1 /* 2 ** $Id: lauxlib.c,v 1.248.1.1 2013/04/12 18:48:47 roberto Exp $ 3 ** Auxiliary functions for building Lua libraries 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 /* This file uses only the official API of Lua. 9 ** Any function declared here could be written as an application function. 10 */ 11 12 #define lauxlib_c 13 #define LUA_LIB 14 15 #include <sys/lua/lua.h> 16 17 #include <sys/lua/lauxlib.h> 18 19 20 /* 21 ** {====================================================== 22 ** Traceback 23 ** ======================================================= 24 */ 25 26 27 #define LEVELS1 12 /* size of the first part of the stack */ 28 #define LEVELS2 10 /* size of the second part of the stack */ 29 30 31 32 /* 33 ** search for 'objidx' in table at index -1. 34 ** return 1 + string at top if find a good name. 35 */ 36 static int findfield (lua_State *L, int objidx, int level) { 37 if (level == 0 || !lua_istable(L, -1)) 38 return 0; /* not found */ 39 lua_pushnil(L); /* start 'next' loop */ 40 while (lua_next(L, -2)) { /* for each pair in table */ 41 if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */ 42 if (lua_rawequal(L, objidx, -1)) { /* found object? */ 43 lua_pop(L, 1); /* remove value (but keep name) */ 44 return 1; 45 } 46 else if (findfield(L, objidx, level - 1)) { /* try recursively */ 47 lua_remove(L, -2); /* remove table (but keep name) */ 48 lua_pushliteral(L, "."); 49 lua_insert(L, -2); /* place '.' between the two names */ 50 lua_concat(L, 3); 51 return 1; 52 } 53 } 54 lua_pop(L, 1); /* remove value */ 55 } 56 return 0; /* not found */ 57 } 58 59 60 static int pushglobalfuncname (lua_State *L, lua_Debug *ar) { 61 int top = lua_gettop(L); 62 lua_getinfo(L, "f", ar); /* push function */ 63 lua_pushglobaltable(L); 64 if (findfield(L, top + 1, 2)) { 65 lua_copy(L, -1, top + 1); /* move name to proper place */ 66 lua_pop(L, 2); /* remove pushed values */ 67 return 1; 68 } 69 else { 70 lua_settop(L, top); /* remove function and global table */ 71 return 0; 72 } 73 } 74 75 76 static void pushfuncname (lua_State *L, lua_Debug *ar) { 77 if (*ar->namewhat != '\0') /* is there a name? */ 78 lua_pushfstring(L, "function " LUA_QS, ar->name); 79 else if (*ar->what == 'm') /* main? */ 80 lua_pushliteral(L, "main chunk"); 81 else if (*ar->what == 'C') { 82 if (pushglobalfuncname(L, ar)) { 83 lua_pushfstring(L, "function " LUA_QS, lua_tostring(L, -1)); 84 lua_remove(L, -2); /* remove name */ 85 } 86 else 87 lua_pushliteral(L, "?"); 88 } 89 else 90 lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined); 91 } 92 93 94 static int countlevels (lua_State *L) { 95 lua_Debug ar; 96 int li = 1, le = 1; 97 /* find an upper bound */ 98 while (lua_getstack(L, le, &ar)) { li = le; le *= 2; } 99 /* do a binary search */ 100 while (li < le) { 101 int m = (li + le)/2; 102 if (lua_getstack(L, m, &ar)) li = m + 1; 103 else le = m; 104 } 105 return le - 1; 106 } 107 108 109 LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, 110 const char *msg, int level) { 111 lua_Debug ar; 112 int top = lua_gettop(L); 113 int numlevels = countlevels(L1); 114 int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0; 115 if (msg) lua_pushfstring(L, "%s\n", msg); 116 lua_pushliteral(L, "stack traceback:"); 117 while (lua_getstack(L1, level++, &ar)) { 118 if (level == mark) { /* too many levels? */ 119 lua_pushliteral(L, "\n\t..."); /* add a '...' */ 120 level = numlevels - LEVELS2; /* and skip to last ones */ 121 } 122 else { 123 lua_getinfo(L1, "Slnt", &ar); 124 lua_pushfstring(L, "\n\t%s:", ar.short_src); 125 if (ar.currentline > 0) 126 lua_pushfstring(L, "%d:", ar.currentline); 127 lua_pushliteral(L, " in "); 128 pushfuncname(L, &ar); 129 if (ar.istailcall) 130 lua_pushliteral(L, "\n\t(...tail calls...)"); 131 lua_concat(L, lua_gettop(L) - top); 132 } 133 } 134 lua_concat(L, lua_gettop(L) - top); 135 } 136 137 /* }====================================================== */ 138 139 140 /* 141 ** {====================================================== 142 ** Error-report functions 143 ** ======================================================= 144 */ 145 146 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) { 147 lua_Debug ar; 148 if (!lua_getstack(L, 0, &ar)) /* no stack frame? */ 149 return luaL_error(L, "bad argument #%d (%s)", narg, extramsg); 150 lua_getinfo(L, "n", &ar); 151 if (strcmp(ar.namewhat, "method") == 0) { 152 narg--; /* do not count `self' */ 153 if (narg == 0) /* error is in the self argument itself? */ 154 return luaL_error(L, "calling " LUA_QS " on bad self (%s)", 155 ar.name, extramsg); 156 } 157 if (ar.name == NULL) 158 ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?"; 159 return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)", 160 narg, ar.name, extramsg); 161 } 162 163 164 static int typeerror (lua_State *L, int narg, const char *tname) { 165 const char *msg = lua_pushfstring(L, "%s expected, got %s", 166 tname, luaL_typename(L, narg)); 167 return luaL_argerror(L, narg, msg); 168 } 169 170 171 static void tag_error (lua_State *L, int narg, int tag) { 172 typeerror(L, narg, lua_typename(L, tag)); 173 } 174 175 176 LUALIB_API void luaL_where (lua_State *L, int level) { 177 lua_Debug ar; 178 if (lua_getstack(L, level, &ar)) { /* check function at level */ 179 lua_getinfo(L, "Sl", &ar); /* get info about it */ 180 if (ar.currentline > 0) { /* is there info? */ 181 lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline); 182 return; 183 } 184 } 185 lua_pushliteral(L, ""); /* else, no information available... */ 186 } 187 188 189 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) { 190 va_list argp; 191 va_start(argp, fmt); 192 luaL_where(L, 1); 193 lua_pushvfstring(L, fmt, argp); 194 va_end(argp); 195 lua_concat(L, 2); 196 return lua_error(L); 197 } 198 199 200 #if !defined(inspectstat) /* { */ 201 202 #if defined(LUA_USE_POSIX) 203 204 #include <sys/wait.h> 205 206 /* 207 ** use appropriate macros to interpret 'pclose' return status 208 */ 209 #define inspectstat(stat,what) \ 210 if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \ 211 else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; } 212 213 #else 214 215 #define inspectstat(stat,what) /* no op */ 216 217 #endif 218 219 #endif /* } */ 220 221 222 /* }====================================================== */ 223 224 225 /* 226 ** {====================================================== 227 ** Userdata's metatable manipulation 228 ** ======================================================= 229 */ 230 231 LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { 232 luaL_getmetatable(L, tname); /* try to get metatable */ 233 if (!lua_isnil(L, -1)) /* name already in use? */ 234 return 0; /* leave previous value on top, but return 0 */ 235 lua_pop(L, 1); 236 lua_newtable(L); /* create metatable */ 237 lua_pushvalue(L, -1); 238 lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */ 239 return 1; 240 } 241 242 243 LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) { 244 luaL_getmetatable(L, tname); 245 lua_setmetatable(L, -2); 246 } 247 248 249 LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) { 250 void *p = lua_touserdata(L, ud); 251 if (p != NULL) { /* value is a userdata? */ 252 if (lua_getmetatable(L, ud)) { /* does it have a metatable? */ 253 luaL_getmetatable(L, tname); /* get correct metatable */ 254 if (!lua_rawequal(L, -1, -2)) /* not the same? */ 255 p = NULL; /* value is a userdata with wrong metatable */ 256 lua_pop(L, 2); /* remove both metatables */ 257 return p; 258 } 259 } 260 return NULL; /* value is not a userdata with a metatable */ 261 } 262 263 264 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { 265 void *p = luaL_testudata(L, ud, tname); 266 if (p == NULL) typeerror(L, ud, tname); 267 return p; 268 } 269 270 /* }====================================================== */ 271 272 273 /* 274 ** {====================================================== 275 ** Argument check functions 276 ** ======================================================= 277 */ 278 279 LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def, 280 const char *const lst[]) { 281 const char *name = (def) ? luaL_optstring(L, narg, def) : 282 luaL_checkstring(L, narg); 283 int i; 284 for (i=0; lst[i]; i++) 285 if (strcmp(lst[i], name) == 0) 286 return i; 287 return luaL_argerror(L, narg, 288 lua_pushfstring(L, "invalid option " LUA_QS, name)); 289 } 290 291 292 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) { 293 /* keep some extra space to run error routines, if needed */ 294 const int extra = LUA_MINSTACK; 295 if (!lua_checkstack(L, space + extra)) { 296 if (msg) 297 luaL_error(L, "stack overflow (%s)", msg); 298 else 299 luaL_error(L, "stack overflow"); 300 } 301 } 302 303 304 LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) { 305 if (lua_type(L, narg) != t) 306 tag_error(L, narg, t); 307 } 308 309 310 LUALIB_API void luaL_checkany (lua_State *L, int narg) { 311 if (lua_type(L, narg) == LUA_TNONE) 312 luaL_argerror(L, narg, "value expected"); 313 } 314 315 316 LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) { 317 const char *s = lua_tolstring(L, narg, len); 318 if (!s) tag_error(L, narg, LUA_TSTRING); 319 return s; 320 } 321 322 323 LUALIB_API const char *luaL_optlstring (lua_State *L, int narg, 324 const char *def, size_t *len) { 325 if (lua_isnoneornil(L, narg)) { 326 if (len) 327 *len = (def ? strlen(def) : 0); 328 return def; 329 } 330 else return luaL_checklstring(L, narg, len); 331 } 332 333 334 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) { 335 int isnum; 336 lua_Number d = lua_tonumberx(L, narg, &isnum); 337 if (!isnum) 338 tag_error(L, narg, LUA_TNUMBER); 339 return d; 340 } 341 342 343 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) { 344 return luaL_opt(L, luaL_checknumber, narg, def); 345 } 346 347 348 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) { 349 int isnum; 350 lua_Integer d = lua_tointegerx(L, narg, &isnum); 351 if (!isnum) 352 tag_error(L, narg, LUA_TNUMBER); 353 return d; 354 } 355 356 357 LUALIB_API lua_Unsigned luaL_checkunsigned (lua_State *L, int narg) { 358 int isnum; 359 lua_Unsigned d = lua_tounsignedx(L, narg, &isnum); 360 if (!isnum) 361 tag_error(L, narg, LUA_TNUMBER); 362 return d; 363 } 364 365 366 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg, 367 lua_Integer def) { 368 return luaL_opt(L, luaL_checkinteger, narg, def); 369 } 370 371 372 LUALIB_API lua_Unsigned luaL_optunsigned (lua_State *L, int narg, 373 lua_Unsigned def) { 374 return luaL_opt(L, luaL_checkunsigned, narg, def); 375 } 376 377 /* }====================================================== */ 378 379 380 /* 381 ** {====================================================== 382 ** Generic Buffer manipulation 383 ** ======================================================= 384 */ 385 386 /* 387 ** check whether buffer is using a userdata on the stack as a temporary 388 ** buffer 389 */ 390 #define buffonstack(B) ((B)->b != (B)->initb) 391 392 393 /* 394 ** returns a pointer to a free area with at least 'sz' bytes 395 */ 396 LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) { 397 lua_State *L = B->L; 398 if (B->size - B->n < sz) { /* not enough space? */ 399 char *newbuff; 400 size_t newsize = B->size * 2; /* double buffer size */ 401 if (newsize - B->n < sz) /* not big enough? */ 402 newsize = B->n + sz; 403 if (newsize < B->n || newsize - B->n < sz) 404 luaL_error(L, "buffer too large"); 405 /* create larger buffer */ 406 newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char)); 407 /* move content to new buffer */ 408 memcpy(newbuff, B->b, B->n * sizeof(char)); 409 if (buffonstack(B)) 410 lua_remove(L, -2); /* remove old buffer */ 411 B->b = newbuff; 412 B->size = newsize; 413 } 414 return &B->b[B->n]; 415 } 416 417 418 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { 419 char *b = luaL_prepbuffsize(B, l); 420 memcpy(b, s, l * sizeof(char)); 421 luaL_addsize(B, l); 422 } 423 424 425 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) { 426 luaL_addlstring(B, s, strlen(s)); 427 } 428 429 430 LUALIB_API void luaL_pushresult (luaL_Buffer *B) { 431 lua_State *L = B->L; 432 lua_pushlstring(L, B->b, B->n); 433 if (buffonstack(B)) 434 lua_remove(L, -2); /* remove old buffer */ 435 } 436 437 438 LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) { 439 luaL_addsize(B, sz); 440 luaL_pushresult(B); 441 } 442 443 444 LUALIB_API void luaL_addvalue (luaL_Buffer *B) { 445 lua_State *L = B->L; 446 size_t l; 447 const char *s = lua_tolstring(L, -1, &l); 448 if (buffonstack(B)) 449 lua_insert(L, -2); /* put value below buffer */ 450 luaL_addlstring(B, s, l); 451 lua_remove(L, (buffonstack(B)) ? -2 : -1); /* remove value */ 452 } 453 454 455 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { 456 B->L = L; 457 B->b = B->initb; 458 B->n = 0; 459 B->size = LUAL_BUFFERSIZE; 460 } 461 462 463 LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) { 464 luaL_buffinit(L, B); 465 return luaL_prepbuffsize(B, sz); 466 } 467 468 /* }====================================================== */ 469 470 471 /* 472 ** {====================================================== 473 ** Reference system 474 ** ======================================================= 475 */ 476 477 /* index of free-list header */ 478 #define freelist 0 479 480 481 LUALIB_API int luaL_ref (lua_State *L, int t) { 482 int ref; 483 if (lua_isnil(L, -1)) { 484 lua_pop(L, 1); /* remove from stack */ 485 return LUA_REFNIL; /* `nil' has a unique fixed reference */ 486 } 487 t = lua_absindex(L, t); 488 lua_rawgeti(L, t, freelist); /* get first free element */ 489 ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */ 490 lua_pop(L, 1); /* remove it from stack */ 491 if (ref != 0) { /* any free element? */ 492 lua_rawgeti(L, t, ref); /* remove it from list */ 493 lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */ 494 } 495 else /* no free elements */ 496 ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */ 497 lua_rawseti(L, t, ref); 498 return ref; 499 } 500 501 502 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) { 503 if (ref >= 0) { 504 t = lua_absindex(L, t); 505 lua_rawgeti(L, t, freelist); 506 lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */ 507 lua_pushinteger(L, ref); 508 lua_rawseti(L, t, freelist); /* t[freelist] = ref */ 509 } 510 } 511 512 /* }====================================================== */ 513 514 515 /* 516 ** {====================================================== 517 ** Load functions 518 ** ======================================================= 519 */ 520 521 typedef struct LoadS { 522 const char *s; 523 size_t size; 524 } LoadS; 525 526 527 static const char *getS (lua_State *L, void *ud, size_t *size) { 528 LoadS *ls = (LoadS *)ud; 529 (void)L; /* not used */ 530 if (ls->size == 0) return NULL; 531 *size = ls->size; 532 ls->size = 0; 533 return ls->s; 534 } 535 536 537 LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size, 538 const char *name, const char *mode) { 539 LoadS ls; 540 ls.s = buff; 541 ls.size = size; 542 return lua_load(L, getS, &ls, name, mode); 543 } 544 545 546 LUALIB_API int luaL_loadstring (lua_State *L, const char *s) { 547 return luaL_loadbuffer(L, s, strlen(s), s); 548 } 549 550 /* }====================================================== */ 551 552 553 554 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) { 555 if (!lua_getmetatable(L, obj)) /* no metatable? */ 556 return 0; 557 lua_pushstring(L, event); 558 lua_rawget(L, -2); 559 if (lua_isnil(L, -1)) { 560 lua_pop(L, 2); /* remove metatable and metafield */ 561 return 0; 562 } 563 else { 564 lua_remove(L, -2); /* remove only metatable */ 565 return 1; 566 } 567 } 568 569 570 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) { 571 obj = lua_absindex(L, obj); 572 if (!luaL_getmetafield(L, obj, event)) /* no metafield? */ 573 return 0; 574 lua_pushvalue(L, obj); 575 lua_call(L, 1, 1); 576 return 1; 577 } 578 579 580 LUALIB_API int luaL_len (lua_State *L, int idx) { 581 int l; 582 int isnum; 583 lua_len(L, idx); 584 l = (int)lua_tointegerx(L, -1, &isnum); 585 if (!isnum) 586 luaL_error(L, "object length is not a number"); 587 lua_pop(L, 1); /* remove object */ 588 return l; 589 } 590 591 592 LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) { 593 if (!luaL_callmeta(L, idx, "__tostring")) { /* no metafield? */ 594 switch (lua_type(L, idx)) { 595 case LUA_TNUMBER: 596 case LUA_TSTRING: 597 lua_pushvalue(L, idx); 598 break; 599 case LUA_TBOOLEAN: 600 lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false")); 601 break; 602 case LUA_TNIL: 603 lua_pushliteral(L, "nil"); 604 break; 605 default: 606 lua_pushfstring(L, "%s: %p", luaL_typename(L, idx), 607 lua_topointer(L, idx)); 608 break; 609 } 610 } 611 return lua_tolstring(L, -1, len); 612 } 613 614 615 /* 616 ** {====================================================== 617 ** Compatibility with 5.1 module functions 618 ** ======================================================= 619 */ 620 #if defined(LUA_COMPAT_MODULE) 621 622 static const char *luaL_findtable (lua_State *L, int idx, 623 const char *fname, int szhint) { 624 const char *e; 625 if (idx) lua_pushvalue(L, idx); 626 do { 627 e = strchr(fname, '.'); 628 if (e == NULL) e = fname + strlen(fname); 629 lua_pushlstring(L, fname, e - fname); 630 lua_rawget(L, -2); 631 if (lua_isnil(L, -1)) { /* no such field? */ 632 lua_pop(L, 1); /* remove this nil */ 633 lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */ 634 lua_pushlstring(L, fname, e - fname); 635 lua_pushvalue(L, -2); 636 lua_settable(L, -4); /* set new table into field */ 637 } 638 else if (!lua_istable(L, -1)) { /* field has a non-table value? */ 639 lua_pop(L, 2); /* remove table and value */ 640 return fname; /* return problematic part of the name */ 641 } 642 lua_remove(L, -2); /* remove previous table */ 643 fname = e + 1; 644 } while (*e == '.'); 645 return NULL; 646 } 647 648 649 /* 650 ** Count number of elements in a luaL_Reg list. 651 */ 652 static int libsize (const luaL_Reg *l) { 653 int size = 0; 654 for (; l && l->name; l++) size++; 655 return size; 656 } 657 658 659 /* 660 ** Find or create a module table with a given name. The function 661 ** first looks at the _LOADED table and, if that fails, try a 662 ** global variable with that name. In any case, leaves on the stack 663 ** the module table. 664 */ 665 LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname, 666 int sizehint) { 667 luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */ 668 lua_getfield(L, -1, modname); /* get _LOADED[modname] */ 669 if (!lua_istable(L, -1)) { /* not found? */ 670 lua_pop(L, 1); /* remove previous result */ 671 /* try global variable (and create one if it does not exist) */ 672 lua_pushglobaltable(L); 673 if (luaL_findtable(L, 0, modname, sizehint) != NULL) 674 luaL_error(L, "name conflict for module " LUA_QS, modname); 675 lua_pushvalue(L, -1); 676 lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */ 677 } 678 lua_remove(L, -2); /* remove _LOADED table */ 679 } 680 681 682 LUALIB_API void luaL_openlib (lua_State *L, const char *libname, 683 const luaL_Reg *l, int nup) { 684 luaL_checkversion(L); 685 if (libname) { 686 luaL_pushmodule(L, libname, libsize(l)); /* get/create library table */ 687 lua_insert(L, -(nup + 1)); /* move library table to below upvalues */ 688 } 689 if (l) 690 luaL_setfuncs(L, l, nup); 691 else 692 lua_pop(L, nup); /* remove upvalues */ 693 } 694 695 #endif 696 /* }====================================================== */ 697 698 /* 699 ** set functions from list 'l' into table at top - 'nup'; each 700 ** function gets the 'nup' elements at the top as upvalues. 701 ** Returns with only the table at the stack. 702 */ 703 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) { 704 luaL_checkversion(L); 705 luaL_checkstack(L, nup, "too many upvalues"); 706 for (; l->name != NULL; l++) { /* fill the table with given functions */ 707 int i; 708 for (i = 0; i < nup; i++) /* copy upvalues to the top */ 709 lua_pushvalue(L, -nup); 710 lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */ 711 lua_setfield(L, -(nup + 2), l->name); 712 } 713 lua_pop(L, nup); /* remove upvalues */ 714 } 715 716 717 /* 718 ** ensure that stack[idx][fname] has a table and push that table 719 ** into the stack 720 */ 721 LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) { 722 lua_getfield(L, idx, fname); 723 if (lua_istable(L, -1)) return 1; /* table already there */ 724 else { 725 lua_pop(L, 1); /* remove previous result */ 726 idx = lua_absindex(L, idx); 727 lua_newtable(L); 728 lua_pushvalue(L, -1); /* copy to be left at top */ 729 lua_setfield(L, idx, fname); /* assign new table to field */ 730 return 0; /* false, because did not find table there */ 731 } 732 } 733 734 735 /* 736 ** stripped-down 'require'. Calls 'openf' to open a module, 737 ** registers the result in 'package.loaded' table and, if 'glb' 738 ** is true, also registers the result in the global table. 739 ** Leaves resulting module on the top. 740 */ 741 LUALIB_API void luaL_requiref (lua_State *L, const char *modname, 742 lua_CFunction openf, int glb) { 743 lua_pushcfunction(L, openf); 744 lua_pushstring(L, modname); /* argument to open function */ 745 lua_call(L, 1, 1); /* open module */ 746 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED"); 747 lua_pushvalue(L, -2); /* make copy of module (call result) */ 748 lua_setfield(L, -2, modname); /* _LOADED[modname] = module */ 749 lua_pop(L, 1); /* remove _LOADED table */ 750 if (glb) { 751 lua_pushvalue(L, -1); /* copy of 'mod' */ 752 lua_setglobal(L, modname); /* _G[modname] = module */ 753 } 754 } 755 756 757 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p, 758 const char *r) { 759 const char *wild; 760 size_t l = strlen(p); 761 luaL_Buffer b; 762 luaL_buffinit(L, &b); 763 while ((wild = strstr(s, p)) != NULL) { 764 luaL_addlstring(&b, s, wild - s); /* push prefix */ 765 luaL_addstring(&b, r); /* push replacement in place of pattern */ 766 s = wild + l; /* continue after `p' */ 767 } 768 luaL_addstring(&b, s); /* push last suffix */ 769 luaL_pushresult(&b); 770 return lua_tostring(L, -1); 771 } 772 773 774 LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver) { 775 const lua_Number *v = lua_version(L); 776 if (v != lua_version(NULL)) 777 luaL_error(L, "multiple Lua VMs detected"); 778 else if (*v != ver) 779 luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f", 780 ver, *v); 781 /* check conversions number -> integer types */ 782 lua_pushnumber(L, -(lua_Number)0x1234); 783 if (lua_tointeger(L, -1) != -0x1234 || 784 lua_tounsigned(L, -1) != (lua_Unsigned)-0x1234) 785 luaL_error(L, "bad conversion number->int;" 786 " must recompile Lua with proper settings"); 787 lua_pop(L, 1); 788 } 789 790 #if defined(_KERNEL) 791 792 EXPORT_SYMBOL(luaL_argerror); 793 EXPORT_SYMBOL(luaL_error); 794 EXPORT_SYMBOL(luaL_loadbufferx); 795 EXPORT_SYMBOL(luaL_newmetatable); 796 EXPORT_SYMBOL(luaL_traceback); 797 798 #endif 799