From e3c6e14afc1f1785370dafec05af0dd10c03b6bd Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue, 6 Mar 2007 07:30:17 +0000
Subject: [PATCH] * doc/autoconf.texi (C Compiler): Warn that AC_C_BIGENDIAN
 suggests AC_CONFIG_HEADERS. * lib/autoconf/c.m4 (AC_C_BIGENDIAN): Warn if not
 using AC_CONFIG_HEADERS.  Problem reported by Peter O'Gorman.

---
 ChangeLog         |  8 ++++++++
 doc/autoconf.texi |  5 +++++
 lib/autoconf/c.m4 | 22 ++++++++++++----------
 3 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 077cabd6..b74d8ba4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2007-03-05  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* doc/autoconf.texi (C Compiler): Warn that AC_C_BIGENDIAN
+	suggests AC_CONFIG_HEADERS.
+	* lib/autoconf/c.m4 (AC_C_BIGENDIAN): Warn if not using
+	AC_CONFIG_HEADERS.  Problem reported by
+	Peter O'Gorman.
+
 2007-02-28  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* lib/autoconf/c.m4 (AC_C_BIGENDIAN): Fix typo "__LITLE_ENDIAN__".
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 5e421cc9..45697101 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -6486,6 +6486,11 @@ abort configure and tell the installer how to bypass this test.
 And finally, the default for @var{action-if-universal} is to define
 @samp{WORDS_BIGENDIAN} or not, depending on the architecture that the
 code is being generated for.
+
+If you use this macro without specifying @var{action-if-universal}, you
+should also use @code{AC_CONFIG_HEADERS}; otherwise
+@samp{WORDS_BIGENDIAN} may be set incorrectly for Mac OS X universal
+binary files.
 @end defmac
 
 @defmac AC_C_CONST
diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index f9105c04..a5b7348f 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -1,6 +1,6 @@
 # This file is part of Autoconf.			-*- Autoconf -*-
 # Programming languages support.
-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software
+# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software
 # Foundation, Inc.
 #
 # This program is free software; you can redistribute it and/or modify
@@ -1381,15 +1381,17 @@ AC_DEFUN([AC_C_BIGENDIAN],
 #endif])dnl
  AC_CACHE_CHECK([whether byte ordering is bigendian], [ac_cv_c_bigendian],
    [ac_cv_c_bigendian=unknown
-    # 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;
-	  #endif
-	  typedef int dummy;
-	 ]])],
-      [ac_cv_c_bigendian=universal])
+    m4_ifval(m4_ifdef([AH_HEADER], 1)[$4],
+      [# 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;
+	     #endif
+	     typedef int dummy;
+	    ]])],
+	 [ac_cv_c_bigendian=universal])],
+      [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.
       AC_COMPILE_IFELSE(
-- 
2.11.4.GIT