Re: [PATCH] Allow calling of C++ methods from python

[Hannes Domani <ssbssa@yahoo.de>]

 Am Samstag, 16. Dezember 2023, 01:30:31 MEZ hat Tom Tromey <tom@tromey.com> Folgendes geschrieben:

> >>>>> "Hannes" == Hannes Domani <ssbssa@yahoo.de> writes:
>
> Hannes>  static int static_func ();
>
> Hannes> (gdb) py b_obj = gdb.parse_and_eval('b_obj')
> Hannes> (gdb) py print(b_obj['static_func']())
> Hannes> Traceback (most recent call last):
> Hannes>  File "<string>", line 1, in <module>
> Hannes> RuntimeError: Value is not callable (not TYPE_CODE_FUNC).
>
> I'm a bit surprised that a static method is not TYPE_CODE_FUNC.
> It seems like it should be, because these are really just functions.

I never really questioned it being TYPE_CODE_METHOD, I was just wondering
instead if there is a flag that tells us that it is a static method.


> Hannes> (gdb) py print(b_obj['arg0_func']())
> Hannes> Traceback (most recent call last):
> Hannes>  File "<string>", line 1, in <module>
> Hannes> gdb.error: Too few arguments in function call.
> Hannes> Error while executing Python code.
> Hannes> (gdb) py print(b_obj['arg0_func'](b_obj))
> Hannes> 198
>
> How does this interact with overloading?

Probably as you expected, it doesn't work, since the [] operator
of gdb.Value doesn't know what to do:

(gdb) py print(b_obj['overloaded_func'])
Traceback (most recent call last):
  File "<string>", line 1, in <module>
gdb.error: cannot resolve overloaded method `overloaded_func': no arguments supplied
Error while executing Python code.


> It seems to me that either b_obj['name'] has to return some kind of
> overload set, or we need a different API, like b_obj.call_method('name', ...).
>
> In the latter case we could have it automatically supply 'this', at
> least when it's needed.

The overload set would probably be relatively easy to implement, while
the call_method would be easier to use, if it automatically chooses the
right one based on the arguments.


Regards
Hannes