From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-return-31916-listarch-gdb=sources.redhat.com@sourceware.org>
Received: (qmail 2690 invoked by alias); 16 May 2008 17:48:53 -0000
Received: (qmail 2682 invoked by uid 22791); 16 May 2008 17:48:52 -0000
X-Spam-Check-By: sourceware.org
Received: from sibelius.xs4all.nl (HELO sibelius.xs4all.nl) (82.92.89.47)     by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 16 May 2008 17:48:35 +0000
Received: from brahms.sibelius.xs4all.nl (kettenis@localhost.sibelius.xs4all.nl [127.0.0.1]) 	by brahms.sibelius.xs4all.nl (8.14.1/8.14.1) with ESMTP id m4GHmRPo032087; 	Fri, 16 May 2008 19:48:27 +0200 (CEST)
Received: (from kettenis@localhost) 	by brahms.sibelius.xs4all.nl (8.14.1/8.14.1/Submit) id m4GHmRdR000890; 	Fri, 16 May 2008 19:48:27 +0200 (CEST)
Date: Fri, 16 May 2008 17:48:00 -0000
Message-Id: <200805161748.m4GHmRdR000890@brahms.sibelius.xs4all.nl>
From: Mark Kettenis <mark.kettenis@xs4all.nl>
To: aristovski@qnx.com
CC: gdb@sourceware.org
In-reply-to: <482DC452.1020102@qnx.com> (message from Aleksandar Ristovski on 	Fri, 16 May 2008 13:28:50 -0400)
Subject: Re: Frame lost after 'leave' and before 'ret' instruction on i386?
References: <482DA814.7030703@qnx.com> <200805161723.m4GHNvWv024856@brahms.sibelius.xs4all.nl> <482DC452.1020102@qnx.com>
Mailing-List: contact gdb-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb.sourceware.org>
List-Subscribe: <mailto:gdb-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb/>
List-Post: <mailto:gdb@sourceware.org>
List-Help: <mailto:gdb-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-owner@sourceware.org
X-SW-Source: 2008-05/txt/msg00134.txt.bz2

> Date: Fri, 16 May 2008 13:28:50 -0400
> From: Aleksandar Ristovski <aristovski@qnx.com>
> 
> Mark Kettenis wrote:
> > The compiler is supposed to give us unwind info for the function's
> > epilogue, but unfortunately GCC doesn't.  There's not much we can do
> > about it in GDB.  Fortunately it isnt an issue that users see a lot.
> > 
> 
> Out of curiosity: what is the problem with specifying epilogue? Am I
> wrong when I say that there can be only so many epilogue types
> (i.e. compiler will not generate infinite number of epilogues)?
> Therefore, only one index in a 'epilogue description table' would
> suffice...
> 
> (or am I over-simplifying?)

A compiler may reschedule instructions into the epilogue (this is what
makes writing prologue analyzers quite difficult).  I don't know
whether GCC does that or not.

I guess the real problem is that nobody has been motivated enough to
fix the problem.

Better ask questions on the GCC mailing lists though if you want an
answer that's not just a guess ;).