[Bug fortran/92065] New: internal compiler error: in expand_expr_real_1

[rp83 at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92065

            Bug ID: 92065
           Summary: internal compiler error: in expand_expr_real_1
           Product: gcc
           Version: 9.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rp83 at gmx dot com
  Target Milestone: ---

The following minimal working example triggers an internal compiler error when
compiled with gfortran -c buggy.f95.

Compiler error appears with gfortran versions 9, 8, 7, 6, but not version 5.
See outputs below.

Tests run on Ubuntu 18.04.3 LTS, 4.15.0-65-generic x86_64.

=================================================
buggy.f95:

module buggy
  implicit none

  type :: bar
    integer :: x
  end type bar

  type :: foo
    integer :: n
  contains
    procedure :: fun1
    procedure :: fun2
  end type foo

contains

  subroutine fun1(this, a)
    implicit none
    class(foo)             :: this
    class(bar), intent(in) :: a(this%n)
  end subroutine fun1

  integer function fun2(this, a)
    implicit none
    class(foo)             :: this
    class(bar), intent(in) :: a(this%n)
    fun2 = a(1)%x
  end function fun2

end module buggy

=================================================
COMPILER OUTPUTS

with GNU Fortran (Ubuntu 9.2.1-8ubuntu1~18.04.york0) 9.2.1 20190909:

$ gfortran-9 -c buggy.f95
during RTL pass: expand
buggy.f95:23:0:

   23 |   integer function fun2(this, a)
      | 
internal compiler error: in expand_expr_real_1, at expr.c:10012
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-9/README.Bugs> for instructions.

with GNU Fortran (Ubuntu 8.3.0-6ubuntu1~18.04.1) 8.3.0:

$ gfortran-8 -c buggy.f95
during RTL pass: expand
buggy.f95:23:0:

   integer function fun2(this, a)

internal compiler error: in expand_expr_real_1, at expr.c:10047
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-8/README.Bugs> for instructions.

with GNU Fortran (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0:

$ gfortran-7 -c buggy.f95
buggy.f95:23:0:

   integer function fun2(this, a)

internal compiler error: in expand_expr_real_1, at expr.c:9912
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-7/README.Bugs> for instructions.

with GNU Fortran (Ubuntu 6.5.0-2ubuntu1~18.04) 6.5.0 20181026:

$ gfortran-6 -c buggy.f95
buggy.f95:23:0:

   integer function fun2(this, a)

internal compiler error: in expand_expr_real_1, at expr.c:9702
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-6/README.Bugs> for instructions.

with GNU Fortran (Ubuntu 5.5.0-12ubuntu1) 5.5.0 20171010: no compiler error.