From 2fc870119910cd77a6fd2ca3b342801065b31777 Mon Sep 17 00:00:00 2001
From: David Griffith <dave@661.org>
Date: Mon, 16 Dec 2013 22:58:25 -0800
Subject: [PATCH] Runtime endian determination.

---
 src/blorb/blorblib.c | 52 +++++++++++++++++++-------------------------
 1 file changed, 22 insertions(+), 30 deletions(-)

diff --git a/src/blorb/blorblib.c b/src/blorb/blorblib.c
index 0ea93a0..988fa20 100644
--- a/src/blorb/blorblib.c
+++ b/src/blorb/blorblib.c
@@ -11,51 +11,43 @@
 #include "blorb.h"
 #include "blorblow.h"
 
-/* This endian stuff needs to be fixed with something from
- * http://www.ibm.com/developerworks/aix/library/au-endianc/index.html
- */
-
-#ifdef BLORB_BIG_ENDIAN
-static char contentsticker[] = "\nBlorb Library 1.0 (big-endian)\n";
-#define bb_native2(v) (v)
-#define bb_native4(v) (v)
-#endif
-
-#ifdef BLORB_LITTLE_ENDIAN
-static char contentsticker[] = "\nBlorb Library 1.0 (little-endian)\n";
-#define bb_native2(v)   \
-    ( (((uint16)(v) >> 8) & 0x00ff)    \
-    | (((uint16)(v) << 8) & 0xff00))
-#define bb_native4(v)   \
-    ( (((uint32)(v) >> 24) & 0x000000ff)    \
-    | (((uint32)(v) >>  8) & 0x0000ff00)    \
-    | (((uint32)(v) <<  8) & 0x00ff0000)   \
-    | (((uint32)(v) << 24) & 0xff000000))
-#endif
-
-#ifdef CRAPOLA
-#ifndef bb_native4
-#error "You must define either BLORB_BIG_ENDIAN"
-#error "or BLORB_LITTLE_ENDIAN in blorb.h in order"
-#error "to compile this library."
-#endif
-#endif /* CRAPOLA */
-
 static int lib_inited = FALSE;
 
 static bb_err_t bb_initialize_map(bb_map_t *map);
 static bb_err_t bb_initialize(void);
 static int sortsplot(const void *p1, const void *p2);
+static int bigendian;
+
+static uint16 bb_native2(uint16 v)
+{
+    if (bigendian) return v;
+    return ( (((uint16)(v) >> 8) & 0x00ff)
+	   | (((uint16)(v) << 8) & 0xff00));
+}
+
+static uint32 bb_native4(uint32 v)
+{
+    if (bigendian) return v;
+    return ( (((uint32)(v) >> 24) & 0x000000ff)
+	   | (((uint32)(v) >>  8) & 0x0000ff00)
+	   | (((uint32)(v) <<  8) & 0x00ff0000)
+	   | (((uint32)(v) << 24) & 0xff000000));
+}
 
 /* Do some one-time startup tests. */
 static bb_err_t bb_initialize()
 {
+    int i = 1;
+    char *p = (char *)&i;
     union {
         uint32 val;
         unsigned char ch[4];
     } test;
     uint32 val;
 
+    if (p[0] == 1) bigendian = 0;
+    else bigendian = 1;
+
     if (sizeof(uint32) != 4 || sizeof(uint16) != 2)
         return bb_err_CompileTime; /* Basic types are the wrong size. */
 
-- 
2.34.1