loadlib.cc (23577B)
1 /* 2 ** $Id: loadlib.c,v 1.130.1.1 2017/04/19 17:20:42 roberto Exp $ 3 ** Dynamic library loader for Lua 4 ** See Copyright Notice in lua.h 5 ** 6 ** This module contains an implementation of loadlib for Unix systems 7 ** that have dlfcn, an implementation for Windows, and a stub for other 8 ** systems. 9 */ 10 11 #define loadlib_c 12 #define LUA_LIB 13 14 #include "lprefix.h" 15 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <string.h> 20 21 #include "lua.h" 22 23 #include "lauxlib.h" 24 #include "lualib.h" 25 26 27 /* 28 ** LUA_IGMARK is a mark to ignore all before it when building the 29 ** luaopen_ function name. 30 */ 31 #if !defined (LUA_IGMARK) 32 #define LUA_IGMARK "-" 33 #endif 34 35 36 /* 37 ** LUA_CSUBSEP is the character that replaces dots in submodule names 38 ** when searching for a C loader. 39 ** LUA_LSUBSEP is the character that replaces dots in submodule names 40 ** when searching for a Lua loader. 41 */ 42 #if !defined(LUA_CSUBSEP) 43 #define LUA_CSUBSEP LUA_DIRSEP 44 #endif 45 46 #if !defined(LUA_LSUBSEP) 47 #define LUA_LSUBSEP LUA_DIRSEP 48 #endif 49 50 51 /* prefix for open functions in C libraries */ 52 #define LUA_POF "luaopen_" 53 54 /* separator for open functions in C libraries */ 55 #define LUA_OFSEP "_" 56 57 58 /* 59 ** unique key for table in the registry that keeps handles 60 ** for all loaded C libraries 61 */ 62 static const int CLIBS = 0; 63 64 #define LIB_FAIL "open" 65 66 67 #define setprogdir(L) ((void)0) 68 69 70 /* 71 ** system-dependent functions 72 */ 73 74 /* 75 ** unload library 'lib' 76 */ 77 static void lsys_unloadlib (void *lib); 78 79 /* 80 ** load C library in file 'path'. If 'seeglb', load with all names in 81 ** the library global. 82 ** Returns the library; in case of error, returns NULL plus an 83 ** error string in the stack. 84 */ 85 static void *lsys_load (lua_State *L, const char *path, int seeglb); 86 87 /* 88 ** Try to find a function named 'sym' in library 'lib'. 89 ** Returns the function; in case of error, returns NULL plus an 90 ** error string in the stack. 91 */ 92 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym); 93 94 95 96 97 #if defined(LUA_USE_DLOPEN) /* { */ 98 /* 99 ** {======================================================================== 100 ** This is an implementation of loadlib based on the dlfcn interface. 101 ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD, 102 ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least 103 ** as an emulation layer on top of native functions. 104 ** ========================================================================= 105 */ 106 107 #include <dlfcn.h> 108 109 /* 110 ** Macro to convert pointer-to-void* to pointer-to-function. This cast 111 ** is undefined according to ISO C, but POSIX assumes that it works. 112 ** (The '__extension__' in gnu compilers is only to avoid warnings.) 113 */ 114 #if defined(__GNUC__) 115 #define cast_func(p) (__extension__ (lua_CFunction)(p)) 116 #else 117 #define cast_func(p) ((lua_CFunction)(p)) 118 #endif 119 120 121 static void lsys_unloadlib (void *lib) { 122 dlclose(lib); 123 } 124 125 126 static void *lsys_load (lua_State *L, const char *path, int seeglb) { 127 void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL)); 128 if (lib == NULL) lua_pushstring(L, dlerror()); 129 return lib; 130 } 131 132 133 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { 134 lua_CFunction f = cast_func(dlsym(lib, sym)); 135 if (f == NULL) lua_pushstring(L, dlerror()); 136 return f; 137 } 138 139 /* }====================================================== */ 140 141 142 143 #elif defined(LUA_DL_DLL) /* }{ */ 144 /* 145 ** {====================================================================== 146 ** This is an implementation of loadlib for Windows using native functions. 147 ** ======================================================================= 148 */ 149 150 #include <windows.h> 151 152 153 /* 154 ** optional flags for LoadLibraryEx 155 */ 156 #if !defined(LUA_LLE_FLAGS) 157 #define LUA_LLE_FLAGS 0 158 #endif 159 160 161 #undef setprogdir 162 163 164 /* 165 ** Replace in the path (on the top of the stack) any occurrence 166 ** of LUA_EXEC_DIR with the executable's path. 167 */ 168 static void setprogdir (lua_State *L) { 169 char buff[MAX_PATH + 1]; 170 char *lb; 171 DWORD nsize = sizeof(buff)/sizeof(char); 172 DWORD n = GetModuleFileNameA(NULL, buff, nsize); /* get exec. name */ 173 if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL) 174 luaL_error(L, "unable to get ModuleFileName"); 175 else { 176 *lb = '\0'; /* cut name on the last '\\' to get the path */ 177 luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff); 178 lua_remove(L, -2); /* remove original string */ 179 } 180 } 181 182 183 184 185 static void pusherror (lua_State *L) { 186 int error = GetLastError(); 187 char buffer[128]; 188 if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM, 189 NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL)) 190 lua_pushstring(L, buffer); 191 else 192 lua_pushfstring(L, "system error %d\n", error); 193 } 194 195 static void lsys_unloadlib (void *lib) { 196 FreeLibrary((HMODULE)lib); 197 } 198 199 200 static void *lsys_load (lua_State *L, const char *path, int seeglb) { 201 HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS); 202 (void)(seeglb); /* not used: symbols are 'global' by default */ 203 if (lib == NULL) pusherror(L); 204 return lib; 205 } 206 207 208 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { 209 lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym); 210 if (f == NULL) pusherror(L); 211 return f; 212 } 213 214 /* }====================================================== */ 215 216 217 #else /* }{ */ 218 /* 219 ** {====================================================== 220 ** Fallback for other systems 221 ** ======================================================= 222 */ 223 224 #undef LIB_FAIL 225 #define LIB_FAIL "absent" 226 227 228 #define DLMSG "dynamic libraries not enabled; check your Lua installation" 229 230 231 static void lsys_unloadlib (void *lib) { 232 (void)(lib); /* not used */ 233 } 234 235 236 static void *lsys_load (lua_State *L, const char *path, int seeglb) { 237 (void)(path); (void)(seeglb); /* not used */ 238 lua_pushliteral(L, DLMSG); 239 return NULL; 240 } 241 242 243 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { 244 (void)(lib); (void)(sym); /* not used */ 245 lua_pushliteral(L, DLMSG); 246 return NULL; 247 } 248 249 /* }====================================================== */ 250 #endif /* } */ 251 252 253 /* 254 ** {================================================================== 255 ** Set Paths 256 ** =================================================================== 257 */ 258 259 /* 260 ** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment 261 ** variables that Lua check to set its paths. 262 */ 263 #if !defined(LUA_PATH_VAR) 264 #define LUA_PATH_VAR "LUA_PATH" 265 #endif 266 267 #if !defined(LUA_CPATH_VAR) 268 #define LUA_CPATH_VAR "LUA_CPATH" 269 #endif 270 271 272 #define AUXMARK "\1" /* auxiliary mark */ 273 274 275 /* 276 ** return registry.LUA_NOENV as a boolean 277 */ 278 static int noenv (lua_State *L) { 279 int b; 280 lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); 281 b = lua_toboolean(L, -1); 282 lua_pop(L, 1); /* remove value */ 283 return b; 284 } 285 286 287 /* 288 ** Set a path 289 */ 290 static void setpath (lua_State *L, const char *fieldname, 291 const char *envname, 292 const char *dft) { 293 const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX); 294 const char *path = getenv(nver); /* use versioned name */ 295 if (path == NULL) /* no environment variable? */ 296 path = getenv(envname); /* try unversioned name */ 297 if (path == NULL || noenv(L)) /* no environment variable? */ 298 lua_pushstring(L, dft); /* use default */ 299 else { 300 /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */ 301 path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP, 302 LUA_PATH_SEP AUXMARK LUA_PATH_SEP); 303 luaL_gsub(L, path, AUXMARK, dft); 304 lua_remove(L, -2); /* remove result from 1st 'gsub' */ 305 } 306 setprogdir(L); 307 lua_setfield(L, -3, fieldname); /* package[fieldname] = path value */ 308 lua_pop(L, 1); /* pop versioned variable name */ 309 } 310 311 /* }================================================================== */ 312 313 314 /* 315 ** return registry.CLIBS[path] 316 */ 317 static void *checkclib (lua_State *L, const char *path) { 318 void *plib; 319 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS); 320 lua_getfield(L, -1, path); 321 plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */ 322 lua_pop(L, 2); /* pop CLIBS table and 'plib' */ 323 return plib; 324 } 325 326 327 /* 328 ** registry.CLIBS[path] = plib -- for queries 329 ** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries 330 */ 331 static void addtoclib (lua_State *L, const char *path, void *plib) { 332 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS); 333 lua_pushlightuserdata(L, plib); 334 lua_pushvalue(L, -1); 335 lua_setfield(L, -3, path); /* CLIBS[path] = plib */ 336 lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */ 337 lua_pop(L, 1); /* pop CLIBS table */ 338 } 339 340 341 /* 342 ** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib 343 ** handles in list CLIBS 344 */ 345 static int gctm (lua_State *L) { 346 lua_Integer n = luaL_len(L, 1); 347 for (; n >= 1; n--) { /* for each handle, in reverse order */ 348 lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */ 349 lsys_unloadlib(lua_touserdata(L, -1)); 350 lua_pop(L, 1); /* pop handle */ 351 } 352 return 0; 353 } 354 355 356 357 /* error codes for 'lookforfunc' */ 358 #define ERRLIB 1 359 #define ERRFUNC 2 360 361 /* 362 ** Look for a C function named 'sym' in a dynamically loaded library 363 ** 'path'. 364 ** First, check whether the library is already loaded; if not, try 365 ** to load it. 366 ** Then, if 'sym' is '*', return true (as library has been loaded). 367 ** Otherwise, look for symbol 'sym' in the library and push a 368 ** C function with that symbol. 369 ** Return 0 and 'true' or a function in the stack; in case of 370 ** errors, return an error code and an error message in the stack. 371 */ 372 static int lookforfunc (lua_State *L, const char *path, const char *sym) { 373 void *reg = checkclib(L, path); /* check loaded C libraries */ 374 if (reg == NULL) { /* must load library? */ 375 reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */ 376 if (reg == NULL) return ERRLIB; /* unable to load library */ 377 addtoclib(L, path, reg); 378 } 379 if (*sym == '*') { /* loading only library (no function)? */ 380 lua_pushboolean(L, 1); /* return 'true' */ 381 return 0; /* no errors */ 382 } 383 else { 384 lua_CFunction f = lsys_sym(L, reg, sym); 385 if (f == NULL) 386 return ERRFUNC; /* unable to find function */ 387 lua_pushcfunction(L, f); /* else create new function */ 388 return 0; /* no errors */ 389 } 390 } 391 392 393 static int ll_loadlib (lua_State *L) { 394 const char *path = luaL_checkstring(L, 1); 395 const char *init = luaL_checkstring(L, 2); 396 int stat = lookforfunc(L, path, init); 397 if (stat == 0) /* no errors? */ 398 return 1; /* return the loaded function */ 399 else { /* error; error message is on stack top */ 400 lua_pushnil(L); 401 lua_insert(L, -2); 402 lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init"); 403 return 3; /* return nil, error message, and where */ 404 } 405 } 406 407 408 409 /* 410 ** {====================================================== 411 ** 'require' function 412 ** ======================================================= 413 */ 414 415 416 static int readable (const char *filename) { 417 FILE *f = fopen(filename, "r"); /* try to open file */ 418 if (f == NULL) return 0; /* open failed */ 419 fclose(f); 420 return 1; 421 } 422 423 424 static const char *pushnexttemplate (lua_State *L, const char *path) { 425 const char *l; 426 while (*path == *LUA_PATH_SEP) path++; /* skip separators */ 427 if (*path == '\0') return NULL; /* no more templates */ 428 l = strchr(path, *LUA_PATH_SEP); /* find next separator */ 429 if (l == NULL) l = path + strlen(path); 430 lua_pushlstring(L, path, l - path); /* template */ 431 return l; 432 } 433 434 435 static const char *searchpath (lua_State *L, const char *name, 436 const char *path, 437 const char *sep, 438 const char *dirsep) { 439 luaL_Buffer msg; /* to build error message */ 440 luaL_buffinit(L, &msg); 441 if (*sep != '\0') /* non-empty separator? */ 442 name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */ 443 while ((path = pushnexttemplate(L, path)) != NULL) { 444 const char *filename = luaL_gsub(L, lua_tostring(L, -1), 445 LUA_PATH_MARK, name); 446 lua_remove(L, -2); /* remove path template */ 447 if (readable(filename)) /* does file exist and is readable? */ 448 return filename; /* return that file name */ 449 lua_pushfstring(L, "\n\tno file '%s'", filename); 450 lua_remove(L, -2); /* remove file name */ 451 luaL_addvalue(&msg); /* concatenate error msg. entry */ 452 } 453 luaL_pushresult(&msg); /* create error message */ 454 return NULL; /* not found */ 455 } 456 457 458 static int ll_searchpath (lua_State *L) { 459 const char *f = searchpath(L, luaL_checkstring(L, 1), 460 luaL_checkstring(L, 2), 461 luaL_optstring(L, 3, "."), 462 luaL_optstring(L, 4, LUA_DIRSEP)); 463 if (f != NULL) return 1; 464 else { /* error message is on top of the stack */ 465 lua_pushnil(L); 466 lua_insert(L, -2); 467 return 2; /* return nil + error message */ 468 } 469 } 470 471 472 static const char *findfile (lua_State *L, const char *name, 473 const char *pname, 474 const char *dirsep) { 475 const char *path; 476 lua_getfield(L, lua_upvalueindex(1), pname); 477 path = lua_tostring(L, -1); 478 if (path == NULL) 479 luaL_error(L, "'package.%s' must be a string", pname); 480 return searchpath(L, name, path, ".", dirsep); 481 } 482 483 484 static int checkload (lua_State *L, int stat, const char *filename) { 485 if (stat) { /* module loaded successfully? */ 486 lua_pushstring(L, filename); /* will be 2nd argument to module */ 487 return 2; /* return open function and file name */ 488 } 489 else 490 return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s", 491 lua_tostring(L, 1), filename, lua_tostring(L, -1)); 492 } 493 494 495 static int searcher_Lua (lua_State *L) { 496 const char *filename; 497 const char *name = luaL_checkstring(L, 1); 498 filename = findfile(L, name, "path", LUA_LSUBSEP); 499 if (filename == NULL) return 1; /* module not found in this path */ 500 return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename); 501 } 502 503 504 /* 505 ** Try to find a load function for module 'modname' at file 'filename'. 506 ** First, change '.' to '_' in 'modname'; then, if 'modname' has 507 ** the form X-Y (that is, it has an "ignore mark"), build a function 508 ** name "luaopen_X" and look for it. (For compatibility, if that 509 ** fails, it also tries "luaopen_Y".) If there is no ignore mark, 510 ** look for a function named "luaopen_modname". 511 */ 512 static int loadfunc (lua_State *L, const char *filename, const char *modname) { 513 const char *openfunc; 514 const char *mark; 515 modname = luaL_gsub(L, modname, ".", LUA_OFSEP); 516 mark = strchr(modname, *LUA_IGMARK); 517 if (mark) { 518 int stat; 519 openfunc = lua_pushlstring(L, modname, mark - modname); 520 openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc); 521 stat = lookforfunc(L, filename, openfunc); 522 if (stat != ERRFUNC) return stat; 523 modname = mark + 1; /* else go ahead and try old-style name */ 524 } 525 openfunc = lua_pushfstring(L, LUA_POF"%s", modname); 526 return lookforfunc(L, filename, openfunc); 527 } 528 529 530 static int searcher_C (lua_State *L) { 531 const char *name = luaL_checkstring(L, 1); 532 const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP); 533 if (filename == NULL) return 1; /* module not found in this path */ 534 return checkload(L, (loadfunc(L, filename, name) == 0), filename); 535 } 536 537 538 static int searcher_Croot (lua_State *L) { 539 const char *filename; 540 const char *name = luaL_checkstring(L, 1); 541 const char *p = strchr(name, '.'); 542 int stat; 543 if (p == NULL) return 0; /* is root */ 544 lua_pushlstring(L, name, p - name); 545 filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP); 546 if (filename == NULL) return 1; /* root not found */ 547 if ((stat = loadfunc(L, filename, name)) != 0) { 548 if (stat != ERRFUNC) 549 return checkload(L, 0, filename); /* real error */ 550 else { /* open function not found */ 551 lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename); 552 return 1; 553 } 554 } 555 lua_pushstring(L, filename); /* will be 2nd argument to module */ 556 return 2; 557 } 558 559 560 static int searcher_preload (lua_State *L) { 561 const char *name = luaL_checkstring(L, 1); 562 lua_getfield(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE); 563 if (lua_getfield(L, -1, name) == LUA_TNIL) /* not found? */ 564 lua_pushfstring(L, "\n\tno field package.preload['%s']", name); 565 return 1; 566 } 567 568 569 static void findloader (lua_State *L, const char *name) { 570 int i; 571 luaL_Buffer msg; /* to build error message */ 572 luaL_buffinit(L, &msg); 573 /* push 'package.searchers' to index 3 in the stack */ 574 if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE) 575 luaL_error(L, "'package.searchers' must be a table"); 576 /* iterate over available searchers to find a loader */ 577 for (i = 1; ; i++) { 578 if (lua_rawgeti(L, 3, i) == LUA_TNIL) { /* no more searchers? */ 579 lua_pop(L, 1); /* remove nil */ 580 luaL_pushresult(&msg); /* create error message */ 581 luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1)); 582 } 583 lua_pushstring(L, name); 584 lua_call(L, 1, 2); /* call it */ 585 if (lua_isfunction(L, -2)) /* did it find a loader? */ 586 return; /* module loader found */ 587 else if (lua_isstring(L, -2)) { /* searcher returned error message? */ 588 lua_pop(L, 1); /* remove extra return */ 589 luaL_addvalue(&msg); /* concatenate error message */ 590 } 591 else 592 lua_pop(L, 2); /* remove both returns */ 593 } 594 } 595 596 597 static int ll_require (lua_State *L) { 598 const char *name = luaL_checkstring(L, 1); 599 lua_settop(L, 1); /* LOADED table will be at index 2 */ 600 lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); 601 lua_getfield(L, 2, name); /* LOADED[name] */ 602 if (lua_toboolean(L, -1)) /* is it there? */ 603 return 1; /* package is already loaded */ 604 /* else must load package */ 605 lua_pop(L, 1); /* remove 'getfield' result */ 606 findloader(L, name); 607 lua_pushstring(L, name); /* pass name as argument to module loader */ 608 lua_insert(L, -2); /* name is 1st argument (before search data) */ 609 lua_call(L, 2, 1); /* run loader to load module */ 610 if (!lua_isnil(L, -1)) /* non-nil return? */ 611 lua_setfield(L, 2, name); /* LOADED[name] = returned value */ 612 if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */ 613 lua_pushboolean(L, 1); /* use true as result */ 614 lua_pushvalue(L, -1); /* extra copy to be returned */ 615 lua_setfield(L, 2, name); /* LOADED[name] = true */ 616 } 617 return 1; 618 } 619 620 /* }====================================================== */ 621 622 623 624 /* 625 ** {====================================================== 626 ** 'module' function 627 ** ======================================================= 628 */ 629 #if defined(LUA_COMPAT_MODULE) 630 631 /* 632 ** changes the environment variable of calling function 633 */ 634 static void set_env (lua_State *L) { 635 lua_Debug ar; 636 if (lua_getstack(L, 1, &ar) == 0 || 637 lua_getinfo(L, "f", &ar) == 0 || /* get calling function */ 638 lua_iscfunction(L, -1)) 639 luaL_error(L, "'module' not called from a Lua function"); 640 lua_pushvalue(L, -2); /* copy new environment table to top */ 641 lua_setupvalue(L, -2, 1); 642 lua_pop(L, 1); /* remove function */ 643 } 644 645 646 static void dooptions (lua_State *L, int n) { 647 int i; 648 for (i = 2; i <= n; i++) { 649 if (lua_isfunction(L, i)) { /* avoid 'calling' extra info. */ 650 lua_pushvalue(L, i); /* get option (a function) */ 651 lua_pushvalue(L, -2); /* module */ 652 lua_call(L, 1, 0); 653 } 654 } 655 } 656 657 658 static void modinit (lua_State *L, const char *modname) { 659 const char *dot; 660 lua_pushvalue(L, -1); 661 lua_setfield(L, -2, "_M"); /* module._M = module */ 662 lua_pushstring(L, modname); 663 lua_setfield(L, -2, "_NAME"); 664 dot = strrchr(modname, '.'); /* look for last dot in module name */ 665 if (dot == NULL) dot = modname; 666 else dot++; 667 /* set _PACKAGE as package name (full module name minus last part) */ 668 lua_pushlstring(L, modname, dot - modname); 669 lua_setfield(L, -2, "_PACKAGE"); 670 } 671 672 673 static int ll_module (lua_State *L) { 674 const char *modname = luaL_checkstring(L, 1); 675 int lastarg = lua_gettop(L); /* last parameter */ 676 luaL_pushmodule(L, modname, 1); /* get/create module table */ 677 /* check whether table already has a _NAME field */ 678 if (lua_getfield(L, -1, "_NAME") != LUA_TNIL) 679 lua_pop(L, 1); /* table is an initialized module */ 680 else { /* no; initialize it */ 681 lua_pop(L, 1); 682 modinit(L, modname); 683 } 684 lua_pushvalue(L, -1); 685 set_env(L); 686 dooptions(L, lastarg); 687 return 1; 688 } 689 690 691 static int ll_seeall (lua_State *L) { 692 luaL_checktype(L, 1, LUA_TTABLE); 693 if (!lua_getmetatable(L, 1)) { 694 lua_createtable(L, 0, 1); /* create new metatable */ 695 lua_pushvalue(L, -1); 696 lua_setmetatable(L, 1); 697 } 698 lua_pushglobaltable(L); 699 lua_setfield(L, -2, "__index"); /* mt.__index = _G */ 700 return 0; 701 } 702 703 #endif 704 /* }====================================================== */ 705 706 707 708 static const luaL_Reg pk_funcs[] = { 709 {"loadlib", ll_loadlib}, 710 {"searchpath", ll_searchpath}, 711 #if defined(LUA_COMPAT_MODULE) 712 {"seeall", ll_seeall}, 713 #endif 714 /* placeholders */ 715 {"preload", NULL}, 716 {"cpath", NULL}, 717 {"path", NULL}, 718 {"searchers", NULL}, 719 {"loaded", NULL}, 720 {NULL, NULL} 721 }; 722 723 724 static const luaL_Reg ll_funcs[] = { 725 #if defined(LUA_COMPAT_MODULE) 726 {"module", ll_module}, 727 #endif 728 {"require", ll_require}, 729 {NULL, NULL} 730 }; 731 732 733 static void createsearcherstable (lua_State *L) { 734 static const lua_CFunction searchers[] = 735 {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL}; 736 int i; 737 /* create 'searchers' table */ 738 lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0); 739 /* fill it with predefined searchers */ 740 for (i=0; searchers[i] != NULL; i++) { 741 lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */ 742 lua_pushcclosure(L, searchers[i], 1); 743 lua_rawseti(L, -2, i+1); 744 } 745 #if defined(LUA_COMPAT_LOADERS) 746 lua_pushvalue(L, -1); /* make a copy of 'searchers' table */ 747 lua_setfield(L, -3, "loaders"); /* put it in field 'loaders' */ 748 #endif 749 lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */ 750 } 751 752 753 /* 754 ** create table CLIBS to keep track of loaded C libraries, 755 ** setting a finalizer to close all libraries when closing state. 756 */ 757 static void createclibstable (lua_State *L) { 758 lua_newtable(L); /* create CLIBS table */ 759 lua_createtable(L, 0, 1); /* create metatable for CLIBS */ 760 lua_pushcfunction(L, gctm); 761 lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */ 762 lua_setmetatable(L, -2); 763 lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS); /* set CLIBS table in registry */ 764 } 765 766 767 LUAMOD_API int luaopen_package (lua_State *L) { 768 createclibstable(L); 769 luaL_newlib(L, pk_funcs); /* create 'package' table */ 770 createsearcherstable(L); 771 /* set paths */ 772 setpath(L, "path", LUA_PATH_VAR, LUA_PATH_DEFAULT); 773 setpath(L, "cpath", LUA_CPATH_VAR, LUA_CPATH_DEFAULT); 774 /* store config information */ 775 lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n" 776 LUA_EXEC_DIR "\n" LUA_IGMARK "\n"); 777 lua_setfield(L, -2, "config"); 778 /* set field 'loaded' */ 779 luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); 780 lua_setfield(L, -2, "loaded"); 781 /* set field 'preload' */ 782 luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE); 783 lua_setfield(L, -2, "preload"); 784 lua_pushglobaltable(L); 785 lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */ 786 luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */ 787 lua_pop(L, 1); /* pop global table */ 788 return 1; /* return 'package' table */ 789 } 790