https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127258
Bug ID: 127258
Summary: Polymorphic actual argument association with a
non-polymorphic pointer dummy is accepted
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: mikael at gcc dot gnu.org
Target Milestone: ---
Testcase:
program prog
implicit none
type :: t1
integer :: c1
end type
type(t1), pointer :: p(:)
class(t1), pointer :: x(:)
allocate(x(5))
call sub(x)
deallocate(x)
contains
subroutine sub(arg)
type(t1), pointer :: arg(:)
end subroutine
end program
This is accepted by gfortran, but is invalid.
The actual argument x is polymporphic, whereas the associated dummy is
non-polymorphic.
>From F2023 (15.5.2.6 Allocatable and pointer dummy variables):
> The actual argument shall be polymorphic if and only if the associated dummy
> argument is polymorphic, and either both the actual and dummy arguments
shall
> be unlimited polymorphic, or the declared type of the actual argument shall
> be the same as the declared type of the dummy argument.
and in the note just below:
> Dynamic type information is not maintained for a nonpolymorphic allocatable
> or pointer dummy argument. However, allocating or pointer-assigning such a
> dummy argument would require maintenance of this information if the
> corresponding actual argument is polymorphic. Therefore, the corresponding
> actual argument needs to be nonpolymorphic.
