From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15696 invoked by alias); 9 Nov 2005 23:55:39 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 15669 invoked by uid 22791); 9 Nov 2005 23:55:36 -0000 Received: from ip127.bb146.pacific.net.hk (HELO stl.com.hk) (202.64.146.127) by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Wed, 09 Nov 2005 23:55:36 +0000 Received: from 86.194.17.210.dyn.pacific.net.hk ([210.17.194.86] helo=[192.168.1.10]) by stl.com.hk with esmtpsa (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.50) id 1EZzkL-0003MI-TX; Thu, 10 Nov 2005 07:52:54 +0800 Message-ID: <43728C6E.5010206@tausq.org> Date: Thu, 10 Nov 2005 01:27:00 -0000 From: Randolph Chung User-Agent: Debian Thunderbird 1.0.2 (X11/20050331) MIME-Version: 1.0 To: Joel Brobecker CC: gdb-patches@sources.redhat.com Subject: Re: [hppa] FYI: confusion in unwind descriptor field meaning References: <20051109203108.GX1635@adacore.com> In-Reply-To: <20051109203108.GX1635@adacore.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2005-11/txt/msg00119.txt.bz2 Joel, > This is really for anybody's FYI, and maybe Randolph if he'd like to > dig in some of the issues with me. > > This is something I'm still working on, so I haven't verified my theory > just yet. But I think there is a confusion in the meaning of Save_SP > in the unwind descriptor. The document I have says: > > 18. Save_SP (bit 27): One if the entry value of SP is saved by this > regions entry sequence in the current frame marker (current_SP - 4); > zero otherwise. > > It doesn't say that the frame has a frame base register. For this, we > have another field: Be careful here, some of this is to work around gcc's interpretation of these fields, which does not always correspond to the documentation. gcc only uses a few of the bits in the unwind record. Dave Anglin (pa gcc maintainer) is the expert on these issues. I only have a few minutes now, will respond in more detail to your two messages later this evening. thanks and I do hope to have a little more time to start looking at gdb again. randolph