Delete gdb::unique_ptr/gdb::move
[deliverable/binutils-gdb.git] / gdb / gnulib / import / canonicalize-lgpl.c
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98399780 1/* Return the canonical absolute name of a given file.
49e4877c 2 Copyright (C) 1996-2016 Free Software Foundation, Inc.
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3 This file is part of the GNU C Library.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17
18#ifndef _LIBC
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19/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc
20 optimizes away the name == NULL test below. */
21# define _GL_ARG_NONNULL(params)
22
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23# define _GL_USE_STDLIB_ALLOC 1
24# include <config.h>
25#endif
26
27#if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC
28
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29/* Specification. */
30#include <stdlib.h>
31
32#include <alloca.h>
33#include <string.h>
34#include <unistd.h>
35#include <limits.h>
36#if HAVE_SYS_PARAM_H || defined _LIBC
37# include <sys/param.h>
38#endif
39#include <sys/stat.h>
40#include <errno.h>
41#include <stddef.h>
42
43#ifdef _LIBC
44# include <shlib-compat.h>
45#else
46# define SHLIB_COMPAT(lib, introduced, obsoleted) 0
47# define versioned_symbol(lib, local, symbol, version) extern int dummy
48# define compat_symbol(lib, local, symbol, version)
49# define weak_alias(local, symbol)
50# define __canonicalize_file_name canonicalize_file_name
51# define __realpath realpath
52# include "pathmax.h"
53# include "malloca.h"
54# include "dosname.h"
55# if HAVE_GETCWD
56# if IN_RELOCWRAPPER
57 /* When building the relocatable program wrapper, use the system's getcwd
58 function, not the gnulib override, otherwise we would get a link error.
59 */
60# undef getcwd
61# endif
62# ifdef VMS
63 /* We want the directory in Unix syntax, not in VMS syntax. */
64# define __getcwd(buf, max) getcwd (buf, max, 0)
65# else
66# define __getcwd getcwd
67# endif
68# else
69# define __getcwd(buf, max) getwd (buf)
70# endif
71# define __readlink readlink
72# define __set_errno(e) errno = (e)
73# ifndef MAXSYMLINKS
74# ifdef SYMLOOP_MAX
75# define MAXSYMLINKS SYMLOOP_MAX
76# else
77# define MAXSYMLINKS 20
78# endif
79# endif
80#endif
81
82#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
83# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
84#endif
85
86#if !FUNC_REALPATH_WORKS || defined _LIBC
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87
88static void
89alloc_failed (void)
90{
91#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
92 /* Avoid errno problem without using the malloc or realloc modules; see:
93 http://lists.gnu.org/archive/html/bug-gnulib/2016-08/msg00025.html */
94 errno = ENOMEM;
95#endif
96}
97
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98/* Return the canonical absolute name of file NAME. A canonical name
99 does not contain any ".", ".." components nor any repeated path
100 separators ('/') or symlinks. All path components must exist. If
101 RESOLVED is null, the result is malloc'd; otherwise, if the
102 canonical name is PATH_MAX chars or more, returns null with 'errno'
103 set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
104 returns the name in RESOLVED. If the name cannot be resolved and
105 RESOLVED is non-NULL, it contains the path of the first component
106 that cannot be resolved. If the path can be resolved, RESOLVED
107 holds the same value as the value returned. */
108
109char *
110__realpath (const char *name, char *resolved)
111{
112 char *rpath, *dest, *extra_buf = NULL;
113 const char *start, *end, *rpath_limit;
114 long int path_max;
115 int num_links = 0;
116 size_t prefix_len;
117
118 if (name == NULL)
119 {
120 /* As per Single Unix Specification V2 we must return an error if
121 either parameter is a null pointer. We extend this to allow
122 the RESOLVED parameter to be NULL in case the we are expected to
123 allocate the room for the return value. */
124 __set_errno (EINVAL);
125 return NULL;
126 }
127
128 if (name[0] == '\0')
129 {
130 /* As per Single Unix Specification V2 we must return an error if
131 the name argument points to an empty string. */
132 __set_errno (ENOENT);
133 return NULL;
134 }
135
136#ifdef PATH_MAX
137 path_max = PATH_MAX;
138#else
139 path_max = pathconf (name, _PC_PATH_MAX);
140 if (path_max <= 0)
141 path_max = 8192;
142#endif
143
144 if (resolved == NULL)
145 {
146 rpath = malloc (path_max);
147 if (rpath == NULL)
148 {
49e4877c 149 alloc_failed ();
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150 return NULL;
151 }
152 }
153 else
154 rpath = resolved;
155 rpath_limit = rpath + path_max;
156
157 /* This is always zero for Posix hosts, but can be 2 for MS-Windows
158 and MS-DOS X:/foo/bar file names. */
159 prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
160
161 if (!IS_ABSOLUTE_FILE_NAME (name))
162 {
163 if (!__getcwd (rpath, path_max))
164 {
165 rpath[0] = '\0';
166 goto error;
167 }
168 dest = strchr (rpath, '\0');
169 start = name;
170 prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath);
171 }
172 else
173 {
174 dest = rpath;
175 if (prefix_len)
176 {
177 memcpy (rpath, name, prefix_len);
178 dest += prefix_len;
179 }
180 *dest++ = '/';
181 if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
182 {
183 if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
184 *dest++ = '/';
185 *dest = '\0';
186 }
187 start = name + prefix_len;
188 }
189
190 for (end = start; *start; start = end)
191 {
192#ifdef _LIBC
193 struct stat64 st;
194#else
195 struct stat st;
196#endif
197 int n;
198
199 /* Skip sequence of multiple path-separators. */
200 while (ISSLASH (*start))
201 ++start;
202
203 /* Find end of path component. */
204 for (end = start; *end && !ISSLASH (*end); ++end)
205 /* Nothing. */;
206
207 if (end - start == 0)
208 break;
209 else if (end - start == 1 && start[0] == '.')
210 /* nothing */;
211 else if (end - start == 2 && start[0] == '.' && start[1] == '.')
212 {
213 /* Back up to previous component, ignore if at root already. */
214 if (dest > rpath + prefix_len + 1)
215 for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
216 continue;
217 if (DOUBLE_SLASH_IS_DISTINCT_ROOT
218 && dest == rpath + 1 && !prefix_len
219 && ISSLASH (*dest) && !ISSLASH (dest[1]))
220 dest++;
221 }
222 else
223 {
224 size_t new_size;
225
226 if (!ISSLASH (dest[-1]))
227 *dest++ = '/';
228
229 if (dest + (end - start) >= rpath_limit)
230 {
231 ptrdiff_t dest_offset = dest - rpath;
232 char *new_rpath;
233
234 if (resolved)
235 {
236 __set_errno (ENAMETOOLONG);
237 if (dest > rpath + prefix_len + 1)
238 dest--;
239 *dest = '\0';
240 goto error;
241 }
242 new_size = rpath_limit - rpath;
243 if (end - start + 1 > path_max)
244 new_size += end - start + 1;
245 else
246 new_size += path_max;
247 new_rpath = (char *) realloc (rpath, new_size);
248 if (new_rpath == NULL)
249 {
49e4877c 250 alloc_failed ();
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251 goto error;
252 }
253 rpath = new_rpath;
254 rpath_limit = rpath + new_size;
255
256 dest = rpath + dest_offset;
257 }
258
259#ifdef _LIBC
260 dest = __mempcpy (dest, start, end - start);
261#else
262 memcpy (dest, start, end - start);
263 dest += end - start;
264#endif
265 *dest = '\0';
266
267#ifdef _LIBC
268 if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
269#else
270 if (lstat (rpath, &st) < 0)
271#endif
272 goto error;
273
274 if (S_ISLNK (st.st_mode))
275 {
276 char *buf;
277 size_t len;
278
279 if (++num_links > MAXSYMLINKS)
280 {
281 __set_errno (ELOOP);
282 goto error;
283 }
284
285 buf = malloca (path_max);
286 if (!buf)
287 {
49e4877c 288 __set_errno (ENOMEM);
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289 goto error;
290 }
291
292 n = __readlink (rpath, buf, path_max - 1);
293 if (n < 0)
294 {
295 int saved_errno = errno;
296 freea (buf);
49e4877c 297 __set_errno (saved_errno);
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298 goto error;
299 }
300 buf[n] = '\0';
301
302 if (!extra_buf)
303 {
304 extra_buf = malloca (path_max);
305 if (!extra_buf)
306 {
307 freea (buf);
49e4877c 308 __set_errno (ENOMEM);
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309 goto error;
310 }
311 }
312
313 len = strlen (end);
314 if ((long int) (n + len) >= path_max)
315 {
316 freea (buf);
317 __set_errno (ENAMETOOLONG);
318 goto error;
319 }
320
321 /* Careful here, end may be a pointer into extra_buf... */
322 memmove (&extra_buf[n], end, len + 1);
323 name = end = memcpy (extra_buf, buf, n);
324
325 if (IS_ABSOLUTE_FILE_NAME (buf))
326 {
327 size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
328
329 if (pfxlen)
330 memcpy (rpath, buf, pfxlen);
331 dest = rpath + pfxlen;
332 *dest++ = '/'; /* It's an absolute symlink */
333 if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
334 {
335 if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
336 *dest++ = '/';
337 *dest = '\0';
338 }
339 /* Install the new prefix to be in effect hereafter. */
340 prefix_len = pfxlen;
341 }
342 else
343 {
344 /* Back up to previous component, ignore if at root
345 already: */
346 if (dest > rpath + prefix_len + 1)
347 for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
348 continue;
349 if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
350 && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
351 dest++;
352 }
353 }
354 else if (!S_ISDIR (st.st_mode) && *end != '\0')
355 {
356 __set_errno (ENOTDIR);
357 goto error;
358 }
359 }
360 }
361 if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1]))
362 --dest;
363 if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len
364 && ISSLASH (*dest) && !ISSLASH (dest[1]))
365 dest++;
366 *dest = '\0';
367
368 if (extra_buf)
369 freea (extra_buf);
370
371 return rpath;
372
373error:
374 {
375 int saved_errno = errno;
376 if (extra_buf)
377 freea (extra_buf);
378 if (resolved == NULL)
379 free (rpath);
49e4877c 380 __set_errno (saved_errno);
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381 }
382 return NULL;
383}
384versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
385#endif /* !FUNC_REALPATH_WORKS || defined _LIBC */
386
387
388#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
389char *
390attribute_compat_text_section
391__old_realpath (const char *name, char *resolved)
392{
393 if (resolved == NULL)
394 {
395 __set_errno (EINVAL);
396 return NULL;
397 }
398
399 return __realpath (name, resolved);
400}
401compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
402#endif
403
404
405char *
406__canonicalize_file_name (const char *name)
407{
408 return __realpath (name, NULL);
409}
410weak_alias (__canonicalize_file_name, canonicalize_file_name)
411
412#else
413
414/* This declaration is solely to ensure that after preprocessing
415 this file is never empty. */
416typedef int dummy;
417
418#endif
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