Re: python API to trigger a "select-frame" like event with a given location

[Andrew Burgess via Gdb <gdb@sourceware.org>]

Simon Sobisch via Gdb <gdb@sourceware.org> writes:

> using a frame filter and decorator I can drop "not interesting" frames 
> and add "artificial - display only" ones:
>
>
> Instead of
>
> (gdb) backtrace
>
> #0  PROG2_ (...) at copybook.cpy:14
> #1  PROG2 (...) at progb.cob:127
> #2  PROG1_ (...) at init.cpy:21
> #3  PROG1 (...) at prog.cob:139
> #4  main  (...) at prog.c:23223
>
> I can show (combined with
>
> (gdb) mybacktrace
>
> #0  PROG2_ (...) at copybook.cpy:14
> #0.0  COPYFUNC SECTION at copybook.cpy:14
> #0.1  PROGFIN SECTION at progb.cob:521
> #0.2  PROGMAIN SECTION at progb.cob:195
> #0.3  PROG2 at progb.cob:127
> #2  PROG1_ (...) at init.cpy:21
> #2.0  PROG-INIT-EXT SECTION at init.cpy:21
> #2.1  PROG-INIT SECTION at init.cpy:41
> #2.2  MAIN-000 SECTION at proga.cob:139
> #2.3  PROG1 at proga.cob:139
>
>
> Also there's the option to add myup and mydown commands which select the 
> "expected" frame (0 and 2, in this example) where all the relevant 
> variables are defined.
>
>
> But currently I see no way to programmatically "select" by location 
> (frame + linespec/LOCATION) [which would, other than "list" also be 
> passed to UIs/MI).
>
> Is there an option that I've overlooked?
>
>
> If not: could there be an extension to "select-frame level"
>
> select-frame level LOCATION
>
> select-frame level -- Select a stack frame by level and show LOCATION in
>                        the UI
>
> or a new command
>
> show-location LOCATION
>
> that executes what select-frame does, but _without_ selecting anything 
> (calling interps_notify() with the location as "selection")?

If I understand what you need, then you are looking for way to implement
your 'myup' and 'mydown' commands such that GDB will appear to move
though the artificial frames (e.g. 0.0, 0.1, 0.2, 0.3, etc).  To do this
you need to select the real frame (#0), but then want some way such that
GDB will notify the various UI's to indicate that their focus should
shift to the source locations corresponding to the artificial frames,
right?

You mention, but seem to dismiss, using 'list'.  Can you expand on why
this doesn't meet your needs?

Which UIs in particular is it that you are interested in seeing update?
I ask because I'm wondering which events it is that would need to be
emitted.  Could you expand with some user stories, which UI is the user
looking at, what actions do they perform, and what is updated as a
consequence.

Thanks,
Andrew