[Bug fortran/77412] New: constructor of an extended type with an allocatable component in the base type crashes gfortran

[daanvanvugt at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77412

            Bug ID: 77412
           Summary: constructor of an extended type with an allocatable
                    component in the base type crashes gfortran
           Product: gcc
           Version: 6.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: daanvanvugt at gmail dot com
  Target Milestone: ---

The below segment causes gfortran 6.1.1 to crash with:
test.f90:11:0:

   a = test_ext(timestep = 1.0)

internal compiler error: in fold_convert_loc, at fold-const.c:2250

program test_allocatable_component
  type, abstract :: test_base
    real*8, allocatable :: timestep
  end type

  type, extends(test_base) :: test_ext
  end type

  type(test_ext) :: a

  a = test_ext(timestep = 1.0)

end program test_allocatable_component

For an integer, dimension(:) variable the exact same situation does work.