(* *********************************************************************)
(*                                                                     *)
(*              The Compcert verified compiler                         *)
(*                                                                     *)
(*          Xavier Leroy, INRIA Paris-Rocquencourt                     *)
(*          Sandrine Blazy, ENSIIE and INRIA Paris-Rocquencourt        *)
(*          with contributions from Andrew Appel, Rob Dockins,         *)
(*          and Gordon Stewart (Princeton University)                  *)
(*                                                                     *)
(*  Copyright Institut National de Recherche en Informatique et en     *)
(*  Automatique.  All rights reserved.  This file is distributed       *)
(*  under the terms of the GNU General Public License as published by  *)
(*  the Free Software Foundation, either version 2 of the License, or  *)
(*  (at your option) any later version.  This file is also distributed *)
(*  under the terms of the INRIA Non-Commercial License Agreement.     *)
(*                                                                     *)
(* *********************************************************************)
(** This file develops the memory model that is used in the dynamic semantics of all the languages used in the compiler. It defines a type [mem] of memory states, the following 4 basic operations over memory states, and their properties: - [load]: read a memory chunk at a given address; - [store]: store a memory chunk at a given address; - [alloc]: allocate a fresh memory block; - [free]: invalidate a memory block. *)
Require Intv.
Require Archi.
Require Export Memdata.
Require Export Memtype.
(* To avoid useless definitions of inductors in extracted code. *)
Local Unset Elimination Schemes.
Local Unset Case Analysis Schemes.
Local Notation "a # b" := (PMap.get b a) (at level 1).
Module Mem <: MEM.
Definition perm_order' (po: option permission) (p: permission) :=
match po with
| Some p' => perm_order p' p
| None => False
end.
Definition perm_order'' (po1 po2: option permission) :=
match po1, po2 with
| Some p1, Some p2 => perm_order p1 p2
| _, None => True
| None, Some _ => False
end.
Record mem' : Type := mkmem {
mem_contents: PMap.t (ZMap.t memval);  (**r [block -> offset -> memval] *)
mem_access: PMap.t (Z -> perm_kind -> option permission);
(**r [block -> offset -> kind -> option permission] *)
nextblock: block;
access_max:
forall b ofs, perm_order'' (mem_access#b ofs Max) (mem_access#b ofs Cur);
nextblock_noaccess:
forall b ofs k, ~(Plt b nextblock) -> mem_access#b ofs k = None;
contents_default:
forall b, fst mem_contents#b = Undef
}.
Definition mem := mem'.

(* Specifications: *)
Lemma mkmem_ext:
forall cont1 cont2 acc1 acc2 next1 next2 a1 a2 b1 b2 c1 c2,
cont1=cont2 -> acc1=acc2 -> next1=next2 ->
mkmem cont1 acc1 next1 a1 b1 c1 = mkmem cont2 acc2 next2 a2 b2 c2.