Re: [reverse RFA] no singlestep-over-BP in reverse

Michael Snyder
2008-09-15T23:09:57Z

Daniel Jacobowitz wrote:
> On Mon, Sep 15, 2008 at 12:05:25PM -0700, Michael Snyder wrote:
>>> If there is a breakpoint on the previous instruction, will you hit it
>>> before or after de-executing that instruction?
>> Well, if trap insns are in place, that's what will be
>> executed (not the shadow insn).
>
> Presumably it'd be a hardware breakpoint. Software breakpoints in
> reverse execution seem... awkward.

Right. I've just been re-thinking the issue.

I don't know how it might work with SW bp, but the three
implementations that I know of right now all use HW bps.

In that case, the target just has to guarantee to un-execute
the instruction before stopping, and then everything will be
OK.

I posted some tests, those all work, but I will go ahead
and try to port (and post) the consecutive.exp test anyway.