On Wed, 3 Nov 2021 21:00:41 +0100
Harald Anlauf via Fortran <fort...@gcc.gnu.org> wrote:
> *PING*
>
> Am 27.10.21 um 21:09 schrieb Harald Anlauf via Fortran:
> > Dear Fortranners,
> >
> > when debugging the testcase, I noticed that a coarray declaration in
> > a COMMON statement wrongly set the dimension attribute instead of the
> > codimension. As a consequence, subsequent checks that catch this
> > invalid situation would not trigger.
> >
> > I see two possible solutions:
> >
> > - in gfc_match_common, replace
> >
> > /* Deal with an optional array specification after the
> > symbol name. */
> > m = gfc_match_array_spec (&as, true, true);
If coarrays are generally forbidden in commons then..
> >
> > by
> >
> > m = gfc_match_array_spec (&as, true, false);
.. this sounds right to me.
> >
> > which in turn would lead to a syntax error. Interestingly, the Intel
> > compiler also takes this route and gives a syntax error.
> >
> > - check the resulting as->corank and emit an error as in the attached
> > patch.
If we want to be more helpful than a mere syntax error (and we
should be) then yes.
Otherwise we'd have to explicitly
@@ -5275,9 +5275,19 @@ gfc_match_common (void)
/* Deal with an optional array specification after the
symbol name. */
- m = gfc_match_array_spec (&as, true, true);
+ m = gfc_match_array_spec (&as, true, false);
if (m == MATCH_ERROR)
goto cleanup;
+ if (m == MATCH_NO)
+ {
+ /* See if it is a coarray and diagnose it nicely. */
+ if (gfc_match_array_spec (&as, false, true) == MATCH_YES)
+ {
+ gfc_error ("Symbol %qs in COMMON at %C cannot be a "
+ "coarray", sym->name);
+ goto cleanup;
+ }
+ }
where your patch works equally well and is more concise.
Maybe you want to add a test for the double-colon variant too?
common /c2/ y[:] ! { dg-error "cannot be a coarray" }
A type with a coarray seems to require to be allocatable so is
rejected (properly, but not mentioning the coarray) with
Error: Derived type variable ‘comm_ty1’ in COMMON at (1) has an ultimate
component that is allocatable
When reading gfc_match_array_spec i thought that it might have been cleaner
to split the coarray handling out to a separate gfc_match_coarray_spec but
that's what we have.
> >
> > The attached patch regtests fine on x86_64-pc-linux-gnu. OK for mainline?
LGTM but i cannot approve it.
Thanks for the patch!
