let get_node env t =
let id = node_type_id t in
try
let n = Hashtbl.find env.stmt_node id in
let _ = match !n, t with
| Vstmt _, Vstmt _ -> ()
| Vstmt _, _ ->
n := t;
Wp_parameters.debug ~level:3
"[cfg] change node %d : %a@." id VL.pretty n
| _, _ -> ();
in n
with Not_found -> add_node env t