1 /*
2 ** $Id: loadlib.c,v 1.124 2015/01/05 13:51:39 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 <stdlib.h>
18 #include <string.h>
19
20 #include "lua.h"
21
22 #include "lauxlib.h"
23 #include "lualib.h"
24
25
26 /*
27 ** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
28 ** variables that Lua check to set its paths.
29 */
30 #if !defined(LUA_PATH_VAR)
31 #define LUA_PATH_VAR "LUA_PATH"
32 #endif
33
34 #if !defined(LUA_CPATH_VAR)
35 #define LUA_CPATH_VAR "LUA_CPATH"
36 #endif
37
38 #define LUA_PATHSUFFIX "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
39
40 #define LUA_PATHVARVERSION LUA_PATH_VAR LUA_PATHSUFFIX
41 #define LUA_CPATHVARVERSION LUA_CPATH_VAR LUA_PATHSUFFIX
42
43 /*
44 ** LUA_PATH_SEP is the character that separates templates in a path.
45 ** LUA_PATH_MARK is the string that marks the substitution points in a
46 ** template.
47 ** LUA_EXEC_DIR in a Windows path is replaced by the executable's
48 ** directory.
49 ** LUA_IGMARK is a mark to ignore all before it when building the
50 ** luaopen_ function name.
51 */
52 #if !defined (LUA_PATH_SEP)
53 #define LUA_PATH_SEP ";"
54 #endif
55 #if !defined (LUA_PATH_MARK)
56 #define LUA_PATH_MARK "?"
57 #endif
58 #if !defined (LUA_EXEC_DIR)
59 #define LUA_EXEC_DIR "!"
60 #endif
61 #if !defined (LUA_IGMARK)
62 #define LUA_IGMARK "-"
63 #endif
64
65
66 /*
67 ** LUA_CSUBSEP is the character that replaces dots in submodule names
68 ** when searching for a C loader.
69 ** LUA_LSUBSEP is the character that replaces dots in submodule names
70 ** when searching for a Lua loader.
71 */
72 #if !defined(LUA_CSUBSEP)
73 #define LUA_CSUBSEP LUA_DIRSEP
74 #endif
75
76 #if !defined(LUA_LSUBSEP)
77 #define LUA_LSUBSEP LUA_DIRSEP
78 #endif
79
80
81 /* prefix for open functions in C libraries */
82 #define LUA_POF "luaopen_"
83
84 /* separator for open functions in C libraries */
85 #define LUA_OFSEP "_"
86
87
88 /*
89 ** unique key for table in the registry that keeps handles
90 ** for all loaded C libraries
91 */
92 static const int CLIBS = 0;
93
94 #define LIB_FAIL "open"
95
96 #define setprogdir(L) ((void)0)
97
98
99 /*
100 ** system-dependent functions
101 */
102
103 /*
104 ** unload library 'lib'
105 */
106 static void lsys_unloadlib (void *lib);
107
108 /*
109 ** load C library in file 'path'. If 'seeglb', load with all names in
110 ** the library global.
111 ** Returns the library; in case of error, returns NULL plus an
112 ** error string in the stack.
113 */
114 static void *lsys_load (lua_State *L, const char *path, int seeglb);
115
116 /*
117 ** Try to find a function named 'sym' in library 'lib'.
118 ** Returns the function; in case of error, returns NULL plus an
119 ** error string in the stack.
120 */
121 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
122
123
124
125
126 #if defined(LUA_USE_DLOPEN) /* { */
127 /*
128 ** {========================================================================
129 ** This is an implementation of loadlib based on the dlfcn interface.
130 ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
131 ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
132 ** as an emulation layer on top of native functions.
133 ** =========================================================================
134 */
135
136 #include <dlfcn.h>
137
138 /*
139 ** Macro to covert pointer to void* to pointer to function. This cast
140 ** is undefined according to ISO C, but POSIX assumes that it must work.
141 ** (The '__extension__' in gnu compilers is only to avoid warnings.)
142 */
143 #if defined(__GNUC__)
144 #define cast_func(p) (__extension__ (lua_CFunction)(p))
145 #else
146 #define cast_func(p) ((lua_CFunction)(p))
147 #endif
148
149
lsys_unloadlib(void * lib)150 static void lsys_unloadlib (void *lib) {
151 dlclose(lib);
152 }
153
154
lsys_load(lua_State * L,const char * path,int seeglb)155 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
156 void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
157 if (lib == NULL) lua_pushstring(L, dlerror());
158 return lib;
159 }
160
161
lsys_sym(lua_State * L,void * lib,const char * sym)162 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
163 lua_CFunction f = cast_func(dlsym(lib, sym));
164 if (f == NULL) lua_pushstring(L, dlerror());
165 return f;
166 }
167
168 /* }====================================================== */
169
170
171
172 #elif defined(LUA_DL_DLL) /* }{ */
173 /*
174 ** {======================================================================
175 ** This is an implementation of loadlib for Windows using native functions.
176 ** =======================================================================
177 */
178
179 #include <windows.h>
180
181 #undef setprogdir
182
183 /*
184 ** optional flags for LoadLibraryEx
185 */
186 #if !defined(LUA_LLE_FLAGS)
187 #define LUA_LLE_FLAGS 0
188 #endif
189
190
setprogdir(lua_State * L)191 static void setprogdir (lua_State *L) {
192 char buff[MAX_PATH + 1];
193 char *lb;
194 DWORD nsize = sizeof(buff)/sizeof(char);
195 DWORD n = GetModuleFileNameA(NULL, buff, nsize);
196 if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
197 luaL_error(L, "unable to get ModuleFileName");
198 else {
199 *lb = '\0';
200 luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
201 lua_remove(L, -2); /* remove original string */
202 }
203 }
204
205
pusherror(lua_State * L)206 static void pusherror (lua_State *L) {
207 int error = GetLastError();
208 char buffer[128];
209 if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
210 NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
211 lua_pushstring(L, buffer);
212 else
213 lua_pushfstring(L, "system error %d\n", error);
214 }
215
lsys_unloadlib(void * lib)216 static void lsys_unloadlib (void *lib) {
217 FreeLibrary((HMODULE)lib);
218 }
219
220
lsys_load(lua_State * L,const char * path,int seeglb)221 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
222 HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
223 (void)(seeglb); /* not used: symbols are 'global' by default */
224 if (lib == NULL) pusherror(L);
225 return lib;
226 }
227
228
lsys_sym(lua_State * L,void * lib,const char * sym)229 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
230 lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
231 if (f == NULL) pusherror(L);
232 return f;
233 }
234
235 /* }====================================================== */
236
237
238 #else /* }{ */
239 /*
240 ** {======================================================
241 ** Fallback for other systems
242 ** =======================================================
243 */
244
245 #undef LIB_FAIL
246 #define LIB_FAIL "absent"
247
248
249 #define DLMSG "dynamic libraries not enabled; check your Lua installation"
250
251
lsys_unloadlib(void * lib)252 static void lsys_unloadlib (void *lib) {
253 (void)(lib); /* not used */
254 }
255
256
lsys_load(lua_State * L,const char * path,int seeglb)257 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
258 (void)(path); (void)(seeglb); /* not used */
259 lua_pushliteral(L, DLMSG);
260 return NULL;
261 }
262
263
lsys_sym(lua_State * L,void * lib,const char * sym)264 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
265 (void)(lib); (void)(sym); /* not used */
266 lua_pushliteral(L, DLMSG);
267 return NULL;
268 }
269
270 /* }====================================================== */
271 #endif /* } */
272
273
274 /*
275 ** return registry.CLIBS[path]
276 */
checkclib(lua_State * L,const char * path)277 static void *checkclib (lua_State *L, const char *path) {
278 void *plib;
279 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
280 lua_getfield(L, -1, path);
281 plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
282 lua_pop(L, 2); /* pop CLIBS table and 'plib' */
283 return plib;
284 }
285
286
287 /*
288 ** registry.CLIBS[path] = plib -- for queries
289 ** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
290 */
addtoclib(lua_State * L,const char * path,void * plib)291 static void addtoclib (lua_State *L, const char *path, void *plib) {
292 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
293 lua_pushlightuserdata(L, plib);
294 lua_pushvalue(L, -1);
295 lua_setfield(L, -3, path); /* CLIBS[path] = plib */
296 lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
297 lua_pop(L, 1); /* pop CLIBS table */
298 }
299
300
301 /*
302 ** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
303 ** handles in list CLIBS
304 */
gctm(lua_State * L)305 static int gctm (lua_State *L) {
306 lua_Integer n = luaL_len(L, 1);
307 for (; n >= 1; n--) { /* for each handle, in reverse order */
308 lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
309 lsys_unloadlib(lua_touserdata(L, -1));
310 lua_pop(L, 1); /* pop handle */
311 }
312 return 0;
313 }
314
315
316
317 /* error codes for 'lookforfunc' */
318 #define ERRLIB 1
319 #define ERRFUNC 2
320
321 /*
322 ** Look for a C function named 'sym' in a dynamically loaded library
323 ** 'path'.
324 ** First, check whether the library is already loaded; if not, try
325 ** to load it.
326 ** Then, if 'sym' is '*', return true (as library has been loaded).
327 ** Otherwise, look for symbol 'sym' in the library and push a
328 ** C function with that symbol.
329 ** Return 0 and 'true' or a function in the stack; in case of
330 ** errors, return an error code and an error message in the stack.
331 */
lookforfunc(lua_State * L,const char * path,const char * sym)332 static int lookforfunc (lua_State *L, const char *path, const char *sym) {
333 void *reg = checkclib(L, path); /* check loaded C libraries */
334 if (reg == NULL) { /* must load library? */
335 reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */
336 if (reg == NULL) return ERRLIB; /* unable to load library */
337 addtoclib(L, path, reg);
338 }
339 if (*sym == '*') { /* loading only library (no function)? */
340 lua_pushboolean(L, 1); /* return 'true' */
341 return 0; /* no errors */
342 }
343 else {
344 lua_CFunction f = lsys_sym(L, reg, sym);
345 if (f == NULL)
346 return ERRFUNC; /* unable to find function */
347 lua_pushcfunction(L, f); /* else create new function */
348 return 0; /* no errors */
349 }
350 }
351
352
ll_loadlib(lua_State * L)353 static int ll_loadlib (lua_State *L) {
354 const char *path = luaL_checkstring(L, 1);
355 const char *init = luaL_checkstring(L, 2);
356 int stat = lookforfunc(L, path, init);
357 if (stat == 0) /* no errors? */
358 return 1; /* return the loaded function */
359 else { /* error; error message is on stack top */
360 lua_pushnil(L);
361 lua_insert(L, -2);
362 lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
363 return 3; /* return nil, error message, and where */
364 }
365 }
366
367
368
369 /*
370 ** {======================================================
371 ** 'require' function
372 ** =======================================================
373 */
374
375
readable(const char * filename)376 static int readable (const char *filename) {
377 FILE *f = fopen(filename, "r"); /* try to open file */
378 if (f == NULL) return 0; /* open failed */
379 fclose(f);
380 return 1;
381 }
382
383
pushnexttemplate(lua_State * L,const char * path)384 static const char *pushnexttemplate (lua_State *L, const char *path) {
385 const char *l;
386 while (*path == *LUA_PATH_SEP) path++; /* skip separators */
387 if (*path == '\0') return NULL; /* no more templates */
388 l = strchr(path, *LUA_PATH_SEP); /* find next separator */
389 if (l == NULL) l = path + strlen(path);
390 lua_pushlstring(L, path, l - path); /* template */
391 return l;
392 }
393
394
searchpath(lua_State * L,const char * name,const char * path,const char * sep,const char * dirsep)395 static const char *searchpath (lua_State *L, const char *name,
396 const char *path,
397 const char *sep,
398 const char *dirsep) {
399 luaL_Buffer msg; /* to build error message */
400 luaL_buffinit(L, &msg);
401 if (*sep != '\0') /* non-empty separator? */
402 name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
403 while ((path = pushnexttemplate(L, path)) != NULL) {
404 const char *filename = luaL_gsub(L, lua_tostring(L, -1),
405 LUA_PATH_MARK, name);
406 lua_remove(L, -2); /* remove path template */
407 if (readable(filename)) /* does file exist and is readable? */
408 return filename; /* return that file name */
409 lua_pushfstring(L, "\n\tno file '%s'", filename);
410 lua_remove(L, -2); /* remove file name */
411 luaL_addvalue(&msg); /* concatenate error msg. entry */
412 }
413 luaL_pushresult(&msg); /* create error message */
414 return NULL; /* not found */
415 }
416
417
ll_searchpath(lua_State * L)418 static int ll_searchpath (lua_State *L) {
419 const char *f = searchpath(L, luaL_checkstring(L, 1),
420 luaL_checkstring(L, 2),
421 luaL_optstring(L, 3, "."),
422 luaL_optstring(L, 4, LUA_DIRSEP));
423 if (f != NULL) return 1;
424 else { /* error message is on top of the stack */
425 lua_pushnil(L);
426 lua_insert(L, -2);
427 return 2; /* return nil + error message */
428 }
429 }
430
431
findfile(lua_State * L,const char * name,const char * pname,const char * dirsep)432 static const char *findfile (lua_State *L, const char *name,
433 const char *pname,
434 const char *dirsep) {
435 const char *path;
436 lua_getfield(L, lua_upvalueindex(1), pname);
437 path = lua_tostring(L, -1);
438 if (path == NULL)
439 luaL_error(L, "'package.%s' must be a string", pname);
440 return searchpath(L, name, path, ".", dirsep);
441 }
442
443
checkload(lua_State * L,int stat,const char * filename)444 static int checkload (lua_State *L, int stat, const char *filename) {
445 if (stat) { /* module loaded successfully? */
446 lua_pushstring(L, filename); /* will be 2nd argument to module */
447 return 2; /* return open function and file name */
448 }
449 else
450 return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s",
451 lua_tostring(L, 1), filename, lua_tostring(L, -1));
452 }
453
454
searcher_Lua(lua_State * L)455 static int searcher_Lua (lua_State *L) {
456 const char *filename;
457 const char *name = luaL_checkstring(L, 1);
458 filename = findfile(L, name, "path", LUA_LSUBSEP);
459 if (filename == NULL) return 1; /* module not found in this path */
460 return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
461 }
462
463
464 /*
465 ** Try to find a load function for module 'modname' at file 'filename'.
466 ** First, change '.' to '_' in 'modname'; then, if 'modname' has
467 ** the form X-Y (that is, it has an "ignore mark"), build a function
468 ** name "luaopen_X" and look for it. (For compatibility, if that
469 ** fails, it also tries "luaopen_Y".) If there is no ignore mark,
470 ** look for a function named "luaopen_modname".
471 */
loadfunc(lua_State * L,const char * filename,const char * modname)472 static int loadfunc (lua_State *L, const char *filename, const char *modname) {
473 const char *openfunc;
474 const char *mark;
475 modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
476 mark = strchr(modname, *LUA_IGMARK);
477 if (mark) {
478 int stat;
479 openfunc = lua_pushlstring(L, modname, mark - modname);
480 openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
481 stat = lookforfunc(L, filename, openfunc);
482 if (stat != ERRFUNC) return stat;
483 modname = mark + 1; /* else go ahead and try old-style name */
484 }
485 openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
486 return lookforfunc(L, filename, openfunc);
487 }
488
489
searcher_C(lua_State * L)490 static int searcher_C (lua_State *L) {
491 const char *name = luaL_checkstring(L, 1);
492 const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
493 if (filename == NULL) return 1; /* module not found in this path */
494 return checkload(L, (loadfunc(L, filename, name) == 0), filename);
495 }
496
497
searcher_Croot(lua_State * L)498 static int searcher_Croot (lua_State *L) {
499 const char *filename;
500 const char *name = luaL_checkstring(L, 1);
501 const char *p = strchr(name, '.');
502 int stat;
503 if (p == NULL) return 0; /* is root */
504 lua_pushlstring(L, name, p - name);
505 filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
506 if (filename == NULL) return 1; /* root not found */
507 if ((stat = loadfunc(L, filename, name)) != 0) {
508 if (stat != ERRFUNC)
509 return checkload(L, 0, filename); /* real error */
510 else { /* open function not found */
511 lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename);
512 return 1;
513 }
514 }
515 lua_pushstring(L, filename); /* will be 2nd argument to module */
516 return 2;
517 }
518
519
searcher_preload(lua_State * L)520 static int searcher_preload (lua_State *L) {
521 const char *name = luaL_checkstring(L, 1);
522 lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
523 if (lua_getfield(L, -1, name) == LUA_TNIL) /* not found? */
524 lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
525 return 1;
526 }
527
528
findloader(lua_State * L,const char * name)529 static void findloader (lua_State *L, const char *name) {
530 int i;
531 luaL_Buffer msg; /* to build error message */
532 luaL_buffinit(L, &msg);
533 /* push 'package.searchers' to index 3 in the stack */
534 if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
535 luaL_error(L, "'package.searchers' must be a table");
536 /* iterate over available searchers to find a loader */
537 for (i = 1; ; i++) {
538 if (lua_rawgeti(L, 3, i) == LUA_TNIL) { /* no more searchers? */
539 lua_pop(L, 1); /* remove nil */
540 luaL_pushresult(&msg); /* create error message */
541 luaL_error(L, "module '%s' not found:%s", 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
ll_require(lua_State * L)557 static 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 if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */
573 lua_pushboolean(L, 1); /* use true as result */
574 lua_pushvalue(L, -1); /* extra copy to be returned */
575 lua_setfield(L, 2, name); /* _LOADED[name] = true */
576 }
577 return 1;
578 }
579
580 /* }====================================================== */
581
582
583
584 /*
585 ** {======================================================
586 ** 'module' function
587 ** =======================================================
588 */
589 #if defined(LUA_COMPAT_MODULE)
590
591 /*
592 ** changes the environment variable of calling function
593 */
set_env(lua_State * L)594 static void set_env (lua_State *L) {
595 lua_Debug ar;
596 if (lua_getstack(L, 1, &ar) == 0 ||
597 lua_getinfo(L, "f", &ar) == 0 || /* get calling function */
598 lua_iscfunction(L, -1))
599 luaL_error(L, "'module' not called from a Lua function");
600 lua_pushvalue(L, -2); /* copy new environment table to top */
601 lua_setupvalue(L, -2, 1);
602 lua_pop(L, 1); /* remove function */
603 }
604
605
dooptions(lua_State * L,int n)606 static void dooptions (lua_State *L, int n) {
607 int i;
608 for (i = 2; i <= n; i++) {
609 if (lua_isfunction(L, i)) { /* avoid 'calling' extra info. */
610 lua_pushvalue(L, i); /* get option (a function) */
611 lua_pushvalue(L, -2); /* module */
612 lua_call(L, 1, 0);
613 }
614 }
615 }
616
617
modinit(lua_State * L,const char * modname)618 static void modinit (lua_State *L, const char *modname) {
619 const char *dot;
620 lua_pushvalue(L, -1);
621 lua_setfield(L, -2, "_M"); /* module._M = module */
622 lua_pushstring(L, modname);
623 lua_setfield(L, -2, "_NAME");
624 dot = strrchr(modname, '.'); /* look for last dot in module name */
625 if (dot == NULL) dot = modname;
626 else dot++;
627 /* set _PACKAGE as package name (full module name minus last part) */
628 lua_pushlstring(L, modname, dot - modname);
629 lua_setfield(L, -2, "_PACKAGE");
630 }
631
632
ll_module(lua_State * L)633 static int ll_module (lua_State *L) {
634 const char *modname = luaL_checkstring(L, 1);
635 int lastarg = lua_gettop(L); /* last parameter */
636 luaL_pushmodule(L, modname, 1); /* get/create module table */
637 /* check whether table already has a _NAME field */
638 if (lua_getfield(L, -1, "_NAME") != LUA_TNIL)
639 lua_pop(L, 1); /* table is an initialized module */
640 else { /* no; initialize it */
641 lua_pop(L, 1);
642 modinit(L, modname);
643 }
644 lua_pushvalue(L, -1);
645 set_env(L);
646 dooptions(L, lastarg);
647 return 1;
648 }
649
650
ll_seeall(lua_State * L)651 static int ll_seeall (lua_State *L) {
652 luaL_checktype(L, 1, LUA_TTABLE);
653 if (!lua_getmetatable(L, 1)) {
654 lua_createtable(L, 0, 1); /* create new metatable */
655 lua_pushvalue(L, -1);
656 lua_setmetatable(L, 1);
657 }
658 lua_pushglobaltable(L);
659 lua_setfield(L, -2, "__index"); /* mt.__index = _G */
660 return 0;
661 }
662
663 #endif
664 /* }====================================================== */
665
666
667
668 /* auxiliary mark (for internal use) */
669 #define AUXMARK "\1"
670
671
672 /*
673 ** return registry.LUA_NOENV as a boolean
674 */
noenv(lua_State * L)675 static int noenv (lua_State *L) {
676 int b;
677 lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
678 b = lua_toboolean(L, -1);
679 lua_pop(L, 1); /* remove value */
680 return b;
681 }
682
683
setpath(lua_State * L,const char * fieldname,const char * envname1,const char * envname2,const char * def)684 static void setpath (lua_State *L, const char *fieldname, const char *envname1,
685 const char *envname2, const char *def) {
686 const char *path = getenv(envname1);
687 if (path == NULL) /* no environment variable? */
688 path = getenv(envname2); /* try alternative name */
689 if (path == NULL || noenv(L)) /* no environment variable? */
690 lua_pushstring(L, def); /* use default */
691 else {
692 /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
693 path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
694 LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
695 luaL_gsub(L, path, AUXMARK, def);
696 lua_remove(L, -2);
697 }
698 setprogdir(L);
699 lua_setfield(L, -2, fieldname);
700 }
701
702
703 static const luaL_Reg pk_funcs[] = {
704 {"loadlib", ll_loadlib},
705 {"searchpath", ll_searchpath},
706 #if defined(LUA_COMPAT_MODULE)
707 {"seeall", ll_seeall},
708 #endif
709 /* placeholders */
710 {"preload", NULL},
711 {"cpath", NULL},
712 {"path", NULL},
713 {"searchers", NULL},
714 {"loaded", NULL},
715 {NULL, NULL}
716 };
717
718
719 static const luaL_Reg ll_funcs[] = {
720 #if defined(LUA_COMPAT_MODULE)
721 {"module", ll_module},
722 #endif
723 {"require", ll_require},
724 {NULL, NULL}
725 };
726
727
createsearcherstable(lua_State * L)728 static void createsearcherstable (lua_State *L) {
729 static const lua_CFunction searchers[] =
730 {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
731 int i;
732 /* create 'searchers' table */
733 lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
734 /* fill it with pre-defined searchers */
735 for (i=0; searchers[i] != NULL; i++) {
736 lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
737 lua_pushcclosure(L, searchers[i], 1);
738 lua_rawseti(L, -2, i+1);
739 }
740 #if defined(LUA_COMPAT_LOADERS)
741 lua_pushvalue(L, -1); /* make a copy of 'searchers' table */
742 lua_setfield(L, -3, "loaders"); /* put it in field 'loaders' */
743 #endif
744 lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
745 }
746
747
748 /*
749 ** create table CLIBS to keep track of loaded C libraries,
750 ** setting a finalizer to close all libraries when closing state.
751 */
createclibstable(lua_State * L)752 static void createclibstable (lua_State *L) {
753 lua_newtable(L); /* create CLIBS table */
754 lua_createtable(L, 0, 1); /* create metatable for CLIBS */
755 lua_pushcfunction(L, gctm);
756 lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */
757 lua_setmetatable(L, -2);
758 lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS); /* set CLIBS table in registry */
759 }
760
761
luaopen_package(lua_State * L)762 LUAMOD_API int luaopen_package (lua_State *L) {
763 createclibstable(L);
764 luaL_newlib(L, pk_funcs); /* create 'package' table */
765 createsearcherstable(L);
766 /* set field 'path' */
767 setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT);
768 /* set field 'cpath' */
769 setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
770 /* store config information */
771 lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
772 LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
773 lua_setfield(L, -2, "config");
774 /* set field 'loaded' */
775 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
776 lua_setfield(L, -2, "loaded");
777 /* set field 'preload' */
778 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
779 lua_setfield(L, -2, "preload");
780 lua_pushglobaltable(L);
781 lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
782 luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
783 lua_pop(L, 1); /* pop global table */
784 return 1; /* return 'package' table */
785 }
786
787