1 /* Copyright (C) 2000-2007, Luca Padovani <padovani@sti.uniurb.it>.
2 *
3 * This file is part of GtkMathView, a flexible, high-quality rendering
4 * engine for MathML documents.
5 *
6 * GtkMathView is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU Lesser General Public License as published
8 * by the Free Software Foundation; either version 3 of the License, or
9 * (at your option) any later version.
10 *
11 * GtkMathView is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 /* WARNING, BEFORE YOU MODIFY PREFIX.C:
21 *
22 * If you make changes to any of the functions in prefix.c, you MUST
23 * change the BR_NAMESPACE macro (in prefix.h).
24 * This way you can avoid symbol table conflicts with other libraries
25 * that also happen to use BinReloc.
26 *
27 * Example:
28 * #define BR_NAMESPACE(funcName) foobar_ ## funcName
29 * --> expands br_locate to foobar_br_locate
30 */
31
32 #ifndef _PREFIX_C_
33 #define _PREFIX_C_
34
35 #ifdef HAVE_CONFIG_H
36 #include "config.h"
37 #endif
38
39 #ifndef BR_PTHREADS
40 /* Change 1 to 0 if you don't want pthread support */
41 #define BR_PTHREADS 1
42 #endif /* BR_PTHREADS */
43
44 #include <stdlib.h>
45 #include <stdio.h>
46 #include <limits.h>
47 #include <string.h>
48 #include "prefix.h"
49
50 #ifdef __cplusplus
51 extern "C" {
52 #endif /* __cplusplus */
53
54
55 #undef NULL
56 #define NULL ((void *) 0)
57
58 #ifdef __GNUC__
59 #define br_return_val_if_fail(expr,val) if (!(expr)) {fprintf (stderr, "** BinReloc (%s): assertion %s failed\n", __PRETTY_FUNCTION__, #expr); return val;}
60 #else
61 #define br_return_val_if_fail(expr,val) if (!(expr)) return val
62 #endif /* __GNUC__ */
63
64
65 static br_locate_fallback_func fallback_func = (br_locate_fallback_func) NULL;
66 static void *fallback_data = NULL;
67
68
69 #ifdef ENABLE_BINRELOC
70 #include <sys/types.h>
71 #include <sys/stat.h>
72 #include <sys/param.h>
73 #include <unistd.h>
74
75
76 /**
77 * br_locate:
78 * symbol: A symbol that belongs to the app/library you want to locate.
79 * Returns: A newly allocated string containing the full path of the
80 * app/library that func belongs to, or NULL on error. This
81 * string should be freed when not when no longer needed.
82 *
83 * Finds out to which application or library symbol belongs, then locate
84 * the full path of that application or library.
85 * Note that symbol cannot be a pointer to a function. That will not work.
86 *
87 * Example:
88 * --> main.c
89 * #include "prefix.h"
90 * #include "libfoo.h"
91 *
92 * int main (int argc, char *argv[]) {
93 * printf ("Full path of this app: %s\n", br_locate (&argc));
94 * libfoo_start ();
95 * return 0;
96 * }
97 *
98 * --> libfoo.c starts here
99 * #include "prefix.h"
100 *
101 * void libfoo_start () {
102 * --> "" is a symbol that belongs to libfoo (because it's called
103 * --> from libfoo_start()); that's why this works.
104 * printf ("libfoo is located in: %s\n", br_locate (""));
105 * }
106 */
107 char *
br_locate(void * symbol)108 br_locate (void *symbol)
109 {
110 char line[5000];
111 FILE *f;
112 char *path;
113
114 br_return_val_if_fail (symbol != NULL, NULL);
115
116 f = fopen ("/proc/self/maps", "r");
117 if (!f) {
118 if (fallback_func)
119 return fallback_func(symbol, fallback_data);
120 else
121 return NULL;
122 }
123
124 while (!feof (f))
125 {
126 unsigned long start, end;
127
128 if (!fgets (line, sizeof (line), f))
129 continue;
130 if (!strstr (line, " r-xp ") || !strchr (line, '/'))
131 continue;
132
133 sscanf (line, "%lx-%lx ", &start, &end);
134 if (symbol >= (void *) start && symbol < (void *) end)
135 {
136 char *tmp;
137 size_t len;
138
139 /* Extract the filename; it is always an absolute path */
140 path = strchr (line, '/');
141
142 /* Get rid of the newline */
143 tmp = strrchr (path, '\n');
144 if (tmp) *tmp = 0;
145
146 /* Get rid of "(deleted)" */
147 len = strlen (path);
148 if (len > 10 && strcmp (path + len - 10, " (deleted)") == 0)
149 {
150 tmp = path + len - 10;
151 *tmp = 0;
152 }
153
154 fclose(f);
155 return strdup (path);
156 }
157 }
158
159 fclose (f);
160 return NULL;
161 }
162
163
164 /**
165 * br_locate_prefix:
166 * symbol: A symbol that belongs to the app/library you want to locate.
167 * Returns: A prefix. This string should be freed when no longer needed.
168 *
169 * Locates the full path of the app/library that symbol belongs to, and return
170 * the prefix of that path, or NULL on error.
171 * Note that symbol cannot be a pointer to a function. That will not work.
172 *
173 * Example:
174 * --> This application is located in /usr/bin/foo
175 * br_locate_prefix (&argc); --> returns: "/usr"
176 */
177 char *
br_locate_prefix(void * symbol)178 br_locate_prefix (void *symbol)
179 {
180 char *path, *prefix;
181
182 br_return_val_if_fail (symbol != NULL, NULL);
183
184 path = br_locate (symbol);
185 if (!path) return NULL;
186
187 prefix = br_extract_prefix (path);
188 free (path);
189 return prefix;
190 }
191
192
193 /**
194 * br_prepend_prefix:
195 * symbol: A symbol that belongs to the app/library you want to locate.
196 * path: The path that you want to prepend the prefix to.
197 * Returns: The new path, or NULL on error. This string should be freed when no
198 * longer needed.
199 *
200 * Gets the prefix of the app/library that symbol belongs to. Prepend that prefix to path.
201 * Note that symbol cannot be a pointer to a function. That will not work.
202 *
203 * Example:
204 * --> The application is /usr/bin/foo
205 * br_prepend_prefix (&argc, "/share/foo/data.png"); --> Returns "/usr/share/foo/data.png"
206 */
207 char *
br_prepend_prefix(void * symbol,char * path)208 br_prepend_prefix (void *symbol, char *path)
209 {
210 char *tmp, *newpath;
211
212 br_return_val_if_fail (symbol != NULL, NULL);
213 br_return_val_if_fail (path != NULL, NULL);
214
215 tmp = br_locate_prefix (symbol);
216 if (!tmp) return NULL;
217
218 if (strcmp (tmp, "/") == 0)
219 newpath = strdup (path);
220 else
221 newpath = br_strcat (tmp, path);
222
223 /* Get rid of compiler warning ("br_prepend_prefix never used") */
224 if (0) br_prepend_prefix (NULL, NULL);
225
226 free (tmp);
227 return newpath;
228 }
229
230 #endif /* ENABLE_BINRELOC */
231
232
233 /* Pthread stuff for thread safetiness */
234 #if BR_PTHREADS && defined(ENABLE_BINRELOC)
235
236 #include <pthread.h>
237
238 static pthread_key_t br_thread_key;
239 static pthread_once_t br_thread_key_once = PTHREAD_ONCE_INIT;
240
241
242 static void
br_thread_local_store_fini()243 br_thread_local_store_fini ()
244 {
245 char *specific;
246
247 specific = (char *) pthread_getspecific (br_thread_key);
248 if (specific)
249 {
250 free (specific);
251 pthread_setspecific (br_thread_key, NULL);
252 }
253 pthread_key_delete (br_thread_key);
254 br_thread_key = 0;
255 }
256
257
258 static void
br_str_free(void * str)259 br_str_free (void *str)
260 {
261 if (str)
262 free (str);
263 }
264
265
266 static void
br_thread_local_store_init()267 br_thread_local_store_init ()
268 {
269 if (pthread_key_create (&br_thread_key, br_str_free) == 0)
270 atexit (br_thread_local_store_fini);
271 }
272
273 #else /* BR_PTHREADS */
274 #ifdef ENABLE_BINRELOC
275
276 static char *br_last_value = (char *) NULL;
277
278 static void
br_free_last_value()279 br_free_last_value ()
280 {
281 if (br_last_value)
282 free (br_last_value);
283 }
284
285 #endif /* ENABLE_BINRELOC */
286 #endif /* BR_PTHREADS */
287
288
289 #ifdef ENABLE_BINRELOC
290
291 /**
292 * br_thread_local_store:
293 * str: A dynamically allocated string.
294 * Returns: str. This return value must not be freed.
295 *
296 * Store str in a thread-local variable and return str. The next
297 * you run this function, that variable is freed too.
298 * This function is created so you don't have to worry about freeing
299 * strings. Just be careful about doing this sort of thing:
300 *
301 * some_function( BR_DATADIR("/one.png"), BR_DATADIR("/two.png") )
302 *
303 * Examples:
304 * char *foo;
305 * foo = br_thread_local_store (strdup ("hello")); --> foo == "hello"
306 * foo = br_thread_local_store (strdup ("world")); --> foo == "world"; "hello" is now freed.
307 */
308 const char *
br_thread_local_store(char * str)309 br_thread_local_store (char *str)
310 {
311 #if BR_PTHREADS
312 char *specific;
313
314 pthread_once (&br_thread_key_once, br_thread_local_store_init);
315
316 specific = (char *) pthread_getspecific (br_thread_key);
317 br_str_free (specific);
318 pthread_setspecific (br_thread_key, str);
319
320 #else /* BR_PTHREADS */
321 static int initialized = 0;
322
323 if (!initialized)
324 {
325 atexit (br_free_last_value);
326 initialized = 1;
327 }
328
329 if (br_last_value)
330 free (br_last_value);
331 br_last_value = str;
332 #endif /* BR_PTHREADS */
333
334 return (const char *) str;
335 }
336
337 #endif /* ENABLE_BINRELOC */
338
339
340 /**
341 * br_strcat:
342 * str1: A string.
343 * str2: Another string.
344 * Returns: A newly-allocated string. This string should be freed when no longer needed.
345 *
346 * Concatenate str1 and str2 to a newly allocated string.
347 */
348 char *
br_strcat(const char * str1,const char * str2)349 br_strcat (const char *str1, const char *str2)
350 {
351 char *result;
352 size_t len1, len2;
353
354 if (!str1) str1 = "";
355 if (!str2) str2 = "";
356
357 len1 = strlen (str1);
358 len2 = strlen (str2);
359
360 result = (char *) malloc (len1 + len2 + 1);
361 memcpy (result, str1, len1);
362 memcpy (result + len1, str2, len2);
363 result[len1 + len2] = '\0';
364
365 return result;
366 }
367
368
369 /* Emulates glibc's strndup() */
370 static char *
br_strndup(char * str,size_t size)371 br_strndup (char *str, size_t size)
372 {
373 char *result = (char *) NULL;
374 size_t len;
375
376 br_return_val_if_fail (str != (char *) NULL, (char *) NULL);
377
378 len = strlen (str);
379 if (!len) return strdup ("");
380 if (size > len) size = len;
381
382 result = (char *) calloc (sizeof (char), len + 1);
383 memcpy (result, str, size);
384 return result;
385 }
386
387
388 /**
389 * br_extract_dir:
390 * path: A path.
391 * Returns: A directory name. This string should be freed when no longer needed.
392 *
393 * Extracts the directory component of path. Similar to g_dirname() or the dirname
394 * commandline application.
395 *
396 * Example:
397 * br_extract_dir ("/usr/local/foobar"); --> Returns: "/usr/local"
398 */
399 char *
br_extract_dir(const char * path)400 br_extract_dir (const char *path)
401 {
402 char *end, *result;
403
404 br_return_val_if_fail (path != (char *) NULL, (char *) NULL);
405
406 end = strrchr (path, '/');
407 if (!end) return strdup (".");
408
409 while (end > path && *end == '/')
410 end--;
411 result = br_strndup ((char *) path, end - path + 1);
412 if (!*result)
413 {
414 free (result);
415 return strdup ("/");
416 } else
417 return result;
418 }
419
420
421 /**
422 * br_extract_prefix:
423 * path: The full path of an executable or library.
424 * Returns: The prefix, or NULL on error. This string should be freed when no longer needed.
425 *
426 * Extracts the prefix from path. This function assumes that your executable
427 * or library is installed in an LSB-compatible directory structure.
428 *
429 * Example:
430 * br_extract_prefix ("/usr/bin/gnome-panel"); --> Returns "/usr"
431 * br_extract_prefix ("/usr/local/lib/libfoo.so"); --> Returns "/usr/local"
432 * br_extract_prefix ("/usr/local/libfoo.so"); --> Returns "/usr"
433 */
434 char *
br_extract_prefix(const char * path)435 br_extract_prefix (const char *path)
436 {
437 char *end, *tmp, *result;
438
439 br_return_val_if_fail (path != (char *) NULL, (char *) NULL);
440
441 if (!*path) return strdup ("/");
442 end = strrchr (path, '/');
443 if (!end) return strdup (path);
444
445 tmp = br_strndup ((char *) path, end - path);
446 if (!*tmp)
447 {
448 free (tmp);
449 return strdup ("/");
450 }
451 end = strrchr (tmp, '/');
452 if (!end) return tmp;
453
454 result = br_strndup (tmp, end - tmp);
455 free (tmp);
456
457 if (!*result)
458 {
459 free (result);
460 result = strdup ("/");
461 }
462
463 return result;
464 }
465
466
467 /**
468 * br_set_fallback_function:
469 * func: A function to call to find the binary.
470 * data: User data to pass to func.
471 *
472 * Sets a function to call to find the path to the binary, in
473 * case "/proc/self/maps" can't be opened. The function set should
474 * return a string that is safe to free with free().
475 */
476 void
br_set_locate_fallback_func(br_locate_fallback_func func,void * data)477 br_set_locate_fallback_func (br_locate_fallback_func func, void *data)
478 {
479 fallback_func = func;
480 fallback_data = data;
481 }
482
483
484 #ifdef __cplusplus
485 }
486 #endif /* __cplusplus */
487
488 #endif /* _PREFIX_C */
489
