From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32601 invoked by alias); 21 Jan 2009 05:23:31 -0000 Received: (qmail 32587 invoked by uid 22791); 21 Jan 2009 05:23:29 -0000 X-SWARE-Spam-Status: No, hits=-1.7 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from ti-out-0910.google.com (HELO ti-out-0910.google.com) (209.85.142.184) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 21 Jan 2009 05:23:25 +0000 Received: by ti-out-0910.google.com with SMTP id y6so3142668tia.18 for ; Tue, 20 Jan 2009 21:23:22 -0800 (PST) MIME-Version: 1.0 Received: by 10.110.57.6 with SMTP id f6mr6266551tia.31.1232515401469; Tue, 20 Jan 2009 21:23:21 -0800 (PST) In-Reply-To: <6D19CA8D71C89C43A057926FE0D4ADAA06CB06BB@ecamlmw720.eamcs.ericsson.se> References: <49463870.6080302@virtutech.com> <494A0A9C.6020809@virtutech.com> <494B5A82.4020004@virtutech.com> <494BF080.9060009@vmware.com> <6D19CA8D71C89C43A057926FE0D4ADAA06B06B04@ecamlmw720.eamcs.ericsson.se> <001401c96dce$5609c060$021d4120$@com> <6D19CA8D71C89C43A057926FE0D4ADAA06CB06BB@ecamlmw720.eamcs.ericsson.se> Date: Wed, 21 Jan 2009 05:23:00 -0000 Message-ID: Subject: Re: reverse for GDB/MI From: teawater To: Marc Khouzam Cc: Jakob Engblom , gdb-patches@sources.redhat.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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: 2009-01/txt/msg00434.txt.bz2 Thanks for the great work that your guys doing. :) On Wed, Jan 21, 2009 at 02:19, Marc Khouzam wro= te: > Hi, > > I am hoping this request can help restart the process > of getting the reverse MI commands approved. > > I have applied the patches of Process Record and Replay > and have built myself a nice GDB that can do reverse debugging > on Linux. > > I then implemented the corresponding support in DSF-GDB > (soon to be committed.) However, I ran into some MI limitations > (explanation below for those interested) which make me need > the MI Commands for Reverse debugging. > > A patch for these commands was submitted in > http://sourceware.org/ml/gdb-patches/2008-12/msg00276.html > but there were many discussions after, which did not seem to > conclude. > > The details of my troubles follow: > > With no MI commands for Reverse I tried to use CLI commands > but ran into a bug causing incomplete MI *stopped event when using CLI co= mmands. > http://sourceware.org/ml/gdb/2008-12/msg00058.html > > As per Nick's finding, I tried Async mode to work around *stopped event b= ug but > realized Process Record and Replay does not support Async. > > So, the solution I currently have is to use "set execution-direction" and= the > MI commands for execution. For example, to perform a 'reverse-continue' = from > DSF-GDB I have to do the set of three commands: > > set execution-direction reverse > -exec-continue > set execution-direction forward > > It would be nice to have the reverse MI commands :-) > > Thanks > > Marc > >> -----Original Message----- >> From: gdb-patches-owner@sourceware.org >> [mailto:gdb-patches-owner@sourceware.org] On Behalf Of Jakob Engblom >> Sent: Saturday, January 03, 2009 1:09 PM >> To: gdb-patches@sources.redhat.com >> Subject: RE: reverse for GDB/MI >> >> >> > Hi, >> > >> > It was pointed out to me that people who have been doing reversible >> > debug for a while seems to >> > have specific commands for reverse debugging and they do >> have a command >> > for "go to time point P". >> > For example http://www.undo-software.com/undodb_man.html: >> > >> > bgoton >> > Move forwards or backwards to the specified time, in simulated >> > nanoseconds. >> > bgoton + | - >> > Step forward/backward the specified number of simulated nanoseconds. >> >> Simics has it to, in some different ways: >> >> skip-to >> reverse n time units >> continue n time units >> >> I think this is a good example of the kind of new commands >> and abilities that >> come with having a reverse ability in the first place, like >> Marc said. >> >> And as the later discussion evolved, it would be jolly nice >> to have an idea of >> time in gdb. I think that is needed anyway to handle >> multicore, multiprocessor, >> and multithreaded debug: when things happen in disparate >> locations under the >> control of a single debugger quickly gets very interesting... >> >> Best regards, >> >> /jakob >> >> _______________________________________________________ >> >> Jakob Engblom, PhD, Technical Marketing Manager >> >> Virtutech Direct: +46 8 690 07 47 >> Drottningholmsv=E4gen 14 Mobile: +46 709 242 646 >> 11243 Stockholm Web: www.virtutech.com >> Sweden >> ________________________________________________________ >> >> >> >> >