Display of read/access watchpoints when HAVE_NONSTEPPABLE_WATCHPOINT

Orjan Friberg orjan.friberg@axis.com
Tue May 4 07:31:00 GMT 2004


Eli Zaretskii wrote:
> 
> So this target could relatively easily support an API where the target
> itself tells GDB which of watchpoints triggered and why, provided that
> we invent a way for GDB to map between its watchpoint numbers and the
> target-size hardware data watchpoints.  Is that true?

Yes (provided the register contents haven't changed since the watchpoint 
hit, of course - I assume the mapping procedure you're describing should 
be done before single-stepping over the watchpoint for targets with 
nonsteppable watchpoints).

Another thing, which may or may not be relevant in this discussion, is 
if the remote protocol should be altered.  Right now, the 
watch/rwatch/awatch part of the stop reply packet when hitting a 
watchpoint is not used (except for parsing out the stopped data 
address).  In addition, it doesn't play nice with multiple watchpoint 
hits, since only one of watch/rwatch/awatch is possible.  I don't have 
any practical suggestion on how to make it more useful though :( .

>>(In addition there is also one hardware instruction breakpoint, but I 
>>guess that doesn't matter in this context.)
> 
> 
> Used for hardware-assisted breakpoints, yes?

(Ugh, I always botch the terminology.)  Yes, invoked by the "hbreak" 
command.

-- 
Orjan Friberg
Axis Communications



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