From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14131 invoked by alias); 1 Aug 2005 20:45:59 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 14115 invoked by uid 22791); 1 Aug 2005 20:45:54 -0000 Received: from mxfep02.bredband.com (HELO mxfep02.bredband.com) (195.54.107.73) by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Mon, 01 Aug 2005 20:45:54 +0000 Received: from efd.lth.se ([217.215.11.93] [217.215.11.93]) by mxfep02.bredband.com with SMTP id <20050801204552.DHDS6295.mxfep02.bredband.com@efd.lth.se> for ; Mon, 1 Aug 2005 22:45:52 +0200 From: Stefan =?ISO-8859-15?Q?Burstr=F6m?= To: gdb@sources.redhat.com Date: Mon, 01 Aug 2005 20:45:00 -0000 Message-ID: <33e255d0bad.2dcea4ea@mail.m.bonet.se> In-Reply-To: <20050801131203.GA4405@nevyn.them.org> Subject: Re: rs6000 / ppc backend in gdb MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable X-SW-Source: 2005-08/txt/msg00004.txt.bz2 Hello Daniel On 2005-08-01, you wrote: > On Sun, Jul 31, 2005 at 11:02:36PM +0100, Stefan Burstr=F6m wrote: > > No, absolutely they aren't! We've learned, over years of debugging > people's real code, that trusting the architecture defined stack layout Well, if you don't have any debugging info available then? > is not a good choice. For instance, on x86 -fomit-frame-pointer is > popular to free up an additional register. Well, I see a lot of problems on architectures where you cannot determine the layout of the stackframe. But on those architectures you are completely screwed anyway without debug info > You weren't very specific about what versions you were testing, but on > x86 you've probably got DWARF2 CFI available, which allows reliable Well, the problem is not when debug info is available. The problem is if the stack chain goes through the OS where no debug info at all is available.=20 I suppose I am pretty much on my own if I want to get this functionality into GDB? One interesting thing about all this is that even if the PPC backend tries to be really nice and look at the prologue to determine various aspects of the frame, it still assumes that the previous sp is saved where the current sp points. regards, Stefan Burstrom