Use a combination of endian macros

1 files changed, 20 insertions, 7 deletions

diff --git a/md5.c b/md5.c
index da3692b..d7934c2 100644
--- a/md5.c
+++ b/md5.c
@@ -42,15 +42,28 @@
 #include <string.h>
 #include "md5.h"
 
-#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#  define HIGHFIRST
-#elif defined(__BYTE_ORDER) && __BYTE_ORDER == __BIG_ENDIAN
-#  define HIGHFIRST
-#elif defined(__sparc) || defined(__mips)
-#  define HIGHFIRST
+/*
+ *	Try and determine endianness of the target system.
+ *
+ *	Other projects seem to use endian.h and variants, but these are
+ *	in non standard locations, and may mess up cross compiling.
+ *
+ *	Here at least the endianess can be set explicitly with
+ *	-DLITTLE_ENDIAN or -DBIG_ENDIAN.
+ */
+#if !defined(LITTLE_ENDIAN) && !defined(BIG_ENDIAN)
+#  if defined(__LITTLE_ENDIAN__) || \
+      (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+#    define LITTLE_ENDIAN 1
+#  elif defined(__BIG_ENDIAN__) || \
+      (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
+#    define BIG_ENDIAN 1
+#  else
+#    error Failed determining endianness of system
+#  endif
 #endif
 
-#ifndef HIGHFIRST
+#ifdef LITTLE_ENDIAN
 #  define byteReverse(buf, len)	/* Nothing */
 #else
 void byteReverse(unsigned char *buf, unsigned longs);