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Re: RFC: Program Breakpoints
On Tue, Mar 24, 2009 at 01:32:57PM -0700, Ross Morley wrote:
>> I read through this; overall, it looks sane. On some targets
>> implementing this would require the remote stub to read from pc
>> anyway; that's faster than GDB doing it, but not necessarily much
>> faster. But on some other targets the stub has to do this anyway,
>> or can pipeline it with other necessary operations, so it's not a big
>> loss.
>>
>>
>
> I think you're saying it's not a big deal performance-wise to do this
> without a remote protocol extension. Is that correct?
No, I was saying the opposite. Sometimes it will still be expensive
to implement the protocol extension. I'm interested in whether anyone
sees an approach that does not require instruction scanning.
GDB has the option to cheat - it can consult the program (ELF file),
separately from the target's view of memory. This would not work for
stray breakpoints inserted in the program at runtime, though.
--
Daniel Jacobowitz
CodeSourcery