2 # Determine whether getcwd aborts when the length of the working directory
3 # name is unusually large. Any length between 4k and 16k trigger the bug
4 # when using glibc-2.4.90-9 or older.
6 # Copyright (C) 2006, 2009-2015 Free Software Foundation, Inc.
7 # This file is free software; the Free Software Foundation
8 # gives unlimited permission to copy and/or distribute it,
9 # with or without modifications, as long as this notice is preserved.
13 # gl_FUNC_GETCWD_ABORT_BUG([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
14 AC_DEFUN([gl_FUNC_GETCWD_ABORT_BUG],
16 AC_CHECK_DECLS_ONCE([getcwd])
17 AC_CHECK_HEADERS_ONCE([unistd.h])
18 AC_REQUIRE([gl_PATHMAX_SNIPPET_PREREQ])
19 AC_CHECK_FUNCS([getpagesize])
20 AC_CACHE_CHECK([whether getcwd aborts when 4k < cwd_length < 16k],
21 gl_cv_func_getcwd_abort_bug,
22 [# Remove any remnants of a previous test.
24 # Arrange for deletion of the temporary directory this test creates.
25 ac_clean_files="$ac_clean_files confdir-14B---"
26 dnl Please keep this in sync with tests/test-getcwd.c.
34 #else /* on Windows with MSVC */
42 /* Don't get link errors because mkdir is redefined to rpl_mkdir. */
49 /* FIXME: skip the run-test altogether on systems without getpagesize. */
50 #if ! HAVE_GETPAGESIZE
51 # define getpagesize() 0
54 /* This size is chosen to be larger than PATH_MAX (4k), yet smaller than
55 the 16kB pagesize on ia64 linux. Those conditions make the code below
56 trigger a bug in glibc's getcwd implementation before 2.4.90-10. */
57 #define TARGET_LEN (5 * 1024)
63 size_t initial_cwd_len;
66 /* The bug is triggered when PATH_MAX < getpagesize (), so skip
67 this relatively expensive and invasive test if that's not true. */
69 int bug_possible = PATH_MAX < getpagesize ();
76 cwd = getcwd (NULL, 0);
80 initial_cwd_len = strlen (cwd);
85 static char const dir_name[] = "confdir-14B---";
86 size_t desired_depth = ((TARGET_LEN - 1 - initial_cwd_len)
89 for (d = 0; d < desired_depth; d++)
91 if (mkdir (dir_name, S_IRWXU) < 0 || chdir (dir_name) < 0)
93 if (! (errno == ERANGE || errno == ENAMETOOLONG
95 fail = 3; /* Unable to construct deep hierarchy. */
100 /* If libc has the bug in question, this invocation of getcwd
101 results in a failed assertion. */
102 cwd = getcwd (NULL, 0);
104 fail = 4; /* getcwd didn't assert, but it failed for a long name
105 where the answer could have been learned. */
108 /* Call rmdir first, in case the above chdir failed. */
112 if (chdir ("..") < 0)
124 [gl_cv_func_getcwd_abort_bug=no],
125 [dnl An abort will provoke an exit code of something like 134 (128 + 6).
126 dnl An exit code of 4 can also occur (in OpenBSD 4.9, NetBSD 5.1 for
127 dnl example): getcwd (NULL, 0) fails rather than returning a string
128 dnl longer than PATH_MAX. This may be POSIX compliant (in some
129 dnl interpretations of POSIX). But gnulib's getcwd module wants to
130 dnl provide a non-NULL value in this case.
132 if test $ret -ge 128 || test $ret = 4; then
133 gl_cv_func_getcwd_abort_bug=yes
135 gl_cv_func_getcwd_abort_bug=no
137 [gl_cv_func_getcwd_abort_bug=yes])
139 AS_IF([test $gl_cv_func_getcwd_abort_bug = yes], [$1], [$2])