From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11930 invoked by alias); 12 Mar 2003 16:57:50 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 11920 invoked from network); 12 Mar 2003 16:57:49 -0000 Received: from unknown (HELO localhost.redhat.com) (172.16.49.200) by 172.16.49.205 with SMTP; 12 Mar 2003 16:57:49 -0000 Received: from redhat.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 976882B11; Wed, 12 Mar 2003 11:57:49 -0500 (EST) Message-ID: <3E6F670D.4030205@redhat.com> Date: Wed, 12 Mar 2003 16:57:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.2) Gecko/20030223 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Daniel Jacobowitz Cc: Michael Elizabeth Chastain , stcarrez@nerim.fr, brobecker@gnat.com, gdb@sources.redhat.com, kettenis@chello.nl Subject: Re: 8-byte register values on a 32-bit machine References: <200303021659.h22Gxc908446@duracef.shout.net> <3E6F53B3.6010803@redhat.com> <20030312155116.GA3669@nevyn.them.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-03/txt/msg00182.txt.bz2 > The new code fixes some reported wrong-value-reported bugs in other debugging > situations; one of them was reported just recently. So I don't think > 'equalled the functionality of the old mechanism' is really quite fair. > > I was also not aware that we had sketchy multi-register support until > it was pointed out to me, because the support isn't in any of the > places I was working in directly; it's off in the generic value code, > isn't it? So I didn't know this was going to happen. We have a plan > to fix it, too. Mark posted it, and then ran out of time (?). You > didn't like his plan because: > I think it is very dangerous. It's assuming a specific algorithm > in the compiler. That locks both GDB and GCC into something of a > death spiral. I think its far better to try and get a proper > location mechanism working. There are other ways forward on this - moving the algorithm to libiberty (like the demangler). > Well, that's what we did before, in the "old mechanism", and we don't > have any new debug info that we didn't have then so it's what we need > to keep doing until support for the new debug info is ready (then GCC > can emit it more broadly). > > By the way, you wrote: > On Sun, Feb 02, 2003 at 11:14:29AM -0500, Andrew Cagney wrote: > >> If only it were that easy. The dwarf2 reader, for instance, also >> contains the assumption that registers are allocated sequentially. >> >> Is the proposal to modify such readers so that they check against this >> next_allocated_regnum algorithm? > > > And I wrote back: > >> Where? I can't find this; it doesn't even acknowledge multi-register >> values. As we've now re-discovered, the assumption is is there, its real, but it is implicit. > > I still don't understand what code you're referring to in the reader. Andrew