524. luaD_throw(L, LUA_YIELD);
  525. }
  526. lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */
  527. lua_unlock(L);
  528. return 0; /* return to 'luaD_hook' */
  529. }
  530. int luaD_pcall (lua_State *L, Pfunc func, void *u,
  531. ptrdiff_t old_top, ptrdiff_t ef) {
  532. int status;
  533. CallInfo *old_ci = L->ci;
  534. lu_byte old_allowhooks = L->allowhook;
  535. unsigned short old_nny = L->nny;
  536. ptrdiff_t old_errfunc = L->errfunc;
  537. L->errfunc = ef;
  538. status = luaD_rawrunprotected(L, func, u);
  539. if (status != LUA_OK) { /* an error occurred? */
  540. StkId oldtop = restorestack(L, old_top);
  541. luaF_close(L, oldtop); /* close possible pending closures */
  542. seterrorobj(L, status, oldtop);
  543. L->ci = old_ci;
  544. L->allowhook = old_allowhooks;
  545. L->nny = old_nny;
  546. luaD_shrinkstack(L);
  547. }
  548. L->errfunc = old_errfunc;
  549. return status;
  550. }
  551. /*
  552. ** Execute a protected parser.
  553. */
  554. struct SParser { /* data to `f_parser' */
  555. ZIO *z;
  556. Mbuffer buff; /* dynamic structure used by the scanner */
  557. Dyndata dyd; /* dynamic structures used by the parser */
  558. const char *mode;
  559. const char *name;
  560. };
  561. static void checkmode (lua_State *L, const char *mode, const char *x) {
  562. if (mode && strchr(mode, x[0]) == NULL) {
  563. luaO_pushfstring(L,
  564. "attempt to load a %s chunk (mode is " LUA_QS ")", x, mode);
  565. luaD_throw(L, LUA_ERRSYNTAX);
  566. }
  567. }
  568. static void f_parser (lua_State *L, void *ud) {
  569. Closure *cl;
  570. struct SParser *p = cast(struct SParser *, ud);
  571. int c = zgetc(p->z); /* read first character */
  572. if (c == LUA_SIGNATURE[0]) {
  573. checkmode(L, p->mode, "binary");
  574. cl = luaU_undump(L, p->z, &p->buff, p->name);
  575. }
  576. else {
  577. checkmode(L, p->mode, "text");
  578. cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
  579. }
  580. lua_assert(cl->l.nupvalues == cl->l.p->sizeupvalues);
  581. luaF_initupvals(L, &cl->l);
  582. }
  583. int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
  584. const char *mode) {
  585. struct SParser p;
  586. int status;
  587. L->nny++; /* cannot yield during parsing */
  588. p.z = z; p.name = name; p.mode = mode;
  589. p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0;
  590. p.dyd.gt.arr = NULL; p.dyd.gt.size = 0;
  591. p.dyd.label.arr = NULL; p.dyd.label.size = 0;
  592. luaZ_initbuffer(L, &p.buff);
  593. status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc);
  594. luaZ_freebuffer(L, &p.buff);
  595. luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size);
  596. luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size);
  597. luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size);
  598. L->nny--;
  599. return status;
  600. }