Found when working on FINALization. It compiles with GCC 4.7 but fails with GCC 4.8 and 4.9.


The following ICEs when passing an optional polymorphic array as argument to an optional dummy argument:


finalize_12.f90:12:0: internal compiler error: in gfc_conv_class_to_class, at fortran/trans-expr.c:740
     call foo_opt(xca=xca)!, xc, xaa, xca)
 ^
0x63c6f9 gfc_conv_class_to_class(gfc_se*, gfc_expr*, gfc_typespec, bool, bool, bool, bool)
        ../../gcc/fortran/trans-expr.c:740
0x637b72 gfc_conv_procedure_call(gfc_se*, gfc_symbol*, gfc_actual_arglist*, gfc_expr*, vec<tree_node*, va_gc, vl_embed>*)
        ../../gcc/fortran/trans-expr.c:4423


module m
  implicit none
  type t
    integer :: i
  end type t
contains
  subroutine opt(xa, xc, xaa, xca)
    type(t),  allocatable, intent(out), optional :: xa
    class(t), allocatable, intent(out), optional :: xc
    type(t),  allocatable, intent(out), optional :: xaa(:)
    class(t), allocatable, intent(out), optional :: xca(:)
    call foo_opt(xca=xca)!, xc, xaa, xca)
  end subroutine opt
  subroutine foo_opt(xa, xc, xaa, xca)
    type(t),  allocatable, intent(out), optional :: xa
    class(t), allocatable, intent(out), optional :: xc
    type(t),  allocatable, intent(out), optional :: xaa(:)
    class(t), allocatable, intent(out), optional :: xca(:)
  end subroutine foo_opt
end module m