mlw_typing.ml 17.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
(**************************************************************************)
(*                                                                        *)
(*  Copyright (C) 2010-2011                                               *)
(*    François Bobot                                                      *)
(*    Jean-Christophe Filliâtre                                           *)
(*    Claude Marché                                                       *)
(*    Andrei Paskevich                                                    *)
(*                                                                        *)
(*  This software is free software; you can redistribute it and/or        *)
(*  modify it under the terms of the GNU Library General Public           *)
(*  License version 2.1, with the special exception on linking            *)
(*  described in file LICENSE.                                            *)
(*                                                                        *)
(*  This software 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.                  *)
(*                                                                        *)
(**************************************************************************)

open Why3
open Util
22
open Ident
23 24 25
open Theory
open Env
open Ptree
26 27 28
open Mlw_ty
open Mlw_expr
open Mlw_decl
29 30
open Mlw_module

31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
(** errors *)

exception DuplicateVar of string
exception DuplicateTypeVar of string
(*
exception PredicateExpected
exception TermExpected
exception FSymExpected of lsymbol
exception PSymExpected of lsymbol
exception ClashTheory of string
exception UnboundTheory of qualid
exception UnboundType of string list
*)
exception UnboundTypeVar of string
exception UnboundSymbol of string list

let error = Loc.error
let errorm = Loc.errorm

let rec print_qualid fmt = function
  | Qident s -> Format.fprintf fmt "%s" s.id
  | Qdot (m, s) -> Format.fprintf fmt "%a.%s" print_qualid m s.id

let () = Exn_printer.register (fun fmt e -> match e with
  | DuplicateTypeVar s ->
      Format.fprintf fmt "Duplicate type parameter %s" s
  | DuplicateVar s ->
      Format.fprintf fmt "Duplicate variable %s" s
(*
  | PredicateExpected ->
      Format.fprintf fmt "syntax error: predicate expected"
  | TermExpected ->
      Format.fprintf fmt "syntax error: term expected"
  | FSymExpected ls ->
      Format.fprintf fmt "%a is not a function symbol" Pretty.print_ls ls
  | PSymExpected ls ->
      Format.fprintf fmt "%a is not a predicate symbol" Pretty.print_ls ls
  | ClashTheory s ->
      Format.fprintf fmt "Clash with previous theory %s" s
  | UnboundTheory q ->
      Format.fprintf fmt "unbound theory %a" print_qualid q
  | UnboundType sl ->
      Format.fprintf fmt "Unbound type '%a'"
        (Pp.print_list Pp.dot Pp.pp_print_string) sl
*)
  | UnboundTypeVar s ->
      Format.fprintf fmt "unbound type variable '%s" s
  | UnboundSymbol sl ->
      Format.fprintf fmt "Unbound symbol '%a'"
        (Pp.print_list Pp.dot Format.pp_print_string) sl
  | _ -> raise e)

(* TODO: let type_only = Debug.test_flag Typing.debug_type_only in *)

(** Type declaration *)

type tys = ProgTS of itysymbol | PureTS of Ty.tysymbol

let find_tysymbol q uc =
  let loc = Typing.qloc q in
  let sl = Typing.string_list_of_qualid [] q in
  try ProgTS (ns_find_it (get_namespace uc) sl)
  with Not_found ->
  try PureTS (ns_find_ts (Theory.get_namespace (get_theory uc)) sl)
  with Not_found -> error ~loc (UnboundSymbol sl)

let add_types uc tdl =
  let add m d =
    let id = d.td_ident.id in
    Mstr.add_new (Loc.Located (d.td_loc, ClashSymbol id)) id d m in
  let def = List.fold_left add Mstr.empty tdl in

  (* detect cycles *)

  let rec cyc_visit x d seen = match Mstr.find_opt x seen with
    | Some true -> seen
    | Some false -> errorm ~loc:d.td_loc "Cyclic type definition"
    | None ->
        let ts_seen seen = function
          | Qident { id = x } ->
              begin try cyc_visit x (Mstr.find x def) seen
              with Not_found -> seen end
          | _ -> seen in
        let rec check seen = function
          | PPTtyvar _ -> seen
          | PPTtyapp (tyl,q) -> List.fold_left check (ts_seen seen q) tyl
          | PPTtuple tyl -> List.fold_left check seen tyl in
        let seen = match d.td_def with
          | TDabstract | TDalgebraic _ | TDrecord _ -> seen
          | TDalias ty -> check (Mstr.add x false seen) ty in
        Mstr.add x true seen in
  ignore (Mstr.fold cyc_visit def Mstr.empty);

  (* detect mutable types *)

  let mutables = Hashtbl.create 5 in
  let rec mut_visit x =
    try Hashtbl.find mutables x
    with Not_found ->
      let ts_mut = function
        | Qident { id = x } when Mstr.mem x def -> mut_visit x
        | q ->
            begin match find_tysymbol q uc with
              | ProgTS s -> s.its_regs <> []
              | PureTS _ -> false end in
      let rec check = function
        | PPTtyvar _ -> false
        | PPTtyapp (tyl,q) -> ts_mut q || List.exists check tyl
        | PPTtuple tyl -> List.exists check tyl in
      Hashtbl.replace mutables x false;
      let mut = match (Mstr.find x def).td_def with
        | TDabstract -> false
        | TDalias ty -> check ty
        | TDalgebraic csl ->
            let proj (_,pty) = check pty in
            List.exists (fun (_,_,l) -> List.exists proj l) csl
        | TDrecord fl ->
            let field f = f.f_mutable || check f.f_pty in
            List.exists field fl in
      Hashtbl.replace mutables x mut;
      mut
  in
  Mstr.iter (fun x _ -> ignore (mut_visit x)) def;

  (* create type symbols and predefinitions for mutable types *)

  let tysymbols = Hashtbl.create 5 in
  let predefs = Hashtbl.create 5 in
  let rec its_visit x =
    try match Hashtbl.find tysymbols x with
      | Some ts -> ts
      | None ->
          let loc = (Mstr.find x def).td_loc in
          errorm ~loc "Mutable type in a recursive type definition"
    with Not_found ->
      let d = Mstr.find x def in
      let add_tv acc id =
        let e = Loc.Located (id.id_loc, DuplicateTypeVar id.id) in
        let tv = Ty.create_tvsymbol (Denv.create_user_id id) in
        Mstr.add_new e id.id tv acc in
      let vars = List.fold_left add_tv Mstr.empty d.td_params in
      let vl = List.map (fun id -> Mstr.find id.id vars) d.td_params in
      let id = Denv.create_user_id d.td_ident in
      let abst = d.td_vis = Abstract in
      let priv = d.td_vis = Private in
      Hashtbl.add tysymbols x None;
      let get_ts = function
        | Qident { id = x } when Mstr.mem x def -> ProgTS (its_visit x)
        | q -> find_tysymbol q uc
      in
      let rec parse = function
        | PPTtyvar { id = v ; id_loc = loc } ->
            let e = Loc.Located (loc, UnboundTypeVar v) in
            ity_var (Mstr.find_exn e v vars)
        | PPTtyapp (tyl,q) ->
            let tyl = List.map parse tyl in
            begin match get_ts q with
              | PureTS ts -> Loc.try2 (Typing.qloc q) ity_pur ts tyl
              | ProgTS ts -> Loc.try2 (Typing.qloc q) ity_app_fresh ts tyl
            end
        | PPTtuple tyl ->
            let ts = Ty.ts_tuple (List.length tyl) in
            ity_pur ts (List.map parse tyl)
      in
      let ts = match d.td_def with
        | TDalias ty ->
            let def = parse ty in
            let s = ity_topregions Sreg.empty def in
            create_itysymbol id ~abst ~priv vl (Sreg.elements s) (Some def)
        | TDalgebraic csl when Hashtbl.mem mutables x ->
            let projs = Hashtbl.create 5 in
            (* to check projections' types we must fix the tyvars *)
            let add s v = let t = ity_var v in ity_match s t t in
            let sbs = List.fold_left add ity_subst_empty vl in
            let mk_proj s (id,pty) =
              let ity = parse pty in
              match id with
                | None ->
                    let pv = create_pvsymbol (id_fresh "pj") ity in
                    ity_topregions s ity, (pv, false)
                | Some id ->
                    try
                      let pv = Hashtbl.find projs id.id in
                      ignore (ity_match sbs pv.pv_ity ity);
                      s, (pv, true)
                    with Not_found ->
                      let pv = create_pvsymbol (Denv.create_user_id id) ity in
                      Hashtbl.replace projs id.id pv;
                      ity_topregions s ity, (pv, true)
            in
            let mk_constr s (_loc,cid,pjl) =
              let s,pjl = Util.map_fold_left mk_proj s pjl in
              s, (Denv.create_user_id cid, pjl)
            in
            let s,def = Util.map_fold_left mk_constr Sreg.empty csl in
            Hashtbl.replace predefs x (PITalgebraic def);
            create_itysymbol id ~abst ~priv vl (Sreg.elements s) None
        | TDrecord fl when Hashtbl.mem mutables x ->
            let mk_field s f =
              let ghost = f.f_ghost in
              let ity = parse f.f_pty in
              let fid = Denv.create_user_id f.f_ident in
              let s,mut = if f.f_mutable then
                let r = create_region fid ~ghost ity in
                Sreg.add r s, Some r
              else
                ity_topregions s ity, None
              in
              s, (create_pvsymbol fid ?mut ~ghost ity, true)
            in
            let s,pjl = Util.map_fold_left mk_field Sreg.empty fl in
            let cid = { d.td_ident with id = "mk " ^ d.td_ident.id } in
            let def = PITalgebraic [Denv.create_user_id cid, pjl] in
            Hashtbl.replace predefs x def;
            create_itysymbol id ~abst ~priv vl (Sreg.elements s) None
        | TDalgebraic _ | TDrecord _ | TDabstract ->
            create_itysymbol id ~abst ~priv vl [] None
      in
      Hashtbl.add tysymbols x (Some ts);
      ts
  in
  Mstr.iter (fun x _ -> ignore (its_visit x)) def;

  (* create predefinitions for immutable types *)

  let def_visit d =
    let x = d.td_ident.id in
    let ts = Util.of_option (Hashtbl.find tysymbols x) in
    let add_tv s x v = Mstr.add x.id v s in
    let vars = List.fold_left2 add_tv Mstr.empty d.td_params ts.its_args in
    let get_ts = function
      | Qident { id = x } when Mstr.mem x def ->
          ProgTS (Util.of_option (Hashtbl.find tysymbols x))
      | q -> find_tysymbol q uc
    in
    let rec parse = function
      | PPTtyvar { id = v ; id_loc = loc } ->
          let e = Loc.Located (loc, UnboundTypeVar v) in
          ity_var (Mstr.find_exn e v vars)
      | PPTtyapp (tyl,q) ->
          let tyl = List.map parse tyl in
          begin match get_ts q with
            | PureTS ts -> Loc.try2 (Typing.qloc q) ity_pur ts tyl
            | ProgTS ts -> Loc.try3 (Typing.qloc q) ity_app ts tyl []
          end
      | PPTtuple tyl ->
          let ts = Ty.ts_tuple (List.length tyl) in
          ity_pur ts (List.map parse tyl)
    in
    match d.td_def with
      | TDabstract | TDalias _ ->
          ts, PITabstract
      | TDalgebraic _ when Hashtbl.mem mutables x ->
          ts, Hashtbl.find predefs x
      | TDrecord _ when Hashtbl.mem mutables x ->
          ts, Hashtbl.find predefs x
      | TDalgebraic csl ->
          let projs = Hashtbl.create 5 in
          let mk_proj (id,pty) =
            let ity = parse pty in
            match id with
              | None ->
                  create_pvsymbol (id_fresh "pj") ity, false
              | Some id ->
                  try
                    let pv = Hashtbl.find projs id.id in
                    ity_equal_check pv.pv_ity ity;
                    pv, true
                  with Not_found ->
                    let pv = create_pvsymbol (Denv.create_user_id id) ity in
                    Hashtbl.replace projs id.id pv;
                    pv, true
          in
          let mk_constr (_loc,cid,pjl) =
            Denv.create_user_id cid, List.map mk_proj pjl in
          ts, PITalgebraic (List.map mk_constr csl)
      | TDrecord fl ->
          let mk_field f =
            let fid = Denv.create_user_id f.f_ident in
            create_pvsymbol fid ~ghost:f.f_ghost (parse f.f_pty), true in
          let cid = { d.td_ident with id = "mk " ^ d.td_ident.id } in
          ts, PITalgebraic [Denv.create_user_id cid, List.map mk_field fl]
  in
  (* TODO: localize exceptions *)
  let pd = create_ity_decl (List.map def_visit tdl) in
  add_pdecl_with_tuples uc pd

(* TODO: if type declaration is pure, declare it in the theory *)

(** Use/Clone of theories and modules *)

322 323 324 325
type mlw_contents = modul Mstr.t
type mlw_library = mlw_contents library
type mlw_file = mlw_contents * Theory.theory Mstr.t

326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351
let find_theory loc lib path s =
  (* search first in .mlw files (using lib) *)
  let thm =
    try Some (Env.read_lib_theory lib path s)
    with LibFileNotFound _ | TheoryNotFound _ -> None
  in
  (* search also in .why files *)
  let th =
    try Some (Env.find_theory (Env.env_of_library lib) path s)
    with LibFileNotFound _ | TheoryNotFound _ -> None
  in
  match thm, th with
    | Some _, Some _ ->
        Loc.errorm ~loc
          "a module/theory %s is defined both in Why and WhyML libraries" s
    | None, None -> Loc.error ~loc (Env.TheoryNotFound (path, s))
    | None, Some t | Some t, None -> t

let find_theory loc lib mt path s = match path with
  | [] -> (* local theory *)
      begin try Mstr.find s mt with Not_found -> find_theory loc lib [] s end
  | _ :: _ -> (* theory in file path *)
      find_theory loc lib path s

type theory_or_module = Theory of Theory.theory | Module of modul

352 353 354
let print_path fmt sl =
  Pp.print_list (Pp.constant_string ".") Format.pp_print_string fmt sl

355 356 357 358 359
let find_module loc lib path s =
  (* search first in .mlw files *)
  let m, thm =
    try
      let mm, mt = Env.read_lib_file lib path in
360
      Mstr.find_opt s mm, Mstr.find_opt s mt
361 362 363 364 365 366 367 368 369 370 371 372 373
    with
      | LibFileNotFound _ -> None, None
  in
  (* search also in .why files *)
  let th =
    try Some (Env.find_theory (Env.env_of_library lib) path s)
    with LibFileNotFound _ | TheoryNotFound _ -> None
  in
  match m, thm, th with
    | Some _, None, _ -> assert false
    | _, Some _, Some _ ->
        Loc.errorm ~loc
          "a module/theory %s is defined both in Why and WhyML libraries" s
374 375
    | None, None, None ->
        Loc.errorm ~loc "Theory/module not found: %a" print_path (path @ [s])
376 377 378
    | Some m, Some _, None -> Module m
    | None, Some t, None | None, None, Some t -> Theory t

379
let find_module loc lib mm mt path s = match path with
380 381 382 383 384 385 386
  | [] -> (* local module/theory *)
      begin try Module (Mstr.find s mm)
        with Not_found -> begin try Theory (Mstr.find s mt)
          with Not_found -> find_module loc lib [] s end end
  | _ :: _ -> (* module/theory in file path *)
      find_module loc lib path s

387 388
(** Main loop *)

389
let add_theory lib path mt m =
390 391 392
  let { id = id; id_loc = loc } = m.pth_name in
  if Mstr.mem id mt then Loc.errorm ~loc "clash with previous theory %s" id;
  let uc = Theory.create_theory ~path (Denv.create_user_id m.pth_name) in
393
  let rec add_decl uc = function
394 395
    | Dlogic d ->
        Typing.add_decl uc d
396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413
    | Duseclone (loc, use, inst) ->
        let path, s = Typing.split_qualid use.use_theory in
        let th = find_theory loc lib mt path s in
        (* open namespace, if any *)
        let uc =
          if use.use_imp_exp <> None then Theory.open_namespace uc else uc in
        (* use or clone *)
        let uc = match inst with
          | None -> Theory.use_export uc th
          | Some inst ->
              let inst = Typing.type_inst uc th inst in
              Theory.clone_export uc th inst
        in
        (* close namespace, if any *)
        begin match use.use_imp_exp with
          | None -> uc
          | Some imp -> Theory.close_namespace uc imp use.use_as
        end
414 415 416
    | Dnamespace (loc, name, import, dl) ->
        let uc = Theory.open_namespace uc in
        let uc = List.fold_left add_decl uc dl in
417
        Loc.try3 loc Theory.close_namespace uc import name
418 419 420 421
    | Dlet _ | Dletrec _ | Dparam _ | Dexn _ | Duse _ ->
        assert false
  in
  let uc = List.fold_left add_decl uc m.pth_decl in
422 423 424 425 426 427 428 429 430
  let th = Theory.close_theory uc in
  Mstr.add id th mt

let add_module lib path mm mt m =
  let { id = id; id_loc = loc } = m.mod_name in
  if Mstr.mem id mm then Loc.errorm ~loc "clash with previous module %s" id;
  if Mstr.mem id mt then Loc.errorm ~loc "clash with previous theory %s" id;
  let uc = create_module ~path (Denv.create_user_id m.mod_name) in
  let rec add_decl uc = function
431 432 433 434
    | Dlogic (TypeDecl tdl) ->
        add_types uc tdl
    | Dlogic d ->
        add_to_theory Typing.add_decl uc d
435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465
    | Duseclone (loc, use, inst) ->
        let path, s = Typing.split_qualid use.use_theory in
        let mth = find_module loc lib mm mt path s in
        (* open namespace, if any *)
        let uc = if use.use_imp_exp <> None then open_namespace uc else uc in
        (* use or clone *)
        let uc = match mth, inst with
          | Theory th, None -> use_export_theory uc th
          | Theory th, Some inst ->
              let inst = Typing.type_inst (get_theory uc) th inst in
              clone_export_theory uc th inst
          | Module m, None -> use_export uc m
          | Module m, Some inst ->
              let inst = Typing.type_inst (get_theory uc) m.mod_theory inst in
              clone_export uc m inst
        in
        (* close namespace, if any *)
        begin match use.use_imp_exp with
          | None -> uc
          | Some imp -> close_namespace uc imp use.use_as
        end
    | Dnamespace (loc, name, import, dl) ->
        let uc = open_namespace uc in
        let uc = List.fold_left add_decl uc dl in
        Loc.try3 loc close_namespace uc import name
    | Dlet _ | Dletrec _ | Dparam _ | Dexn _ | Duse _ ->
        assert false
  in
  let uc = List.fold_left add_decl uc m.mod_decl in
  let m = close_module uc in
  Mstr.add id m mm, Mstr.add id m.mod_theory mt
466 467 468

let add_theory_module lib path (mm, mt) = function
  | Ptheory th -> mm, add_theory lib path mt th
469
  | Pmodule m -> add_module lib path mm mt m
470