2 # See if we need to provide utimensat replacement.
4 dnl Copyright (C) 2009, 2010 Free Software Foundation, Inc.
5 dnl This file is free software; the Free Software Foundation
6 dnl gives unlimited permission to copy and/or distribute it,
7 dnl with or without modifications, as long as this notice is preserved.
9 # Written by Eric Blake.
11 AC_DEFUN([gl_FUNC_UTIMENSAT],
13 AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
15 AC_CHECK_FUNCS_ONCE([utimensat])
16 if test $ac_cv_func_utimensat = no; then
18 AC_LIBOBJ([utimensat])
20 AC_CACHE_CHECK([whether utimensat works],
21 [gl_cv_func_utimensat_works],
22 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
26 ]], [[struct timespec ts[2] = { { 1, UTIME_OMIT }, { 1, UTIME_NOW } };
28 const char *f = "conftest.file";
29 if (close (creat (f, 0600))) return 1;
30 if (utimensat (AT_FDCWD, f, NULL, AT_SYMLINK_NOFOLLOW)) return 2;
31 if (utimensat (AT_FDCWD, f, ts, 0)) return 3;
33 ts[0].tv_nsec = UTIME_NOW;
34 ts[1].tv_nsec = UTIME_OMIT;
35 if (utimensat (AT_FDCWD, f, ts, 0)) return 4;
36 if (stat (f, &st)) return 5;
37 if (st.st_ctime < st.st_atime) return 6;]])],
38 dnl FIXME: simplify this in 2012, when file system bugs are no longer common
39 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
41 /* The Linux kernel added utimensat in 2.6.22, but has bugs with UTIME_OMIT
42 in several file systems as recently as 2.6.32. Always replace utimensat
43 to support older kernels. */
47 [gl_cv_func_utimensat_works=yes],
48 [gl_cv_func_utimensat_works="needs runtime check"])],
49 [gl_cv_func_utimensat_works=no],
50 [gl_cv_func_utimensat_works="guessing no"])])
51 if test "$gl_cv_func_utimensat_works" != yes; then
53 AC_LIBOBJ([utimensat])