(*
 * Copyright (c) 2017 - 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 F = Format

type error = ExternalError | InternalError | UserError

exception InferExternalError of string

exception InferInternalError of string

exception InferUserError of string

exception InferExit of int

let raise_error error ~msg =
  match error with
  | ExternalError
   -> raise (InferExternalError msg)
  | InternalError
   -> raise (InferInternalError msg)
  | UserError
   -> raise (InferUserError msg)

let die error fmt = F.kasprintf (fun msg -> raise_error error ~msg) fmt

let exit exitcode = raise (InferExit exitcode)

let exit_code_of_exception = function
  | InferUserError _
   -> 1
  | InferExternalError _
   -> 3
  | InferInternalError _
   -> 4
  | InferExit exitcode
   -> exitcode
  | _
   -> (* exit code 2 is used by the OCaml runtime in cases of uncaught exceptions *) 2