From: Satoshi Nakagawa <snakagawa@...>
Date: 2007-10-26T20:02:26+09:00
Subject: [ruby-dev:32160] WORDS_BIGENDIAN on Mac OS X

中川といいます。

ruby-core:12895 で Laurent が ruby 1.8 について

> words-bigendian-from-arch.diff: This patch moves some code that was
> only effective for NeXT systems, for both Mac OS X and NeXT.
> WORDS_BIGENDIAN isn't trusted from configure, but instead we use
> __BIG_ENDIAN__. This is to make sure you can build Ruby for both ppc
> and i386 architectures (as a fat binary) on ppc, then use the binary
> on i386 without getting endianness problems.

と書いていますが、これは trunk にもあてはまります。

ruby-dev:31626 の strtod の件以来、気になっていたのですが、
Intel Mac で -arch i386 -arch ppc を指定して make してみると
WORDS_BIGENDIAN は i386 と ppc のバイナリのどちらでも
define されていないことを確認しました。

したがって、WORDS_BIGENDIAN を利用している部分は、
fat binary ではちゃんと動作していないはずだと思います。


Index: include/ruby/defines.h
===================================================================
--- include/ruby/defines.h      (revision 13787)
+++ include/ruby/defines.h      (working copy)
@@ -106,6 +106,16 @@
#endif
#endif
+#if defined(__NeXT__) || defined(__APPLE__)
+/* Do not trust WORDS_BIGENDIAN from configure since -arch compiler flag may
+   result in a different endian.  Instead trust __BIG_ENDIAN__ and
+   __LITTLE_ENDIAN__ which are set correctly by -arch. */
+#undef WORDS_BIGENDIAN
+#ifdef __BIG_ENDIAN__
+#define WORDS_BIGENDIAN
+#endif
+#endif
+
#ifdef __NeXT__
/* NextStep, OpenStep, Rhapsody */
#ifndef S_IRUSR
@@ -159,13 +169,6 @@
#ifndef S_ISREG
#define S_ISREG(mode)  (((mode) & (0170000)) == (0100000))
#endif
-/* Do not trust WORDS_BIGENDIAN from configure since -arch compiler flag may
-   result in a different endian.  Instead trust __BIG_ENDIAN__ and
-   __LITTLE_ENDIAN__ which are set correctly by -arch. */
-#undef WORDS_BIGENDIAN
-#ifdef __BIG_ENDIAN__
-#define WORDS_BIGENDIAN
-#endif
#ifndef __APPLE__
/* NextStep, OpenStep (but not Rhapsody) */
#ifndef GETPGRP_VOID


--
Satoshi Nakagawa
http://d.hatena.ne.jp/Psychs/