Index: ChangeLog
from  Alexandre Duret-Lutz  <address@hidden>

	* aclang.m4 (AC_C_BIGENDIAN): Handle ACTION-IF-TRUE, 
	ACTION-IF-FALSE and ACTION-IF-UNKNOWN.
	* doc/autoconf.texi (C Compiler Characteristics): Update
	documentation for AC_C_BIGENDIAN.

Index: aclang.m4
===================================================================
RCS file: /home/adl/CVSROOT/ac/aclang.m4,v
retrieving revision 1.3
diff -u -r1.3 aclang.m4
--- aclang.m4	2000/10/07 17:52:33	1.3
+++ aclang.m4	2000/10/07 18:49:57
@@ -1137,7 +1137,7 @@
 ])# AC_C_LONG_DOUBLE
 
 
-# AC_C_BIGENDIAN
+# AC_C_BIGENDIAN ([ACTION-IF-TRUE], [ACTION-IF-FALSE], [ACTION-IF-UNKNOWN])
 # --------------
 AC_DEFUN([AC_C_BIGENDIAN],
 [AC_CACHE_CHECK(whether byte ordering is bigendian, ac_cv_c_bigendian,
@@ -1199,14 +1199,16 @@
   rm -f conftest.$ac_objext conftest.$ac_ext])])])
 case $ac_cv_c_bigendian in
   yes)
-    AC_DEFINE(WORDS_BIGENDIAN, 1,
-	      [Define if your processor stores words with the most significant
-	       byte first (like Motorola and SPARC, unlike Intel and VAX).]);;
+    m4_default([$1],
+      [AC_DEFINE([WORDS_BIGENDIAN], 1,
+        [Define if your processor stores words with the most significant
+	 byte first (like Motorola and SPARC, unlike Intel and VAX).])]) ;;
   no)
-    ;;
+    $2 ;;
   *)
-    AC_MSG_ERROR([unknown endianess
-presetting ac_cv_c_bigendian=no (or yes) will help]);;
+    m4_default([$3],
+      [AC_MSG_ERROR([unknown endianess
+presetting ac_cv_c_bigendian=no (or yes) will help])]) ;;
 esac
 ])# AC_C_BIGENDIAN
 
Index: doc/autoconf.texi
===================================================================
RCS file: /home/adl/CVSROOT/ac/doc/autoconf.texi,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 autoconf.texi
--- doc/autoconf.texi	2000/10/06 18:41:05	1.1.1.1
+++ doc/autoconf.texi	2000/10/07 18:41:22
@@ -4105,14 +4105,20 @@
 @code{AC_TRY_COMPILE} (@pxref{Examining Syntax}) or @code{AC_TRY_RUN}
 (@pxref{Run Time})
 
address@hidden AC_C_BIGENDIAN
address@hidden AC_C_BIGENDIAN (@ovar{action-if-true}, @ovar{action-if-false}, @ovar{action-if-unknown})
 @maindex C_BIGENDIAN
 @cvindex WORDS_BIGENDIAN
 @cindex Endianness
 If words are stored with the most significant byte first (like Motorola
-and SPARC, but not Intel and VAX, CPUs), define @code{WORDS_BIGENDIAN}.
address@hidden defmac
+and SPARC CPUs), execute @var{action-if-true}.  If words are stored with
+the less significant byte first (like Intel and VAX CPUs), execute
address@hidden  If the endianess cannot be determined (this can
+happen when cross-compiling), execute @var{action-unknown}.
 
+The default for @var{action-if-true} is to define
address@hidden  The default for @var{action-if-unknown} is to
+abort configure.
address@hidden defmac
 
 @defmac AC_C_CONST
 @maindex C_CONST