RE: [PATCH v9 29/29] record-btrace: add (reverse-)stepping support

["Metzger, Markus T" <markus dot t dot metzger at intel dot com>]

> -----Original Message-----
> From: Pedro Alves [mailto:palves@redhat.com]
> Sent: Thursday, December 19, 2013 9:10 PM


> > +  if (non_stop)
> > +    error (_("Record btrace can't debug inferior in non-stop mode "
> > +	     "(non-stop)."));
> 
> What's the intent of saying non-stop twice, in:
> 
>  "in non-stop mode (non-stop)"

I took this from s/w record without thinking.  Fixed.


> > +  /* Stop all other threads. */
> > +  if (!non_stop)
> > +    ALL_THREADS (other)
> > +      other->btrace.flags &= ~BTHR_MOVE;
> 
> (I know it doesn't work currently), but in non-stop, the
> event thread should also get its BTHR_MOVE flag cleared.
> I didn't spot where that was being done.

It's done in record_btrace_step_thread right at the beginning.


> > +  /* GDB seems to need this.  Without, a stale PC seems to be used
> resulting in
> > +     the current location to be displayed incorrectly.  */
> > +  registers_changed_ptid (tp->ptid);
> 
> This really shouldn't be necessary, given target_resume does
> it for you.  If you still needed, you're papering over some
> problem.

If we start replaying in to_wait, we'll call get_current_frame
to fix up some stepping related frames.  This will be done on
the current PC.

When we step later on in record_btrace_step_thread, we change
the replay position but not the PC.

I guess it will be more clear when I move this into
record_btrace_step_thread and change the comment.

Regards,
Markus.
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