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, 2009-2013 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 /* Use the getcwd function, not any macro. */
58 /* Don't get link errors because mkdir is redefined to rpl_mkdir. */
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)
70 /* The length of "../". */
71 #define DOTDOTSLASH_LEN 3
73 /* Leftover bytes in the buffer, to work around library or OS bugs. */
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. */
85 #elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \
86 - DIR_NAME_SIZE - BUF_SLOP) \
88 /* FIXME: Assuming there's a system for which this is true,
89 this should be done in a compile test. */
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;
103 cwd_len = initial_cwd_len = strlen (cwd);
107 size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN);
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
114 be too long for getcwd if it can't even be created. For other
115 errors, be pessimistic and consider that as a failure, too. */
116 if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0)
118 if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
123 if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE)
125 c = getcwd (buf, PATH_MAX);
126 if (!c && errno == ENOENT)
136 if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
143 if (dotdot_max <= cwd_len - initial_cwd_len)
145 if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len)
147 c = getcwd (buf, cwd_len + 1);
150 if (! (errno == ERANGE || errno == ENOENT
151 || is_ENAMETOOLONG (errno)))
156 if (AT_FDCWD || errno == ERANGE || errno == ENOENT)
164 if (c && strlen (c) != cwd_len)
172 /* Leaving behind such a deep directory is not polite.
173 So clean up here, right away, even though the driving
174 shell script would also clean up. */
178 /* Try rmdir first, in case the chdir failed. */
180 for (i = 0; i <= n_chdirs; i++)
182 if (chdir ("..") < 0)
184 if (rmdir (DIR_NAME) != 0)
193 [gl_cv_func_getcwd_path_max=yes],
195 10|11|12) gl_cv_func_getcwd_path_max='no, but it is partly working';;
196 31) gl_cv_func_getcwd_path_max='no, it has the AIX bug';;
197 *) gl_cv_func_getcwd_path_max=no;;
200 aix*) gl_cv_func_getcwd_path_max='no, it has the AIX bug';;
201 *) gl_cv_func_getcwd_path_max=no;;