mlw_typing.ml 54 KB
Newer Older
1 2
(**************************************************************************)
(*                                                                        *)
MARCHE Claude's avatar
MARCHE Claude committed
3
(*  Copyright (C) 2010-2012                                               *)
4 5 6
(*    François Bobot                                                      *)
(*    Jean-Christophe Filliâtre                                           *)
(*    Claude Marché                                                       *)
MARCHE Claude's avatar
MARCHE Claude committed
7
(*    Guillaume Melquiond                                                 *)
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
(*    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
23
open Ident
24 25 26
open Ty
open Term
open Decl
27 28 29
open Theory
open Env
open Ptree
30
open Mlw_dtree
31
open Mlw_ty
32
open Mlw_ty.T
33 34
open Mlw_expr
open Mlw_decl
35
open Mlw_pretty
36
open Mlw_module
Andrei Paskevich's avatar
Andrei Paskevich committed
37
open Mlw_wp
38
open Mlw_dty
39

40 41
(** errors *)

42
exception DuplicateProgVar of string
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58
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

59 60
let qloc = Typing.qloc
let print_qualid = Typing.print_qualid
61 62 63

let () = Exn_printer.register (fun fmt e -> match e with
  | DuplicateTypeVar s ->
64 65 66
      Format.fprintf fmt "Type parameter %s is used twice" s
  | DuplicateProgVar s ->
      Format.fprintf fmt "Parameter %s is used twice" s
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
(*
  | 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 *)

93 94 95 96
type denv = {
  uc     : module_uc;
  locals : (tvars * dity) Mstr.t;
  tvars  : tvars;
Andrei Paskevich's avatar
Andrei Paskevich committed
97
  uloc   : Ptree.loc option;
98
}
99

100 101 102 103
let create_denv uc = {
  uc     = uc;
  locals = Mstr.empty;
  tvars  = empty_tvars;
Andrei Paskevich's avatar
Andrei Paskevich committed
104
  uloc   = None;
105
}
106

107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122
(** Typing type expressions *)

let rec dity_of_pty ~user denv = function
  | Ptree.PPTtyvar id ->
      create_user_type_variable id
  | Ptree.PPTtyapp (pl, p) ->
      let dl = List.map (dity_of_pty ~user denv) pl in
      let x = Typing.string_list_of_qualid [] p in
      begin
        try
          let its = ns_find_it (get_namespace denv.uc) x in
          its_app ~user its dl
        with Not_found -> try
          let ts = ns_find_ts (Theory.get_namespace (get_theory denv.uc)) x in
          ts_app ts dl
        with Not_found ->
123
          errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
124 125 126
      end
  | Ptree.PPTtuple pl ->
      ts_app (ts_tuple (List.length pl)) (List.map (dity_of_pty ~user denv) pl)
127 128 129

(** Typing program expressions *)

Andrei Paskevich's avatar
Andrei Paskevich committed
130
let dity_int  = ts_app ts_int  []
131
let dity_real = ts_app ts_real []
132
let dity_bool = ts_app ts_bool []
Andrei Paskevich's avatar
Andrei Paskevich committed
133 134
let dity_unit = ts_app ts_unit []
let dity_mark = ts_app ts_mark []
135

136 137
let unify_loc loc fn_unify x1 x2 =
  try fn_unify x1 x2 with
138
    | TypeMismatch (ity1,ity2) ->
139
        errorm ~loc "This expression has type %a, \
140
          but is expected to have type %a"
141 142 143 144 145
        Mlw_pretty.print_ity ity2 Mlw_pretty.print_ity ity1
    | exn -> error ~loc exn

let expected_type ?(weak=false) e dity =
  unify_loc e.de_loc (unify ~weak) dity e.de_type
146

147
let rec extract_labels labs loc e = match e.Ptree.expr_desc with
148
  | Ptree.Enamed (Ptree.Lstr s, e) -> extract_labels (Slab.add s labs) loc e
149 150 151 152
  | Ptree.Enamed (Ptree.Lpos p, e) -> extract_labels labs (Some p) e
  | Ptree.Ecast  (e, ty) ->
      let labs, loc, d = extract_labels labs loc e in
      labs, loc, Ptree.Ecast ({ e with Ptree.expr_desc = d }, ty)
153
  | e -> labs, loc, e
154

155 156 157
let rec decompose_app args e = match e.Ptree.expr_desc with
  | Eapply (e1, e2) -> decompose_app (e2 :: args) e1
  | _ -> e, args
158

159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178
(* record parsing *)

let parse_record uc fll =
  let pl = match fll with
    | [] -> raise EmptyRecord
    | (pl,_)::_ -> pl in
  let its = match pl.pl_args with
    | [{ vtv_ity = { ity_node = Ityapp (its,_,_) }}] -> its
    | _ -> raise (BadRecordField pl.pl_ls) in
  let cs, pjl = match find_constructors (get_known uc) its with
    | [cs,pjl] -> cs, List.map (exn_option (BadRecordField pl.pl_ls)) pjl
    | _ -> raise (BadRecordField pl.pl_ls) in
  let pjs = List.fold_left (fun s pj -> Sls.add pj.pl_ls s) Sls.empty pjl in
  let flm = List.fold_left (fun m (pj,v) -> let pj = pj.pl_ls in
    if not (Sls.mem pj pjs) then raise (BadRecordField pj) else
      Mls.add_new (DuplicateRecordField (cs.pl_ls,pj)) pj v m)
    Mls.empty fll
  in
  cs,pjl,flm

179
let find_field uc (p,e) =
180 181 182
  let x = Typing.string_list_of_qualid [] p in
  try match ns_find_ps (get_namespace uc) x with
    | PL pl -> (pl,e)
183 184
    | _ -> errorm ~loc:(qloc p) "bad record field %a" print_qualid p
  with Not_found -> errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
185

186
let find_pure_field uc (p,e) =
187 188
  let x = Typing.string_list_of_qualid [] p in
  try ns_find_ls (Theory.get_namespace (get_theory uc)) x, e
189
  with Not_found -> errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
190

191 192
let pure_record uc = function
  | [] -> raise Decl.EmptyRecord
193 194 195 196 197 198
  | (p,_)::_ ->
      let x = Typing.string_list_of_qualid [] p in
      begin try ignore (ns_find_ps (get_namespace uc) x); false
      with Not_found -> true end

let hidden_pl ~loc pl =
199 200
  { de_desc = DEglobal_pl pl;
    de_type = specialize_plsymbol pl;
201
    de_loc  = loc; de_lab = Slab.empty }
202 203

let hidden_ls ~loc ls =
204 205
  { de_desc = DEglobal_ls ls;
    de_type = specialize_lsymbol ls;
206
    de_loc  = loc; de_lab = Slab.empty }
207 208

(* helper functions for let-expansion *)
209
let test_var e = match e.de_desc with
210 211 212 213 214
  | DElocal _ | DEglobal_pv _ -> true
  | _ -> false

let mk_var e =
  if test_var e then e else
215 216 217
  { de_desc = DElocal "q";
    de_type = e.de_type;
    de_loc  = e.de_loc;
218
    de_lab  = Slab.empty }
219

220 221 222 223
let mk_id s loc =
  { id = s; id_loc = loc; id_lab = [] }

let mk_dexpr desc dity loc labs =
224
  { de_desc = desc; de_type = dity; de_loc = loc; de_lab = labs }
225

Andrei Paskevich's avatar
Andrei Paskevich committed
226
let mk_let ~loc ~uloc e (desc,dity) =
227
  if test_var e then desc, dity else
Andrei Paskevich's avatar
Andrei Paskevich committed
228
  let loc = def_option loc uloc in
229
  let e1 = mk_dexpr desc dity loc Slab.empty in
230
  DElet (mk_id "q" loc, false, e, e1), dity
231

232 233 234 235 236 237 238
(* patterns *)

let add_var id dity denv =
  let tvars = add_tvars denv.tvars dity in
  let locals = Mstr.add id.id (tvars,dity) denv.locals in
  { denv with locals = locals; tvars = tvars }

239
let specialize_qualid uc p =
240 241 242 243 244
  let x = Typing.string_list_of_qualid [] p in
  try match ns_find_ps (get_namespace uc) x with
    | PV pv -> DEglobal_pv pv, specialize_pvsymbol pv
    | PS ps -> DEglobal_ps ps, specialize_psymbol  ps
    | PL pl -> DEglobal_pl pl, specialize_plsymbol pl
245 246
    | PX xs ->
        errorm ~loc:(qloc p) "unexpected exception symbol %a" print_xs xs
247 248 249 250
  with Not_found -> try
    let ls = ns_find_ls (Theory.get_namespace (get_theory uc)) x in
    DEglobal_ls ls, specialize_lsymbol ls
  with Not_found ->
251
    errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
252

253
let find_xsymbol uc p =
Andrei Paskevich's avatar
Andrei Paskevich committed
254 255
  let x = Typing.string_list_of_qualid [] p in
  try match ns_find_ps (get_namespace uc) x with
256
    | PX xs -> xs
257
    | _ -> errorm ~loc:(qloc p) "exception symbol expected"
Andrei Paskevich's avatar
Andrei Paskevich committed
258
  with Not_found ->
259
    errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
Andrei Paskevich's avatar
Andrei Paskevich committed
260

261
let find_variant_ls uc p =
262 263
  let x = Typing.string_list_of_qualid [] p in
  try match ns_find_ps (get_namespace uc) x with
264
    | _ -> errorm ~loc:(qloc p) "%a is not a binary relation" print_qualid p
265 266 267
  with Not_found -> try
    match ns_find_ls (Theory.get_namespace (get_theory uc)) x with
      | { ls_args = [u;v]; ls_value = None } as ls when ty_equal u v -> ls
268 269
      | ls ->
          errorm ~loc:(qloc p) "%a is not a binary relation" Pretty.print_ls ls
270
  with Not_found ->
271
    errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
272

273 274 275 276 277 278 279
let find_global_vs uc p =
  let x = Typing.string_list_of_qualid [] p in
  try match ns_find_ps (get_namespace uc) x with
    | PV pv -> Some pv.pv_vs
    | _ -> None
  with Not_found -> None

280 281 282 283 284
let rec dpattern denv ({ pat_loc = loc } as pp) = match pp.pat_desc with
  | Ptree.PPpwild ->
      PPwild, create_type_variable (), denv
  | Ptree.PPpvar id ->
      let dity = create_type_variable () in
285
      PPvar (Denv.create_user_id id), dity, add_var id dity denv
286
  | Ptree.PPpapp (q,ppl) ->
287
      let sym, dity = specialize_qualid denv.uc q in
288
      dpat_app denv loc (mk_dexpr sym dity loc Slab.empty) ppl
289
  | Ptree.PPprec fl when pure_record denv.uc fl ->
290
      let kn = Theory.get_known (get_theory denv.uc) in
291
      let fl = List.map (find_pure_field denv.uc) fl in
292 293 294
      let cs,pjl,flm = Loc.try2 loc Decl.parse_record kn fl in
      let wild = { pat_desc = Ptree.PPpwild; pat_loc = loc } in
      let get_val pj = Mls.find_def wild pj flm in
295
      dpat_app denv loc (hidden_ls ~loc cs) (List.map get_val pjl)
296
  | Ptree.PPprec fl ->
297
      let fl = List.map (find_field denv.uc) fl in
298 299 300
      let cs,pjl,flm = Loc.try2 loc parse_record denv.uc fl in
      let wild = { pat_desc = Ptree.PPpwild; pat_loc = loc } in
      let get_val pj = Mls.find_def wild pj.pl_ls flm in
301
      dpat_app denv loc (hidden_pl ~loc cs) (List.map get_val pjl)
302 303
  | Ptree.PPptuple ppl ->
      let cs = fs_tuple (List.length ppl) in
304 305 306 307 308
      dpat_app denv loc (hidden_ls ~loc cs) ppl
  | Ptree.PPpor (lpp1, lpp2) ->
      let pp1, dity1, denv = dpattern denv lpp1 in
      let pp2, dity2, denv = dpattern denv lpp2 in
      unify_loc lpp2.pat_loc unify dity1 dity2;
309 310 311
      PPor (pp1, pp2), dity1, denv
  | Ptree.PPpas (pp, id) ->
      let pp, dity, denv = dpattern denv pp in
312
      PPas (pp, Denv.create_user_id id), dity, add_var id dity denv
313

314 315 316 317
and dpat_app denv gloc ({ de_loc = loc } as de) ppl =
  let add_pp lp (ppl, tyl, denv) =
    let pp, ty, denv = dpattern denv lp in
    pp::ppl, (lp.pat_loc,ty)::tyl, denv in
318
  let ppl, tyl, denv = List.fold_right add_pp ppl ([],[],denv) in
319
  let pp = match de.de_desc with
320 321
    | DEglobal_pl pl -> Mlw_expr.PPpapp (pl, ppl)
    | DEglobal_ls ls -> PPlapp (ls, ppl)
322 323
    | DEglobal_pv pv -> errorm ~loc "%a is not a constructor" print_pv pv
    | DEglobal_ps ps -> errorm ~loc "%a is not a constructor" print_ps ps
324 325 326
    | _ -> assert false
  in
  let res = create_type_variable () in
327
  Loc.try2 gloc unify_list de.de_type tyl res;
328 329
  pp, res, denv

330 331
(* specifications *)

332
let dbinders denv bl =
333
  let hv = Hashtbl.create 3 in
334
  let dbinder (id,gh,pty) (denv,bl,tyl) =
335 336
    if Hashtbl.mem hv id.id then errorm "duplicate argument %s" id.id;
    Hashtbl.add hv id.id ();
337 338 339
    let dity = match pty with
      | Some pty -> dity_of_pty ~user:true denv pty
      | None -> create_type_variable () in
340
    add_var id dity denv, (id,gh,dity)::bl, dity::tyl
341 342
  in
  List.fold_right dbinder bl (denv,[],[])
343 344

let deff_of_peff uc pe =
345 346 347
  { deff_reads  = pe.pe_reads;
    deff_writes = pe.pe_writes;
    deff_raises = List.map (fun (gh,q) -> gh, find_xsymbol uc q) pe.pe_raises; }
348 349 350 351 352 353 354 355 356 357 358 359 360 361 362

let dxpost uc ql = List.map (fun (q,f) -> find_xsymbol uc q, f) ql

let rec dtype_c denv tyc =
  let tyv, dity = dtype_v denv tyc.pc_result_type in
  { dc_result = tyv;
    dc_effect = deff_of_peff denv.uc tyc.pc_effect;
    dc_pre    = tyc.pc_pre;
    dc_post   = fst tyc.pc_post;
    dc_xpost  = dxpost denv.uc (snd tyc.pc_post); },
  dity

and dtype_v denv = function
  | Tpure pty ->
      let dity = dity_of_pty ~user:true denv pty in
363
      DSpecV (false,dity), dity
364 365 366 367
  | Tarrow (bl,tyc) ->
      let denv,bl,tyl = dbinders denv bl in
      let tyc,dity = dtype_c denv tyc in
      DSpecA (bl,tyc), make_arrow_type tyl dity
368

369 370 371 372 373 374 375 376
let dvariant uc = function
  | Some (le, Some q) -> [le, Some (find_variant_ls uc q)]
  | Some (le, None) -> [le, None]
  | None -> []
(* TODO: accept a list of variants in the surface language
  List.map (fun (le,q) -> le, Util.option_map (find_variant_ls uc) q) var
*)

377
(* expressions *)
378

379 380
let de_unit ~loc = hidden_ls ~loc (fs_tuple 0)

381
let de_app loc e el =
382
  let res = create_type_variable () in
383 384
  let tyl = List.map (fun a -> (a.de_loc, a.de_type)) el in
  Loc.try2 loc unify_list e.de_type tyl res;
385 386
  DEapply (e, el), res

Andrei Paskevich's avatar
Andrei Paskevich committed
387
let rec dexpr denv e =
388
  let loc = e.Ptree.expr_loc in
389
  let labs, uloc, d = extract_labels Slab.empty denv.uloc e in
Andrei Paskevich's avatar
Andrei Paskevich committed
390
  let denv = { denv with uloc = uloc } in
391
  let d, ty = de_desc denv loc d in
Andrei Paskevich's avatar
Andrei Paskevich committed
392
  let loc = def_option loc uloc in
393
  mk_dexpr d ty loc labs
394

395
and de_desc denv loc = function
396 397
  | Ptree.Eident (Qident {id=x}) when Mstr.mem x denv.locals ->
      (* local variable *)
398 399 400
      let tvs, dity = Mstr.find x denv.locals in
      let dity = specialize_scheme tvs dity in
      DElocal x, dity
401
  | Ptree.Eident p ->
402
      specialize_qualid denv.uc p
403 404
  | Ptree.Eapply (e1, e2) ->
      let e, el = decompose_app [e2] e1 in
Andrei Paskevich's avatar
Andrei Paskevich committed
405
      let el = List.map (dexpr denv) el in
406
      de_app loc (dexpr denv e) el
407
  | Ptree.Elet (id, gh, e1, e2) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
408
      let e1 = dexpr denv e1 in
409 410
      let dity = e1.de_type in
      let tvars = match e1.de_desc with
Andrei Paskevich's avatar
Andrei Paskevich committed
411 412
        | DEfun _ -> denv.tvars
        | _ -> add_tvars denv.tvars dity in
413 414
      let locals = Mstr.add id.id (tvars, dity) denv.locals in
      let denv = { denv with locals = locals; tvars = tvars } in
Andrei Paskevich's avatar
Andrei Paskevich committed
415
      let e2 = dexpr denv e2 in
416
      DElet (id, gh, e1, e2), e2.de_type
Andrei Paskevich's avatar
Andrei Paskevich committed
417
  | Ptree.Eletrec (rdl, e1) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
418
      let rdl = dletrec denv rdl in
419
      let add_one denv (_, { id = id }, _, dity, _) =
420 421
        { denv with locals = Mstr.add id (denv.tvars, dity) denv.locals } in
      let denv = List.fold_left add_one denv rdl in
Andrei Paskevich's avatar
Andrei Paskevich committed
422
      let e1 = dexpr denv e1 in
423
      DEletrec (rdl, e1), e1.de_type
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
424
  | Ptree.Efun (bl, tr) ->
425
      let lam, dity = dlambda denv bl None tr in
426
      DEfun lam, dity
427
  | Ptree.Ecast (e1, pty) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
428
      let e1 = dexpr denv e1 in
429
      expected_type e1 (dity_of_pty ~user:false denv pty);
430
      e1.de_desc, e1.de_type
431 432
  | Ptree.Enamed _ ->
      assert false
433
  | Ptree.Esequence (e1, e2) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
434
      let e1 = dexpr denv e1 in
435
      expected_type e1 dity_unit;
Andrei Paskevich's avatar
Andrei Paskevich committed
436
      let e2 = dexpr denv e2 in
437
      DElet (mk_id "_" loc, false, e1, e2), e2.de_type
438
  | Ptree.Eif (e1, e2, e3) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
439
      let e1 = dexpr denv e1 in
440
      expected_type e1 dity_bool;
Andrei Paskevich's avatar
Andrei Paskevich committed
441 442
      let e2 = dexpr denv e2 in
      let e3 = dexpr denv e3 in
443 444
      expected_type e3 e2.de_type;
      DEif (e1, e2, e3), e2.de_type
445 446
  | Ptree.Etuple el ->
      let ls = fs_tuple (List.length el) in
Andrei Paskevich's avatar
Andrei Paskevich committed
447
      let el = List.map (dexpr denv) el in
448
      de_app loc (hidden_ls ~loc ls) el
449
  | Ptree.Erecord fl when pure_record denv.uc fl ->
450
      let kn = Theory.get_known (get_theory denv.uc) in
451
      let fl = List.map (find_pure_field denv.uc) fl in
452 453
      let cs,pjl,flm = Loc.try2 loc Decl.parse_record kn fl in
      let get_val pj = match Mls.find_opt pj flm with
Andrei Paskevich's avatar
Andrei Paskevich committed
454
        | Some e -> dexpr denv e
455
        | None -> error ~loc (Decl.RecordFieldMissing (cs,pj)) in
456
      de_app loc (hidden_ls ~loc cs) (List.map get_val pjl)
457
  | Ptree.Erecord fl ->
458
      let fl = List.map (find_field denv.uc) fl in
459 460
      let cs,pjl,flm = Loc.try2 loc parse_record denv.uc fl in
      let get_val pj = match Mls.find_opt pj.pl_ls flm with
Andrei Paskevich's avatar
Andrei Paskevich committed
461
        | Some e -> dexpr denv e
462
        | None -> error ~loc (Decl.RecordFieldMissing (cs.pl_ls,pj.pl_ls)) in
463
      de_app loc (hidden_pl ~loc cs) (List.map get_val pjl)
464
  | Ptree.Eupdate (e1, fl) when pure_record denv.uc fl ->
Andrei Paskevich's avatar
Andrei Paskevich committed
465
      let e1 = dexpr denv e1 in
466 467
      let e0 = mk_var e1 in
      let kn = Theory.get_known (get_theory denv.uc) in
468
      let fl = List.map (find_pure_field denv.uc) fl in
469 470
      let cs,pjl,flm = Loc.try2 loc Decl.parse_record kn fl in
      let get_val pj = match Mls.find_opt pj flm with
Andrei Paskevich's avatar
Andrei Paskevich committed
471
        | Some e -> dexpr denv e
472
        | None ->
473 474
            let loc = Loc.dummy_position in
            let d, dity = de_app loc (hidden_ls ~loc pj) [e0] in
475
            mk_dexpr d dity loc Slab.empty in
476
      let res = de_app loc (hidden_ls ~loc cs) (List.map get_val pjl) in
Andrei Paskevich's avatar
Andrei Paskevich committed
477
      mk_let ~loc ~uloc:denv.uloc e1 res
478
  | Ptree.Eupdate (e1, fl) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
479
      let e1 = dexpr denv e1 in
480
      let e0 = mk_var e1 in
481
      let fl = List.map (find_field denv.uc) fl in
482 483
      let cs,pjl,flm = Loc.try2 loc parse_record denv.uc fl in
      let get_val pj = match Mls.find_opt pj.pl_ls flm with
Andrei Paskevich's avatar
Andrei Paskevich committed
484
        | Some e -> dexpr denv e
485
        | None ->
486 487
            let loc = Loc.dummy_position in
            let d, dity = de_app loc (hidden_pl ~loc pj) [e0] in
488
            mk_dexpr d dity loc Slab.empty in
489
      let res = de_app loc (hidden_pl ~loc cs) (List.map get_val pjl) in
Andrei Paskevich's avatar
Andrei Paskevich committed
490
      mk_let ~loc ~uloc:denv.uloc e1 res
Andrei Paskevich's avatar
Andrei Paskevich committed
491
  | Ptree.Eassign (e1, q, e2) ->
492 493
      let fl = { expr_desc = Eident q; expr_loc = loc } in
      let e1 = { expr_desc = Eapply (fl,e1); expr_loc = loc } in
Andrei Paskevich's avatar
Andrei Paskevich committed
494 495
      let e1 = dexpr denv e1 in
      let e2 = dexpr denv e2 in
496
      expected_type ~weak:true e2 e1.de_type;
Andrei Paskevich's avatar
Andrei Paskevich committed
497
      DEassign (e1, e2), dity_unit
498 499 500 501 502
  | Ptree.Econstant (ConstInt _ as c) ->
      DEconstant c, dity_int
  | Ptree.Econstant (ConstReal _ as c) ->
      DEconstant c, dity_real
  | Ptree.Enot e1 ->
Andrei Paskevich's avatar
Andrei Paskevich committed
503
      let e1 = dexpr denv e1 in
504 505 506
      expected_type e1 dity_bool;
      DEnot e1, dity_bool
  | Ptree.Elazy (op, e1, e2) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
507 508
      let e1 = dexpr denv e1 in
      let e2 = dexpr denv e2 in
509 510 511
      expected_type e1 dity_bool;
      expected_type e2 dity_bool;
      DElazy (op, e1, e2), dity_bool
512
  | Ptree.Ematch (e1, bl) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
513
      let e1 = dexpr denv e1 in
514 515 516
      let res = create_type_variable () in
      let branch (pp,e) =
        let ppat, dity, denv = dpattern denv pp in
517
        unify_loc pp.pat_loc unify e1.de_type dity;
Andrei Paskevich's avatar
Andrei Paskevich committed
518
        let e = dexpr denv e in
519 520 521
        expected_type e res;
        ppat, e in
      DEmatch (e1, List.map branch bl), res
Andrei Paskevich's avatar
Andrei Paskevich committed
522 523
  | Ptree.Eraise (q, e1) ->
      let res = create_type_variable () in
524
      let xs = find_xsymbol denv.uc q in
525
      let dity = specialize_xsymbol xs in
Andrei Paskevich's avatar
Andrei Paskevich committed
526
      let e1 = match e1 with
Andrei Paskevich's avatar
Andrei Paskevich committed
527
        | Some e1 -> dexpr denv e1
528
        | None when ity_equal xs.xs_ity ity_unit -> de_unit ~loc
Andrei Paskevich's avatar
Andrei Paskevich committed
529 530 531 532
        | _ -> errorm ~loc "exception argument expected" in
      expected_type e1 dity;
      DEraise (xs, e1), res
  | Ptree.Etry (e1, cl) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
533
      let e1 = dexpr denv e1 in
Andrei Paskevich's avatar
Andrei Paskevich committed
534
      let branch (q, id, e) =
535
        let xs = find_xsymbol denv.uc q in
536
        let dity = specialize_xsymbol xs in
Andrei Paskevich's avatar
Andrei Paskevich committed
537 538
        let id, denv = match id with
          | Some id -> id, add_var id dity denv
539
          | None -> mk_id "void" loc, denv in
Andrei Paskevich's avatar
Andrei Paskevich committed
540
        xs, id, dexpr denv e
Andrei Paskevich's avatar
Andrei Paskevich committed
541 542
      in
      let cl = List.map branch cl in
543
      DEtry (e1, cl), e1.de_type
544
  | Ptree.Eabsurd ->
545
      DEabsurd, create_type_variable ()
546 547
  | Ptree.Eassert (ak, lexpr) ->
      DEassert (ak, lexpr), dity_unit
Andrei Paskevich's avatar
Andrei Paskevich committed
548 549
  | Ptree.Emark (id, e1) ->
      let e1 = dexpr denv e1 in
550
      DEmark (id, e1), e1.de_type
551
  | Ptree.Eany tyc ->
552 553
      let tyc, dity = dtype_c denv tyc in
      DEany tyc, dity
554 555 556
  | Ptree.Eghost e1 ->
      let e1 = dexpr denv e1 in
      DEghost e1, e1.de_type
557 558 559 560
  | Ptree.Eabstract (e1, (q,xq)) ->
      let e1 = dexpr denv e1 in
      let xq = dxpost denv.uc xq in
      DEabstract (e1, q, xq), e1.de_type
561 562 563 564 565 566 567 568 569 570 571 572 573 574
  | Ptree.Eloop ({ loop_invariant = inv; loop_variant = var }, e1) ->
      let e1 = dexpr denv e1 in
      let var = dvariant denv.uc var in
      expected_type e1 dity_unit;
      DEloop (var,inv,e1), e1.de_type
  | Ptree.Efor (id, efrom, dir, eto, inv, e1) ->
      let efrom = dexpr denv efrom in
      let eto = dexpr denv eto in
      let denv = add_var id dity_int denv in
      let e1 = dexpr denv e1 in
      expected_type efrom dity_int;
      expected_type eto dity_int;
      expected_type e1 dity_unit;
      DEfor (id,efrom,dir,eto,inv,e1), e1.de_type
575

Andrei Paskevich's avatar
Andrei Paskevich committed
576
and dletrec denv rdl =
Andrei Paskevich's avatar
Andrei Paskevich committed
577
  (* add all functions into environment *)
578
  let add_one denv (_,id,_,_,_,_) =
Andrei Paskevich's avatar
Andrei Paskevich committed
579
    let res = create_type_variable () in
580 581
    add_var id res denv, res in
  let denv, tyl = Util.map_fold_left add_one denv rdl in
Andrei Paskevich's avatar
Andrei Paskevich committed
582
  (* then type-check all of them and unify *)
583
  let type_one (loc, id, gh, bl, var, tr) res =
584
    let lam, dity = dlambda denv bl var tr in
Andrei Paskevich's avatar
Andrei Paskevich committed
585
    Loc.try2 id.id_loc unify dity res;
586 587
    loc, id, gh, dity, lam in
  List.map2 type_one rdl tyl
Andrei Paskevich's avatar
Andrei Paskevich committed
588

589 590
and dlambda denv bl var (p, e, (q, xq)) =
  let denv,bl,tyl = dbinders denv bl in
Andrei Paskevich's avatar
Andrei Paskevich committed
591
  let e = dexpr denv e in
592 593 594
  let var = dvariant denv.uc var in
  let xq = dxpost denv.uc xq in
  (bl, var, p, e, q, xq), make_arrow_type tyl e.de_type
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
595

596
(** stage 2 *)
597

Andrei Paskevich's avatar
Andrei Paskevich committed
598 599 600 601 602
type lenv = {
  mod_uc   : module_uc;
  let_vars : let_var Mstr.t;
  log_vars : vsymbol Mstr.t;
  log_denv : Typing.denv;
603 604
}

Andrei Paskevich's avatar
Andrei Paskevich committed
605
let create_lenv uc = {
606
  mod_uc   = use_export_theory uc Mlw_wp.th_mark;
607 608
  let_vars = Mstr.empty;
  log_vars = Mstr.empty;
609
  log_denv = Typing.denv_empty_with_globals (find_global_vs uc);
610 611 612 613 614 615 616 617
}

let rec dty_of_ty ty = match ty.ty_node with
  | Ty.Tyvar v ->
      Typing.create_user_type_var v.tv_name.id_string
  | Ty.Tyapp (ts, tyl) ->
      Denv.tyapp ts (List.map dty_of_ty tyl)

618 619 620 621
let create_post lenv x ty f =
  let res = create_vsymbol (id_fresh x) ty in
  let log_vars = Mstr.add x res lenv.log_vars in
  let log_denv = Typing.add_var x (dty_of_ty ty) lenv.log_denv in
622 623
  let f = Typing.type_fmla (get_theory lenv.mod_uc) log_denv log_vars f in
  create_post res f
624 625 626 627

let create_pre lenv f =
  Typing.type_fmla (get_theory lenv.mod_uc) lenv.log_denv lenv.log_vars f

628 629 630 631
let create_variant lenv (t,r) =
  let t =
    Typing.type_term (get_theory lenv.mod_uc) lenv.log_denv lenv.log_vars t in
  { v_term = t; v_rel = r }
Andrei Paskevich's avatar
Andrei Paskevich committed
632

Andrei Paskevich's avatar
Andrei Paskevich committed
633
let add_local x lv lenv = match lv with
634
  | LetA _ ->
Andrei Paskevich's avatar
Andrei Paskevich committed
635
      { lenv with let_vars = Mstr.add x lv lenv.let_vars }
636 637
  | LetV pv ->
      let dty = dty_of_ty pv.pv_vs.vs_ty in
Andrei Paskevich's avatar
Andrei Paskevich committed
638 639 640 641
      { mod_uc   = lenv.mod_uc;
        let_vars = Mstr.add x lv lenv.let_vars;
        log_vars = Mstr.add x pv.pv_vs lenv.log_vars;
        log_denv = Typing.add_var x dty lenv.log_denv }
642

643 644
exception DuplicateException of xsymbol

645 646 647 648 649 650 651 652 653 654 655 656 657
let binders lenv bl =
  let binder lenv (id, ghost, dity) =
    let vtv = vty_value ~ghost (ity_of_dity dity) in
    let pv = create_pvsymbol (Denv.create_user_id id) vtv in
    add_local id.id (LetV pv) lenv, pv in
  Util.map_fold_left binder lenv bl

let xpost lenv xq =
  let add_exn m (xs,f) =
    let f = create_post lenv "result" (ty_of_ity xs.xs_ity) f in
    Mexn.add_new (DuplicateException xs) xs f m in
  List.fold_left add_exn Mexn.empty xq

658 659 660 661 662 663 664 665 666 667 668 669 670
(* TODO: devise a good grammar for effect expressions *)
let rec get_eff_expr lenv { pp_desc = d; pp_loc = loc } = match d with
  | Ptree.PPvar (Ptree.Qident {id=x}) when Mstr.mem x lenv.let_vars ->
      begin match Mstr.find x lenv.let_vars with
        | LetV pv -> e_value pv
        | LetA _ -> errorm ~loc "%s must be a first-order value" x
      end
  | Ptree.PPvar p ->
      let x = Typing.string_list_of_qualid [] p in
      begin try match ns_find_ps (get_namespace lenv.mod_uc) x with
        | PV pv -> e_value pv
        | _ -> errorm ~loc:(qloc p) "%a is not a variable" print_qualid p
      with Not_found -> errorm ~loc "unbound variable %a" print_qualid p end
671 672
  | Ptree.PPapp (p, [le]) ->
      let e = get_eff_expr lenv le in
673 674 675 676 677 678
      let ity = (vtv_of_expr e).vtv_ity in
      let x = Typing.string_list_of_qualid [] p in
      let quit () =
        errorm ~loc:(qloc p) "%a is not a projection symbol" print_qualid p in
      begin try match ns_find_ps (get_namespace lenv.mod_uc) x with
        | PL ({pl_args = [{vtv_ity = ta}]; pl_value = {vtv_ity = tr}} as pl) ->
679
            let sbs = unify_loc le.pp_loc (ity_match ity_subst_empty) ta ity in
680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728
            let res = try ity_full_inst sbs tr with Not_found -> quit () in
            e_plapp pl [e] res
        | _ -> quit ()
      with Not_found -> try
        let th = get_theory lenv.mod_uc in
        match ns_find_ls (Theory.get_namespace th) x with
        | { ls_args = [ta]; ls_value = Some tr } as ls ->
            let sbs = ity_match ity_subst_empty (ity_of_ty ta) ity in
            let res = try ity_full_inst sbs (ity_of_ty tr) with _ -> quit () in
            e_lapp ls [e] res
        | _ -> quit ()
      with Not_found ->
        errorm ~loc:(qloc p) "unbound symbol %a" print_qualid p
      end
  | Ptree.PPcast (e,_) | Ptree.PPnamed (_,e) ->
      get_eff_expr lenv e
  | _ ->
      errorm ~loc "unsupported effect expression"

let get_eff_regs lenv fn eff ghost le =
  let e = get_eff_expr lenv le in
  let vtv = vtv_of_expr e in
  let ghost = ghost || vtv.vtv_ghost in
  match vtv.vtv_mut, vtv.vtv_ity.ity_node with
  | Some reg, _ ->
      fn eff ?ghost:(Some ghost) reg
  | None, Ityapp (its,_,(_::_ as regl)) ->
      let add_arg regs vtv = match vtv.vtv_mut with
        | Some r when vtv.vtv_ghost -> Sreg.add r regs | _ -> regs in
      let add_cs regs (cs,_) = List.fold_left add_arg regs cs.pl_args in
      let csl = find_constructors (get_known lenv.mod_uc) its in
      let ghost_regs = List.fold_left add_cs Sreg.empty csl in
      let add_reg eff reg0 reg =
        let ghost = ghost || Sreg.mem reg0 ghost_regs in
        fn eff ?ghost:(Some ghost) reg
      in
      List.fold_left2 add_reg eff its.its_regs regl
  | _ ->
      errorm ~loc:le.pp_loc "mutable expression expected"

let eff_of_deff lenv deff =
  let add_read eff (gh,e) = get_eff_regs lenv eff_read eff gh e in
  let eff = List.fold_left add_read eff_empty deff.deff_reads in
  let add_write eff (gh,e) = get_eff_regs lenv eff_write eff gh e in
  let eff = List.fold_left add_write eff deff.deff_writes in
  let add_raise eff (gh,xs) = eff_raise eff ~ghost:gh xs in
  let eff = List.fold_left add_raise eff deff.deff_raises in
  eff

729 730
let rec type_c lenv gh vars dtyc =
  let result = type_v lenv gh vars dtyc.dc_result in
731 732 733
  let ty = match result with
    | SpecV v -> ty_of_ity v.vtv_ity
    | SpecA _ -> ty_unit in
734 735 736 737 738 739 740 741 742
  let eff = eff_of_deff lenv dtyc.dc_effect in
  (* reset every new region in the result *)
  let eff = match result with
    | SpecV v ->
        let rec add_reg r eff =
          if reg_occurs r vars then eff else eff_reset (add_ity r.reg_ity eff) r
        and add_ity ity eff = Sreg.fold add_reg ity.ity_vars.vars_reg eff in
        add_ity v.vtv_ity eff
    | SpecA _ -> eff in
743
  { c_pre    = create_pre lenv dtyc.dc_pre;
744
    c_effect = eff;
745 746 747 748
    c_result = result;
    c_post   = create_post lenv "result" ty dtyc.dc_post;
    c_xpost  = xpost lenv dtyc.dc_xpost; }

749
and type_v lenv gh vars = function
750
  | DSpecV (ghost,v) ->
751
      let ghost = ghost || gh in
752 753 754
      SpecV (vty_value ~ghost (ity_of_dity v))
  | DSpecA (bl,tyc) ->
      let lenv, pvl = binders lenv bl in
755 756
      let add_pv s pv = vars_union s pv.pv_vtv.vtv_vars in
      let vars = List.fold_left add_pv vars pvl in
757
      SpecA (pvl, type_c lenv gh vars tyc)
758 759 760

(* expressions *)

761 762 763 764 765 766
let vty_ghostify gh vty =
  if gh && not (vty_ghost vty) then vty_ghostify vty else vty

let e_ghostify gh e =
  if gh && not (vty_ghost e.e_vty) then e_ghost e else e

767 768 769 770 771 772
let rec expr lenv de =
  let loc = de.de_loc in
  let e = Loc.try3 loc expr_desc lenv loc de in
  e_label ~loc de.de_lab e

and expr_desc lenv loc de = match de.de_desc with
773
  | DElocal x ->
Andrei Paskevich's avatar
Andrei Paskevich committed
774 775
      assert (Mstr.mem x lenv.let_vars);
      begin match Mstr.find x lenv.let_vars with
776
      | LetV pv -> e_value pv
777
      | LetA ps -> e_cast ps (vty_of_dity de.de_type)
778
      end
779 780
  | DElet (x, gh, { de_desc = DEfun lam }, de2) ->
      let def = expr_fun lenv x gh lam in
781
      let lenv = add_local x.id (LetA def.rec_ps) lenv in
Andrei Paskevich's avatar
Andrei Paskevich committed
782
      let e2 = expr lenv de2 in
783 784
      e_rec [def] e2
  | DEfun lam ->
785
      let x = mk_id "fn" loc in
786
      let def = expr_fun lenv x false lam in
787 788
      let e2 = e_cast def.rec_ps (VTarrow def.rec_ps.ps_vta) in
      e_rec [def] e2
789 790 791 792 793 794 795 796 797 798 799 800 801
  (* FIXME? (ghost "lab" fun x -> ...) loses the label "lab" *)
  | DEghost { de_desc = DEfun lam } ->
      let x = mk_id "fn" loc in
      let def = expr_fun lenv x true lam in
      let e2 = e_cast def.rec_ps (VTarrow def.rec_ps.ps_vta) in
      e_rec [def] e2
  | DElet (x, gh, de1, de2) ->
      let e1 = e_ghostify gh (expr lenv de1) in
      begin match e1.e_vty with
        | VTarrow { vta_ghost = true } when not gh ->
            errorm ~loc "%s must be a ghost function" x.id
        | _ -> ()
      end;
802
      let def1 = create_let_defn (Denv.create_user_id x) e1 in
Andrei Paskevich's avatar
Andrei Paskevich committed
803 804
      let lenv = add_local x.id def1.let_var lenv in
      let e2 = expr lenv de2 in
805
      e_let def1 e2
Andrei Paskevich's avatar
Andrei Paskevich committed
806
  | DEletrec (rdl, de1) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
807
      let rdl = expr_rec lenv rdl in
808
      let add_rd { rec_ps = ps } = add_local ps.ps_name.id_string (LetA ps) in
Andrei Paskevich's avatar
Andrei Paskevich committed
809
      let e1 = expr (List.fold_right add_rd rdl lenv) de1 in
Andrei Paskevich's avatar
Andrei Paskevich committed
810
      e_rec rdl e1
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
811
  | DEapply (de1, del) ->
Andrei Paskevich's avatar
Andrei Paskevich committed
812
      let el = List.map (expr lenv) del in
813 814 815
      begin match de1.de_desc with
        | DEglobal_pl pls -> e_plapp pls el (ity_of_dity de.de_type)
        | DEglobal_ls ls  -> e_lapp  ls  el (ity_of_dity de.de_type)
Andrei Paskevich's avatar
Andrei Paskevich committed
816
        | _               -> e_app (expr lenv de1) el
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
817
      end
818 819 820
  | DEglobal_pv pv ->
      e_value pv
  | DEglobal_ps ps ->
821
      e_cast ps (vty_of_dity de.de_type)