From a5ba0f4e08b0a589a5c061a43f590bd823fe1e1c Mon Sep 17 00:00:00 2001
From: kan <kan@FreeBSD.org>
Date: Thu, 21 Sep 2006 01:38:58 +0000
Subject: [PATCH] Use __builtin_offsetof for GCC 4.1.
---
sys/sys/cdefs.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index 544338c73f0a..d7dff1f2be55 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -304,6 +304,9 @@
* We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
* require it.
*/
+#if __GNUC_PREREQ__(4, 1)
+#define __offsetof(type, field) __builtin_offsetof(type, field)
+#else
#ifndef __cplusplus
#define __offsetof(type, field) ((size_t)(&((type *)0)->field))
#else
@@ -312,6 +315,7 @@
(&reinterpret_cast <const volatile char &> \
(static_cast<type *> (0)->field))))
#endif
+#endif
#define __rangeof(type, start, end) \
(__offsetof(type, end) - __offsetof(type, start))