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59 lines
1.6 KiB
59 lines
1.6 KiB
10 years ago
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(*
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* Copyright (c) 2013 - Facebook. All rights reserved.
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*)
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(** Environment for temporary identifiers used in instructions.
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Lazy implementation: only created when actually used. *)
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type t = (Sil.exp Ident.IdentHash.t) Lazy.t * Cfg.cfg
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let _create cfg proc_desc =
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let map = Ident.IdentHash.create 1 in
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let do_instr node = function
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| Sil.Letderef (id, e, t, loc) ->
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Ident.IdentHash.add map id e
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| _ -> () in
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Cfg.Procdesc.iter_instrs do_instr proc_desc;
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map
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(* lazy implementation, only create when used *)
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let create cfg proc_desc =
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let map = lazy (_create cfg proc_desc) in
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map, cfg
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(* create an idenv for another procedure *)
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let create_from_idenv (_, cfg) proc_desc =
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let map = lazy (_create cfg proc_desc) in
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map, cfg
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let lookup (_map, _) id =
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let map = Lazy.force _map in
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try
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Some (Ident.IdentHash.find map id)
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with Not_found -> None
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let expand_expr idenv e = match e with
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| Sil.Var id ->
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(match lookup idenv id with
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| Some e' -> e'
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| None -> e)
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| _ -> e
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let expand_expr_temps idenv node _exp =
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let exp = expand_expr idenv _exp in
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match exp with
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| Sil.Lvar pvar when Errdesc.pvar_is_frontend_tmp pvar ->
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(match Errdesc.find_program_variable_assignment node pvar with
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| None -> exp
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| Some (_, id) ->
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expand_expr idenv (Sil.Var id))
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| _ -> exp
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(** Return true if the expression is a temporary variable introduced by the front-end. *)
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let exp_is_temp idenv e =
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match expand_expr idenv e with
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| Sil.Lvar pvar ->
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Errdesc.pvar_is_frontend_tmp pvar
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| _ -> false
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