typing.ml 48.2 KB
Newer Older
Andrei Paskevich's avatar
Andrei Paskevich committed
1 2 3
(********************************************************************)
(*                                                                  *)
(*  The Why3 Verification Platform   /   The Why3 Development Team  *)
MARCHE Claude's avatar
MARCHE Claude committed
4
(*  Copyright 2010-2017   --   INRIA - CNRS - Paris-Sud University  *)
Andrei Paskevich's avatar
Andrei Paskevich committed
5 6 7 8
(*                                                                  *)
(*  This software is distributed under the terms of the GNU Lesser  *)
(*  General Public License version 2.1, with the special exception  *)
(*  on linking described in file LICENSE.                           *)
9
(*                                                                  *)
Andrei Paskevich's avatar
Andrei Paskevich committed
10
(********************************************************************)
11

12
open Stdlib
13
open Ident
14
open Ptree
15
open Ty
16
open Term
Andrei Paskevich's avatar
Andrei Paskevich committed
17
open Decl
18
open Theory
19
open Dterm
Andrei Paskevich's avatar
Andrei Paskevich committed
20
open Ity
21
open Expr
22 23
open Pdecl
open Pmodule
Andrei Paskevich's avatar
Andrei Paskevich committed
24

25
(** debug flags *)
26

27
let debug_parse_only = Debug.register_flag "parse_only"
Andrei Paskevich's avatar
Andrei Paskevich committed
28
  ~desc:"Stop@ after@ parsing."
29

30
let debug_type_only  = Debug.register_flag "type_only"
Andrei Paskevich's avatar
Andrei Paskevich committed
31
  ~desc:"Stop@ after@ type-checking."
32

33
(** symbol lookup *)
34 35

let rec qloc = function
36 37 38
  | Qdot (p, id) -> Loc.join (qloc p) id.id_loc
  | Qident id    -> id.id_loc

39 40 41
let qloc_last = function
  | Qdot (_, id) | Qident id -> id.id_loc

42
let rec print_qualid fmt = function
43 44
  | Qdot (p, id) -> Format.fprintf fmt "%a.%s" print_qualid p id.id_str
  | Qident id    -> Format.fprintf fmt "%s" id.id_str
45

46 47
let string_list_of_qualid q =
  let rec sloq acc = function
48 49
    | Qdot (p, id) -> sloq (id.id_str :: acc) p
    | Qident id -> id.id_str :: acc in
50
  sloq [] q
51

52
exception UnboundSymbol of qualid
53

54
let find_qualid get_id find ns q =
55 56 57
  let sl = string_list_of_qualid q in
  let r = try find ns sl with Not_found ->
    Loc.error ~loc:(qloc q) (UnboundSymbol q) in
58
  if Debug.test_flag Glob.flag then Glob.use (qloc_last q) (get_id r);
59
  r
60

61 62 63
let find_prop_ns     ns q = find_qualid (fun pr -> pr.pr_name) ns_find_pr ns q
let find_tysymbol_ns ns q = find_qualid (fun ts -> ts.ts_name) ns_find_ts ns q
let find_lsymbol_ns  ns q = find_qualid (fun ls -> ls.ls_name) ns_find_ls ns q
64

65 66
let find_fsymbol_ns ns q =
  let ls = find_lsymbol_ns ns q in
67 68
  if ls.ls_value <> None then ls else
    Loc.error ~loc:(qloc q) (FunctionSymbolExpected ls)
69

70 71
let find_psymbol_ns ns q =
  let ls = find_lsymbol_ns ns q in
72 73
  if ls.ls_value = None then ls else
    Loc.error ~loc:(qloc q) (PredicateSymbolExpected ls)
74

75 76 77 78
let find_tysymbol tuc q = find_tysymbol_ns (Theory.get_namespace tuc) q
let find_lsymbol  tuc q = find_lsymbol_ns  (Theory.get_namespace tuc) q
let find_fsymbol  tuc q = find_fsymbol_ns  (Theory.get_namespace tuc) q
let find_psymbol  tuc q = find_psymbol_ns  (Theory.get_namespace tuc) q
79 80 81 82
let find_prop     tuc q = find_prop_ns     (Theory.get_namespace tuc) q

let find_prop_of_kind k tuc q =
  let pr = find_prop tuc q in
Andrei Paskevich's avatar
Andrei Paskevich committed
83
  match (Mid.find pr.pr_name tuc.uc_known).d_node with
84
  | Dind _ when k = Paxiom -> pr
85 86 87
  | Dprop (l,_,_) when l = k -> pr
  | _ -> Loc.errorm ~loc:(qloc q) "proposition %a is not %s"
      print_qualid q (match k with
88
        | Plemma -> "a lemma" | Paxiom -> "an axiom" | Pgoal -> "a goal")
89

Andrei Paskevich's avatar
Andrei Paskevich committed
90 91 92
let find_itysymbol_ns ns q =
  find_qualid (fun s -> s.its_ts.ts_name) Pmodule.ns_find_its ns q

93 94 95
let find_xsymbol_ns ns q =
  find_qualid (fun s -> s.xs_name) Pmodule.ns_find_xs ns q

96 97 98
let find_prog_symbol_ns ns p =
  let get_id_ps = function
    | PV pv -> pv.pv_vs.vs_name
99 100 101 102
    | RS rs -> rs.rs_name
      (* FIXME: this is incorrect, but we cannot
        know the correct symbol at this stage *)
    | OO ss -> (Srs.choose ss).rs_name in
103 104 105 106
  find_qualid get_id_ps ns_find_prog_symbol ns p

let get_namespace muc = List.hd muc.Pmodule.muc_import

107
let find_xsymbol     muc q = find_xsymbol_ns     (get_namespace muc) q
108 109
let find_itysymbol   muc q = find_itysymbol_ns   (get_namespace muc) q
let find_prog_symbol muc q = find_prog_symbol_ns (get_namespace muc) q
Andrei Paskevich's avatar
Andrei Paskevich committed
110

111 112 113
let find_rsymbol muc q = match find_prog_symbol muc q with RS rs -> rs
  | _ -> Loc.errorm ~loc:(qloc q) "program symbol expected"

114 115
(** Parsing types *)

116
let ty_of_pty tuc pty =
117
  let rec get_ty = function
118
    | PTtyvar {id_str = x} ->
119
        ty_var (tv_of_string x)
120
    | PTtyapp (q, tyl) ->
121
        let s = find_tysymbol tuc q in
122
        let tyl = List.map get_ty tyl in
123
        Loc.try2 ~loc:(qloc q) ty_app s tyl
124
    | PTtuple tyl ->
125 126
        let s = its_tuple (List.length tyl) in
        ty_app s.its_ts (List.map get_ty tyl)
127
    | PTarrow (ty1, ty2) ->
128
        ty_func (get_ty ty1) (get_ty ty2)
Andrei Paskevich's avatar
Andrei Paskevich committed
129
    | PTpure ty | PTparen ty ->
130 131 132 133
        get_ty ty
  in
  get_ty pty

134 135 136 137 138 139 140
let dty_of_pty tuc pty =
  Dterm.dty_of_ty (ty_of_pty tuc pty)

let dty_of_opt tuc = function
  | Some pty -> dty_of_pty tuc pty
  | None -> Dterm.dty_fresh ()

141 142 143 144 145 146 147
let ity_of_pty muc pty =
  let rec get_ity = function
    | PTtyvar {id_str = x} ->
        ity_var (tv_of_string x)
    | PTtyapp (q, tyl) ->
        let s = find_itysymbol muc q in
        let tyl = List.map get_ity tyl in
148
        Loc.try3 ~loc:(qloc q) ity_app s tyl []
149 150 151 152
    | PTtuple tyl ->
        ity_tuple (List.map get_ity tyl)
    | PTarrow (ty1, ty2) ->
        ity_func (get_ity ty1) (get_ity ty2)
Andrei Paskevich's avatar
Andrei Paskevich committed
153 154
    | PTpure ty ->
        ity_purify (get_ity ty)
155 156 157 158 159
    | PTparen ty ->
        get_ity ty
  in
  get_ity pty

160 161 162 163 164 165 166
let dity_of_pty muc pty =
  Dexpr.dity_of_ity (ity_of_pty muc pty)

let dity_of_opt muc = function
  | Some pty -> dity_of_pty muc pty
  | None -> Dexpr.dity_fresh ()

167
(** typing using destructive type variables
168

169 170 171 172 173 174
    parsed trees        intermediate trees       typed trees
      (Ptree)                (Dterm)               (Term)
   -----------------------------------------------------------
     ppure_type  ---dty--->   dty       ---ty--->    ty
      lexpr      --dterm-->   dterm     --term-->    term
*)
175

176 177
(** Typing patterns, terms, and formulas *)

178
let create_user_id {id_str = n; id_lab = label; id_loc = loc} =
179 180 181 182
  let get_labels (label, loc) = function
    | Lstr lab -> Slab.add lab label, loc | Lpos loc -> label, loc in
  let label,loc = List.fold_left get_labels (Slab.empty,loc) label in
  id_user ~label n loc
183

184 185
let parse_record ~loc tuc get_val fl =
  let fl = List.map (fun (q,e) -> find_lsymbol tuc q, e) fl in
Andrei Paskevich's avatar
Andrei Paskevich committed
186
  let cs,pjl,flm = Loc.try2 ~loc parse_record tuc.uc_known fl in
187 188 189
  let get_val pj = get_val cs pj (Mls.find_opt pj flm) in
  cs, List.map get_val pjl

190
let rec dpattern tuc { pat_desc = desc; pat_loc = loc } =
191
  Dterm.dpattern ~loc (match desc with
192
    | Ptree.Pwild -> DPwild
193 194
    | Ptree.Pvar (x, false) -> DPvar (create_user_id x)
    | Ptree.Papp (q, pl) ->
195 196
        let pl = List.map (dpattern tuc) pl in
        DPapp (find_lsymbol tuc q, pl)
197
    | Ptree.Ptuple pl ->
198
        let pl = List.map (dpattern tuc) pl in
199
        DPapp (fs_tuple (List.length pl), pl)
200
    | Ptree.Prec fl ->
201
        let get_val _ _ = function
202
          | Some p -> dpattern tuc p
203
          | None -> Dterm.dpattern DPwild in
204
        let cs,fl = parse_record ~loc tuc get_val fl in
205
        DPapp (cs,fl)
206
    | Ptree.Pas (p, x, false) -> DPas (dpattern tuc p, create_user_id x)
207
    | Ptree.Por (p, q) -> DPor (dpattern tuc p, dpattern tuc q)
208
    | Ptree.Pcast (p, ty) -> DPcast (dpattern tuc p, dty_of_pty tuc ty)
209 210
    | Ptree.Pvar (_, true) | Ptree.Pas (_, _, true) -> Loc.errorm ~loc
        "ghost variables are only allowed in programs")
211

212
let quant_var tuc (loc, id, gh, ty) =
213
  if gh then Loc.errorm ~loc "ghost variables are only allowed in programs";
214
  Opt.map create_user_id id, dty_of_opt tuc ty, Some loc
215

216 217 218 219 220 221
let loc_cutoff loc13 loc23 loc2 =
  let f,l,b,e = Loc.get loc13 in
  let _,_,_,w = Loc.get loc23 in
  let _,_,_,m = Loc.get loc2 in
  Loc.user_position f l b (e - (w - m))

222 223 224 225 226
let is_reusable dt = match dt.dt_node with
  | DTvar _ | DTgvar _ | DTconst _ | DTtrue | DTfalse -> true
  | DTapp (_,[]) -> true
  | _ -> false

Leon Gondelman's avatar
Leon Gondelman committed
227
let mk_var tuc n dt =
228 229 230
  let dty = match dt.dt_dty with
    | None -> dty_of_ty ty_bool
    | Some dty -> dty in
Leon Gondelman's avatar
Leon Gondelman committed
231
  Dterm.dterm tuc ?loc:dt.dt_loc (DTvar (n, dty))
232

Leon Gondelman's avatar
Leon Gondelman committed
233 234
let mk_let tuc ~loc n dt node =
  DTlet (dt, id_user n loc, Dterm.dterm tuc ~loc node)
235

Leon Gondelman's avatar
Leon Gondelman committed
236 237
let mk_closure tuc loc ls =
  let mk dt = Dterm.dterm tuc ~loc dt in
238
  let mk_v i _ =
239 240
    Some (id_user ("y" ^ string_of_int i) loc), dty_fresh (), None in
  let mk_t (id, dty, _) = mk (DTvar ((Opt.get id).pre_name, dty)) in
241
  let vl = Lists.mapi mk_v ls.ls_args in
Andrei Paskevich's avatar
Andrei Paskevich committed
242
  DTquant (DTlambda, vl, [], mk (DTapp (ls, List.map mk_t vl)))
243

244
let rec dterm tuc gvars at denv {term_desc = desc; term_loc = loc} =
245 246
  let func_app e el =
    List.fold_left (fun e1 (loc, e2) ->
Leon Gondelman's avatar
Leon Gondelman committed
247
      DTfapp (Dterm.dterm tuc ~loc e1, e2)) e el
248
  in
249 250 251
  let rec apply_ls loc ls al l el = match l, el with
    | (_::l), (e::el) -> apply_ls loc ls (e::al) l el
    | [], _ -> func_app (DTapp (ls, List.rev_map snd al)) el
Leon Gondelman's avatar
Leon Gondelman committed
252
    | _, [] -> func_app (mk_closure tuc loc ls) (List.rev_append al el)
253
  in
254
  let qualid_app q el = match gvars at q with
255
    | Some v -> func_app (DTgvar v.pv_vs) el
256
    | None ->
257
        let ls = find_lsymbol tuc q in
258
        apply_ls (qloc q) ls [] ls.ls_args el
259
  in
260
  let qualid_app q el = match q with
261
    | Qident {id_str = n} ->
262
        (match denv_get_opt denv n with
263 264 265 266
        | Some d -> func_app d el
        | None -> qualid_app q el)
    | _ -> qualid_app q el
  in
267
  let rec unfold_app e1 e2 el = match e1.term_desc with
268 269
    | Ptree.Tapply (e11,e12) ->
        let e12 = dterm tuc gvars at denv e12 in
270
        unfold_app e11 e12 ((e1.term_loc, e2)::el)
271
    | Ptree.Tident q ->
272
        qualid_app q ((e1.term_loc, e2)::el)
273
    | _ ->
274
        func_app (DTfapp (dterm tuc gvars at denv e1, e2)) el
275
  in
Leon Gondelman's avatar
Leon Gondelman committed
276
  Dterm.dterm tuc ~loc (match desc with
277
  | Ptree.Tident q ->
278
      qualid_app q []
279
  | Ptree.Tidapp (q, tl) ->
280
      let tl = List.map (dterm tuc gvars at denv) tl in
281
      DTapp (find_lsymbol tuc q, tl)
282
  | Ptree.Tapply (e1, e2) ->
283
      unfold_app e1 (dterm tuc gvars at denv e2) []
284
  | Ptree.Ttuple tl ->
285
      let tl = List.map (dterm tuc gvars at denv) tl in
286
      DTapp (fs_tuple (List.length tl), tl)
287 288 289 290 291 292
  | Ptree.Tinfix (e1, op1, e23)
  | Ptree.Tinnfix (e1, op1, e23) ->
      let apply loc de1 op de2 =
        if op.id_str = "infix <>" then
          let op = { op with id_str = "infix =" } in
          let ls = find_lsymbol tuc (Qident op) in
Leon Gondelman's avatar
Leon Gondelman committed
293
          DTnot (Dterm.dterm tuc ~loc (DTapp (ls, [de1;de2])))
294 295 296 297 298 299
        else
          DTapp (find_lsymbol tuc (Qident op), [de1;de2]) in
      let rec chain loc de1 op1 = function
        | { term_desc = Ptree.Tinfix (e2, op2, e3); term_loc = loc23 } ->
            let de2 = dterm tuc gvars at denv e2 in
            let loc12 = loc_cutoff loc loc23 e2.term_loc in
Leon Gondelman's avatar
Leon Gondelman committed
300 301
            let de12 = Dterm.dterm tuc ~loc:loc12 (apply loc12 de1 op1 de2) in
            let de23 = Dterm.dterm tuc ~loc:loc23 (chain loc23 de2 op2 e3) in
302
            DTbinop (DTand, de12, de23)
303 304 305
        | e23 ->
            apply loc de1 op1 (dterm tuc gvars at denv e23) in
      chain loc (dterm tuc gvars at denv e1) op1 e23
Clément Fumex's avatar
Clément Fumex committed
306
  | Ptree.Tconst (Number.ConstInt _ as c) ->
307
      DTconst (c, dty_int)
Clément Fumex's avatar
Clément Fumex committed
308
  | Ptree.Tconst (Number.ConstReal _ as c) ->
309
      DTconst (c, dty_real)
310
  | Ptree.Tlet (x, e1, e2) ->
311
      let id = create_user_id x in
312
      let e1 = dterm tuc gvars at denv e1 in
313
      let denv = denv_add_let denv e1 id in
314
      let e2 = dterm tuc gvars at denv e2 in
315
      DTlet (e1, id, e2)
316
  | Ptree.Tmatch (e1, bl) ->
317
      let e1 = dterm tuc gvars at denv e1 in
318
      let branch (p, e) =
319
        let p = dpattern tuc p in
320
        let denv = denv_add_pat denv p in
321
        p, dterm tuc gvars at denv e in
322
      DTcase (e1, List.map branch bl)
323
  | Ptree.Tif (e1, e2, e3) ->
324 325 326
      let e1 = dterm tuc gvars at denv e1 in
      let e2 = dterm tuc gvars at denv e2 in
      let e3 = dterm tuc gvars at denv e3 in
327
      DTif (e1, e2, e3)
328
  | Ptree.Ttrue ->
329
      DTtrue
330
  | Ptree.Tfalse ->
331
      DTfalse
Andrei Paskevich's avatar
Andrei Paskevich committed
332
  | Ptree.Tnot e1 ->
333
      DTnot (dterm tuc gvars at denv e1)
Andrei Paskevich's avatar
Andrei Paskevich committed
334 335 336 337 338 339
  | Ptree.Tbinop (e1, Dterm.DTiff, e23)
  | Ptree.Tbinnop (e1, Dterm.DTiff, e23) ->
      let rec chain loc de1 = function
        | { term_desc = Ptree.Tbinop (e2, DTiff, e3); term_loc = loc23 } ->
            let de2 = dterm tuc gvars at denv e2 in
            let loc12 = loc_cutoff loc loc23 e2.term_loc in
Leon Gondelman's avatar
Leon Gondelman committed
340 341
            let de12 = Dterm.dterm tuc ~loc:loc12 (DTbinop (DTiff, de1, de2)) in
            let de23 = Dterm.dterm tuc ~loc:loc23 (chain loc23 de2 e3) in
Andrei Paskevich's avatar
Andrei Paskevich committed
342 343 344 345 346 347 348 349 350
            DTbinop (DTand, de12, de23)
        | { term_desc = Ptree.Tbinop (_, DTimplies, _); term_loc = loc23 } ->
            Loc.errorm ~loc:loc23 "An unparenthesized implication cannot be \
              placed at the right hand side of an equivalence"
        | e23 ->
            DTbinop (DTiff, de1, (dterm tuc gvars at denv e23)) in
      chain loc (dterm tuc gvars at denv e1) e23
  | Ptree.Tbinop (e1, op, e2)
  | Ptree.Tbinnop (e1, op, e2) ->
351 352
      let e1 = dterm tuc gvars at denv e1 in
      let e2 = dterm tuc gvars at denv e2 in
353
      DTbinop (op, e1, e2)
354
  | Ptree.Tquant (q, uqu, trl, e1) ->
355
      let qvl = List.map (quant_var tuc) uqu in
356
      let denv = denv_add_quant denv qvl in
357
      let dterm e = dterm tuc gvars at denv e in
358 359
      let trl = List.map (List.map dterm) trl in
      let e1 = dterm e1 in
Andrei Paskevich's avatar
Andrei Paskevich committed
360
      DTquant (q, qvl, trl, e1)
361
  | Ptree.Trecord fl ->
362
      let get_val _cs pj = function
363
        | Some e -> dterm tuc gvars at denv e
364
        | None -> Loc.error ~loc (RecordFieldMissing pj) in
365
      let cs, fl = parse_record ~loc tuc get_val fl in
366
      DTapp (cs, fl)
367
  | Ptree.Tupdate (e1, fl) ->
368
      let e1 = dterm tuc gvars at denv e1 in
369
      let re = is_reusable e1 in
Leon Gondelman's avatar
Leon Gondelman committed
370
      let v = if re then e1 else mk_var tuc "q " e1 in
371
      let get_val _ pj = function
372
        | Some e -> dterm tuc gvars at denv e
Leon Gondelman's avatar
Leon Gondelman committed
373
        | None -> Dterm.dterm tuc ~loc (DTapp (pj,[v])) in
374
      let cs, fl = parse_record ~loc tuc get_val fl in
375
      let d = DTapp (cs, fl) in
Leon Gondelman's avatar
Leon Gondelman committed
376
      if re then d else mk_let tuc ~loc "q " e1 d
377 378
  | Ptree.Tat (e1, l) ->
      DTlabel (dterm tuc gvars (Some l.id_str) denv e1, Slab.empty)
379
  | Ptree.Tnamed (Lpos uloc, e1) ->
380
      DTuloc (dterm tuc gvars at denv e1, uloc)
381
  | Ptree.Tnamed (Lstr lab, e1) ->
382
      DTlabel (dterm tuc gvars at denv e1, Slab.singleton lab)
383
  | Ptree.Tcast ({term_desc = Ptree.Tconst c}, pty) ->
384
      DTconst (c, dty_of_pty tuc pty)
385 386
  | Ptree.Tcast (e1, pty) ->
      let d1 = dterm tuc gvars at denv e1 in
387
      DTcast (d1, dty_of_pty tuc pty))
388

389
(** typing program expressions *)
Andrei Paskevich's avatar
Andrei Paskevich committed
390

391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409
open Dexpr

(* records *)

let find_record_field muc q =
  match find_prog_symbol muc q with RS ({rs_field = Some _} as s) -> s
  | _ -> Loc.errorm ~loc:(qloc q) "Not a record field: %a" print_qualid q

let find_record_field2 muc (q,e) = find_record_field muc q, e

let parse_record muc fll =
  (* we assume that every rsymbol in fll was resolved
     using find_record_field, so they are all fields *)
  let ls_of_rs rs = match rs.rs_logic with
    | RLls ls -> ls | _ -> assert false in
  let rs = match fll with
    | (rs, _)::_ -> rs
    | [] -> raise EmptyRecord in
  let its = match rs.rs_cty.cty_args with
410
    | [{pv_ity = {ity_node = (Ityreg {reg_its = s} | Ityapp (s,_,_))}}] -> s
411 412 413 414 415 416 417 418 419 420
    | _ -> raise (BadRecordField (ls_of_rs rs)) in
  let itd = find_its_defn muc.muc_known its in
  let check v s = match s.rs_field with
    | Some u -> pv_equal v u
    | _ -> false in
  let cs = match itd.itd_constructors with
    | [cs] when Lists.equal check cs.rs_cty.cty_args itd.itd_fields -> cs
    | _ -> raise (BadRecordField (ls_of_rs rs)) in
  let pjs = Srs.of_list itd.itd_fields in
  let flm = List.fold_left (fun m (pj,v) -> if Srs.mem pj pjs then
421
    Mrs.add_new (DuplicateRecordField (ls_of_rs pj)) pj v m
422 423 424 425 426 427 428 429 430 431 432 433 434 435
    else raise (BadRecordField (ls_of_rs pj))) Mrs.empty fll in
  cs, itd.itd_fields, flm

let parse_record ~loc muc get_val fl =
  let fl = List.map (find_record_field2 muc) fl in
  let cs,pjl,flm = Loc.try2 ~loc parse_record muc fl in
  let get_val pj = get_val cs pj (Mrs.find_opt pj flm) in
  cs, List.map get_val pjl

(* patterns *)

let rec dpattern muc { pat_desc = desc; pat_loc = loc } =
  Dexpr.dpattern ~loc (match desc with
    | Ptree.Pwild -> DPwild
436 437
    | Ptree.Pvar (x, gh) -> DPvar (create_user_id x, gh)
    | Ptree.Papp (q, pl) ->
438 439 440 441 442 443 444 445 446
        DPapp (find_rsymbol muc q, List.map (fun p -> dpattern muc p) pl)
    | Ptree.Prec fl ->
        let get_val _ _ = function
          | Some p -> dpattern muc p
          | None -> Dexpr.dpattern DPwild in
        let cs,fl = parse_record ~loc muc get_val fl in
        DPapp (cs,fl)
    | Ptree.Ptuple pl ->
        DPapp (rs_tuple (List.length pl), List.map (dpattern muc) pl)
447
    | Ptree.Pcast (p, pty) -> DPcast (dpattern muc p, dity_of_pty muc pty)
448
    | Ptree.Pas (p, x, gh) -> DPas (dpattern muc p, create_user_id x, gh)
449 450 451 452 453 454 455 456 457 458 459 460
    | Ptree.Por (p, q) -> DPor (dpattern muc p, dpattern muc q))

(* specifications *)

let find_global_pv muc q = try match find_prog_symbol muc q with
  | PV v -> Some v | _ -> None with _ -> None

let find_local_pv muc lvm q = match q with
  | Qdot _ -> find_global_pv muc q
  | Qident id -> let ovs = Mstr.find_opt id.id_str lvm in
      if ovs = None then find_global_pv muc q else ovs

461 462 463 464 465 466 467 468
let mk_gvars muc lvm old = fun at q ->
  match find_local_pv muc lvm q, at with
  | Some v, Some l -> Some (old v l)
  | v, _ -> v

let type_term muc lvm old t =
  let gvars = mk_gvars muc lvm old in
  let t = dterm muc.muc_theory gvars None Dterm.denv_empty t in
469
  Dterm.term ~strict:true ~keep_loc:true t
Andrei Paskevich's avatar
Andrei Paskevich committed
470

471 472 473
let type_fmla muc lvm old f =
  let gvars = mk_gvars muc lvm old in
  let f = dterm muc.muc_theory gvars None Dterm.denv_empty f in
474
  Dterm.fmla ~strict:true ~keep_loc:true f
Andrei Paskevich's avatar
Andrei Paskevich committed
475

476 477
let dpre muc pl lvm old =
  let dpre f = type_fmla muc lvm old f in
478 479
  List.map dpre pl

480
let dpost muc ql lvm old ity =
481 482 483
  let dpost (loc,pfl) = match pfl with
    | [{ pat_desc = Ptree.Pwild | Ptree.Ptuple [] }, f] ->
        let v = create_pvsymbol (id_fresh "result") ity in
484
        v, Loc.try3 ~loc type_fmla muc lvm old f
485
    | [{ pat_desc = Ptree.Pvar (id,false) }, f] ->
486 487
        let v = create_pvsymbol (create_user_id id) ity in
        let lvm = Mstr.add id.id_str v lvm in
488
        v, Loc.try3 ~loc type_fmla muc lvm old f
489 490 491 492 493 494
    | _ ->
        let v = create_pvsymbol (id_fresh "result") ity in
        let i = { id_str = "(null)"; id_loc = loc; id_lab = [] } in
        let t = { term_desc = Tident (Qident i); term_loc = loc } in
        let f = { term_desc = Tmatch (t, pfl); term_loc = loc } in
        let lvm = Mstr.add "(null)" v lvm in
495
        v, Loc.try3 ~loc type_fmla muc lvm old f in
496 497
  List.map dpost ql

498
let dxpost muc ql lvm xsm old =
Andrei Paskevich's avatar
Andrei Paskevich committed
499
  let add_exn (q,pf) m =
500 501 502 503 504
    let xs = match q with
      | Qident i ->
          begin try Mstr.find i.id_str xsm with
          | Not_found -> find_xsymbol muc q end
      | _ -> find_xsymbol muc q in
505
    Mxs.change (fun l -> match pf, l with
Andrei Paskevich's avatar
Andrei Paskevich committed
506 507 508 509
      | Some pf, Some l -> Some (pf :: l)
      | Some pf, None   -> Some (pf :: [])
      | None,    None   -> Some []
      | None,    Some _ -> l) xs m in
510
  let mk_xpost loc xs pfl =
Andrei Paskevich's avatar
Andrei Paskevich committed
511
    if pfl = [] then [] else
512
    dpost muc [loc,pfl] lvm old xs.xs_ity in
513
  let exn_map (loc,xpfl) =
514 515
    let m = List.fold_right add_exn xpfl Mxs.empty in
    Mxs.mapi (fun xs pfl -> mk_xpost loc xs pfl) m in
516
  let add_map ql m =
517 518
    Mxs.union (fun _ l r -> Some (l @ r)) (exn_map ql) m in
  List.fold_right add_map ql Mxs.empty
519 520 521 522 523 524 525

let dreads muc rl lvm =
  let dreads q = match find_local_pv muc lvm q with Some v -> v
    | None -> Loc.errorm ~loc:(qloc q) "Not a variable: %a" print_qualid q in
  List.map dreads rl

let dwrites muc wl lvm =
526 527 528
  let old _ _ = Loc.errorm
    "`at' and `old' cannot be used in the `writes' clause" in
  let dwrites t = type_term muc lvm old t in
529 530 531 532 533 534
  List.map dwrites wl

let find_variant_ls muc q = match find_lsymbol muc.muc_theory q with
  | { ls_args = [u;v]; ls_value = None } as ls when ty_equal u v -> ls
  | s -> Loc.errorm ~loc:(qloc q) "Not an order relation: %a" Pretty.print_ls s

535
let dvariant muc varl lvm _xsm old =
536
  let dvar t = type_term muc lvm old t in
537 538 539
  let dvar (t,q) = dvar t, Opt.map (find_variant_ls muc) q in
  List.map dvar varl

540
let dspec muc sp lvm xsm old ity = {
541 542
  ds_pre     = dpre muc sp.sp_pre lvm old;
  ds_post    = dpost muc sp.sp_post lvm old ity;
543
  ds_xpost   = dxpost muc sp.sp_xpost lvm xsm old;
544 545 546 547 548
  ds_reads   = dreads muc sp.sp_reads lvm;
  ds_writes  = dwrites muc sp.sp_writes lvm;
  ds_checkrw = sp.sp_checkrw;
  ds_diverge = sp.sp_diverge; }

549
let dassert muc f lvm _xsm old = type_fmla muc lvm old f
550

551
let dinvariant muc f lvm _xsm old = dpre muc f lvm old
552 553 554

(* abstract values *)

555 556
let dparam muc (_,id,gh,pty) =
  Opt.map create_user_id id, gh, dity_of_pty muc pty
557

558 559
let dbinder muc (_,id,gh,opt) =
  Opt.map create_user_id id, gh, dity_of_opt muc opt
560 561 562 563

(* expressions *)

let is_reusable de = match de.de_node with
564
  | DEvar _ | DEsym _ -> true | _ -> false
565 566 567 568 569 570 571 572

let mk_var n de =
  Dexpr.dexpr ?loc:de.de_loc (DEvar (n, de.de_dvty))

let mk_let ~loc n de node =
  let de1 = Dexpr.dexpr ~loc node in
  DElet ((id_user n loc, false, RKnone, de), de1)

573
let update_any kind e = match e.expr_desc with
574 575
  | Ptree.Eany (pl, _, pty, msk, sp) ->
      { e with expr_desc = Ptree.Eany (pl, kind, pty, msk, sp) }
576 577 578 579 580 581
  | _ -> e

let local_kind = function
  | RKfunc | RKpred -> RKlocal
  | k -> k

582 583 584 585 586
let rec dexpr muc denv {expr_desc = desc; expr_loc = loc} =
  let expr_app loc e el =
    List.fold_left (fun e1 e2 ->
      DEapp (Dexpr.dexpr ~loc e1, e2)) e el
  in
587
  let qualid_app loc q el =
588
    let e = try DEsym (find_prog_symbol muc q) with
589
      | _ -> DEls (find_lsymbol muc.muc_theory q) in
590
    expr_app loc e el
591 592 593 594 595 596 597 598
  in
  let qualid_app loc q el = match q with
    | Qident {id_str = n} ->
        (match denv_get_opt denv n with
        | Some d -> expr_app loc d el
        | None -> qualid_app loc q el)
    | _ -> qualid_app loc q el
  in
599 600 601 602 603 604
  let find_dxsymbol q = match q with
    | Qident {id_str = n} ->
        (try denv_get_exn denv n with _
        -> DEgexn (find_xsymbol muc q))
    | _ -> DEgexn (find_xsymbol muc q)
  in
605
  Dexpr.dexpr ~loc begin match desc with
606 607 608 609 610 611 612
  | Ptree.Eident q ->
      qualid_app loc q []
  | Ptree.Eidapp (q, el) ->
      qualid_app loc q (List.map (dexpr muc denv) el)
  | Ptree.Eapply (e1, e2) ->
      DEapp (dexpr muc denv e1, dexpr muc denv e2)
  | Ptree.Etuple el ->
613
      let e = DEsym (RS (rs_tuple (List.length el))) in
614
      expr_app loc e (List.map (dexpr muc denv) el)
615 616 617 618 619 620 621 622 623 624 625 626
  | Ptree.Einfix (e1, op1, e23)
  | Ptree.Einnfix (e1, op1, e23) ->
      let apply loc de1 op de2 =
        if op.id_str = "infix <>" then
          let oq = Qident { op with id_str = "infix =" } in
          let dt = qualid_app op.id_loc oq [de1;de2] in
          DEnot (Dexpr.dexpr ~loc dt)
        else
          qualid_app op.id_loc (Qident op) [de1;de2] in
      let rec chain n1 n2 loc de1 op1 = function
        | { expr_desc = Ptree.Einfix (e2, op2, e3); expr_loc = loc23 } ->
            let de2 = dexpr muc denv e2 in
627 628
            let re = is_reusable de2 in
            let v = if re then de2 else mk_var n1 de2 in
629 630 631
            let loc12 = loc_cutoff loc loc23 e2.expr_loc in
            let de12 = Dexpr.dexpr ~loc:loc12 (apply loc12 de1 op1 v) in
            let de23 = Dexpr.dexpr ~loc:loc23 (chain n2 n1 loc23 v op2 e3) in
632 633
            let d = DEand (de12, de23) in
            if re then d else mk_let ~loc n1 de2 d
634 635 636
        | e23 ->
            apply loc de1 op1 (dexpr muc denv e23) in
      chain "q1 " "q2 " loc (dexpr muc denv e1) op1 e23
637 638
  | Ptree.Econst (Number.ConstInt _ as c) -> DEconst(c, dity_int)
  | Ptree.Econst (Number.ConstReal _ as c) -> DEconst(c, dity_real)
639 640 641
  | Ptree.Erecord fl ->
      let ls_of_rs rs = match rs.rs_logic with
        | RLls ls -> ls | _ -> assert false in
642 643
      let get_val _cs pj = function
        | None -> Loc.error ~loc (Decl.RecordFieldMissing (ls_of_rs pj))
644 645
        | Some e -> dexpr muc denv e in
      let cs,fl = parse_record ~loc muc get_val fl in
646
      expr_app loc (DEsym (RS cs)) fl
647 648 649
  | Ptree.Eupdate (e1, fl) ->
      let e1 = dexpr muc denv e1 in
      let re = is_reusable e1 in
650
      let v = if re then e1 else mk_var "q " e1 in
651 652
      let get_val _ pj = function
        | None ->
653
            let pj = Dexpr.dexpr ~loc (DEsym (RS pj)) in
654 655 656
            Dexpr.dexpr ~loc (DEapp (pj, v))
        | Some e -> dexpr muc denv e in
      let cs,fl = parse_record ~loc muc get_val fl in
657
      let d = expr_app loc (DEsym (RS cs)) fl in
658
      if re then d else mk_let ~loc "q " e1 d
659
  | Ptree.Elet (id, gh, kind, e1, e2) ->
660 661
      let e1 = update_any kind e1 in
      let kind = local_kind kind in
662 663 664
      let ld = create_user_id id, gh, kind, dexpr muc denv e1 in
      DElet (ld, dexpr muc (denv_add_let denv ld) e2)
  | Ptree.Erec (fdl, e1) ->
665 666
      let update_kind (id, gh, k, bl, pty, msk, sp, e) =
        id, gh, local_kind k, bl, pty, msk, sp, e in
667
      let fdl = List.map update_kind fdl in
668 669
      let denv, rd = drec_defn muc denv fdl in
      DErec (rd, dexpr muc denv e1)
670
  | Ptree.Efun (bl, pty, msk, sp, e) ->
671 672 673 674 675
      let bl = List.map (dbinder muc) bl in
      let ds = match sp.sp_variant with
        | ({term_loc = loc},_)::_ ->
            Loc.errorm ~loc "unexpected 'variant' clause"
        | _ -> dspec muc sp in
676
      let dity = dity_of_opt muc pty in
677 678 679
      let denv = denv_add_args denv bl in
      let denv = denv_add_exn denv old_mark_id dity in
      DEfun (bl, dity, msk, ds, dexpr muc denv e)
680
  | Ptree.Eany (pl, kind, pty, msk, sp) ->
681 682 683 684 685
      let pl = List.map (dparam muc) pl in
      let ds = match sp.sp_variant with
        | ({term_loc = loc},_)::_ ->
            Loc.errorm ~loc "unexpected 'variant' clause"
        | _ -> dspec muc sp in
686 687 688 689 690
      let ity = match kind, pty with
        | _, Some pty -> ity_of_pty muc pty
        | RKlemma, None -> ity_unit
        | RKpred, None -> ity_bool
        | _ -> Loc.errorm ~loc "cannot determine the type of the result" in
691
      DEany (pl, dity_of_ity ity, msk, ds)
692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712
  | Ptree.Ematch (e1, bl) ->
      let e1 = dexpr muc denv e1 in
      let branch (pp, e) =
        let pp = dpattern muc pp in
        let denv = denv_add_pat denv pp in
        pp, dexpr muc denv e in
      DEcase (e1, List.map branch bl)
  | Ptree.Eif (e1, e2, e3) ->
      let e1 = dexpr muc denv e1 in
      let e2 = dexpr muc denv e2 in
      let e3 = dexpr muc denv e3 in
      DEif (e1, e2, e3)
  | Ptree.Enot e1 ->
      DEnot (dexpr muc denv e1)
  | Ptree.Eand (e1, e2) ->
      DEand (dexpr muc denv e1, dexpr muc denv e2)
  | Ptree.Eor (e1, e2) ->
      DEor (dexpr muc denv e1, dexpr muc denv e2)
  | Ptree.Etrue -> DEtrue
  | Ptree.Efalse -> DEfalse
  | Ptree.Esequence (e1, e2) ->
713
      let e1 = { e1 with expr_desc = Ecast (e1, PTtuple []) } in
714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729
      let e1 = dexpr muc denv e1 in
      let e2 = dexpr muc denv e2 in
      DElet ((id_user "_" loc, false, RKnone, e1), e2)
  | Ptree.Ewhile (e1, inv, var, e2) ->
      let e1 = dexpr muc denv e1 in
      let e2 = dexpr muc denv e2 in
      let inv = dinvariant muc inv in
      let var = dvariant muc var in
      DEwhile (e1, inv, var, e2)
  | Ptree.Efor (id, efrom, dir, eto, inv, e1) ->
      let efrom = dexpr muc denv efrom in
      let eto = dexpr muc denv eto in
      let inv = dinvariant muc inv in
      let id = create_user_id id in
      let denv = denv_add_var denv id (dity_of_ity ity_int) in
      DEfor (id, efrom, dir, eto, inv, dexpr muc denv e1)
730 731 732 733
  | Ptree.Eassign asl ->
      let mk_assign (e1,q,e2) =
        dexpr muc denv e1, find_record_field muc q, dexpr muc denv e2 in
      DEassign (List.map mk_assign asl)
734
  | Ptree.Eraise (q, e1) ->
735 736 737 738
      let xs = find_dxsymbol q in
      let mb_unit = match xs with
        | DEgexn xs -> ity_equal xs.xs_ity ity_unit
        | DElexn _ -> true in
739 740
      let e1 = match e1 with
        | Some e1 -> dexpr muc denv e1
741
        | None when mb_unit -> Dexpr.dexpr ~loc (DEsym (RS rs_void))
742 743 744 745 746
        | _ -> Loc.errorm ~loc "exception argument expected" in
      DEraise (xs, e1)
  | Ptree.Etry (e1, cl) ->
      let e1 = dexpr muc denv e1 in
      let branch (q, pp, e) =
747 748 749 750
        let xs = find_dxsymbol q in
        let mb_unit = match xs with
          | DEgexn xs -> ity_equal xs.xs_ity ity_unit
          | DElexn _ -> true in
751 752
        let pp = match pp with
          | Some pp -> dpattern muc pp
753
          | None when mb_unit -> Dexpr.dpattern ~loc (DPapp (rs_void, []))
754 755 756 757 758 759 760
          | _ -> Loc.errorm ~loc "exception argument expected" in
        let denv = denv_add_pat denv pp in
        let e = dexpr muc denv e in
        xs, pp, e in
      DEtry (e1, List.map branch cl)
  | Ptree.Eghost e1 ->
      DEghost (dexpr muc denv e1)
761 762
  | Ptree.Eexn (id, pty, mask, e1) ->
      let id = create_user_id id in
763
      let dity = dity_of_pty muc pty in
764 765 766 767
      let denv = denv_add_exn denv id dity in
      DEexn (id, dity, mask, dexpr muc denv e1)
  | Ptree.Eabsurd ->
      DEabsurd
768
  | Ptree.Epure t ->
769
      let get_term lvm _xsm old = type_term muc lvm old t in
770 771 772 773 774 775 776 777
      let gvars _at q = try match find_prog_symbol muc q with
        | PV v -> Some v | _ -> None with _ -> None in
      let get_dty pure_denv =
        let dt = dterm muc.muc_theory gvars None pure_denv t in
        match dt.dt_dty with Some dty -> dty | None -> dty_bool in
      DEpure (get_term, denv_pure denv get_dty)
  | Ptree.Eassert (ak, f) ->
      DEassert (ak, dassert muc f)