Re: [Patch, Fortran, OOP] PR 56261: seg fault call procedure pointer on polymorphic array

[Janus Weil <janus at gcc dot gnu dot org>]

>>> Thus, I think one should be strict about the requires-explicit-interface
>>> diagnostic (= new code, using F90+), but for interface mismatch (= could
>>> be
>>> old Fortran 66 code),  it should be either disabled or - as currently -
>>> just
>>> be a warning.
>>
>> How about enabling it by default, but having -std=legacy disable the
>> checks?
>
> Hmm, I think I'd prefer to have for the arguments only a warning with
> -std=gnu - except for the function result value, which should always be an
> error. And also the "requires an explicit interface" checks should always
> use an error.

Why the distinction (apart from: NAG does it this way)?

The nice thing about the current patch is that it just relies on the
full machinery of "gfc_compare_interfaces". Making distinctions about
where to give an error or warning probably requires again a certain
amount of code-duplication from interface.c. Or do you see a
technically simple way to do this?


> However, if one goes for an error with -std=gnu, the error should explicitly
> mention that "-std=legacy" disables the error. At least I do not recall all
> the special flags which enable certain features, nor whether such a flag
> exists at all. And I doubt that a normal user do.

That's right. Might be worth to add it. Although the folks which
operate such 'dirty' legacy codes hopefully know about the usefulness
of -std=legacy ...

Cheers,
Janus