(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*          Damien Doligez, projet Moscova, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 2003 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* $Id: stypes.ml,v 1.3 2005/03/25 23:56:44 kswadi Exp $ *)

(* Recording and dumping (partial) type information *)

(*
  We record all types in a list as they are created.
  This means we can dump type information even if type inference fails,
  which is extremely important, since type information is most
  interesting in case of errors.
*)

open Format;;
open Lexing;;
open Location;;
open Typedtree;;

type type_info =
    Ti_pat   of pattern
  | Ti_expr  of expression
  | Ti_class of class_expr
  | Ti_mod   of module_expr
;;

let get_location ti =
  match ti with
    Ti_pat p   -> p.pat_loc
  | Ti_expr e  -> e.exp_loc
  | Ti_class c -> c.cl_loc
  | Ti_mod m   -> m.mod_loc
;;

let type_info = ref ([] : type_info list);;
let phrases = ref ([] : Location.t list);;

let record ti =
  if !Clflags.save_types && not (get_location ti).Location.loc_ghost then
    type_info := ti :: !type_info
;;

let record_phrase loc =
  if !Clflags.save_types then phrases := loc :: !phrases;
;;

(* comparison order:
   the intervals are sorted by order of increasing upper bound
   same upper bound -> sorted by decreasing lower bound
*)
let cmp_loc_inner_first loc1 loc2 =
  match compare loc1.loc_end.pos_cnum loc2.loc_end.pos_cnum with
  | 0 -> compare loc2.loc_start.pos_cnum loc1.loc_start.pos_cnum
  | x -> x
;;
let cmp_ti_inner_first ti1 ti2 =
  cmp_loc_inner_first (get_location ti1) (get_location ti2)
;;

let print_position pp pos =
  fprintf pp "%S %d %d %d" pos.pos_fname pos.pos_lnum pos.pos_bol pos.pos_cnum;
;;

let sort_filter_phrases () =
  let ph = List.sort (fun x y -> cmp_loc_inner_first y x) !phrases in
  let rec loop accu cur l =
    match l with
    | [] -> accu
    | loc :: t ->
       if cur.loc_start.pos_cnum <= loc.loc_start.pos_cnum
          && cur.loc_end.pos_cnum >= loc.loc_end.pos_cnum
       then loop accu cur t
       else loop (loc :: accu) loc t
  in
  phrases := loop [] Location.none ph;
;;

let rec printtyp_reset_maybe loc =
  match !phrases with
  | cur :: t when cur.loc_start.pos_cnum <= loc.loc_start.pos_cnum ->
     Printtyp.reset ();
     phrases := t;
     printtyp_reset_maybe loc;
  | _ -> ()
;;


(* The format of the annotation file is documented in emacs/caml-types.el. *)

let print_info pp ti =
  match ti with
  | Ti_class _ | Ti_mod _ -> ()
  | Ti_pat  {pat_loc = loc; pat_type = typ}
  | Ti_expr {exp_loc = loc; exp_type = typ} ->
      print_position pp loc.loc_start;
      fprintf pp " ";
      print_position pp loc.loc_end;
      fprintf pp "@.type(@.  ";
      printtyp_reset_maybe loc;
      Printtyp.mark_loops typ;
      Printtyp.type_expr pp typ;
      fprintf pp "@.)@.";
;;

let get_info () =
  let info = List.fast_sort cmp_ti_inner_first !type_info in
  type_info := [];
  info
;;

let dump filename =
  if !Clflags.save_types then begin
    let info = get_info () in
    let pp = formatter_of_out_channel (open_out filename) in
    sort_filter_phrases ();
    List.iter (print_info pp) info;
    phrases := [];
  end else begin
    type_info := [];
  end;
;;
