(*
 * 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 Domain = AbstractDomain.FiniteSet (struct
  include Pvar

  let pp = pp Pp.text
end)

module TransferFunctions (CFG : ProcCfg.S) = struct
  module CFG = CFG
  module Domain = Domain

  type extras = ProcData.no_extras

  let rec add_address_taken_pvars exp astate =
    match exp with
    | Exp.Lvar pvar ->
        Domain.add pvar astate
    | Exp.Cast (_, e) | UnOp (_, e, _) | Lfield (e, _, _) ->
        add_address_taken_pvars e astate
    | Exp.BinOp (_, e1, e2) | Lindex (e1, e2) ->
        add_address_taken_pvars e1 astate |> add_address_taken_pvars e2
    | Exp.Exn _
    | Exp.Closure _
    | Exp.Const (Cint _ | Cfun _ | Cstr _ | Cfloat _ | Cclass _)
    | Exp.Var _
    | Exp.Sizeof _ ->
        astate


  let exec_instr astate _ _ = function
    | Sil.Store (_, {desc= Tptr _}, rhs_exp, _) ->
        add_address_taken_pvars rhs_exp astate
    | Sil.Call (_, _, actuals, _, _) ->
        let add_actual_by_ref astate_acc = function
          | actual_exp, {Typ.desc= Tptr _} ->
              add_address_taken_pvars actual_exp astate_acc
          | _ ->
              astate_acc
        in
        List.fold ~f:add_actual_by_ref ~init:astate actuals
    | Sil.Store _ | Load _ | Prune _ | Nullify _ | Abstract _ | Remove_temps _ | Declare_locals _ ->
        astate
end

module Analyzer = AbstractInterpreter.Make (ProcCfg.Exceptional) (TransferFunctions)