module ftncode_mod
   use, intrinsic :: iso_c_binding
   implicit none

   type, public :: t_clb
     character(8) :: corf
   end type

   type, public  :: t_bstuff
     type (t_clb) :: clb
   end type t_bstuff

   type, public :: t_stuff
     type (t_bstuff) :: substuff
   end type t_stuff

   contains

      subroutine c2fstr(cptr,fstr)
        type(c_ptr), value, intent(in ) :: cptr
        character(*),       intent(out) :: fstr
        character(256),     pointer     :: lfstr
        integer                         :: id
        call c_f_pointer(cptr,lfstr)
        id = index(lfstr,char(0))-1
        if(id.le.0) id=len(lfstr)
        fstr = lfstr(1:id)
      end subroutine

      function crfl() result(cp) bind(c)
      !DEC$ ATTRIBUTES DLLEXPORT :: crfl
        type(c_ptr     )          :: cp
        type(t_bstuff), pointer :: fp
        allocate(fp)
        cp = c_loc(fp)
      end function

      function stfl(cstuff,cne) result(ierr) bind(c)
      !DEC$ Attributes dllexport :: stfl
        type(c_ptr), value, intent(in)     :: cstuff
        type(c_ptr), value, intent(in)     :: cne 
        integer                            :: ierr  
        type(t_bstuff)    ,  pointer       :: fstuff
        character(24)                      :: cwk 
        ierr = 0  
        call c_f_pointer(cstuff,fstuff)
        call c2fstr(cne,cwk)
        fstuff%clb%corf = trim(cwk)
      end function

      subroutine test2(stuff) bind(c)
      !DEC$ATTRIBUTES DLLEXPORT :: test2
        use iso_c_binding
        type(t_stuff), target, intent(in) :: stuff
        integer :: i

        i = 0
      end subroutine test2
end module