[Bug fortran/48095] New: [OOP] Invalid assignment to procedure pointer component not rejected

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48095

           Summary: [OOP] Invalid assignment to procedure pointer
                    component not rejected
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: janus@gcc.gnu.org


Reported by Arjen Markus at
http://gcc.gnu.org/ml/fortran/2011-03/msg00057.html:

The following program (slightly modified from the original) does not produce
the expected result:


module proc_pointers

  implicit none

  type :: rectangle
    real :: width, height
    procedure(get_area), pointer, pass(this) :: get_special_area => get_my_area
  end type rectangle

  abstract interface
    real function get_area( this )
      import                       :: rectangle
      class(rectangle), intent(in) :: this
    end function get_area
  end interface

contains

  real function get_my_area( this )
    type(rectangle), intent(in) :: this
    write(*,*) 'This: ', this%width, this%height
    get_my_area = 3.0 * this%width * this%height
  end function get_my_area

end module proc_pointers


program test_objects

   use proc_pointers
   implicit none

   type(rectangle) :: rect
   real            :: area

   rect  = rectangle (1.0,2.0)
   write(*,*) 'Rect: ', rect%width, rect%height
   area = rect%get_special_area()
   write(*,*) 'Special area:', area

end program test_objects


I think it is invalid, because the PPC 'get_special_area' is declared to expect
a CLASS argument, but then the procedure it points to has a TYPE argument.

One should check the standard on this.