X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Futimes.m4;h=f8b19285997bf0dbef6eac9ff9cf40b463fad5eb;hb=68f90afdb82204c27a50e7bce169d2b3795a1ddd;hp=3b8d945ac25558fc0dd327cf9c4bf1128f5dff93;hpb=078bf4ac2813c5a3a93e5d57b5b42c3419aa63a0;p=gnulib.git

diff --git a/m4/utimes.m4 b/m4/utimes.m4
index 3b8d945ac..f8b192859 100644
--- a/m4/utimes.m4
+++ b/m4/utimes.m4
@@ -1,39 +1,129 @@
+# Detect some bugs in glibc's implementation of utimes.
+# serial 3
+
+dnl Copyright (C) 2003-2005, 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.
+
 # See if we need to work around bugs in glibc's implementation of
-# utimes from around July/August 2003.
+# utimes from 2003-07-12 to 2003-09-17.
 # First, there was a bug that would make utimes set mtime
 # and atime to zero (1970-01-01) unconditionally.
-# Then, there is/was code to round rather than truncate.
+# Then, there was code to round rather than truncate.
+# Then, there was an implementation (sparc64, Linux-2.4.28, glibc-2.3.3)
+# that didn't honor the NULL-means-set-to-current-time semantics.
+# Finally, there was also a version of utimes that failed on read-only
+# files, while utime worked fine (linux-2.2.20, glibc-2.2.5).
 #
 # From Jim Meyering, with suggestions from Paul Eggert.
 
 AC_DEFUN([gl_FUNC_UTIMES],
 [
-  AC_CACHE_CHECK([determine whether the utimes function works],
-		 gl_cv_func_working_utimes,
+  AC_CACHE_CHECK([whether the utimes function works],
+                 [gl_cv_func_working_utimes],
   [
   AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 #include <sys/time.h>
+#include <time.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <utime.h>
 
+static int
+inorder (time_t a, time_t b, time_t c)
+{
+  return a <= b && b <= c;
+}
+
 int
 main ()
 {
-  static struct timeval timeval[2] = {{9, 10}, {999999, 999999}};
-  struct stat sbuf;
+  int result = 0;
   char const *file = "conftest.utimes";
-  FILE *f;
-
-  exit ( ! ((f = fopen (file, "w"))
-	    && fclose (f) == 0
-	    && utimes (file, timeval) == 0
-	    && lstat (file, &sbuf) == 0
-	    && sbuf.st_atime == timeval[0].tv_sec
-	    && sbuf.st_mtime == timeval[1].tv_sec) );
+  static struct timeval timeval[2] = {{9, 10}, {999999, 999999}};
+
+  /* Test whether utimes() essentially works.  */
+  {
+    struct stat sbuf;
+    FILE *f = fopen (file, "w");
+    if (f == NULL)
+      result |= 1;
+    else if (fclose (f) != 0)
+      result |= 1;
+    else if (utimes (file, timeval) != 0)
+      result |= 2;
+    else if (lstat (file, &sbuf) != 0)
+      result |= 1;
+    else if (!(sbuf.st_atime == timeval[0].tv_sec
+               && sbuf.st_mtime == timeval[1].tv_sec))
+      result |= 4;
+    if (unlink (file) != 0)
+      result |= 1;
+  }
+
+  /* Test whether utimes() with a NULL argument sets the file's timestamp
+     to the current time.  Use 'fstat' as well as 'time' to
+     determine the "current" time, to accommodate NFS file systems
+     if there is a time skew between the host and the NFS server.  */
+  {
+    int fd = open (file, O_WRONLY|O_CREAT, 0644);
+    if (fd < 0)
+      result |= 1;
+    else
+      {
+        time_t t0, t2;
+        struct stat st0, st1, st2;
+        if (time (&t0) == (time_t) -1)
+          result |= 1;
+        else if (fstat (fd, &st0) != 0)
+          result |= 1;
+        else if (utimes (file, timeval) != 0)
+          result |= 2;
+        else if (utimes (file, NULL) != 0)
+          result |= 8;
+        else if (fstat (fd, &st1) != 0)
+          result |= 1;
+        else if (write (fd, "\n", 1) != 1)
+          result |= 1;
+        else if (fstat (fd, &st2) != 0)
+          result |= 1;
+        else if (time (&t2) == (time_t) -1)
+          result |= 1;
+        else
+          {
+            int m_ok_POSIX = inorder (t0, st1.st_mtime, t2);
+            int m_ok_NFS = inorder (st0.st_mtime, st1.st_mtime, st2.st_mtime);
+            if (! (st1.st_atime == st1.st_mtime))
+              result |= 16;
+            if (! (m_ok_POSIX || m_ok_NFS))
+              result |= 32;
+          }
+        if (close (fd) != 0)
+          result |= 1;
+      }
+    if (unlink (file) != 0)
+      result |= 1;
+  }
+
+  /* Test whether utimes() with a NULL argument works on read-only files.  */
+  {
+    int fd = open (file, O_WRONLY|O_CREAT, 0444);
+    if (fd < 0)
+      result |= 1;
+    else if (close (fd) != 0)
+      result |= 1;
+    else if (utimes (file, NULL) != 0)
+      result |= 64;
+    if (unlink (file) != 0)
+      result |= 1;
+  }
+
+  return result;
 }
   ]])],
        [gl_cv_func_working_utimes=yes],
@@ -41,6 +131,6 @@ main ()
        [gl_cv_func_working_utimes=no])])
 
   if test $gl_cv_func_working_utimes = yes; then
-    AC_DEFINE([HAVE_WORKING_UTIMES], 1, [Define if utimes works properly. ])
+    AC_DEFINE([HAVE_WORKING_UTIMES], [1], [Define if utimes works properly. ])
   fi
 ])