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, 2009-2020 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_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
17 AC_CHECK_DECLS_ONCE([getcwd])
18 AC_CHECK_HEADERS_ONCE([unistd.h])
19 AC_REQUIRE([gl_PATHMAX_SNIPPET_PREREQ])
21 gl_CHECK_FUNC_GETPAGESIZE
22 if test $gl_cv_func_getpagesize = yes; then
23 AC_DEFINE_UNQUOTED([HAVE_GETPAGESIZE], [1],
24 [Define to 1 if the system has the 'getpagesize' function.])
27 AC_CACHE_CHECK([whether getcwd aborts when 4k < cwd_length < 16k],
28 [gl_cv_func_getcwd_abort_bug],
29 [# Remove any remnants of a previous test.
31 # Arrange for deletion of the temporary directory this test creates.
32 ac_clean_files="$ac_clean_files confdir-14B---"
33 dnl Please keep this in sync with tests/test-getcwd.c.
41 #else /* on Windows with MSVC */
49 /* Don't get link errors because mkdir is redefined to rpl_mkdir. */
56 /* FIXME: skip the run-test altogether on systems without getpagesize. */
57 #if ! HAVE_GETPAGESIZE
58 # define getpagesize() 0
61 /* This size is chosen to be larger than PATH_MAX (4k), yet smaller than
62 the 16kB pagesize on ia64 linux. Those conditions make the code below
63 trigger a bug in glibc's getcwd implementation before 2.4.90-10. */
64 #define TARGET_LEN (5 * 1024)
70 size_t initial_cwd_len;
73 /* The bug is triggered when PATH_MAX < getpagesize (), so skip
74 this relatively expensive and invasive test if that's not true. */
76 int bug_possible = PATH_MAX < getpagesize ();
83 cwd = getcwd (NULL, 0);
87 initial_cwd_len = strlen (cwd);
92 static char const dir_name[] = "confdir-14B---";
93 size_t desired_depth = ((TARGET_LEN - 1 - initial_cwd_len)
96 for (d = 0; d < desired_depth; d++)
98 if (mkdir (dir_name, S_IRWXU) < 0 || chdir (dir_name) < 0)
100 if (! (errno == ERANGE || errno == ENAMETOOLONG
102 fail = 3; /* Unable to construct deep hierarchy. */
107 /* If libc has the bug in question, this invocation of getcwd
108 results in a failed assertion. */
109 cwd = getcwd (NULL, 0);
111 fail = 4; /* getcwd didn't assert, but it failed for a long name
112 where the answer could have been learned. */
115 /* Call rmdir first, in case the above chdir failed. */
119 if (chdir ("..") < 0)
131 [gl_cv_func_getcwd_abort_bug=no],
132 [dnl An abort will provoke an exit code of something like 134 (128 + 6).
133 dnl An exit code of 4 can also occur (in OpenBSD 4.9, NetBSD 5.1 for
134 dnl example): getcwd (NULL, 0) fails rather than returning a string
135 dnl longer than PATH_MAX. This may be POSIX compliant (in some
136 dnl interpretations of POSIX). But gnulib's getcwd module wants to
137 dnl provide a non-NULL value in this case.
139 if test $ret -ge 128 || test $ret = 4; then
140 gl_cv_func_getcwd_abort_bug=yes
142 gl_cv_func_getcwd_abort_bug=no
146 # Guess no on musl systems.
147 *-musl*) gl_cv_func_getcwd_abort_bug="guessing no" ;;
148 # Guess yes otherwise, even on glibc systems.
149 *) gl_cv_func_getcwd_abort_bug="guessing yes"
153 case "$gl_cv_func_getcwd_abort_bug" in