Re: [PATCH 8/9] Implement gdb.execute_mi

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 04 Apr 2023 11:08:56 -0600
> From: Tom Tromey via Gdb-patches <gdb-patches@sourceware.org>
> 
> This adds a new Python function, gdb.execute_mi, that can be used to
> invoke an MI command but get the output as a Python object, rather
> than a string.  This is done by implementing a new ui_out subclass
> that builds a Python object.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=11688
> ---
>  gdb/Makefile.in                         |   1 +
>  gdb/NEWS                                |   3 +
>  gdb/doc/python.texi                     |  29 ++++
>  gdb/mi/mi-cmds.h                        |   5 +
>  gdb/mi/mi-main.c                        |  15 ++
>  gdb/python/py-mi.c                      | 298 ++++++++++++++++++++++++++++++++
>  gdb/python/python-internal.h            |   3 +
>  gdb/python/python.c                     |   5 +
>  gdb/testsuite/gdb.python/py-exec-mi.exp |  32 ++++
>  gdb/testsuite/gdb.python/py-mi-cmd.py   |  18 ++
>  10 files changed, 409 insertions(+)

Thanks.

> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -152,6 +152,9 @@ info main
>       (program-counter) values, and can be used as the frame-id when
>       calling gdb.PendingFrame.create_unwind_info.
>  
> +  ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
> +     GDB/MI command and returns the output as a Python dictionary.

This part is OK.

> +Conversely, it is possible to execute @sc{GDB/MI} commands from
                                         ^^^^^^^^^^^
In print, @sc produces "small caps" only for lower-case letters, so
the above should use @sc{gdb/mi} (here and elsewhere).

> +Invoke a @sc{GDB/MI} command.  @var{command} is the name of the
> +command, a string.  (Note that the leading @samp{-} should be omitted
> +here.)

Why is it a good idea to omit the leading dash?

And what does it mean for command switches, which start with two
dashes?

> +This function returns a Python dictionary whose contents reflect the
> +corresponding @sc{GDB/MI} command's output.  Refer to the
> +documentation for these commands for details.  Lists are represented
> +as Python lists, and tuples are represented as Python dictionaries.

Is this description enough to understand what will be returned?  What
about error messages, for example -- how are those returned?

Reviewed-By: Eli Zaretskii <eliz@gnu.org>