From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13929 invoked by alias); 4 Oct 2011 17:16:23 -0000 Received: (qmail 13910 invoked by uid 22791); 4 Oct 2011 17:16:21 -0000 X-SWARE-Spam-Status: No, hits=-7.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 04 Oct 2011 17:15:47 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p94HFAYD031854 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 4 Oct 2011 13:15:10 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p94HF9Qu016299; Tue, 4 Oct 2011 13:15:10 -0400 Received: from barimba (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p94HF8wG029986; Tue, 4 Oct 2011 13:15:08 -0400 From: Tom Tromey To: Joel Brobecker Cc: gdb-patches@sourceware.org, Jan Kratochvil Subject: Re: [RFA] fetch result of locdesc expressions as integer (not address) References: <1317676214-7683-1-git-send-email-brobecker@adacore.com> Date: Tue, 04 Oct 2011 17:16:00 -0000 In-Reply-To: <1317676214-7683-1-git-send-email-brobecker@adacore.com> (Joel Brobecker's message of "Mon, 3 Oct 2011 14:10:14 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain 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: 2011-10/txt/msg00102.txt.bz2 >>>>> "Joel" == Joel Brobecker writes: Joel> The problem is that the debugger is treating the result of Joel> the DWARF location expressions as addresses, whereas this is Joel> just an offset in this case. I think that this was an unintentional Joel> side-effect of simplifying the code that fetches the result Joel> from the DWARF expression computation stack. We had a bit of Joel> code that used to fetch it, and turn it into a struct value. Joel> And we replaced it by one call to a function that seemed to Joel> be doing the same: dwarf_expr_fetch_address. The problem is Joel> that dwarf_expr_fetch_address treats the result as an address, Joel> and thus applies the integer_to_address gdbarch method. We do Joel> not want that for struct field offsets... dwarf_expr_fetch_address also calls dwarf_require_integral, which seems like a good defensive thing to do in the replacement code. I think the patch makes sense, but I'd like Jan to weigh in. Tom