Re: [Patch, Fortran, F08] PR 84313: reject procedure pointers in COMMON blocks

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

2018-02-14 12:47 GMT+01:00 Jakub Jelinek <jakub@redhat.com>:
> On Wed, Feb 14, 2018 at 12:30:14PM +0100, Jakub Jelinek wrote:
>> On Tue, Feb 13, 2018 at 07:24:35PM +0100, Janus Weil wrote:
>> > as the subject line says, the attached patch rejects procedure
>> > pointers in COMMON blocks (which is forbidden in F08). Since it's
>> > apparently legal in F03, I'm still accepting it with -std=f2003 and
>> > add that flag to a test case where this 'feature' is used. In another
>> > one, I'm adding the error message that one gets with -std=f2008.
>> >
>> > As my last submission, this fixes fallout from
>> > https://groups.google.com/forum/?fromgroups#!topic/comp.lang.fortran/AIHRQ2kJv3c.
>> > As the last one, it is a very simple fix for an accepts-invalid
>> > problem (which is not a regression), so I hope this one will also
>> > still be suitable for trunk (if not, I hope the release managers, in
>> > CC, will stop me).
>> >
>> > It does regtest cleanly on x86_64-linux-gnu. Ok for trunk?
>>
>> This broke libgomp.fortran/threadprivate4.f90 test.

Sorry about that! I regtested with "make check-gfortran", which
doesn't run the libgomp tests, I guess?


>> Adding ! { dg-additional-options "-std=f2003" }
>> doesn't work, because the test uses
>>   call abort

I actually think we should get rid of such extensions in the
testsuite, where possible. This particular one is used all over the
place, but could be easily replaces by something like "stop 1", which
is standard Fortran.


>> which is a GNU extension and I have no idea how to choose allow_std
>> which includes GNU but doesn't include F2008.
>
> ! { dg-additional-options "-std=f2003 -fdec" }
>
> seems to work (because -std=f2003 sets
>       gfc_option.allow_std = GFC_STD_F95_OBS | GFC_STD_F77
>         | GFC_STD_F2003 | GFC_STD_F95 | GFC_STD_F2008_OBS;
> and -fdec adds:
>       gfc_option.allow_std |= GFC_STD_F95_OBS | GFC_STD_F95_DEL
>         | GFC_STD_GNU | GFC_STD_LEGACY;
> ), but it is quite nasty.  Isn't there a better way?

Yes, there is "-std=f2003 -fall-intrinsics", which is a little better
at least. It's what I did with proc_ptr_common1.f90 as well ...

https://gcc.gnu.org/viewcvs/gcc/trunk/gcc/testsuite/gfortran.dg/proc_ptr_common_1.f90?r1=257636&r2=257635&pathrev=257636


> Kind like -std=gnu++17 vs. -std=c++17 where the latter is standard
> and former standard + GNU extensions (which would roughly be
> "| GFC_STD_GNU | GFC_STD_LEGACY" in the fortran world).

Huh, I suppose it would be nice to have options like -std=gnu2003 and
-std=gnu2008, in analogy to those C++ options ...

Cheers,
Janus