(*
 * Copyright (c) 2013 - 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! Utils

(* Take as input an ast file and a C or ObjectiveC file such that the ast file
   corresponds to the compilation of the C file with clang.
   Parse the ast file into a data structure and translates it into a cfg. *)

module L = Logging

open CFrontend_utils

let buffer_len = 16384

(* This function reads the json file in fname, validates it, and encoded in the AST data structure*)
(* defined in Clang_ast_t.  *)
let validate_decl_from_file fname =
  try
    Ag_util.Biniou.from_file ~len:buffer_len Clang_ast_b.read_decl fname
  with (Invalid_argument "Bi_inbuf.refill_from_channel") ->
    Printing.log_stats "WARNING: biniou buffer too short, skipping the file\n";
    assert false

let validate_decl_from_stdin () =
  try
    Ag_util.Biniou.from_channel ~len:buffer_len Clang_ast_b.read_decl stdin
  with (Invalid_argument "Bi_inbuf.refill_from_channel") ->
    Printing.log_stats "WARNING: biniou buffer too short, skipping the file\n";
    assert false


let do_run source_path ast_path =
  let init_time = Unix.gettimeofday () in
  let print_elapsed () =
    let elapsed = Unix.gettimeofday () -. init_time in
    Printf.printf "Elapsed: %07.3f seconds.\n" elapsed in
  try
    let ast_filename, ast_decl =
      match ast_path with
      | Some path ->
          path, validate_decl_from_file path
      | None ->
          "stdin of " ^ source_path, validate_decl_from_stdin () in

    let decl_index, stmt_index, type_index = Clang_ast_main.index_node_pointers ast_decl in
    CFrontend_config.pointer_decl_index := decl_index;
    CFrontend_config.pointer_stmt_index := stmt_index;
    CFrontend_config.pointer_type_index := type_index;
    CFrontend_config.json := ast_filename;
    CLocation.check_source_file source_path;
    let source_file = CLocation.source_file_from_path source_path in
    Printf.printf "Start translation of AST from %s\n" !CFrontend_config.json;
    CFrontend.do_source_file  source_file ast_decl;
    Printf.printf "End translation AST file %s... OK!\n" !CFrontend_config.json;
    print_elapsed ();
  with
    (Yojson.Json_error s) as exc ->
      Printing.log_err "%s\n" s;
      print_elapsed ();
      raise exc

let () =
  match Config.source_file with
  | Some path ->
      do_run path Config.ast_file
  | None ->
      Printing.log_err "Incorrect command line arguments\n";
      Config.print_usage_exit ()