From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757889Ab0JSVPm (ORCPT ); Tue, 19 Oct 2010 17:15:42 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53559 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757850Ab0JSVPk (ORCPT ); Tue, 19 Oct 2010 17:15:40 -0400 Message-ID: <4CBE0A34.4060002@zytor.com> Date: Tue, 19 Oct 2010 14:14:28 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: Jan Beulich CC: mingo@elte.hu, tglx@linutronix.de, akpm@linux-foundation.org, heukelum@fastmail.fm, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: fix CFI macro invocations to deal with shortcomings in gas References: <4CBDBEBA020000780001E05A@vpn.id2.novell.com> In-Reply-To: <4CBDBEBA020000780001E05A@vpn.id2.novell.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/19/2010 06:52 AM, Jan Beulich wrote: > gas prior to (perhaps) 2.16.90 has problems with passing non- > parenthesized expressions containing spaces to macros. Spaces, however, > get inserted by cpp between any macro expanding to a number and a > subsequent + or -. For the +, current x86 gas then removes the space > again (future gas may not do so), but for the - the space gets retained > and is then considered a separator between macro arguments. > > Fix the respective definitions for both the - and + cases, so that they > neither contain spaces nor make cpp insert any (the latter by adding > seemingly redundant parentheses). > > Signed-off-by: Jan Beulich > Cc: Alexander van Heukelum > It's ugly -- very ugly -- and will almost certainly bitrot and break again, but it's a lot less ugly than any other alternative I can think of. Unfortunately these versions of gas are not old enough that we can just kill them off, I don't think. -hpa