1 /*
2 ** $Id: loadlib.c,v 1.127 2015/11/23 11:30:45 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
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 ** This determines the location of the executable for relative module loading
126 ** Modified by the LuaDist project for UNIX platforms
127 ** ==========================================================================
128 */
129 #if defined(_WIN32)
130 #include <windows.h>
131 #define _PATH_MAX MAX_PATH
132 #else
133 #define _PATH_MAX PATH_MAX
134 #endif
135
136 #if defined (__CYGWIN__)
137 #include <sys/cygwin.h>
138 #endif
139
140 #if defined(__linux__) || defined(__sun)
141 #include <unistd.h> /* readlink */
142 #endif
143
144 #if defined(__APPLE__)
145 #include <sys/param.h>
146 #include <mach-o/dyld.h>
147 #endif
148
149 #if defined(__FreeBSD__)
150 #include <sys/types.h>
151 #include <sys/sysctl.h>
152 #endif
153
154 static void setprogdir(lua_State *L) {
155 char progdir[_PATH_MAX + 1];
156 char *lb;
157 int nsize = sizeof(progdir)/sizeof(char);
158 int n = 0;
159 #if defined(__CYGWIN__)
160 char win_buff[_PATH_MAX + 1];
161 GetModuleFileNameA(NULL, win_buff, nsize);
162 cygwin_conv_path(CCP_WIN_A_TO_POSIX, win_buff, progdir, nsize);
163 n = strlen(progdir);
164 #elif defined(_WIN32)
165 n = GetModuleFileNameA(NULL, progdir, nsize);
166 #elif defined(__linux__)
|
(2) Event identity_transfer: |
Passing "nsize" as argument 3 to function "readlink", which returns that argument. |
|
(3) Event assignment: |
Assigning: "n" = "readlink("/proc/self/exe", progdir, nsize)". The value of "n" is now 4097. |
| Also see events: |
[assignment][overrun-local] |
167 n = readlink("/proc/self/exe", progdir, nsize);
|
(4) Event cond_true: |
Condition "n > 0", taking true branch. |
|
(5) Event overrun-local: |
Overrunning array "progdir" of 4097 bytes at byte offset 4097 using index "n" (which evaluates to 4097). |
| Also see events: |
[assignment][identity_transfer][assignment] |
168 if (n > 0) progdir[n] = 0;
169 #elif defined(__sun)
170 pid_t pid = getpid();
171 char linkname[256];
172 sprintf(linkname, "/proc/%d/path/a.out", pid);
173 n = readlink(linkname, progdir, nsize);
174 if (n > 0) progdir[n] = 0;
175 #elif defined(__FreeBSD__)
176 int mib[4];
177 mib[0] = CTL_KERN;
178 mib[1] = KERN_PROC;
179 mib[2] = KERN_PROC_PATHNAME;
180 mib[3] = -1;
181 size_t cb = nsize;
182 sysctl(mib, 4, progdir, &cb, NULL, 0);
183 n = cb;
184 #elif defined(__BSD__)
185 n = readlink("/proc/curproc/file", progdir, nsize);
186 if (n > 0) progdir[n] = 0;
187 #elif defined(__APPLE__)
188 uint32_t nsize_apple = nsize;
189 if (_NSGetExecutablePath(progdir, &nsize_apple) == 0)
190 n = strlen(progdir);
191 #else
192 // FALLBACK
193 // Use 'lsof' ... should work on most UNIX systems (incl. OSX)
194 // lsof will list open files, this captures the 1st file listed (usually the executable)
195 int pid;
196 FILE* fd;
197 char cmd[80];
198 pid = getpid();
199
200 sprintf(cmd, "lsof -p %d | awk '{if ($5==\"REG\") { print $9 ; exit}}' 2> /dev/null", pid);
201 fd = popen(cmd, "r");
202 n = fread(progdir, 1, nsize, fd);
203 pclose(fd);
204
205 // remove newline
206 if (n > 1) progdir[--n] = '\0';
207 #endif
208 if (n == 0 || n == nsize || (lb = strrchr(progdir, (int)LUA_DIRSEP[0])) == NULL)
209 luaL_error(L, "unable to get process executable path");
210 else {
211 *lb = '\0';
212
213 // Replace the relative path placeholder
214 luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, progdir);
215 lua_remove(L, -2);
216 }
217 }
218
219 #if defined(LUA_USE_DLOPEN) /* { */
220 /*
221 ** {========================================================================
222 ** This is an implementation of loadlib based on the dlfcn interface.
223 ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
224 ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
225 ** as an emulation layer on top of native functions.
226 ** =========================================================================
227 */
228
229 #include <dlfcn.h>
230
231 /*
232 ** Macro to convert pointer-to-void* to pointer-to-function. This cast
233 ** is undefined according to ISO C, but POSIX assumes that it works.
234 ** (The '__extension__' in gnu compilers is only to avoid warnings.)
235 */
236 #if defined(__GNUC__)
237 #define cast_func(p) (__extension__ (lua_CFunction)(p))
238 #else
239 #define cast_func(p) ((lua_CFunction)(p))
240 #endif
241
242
243 static void lsys_unloadlib (void *lib) {
244 dlclose(lib);
245 }
246
247
248 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
249 void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
250 if (lib == NULL) lua_pushstring(L, dlerror());
251 return lib;
252 }
253
254
255 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
256 lua_CFunction f = cast_func(dlsym(lib, sym));
257 if (f == NULL) lua_pushstring(L, dlerror());
258 return f;
259 }
260
261 /* }====================================================== */
262
263
264
265 #elif defined(LUA_DL_DLL) /* }{ */
266 /*
267 ** {======================================================================
268 ** This is an implementation of loadlib for Windows using native functions.
269 ** =======================================================================
270 */
271
272 /*
273 ** optional flags for LoadLibraryEx
274 */
275 #if !defined(LUA_LLE_FLAGS)
276 #define LUA_LLE_FLAGS 0
277 #endif
278
279 static void pusherror (lua_State *L) {
280 int error = GetLastError();
281 char buffer[128];
282 if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
283 NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
284 lua_pushstring(L, buffer);
285 else
286 lua_pushfstring(L, "system error %d\n", error);
287 }
288
289 static void lsys_unloadlib (void *lib) {
290 FreeLibrary((HMODULE)lib);
291 }
292
293
294 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
295 HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
296 (void)(seeglb); /* not used: symbols are 'global' by default */
297 if (lib == NULL) pusherror(L);
298 return lib;
299 }
300
301
302 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
303 lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
304 if (f == NULL) pusherror(L);
305 return f;
306 }
307
308 /* }====================================================== */
309
310
311 #else /* }{ */
312 /*
313 ** {======================================================
314 ** Fallback for other systems
315 ** =======================================================
316 */
317
318 #undef LIB_FAIL
319 #define LIB_FAIL "absent"
320
321
322 #define DLMSG "dynamic libraries not enabled; check your Lua installation"
323
324
325 static void lsys_unloadlib (void *lib) {
326 (void)(lib); /* not used */
327 }
328
329
330 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
331 (void)(path); (void)(seeglb); /* not used */
332 lua_pushliteral(L, DLMSG);
333 return NULL;
334 }
335
336
337 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
338 (void)(lib); (void)(sym); /* not used */
339 lua_pushliteral(L, DLMSG);
340 return NULL;
341 }
342
343 /* }====================================================== */
344 #endif /* } */
345
346
347 /*
348 ** return registry.CLIBS[path]
349 */
350 static void *checkclib (lua_State *L, const char *path) {
351 void *plib;
352 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
353 lua_getfield(L, -1, path);
354 plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
355 lua_pop(L, 2); /* pop CLIBS table and 'plib' */
356 return plib;
357 }
358
359
360 /*
361 ** registry.CLIBS[path] = plib -- for queries
362 ** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
363 */
364 static void addtoclib (lua_State *L, const char *path, void *plib) {
365 lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
366 lua_pushlightuserdata(L, plib);
367 lua_pushvalue(L, -1);
368 lua_setfield(L, -3, path); /* CLIBS[path] = plib */
369 lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
370 lua_pop(L, 1); /* pop CLIBS table */
371 }
372
373
374 /*
375 ** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
376 ** handles in list CLIBS
377 */
378 static int gctm (lua_State *L) {
379 lua_Integer n = luaL_len(L, 1);
380 for (; n >= 1; n--) { /* for each handle, in reverse order */
381 lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
382 lsys_unloadlib(lua_touserdata(L, -1));
383 lua_pop(L, 1); /* pop handle */
384 }
385 return 0;
386 }
387
388
389
390 /* error codes for 'lookforfunc' */
391 #define ERRLIB 1
392 #define ERRFUNC 2
393
394 /*
395 ** Look for a C function named 'sym' in a dynamically loaded library
396 ** 'path'.
397 ** First, check whether the library is already loaded; if not, try
398 ** to load it.
399 ** Then, if 'sym' is '*', return true (as library has been loaded).
400 ** Otherwise, look for symbol 'sym' in the library and push a
401 ** C function with that symbol.
402 ** Return 0 and 'true' or a function in the stack; in case of
403 ** errors, return an error code and an error message in the stack.
404 */
405 static int lookforfunc (lua_State *L, const char *path, const char *sym) {
406 void *reg = checkclib(L, path); /* check loaded C libraries */
407 if (reg == NULL) { /* must load library? */
408 reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */
409 if (reg == NULL) return ERRLIB; /* unable to load library */
410 addtoclib(L, path, reg);
411 }
412 if (*sym == '*') { /* loading only library (no function)? */
413 lua_pushboolean(L, 1); /* return 'true' */
414 return 0; /* no errors */
415 }
416 else {
417 lua_CFunction f = lsys_sym(L, reg, sym);
418 if (f == NULL)
419 return ERRFUNC; /* unable to find function */
420 lua_pushcfunction(L, f); /* else create new function */
421 return 0; /* no errors */
422 }
423 }
424
425
426 static int ll_loadlib (lua_State *L) {
427 const char *path = luaL_checkstring(L, 1);
428 const char *init = luaL_checkstring(L, 2);
429 int stat = lookforfunc(L, path, init);
430 if (stat == 0) /* no errors? */
431 return 1; /* return the loaded function */
432 else { /* error; error message is on stack top */
433 lua_pushnil(L);
434 lua_insert(L, -2);
435 lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
436 return 3; /* return nil, error message, and where */
437 }
438 }
439
440
441
442 /*
443 ** {======================================================
444 ** 'require' function
445 ** =======================================================
446 */
447
448
449 static int readable (const char *filename) {
450 FILE *f = fopen(filename, "r"); /* try to open file */
451 if (f == NULL) return 0; /* open failed */
452 fclose(f);
453 return 1;
454 }
455
456
457 static const char *pushnexttemplate (lua_State *L, const char *path) {
458 const char *l;
459 while (*path == *LUA_PATH_SEP) path++; /* skip separators */
460 if (*path == '\0') return NULL; /* no more templates */
461 l = strchr(path, *LUA_PATH_SEP); /* find next separator */
462 if (l == NULL) l = path + strlen(path);
463 lua_pushlstring(L, path, l - path); /* template */
464 return l;
465 }
466
467
468 static const char *searchpath (lua_State *L, const char *name,
469 const char *path,
470 const char *sep,
471 const char *dirsep) {
472 luaL_Buffer msg; /* to build error message */
473 luaL_buffinit(L, &msg);
474 if (*sep != '\0') /* non-empty separator? */
475 name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
476 while ((path = pushnexttemplate(L, path)) != NULL) {
477 const char *filename = luaL_gsub(L, lua_tostring(L, -1),
478 LUA_PATH_MARK, name);
479 lua_remove(L, -2); /* remove path template */
480 if (readable(filename)) /* does file exist and is readable? */
481 return filename; /* return that file name */
482 lua_pushfstring(L, "\n\tno file '%s'", filename);
483 lua_remove(L, -2); /* remove file name */
484 luaL_addvalue(&msg); /* concatenate error msg. entry */
485 }
486 luaL_pushresult(&msg); /* create error message */
487 return NULL; /* not found */
488 }
489
490
491 static int ll_searchpath (lua_State *L) {
492 const char *f = searchpath(L, luaL_checkstring(L, 1),
493 luaL_checkstring(L, 2),
494 luaL_optstring(L, 3, "."),
495 luaL_optstring(L, 4, LUA_DIRSEP));
496 if (f != NULL) return 1;
497 else { /* error message is on top of the stack */
498 lua_pushnil(L);
499 lua_insert(L, -2);
500 return 2; /* return nil + error message */
501 }
502 }
503
504
505 static const char *findfile (lua_State *L, const char *name,
506 const char *pname,
507 const char *dirsep) {
508 const char *path;
509 lua_getfield(L, lua_upvalueindex(1), pname);
510 path = lua_tostring(L, -1);
511 if (path == NULL)
512 luaL_error(L, "'package.%s' must be a string", pname);
513 return searchpath(L, name, path, ".", dirsep);
514 }
515
516
517 static int checkload (lua_State *L, int stat, const char *filename) {
518 if (stat) { /* module loaded successfully? */
519 lua_pushstring(L, filename); /* will be 2nd argument to module */
520 return 2; /* return open function and file name */
521 }
522 else
523 return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s",
524 lua_tostring(L, 1), filename, lua_tostring(L, -1));
525 }
526
527
528 static int searcher_Lua (lua_State *L) {
529 const char *filename;
530 const char *name = luaL_checkstring(L, 1);
531 filename = findfile(L, name, "path", LUA_LSUBSEP);
532 if (filename == NULL) return 1; /* module not found in this path */
533 return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
534 }
535
536
537 /*
538 ** Try to find a load function for module 'modname' at file 'filename'.
539 ** First, change '.' to '_' in 'modname'; then, if 'modname' has
540 ** the form X-Y (that is, it has an "ignore mark"), build a function
541 ** name "luaopen_X" and look for it. (For compatibility, if that
542 ** fails, it also tries "luaopen_Y".) If there is no ignore mark,
543 ** look for a function named "luaopen_modname".
544 */
545 static int loadfunc (lua_State *L, const char *filename, const char *modname) {
546 const char *openfunc;
547 const char *mark;
548 modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
549 mark = strchr(modname, *LUA_IGMARK);
550 if (mark) {
551 int stat;
552 openfunc = lua_pushlstring(L, modname, mark - modname);
553 openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
554 stat = lookforfunc(L, filename, openfunc);
555 if (stat != ERRFUNC) return stat;
556 modname = mark + 1; /* else go ahead and try old-style name */
557 }
558 openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
559 return lookforfunc(L, filename, openfunc);
560 }
561
562
563 static int searcher_C (lua_State *L) {
564 const char *name = luaL_checkstring(L, 1);
565 const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
566 if (filename == NULL) return 1; /* module not found in this path */
567 return checkload(L, (loadfunc(L, filename, name) == 0), filename);
568 }
569
570
571 static int searcher_Croot (lua_State *L) {
572 const char *filename;
573 const char *name = luaL_checkstring(L, 1);
574 const char *p = strchr(name, '.');
575 int stat;
576 if (p == NULL) return 0; /* is root */
577 lua_pushlstring(L, name, p - name);
578 filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
579 if (filename == NULL) return 1; /* root not found */
580 if ((stat = loadfunc(L, filename, name)) != 0) {
581 if (stat != ERRFUNC)
582 return checkload(L, 0, filename); /* real error */
583 else { /* open function not found */
584 lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename);
585 return 1;
586 }
587 }
588 lua_pushstring(L, filename); /* will be 2nd argument to module */
589 return 2;
590 }
591
592
593 static int searcher_preload (lua_State *L) {
594 const char *name = luaL_checkstring(L, 1);
595 lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
596 if (lua_getfield(L, -1, name) == LUA_TNIL) /* not found? */
597 lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
598 return 1;
599 }
600
601
602 static void findloader (lua_State *L, const char *name) {
603 int i;
604 luaL_Buffer msg; /* to build error message */
605 luaL_buffinit(L, &msg);
606 /* push 'package.searchers' to index 3 in the stack */
607 if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
608 luaL_error(L, "'package.searchers' must be a table");
609 /* iterate over available searchers to find a loader */
610 for (i = 1; ; i++) {
611 if (lua_rawgeti(L, 3, i) == LUA_TNIL) { /* no more searchers? */
612 lua_pop(L, 1); /* remove nil */
613 luaL_pushresult(&msg); /* create error message */
614 luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
615 }
616 lua_pushstring(L, name);
617 lua_call(L, 1, 2); /* call it */
618 if (lua_isfunction(L, -2)) /* did it find a loader? */
619 return; /* module loader found */
620 else if (lua_isstring(L, -2)) { /* searcher returned error message? */
621 lua_pop(L, 1); /* remove extra return */
622 luaL_addvalue(&msg); /* concatenate error message */
623 }
624 else
625 lua_pop(L, 2); /* remove both returns */
626 }
627 }
628
629
630 static int ll_require (lua_State *L) {
631 const char *name = luaL_checkstring(L, 1);
632 lua_settop(L, 1); /* _LOADED table will be at index 2 */
633 lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
634 lua_getfield(L, 2, name); /* _LOADED[name] */
635 if (lua_toboolean(L, -1)) /* is it there? */
636 return 1; /* package is already loaded */
637 /* else must load package */
638 lua_pop(L, 1); /* remove 'getfield' result */
639 findloader(L, name);
640 lua_pushstring(L, name); /* pass name as argument to module loader */
641 lua_insert(L, -2); /* name is 1st argument (before search data) */
642 lua_call(L, 2, 1); /* run loader to load module */
643 if (!lua_isnil(L, -1)) /* non-nil return? */
644 lua_setfield(L, 2, name); /* _LOADED[name] = returned value */
645 if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */
646 lua_pushboolean(L, 1); /* use true as result */
647 lua_pushvalue(L, -1); /* extra copy to be returned */
648 lua_setfield(L, 2, name); /* _LOADED[name] = true */
649 }
650 return 1;
651 }
652
653 /* }====================================================== */
654
655
656
657 /*
658 ** {======================================================
659 ** 'module' function
660 ** =======================================================
661 */
662 #if defined(LUA_COMPAT_MODULE)
663
664 /*
665 ** changes the environment variable of calling function
666 */
667 static void set_env (lua_State *L) {
668 lua_Debug ar;
669 if (lua_getstack(L, 1, &ar) == 0 ||
670 lua_getinfo(L, "f", &ar) == 0 || /* get calling function */
671 lua_iscfunction(L, -1))
672 luaL_error(L, "'module' not called from a Lua function");
673 lua_pushvalue(L, -2); /* copy new environment table to top */
674 lua_setupvalue(L, -2, 1);
675 lua_pop(L, 1); /* remove function */
676 }
677
678
679 static void dooptions (lua_State *L, int n) {
680 int i;
681 for (i = 2; i <= n; i++) {
682 if (lua_isfunction(L, i)) { /* avoid 'calling' extra info. */
683 lua_pushvalue(L, i); /* get option (a function) */
684 lua_pushvalue(L, -2); /* module */
685 lua_call(L, 1, 0);
686 }
687 }
688 }
689
690
691 static void modinit (lua_State *L, const char *modname) {
692 const char *dot;
693 lua_pushvalue(L, -1);
694 lua_setfield(L, -2, "_M"); /* module._M = module */
695 lua_pushstring(L, modname);
696 lua_setfield(L, -2, "_NAME");
697 dot = strrchr(modname, '.'); /* look for last dot in module name */
698 if (dot == NULL) dot = modname;
699 else dot++;
700 /* set _PACKAGE as package name (full module name minus last part) */
701 lua_pushlstring(L, modname, dot - modname);
702 lua_setfield(L, -2, "_PACKAGE");
703 }
704
705
706 static int ll_module (lua_State *L) {
707 const char *modname = luaL_checkstring(L, 1);
708 int lastarg = lua_gettop(L); /* last parameter */
709 luaL_pushmodule(L, modname, 1); /* get/create module table */
710 /* check whether table already has a _NAME field */
711 if (lua_getfield(L, -1, "_NAME") != LUA_TNIL)
712 lua_pop(L, 1); /* table is an initialized module */
713 else { /* no; initialize it */
714 lua_pop(L, 1);
715 modinit(L, modname);
716 }
717 lua_pushvalue(L, -1);
718 set_env(L);
719 dooptions(L, lastarg);
720 return 1;
721 }
722
723
724 static int ll_seeall (lua_State *L) {
725 luaL_checktype(L, 1, LUA_TTABLE);
726 if (!lua_getmetatable(L, 1)) {
727 lua_createtable(L, 0, 1); /* create new metatable */
728 lua_pushvalue(L, -1);
729 lua_setmetatable(L, 1);
730 }
731 lua_pushglobaltable(L);
732 lua_setfield(L, -2, "__index"); /* mt.__index = _G */
733 return 0;
734 }
735
736 #endif
737 /* }====================================================== */
738
739
740
741 /* auxiliary mark (for internal use) */
742 #define AUXMARK "\1"
743
744
745 /*
746 ** return registry.LUA_NOENV as a boolean
747 */
748 static int noenv (lua_State *L) {
749 int b;
750 lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
751 b = lua_toboolean(L, -1);
752 lua_pop(L, 1); /* remove value */
753 return b;
754 }
755
756
757 static void setpath (lua_State *L, const char *fieldname, const char *envname1,
758 const char *envname2, const char *def) {
759 const char *path = getenv(envname1);
760 if (path == NULL) /* no environment variable? */
761 path = getenv(envname2); /* try alternative name */
762 if (path == NULL || noenv(L)) /* no environment variable? */
763 lua_pushstring(L, def); /* use default */
764 else {
765 /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
766 path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
767 LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
768 luaL_gsub(L, path, AUXMARK, def);
769 lua_remove(L, -2);
770 }
771 setprogdir(L);
772 lua_setfield(L, -2, fieldname);
773 }
774
775
776 static const luaL_Reg pk_funcs[] = {
777 {"loadlib", ll_loadlib},
778 {"searchpath", ll_searchpath},
779 #if defined(LUA_COMPAT_MODULE)
780 {"seeall", ll_seeall},
781 #endif
782 /* placeholders */
783 {"preload", NULL},
784 {"cpath", NULL},
785 {"path", NULL},
786 {"searchers", NULL},
787 {"loaded", NULL},
788 {NULL, NULL}
789 };
790
791
792 static const luaL_Reg ll_funcs[] = {
793 #if defined(LUA_COMPAT_MODULE)
794 {"module", ll_module},
795 #endif
796 {"require", ll_require},
797 {NULL, NULL}
798 };
799
800
801 static void createsearcherstable (lua_State *L) {
802 static const lua_CFunction searchers[] =
803 {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
804 int i;
805 /* create 'searchers' table */
806 lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
807 /* fill it with predefined searchers */
808 for (i=0; searchers[i] != NULL; i++) {
809 lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
810 lua_pushcclosure(L, searchers[i], 1);
811 lua_rawseti(L, -2, i+1);
812 }
813 #if defined(LUA_COMPAT_LOADERS)
814 lua_pushvalue(L, -1); /* make a copy of 'searchers' table */
815 lua_setfield(L, -3, "loaders"); /* put it in field 'loaders' */
816 #endif
817 lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
818 }
819
820
821 /*
822 ** create table CLIBS to keep track of loaded C libraries,
823 ** setting a finalizer to close all libraries when closing state.
824 */
825 static void createclibstable (lua_State *L) {
826 lua_newtable(L); /* create CLIBS table */
827 lua_createtable(L, 0, 1); /* create metatable for CLIBS */
828 lua_pushcfunction(L, gctm);
829 lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */
830 lua_setmetatable(L, -2);
831 lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS); /* set CLIBS table in registry */
832 }
833
834
835 LUAMOD_API int luaopen_package (lua_State *L) {
836 createclibstable(L);
837 luaL_newlib(L, pk_funcs); /* create 'package' table */
838 createsearcherstable(L);
839 /* set field 'path' */
840 setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT);
841 /* set field 'cpath' */
842 setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
843 /* store config information */
844 lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
845 LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
846 lua_setfield(L, -2, "config");
847 /* set field 'loaded' */
848 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
849 lua_setfield(L, -2, "loaded");
850 /* set field 'preload' */
851 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
852 lua_setfield(L, -2, "preload");
853 lua_pushglobaltable(L);
854 lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
855 luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
856 lua_pop(L, 1); /* pop global table */
857 return 1; /* return 'package' table */
858 }
859
860