2 ** $Id: loadlib.c,v 1.52 2006/04/10 18:27:23 roberto Exp $
3 ** Dynamic library loader for Lua
4 ** See Copyright Notice in lua.h
6 ** This module contains an implementation of loadlib for Unix systems
7 ** that have dlfcn, an implementation for Darwin (Mac OS X), an
8 ** implementation for Windows, and a stub for other systems.
25 /* prefix for open functions in C libraries */
26 #define LUA_POF "luaopen_"
28 /* separator for open functions in C libraries */
32 #define LIBPREFIX "LOADLIB: "
35 #define LIB_FAIL "open"
38 /* error codes for ll_loadfunc */
42 #define setprogdir(L) ((void)0)
45 static void ll_unloadlib (void *lib
);
46 static void *ll_load (lua_State
*L
, const char *path
);
47 static lua_CFunction
ll_sym (lua_State
*L
, void *lib
, const char *sym
);
51 #if defined(LUA_DL_DLOPEN)
53 ** {========================================================================
54 ** This is an implementation of loadlib based on the dlfcn interface.
55 ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
56 ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
57 ** as an emulation layer on top of native functions.
58 ** =========================================================================
63 static void ll_unloadlib (void *lib
) {
68 static void *ll_load (lua_State
*L
, const char *path
) {
69 void *lib
= dlopen(path
, RTLD_NOW
);
70 if (lib
== NULL
) lua_pushstring(L
, dlerror());
75 static lua_CFunction
ll_sym (lua_State
*L
, void *lib
, const char *sym
) {
76 lua_CFunction f
= (lua_CFunction
)dlsym(lib
, sym
);
77 if (f
== NULL
) lua_pushstring(L
, dlerror());
81 /* }====================================================== */
85 #elif defined(LUA_DL_DLL)
87 ** {======================================================================
88 ** This is an implementation of loadlib for Windows using native functions.
89 ** =======================================================================
97 static void setprogdir (lua_State
*L
) {
98 char buff
[MAX_PATH
+ 1];
100 DWORD nsize
= sizeof(buff
)/sizeof(char);
101 DWORD n
= GetModuleFileName(NULL
, buff
, nsize
);
102 if (n
== 0 || n
== nsize
|| (lb
= strrchr(buff
, '\\')) == NULL
)
103 luaL_error(L
, "unable to get ModuleFileName");
106 luaL_gsub(L
, lua_tostring(L
, -1), LUA_EXECDIR
, buff
);
107 lua_remove(L
, -2); /* remove original string */
112 static void pusherror (lua_State
*L
) {
113 int error
= GetLastError();
115 if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS
| FORMAT_MESSAGE_FROM_SYSTEM
,
116 NULL
, error
, 0, buffer
, sizeof(buffer
), NULL
))
117 lua_pushstring(L
, buffer
);
119 lua_pushfstring(L
, "system error %d\n", error
);
122 static void ll_unloadlib (void *lib
) {
123 FreeLibrary((HINSTANCE
)lib
);
127 static void *ll_load (lua_State
*L
, const char *path
) {
128 HINSTANCE lib
= LoadLibrary(path
);
129 if (lib
== NULL
) pusherror(L
);
134 static lua_CFunction
ll_sym (lua_State
*L
, void *lib
, const char *sym
) {
135 lua_CFunction f
= (lua_CFunction
)GetProcAddress((HINSTANCE
)lib
, sym
);
136 if (f
== NULL
) pusherror(L
);
140 /* }====================================================== */
144 #elif defined(LUA_DL_DYLD)
146 ** {======================================================================
147 ** Native Mac OS X / Darwin Implementation
148 ** =======================================================================
151 #include <mach-o/dyld.h>
154 /* Mac appends a `_' before C function names */
156 #define POF "_" LUA_POF
159 static void pusherror (lua_State
*L
) {
161 const char *err_file
;
162 NSLinkEditErrors err
;
164 NSLinkEditError(&err
, &err_num
, &err_file
, &err_str
);
165 lua_pushstring(L
, err_str
);
169 static const char *errorfromcode (NSObjectFileImageReturnCode ret
) {
171 case NSObjectFileImageInappropriateFile
:
172 return "file is not a bundle";
173 case NSObjectFileImageArch
:
174 return "library is for wrong CPU type";
175 case NSObjectFileImageFormat
:
177 case NSObjectFileImageAccess
:
178 return "cannot access file";
179 case NSObjectFileImageFailure
:
181 return "unable to load library";
186 static void ll_unloadlib (void *lib
) {
187 NSUnLinkModule((NSModule
)lib
, NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES
);
191 static void *ll_load (lua_State
*L
, const char *path
) {
192 NSObjectFileImage img
;
193 NSObjectFileImageReturnCode ret
;
194 /* this would be a rare case, but prevents crashing if it happens */
195 if(!_dyld_present()) {
196 lua_pushliteral(L
, "dyld not present");
199 ret
= NSCreateObjectFileImageFromFile(path
, &img
);
200 if (ret
== NSObjectFileImageSuccess
) {
201 NSModule mod
= NSLinkModule(img
, path
, NSLINKMODULE_OPTION_PRIVATE
|
202 NSLINKMODULE_OPTION_RETURN_ON_ERROR
);
203 NSDestroyObjectFileImage(img
);
204 if (mod
== NULL
) pusherror(L
);
207 lua_pushstring(L
, errorfromcode(ret
));
212 static lua_CFunction
ll_sym (lua_State
*L
, void *lib
, const char *sym
) {
213 NSSymbol nss
= NSLookupSymbolInModule((NSModule
)lib
, sym
);
215 lua_pushfstring(L
, "symbol " LUA_QS
" not found", sym
);
218 return (lua_CFunction
)NSAddressOfSymbol(nss
);
221 /* }====================================================== */
227 ** {======================================================
228 ** Fallback for other systems
229 ** =======================================================
233 #define LIB_FAIL "absent"
236 #define DLMSG "dynamic libraries not enabled; check your Lua installation"
239 static void ll_unloadlib (void *lib
) {
240 (void)lib
; /* to avoid warnings */
244 static void *ll_load (lua_State
*L
, const char *path
) {
245 (void)path
; /* to avoid warnings */
246 lua_pushliteral(L
, DLMSG
);
251 static lua_CFunction
ll_sym (lua_State
*L
, void *lib
, const char *sym
) {
252 (void)lib
; (void)sym
; /* to avoid warnings */
253 lua_pushliteral(L
, DLMSG
);
257 /* }====================================================== */
262 static void **ll_register (lua_State
*L
, const char *path
) {
264 lua_pushfstring(L
, "%s%s", LIBPREFIX
, path
);
265 lua_gettable(L
, LUA_REGISTRYINDEX
); /* check library in registry? */
266 if (!lua_isnil(L
, -1)) /* is there an entry? */
267 plib
= (void **)lua_touserdata(L
, -1);
268 else { /* no entry yet; create one */
270 plib
= (void **)lua_newuserdata(L
, sizeof(const void *));
272 luaL_getmetatable(L
, "_LOADLIB");
273 lua_setmetatable(L
, -2);
274 lua_pushfstring(L
, "%s%s", LIBPREFIX
, path
);
275 lua_pushvalue(L
, -2);
276 lua_settable(L
, LUA_REGISTRYINDEX
);
283 ** __gc tag method: calls library's `ll_unloadlib' function with the lib
286 static int gctm (lua_State
*L
) {
287 void **lib
= (void **)luaL_checkudata(L
, 1, "_LOADLIB");
288 if (*lib
) ll_unloadlib(*lib
);
289 *lib
= NULL
; /* mark library as closed */
294 static int ll_loadfunc (lua_State
*L
, const char *path
, const char *sym
) {
295 void **reg
= ll_register(L
, path
);
296 if (*reg
== NULL
) *reg
= ll_load(L
, path
);
298 return ERRLIB
; /* unable to load library */
300 lua_CFunction f
= ll_sym(L
, *reg
, sym
);
302 return ERRFUNC
; /* unable to find function */
303 lua_pushcfunction(L
, f
);
304 return 0; /* return function */
309 static int ll_loadlib (lua_State
*L
) {
310 const char *path
= luaL_checkstring(L
, 1);
311 const char *init
= luaL_checkstring(L
, 2);
312 int stat
= ll_loadfunc(L
, path
, init
);
313 if (stat
== 0) /* no errors? */
314 return 1; /* return the loaded function */
315 else { /* error; error message is on stack top */
318 lua_pushstring(L
, (stat
== ERRLIB
) ? LIB_FAIL
: "init");
319 return 3; /* return nil, error message, and where */
326 ** {======================================================
327 ** 'require' function
328 ** =======================================================
332 static int readable (const char *filename
) {
333 FILE *f
= fopen(filename
, "r"); /* try to open file */
334 if (f
== NULL
) return 0; /* open failed */
340 static const char *pushnexttemplate (lua_State
*L
, const char *path
) {
342 while (*path
== *LUA_PATHSEP
) path
++; /* skip separators */
343 if (*path
== '\0') return NULL
; /* no more templates */
344 l
= strchr(path
, *LUA_PATHSEP
); /* find next separator */
345 if (l
== NULL
) l
= path
+ strlen(path
);
346 lua_pushlstring(L
, path
, l
- path
); /* template */
351 static const char *findfile (lua_State
*L
, const char *name
,
354 name
= luaL_gsub(L
, name
, ".", LUA_DIRSEP
);
355 lua_getfield(L
, LUA_ENVIRONINDEX
, pname
);
356 path
= lua_tostring(L
, -1);
358 luaL_error(L
, LUA_QL("package.%s") " must be a string", pname
);
359 lua_pushstring(L
, ""); /* error accumulator */
360 while ((path
= pushnexttemplate(L
, path
)) != NULL
) {
361 const char *filename
;
362 filename
= luaL_gsub(L
, lua_tostring(L
, -1), LUA_PATH_MARK
, name
);
363 if (readable(filename
)) /* does file exist and is readable? */
364 return filename
; /* return that file name */
365 lua_pop(L
, 2); /* remove path template and file name */
366 luaO_pushfstring(L
, "\n\tno file " LUA_QS
, filename
);
369 return NULL
; /* not found */
373 static void loaderror (lua_State
*L
, const char *filename
) {
374 luaL_error(L
, "error loading module " LUA_QS
" from file " LUA_QS
":\n\t%s",
375 lua_tostring(L
, 1), filename
, lua_tostring(L
, -1));
379 static int loader_Lua (lua_State
*L
) {
380 const char *filename
;
381 const char *name
= luaL_checkstring(L
, 1);
382 filename
= findfile(L
, name
, "path");
383 if (filename
== NULL
) return 1; /* library not found in this path */
384 if (luaL_loadfile(L
, filename
) != 0)
385 loaderror(L
, filename
);
386 return 1; /* library loaded successfully */
390 static const char *mkfuncname (lua_State
*L
, const char *modname
) {
391 const char *funcname
;
392 const char *mark
= strchr(modname
, *LUA_IGMARK
);
393 if (mark
) modname
= mark
+ 1;
394 funcname
= luaL_gsub(L
, modname
, ".", LUA_OFSEP
);
395 funcname
= lua_pushfstring(L
, POF
"%s", funcname
);
396 lua_remove(L
, -2); /* remove 'gsub' result */
401 static int loader_C (lua_State
*L
) {
402 const char *funcname
;
403 const char *name
= luaL_checkstring(L
, 1);
404 const char *filename
= findfile(L
, name
, "cpath");
405 if (filename
== NULL
) return 1; /* library not found in this path */
406 funcname
= mkfuncname(L
, name
);
407 if (ll_loadfunc(L
, filename
, funcname
) != 0)
408 loaderror(L
, filename
);
409 return 1; /* library loaded successfully */
413 static int loader_Croot (lua_State
*L
) {
414 const char *funcname
;
415 const char *filename
;
416 const char *name
= luaL_checkstring(L
, 1);
417 const char *p
= strchr(name
, '.');
419 if (p
== NULL
) return 0; /* is root */
420 lua_pushlstring(L
, name
, p
- name
);
421 filename
= findfile(L
, lua_tostring(L
, -1), "cpath");
422 if (filename
== NULL
) return 1; /* root not found */
423 funcname
= mkfuncname(L
, name
);
424 if ((stat
= ll_loadfunc(L
, filename
, funcname
)) != 0) {
425 if (stat
!= ERRFUNC
) loaderror(L
, filename
); /* real error */
426 luaO_pushfstring(L
, "\n\tno module " LUA_QS
" in file " LUA_QS
,
428 return 1; /* function not found */
434 static int loader_preload (lua_State
*L
) {
435 const char *name
= luaL_checkstring(L
, 1);
436 lua_getfield(L
, LUA_ENVIRONINDEX
, "preload");
437 if (!lua_istable(L
, -1))
438 luaL_error(L
, LUA_QL("package.preload") " must be a table");
439 lua_getfield(L
, -1, name
);
440 if (lua_isnil(L
, -1)) /* not found? */
441 luaO_pushfstring(L
, "\n\tno field package.preload['%s']", name
);
446 static const int sentinel_
= 0;
447 #define sentinel ((void *)&sentinel_)
450 static int ll_require (lua_State
*L
) {
451 const char *name
= luaL_checkstring(L
, 1);
453 lua_settop(L
, 1); /* _LOADED table will be at index 2 */
454 lua_getfield(L
, LUA_REGISTRYINDEX
, "_LOADED");
455 lua_getfield(L
, 2, name
);
456 if (lua_toboolean(L
, -1)) { /* is it there? */
457 if (lua_touserdata(L
, -1) == sentinel
) /* check loops */
458 luaL_error(L
, "loop or previous error loading module " LUA_QS
, name
);
459 return 1; /* package is already loaded */
461 /* else must load it; iterate over available loaders */
462 lua_getfield(L
, LUA_ENVIRONINDEX
, "loaders");
463 if (!lua_istable(L
, -1))
464 luaL_error(L
, LUA_QL("package.loaders") " must be a table");
465 lua_pushstring(L
, ""); /* error message accumulator */
467 lua_rawgeti(L
, -2, i
); /* get a loader */
468 if (lua_isnil(L
, -1))
469 luaL_error(L
, "module " LUA_QS
" not found:%s",
470 name
, lua_tostring(L
, -2));
471 lua_pushstring(L
, name
);
472 lua_call(L
, 1, 1); /* call it */
473 if (lua_isfunction(L
, -1)) /* did it find module? */
474 break; /* module loaded successfully */
475 else if (lua_isstring(L
, -1)) /* loader returned error message? */
476 lua_concat(L
, 2); /* accumulate it */
480 lua_pushlightuserdata(L
, sentinel
);
481 lua_setfield(L
, 2, name
); /* _LOADED[name] = sentinel */
482 lua_pushstring(L
, name
); /* pass name as argument to module */
483 lua_call(L
, 1, 1); /* run loaded module */
484 if (!lua_isnil(L
, -1)) /* non-nil return? */
485 lua_setfield(L
, 2, name
); /* _LOADED[name] = returned value */
486 lua_getfield(L
, 2, name
);
487 if (lua_touserdata(L
, -1) == sentinel
) { /* module did not set a value? */
488 lua_pushboolean(L
, 1); /* use true as result */
489 lua_pushvalue(L
, -1); /* extra copy to be returned */
490 lua_setfield(L
, 2, name
); /* _LOADED[name] = true */
495 /* }====================================================== */
500 ** {======================================================
502 ** =======================================================
506 static void setfenv (lua_State
*L
) {
508 lua_getstack(L
, 1, &ar
);
509 lua_getinfo(L
, "f", &ar
);
510 lua_pushvalue(L
, -2);
516 static void dooptions (lua_State
*L
, int n
) {
518 for (i
= 2; i
<= n
; i
++) {
519 lua_pushvalue(L
, i
); /* get option (a function) */
520 lua_pushvalue(L
, -2); /* module */
526 static void modinit (lua_State
*L
, const char *modname
) {
528 lua_pushvalue(L
, -1);
529 lua_setfield(L
, -2, "_M"); /* module._M = module */
530 lua_pushstring(L
, modname
);
531 lua_setfield(L
, -2, "_NAME");
532 dot
= strrchr(modname
, '.'); /* look for last dot in module name */
533 if (dot
== NULL
) dot
= modname
;
535 /* set _PACKAGE as package name (full module name minus last part) */
536 lua_pushlstring(L
, modname
, dot
- modname
);
537 lua_setfield(L
, -2, "_PACKAGE");
541 static int ll_module (lua_State
*L
) {
542 const char *modname
= luaL_checkstring(L
, 1);
543 int loaded
= lua_gettop(L
) + 1; /* index of _LOADED table */
544 lua_getfield(L
, LUA_REGISTRYINDEX
, "_LOADED");
545 lua_getfield(L
, loaded
, modname
); /* get _LOADED[modname] */
546 if (!lua_istable(L
, -1)) { /* not found? */
547 lua_pop(L
, 1); /* remove previous result */
548 /* try global variable (and create one if it does not exist) */
549 if (luaL_findtable(L
, LUA_GLOBALSINDEX
, modname
, 1) != NULL
)
550 return luaL_error(L
, "name conflict for module " LUA_QS
, modname
);
551 lua_pushvalue(L
, -1);
552 lua_setfield(L
, loaded
, modname
); /* _LOADED[modname] = new table */
554 /* check whether table already has a _NAME field */
555 lua_getfield(L
, -1, "_NAME");
556 if (!lua_isnil(L
, -1)) /* is table an initialized module? */
558 else { /* no; initialize it */
562 lua_pushvalue(L
, -1);
564 dooptions(L
, loaded
- 1);
569 static int ll_seeall (lua_State
*L
) {
570 luaL_checktype(L
, 1, LUA_TTABLE
);
571 if (!lua_getmetatable(L
, 1)) {
572 lua_createtable(L
, 0, 1); /* create new metatable */
573 lua_pushvalue(L
, -1);
574 lua_setmetatable(L
, 1);
576 lua_pushvalue(L
, LUA_GLOBALSINDEX
);
577 lua_setfield(L
, -2, "__index"); /* mt.__index = _G */
582 /* }====================================================== */
586 /* auxiliary mark (for internal use) */
589 static void setpath (lua_State
*L
, const char *fieldname
, const char *envname
,
591 const char *path
= getenv(envname
);
592 if (path
== NULL
) /* no environment variable? */
593 lua_pushstring(L
, def
); /* use default */
595 /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
596 path
= luaL_gsub(L
, path
, LUA_PATHSEP LUA_PATHSEP
,
597 LUA_PATHSEP AUXMARK LUA_PATHSEP
);
598 luaL_gsub(L
, path
, AUXMARK
, def
);
602 lua_setfield(L
, -2, fieldname
);
606 static const luaL_Reg pk_funcs
[] = {
607 {"loadlib", ll_loadlib
},
608 {"seeall", ll_seeall
},
613 static const luaL_Reg ll_funcs
[] = {
614 {"module", ll_module
},
615 {"require", ll_require
},
620 static const lua_CFunction loaders
[] =
621 {loader_preload
, loader_Lua
, loader_C
, loader_Croot
, NULL
};
624 LUALIB_API
int luaopen_package (lua_State
*L
) {
626 /* create new type _LOADLIB */
627 luaL_newmetatable(L
, "_LOADLIB");
628 lua_pushcfunction(L
, gctm
);
629 lua_setfield(L
, -2, "__gc");
630 /* create `package' table */
631 luaL_register(L
, LUA_LOADLIBNAME
, pk_funcs
);
632 #if defined(LUA_COMPAT_LOADLIB)
633 lua_getfield(L
, -1, "loadlib");
634 lua_setfield(L
, LUA_GLOBALSINDEX
, "loadlib");
636 lua_pushvalue(L
, -1);
637 lua_replace(L
, LUA_ENVIRONINDEX
);
638 /* create `loaders' table */
639 lua_createtable(L
, 0, sizeof(loaders
)/sizeof(loaders
[0]) - 1);
640 /* fill it with pre-defined loaders */
641 for (i
=0; loaders
[i
] != NULL
; i
++) {
642 lua_pushcfunction(L
, loaders
[i
]);
643 lua_rawseti(L
, -2, i
+1);
645 lua_setfield(L
, -2, "loaders"); /* put it in field `loaders' */
646 setpath(L
, "path", LUA_PATH
, LUA_PATH_DEFAULT
); /* set field `path' */
647 setpath(L
, "cpath", LUA_CPATH
, LUA_CPATH_DEFAULT
); /* set field `cpath' */
648 /* store config information */
649 lua_pushstring(L
, LUA_DIRSEP
"\n" LUA_PATHSEP
"\n" LUA_PATH_MARK
"\n"
650 LUA_EXECDIR
"\n" LUA_IGMARK
);
651 lua_setfield(L
, -2, "config");
652 /* set field `loaded' */
653 luaL_findtable(L
, LUA_REGISTRYINDEX
, "_LOADED", 2);
654 lua_setfield(L
, -2, "loaded");
655 /* set field `preload' */
657 lua_setfield(L
, -2, "preload");
658 lua_pushvalue(L
, LUA_GLOBALSINDEX
);
659 luaL_register(L
, NULL
, ll_funcs
); /* open lib into global table */
661 return 1; /* return 'package' table */