X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=m4%2Futimensat.m4;h=78472a5fbd7edcbfd569161e9c0b7f8753748d21;hb=9436b51b876432bb26c2345e138e8ddd7c6a7fb2;hp=2a6033f2c08540db8e2ecfbf78ca9b676882fe7c;hpb=791cc509ac459a2555f8d633ad67455cf8d3fe4d;p=gnulib.git

diff --git a/m4/utimensat.m4 b/m4/utimensat.m4
index 2a6033f2c..78472a5fb 100644
--- a/m4/utimensat.m4
+++ b/m4/utimensat.m4
@@ -1,7 +1,7 @@
-# serial 1
+# serial 4
 # See if we need to provide utimensat replacement.
 
-dnl Copyright (C) 2009 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2011 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.
@@ -19,18 +19,51 @@ AC_DEFUN([gl_FUNC_UTIMENSAT],
   else
     AC_CACHE_CHECK([whether utimensat works],
       [gl_cv_func_utimensat_works],
-      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+      [AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM([[
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <unistd.h>
+]],         [[int result = 0;
+              const char *f = "conftest.file";
+              if (close (creat (f, 0600)))
+                return 1;
+              /* Test whether the AT_SYMLINK_NOFOLLOW flag is supported.  */
+              {
+                if (utimensat (AT_FDCWD, f, NULL, AT_SYMLINK_NOFOLLOW))
+                  result |= 2;
+              }
+              /* Test whether UTIME_NOW and UTIME_OMIT work.  */
+              {
+                struct timespec ts[2] = { { 1, UTIME_OMIT }, { 1, UTIME_NOW } };
+                if (utimensat (AT_FDCWD, f, ts, 0))
+                  result |= 4;
+              }
+              sleep (1);
+              {
+                struct timespec ts[2] = { { 1, UTIME_NOW }, { 1, UTIME_OMIT } };
+                struct stat st;
+                if (utimensat (AT_FDCWD, f, ts, 0))
+                  result |= 8;
+                if (stat (f, &st))
+                  result |= 16;
+                else if (st.st_ctime < st.st_atime)
+                  result |= 32;
+              }
+              return result;
+            ]])],
+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 utimensat in 2.6.22, but it had bugs until 2.6.26.
-   Always replace utimensat to support older kernels.  */
+/* The Linux kernel added utimensat in 2.6.22, but has bugs with UTIME_OMIT
+   in several file systems as recently as 2.6.32.  Always replace utimensat
+   to support older kernels.  */
 choke me
 #endif
-]], [[struct timespec ts[2] = { { 1, UTIME_OMIT }, { 1, UTIME_OMIT } };
-      return utimensat (AT_FDCWD, ".", NULL, AT_SYMLINK_NOFOLLOW);]])],
-         [gl_cv_func_utimensat_works=yes],
-         [gl_cv_func_utimensat_works="needs runtime check"],
+      ]])],
+           [gl_cv_func_utimensat_works=yes],
+           [gl_cv_func_utimensat_works="needs runtime check"])],
+         [gl_cv_func_utimensat_works=no],
          [gl_cv_func_utimensat_works="guessing no"])])
     if test "$gl_cv_func_utimensat_works" != yes; then
       REPLACE_UTIMENSAT=1