Commit | Line | Data |
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c0c3707f | 1 | # serial 23 |
6ec2e0f5 SDJ |
2 | # Check for several getcwd bugs with long file names. |
3 | # If so, arrange to compile the wrapper function. | |
4 | ||
5 | # This is necessary for at least GNU libc on linux-2.4.19 and 2.4.20. | |
6 | # I've heard that this is due to a Linux kernel bug, and that it has | |
7 | # been fixed between 2.4.21-pre3 and 2.4.21-pre4. | |
8 | ||
c0c3707f | 9 | # Copyright (C) 2003-2007, 2009-2019 Free Software Foundation, Inc. |
6ec2e0f5 SDJ |
10 | # This file is free software; the Free Software Foundation |
11 | # gives unlimited permission to copy and/or distribute it, | |
12 | # with or without modifications, as long as this notice is preserved. | |
13 | ||
14 | # From Jim Meyering | |
15 | ||
16 | AC_DEFUN([gl_FUNC_GETCWD_PATH_MAX], | |
17 | [ | |
18 | AC_CHECK_DECLS_ONCE([getcwd]) | |
19 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles | |
20 | AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) | |
21 | AC_CHECK_HEADERS_ONCE([unistd.h]) | |
22 | AC_REQUIRE([gl_PATHMAX_SNIPPET_PREREQ]) | |
23 | AC_CACHE_CHECK([whether getcwd handles long file names properly], | |
c0c3707f | 24 | [gl_cv_func_getcwd_path_max], |
6ec2e0f5 SDJ |
25 | [# Arrange for deletion of the temporary directory this test creates. |
26 | ac_clean_files="$ac_clean_files confdir3" | |
27 | dnl Please keep this in sync with tests/test-getcwd.c. | |
28 | AC_RUN_IFELSE( | |
29 | [AC_LANG_SOURCE( | |
30 | [[ | |
31 | #include <errno.h> | |
32 | #include <stdlib.h> | |
33 | #if HAVE_UNISTD_H | |
34 | # include <unistd.h> | |
35 | #else | |
36 | # include <direct.h> | |
37 | #endif | |
38 | #include <string.h> | |
39 | #include <limits.h> | |
40 | #include <sys/stat.h> | |
41 | #include <sys/types.h> | |
42 | #include <fcntl.h> | |
43 | ||
44 | ]gl_PATHMAX_SNIPPET[ | |
45 | ||
46 | #ifndef AT_FDCWD | |
47 | # define AT_FDCWD 0 | |
48 | #endif | |
49 | #ifdef ENAMETOOLONG | |
50 | # define is_ENAMETOOLONG(x) ((x) == ENAMETOOLONG) | |
51 | #else | |
52 | # define is_ENAMETOOLONG(x) 0 | |
53 | #endif | |
54 | ||
55 | /* Use the getcwd function, not any macro. */ | |
56 | #undef getcwd | |
57 | ||
58 | /* Don't get link errors because mkdir is redefined to rpl_mkdir. */ | |
59 | #undef mkdir | |
60 | ||
61 | #ifndef S_IRWXU | |
62 | # define S_IRWXU 0700 | |
63 | #endif | |
64 | ||
65 | /* The length of this name must be 8. */ | |
66 | #define DIR_NAME "confdir3" | |
67 | #define DIR_NAME_LEN 8 | |
68 | #define DIR_NAME_SIZE (DIR_NAME_LEN + 1) | |
69 | ||
70 | /* The length of "../". */ | |
71 | #define DOTDOTSLASH_LEN 3 | |
72 | ||
73 | /* Leftover bytes in the buffer, to work around library or OS bugs. */ | |
74 | #define BUF_SLOP 20 | |
75 | ||
76 | int | |
77 | main () | |
78 | { | |
79 | #ifndef PATH_MAX | |
80 | /* The Hurd doesn't define this, so getcwd can't exhibit the bug -- | |
81 | at least not on a local file system. And if we were to start worrying | |
82 | about remote file systems, we'd have to enable the wrapper function | |
83 | all of the time, just to be safe. That's not worth the cost. */ | |
84 | exit (0); | |
85 | #elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \ | |
86 | - DIR_NAME_SIZE - BUF_SLOP) \ | |
87 | <= PATH_MAX) | |
88 | /* FIXME: Assuming there's a system for which this is true, | |
89 | this should be done in a compile test. */ | |
90 | exit (0); | |
91 | #else | |
92 | char buf[PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) | |
93 | + DIR_NAME_SIZE + BUF_SLOP]; | |
94 | char *cwd = getcwd (buf, PATH_MAX); | |
95 | size_t initial_cwd_len; | |
96 | size_t cwd_len; | |
97 | int fail = 0; | |
98 | size_t n_chdirs = 0; | |
99 | ||
100 | if (cwd == NULL) | |
101 | exit (10); | |
102 | ||
103 | cwd_len = initial_cwd_len = strlen (cwd); | |
104 | ||
105 | while (1) | |
106 | { | |
107 | size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN); | |
108 | char *c = NULL; | |
109 | ||
110 | cwd_len += DIR_NAME_SIZE; | |
111 | /* If mkdir or chdir fails, it could be that this system cannot create | |
112 | any file with an absolute name longer than PATH_MAX, such as cygwin. | |
113 | If so, leave fail as 0, because the current working directory can't | |
c0c3707f CB |
114 | be too long for getcwd if it can't even be created. On Linux with |
115 | the 9p file system, mkdir fails with error EINVAL when cwd_len gets | |
116 | too long; ignore this failure because the getcwd() system call | |
117 | produces good results whereas the gnulib substitute calls getdents64 | |
118 | which fails with error EPROTO. | |
119 | For other errors, be pessimistic and consider that as a failure, | |
120 | too. */ | |
6ec2e0f5 SDJ |
121 | if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0) |
122 | { | |
123 | if (! (errno == ERANGE || is_ENAMETOOLONG (errno))) | |
c0c3707f CB |
124 | #ifdef __linux__ |
125 | if (! (errno == EINVAL)) | |
126 | #endif | |
127 | fail = 20; | |
6ec2e0f5 SDJ |
128 | break; |
129 | } | |
130 | ||
131 | if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE) | |
132 | { | |
133 | struct stat sb; | |
134 | ||
135 | c = getcwd (buf, PATH_MAX); | |
136 | if (!c && errno == ENOENT) | |
137 | { | |
138 | fail = 11; | |
139 | break; | |
140 | } | |
141 | if (c) | |
142 | { | |
143 | fail = 31; | |
144 | break; | |
145 | } | |
146 | if (! (errno == ERANGE || is_ENAMETOOLONG (errno))) | |
147 | { | |
148 | fail = 21; | |
149 | break; | |
150 | } | |
151 | ||
152 | /* Our replacement needs to be able to stat() long ../../paths, | |
153 | so generate a path larger than PATH_MAX to check, | |
154 | avoiding the replacement if we can't stat(). */ | |
155 | c = getcwd (buf, cwd_len + 1); | |
156 | if (c && !AT_FDCWD && stat (c, &sb) != 0 && is_ENAMETOOLONG (errno)) | |
157 | { | |
158 | fail = 32; | |
159 | break; | |
160 | } | |
161 | } | |
162 | ||
163 | if (dotdot_max <= cwd_len - initial_cwd_len) | |
164 | { | |
165 | if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len) | |
166 | break; | |
167 | c = getcwd (buf, cwd_len + 1); | |
168 | if (!c) | |
169 | { | |
170 | if (! (errno == ERANGE || errno == ENOENT | |
171 | || is_ENAMETOOLONG (errno))) | |
172 | { | |
173 | fail = 22; | |
174 | break; | |
175 | } | |
176 | if (AT_FDCWD || errno == ERANGE || errno == ENOENT) | |
177 | { | |
178 | fail = 12; | |
179 | break; | |
180 | } | |
181 | } | |
182 | } | |
183 | ||
184 | if (c && strlen (c) != cwd_len) | |
185 | { | |
186 | fail = 23; | |
187 | break; | |
188 | } | |
189 | ++n_chdirs; | |
190 | } | |
191 | ||
192 | /* Leaving behind such a deep directory is not polite. | |
193 | So clean up here, right away, even though the driving | |
194 | shell script would also clean up. */ | |
195 | { | |
196 | size_t i; | |
197 | ||
198 | /* Try rmdir first, in case the chdir failed. */ | |
199 | rmdir (DIR_NAME); | |
200 | for (i = 0; i <= n_chdirs; i++) | |
201 | { | |
202 | if (chdir ("..") < 0) | |
203 | break; | |
204 | if (rmdir (DIR_NAME) != 0) | |
205 | break; | |
206 | } | |
207 | } | |
208 | ||
209 | exit (fail); | |
210 | #endif | |
211 | } | |
212 | ]])], | |
c0c3707f CB |
213 | [gl_cv_func_getcwd_path_max=yes], |
214 | [case $? in | |
215 | 10|11|12) gl_cv_func_getcwd_path_max='no, but it is partly working';; | |
216 | 31) gl_cv_func_getcwd_path_max='no, it has the AIX bug';; | |
217 | 32) gl_cv_func_getcwd_path_max='yes, but with shorter paths';; | |
218 | *) gl_cv_func_getcwd_path_max=no;; | |
219 | esac], | |
220 | [# Cross-compilation guesses: | |
221 | case "$host_os" in | |
222 | aix*) # On AIX, it has the AIX bug. | |
223 | gl_cv_func_getcwd_path_max='guessing no, it has the AIX bug' ;; | |
224 | gnu*) # On Hurd, it is 'yes'. | |
225 | gl_cv_func_getcwd_path_max='guessing yes' ;; | |
226 | linux* | kfreebsd*) | |
227 | # On older Linux+glibc it's 'no, but it is partly working', | |
228 | # on newer Linux+glibc it's 'yes'. | |
229 | # On Linux+musl libc, it's 'no, but it is partly working'. | |
230 | # On kFreeBSD+glibc, it's 'no, but it is partly working'. | |
231 | gl_cv_func_getcwd_path_max='guessing no, but it is partly working' ;; | |
232 | *) # If we don't know, obey --enable-cross-guesses. | |
233 | gl_cv_func_getcwd_path_max="$gl_cross_guess_normal" ;; | |
234 | esac | |
235 | ]) | |
e2fc52e7 | 236 | ]) |
6ec2e0f5 | 237 | ]) |