CompilerConstruction/Error.ml at student · dejohansson/CompilerConstruction · GitHub

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(* Copyright Per Lindgren 2016-2018, see the file "LICENSE" *)
(* for the full license governing this code.                *)

(* cimp/Error *)

open Lexing
open Common

type comment_info = {
  mutable ci_lnum : int;
  mutable ci_cnum : int;
  mutable ci_bol  : int;
}

let ci = {
  ci_lnum = 0;
  ci_cnum = 0;
  ci_bol  = 0;
}

let next_line lexbuf = Lexing.new_line lexbuf

let parse_err_msg ch lexbuf =
  try
    let pos = lexbuf.lex_curr_p in
    let index = pos.pos_cnum - pos.pos_bol -1 in
    let info =
      " File " ^ pos.pos_fname ^
      " : Line " ^ string_of_int pos.pos_lnum ^
      " : Position " ^ string_of_int index ^ nl in
    let _ = seek_in ch pos.pos_bol in
    let line = input_line ch in (* might raise End_of_file *)
    info ^ line ^ nl ^
    (String.make index ' ' ) ^ "^" ^ nl
  with
    End_of_file ->
    let pos = lexbuf.lex_curr_p in
    let index = pos.pos_cnum - pos.pos_bol -1 in

    " File " ^ pos.pos_fname ^
    " : Line " ^ string_of_int pos.pos_lnum ^
    " : Position " ^ string_of_int index ^ nl ^
    " Error at EOF" ^ nl

let set_info lexbuf =
  let pos = lexbuf.lex_curr_p in
  ci.ci_lnum <- pos.pos_lnum;
  ci.ci_cnum <- pos.pos_cnum;
  ci.ci_bol  <- pos.pos_bol;;

let bol lexbuf =
  let pos = lexbuf.lex_curr_p in
  lexbuf.lex_curr_p <-
    { pos with
      pos_bol  = ci.ci_bol;
      pos_lnum = ci.ci_lnum;
      pos_cnum = ci.ci_cnum;
    }