gettimeofday: port recent C++ fix to Emacs

[gnulib.git] / m4 / futimens.m4

diff --git a/m4/futimens.m4 b/m4/futimens.m4
index ba5d6b6..a159207 100644 (file)
--- a/m4/futimens.m4
+++ b/m4/futimens.m4
@@ -1,7 +1,7 @@
-# serial 2
+# serial 6
 # See if we need to provide futimens replacement.
 
-dnl Copyright (C) 2009 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2013 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.
@@ -15,7 +15,6 @@ AC_DEFUN([gl_FUNC_FUTIMENS],
   AC_CHECK_FUNCS_ONCE([futimens])
   if test $ac_cv_func_futimens = no; then
     HAVE_FUTIMENS=0
-    AC_LIBOBJ([futimens])
   else
     AC_CACHE_CHECK([whether futimens works],
       [gl_cv_func_futimens_works],
@@ -23,23 +22,28 @@ AC_DEFUN([gl_FUNC_FUTIMENS],
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <errno.h>
 ]], [[struct timespec ts[2] = { { 1, UTIME_OMIT }, { 1, UTIME_NOW } };
       int fd = creat ("conftest.file", 0600);
       struct stat st;
       if (fd < 0) return 1;
-      if (futimens (AT_FDCWD, NULL)) return 2;
-      if (futimens (fd, ts)) return 3;
+      errno = 0;
+      if (futimens (AT_FDCWD, NULL) == 0) return 2;
+      if (errno != EBADF) return 3;
+      if (futimens (fd, ts)) return 4;
       sleep (1);
       ts[0].tv_nsec = UTIME_NOW;
       ts[1].tv_nsec = UTIME_OMIT;
-      if (futimens (fd, ts)) return 4;
-      if (fstat (fd, &st)) return 5;
-      if (st.st_ctime < st.st_atime) return 6;
+      if (futimens (fd, ts)) return 5;
+      if (fstat (fd, &st)) return 6;
+      if (st.st_ctime < st.st_atime) return 7;
       ]])],
+dnl FIXME: simplify this in 2012, when file system bugs are no longer common
          [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #ifdef __linux__
 /* The Linux kernel added futimens in 2.6.22, but has bugs with UTIME_OMIT
-   in 2.6.32.  Always replace futimens to support older kernels.  */
+   in several file systems as recently as 2.6.32.  Always replace futimens
+   to support older kernels.  */
 choke me
 #endif
       ]])],
@@ -50,7 +54,6 @@ choke me
       rm -f conftest.file])
     if test "$gl_cv_func_futimens_works" != yes; then
       REPLACE_FUTIMENS=1
-      AC_LIBOBJ([futimens])
     fi
   fi
 ])