https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88169
--- Comment #7 from kargl at gcc dot gnu.org ---
(In reply to kargl from comment #6)
> (In reply to Neil Carlson from comment #5)
> > Stated a bit more clearly, the question is, whether in
> >
> > The namelist-group-name shall not be a name accessed by use association.
> >
> > the name (in the scope of the declaration) is accessed by use association,
> > or the name is accessed in another scope by use association.
>
> I've asked on the J3 mailing list for clairfication. 14.2.2
> say ", identifiers, and namelist groups in a module." Namelist
> groups is a bit vague, here. Does this mean namelist group names
> or namelist group objects. My current thinking is C8102 is to
> prevent
>
> module foo
> ....
> namelist /bar/ ...
> end module
>
> program bah
> use foo
> real x
> namelist /bar/x
> ...
> end program bah
>
> where program bar is trying to extend the namelist-group-object-list.
So, I've asked on J3 mailing list (and after a rather condescending reply),
it is definitely a bug in gfortran. Constraint c8102 from F2018 applies
to a namelist-group-name in the scoping unit that USEs the module. Thus,
in the above code, using 'bar' in program 'bah' as a namelist-group-name is
invalid as 'bar' has been made available via USE association.
This patch allows a slightly modify version of Neil's code to compile and
run (x in main is implicitly defined local variable, which is different
than the x in module foo).
Index: module.c
===================================================================
--- module.c (revision 266386)
+++ module.c (working copy)
@@ -3711,7 +3711,6 @@ static void
mio_namelist (gfc_symbol *sym)
{
gfc_namelist *n, *m;
- const char *check_name;
mio_lparen ();
@@ -3722,17 +3721,6 @@ mio_namelist (gfc_symbol *sym)
}
else
{
- /* This departure from the standard is flagged as an error.
- It does, in fact, work correctly. TODO: Allow it
- conditionally? */
- if (sym->attr.flavor == FL_NAMELIST)
- {
- check_name = find_use_name (sym->name, false);
- if (check_name && strcmp (check_name, sym->name) != 0)
- gfc_error ("Namelist %s cannot be renamed by USE "
- "association to %s", sym->name, check_name);
- }
-
m = NULL;
while (peek_atom () != ATOM_RPAREN)
{
% cat a.f90
module foo_nml
implicit none
real :: x
namelist /foo/ x
end module
program main
use foo_nml, only: bar => foo, x
implicit none
x = 42
write(*,nml=bar)
end program
% gfcx -o z a.f90 && ./z
&FOO
X= 42.0000000 ,
/
