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(*
* Copyright (c) 2016 - present Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*)
open! IStd
module IdMap = Var.Map
type astate = AccessPath.raw IdMap.t
include IdMap
let pp fmt astate =
IdMap.pp ~pp_value:AccessPath.pp_raw fmt astate
let (<=) ~lhs ~rhs =
if phys_equal lhs rhs
then true
else
try
IdMap.for_all
(fun id lhs_ap ->
let rhs_ap = IdMap.find id rhs in
let eq = AccessPath.equal_raw lhs_ap rhs_ap in
if not eq && Config.debug_exceptions
then
failwithf "Id %a maps to both %a and %a@."
Var.pp id
AccessPath.pp_raw lhs_ap
AccessPath.pp_raw rhs_ap;
eq)
lhs
with Not_found -> false
(* in principle, could do a join here if the access paths have the same root. but they should
always be equal if we are using the map correctly *)
let check_invariant ap1 ap2 = function
| Var.ProgramVar pvar when Pvar.is_frontend_tmp pvar ->
(* Sawja reuses temporary variables which sometimes breaks this invariant *)
(* TODO: fix (13370224) *)
()
| id ->
if not (AccessPath.equal_raw ap1 ap2)
then
failwithf "Id %a maps to both %a and %a@."
Var.pp id
AccessPath.pp_raw ap1
AccessPath.pp_raw ap2
let join astate1 astate2 =
if phys_equal astate1 astate2
then astate1
else
IdMap.merge
(fun var ap1_opt ap2_opt -> match ap1_opt, ap2_opt with
| Some ap1, Some ap2 ->
if Config.debug_exceptions then check_invariant ap1 ap2 var;
ap1_opt
| Some _, None -> ap1_opt
| None, Some _ -> ap2_opt
| None, None -> None)
astate1
astate2
let widen ~prev ~next ~num_iters:_ =
join prev next