Re: [PATCH 2/2] new tracepoint downloaded MI notification.

Yao Qi
2012-11-01T00:34:26Z

On 11/01/2012 01:59 AM, Pedro Alves wrote:
>> From the frontend's point of view, {number, location number} is better, and the schema "number.location_number" has been used in "=breakpoint-modified" notification. However, if we want to use {number, location number} here, we have to guarantee that the location number is an attribute of bp_location, because:
> This is not a particular issue of tracepoint locations, so, if it was a problem, it
> would be a problem for the existing notifications and MI commands as well.
>
> IOW, this would need to be fixed for all those other cases that expose location
> numbers, not just come up with an ad hoc solution.
>

I agree.

> IOW, there's no good justification for deviating this notification from
> existing practice.
>

What do you mean by "existing practice"? Is {number, location number}
the "existing practise"?

>> >In short, if we can make location number persistent (unchanged for a given bp_location object), then {number, location number} is fine, otherwise, I'd prefer {number, address}.
> {number, address} may looks stabler, but not even that is completely stable.
> Change the program's code a little, recompile, reload symbols, and you'll see the
> address change. Whatever smarts you'd want the frontend to have to track
> locations, GDB could do instead, once for all frontends, and better, because
^^^^^^^^^
IIUC, "locations" here mean location address instead of location number.

> it may use properties other than the address to decided whether a new instance
> of a location is logically the same as the old one (think of stap probes or static
> tracepoints, where the address is really a very low target side detail; or just
> consider line number instead of address). I think all this goes hand in hand with
> redesigning how GDB handles breakpoint re-setting (or rather, get rid of re-setting as is),
> which will make this whole stabler locations issue better. Keith will be going to
> work on that very soon, IIUC.

FAOD, we should continue to use {number, location number}, and it
requires improvement of breakpoint re-setting, correct?

--
Yao