From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757848Ab0JEHtu (ORCPT ); Tue, 5 Oct 2010 03:49:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53100 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757832Ab0JEHtt (ORCPT ); Tue, 5 Oct 2010 03:49:49 -0400 Message-ID: <4CAAD85B.7020607@redhat.com> Date: Tue, 05 Oct 2010 09:48:43 +0200 From: Avi Kivity 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: "H. Peter Anvin" CC: Jan Beulich , Ingo Molnar , heukelum@fastmail.fm, tglx@linutronix.de, akpm@linux-foundation.org, LKML Subject: Re: gas 2.16 and assembly macros -- entry_64.S build failure References: <201009152110.o8FLAJeJ015584@imap1.linux-foundation.org> <4C91F07E0200007800016B50@vpn.id2.novell.com> <20100916082816.GA25681@elte.hu> <4C91F3A30200007800016B64@vpn.id2.novell.com> <20100916101355.GA31458@elte.hu> <4C9219BC0200007800016C53@vpn.id2.novell.com> <4CA52AA5.5040402@zytor.com> <4CA9A69F.8000006@redhat.com> <4CA9F625.7090709@zytor.com> <4CA9FEE2.7000900@redhat.com> <4CAA1BA3.1010306@zytor.com> In-Reply-To: <4CAA1BA3.1010306@zytor.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/04/2010 08:23 PM, H. Peter Anvin wrote: > On 10/04/2010 09:20 AM, Avi Kivity wrote: > > On 10/04/2010 05:43 PM, H. Peter Anvin wrote: > >> On 10/04/2010 03:04 AM, Avi Kivity wrote: > >>> On 10/01/2010 02:26 AM, H. Peter Anvin wrote: > >>>> ... but that doesn't work with the macros like movq_cfi. On those, we > >>>> could argue that at least people won't put $ on them, but cpp will still > >>>> split them apart with spaces; this apparently causes problems at least > >>>> as soon as there is an expression more complicated than addition > >>>> involved (apparently plus signs are okay, but minus signs aren't!) > >>> > >>> Likely due to the fact that a minus sign can later join with a number > >>> and become a new token, but a plug sign cannot. > >>> > >> > >> ... except the same thing applies to other operators, other than the > >> plus sign. This kind of characterization is insanely frustrating, and > >> really doesn't seem to follow logical rules ... we had a previous one > >> where changing a macro name from upper case to lower case made gas 2.16 > >> work... > >> > > > > Well, / and * do join. % doesn't. In a way, + does. > > > > cpp is not a pure text processing language. It's specifically geared to > > C, and is fairly creaky when applying it to something other than C (and > > is only somewhat creaky when applying it to C). > > > > The problem isn't with cpp, though, it's with gas. There are bugs in > the gas 2.16 macro features that don't apply to any other gas version, > before *or* after. I see. I suppose it isn't possible to refuse to build with the broken version? -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.