rename.c@ 3613

Last change on this file since 3613 was 3611, checked in by bird, 7 months ago
vendor/sed/current: GNU sed 4.9 (sed-4.9.tar.xz sha256:6e226b732e1cd739464ad6862bd1a1aba42d7982922da7a53519631d24975181)
File size: 13.1 KB

Line
1	/* Work around rename bugs in some systems.
2
3	Copyright (C) 2001-2003, 2005-2006, 2009-2022 Free Software Foundation, Inc.
4
5	This file is free software: you can redistribute it and/or modify
6	it under the terms of the GNU Lesser General Public License as
7	published by the Free Software Foundation; either version 2.1 of the
8	License, or (at your option) any later version.
9
10	This file 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 Lesser General Public License for more details.
14
15	You should have received a copy of the GNU Lesser General Public License
16	along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18	/* Written by Volker Borchert, Eric Blake. */
19
20	#include <config.h>
21
22	#include <stdio.h>
23
24	#undef rename
25
26	#if defined _WIN32 && ! defined __CYGWIN__
27	/* The mingw rename has problems with trailing slashes; it also
28	requires use of native Windows calls to allow atomic renames over
29	existing files. */
30
31	# include <errno.h>
32	# include <stdlib.h>
33	# include <sys/stat.h>
34	# include <unistd.h>
35
36	# define WIN32_LEAN_AND_MEAN
37	# include <windows.h>
38
39	# include "dirname.h"
40
41	/* Don't assume that UNICODE is not defined. */
42	# undef MoveFileEx
43	# define MoveFileEx MoveFileExA
44
45	/* Rename the file SRC to DST. This replacement is necessary on
46	Windows, on which the system rename function will not replace
47	an existing DST. */
48	int
49	rpl_rename (char const src, char const dst)
50	{
51	int error;
52	size_t src_len = strlen (src);
53	size_t dst_len = strlen (dst);
54	char *src_base = last_component (src);
55	char *dst_base = last_component (dst);
56	bool src_slash;
57	bool dst_slash;
58	bool dst_exists;
59	struct stat src_st;
60	struct stat dst_st;
61
62	/* Filter out dot as last component. */
63	if (!src_len \|\| !dst_len)
64	{
65	errno = ENOENT;
66	return -1;
67	}
68	if (*src_base == '.')
69	{
70	size_t len = base_len (src_base);
71	if (len == 1 \|\| (len == 2 && src_base[1] == '.'))
72	{
73	errno = EINVAL;
74	return -1;
75	}
76	}
77	if (*dst_base == '.')
78	{
79	size_t len = base_len (dst_base);
80	if (len == 1 \|\| (len == 2 && dst_base[1] == '.'))
81	{
82	errno = EINVAL;
83	return -1;
84	}
85	}
86
87	/* Presence of a trailing slash requires directory semantics. If
88	the source does not exist, or if the destination cannot be turned
89	into a directory, give up now. Otherwise, strip trailing slashes
90	before calling rename. There are no symlinks on mingw, so stat
91	works instead of lstat. */
92	src_slash = ISSLASH (src[src_len - 1]);
93	dst_slash = ISSLASH (dst[dst_len - 1]);
94	if (stat (src, &src_st))
95	return -1;
96	if (stat (dst, &dst_st))
97	{
98	if (errno != ENOENT \|\| (!S_ISDIR (src_st.st_mode) && dst_slash))
99	return -1;
100	dst_exists = false;
101	}
102	else
103	{
104	if (S_ISDIR (dst_st.st_mode) != S_ISDIR (src_st.st_mode))
105	{
106	errno = S_ISDIR (dst_st.st_mode) ? EISDIR : ENOTDIR;
107	return -1;
108	}
109	dst_exists = true;
110	}
111
112	/* There are no symlinks, so if a file existed with a trailing
113	slash, it must be a directory, and we don't have to worry about
114	stripping strip trailing slash. However, mingw refuses to
115	replace an existing empty directory, so we have to help it out.
116	And canonicalize_file_name is not yet ported to mingw; however,
117	for directories, getcwd works as a viable alternative. Ensure
118	that we can get back to where we started before using it; later
119	attempts to return are fatal. Note that we can end up losing a
120	directory if rename then fails, but it was empty, so not much
121	damage was done. */
122	if (dst_exists && S_ISDIR (dst_st.st_mode))
123	{
124	char *cwd = getcwd (NULL, 0);
125	char *src_temp;
126	char *dst_temp;
127	if (!cwd \|\| chdir (cwd))
128	return -1;
129	if (IS_ABSOLUTE_FILE_NAME (src))
130	{
131	dst_temp = chdir (dst) ? NULL : getcwd (NULL, 0);
132	src_temp = chdir (src) ? NULL : getcwd (NULL, 0);
133	}
134	else
135	{
136	src_temp = chdir (src) ? NULL : getcwd (NULL, 0);
137	if (!IS_ABSOLUTE_FILE_NAME (dst) && chdir (cwd))
138	abort ();
139	dst_temp = chdir (dst) ? NULL : getcwd (NULL, 0);
140	}
141	if (chdir (cwd))
142	abort ();
143	free (cwd);
144	if (!src_temp \|\| !dst_temp)
145	{
146	free (src_temp);
147	free (dst_temp);
148	errno = ENOMEM;
149	return -1;
150	}
151	src_len = strlen (src_temp);
152	if (strncmp (src_temp, dst_temp, src_len) == 0
153	&& (ISSLASH (dst_temp[src_len]) \|\| dst_temp[src_len] == '\0'))
154	{
155	error = dst_temp[src_len];
156	free (src_temp);
157	free (dst_temp);
158	if (error)
159	{
160	errno = EINVAL;
161	return -1;
162	}
163	return 0;
164	}
165	if (rmdir (dst))
166	{
167	free (src_temp);
168	free (dst_temp);
169	return -1;
170	}
171	free (src_temp);
172	free (dst_temp);
173	}
174
175	/* MoveFileEx works if SRC is a directory without any flags, but
176	fails with MOVEFILE_REPLACE_EXISTING, so try without flags first.
177	Thankfully, MoveFileEx handles hard links correctly, even though
178	rename() does not. */
179	if (MoveFileEx (src, dst, 0))
180	return 0;
181
182	/* Retry with MOVEFILE_REPLACE_EXISTING if the move failed
183	due to the destination already existing. */
184	error = GetLastError ();
185	if (error == ERROR_FILE_EXISTS \|\| error == ERROR_ALREADY_EXISTS)
186	{
187	if (MoveFileEx (src, dst, MOVEFILE_REPLACE_EXISTING))
188	return 0;
189
190	error = GetLastError ();
191	}
192
193	switch (error)
194	{
195	case ERROR_FILE_NOT_FOUND:
196	case ERROR_PATH_NOT_FOUND:
197	case ERROR_BAD_PATHNAME:
198	case ERROR_DIRECTORY:
199	errno = ENOENT;
200	break;
201
202	case ERROR_ACCESS_DENIED:
203	case ERROR_SHARING_VIOLATION:
204	errno = EACCES;
205	break;
206
207	case ERROR_OUTOFMEMORY:
208	errno = ENOMEM;
209	break;
210
211	case ERROR_CURRENT_DIRECTORY:
212	errno = EBUSY;
213	break;
214
215	case ERROR_NOT_SAME_DEVICE:
216	errno = EXDEV;
217	break;
218
219	case ERROR_WRITE_PROTECT:
220	errno = EROFS;
221	break;
222
223	case ERROR_WRITE_FAULT:
224	case ERROR_READ_FAULT:
225	case ERROR_GEN_FAILURE:
226	errno = EIO;
227	break;
228
229	case ERROR_HANDLE_DISK_FULL:
230	case ERROR_DISK_FULL:
231	case ERROR_DISK_TOO_FRAGMENTED:
232	errno = ENOSPC;
233	break;
234
235	case ERROR_FILE_EXISTS:
236	case ERROR_ALREADY_EXISTS:
237	errno = EEXIST;
238	break;
239
240	case ERROR_BUFFER_OVERFLOW:
241	case ERROR_FILENAME_EXCED_RANGE:
242	errno = ENAMETOOLONG;
243	break;
244
245	case ERROR_INVALID_NAME:
246	case ERROR_DELETE_PENDING:
247	errno = EPERM; /* ? */
248	break;
249
250	# ifndef ERROR_FILE_TOO_LARGE
251	/* This value is documented but not defined in all versions of windows.h. */
252	# define ERROR_FILE_TOO_LARGE 223
253	# endif
254	case ERROR_FILE_TOO_LARGE:
255	errno = EFBIG;
256	break;
257
258	default:
259	errno = EINVAL;
260	break;
261	}
262
263	return -1;
264	}
265
266	#else /* ! W32 platform */
267
268	# include <errno.h>
269	# include <stdio.h>
270	# include <stdlib.h>
271	# include <string.h>
272	# include <sys/stat.h>
273	# include <unistd.h>
274
275	# include "dirname.h"
276	# include "same-inode.h"
277
278	/* Rename the file SRC to DST, fixing any trailing slash bugs. */
279
280	int
281	rpl_rename (char const src, char const dst)
282	{
283	size_t src_len = strlen (src);
284	size_t dst_len = strlen (dst);
285	char src_temp = (char ) src;
286	char dst_temp = (char ) dst;
287	bool src_slash;
288	bool dst_slash;
289	_GL_UNUSED bool dst_exists;
290	int ret_val = -1;
291	int rename_errno = ENOTDIR;
292	struct stat src_st;
293	struct stat dst_st;
294
295	if (!src_len \|\| !dst_len)
296	return rename (src, dst); /* Let strace see the ENOENT failure. */
297
298	# if RENAME_DEST_EXISTS_BUG
299	{
300	char *src_base = last_component (src);
301	char *dst_base = last_component (dst);
302	if (*src_base == '.')
303	{
304	size_t len = base_len (src_base);
305	if (len == 1 \|\| (len == 2 && src_base[1] == '.'))
306	{
307	errno = EINVAL;
308	return -1;
309	}
310	}
311	if (*dst_base == '.')
312	{
313	size_t len = base_len (dst_base);
314	if (len == 1 \|\| (len == 2 && dst_base[1] == '.'))
315	{
316	errno = EINVAL;
317	return -1;
318	}
319	}
320	}
321	# endif /* RENAME_DEST_EXISTS_BUG */
322
323	src_slash = src[src_len - 1] == '/';
324	dst_slash = dst[dst_len - 1] == '/';
325
326	# if !RENAME_HARD_LINK_BUG && !RENAME_DEST_EXISTS_BUG
327	/* If there are no trailing slashes, then trust the native
328	implementation unless we also suspect issues with hard link
329	detection or file/directory conflicts. */
330	if (!src_slash && !dst_slash)
331	return rename (src, dst);
332	# endif /* !RENAME_HARD_LINK_BUG && !RENAME_DEST_EXISTS_BUG */
333
334	/* Presence of a trailing slash requires directory semantics. If
335	the source does not exist, or if the destination cannot be turned
336	into a directory, give up now. Otherwise, strip trailing slashes
337	before calling rename. */
338	if (lstat (src, &src_st))
339	return -1;
340	if (lstat (dst, &dst_st))
341	{
342	if (errno != ENOENT \|\| (!S_ISDIR (src_st.st_mode) && dst_slash))
343	return -1;
344	dst_exists = false;
345	}
346	else
347	{
348	if (S_ISDIR (dst_st.st_mode) != S_ISDIR (src_st.st_mode))
349	{
350	errno = S_ISDIR (dst_st.st_mode) ? EISDIR : ENOTDIR;
351	return -1;
352	}
353	# if RENAME_HARD_LINK_BUG
354	if (SAME_INODE (src_st, dst_st))
355	return 0;
356	# endif /* RENAME_HARD_LINK_BUG */
357	dst_exists = true;
358	}
359
360	# if (RENAME_TRAILING_SLASH_SOURCE_BUG \|\| RENAME_DEST_EXISTS_BUG \
361	\|\| RENAME_HARD_LINK_BUG)
362	/* If the only bug was that a trailing slash was allowed on a
363	non-existing file destination, as in Solaris 10, then we've
364	already covered that situation. But if there is any problem with
365	a trailing slash on an existing source or destination, as in
366	Solaris 9, or if a directory can overwrite a symlink, as on
367	Cygwin 1.5, or if directories cannot be created with trailing
368	slash, as on NetBSD 1.6, then we must strip the offending slash
369	and check that we have not encountered a symlink instead of a
370	directory.
371
372	Stripping a trailing slash interferes with POSIX semantics, where
373	rename behavior on a symlink with a trailing slash operates on
374	the corresponding target directory. We prefer the GNU semantics
375	of rejecting any use of a symlink with trailing slash, but do not
376	enforce them, since Solaris 10 is able to obey POSIX semantics
377	and there might be clients expecting it, as counter-intuitive as
378	those semantics are.
379
380	Technically, we could also follow the POSIX behavior by chasing a
381	readlink trail, but that is harder to implement. */
382	if (src_slash)
383	{
384	src_temp = strdup (src);
385	if (!src_temp)
386	{
387	/* Rather than rely on strdup-posix, we set errno ourselves. */
388	rename_errno = ENOMEM;
389	goto out;
390	}
391	strip_trailing_slashes (src_temp);
392	if (lstat (src_temp, &src_st))
393	{
394	rename_errno = errno;
395	goto out;
396	}
397	if (S_ISLNK (src_st.st_mode))
398	goto out;
399	}
400	if (dst_slash)
401	{
402	dst_temp = strdup (dst);
403	if (!dst_temp)
404	{
405	rename_errno = ENOMEM;
406	goto out;
407	}
408	strip_trailing_slashes (dst_temp);
409	if (lstat (dst_temp, &dst_st))
410	{
411	if (errno != ENOENT)
412	{
413	rename_errno = errno;
414	goto out;
415	}
416	}
417	else if (S_ISLNK (dst_st.st_mode))
418	goto out;
419	}
420	# endif /* RENAME_TRAILING_SLASH_SOURCE_BUG \|\| RENAME_DEST_EXISTS_BUG
421	\|\| RENAME_HARD_LINK_BUG */
422
423	# if RENAME_DEST_EXISTS_BUG
424	/* Cygwin 1.5 sometimes behaves oddly when moving a non-empty
425	directory on top of an empty one (the old directory name can
426	reappear if the new directory tree is removed). Work around this
427	by removing the target first, but don't remove the target if it
428	is a subdirectory of the source. Note that we can end up losing
429	a directory if rename then fails, but it was empty, so not much
430	damage was done. */
431	if (dst_exists && S_ISDIR (dst_st.st_mode))
432	{
433	if (src_st.st_dev != dst_st.st_dev)
434	{
435	rename_errno = EXDEV;
436	goto out;
437	}
438	if (src_temp != src)
439	free (src_temp);
440	src_temp = canonicalize_file_name (src);
441	if (dst_temp != dst)
442	free (dst_temp);
443	dst_temp = canonicalize_file_name (dst);
444	if (!src_temp \|\| !dst_temp)
445	{
446	rename_errno = ENOMEM;
447	goto out;
448	}
449	src_len = strlen (src_temp);
450	if (strncmp (src_temp, dst_temp, src_len) == 0
451	&& dst_temp[src_len] == '/')
452	{
453	rename_errno = EINVAL;
454	goto out;
455	}
456	if (rmdir (dst))
457	{
458	rename_errno = errno;
459	goto out;
460	}
461	}
462	# endif /* RENAME_DEST_EXISTS_BUG */
463
464	ret_val = rename (src_temp, dst_temp);
465	rename_errno = errno;
466
467	out: _GL_UNUSED_LABEL;
468
469	if (src_temp != src)
470	free (src_temp);
471	if (dst_temp != dst)
472	free (dst_temp);
473	errno = rename_errno;
474	return ret_val;
475	}
476	#endif /* ! W32 platform */

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source: kBuild/vendor/sed/current/lib/rename.c@ 3613

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