let get_var m lv =
try Varinfo.Hashtbl.find m lv
with Not_found ->
let ty = lv.vtype in
let t = tau_of_object (Ctypes.object_of ty) in
let v = L.fresh lv.vname (Formula.Acsl(t,Ctype ty)) in
Varinfo.Hashtbl.add m lv v; v