2 # Check for several getcwd bugs with long file names.
3 # If so, arrange to compile the wrapper function.
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.
9 # Copyright (C) 2003-2007, 2009-2011 Free Software Foundation, Inc.
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.
16 AC_DEFUN([gl_FUNC_GETCWD_PATH_MAX],
18 AC_CHECK_DECLS_ONCE([getcwd])
19 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
20 AC_CHECK_HEADERS_ONCE([unistd.h])
21 AC_CACHE_CHECK([whether getcwd handles long file names properly],
22 gl_cv_func_getcwd_path_max,
23 [# Arrange for deletion of the temporary directory this test creates.
24 ac_clean_files="$ac_clean_files confdir3"
25 dnl Please keep this in sync with tests/test-getcwd.c.
39 #include <sys/types.h>
46 # define is_ENAMETOOLONG(x) ((x) == ENAMETOOLONG)
48 # define is_ENAMETOOLONG(x) 0
51 /* Don't get link errors because mkdir is redefined to rpl_mkdir. */
58 /* The length of this name must be 8. */
59 #define DIR_NAME "confdir3"
60 #define DIR_NAME_LEN 8
61 #define DIR_NAME_SIZE (DIR_NAME_LEN + 1)
63 /* The length of "../". */
64 #define DOTDOTSLASH_LEN 3
66 /* Leftover bytes in the buffer, to work around library or OS bugs. */
73 /* The Hurd doesn't define this, so getcwd can't exhibit the bug --
74 at least not on a local file system. And if we were to start worrying
75 about remote file systems, we'd have to enable the wrapper function
76 all of the time, just to be safe. That's not worth the cost. */
78 #elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \
79 - DIR_NAME_SIZE - BUF_SLOP) \
81 /* FIXME: Assuming there's a system for which this is true,
82 this should be done in a compile test. */
85 char buf[PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1)
86 + DIR_NAME_SIZE + BUF_SLOP];
87 char *cwd = getcwd (buf, PATH_MAX);
88 size_t initial_cwd_len;
96 cwd_len = initial_cwd_len = strlen (cwd);
100 size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN);
103 cwd_len += DIR_NAME_SIZE;
104 /* If mkdir or chdir fails, it could be that this system cannot create
105 any file with an absolute name longer than PATH_MAX, such as cygwin.
106 If so, leave fail as 0, because the current working directory can't
107 be too long for getcwd if it can't even be created. For other
108 errors, be pessimistic and consider that as a failure, too. */
109 if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0)
111 if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
116 if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE)
118 c = getcwd (buf, PATH_MAX);
119 if (!c && errno == ENOENT)
124 if (c || ! (errno == ERANGE || is_ENAMETOOLONG (errno)))
131 if (dotdot_max <= cwd_len - initial_cwd_len)
133 if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len)
135 c = getcwd (buf, cwd_len + 1);
138 if (! (errno == ERANGE || errno == ENOENT
139 || is_ENAMETOOLONG (errno)))
144 if (AT_FDCWD || errno == ERANGE || errno == ENOENT)
152 if (c && strlen (c) != cwd_len)
160 /* Leaving behind such a deep directory is not polite.
161 So clean up here, right away, even though the driving
162 shell script would also clean up. */
166 /* Try rmdir first, in case the chdir failed. */
168 for (i = 0; i <= n_chdirs; i++)
170 if (chdir ("..") < 0)
172 if (rmdir (DIR_NAME) != 0)
181 [gl_cv_func_getcwd_path_max=yes],
183 10|11|12) gl_cv_func_getcwd_path_max='no, but it is partly working';;
184 *) gl_cv_func_getcwd_path_max=no;;
186 [gl_cv_func_getcwd_path_max=no])
188 case $gl_cv_func_getcwd_path_max in
190 AC_DEFINE([HAVE_PARTLY_WORKING_GETCWD], [1],
191 [Define to 1 if getcwd works, except it sometimes fails when it shouldn't,
192 setting errno to ERANGE, ENAMETOOLONG, or ENOENT.]);;