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

Marc Khouzam
2012-10-31T19:10:24Z

> -----Original Message-----
> From: gdb-patches-owner@sourceware.org
> [mailto:gdb-patches-owner@sourceware.org] On Behalf Of Pedro Alves
> Sent: Wednesday, October 31, 2012 2:03 PM
> To: dje@google.com
> Cc: Yao Qi; gdb-patches@sourceware.org
> Subject: Re: [PATCH 2/2] new tracepoint downloaded MI notification.
>
> > > 2012-09-27 Yao Qi <yao@codesourcery.com>
> > >
> > > * gdb.trace/mi-traceframe-changed.exp
> (test_tfind_remote): Adjust.
> > > * gdb.trace/mi-tracepoint-downloaded.exp: New.
> >
> > Hi.
> > It would be useful if the reason why this notification
> exists was specified in the code.
> > E.g, "This notification exists because frontends ... [fill
> in the blank]."
>
> Yes, indeed. I'll probably upgrade that "useful" to "required". :-)
> It is not clear for example, why would the frontend
> care about a particular tracepoint having been downloaded. I can see
> it wanting to know when a trace run has started from the CLI,
> for instance,
> which already implies that tracepoints have been downloaded.

In older GDB versions, when creating a tracepoint during a trace run,
that tracepoint would not be pushed to the target until the next
trace run. The idea is that a frontend could indicate which tracespoints
were active on the target and which were not.

Now that GDB pushes new tracepoints to the target immediately, that
use-case may not apply, but I wonder if there are other situations
where some tracepoints will be on the target and other will not?

Marc