From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1931 invoked by alias); 26 Nov 2012 20:14:50 -0000 Received: (qmail 1772 invoked by uid 22791); 26 Nov 2012 20:14:44 -0000 X-SWARE-Spam-Status: No, hits=-3.2 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from sibelius.xs4all.nl (HELO glazunov.sibelius.xs4all.nl) (83.163.83.176) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 26 Nov 2012 20:14:43 +0000 Received: from glazunov.sibelius.xs4all.nl (kettenis@localhost [127.0.0.1]) by glazunov.sibelius.xs4all.nl (8.14.5/8.14.3) with ESMTP id qAQKEMOe025112; Mon, 26 Nov 2012 21:14:22 +0100 (CET) Received: (from kettenis@localhost) by glazunov.sibelius.xs4all.nl (8.14.5/8.14.3/Submit) id qAQKELci009794; Mon, 26 Nov 2012 21:14:21 +0100 (CET) Date: Mon, 26 Nov 2012 20:14:00 -0000 Message-Id: <201211262014.qAQKELci009794@glazunov.sibelius.xs4all.nl> From: Mark Kettenis To: uweigand@de.ibm.com CC: dje.gcc@gmail.com, geoffk@geoffk.org, jakub@redhat.com, gcc-patches@gcc.gnu.org, binutils@sourceware.org, gdb-patches@sourceware.org In-reply-to: <201211261910.qAQJA63I009670@d06av02.portsmouth.uk.ibm.com> (uweigand@de.ibm.com) Subject: Re: [RFC] Wrong register numbers in .dwarf_frame on Linux/PowerPC References: <201211261910.qAQJA63I009670@d06av02.portsmouth.uk.ibm.com> Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2012-11/txt/msg00687.txt.bz2 > Date: Mon, 26 Nov 2012 20:10:06 +0100 (CET) > From: "Ulrich Weigand" > > Hello, > > I noticed what appears to be a long-standing bug in generating .dwarf_frame > sections with GCC on Linux on PowerPC. > > ... > > So I'm wondering where to go from here. I guess we could: > > 1. Bring GCC (and gas) behaviour in compliance with the documented ABI > by removing the #undef DBX_REGISTER_NUMBER and changing gas's > md_reg_eh_frame_to_debug_frame to the original implementation from > Jakub's patch. That would make GDB work well on new files, but > there are a large number of binaries out there where we continue > to have the same behaviour as today ... > > 2. Leave GCC and gas as-is and modify GDB to expect GCC numbering in > .dwarf_frame, except for the condition code register. This would > break debugging of files built with GCC 4.0 and 4.1 unless we > want to add a special hack for that. > > 3. Like 2., but remove the condition code hack: simply use identical > numbers in .eh_frame and .dwarf_frame. This would make PowerPC > like other Linux platforms in that respect. > > Thoughts? What do other compilers (in particular XLC) do? From a GDB standpoint it would be a major PITA if different compilers would use different encodings for .dwarf_frame.