[Patch, fortran] PR80477 - [OOP] Polymorphic function result generates memory leak

[Janus Weil]

Hi Paul,

2018-07-28 9:32 GMT+02:00 Paul Richard Thomas <paul.richard.thomas@gmail.com>:
> Several attempts, including mine, were made to fix this bug since it
> was posted. They were all attacking the wrong place. Instead of
> providing the free of the class _data as part of the call to
> 'add_a_type' it should be included in the post block of the argument
> processing in the call to 'assign_a_type'. The comment in the patch
> says the rest.
>
> Bootstrapped and regtested on FC28/x86_64 - OK for trunk?

great that you managed to solve this one! The patch looks very good to
me, but I'm afraid two details may be missing:

1) If the type has allocatable components, those need to be freed first.
2) If the type has a finalizer, that needs to be called as well.

I believe that both points can be fixed by calling the _final
component of the vtab before freeing the class data. Should not be
hard to add, I hope (gfc_add_finalizer_call might be useful).

Thanks for your efforts ...

Cheers,
Janus