strtod: aid debugging

[gnulib.git] / m4 / getdate.m4

diff --git a/m4/getdate.m4 b/m4/getdate.m4
index a70cba8..5f98229 100644 (file)
--- a/m4/getdate.m4
+++ b/m4/getdate.m4
@@ -1,5 +1,5 @@
-# getdate.m4 serial 15
-dnl Copyright (C) 2002-2006, 2008, 2009 Free Software Foundation, Inc.
+# getdate.m4 serial 16
+dnl Copyright (C) 2002-2006, 2008-2010 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.
@@ -36,4 +36,18 @@ AC_DEFUN([gl_GETDATE],
   AC_STRUCT_TIMEZONE
   AC_REQUIRE([gl_CLOCK_TIME])
   AC_REQUIRE([gl_TM_GMTOFF])
+  AC_COMPILE_IFELSE(
+    [AC_LANG_SOURCE([[
+#include <time.h> /* for time_t */
+#include <limits.h> /* for CHAR_BIT, LONG_MIN, LONG_MAX */
+#define TYPE_MINIMUM(t) \
+  ((t) ((t) 0 < (t) -1 ? (t) 0 : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
+#define TYPE_MAXIMUM(t) \
+  ((t) ((t) 0 < (t) -1 ? (t) -1 : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
+typedef int verify_min[2 * (LONG_MIN <= TYPE_MINIMUM (time_t)) - 1];
+typedef int verify_max[2 * (TYPE_MAXIMUM (time_t) <= LONG_MAX) - 1];
+       ]])],
+    [AC_DEFINE([TIME_T_FITS_IN_LONG_INT], [1],
+       [Define to 1 if all 'time_t' values fit in a 'long int'.])
+    ])
 ])