[Bug fortran/55978] [4.8 Regression] class_optional_2.f90 -Os fails

["janus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55978

--- Comment #16 from janus at gcc dot gnu.org 2013-02-06 10:54:39 UTC ---
(In reply to comment #15)
> (In reply to comment #14)
> > +      if (fsym && fsym->attr.optional && sym && sym->attr.pointer)
> 
> Shouldn't you use something like
>   gfc_expr_attr(expr).pointer 
> Otherwise, I fear it will fail for var%comp

Agreed.


> Additionally, one might have to handle
> - unallocated allocatables
> - NULL()  [= EXPR_NULL]
> - CLASS(), (pointer|allocatable)?

Huh, good point. Here is an extended test case which tests some of these:

program main
  implicit none

  integer, pointer :: p(:)
  integer, allocatable :: a(:)

  type t
    integer, pointer :: p(:)
    integer, allocatable :: a(:)
  end type

  type(t) :: d

  ! (1) pointer
  p => null()
  call sub(p)

  ! (2) allocatable
  call sub(a)

  ! (3) pointer component
  d%p => null ()
  call sub(d%p)

  ! (4) NULL
  call sub(null())

contains

 subroutine sub(x)
   integer, intent(in), optional :: x(4)
 end subroutine

end



In fact the NULL case is rejected with (certainly a bug):

  call sub(null())
           1
Warning: Actual argument contains too few elements for dummy argument 'x' (1/4)
at (1)


For the allocatable case, no packing is done at all (I guess it's just not
needed there, since an allocatable array, contrary to a pointer, is always
contiguous, right?).


The pointer component case looks completely analogous to the simple pointer
case in the dump, but for some reason I do not see the valgrind errors there.