Source file `check_cfg_generic.ml`

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(* Yoann Padioleau
 *
 * Copyright (C) 2010 Facebook
 * Copyright (C) 2019 r2c
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * version 2.1 as published by the Free Software Foundation, with the
 * special exception on linking described in file license.txt.
 * 
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the file
 * license.txt for more details.
 *)
open Common

open Ast_generic
module V = Visitor_ast
module E = Error_code
module CFGB = Controlflow_build

(*****************************************************************************)
(* Prelude *)
(*****************************************************************************)
(*
 * Most of the hard work is done by Controlflow_build_generic.ml.
 * 
 * TODO: check dead statements for toplevel blocks ?
 *)

(*****************************************************************************)
(* Helpers *)
(*****************************************************************************)

let check_func_def fdef =
  try 
    let flow = Controlflow_build.cfg_of_func fdef in
    Controlflow_build.deadcode_detection flow;
  with Controlflow_build.Error (err, loc) ->
      let s = Controlflow_build.string_of_error_kind err in
      (match err, loc with
      | CFGB.UnreachableStatement _, Some tok ->
          E.error tok (E.UnreachableStatement s)
      | CFGB.UnreachableStatement _, None ->
          pr2 "TODO: unreachable statement detected but no location";
      | _, Some tok ->
          E.error tok (E.CFGError s)
      | _, None ->
          pr2 (spf "TODO: CFG error detected but no location: %s" s);
      )

(*****************************************************************************)
(* Main entry point *)
(*****************************************************************************)

let check_program2 prog =
  let visitor = V.mk_visitor { V.default_visitor with
    (* also valid for methods *)
    V.kdef = (fun (k, _) x ->
      let (_entity, def) = x in
      (match def with
      | FuncDef fdef -> check_func_def fdef
      | _ -> ()
      );
      (* process nested definitions *)
      k x
    );
  }
  in
  visitor (Pr prog)

let check_program a = 
  Common.profile_code "Checker.cfg" (fun () -> check_program2 a)