>From 62fb792c746a31c56b98dc6e89c5c0793f2b811f Mon Sep 17 00:00:00 2001
From: Peter O'Gorman <address@hidden>
Date: Thu, 14 Aug 2008 01:12:21 -0500
Subject: [PATCH] Limit AC_C_BIGENDIAN univeral checks to Mac OS X.

* lib/autoconf/c.m4 (AC_C_BIGENDIAN): Limit the check to __APPLE_C__ with possible -arch flags.
---
 ChangeLog         |    6 ++++++
 lib/autoconf/c.m4 |   32 ++++++++++++++++++++++++--------
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index aa82465..867552d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-08-14  Peter O'Gorman  <address@hidden>
+
+	Limit AC_C_BIGENDIAN univeral checks to Mac OS X.
+	* lib/autoconf/c.m4 (AC_C_BIGENDIAN): Limit the check to
+	__APPLE_C__ with possible -arch flags.
+
 2008-08-12  Eric Blake  <address@hidden>
 
 	Optimize m4_bmatch.
diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index ffaa06e..335a9c6 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -1399,11 +1399,20 @@ fi
 AC_DEFUN([AC_C_BIGENDIAN],
 [AH_VERBATIM([WORDS_BIGENDIAN],
 [/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
-   significant byte first (like Motorola and SPARC, unlike Intel and VAX). */
-#if defined __BIG_ENDIAN__
-# define WORDS_BIGENDIAN 1
-#elif ! defined __LITTLE_ENDIAN__
-# undef WORDS_BIGENDIAN
+   significant byte first (like Motorola and SPARC, unlike Intel). */
+#if defined AC_APPLE_UNIVERSAL_BUILD
+# if defined __BIG_ENDIAN__
+#  define WORDS_BIGENDIAN 1
+# else
+  /* This is not really correct, but there is little that we can do about
+   * it, #undef WORDS_BIGENDIAN would have some value substituted by
+   * config.status, not necessarily the correct one. */
+#  define WORDS_BIGENDIAN 0
+# endif
+#else
+# ifndef WORDS_BIGENDIAN
+#  undef WORDS_BIGENDIAN
+# endif
 #endif])dnl
  AC_CACHE_CHECK([whether byte ordering is bigendian], [ac_cv_c_bigendian],
    [ac_cv_c_bigendian=unknown
@@ -1411,12 +1420,18 @@ AC_DEFUN([AC_C_BIGENDIAN],
       [# See if __BIG_ENDIAN__ or __LITTLE_ENDIAN__ is defined.
        AC_COMPILE_IFELSE(
 	 [AC_LANG_SOURCE(
-	    [[#if ! (defined __BIG_ENDIAN__ || defined __LITTLE_ENDIAN__)
-	       neither is defined;
+	    [[#ifndef __APPLE_CC__
+	       not a universal capable compiler 
 	     #endif
 	     typedef int dummy;
 	    ]])],
-	 [ac_cv_c_bigendian=universal])],
+	 [
+	# Check for potential -arch flags it is not universal unless
+	# there are some -arch flags, note that *ppc* also matches
+	# ppc64. This check is also rather less than ideal.
+	case "${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}" in  #(
+	  *"ppc"*|*"i386"*|*"x86_64"*) ac_cv_c_bigendian=universal;;
+	esac])],
       [AC_DIAGNOSE([obsolete], [AC_C_BIGENDIAN suggests AC_CONFIG_HEADERS])])
     if test $ac_cv_c_bigendian = unknown; then
       # See if sys/param.h defines the BYTE_ORDER macro.
@@ -1521,6 +1536,7 @@ AC_DEFUN([AC_C_BIGENDIAN],
    no)
      $2 ;; #(
    universal)
+     AC_DEFINE([AC_APPLE_UNIVERSAL_BUILD],1,[Define if building universal])
      $4 ;; #(
    *)
      m4_default([$3],
-- 
1.5.4.1