let rec align_of_type ~env t =
match t.ct_ty with
Tvoid -> None
| Tbuiltin bt ->
Some (big_int_of_int (align_of_builtin_type bt))
| Tarray(et,_) ->
align_of_type ~env et
| Tfunction(_) -> None
| Tpointer(_) -> Some (big_int_of_int sizeof_pointer)
| Tstruct(id) ->
let sd = get_struct_desc ~env id in
sd.str_align