barotropic_workstate_enter_data_impl Subroutine

   subroutine barotropic_workstate_enter_data_impl(this)
      type(barotropic_workstate_t), intent(inout) :: this
      !$acc enter data copyin(this%bt_eta, this%bt_H_ref)
      !$acc enter data copyin(this%bt_ubt, this%bt_vbt)
      !$acc enter data copyin(this%eta_sum, this%ubt_sum, this%vbt_sum)
      !$acc enter data copyin(this%uhbt_sum, this%vhbt_sum, this%bt_uhbt, this%bt_vhbt)
      !$acc enter data copyin(this%bt_ubt_end, this%bt_vbt_end, this%bt_eta_end)
      !$acc enter data copyin(this%bt_zeta_corner, this%bt_ke_centre, this%bt_eta_new)
      !$acc enter data copyin(this%cor_ref_u, this%cor_ref_v)
      !$acc enter data copyin(this%bt_ubt_prev, this%bt_vbt_prev)
      ! bt_rem_u/v: always present (barotropic-only path uses them too)
      !$acc enter data copyin(this%bt_rem_u, this%bt_rem_v)
      ! av_rem_u/v: PR-2, same "always present" posture as bt_rem_u/v.
      !$acc enter data copyin(this%av_rem_u, this%av_rem_v)
      ! Wave-drag piston-velocity maps: filled on the host at configure
      ! time and never written on the device, so this MUST be `copyin`
      ! (not `create`) — see CLAUDE.md gotcha (2).  Lazy: allocated only
      ! when `lwd_enable`.
      if (allocated(this%lwd_drag_u)) then
         !$acc enter data copyin(this%lwd_drag_u, this%lwd_drag_v)
      end if
      if (allocated(this%F_slow_u)) then
         !$acc enter data copyin(this%F_slow_u, this%F_slow_v)
         !$acc enter data copyin(this%F_bt_u, this%F_bt_v)
         !$acc enter data copyin(this%F_bt_u_fast, this%F_bt_v_fast)
         !$acc enter data copyin(this%ubt_at_n, this%vbt_at_n)
         !$acc enter data copyin(this%pbce)
         !$acc enter data copyin(this%gtot_E, this%gtot_W, this%gtot_N, this%gtot_S)
         !$acc enter data copyin(this%e_anom, this%eta_PF)
         !$acc enter data copyin(this%visc_rem_u, this%visc_rem_v)
      end if
      ! BTCL_u/v are arrays of derived type with POD scalar components,
      ! so copying the array body is enough (parent before components
      ! on enter, reverse on exit).
      if (allocated(this%BTCL_u)) then
         !$acc enter data copyin(this%BTCL_u)
      end if
      if (allocated(this%BTCL_v)) then
         !$acc enter data copyin(this%BTCL_v)
      end if
      ! Upstream-h-face slots — same lazy pattern as BTCL_u/v.
      if (allocated(this%h_face_up_x)) then
         !$acc enter data copyin(this%h_face_up_x)
      end if
      if (allocated(this%h_face_up_y)) then
         !$acc enter data copyin(this%h_face_up_y)
      end if
      ! Wet/dry workspaces — same lazy pattern (allocated only when
      ! `wetdry_enable`); missing this attach = the per-launch memcpy
      ! explosion foot-gun, so every wd_* array is listed.
      if (allocated(this%wd_wet_dyn)) then
         !$acc enter data copyin(this%wd_wet_dyn, this%wd_theta)
         !$acc enter data copyin(this%wd_flux_x, this%wd_flux_y)
         !$acc enter data copyin(this%wd_open_u, this%wd_open_v)
      end if
   end subroutine barotropic_workstate_enter_data_impl