Re: [RFA 2/3] Demote to sw watchpoint only in update_watchpoint

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Thiago Jung Bauermann wrote:

> On the other hand, the current code is already broken in that regard,
> and creating several read and access watchpoints on today's GDB will
> confuse it and allow creating more hardware watchpoints (read, access or
> regular) than possible. Thus, this patch doesn't make the situation any
> worse. So now I just use b->type.
> 
> The real fix IMHO would be to make the -tdep code manage the creation
> and deletion of bp_locations, so that it could always make an informed
> decision about what can and cannot be done with the available hardware
> debug resources. But that's out of the scope of this patch series.

Yes, I'd agree with Eli and Pedro that this really ought to be fixed.
I also agree that this is independent of this patch (and in fact I'd
consider the patch a (small) step in the right direction anyway,
since it reduced the number of locations in the code where resource
accounting is done) ...

> 2011-05-03  Thiago Jung Bauermann  <bauerman@br.ibm.com>
> 
> 	* breakpoint.c (update_watchpoint): Change between software and
> 	hardware watchpoint for all kinds of watchpoints, not just
> 	read/write ones.  Determine b->exact value here instead of
> 	in watch_command_1.  Error out if there are not enough resources
> 	for a read or access hardware watchpoint.
> 	(watch_command_1): Remove logic of checking whether there are
> 	enough resources available, since update_watchpoint will do that
> 	work now.  Don't set b->exact here.  Catch exceptions thrown by
> 	update_watchpoint and delete the watchpoint.
> 	(can_use_hardware_watchpoint): Remove exact_watchpoints argument.
> 	Use target_exact_watchpoints instead.
> 	(delete_breakpoint): Notify observers only if deleted watchpoint
> 	has a breakpoint number assigned to it.

As Eli has withdrawn objections to the patch, this is OK.

Thanks,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com