From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16699 invoked by alias); 15 Sep 2008 18:43:27 -0000 Received: (qmail 16688 invoked by uid 22791); 15 Sep 2008 18:43:26 -0000 X-Spam-Check-By: sourceware.org Received: from NaN.false.org (HELO nan.false.org) (208.75.86.248) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 15 Sep 2008 18:42:47 +0000 Received: from nan.false.org (localhost [127.0.0.1]) by nan.false.org (Postfix) with ESMTP id 26B3410CEF; Mon, 15 Sep 2008 18:42:46 +0000 (GMT) Received: from caradoc.them.org (22.svnf5.xdsl.nauticom.net [209.195.183.55]) by nan.false.org (Postfix) with ESMTP id EF66910CEE; Mon, 15 Sep 2008 18:42:45 +0000 (GMT) Received: from drow by caradoc.them.org with local (Exim 4.69) (envelope-from ) id 1KfJ25-0005ZK-Az; Mon, 15 Sep 2008 14:42:45 -0400 Date: Mon, 15 Sep 2008 18:43:00 -0000 From: Daniel Jacobowitz To: Michael Snyder Cc: "gdb-patches@sourceware.org" , teawater Subject: Re: [reverse RFA] no singlestep-over-BP in reverse Message-ID: <20080915184245.GA21388@caradoc.them.org> Mail-Followup-To: Michael Snyder , "gdb-patches@sourceware.org" , teawater References: <48CEAA05.8050006@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48CEAA05.8050006@vmware.com> User-Agent: Mutt/1.5.17 (2008-05-11) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2008-09/txt/msg00337.txt.bz2 On Mon, Sep 15, 2008 at 11:31:33AM -0700, Michael Snyder wrote: > When we're stopped at a breakpoint and we want to > continue in reverse, we're not actually going to > execute the instruction at the breakpoint -- we're > going to de-execute the previous instruction. > > Therefore there's no need to singlestep before > inserting breakpoints. In fact it would be a bad > idea to do so, because if there is a breakpoint at > the previous instruction, we WANT to hit it. > > Note that this patch is to be applied to the reverse branch. If there is a breakpoint on the previous instruction, will you hit it before or after de-executing that instruction? It seems like this logic should be somehow still necessary... but I can't put my finger on when. -- Daniel Jacobowitz CodeSourcery