Import upstream version 1.26

[debian/tar] / m4 / mktime.m4

diff --git a/m4/mktime.m4 b/m4/mktime.m4
index 1e926e86b095eda7475aaac4dcbf58ec3314f25e..56b2416d619302fba98577929692500717d61f3c 100644 (file)
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -1,15 +1,13 @@
-# serial 15
-dnl Copyright (C) 2002-2003, 2005-2007, 2009 Free Software Foundation, Inc.
+# serial 19
+dnl Copyright (C) 2002-2003, 2005-2007, 2009-2011 Free Software Foundation,
+dnl 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.
 
 dnl From Jim Meyering.
 
-# Redefine AC_FUNC_MKTIME, to fix a bug in Autoconf 2.61a and earlier.
-# This redefinition can be removed once a new version of Autoconf is assumed.
-# The redefinition is taken from
-# <http://cvs.sv.gnu.org/viewcvs/*checkout*/autoconf/autoconf/lib/autoconf/functions.m4?rev=1.119>.
+# Redefine AC_FUNC_MKTIME, because it is no longer maintained in Autoconf.
 # AC_FUNC_MKTIME
 # --------------
 AC_DEFUN([AC_FUNC_MKTIME],
@@ -85,8 +83,8 @@ static int
 mktime_test (time_t now)
 {
   return (mktime_test1 (now)
-         && mktime_test1 ((time_t) (time_t_max - now))
-         && mktime_test1 ((time_t) (time_t_min + now)));
+          && mktime_test1 ((time_t) (time_t_max - now))
+          && mktime_test1 ((time_t) (time_t_min + now)));
 }
 
 static int
@@ -116,17 +114,17 @@ bigtime_test (int j)
     {
       struct tm *lt = localtime (&now);
       if (! (lt
-            && lt->tm_year == tm.tm_year
-            && lt->tm_mon == tm.tm_mon
-            && lt->tm_mday == tm.tm_mday
-            && lt->tm_hour == tm.tm_hour
-            && lt->tm_min == tm.tm_min
-            && lt->tm_sec == tm.tm_sec
-            && lt->tm_yday == tm.tm_yday
-            && lt->tm_wday == tm.tm_wday
-            && ((lt->tm_isdst < 0 ? -1 : 0 < lt->tm_isdst)
-                 == (tm.tm_isdst < 0 ? -1 : 0 < tm.tm_isdst))))
-       return 0;
+             && lt->tm_year == tm.tm_year
+             && lt->tm_mon == tm.tm_mon
+             && lt->tm_mday == tm.tm_mday
+             && lt->tm_hour == tm.tm_hour
+             && lt->tm_min == tm.tm_min
+             && lt->tm_sec == tm.tm_sec
+             && lt->tm_yday == tm.tm_yday
+             && lt->tm_wday == tm.tm_wday
+             && ((lt->tm_isdst < 0 ? -1 : 0 < lt->tm_isdst)
+                  == (tm.tm_isdst < 0 ? -1 : 0 < tm.tm_isdst))))
+        return 0;
     }
   return 1;
 }
@@ -158,56 +156,66 @@ year_2050_test ()
      to the correct answer that we can assume the discrepancy is
      due to leap seconds.  */
   return (t == (time_t) -1
-         || (0 < t && answer - 120 <= t && t <= answer + 120));
+          || (0 < t && answer - 120 <= t && t <= answer + 120));
 }
 
 int
 main ()
 {
+  int result = 0;
   time_t t, delta;
   int i, j;
+  int time_t_signed_magnitude = (time_t) ~ (time_t) 0 < (time_t) -1;
+  int time_t_signed = ! ((time_t) 0 < (time_t) -1);
 
   /* This test makes some buggy mktime implementations loop.
      Give up after 60 seconds; a mktime slower than that
      isn't worth using anyway.  */
   alarm (60);
 
-  for (;;)
-    {
-      t = (time_t_max << 1) + 1;
-      if (t <= time_t_max)
-       break;
-      time_t_max = t;
-    }
-  time_t_min = - ((time_t) ~ (time_t) 0 == (time_t) -1) - time_t_max;
+  time_t_max = (! time_t_signed
+                ? (time_t) -1
+                : ((((time_t) 1 << (sizeof (time_t) * CHAR_BIT - 2)) - 1)
+                   * 2 + 1));
+  time_t_min = (! time_t_signed
+                ? (time_t) 0
+                : time_t_signed_magnitude
+                ? ~ (time_t) 0
+                : ~ time_t_max);
 
   delta = time_t_max / 997; /* a suitable prime number */
   for (i = 0; i < N_STRINGS; i++)
     {
       if (tz_strings[i])
-       putenv (tz_strings[i]);
+        putenv (tz_strings[i]);
 
       for (t = 0; t <= time_t_max - delta; t += delta)
-       if (! mktime_test (t))
-         return 1;
+        if (! mktime_test (t))
+          result |= 1;
       if (! (mktime_test ((time_t) 1)
-            && mktime_test ((time_t) (60 * 60))
-            && mktime_test ((time_t) (60 * 60 * 24))))
-       return 1;
+             && mktime_test ((time_t) (60 * 60))
+             && mktime_test ((time_t) (60 * 60 * 24))))
+        result |= 2;
 
       for (j = 1; ; j <<= 1)
-       if (! bigtime_test (j))
-         return 1;
-       else if (INT_MAX / 2 < j)
-         break;
+        if (! bigtime_test (j))
+          result |= 4;
+        else if (INT_MAX / 2 < j)
+          break;
       if (! bigtime_test (INT_MAX))
-       return 1;
+        result |= 8;
     }
-  return ! (irix_6_4_bug () && spring_forward_gap () && year_2050_test ());
+  if (! irix_6_4_bug ())
+    result |= 16;
+  if (! spring_forward_gap ())
+    result |= 32;
+  if (! year_2050_test ())
+    result |= 64;
+  return result;
 }]])],
-              [ac_cv_func_working_mktime=yes],
-              [ac_cv_func_working_mktime=no],
-              [ac_cv_func_working_mktime=no])])
+               [ac_cv_func_working_mktime=yes],
+               [ac_cv_func_working_mktime=no],
+               [ac_cv_func_working_mktime=no])])
 if test $ac_cv_func_working_mktime = no; then
   AC_LIBOBJ([mktime])
 fi
@@ -215,12 +223,14 @@ fi
 
 AC_DEFUN([gl_FUNC_MKTIME],
 [
+  AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
   AC_FUNC_MKTIME
   dnl Note: AC_FUNC_MKTIME does AC_LIBOBJ([mktime]).
   if test $ac_cv_func_working_mktime = no; then
-    AC_DEFINE([mktime], [rpl_mktime],
-      [Define to rpl_mktime if the replacement function should be used.])
+    REPLACE_MKTIME=1
     gl_PREREQ_MKTIME
+  else
+    REPLACE_MKTIME=0
   fi
 ])