From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27154 invoked by alias); 21 Mar 2003 15:18:36 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 27147 invoked from network); 21 Mar 2003 15:18:35 -0000 Received: from unknown (HELO Cantor.suse.de) (213.95.15.193) by sources.redhat.com with SMTP; 21 Mar 2003 15:18:35 -0000 Received: from Hermes.suse.de (Hermes.suse.de [213.95.15.136]) by Cantor.suse.de (Postfix) with ESMTP id 2A20D14B4F; Fri, 21 Mar 2003 16:18:35 +0100 (MET) Date: Fri, 21 Mar 2003 15:39:00 -0000 From: Michael Matz To: Jason Merrill Cc: , Andrew Haley , Jakub Jelinek Subject: Re: On alignment In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SW-Source: 2003-03/txt/msg01363.txt.bz2 Hi, On Thu, 20 Mar 2003, Jason Merrill wrote: > Do people think this bug is worth fixing? The behavior is rather > surprising, but changing it might break binary compatibility for affected > code--of which there's not likely to be very much, but there could be some. > Code which really wants, say, aligment of 4 for long long could say > __attribute__ ((packed, aligned (4))). On the other hand, the change would > restore binary compatibility with 2.95 for C code. This would change e.g the layout of things like: struct A { int i; }; struct B { struct A a; long long int __attribute__((aligned(4))) li; }; struct C { struct B b; int j; }; , right? If yes I think there is not exactly few code which would be broken binary compatibility wise. I've seen strange things for instance in OpenOffice, where they play with alignments. And to this end compatibility with 3.x matters more that with 2.95.x. Ciao, Michael.