1 /* BEGIN CSTYLED */ 2 /* 3 ** $Id: lauxlib.c,v 1.248.1.1 2013/04/12 18:48:47 roberto Exp $ 4 ** Auxiliary functions for building Lua libraries 5 ** See Copyright Notice in lua.h 6 */ 7 8 9 /* This file uses only the official API of Lua. 10 ** Any function declared here could be written as an application function. 11 */ 12 13 #define lauxlib_c 14 #define LUA_LIB 15 16 #include <sys/lua/lua.h> 17 18 #include <sys/lua/lauxlib.h> 19 20 21 /* 22 ** {====================================================== 23 ** Traceback 24 ** ======================================================= 25 */ 26 27 28 #define LEVELS1 12 /* size of the first part of the stack */ 29 #define LEVELS2 10 /* size of the second part of the stack */ 30 31 32 33 /* 34 ** search for 'objidx' in table at index -1. 35 ** return 1 + string at top if find a good name. 36 */ 37 static int findfield (lua_State *L, int objidx, int level) { 38 if (level == 0 || !lua_istable(L, -1)) 39 return 0; /* not found */ 40 lua_pushnil(L); /* start 'next' loop */ 41 while (lua_next(L, -2)) { /* for each pair in table */ 42 if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */ 43 if (lua_rawequal(L, objidx, -1)) { /* found object? */ 44 lua_pop(L, 1); /* remove value (but keep name) */ 45 return 1; 46 } 47 else if (findfield(L, objidx, level - 1)) { /* try recursively */ 48 lua_remove(L, -2); /* remove table (but keep name) */ 49 lua_pushliteral(L, "."); 50 lua_insert(L, -2); /* place '.' between the two names */ 51 lua_concat(L, 3); 52 return 1; 53 } 54 } 55 lua_pop(L, 1); /* remove value */ 56 } 57 return 0; /* not found */ 58 } 59 60 61 static int pushglobalfuncname (lua_State *L, lua_Debug *ar) { 62 int top = lua_gettop(L); 63 lua_getinfo(L, "f", ar); /* push function */ 64 lua_pushglobaltable(L); 65 if (findfield(L, top + 1, 2)) { 66 lua_copy(L, -1, top + 1); /* move name to proper place */ 67 lua_pop(L, 2); /* remove pushed values */ 68 return 1; 69 } 70 else { 71 lua_settop(L, top); /* remove function and global table */ 72 return 0; 73 } 74 } 75 76 77 static void pushfuncname (lua_State *L, lua_Debug *ar) { 78 if (*ar->namewhat != '\0') /* is there a name? */ 79 lua_pushfstring(L, "function " LUA_QS, ar->name); 80 else if (*ar->what == 'm') /* main? */ 81 lua_pushliteral(L, "main chunk"); 82 else if (*ar->what == 'C') { 83 if (pushglobalfuncname(L, ar)) { 84 lua_pushfstring(L, "function " LUA_QS, lua_tostring(L, -1)); 85 lua_remove(L, -2); /* remove name */ 86 } 87 else 88 lua_pushliteral(L, "?"); 89 } 90 else 91 lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined); 92 } 93 94 95 static int countlevels (lua_State *L) { 96 lua_Debug ar; 97 int li = 1, le = 1; 98 /* find an upper bound */ 99 while (lua_getstack(L, le, &ar)) { li = le; le *= 2; } 100 /* do a binary search */ 101 while (li < le) { 102 int m = (li + le)/2; 103 if (lua_getstack(L, m, &ar)) li = m + 1; 104 else le = m; 105 } 106 return le - 1; 107 } 108 109 110 LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, 111 const char *msg, int level) { 112 lua_Debug ar; 113 int top = lua_gettop(L); 114 int numlevels = countlevels(L1); 115 int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0; 116 if (msg) lua_pushfstring(L, "%s\n", msg); 117 lua_pushliteral(L, "stack traceback:"); 118 while (lua_getstack(L1, level++, &ar)) { 119 if (level == mark) { /* too many levels? */ 120 lua_pushliteral(L, "\n\t..."); /* add a '...' */ 121 level = numlevels - LEVELS2; /* and skip to last ones */ 122 } 123 else { 124 lua_getinfo(L1, "Slnt", &ar); 125 lua_pushfstring(L, "\n\t%s:", ar.short_src); 126 if (ar.currentline > 0) 127 lua_pushfstring(L, "%d:", ar.currentline); 128 lua_pushliteral(L, " in "); 129 pushfuncname(L, &ar); 130 if (ar.istailcall) 131 lua_pushliteral(L, "\n\t(...tail calls...)"); 132 lua_concat(L, lua_gettop(L) - top); 133 } 134 } 135 lua_concat(L, lua_gettop(L) - top); 136 } 137 138 /* }====================================================== */ 139 140 141 /* 142 ** {====================================================== 143 ** Error-report functions 144 ** ======================================================= 145 */ 146 147 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) { 148 lua_Debug ar; 149 if (!lua_getstack(L, 0, &ar)) /* no stack frame? */ 150 return luaL_error(L, "bad argument #%d (%s)", narg, extramsg); 151 lua_getinfo(L, "n", &ar); 152 if (strcmp(ar.namewhat, "method") == 0) { 153 narg--; /* do not count `self' */ 154 if (narg == 0) /* error is in the self argument itself? */ 155 return luaL_error(L, "calling " LUA_QS " on bad self (%s)", 156 ar.name, extramsg); 157 } 158 if (ar.name == NULL) 159 ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?"; 160 return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)", 161 narg, ar.name, extramsg); 162 } 163 164 165 static int typeerror (lua_State *L, int narg, const char *tname) { 166 const char *msg = lua_pushfstring(L, "%s expected, got %s", 167 tname, luaL_typename(L, narg)); 168 return luaL_argerror(L, narg, msg); 169 } 170 171 172 static void tag_error (lua_State *L, int narg, int tag) { 173 typeerror(L, narg, lua_typename(L, tag)); 174 } 175 176 177 LUALIB_API void luaL_where (lua_State *L, int level) { 178 lua_Debug ar; 179 if (lua_getstack(L, level, &ar)) { /* check function at level */ 180 lua_getinfo(L, "Sl", &ar); /* get info about it */ 181 if (ar.currentline > 0) { /* is there info? */ 182 lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline); 183 return; 184 } 185 } 186 lua_pushliteral(L, ""); /* else, no information available... */ 187 } 188 189 190 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) { 191 va_list argp; 192 va_start(argp, fmt); 193 luaL_where(L, 1); 194 lua_pushvfstring(L, fmt, argp); 195 va_end(argp); 196 lua_concat(L, 2); 197 return lua_error(L); 198 } 199 200 201 #if !defined(inspectstat) /* { */ 202 203 #if defined(LUA_USE_POSIX) 204 205 #include <sys/wait.h> 206 207 /* 208 ** use appropriate macros to interpret 'pclose' return status 209 */ 210 #define inspectstat(stat,what) \ 211 if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \ 212 else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; } 213 214 #else 215 216 #define inspectstat(stat,what) /* no op */ 217 218 #endif 219 220 #endif /* } */ 221 222 223 /* }====================================================== */ 224 225 226 /* 227 ** {====================================================== 228 ** Userdata's metatable manipulation 229 ** ======================================================= 230 */ 231 232 LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { 233 luaL_getmetatable(L, tname); /* try to get metatable */ 234 if (!lua_isnil(L, -1)) /* name already in use? */ 235 return 0; /* leave previous value on top, but return 0 */ 236 lua_pop(L, 1); 237 lua_newtable(L); /* create metatable */ 238 lua_pushvalue(L, -1); 239 lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */ 240 return 1; 241 } 242 243 244 LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) { 245 luaL_getmetatable(L, tname); 246 lua_setmetatable(L, -2); 247 } 248 249 250 LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) { 251 void *p = lua_touserdata(L, ud); 252 if (p != NULL) { /* value is a userdata? */ 253 if (lua_getmetatable(L, ud)) { /* does it have a metatable? */ 254 luaL_getmetatable(L, tname); /* get correct metatable */ 255 if (!lua_rawequal(L, -1, -2)) /* not the same? */ 256 p = NULL; /* value is a userdata with wrong metatable */ 257 lua_pop(L, 2); /* remove both metatables */ 258 return p; 259 } 260 } 261 return NULL; /* value is not a userdata with a metatable */ 262 } 263 264 265 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { 266 void *p = luaL_testudata(L, ud, tname); 267 if (p == NULL) typeerror(L, ud, tname); 268 return p; 269 } 270 271 /* }====================================================== */ 272 273 274 /* 275 ** {====================================================== 276 ** Argument check functions 277 ** ======================================================= 278 */ 279 280 LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def, 281 const char *const lst[]) { 282 const char *name = (def) ? luaL_optstring(L, narg, def) : 283 luaL_checkstring(L, narg); 284 int i; 285 for (i=0; lst[i]; i++) 286 if (strcmp(lst[i], name) == 0) 287 return i; 288 return luaL_argerror(L, narg, 289 lua_pushfstring(L, "invalid option " LUA_QS, name)); 290 } 291 292 293 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) { 294 /* keep some extra space to run error routines, if needed */ 295 const int extra = LUA_MINSTACK; 296 if (!lua_checkstack(L, space + extra)) { 297 if (msg) 298 luaL_error(L, "stack overflow (%s)", msg); 299 else 300 luaL_error(L, "stack overflow"); 301 } 302 } 303 304 305 LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) { 306 if (lua_type(L, narg) != t) 307 tag_error(L, narg, t); 308 } 309 310 311 LUALIB_API void luaL_checkany (lua_State *L, int narg) { 312 if (lua_type(L, narg) == LUA_TNONE) 313 luaL_argerror(L, narg, "value expected"); 314 } 315 316 317 LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) { 318 const char *s = lua_tolstring(L, narg, len); 319 if (!s) tag_error(L, narg, LUA_TSTRING); 320 return s; 321 } 322 323 324 LUALIB_API const char *luaL_optlstring (lua_State *L, int narg, 325 const char *def, size_t *len) { 326 if (lua_isnoneornil(L, narg)) { 327 if (len) 328 *len = (def ? strlen(def) : 0); 329 return def; 330 } 331 else return luaL_checklstring(L, narg, len); 332 } 333 334 335 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) { 336 int isnum; 337 lua_Number d = lua_tonumberx(L, narg, &isnum); 338 if (!isnum) 339 tag_error(L, narg, LUA_TNUMBER); 340 return d; 341 } 342 343 344 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) { 345 return luaL_opt(L, luaL_checknumber, narg, def); 346 } 347 348 349 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) { 350 int isnum; 351 lua_Integer d = lua_tointegerx(L, narg, &isnum); 352 if (!isnum) 353 tag_error(L, narg, LUA_TNUMBER); 354 return d; 355 } 356 357 358 LUALIB_API lua_Unsigned luaL_checkunsigned (lua_State *L, int narg) { 359 int isnum; 360 lua_Unsigned d = lua_tounsignedx(L, narg, &isnum); 361 if (!isnum) 362 tag_error(L, narg, LUA_TNUMBER); 363 return d; 364 } 365 366 367 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg, 368 lua_Integer def) { 369 return luaL_opt(L, luaL_checkinteger, narg, def); 370 } 371 372 373 LUALIB_API lua_Unsigned luaL_optunsigned (lua_State *L, int narg, 374 lua_Unsigned def) { 375 return luaL_opt(L, luaL_checkunsigned, narg, def); 376 } 377 378 /* }====================================================== */ 379 380 381 /* 382 ** {====================================================== 383 ** Generic Buffer manipulation 384 ** ======================================================= 385 */ 386 387 /* 388 ** check whether buffer is using a userdata on the stack as a temporary 389 ** buffer 390 */ 391 #define buffonstack(B) ((B)->b != (B)->initb) 392 393 394 /* 395 ** returns a pointer to a free area with at least 'sz' bytes 396 */ 397 LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) { 398 lua_State *L = B->L; 399 if (B->size - B->n < sz) { /* not enough space? */ 400 char *newbuff; 401 size_t newsize = B->size * 2; /* double buffer size */ 402 if (newsize - B->n < sz) /* not big enough? */ 403 newsize = B->n + sz; 404 if (newsize < B->n || newsize - B->n < sz) 405 luaL_error(L, "buffer too large"); 406 /* create larger buffer */ 407 newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char)); 408 /* move content to new buffer */ 409 memcpy(newbuff, B->b, B->n * sizeof(char)); 410 if (buffonstack(B)) 411 lua_remove(L, -2); /* remove old buffer */ 412 B->b = newbuff; 413 B->size = newsize; 414 } 415 return &B->b[B->n]; 416 } 417 418 419 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { 420 char *b = luaL_prepbuffsize(B, l); 421 memcpy(b, s, l * sizeof(char)); 422 luaL_addsize(B, l); 423 } 424 425 426 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) { 427 luaL_addlstring(B, s, strlen(s)); 428 } 429 430 431 LUALIB_API void luaL_pushresult (luaL_Buffer *B) { 432 lua_State *L = B->L; 433 lua_pushlstring(L, B->b, B->n); 434 if (buffonstack(B)) 435 lua_remove(L, -2); /* remove old buffer */ 436 } 437 438 439 LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) { 440 luaL_addsize(B, sz); 441 luaL_pushresult(B); 442 } 443 444 445 LUALIB_API void luaL_addvalue (luaL_Buffer *B) { 446 lua_State *L = B->L; 447 size_t l; 448 const char *s = lua_tolstring(L, -1, &l); 449 if (buffonstack(B)) 450 lua_insert(L, -2); /* put value below buffer */ 451 luaL_addlstring(B, s, l); 452 lua_remove(L, (buffonstack(B)) ? -2 : -1); /* remove value */ 453 } 454 455 456 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { 457 B->L = L; 458 B->b = B->initb; 459 B->n = 0; 460 B->size = LUAL_BUFFERSIZE; 461 } 462 463 464 LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) { 465 luaL_buffinit(L, B); 466 return luaL_prepbuffsize(B, sz); 467 } 468 469 /* }====================================================== */ 470 471 472 /* 473 ** {====================================================== 474 ** Reference system 475 ** ======================================================= 476 */ 477 478 /* index of free-list header */ 479 #define freelist 0 480 481 482 LUALIB_API int luaL_ref (lua_State *L, int t) { 483 int ref; 484 if (lua_isnil(L, -1)) { 485 lua_pop(L, 1); /* remove from stack */ 486 return LUA_REFNIL; /* `nil' has a unique fixed reference */ 487 } 488 t = lua_absindex(L, t); 489 lua_rawgeti(L, t, freelist); /* get first free element */ 490 ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */ 491 lua_pop(L, 1); /* remove it from stack */ 492 if (ref != 0) { /* any free element? */ 493 lua_rawgeti(L, t, ref); /* remove it from list */ 494 lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */ 495 } 496 else /* no free elements */ 497 ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */ 498 lua_rawseti(L, t, ref); 499 return ref; 500 } 501 502 503 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) { 504 if (ref >= 0) { 505 t = lua_absindex(L, t); 506 lua_rawgeti(L, t, freelist); 507 lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */ 508 lua_pushinteger(L, ref); 509 lua_rawseti(L, t, freelist); /* t[freelist] = ref */ 510 } 511 } 512 513 /* }====================================================== */ 514 515 516 /* 517 ** {====================================================== 518 ** Load functions 519 ** ======================================================= 520 */ 521 522 typedef struct LoadS { 523 const char *s; 524 size_t size; 525 } LoadS; 526 527 528 static const char *getS (lua_State *L, void *ud, size_t *size) { 529 LoadS *ls = (LoadS *)ud; 530 (void)L; /* not used */ 531 if (ls->size == 0) return NULL; 532 *size = ls->size; 533 ls->size = 0; 534 return ls->s; 535 } 536 537 538 LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size, 539 const char *name, const char *mode) { 540 LoadS ls; 541 ls.s = buff; 542 ls.size = size; 543 return lua_load(L, getS, &ls, name, mode); 544 } 545 546 547 LUALIB_API int luaL_loadstring (lua_State *L, const char *s) { 548 return luaL_loadbuffer(L, s, strlen(s), s); 549 } 550 551 /* }====================================================== */ 552 553 554 555 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) { 556 if (!lua_getmetatable(L, obj)) /* no metatable? */ 557 return 0; 558 lua_pushstring(L, event); 559 lua_rawget(L, -2); 560 if (lua_isnil(L, -1)) { 561 lua_pop(L, 2); /* remove metatable and metafield */ 562 return 0; 563 } 564 else { 565 lua_remove(L, -2); /* remove only metatable */ 566 return 1; 567 } 568 } 569 570 571 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) { 572 obj = lua_absindex(L, obj); 573 if (!luaL_getmetafield(L, obj, event)) /* no metafield? */ 574 return 0; 575 lua_pushvalue(L, obj); 576 lua_call(L, 1, 1); 577 return 1; 578 } 579 580 581 LUALIB_API int luaL_len (lua_State *L, int idx) { 582 int l; 583 int isnum; 584 lua_len(L, idx); 585 l = (int)lua_tointegerx(L, -1, &isnum); 586 if (!isnum) 587 luaL_error(L, "object length is not a number"); 588 lua_pop(L, 1); /* remove object */ 589 return l; 590 } 591 592 593 LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) { 594 if (!luaL_callmeta(L, idx, "__tostring")) { /* no metafield? */ 595 switch (lua_type(L, idx)) { 596 case LUA_TNUMBER: 597 case LUA_TSTRING: 598 lua_pushvalue(L, idx); 599 break; 600 case LUA_TBOOLEAN: 601 lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false")); 602 break; 603 case LUA_TNIL: 604 lua_pushliteral(L, "nil"); 605 break; 606 default: 607 lua_pushfstring(L, "%s: %p", luaL_typename(L, idx), 608 lua_topointer(L, idx)); 609 break; 610 } 611 } 612 return lua_tolstring(L, -1, len); 613 } 614 615 616 /* 617 ** {====================================================== 618 ** Compatibility with 5.1 module functions 619 ** ======================================================= 620 */ 621 #if defined(LUA_COMPAT_MODULE) 622 623 static const char *luaL_findtable (lua_State *L, int idx, 624 const char *fname, int szhint) { 625 const char *e; 626 if (idx) lua_pushvalue(L, idx); 627 do { 628 e = strchr(fname, '.'); 629 if (e == NULL) e = fname + strlen(fname); 630 lua_pushlstring(L, fname, e - fname); 631 lua_rawget(L, -2); 632 if (lua_isnil(L, -1)) { /* no such field? */ 633 lua_pop(L, 1); /* remove this nil */ 634 lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */ 635 lua_pushlstring(L, fname, e - fname); 636 lua_pushvalue(L, -2); 637 lua_settable(L, -4); /* set new table into field */ 638 } 639 else if (!lua_istable(L, -1)) { /* field has a non-table value? */ 640 lua_pop(L, 2); /* remove table and value */ 641 return fname; /* return problematic part of the name */ 642 } 643 lua_remove(L, -2); /* remove previous table */ 644 fname = e + 1; 645 } while (*e == '.'); 646 return NULL; 647 } 648 649 650 /* 651 ** Count number of elements in a luaL_Reg list. 652 */ 653 static int libsize (const luaL_Reg *l) { 654 int size = 0; 655 for (; l && l->name; l++) size++; 656 return size; 657 } 658 659 660 /* 661 ** Find or create a module table with a given name. The function 662 ** first looks at the _LOADED table and, if that fails, try a 663 ** global variable with that name. In any case, leaves on the stack 664 ** the module table. 665 */ 666 LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname, 667 int sizehint) { 668 luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */ 669 lua_getfield(L, -1, modname); /* get _LOADED[modname] */ 670 if (!lua_istable(L, -1)) { /* not found? */ 671 lua_pop(L, 1); /* remove previous result */ 672 /* try global variable (and create one if it does not exist) */ 673 lua_pushglobaltable(L); 674 if (luaL_findtable(L, 0, modname, sizehint) != NULL) 675 luaL_error(L, "name conflict for module " LUA_QS, modname); 676 lua_pushvalue(L, -1); 677 lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */ 678 } 679 lua_remove(L, -2); /* remove _LOADED table */ 680 } 681 682 683 LUALIB_API void luaL_openlib (lua_State *L, const char *libname, 684 const luaL_Reg *l, int nup) { 685 luaL_checkversion(L); 686 if (libname) { 687 luaL_pushmodule(L, libname, libsize(l)); /* get/create library table */ 688 lua_insert(L, -(nup + 1)); /* move library table to below upvalues */ 689 } 690 if (l) 691 luaL_setfuncs(L, l, nup); 692 else 693 lua_pop(L, nup); /* remove upvalues */ 694 } 695 696 #endif 697 /* }====================================================== */ 698 699 /* 700 ** set functions from list 'l' into table at top - 'nup'; each 701 ** function gets the 'nup' elements at the top as upvalues. 702 ** Returns with only the table at the stack. 703 */ 704 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) { 705 luaL_checkversion(L); 706 luaL_checkstack(L, nup, "too many upvalues"); 707 for (; l->name != NULL; l++) { /* fill the table with given functions */ 708 int i; 709 for (i = 0; i < nup; i++) /* copy upvalues to the top */ 710 lua_pushvalue(L, -nup); 711 lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */ 712 lua_setfield(L, -(nup + 2), l->name); 713 } 714 lua_pop(L, nup); /* remove upvalues */ 715 } 716 717 718 /* 719 ** ensure that stack[idx][fname] has a table and push that table 720 ** into the stack 721 */ 722 LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) { 723 lua_getfield(L, idx, fname); 724 if (lua_istable(L, -1)) return 1; /* table already there */ 725 else { 726 lua_pop(L, 1); /* remove previous result */ 727 idx = lua_absindex(L, idx); 728 lua_newtable(L); 729 lua_pushvalue(L, -1); /* copy to be left at top */ 730 lua_setfield(L, idx, fname); /* assign new table to field */ 731 return 0; /* false, because did not find table there */ 732 } 733 } 734 735 736 /* 737 ** stripped-down 'require'. Calls 'openf' to open a module, 738 ** registers the result in 'package.loaded' table and, if 'glb' 739 ** is true, also registers the result in the global table. 740 ** Leaves resulting module on the top. 741 */ 742 LUALIB_API void luaL_requiref (lua_State *L, const char *modname, 743 lua_CFunction openf, int glb) { 744 lua_pushcfunction(L, openf); 745 lua_pushstring(L, modname); /* argument to open function */ 746 lua_call(L, 1, 1); /* open module */ 747 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED"); 748 lua_pushvalue(L, -2); /* make copy of module (call result) */ 749 lua_setfield(L, -2, modname); /* _LOADED[modname] = module */ 750 lua_pop(L, 1); /* remove _LOADED table */ 751 if (glb) { 752 lua_pushvalue(L, -1); /* copy of 'mod' */ 753 lua_setglobal(L, modname); /* _G[modname] = module */ 754 } 755 } 756 757 758 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p, 759 const char *r) { 760 const char *wild; 761 size_t l = strlen(p); 762 luaL_Buffer b; 763 luaL_buffinit(L, &b); 764 while ((wild = strstr(s, p)) != NULL) { 765 luaL_addlstring(&b, s, wild - s); /* push prefix */ 766 luaL_addstring(&b, r); /* push replacement in place of pattern */ 767 s = wild + l; /* continue after `p' */ 768 } 769 luaL_addstring(&b, s); /* push last suffix */ 770 luaL_pushresult(&b); 771 return lua_tostring(L, -1); 772 } 773 774 775 LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver) { 776 const lua_Number *v = lua_version(L); 777 if (v != lua_version(NULL)) 778 luaL_error(L, "multiple Lua VMs detected"); 779 else if (*v != ver) 780 luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f", 781 ver, *v); 782 /* check conversions number -> integer types */ 783 lua_pushnumber(L, -(lua_Number)0x1234); 784 if (lua_tointeger(L, -1) != -0x1234 || 785 lua_tounsigned(L, -1) != (lua_Unsigned)-0x1234) 786 luaL_error(L, "bad conversion number->int;" 787 " must recompile Lua with proper settings"); 788 lua_pop(L, 1); 789 } 790 791 #if defined(_KERNEL) 792 793 EXPORT_SYMBOL(luaL_argerror); 794 EXPORT_SYMBOL(luaL_error); 795 EXPORT_SYMBOL(luaL_loadbufferx); 796 EXPORT_SYMBOL(luaL_newmetatable); 797 EXPORT_SYMBOL(luaL_traceback); 798 799 #endif 800 /* END CSTYLED */ 801