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1 | /* |
2 | ** $Id: loadlib.c,v 1.126 2015/02/16 13:14:33 roberto Exp $ | |
3 | ** Dynamic library loader for Lua | |
4 | ** See Copyright Notice in lua.h | |
5 | ** | |
6 | ** This module contains an implementation of loadlib for Unix systems | |
7 | ** that have dlfcn, an implementation for Windows, and a stub for other | |
8 | ** systems. | |
9 | */ | |
10 | ||
11 | #define loadlib_c | |
12 | #define LUA_LIB | |
13 | ||
14 | #include "lprefix.h" | |
15 | ||
16 | ||
17 | #include <stdio.h> | |
18 | #include <stdlib.h> | |
19 | #include <string.h> | |
20 | ||
21 | #include "lua.h" | |
22 | ||
23 | #include "lauxlib.h" | |
24 | #include "lualib.h" | |
25 | ||
26 | ||
27 | /* | |
28 | ** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment | |
29 | ** variables that Lua check to set its paths. | |
30 | */ | |
31 | #if !defined(LUA_PATH_VAR) | |
32 | #define LUA_PATH_VAR "LUA_PATH" | |
33 | #endif | |
34 | ||
35 | #if !defined(LUA_CPATH_VAR) | |
36 | #define LUA_CPATH_VAR "LUA_CPATH" | |
37 | #endif | |
38 | ||
39 | #define LUA_PATHSUFFIX "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR | |
40 | ||
41 | #define LUA_PATHVARVERSION LUA_PATH_VAR LUA_PATHSUFFIX | |
42 | #define LUA_CPATHVARVERSION LUA_CPATH_VAR LUA_PATHSUFFIX | |
43 | ||
44 | /* | |
45 | ** LUA_PATH_SEP is the character that separates templates in a path. | |
46 | ** LUA_PATH_MARK is the string that marks the substitution points in a | |
47 | ** template. | |
48 | ** LUA_EXEC_DIR in a Windows path is replaced by the executable's | |
49 | ** directory. | |
50 | ** LUA_IGMARK is a mark to ignore all before it when building the | |
51 | ** luaopen_ function name. | |
52 | */ | |
53 | #if !defined (LUA_PATH_SEP) | |
54 | #define LUA_PATH_SEP ";" | |
55 | #endif | |
56 | #if !defined (LUA_PATH_MARK) | |
57 | #define LUA_PATH_MARK "?" | |
58 | #endif | |
59 | #if !defined (LUA_EXEC_DIR) | |
60 | #define LUA_EXEC_DIR "!" | |
61 | #endif | |
62 | #if !defined (LUA_IGMARK) | |
63 | #define LUA_IGMARK "-" | |
64 | #endif | |
65 | ||
66 | ||
67 | /* | |
68 | ** LUA_CSUBSEP is the character that replaces dots in submodule names | |
69 | ** when searching for a C loader. | |
70 | ** LUA_LSUBSEP is the character that replaces dots in submodule names | |
71 | ** when searching for a Lua loader. | |
72 | */ | |
73 | #if !defined(LUA_CSUBSEP) | |
74 | #define LUA_CSUBSEP LUA_DIRSEP | |
75 | #endif | |
76 | ||
77 | #if !defined(LUA_LSUBSEP) | |
78 | #define LUA_LSUBSEP LUA_DIRSEP | |
79 | #endif | |
80 | ||
81 | ||
82 | /* prefix for open functions in C libraries */ | |
83 | #define LUA_POF "luaopen_" | |
84 | ||
85 | /* separator for open functions in C libraries */ | |
86 | #define LUA_OFSEP "_" | |
87 | ||
88 | ||
89 | /* | |
90 | ** unique key for table in the registry that keeps handles | |
91 | ** for all loaded C libraries | |
92 | */ | |
93 | static const int CLIBS = 0; | |
94 | ||
95 | #define LIB_FAIL "open" | |
96 | ||
97 | #define setprogdir(L) ((void)0) | |
98 | ||
99 | ||
100 | /* | |
101 | ** system-dependent functions | |
102 | */ | |
103 | ||
104 | /* | |
105 | ** unload library 'lib' | |
106 | */ | |
107 | static void lsys_unloadlib (void *lib); | |
108 | ||
109 | /* | |
110 | ** load C library in file 'path'. If 'seeglb', load with all names in | |
111 | ** the library global. | |
112 | ** Returns the library; in case of error, returns NULL plus an | |
113 | ** error string in the stack. | |
114 | */ | |
115 | static void *lsys_load (lua_State *L, const char *path, int seeglb); | |
116 | ||
117 | /* | |
118 | ** Try to find a function named 'sym' in library 'lib'. | |
119 | ** Returns the function; in case of error, returns NULL plus an | |
120 | ** error string in the stack. | |
121 | */ | |
122 | static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym); | |
123 | ||
124 | ||
125 | ||
126 | ||
127 | #if defined(LUA_USE_DLOPEN) /* { */ | |
128 | /* | |
129 | ** {======================================================================== | |
130 | ** This is an implementation of loadlib based on the dlfcn interface. | |
131 | ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD, | |
132 | ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least | |
133 | ** as an emulation layer on top of native functions. | |
134 | ** ========================================================================= | |
135 | */ | |
136 | ||
137 | #include <dlfcn.h> | |
138 | ||
139 | /* | |
140 | ** Macro to convert pointer-to-void* to pointer-to-function. This cast | |
141 | ** is undefined according to ISO C, but POSIX assumes that it works. | |
142 | ** (The '__extension__' in gnu compilers is only to avoid warnings.) | |
143 | */ | |
144 | #if defined(__GNUC__) | |
145 | #define cast_func(p) (__extension__ (lua_CFunction)(p)) | |
146 | #else | |
147 | #define cast_func(p) ((lua_CFunction)(p)) | |
148 | #endif | |
149 | ||
150 | ||
151 | static void lsys_unloadlib (void *lib) { | |
152 | dlclose(lib); | |
153 | } | |
154 | ||
155 | ||
156 | static void *lsys_load (lua_State *L, const char *path, int seeglb) { | |
157 | void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL)); | |
158 | if (lib == NULL) lua_pushstring(L, dlerror()); | |
159 | return lib; | |
160 | } | |
161 | ||
162 | ||
163 | static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { | |
164 | lua_CFunction f = cast_func(dlsym(lib, sym)); | |
165 | if (f == NULL) lua_pushstring(L, dlerror()); | |
166 | return f; | |
167 | } | |
168 | ||
169 | /* }====================================================== */ | |
170 | ||
171 | ||
172 | ||
173 | #elif defined(LUA_DL_DLL) /* }{ */ | |
174 | /* | |
175 | ** {====================================================================== | |
176 | ** This is an implementation of loadlib for Windows using native functions. | |
177 | ** ======================================================================= | |
178 | */ | |
179 | ||
180 | #include <windows.h> | |
181 | ||
182 | #undef setprogdir | |
183 | ||
184 | /* | |
185 | ** optional flags for LoadLibraryEx | |
186 | */ | |
187 | #if !defined(LUA_LLE_FLAGS) | |
188 | #define LUA_LLE_FLAGS 0 | |
189 | #endif | |
190 | ||
191 | ||
192 | static void setprogdir (lua_State *L) { | |
193 | char buff[MAX_PATH + 1]; | |
194 | char *lb; | |
195 | DWORD nsize = sizeof(buff)/sizeof(char); | |
196 | DWORD n = GetModuleFileNameA(NULL, buff, nsize); | |
197 | if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL) | |
198 | luaL_error(L, "unable to get ModuleFileName"); | |
199 | else { | |
200 | *lb = '\0'; | |
201 | luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff); | |
202 | lua_remove(L, -2); /* remove original string */ | |
203 | } | |
204 | } | |
205 | ||
206 | ||
207 | static void pusherror (lua_State *L) { | |
208 | int error = GetLastError(); | |
209 | char buffer[128]; | |
210 | if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM, | |
211 | NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL)) | |
212 | lua_pushstring(L, buffer); | |
213 | else | |
214 | lua_pushfstring(L, "system error %d\n", error); | |
215 | } | |
216 | ||
217 | static void lsys_unloadlib (void *lib) { | |
218 | FreeLibrary((HMODULE)lib); | |
219 | } | |
220 | ||
221 | ||
222 | static void *lsys_load (lua_State *L, const char *path, int seeglb) { | |
223 | HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS); | |
224 | (void)(seeglb); /* not used: symbols are 'global' by default */ | |
225 | if (lib == NULL) pusherror(L); | |
226 | return lib; | |
227 | } | |
228 | ||
229 | ||
230 | static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { | |
231 | lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym); | |
232 | if (f == NULL) pusherror(L); | |
233 | return f; | |
234 | } | |
235 | ||
236 | /* }====================================================== */ | |
237 | ||
238 | ||
239 | #else /* }{ */ | |
240 | /* | |
241 | ** {====================================================== | |
242 | ** Fallback for other systems | |
243 | ** ======================================================= | |
244 | */ | |
245 | ||
246 | #undef LIB_FAIL | |
247 | #define LIB_FAIL "absent" | |
248 | ||
249 | ||
250 | #define DLMSG "dynamic libraries not enabled; check your Lua installation" | |
251 | ||
252 | ||
253 | static void lsys_unloadlib (void *lib) { | |
254 | (void)(lib); /* not used */ | |
255 | } | |
256 | ||
257 | ||
258 | static void *lsys_load (lua_State *L, const char *path, int seeglb) { | |
259 | (void)(path); (void)(seeglb); /* not used */ | |
260 | lua_pushliteral(L, DLMSG); | |
261 | return NULL; | |
262 | } | |
263 | ||
264 | ||
265 | static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { | |
266 | (void)(lib); (void)(sym); /* not used */ | |
267 | lua_pushliteral(L, DLMSG); | |
268 | return NULL; | |
269 | } | |
270 | ||
271 | /* }====================================================== */ | |
272 | #endif /* } */ | |
273 | ||
274 | ||
275 | /* | |
276 | ** return registry.CLIBS[path] | |
277 | */ | |
278 | static void *checkclib (lua_State *L, const char *path) { | |
279 | void *plib; | |
280 | lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS); | |
281 | lua_getfield(L, -1, path); | |
282 | plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */ | |
283 | lua_pop(L, 2); /* pop CLIBS table and 'plib' */ | |
284 | return plib; | |
285 | } | |
286 | ||
287 | ||
288 | /* | |
289 | ** registry.CLIBS[path] = plib -- for queries | |
290 | ** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries | |
291 | */ | |
292 | static void addtoclib (lua_State *L, const char *path, void *plib) { | |
293 | lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS); | |
294 | lua_pushlightuserdata(L, plib); | |
295 | lua_pushvalue(L, -1); | |
296 | lua_setfield(L, -3, path); /* CLIBS[path] = plib */ | |
297 | lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */ | |
298 | lua_pop(L, 1); /* pop CLIBS table */ | |
299 | } | |
300 | ||
301 | ||
302 | /* | |
303 | ** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib | |
304 | ** handles in list CLIBS | |
305 | */ | |
306 | static int gctm (lua_State *L) { | |
307 | lua_Integer n = luaL_len(L, 1); | |
308 | for (; n >= 1; n--) { /* for each handle, in reverse order */ | |
309 | lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */ | |
310 | lsys_unloadlib(lua_touserdata(L, -1)); | |
311 | lua_pop(L, 1); /* pop handle */ | |
312 | } | |
313 | return 0; | |
314 | } | |
315 | ||
316 | ||
317 | ||
318 | /* error codes for 'lookforfunc' */ | |
319 | #define ERRLIB 1 | |
320 | #define ERRFUNC 2 | |
321 | ||
322 | /* | |
323 | ** Look for a C function named 'sym' in a dynamically loaded library | |
324 | ** 'path'. | |
325 | ** First, check whether the library is already loaded; if not, try | |
326 | ** to load it. | |
327 | ** Then, if 'sym' is '*', return true (as library has been loaded). | |
328 | ** Otherwise, look for symbol 'sym' in the library and push a | |
329 | ** C function with that symbol. | |
330 | ** Return 0 and 'true' or a function in the stack; in case of | |
331 | ** errors, return an error code and an error message in the stack. | |
332 | */ | |
333 | static int lookforfunc (lua_State *L, const char *path, const char *sym) { | |
334 | void *reg = checkclib(L, path); /* check loaded C libraries */ | |
335 | if (reg == NULL) { /* must load library? */ | |
336 | reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */ | |
337 | if (reg == NULL) return ERRLIB; /* unable to load library */ | |
338 | addtoclib(L, path, reg); | |
339 | } | |
340 | if (*sym == '*') { /* loading only library (no function)? */ | |
341 | lua_pushboolean(L, 1); /* return 'true' */ | |
342 | return 0; /* no errors */ | |
343 | } | |
344 | else { | |
345 | lua_CFunction f = lsys_sym(L, reg, sym); | |
346 | if (f == NULL) | |
347 | return ERRFUNC; /* unable to find function */ | |
348 | lua_pushcfunction(L, f); /* else create new function */ | |
349 | return 0; /* no errors */ | |
350 | } | |
351 | } | |
352 | ||
353 | ||
354 | static int ll_loadlib (lua_State *L) { | |
355 | const char *path = luaL_checkstring(L, 1); | |
356 | const char *init = luaL_checkstring(L, 2); | |
357 | int stat = lookforfunc(L, path, init); | |
358 | if (stat == 0) /* no errors? */ | |
359 | return 1; /* return the loaded function */ | |
360 | else { /* error; error message is on stack top */ | |
361 | lua_pushnil(L); | |
362 | lua_insert(L, -2); | |
363 | lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init"); | |
364 | return 3; /* return nil, error message, and where */ | |
365 | } | |
366 | } | |
367 | ||
368 | ||
369 | ||
370 | /* | |
371 | ** {====================================================== | |
372 | ** 'require' function | |
373 | ** ======================================================= | |
374 | */ | |
375 | ||
376 | ||
377 | static int readable (const char *filename) { | |
378 | FILE *f = fopen(filename, "r"); /* try to open file */ | |
379 | if (f == NULL) return 0; /* open failed */ | |
380 | fclose(f); | |
381 | return 1; | |
382 | } | |
383 | ||
384 | ||
385 | static const char *pushnexttemplate (lua_State *L, const char *path) { | |
386 | const char *l; | |
387 | while (*path == *LUA_PATH_SEP) path++; /* skip separators */ | |
388 | if (*path == '\0') return NULL; /* no more templates */ | |
389 | l = strchr(path, *LUA_PATH_SEP); /* find next separator */ | |
390 | if (l == NULL) l = path + strlen(path); | |
391 | lua_pushlstring(L, path, l - path); /* template */ | |
392 | return l; | |
393 | } | |
394 | ||
395 | ||
396 | static const char *searchpath (lua_State *L, const char *name, | |
397 | const char *path, | |
398 | const char *sep, | |
399 | const char *dirsep) { | |
400 | luaL_Buffer msg; /* to build error message */ | |
401 | luaL_buffinit(L, &msg); | |
402 | if (*sep != '\0') /* non-empty separator? */ | |
403 | name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */ | |
404 | while ((path = pushnexttemplate(L, path)) != NULL) { | |
405 | const char *filename = luaL_gsub(L, lua_tostring(L, -1), | |
406 | LUA_PATH_MARK, name); | |
407 | lua_remove(L, -2); /* remove path template */ | |
408 | if (readable(filename)) /* does file exist and is readable? */ | |
409 | return filename; /* return that file name */ | |
410 | lua_pushfstring(L, "\n\tno file '%s'", filename); | |
411 | lua_remove(L, -2); /* remove file name */ | |
412 | luaL_addvalue(&msg); /* concatenate error msg. entry */ | |
413 | } | |
414 | luaL_pushresult(&msg); /* create error message */ | |
415 | return NULL; /* not found */ | |
416 | } | |
417 | ||
418 | ||
419 | static int ll_searchpath (lua_State *L) { | |
420 | const char *f = searchpath(L, luaL_checkstring(L, 1), | |
421 | luaL_checkstring(L, 2), | |
422 | luaL_optstring(L, 3, "."), | |
423 | luaL_optstring(L, 4, LUA_DIRSEP)); | |
424 | if (f != NULL) return 1; | |
425 | else { /* error message is on top of the stack */ | |
426 | lua_pushnil(L); | |
427 | lua_insert(L, -2); | |
428 | return 2; /* return nil + error message */ | |
429 | } | |
430 | } | |
431 | ||
432 | ||
433 | static const char *findfile (lua_State *L, const char *name, | |
434 | const char *pname, | |
435 | const char *dirsep) { | |
436 | const char *path; | |
437 | lua_getfield(L, lua_upvalueindex(1), pname); | |
438 | path = lua_tostring(L, -1); | |
439 | if (path == NULL) | |
440 | luaL_error(L, "'package.%s' must be a string", pname); | |
441 | return searchpath(L, name, path, ".", dirsep); | |
442 | } | |
443 | ||
444 | ||
445 | static int checkload (lua_State *L, int stat, const char *filename) { | |
446 | if (stat) { /* module loaded successfully? */ | |
447 | lua_pushstring(L, filename); /* will be 2nd argument to module */ | |
448 | return 2; /* return open function and file name */ | |
449 | } | |
450 | else | |
451 | return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s", | |
452 | lua_tostring(L, 1), filename, lua_tostring(L, -1)); | |
453 | } | |
454 | ||
455 | ||
456 | static int searcher_Lua (lua_State *L) { | |
457 | const char *filename; | |
458 | const char *name = luaL_checkstring(L, 1); | |
459 | filename = findfile(L, name, "path", LUA_LSUBSEP); | |
460 | if (filename == NULL) return 1; /* module not found in this path */ | |
461 | return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename); | |
462 | } | |
463 | ||
464 | ||
465 | /* | |
466 | ** Try to find a load function for module 'modname' at file 'filename'. | |
467 | ** First, change '.' to '_' in 'modname'; then, if 'modname' has | |
468 | ** the form X-Y (that is, it has an "ignore mark"), build a function | |
469 | ** name "luaopen_X" and look for it. (For compatibility, if that | |
470 | ** fails, it also tries "luaopen_Y".) If there is no ignore mark, | |
471 | ** look for a function named "luaopen_modname". | |
472 | */ | |
473 | static int loadfunc (lua_State *L, const char *filename, const char *modname) { | |
474 | const char *openfunc; | |
475 | const char *mark; | |
476 | modname = luaL_gsub(L, modname, ".", LUA_OFSEP); | |
477 | mark = strchr(modname, *LUA_IGMARK); | |
478 | if (mark) { | |
479 | int stat; | |
480 | openfunc = lua_pushlstring(L, modname, mark - modname); | |
481 | openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc); | |
482 | stat = lookforfunc(L, filename, openfunc); | |
483 | if (stat != ERRFUNC) return stat; | |
484 | modname = mark + 1; /* else go ahead and try old-style name */ | |
485 | } | |
486 | openfunc = lua_pushfstring(L, LUA_POF"%s", modname); | |
487 | return lookforfunc(L, filename, openfunc); | |
488 | } | |
489 | ||
490 | ||
491 | static int searcher_C (lua_State *L) { | |
492 | const char *name = luaL_checkstring(L, 1); | |
493 | const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP); | |
494 | if (filename == NULL) return 1; /* module not found in this path */ | |
495 | return checkload(L, (loadfunc(L, filename, name) == 0), filename); | |
496 | } | |
497 | ||
498 | ||
499 | static int searcher_Croot (lua_State *L) { | |
500 | const char *filename; | |
501 | const char *name = luaL_checkstring(L, 1); | |
502 | const char *p = strchr(name, '.'); | |
503 | int stat; | |
504 | if (p == NULL) return 0; /* is root */ | |
505 | lua_pushlstring(L, name, p - name); | |
506 | filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP); | |
507 | if (filename == NULL) return 1; /* root not found */ | |
508 | if ((stat = loadfunc(L, filename, name)) != 0) { | |
509 | if (stat != ERRFUNC) | |
510 | return checkload(L, 0, filename); /* real error */ | |
511 | else { /* open function not found */ | |
512 | lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename); | |
513 | return 1; | |
514 | } | |
515 | } | |
516 | lua_pushstring(L, filename); /* will be 2nd argument to module */ | |
517 | return 2; | |
518 | } | |
519 | ||
520 | ||
521 | static int searcher_preload (lua_State *L) { | |
522 | const char *name = luaL_checkstring(L, 1); | |
523 | lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD"); | |
524 | if (lua_getfield(L, -1, name) == LUA_TNIL) /* not found? */ | |
525 | lua_pushfstring(L, "\n\tno field package.preload['%s']", name); | |
526 | return 1; | |
527 | } | |
528 | ||
529 | ||
530 | static void findloader (lua_State *L, const char *name) { | |
531 | int i; | |
532 | luaL_Buffer msg; /* to build error message */ | |
533 | luaL_buffinit(L, &msg); | |
534 | /* push 'package.searchers' to index 3 in the stack */ | |
535 | if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE) | |
536 | luaL_error(L, "'package.searchers' must be a table"); | |
537 | /* iterate over available searchers to find a loader */ | |
538 | for (i = 1; ; i++) { | |
539 | if (lua_rawgeti(L, 3, i) == LUA_TNIL) { /* no more searchers? */ | |
540 | lua_pop(L, 1); /* remove nil */ | |
541 | luaL_pushresult(&msg); /* create error message */ | |
542 | luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1)); | |
543 | } | |
544 | lua_pushstring(L, name); | |
545 | lua_call(L, 1, 2); /* call it */ | |
546 | if (lua_isfunction(L, -2)) /* did it find a loader? */ | |
547 | return; /* module loader found */ | |
548 | else if (lua_isstring(L, -2)) { /* searcher returned error message? */ | |
549 | lua_pop(L, 1); /* remove extra return */ | |
550 | luaL_addvalue(&msg); /* concatenate error message */ | |
551 | } | |
552 | else | |
553 | lua_pop(L, 2); /* remove both returns */ | |
554 | } | |
555 | } | |
556 | ||
557 | ||
558 | static int ll_require (lua_State *L) { | |
559 | const char *name = luaL_checkstring(L, 1); | |
560 | lua_settop(L, 1); /* _LOADED table will be at index 2 */ | |
561 | lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED"); | |
562 | lua_getfield(L, 2, name); /* _LOADED[name] */ | |
563 | if (lua_toboolean(L, -1)) /* is it there? */ | |
564 | return 1; /* package is already loaded */ | |
565 | /* else must load package */ | |
566 | lua_pop(L, 1); /* remove 'getfield' result */ | |
567 | findloader(L, name); | |
568 | lua_pushstring(L, name); /* pass name as argument to module loader */ | |
569 | lua_insert(L, -2); /* name is 1st argument (before search data) */ | |
570 | lua_call(L, 2, 1); /* run loader to load module */ | |
571 | if (!lua_isnil(L, -1)) /* non-nil return? */ | |
572 | lua_setfield(L, 2, name); /* _LOADED[name] = returned value */ | |
573 | if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no 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 | */ | |
595 | static 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, "'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 | ||
607 | static 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 | ||
619 | static 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 | ||
634 | static 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 | if (lua_getfield(L, -1, "_NAME") != LUA_TNIL) | |
640 | lua_pop(L, 1); /* table is an initialized module */ | |
641 | else { /* no; initialize it */ | |
642 | lua_pop(L, 1); | |
643 | modinit(L, modname); | |
644 | } | |
645 | lua_pushvalue(L, -1); | |
646 | set_env(L); | |
647 | dooptions(L, lastarg); | |
648 | return 1; | |
649 | } | |
650 | ||
651 | ||
652 | static int ll_seeall (lua_State *L) { | |
653 | luaL_checktype(L, 1, LUA_TTABLE); | |
654 | if (!lua_getmetatable(L, 1)) { | |
655 | lua_createtable(L, 0, 1); /* create new metatable */ | |
656 | lua_pushvalue(L, -1); | |
657 | lua_setmetatable(L, 1); | |
658 | } | |
659 | lua_pushglobaltable(L); | |
660 | lua_setfield(L, -2, "__index"); /* mt.__index = _G */ | |
661 | return 0; | |
662 | } | |
663 | ||
664 | #endif | |
665 | /* }====================================================== */ | |
666 | ||
667 | ||
668 | ||
669 | /* auxiliary mark (for internal use) */ | |
670 | #define AUXMARK "\1" | |
671 | ||
672 | ||
673 | /* | |
674 | ** return registry.LUA_NOENV as a boolean | |
675 | */ | |
676 | static int noenv (lua_State *L) { | |
677 | int b; | |
678 | lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); | |
679 | b = lua_toboolean(L, -1); | |
680 | lua_pop(L, 1); /* remove value */ | |
681 | return b; | |
682 | } | |
683 | ||
684 | ||
685 | static void setpath (lua_State *L, const char *fieldname, const char *envname1, | |
686 | const char *envname2, const char *def) { | |
687 | const char *path = getenv(envname1); | |
688 | if (path == NULL) /* no environment variable? */ | |
689 | path = getenv(envname2); /* try alternative name */ | |
690 | if (path == NULL || noenv(L)) /* no environment variable? */ | |
691 | lua_pushstring(L, def); /* use default */ | |
692 | else { | |
693 | /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */ | |
694 | path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP, | |
695 | LUA_PATH_SEP AUXMARK LUA_PATH_SEP); | |
696 | luaL_gsub(L, path, AUXMARK, def); | |
697 | lua_remove(L, -2); | |
698 | } | |
699 | setprogdir(L); | |
700 | lua_setfield(L, -2, fieldname); | |
701 | } | |
702 | ||
703 | ||
704 | static const luaL_Reg pk_funcs[] = { | |
705 | {"loadlib", ll_loadlib}, | |
706 | {"searchpath", ll_searchpath}, | |
707 | #if defined(LUA_COMPAT_MODULE) | |
708 | {"seeall", ll_seeall}, | |
709 | #endif | |
710 | /* placeholders */ | |
711 | {"preload", NULL}, | |
712 | {"cpath", NULL}, | |
713 | {"path", NULL}, | |
714 | {"searchers", NULL}, | |
715 | {"loaded", NULL}, | |
716 | {NULL, NULL} | |
717 | }; | |
718 | ||
719 | ||
720 | static const luaL_Reg ll_funcs[] = { | |
721 | #if defined(LUA_COMPAT_MODULE) | |
722 | {"module", ll_module}, | |
723 | #endif | |
724 | {"require", ll_require}, | |
725 | {NULL, NULL} | |
726 | }; | |
727 | ||
728 | ||
729 | static void createsearcherstable (lua_State *L) { | |
730 | static const lua_CFunction searchers[] = | |
731 | {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL}; | |
732 | int i; | |
733 | /* create 'searchers' table */ | |
734 | lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0); | |
735 | /* fill it with pre-defined searchers */ | |
736 | for (i=0; searchers[i] != NULL; i++) { | |
737 | lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */ | |
738 | lua_pushcclosure(L, searchers[i], 1); | |
739 | lua_rawseti(L, -2, i+1); | |
740 | } | |
741 | #if defined(LUA_COMPAT_LOADERS) | |
742 | lua_pushvalue(L, -1); /* make a copy of 'searchers' table */ | |
743 | lua_setfield(L, -3, "loaders"); /* put it in field 'loaders' */ | |
744 | #endif | |
745 | lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */ | |
746 | } | |
747 | ||
748 | ||
749 | /* | |
750 | ** create table CLIBS to keep track of loaded C libraries, | |
751 | ** setting a finalizer to close all libraries when closing state. | |
752 | */ | |
753 | static void createclibstable (lua_State *L) { | |
754 | lua_newtable(L); /* create CLIBS table */ | |
755 | lua_createtable(L, 0, 1); /* create metatable for CLIBS */ | |
756 | lua_pushcfunction(L, gctm); | |
757 | lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */ | |
758 | lua_setmetatable(L, -2); | |
759 | lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS); /* set CLIBS table in registry */ | |
760 | } | |
761 | ||
762 | ||
763 | LUAMOD_API int luaopen_package (lua_State *L) { | |
764 | createclibstable(L); | |
765 | luaL_newlib(L, pk_funcs); /* create 'package' table */ | |
766 | createsearcherstable(L); | |
767 | /* set field 'path' */ | |
768 | setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT); | |
769 | /* set field 'cpath' */ | |
770 | setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT); | |
771 | /* store config information */ | |
772 | lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n" | |
773 | LUA_EXEC_DIR "\n" LUA_IGMARK "\n"); | |
774 | lua_setfield(L, -2, "config"); | |
775 | /* set field 'loaded' */ | |
776 | luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED"); | |
777 | lua_setfield(L, -2, "loaded"); | |
778 | /* set field 'preload' */ | |
779 | luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD"); | |
780 | lua_setfield(L, -2, "preload"); | |
781 | lua_pushglobaltable(L); | |
782 | lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */ | |
783 | luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */ | |
784 | lua_pop(L, 1); /* pop global table */ | |
785 | return 1; /* return 'package' table */ | |
786 | } | |
787 |