[Bug fortran/69965] New: ICE: tree check: expected tree that contains âtypedâ structure, have â<invalid tree code>â in gfc_get_character_type, at fortran/trans-types.c:1048

["gerhard dot steinmetz dot fortran at t-online dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69965

            Bug ID: 69965
           Summary: ICE: tree check: expected tree that contains âtypedâ
                    structure, have â<invalid tree code>â in
                    gfc_get_character_type, at fortran/trans-types.c:1048
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gerhard.steinmetz.fortran@t-online.de
  Target Milestone: ---

With an abstract class dummy argument :


$ cat z1.f90
module m
   type, abstract :: tab
   contains
      procedure(fab), deferred :: f
   end type

   type, extends(tab) :: t
   contains
      procedure :: f
   end type

   abstract interface
      function fab(x) result(z)
         import tab
         class(tab) :: x
         character(*) :: z
      end
   end interface

contains

   function f(x)
      class(t) :: x
      character(1) :: f
      f = 'a'
   end

   subroutine s(x)
      class(tab) :: x
      print *, x%f()
   end
end module


$ gfortran-6 --version
GNU Fortran (SUSE Linux) 6.0.0 20160202 (experimental) [trunk revision 233076]


$ gfortran-6 -c z1.f90
z1.f90:30:0:

       print *, x%f()

internal compiler error: Segmentation fault


In approximately 3 out of 100 runs the error message is :

internal compiler error: tree check: expected tree that contains âtypedâ
structure, have â<invalid tree code>â in gfc_get_character_type, at
fortran/trans-types.c:1048