[deliverable/binutils-gdb.git] / libiberty / make-relative-prefix.c

/* Relative (relocatable) prefix support.
   Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 2000, 2001, 2002 Free Software Foundation, Inc.

This file is part of libiberty.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

/*

@deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, const char *@var{bin_prefix}, const char *@var{prefix})

Given three strings @var{progname}, @var{bin_prefix}, @var{prefix}, return a string
that gets to @var{prefix} starting with the directory portion of @var{progname} and
a relative pathname of the difference between @var{bin_prefix} and @var{prefix}.

For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta}, @var{prefix}
is @code{/alpha/beta/gamma/omega/}, and @var{progname} is @code{/red/green/blue/gcc},
then this function will return @code{/red/green/blue/../../omega/}.

The return value is normally allocated via @code{malloc}.  If no relative prefix
can be found, return @code{NULL}.

@end deftypefn

*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <string.h>

#include "ansidecl.h"
#include "libiberty.h"

#ifndef R_OK
#define R_OK 4
#define W_OK 2
#define X_OK 1
#endif

#ifndef DIR_SEPARATOR
#  define DIR_SEPARATOR '/'
#endif

#if defined (_WIN32) || defined (__MSDOS__) \
    || defined (__DJGPP__) || defined (__OS2__)
#  define HAVE_DOS_BASED_FILE_SYSTEM
#  define HAVE_HOST_EXECUTABLE_SUFFIX
#  define HOST_EXECUTABLE_SUFFIX ".exe"
#  ifndef DIR_SEPARATOR_2 
#    define DIR_SEPARATOR_2 '\\'
#  endif
#  define PATH_SEPARATOR ';'
#else
#  define PATH_SEPARATOR ':'
#endif

#ifndef DIR_SEPARATOR_2
#  define IS_DIR_SEPARATOR(ch) ((ch) == DIR_SEPARATOR)
#else
#  define IS_DIR_SEPARATOR(ch) \
	(((ch) == DIR_SEPARATOR) || ((ch) == DIR_SEPARATOR_2))
#endif

#define DIR_UP ".."

static char *save_string PARAMS ((const char *, int));
static char **split_directories	PARAMS ((const char *, int *));
static void free_split_directories PARAMS ((char **));

static char *
save_string (s, len)
     const char *s;
     int len;
{
  char *result = malloc (len + 1);

  memcpy (result, s, len);
  result[len] = 0;
  return result;
}

/* Split a filename into component directories.  */

static char **
split_directories (name, ptr_num_dirs)
     const char *name;
     int *ptr_num_dirs;
{
  int num_dirs = 0;
  char **dirs;
  const char *p, *q;
  int ch;

  /* Count the number of directories.  Special case MSDOS disk names as part
     of the initial directory.  */
  p = name;
#ifdef HAVE_DOS_BASED_FILE_SYSTEM
  if (name[1] == ':' && IS_DIR_SEPARATOR (name[2]))
    {
      p += 3;
      num_dirs++;
    }
#endif /* HAVE_DOS_BASED_FILE_SYSTEM */

  while ((ch = *p++) != '\0')
    {
      if (IS_DIR_SEPARATOR (ch))
	{
	  num_dirs++;
	  while (IS_DIR_SEPARATOR (*p))
	    p++;
	}
    }

  dirs = (char **) malloc (sizeof (char *) * (num_dirs + 2));
  if (dirs == NULL)
    return NULL;

  /* Now copy the directory parts.  */
  num_dirs = 0;
  p = name;
#ifdef HAVE_DOS_BASED_FILE_SYSTEM
  if (name[1] == ':' && IS_DIR_SEPARATOR (name[2]))
    {
      dirs[num_dirs++] = save_string (p, 3);
      if (dirs[num_dirs - 1] == NULL)
	{
	  free (dirs);
	  return NULL;
	}
      p += 3;
    }
#endif /* HAVE_DOS_BASED_FILE_SYSTEM */

  q = p;
  while ((ch = *p++) != '\0')
    {
      if (IS_DIR_SEPARATOR (ch))
	{
	  while (IS_DIR_SEPARATOR (*p))
	    p++;

	  dirs[num_dirs++] = save_string (q, p - q);
	  if (dirs[num_dirs - 1] == NULL)
	    {
	      dirs[num_dirs] = NULL;
	      free_split_directories (dirs);
	      return NULL;
	    }
	  q = p;
	}
    }

  if (p - 1 - q > 0)
    dirs[num_dirs++] = save_string (q, p - 1 - q);
  dirs[num_dirs] = NULL;

  if (dirs[num_dirs - 1] == NULL)
    {
      free_split_directories (dirs);
      return NULL;
    }

  if (ptr_num_dirs)
    *ptr_num_dirs = num_dirs;
  return dirs;
}

/* Release storage held by split directories.  */

static void
free_split_directories (dirs)
     char **dirs;
{
  int i = 0;

  while (dirs[i] != NULL)
    free (dirs[i++]);

  free ((char *) dirs);
}

/* Given three strings PROGNAME, BIN_PREFIX, PREFIX, return a string that gets
   to PREFIX starting with the directory portion of PROGNAME and a relative
   pathname of the difference between BIN_PREFIX and PREFIX.

   For example, if BIN_PREFIX is /alpha/beta/gamma/gcc/delta, PREFIX is
   /alpha/beta/gamma/omega/, and PROGNAME is /red/green/blue/gcc, then this
   function will return /red/green/blue/../../omega/.

   If no relative prefix can be found, return NULL.  */

char *
make_relative_prefix (progname, bin_prefix, prefix)
     const char *progname;
     const char *bin_prefix;
     const char *prefix;
{
  char **prog_dirs, **bin_dirs, **prefix_dirs;
  int prog_num, bin_num, prefix_num;
  int i, n, common;
  int needed_len;
  char *ret, *ptr;

  if (progname == NULL || bin_prefix == NULL || prefix == NULL)
    return NULL;

  prog_dirs = split_directories (progname, &prog_num);
  bin_dirs = split_directories (bin_prefix, &bin_num);
  if (bin_dirs == NULL || prog_dirs == NULL)
    return NULL;

  /* If there is no full pathname, try to find the program by checking in each
     of the directories specified in the PATH environment variable.  */
  if (prog_num == 1)
    {
      char *temp;

      temp = getenv ("PATH");
      if (temp)
	{
	  char *startp, *endp, *nstore;
	  size_t prefixlen = strlen (temp) + 1;
	  if (prefixlen < 2)
	    prefixlen = 2;

	  nstore = (char *) alloca (prefixlen + strlen (progname) + 1);

	  startp = endp = temp;
	  while (1)
	    {
	      if (*endp == PATH_SEPARATOR || *endp == 0)
		{
		  if (endp == startp)
		    {
		      nstore[0] = '.';
		      nstore[1] = DIR_SEPARATOR;
		      nstore[2] = '\0';
		    }
		  else
		    {
		      strncpy (nstore, startp, endp - startp);
		      if (! IS_DIR_SEPARATOR (endp[-1]))
			{
			  nstore[endp - startp] = DIR_SEPARATOR;
			  nstore[endp - startp + 1] = 0;
			}
		      else
			nstore[endp - startp] = 0;
		    }
		  strcat (nstore, progname);
		  if (! access (nstore, X_OK)
#ifdef HAVE_HOST_EXECUTABLE_SUFFIX
                      || ! access (strcat (nstore, HOST_EXECUTABLE_SUFFIX), X_OK)
#endif
		      )
		    {
		      free_split_directories (prog_dirs);
		      progname = nstore;
		      prog_dirs = split_directories (progname, &prog_num);
		      if (prog_dirs == NULL)
			{
			  free_split_directories (bin_dirs);
			  return NULL;
			}
		      break;
		    }

		  if (*endp == 0)
		    break;
		  endp = startp = endp + 1;
		}
	      else
		endp++;
	    }
	}
    }

  /* Remove the program name from comparison of directory names.  */
  prog_num--;

  /* If we are still installed in the standard location, we don't need to
     specify relative directories.  Also, if argv[0] still doesn't contain
     any directory specifiers after the search above, then there is not much
     we can do.  */
  if (prog_num == bin_num)
    {
      for (i = 0; i < bin_num; i++)
	{
	  if (strcmp (prog_dirs[i], bin_dirs[i]) != 0)
	    break;
	}

      if (prog_num <= 0 || i == bin_num)
	{
	  free_split_directories (prog_dirs);
	  free_split_directories (bin_dirs);
	  prog_dirs = bin_dirs = (char **) 0;
	  return NULL;
	}
    }

  prefix_dirs = split_directories (prefix, &prefix_num);
  if (prefix_dirs == NULL)
    {
      free_split_directories (prog_dirs);
      free_split_directories (bin_dirs);
      return NULL;
    }

  /* Find how many directories are in common between bin_prefix & prefix.  */
  n = (prefix_num < bin_num) ? prefix_num : bin_num;
  for (common = 0; common < n; common++)
    {
      if (strcmp (bin_dirs[common], prefix_dirs[common]) != 0)
	break;
    }

  /* If there are no common directories, there can be no relative prefix.  */
  if (common == 0)
    {
      free_split_directories (prog_dirs);
      free_split_directories (bin_dirs);
      free_split_directories (prefix_dirs);
      return NULL;
    }

  /* Two passes: first figure out the size of the result string, and
     then construct it.  */
  needed_len = 0;
  for (i = 0; i < prog_num; i++)
    needed_len += strlen (prog_dirs[i]);
  needed_len += sizeof (DIR_UP) * (bin_num - common);
  for (i = common; i < prefix_num; i++)
    needed_len += strlen (prefix_dirs[i]);
  needed_len += 1; /* Trailing NUL.  */

  ret = (char *) malloc (needed_len);
  if (ret == NULL)
    return NULL;

  /* Build up the pathnames in argv[0].  */
  *ret = '\0';
  for (i = 0; i < prog_num; i++)
    strcat (ret, prog_dirs[i]);

  /* Now build up the ..'s.  */
  ptr = ret + strlen(ret);
  for (i = common; i < bin_num; i++)
    {
      strcpy (ptr, DIR_UP);
      ptr += sizeof (DIR_UP) - 1;
      *(ptr++) = DIR_SEPARATOR;
    }
  *ptr = '\0';

  /* Put in directories to move over to prefix.  */
  for (i = common; i < prefix_num; i++)
    strcat (ret, prefix_dirs[i]);

  free_split_directories (prog_dirs);
  free_split_directories (bin_dirs);
  free_split_directories (prefix_dirs);

  return ret;
}
Commit	Line	Data
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
	26	Given three strings @var{progname}, @var{bin_prefix}, @var{prefix}, return a string
	27	that gets to @var{prefix} starting with the directory portion of @var{progname} and
	28	a relative pathname of the difference between @var{bin_prefix} and @var{prefix}.
	29
	30	For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta}, @var{prefix}
	31	is @code{/alpha/beta/gamma/omega/}, and @var{progname} is @code{/red/green/blue/gcc},
	32	then this function will return @code{/red/green/blue/../../omega/}.
	33
	34	The return value is normally allocated via @code{malloc}. If no relative prefix
	35	can be found, return @code{NULL}.
	36
	37	@end deftypefn
	38
	39	*/
	40
	41	#ifdef HAVE_CONFIG_H
	42	#include "config.h"
	43	#endif
	44
	45	#ifdef HAVE_STDLIB_H
	46	#include <stdlib.h>
	47	#endif
	48	#ifdef HAVE_UNISTD_H
	49	#include <unistd.h>
	50	#endif
	51
	52	#include <string.h>
	53
	54	#include "ansidecl.h"
	55	#include "libiberty.h"
	56
	57	#ifndef R_OK
	58	#define R_OK 4
	59	#define W_OK 2
	60	#define X_OK 1
	61	#endif
	62
	63	#ifndef DIR_SEPARATOR
	64	# define DIR_SEPARATOR '/'
65	#endif
66
67	#if defined (_WIN32) \|\| defined (__MSDOS__) \
68	\|\| defined (__DJGPP__) \|\| defined (__OS2__)
69	# define HAVE_DOS_BASED_FILE_SYSTEM
b51c1553	70	# define HAVE_HOST_EXECUTABLE_SUFFIX
2a80c0a4 DD	71	# define HOST_EXECUTABLE_SUFFIX ".exe"
	72	# ifndef DIR_SEPARATOR_2
	73	# define DIR_SEPARATOR_2 '\\'
	74	# endif
	75	# define PATH_SEPARATOR ';'
	76	#else
	77	# define PATH_SEPARATOR ':'
	78	#endif
	79
	80	#ifndef DIR_SEPARATOR_2
	81	# define IS_DIR_SEPARATOR(ch) ((ch) == DIR_SEPARATOR)
	82	#else
	83	# define IS_DIR_SEPARATOR(ch) \
	84	(((ch) == DIR_SEPARATOR) \|\| ((ch) == DIR_SEPARATOR_2))
	85	#endif
	86
	87	#define DIR_UP ".."
	88
	89	static char save_string PARAMS ((const char , int));
	90	static char *split_directories PARAMS ((const char , int *));
	91	static void free_split_directories PARAMS ((char **));
	92
	93	static char *
	94	save_string (s, len)
	95	const char *s;
	96	int len;
	97	{
	98	char *result = malloc (len + 1);
	99
	100	memcpy (result, s, len);
	101	result[len] = 0;
	102	return result;
	103	}
	104
	105	/* Split a filename into component directories. */
	106
	107	static char **
	108	split_directories (name, ptr_num_dirs)
	109	const char *name;
	110	int *ptr_num_dirs;
	111	{
	112	int num_dirs = 0;
	113	char **dirs;
	114	const char p, q;
	115	int ch;
	116
	117	/* Count the number of directories. Special case MSDOS disk names as part
	118	of the initial directory. */
	119	p = name;
	120	#ifdef HAVE_DOS_BASED_FILE_SYSTEM
	121	if (name[1] == ':' && IS_DIR_SEPARATOR (name[2]))
	122	{
	123	p += 3;
	124	num_dirs++;
	125	}
	126	#endif /* HAVE_DOS_BASED_FILE_SYSTEM */
	127
	128	while ((ch = *p++) != '\0')
	129	{
	130	if (IS_DIR_SEPARATOR (ch))
	131	{
	132	num_dirs++;
	133	while (IS_DIR_SEPARATOR (*p))
	134	p++;
135	}
136	}
137
138	dirs = (char *) malloc (sizeof (char ) * (num_dirs + 2));
139	if (dirs == NULL)
140	return NULL;
141
142	/* Now copy the directory parts. */
143	num_dirs = 0;
144	p = name;
145	#ifdef HAVE_DOS_BASED_FILE_SYSTEM
146	if (name[1] == ':' && IS_DIR_SEPARATOR (name[2]))
147	{
148	dirs[num_dirs++] = save_string (p, 3);
149	if (dirs[num_dirs - 1] == NULL)
150	{
151	free (dirs);
152	return NULL;
153	}
154	p += 3;
155	}
156	#endif /* HAVE_DOS_BASED_FILE_SYSTEM */
157
158	q = p;
159	while ((ch = *p++) != '\0')
160	{
161	if (IS_DIR_SEPARATOR (ch))
162	{
163	while (IS_DIR_SEPARATOR (*p))
164	p++;
165
166	dirs[num_dirs++] = save_string (q, p - q);
167	if (dirs[num_dirs - 1] == NULL)
168	{
169	dirs[num_dirs] = NULL;
170	free_split_directories (dirs);
171	return NULL;
172	}
173	q = p;
174	}
175	}
176
177	if (p - 1 - q > 0)
178	dirs[num_dirs++] = save_string (q, p - 1 - q);
179	dirs[num_dirs] = NULL;
180
181	if (dirs[num_dirs - 1] == NULL)
182	{
183	free_split_directories (dirs);
184	return NULL;
185	}
186
187	if (ptr_num_dirs)
188	*ptr_num_dirs = num_dirs;
189	return dirs;
190	}
191
192	/* Release storage held by split directories. */
193
194	static void
195	free_split_directories (dirs)
196	char **dirs;
197	{
198	int i = 0;
199
200	while (dirs[i] != NULL)
201	free (dirs[i++]);
202
203	free ((char *) dirs);
204	}
205
206	/* Given three strings PROGNAME, BIN_PREFIX, PREFIX, return a string that gets
207	to PREFIX starting with the directory portion of PROGNAME and a relative
208	pathname of the difference between BIN_PREFIX and PREFIX.
209
210	For example, if BIN_PREFIX is /alpha/beta/gamma/gcc/delta, PREFIX is
211	/alpha/beta/gamma/omega/, and PROGNAME is /red/green/blue/gcc, then this
212	function will return /red/green/blue/../../omega/.
213
214	If no relative prefix can be found, return NULL. */
215
216	char *
217	make_relative_prefix (progname, bin_prefix, prefix)
218	const char *progname;
219	const char *bin_prefix;
220	const char *prefix;
221	{
222	char prog_dirs, bin_dirs, **prefix_dirs;
223	int prog_num, bin_num, prefix_num;
224	int i, n, common;
225	int needed_len;
226	char ret, ptr;
227
228	if (progname == NULL \|\| bin_prefix == NULL \|\| prefix == NULL)
229	return NULL;
230
231	prog_dirs = split_directories (progname, &prog_num);
232	bin_dirs = split_directories (bin_prefix, &bin_num);
233	if (bin_dirs == NULL \|\| prog_dirs == NULL)
234	return NULL;
235
236	/* If there is no full pathname, try to find the program by checking in each
237	of the directories specified in the PATH environment variable. */
238	if (prog_num == 1)
239	{
240	char *temp;
241
242	temp = getenv ("PATH");
243	if (temp)
244	{
245	char startp, endp, *nstore;
246	size_t prefixlen = strlen (temp) + 1;
247	if (prefixlen < 2)
248	prefixlen = 2;
249
250	nstore = (char *) alloca (prefixlen + strlen (progname) + 1);
251
252	startp = endp = temp;
253	while (1)
254	{
255	if (endp == PATH_SEPARATOR \|\| endp == 0)
256	{
257	if (endp == startp)
258	{
259	nstore[0] = '.';
260	nstore[1] = DIR_SEPARATOR;
261	nstore[2] = '\0';
262	}
263	else
264	{
265	strncpy (nstore, startp, endp - startp);
266	if (! IS_DIR_SEPARATOR (endp[-1]))
267	{
268	nstore[endp - startp] = DIR_SEPARATOR;
269	nstore[endp - startp + 1] = 0;
270	}
271	else
272	nstore[endp - startp] = 0;
273	}
274	strcat (nstore, progname);
275	if (! access (nstore, X_OK)
276	#ifdef HAVE_HOST_EXECUTABLE_SUFFIX
277	\|\| ! access (strcat (nstore, HOST_EXECUTABLE_SUFFIX), X_OK)
278	#endif
279	)
280	{
281	free_split_directories (prog_dirs);
282	progname = nstore;
283	prog_dirs = split_directories (progname, &prog_num);
284	if (prog_dirs == NULL)
285	{
286	free_split_directories (bin_dirs);
287	return NULL;
288	}
289	break;
290	}
291
292	if (*endp == 0)
293	break;
294	endp = startp = endp + 1;
295	}
296	else
297	endp++;
298	}
299	}
300	}
301
302	/* Remove the program name from comparison of directory names. */
303	prog_num--;
304
305	/* If we are still installed in the standard location, we don't need to
306	specify relative directories. Also, if argv[0] still doesn't contain
307	any directory specifiers after the search above, then there is not much
308	we can do. */
309	if (prog_num == bin_num)
310	{
311	for (i = 0; i < bin_num; i++)
312	{
313	if (strcmp (prog_dirs[i], bin_dirs[i]) != 0)
314	break;
315	}
316
317	if (prog_num <= 0 \|\| i == bin_num)
318	{
319	free_split_directories (prog_dirs);
320	free_split_directories (bin_dirs);
321	prog_dirs = bin_dirs = (char **) 0;
322	return NULL;
323	}
324	}
325
326	prefix_dirs = split_directories (prefix, &prefix_num);
327	if (prefix_dirs == NULL)
328	{
329	free_split_directories (prog_dirs);
330	free_split_directories (bin_dirs);
331	return NULL;
332	}
333
334	/* Find how many directories are in common between bin_prefix & prefix. */
335	n = (prefix_num < bin_num) ? prefix_num : bin_num;
336	for (common = 0; common < n; common++)
337	{
338	if (strcmp (bin_dirs[common], prefix_dirs[common]) != 0)
339	break;
340	}
341
342	/* If there are no common directories, there can be no relative prefix. */
343	if (common == 0)
344	{
345	free_split_directories (prog_dirs);
346	free_split_directories (bin_dirs);
347	free_split_directories (prefix_dirs);
348	return NULL;
349	}
350
351	/* Two passes: first figure out the size of the result string, and
352	then construct it. */
353	needed_len = 0;
354	for (i = 0; i < prog_num; i++)
355	needed_len += strlen (prog_dirs[i]);
356	needed_len += sizeof (DIR_UP) * (bin_num - common);
357	for (i = common; i < prefix_num; i++)
358	needed_len += strlen (prefix_dirs[i]);
359	needed_len += 1; /* Trailing NUL. */
360
361	ret = (char *) malloc (needed_len);
362	if (ret == NULL)
363	return NULL;
364
365	/* Build up the pathnames in argv[0]. */
756954c3	366	*ret = '\0';
2a80c0a4 DD	367	for (i = 0; i < prog_num; i++)
	368	strcat (ret, prog_dirs[i]);
	369
	370	/* Now build up the ..'s. */
	371	ptr = ret + strlen(ret);
	372	for (i = common; i < bin_num; i++)
	373	{
	374	strcpy (ptr, DIR_UP);
	375	ptr += sizeof (DIR_UP) - 1;
	376	*(ptr++) = DIR_SEPARATOR;
	377	}
	378	*ptr = '\0';
	379
	380	/* Put in directories to move over to prefix. */
	381	for (i = common; i < prefix_num; i++)
	382	strcat (ret, prefix_dirs[i]);
	383
	384	free_split_directories (prog_dirs);
	385	free_split_directories (bin_dirs);
	386	free_split_directories (prefix_dirs);
	387
	388	return ret;
	389	}