support for universal binaries on MacOS X (5/6)

[Bruno Haible]

Jim,

The configure test whether mktime works produces the result "yes" in 32-bit
mode and "no" in 64-bit mode. In universal builds, we cannot manage these
different results (it would become a #ifdef mess). Therefore I propose to
combine the results to "no". OK to commit?


2008-12-25  Bruno Haible  <address@hidden>

        * m4/mktime.m4 (AC_FUNC_MKTIME): Require gl_MULTIARCH. In Apple
        universal builds, assume that mktime does not work.
        * modules/mktime (Depends-on): Add multiarch.

--- m4/mktime.m4.orig   2008-12-25 20:19:39.000000000 +0100
+++ m4/mktime.m4        2008-12-25 19:09:45.000000000 +0100
@@ -1,5 +1,5 @@
-#serial 13
-dnl Copyright (C) 2002, 2003, 2005, 2006, 2007 Free Software Foundation, Inc.
+#serial 14
+dnl Copyright (C) 2002, 2003, 2005, 2006, 2007, 2008 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.
@@ -13,10 +13,12 @@
 # AC_FUNC_MKTIME
 # --------------
 AC_DEFUN([AC_FUNC_MKTIME],
-[AC_CHECK_HEADERS_ONCE(unistd.h)
+[AC_REQUIRE([gl_MULTIARCH])
+AC_CHECK_HEADERS_ONCE(unistd.h)
 AC_CHECK_FUNCS_ONCE(alarm)
 AC_CACHE_CHECK([for working mktime], ac_cv_func_working_mktime,
-[AC_RUN_IFELSE([AC_LANG_SOURCE(
+[if test $APPLE_UNIVERSAL_BUILD = 0; then
+AC_RUN_IFELSE([AC_LANG_SOURCE(
 [[/* Test program from Paul Eggert and Tony Leneis.  */
 #include <limits.h>
 #include <stdlib.h>
@@ -203,7 +205,14 @@
 }]])],
               [ac_cv_func_working_mktime=yes],
               [ac_cv_func_working_mktime=no],
-              [ac_cv_func_working_mktime=no])])
+              [ac_cv_func_working_mktime=no])
+  else
+    # A universal build on Apple MacOS X platforms.
+    # The test result would be 'yes' in 32-bit mode and 'no' in 64-bit mode.
+    # But we need a configuration result that is valid in both modes.
+    ac_cv_func_working_mktime=no
+  fi
+])
 if test $ac_cv_func_working_mktime = no; then
   AC_LIBOBJ([mktime])
 fi
--- modules/mktime.orig 2008-12-25 20:19:39.000000000 +0100
+++ modules/mktime      2008-12-25 20:19:26.000000000 +0100
@@ -6,6 +6,7 @@
 m4/mktime.m4
 
 Depends-on:
+multiarch
 time_r
 
 configure.ac: