Commit | Line | Data |
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9c9d63b1 | 1 | # serial 25 |
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 | ||
9c9d63b1 | 9 | # Copyright (C) 2003-2007, 2009-2021 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 | ||
9c9d63b1 | 58 | ]GL_MDA_DEFINES[ |
6ec2e0f5 SDJ |
59 | |
60 | #ifndef S_IRWXU | |
61 | # define S_IRWXU 0700 | |
62 | #endif | |
63 | ||
64 | /* The length of this name must be 8. */ | |
65 | #define DIR_NAME "confdir3" | |
66 | #define DIR_NAME_LEN 8 | |
67 | #define DIR_NAME_SIZE (DIR_NAME_LEN + 1) | |
68 | ||
69 | /* The length of "../". */ | |
70 | #define DOTDOTSLASH_LEN 3 | |
71 | ||
72 | /* Leftover bytes in the buffer, to work around library or OS bugs. */ | |
73 | #define BUF_SLOP 20 | |
74 | ||
75 | int | |
76 | main () | |
77 | { | |
78 | #ifndef PATH_MAX | |
79 | /* The Hurd doesn't define this, so getcwd can't exhibit the bug -- | |
80 | at least not on a local file system. And if we were to start worrying | |
81 | about remote file systems, we'd have to enable the wrapper function | |
82 | all of the time, just to be safe. That's not worth the cost. */ | |
83 | exit (0); | |
84 | #elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \ | |
85 | - DIR_NAME_SIZE - BUF_SLOP) \ | |
86 | <= PATH_MAX) | |
87 | /* FIXME: Assuming there's a system for which this is true, | |
88 | this should be done in a compile test. */ | |
89 | exit (0); | |
90 | #else | |
91 | char buf[PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) | |
92 | + DIR_NAME_SIZE + BUF_SLOP]; | |
93 | char *cwd = getcwd (buf, PATH_MAX); | |
94 | size_t initial_cwd_len; | |
95 | size_t cwd_len; | |
96 | int fail = 0; | |
97 | size_t n_chdirs = 0; | |
98 | ||
99 | if (cwd == NULL) | |
100 | exit (10); | |
101 | ||
102 | cwd_len = initial_cwd_len = strlen (cwd); | |
103 | ||
104 | while (1) | |
105 | { | |
106 | size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN); | |
107 | char *c = NULL; | |
108 | ||
109 | cwd_len += DIR_NAME_SIZE; | |
110 | /* If mkdir or chdir fails, it could be that this system cannot create | |
111 | any file with an absolute name longer than PATH_MAX, such as cygwin. | |
112 | If so, leave fail as 0, because the current working directory can't | |
c0c3707f CB |
113 | be too long for getcwd if it can't even be created. On Linux with |
114 | the 9p file system, mkdir fails with error EINVAL when cwd_len gets | |
115 | too long; ignore this failure because the getcwd() system call | |
116 | produces good results whereas the gnulib substitute calls getdents64 | |
117 | which fails with error EPROTO. | |
118 | For other errors, be pessimistic and consider that as a failure, | |
119 | too. */ | |
6ec2e0f5 SDJ |
120 | if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0) |
121 | { | |
122 | if (! (errno == ERANGE || is_ENAMETOOLONG (errno))) | |
c0c3707f CB |
123 | #ifdef __linux__ |
124 | if (! (errno == EINVAL)) | |
125 | #endif | |
126 | fail = 20; | |
6ec2e0f5 SDJ |
127 | break; |
128 | } | |
129 | ||
130 | if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE) | |
131 | { | |
132 | struct stat sb; | |
133 | ||
134 | c = getcwd (buf, PATH_MAX); | |
135 | if (!c && errno == ENOENT) | |
136 | { | |
137 | fail = 11; | |
138 | break; | |
139 | } | |
140 | if (c) | |
141 | { | |
142 | fail = 31; | |
143 | break; | |
144 | } | |
145 | if (! (errno == ERANGE || is_ENAMETOOLONG (errno))) | |
146 | { | |
147 | fail = 21; | |
148 | break; | |
149 | } | |
150 | ||
151 | /* Our replacement needs to be able to stat() long ../../paths, | |
152 | so generate a path larger than PATH_MAX to check, | |
153 | avoiding the replacement if we can't stat(). */ | |
154 | c = getcwd (buf, cwd_len + 1); | |
155 | if (c && !AT_FDCWD && stat (c, &sb) != 0 && is_ENAMETOOLONG (errno)) | |
156 | { | |
157 | fail = 32; | |
158 | break; | |
159 | } | |
160 | } | |
161 | ||
162 | if (dotdot_max <= cwd_len - initial_cwd_len) | |
163 | { | |
164 | if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len) | |
165 | break; | |
166 | c = getcwd (buf, cwd_len + 1); | |
167 | if (!c) | |
168 | { | |
169 | if (! (errno == ERANGE || errno == ENOENT | |
170 | || is_ENAMETOOLONG (errno))) | |
171 | { | |
172 | fail = 22; | |
173 | break; | |
174 | } | |
175 | if (AT_FDCWD || errno == ERANGE || errno == ENOENT) | |
176 | { | |
177 | fail = 12; | |
178 | break; | |
179 | } | |
180 | } | |
181 | } | |
182 | ||
183 | if (c && strlen (c) != cwd_len) | |
184 | { | |
185 | fail = 23; | |
186 | break; | |
187 | } | |
188 | ++n_chdirs; | |
189 | } | |
190 | ||
191 | /* Leaving behind such a deep directory is not polite. | |
192 | So clean up here, right away, even though the driving | |
193 | shell script would also clean up. */ | |
194 | { | |
195 | size_t i; | |
196 | ||
197 | /* Try rmdir first, in case the chdir failed. */ | |
198 | rmdir (DIR_NAME); | |
199 | for (i = 0; i <= n_chdirs; i++) | |
200 | { | |
201 | if (chdir ("..") < 0) | |
202 | break; | |
203 | if (rmdir (DIR_NAME) != 0) | |
204 | break; | |
205 | } | |
206 | } | |
207 | ||
208 | exit (fail); | |
209 | #endif | |
210 | } | |
211 | ]])], | |
c0c3707f CB |
212 | [gl_cv_func_getcwd_path_max=yes], |
213 | [case $? in | |
214 | 10|11|12) gl_cv_func_getcwd_path_max='no, but it is partly working';; | |
215 | 31) gl_cv_func_getcwd_path_max='no, it has the AIX bug';; | |
216 | 32) gl_cv_func_getcwd_path_max='yes, but with shorter paths';; | |
217 | *) gl_cv_func_getcwd_path_max=no;; | |
218 | esac], | |
219 | [# Cross-compilation guesses: | |
220 | case "$host_os" in | |
221 | aix*) # On AIX, it has the AIX bug. | |
222 | gl_cv_func_getcwd_path_max='guessing no, it has the AIX bug' ;; | |
223 | gnu*) # On Hurd, it is 'yes'. | |
224 | gl_cv_func_getcwd_path_max='guessing yes' ;; | |
225 | linux* | kfreebsd*) | |
226 | # On older Linux+glibc it's 'no, but it is partly working', | |
227 | # on newer Linux+glibc it's 'yes'. | |
228 | # On Linux+musl libc, it's 'no, but it is partly working'. | |
229 | # On kFreeBSD+glibc, it's 'no, but it is partly working'. | |
230 | gl_cv_func_getcwd_path_max='guessing no, but it is partly working' ;; | |
231 | *) # If we don't know, obey --enable-cross-guesses. | |
232 | gl_cv_func_getcwd_path_max="$gl_cross_guess_normal" ;; | |
233 | esac | |
234 | ]) | |
e2fc52e7 | 235 | ]) |
6ec2e0f5 | 236 | ]) |