From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9849 invoked by alias); 10 Nov 2005 01:31:27 -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 9841 invoked by uid 22791); 10 Nov 2005 01:31:24 -0000 Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Thu, 10 Nov 2005 01:31:24 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1Ea1He-0002zJ-Sw; Wed, 09 Nov 2005 20:31:22 -0500 Date: Thu, 10 Nov 2005 04:27:00 -0000 From: Daniel Jacobowitz To: Andrew STUBBS Cc: gdb-patches@sources.redhat.com Subject: Re: [SH][PATCH] Disable ABI frame sniffer Message-ID: <20051110013122.GB11334@nevyn.them.org> Mail-Followup-To: Andrew STUBBS , gdb-patches@sources.redhat.com References: <43722DEF.8060300@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43722DEF.8060300@st.com> User-Agent: Mutt/1.5.8i X-SW-Source: 2005-11/txt/msg00123.txt.bz2 On Wed, Nov 09, 2005 at 05:12:15PM +0000, Andrew STUBBS wrote: > Hi, > > The attached patch adds a new sh-specific command: > > set backtrace abi-sniffer > > This command allows the ABI frame sniffer to be disabled. The default > state remains 'on', as it is now. I had to look up what you meant by "ABI frame sniffer"; we normally call this the prologue analyzer. > With the ABI sniffer 'off' it is not possible to backtrace through code > that does not have CFI. On sh-elf, at least, there is always CFI when > there is debug info, so it is relatively rare that the ABI sniffer is > actually required. > > I have not set the default to 'off' because that causes quite a number > of FAILs in the testsuite. That should be a hint... Obviously the SH maintainers have final say, but I strongly discourage any patch along these lines. If you want to improve the fallback unwinder, go ahead. If you want to add more generic tests to terminate backtraces without annoying messages, we can discuss that. But turning it off is not viable. -- Daniel Jacobowitz CodeSourcery, LLC