[Bug fortran/46174] [OOP] ALLOCATE with SOURCE: Deep copy missing

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46174

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2010-10-26 07:44:15 UTC ---
(In reply to comment #1)
> What about MOLD= for polymorphic variables?

MOLD= should work. Allocate with mold= allocates memory for the effective type
of mold and initializes with the default initializer. By default, allocatable
components are not allocated and thus there is no problem. (SOURCE= also works
if (currently: and only if) all allocatable components are not allocated.)

 * * *

Similarly affected: Deallocation when leaving the scope: The allocatable
components of the effective type are not deallocated. Example:

implicit none
type t
end type t

type, extends(t) :: t2
  integer, allocatable :: all
end type t2

class(t), allocatable :: a
if (allocated(a)) call foo()
end

If one looks at the dump, one sees that only allocatable components of the
declared type ("t", here: none) but not allocatable components of the effective
type are freed. I think that's tightly coupled to FINALization subroutines,
i.e. PR 37336.