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84 lines
3.0 KiB
84 lines
3.0 KiB
6 years ago
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(*
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* Copyright (c) 2018-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*)
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open! IStd
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module F = Format
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module L = Logging
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module Dead = AbstractDomain.InvertedSet (Var)
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module Reverse = AbstractDomain.FiniteMultiMap (Var) (Var)
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type t =
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{ resolve: IdAccessPathMapDomain.t
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; reverse: Reverse.t
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(** there is a [x -> y] mapping in reverse for each variable [y] appearing in [resolve x] *)
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; dead: Dead.t }
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let empty = {resolve= IdAccessPathMapDomain.empty; reverse= Reverse.empty; dead= Dead.empty}
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let add id ap {resolve; reverse; dead} =
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let resolve = IdAccessPathMapDomain.add id ap resolve in
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let reverse =
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HilExp.AccessExpression.fold_vars ap ~init:reverse ~f:(fun acc var_in_ap ->
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Reverse.add var_in_ap id acc )
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in
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let dead = Dead.remove id dead in
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{resolve; reverse; dead}
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let exit_scope id bindings =
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let {resolve; reverse; dead} = bindings in
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match (Reverse.mem id reverse, IdAccessPathMapDomain.find_opt id resolve) with
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| true, None ->
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let dead = Dead.add id dead in
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({resolve; reverse; dead}, [])
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| true, Some _ ->
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L.(die InternalError) "Variable appearing on both sides of bindings"
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| false, None ->
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(bindings, [id])
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| false, Some ap ->
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let resolve = IdAccessPathMapDomain.remove id resolve in
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let reverse, vars, dead =
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HilExp.AccessExpression.fold_vars ap ~init:(reverse, [], dead)
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~f:(fun (reverse, vars, dead) var_in_ap ->
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let reverse = Reverse.remove var_in_ap id reverse in
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if (not (Reverse.mem var_in_ap reverse)) && Dead.mem var_in_ap dead then
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(reverse, var_in_ap :: vars, Dead.remove var_in_ap dead)
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else (reverse, vars, dead) )
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in
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({resolve; reverse; dead}, vars)
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let resolve {resolve} id = IdAccessPathMapDomain.find_opt id resolve
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let fold {resolve} ~init ~f = IdAccessPathMapDomain.fold f resolve init
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let pp f {resolve; reverse; dead} =
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F.fprintf f "{@[<v1> resolve=@[<hv>%a@];@;reverse=@[<hv>%a@];@;dead=@[<hv>%a@];@]}"
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IdAccessPathMapDomain.pp resolve Reverse.pp reverse Dead.pp dead
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let ( <= ) ~lhs ~rhs = IdAccessPathMapDomain.( <= ) ~lhs:lhs.resolve ~rhs:rhs.resolve
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let join bindings1 bindings2 =
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if phys_equal bindings1 bindings2 then bindings1
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else
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let {resolve= resolve1; reverse= reverse1; dead= dead1} = bindings1 in
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let {resolve= resolve2; reverse= reverse2; dead= dead2} = bindings2 in
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{ resolve= IdAccessPathMapDomain.join resolve1 resolve2
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; reverse= Reverse.join reverse1 reverse2
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; dead= Dead.join dead1 dead2 }
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let widen ~prev ~next ~num_iters =
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if phys_equal prev next then prev
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else
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let {resolve= resolve1; reverse= reverse1; dead= dead1} = prev in
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let {resolve= resolve2; reverse= reverse2; dead= dead2} = next in
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{ resolve= IdAccessPathMapDomain.widen ~prev:resolve1 ~next:resolve2 ~num_iters
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; reverse= Reverse.widen ~prev:reverse1 ~next:reverse2 ~num_iters
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; dead= Dead.widen ~prev:dead1 ~next:dead2 ~num_iters }
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