1 /* Relative (relocatable) prefix support.
2 Copyright (C) 1987-2018 Free Software Foundation, Inc.
4 This file is part of libiberty.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 2, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
23 @deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, @
24 const char *@var{bin_prefix}, const char *@var{prefix})
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}.
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.
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/}.
43 The return value is normally allocated via @code{malloc}. If no
44 relative prefix can be found, return @code{NULL}.
60 #ifdef HAVE_SYS_STAT_H
67 #include "libiberty.h"
76 # define DIR_SEPARATOR '/'
79 #if defined (_WIN32) || defined (__MSDOS__) \
80 || defined (__DJGPP__) || defined (__OS2__)
81 # define HAVE_DOS_BASED_FILE_SYSTEM
82 # define HAVE_HOST_EXECUTABLE_SUFFIX
83 # define HOST_EXECUTABLE_SUFFIX ".exe"
84 # ifndef DIR_SEPARATOR_2
85 # define DIR_SEPARATOR_2 '\\'
87 # define PATH_SEPARATOR ';'
89 # define PATH_SEPARATOR ':'
92 #ifndef DIR_SEPARATOR_2
93 # define IS_DIR_SEPARATOR(ch) ((ch) == DIR_SEPARATOR)
95 # define IS_DIR_SEPARATOR(ch) \
96 (((ch) == DIR_SEPARATOR) || ((ch) == DIR_SEPARATOR_2))
101 static char *save_string (const char *, int);
102 static char **split_directories (const char *, int *);
103 static void free_split_directories (char **);
106 save_string (const char *s
, int len
)
108 char *result
= (char *) malloc (len
+ 1);
110 memcpy (result
, s
, len
);
115 /* Split a filename into component directories. */
118 split_directories (const char *name
, int *ptr_num_dirs
)
125 /* Count the number of directories. Special case MSDOS disk names as part
126 of the initial directory. */
128 #ifdef HAVE_DOS_BASED_FILE_SYSTEM
129 if (name
[1] == ':' && IS_DIR_SEPARATOR (name
[2]))
134 #endif /* HAVE_DOS_BASED_FILE_SYSTEM */
136 while ((ch
= *p
++) != '\0')
138 if (IS_DIR_SEPARATOR (ch
))
141 while (IS_DIR_SEPARATOR (*p
))
146 dirs
= (char **) malloc (sizeof (char *) * (num_dirs
+ 2));
150 /* Now copy the directory parts. */
153 #ifdef HAVE_DOS_BASED_FILE_SYSTEM
154 if (name
[1] == ':' && IS_DIR_SEPARATOR (name
[2]))
156 dirs
[num_dirs
++] = save_string (p
, 3);
157 if (dirs
[num_dirs
- 1] == NULL
)
164 #endif /* HAVE_DOS_BASED_FILE_SYSTEM */
167 while ((ch
= *p
++) != '\0')
169 if (IS_DIR_SEPARATOR (ch
))
171 while (IS_DIR_SEPARATOR (*p
))
174 dirs
[num_dirs
++] = save_string (q
, p
- q
);
175 if (dirs
[num_dirs
- 1] == NULL
)
177 dirs
[num_dirs
] = NULL
;
178 free_split_directories (dirs
);
186 dirs
[num_dirs
++] = save_string (q
, p
- 1 - q
);
187 dirs
[num_dirs
] = NULL
;
189 if (dirs
[num_dirs
- 1] == NULL
)
191 free_split_directories (dirs
);
196 *ptr_num_dirs
= num_dirs
;
200 /* Release storage held by split directories. */
203 free_split_directories (char **dirs
)
209 while (dirs
[i
] != NULL
)
212 free ((char *) dirs
);
216 /* Given three strings PROGNAME, BIN_PREFIX, PREFIX, return a string that gets
217 to PREFIX starting with the directory portion of PROGNAME and a relative
218 pathname of the difference between BIN_PREFIX and PREFIX.
220 For example, if BIN_PREFIX is /alpha/beta/gamma/gcc/delta, PREFIX is
221 /alpha/beta/gamma/omega/, and PROGNAME is /red/green/blue/gcc, then this
222 function will return /red/green/blue/../../omega/.
224 If no relative prefix can be found, return NULL. */
227 make_relative_prefix_1 (const char *progname
, const char *bin_prefix
,
228 const char *prefix
, const int resolve_links
)
230 char **prog_dirs
= NULL
, **bin_dirs
= NULL
, **prefix_dirs
= NULL
;
231 int prog_num
, bin_num
, prefix_num
;
234 char *ret
= NULL
, *ptr
, *full_progname
;
235 char *alloc_ptr
= NULL
;
237 if (progname
== NULL
|| bin_prefix
== NULL
|| prefix
== NULL
)
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. */
242 if (lbasename (progname
) == progname
)
246 temp
= getenv ("PATH");
249 char *startp
, *endp
, *nstore
;
250 size_t prefixlen
= strlen (temp
) + 1;
255 len
= prefixlen
+ strlen (progname
) + 1;
256 #ifdef HAVE_HOST_EXECUTABLE_SUFFIX
257 len
+= strlen (HOST_EXECUTABLE_SUFFIX
);
259 if (len
< MAX_ALLOCA_SIZE
)
260 nstore
= (char *) alloca (len
);
262 alloc_ptr
= nstore
= (char *) malloc (len
);
264 startp
= endp
= temp
;
267 if (*endp
== PATH_SEPARATOR
|| *endp
== 0)
272 nstore
[1] = DIR_SEPARATOR
;
277 memcpy (nstore
, startp
, endp
- startp
);
278 if (! IS_DIR_SEPARATOR (endp
[-1]))
280 nstore
[endp
- startp
] = DIR_SEPARATOR
;
281 nstore
[endp
- startp
+ 1] = 0;
284 nstore
[endp
- startp
] = 0;
286 strcat (nstore
, progname
);
287 if (! access (nstore
, X_OK
)
288 #ifdef HAVE_HOST_EXECUTABLE_SUFFIX
289 || ! access (strcat (nstore
, HOST_EXECUTABLE_SUFFIX
), X_OK
)
293 #if defined (HAVE_SYS_STAT_H) && defined (S_ISREG)
295 if (stat (nstore
, &st
) >= 0 && S_ISREG (st
.st_mode
))
305 endp
= startp
= endp
+ 1;
314 full_progname
= lrealpath (progname
);
316 full_progname
= strdup (progname
);
317 if (full_progname
== NULL
)
320 prog_dirs
= split_directories (full_progname
, &prog_num
);
321 free (full_progname
);
322 if (prog_dirs
== NULL
)
325 bin_dirs
= split_directories (bin_prefix
, &bin_num
);
326 if (bin_dirs
== NULL
)
329 /* Remove the program name from comparison of directory names. */
332 /* If we are still installed in the standard location, we don't need to
333 specify relative directories. Also, if argv[0] still doesn't contain
334 any directory specifiers after the search above, then there is not much
336 if (prog_num
== bin_num
)
338 for (i
= 0; i
< bin_num
; i
++)
340 if (strcmp (prog_dirs
[i
], bin_dirs
[i
]) != 0)
344 if (prog_num
<= 0 || i
== bin_num
)
348 prefix_dirs
= split_directories (prefix
, &prefix_num
);
349 if (prefix_dirs
== NULL
)
352 /* Find how many directories are in common between bin_prefix & prefix. */
353 n
= (prefix_num
< bin_num
) ? prefix_num
: bin_num
;
354 for (common
= 0; common
< n
; common
++)
356 if (strcmp (bin_dirs
[common
], prefix_dirs
[common
]) != 0)
360 /* If there are no common directories, there can be no relative prefix. */
364 /* Two passes: first figure out the size of the result string, and
365 then construct it. */
367 for (i
= 0; i
< prog_num
; i
++)
368 needed_len
+= strlen (prog_dirs
[i
]);
369 needed_len
+= sizeof (DIR_UP
) * (bin_num
- common
);
370 for (i
= common
; i
< prefix_num
; i
++)
371 needed_len
+= strlen (prefix_dirs
[i
]);
372 needed_len
+= 1; /* Trailing NUL. */
374 ret
= (char *) malloc (needed_len
);
378 /* Build up the pathnames in argv[0]. */
380 for (i
= 0; i
< prog_num
; i
++)
381 strcat (ret
, prog_dirs
[i
]);
383 /* Now build up the ..'s. */
384 ptr
= ret
+ strlen(ret
);
385 for (i
= common
; i
< bin_num
; i
++)
387 strcpy (ptr
, DIR_UP
);
388 ptr
+= sizeof (DIR_UP
) - 1;
389 *(ptr
++) = DIR_SEPARATOR
;
393 /* Put in directories to move over to prefix. */
394 for (i
= common
; i
< prefix_num
; i
++)
395 strcat (ret
, prefix_dirs
[i
]);
398 free_split_directories (prog_dirs
);
399 free_split_directories (bin_dirs
);
400 free_split_directories (prefix_dirs
);
407 /* Do the full job, including symlink resolution.
408 This path will find files installed in the same place as the
409 program even when a soft link has been made to the program
410 from somwhere else. */
413 make_relative_prefix (const char *progname
, const char *bin_prefix
,
416 return make_relative_prefix_1 (progname
, bin_prefix
, prefix
, 1);
419 /* Make the relative pathname without attempting to resolve any links.
420 '..' etc may also be left in the pathname.
421 This will find the files the user meant the program to find if the
422 installation is patched together with soft links. */
425 make_relative_prefix_ignore_links (const char *progname
,
426 const char *bin_prefix
,
429 return make_relative_prefix_1 (progname
, bin_prefix
, prefix
, 0);
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