RE: [RFA] Reverse Debugging, 5/5

[Michael Snyder <msnyder at vmware dot com>]

Done and done.
Excellent!  We seem to be approaching convergence!

________________________________________
From: Eli Zaretskii [eliz@gnu.org]
Sent: Saturday, October 04, 2008 1:11 AM
To: Michael Snyder
Cc: gdb-patches@sourceware.org; drow@false.org; pedro@codesourcery.com; teawater@gmail.com
Subject: Re: [RFA] Reverse Debugging, 5/5

> Date: Fri, 03 Oct 2008 11:05:17 -0700
> From: Michael Snyder <msnyder@vmware.com>
> CC: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>,   "drow@false.org" <drow@false.org>,  "pedro@codesourcery.com" <pedro@codesourcery.com>,   "teawater@gmail.com" <teawater@gmail.com>
>
> Eli Zaretskii wrote:
> >> Date: Thu, 02 Oct 2008 14:40:51 -0700
> >> From: Michael Snyder <msnyder@vmware.com>
>
> >> 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.