From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1537 invoked by alias); 4 Oct 2008 08:13:03 -0000 Received: (qmail 1525 invoked by uid 22791); 4 Oct 2008 08:13:02 -0000 X-Spam-Check-By: sourceware.org Received: from mtaout4.012.net.il (HELO mtaout4.012.net.il) (84.95.2.10) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sat, 04 Oct 2008 08:12:23 +0000 Received: from HOME-C4E4A596F7 ([77.127.170.116]) by i_mtaout4.012.net.il (HyperSendmail v2004.12) with ESMTPA id <0K8700JQYG5LGZ60@i_mtaout4.012.net.il> for gdb-patches@sourceware.org; Sat, 04 Oct 2008 11:12:58 +0300 (IDT) Date: Sat, 04 Oct 2008 08:13:00 -0000 From: Eli Zaretskii Subject: Re: [RFA] Reverse Debugging, 5/5 In-reply-to: <48E65EDD.8060004@vmware.com> X-012-Sender: halo1@inter.net.il To: Michael Snyder Cc: gdb-patches@sourceware.org, drow@false.org, pedro@codesourcery.com, teawater@gmail.com Reply-to: Eli Zaretskii Message-id: References: <48E3CD66.9020600@vmware.com> <48E53FE3.8090306@vmware.com> <48E65EDD.8060004@vmware.com> 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/msg00102.txt.bz2 > Date: Fri, 03 Oct 2008 11:05:17 -0700 > From: Michael Snyder > CC: "gdb-patches@sourceware.org" , "drow@false.org" , "pedro@codesourcery.com" , "teawater@gmail.com" > > Eli Zaretskii wrote: > >> Date: Thu, 02 Oct 2008 14:40:51 -0700 > >> From: Michael Snyder > > >> The context is, the user says "show exec-direction" > >> with a target that doesn't support reverse. > >> > >> Is it better to just say "Forward", with no comment, > >> or is it better to let the user know that the question > >> is not applicable? Or both? > > > > Both, I'd say. > > OK, how about this? > > (gdb) show exec-direction > Forward (target `None' does not support exec-direction). Fine with me. > >>> Shouldn't we have some kind of caveat here regarding function prologue > >>> and epilogue? > >> Like what? > >> > >> If I've done my job right, prologues and epilogues > >> should be handled transparently, just like they are > >> when stepping forward. > > > > Are they treated transparently when we step forward? I had an > > impression that in optimized code, they aren't always transparent. > > OK, I should have said "we do our best to treat them > transparently". I suppose if the code is too optimized > for us to do a good job when we're going forward, we will > also have problems in reverse. Yes, that's what I had in mind. So perhaps the text should be a little vaguer and maybe with some reasonable qualifier, like "unless the code is too heavily optimized". Maybe have that in a @footnote.