1 /* GMODULE - GLIB wrapper code for dynamic module loading
2 * Copyright (C) 1998 Tim Janik
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
18 */
19
20 /*
21 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
22 * file for a list of people on the GLib Team. See the ChangeLog
23 * files for a list of changes. These files are distributed with
24 * GLib at ftp://ftp.gtk.org/pub/gtk/.
25 */
26
27 /*
28 * MT safe
29 */
30
31 #include "config.h"
32
33 #include "glib.h"
34 #include "gmodule.h"
35
36 #include <errno.h>
37 #include <string.h>
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <fcntl.h>
41 #ifdef HAVE_UNISTD_H
42 #include <unistd.h>
43 #endif
44 #ifdef G_OS_WIN32
45 #include <io.h> /* For open() and close() prototypes. */
46 #endif
47
48 #include "gmoduleconf.h"
49 #include "gstdio.h"
50
51 /* We maintain a list of modules, so we can reference count them.
52 * That's needed because some platforms don't support refernce counts on
53 * modules e.g. the shl_* implementation of HP-UX
54 * (http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html).
55 * Also, the module for the program itself is kept seperatedly for
56 * faster access and because it has special semantics.
57 */
58
59
60 /* --- structures --- */
61 struct _GModule
62 {
63 gchar *file_name;
64 #if defined (G_OS_WIN32) && !defined(_WIN64)
65 gchar *cp_file_name;
66 #endif
67 gpointer handle;
68 guint ref_count : 31;
69 guint is_resident : 1;
70 GModuleUnload unload;
71 GModule *next;
72 };
73
74
75 /* --- prototypes --- */
76 static gpointer _g_module_open (const gchar *file_name,
77 gboolean bind_lazy,
78 gboolean bind_local);
79 static void _g_module_close (gpointer handle,
80 gboolean is_unref);
81 static gpointer _g_module_self (void);
82 static gpointer _g_module_symbol (gpointer handle,
83 const gchar *symbol_name);
84 static gchar* _g_module_build_path (const gchar *directory,
85 const gchar *module_name);
86 static inline void g_module_set_error (const gchar *error);
87 static inline GModule* g_module_find_by_handle (gpointer handle);
88 static inline GModule* g_module_find_by_name (const gchar *name);
89
90
91 /* --- variables --- */
92 static GModule *modules = NULL;
93 static GModule *main_module = NULL;
94 static GStaticPrivate module_error_private = G_STATIC_PRIVATE_INIT;
95 static gboolean module_debug_initialized = FALSE;
96 static guint module_debug_flags = 0;
97
98
99 /* --- inline functions --- */
100 static inline GModule*
g_module_find_by_handle(gpointer handle)101 g_module_find_by_handle (gpointer handle)
102 {
103 GModule *module;
104 GModule *retval = NULL;
105
106 if (main_module && main_module->handle == handle)
107 retval = main_module;
108 else
109 for (module = modules; module; module = module->next)
110 if (handle == module->handle)
111 {
112 retval = module;
113 break;
114 }
115
116 return retval;
117 }
118
119 static inline GModule*
g_module_find_by_name(const gchar * name)120 g_module_find_by_name (const gchar *name)
121 {
122 GModule *module;
123 GModule *retval = NULL;
124
125 for (module = modules; module; module = module->next)
126 if (strcmp (name, module->file_name) == 0)
127 {
128 retval = module;
129 break;
130 }
131
132 return retval;
133 }
134
135 static inline void
g_module_set_error_unduped(gchar * error)136 g_module_set_error_unduped (gchar *error)
137 {
138 g_static_private_set (&module_error_private, error, g_free);
139 errno = 0;
140 }
141
142 static inline void
g_module_set_error(const gchar * error)143 g_module_set_error (const gchar *error)
144 {
145 g_module_set_error_unduped (g_strdup (error));
146 }
147
148
149 /* --- include platform specifc code --- */
150 #define SUPPORT_OR_RETURN(rv) { g_module_set_error (NULL); }
151 #if (G_MODULE_IMPL == G_MODULE_IMPL_DL)
152 #include "gmodule-dl.c"
153 #elif (G_MODULE_IMPL == G_MODULE_IMPL_DLD)
154 #include "gmodule-dld.c"
155 #elif (G_MODULE_IMPL == G_MODULE_IMPL_WIN32)
156 #include "gmodule-win32.c"
157 #elif (G_MODULE_IMPL == G_MODULE_IMPL_DYLD)
158 #include "gmodule-dyld.c"
159 #elif (G_MODULE_IMPL == G_MODULE_IMPL_AR)
160 #include "gmodule-ar.c"
161 #else
162 #undef SUPPORT_OR_RETURN
163 #define SUPPORT_OR_RETURN(rv) { g_module_set_error ("dynamic modules are " \
164 "not supported by this system"); return rv; }
165 static gpointer
_g_module_open(const gchar * file_name,gboolean bind_lazy,gboolean bind_local)166 _g_module_open (const gchar *file_name,
167 gboolean bind_lazy,
168 gboolean bind_local)
169 {
170 return NULL;
171 }
172 static void
_g_module_close(gpointer handle,gboolean is_unref)173 _g_module_close (gpointer handle,
174 gboolean is_unref)
175 {
176 }
177 static gpointer
_g_module_self(void)178 _g_module_self (void)
179 {
180 return NULL;
181 }
182 static gpointer
_g_module_symbol(gpointer handle,const gchar * symbol_name)183 _g_module_symbol (gpointer handle,
184 const gchar *symbol_name)
185 {
186 return NULL;
187 }
188 static gchar*
_g_module_build_path(const gchar * directory,const gchar * module_name)189 _g_module_build_path (const gchar *directory,
190 const gchar *module_name)
191 {
192 return NULL;
193 }
194 #endif /* no implementation */
195
196 /* --- functions --- */
197 gboolean
g_module_supported(void)198 g_module_supported (void)
199 {
200 SUPPORT_OR_RETURN (FALSE);
201
202 return TRUE;
203 }
204
205 static gchar*
parse_libtool_archive(const gchar * libtool_name)206 parse_libtool_archive (const gchar* libtool_name)
207 {
208 const guint TOKEN_DLNAME = G_TOKEN_LAST + 1;
209 const guint TOKEN_INSTALLED = G_TOKEN_LAST + 2;
210 const guint TOKEN_LIBDIR = G_TOKEN_LAST + 3;
211 gchar *lt_dlname = NULL;
212 gboolean lt_installed = TRUE;
213 gchar *lt_libdir = NULL;
214 gchar *name;
215 GTokenType token;
216 GScanner *scanner;
217
218 int fd = g_open (libtool_name, O_RDONLY, 0);
219 if (fd < 0)
220 {
221 gchar *display_libtool_name = g_filename_display_name (libtool_name);
222 g_module_set_error_unduped (g_strdup_printf ("failed to open libtool archive \"%s\"", display_libtool_name));
223 g_free (display_libtool_name);
224 return NULL;
225 }
226 /* search libtool's dlname specification */
227 scanner = g_scanner_new (NULL);
228 g_scanner_input_file (scanner, fd);
229 scanner->config->symbol_2_token = TRUE;
230 g_scanner_scope_add_symbol (scanner, 0, "dlname",
231 GUINT_TO_POINTER (TOKEN_DLNAME));
232 g_scanner_scope_add_symbol (scanner, 0, "installed",
233 GUINT_TO_POINTER (TOKEN_INSTALLED));
234 g_scanner_scope_add_symbol (scanner, 0, "libdir",
235 GUINT_TO_POINTER (TOKEN_LIBDIR));
236 while (!g_scanner_eof (scanner))
237 {
238 token = g_scanner_get_next_token (scanner);
239 if (token == TOKEN_DLNAME || token == TOKEN_INSTALLED ||
240 token == TOKEN_LIBDIR)
241 {
242 if (g_scanner_get_next_token (scanner) != '=' ||
243 g_scanner_get_next_token (scanner) !=
244 (token == TOKEN_INSTALLED ?
245 G_TOKEN_IDENTIFIER : G_TOKEN_STRING))
246 {
247 gchar *display_libtool_name = g_filename_display_name (libtool_name);
248 g_module_set_error_unduped (g_strdup_printf ("unable to parse libtool archive \"%s\"", display_libtool_name));
249 g_free (display_libtool_name);
250
251 g_free (lt_dlname);
252 g_free (lt_libdir);
253 g_scanner_destroy (scanner);
254 close (fd);
255
256 return NULL;
257 }
258 else
259 {
260 if (token == TOKEN_DLNAME)
261 {
262 g_free (lt_dlname);
263 lt_dlname = g_strdup (scanner->value.v_string);
264 }
265 else if (token == TOKEN_INSTALLED)
266 lt_installed =
267 strcmp (scanner->value.v_identifier, "yes") == 0;
268 else /* token == TOKEN_LIBDIR */
269 {
270 g_free (lt_libdir);
271 lt_libdir = g_strdup (scanner->value.v_string);
272 }
273 }
274 }
275 }
276
277 if (!lt_installed)
278 {
279 gchar *dir = g_path_get_dirname (libtool_name);
280 g_free (lt_libdir);
281 lt_libdir = g_strconcat (dir, G_DIR_SEPARATOR_S ".libs", NULL);
282 g_free (dir);
283 }
284
285 name = g_strconcat (lt_libdir, G_DIR_SEPARATOR_S, lt_dlname, NULL);
286
287 g_free (lt_dlname);
288 g_free (lt_libdir);
289 g_scanner_destroy (scanner);
290 close (fd);
291
292 return name;
293 }
294
295 static inline gboolean
str_check_suffix(const gchar * string,const gchar * suffix)296 str_check_suffix (const gchar* string,
297 const gchar* suffix)
298 {
299 gsize string_len = strlen (string);
300 gsize suffix_len = strlen (suffix);
301
302 return string_len >= suffix_len &&
303 strcmp (string + string_len - suffix_len, suffix) == 0;
304 }
305
306 enum
307 {
308 G_MODULE_DEBUG_RESIDENT_MODULES = 1 << 0,
309 G_MODULE_DEBUG_BIND_NOW_MODULES = 1 << 1
310 };
311
312 static void
_g_module_debug_init(void)313 _g_module_debug_init (void)
314 {
315 const GDebugKey keys[] = {
316 { "resident-modules", G_MODULE_DEBUG_RESIDENT_MODULES },
317 { "bind-now-modules", G_MODULE_DEBUG_BIND_NOW_MODULES }
318 };
319 const gchar *env;
320
321 env = g_getenv ("G_DEBUG");
322
323 module_debug_flags =
324 !env ? 0 : g_parse_debug_string (env, keys, G_N_ELEMENTS (keys));
325
326 module_debug_initialized = TRUE;
327 }
328
329 static GStaticRecMutex g_module_global_lock = G_STATIC_REC_MUTEX_INIT;
330
331 GModule*
g_module_open(const gchar * file_name,GModuleFlags flags)332 g_module_open (const gchar *file_name,
333 GModuleFlags flags)
334 {
335 GModule *module;
336 gpointer handle = NULL;
337 gchar *name = NULL;
338
339 SUPPORT_OR_RETURN (NULL);
340
341 g_static_rec_mutex_lock (&g_module_global_lock);
342
343 if (G_UNLIKELY (!module_debug_initialized))
344 _g_module_debug_init ();
345
346 if (module_debug_flags & G_MODULE_DEBUG_BIND_NOW_MODULES)
347 flags &= ~G_MODULE_BIND_LAZY;
348
349 if (!file_name)
350 {
351 if (!main_module)
352 {
353 handle = _g_module_self ();
354 if (handle)
355 {
356 main_module = g_new (GModule, 1);
357 main_module->file_name = NULL;
358 #if defined (G_OS_WIN32) && !defined(_WIN64)
359 main_module->cp_file_name = NULL;
360 #endif
361 main_module->handle = handle;
362 main_module->ref_count = 1;
363 main_module->is_resident = TRUE;
364 main_module->unload = NULL;
365 main_module->next = NULL;
366 }
367 }
368 else
369 main_module->ref_count++;
370
371 g_static_rec_mutex_unlock (&g_module_global_lock);
372 return main_module;
373 }
374
375 /* we first search the module list by name */
376 module = g_module_find_by_name (file_name);
377 if (module)
378 {
379 module->ref_count++;
380
381 g_static_rec_mutex_unlock (&g_module_global_lock);
382 return module;
383 }
384
385 /* check whether we have a readable file right away */
386 if (g_file_test (file_name, G_FILE_TEST_IS_REGULAR))
387 name = g_strdup (file_name);
388 /* try completing file name with standard library suffix */
389 if (!name)
390 {
391 name = g_strconcat (file_name, "." G_MODULE_SUFFIX, NULL);
392 if (!g_file_test (name, G_FILE_TEST_IS_REGULAR))
393 {
394 g_free (name);
395 name = NULL;
396 }
397 }
398 /* try completing by appending libtool suffix */
399 if (!name)
400 {
401 name = g_strconcat (file_name, ".la", NULL);
402 if (!g_file_test (name, G_FILE_TEST_IS_REGULAR))
403 {
404 g_free (name);
405 name = NULL;
406 }
407 }
408 /* we can't access() the file, lets hope the platform backends finds
409 * it via library paths
410 */
411 if (!name)
412 {
413 gchar *dot = strrchr (file_name, '.');
414 gchar *slash = strrchr (file_name, G_DIR_SEPARATOR);
415
416 /* make sure the name has a suffix */
417 if (!dot || dot < slash)
418 name = g_strconcat (file_name, "." G_MODULE_SUFFIX, NULL);
419 else
420 name = g_strdup (file_name);
421 }
422
423 /* ok, try loading the module */
424 if (name)
425 {
426 /* if it's a libtool archive, figure library file to load */
427 if (str_check_suffix (name, ".la")) /* libtool archive? */
428 {
429 gchar *real_name = parse_libtool_archive (name);
430
431 /* real_name might be NULL, but then module error is already set */
432 if (real_name)
433 {
434 g_free (name);
435 name = real_name;
436 }
437 }
438 if (name)
439 handle = _g_module_open (name, (flags & G_MODULE_BIND_LAZY) != 0,
440 (flags & G_MODULE_BIND_LOCAL) != 0);
441 }
442 else
443 {
444 gchar *display_file_name = g_filename_display_name (file_name);
445 g_module_set_error_unduped (g_strdup_printf ("unable to access file \"%s\"", display_file_name));
446 g_free (display_file_name);
447 }
448 g_free (name);
449
450 if (handle)
451 {
452 gchar *saved_error;
453 GModuleCheckInit check_init;
454 const gchar *check_failed = NULL;
455
456 /* search the module list by handle, since file names are not unique */
457 module = g_module_find_by_handle (handle);
458 if (module)
459 {
460 _g_module_close (module->handle, TRUE);
461 module->ref_count++;
462 g_module_set_error (NULL);
463
464 g_static_rec_mutex_unlock (&g_module_global_lock);
465 return module;
466 }
467
468 saved_error = g_strdup (g_module_error ());
469 g_module_set_error (NULL);
470
471 module = g_new (GModule, 1);
472 module->file_name = g_strdup (file_name);
473 #if defined (G_OS_WIN32) && !defined(_WIN64)
474 module->cp_file_name = g_locale_from_utf8 (file_name, -1,
475 NULL, NULL, NULL);
476 #endif
477 module->handle = handle;
478 module->ref_count = 1;
479 module->is_resident = FALSE;
480 module->unload = NULL;
481 module->next = modules;
482 modules = module;
483
484 /* check initialization */
485 if (g_module_symbol (module, "g_module_check_init", (gpointer) &check_init) && check_init != NULL)
486 check_failed = check_init (module);
487
488 /* we don't call unload() if the initialization check failed. */
489 if (!check_failed)
490 g_module_symbol (module, "g_module_unload", (gpointer) &module->unload);
491
492 if (check_failed)
493 {
494 gchar *error;
495
496 error = g_strconcat ("GModule (",
497 file_name ? file_name : "NULL",
498 ") initialization check failed: ",
499 check_failed, NULL);
500 g_module_close (module);
501 module = NULL;
502 g_module_set_error (error);
503 g_free (error);
504 }
505 else
506 g_module_set_error (saved_error);
507
508 g_free (saved_error);
509 }
510
511 if (module != NULL &&
512 (module_debug_flags & G_MODULE_DEBUG_RESIDENT_MODULES))
513 g_module_make_resident (module);
514
515 g_static_rec_mutex_unlock (&g_module_global_lock);
516 return module;
517 }
518
519 #if defined (G_OS_WIN32) && !defined(_WIN64)
520
521 #undef g_module_open
522
523 GModule*
g_module_open(const gchar * file_name,GModuleFlags flags)524 g_module_open (const gchar *file_name,
525 GModuleFlags flags)
526 {
527 gchar *utf8_file_name = g_locale_to_utf8 (file_name, -1, NULL, NULL, NULL);
528 GModule *retval = g_module_open_utf8 (utf8_file_name, flags);
529
530 g_free (utf8_file_name);
531
532 return retval;
533 }
534
535 #endif
536
537 gboolean
g_module_close(GModule * module)538 g_module_close (GModule *module)
539 {
540 SUPPORT_OR_RETURN (FALSE);
541
542 g_return_val_if_fail (module != NULL, FALSE);
543 g_return_val_if_fail (module->ref_count > 0, FALSE);
544
545 g_static_rec_mutex_lock (&g_module_global_lock);
546
547 module->ref_count--;
548
549 if (!module->ref_count && !module->is_resident && module->unload)
550 {
551 GModuleUnload unload;
552
553 unload = module->unload;
554 module->unload = NULL;
555 unload (module);
556 }
557
558 if (!module->ref_count && !module->is_resident)
559 {
560 GModule *last;
561 GModule *node;
562
563 last = NULL;
564
565 node = modules;
566 while (node)
567 {
568 if (node == module)
569 {
570 if (last)
571 last->next = node->next;
572 else
573 modules = node->next;
574 break;
575 }
576 last = node;
577 node = last->next;
578 }
579 module->next = NULL;
580
581 _g_module_close (module->handle, FALSE);
582 g_free (module->file_name);
583 #if defined (G_OS_WIN32) && !defined(_WIN64)
584 g_free (module->cp_file_name);
585 #endif
586 g_free (module);
587 }
588
589 g_static_rec_mutex_unlock (&g_module_global_lock);
590 return g_module_error() == NULL;
591 }
592
593 void
g_module_make_resident(GModule * module)594 g_module_make_resident (GModule *module)
595 {
596 g_return_if_fail (module != NULL);
597
598 module->is_resident = TRUE;
599 }
600
601 G_CONST_RETURN gchar*
g_module_error(void)602 g_module_error (void)
603 {
604 return g_static_private_get (&module_error_private);
605 }
606
607 gboolean
g_module_symbol(GModule * module,const gchar * symbol_name,gpointer * symbol)608 g_module_symbol (GModule *module,
609 const gchar *symbol_name,
610 gpointer *symbol)
611 {
612 const gchar *module_error;
613
614 if (symbol)
615 *symbol = NULL;
616 SUPPORT_OR_RETURN (FALSE);
617
618 g_return_val_if_fail (module != NULL, FALSE);
619 g_return_val_if_fail (symbol_name != NULL, FALSE);
620 g_return_val_if_fail (symbol != NULL, FALSE);
621
622 g_static_rec_mutex_lock (&g_module_global_lock);
623
624 #ifdef G_MODULE_NEED_USCORE
625 {
626 gchar *name;
627
628 name = g_strconcat ("_", symbol_name, NULL);
629 *symbol = _g_module_symbol (module->handle, name);
630 g_free (name);
631 }
632 #else /* !G_MODULE_NEED_USCORE */
633 *symbol = _g_module_symbol (module->handle, symbol_name);
634 #endif /* !G_MODULE_NEED_USCORE */
635
636 module_error = g_module_error ();
637 if (module_error)
638 {
639 gchar *error;
640
641 error = g_strconcat ("`", symbol_name, "': ", module_error, NULL);
642 g_module_set_error (error);
643 g_free (error);
644 *symbol = NULL;
645 }
646
647 g_static_rec_mutex_unlock (&g_module_global_lock);
648 return !module_error;
649 }
650
651 G_CONST_RETURN gchar*
g_module_name(GModule * module)652 g_module_name (GModule *module)
653 {
654 g_return_val_if_fail (module != NULL, NULL);
655
656 if (module == main_module)
657 return "main";
658
659 return module->file_name;
660 }
661
662 #if defined (G_OS_WIN32) && !defined(_WIN64)
663
664 #undef g_module_name
665
666 G_CONST_RETURN gchar*
g_module_name(GModule * module)667 g_module_name (GModule *module)
668 {
669 g_return_val_if_fail (module != NULL, NULL);
670
671 if (module == main_module)
672 return "main";
673
674 return module->cp_file_name;
675 }
676
677 #endif
678
679 gchar*
g_module_build_path(const gchar * directory,const gchar * module_name)680 g_module_build_path (const gchar *directory,
681 const gchar *module_name)
682 {
683 g_return_val_if_fail (module_name != NULL, NULL);
684
685 return _g_module_build_path (directory, module_name);
686 }
687