[Patch, fortran] PR67171 - [6 regression] sourced allocation

[Paul Richard Thomas <paul dot richard dot thomas at gmail dot com>]

Dear All,

This patch does four things:
(i) On deallocating class components, the vptr is set to point to the
vtable of the declared type;
(ii) When digging out the last class reference, a NULL is returned if
the allocatable component is to the right of a part reference with
non-zero rank, so that the resulting ICE is removed. The previous
modification takes care of these cases for gfc_reset_vptr and
gfc_reset_len;
(iii) gfc_reset_vptr has been simplified by the use of
gfc_get_vptr_from_expr; and
(iv) All variable expressions for the source are passed to
gfc_trans-assignment, so that array sections work correctly.

I see that Andre has already reserved the testcase
allocate_with_source_10, for the pending patch that I undertook to
review, so I will change this to #12 on submission

OK for trunk?

Cheers

Paul

2015-01-24  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/67171
    * trans-array.c (structure_alloc_comps): On deallocation of
    class components, reset the vptr to the declared type vtable
    and reset the _len field of unlimited polymorphic components.
    *trans-expr.c (gfc_find_and_cut_at_last_class_ref): Bail out on
    allocatable component references to the right of part reference
    with non-zero rank and return NULL.
    (gfc_reset_vptr): Simplify this function by using the function
    gfc_get_vptr_from_expr. Return if the vptr is NULL_TREE.
    (gfc_reset_len): If gfc_find_and_cut_at_last_class_ref returns
    NULL return.
    * trans-stmt.c (gfc_trans_allocate): Rely on the use of
    gfc_trans_assignment if expr3 is a variable expression since
    this deals correctly with array sections.

2015-01-24  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/67171
    * gfortran.dg/allocate_with_source_10.f03: New test