From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Santos <daniel.santos@pobox.com>
Subject: [PATCH v4 3/13] compiler-gcc.h: Add gcc-recommended GCC_VERSION macro
Date: Fri, 22 Jun 2012 23:00:38 -0500
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To: Andrew Morton <akpm@linux-foundation.org>, Christopher Li <sparse@chrisli.org>, Daniel Santos <daniel.santos@pobox.com>, David Daney <david.daney@cavium.com>, David Howells <dhowells@redhat.com>, David Rientjes <rientjes@google.com>, Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>, "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>, Ingo Molnar <mingo@kernel.org>, Joe Perches <joe@perches.com>, Konstantin Khlebnikov <khlebnikov@openvz.org>, linux-doc@vger.kernel.org, linux-sparse@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, Paul Gortmaker <paul.gortmaker@windriver.com>, Paul Turner <pjt@google.com>, Pavel Pisa <pisa@cmp.felk.cvut.cz>, Peter Zijlstra <a.p.zijlstra@chello.nl>, Richard Weinberger <richard@nod.at>, Rob Landley <rob@landley.net>, Steven Rostedt <rostedt@goodmis.org>, Suresh Siddha <suresh.b.siddha@intel.com>
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Throughout compiler*.h, many version checks are made.  These can be
simplified by using the macro that gcc's documentation recommends.
However, my primary reason for adding this is that I need bug-check
macros that are enabled at certain gcc versions and it's cleaner to use
this macro than the tradition method:

if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ => 2)

If you add patch level, it gets this ugly:

if __GNUC__ > 4 || (__GNUC__ == 4 && (__GNUC_MINOR__ > 2 || \
   __GNUC_MINOR__ == 2 __GNUC_PATCHLEVEL__ >= 1))

As opposed to:

if GCC_VERSION >= 40201

While having separate headers for gcc 3 & 4 eliminates some of this
verbosity, they can still be cleaned up by this.

See also:
http://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html

Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
---
 include/linux/compiler-gcc.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index e5834aa..7970e31 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -5,6 +5,9 @@
 /*
  * Common definitions for all gcc versions go here.
  */
+#define GCC_VERSION (__GNUC__ * 10000 \
+		   + __GNUC_MINOR__ * 100 \
+		   + __GNUC_PATCHLEVEL__)
 
 
 /* Optimization barrier */
-- 
1.7.3.4