From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9915 invoked by alias); 28 Jan 2008 21:08:28 -0000 Received: (qmail 9906 invoked by uid 22791); 28 Jan 2008 21:08:28 -0000 X-Spam-Check-By: sourceware.org Received: from NaN.false.org (HELO nan.false.org) (208.75.86.248) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 28 Jan 2008 21:08:00 +0000 Received: from nan.false.org (localhost [127.0.0.1]) by nan.false.org (Postfix) with ESMTP id AAC0B98234; Mon, 28 Jan 2008 21:07:58 +0000 (GMT) Received: from caradoc.them.org (22.svnf5.xdsl.nauticom.net [209.195.183.55]) by nan.false.org (Postfix) with ESMTP id 707C198118; Mon, 28 Jan 2008 21:07:58 +0000 (GMT) Received: from drow by caradoc.them.org with local (Exim 4.68) (envelope-from ) id 1JJbCv-000539-LL; Mon, 28 Jan 2008 16:07:57 -0500 Date: Mon, 28 Jan 2008 23:48:00 -0000 From: Daniel Jacobowitz To: Ulrich Weigand Cc: jimb@codesourcery.com, gdb-patches@sourceware.org Subject: Re: [rfc] Make DWARF-2 "address size" explicit Message-ID: <20080128210757.GA19391@caradoc.them.org> Mail-Followup-To: Ulrich Weigand , jimb@codesourcery.com, gdb-patches@sourceware.org References: <200801141554.m0EFskPB011384@d12av02.megacenter.de.ibm.com> <200801282052.m0SKqW4K030059@d12av02.megacenter.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200801282052.m0SKqW4K030059@d12av02.megacenter.de.ibm.com> User-Agent: Mutt/1.5.17 (2007-12-11) X-IsSubscribed: yes 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: 2008-01/txt/msg00656.txt.bz2 On Mon, Jan 28, 2008 at 09:52:32PM +0100, Ulrich Weigand wrote: > When comparing all this with what GDB currently does, there is > one obvious error: GDB does not take the FDE encoding into > account *at all* when accessing the operand of DW_CFA_set_loc > in the .eh_frame section. It looks like this was already noticed > by Dan some time ago, but the associated patch: > > http://www.cygwin.com/ml/gdb-patches/2006-10/msg00063.html > > apparently was never applied. Dan, are you still planning on > applying this patch? If you could look over that patch and tell me if it looks right, I'll apply it. I had no way to test it with valid debug information. > Apart from that, it would appear that the most logical size to > use for target addresses in DWARF expression evaluation would > be the target "void *" size for .eh_frame FDEs, and the value > of the associated compilation unit's .debug_info address size > header field value for .debug_frame FDEs (however, I'm not sure > how to best determine that). DJ Delorie ran into this same mess on the GCC list a few days ago and Ian had the helpful suggestion to just avoid the bits that depend on the ambiguous "address size". If enough people do that, maybe it won't matter what we pick... I think your choices sound correct. It's hard for .debug_info, though, as there is no direct correlation or dependency between the sections. -- Daniel Jacobowitz CodeSourcery