1 /* 2 ** $Id: lauxlib.c,v 1.248 2013/03/21 13:54:57 roberto Exp $ 3 ** Auxiliary functions for building Lua libraries 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #include <errno.h> 9 #include <stdarg.h> 10 #include <stdio.h> 11 #include <stdlib.h> 12 #include <string.h> 13 14 15 /* This file uses only the official API of Lua. 16 ** Any function declared here could be written as an application function. 17 */ 18 19 #define lauxlib_c 20 #define LUA_LIB 21 22 #include "lua.h" 23 24 #include "lauxlib.h" 25 26 27 /* 28 ** {====================================================== 29 ** Traceback 30 ** ======================================================= 31 */ 32 33 34 #define LEVELS1 12 /* size of the first part of the stack */ 35 #define LEVELS2 10 /* size of the second part of the stack */ 36 37 38 39 /* 40 ** search for 'objidx' in table at index -1. 41 ** return 1 + string at top if find a good name. 42 */ 43 static int findfield (lua_State *L, int objidx, int level) { 44 if (level == 0 || !lua_istable(L, -1)) 45 return 0; /* not found */ 46 lua_pushnil(L); /* start 'next' loop */ 47 while (lua_next(L, -2)) { /* for each pair in table */ 48 if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */ 49 if (lua_rawequal(L, objidx, -1)) { /* found object? */ 50 lua_pop(L, 1); /* remove value (but keep name) */ 51 return 1; 52 } 53 else if (findfield(L, objidx, level - 1)) { /* try recursively */ 54 lua_remove(L, -2); /* remove table (but keep name) */ 55 lua_pushliteral(L, "."); 56 lua_insert(L, -2); /* place '.' between the two names */ 57 lua_concat(L, 3); 58 return 1; 59 } 60 } 61 lua_pop(L, 1); /* remove value */ 62 } 63 return 0; /* not found */ 64 } 65 66 67 static int pushglobalfuncname (lua_State *L, lua_Debug *ar) { 68 int top = lua_gettop(L); 69 lua_getinfo(L, "f", ar); /* push function */ 70 lua_pushglobaltable(L); 71 if (findfield(L, top + 1, 2)) { 72 lua_copy(L, -1, top + 1); /* move name to proper place */ 73 lua_pop(L, 2); /* remove pushed values */ 74 return 1; 75 } 76 else { 77 lua_settop(L, top); /* remove function and global table */ 78 return 0; 79 } 80 } 81 82 83 static void pushfuncname (lua_State *L, lua_Debug *ar) { 84 if (*ar->namewhat != '\0') /* is there a name? */ 85 lua_pushfstring(L, "function " LUA_QS, ar->name); 86 else if (*ar->what == 'm') /* main? */ 87 lua_pushliteral(L, "main chunk"); 88 else if (*ar->what == 'C') { 89 if (pushglobalfuncname(L, ar)) { 90 lua_pushfstring(L, "function " LUA_QS, lua_tostring(L, -1)); 91 lua_remove(L, -2); /* remove name */ 92 } 93 else 94 lua_pushliteral(L, "?"); 95 } 96 else 97 lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined); 98 } 99 100 101 static int countlevels (lua_State *L) { 102 lua_Debug ar; 103 int li = 1, le = 1; 104 /* find an upper bound */ 105 while (lua_getstack(L, le, &ar)) { li = le; le *= 2; } 106 /* do a binary search */ 107 while (li < le) { 108 int m = (li + le)/2; 109 if (lua_getstack(L, m, &ar)) li = m + 1; 110 else le = m; 111 } 112 return le - 1; 113 } 114 115 116 LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, 117 const char *msg, int level) { 118 lua_Debug ar; 119 int top = lua_gettop(L); 120 int numlevels = countlevels(L1); 121 int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0; 122 if (msg) lua_pushfstring(L, "%s\n", msg); 123 lua_pushliteral(L, "stack traceback:"); 124 while (lua_getstack(L1, level++, &ar)) { 125 if (level == mark) { /* too many levels? */ 126 lua_pushliteral(L, "\n\t..."); /* add a '...' */ 127 level = numlevels - LEVELS2; /* and skip to last ones */ 128 } 129 else { 130 lua_getinfo(L1, "Slnt", &ar); 131 lua_pushfstring(L, "\n\t%s:", ar.short_src); 132 if (ar.currentline > 0) 133 lua_pushfstring(L, "%d:", ar.currentline); 134 lua_pushliteral(L, " in "); 135 pushfuncname(L, &ar); 136 if (ar.istailcall) 137 lua_pushliteral(L, "\n\t(...tail calls...)"); 138 lua_concat(L, lua_gettop(L) - top); 139 } 140 } 141 lua_concat(L, lua_gettop(L) - top); 142 } 143 144 /* }====================================================== */ 145 146 147 /* 148 ** {====================================================== 149 ** Error-report functions 150 ** ======================================================= 151 */ 152 153 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) { 154 lua_Debug ar; 155 if (!lua_getstack(L, 0, &ar)) /* no stack frame? */ 156 return luaL_error(L, "bad argument #%d (%s)", narg, extramsg); 157 lua_getinfo(L, "n", &ar); 158 if (strcmp(ar.namewhat, "method") == 0) { 159 narg--; /* do not count `self' */ 160 if (narg == 0) /* error is in the self argument itself? */ 161 return luaL_error(L, "calling " LUA_QS " on bad self (%s)", 162 ar.name, extramsg); 163 } 164 if (ar.name == NULL) 165 ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?"; 166 return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)", 167 narg, ar.name, extramsg); 168 } 169 170 171 static int typeerror (lua_State *L, int narg, const char *tname) { 172 const char *msg = lua_pushfstring(L, "%s expected, got %s", 173 tname, luaL_typename(L, narg)); 174 return luaL_argerror(L, narg, msg); 175 } 176 177 178 static void tag_error (lua_State *L, int narg, int tag) { 179 typeerror(L, narg, lua_typename(L, tag)); 180 } 181 182 183 LUALIB_API void luaL_where (lua_State *L, int level) { 184 lua_Debug ar; 185 if (lua_getstack(L, level, &ar)) { /* check function at level */ 186 lua_getinfo(L, "Sl", &ar); /* get info about it */ 187 if (ar.currentline > 0) { /* is there info? */ 188 lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline); 189 return; 190 } 191 } 192 lua_pushliteral(L, ""); /* else, no information available... */ 193 } 194 195 196 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) { 197 va_list argp; 198 va_start(argp, fmt); 199 luaL_where(L, 1); 200 lua_pushvfstring(L, fmt, argp); 201 va_end(argp); 202 lua_concat(L, 2); 203 return lua_error(L); 204 } 205 206 207 LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) { 208 int en = errno; /* calls to Lua API may change this value */ 209 if (stat) { 210 lua_pushboolean(L, 1); 211 return 1; 212 } 213 else { 214 lua_pushnil(L); 215 if (fname) 216 lua_pushfstring(L, "%s: %s", fname, strerror(en)); 217 else 218 lua_pushstring(L, strerror(en)); 219 lua_pushinteger(L, en); 220 return 3; 221 } 222 } 223 224 225 #if !defined(inspectstat) /* { */ 226 227 #if defined(LUA_USE_POSIX) 228 229 #include <sys/wait.h> 230 231 /* 232 ** use appropriate macros to interpret 'pclose' return status 233 */ 234 #define inspectstat(stat,what) \ 235 if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \ 236 else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; } 237 238 #else 239 240 #define inspectstat(stat,what) /* no op */ 241 242 #endif 243 244 #endif /* } */ 245 246 247 LUALIB_API int luaL_execresult (lua_State *L, int stat) { 248 const char *what = "exit"; /* type of termination */ 249 if (stat == -1) /* error? */ 250 return luaL_fileresult(L, 0, NULL); 251 else { 252 inspectstat(stat, what); /* interpret result */ 253 if (*what == 'e' && stat == 0) /* successful termination? */ 254 lua_pushboolean(L, 1); 255 else 256 lua_pushnil(L); 257 lua_pushstring(L, what); 258 lua_pushinteger(L, stat); 259 return 3; /* return true/nil,what,code */ 260 } 261 } 262 263 /* }====================================================== */ 264 265 266 /* 267 ** {====================================================== 268 ** Userdata's metatable manipulation 269 ** ======================================================= 270 */ 271 272 LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { 273 luaL_getmetatable(L, tname); /* try to get metatable */ 274 if (!lua_isnil(L, -1)) /* name already in use? */ 275 return 0; /* leave previous value on top, but return 0 */ 276 lua_pop(L, 1); 277 lua_newtable(L); /* create metatable */ 278 lua_pushvalue(L, -1); 279 lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */ 280 return 1; 281 } 282 283 284 LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) { 285 luaL_getmetatable(L, tname); 286 lua_setmetatable(L, -2); 287 } 288 289 290 LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) { 291 void *p = lua_touserdata(L, ud); 292 if (p != NULL) { /* value is a userdata? */ 293 if (lua_getmetatable(L, ud)) { /* does it have a metatable? */ 294 luaL_getmetatable(L, tname); /* get correct metatable */ 295 if (!lua_rawequal(L, -1, -2)) /* not the same? */ 296 p = NULL; /* value is a userdata with wrong metatable */ 297 lua_pop(L, 2); /* remove both metatables */ 298 return p; 299 } 300 } 301 return NULL; /* value is not a userdata with a metatable */ 302 } 303 304 305 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { 306 void *p = luaL_testudata(L, ud, tname); 307 if (p == NULL) typeerror(L, ud, tname); 308 return p; 309 } 310 311 /* }====================================================== */ 312 313 314 /* 315 ** {====================================================== 316 ** Argument check functions 317 ** ======================================================= 318 */ 319 320 LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def, 321 const char *const lst[]) { 322 const char *name = (def) ? luaL_optstring(L, narg, def) : 323 luaL_checkstring(L, narg); 324 int i; 325 for (i=0; lst[i]; i++) 326 if (strcmp(lst[i], name) == 0) 327 return i; 328 return luaL_argerror(L, narg, 329 lua_pushfstring(L, "invalid option " LUA_QS, name)); 330 } 331 332 333 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) { 334 /* keep some extra space to run error routines, if needed */ 335 const int extra = LUA_MINSTACK; 336 if (!lua_checkstack(L, space + extra)) { 337 if (msg) 338 luaL_error(L, "stack overflow (%s)", msg); 339 else 340 luaL_error(L, "stack overflow"); 341 } 342 } 343 344 345 LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) { 346 if (lua_type(L, narg) != t) 347 tag_error(L, narg, t); 348 } 349 350 351 LUALIB_API void luaL_checkany (lua_State *L, int narg) { 352 if (lua_type(L, narg) == LUA_TNONE) 353 luaL_argerror(L, narg, "value expected"); 354 } 355 356 357 LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) { 358 const char *s = lua_tolstring(L, narg, len); 359 if (!s) tag_error(L, narg, LUA_TSTRING); 360 return s; 361 } 362 363 364 LUALIB_API const char *luaL_optlstring (lua_State *L, int narg, 365 const char *def, size_t *len) { 366 if (lua_isnoneornil(L, narg)) { 367 if (len) 368 *len = (def ? strlen(def) : 0); 369 return def; 370 } 371 else return luaL_checklstring(L, narg, len); 372 } 373 374 375 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) { 376 int isnum; 377 lua_Number d = lua_tonumberx(L, narg, &isnum); 378 if (!isnum) 379 tag_error(L, narg, LUA_TNUMBER); 380 return d; 381 } 382 383 384 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) { 385 return luaL_opt(L, luaL_checknumber, narg, def); 386 } 387 388 389 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) { 390 int isnum; 391 lua_Integer d = lua_tointegerx(L, narg, &isnum); 392 if (!isnum) 393 tag_error(L, narg, LUA_TNUMBER); 394 return d; 395 } 396 397 398 LUALIB_API lua_Unsigned luaL_checkunsigned (lua_State *L, int narg) { 399 int isnum; 400 lua_Unsigned d = lua_tounsignedx(L, narg, &isnum); 401 if (!isnum) 402 tag_error(L, narg, LUA_TNUMBER); 403 return d; 404 } 405 406 407 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg, 408 lua_Integer def) { 409 return luaL_opt(L, luaL_checkinteger, narg, def); 410 } 411 412 413 LUALIB_API lua_Unsigned luaL_optunsigned (lua_State *L, int narg, 414 lua_Unsigned def) { 415 return luaL_opt(L, luaL_checkunsigned, narg, def); 416 } 417 418 /* }====================================================== */ 419 420 421 /* 422 ** {====================================================== 423 ** Generic Buffer manipulation 424 ** ======================================================= 425 */ 426 427 /* 428 ** check whether buffer is using a userdata on the stack as a temporary 429 ** buffer 430 */ 431 #define buffonstack(B) ((B)->b != (B)->initb) 432 433 434 /* 435 ** returns a pointer to a free area with at least 'sz' bytes 436 */ 437 LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) { 438 lua_State *L = B->L; 439 if (B->size - B->n < sz) { /* not enough space? */ 440 char *newbuff; 441 size_t newsize = B->size * 2; /* double buffer size */ 442 if (newsize - B->n < sz) /* not big enough? */ 443 newsize = B->n + sz; 444 if (newsize < B->n || newsize - B->n < sz) 445 luaL_error(L, "buffer too large"); 446 /* create larger buffer */ 447 newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char)); 448 /* move content to new buffer */ 449 memcpy(newbuff, B->b, B->n * sizeof(char)); 450 if (buffonstack(B)) 451 lua_remove(L, -2); /* remove old buffer */ 452 B->b = newbuff; 453 B->size = newsize; 454 } 455 return &B->b[B->n]; 456 } 457 458 459 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { 460 char *b = luaL_prepbuffsize(B, l); 461 memcpy(b, s, l * sizeof(char)); 462 luaL_addsize(B, l); 463 } 464 465 466 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) { 467 luaL_addlstring(B, s, strlen(s)); 468 } 469 470 471 LUALIB_API void luaL_pushresult (luaL_Buffer *B) { 472 lua_State *L = B->L; 473 lua_pushlstring(L, B->b, B->n); 474 if (buffonstack(B)) 475 lua_remove(L, -2); /* remove old buffer */ 476 } 477 478 479 LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) { 480 luaL_addsize(B, sz); 481 luaL_pushresult(B); 482 } 483 484 485 LUALIB_API void luaL_addvalue (luaL_Buffer *B) { 486 lua_State *L = B->L; 487 size_t l; 488 const char *s = lua_tolstring(L, -1, &l); 489 if (buffonstack(B)) 490 lua_insert(L, -2); /* put value below buffer */ 491 luaL_addlstring(B, s, l); 492 lua_remove(L, (buffonstack(B)) ? -2 : -1); /* remove value */ 493 } 494 495 496 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { 497 B->L = L; 498 B->b = B->initb; 499 B->n = 0; 500 B->size = LUAL_BUFFERSIZE; 501 } 502 503 504 LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) { 505 luaL_buffinit(L, B); 506 return luaL_prepbuffsize(B, sz); 507 } 508 509 /* }====================================================== */ 510 511 512 /* 513 ** {====================================================== 514 ** Reference system 515 ** ======================================================= 516 */ 517 518 /* index of free-list header */ 519 #define freelist 0 520 521 522 LUALIB_API int luaL_ref (lua_State *L, int t) { 523 int ref; 524 if (lua_isnil(L, -1)) { 525 lua_pop(L, 1); /* remove from stack */ 526 return LUA_REFNIL; /* `nil' has a unique fixed reference */ 527 } 528 t = lua_absindex(L, t); 529 lua_rawgeti(L, t, freelist); /* get first free element */ 530 ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */ 531 lua_pop(L, 1); /* remove it from stack */ 532 if (ref != 0) { /* any free element? */ 533 lua_rawgeti(L, t, ref); /* remove it from list */ 534 lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */ 535 } 536 else /* no free elements */ 537 ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */ 538 lua_rawseti(L, t, ref); 539 return ref; 540 } 541 542 543 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) { 544 if (ref >= 0) { 545 t = lua_absindex(L, t); 546 lua_rawgeti(L, t, freelist); 547 lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */ 548 lua_pushinteger(L, ref); 549 lua_rawseti(L, t, freelist); /* t[freelist] = ref */ 550 } 551 } 552 553 /* }====================================================== */ 554 555 556 /* 557 ** {====================================================== 558 ** Load functions 559 ** ======================================================= 560 */ 561 562 typedef struct LoadF { 563 int n; /* number of pre-read characters */ 564 FILE *f; /* file being read */ 565 char buff[LUAL_BUFFERSIZE]; /* area for reading file */ 566 } LoadF; 567 568 569 static const char *getF (lua_State *L, void *ud, size_t *size) { 570 LoadF *lf = (LoadF *)ud; 571 (void)L; /* not used */ 572 if (lf->n > 0) { /* are there pre-read characters to be read? */ 573 *size = lf->n; /* return them (chars already in buffer) */ 574 lf->n = 0; /* no more pre-read characters */ 575 } 576 else { /* read a block from file */ 577 /* 'fread' can return > 0 *and* set the EOF flag. If next call to 578 'getF' called 'fread', it might still wait for user input. 579 The next check avoids this problem. */ 580 if (feof(lf->f)) return NULL; 581 *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */ 582 } 583 return lf->buff; 584 } 585 586 587 static int errfile (lua_State *L, const char *what, int fnameindex) { 588 const char *serr = strerror(errno); 589 const char *filename = lua_tostring(L, fnameindex) + 1; 590 lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr); 591 lua_remove(L, fnameindex); 592 return LUA_ERRFILE; 593 } 594 595 596 static int skipBOM (LoadF *lf) { 597 const char *p = "\xEF\xBB\xBF"; /* Utf8 BOM mark */ 598 int c; 599 lf->n = 0; 600 do { 601 c = getc(lf->f); 602 if (c == EOF || c != *(const unsigned char *)p++) return c; 603 lf->buff[lf->n++] = c; /* to be read by the parser */ 604 } while (*p != '\0'); 605 lf->n = 0; /* prefix matched; discard it */ 606 return getc(lf->f); /* return next character */ 607 } 608 609 610 /* 611 ** reads the first character of file 'f' and skips an optional BOM mark 612 ** in its beginning plus its first line if it starts with '#'. Returns 613 ** true if it skipped the first line. In any case, '*cp' has the 614 ** first "valid" character of the file (after the optional BOM and 615 ** a first-line comment). 616 */ 617 static int skipcomment (LoadF *lf, int *cp) { 618 int c = *cp = skipBOM(lf); 619 if (c == '#') { /* first line is a comment (Unix exec. file)? */ 620 do { /* skip first line */ 621 c = getc(lf->f); 622 } while (c != EOF && c != '\n') ; 623 *cp = getc(lf->f); /* skip end-of-line, if present */ 624 return 1; /* there was a comment */ 625 } 626 else return 0; /* no comment */ 627 } 628 629 630 LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename, 631 const char *mode) { 632 LoadF lf; 633 int status, readstatus; 634 int c; 635 int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */ 636 if (filename == NULL) { 637 lua_pushliteral(L, "=stdin"); 638 lf.f = stdin; 639 } 640 else { 641 lua_pushfstring(L, "@%s", filename); 642 lf.f = fopen(filename, "r"); 643 if (lf.f == NULL) return errfile(L, "open", fnameindex); 644 } 645 if (skipcomment(&lf, &c)) /* read initial portion */ 646 lf.buff[lf.n++] = '\n'; /* add line to correct line numbers */ 647 if (c == LUA_SIGNATURE[0] && filename) { /* binary file? */ 648 lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */ 649 if (lf.f == NULL) return errfile(L, "reopen", fnameindex); 650 skipcomment(&lf, &c); /* re-read initial portion */ 651 } 652 if (c != EOF) 653 lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */ 654 status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode); 655 readstatus = ferror(lf.f); 656 if (filename) fclose(lf.f); /* close file (even in case of errors) */ 657 if (readstatus) { 658 lua_settop(L, fnameindex); /* ignore results from `lua_load' */ 659 return errfile(L, "read", fnameindex); 660 } 661 lua_remove(L, fnameindex); 662 return status; 663 } 664 665 666 typedef struct LoadS { 667 const char *s; 668 size_t size; 669 } LoadS; 670 671 672 static const char *getS (lua_State *L, void *ud, size_t *size) { 673 LoadS *ls = (LoadS *)ud; 674 (void)L; /* not used */ 675 if (ls->size == 0) return NULL; 676 *size = ls->size; 677 ls->size = 0; 678 return ls->s; 679 } 680 681 682 LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size, 683 const char *name, const char *mode) { 684 LoadS ls; 685 ls.s = buff; 686 ls.size = size; 687 return lua_load(L, getS, &ls, name, mode); 688 } 689 690 691 LUALIB_API int luaL_loadstring (lua_State *L, const char *s) { 692 return luaL_loadbuffer(L, s, strlen(s), s); 693 } 694 695 /* }====================================================== */ 696 697 698 699 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) { 700 if (!lua_getmetatable(L, obj)) /* no metatable? */ 701 return 0; 702 lua_pushstring(L, event); 703 lua_rawget(L, -2); 704 if (lua_isnil(L, -1)) { 705 lua_pop(L, 2); /* remove metatable and metafield */ 706 return 0; 707 } 708 else { 709 lua_remove(L, -2); /* remove only metatable */ 710 return 1; 711 } 712 } 713 714 715 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) { 716 obj = lua_absindex(L, obj); 717 if (!luaL_getmetafield(L, obj, event)) /* no metafield? */ 718 return 0; 719 lua_pushvalue(L, obj); 720 lua_call(L, 1, 1); 721 return 1; 722 } 723 724 725 LUALIB_API int luaL_len (lua_State *L, int idx) { 726 int l; 727 int isnum; 728 lua_len(L, idx); 729 l = (int)lua_tointegerx(L, -1, &isnum); 730 if (!isnum) 731 luaL_error(L, "object length is not a number"); 732 lua_pop(L, 1); /* remove object */ 733 return l; 734 } 735 736 737 LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) { 738 if (!luaL_callmeta(L, idx, "__tostring")) { /* no metafield? */ 739 switch (lua_type(L, idx)) { 740 case LUA_TNUMBER: 741 case LUA_TSTRING: 742 lua_pushvalue(L, idx); 743 break; 744 case LUA_TBOOLEAN: 745 lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false")); 746 break; 747 case LUA_TNIL: 748 lua_pushliteral(L, "nil"); 749 break; 750 default: 751 lua_pushfstring(L, "%s: %p", luaL_typename(L, idx), 752 lua_topointer(L, idx)); 753 break; 754 } 755 } 756 return lua_tolstring(L, -1, len); 757 } 758 759 760 /* 761 ** {====================================================== 762 ** Compatibility with 5.1 module functions 763 ** ======================================================= 764 */ 765 #if defined(LUA_COMPAT_MODULE) 766 767 static const char *luaL_findtable (lua_State *L, int idx, 768 const char *fname, int szhint) { 769 const char *e; 770 if (idx) lua_pushvalue(L, idx); 771 do { 772 e = strchr(fname, '.'); 773 if (e == NULL) e = fname + strlen(fname); 774 lua_pushlstring(L, fname, e - fname); 775 lua_rawget(L, -2); 776 if (lua_isnil(L, -1)) { /* no such field? */ 777 lua_pop(L, 1); /* remove this nil */ 778 lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */ 779 lua_pushlstring(L, fname, e - fname); 780 lua_pushvalue(L, -2); 781 lua_settable(L, -4); /* set new table into field */ 782 } 783 else if (!lua_istable(L, -1)) { /* field has a non-table value? */ 784 lua_pop(L, 2); /* remove table and value */ 785 return fname; /* return problematic part of the name */ 786 } 787 lua_remove(L, -2); /* remove previous table */ 788 fname = e + 1; 789 } while (*e == '.'); 790 return NULL; 791 } 792 793 794 /* 795 ** Count number of elements in a luaL_Reg list. 796 */ 797 static int libsize (const luaL_Reg *l) { 798 int size = 0; 799 for (; l && l->name; l++) size++; 800 return size; 801 } 802 803 804 /* 805 ** Find or create a module table with a given name. The function 806 ** first looks at the _LOADED table and, if that fails, try a 807 ** global variable with that name. In any case, leaves on the stack 808 ** the module table. 809 */ 810 LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname, 811 int sizehint) { 812 luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */ 813 lua_getfield(L, -1, modname); /* get _LOADED[modname] */ 814 if (!lua_istable(L, -1)) { /* not found? */ 815 lua_pop(L, 1); /* remove previous result */ 816 /* try global variable (and create one if it does not exist) */ 817 lua_pushglobaltable(L); 818 if (luaL_findtable(L, 0, modname, sizehint) != NULL) 819 luaL_error(L, "name conflict for module " LUA_QS, modname); 820 lua_pushvalue(L, -1); 821 lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */ 822 } 823 lua_remove(L, -2); /* remove _LOADED table */ 824 } 825 826 827 LUALIB_API void luaL_openlib (lua_State *L, const char *libname, 828 const luaL_Reg *l, int nup) { 829 luaL_checkversion(L); 830 if (libname) { 831 luaL_pushmodule(L, libname, libsize(l)); /* get/create library table */ 832 lua_insert(L, -(nup + 1)); /* move library table to below upvalues */ 833 } 834 if (l) 835 luaL_setfuncs(L, l, nup); 836 else 837 lua_pop(L, nup); /* remove upvalues */ 838 } 839 840 #endif 841 /* }====================================================== */ 842 843 /* 844 ** set functions from list 'l' into table at top - 'nup'; each 845 ** function gets the 'nup' elements at the top as upvalues. 846 ** Returns with only the table at the stack. 847 */ 848 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) { 849 luaL_checkversion(L); 850 luaL_checkstack(L, nup, "too many upvalues"); 851 for (; l->name != NULL; l++) { /* fill the table with given functions */ 852 int i; 853 for (i = 0; i < nup; i++) /* copy upvalues to the top */ 854 lua_pushvalue(L, -nup); 855 lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */ 856 lua_setfield(L, -(nup + 2), l->name); 857 } 858 lua_pop(L, nup); /* remove upvalues */ 859 } 860 861 862 /* 863 ** ensure that stack[idx][fname] has a table and push that table 864 ** into the stack 865 */ 866 LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) { 867 lua_getfield(L, idx, fname); 868 if (lua_istable(L, -1)) return 1; /* table already there */ 869 else { 870 lua_pop(L, 1); /* remove previous result */ 871 idx = lua_absindex(L, idx); 872 lua_newtable(L); 873 lua_pushvalue(L, -1); /* copy to be left at top */ 874 lua_setfield(L, idx, fname); /* assign new table to field */ 875 return 0; /* false, because did not find table there */ 876 } 877 } 878 879 880 /* 881 ** stripped-down 'require'. Calls 'openf' to open a module, 882 ** registers the result in 'package.loaded' table and, if 'glb' 883 ** is true, also registers the result in the global table. 884 ** Leaves resulting module on the top. 885 */ 886 LUALIB_API void luaL_requiref (lua_State *L, const char *modname, 887 lua_CFunction openf, int glb) { 888 lua_pushcfunction(L, openf); 889 lua_pushstring(L, modname); /* argument to open function */ 890 lua_call(L, 1, 1); /* open module */ 891 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED"); 892 lua_pushvalue(L, -2); /* make copy of module (call result) */ 893 lua_setfield(L, -2, modname); /* _LOADED[modname] = module */ 894 lua_pop(L, 1); /* remove _LOADED table */ 895 if (glb) { 896 lua_pushvalue(L, -1); /* copy of 'mod' */ 897 lua_setglobal(L, modname); /* _G[modname] = module */ 898 } 899 } 900 901 902 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p, 903 const char *r) { 904 const char *wild; 905 size_t l = strlen(p); 906 luaL_Buffer b; 907 luaL_buffinit(L, &b); 908 while ((wild = strstr(s, p)) != NULL) { 909 luaL_addlstring(&b, s, wild - s); /* push prefix */ 910 luaL_addstring(&b, r); /* push replacement in place of pattern */ 911 s = wild + l; /* continue after `p' */ 912 } 913 luaL_addstring(&b, s); /* push last suffix */ 914 luaL_pushresult(&b); 915 return lua_tostring(L, -1); 916 } 917 918 919 static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) { 920 (void)ud; (void)osize; /* not used */ 921 if (nsize == 0) { 922 free(ptr); 923 return NULL; 924 } 925 else 926 return realloc(ptr, nsize); 927 } 928 929 930 static int panic (lua_State *L) { 931 luai_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n", 932 lua_tostring(L, -1)); 933 return 0; /* return to Lua to abort */ 934 } 935 936 937 LUALIB_API lua_State *luaL_newstate (void) { 938 lua_State *L = lua_newstate(l_alloc, NULL); 939 if (L) lua_atpanic(L, &panic); 940 return L; 941 } 942 943 944 LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver) { 945 const lua_Number *v = lua_version(L); 946 if (v != lua_version(NULL)) 947 luaL_error(L, "multiple Lua VMs detected"); 948 else if (*v != ver) 949 luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f", 950 ver, *v); 951 /* check conversions number -> integer types */ 952 lua_pushnumber(L, -(lua_Number)0x1234); 953 if (lua_tointeger(L, -1) != -0x1234 || 954 lua_tounsigned(L, -1) != (lua_Unsigned)-0x1234) 955 luaL_error(L, "bad conversion number->int;" 956 " must recompile Lua with proper settings"); 957 lua_pop(L, 1); 958 } 959 960
