1 /* $NetBSD: loadlib.c,v 1.4 2015/10/08 13:21:00 mbalmer Exp $ */
2
3 /*
4 ** Id: loadlib.c,v 1.126 2015/02/16 13:14:33 roberto Exp
5 ** Dynamic library loader for Lua
6 ** See Copyright Notice in lua.h
7 **
8 ** This module contains an implementation of loadlib for Unix systems
9 ** that have dlfcn, an implementation for Windows, and a stub for other
10 ** systems.
11 */
12
13 #define loadlib_c
14 #define LUA_LIB
15
16 #include "lprefix.h"
17
18
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22
23 #include "lua.h"
24
25 #include "lauxlib.h"
26 #include "lualib.h"
27
28
29 /*
30 ** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
31 ** variables that Lua check to set its paths.
32 */
33 #if !defined(LUA_PATH_VAR)
34 #define LUA_PATH_VAR "LUA_PATH"
35 #endif
36
37 #if !defined(LUA_CPATH_VAR)
38 #define LUA_CPATH_VAR "LUA_CPATH"
39 #endif
40
41 #define LUA_PATHSUFFIX "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
42
43 #define LUA_PATHVARVERSION LUA_PATH_VAR LUA_PATHSUFFIX
44 #define LUA_CPATHVARVERSION LUA_CPATH_VAR LUA_PATHSUFFIX
45
46 /*
47 ** LUA_PATH_SEP is the character that separates templates in a path.
48 ** LUA_PATH_MARK is the string that marks the substitution points in a
49 ** template.
50 ** LUA_EXEC_DIR in a Windows path is replaced by the executable's
51 ** directory.
52 ** LUA_IGMARK is a mark to ignore all before it when building the
53 ** luaopen_ function name.
54 */
55 #if !defined (LUA_PATH_SEP)
56 #define LUA_PATH_SEP ";"
57 #endif
58 #if !defined (LUA_PATH_MARK)
59 #define LUA_PATH_MARK "?"
60 #endif
61 #if !defined (LUA_EXEC_DIR)
62 #define LUA_EXEC_DIR "!"
63 #endif
64 #if !defined (LUA_IGMARK)
65 #define LUA_IGMARK "-"
66 #endif
67
68
69 /*
70 ** LUA_CSUBSEP is the character that replaces dots in submodule names
71 ** when searching for a C loader.
72 ** LUA_LSUBSEP is the character that replaces dots in submodule names
73 ** when searching for a Lua loader.
74 */
75 #if !defined(LUA_CSUBSEP)
76 #define LUA_CSUBSEP LUA_DIRSEP
77 #endif
78
79 #if !defined(LUA_LSUBSEP)
80 #define LUA_LSUBSEP LUA_DIRSEP
81 #endif
82
83
84 /* prefix for open functions in C libraries */
85 #define LUA_POF "luaopen_"
86
87 /* separator for open functions in C libraries */
88 #define LUA_OFSEP "_"
89
90
91 /*
92 ** unique key for table in the registry that keeps handles
93 ** for all loaded C libraries
94 */
95 static const int CLIBS = 0;
96
97 #define LIB_FAIL "open"
98
99 #define setprogdir(L) ((void)0)
100
101
102 /*
103 ** system-dependent functions
104 */
105
106 /*
107 ** unload library 'lib'
108 */
109 static void lsys_unloadlib (void *lib);
110
111 /*
112 ** load C library in file 'path'. If 'seeglb', load with all names in
113 ** the library global.
114 ** Returns the library; in case of error, returns NULL plus an
115 ** error string in the stack.
116 */
117 static void *lsys_load (lua_State *L, const char *path, int seeglb);
118
119 /*
120 ** Try to find a function named 'sym' in library 'lib'.
121 ** Returns the function; in case of error, returns NULL plus an
122 ** error string in the stack.
123 */
124 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
125
126
127
128
129 #if defined(LUA_USE_DLOPEN) /* { */
130 /*
131 ** {========================================================================
132 ** This is an implementation of loadlib based on the dlfcn interface.
133 ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
134 ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
135 ** as an emulation layer on top of native functions.
136 ** =========================================================================
137 */
138
139 #include <dlfcn.h>
140
141 /*
142 ** Macro to convert pointer-to-void* to pointer-to-function. This cast
143 ** is undefined according to ISO C, but POSIX assumes that it works.
144 ** (The '__extension__' in gnu compilers is only to avoid warnings.)
145 */
146 #if defined(__GNUC__)
147 #define cast_func(p) (__extension__ (lua_CFunction)(p))
148 #else
149 #define cast_func(p) ((lua_CFunction)(p))
150 #endif
151
152
lsys_unloadlib(void * lib)153 static void lsys_unloadlib (void *lib) {
154 dlclose(lib);
155 }
156
157
lsys_load(lua_State * L,const char * path,int seeglb)158 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
159 void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
160 if (lib == NULL) lua_pushstring(L, dlerror());
161 return lib;
162 }
163
164
lsys_sym(lua_State * L,void * lib,const char * sym)165 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
166 lua_CFunction f = cast_func(dlsym(lib, sym));
167 if (f == NULL) lua_pushstring(L, dlerror());
168 return f;
169 }
170
171 /* }====================================================== */
172
173
174
175 #elif defined(LUA_DL_DLL) /* }{ */
176 /*
177 ** {======================================================================
178 ** This is an implementation of loadlib for Windows using native functions.
179 ** =======================================================================
180 */
181
182 #include <windows.h>
183
184 #undef setprogdir
185
186 /*
187 ** optional flags for LoadLibraryEx
188 */
189 #if !defined(LUA_LLE_FLAGS)
190 #define LUA_LLE_FLAGS 0
191 #endif
192
193
setprogdir(lua_State * L)194 static void setprogdir (lua_State *L) {
195 char buff[MAX_PATH + 1];
196 char *lb;
197 DWORD nsize = sizeof(buff)/sizeof(char);
198 DWORD n = GetModuleFileNameA(NULL, buff, nsize);
199 if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
200 luaL_error(L, "unable to get ModuleFileName");
201 else {
202 *lb = '\0';
203 luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
204 lua_remove(L, -2); /* remove original string */
205 }
206 }
207
208
pusherror(lua_State * L)209 static void pusherror (lua_State *L) {
210 int error = GetLastError();
211 char buffer[128];
212 if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
213 NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
214 lua_pushstring(L, buffer);
215 else
216 lua_pushfstring(L, "system error %d\n", error);
217 }
218
lsys_unloadlib(void * lib)219 static void lsys_unloadlib (void *lib) {
220 FreeLibrary((HMODULE)lib);
221 }
222
223
lsys_load(lua_State * L,const char * path,int seeglb)224 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
225 HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
226 (void)(seeglb); /* not used: symbols are 'global' by default */
227 if (lib == NULL) pusherror(L);
228 return lib;
229 }
230
231
lsys_sym(lua_State * L,void * lib,const char * sym)232 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
233 lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
234 if (f == NULL) pusherror(L);
235 return f;
236 }
237
238 /* }====================================================== */
239
240
241 #else /* }{ */
242 /*
243 ** {======================================================
244 ** Fallback for other systems
245 ** =======================================================
246 */
247
248 #undef LIB_FAIL
249 #define LIB_FAIL "absent"
250
251
252 #define DLMSG "dynamic libraries not enabled; check your Lua installation"
253
254
lsys_unloadlib(void * lib)255 static void lsys_unloadlib (void *lib) {
256 (void)(lib); /* not used */
257 }
258
259
lsys_load(lua_State * L,const char * path,int seeglb)260 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
261 (void)(path); (void)(seeglb); /* not used */
262 lua_pushliteral(L, DLMSG);
263 return NULL;
264 }
265
266
lsys_sym(lua_State * L,void * lib,const char * sym)267 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
268 (void)(lib); (void)(sym); /* not used */
269 lua_pushliteral(L, DLMSG);
270 return NULL;
271 }
272
273 /* }====================================================== */
274 #endif /* } */
275
276
277 /*
278 ** return registry.CLIBS[path]
279 */
checkclib(lua_State * L,const char * path)280 static void *checkclib (lua_State *L, const char *path) {
281 void *plib;
282 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
283 lua_getfield(L, -1, path);
284 plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
285 lua_pop(L, 2); /* pop CLIBS table and 'plib' */
286 return plib;
287 }
288
289
290 /*
291 ** registry.CLIBS[path] = plib -- for queries
292 ** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
293 */
addtoclib(lua_State * L,const char * path,void * plib)294 static void addtoclib (lua_State *L, const char *path, void *plib) {
295 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
296 lua_pushlightuserdata(L, plib);
297 lua_pushvalue(L, -1);
298 lua_setfield(L, -3, path); /* CLIBS[path] = plib */
299 lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
300 lua_pop(L, 1); /* pop CLIBS table */
301 }
302
303
304 /*
305 ** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
306 ** handles in list CLIBS
307 */
gctm(lua_State * L)308 static int gctm (lua_State *L) {
309 lua_Integer n = luaL_len(L, 1);
310 for (; n >= 1; n--) { /* for each handle, in reverse order */
311 lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
312 lsys_unloadlib(lua_touserdata(L, -1));
313 lua_pop(L, 1); /* pop handle */
314 }
315 return 0;
316 }
317
318
319
320 /* error codes for 'lookforfunc' */
321 #define ERRLIB 1
322 #define ERRFUNC 2
323
324 /*
325 ** Look for a C function named 'sym' in a dynamically loaded library
326 ** 'path'.
327 ** First, check whether the library is already loaded; if not, try
328 ** to load it.
329 ** Then, if 'sym' is '*', return true (as library has been loaded).
330 ** Otherwise, look for symbol 'sym' in the library and push a
331 ** C function with that symbol.
332 ** Return 0 and 'true' or a function in the stack; in case of
333 ** errors, return an error code and an error message in the stack.
334 */
lookforfunc(lua_State * L,const char * path,const char * sym)335 static int lookforfunc (lua_State *L, const char *path, const char *sym) {
336 void *reg = checkclib(L, path); /* check loaded C libraries */
337 if (reg == NULL) { /* must load library? */
338 reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */
339 if (reg == NULL) return ERRLIB; /* unable to load library */
340 addtoclib(L, path, reg);
341 }
342 if (*sym == '*') { /* loading only library (no function)? */
343 lua_pushboolean(L, 1); /* return 'true' */
344 return 0; /* no errors */
345 }
346 else {
347 lua_CFunction f = lsys_sym(L, reg, sym);
348 if (f == NULL)
349 return ERRFUNC; /* unable to find function */
350 lua_pushcfunction(L, f); /* else create new function */
351 return 0; /* no errors */
352 }
353 }
354
355
ll_loadlib(lua_State * L)356 static int ll_loadlib (lua_State *L) {
357 const char *path = luaL_checkstring(L, 1);
358 const char *init = luaL_checkstring(L, 2);
359 int stat = lookforfunc(L, path, init);
360 if (stat == 0) /* no errors? */
361 return 1; /* return the loaded function */
362 else { /* error; error message is on stack top */
363 lua_pushnil(L);
364 lua_insert(L, -2);
365 lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
366 return 3; /* return nil, error message, and where */
367 }
368 }
369
370
371
372 /*
373 ** {======================================================
374 ** 'require' function
375 ** =======================================================
376 */
377
378
readable(const char * filename)379 static int readable (const char *filename) {
380 FILE *f = fopen(filename, "r"); /* try to open file */
381 if (f == NULL) return 0; /* open failed */
382 fclose(f);
383 return 1;
384 }
385
386
pushnexttemplate(lua_State * L,const char * path)387 static const char *pushnexttemplate (lua_State *L, const char *path) {
388 const char *l;
389 while (*path == *LUA_PATH_SEP) path++; /* skip separators */
390 if (*path == '\0') return NULL; /* no more templates */
391 l = strchr(path, *LUA_PATH_SEP); /* find next separator */
392 if (l == NULL) l = path + strlen(path);
393 lua_pushlstring(L, path, l - path); /* template */
394 return l;
395 }
396
397
searchpath(lua_State * L,const char * name,const char * path,const char * sep,const char * dirsep)398 static const char *searchpath (lua_State *L, const char *name,
399 const char *path,
400 const char *sep,
401 const char *dirsep) {
402 luaL_Buffer msg; /* to build error message */
403 luaL_buffinit(L, &msg);
404 if (*sep != '\0') /* non-empty separator? */
405 name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
406 while ((path = pushnexttemplate(L, path)) != NULL) {
407 const char *filename = luaL_gsub(L, lua_tostring(L, -1),
408 LUA_PATH_MARK, name);
409 lua_remove(L, -2); /* remove path template */
410 if (readable(filename)) /* does file exist and is readable? */
411 return filename; /* return that file name */
412 lua_pushfstring(L, "\n\tno file '%s'", filename);
413 lua_remove(L, -2); /* remove file name */
414 luaL_addvalue(&msg); /* concatenate error msg. entry */
415 }
416 luaL_pushresult(&msg); /* create error message */
417 return NULL; /* not found */
418 }
419
420
ll_searchpath(lua_State * L)421 static int ll_searchpath (lua_State *L) {
422 const char *f = searchpath(L, luaL_checkstring(L, 1),
423 luaL_checkstring(L, 2),
424 luaL_optstring(L, 3, "."),
425 luaL_optstring(L, 4, LUA_DIRSEP));
426 if (f != NULL) return 1;
427 else { /* error message is on top of the stack */
428 lua_pushnil(L);
429 lua_insert(L, -2);
430 return 2; /* return nil + error message */
431 }
432 }
433
434
findfile(lua_State * L,const char * name,const char * pname,const char * dirsep)435 static const char *findfile (lua_State *L, const char *name,
436 const char *pname,
437 const char *dirsep) {
438 const char *path;
439 lua_getfield(L, lua_upvalueindex(1), pname);
440 path = lua_tostring(L, -1);
441 if (path == NULL)
442 luaL_error(L, "'package.%s' must be a string", pname);
443 return searchpath(L, name, path, ".", dirsep);
444 }
445
446
checkload(lua_State * L,int stat,const char * filename)447 static int checkload (lua_State *L, int stat, const char *filename) {
448 if (stat) { /* module loaded successfully? */
449 lua_pushstring(L, filename); /* will be 2nd argument to module */
450 return 2; /* return open function and file name */
451 }
452 else
453 return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s",
454 lua_tostring(L, 1), filename, lua_tostring(L, -1));
455 }
456
457
searcher_Lua(lua_State * L)458 static int searcher_Lua (lua_State *L) {
459 const char *filename;
460 const char *name = luaL_checkstring(L, 1);
461 filename = findfile(L, name, "path", LUA_LSUBSEP);
462 if (filename == NULL) return 1; /* module not found in this path */
463 return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
464 }
465
466
467 /*
468 ** Try to find a load function for module 'modname' at file 'filename'.
469 ** First, change '.' to '_' in 'modname'; then, if 'modname' has
470 ** the form X-Y (that is, it has an "ignore mark"), build a function
471 ** name "luaopen_X" and look for it. (For compatibility, if that
472 ** fails, it also tries "luaopen_Y".) If there is no ignore mark,
473 ** look for a function named "luaopen_modname".
474 */
loadfunc(lua_State * L,const char * filename,const char * modname)475 static int loadfunc (lua_State *L, const char *filename, const char *modname) {
476 const char *openfunc;
477 const char *mark;
478 modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
479 mark = strchr(modname, *LUA_IGMARK);
480 if (mark) {
481 int stat;
482 openfunc = lua_pushlstring(L, modname, mark - modname);
483 openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
484 stat = lookforfunc(L, filename, openfunc);
485 if (stat != ERRFUNC) return stat;
486 modname = mark + 1; /* else go ahead and try old-style name */
487 }
488 openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
489 return lookforfunc(L, filename, openfunc);
490 }
491
492
searcher_C(lua_State * L)493 static int searcher_C (lua_State *L) {
494 const char *name = luaL_checkstring(L, 1);
495 const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
496 if (filename == NULL) return 1; /* module not found in this path */
497 return checkload(L, (loadfunc(L, filename, name) == 0), filename);
498 }
499
500
searcher_Croot(lua_State * L)501 static int searcher_Croot (lua_State *L) {
502 const char *filename;
503 const char *name = luaL_checkstring(L, 1);
504 const char *p = strchr(name, '.');
505 int stat;
506 if (p == NULL) return 0; /* is root */
507 lua_pushlstring(L, name, p - name);
508 filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
509 if (filename == NULL) return 1; /* root not found */
510 if ((stat = loadfunc(L, filename, name)) != 0) {
511 if (stat != ERRFUNC)
512 return checkload(L, 0, filename); /* real error */
513 else { /* open function not found */
514 lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename);
515 return 1;
516 }
517 }
518 lua_pushstring(L, filename); /* will be 2nd argument to module */
519 return 2;
520 }
521
522
searcher_preload(lua_State * L)523 static int searcher_preload (lua_State *L) {
524 const char *name = luaL_checkstring(L, 1);
525 lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
526 if (lua_getfield(L, -1, name) == LUA_TNIL) /* not found? */
527 lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
528 return 1;
529 }
530
531
findloader(lua_State * L,const char * name)532 static void findloader (lua_State *L, const char *name) {
533 int i;
534 luaL_Buffer msg; /* to build error message */
535 luaL_buffinit(L, &msg);
536 /* push 'package.searchers' to index 3 in the stack */
537 if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
538 luaL_error(L, "'package.searchers' must be a table");
539 /* iterate over available searchers to find a loader */
540 for (i = 1; ; i++) {
541 if (lua_rawgeti(L, 3, i) == LUA_TNIL) { /* no more searchers? */
542 lua_pop(L, 1); /* remove nil */
543 luaL_pushresult(&msg); /* create error message */
544 luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
545 }
546 lua_pushstring(L, name);
547 lua_call(L, 1, 2); /* call it */
548 if (lua_isfunction(L, -2)) /* did it find a loader? */
549 return; /* module loader found */
550 else if (lua_isstring(L, -2)) { /* searcher returned error message? */
551 lua_pop(L, 1); /* remove extra return */
552 luaL_addvalue(&msg); /* concatenate error message */
553 }
554 else
555 lua_pop(L, 2); /* remove both returns */
556 }
557 }
558
559
ll_require(lua_State * L)560 static int ll_require (lua_State *L) {
561 const char *name = luaL_checkstring(L, 1);
562 lua_settop(L, 1); /* _LOADED table will be at index 2 */
563 lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
564 lua_getfield(L, 2, name); /* _LOADED[name] */
565 if (lua_toboolean(L, -1)) /* is it there? */
566 return 1; /* package is already loaded */
567 /* else must load package */
568 lua_pop(L, 1); /* remove 'getfield' result */
569 findloader(L, name);
570 lua_pushstring(L, name); /* pass name as argument to module loader */
571 lua_insert(L, -2); /* name is 1st argument (before search data) */
572 lua_call(L, 2, 1); /* run loader to load module */
573 if (!lua_isnil(L, -1)) /* non-nil return? */
574 lua_setfield(L, 2, name); /* _LOADED[name] = returned value */
575 if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */
576 lua_pushboolean(L, 1); /* use true as result */
577 lua_pushvalue(L, -1); /* extra copy to be returned */
578 lua_setfield(L, 2, name); /* _LOADED[name] = true */
579 }
580 return 1;
581 }
582
583 /* }====================================================== */
584
585
586
587 /*
588 ** {======================================================
589 ** 'module' function
590 ** =======================================================
591 */
592 #if defined(LUA_COMPAT_MODULE)
593
594 /*
595 ** changes the environment variable of calling function
596 */
set_env(lua_State * L)597 static void set_env (lua_State *L) {
598 lua_Debug ar;
599 if (lua_getstack(L, 1, &ar) == 0 ||
600 lua_getinfo(L, "f", &ar) == 0 || /* get calling function */
601 lua_iscfunction(L, -1))
602 luaL_error(L, "'module' not called from a Lua function");
603 lua_pushvalue(L, -2); /* copy new environment table to top */
604 lua_setupvalue(L, -2, 1);
605 lua_pop(L, 1); /* remove function */
606 }
607
608
dooptions(lua_State * L,int n)609 static void dooptions (lua_State *L, int n) {
610 int i;
611 for (i = 2; i <= n; i++) {
612 if (lua_isfunction(L, i)) { /* avoid 'calling' extra info. */
613 lua_pushvalue(L, i); /* get option (a function) */
614 lua_pushvalue(L, -2); /* module */
615 lua_call(L, 1, 0);
616 }
617 }
618 }
619
620
modinit(lua_State * L,const char * modname)621 static void modinit (lua_State *L, const char *modname) {
622 const char *dot;
623 lua_pushvalue(L, -1);
624 lua_setfield(L, -2, "_M"); /* module._M = module */
625 lua_pushstring(L, modname);
626 lua_setfield(L, -2, "_NAME");
627 dot = strrchr(modname, '.'); /* look for last dot in module name */
628 if (dot == NULL) dot = modname;
629 else dot++;
630 /* set _PACKAGE as package name (full module name minus last part) */
631 lua_pushlstring(L, modname, dot - modname);
632 lua_setfield(L, -2, "_PACKAGE");
633 }
634
635
ll_module(lua_State * L)636 static int ll_module (lua_State *L) {
637 const char *modname = luaL_checkstring(L, 1);
638 int lastarg = lua_gettop(L); /* last parameter */
639 luaL_pushmodule(L, modname, 1); /* get/create module table */
640 /* check whether table already has a _NAME field */
641 if (lua_getfield(L, -1, "_NAME") != LUA_TNIL)
642 lua_pop(L, 1); /* table is an initialized module */
643 else { /* no; initialize it */
644 lua_pop(L, 1);
645 modinit(L, modname);
646 }
647 lua_pushvalue(L, -1);
648 set_env(L);
649 dooptions(L, lastarg);
650 return 1;
651 }
652
653
ll_seeall(lua_State * L)654 static int ll_seeall (lua_State *L) {
655 luaL_checktype(L, 1, LUA_TTABLE);
656 if (!lua_getmetatable(L, 1)) {
657 lua_createtable(L, 0, 1); /* create new metatable */
658 lua_pushvalue(L, -1);
659 lua_setmetatable(L, 1);
660 }
661 lua_pushglobaltable(L);
662 lua_setfield(L, -2, "__index"); /* mt.__index = _G */
663 return 0;
664 }
665
666 #endif
667 /* }====================================================== */
668
669
670
671 /* auxiliary mark (for internal use) */
672 #define AUXMARK "\1"
673
674
675 /*
676 ** return registry.LUA_NOENV as a boolean
677 */
noenv(lua_State * L)678 static int noenv (lua_State *L) {
679 int b;
680 lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
681 b = lua_toboolean(L, -1);
682 lua_pop(L, 1); /* remove value */
683 return b;
684 }
685
686
setpath(lua_State * L,const char * fieldname,const char * envname1,const char * envname2,const char * def)687 static void setpath (lua_State *L, const char *fieldname, const char *envname1,
688 const char *envname2, const char *def) {
689 const char *path = getenv(envname1);
690 if (path == NULL) /* no environment variable? */
691 path = getenv(envname2); /* try alternative name */
692 if (path == NULL || noenv(L)) /* no environment variable? */
693 lua_pushstring(L, def); /* use default */
694 else {
695 /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
696 path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
697 LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
698 luaL_gsub(L, path, AUXMARK, def);
699 lua_remove(L, -2);
700 }
701 setprogdir(L);
702 lua_setfield(L, -2, fieldname);
703 }
704
705
706 static const luaL_Reg pk_funcs[] = {
707 {"loadlib", ll_loadlib},
708 {"searchpath", ll_searchpath},
709 #if defined(LUA_COMPAT_MODULE)
710 {"seeall", ll_seeall},
711 #endif
712 /* placeholders */
713 {"preload", NULL},
714 {"cpath", NULL},
715 {"path", NULL},
716 {"searchers", NULL},
717 {"loaded", NULL},
718 {NULL, NULL}
719 };
720
721
722 static const luaL_Reg ll_funcs[] = {
723 #if defined(LUA_COMPAT_MODULE)
724 {"module", ll_module},
725 #endif
726 {"require", ll_require},
727 {NULL, NULL}
728 };
729
730
createsearcherstable(lua_State * L)731 static void createsearcherstable (lua_State *L) {
732 static const lua_CFunction searchers[] =
733 {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
734 int i;
735 /* create 'searchers' table */
736 lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
737 /* fill it with pre-defined searchers */
738 for (i=0; searchers[i] != NULL; i++) {
739 lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
740 lua_pushcclosure(L, searchers[i], 1);
741 lua_rawseti(L, -2, i+1);
742 }
743 #if defined(LUA_COMPAT_LOADERS)
744 lua_pushvalue(L, -1); /* make a copy of 'searchers' table */
745 lua_setfield(L, -3, "loaders"); /* put it in field 'loaders' */
746 #endif
747 lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
748 }
749
750
751 /*
752 ** create table CLIBS to keep track of loaded C libraries,
753 ** setting a finalizer to close all libraries when closing state.
754 */
createclibstable(lua_State * L)755 static void createclibstable (lua_State *L) {
756 lua_newtable(L); /* create CLIBS table */
757 lua_createtable(L, 0, 1); /* create metatable for CLIBS */
758 lua_pushcfunction(L, gctm);
759 lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */
760 lua_setmetatable(L, -2);
761 lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS); /* set CLIBS table in registry */
762 }
763
764
luaopen_package(lua_State * L)765 LUAMOD_API int luaopen_package (lua_State *L) {
766 createclibstable(L);
767 luaL_newlib(L, pk_funcs); /* create 'package' table */
768 createsearcherstable(L);
769 /* set field 'path' */
770 setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT);
771 /* set field 'cpath' */
772 setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
773 /* store config information */
774 lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
775 LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
776 lua_setfield(L, -2, "config");
777 /* set field 'loaded' */
778 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
779 lua_setfield(L, -2, "loaded");
780 /* set field 'preload' */
781 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
782 lua_setfield(L, -2, "preload");
783 lua_pushglobaltable(L);
784 lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
785 luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
786 lua_pop(L, 1); /* pop global table */
787 return 1; /* return 'package' table */
788 }
789
790