(* TODO those definitions are also in sync_preds_defs, see if we can
include without changing the dep DAG too badly *)

(* The TT branch of the jam below might seem too weak, but we already
keep enough control over joining with other rmaps that it should be
enough *)

Definition LKspec_ext (R: pred rmap) lksize : spec :=
   fun (sh: Share.t) (l: AV.address)  =>
    allp (jam (adr_range_dec l lksize)
              (fun l' => yesat (SomeP rmaps.Mpred (fun _ => R)) (LK lksize (snd l' - snd l)) sh l')
              (fun _ => TT)).Definition LK_at R lksize sh :=
  LKspec_ext R lksize sh.

Lemma data_at_rmap_makelock CS sh b ofs R phi length : 0 < length -> writable0_share sh -> app_pred (@data_at_ CS sh (Tarray (Tpointer Tvoid noattr) length noattr) (Vptr b ofs)) phi -> exists phi', rmap_makelock phi phi' (b, Ptrofs.unsigned ofs) R (size_chunk Mptr * length) /\ LK_at R (size_chunk Mptr * length) sh (b, Ptrofs.unsigned ofs) phi'.