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, 2009-2012 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([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],
24 gl_cv_func_getcwd_path_max,
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.
41 #include <sys/types.h>
50 # define is_ENAMETOOLONG(x) ((x) == ENAMETOOLONG)
52 # define is_ENAMETOOLONG(x) 0
55 /* Don't get link errors because mkdir is redefined to rpl_mkdir. */
62 /* The length of this name must be 8. */
63 #define DIR_NAME "confdir3"
64 #define DIR_NAME_LEN 8
65 #define DIR_NAME_SIZE (DIR_NAME_LEN + 1)
67 /* The length of "../". */
68 #define DOTDOTSLASH_LEN 3
70 /* Leftover bytes in the buffer, to work around library or OS bugs. */
77 /* The Hurd doesn't define this, so getcwd can't exhibit the bug --
78 at least not on a local file system. And if we were to start worrying
79 about remote file systems, we'd have to enable the wrapper function
80 all of the time, just to be safe. That's not worth the cost. */
82 #elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \
83 - DIR_NAME_SIZE - BUF_SLOP) \
85 /* FIXME: Assuming there's a system for which this is true,
86 this should be done in a compile test. */
89 char buf[PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1)
90 + DIR_NAME_SIZE + BUF_SLOP];
91 char *cwd = getcwd (buf, PATH_MAX);
92 size_t initial_cwd_len;
100 cwd_len = initial_cwd_len = strlen (cwd);
104 size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN);
107 cwd_len += DIR_NAME_SIZE;
108 /* If mkdir or chdir fails, it could be that this system cannot create
109 any file with an absolute name longer than PATH_MAX, such as cygwin.
110 If so, leave fail as 0, because the current working directory can't
111 be too long for getcwd if it can't even be created. For other
112 errors, be pessimistic and consider that as a failure, too. */
113 if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0)
115 if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
120 if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE)
122 c = getcwd (buf, PATH_MAX);
123 if (!c && errno == ENOENT)
133 if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
140 if (dotdot_max <= cwd_len - initial_cwd_len)
142 if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len)
144 c = getcwd (buf, cwd_len + 1);
147 if (! (errno == ERANGE || errno == ENOENT
148 || is_ENAMETOOLONG (errno)))
153 if (AT_FDCWD || errno == ERANGE || errno == ENOENT)
161 if (c && strlen (c) != cwd_len)
169 /* Leaving behind such a deep directory is not polite.
170 So clean up here, right away, even though the driving
171 shell script would also clean up. */
175 /* Try rmdir first, in case the chdir failed. */
177 for (i = 0; i <= n_chdirs; i++)
179 if (chdir ("..") < 0)
181 if (rmdir (DIR_NAME) != 0)
190 [gl_cv_func_getcwd_path_max=yes],
192 10|11|12) gl_cv_func_getcwd_path_max='no, but it is partly working';;
193 31) gl_cv_func_getcwd_path_max='no, it has the AIX bug';;
194 *) gl_cv_func_getcwd_path_max=no;;
197 aix*) gl_cv_func_getcwd_path_max='no, it has the AIX bug';;
198 *) gl_cv_func_getcwd_path_max=no;;