Re: support for BookE hardware debug features

[Joel Brobecker <brobecker@adacore.com>]

> I was thinking about something along those lines too. Possibly adding a
> target hook which would receive a struct expression with the condition
> and a watchpoint address, and return true if it can be
> hardware-accelerated. That hook would also set up the hardware debug
> registers accordingly.

That should work, at least for now. The downside, as I was saying,
is that each target will possibly have to duplicate the expression
tree analysis. I more targets start popping up with this feature,
perhaps we'll have to think of a more generic approach where we pass
the result of the analysis to the hook rather than let the hook do
the analysis. In the meantime, it's probably not worth worrying too
much about genericity if only one target in the FSF tree supports it.
(our VxWorks implementation has still a couple of key parts that need
to be improved before we can think of contributing it)

> Regarding what is a viable approach, our main concern is that we do it
> in a way which will be accepted upstream.

I personally don't see any problem with that, if it's just a well
defined hook.

> Thanks for sharing this code, by the way. Just a question to be on the
> safe side: is there any copyright implication if we stare at it for too
> long (half-joking)?

No problem at all, I wrote the code, and it's not confidential.
If it's any help to you, then by all means, use it in any way.

-- 
Joel