From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27340 invoked by alias); 10 Dec 2003 18:52:56 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 27329 invoked from network); 10 Dec 2003 18:52:53 -0000 Received: from unknown (HELO faui10.informatik.uni-erlangen.de) (131.188.31.10) by sources.redhat.com with SMTP; 10 Dec 2003 18:52:53 -0000 Received: from faui1d.informatik.uni-erlangen.de (faui1d [131.188.31.34]) by faui10.informatik.uni-erlangen.de (8.9.3p3/8.1.9-FAU) with ESMTP id TAA03292; Wed, 10 Dec 2003 19:52:51 +0100 (CET) From: Ulrich Weigand Received: (from weigand@localhost) by faui1d.informatik.uni-erlangen.de (8.9.3p3/8.1.6-FAU) id TAA16413; Wed, 10 Dec 2003 19:52:51 +0100 (CET) Message-Id: <200312101852.TAA16413@faui1d.informatik.uni-erlangen.de> Subject: Re: [PATCH] S/390 DWARF-2 CFI frame support To: cagney@gnu.org (Andrew Cagney) Date: Wed, 10 Dec 2003 18:52:00 -0000 Cc: cagney@gnu.org (Andrew Cagney), kettenis@chello.nl (Mark Kettenis), weigand@i1.informatik.uni-erlangen.de (Ulrich Weigand), gdb-patches@sources.redhat.com, uweigand@de.ibm.com In-Reply-To: <3FD7548D.7080300@gnu.org> from "Andrew Cagney" at Dec 10, 2003 12:14:53 PM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SW-Source: 2003-12/txt/msg00299.txt.bz2 Andrew, > > I'm wondering if it would be easier, here to "give up". Throw the whole problem back at the architecture vis: > > > > - initialize unwind table using per OSABI (?) method > > > > - update the unwind table using the CFI initialize info > > > > - update the unwind table using the PC's CFI unwind info > > > > - if after all this a register is still unspecified, we complain > > (btw, the compaint is only ment to appear once but apparently appears repeatedly?). > > > > Thoughts for the moment on the theory? Mark? I don't quite see how to map the existing issues in this ABI: - On s390, we need to copy %r14 *after it was unwound* to the PC register. I see how to do that if an arch-specific routine is called after the CFI data is parsed, but not how to do it if the arch-specific routine is called *before*. - On x86_64, you need to specific that the stack pointer is unwound to the CFA. How should the arch-specific routine do that? (Again, if the arch-specific routine were called after the CFI is parsed, it could presumably copy the expression for the CFA as stack pointer unwind expression. But before?) However, this interface would solve the call-saved registers issue. Bye, Ulrich -- Dr. Ulrich Weigand weigand@informatik.uni-erlangen.de