From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30038 invoked by alias); 27 Nov 2005 16:30:11 -0000 Received: (qmail 30029 invoked by uid 22791); 27 Nov 2005 16:30:10 -0000 X-Spam-Check-By: sourceware.org Received: from hiauly1.hia.nrc.ca (HELO hiauly1.hia.nrc.ca) (132.246.100.193) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 27 Nov 2005 16:30:08 +0000 Received: from hiauly1.hia.nrc.ca (hiauly1.hia.nrc.ca [127.0.0.1] (may be forged)) by hiauly1.hia.nrc.ca (8.12.9-20030917/8.12.9) with ESMTP id jARGU5qO003729; Sun, 27 Nov 2005 11:30:06 -0500 (EST) Received: (from dave@localhost) by hiauly1.hia.nrc.ca (8.12.9-20030917/8.12.9/Submit) id jARGU4SF003726; Sun, 27 Nov 2005 11:30:04 -0500 (EST) Message-Id: <200511271630.jARGU4SF003726@hiauly1.hia.nrc.ca> Subject: Re: Register numbers on hppa64 To: randolph@tausq.org (Randolph Chung) Date: Sun, 27 Nov 2005 16:52:00 -0000 From: "John David Anglin" Cc: mark.kettenis@xs4all.nl, gdb@sources.redhat.com, brobecker@adacore.com In-Reply-To: <4389CBA4.6010906@tausq.org> from "Randolph Chung" at Nov 27, 2005 11:07:16 pm MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2005-11/txt/msg00594.txt.bz2 > > If we change the register use in .dwarf_frame, then we are breaking > > compatibility with previously compiled code. This isn't a big deal > > under HP-UX (dwarf debugging was totally broken on hppa64 until a > > recent assembler fix). However, there is a fair bit of installed > > code running linux. Thus, I would say not change the status quo > > if the above confusion can be handled. The actual numbers used for > > the FP registers are obscure and I doubt many people actually care > > what they are. It's only people maintaining the dwarf code that > > are likely to get confused. If readelf produced a text rather than > > numeric representation, then the problem would largely go away. > > If I understand Mark correctly, the suggestion would change the > numbering used for dwarf cfi/eh, but not the register numbers emitted > for .debug_info, right? It would change the numbering in .debug_frame but not .eh_frame if I understand correctly. We could change to dbx numbers everwhere but that would have a much more significant on the ABI and make the frame tables for unwinding much larger. The positive side is that it would allow recording more information in the frame state if required. > FWIW currently on hppa-linux, gdb does not use dwarf cfi for frame > unwinding. It's on my list of things to do, but if something need > changing in gcc for whatever reason, now is a good time to do it as far > as I'm concerned. That certainly would provide a test as to whether we are providing the correct call frame information in all cases. I guess there may be problems with unwinding through signal frames with really old kernels. I'm still not convinced that the numbers in gcc need changing. Dave -- J. David Anglin dave.anglin@nrc-cnrc.gc.ca National Research Council of Canada (613) 990-0752 (FAX: 952-6602)