1/*
2** $Id: loadlib.c,v 1.111.1.1 2013/04/12 18:48:47 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/* Base the Lua paths on the Syslinux path */
20#ifdef SYSLINUX
21#include <fs.h>
22#endif
23
24#include <stdlib.h>
25#include <string.h>
26
27
28#define loadlib_c
29#define LUA_LIB
30
31#include "lua.h"
32
33#include "lauxlib.h"
34#include "lualib.h"
35
36
37/*
38** LUA_PATH and LUA_CPATH are the names of the environment
39** variables that Lua check to set its paths.
40*/
41#if !defined(LUA_PATH)
42#define LUA_PATH	"LUA_PATH"
43#endif
44
45#if !defined(LUA_CPATH)
46#define LUA_CPATH	"LUA_CPATH"
47#endif
48
49#define LUA_PATHSUFFIX		"_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
50
51#define LUA_PATHVERSION		LUA_PATH LUA_PATHSUFFIX
52#define LUA_CPATHVERSION	LUA_CPATH LUA_PATHSUFFIX
53
54/*
55** LUA_PATH_SEP is the character that separates templates in a path.
56** LUA_PATH_MARK is the string that marks the substitution points in a
57** template.
58** LUA_EXEC_DIR in a Windows path is replaced by the executable's
59** directory.
60** LUA_IGMARK is a mark to ignore all before it when building the
61** luaopen_ function name.
62*/
63#if !defined (LUA_PATH_SEP)
64#define LUA_PATH_SEP		";"
65#endif
66#if !defined (LUA_PATH_MARK)
67#define LUA_PATH_MARK		"?"
68#endif
69#if !defined (LUA_EXEC_DIR)
70#define LUA_EXEC_DIR		"!"
71#endif
72#if !defined (LUA_IGMARK)
73#define LUA_IGMARK		"-"
74#endif
75
76
77/*
78** LUA_CSUBSEP is the character that replaces dots in submodule names
79** when searching for a C loader.
80** LUA_LSUBSEP is the character that replaces dots in submodule names
81** when searching for a Lua loader.
82*/
83#if !defined(LUA_CSUBSEP)
84#define LUA_CSUBSEP		LUA_DIRSEP
85#endif
86
87#if !defined(LUA_LSUBSEP)
88#define LUA_LSUBSEP		LUA_DIRSEP
89#endif
90
91
92/* prefix for open functions in C libraries */
93#define LUA_POF		"luaopen_"
94
95/* separator for open functions in C libraries */
96#define LUA_OFSEP	"_"
97
98
99/* table (in the registry) that keeps handles for all loaded C libraries */
100#define CLIBS		"_CLIBS"
101
102#define LIB_FAIL	"open"
103
104
105/* error codes for ll_loadfunc */
106#define ERRLIB		1
107#define ERRFUNC		2
108
109#define setprogdir(L)		((void)0)
110
111
112/*
113** system-dependent functions
114*/
115static void ll_unloadlib (void *lib);
116static void *ll_load (lua_State *L, const char *path, int seeglb);
117static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
118
119
120
121#if defined(LUA_USE_DLOPEN)
122/*
123** {========================================================================
124** This is an implementation of loadlib based on the dlfcn interface.
125** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
126** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
127** as an emulation layer on top of native functions.
128** =========================================================================
129*/
130
131#include <dlfcn.h>
132
133static void ll_unloadlib (void *lib) {
134  dlclose(lib);
135}
136
137
138static void *ll_load (lua_State *L, const char *path, int seeglb) {
139  void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
140  if (lib == NULL) lua_pushstring(L, dlerror());
141  return lib;
142}
143
144
145static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
146  lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
147  if (f == NULL) lua_pushstring(L, dlerror());
148  return f;
149}
150
151/* }====================================================== */
152
153
154
155#elif defined(LUA_DL_DLL)
156/*
157** {======================================================================
158** This is an implementation of loadlib for Windows using native functions.
159** =======================================================================
160*/
161
162#undef setprogdir
163
164/*
165** optional flags for LoadLibraryEx
166*/
167#if !defined(LUA_LLE_FLAGS)
168#define LUA_LLE_FLAGS	0
169#endif
170
171
172static void setprogdir (lua_State *L) {
173  char buff[MAX_PATH + 1];
174  char *lb;
175  DWORD nsize = sizeof(buff)/sizeof(char);
176  DWORD n = GetModuleFileNameA(NULL, buff, nsize);
177  if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
178    luaL_error(L, "unable to get ModuleFileName");
179  else {
180    *lb = '\0';
181    luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
182    lua_remove(L, -2);  /* remove original string */
183  }
184}
185
186
187static void pusherror (lua_State *L) {
188  int error = GetLastError();
189  char buffer[128];
190  if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
191      NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
192    lua_pushstring(L, buffer);
193  else
194    lua_pushfstring(L, "system error %d\n", error);
195}
196
197static void ll_unloadlib (void *lib) {
198  FreeLibrary((HMODULE)lib);
199}
200
201
202static void *ll_load (lua_State *L, const char *path, int seeglb) {
203  HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
204  (void)(seeglb);  /* not used: symbols are 'global' by default */
205  if (lib == NULL) pusherror(L);
206  return lib;
207}
208
209
210static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
211  lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
212  if (f == NULL) pusherror(L);
213  return f;
214}
215
216/* }====================================================== */
217
218
219#elif defined(SYSLINUX)
220/*
221** {=========================================================================
222** This is an implementation of loadlib for the Syslinux COM32 module system.
223** ==========================================================================
224*/
225
226#include <sys/module.h>
227
228static void ll_unloadlib (void *lib) {
229  module_unload ((struct elf_module *)lib);
230}
231
232
233static void *ll_load (lua_State *L, const char *path, int seeglb) {
234  int err;
235  struct elf_module *lib = module_alloc (path);
236  if (lib == NULL) {
237    lua_pushstring (L, "module not found");
238    return NULL;
239  }
240  (void)seeglb; /* gcc, ignore it */
241  err = module_load (lib);
242  if (err) {
243    printf ("module load error: %d\n", err);
244    lua_pushstring (L, "failed to load module");
245    return NULL;
246  }
247  return (void *)lib;
248}
249
250
251static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
252  Elf_Sym *p = module_find_symbol (sym, (struct elf_module *)lib);
253  if (p == NULL) {
254    lua_pushstring (L, "symbol not found in module");
255    return NULL;
256  }
257  return (lua_CFunction)module_get_absolute(p->st_value, (struct elf_module *)lib);
258}
259
260/* }====================================================== */
261
262
263
264#else
265/*
266** {======================================================
267** Fallback for other systems
268** =======================================================
269*/
270
271#undef LIB_FAIL
272#define LIB_FAIL	"absent"
273
274
275#define DLMSG	"dynamic libraries not enabled; check your Lua installation"
276
277
278static void ll_unloadlib (void *lib) {
279  (void)(lib);  /* not used */
280}
281
282
283static void *ll_load (lua_State *L, const char *path, int seeglb) {
284  (void)(path); (void)(seeglb);  /* not used */
285  lua_pushliteral(L, DLMSG);
286  return NULL;
287}
288
289
290static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
291  (void)(lib); (void)(sym);  /* not used */
292  lua_pushliteral(L, DLMSG);
293  return NULL;
294}
295
296/* }====================================================== */
297#endif
298
299
300static void *ll_checkclib (lua_State *L, const char *path) {
301  void *plib;
302  lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
303  lua_getfield(L, -1, path);
304  plib = lua_touserdata(L, -1);  /* plib = CLIBS[path] */
305  lua_pop(L, 2);  /* pop CLIBS table and 'plib' */
306  return plib;
307}
308
309
310static void ll_addtoclib (lua_State *L, const char *path, void *plib) {
311  lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
312  lua_pushlightuserdata(L, plib);
313  lua_pushvalue(L, -1);
314  lua_setfield(L, -3, path);  /* CLIBS[path] = plib */
315  lua_rawseti(L, -2, luaL_len(L, -2) + 1);  /* CLIBS[#CLIBS + 1] = plib */
316  lua_pop(L, 1);  /* pop CLIBS table */
317}
318
319
320/*
321** __gc tag method for CLIBS table: calls 'll_unloadlib' for all lib
322** handles in list CLIBS
323*/
324static int gctm (lua_State *L) {
325  int n = luaL_len(L, 1);
326  for (; n >= 1; n--) {  /* for each handle, in reverse order */
327    lua_rawgeti(L, 1, n);  /* get handle CLIBS[n] */
328    ll_unloadlib(lua_touserdata(L, -1));
329    lua_pop(L, 1);  /* pop handle */
330  }
331  return 0;
332}
333
334
335static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
336  void *reg = ll_checkclib(L, path);  /* check loaded C libraries */
337  if (reg == NULL) {  /* must load library? */
338    reg = ll_load(L, path, *sym == '*');
339    if (reg == NULL) return ERRLIB;  /* unable to load library */
340    ll_addtoclib(L, path, reg);
341  }
342  if (*sym == '*') {  /* loading only library (no function)? */
343    lua_pushboolean(L, 1);  /* return 'true' */
344    return 0;  /* no errors */
345  }
346  else {
347    lua_CFunction f = ll_sym(L, reg, sym);
348    if (f == NULL)
349      return ERRFUNC;  /* unable to find function */
350    lua_pushcfunction(L, f);  /* else create new function */
351    return 0;  /* no errors */
352  }
353}
354
355
356static int ll_loadlib (lua_State *L) {
357  const char *path = luaL_checkstring(L, 1);
358  const char *init = luaL_checkstring(L, 2);
359  int stat = ll_loadfunc(L, path, init);
360  if (stat == 0)  /* no errors? */
361    return 1;  /* return the loaded function */
362  else {  /* error; error message is on stack top */
363    lua_pushnil(L);
364    lua_insert(L, -2);
365    lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
366    return 3;  /* return nil, error message, and where */
367  }
368}
369
370
371
372/*
373** {======================================================
374** 'require' function
375** =======================================================
376*/
377
378
379static int readable (const char *filename) {
380  FILE *f = fopen(filename, "r");  /* try to open file */
381  if (f == NULL) return 0;  /* open failed */
382  fclose(f);
383  return 1;
384}
385
386
387static const char *pushnexttemplate (lua_State *L, const char *path) {
388  const char *l;
389  while (*path == *LUA_PATH_SEP) path++;  /* skip separators */
390  if (*path == '\0') return NULL;  /* no more templates */
391  l = strchr(path, *LUA_PATH_SEP);  /* find next separator */
392  if (l == NULL) l = path + strlen(path);
393  lua_pushlstring(L, path, l - path);  /* template */
394  return l;
395}
396
397
398static const char *searchpath (lua_State *L, const char *name,
399                                             const char *path,
400                                             const char *sep,
401                                             const char *dirsep) {
402  luaL_Buffer msg;  /* to build error message */
403  luaL_buffinit(L, &msg);
404  if (*sep != '\0')  /* non-empty separator? */
405    name = luaL_gsub(L, name, sep, dirsep);  /* replace it by 'dirsep' */
406  while ((path = pushnexttemplate(L, path)) != NULL) {
407    const char *filename = luaL_gsub(L, lua_tostring(L, -1),
408                                     LUA_PATH_MARK, name);
409    lua_remove(L, -2);  /* remove path template */
410    if (readable(filename))  /* does file exist and is readable? */
411      return filename;  /* return that file name */
412    lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
413    lua_remove(L, -2);  /* remove file name */
414    luaL_addvalue(&msg);  /* concatenate error msg. entry */
415  }
416  luaL_pushresult(&msg);  /* create error message */
417  return NULL;  /* not found */
418}
419
420
421static int ll_searchpath (lua_State *L) {
422  const char *f = searchpath(L, luaL_checkstring(L, 1),
423                                luaL_checkstring(L, 2),
424                                luaL_optstring(L, 3, "."),
425                                luaL_optstring(L, 4, LUA_DIRSEP));
426  if (f != NULL) return 1;
427  else {  /* error message is on top of the stack */
428    lua_pushnil(L);
429    lua_insert(L, -2);
430    return 2;  /* return nil + error message */
431  }
432}
433
434
435static const char *findfile (lua_State *L, const char *name,
436                                           const char *pname,
437                                           const char *dirsep) {
438  const char *path;
439  lua_getfield(L, lua_upvalueindex(1), pname);
440  path = lua_tostring(L, -1);
441  if (path == NULL)
442    luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
443  return searchpath(L, name, path, ".", dirsep);
444}
445
446
447static int checkload (lua_State *L, int stat, const char *filename) {
448  if (stat) {  /* module loaded successfully? */
449    lua_pushstring(L, filename);  /* will be 2nd argument to module */
450    return 2;  /* return open function and file name */
451  }
452  else
453    return luaL_error(L, "error loading module " LUA_QS
454                         " from file " LUA_QS ":\n\t%s",
455                          lua_tostring(L, 1), filename, lua_tostring(L, -1));
456}
457
458
459static int searcher_Lua (lua_State *L) {
460  const char *filename;
461  const char *name = luaL_checkstring(L, 1);
462  filename = findfile(L, name, "path", LUA_LSUBSEP);
463  if (filename == NULL) return 1;  /* module not found in this path */
464  return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
465}
466
467
468static int loadfunc (lua_State *L, const char *filename, const char *modname) {
469  const char *funcname;
470  const char *mark;
471  modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
472  mark = strchr(modname, *LUA_IGMARK);
473  if (mark) {
474    int stat;
475    funcname = lua_pushlstring(L, modname, mark - modname);
476    funcname = lua_pushfstring(L, LUA_POF"%s", funcname);
477    stat = ll_loadfunc(L, filename, funcname);
478    if (stat != ERRFUNC) return stat;
479    modname = mark + 1;  /* else go ahead and try old-style name */
480  }
481  funcname = lua_pushfstring(L, LUA_POF"%s", modname);
482  return ll_loadfunc(L, filename, funcname);
483}
484
485
486static int searcher_C (lua_State *L) {
487  const char *name = luaL_checkstring(L, 1);
488  const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
489  if (filename == NULL) return 1;  /* module not found in this path */
490  return checkload(L, (loadfunc(L, filename, name) == 0), filename);
491}
492
493
494static int searcher_Croot (lua_State *L) {
495  const char *filename;
496  const char *name = luaL_checkstring(L, 1);
497  const char *p = strchr(name, '.');
498  int stat;
499  if (p == NULL) return 0;  /* is root */
500  lua_pushlstring(L, name, p - name);
501  filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
502  if (filename == NULL) return 1;  /* root not found */
503  if ((stat = loadfunc(L, filename, name)) != 0) {
504    if (stat != ERRFUNC)
505      return checkload(L, 0, filename);  /* real error */
506    else {  /* open function not found */
507      lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
508                         name, filename);
509      return 1;
510    }
511  }
512  lua_pushstring(L, filename);  /* will be 2nd argument to module */
513  return 2;
514}
515
516
517static int searcher_preload (lua_State *L) {
518  const char *name = luaL_checkstring(L, 1);
519  lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
520  lua_getfield(L, -1, name);
521  if (lua_isnil(L, -1))  /* not found? */
522    lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
523  return 1;
524}
525
526
527static void findloader (lua_State *L, const char *name) {
528  int i;
529  luaL_Buffer msg;  /* to build error message */
530  luaL_buffinit(L, &msg);
531  lua_getfield(L, lua_upvalueindex(1), "searchers");  /* will be at index 3 */
532  if (!lua_istable(L, 3))
533    luaL_error(L, LUA_QL("package.searchers") " must be a table");
534  /*  iterate over available searchers to find a loader */
535  for (i = 1; ; i++) {
536    lua_rawgeti(L, 3, i);  /* get a searcher */
537    if (lua_isnil(L, -1)) {  /* no more searchers? */
538      lua_pop(L, 1);  /* remove nil */
539      luaL_pushresult(&msg);  /* create error message */
540      luaL_error(L, "module " LUA_QS " not found:%s",
541                    name, lua_tostring(L, -1));
542    }
543    lua_pushstring(L, name);
544    lua_call(L, 1, 2);  /* call it */
545    if (lua_isfunction(L, -2))  /* did it find a loader? */
546      return;  /* module loader found */
547    else if (lua_isstring(L, -2)) {  /* searcher returned error message? */
548      lua_pop(L, 1);  /* remove extra return */
549      luaL_addvalue(&msg);  /* concatenate error message */
550    }
551    else
552      lua_pop(L, 2);  /* remove both returns */
553  }
554}
555
556
557static int ll_require (lua_State *L) {
558  const char *name = luaL_checkstring(L, 1);
559  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
560  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
561  lua_getfield(L, 2, name);  /* _LOADED[name] */
562  if (lua_toboolean(L, -1))  /* is it there? */
563    return 1;  /* package is already loaded */
564  /* else must load package */
565  lua_pop(L, 1);  /* remove 'getfield' result */
566  findloader(L, name);
567  lua_pushstring(L, name);  /* pass name as argument to module loader */
568  lua_insert(L, -2);  /* name is 1st argument (before search data) */
569  lua_call(L, 2, 1);  /* run loader to load module */
570  if (!lua_isnil(L, -1))  /* non-nil return? */
571    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
572  lua_getfield(L, 2, name);
573  if (lua_isnil(L, -1)) {   /* module did not set a value? */
574    lua_pushboolean(L, 1);  /* use true as result */
575    lua_pushvalue(L, -1);  /* extra copy to be returned */
576    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
577  }
578  return 1;
579}
580
581/* }====================================================== */
582
583
584
585/*
586** {======================================================
587** 'module' function
588** =======================================================
589*/
590#if defined(LUA_COMPAT_MODULE)
591
592/*
593** changes the environment variable of calling function
594*/
595static void set_env (lua_State *L) {
596  lua_Debug ar;
597  if (lua_getstack(L, 1, &ar) == 0 ||
598      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
599      lua_iscfunction(L, -1))
600    luaL_error(L, LUA_QL("module") " not called from a Lua function");
601  lua_pushvalue(L, -2);  /* copy new environment table to top */
602  lua_setupvalue(L, -2, 1);
603  lua_pop(L, 1);  /* remove function */
604}
605
606
607static void dooptions (lua_State *L, int n) {
608  int i;
609  for (i = 2; i <= n; i++) {
610    if (lua_isfunction(L, i)) {  /* avoid 'calling' extra info. */
611      lua_pushvalue(L, i);  /* get option (a function) */
612      lua_pushvalue(L, -2);  /* module */
613      lua_call(L, 1, 0);
614    }
615  }
616}
617
618
619static void modinit (lua_State *L, const char *modname) {
620  const char *dot;
621  lua_pushvalue(L, -1);
622  lua_setfield(L, -2, "_M");  /* module._M = module */
623  lua_pushstring(L, modname);
624  lua_setfield(L, -2, "_NAME");
625  dot = strrchr(modname, '.');  /* look for last dot in module name */
626  if (dot == NULL) dot = modname;
627  else dot++;
628  /* set _PACKAGE as package name (full module name minus last part) */
629  lua_pushlstring(L, modname, dot - modname);
630  lua_setfield(L, -2, "_PACKAGE");
631}
632
633
634static int ll_module (lua_State *L) {
635  const char *modname = luaL_checkstring(L, 1);
636  int lastarg = lua_gettop(L);  /* last parameter */
637  luaL_pushmodule(L, modname, 1);  /* get/create module table */
638  /* check whether table already has a _NAME field */
639  lua_getfield(L, -1, "_NAME");
640  if (!lua_isnil(L, -1))  /* is table an initialized module? */
641    lua_pop(L, 1);
642  else {  /* no; initialize it */
643    lua_pop(L, 1);
644    modinit(L, modname);
645  }
646  lua_pushvalue(L, -1);
647  set_env(L);
648  dooptions(L, lastarg);
649  return 1;
650}
651
652
653static int ll_seeall (lua_State *L) {
654  luaL_checktype(L, 1, LUA_TTABLE);
655  if (!lua_getmetatable(L, 1)) {
656    lua_createtable(L, 0, 1); /* create new metatable */
657    lua_pushvalue(L, -1);
658    lua_setmetatable(L, 1);
659  }
660  lua_pushglobaltable(L);
661  lua_setfield(L, -2, "__index");  /* mt.__index = _G */
662  return 0;
663}
664
665#endif
666/* }====================================================== */
667
668
669
670/* auxiliary mark (for internal use) */
671#define AUXMARK		"\1"
672
673
674#ifdef SYSLINUX
675static void setpath (lua_State *L, const char *fieldname, const char *envname1,
676                                   const char *envname2, const char *def) {
677  struct path_entry *entry;
678  luaL_Buffer b;
679  luaL_buffinit (L, &b);
680  (void)envname1;
681  (void)envname2;
682  list_for_each_entry(entry, &PATH, list) {
683    const char *e = entry->str;
684    int need_slash = e[strlen(e)-1] != '/';
685    void add (const char *stem) {
686      luaL_addstring (&b, e);
687      if (need_slash) luaL_addchar (&b, '/');
688      luaL_addstring (&b, stem);
689      luaL_addstring (&b, def);
690      luaL_addchar (&b, ';');
691    }
692    add ("?");
693    add ("?/init");
694  }
695  luaL_addstring (&b, "./?");
696  luaL_addstring (&b, def);
697  luaL_pushresult (&b);
698  lua_setfield(L, -2, fieldname);
699}
700#else
701/*
702** return registry.LUA_NOENV as a boolean
703*/
704static int noenv (lua_State *L) {
705  int b;
706  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
707  b = lua_toboolean(L, -1);
708  lua_pop(L, 1);  /* remove value */
709  return b;
710}
711
712
713static void setpath (lua_State *L, const char *fieldname, const char *envname1,
714                                   const char *envname2, const char *def) {
715  const char *path = getenv(envname1);
716  if (path == NULL)  /* no environment variable? */
717    path = getenv(envname2);  /* try alternative name */
718  if (path == NULL || noenv(L))  /* no environment variable? */
719    lua_pushstring(L, def);  /* use default */
720  else {
721    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
722    path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
723                              LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
724    luaL_gsub(L, path, AUXMARK, def);
725    lua_remove(L, -2);
726  }
727  setprogdir(L);
728  lua_setfield(L, -2, fieldname);
729}
730#endif
731
732
733static const luaL_Reg pk_funcs[] = {
734  {"loadlib", ll_loadlib},
735  {"searchpath", ll_searchpath},
736#if defined(LUA_COMPAT_MODULE)
737  {"seeall", ll_seeall},
738#endif
739  {NULL, NULL}
740};
741
742
743static const luaL_Reg ll_funcs[] = {
744#if defined(LUA_COMPAT_MODULE)
745  {"module", ll_module},
746#endif
747  {"require", ll_require},
748  {NULL, NULL}
749};
750
751
752static void createsearcherstable (lua_State *L) {
753  static const lua_CFunction searchers[] =
754    {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
755  int i;
756  /* create 'searchers' table */
757  lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
758  /* fill it with pre-defined searchers */
759  for (i=0; searchers[i] != NULL; i++) {
760    lua_pushvalue(L, -2);  /* set 'package' as upvalue for all searchers */
761    lua_pushcclosure(L, searchers[i], 1);
762    lua_rawseti(L, -2, i+1);
763  }
764}
765
766
767LUAMOD_API int luaopen_package (lua_State *L) {
768  /* create table CLIBS to keep track of loaded C libraries */
769  luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);
770  lua_createtable(L, 0, 1);  /* metatable for CLIBS */
771  lua_pushcfunction(L, gctm);
772  lua_setfield(L, -2, "__gc");  /* set finalizer for CLIBS table */
773  lua_setmetatable(L, -2);
774  /* create `package' table */
775  luaL_newlib(L, pk_funcs);
776  createsearcherstable(L);
777#if defined(LUA_COMPAT_LOADERS)
778  lua_pushvalue(L, -1);  /* make a copy of 'searchers' table */
779  lua_setfield(L, -3, "loaders");  /* put it in field `loaders' */
780#endif
781  lua_setfield(L, -2, "searchers");  /* put it in field 'searchers' */
782  /* set field 'path' */
783  setpath(L, "path", LUA_PATHVERSION, LUA_PATH, LUA_PATH_DEFAULT);
784  /* set field 'cpath' */
785  setpath(L, "cpath", LUA_CPATHVERSION, LUA_CPATH, LUA_CPATH_DEFAULT);
786  /* store config information */
787  lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
788                     LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
789  lua_setfield(L, -2, "config");
790  /* set field `loaded' */
791  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
792  lua_setfield(L, -2, "loaded");
793  /* set field `preload' */
794  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
795  lua_setfield(L, -2, "preload");
796  lua_pushglobaltable(L);
797  lua_pushvalue(L, -2);  /* set 'package' as upvalue for next lib */
798  luaL_setfuncs(L, ll_funcs, 1);  /* open lib into global table */
799  lua_pop(L, 1);  /* pop global table */
800  return 1;  /* return 'package' table */
801}
802
803