diff options
Diffstat (limited to 'm4/futimens.m4')
| -rw-r--r-- | m4/futimens.m4 | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/m4/futimens.m4 b/m4/futimens.m4 new file mode 100644 index 0000000..b2f4da0 --- /dev/null +++ b/m4/futimens.m4 @@ -0,0 +1,59 @@ +# serial 6 +# See if we need to provide futimens replacement. + +dnl Copyright (C) 2009-2015 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +# Written by Eric Blake. + +AC_DEFUN([gl_FUNC_FUTIMENS], +[ + AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS]) + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + AC_CHECK_FUNCS_ONCE([futimens]) + if test $ac_cv_func_futimens = no; then + HAVE_FUTIMENS=0 + else + AC_CACHE_CHECK([whether futimens works], + [gl_cv_func_futimens_works], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ +#include <fcntl.h> +#include <sys/stat.h> +#include <unistd.h> +#include <errno.h> +]], [[struct timespec ts[2] = { { 1, UTIME_OMIT }, { 1, UTIME_NOW } }; + int fd = creat ("conftest.file", 0600); + struct stat st; + if (fd < 0) return 1; + errno = 0; + if (futimens (AT_FDCWD, NULL) == 0) return 2; + if (errno != EBADF) return 3; + if (futimens (fd, ts)) return 4; + sleep (1); + ts[0].tv_nsec = UTIME_NOW; + ts[1].tv_nsec = UTIME_OMIT; + if (futimens (fd, ts)) return 5; + if (fstat (fd, &st)) return 6; + if (st.st_ctime < st.st_atime) return 7; + ]])], +dnl FIXME: simplify this in 2012, when file system bugs are no longer common + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ +#ifdef __linux__ +/* The Linux kernel added futimens in 2.6.22, but has bugs with UTIME_OMIT + in several file systems as recently as 2.6.32. Always replace futimens + to support older kernels. */ +choke me +#endif + ]])], + [gl_cv_func_futimens_works=yes], + [gl_cv_func_futimens_works="needs runtime check"])], + [gl_cv_func_futimens_works=no], + [gl_cv_func_futimens_works="guessing no"]) + rm -f conftest.file]) + if test "$gl_cv_func_futimens_works" != yes; then + REPLACE_FUTIMENS=1 + fi + fi +]) |