Destroying frame caches

Destroying frame caches

[Andreas Schwab]

What function does gdb call to destroy a frame cache object?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Destroying frame caches

[Daniel Jacobowitz]

On Tue, Jun 05, 2007 at 02:47:34PM +0200, Andreas Schwab wrote:
> What function does gdb call to destroy a frame cache object?

reinit_frame_cache destroys the whole cache; is that what you mean?

-- 
Daniel Jacobowitz
CodeSourcery

Re: Destroying frame caches

[Andreas Schwab]

Daniel Jacobowitz <drow@false.org> writes:

> On Tue, Jun 05, 2007 at 02:47:34PM +0200, Andreas Schwab wrote:
>> What function does gdb call to destroy a frame cache object?
>
> reinit_frame_cache destroys the whole cache; is that what you mean?

How can you deallocate any extra memory?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Destroying frame caches

[Daniel Jacobowitz]

On Tue, Jun 05, 2007 at 03:06:14PM +0200, Andreas Schwab wrote:
> Daniel Jacobowitz <drow@false.org> writes:
> 
> > On Tue, Jun 05, 2007 at 02:47:34PM +0200, Andreas Schwab wrote:
> >> What function does gdb call to destroy a frame cache object?
> >
> > reinit_frame_cache destroys the whole cache; is that what you mean?
> 
> How can you deallocate any extra memory?

Extra memory normally goes on the frame obstack using
frame_obstack_zalloc.  There's no hook for target-specific cleanup.

-- 
Daniel Jacobowitz
CodeSourcery

Re: Destroying frame caches

[Andreas Schwab]

Daniel Jacobowitz <drow@false.org> writes:

> On Tue, Jun 05, 2007 at 03:06:14PM +0200, Andreas Schwab wrote:
>> Daniel Jacobowitz <drow@false.org> writes:
>> 
>> > On Tue, Jun 05, 2007 at 02:47:34PM +0200, Andreas Schwab wrote:
>> >> What function does gdb call to destroy a frame cache object?
>> >
>> > reinit_frame_cache destroys the whole cache; is that what you mean?
>> 
>> How can you deallocate any extra memory?
>
> Extra memory normally goes on the frame obstack using
> frame_obstack_zalloc.

This is not possible.  There is no way to tell libunwind not to use
malloc.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Destroying frame caches

[Daniel Jacobowitz]

On Tue, Jun 05, 2007 at 03:30:10PM +0200, Andreas Schwab wrote:
> This is not possible.  There is no way to tell libunwind not to use
> malloc.

Well, then you'll have to either change that, or add a new interface.
Probably to struct frame_unwind.

-- 
Daniel Jacobowitz
CodeSourcery

Re: Destroying frame caches

[Mark Kettenis]

> Date: Tue, 5 Jun 2007 09:25:47 -0400
> From: Daniel Jacobowitz <drow@false.org>
> 
> On Tue, Jun 05, 2007 at 03:06:14PM +0200, Andreas Schwab wrote:
> > Daniel Jacobowitz <drow@false.org> writes:
> > 
> > > On Tue, Jun 05, 2007 at 02:47:34PM +0200, Andreas Schwab wrote:
> > >> What function does gdb call to destroy a frame cache object?
> > >
> > > reinit_frame_cache destroys the whole cache; is that what you mean?
> > 
> > How can you deallocate any extra memory?
> 
> Extra memory normally goes on the frame obstack using
> frame_obstack_zalloc.  There's no hook for target-specific cleanup.

Targets should therefore use the same obstack for any additional
memory they need.

Re: Destroying frame caches

[Mark Kettenis]

> From: Andreas Schwab <schwab@suse.de>
> Date: Tue, 05 Jun 2007 14:47:34 +0200
> 
> What function does gdb call to destroy a frame cache object?

IIRC we use obstacks for frame caches, so they disappear automagically
whenever the part of the stack that contains the frame cache is freed.