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*/
111static void ll_unloadlib (void *lib);
112static void *ll_load (lua_State *L, const char *path, int seeglb);
113static 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
129static void ll_unloadlib (void *lib) {
130  dlclose(lib);
131}
132
133
134static 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
141static 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
168static 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
183static 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
193static void ll_unloadlib (void *lib) {
194  FreeLibrary((HMODULE)lib);
195}
196
197
198static 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
206static 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
229static void ll_unloadlib (void *lib) {
230  (void)(lib);  /* not used */
231}
232
233
234static 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
241static 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
251static 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
261static 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*/
275static 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
286static 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
307static 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
330static 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
338static 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
349static 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
372static 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
386static 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
398static 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
410static 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
419static 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
437static 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
445static 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
468static 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
478static 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
508static 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*/
546static 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
558static 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
570static 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
585static 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
604static 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*/
628static 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
637static 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
656static 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
666static 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
675static 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
690LUAMOD_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
726