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2a80c0a4 DD |
1 | /* Relative (relocatable) prefix support. |
2 | Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
3 | 1999, 2000, 2001, 2002 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of libiberty. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
22 | /* | |
23 | ||
24 | @deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, const char *@var{bin_prefix}, const char *@var{prefix}) | |
25 | ||
ba61a412 DJ |
26 | Given three paths @var{progname}, @var{bin_prefix}, @var{prefix}, |
27 | return the path that is in the same position relative to | |
28 | @var{progname}'s directory as @var{prefix} is relative to | |
29 | @var{bin_prefix}. That is, a string starting with the directory | |
30 | portion of @var{progname}, followed by a relative pathname of the | |
31 | difference between @var{bin_prefix} and @var{prefix}. | |
32 | ||
33 | If @var{progname} does not contain any directory separators, | |
34 | @code{make_relative_prefix} will search @env{PATH} to find a program | |
35 | named @var{progname}. Also, if @var{progname} is a symbolic link, | |
36 | the symbolic link will be resolved. | |
37 | ||
38 | For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta}, | |
39 | @var{prefix} is @code{/alpha/beta/gamma/omega/}, and @var{progname} is | |
40 | @code{/red/green/blue/gcc}, then this function will return | |
41 | @code{/red/green/blue/../../omega/}. | |
42 | ||
43 | The return value is normally allocated via @code{malloc}. If no | |
44 | relative prefix can be found, return @code{NULL}. | |
2a80c0a4 DD |
45 | |
46 | @end deftypefn | |
47 | ||
48 | */ | |
49 | ||
50 | #ifdef HAVE_CONFIG_H | |
51 | #include "config.h" | |
52 | #endif | |
53 | ||
54 | #ifdef HAVE_STDLIB_H | |
55 | #include <stdlib.h> | |
56 | #endif | |
57 | #ifdef HAVE_UNISTD_H | |
58 | #include <unistd.h> | |
59 | #endif | |
60 | ||
61 | #include <string.h> | |
62 | ||
63 | #include "ansidecl.h" | |
64 | #include "libiberty.h" | |
65 | ||
66 | #ifndef R_OK | |
67 | #define R_OK 4 | |
68 | #define W_OK 2 | |
69 | #define X_OK 1 | |
70 | #endif | |
71 | ||
72 | #ifndef DIR_SEPARATOR | |
73 | # define DIR_SEPARATOR '/' | |
74 | #endif | |
75 | ||
76 | #if defined (_WIN32) || defined (__MSDOS__) \ | |
77 | || defined (__DJGPP__) || defined (__OS2__) | |
78 | # define HAVE_DOS_BASED_FILE_SYSTEM | |
b51c1553 | 79 | # define HAVE_HOST_EXECUTABLE_SUFFIX |
2a80c0a4 DD |
80 | # define HOST_EXECUTABLE_SUFFIX ".exe" |
81 | # ifndef DIR_SEPARATOR_2 | |
82 | # define DIR_SEPARATOR_2 '\\' | |
83 | # endif | |
84 | # define PATH_SEPARATOR ';' | |
85 | #else | |
86 | # define PATH_SEPARATOR ':' | |
87 | #endif | |
88 | ||
89 | #ifndef DIR_SEPARATOR_2 | |
90 | # define IS_DIR_SEPARATOR(ch) ((ch) == DIR_SEPARATOR) | |
91 | #else | |
92 | # define IS_DIR_SEPARATOR(ch) \ | |
93 | (((ch) == DIR_SEPARATOR) || ((ch) == DIR_SEPARATOR_2)) | |
94 | #endif | |
95 | ||
96 | #define DIR_UP ".." | |
97 | ||
98 | static char *save_string PARAMS ((const char *, int)); | |
99 | static char **split_directories PARAMS ((const char *, int *)); | |
100 | static void free_split_directories PARAMS ((char **)); | |
101 | ||
102 | static char * | |
103 | save_string (s, len) | |
104 | const char *s; | |
105 | int len; | |
106 | { | |
107 | char *result = malloc (len + 1); | |
108 | ||
109 | memcpy (result, s, len); | |
110 | result[len] = 0; | |
111 | return result; | |
112 | } | |
113 | ||
114 | /* Split a filename into component directories. */ | |
115 | ||
116 | static char ** | |
117 | split_directories (name, ptr_num_dirs) | |
118 | const char *name; | |
119 | int *ptr_num_dirs; | |
120 | { | |
121 | int num_dirs = 0; | |
122 | char **dirs; | |
123 | const char *p, *q; | |
124 | int ch; | |
125 | ||
126 | /* Count the number of directories. Special case MSDOS disk names as part | |
127 | of the initial directory. */ | |
128 | p = name; | |
129 | #ifdef HAVE_DOS_BASED_FILE_SYSTEM | |
130 | if (name[1] == ':' && IS_DIR_SEPARATOR (name[2])) | |
131 | { | |
132 | p += 3; | |
133 | num_dirs++; | |
134 | } | |
135 | #endif /* HAVE_DOS_BASED_FILE_SYSTEM */ | |
136 | ||
137 | while ((ch = *p++) != '\0') | |
138 | { | |
139 | if (IS_DIR_SEPARATOR (ch)) | |
140 | { | |
141 | num_dirs++; | |
142 | while (IS_DIR_SEPARATOR (*p)) | |
143 | p++; | |
144 | } | |
145 | } | |
146 | ||
147 | dirs = (char **) malloc (sizeof (char *) * (num_dirs + 2)); | |
148 | if (dirs == NULL) | |
149 | return NULL; | |
150 | ||
151 | /* Now copy the directory parts. */ | |
152 | num_dirs = 0; | |
153 | p = name; | |
154 | #ifdef HAVE_DOS_BASED_FILE_SYSTEM | |
155 | if (name[1] == ':' && IS_DIR_SEPARATOR (name[2])) | |
156 | { | |
157 | dirs[num_dirs++] = save_string (p, 3); | |
158 | if (dirs[num_dirs - 1] == NULL) | |
159 | { | |
160 | free (dirs); | |
161 | return NULL; | |
162 | } | |
163 | p += 3; | |
164 | } | |
165 | #endif /* HAVE_DOS_BASED_FILE_SYSTEM */ | |
166 | ||
167 | q = p; | |
168 | while ((ch = *p++) != '\0') | |
169 | { | |
170 | if (IS_DIR_SEPARATOR (ch)) | |
171 | { | |
172 | while (IS_DIR_SEPARATOR (*p)) | |
173 | p++; | |
174 | ||
175 | dirs[num_dirs++] = save_string (q, p - q); | |
176 | if (dirs[num_dirs - 1] == NULL) | |
177 | { | |
178 | dirs[num_dirs] = NULL; | |
179 | free_split_directories (dirs); | |
180 | return NULL; | |
181 | } | |
182 | q = p; | |
183 | } | |
184 | } | |
185 | ||
186 | if (p - 1 - q > 0) | |
187 | dirs[num_dirs++] = save_string (q, p - 1 - q); | |
188 | dirs[num_dirs] = NULL; | |
189 | ||
190 | if (dirs[num_dirs - 1] == NULL) | |
191 | { | |
192 | free_split_directories (dirs); | |
193 | return NULL; | |
194 | } | |
195 | ||
196 | if (ptr_num_dirs) | |
197 | *ptr_num_dirs = num_dirs; | |
198 | return dirs; | |
199 | } | |
200 | ||
201 | /* Release storage held by split directories. */ | |
202 | ||
203 | static void | |
204 | free_split_directories (dirs) | |
205 | char **dirs; | |
206 | { | |
207 | int i = 0; | |
208 | ||
209 | while (dirs[i] != NULL) | |
210 | free (dirs[i++]); | |
211 | ||
212 | free ((char *) dirs); | |
213 | } | |
214 | ||
215 | /* Given three strings PROGNAME, BIN_PREFIX, PREFIX, return a string that gets | |
216 | to PREFIX starting with the directory portion of PROGNAME and a relative | |
217 | pathname of the difference between BIN_PREFIX and PREFIX. | |
218 | ||
219 | For example, if BIN_PREFIX is /alpha/beta/gamma/gcc/delta, PREFIX is | |
220 | /alpha/beta/gamma/omega/, and PROGNAME is /red/green/blue/gcc, then this | |
221 | function will return /red/green/blue/../../omega/. | |
222 | ||
223 | If no relative prefix can be found, return NULL. */ | |
224 | ||
225 | char * | |
226 | make_relative_prefix (progname, bin_prefix, prefix) | |
227 | const char *progname; | |
228 | const char *bin_prefix; | |
229 | const char *prefix; | |
230 | { | |
231 | char **prog_dirs, **bin_dirs, **prefix_dirs; | |
232 | int prog_num, bin_num, prefix_num; | |
233 | int i, n, common; | |
234 | int needed_len; | |
ba61a412 | 235 | char *ret, *ptr, *full_progname = NULL; |
2a80c0a4 DD |
236 | |
237 | if (progname == NULL || bin_prefix == NULL || prefix == NULL) | |
238 | return NULL; | |
239 | ||
2a80c0a4 DD |
240 | /* If there is no full pathname, try to find the program by checking in each |
241 | of the directories specified in the PATH environment variable. */ | |
ba61a412 | 242 | if (lbasename (progname) == progname) |
2a80c0a4 DD |
243 | { |
244 | char *temp; | |
245 | ||
246 | temp = getenv ("PATH"); | |
247 | if (temp) | |
248 | { | |
249 | char *startp, *endp, *nstore; | |
250 | size_t prefixlen = strlen (temp) + 1; | |
251 | if (prefixlen < 2) | |
252 | prefixlen = 2; | |
253 | ||
254 | nstore = (char *) alloca (prefixlen + strlen (progname) + 1); | |
255 | ||
256 | startp = endp = temp; | |
257 | while (1) | |
258 | { | |
259 | if (*endp == PATH_SEPARATOR || *endp == 0) | |
260 | { | |
261 | if (endp == startp) | |
262 | { | |
263 | nstore[0] = '.'; | |
264 | nstore[1] = DIR_SEPARATOR; | |
265 | nstore[2] = '\0'; | |
266 | } | |
267 | else | |
268 | { | |
269 | strncpy (nstore, startp, endp - startp); | |
270 | if (! IS_DIR_SEPARATOR (endp[-1])) | |
271 | { | |
272 | nstore[endp - startp] = DIR_SEPARATOR; | |
273 | nstore[endp - startp + 1] = 0; | |
274 | } | |
275 | else | |
276 | nstore[endp - startp] = 0; | |
277 | } | |
278 | strcat (nstore, progname); | |
279 | if (! access (nstore, X_OK) | |
280 | #ifdef HAVE_HOST_EXECUTABLE_SUFFIX | |
281 | || ! access (strcat (nstore, HOST_EXECUTABLE_SUFFIX), X_OK) | |
282 | #endif | |
283 | ) | |
284 | { | |
2a80c0a4 | 285 | progname = nstore; |
2a80c0a4 DD |
286 | break; |
287 | } | |
288 | ||
289 | if (*endp == 0) | |
290 | break; | |
291 | endp = startp = endp + 1; | |
292 | } | |
293 | else | |
294 | endp++; | |
295 | } | |
296 | } | |
297 | } | |
298 | ||
ba61a412 DJ |
299 | full_progname = lrealpath (progname); |
300 | if (full_progname == NULL) | |
301 | return NULL; | |
302 | ||
303 | prog_dirs = split_directories (full_progname, &prog_num); | |
304 | bin_dirs = split_directories (bin_prefix, &bin_num); | |
305 | free (full_progname); | |
306 | if (bin_dirs == NULL || prog_dirs == NULL) | |
307 | return NULL; | |
308 | ||
2a80c0a4 DD |
309 | /* Remove the program name from comparison of directory names. */ |
310 | prog_num--; | |
311 | ||
312 | /* If we are still installed in the standard location, we don't need to | |
313 | specify relative directories. Also, if argv[0] still doesn't contain | |
314 | any directory specifiers after the search above, then there is not much | |
315 | we can do. */ | |
316 | if (prog_num == bin_num) | |
317 | { | |
318 | for (i = 0; i < bin_num; i++) | |
319 | { | |
320 | if (strcmp (prog_dirs[i], bin_dirs[i]) != 0) | |
321 | break; | |
322 | } | |
323 | ||
324 | if (prog_num <= 0 || i == bin_num) | |
325 | { | |
326 | free_split_directories (prog_dirs); | |
327 | free_split_directories (bin_dirs); | |
328 | prog_dirs = bin_dirs = (char **) 0; | |
329 | return NULL; | |
330 | } | |
331 | } | |
332 | ||
333 | prefix_dirs = split_directories (prefix, &prefix_num); | |
334 | if (prefix_dirs == NULL) | |
335 | { | |
336 | free_split_directories (prog_dirs); | |
337 | free_split_directories (bin_dirs); | |
338 | return NULL; | |
339 | } | |
340 | ||
341 | /* Find how many directories are in common between bin_prefix & prefix. */ | |
342 | n = (prefix_num < bin_num) ? prefix_num : bin_num; | |
343 | for (common = 0; common < n; common++) | |
344 | { | |
345 | if (strcmp (bin_dirs[common], prefix_dirs[common]) != 0) | |
346 | break; | |
347 | } | |
348 | ||
349 | /* If there are no common directories, there can be no relative prefix. */ | |
350 | if (common == 0) | |
351 | { | |
352 | free_split_directories (prog_dirs); | |
353 | free_split_directories (bin_dirs); | |
354 | free_split_directories (prefix_dirs); | |
355 | return NULL; | |
356 | } | |
357 | ||
358 | /* Two passes: first figure out the size of the result string, and | |
359 | then construct it. */ | |
360 | needed_len = 0; | |
361 | for (i = 0; i < prog_num; i++) | |
362 | needed_len += strlen (prog_dirs[i]); | |
363 | needed_len += sizeof (DIR_UP) * (bin_num - common); | |
364 | for (i = common; i < prefix_num; i++) | |
365 | needed_len += strlen (prefix_dirs[i]); | |
366 | needed_len += 1; /* Trailing NUL. */ | |
367 | ||
368 | ret = (char *) malloc (needed_len); | |
369 | if (ret == NULL) | |
370 | return NULL; | |
371 | ||
372 | /* Build up the pathnames in argv[0]. */ | |
756954c3 | 373 | *ret = '\0'; |
2a80c0a4 DD |
374 | for (i = 0; i < prog_num; i++) |
375 | strcat (ret, prog_dirs[i]); | |
376 | ||
377 | /* Now build up the ..'s. */ | |
378 | ptr = ret + strlen(ret); | |
379 | for (i = common; i < bin_num; i++) | |
380 | { | |
381 | strcpy (ptr, DIR_UP); | |
382 | ptr += sizeof (DIR_UP) - 1; | |
383 | *(ptr++) = DIR_SEPARATOR; | |
384 | } | |
385 | *ptr = '\0'; | |
386 | ||
387 | /* Put in directories to move over to prefix. */ | |
388 | for (i = common; i < prefix_num; i++) | |
389 | strcat (ret, prefix_dirs[i]); | |
390 | ||
391 | free_split_directories (prog_dirs); | |
392 | free_split_directories (bin_dirs); | |
393 | free_split_directories (prefix_dirs); | |
394 | ||
395 | return ret; | |
396 | } |