[Patch, Fortran] PR57217 - re-add type checks for TBP overriding

[Janus Weil]

Hi Tobias,

> GCC 4.7 added some additional checks for type-bound procedure overriding.
> However, doing so it weakened the check whether the nonpass argument has the
> same type.
>
> While for normal arguments, passing the parent type to an extended type is
> fine, for overriding the type (of nonpass arguments) must be exactly the
> same as in the original type.

in principle I think your idea to tighten up the type check by
symmetrizing it is ok.

However, I'm not sure if the place where you do it is the most
preferable: I think it should rather go inside of
check_dummy_characteristics (since any check for the dummy
characteristics should include the 'strict' type check, and not only a
check of type compatibility, cf. F08:12.3.2.2).

Anyway, there already is a call to 'compare_type_rank' in
'check_dummy_characteristics'. So, you could either just symmetrize
this, or alternatively use a double 'gfc_compare_types' and a separate
check for the rank.

Moreover, I think your current patch misses e.g. the assumed-type
handling that is present in compare_type_rank.

Cheers,
Janus