git.zerfleddert.de Git - proxmark3-svn/blob - liblua/loadlib.c

   1 /*
   2 ** $Id: loadlib.c,v 1.111 2012/05/30 12:33:44 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
  12 /*
  13 ** if needed, includes windows header before everything else
  14 */
  15 #if defined(_WIN32)
  16 #include <windows.h>
  17 #endif
  18
  19
  20 #include <stdlib.h>
  21 #include <string.h>
  22
  23
  24 #define loadlib_c
  25 #define LUA_LIB
  26
  27 #include "lua.h"
  28
  29 #include "lauxlib.h"
  30 #include "lualib.h"
  31
  32
  33 /*
  34 ** LUA_PATH and LUA_CPATH are the names of the environment
  35 ** variables that Lua check to set its paths.
  36 */
  37 #if !defined(LUA_PATH)
  38 #define LUA_PATH        "LUA_PATH"
  39 #endif
  40
  41 #if !defined(LUA_CPATH)
  42 #define LUA_CPATH       "LUA_CPATH"
  43 #endif
  44
  45 #define LUA_PATHSUFFIX          "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
  46
  47 #define LUA_PATHVERSION         LUA_PATH LUA_PATHSUFFIX
  48 #define LUA_CPATHVERSION        LUA_CPATH LUA_PATHSUFFIX
  49
  50 /*
  51 ** LUA_PATH_SEP is the character that separates templates in a path.
  52 ** LUA_PATH_MARK is the string that marks the substitution points in a
  53 ** template.
  54 ** LUA_EXEC_DIR in a Windows path is replaced by the executable's
  55 ** directory.
  56 ** LUA_IGMARK is a mark to ignore all before it when building the
  57 ** luaopen_ function name.
  58 */
  59 #if !defined (LUA_PATH_SEP)
  60 #define LUA_PATH_SEP            ";"
  61 #endif
  62 #if !defined (LUA_PATH_MARK)
  63 #define LUA_PATH_MARK           "?"
  64 #endif
  65 #if !defined (LUA_EXEC_DIR)
  66 #define LUA_EXEC_DIR            "!"
  67 #endif
  68 #if !defined (LUA_IGMARK)
  69 #define LUA_IGMARK              "-"
  70 #endif
  71
  72
  73 /*
  74 ** LUA_CSUBSEP is the character that replaces dots in submodule names
  75 ** when searching for a C loader.
  76 ** LUA_LSUBSEP is the character that replaces dots in submodule names
  77 ** when searching for a Lua loader.
  78 */
  79 #if !defined(LUA_CSUBSEP)
  80 #define LUA_CSUBSEP             LUA_DIRSEP
  81 #endif
  82
  83 #if !defined(LUA_LSUBSEP)
  84 #define LUA_LSUBSEP             LUA_DIRSEP
  85 #endif
  86
  87
  88 /* prefix for open functions in C libraries */
  89 #define LUA_POF         "luaopen_"
  90
  91 /* separator for open functions in C libraries */
  92 #define LUA_OFSEP       "_"
  93
  94
  95 /* table (in the registry) that keeps handles for all loaded C libraries */
  96 #define CLIBS           "_CLIBS"
  97
  98 #define LIB_FAIL        "open"
  99
 100
 101 /* error codes for ll_loadfunc */
 102 #define ERRLIB          1
 103 #define ERRFUNC         2
 104
 105 #define setprogdir(L)           ((void)0)
 106
 107
 108 /*
 109 ** system-dependent functions
 110 */
 111 static void ll_unloadlib (void *lib);
 112 static void *ll_load (lua_State *L, const char *path, int seeglb);
 113 static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
 114
 115
 116
 117 #if defined(LUA_USE_DLOPEN)
 118 /*
 119 ** {========================================================================
 120 ** This is an implementation of loadlib based on the dlfcn interface.
 121 ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
 122 ** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
 123 ** as an emulation layer on top of native functions.
 124 ** =========================================================================
 125 */
 126
 127 #include <dlfcn.h>
 128
 129 static void ll_unloadlib (void *lib) {
 130   dlclose(lib);
 131 }
 132
 133
 134 static void *ll_load (lua_State *L, const char *path, int seeglb) {
 135   void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
 136   if (lib == NULL) lua_pushstring(L, dlerror());
 137   return lib;
 138 }
 139
 140
 141 static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
 142   lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
 143   if (f == NULL) lua_pushstring(L, dlerror());
 144   return f;
 145 }
 146
 147 /* }====================================================== */
 148
 149
 150
 151 #elif defined(LUA_DL_DLL)
 152 /*
 153 ** {======================================================================
 154 ** This is an implementation of loadlib for Windows using native functions.
 155 ** =======================================================================
 156 */
 157
 158 #undef setprogdir
 159
 160 /*
 161 ** optional flags for LoadLibraryEx
 162 */
 163 #if !defined(LUA_LLE_FLAGS)
 164 #define LUA_LLE_FLAGS   0
 165 #endif
 166
 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);
 173   if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
 174     luaL_error(L, "unable to get ModuleFileName");
 175   else {
 176     *lb = '\0';
 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 static void pusherror (lua_State *L) {
 184   int error = GetLastError();
 185   char buffer[128];
 186   if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
 187       NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
 188     lua_pushstring(L, buffer);
 189   else
 190     lua_pushfstring(L, "system error %d\n", error);
 191 }
 192
 193 static void ll_unloadlib (void *lib) {
 194   FreeLibrary((HMODULE)lib);
 195 }
 196
 197
 198 static void *ll_load (lua_State *L, const char *path, int seeglb) {
 199   HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
 200   (void)(seeglb);  /* not used: symbols are 'global' by default */
 201   if (lib == NULL) pusherror(L);
 202   return lib;
 203 }
 204
 205
 206 static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
 207   lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
 208   if (f == NULL) pusherror(L);
 209   return f;
 210 }
 211
 212 /* }====================================================== */
 213
 214
 215 #else
 216 /*
 217 ** {======================================================
 218 ** Fallback for other systems
 219 ** =======================================================
 220 */
 221
 222 #undef LIB_FAIL
 223 #define LIB_FAIL        "absent"
 224
 225
 226 #define DLMSG   "dynamic libraries not enabled; check your Lua installation"
 227
 228
 229 static void ll_unloadlib (void *lib) {
 230   (void)(lib);  /* not used */
 231 }
 232
 233
 234 static void *ll_load (lua_State *L, const char *path, int seeglb) {
 235   (void)(path); (void)(seeglb);  /* not used */
 236   lua_pushliteral(L, DLMSG);
 237   return NULL;
 238 }
 239
 240
 241 static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
 242   (void)(lib); (void)(sym);  /* not used */
 243   lua_pushliteral(L, DLMSG);
 244   return NULL;
 245 }
 246
 247 /* }====================================================== */
 248 #endif
 249
 250
 251 static void *ll_checkclib (lua_State *L, const char *path) {
 252   void *plib;
 253   lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
 254   lua_getfield(L, -1, path);
 255   plib = lua_touserdata(L, -1);  /* plib = CLIBS[path] */
 256   lua_pop(L, 2);  /* pop CLIBS table and 'plib' */
 257   return plib;
 258 }
 259
 260
 261 static void ll_addtoclib (lua_State *L, const char *path, void *plib) {
 262   lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
 263   lua_pushlightuserdata(L, plib);
 264   lua_pushvalue(L, -1);
 265   lua_setfield(L, -3, path);  /* CLIBS[path] = plib */
 266   lua_rawseti(L, -2, luaL_len(L, -2) + 1);  /* CLIBS[#CLIBS + 1] = plib */
 267   lua_pop(L, 1);  /* pop CLIBS table */
 268 }
 269
 270
 271 /*
 272 ** __gc tag method for CLIBS table: calls 'll_unloadlib' for all lib
 273 ** handles in list CLIBS
 274 */
 275 static int gctm (lua_State *L) {
 276   int n = luaL_len(L, 1);
 277   for (; n >= 1; n--) {  /* for each handle, in reverse order */
 278     lua_rawgeti(L, 1, n);  /* get handle CLIBS[n] */
 279     ll_unloadlib(lua_touserdata(L, -1));
 280     lua_pop(L, 1);  /* pop handle */
 281   }
 282   return 0;
 283 }
 284
 285
 286 static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
 287   void *reg = ll_checkclib(L, path);  /* check loaded C libraries */
 288   if (reg == NULL) {  /* must load library? */
 289     reg = ll_load(L, path, *sym == '*');
 290     if (reg == NULL) return ERRLIB;  /* unable to load library */
 291     ll_addtoclib(L, path, reg);
 292   }
 293   if (*sym == '*') {  /* loading only library (no function)? */
 294     lua_pushboolean(L, 1);  /* return 'true' */
 295     return 0;  /* no errors */
 296   }
 297   else {
 298     lua_CFunction f = ll_sym(L, reg, sym);
 299     if (f == NULL)
 300       return ERRFUNC;  /* unable to find function */
 301     lua_pushcfunction(L, f);  /* else create new function */
 302     return 0;  /* no errors */
 303   }
 304 }
 305
 306
 307 static int ll_loadlib (lua_State *L) {
 308   const char *path = luaL_checkstring(L, 1);
 309   const char *init = luaL_checkstring(L, 2);
 310   int stat = ll_loadfunc(L, path, init);
 311   if (stat == 0)  /* no errors? */
 312     return 1;  /* return the loaded function */
 313   else {  /* error; error message is on stack top */
 314     lua_pushnil(L);
 315     lua_insert(L, -2);
 316     lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
 317     return 3;  /* return nil, error message, and where */
 318   }
 319 }
 320
 321
 322
 323 /*
 324 ** {======================================================
 325 ** 'require' function
 326 ** =======================================================
 327 */
 328
 329
 330 static int readable (const char *filename) {
 331   FILE *f = fopen(filename, "r");  /* try to open file */
 332   if (f == NULL) return 0;  /* open failed */
 333   fclose(f);
 334   return 1;
 335 }
 336
 337
 338 static const char *pushnexttemplate (lua_State *L, const char *path) {
 339   const char *l;
 340   while (*path == *LUA_PATH_SEP) path++;  /* skip separators */
 341   if (*path == '\0') return NULL;  /* no more templates */
 342   l = strchr(path, *LUA_PATH_SEP);  /* find next separator */
 343   if (l == NULL) l = path + strlen(path);
 344   lua_pushlstring(L, path, l - path);  /* template */
 345   return l;
 346 }
 347
 348
 349 static const char *searchpath (lua_State *L, const char *name,
 350                                              const char *path,
 351                                              const char *sep,
 352                                              const char *dirsep) {
 353   luaL_Buffer msg;  /* to build error message */
 354   luaL_buffinit(L, &msg);
 355   if (*sep != '\0')  /* non-empty separator? */
 356     name = luaL_gsub(L, name, sep, dirsep);  /* replace it by 'dirsep' */
 357   while ((path = pushnexttemplate(L, path)) != NULL) {
 358     const char *filename = luaL_gsub(L, lua_tostring(L, -1),
 359                                      LUA_PATH_MARK, name);
 360     lua_remove(L, -2);  /* remove path template */
 361     if (readable(filename))  /* does file exist and is readable? */
 362       return filename;  /* return that file name */
 363     lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
 364     lua_remove(L, -2);  /* remove file name */
 365     luaL_addvalue(&msg);  /* concatenate error msg. entry */
 366   }
 367   luaL_pushresult(&msg);  /* create error message */
 368   return NULL;  /* not found */
 369 }
 370
 371
 372 static int ll_searchpath (lua_State *L) {
 373   const char *f = searchpath(L, luaL_checkstring(L, 1),
 374                                 luaL_checkstring(L, 2),
 375                                 luaL_optstring(L, 3, "."),
 376                                 luaL_optstring(L, 4, LUA_DIRSEP));
 377   if (f != NULL) return 1;
 378   else {  /* error message is on top of the stack */
 379     lua_pushnil(L);
 380     lua_insert(L, -2);
 381     return 2;  /* return nil + error message */
 382   }
 383 }
 384
 385
 386 static const char *findfile (lua_State *L, const char *name,
 387                                            const char *pname,
 388                                            const char *dirsep) {
 389   const char *path;
 390   lua_getfield(L, lua_upvalueindex(1), pname);
 391   path = lua_tostring(L, -1);
 392   if (path == NULL)
 393     luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
 394   return searchpath(L, name, path, ".", dirsep);
 395 }
 396
 397
 398 static int checkload (lua_State *L, int stat, const char *filename) {
 399   if (stat) {  /* module loaded successfully? */
 400     lua_pushstring(L, filename);  /* will be 2nd argument to module */
 401     return 2;  /* return open function and file name */
 402   }
 403   else
 404     return luaL_error(L, "error loading module " LUA_QS
 405                          " from file " LUA_QS ":\n\t%s",
 406                           lua_tostring(L, 1), filename, lua_tostring(L, -1));
 407 }
 408
 409
 410 static int searcher_Lua (lua_State *L) {
 411   const char *filename;
 412   const char *name = luaL_checkstring(L, 1);
 413   filename = findfile(L, name, "path", LUA_LSUBSEP);
 414   if (filename == NULL) return 1;  /* module not found in this path */
 415   return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
 416 }
 417
 418
 419 static int loadfunc (lua_State *L, const char *filename, const char *modname) {
 420   const char *funcname;
 421   const char *mark;
 422   modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
 423   mark = strchr(modname, *LUA_IGMARK);
 424   if (mark) {
 425     int stat;
 426     funcname = lua_pushlstring(L, modname, mark - modname);
 427     funcname = lua_pushfstring(L, LUA_POF"%s", funcname);
 428     stat = ll_loadfunc(L, filename, funcname);
 429     if (stat != ERRFUNC) return stat;
 430     modname = mark + 1;  /* else go ahead and try old-style name */
 431   }
 432   funcname = lua_pushfstring(L, LUA_POF"%s", modname);
 433   return ll_loadfunc(L, filename, funcname);
 434 }
 435
 436
 437 static int searcher_C (lua_State *L) {
 438   const char *name = luaL_checkstring(L, 1);
 439   const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
 440   if (filename == NULL) return 1;  /* module not found in this path */
 441   return checkload(L, (loadfunc(L, filename, name) == 0), filename);
 442 }
 443
 444
 445 static int searcher_Croot (lua_State *L) {
 446   const char *filename;
 447   const char *name = luaL_checkstring(L, 1);
 448   const char *p = strchr(name, '.');
 449   int stat;
 450   if (p == NULL) return 0;  /* is root */
 451   lua_pushlstring(L, name, p - name);
 452   filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
 453   if (filename == NULL) return 1;  /* root not found */
 454   if ((stat = loadfunc(L, filename, name)) != 0) {
 455     if (stat != ERRFUNC)
 456       return checkload(L, 0, filename);  /* real error */
 457     else {  /* open function not found */
 458       lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
 459                          name, filename);
 460       return 1;
 461     }
 462   }
 463   lua_pushstring(L, filename);  /* will be 2nd argument to module */
 464   return 2;
 465 }
 466
 467
 468 static int searcher_preload (lua_State *L) {
 469   const char *name = luaL_checkstring(L, 1);
 470   lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
 471   lua_getfield(L, -1, name);
 472   if (lua_isnil(L, -1))  /* not found? */
 473     lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
 474   return 1;
 475 }
 476
 477
 478 static void findloader (lua_State *L, const char *name) {
 479   int i;
 480   luaL_Buffer msg;  /* to build error message */
 481   luaL_buffinit(L, &msg);
 482   lua_getfield(L, lua_upvalueindex(1), "searchers");  /* will be at index 3 */
 483   if (!lua_istable(L, 3))
 484     luaL_error(L, LUA_QL("package.searchers") " must be a table");
 485   /*  iterate over available searchers to find a loader */
 486   for (i = 1; ; i++) {
 487     lua_rawgeti(L, 3, i);  /* get a searcher */
 488     if (lua_isnil(L, -1)) {  /* no more searchers? */
 489       lua_pop(L, 1);  /* remove nil */
 490       luaL_pushresult(&msg);  /* create error message */
 491       luaL_error(L, "module " LUA_QS " not found:%s",
 492                     name, lua_tostring(L, -1));
 493     }
 494     lua_pushstring(L, name);
 495     lua_call(L, 1, 2);  /* call it */
 496     if (lua_isfunction(L, -2))  /* did it find a loader? */
 497       return;  /* module loader found */
 498     else if (lua_isstring(L, -2)) {  /* searcher returned error message? */
 499       lua_pop(L, 1);  /* remove extra return */
 500       luaL_addvalue(&msg);  /* concatenate error message */
 501     }
 502     else
 503       lua_pop(L, 2);  /* remove both returns */
 504   }
 505 }
 506
 507
 508 static int ll_require (lua_State *L) {
 509   const char *name = luaL_checkstring(L, 1);
 510   lua_settop(L, 1);  /* _LOADED table will be at index 2 */
 511   lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
 512   lua_getfield(L, 2, name);  /* _LOADED[name] */
 513   if (lua_toboolean(L, -1))  /* is it there? */
 514     return 1;  /* package is already loaded */
 515   /* else must load package */
 516   lua_pop(L, 1);  /* remove 'getfield' result */
 517   findloader(L, name);
 518   lua_pushstring(L, name);  /* pass name as argument to module loader */
 519   lua_insert(L, -2);  /* name is 1st argument (before search data) */
 520   lua_call(L, 2, 1);  /* run loader to load module */
 521   if (!lua_isnil(L, -1))  /* non-nil return? */
 522     lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
 523   lua_getfield(L, 2, name);
 524   if (lua_isnil(L, -1)) {   /* module did not set a value? */
 525     lua_pushboolean(L, 1);  /* use true as result */
 526     lua_pushvalue(L, -1);  /* extra copy to be returned */
 527     lua_setfield(L, 2, name);  /* _LOADED[name] = true */
 528   }
 529   return 1;
 530 }
 531
 532 /* }====================================================== */
 533
 534
 535
 536 /*
 537 ** {======================================================
 538 ** 'module' function
 539 ** =======================================================
 540 */
 541 #if defined(LUA_COMPAT_MODULE)
 542
 543 /*
 544 ** changes the environment variable of calling function
 545 */
 546 static void set_env (lua_State *L) {
 547   lua_Debug ar;
 548   if (lua_getstack(L, 1, &ar) == 0 ||
 549       lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
 550       lua_iscfunction(L, -1))
 551     luaL_error(L, LUA_QL("module") " not called from a Lua function");
 552   lua_pushvalue(L, -2);  /* copy new environment table to top */
 553   lua_setupvalue(L, -2, 1);
 554   lua_pop(L, 1);  /* remove function */
 555 }
 556
 557
 558 static void dooptions (lua_State *L, int n) {
 559   int i;
 560   for (i = 2; i <= n; i++) {
 561     if (lua_isfunction(L, i)) {  /* avoid 'calling' extra info. */
 562       lua_pushvalue(L, i);  /* get option (a function) */
 563       lua_pushvalue(L, -2);  /* module */
 564       lua_call(L, 1, 0);
 565     }
 566   }
 567 }
 568
 569
 570 static void modinit (lua_State *L, const char *modname) {
 571   const char *dot;
 572   lua_pushvalue(L, -1);
 573   lua_setfield(L, -2, "_M");  /* module._M = module */
 574   lua_pushstring(L, modname);
 575   lua_setfield(L, -2, "_NAME");
 576   dot = strrchr(modname, '.');  /* look for last dot in module name */
 577   if (dot == NULL) dot = modname;
 578   else dot++;
 579   /* set _PACKAGE as package name (full module name minus last part) */
 580   lua_pushlstring(L, modname, dot - modname);
 581   lua_setfield(L, -2, "_PACKAGE");
 582 }
 583
 584
 585 static int ll_module (lua_State *L) {
 586   const char *modname = luaL_checkstring(L, 1);
 587   int lastarg = lua_gettop(L);  /* last parameter */
 588   luaL_pushmodule(L, modname, 1);  /* get/create module table */
 589   /* check whether table already has a _NAME field */
 590   lua_getfield(L, -1, "_NAME");
 591   if (!lua_isnil(L, -1))  /* is table an initialized module? */
 592     lua_pop(L, 1);
 593   else {  /* no; initialize it */
 594     lua_pop(L, 1);
 595     modinit(L, modname);
 596   }
 597   lua_pushvalue(L, -1);
 598   set_env(L);
 599   dooptions(L, lastarg);
 600   return 1;
 601 }
 602
 603
 604 static int ll_seeall (lua_State *L) {
 605   luaL_checktype(L, 1, LUA_TTABLE);
 606   if (!lua_getmetatable(L, 1)) {
 607     lua_createtable(L, 0, 1); /* create new metatable */
 608     lua_pushvalue(L, -1);
 609     lua_setmetatable(L, 1);
 610   }
 611   lua_pushglobaltable(L);
 612   lua_setfield(L, -2, "__index");  /* mt.__index = _G */
 613   return 0;
 614 }
 615
 616 #endif
 617 /* }====================================================== */
 618
 619
 620
 621 /* auxiliary mark (for internal use) */
 622 #define AUXMARK         "\1"
 623
 624
 625 /*
 626 ** return registry.LUA_NOENV as a boolean
 627 */
 628 static int noenv (lua_State *L) {
 629   int b;
 630   lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
 631   b = lua_toboolean(L, -1);
 632   lua_pop(L, 1);  /* remove value */
 633   return b;
 634 }
 635
 636
 637 static void setpath (lua_State *L, const char *fieldname, const char *envname1,
 638                                    const char *envname2, const char *def) {
 639   const char *path = getenv(envname1);
 640   if (path == NULL)  /* no environment variable? */
 641     path = getenv(envname2);  /* try alternative name */
 642   if (path == NULL || noenv(L))  /* no environment variable? */
 643     lua_pushstring(L, def);  /* use default */
 644   else {
 645     /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
 646     path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
 647                               LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
 648     luaL_gsub(L, path, AUXMARK, def);
 649     lua_remove(L, -2);
 650   }
 651   setprogdir(L);
 652   lua_setfield(L, -2, fieldname);
 653 }
 654
 655
 656 static const luaL_Reg pk_funcs[] = {
 657   {"loadlib", ll_loadlib},
 658   {"searchpath", ll_searchpath},
 659 #if defined(LUA_COMPAT_MODULE)
 660   {"seeall", ll_seeall},
 661 #endif
 662   {NULL, NULL}
 663 };
 664
 665
 666 static const luaL_Reg ll_funcs[] = {
 667 #if defined(LUA_COMPAT_MODULE)
 668   {"module", ll_module},
 669 #endif
 670   {"require", ll_require},
 671   {NULL, NULL}
 672 };
 673
 674
 675 static void createsearcherstable (lua_State *L) {
 676   static const lua_CFunction searchers[] =
 677     {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
 678   int i;
 679   /* create 'searchers' table */
 680   lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
 681   /* fill it with pre-defined searchers */
 682   for (i=0; searchers[i] != NULL; i++) {
 683     lua_pushvalue(L, -2);  /* set 'package' as upvalue for all searchers */
 684     lua_pushcclosure(L, searchers[i], 1);
 685     lua_rawseti(L, -2, i+1);
 686   }
 687 }
 688
 689
 690 LUAMOD_API int luaopen_package (lua_State *L) {
 691   /* create table CLIBS to keep track of loaded C libraries */
 692   luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);
 693   lua_createtable(L, 0, 1);  /* metatable for CLIBS */
 694   lua_pushcfunction(L, gctm);
 695   lua_setfield(L, -2, "__gc");  /* set finalizer for CLIBS table */
 696   lua_setmetatable(L, -2);
 697   /* create `package' table */
 698   luaL_newlib(L, pk_funcs);
 699   createsearcherstable(L);
 700 #if defined(LUA_COMPAT_LOADERS)
 701   lua_pushvalue(L, -1);  /* make a copy of 'searchers' table */
 702   lua_setfield(L, -3, "loaders");  /* put it in field `loaders' */
 703 #endif
 704   lua_setfield(L, -2, "searchers");  /* put it in field 'searchers' */
 705   /* set field 'path' */
 706   setpath(L, "path", LUA_PATHVERSION, LUA_PATH, LUA_PATH_DEFAULT);
 707   /* set field 'cpath' */
 708   setpath(L, "cpath", LUA_CPATHVERSION, LUA_CPATH, LUA_CPATH_DEFAULT);
 709   /* store config information */
 710   lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
 711                      LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
 712   lua_setfield(L, -2, "config");
 713   /* set field `loaded' */
 714   luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
 715   lua_setfield(L, -2, "loaded");
 716   /* set field `preload' */
 717   luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
 718   lua_setfield(L, -2, "preload");
 719   lua_pushglobaltable(L);
 720   lua_pushvalue(L, -2);  /* set 'package' as upvalue for next lib */
 721   luaL_setfuncs(L, ll_funcs, 1);  /* open lib into global table */
 722   lua_pop(L, 1);  /* pop global table */
 723   return 1;  /* return 'package' table */
 724 }
 725