From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13818 invoked by alias); 20 May 2005 22:08:25 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 13471 invoked from network); 20 May 2005 22:08:17 -0000 Received: from unknown (HELO nevyn.them.org) (66.93.172.17) by sourceware.org with SMTP; 20 May 2005 22:08:16 -0000 Received: from drow by nevyn.them.org with local (Exim 4.50) id 1DZFf5-00030O-Id; Fri, 20 May 2005 18:08:07 -0400 Date: Fri, 20 May 2005 22:08:00 -0000 From: Daniel Jacobowitz To: Paul Schlie Cc: Dan Shearer , gdb@sources.redhat.com Subject: Re: [discuss] Support for reverse-execution Message-ID: <20050520220807.GA11445@nevyn.them.org> Mail-Followup-To: Paul Schlie , Dan Shearer , gdb@sources.redhat.com References: <20050520174133.GT19642@erizo.shearer.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i X-SW-Source: 2005-05/txt/msg00247.txt.bz2 On Fri, May 20, 2005 at 06:01:44PM -0400, Paul Schlie wrote: > > From: Dan Shearer > > In the longer term yes, GDB should be able to debug with a sense of > > direction and time. But I think it will take quite a bit of experimentation > > before we have a clear model of how to do this, and the only way I can think > > of for both having a reversible GDB and not touching GDB too much is by > > considering remote targets first. > > - Then you'll end up with nothing more than an interface to a propriety > simulator, which doesn't seem like a good goal or approach for GDB. This argument is so bogus that I need to call you on it. You end up with a reasonable interface to _any_ simulator, whether proprietary or not. The details of an efficient implementation will be obviously dependent on the simulator's state and implementation. I am inclined to agree with the posted proposals that the implementation of reverse-stepi should be opaque to GDB, at least for now. The performance of shuffling state diffs over the remote protocol - or even just references to them - would be horrid. It also means that GDB will be limited to a particular class of implementations of reversible simulation instead of the concept of reversible simulation. You're describing something which may be interesting, someday. Do feel welcome to implement it; we'll be glad to help. I don't think that it's inherently more appropriate than the proposed interface, though. -- Daniel Jacobowitz CodeSourcery, LLC