Tracepoint enhancements

Stan Shebs
2008-10-31T19:57:46Z

There is some interest in pumping up GDB's tracepoint capabilities, in
particular to make it more suitable for cross-debugging a target with
serious performance constraints. While a lot of the detail is centered
around making a faster stub and other low-level tweaks, we are going to
do MI for tracing finally, plus it's an opportunity to review the
existing trace commands and consider what interface changes are
desirable. In particular, we will want to think about how tracing should
interoperate with non-stop debugging and multi-process.

So the first question that comes to my mind is: how many people are
actually using the trace commands right now? If they're not being much
used, then we have more flexibility about making user-visible changes.

One possible change to consider is to merge tracepoint setting into
breakpoint setting. Among other benefits would be a single numbering
scheme for breakpoints and tracepoints, plus we will be able to share
some machinery and make things more consistent.

A bigger change would be to introduce a general notion of execution
history, which could subsume fork checkpoints and trace snapshots, maybe
tie into some versions of reverse debugging as well.

What else should we be thinking about doing?

(There are of course all kinds of implementation-level changes to make,
but at the moment I'm focussed on the user experience.)

Stan