X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Futimes.m4;h=593e43d88c8aadbff8fe46c4cca67d7abf6fe05e;hb=9f60473985e5f20c3efabadf2c1756b5ff560458;hp=4c5bebb5b0ae2583844505ea6a1545fe463f7e52;hpb=60c9d678fcb2c4de125437bea56ae6ea89af985d;p=gnulib.git

diff --git a/m4/utimes.m4 b/m4/utimes.m4
index 4c5bebb5b..593e43d88 100644
--- a/m4/utimes.m4
+++ b/m4/utimes.m4
@@ -1,37 +1,136 @@
-#serial 2
+# Detect some bugs in glibc's implementation of utimes.
+# serial 3
 
-dnl Shamelessly cloned from acspecific.m4's AC_FUNC_UTIME_NULL.
+dnl Copyright (C) 2003-2005, 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.
 
-AC_DEFUN(jm_FUNC_UTIMES_NULL,
-[AC_CACHE_CHECK(whether utimes accepts a null argument, ac_cv_func_utimes_null,
-[rm -f conftestdata; > conftestdata
-AC_TRY_RUN([
-/* In case stat has been defined to rpl_stat, undef it here.  */
-#undef stat
+# See if we need to work around bugs in glibc's implementation of
+# 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 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([whether the utimes function works],
+                 [gl_cv_func_working_utimes],
+  [
+  AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <sys/types.h>
 #include <sys/stat.h>
-main() {
-struct stat s, t;
-exit(!(stat ("conftestdata", &s) == 0 && utimes("conftestdata", (long *)0) == 0
-&& stat("conftestdata", &t) == 0 && t.st_mtime >= s.st_mtime
-&& t.st_mtime - s.st_mtime < 120));
-}], ac_cv_func_utimes_null=yes, ac_cv_func_utimes_null=no,
-  ac_cv_func_utimes_null=no)
-rm -f core core.* *.core])
-
-    if test $ac_cv_func_utimes_null = yes; then
-      if test x = y; then
-	# This code is deliberately never run via ./configure.
-	# FIXME: this is a hack to make autoheader put the corresponding
-	# HAVE_* undef for this symbol in config.h.in.  This saves me the
-	# trouble of having to maintain the #undef in acconfig.h manually.
-	AC_CHECK_FUNCS(UTIMES_NULL)
-      fi
-      # Defining it this way (rather than via AC_DEFINE) short-circuits the
-      # autoheader check -- autoheader doesn't know it's already been taken
-      # care of by the hack above.
-      ac_kludge=HAVE_UTIMES_NULL
-      AC_DEFINE_UNQUOTED($ac_kludge)
-    fi
-  ]
-)
+#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 ()
+{
+  int result = 0;
+  char const *file = "conftest.utimes";
+  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],
+       [gl_cv_func_working_utimes=no],
+       [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. ])
+  fi
+])