[Bug fortran/114475] New: [14.0 Regression] Regression with iso_c_binding and submodules

["juergen.reuter at desy dot de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

            Bug ID: 114475
           Summary: [14.0 Regression] Regression with iso_c_binding and
                    submodules
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: juergen.reuter at desy dot de
  Target Milestone: ---

Between ca. March 18 and March 25, a regression has been introduced into the
gfortran 14.0.1 code, which makes the following valid code fail to compile, cf.
below:
gfortran  -c t1.f90
t1.f90:28:13:

   28 | submodule (t1) t1_s
      |             1
Error: Variable ‘n_external’ cannot appear in the expression at (1)

It would be cool if that could be fixed before the release of gcc 14.1 which I
believe is very soon. 



module t1
  use, intrinsic :: iso_c_binding !NODEP!                                       
  implicit none
  private
  public :: t1_t
  integer :: N_EXTERNAL = 0

  type :: t1_t
  contains
    procedure :: set_n_external => t1_set_n_external
  end type t1_t

  abstract interface
     subroutine ol_eval (id, pp, emitter) bind(C)
       import
       real(kind = c_double), intent(in) :: pp(5 * N_EXTERNAL)
     end subroutine ol_eval
  end interface
  interface
    module subroutine t1_set_n_external (object, n)
      class(t1_t), intent(inout) :: object
      integer, intent(in) :: n
    end subroutine t1_set_n_external
  end interface

end module t1

submodule (t1) t1_s
  implicit none
contains
  module subroutine t1_set_n_external (object, n)
    class(t1_t), intent(inout) :: object
    integer, intent(in) :: n
    N_EXTERNAL = n
  end subroutine t1_set_n_external

end submodule t1_s