[RFA] Fix hw watchpoints in process record.

[Pedro Alves]

On Thursday 05 November 2009 18:40:31, Michael Snyder wrote:
> Hui Zhu wrote:
> > Hi Michael,
> > 
> > I do some test with this patch.  But sometime hb didn't work in replay mode.
> 
> OK, thanks, I see the problem.
> 
> Try this patch instead.
> 
> 

Quick comment:

this assumes the target/arch has continuable watchpoints,
like x86/x86_64.  You'll see this misbehave on mips, when Hui
contributes the support.

You're evaluating the watchpoint expression on every event --- I
have a feeling it would make more sense to decouple precord from
that, like all other targets are decoupled.  That is, have precord
check for low level watchpoint triggers --- given [addr,length,type]
low level watchpoints --- when memory changes (at record_mem_entry time),
instead of evaluating the whole high-level watchpoint expression.

[IMO, we should mostly think of precord as just another a
simulator that mostly only interfaces gdb's core through
the target_ methods.]

-- 
Pedro Alves