[Bug fortran/52052] New: [Coarray] Properly handle coarray components of derived types

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52052

             Bug #: 52052
           Summary: [Coarray] Properly handle coarray components of
                    derived types
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org


Special care needs to be taken with coarrays - and in particular coarray
components; they may only be collectively allocated and deallocated.

In particular:

Intrinsic assignment: Contrary to normal allocatable components,
no reallocation is allowed. The programmer guarantees that the shape and
type parameters are suitable.

Caveat: Be aware of allocatable components nested within coarray components -
and issues with polymorphism.

Please also check that:
- Calling caf_register is done with ALLOCATE, also with SOURCE=
- Calling of caf_deregister when leaving the scope/calling DEALLOCATE
- Special handling of polymorphic coarray components
- Whether there are issues regarding _def_init and _copy; cf. PR 51947.
Consider whether a simple INTENT_INOUT for _copy would be more appropriate.
- Check that there is indeed no realloc on assignment for coarray variables.