compile.ml 27.9 KB
Newer Older
1 2 3
(********************************************************************)
(*                                                                  *)
(*  The Why3 Verification Platform   /   The Why3 Development Team  *)
Guillaume Melquiond's avatar
Guillaume Melquiond committed
4
(*  Copyright 2010-2018   --   Inria - CNRS - Paris-Sud University  *)
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
(*                                                                  *)
(*  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.                           *)
(*                                                                  *)
(********************************************************************)

(*
  - "use (im|ex)port" -> "open"
    but OCaml's open is not transitive, so requires some extra work
    to figure out all the opens

  - if a WhyML module M is extracted to something that is a signature,
    then extract "module type B_sig = ..." (as well as "module B = ...")
*)

(** Abstract syntax of ML *)

open Ident
open Ity
Mário Pereira's avatar
Mário Pereira committed
25
open Ty
Mário Pereira's avatar
Mário Pereira committed
26
open Term
27

Mário Pereira's avatar
Mário Pereira committed
28 29 30 31 32 33 34 35
let clean_name fname =
  (* TODO: replace with Filename.remove_extension
   * after migration to OCaml 4.04+ *)
  let remove_extension s =
    try Filename.chop_extension s with Invalid_argument _ -> s in
  let f = Filename.basename fname in (remove_extension f)

let module_name ?fname path t =
Mário Pereira's avatar
Mário Pereira committed
36
  let fname = match fname, path with
Mário Pereira's avatar
Mário Pereira committed
37 38 39 40 41
    | None, "why3"::_ -> "why3"
    | None, _   -> String.concat "__" path
    | Some f, _ -> clean_name f in
  fname ^ "__" ^ t

Mário Pereira's avatar
Mário Pereira committed
42 43 44 45
(** Translation from Mlw to ML *)

module Translate = struct

Mário Pereira's avatar
Mário Pereira committed
46 47 48
  open Expr
  open Pmodule
  open Pdecl
Mário Pereira's avatar
Mário Pereira committed
49

50 51 52 53 54
  module ML = Mltree

  let debug_compile =
    Debug.register_info_flag ~desc:"Compilation" "compile"

Mário Pereira's avatar
Mário Pereira committed
55 56 57
  (* useful predicates and transformations *)
  let pv_not_ghost e = not e.pv_ghost

Mário Pereira's avatar
Mário Pereira committed
58
  (* remove ghost components from tuple, using mask *)
59
  (* TODO : completely remove this function *)
Mário Pereira's avatar
Mário Pereira committed
60 61 62 63
  let visible_of_mask m sl = match m with
    | MaskGhost    -> assert false (* FIXME ? *)
    | MaskVisible  -> sl
    | MaskTuple ml ->
64 65
        let add_ity acc m ity = if mask_ghost m then acc else ity :: acc in
        if List.length sl < List.length ml then sl (* FIXME ? much likely... *)
66
        else List.rev (List.fold_left2 add_ity [] ml sl)
Mário Pereira's avatar
Mário Pereira committed
67

Mário Pereira's avatar
Mário Pereira committed
68 69 70 71
  (* types *)
  let rec type_ ty =
    match ty.ty_node with
    | Tyvar tvs ->
72
        ML.Tvar tvs
Mário Pereira's avatar
Mário Pereira committed
73
    | Tyapp (ts, tyl) when is_ts_tuple ts ->
74
        ML.Ttuple (List.map type_ tyl)
Mário Pereira's avatar
Mário Pereira committed
75
    | Tyapp (ts, tyl) ->
76
        ML.Tapp (ts.ts_name, List.map type_ tyl)
Mário Pereira's avatar
Mário Pereira committed
77 78 79 80

  let vsty vs =
    vs.vs_name, type_ vs.vs_ty

Mário Pereira's avatar
Mário Pereira committed
81 82 83
  let rec filter_ghost_params p def = function
    | [] -> []
    | pv :: l ->
84 85
        if p pv then def pv :: (filter_ghost_params p def l)
        else filter_ghost_params p def l
86

87
  let rec filter_out_ghost_rdef = function
Mário Pereira's avatar
Mário Pereira committed
88
    | [] -> []
89
    | { rec_sym = rs; rec_rsym = rrs } :: l when rs_ghost rs || rs_ghost rrs ->
90
        filter_out_ghost_rdef l
Mário Pereira's avatar
Mário Pereira committed
91
    | rdef :: l ->
92
        rdef :: filter_out_ghost_rdef l
Mário Pereira's avatar
Mário Pereira committed
93

Mário Pereira's avatar
Mário Pereira committed
94
  let rec pat m p = match p.pat_node with
95
    | Pwild ->
96
        ML.Pwild
97
    | Pvar vs when (restore_pv vs).pv_ghost ->
98
        ML.Pwild
99
    | Pvar vs ->
100
        ML.Pvar vs
101
    | Por (p1, p2) ->
102
        ML.Por (pat m p1, pat m p2)
103
    | Pas (p, vs) when (restore_pv vs).pv_ghost ->
104
        pat m p
105
    | Pas (p, vs) ->
106
        ML.Pas (pat m p, vs)
107
    | Papp (ls, pl) when is_fs_tuple ls ->
108
        let pl = visible_of_mask m pl in
109
        begin match pl with
110
          | [] -> ML.Pwild
111
          | [p] -> pat m p
112
          | _ -> ML.Ptuple (List.map (pat m) pl) end
113
    | Papp (ls, pl) ->
114 115 116 117
        let rs = restore_rs ls in
        let args = rs.rs_cty.cty_args in
        let mk acc pv pp = if not pv.pv_ghost then pat m pp :: acc else acc in
        let pat_pl = List.fold_left2 mk [] args pl in
118
        ML.Papp (ls, List.rev pat_pl)
119

Mário Pereira's avatar
Mário Pereira committed
120 121
  (** programs *)

122 123
  let pv_name pv = pv.pv_vs.vs_name

124
  (* individual types *)
Mário Pereira's avatar
Mário Pereira committed
125 126
  let mlty_of_ity mask t =
    let rec loop t = match t.ity_node with
127
      | _ when mask_equal mask MaskGhost -> ML.tunit
128
      | Ityvar tvs ->
129
          ML.Tvar tvs
130
      | Ityapp ({its_ts = ts}, itl, _) when is_ts_tuple ts ->
131
          let itl = visible_of_mask mask itl in
132
          ML.Ttuple (List.map loop itl)
133
      | Ityapp ({its_ts = ts}, itl, _) ->
134
          ML.Tapp (ts.ts_name, List.map loop itl)
135 136
      | Ityreg {reg_its = its; reg_args = args} ->
          let args = List.map loop args in
137
          ML.Tapp (its.its_ts.ts_name, args) in
Mário Pereira's avatar
Mário Pereira committed
138
    loop t
Mário Pereira's avatar
Mário Pereira committed
139

Mário Pereira's avatar
Mário Pereira committed
140
  let pvty pv =
Mário Pereira's avatar
Mário Pereira committed
141
    if pv.pv_ghost then ML.mk_var (pv_name pv) ML.tunit true
Mário Pereira's avatar
Mário Pereira committed
142
    else let (vs, vs_ty) = vsty pv.pv_vs in ML.mk_var vs vs_ty false
Mário Pereira's avatar
Mário Pereira committed
143

144
  let for_direction = function
145 146
    | To -> ML.To
    | DownTo -> ML.DownTo
147

148
  let isconstructor info rs = (* TODO *)
149
    match Mid.find_opt rs.rs_name info.ML.from_km with
Mário Pereira's avatar
Mário Pereira committed
150
    | Some {pd_node = PDtype its} ->
151 152 153
        let is_constructor its =
          List.exists (rs_equal rs) its.itd_constructors in
        List.exists is_constructor its
Mário Pereira's avatar
Mário Pereira committed
154 155
    | _ -> false

Mário Pereira's avatar
Mário Pereira committed
156 157 158 159
  let is_singleton_imutable itd =
    let not_g e = not (rs_ghost e) in
    let pjl = itd.itd_fields in
    let mfields = itd.itd_its.its_mfields in
160
    let pv_equal_field rs = pv_equal (fd_of_rs rs) in
Mário Pereira's avatar
Mário Pereira committed
161 162 163 164
    let get_mutable rs = List.exists (pv_equal_field rs) mfields in
    match filter_ghost_params not_g get_mutable pjl with
    | [is_mutable] -> not is_mutable
    | _ -> false
Mário Pereira's avatar
Mário Pereira committed
165

166
  let get_record_itd info rs =
167
    match Mid.find_opt rs.rs_name info.ML.from_km with
Mário Pereira's avatar
Mário Pereira committed
168
    | Some {pd_node = PDtype itdl} ->
169 170 171 172 173
        let f pjl_constr = List.exists (rs_equal rs) pjl_constr in
        let itd = match rs.rs_field with
          | Some _ -> List.find (fun itd -> f itd.itd_fields) itdl
          | None -> List.find (fun itd -> f itd.itd_constructors) itdl in
        if itd.itd_fields = [] then None else Some itd
174 175 176 177 178 179 180 181 182 183 184 185 186 187
    | _ -> None

  let is_optimizable_record_itd itd =
    not itd.itd_its.its_private && is_singleton_imutable itd

  let is_optimizable_record_rs info rs =
    Opt.fold (fun _ -> is_optimizable_record_itd) false (get_record_itd info rs)

  let is_empty_record_itd itd =
    let is_ghost rs = rs_ghost rs in
    List.for_all is_ghost itd.itd_fields

  let is_empty_record info rs =
    Opt.fold (fun _ -> is_empty_record_itd) false (get_record_itd info rs)
Mário Pereira's avatar
Mário Pereira committed
188

Mário Pereira's avatar
Mário Pereira committed
189
  let mk_eta_expansion rs pvl ({cty_args = ca; cty_effect = ce} as c) =
Mário Pereira's avatar
Mário Pereira committed
190
    (* FIXME : effects and types of the expression in this situation *)
191
    let mv = MaskVisible in
Mário Pereira's avatar
Mário Pereira committed
192
    let args_f =
Mário Pereira's avatar
Mário Pereira committed
193
      let def pv =
194
        pv_name pv, mlty_of_ity (mask_of_pv pv) pv.pv_ity, pv.pv_ghost in
Mário Pereira's avatar
Mário Pereira committed
195
      filter_ghost_params pv_not_ghost def ca in
Mário Pereira's avatar
Mário Pereira committed
196
    let args =
197
      let def pv = ML.mk_expr (ML.Evar pv) (ML.I pv.pv_ity) mv
198
        eff_empty Slab.empty in
Mário Pereira's avatar
Mário Pereira committed
199
      let args = filter_ghost_params pv_not_ghost def pvl in
Mário Pereira's avatar
Mário Pereira committed
200
      let extra_args = List.map def ca in args @ extra_args in
201
    let eapp = ML.mk_expr (ML.Eapp (rs, args)) (ML.C c) mv
202
      ce Slab.empty in
203
    ML.mk_expr (ML.Efun (args_f, eapp)) (ML.C c) mv ce Slab.empty
Mário Pereira's avatar
Mário Pereira committed
204

205 206 207 208 209 210
  (* function arguments *)
  let filter_params args =
    let args = List.map pvty args in
    let p (_, _, is_ghost) = not is_ghost in
    List.filter p args

211 212 213 214
  let params = function
    | [] -> []
    | args -> let args = filter_params args in
        if args = [] then [ML.mk_var_unit] else args
215

Mário Pereira's avatar
Mário Pereira committed
216 217
  let filter_params_cty p def pvl cty_args =
    let rec loop = function
Mário Pereira's avatar
Mário Pereira committed
218
      | [], _ -> []
Mário Pereira's avatar
Mário Pereira committed
219
      | pv :: l1, arg :: l2 ->
Mário Pereira's avatar
Mário Pereira committed
220
          if p pv && p arg then def pv :: loop (l1, l2) else loop (l1, l2)
Mário Pereira's avatar
Mário Pereira committed
221 222 223
      | _ -> assert false
    in loop (pvl, cty_args)

224
  let app pvl cty_args f_zero =
225
    let def pv = ML.mk_expr (ML.Evar pv) (ML.I pv.pv_ity) MaskVisible
226 227 228
      eff_empty Slab.empty in
    let args = filter_params_cty pv_not_ghost def pvl cty_args in
    f_zero args
Mário Pereira's avatar
Mário Pereira committed
229

230 231
  (* build the set of type variables from functions arguments *)
  let rec add_tvar acc = function
232 233
    | ML.Tvar tv -> Stv.add tv acc
    | ML.Tapp (_, tyl) | ML.Ttuple tyl ->
234
        List.fold_left add_tvar acc tyl
235

Mário Pereira's avatar
Mário Pereira committed
236
  (* expressions *)
237
  let rec expr info svar mask ({e_effect = eff; e_label = lbl} as e) =
238
    assert (not (e_ghost e));
239
    assert (not (mask_spill e.e_mask mask));
Mário Pereira's avatar
Mário Pereira committed
240 241 242 243 244 245 246 247
    let pv_list_of_mask pvl mask =
      let mk_pv_of_mask acc pv = function MaskGhost -> acc | _ -> pv :: acc in
      match mask with
      | MaskGhost   -> []
      | MaskVisible -> pvl
      | MaskTuple m -> assert (List.length m = List.length pvl);
          let pvl = List.fold_left2 mk_pv_of_mask [] pvl m in
          List.rev pvl in
Mário Pereira's avatar
Mário Pereira committed
248
    match e.e_node with
249 250 251 252
    | Econst _ | Evar _ when mask = MaskGhost ->
        ML.e_unit
    | Eexec ({c_node = Cfun _; c_cty = {cty_args}}, _)
      when cty_args <> [] && mask = MaskGhost ->
253
        ML.e_unit
254
    | Econst c ->
255
        Debug.dprintf debug_compile "compiling constant@.";
256
        let c = match c with Number.ConstInt c -> c | _ -> assert false in
257
        ML.mk_expr (ML.Econst c) (ML.I e.e_ity) mask eff lbl
258
    | Evar pv ->
259
        ML.mk_expr (ML.Evar pv) (ML.I e.e_ity) mask eff lbl
260 261
    | Elet (LDvar (_, e1), e2) when e_ghost e1 ->
        expr info svar mask e2
262
    | Elet (LDvar (_, e1), e2) when e_ghost e2 ->
263
        (* sequences are transformed into [let o = e1 in e2] by A-normal form *)
264
        expr info svar MaskGhost e1
Mário Pereira's avatar
Mário Pereira committed
265 266
    | Elet (LDvar (pv, e1), e2)
      when pv.pv_ghost || not (Mpv.mem pv e2.e_effect.eff_reads) ->
267
        if eff_pure e1.e_effect then expr info svar mask e2
268
        else let e1 = expr info svar MaskGhost e1 in
269
          ML.e_seq e1 (expr info svar mask e2) (ML.I e.e_ity) mask eff lbl
Mário Pereira's avatar
Mário Pereira committed
270
    | Elet (LDvar (pv, e1), e2) ->
271 272
        Debug.dprintf debug_compile "compiling local definition of %s@."
          (pv_name pv).id_string;
273
        let ld = ML.var_defn pv (expr info svar MaskVisible e1) in
274
        ML.e_let ld (expr info svar mask e2) (ML.I e.e_ity) mask eff lbl
275 276
    | Elet (LDsym (rs, _), ein) when rs_ghost rs ->
        expr info svar mask ein
277
    | Elet (LDsym (rs, {c_node = Cfun ef; c_cty = cty}), ein) ->
278 279
        Debug.dprintf debug_compile "compiling local function definition %s@."
          rs.rs_name.id_string;
280 281
        let args = params cty.cty_args in
        let res = mlty_of_ity cty.cty_mask cty.cty_result in
282
        let ld = ML.sym_defn rs res args (expr info svar cty.cty_mask ef) in
283
        ML.e_let ld (expr info svar mask ein) (ML.I e.e_ity) mask eff lbl
284
    | Elet (LDsym (rs, {c_node = Capp (rs_app, pvl); c_cty = cty}), ein)
285
      when isconstructor info rs_app -> (* partial application of constructor *)
286 287 288 289 290
        let eta_app = mk_eta_expansion rs_app pvl cty in
        let mk_func pv f = ity_func pv.pv_ity f in
        let func = List.fold_right mk_func cty.cty_args cty.cty_result in
        let res = mlty_of_ity cty.cty_mask func in
        let ld = ML.sym_defn rs res [] eta_app in
291
        let ein = expr info svar mask ein in
292
        ML.e_let ld ein (ML.I e.e_ity) mask eff lbl
Mário Pereira's avatar
Mário Pereira committed
293
    | Elet (LDsym (rsf, {c_node = Capp (rs_app, pvl); c_cty = cty}), ein) ->
294
        (* partial application *) (* FIXME -> zero arguments functions *)
295 296
        Debug.dprintf debug_compile "compiling partial application of %s@."
          rsf.rs_name.id_string;
297 298 299
        let cmk = cty.cty_mask in
        let ceff = cty.cty_effect in
        let pvl = app pvl rs_app.rs_cty.cty_args (fun x -> x) in
300
        let eapp = ML.e_app rs_app pvl (ML.C cty) cmk ceff Slab.empty in
301 302
        let res = mlty_of_ity cty.cty_mask cty.cty_result in
        let ld = ML.sym_defn rsf res (params cty.cty_args) eapp in
303
        let ein = expr info svar mask ein in
304
        ML.e_let ld ein (ML.I e.e_ity) mask eff lbl
Mário Pereira's avatar
Mário Pereira committed
305
    | Elet (LDrec rdefl, ein) ->
306 307
        let rdefl = filter_out_ghost_rdef rdefl in
        let def = function
308 309
          | { rec_sym = rs1; rec_rsym = rs2;
              rec_fun = {c_node = Cfun ef; c_cty = cty} } ->
310 311
              let res = mlty_of_ity rs1.rs_cty.cty_mask rs1.rs_cty.cty_result in
              let args = params cty.cty_args in
312
              let new_svar =
313 314 315
                let args' = List.map (fun (_, ty, _) -> ty) args in
                let svar  = List.fold_left add_tvar Stv.empty args' in
                add_tvar svar res in
316
              let new_svar = Stv.diff svar new_svar in
317
              let ef = expr info (Stv.union svar new_svar) ef.e_mask ef in
318 319 320
              { ML.rec_sym  = rs1;  ML.rec_rsym = rs2;
                ML.rec_args = args; ML.rec_exp  = ef;
                ML.rec_res  = res;  ML.rec_svar = new_svar; }
321 322 323
          | _ -> assert false in
        let rdefl = List.map def rdefl in
        if rdefl <> [] then
324
          let ein = expr info svar mask ein in
325 326
          let ml_letrec = ML.Elet (ML.Lrec rdefl, ein) in
          ML.mk_expr ml_letrec (ML.I e.e_ity) mask e.e_effect lbl
327 328 329 330 331
        else expr info svar mask ein
    | Eexec ({c_node = Capp (rs, [])}, _)  when is_rs_tuple rs ->
        ML.e_unit
    | Eexec ({c_node = Capp (rs, pvl)}, _) when is_rs_tuple rs ->
        let pvl = pv_list_of_mask pvl mask in
Mário Pereira's avatar
Mário Pereira committed
332
        let res_ity = ity_tuple (List.map (fun v -> v.pv_ity) pvl) in
333
        let pvl = ML.var_list_of_pv_list pvl in
334
        ML.e_app rs pvl (ML.I res_ity) mask eff lbl
335
    | Eexec ({c_node = Capp (rs, _)}, _) when is_empty_record info rs ->
Mário Pereira's avatar
Mário Pereira committed
336
        ML.e_unit
Mário Pereira's avatar
Mário Pereira committed
337
    | Eexec ({c_node = Capp (rs, pvl); c_cty = cty}, _)
Mário Pereira's avatar
Mário Pereira committed
338
      when isconstructor info rs && cty.cty_args <> [] ->
339 340
        (* partial application of constructors *)
        mk_eta_expansion rs pvl cty
Mário Pereira's avatar
Mário Pereira committed
341
    | Eexec ({c_node = Capp (rs, pvl); _}, _) ->
342 343
        Debug.dprintf debug_compile "compiling total application of %s@."
          rs.rs_name.id_string;
344
        let add_unit = function [] -> [ML.e_unit] | args -> args in
345 346 347 348 349
        let is_pvl_ghost = List.for_all (fun {pv_ghost} -> pv_ghost) pvl in
        let f_zero =
          if isconstructor info rs || pvl = [] || not is_pvl_ghost then
            fun x -> x
          else add_unit in
350
        let pvl = app pvl rs.rs_cty.cty_args f_zero in
351 352
        begin match pvl with
          | [pv_expr] when is_optimizable_record_rs info rs -> pv_expr
353
          | _ -> ML.e_app rs pvl (ML.I e.e_ity) mask eff lbl end
Mário Pereira's avatar
Mário Pereira committed
354
    | Eexec ({c_node = Cfun e; c_cty = {cty_args = []}}, _) ->
355
        (* abstract block *)
356
        Debug.dprintf debug_compile "compiling abstract block@.";
357
        expr info svar e.e_mask e
358 359
    | Eexec ({c_node = Cfun ef; c_cty = cty}, _) ->
        let ef = expr info svar e.e_mask ef in
360
        ML.e_fun (params cty.cty_args) ef (ML.I e.e_ity) mask eff lbl
361
    | Eexec ({c_node = Cany}, _) ->
362
        ML.mk_hole
363
    | Eabsurd ->
364
        ML.e_absurd (ML.I e.e_ity) mask eff lbl
365 366
    | Eassert _ ->
        ML.e_unit
367
    | Eif (e1, e2, e3) when e_ghost e1 ->
368 369
        (* if [e1] is ghost but the entire [if-then-else] expression doesn't,
           it must be the case one of the branches is [Eabsurd] *)
370 371
        if e2.e_node = Eabsurd then expr info svar mask e3
        else expr info svar mask e2
Mário Pereira's avatar
Mário Pereira committed
372
    | Eif (e1, e2, e3) when e_ghost e3 ->
373 374
        let e1 = expr info svar e1.e_mask e1 in
        let e2 = expr info svar mask e2 in
375
        ML.e_if e1 e2 ML.e_unit mask eff lbl
Mário Pereira's avatar
Mário Pereira committed
376
    | Eif (e1, e2, e3) when e_ghost e2 ->
377 378
        let e1 = expr info svar e1.e_mask e1 in
        let e3 = expr info svar mask e3 in
379
        ML.e_if e1 ML.e_unit e3 mask eff lbl
380
    | Eif (e1, e2, e3) ->
381
        Debug.dprintf debug_compile "compiling if block@.";
382 383 384
        let e1 = expr info svar e1.e_mask e1 in
        let e2 = expr info svar mask e2 in
        let e3 = expr info svar mask e3 in
385
        ML.e_if e1 e2 e3 mask eff lbl
Mário Pereira's avatar
Mário Pereira committed
386
    | Ewhile (e1, _, _, e2) ->
387 388
        let e1 = expr info svar e1.e_mask e1 in
        let e2 = expr info svar e2.e_mask e2 in
389
        ML.e_while e1 e2 mask eff lbl
390 391
    | Efor (pv1, (pv2, dir, pv3), _, _, efor) ->
        let dir = for_direction dir in
392
        let efor = expr info svar efor.e_mask efor in
393
        ML.e_for pv1 pv2 dir pv3 efor mask eff lbl
394 395
    | Eghost _ | Epure _ ->
        assert false
396
    | Eassign al ->
397 398
        let rm_ghost (_, rs, _) = not (rs_ghost rs) in
        let al = List.filter rm_ghost al in
399
        ML.e_assign al (ML.I e.e_ity) mask eff lbl
400
    | Ematch (e1, [], xl) when Mxs.is_empty xl ->
401
        expr info svar e1.e_mask e1
402
    | Ematch (e1, bl, xl) when e_ghost e1 ->
403 404 405 406 407
        assert (Mxs.is_empty xl); (* Expr ensures this for the time being *)
        (* if [e1] is ghost but the entire [match-with] expression isn't,
           it must be the case the first non-absurd branch is irrefutable *)
        (match bl with (* FIXME: skip absurd branches *)
         | [] -> assert false | (_, e) :: _ -> expr info svar e.e_mask e)
408
    | Ematch (e1, bl, xl) ->
409 410 411
        let e1 = expr info svar e1.e_mask e1 in
        let bl = List.map (ebranch info svar mask) bl in
        (* NOTE: why no pv_list_of_mask here? *)
412
        let mk_xl (xs, (pvl, e)) = xs, pvl, expr info svar mask e in
413
        let xl = List.map mk_xl (Mxs.bindings xl) in
414
        ML.e_match e1 bl xl (ML.I e.e_ity) mask eff lbl
415
    | Eraise (xs, ex) -> let ex = match expr info svar xs.xs_mask ex with
416
        | {ML.e_node = ML.Eblock []} -> None
417
        | e -> Some e in
418
        ML.mk_expr (ML.Eraise (xs, ex)) (ML.I e.e_ity) mask eff lbl
419
    | Eexn (xs, e1) ->
420
        if mask_ghost e1.e_mask then ML.mk_expr
421
          (ML.Eexn (xs, None, ML.e_unit)) (ML.I e.e_ity) mask eff lbl
422 423 424
        else let e1 = expr info svar xs.xs_mask e1 in
          let ty = if ity_equal xs.xs_ity ity_unit then None
            else Some (mlty_of_ity xs.xs_mask xs.xs_ity) in
425
        ML.mk_expr (ML.Eexn (xs, ty, e1)) (ML.I e.e_ity) mask eff lbl
Mário Pereira's avatar
Mário Pereira committed
426 427
    | Elet (LDsym (_, {c_node=(Cany|Cpur (_, _)); _ }), _)
    | Eexec ({c_node=Cpur (_, _); _ }, _) -> ML.mk_hole
428

429
  and ebranch info svar mask ({pp_pat = p; pp_mask = m}, e) =
Mário Pereira's avatar
Mário Pereira committed
430 431 432
    (* if the [case] expression is not ghost but there is (at least) one ghost
       branch, then it must be the case that all the branches return [unit]
       and at least one of the non-ghost branches is effectful *)
433
    if e.e_effect.eff_ghost then (pat m p, ML.e_unit)
434
    else (pat m p, expr info svar mask e)
435

436
  (* type declarations/definitions *)
Mário Pereira's avatar
Mário Pereira committed
437
  let tdef itd =
438
    let s = itd.itd_its in
439
    let ddata_constructs = (* point-free *)
Mário Pereira's avatar
Mário Pereira committed
440
      List.map (fun ({rs_cty = cty} as rs) ->
441
          rs.rs_name,
Mário Pereira's avatar
Mário Pereira committed
442
          let args = List.filter pv_not_ghost cty.cty_args in
Mário Pereira's avatar
Mário Pereira committed
443
          List.map (fun {pv_vs = vs} -> type_ vs.vs_ty) args) in
Mário Pereira's avatar
Mário Pereira committed
444
    let drecord_fields ({rs_cty = cty} as rs) =
445
      (List.exists (pv_equal (fd_of_rs rs)) s.its_mfields),
Mário Pereira's avatar
Mário Pereira committed
446
      rs.rs_name,
Mário Pereira's avatar
Mário Pereira committed
447
      mlty_of_ity cty.cty_mask cty.cty_result in
448 449 450
    let id = s.its_ts.ts_name in
    let is_private = s.its_private in
    let args = s.its_ts.ts_args in
451
    begin match s.its_def, itd.itd_constructors, itd.itd_fields with
452
      | NoDef, [], [] ->
453
          ML.mk_its_defn id args is_private None
454
      | NoDef, cl, [] ->
455
          let cl = ddata_constructs cl in
456
          ML.mk_its_defn id args is_private (Some (ML.Ddata cl))
457
      | NoDef, _, pjl ->
458 459 460 461
          let p e = not (rs_ghost e) in
          let pjl = filter_ghost_params p drecord_fields pjl in
          begin match pjl with
            | [] -> ML.mk_its_defn id args is_private
462
                      (Some (ML.Dalias ML.tunit))
463
            | [_, _, ty_pj] when is_optimizable_record_itd itd ->
464
                ML.mk_its_defn id args is_private (Some (ML.Dalias ty_pj))
465
            | pjl ->
466
                ML.mk_its_defn id args is_private (Some (ML.Drecord pjl))
467
          end
468
      | Alias t, _, _ ->
469
          ML.mk_its_defn id args is_private (* FIXME ? is this a good mask ? *)
470
            (Some (ML.Dalias (mlty_of_ity MaskVisible t)))
471 472
      | Range r, [], [] ->
          assert (args = []); (* a range type is not polymorphic *)
473
          ML.mk_its_defn id [] is_private (Some (ML.Drange r))
474
      | Float ff, [], [] ->
Mário Pereira's avatar
Mário Pereira committed
475
          assert (args = []); (* a float type is not polymorphic *)
476
          ML.mk_its_defn id [] is_private (Some (ML.Dfloat ff))
477 478
      | (Range _ | Float _), _, _ ->
          assert false (* cannot have constructors or fields *)
479
    end
Mário Pereira's avatar
Mário Pereira committed
480

Mário Pereira's avatar
Mário Pereira committed
481 482 483 484
  let is_val = function
    | Eexec ({c_node = Cany}, _) -> true
    | _ -> false

485
  let pdecl info pd =
Mário Pereira's avatar
Mário Pereira committed
486
    match pd.pd_node with
487 488 489 490 491
    | PDlet (LDvar (_, e)) when e_ghost e ->
        []
    | PDlet (LDvar (pv, e)) when pv.pv_ghost ->
        if eff_pure e.e_effect then []
        else let unit_ = create_pvsymbol (id_fresh "()") ity_unit in
492
          [ML.Dlet (ML.Lvar (unit_, expr info Stv.empty e.e_mask e))]
493
    | PDlet (LDvar (pv, e)) ->
494
        [ML.Dlet (ML.Lvar (pv, expr info Stv.empty e.e_mask e))]
495
    | PDlet (LDsym (rs, _)) when rs_ghost rs ->
496
        []
Mário Pereira's avatar
Mário Pereira committed
497
    | PDlet (LDsym ({rs_cty = cty} as rs, {c_node = Cany})) ->
498 499
        let args = params cty.cty_args in
        let res = mlty_of_ity cty.cty_mask cty.cty_result in
500
        [ML.Dlet (ML.Lany (rs, res, args))]
501 502 503
    | PDlet (LDsym ({rs_cty = cty} as rs, {c_node = Cfun e}))
      when is_val e.e_node -> (* zero argument functions *)
        let res = mlty_of_ity cty.cty_mask cty.cty_result in
504
        [ML.Dlet (ML.Lany (rs, res, []))]
505
    | PDlet (LDsym ({rs_cty = cty} as rs, {c_node = Cfun e})) ->
506
        Debug.dprintf debug_compile "compiling function %a@." Expr.print_rs rs;
507 508
        let args = params cty.cty_args in
        let res = mlty_of_ity cty.cty_mask cty.cty_result in
Mário Pereira's avatar
Mário Pereira committed
509 510 511 512
        let svar =
          let args' = List.map (fun (_, ty, _) -> ty) args in
          let svar  = List.fold_left add_tvar Stv.empty args' in
          add_tvar svar res in
513
        let e = expr info svar cty.cty_mask e in
514
        [ML.Dlet (ML.Lsym (rs, res, args, e))]
515
    | PDlet (LDrec rl) ->
516 517 518 519 520 521 522 523 524
        let rl = filter_out_ghost_rdef rl in
        let def {rec_fun = e; rec_sym = rs1; rec_rsym = rs2} =
          let e = match e.c_node with Cfun e -> e | _ -> assert false in
          let args = params rs1.rs_cty.cty_args in
          let res  = mlty_of_ity rs1.rs_cty.cty_mask rs1.rs_cty.cty_result in
          let svar =
            let args' = List.map (fun (_, ty, _) -> ty) args in
            let svar  = List.fold_left add_tvar Stv.empty args' in
            add_tvar svar res in
525
          let e = expr info svar rs1.rs_cty.cty_mask e in
526 527 528 529
          { ML.rec_sym  = rs1;  ML.rec_rsym = rs2;
            ML.rec_args = args; ML.rec_exp  = e;
            ML.rec_res  = res;  ML.rec_svar = svar; } in
        if rl = [] then [] else [ML.Dlet (ML.Lrec (List.map def rl))]
530
    | PDlet (LDsym _) | PDpure ->
531
        []
532
    | PDtype itl ->
533
        let itsd = List.map tdef itl in
534
        [ML.Dtype itsd]
535
    | PDexn xs ->
536
        if ity_equal xs.xs_ity ity_unit || xs.xs_mask = MaskGhost then
537 538
          [ML.Dexn (xs, None)]
        else [ML.Dexn (xs, Some (mlty_of_ity xs.xs_mask xs.xs_ity))]
Mário Pereira's avatar
Mário Pereira committed
539

Mário Pereira's avatar
Mário Pereira committed
540
  let pdecl_m m pd =
541
    let info = { ML.from_mod = Some m; ML.from_km = m.mod_known; } in
542
    pdecl info pd
543

Mário Pereira's avatar
Mário Pereira committed
544
  (* unit module declarations *)
545 546
  let rec mdecl info = function
    | Udecl pd -> pdecl info pd
Mário Pereira's avatar
Mário Pereira committed
547
    | Uscope (_, ([Uuse _] | [Uclone _])) -> []
548
    | Uscope (s, dl) -> let dl = List.concat (List.map (mdecl info) dl) in
549
        [ML.Dmodule (s, dl)]
Mário Pereira's avatar
Mário Pereira committed
550
    | Uuse _ | Uclone _ | Umeta _ -> []
551

Mário Pereira's avatar
Mário Pereira committed
552
  (* modules *)
Mário Pereira's avatar
Mário Pereira committed
553
  let module_ m =
554
    let from = { ML.from_mod = Some m; ML.from_km = m.mod_known; } in
555
    let mod_decl = List.concat (List.map (mdecl from) m.mod_units) in
556
    let add_decl known_map decl = let idl = ML.get_decl_name decl in
Mário Pereira's avatar
Mário Pereira committed
557
      List.fold_left (ML.add_known_decl decl) known_map idl in
558
    let mod_known = List.fold_left add_decl Mid.empty mod_decl in {
559 560 561
      ML.mod_from = from;
      ML.mod_decl = mod_decl;
      ML.mod_known = mod_known;
562 563
    }

Mário Pereira's avatar
Mário Pereira committed
564 565
end

566 567 568 569
(** Some transformations *)

module Transform = struct

570
  open Mltree
571

Mário Pereira's avatar
Mário Pereira committed
572
  let no_reads_writes_conflict spv spv_mreg =
573
    let is_not_write {pv_ity = ity} = match ity.ity_node with
574 575
      | Ityreg rho -> not (Mreg.mem rho spv_mreg)
      | _ -> true in
576
    Spv.for_all is_not_write spv
Mário Pereira's avatar
Mário Pereira committed
577

Mário Pereira's avatar
Mário Pereira committed
578 579 580 581 582
  let mk_list_eb ebl f =
    let mk_acc e (e_acc, s_acc) =
      let e, s = f e in e::e_acc, Spv.union s s_acc in
    List.fold_right mk_acc ebl ([], Spv.empty)

Mário Pereira's avatar
Mário Pereira committed
583
  let rec expr info subst e =
Mário Pereira's avatar
Mário Pereira committed
584
    let mk e_node = { e with e_node = e_node } in
Mário Pereira's avatar
Mário Pereira committed
585
    let add_subst pv e1 e2 = expr info (Mpv.add pv e1 subst) e2 in
586
    match e.e_node with
Mário Pereira's avatar
Mário Pereira committed
587 588
    | Evar pv -> begin try Mpv.find pv subst, Spv.singleton pv
        with Not_found -> e, Spv.empty end
Mário Pereira's avatar
Mário Pereira committed
589
    | Elet (Lvar (pv, ({e_effect = eff1} as e1)), ({e_effect = eff2} as e2))
Mário Pereira's avatar
Mário Pereira committed
590
      when Slab.mem Expr.proxy_label pv.pv_vs.vs_name.id_label &&
Mário Pereira's avatar
Mário Pereira committed
591
           eff_pure eff1 &&
Mário Pereira's avatar
Mário Pereira committed
592
           no_reads_writes_conflict eff1.eff_reads eff2.eff_writes ->
593 594 595 596 597 598
        let e1, s1 = expr info subst e1 in
        let e2, s2 = add_subst pv e1 e2 in
        let s_union = Spv.union s1 s2 in
        if Spv.mem pv s2 then e2, s_union (* [pv] was substituted in [e2] *)
        else (* [pv] was not substituted in [e2], e.g [e2] is an [Efun] *)
          mk (Elet (Lvar (pv, e1), e2)), s_union
599
    | Elet (ld, e) ->
600 601 602
        let e, spv = expr info subst e in
        let e_let, spv_let = let_def info subst ld in
        mk (Elet (e_let, e)), Spv.union spv spv_let
603
    | Eapp (rs, el) ->
604 605
        let e_app, spv = mk_list_eb el (expr info subst) in
        mk (Eapp (rs, e_app)), spv
606
    | Efun (vl, e) ->
607 608 609 610 611 612 613 614 615 616 617 618
        (* For now, we accept to inline constants and constructors
           with zero arguments inside a [Efun]. *)
        let p _k e = match e.e_node with
          | Econst _ -> true
          | Eapp (rs, []) when Translate.isconstructor info rs -> true
          | _ -> false in
        let restrict_subst = Mpv.filter p subst in
        (* We begin the inlining of proxy variables in an [Efun] with a
           restricted substitution. This keeps some proxy lets, preventing
           undiserable captures inside the [Efun] expression. *)
        let e, spv = expr info restrict_subst e in
        mk (Efun (vl, e)), spv
619
    | Eif (e1, e2, e3) ->
620 621 622 623
        let e1, s1 = expr info subst e1 in
        let e2, s2 = expr info subst e2 in
        let e3, s3 = expr info subst e3 in
        mk (Eif (e1, e2, e3)), Spv.union (Spv.union s1 s2) s3
624
    | Eexn (xs, ty, e1) ->
625 626
        let e1, s1 = expr info subst e1 in
        mk (Eexn (xs, ty, e1)), s1
627
    | Ematch (e, bl, xl) ->
628 629
        let e, spv = expr info subst e in
        let e_bl, spv_bl = mk_list_eb bl (branch info subst) in
630 631 632 633 634 635 636 637
        let e_xl, spv_xl = mk_list_eb xl (xbranch info subst) in
        mk (Ematch (e, e_bl, e_xl)), Spv.union (Spv.union spv spv_bl) spv_xl
(*
    | Etry (e, case, bl) ->
        let e, spv = expr info subst e in
        let e_bl, spv_bl = mk_list_eb bl (xbranch info subst) in
        mk (Etry (e, case, e_bl)), Spv.union spv spv_bl
*)
638
    | Eblock el ->
639 640
        let e_app, spv = mk_list_eb el (expr info subst) in
        mk (Eblock e_app), spv
641
    | Ewhile (e1, e2) ->
642 643 644
        let e1, s1 = expr info subst e1 in
        let e2, s2 = expr info subst e2 in
        mk (Ewhile (e1, e2)), Spv.union s1 s2
645
    | Efor (x, pv1, dir, pv2, e) ->
646
        let e, spv = expr info subst e in
647
        mk (Efor (x, pv1, dir, pv2, e)), spv
Mário Pereira's avatar
Mário Pereira committed
648 649
    | Eraise (exn, None) -> mk (Eraise (exn, None)), Spv.empty
    | Eraise (exn, Some e) ->
650 651
        let e, spv = expr info subst e in
        mk (Eraise (exn, Some e)), spv
Mário Pereira's avatar
Mário Pereira committed
652 653
    | Eassign _al ->
        e, Spv.empty
Mário Pereira's avatar
Mário Pereira committed
654 655
    | Econst _ | Eabsurd | Ehole -> e, Spv.empty
    | Eignore e ->
656 657
        let e, spv = expr info subst e in
        mk (Eignore e), spv
658

Mário Pereira's avatar
Mário Pereira committed
659 660 661 662
  and branch info subst (pat, e) =
    let e, spv = expr info subst e in (pat, e), spv
  and xbranch info subst (exn, pvl, e) =
    let e, spv = expr info subst e in (exn, pvl, e), spv
663

Mário Pereira's avatar
Mário Pereira committed
664
  and let_def info subst = function
665
    | Lvar (pv, e) ->
666 667 668
        assert (not (Mpv.mem pv subst)); (* no capture *)
        let e, spv = expr info subst e in
        Lvar (pv, e), spv
Mário Pereira's avatar
Mário Pereira committed
669
    | Lsym (rs, res, args, e) ->
670 671
        let e, spv = expr info subst e in
        Lsym (rs, res, args, e), spv
Mário Pereira's avatar
Mário Pereira committed
672
    | Lany _ as lany -> lany, Mpv.empty
Mário Pereira's avatar
Mário Pereira committed
673
    | Lrec rl ->
674 675
        let rdef, spv = mk_list_eb rl (rdef info subst) in
        Lrec rdef, spv
676

Mário Pereira's avatar
Mário Pereira committed
677
  and rdef info subst r =
Mário Pereira's avatar
Mário Pereira committed
678 679
    let rec_exp, spv = expr info subst r.rec_exp in
    { r with rec_exp = rec_exp }, spv
680

681
  let rec pdecl info = function
682 683
    | Dtype _ | Dexn _ as d -> d
    | Dmodule (id, dl) ->
684
        let dl = List.map (pdecl info) dl in Dmodule (id, dl)
Mário Pereira's avatar
Mário Pereira committed
685
    | Dlet def ->
686 687
        (* for top-level symbols we can forget the set of inlined variables *)
        let e, _ = let_def info Mpv.empty def in Dlet e
688