From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-patches-return-86639-listarch-gdb-patches=sources.redhat.com@sourceware.org>
Received: (qmail 11228 invoked by alias); 2 Jan 2012 14:20:04 -0000
Received: (qmail 11177 invoked by uid 22791); 2 Jan 2012 14:20:02 -0000
X-SWARE-Spam-Status: No, hits=-7.3 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; Mon, 02 Jan 2012 14:19:42 +0000
Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12])	by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q02EJfrk016241	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK);	Mon, 2 Jan 2012 09:19:41 -0500
Received: from host2.jankratochvil.net (ovpn-116-32.ams2.redhat.com [10.36.116.32])	by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q02EJbkK027155	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO);	Mon, 2 Jan 2012 09:19:40 -0500
Date: Mon, 02 Jan 2012 14:20:00 -0000
From: Jan Kratochvil <jan.kratochvil@redhat.com>
To: Pedro Alves <alves.ped@gmail.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7
Message-ID: <20120102141937.GA14138@host2.jankratochvil.net>
References: <20111222202047.GA16110@host2.jankratochvil.net> <4F01BAA6.8000004@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4F01BAA6.8000004@gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
X-IsSubscribed: yes
Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb-patches.sourceware.org>
List-Subscribe: <mailto:gdb-patches-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb-patches/>
List-Post: <mailto:gdb-patches@sourceware.org>
List-Help: <mailto:gdb-patches-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-patches-owner@sourceware.org
X-SW-Source: 2012-01/txt/msg00036.txt.bz2

On Mon, 02 Jan 2012 15:09:42 +0100, Pedro Alves wrote:
> I'm confused.  Shouldn't this instead be handled in the unwind
> machinery?  Is this subtraction you refer to the
> get_frame_address_in_block one?  That already has special
> handling for something like this.  Why doesn't it work?

This `- 1' is in inferior's:

gcc/libgcc/unwind-dw2.c:
uw_frame_state_for:
  fde = _Unwind_Find_FDE (context->ra + _Unwind_IsSignalFrame (context) - 1,
                          &context->bases);

GDB can only change the address put on inferior stack and later picked up by
the inferior's exceptions unwinder.


Thanks,
Jan