On Thu, 07 Nov 2013 16:41:40 +0100, Metzger, Markus T wrote:
> I hacked a first prototype of this (see below).  It passes most tests but
> results in three fails in the record_goto suite.
> 
> One thing that it shows, though, is that it only removes the 'mostly harmless'
> hack in the various goto functions shown above.
> 
> The more serious hacks in record_btrace_start_replaying
> 
> 	  /* Make sure we're not using any stale registers.  */
> 	  registers_changed_ptid (tp->ptid);
> 
> 	  /* We just started replaying.  The frame id cached for stepping is based
> 	     on unwinding, not on branch tracing.  Recompute it.  */
> 	  frame = get_current_frame_nocheck ();
> 	  insn = btrace_insn_get (replay);
> 	  sal = find_pc_line (insn->pc, 0);
> 	  set_step_info (frame, sal);
> 
> and record_btrace_stop_replaying
> 
> 	  /* Make sure we're not leaving any stale registers.  */
> 	  registers_changed_ptid (tp->ptid);
> 
> however, are not removed by this.

In such case it is not finished.  These hacks should not be needed.


> They are required when reverse-stepping the first time or when
> stepping past the end of the execution trace.

I have patched what you describe as the problem.  But as I do not have a box
with reliably working BTS so it is difficult for me to say whether it works or
not.  I can look at other problems if you describe them from a reliable box.


> Plus the patch has the potential of messing things up pretty badly if
> somehow (maybe due to some unexpected error () somewhere in proceed ()) the
> record goto command does not complete and BTHR_GOTO remains set.

It can be cleaned up as I did there, thanks for catching it.


Thanks,
Jan