From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7419 invoked by alias); 27 Oct 2008 04:48:24 -0000 Received: (qmail 7411 invoked by uid 22791); 27 Oct 2008 04:48:24 -0000 X-Spam-Check-By: sourceware.org Received: from smtp-outbound-2.vmware.com (HELO smtp-outbound-2.vmware.com) (65.115.85.73) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 27 Oct 2008 04:47:49 +0000 Received: from mailhost2.vmware.com (mailhost2.vmware.com [10.16.67.167]) by smtp-outbound-2.vmware.com (Postfix) with ESMTP id 981E39000; Sun, 26 Oct 2008 21:47:45 -0700 (PDT) Received: from [10.20.92.59] (promb-2s-dhcp59.eng.vmware.com [10.20.92.59]) by mailhost2.vmware.com (Postfix) with ESMTP id 8096A8E558; Sun, 26 Oct 2008 21:47:45 -0700 (PDT) Message-ID: <490546A7.9020002@vmware.com> Date: Mon, 27 Oct 2008 04:48:00 -0000 From: Michael Snyder User-Agent: Thunderbird 1.5.0.12 (X11/20080411) MIME-Version: 1.0 To: Joel Brobecker CC: "gdb-patches@sourceware.org" , teawater Subject: Re: [RFA] Handle runtime loader dyn sym resolution in reverse References: <49028B5C.2000508@vmware.com> <20081025160945.GI29998@adacore.com> In-Reply-To: <20081025160945.GI29998@adacore.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: 2008-10/txt/msg00652.txt.bz2 Joel Brobecker wrote: > >> 2008-10-24 Michael Snyder >> >> * infrun.c (handle_inferior_event): Handle dynamic symbol >> resolution in reverse. > > Looks OK to me, but I don't understand why you check that stop_func_start > is zero. If I were to make a guess, it would be to quickly dismiss > the case were we reverse stepped into a function call, and so don't > need to check for trampolines (in other words, a CPU saver). Correct, but it's more than a CPU saver. If we are in a function (stop_func_start is non-zero), then we can set a step_resume breakpoint and continue, which is way faster than single stepping. We single-step only when we have to, ie. when we have actually stepped into the fixup jump table.