getline: Move AC_LIBOBJ invocations to module description.

[gnulib.git] / m4 / mktime.m4

diff --git a/m4/mktime.m4 b/m4/mktime.m4
index a15cf2f..01167a1 100644 (file)
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -1,5 +1,5 @@
-# serial 17
-dnl Copyright (C) 2002-2003, 2005-2007, 2009-2010 Free Software Foundation,
+# serial 20
+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,
@@ -165,20 +165,23 @@ 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++)
@@ -231,6 +234,23 @@ AC_DEFUN([gl_FUNC_MKTIME],
   fi
 ])
 
+AC_DEFUN([gl_FUNC_MKTIME_INTERNAL], [
+  AC_REQUIRE([gl_FUNC_MKTIME])
+  if test $REPLACE_MKTIME = 0; then
+    dnl BeOS has __mktime_internal in libc, but other platforms don't.
+    AC_CHECK_FUNC([__mktime_internal],
+      [AC_DEFINE([mktime_internal], [__mktime_internal],
+         [Define to the real name of the mktime_internal function.])
+      ],
+      [dnl mktime works but it doesn't export __mktime_internal,
+       dnl so we need to substitute our own mktime implementation.
+       REPLACE_MKTIME=1
+       AC_LIBOBJ([mktime])
+       gl_PREREQ_MKTIME
+      ])
+  fi
+])
+
 # Prerequisites of lib/mktime.c.
 AC_DEFUN([gl_PREREQ_MKTIME],
 [