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(* ----------------------------------------------------------------------------
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 * SchedMCore - A MultiCore Scheduling Framework
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 * Copyright (C) 2009-2011, ONERA, Toulouse, FRANCE - LIFL, Lille, FRANCE
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 *
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 * This file is part of Prelude
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 *
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 * Prelude is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public License
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 * as published by the Free Software Foundation ; either version 2 of
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 * the License, or (at your option) any later version.
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 *
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 * Prelude is distributed in the hope that it will be useful, but
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 * WITHOUT ANY WARRANTY ; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this program ; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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 * USA
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 *---------------------------------------------------------------------------- *)
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(** Main typing module. Classic inference algorithm with destructive
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    unification. *)
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let debug fmt args = () (* Format.eprintf "%a"  *)
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(* Though it shares similarities with the clock calculus module, no code
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    is shared.  Simple environments, very limited identifier scoping, no
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    identifier redefinition allowed. *)
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open Utils
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(* Yes, opening both modules is dirty as some type names will be
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   overwritten, yet this makes notations far lighter.*)
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open LustreSpec
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open Corelang
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open Types
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open Format
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let pp_typing_env fmt env =
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  Env.pp_env print_ty fmt env
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(** [occurs tvar ty] returns true if the type variable [tvar] occurs in
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    type [ty]. False otherwise. *)
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let rec occurs tvar ty =
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  let ty = repr ty in
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  match ty.tdesc with
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  | Tvar -> ty=tvar
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  | Tarrow (t1, t2) ->
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      (occurs tvar t1) || (occurs tvar t2)
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  | Ttuple tl ->
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     List.exists (occurs tvar) tl
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  | Tstruct fl ->
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     List.exists (fun (f, t) -> occurs tvar t) fl
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  | Tarray (_, t)
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  | Tstatic (_, t)
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  | Tclock t
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  | Tlink t -> occurs tvar t
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  | Tenum _ | Tconst _ | Tunivar | Tint | Treal | Tbool | Trat -> false
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(** Promote monomorphic type variables to polymorphic type variables. *)
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(* Generalize by side-effects *)
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let rec generalize ty =
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  match ty.tdesc with
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  | Tvar ->
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      (* No scopes, always generalize *)
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      ty.tdesc <- Tunivar
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  | Tarrow (t1,t2) ->
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      generalize t1; generalize t2
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  | Ttuple tl ->
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     List.iter generalize tl
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  | Tstruct fl ->
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     List.iter (fun (f, t) -> generalize t) fl
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  | Tstatic (d, t)
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  | Tarray (d, t) -> Dimension.generalize d; generalize t
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  | Tclock t
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  | Tlink t ->
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      generalize t
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  | Tenum _ | Tconst _ | Tunivar | Tint | Treal | Tbool | Trat -> ()
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(** Downgrade polymorphic type variables to monomorphic type variables *)
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let rec instantiate inst_vars inst_dim_vars ty =
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  let ty = repr ty in
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  match ty.tdesc with
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  | Tenum _ | Tconst _ | Tvar | Tint | Treal | Tbool | Trat -> ty
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  | Tarrow (t1,t2) ->
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      {ty with tdesc =
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       Tarrow ((instantiate inst_vars inst_dim_vars t1), (instantiate inst_vars inst_dim_vars t2))}
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  | Ttuple tlist ->
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      {ty with tdesc = Ttuple (List.map (instantiate inst_vars inst_dim_vars) tlist)}
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  | Tstruct flist ->
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      {ty with tdesc = Tstruct (List.map (fun (f, t) -> (f, instantiate inst_vars inst_dim_vars t)) flist)}
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  | Tclock t ->
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	{ty with tdesc = Tclock (instantiate inst_vars inst_dim_vars t)}
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  | Tstatic (d, t) ->
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	{ty with tdesc = Tstatic (Dimension.instantiate inst_dim_vars d, instantiate inst_vars inst_dim_vars t)}
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  | Tarray (d, t) ->
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	{ty with tdesc = Tarray (Dimension.instantiate inst_dim_vars d, instantiate inst_vars inst_dim_vars t)}
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  | Tlink t ->
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	(* should not happen *)
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	{ty with tdesc = Tlink (instantiate inst_vars inst_dim_vars t)}
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  | Tunivar ->
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      try
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        List.assoc ty.tid !inst_vars
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      with Not_found ->
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        let var = new_var () in
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	inst_vars := (ty.tid, var)::!inst_vars;
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	var
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(* [type_coretype cty] types the type declaration [cty] *)
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let rec type_coretype type_dim cty =
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  match (*get_repr_type*) cty with
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  | Tydec_any -> new_var ()
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  | Tydec_int -> Type_predef.type_int
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  | Tydec_real -> Type_predef.type_real
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  | Tydec_float -> Type_predef.type_real
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  | Tydec_bool -> Type_predef.type_bool
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  | Tydec_clock ty -> Type_predef.type_clock (type_coretype type_dim ty)
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  | Tydec_const c -> Type_predef.type_const c
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  | Tydec_enum tl -> Type_predef.type_enum tl
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  | Tydec_struct fl -> Type_predef.type_struct (List.map (fun (f, ty) -> (f, type_coretype type_dim ty)) fl)
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  | Tydec_array (d, ty) ->
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    begin
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      type_dim d;
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      Type_predef.type_array d (type_coretype type_dim ty)
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    end
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127
(* [coretype_type] is the reciprocal of [type_typecore] *)
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let rec coretype_type ty =
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 match (repr ty).tdesc with
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 | Tvar           -> Tydec_any
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 | Tint           -> Tydec_int
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 | Treal          -> Tydec_real
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 | Tbool          -> Tydec_bool
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 | Tconst c       -> Tydec_const c
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 | Tclock t       -> Tydec_clock (coretype_type t)
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 | Tenum tl       -> Tydec_enum tl
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 | Tstruct fl     -> Tydec_struct (List.map (fun (f, t) -> (f, coretype_type t)) fl)
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 | Tarray (d, t)  -> Tydec_array (d, coretype_type t)
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 | Tstatic (_, t) -> coretype_type t
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 | _         -> assert false
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let get_type_definition tname =
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  try
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    type_coretype (fun d -> ()) (Hashtbl.find type_table (Tydec_const tname))
145
  with Not_found -> raise (Error (Location.dummy_loc, Unbound_type tname))
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(* Equality on ground types only *)
148
(* Should be used between local variables which must have a ground type *)
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let rec eq_ground t1 t2 =
150
  match t1.tdesc, t2.tdesc with
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  | Tint, Tint | Tbool, Tbool | Trat, Trat -> true
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  | Tenum tl, Tenum tl' when tl == tl' -> true
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  | Ttuple tl, Ttuple tl' when List.length tl = List.length tl' -> List.for_all2 eq_ground tl tl'
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  | Tstruct fl, Tstruct fl' when List.map fst fl = List.map fst fl' -> List.for_all2 (fun (_, t) (_, t') -> eq_ground t t') fl fl'
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  | (Tconst t, _) ->
156
    let def_t = get_type_definition t in
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    eq_ground def_t t2
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  | (_, Tconst t)  ->
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    let def_t = get_type_definition t in
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    eq_ground t1 def_t
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  | Tarrow (t1,t2), Tarrow (t1',t2') -> eq_ground t1 t1' && eq_ground t2 t2'
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  | Tclock t1', _ -> eq_ground t1' t2
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  | _, Tclock t2' -> eq_ground t1 t2'
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  | Tstatic (e1, t1'), Tstatic (e2, t2')
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  | Tarray (e1, t1'), Tarray (e2, t2') -> Dimension.is_eq_dimension e1 e2 && eq_ground t1' t2'
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  | _ -> false
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168
(** [unify t1 t2] unifies types [t1] and [t2]. Raises [Unify
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    (t1,t2)] if the types are not unifiable.*)
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(* Standard destructive unification *)
171
let rec unify t1 t2 =
172
  let t1 = repr t1 in
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  let t2 = repr t2 in
174
  if t1=t2 then
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    ()
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  else
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    (* No type abbreviations resolution for now *)
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    match t1.tdesc,t2.tdesc with
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      (* This case is not mandory but will keep "older" types *)
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    | Tvar, Tvar ->
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        if t1.tid < t2.tid then
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          t2.tdesc <- Tlink t1
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        else
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          t1.tdesc <- Tlink t2
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    | (Tvar, _) when (not (occurs t1 t2)) ->
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        t1.tdesc <- Tlink t2
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    | (_,Tvar) when (not (occurs t2 t1)) ->
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        t2.tdesc <- Tlink t1
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    | Tarrow (t1,t2), Tarrow (t1',t2') ->
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      begin
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        unify t1 t1';
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	unify t2 t2'
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      end
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    | Ttuple tl, Ttuple tl' when List.length tl = List.length tl' ->
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      List.iter2 unify tl tl'
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    | Tstruct fl, Tstruct fl' when List.map fst fl = List.map fst fl' ->
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      List.iter2 (fun (_, t) (_, t') -> unify t t') fl fl'
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    | Tclock _, Tstatic _
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    | Tstatic _, Tclock _ -> raise (Unify (t1, t2))
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    | Tclock t1', _ -> unify t1' t2
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    | _, Tclock t2' -> unify t1 t2'
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    | Tint, Tint | Tbool, Tbool | Trat, Trat
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    | Tunivar, _ | _, Tunivar -> ()
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    | (Tconst t, _) ->
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      let def_t = get_type_definition t in
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      unify def_t t2
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    | (_, Tconst t)  ->
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      let def_t = get_type_definition t in
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      unify t1 def_t
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    | Tenum tl, Tenum tl' when tl == tl' -> ()
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    | Tstatic (e1, t1'), Tstatic (e2, t2')
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    | Tarray (e1, t1'), Tarray (e2, t2') ->
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      begin
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	unify t1' t2';
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	Dimension.eval Basic_library.eval_env (fun c -> None) e1;
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	Dimension.eval Basic_library.eval_env (fun c -> None) e2;
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	Dimension.unify e1 e2;
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      end
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    | _,_ -> raise (Unify (t1, t2))
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(** [semi_unify t1 t2] checks whether type [t1] is an instance of type [t2]. Raises [Unify
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    (t1,t2)] if the types are not semi-unifiable.*)
223
(* Standard destructive semi-unification *)
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let rec semi_unify t1 t2 =
225
  let t1 = repr t1 in
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  let t2 = repr t2 in
227
  if t1=t2 then
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    ()
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  else
230
    (* No type abbreviations resolution for now *)
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    match t1.tdesc,t2.tdesc with
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      (* This case is not mandory but will keep "older" types *)
233
    | Tvar, Tvar ->
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        if t1.tid < t2.tid then
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          t2.tdesc <- Tlink t1
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        else
237
          t1.tdesc <- Tlink t2
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    | (Tvar, _) -> raise (Unify (t1, t2))
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    | (_,Tvar) when (not (occurs t2 t1)) ->
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        t2.tdesc <- Tlink t1
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    | Tarrow (t1,t2), Tarrow (t1',t2') ->
242
      begin
243
        semi_unify t1 t1';
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	semi_unify t2 t2'
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      end
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    | Ttuple tl, Ttuple tl' when List.length tl = List.length tl' ->
247
      List.iter2 semi_unify tl tl'
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    | Tstruct fl, Tstruct fl' when List.map fst fl = List.map fst fl' ->
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      List.iter2 (fun (_, t) (_, t') -> semi_unify t t') fl fl'
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    | Tclock _, Tstatic _
251
    | Tstatic _, Tclock _ -> raise (Unify (t1, t2))
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    | Tclock t1', _ -> semi_unify t1' t2
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    | _, Tclock t2' -> semi_unify t1 t2'
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    | Tint, Tint | Tbool, Tbool | Trat, Trat
255
    | Tunivar, _ | _, Tunivar -> ()
256
    | (Tconst t, _) ->
257
      let def_t = get_type_definition t in
258
      semi_unify def_t t2
259
    | (_, Tconst t)  ->
260
      let def_t = get_type_definition t in
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      semi_unify t1 def_t
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    | Tenum tl, Tenum tl' when tl == tl' -> ()
263

    
264
    | Tstatic (e1, t1'), Tstatic (e2, t2')
265
    | Tarray (e1, t1'), Tarray (e2, t2') ->
266
      begin
267
	semi_unify t1' t2';
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	Dimension.eval Basic_library.eval_env (fun c -> Some (Dimension.mkdim_ident Location.dummy_loc c)) e1;
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	Dimension.eval Basic_library.eval_env (fun c -> Some (Dimension.mkdim_ident Location.dummy_loc c)) e2;
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	Dimension.semi_unify e1 e2;
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      end
272
    | _,_ -> raise (Unify (t1, t2))
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274
(* Expected type ty1, got type ty2 *)
275
let try_unify ty1 ty2 loc =
276
  try
277
    unify ty1 ty2
278
  with
279
  | Unify _ ->
280
    raise (Error (loc, Type_clash (ty1,ty2)))
281
  | Dimension.Unify _ ->
282
    raise (Error (loc, Type_clash (ty1,ty2)))
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284
let try_semi_unify ty1 ty2 loc =
285
  try
286
    semi_unify ty1 ty2
287
  with
288
  | Unify _ ->
289
    raise (Error (loc, Type_clash (ty1,ty2)))
290
  | Dimension.Unify _ ->
291
    raise (Error (loc, Type_clash (ty1,ty2)))
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293
(* ty1 is a subtype of ty2 *)
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let rec sub_unify sub ty1 ty2 =
295
  match (repr ty1).tdesc, (repr ty2).tdesc with
296
  | Ttuple tl1         , Ttuple tl2         ->
297
    if List.length tl1 <> List.length tl2
298
    then raise (Unify (ty1, ty2))
299
    else List.iter2 (sub_unify sub) tl1 tl2
300
  | Ttuple [t1]        , _                  -> sub_unify sub t1 ty2
301
  | _                  , Ttuple [t2]        -> sub_unify sub ty1 t2
302
  | Tstruct tl1        , Tstruct tl2        ->
303
    if List.map fst tl1 <> List.map fst tl2
304
    then raise (Unify (ty1, ty2))
305
    else List.iter2 (fun (_, t1) (_, t2) -> sub_unify sub t1 t2) tl1 tl2
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  | Tclock t1          , Tclock t2          -> sub_unify sub t1 t2
307
  | Tclock t1          , _   when sub       -> sub_unify sub t1 ty2
308
  | Tstatic (d1, t1)   , Tstatic (d2, t2)   ->
309
    begin
310
      sub_unify sub t1 t2;
311
      Dimension.eval Basic_library.eval_env (fun c -> None) d1;
312
      Dimension.eval Basic_library.eval_env (fun c -> None) d2;
313
      Dimension.unify d1 d2
314
    end
315
  | Tstatic (r_d, t1)  , _         when sub -> sub_unify sub t1 ty2
316
  | _                                       -> unify ty1 ty2
317

    
318
let try_sub_unify sub ty1 ty2 loc =
319
  try
320
    sub_unify sub ty1 ty2
321
  with
322
  | Unify _ ->
323
    raise (Error (loc, Type_clash (ty1,ty2)))
324
  | Dimension.Unify _ ->
325
    raise (Error (loc, Type_clash (ty1,ty2)))
326

    
327
let rec type_struct_const_field loc (label, c) =
328
  if Hashtbl.mem field_table label
329
  then let tydec = Hashtbl.find field_table label in
330
       let tydec_struct = get_struct_type_fields tydec in
331
       let ty_label = type_coretype (fun d -> ()) (List.assoc label tydec_struct) in
332
       begin
333
	 try_unify ty_label (type_const loc c) loc;
334
	 type_coretype (fun d -> ()) tydec
335
       end
336
  else raise (Error (loc, Unbound_value ("struct field " ^ label)))
337

    
338
and type_const loc c = 
339
  match c with
340
  | Const_int _     -> Type_predef.type_int
341
  | Const_real _    -> Type_predef.type_real
342
  | Const_float _   -> Type_predef.type_real
343
  | Const_array ca  -> let d = Dimension.mkdim_int loc (List.length ca) in
344
		      let ty = new_var () in
345
		      List.iter (fun e -> try_unify ty (type_const loc e) loc) ca;
346
		      Type_predef.type_array d ty
347
  | Const_tag t     ->
348
    if Hashtbl.mem tag_table t
349
    then type_coretype (fun d -> ()) (Hashtbl.find tag_table t)
350
    else raise (Error (loc, Unbound_value ("enum tag " ^ t)))
351
  | Const_struct fl ->
352
    let ty_struct = new_var () in
353
    begin
354
      let used =
355
	List.fold_left
356
	  (fun acc (l, c) ->
357
	    if List.mem l acc
358
	    then raise (Error (loc, Already_bound ("struct field " ^ l)))
359
	    else try_unify ty_struct (type_struct_const_field loc (l, c)) loc; l::acc)
360
	  [] fl in
361
      try
362
	let total = List.map fst (get_struct_type_fields (coretype_type ty_struct)) in
363
(*	List.iter (fun l -> Format.eprintf "total: %s@." l) total;
364
	List.iter (fun l -> Format.eprintf "used: %s@." l) used; *)
365
	let undef = List.find (fun l -> not (List.mem l used)) total
366
	in raise (Error (loc, Unbound_value ("struct field " ^ undef)))
367
      with Not_found -> 
368
	ty_struct
369
    end
370

    
371
(* The following typing functions take as parameter an environment [env]
372
   and whether the element being typed is expected to be constant [const]. 
373
   [env] is a pair composed of:
374
  - a map from ident to type, associating to each ident, i.e. 
375
    variables, constants and (imported) nodes, its type including whether
376
    it is constant or not. This latter information helps in checking constant 
377
    propagation policy in Lustre.
378
  - a vdecl list, in order to modify types of declared variables that are
379
    later discovered to be clocks during the typing process.
380
*)
381
let check_constant loc const_expected const_real =
382
  if const_expected && not const_real
383
  then raise (Error (loc, Not_a_constant))
384

    
385
let rec type_standard_args env in_main const expr_list =
386
  let ty_list = List.map (fun e -> dynamic_type (type_expr env in_main const e)) expr_list in
387
  let ty_res = new_var () in
388
  List.iter2 (fun e ty -> try_unify ty_res ty e.expr_loc) expr_list ty_list;
389
  ty_res
390

    
391
(* emulates a subtyping relation between types t and (d : t),
392
   used during node applications and assignments *)
393
and type_subtyping_arg env in_main ?(sub=true) const real_arg formal_type =
394
  let loc = real_arg.expr_loc in
395
  let const = const || (Types.get_static_value formal_type <> None) in
396
  let real_type = type_expr env in_main const real_arg in
397
  let real_type =
398
    if const
399
    then let d =
400
	   if is_dimension_type real_type
401
	   then dimension_of_expr real_arg
402
	   else Dimension.mkdim_var () in
403
	 let eval_const id = Types.get_static_value (Env.lookup_value (fst env) id) in
404
	 Dimension.eval Basic_library.eval_env eval_const d;
405
	 let real_static_type = Type_predef.type_static d (Types.dynamic_type real_type) in
406
	 (match Types.get_static_value real_type with
407
	 | None    -> ()
408
	 | Some d' -> try_unify real_type real_static_type loc);
409
	 real_static_type
410
    else real_type in
411
  (*Format.eprintf "subtyping const %B real %a:%a vs formal %a@." const Printers.pp_expr real_arg Types.print_ty real_type Types.print_ty formal_type;*)
412
  try_sub_unify sub real_type formal_type loc
413

    
414
and type_ident env in_main loc const id =
415
  type_expr env in_main const (expr_of_ident id loc)
416

    
417
(* typing an application implies:
418
   - checking that const formal parameters match real const (maybe symbolic) arguments
419
   - checking type adequation between formal and real arguments
420
*)
421
and type_appl env in_main loc const f args =
422
  let tfun = type_ident env in_main loc const f in
423
  let tins, touts = split_arrow tfun in
424
  let tins = type_list_of_type tins in
425
  let args = expr_list_of_expr args in
426
  if List.length args <> List.length tins then
427
    raise (Error (loc, WrongArity (List.length args, List.length tins)))
428
  else
429
    List.iter2 (type_subtyping_arg env in_main const) args tins;
430
  touts
431

    
432
(** [type_expr env in_main expr] types expression [expr] in environment
433
    [env], expecting it to be [const] or not. *)
434
and type_expr env in_main const expr =
435
  let res = 
436
  match expr.expr_desc with
437
  | Expr_const c ->
438
    let ty = type_const expr.expr_loc c in
439
    let ty = Type_predef.type_static (Dimension.mkdim_var ()) ty in
440
    expr.expr_type <- ty;
441
    ty
442
  | Expr_ident v ->
443
    let tyv =
444
      try
445
        Env.lookup_value (fst env) v
446
      with Not_found ->
447
	Format.eprintf "Failure in typing expr %a@." Printers.pp_expr expr;
448
        raise (Error (expr.expr_loc, Unbound_value ("identifier " ^ v)))
449
    in
450
    let ty = instantiate (ref []) (ref []) tyv in
451
    let ty' =
452
      if const
453
      then Type_predef.type_static (Dimension.mkdim_var ()) (new_var ())
454
      else new_var () in
455
    try_unify ty ty' expr.expr_loc;
456
    expr.expr_type <- ty;
457
    ty 
458
  | Expr_array elist ->
459
    let ty_elt = type_standard_args env in_main const elist in
460
    let d = Dimension.mkdim_int expr.expr_loc (List.length elist) in
461
    let ty = Type_predef.type_array d ty_elt in
462
    expr.expr_type <- ty;
463
    ty
464
  | Expr_access (e1, d) ->
465
    type_subtyping_arg env in_main true (expr_of_dimension d) Type_predef.type_int;
466
    let ty_elt = new_var () in
467
    let d = Dimension.mkdim_var () in
468
    type_subtyping_arg env in_main const e1 (Type_predef.type_array d ty_elt);
469
    expr.expr_type <- ty_elt;
470
    ty_elt
471
  | Expr_power (e1, d) ->
472
    let eval_const id = Types.get_static_value (Env.lookup_value (fst env) id) in
473
    type_subtyping_arg env in_main true (expr_of_dimension d) Type_predef.type_int;
474
    Dimension.eval Basic_library.eval_env eval_const d;
475
    let ty_elt = type_standard_args env in_main const [e1] in
476
    let ty = Type_predef.type_array d ty_elt in
477
    expr.expr_type <- ty;
478
    ty
479
  | Expr_tuple elist ->
480
    let ty = new_ty (Ttuple (List.map (type_expr env in_main const) elist)) in
481
    expr.expr_type <- ty;
482
    ty
483
  | Expr_ite (c, t, e) ->
484
    type_subtyping_arg env in_main const c Type_predef.type_bool;
485
    let ty = type_standard_args env in_main const [t; e] in
486
    expr.expr_type <- ty;
487
    ty
488
  | Expr_appl (id, args, r) ->
489
    (* application of non internal function is not legal in a constant
490
       expression *)
491
    (match r with
492
    | None        -> ()
493
    | Some (x, l) -> 
494
      check_constant expr.expr_loc const false;
495
      let expr_x = expr_of_ident x expr.expr_loc in	
496
      let typ_l = 
497
	Type_predef.type_clock 
498
	  (type_const expr.expr_loc (Const_tag l)) in
499
      type_subtyping_arg env in_main ~sub:false const expr_x typ_l);
500
    let touts = type_appl env in_main expr.expr_loc const id args in
501
    expr.expr_type <- touts;
502
    touts
503
  | Expr_fby (e1,e2)
504
  | Expr_arrow (e1,e2) ->
505
    (* fby/arrow is not legal in a constant expression *)
506
    check_constant expr.expr_loc const false;
507
    let ty = type_standard_args env in_main const [e1; e2] in
508
    expr.expr_type <- ty;
509
    ty
510
  | Expr_pre e ->
511
    (* pre is not legal in a constant expression *)
512
    check_constant expr.expr_loc const false;
513
    let ty = type_standard_args env in_main const [e] in
514
    expr.expr_type <- ty;
515
    ty
516
  | Expr_when (e1,c,l) ->
517
    (* when is not legal in a constant expression *)
518
    check_constant expr.expr_loc const false;
519
    let typ_l = Type_predef.type_clock (type_const expr.expr_loc (Const_tag l)) in
520
    let expr_c = expr_of_ident c expr.expr_loc in
521
    type_subtyping_arg env in_main ~sub:false const expr_c typ_l;
522
    update_clock env in_main c expr.expr_loc typ_l;
523
    let ty = type_standard_args env in_main const [e1] in
524
    expr.expr_type <- ty;
525
    ty
526
  | Expr_merge (c,hl) ->
527
    (* merge is not legal in a constant expression *)
528
    check_constant expr.expr_loc const false;
529
    let typ_in, typ_out = type_branches env in_main expr.expr_loc const hl in
530
    let expr_c = expr_of_ident c expr.expr_loc in
531
    let typ_l = Type_predef.type_clock typ_in in
532
    type_subtyping_arg env in_main ~sub:false const expr_c typ_l;
533
    update_clock env in_main c expr.expr_loc typ_l;
534
    expr.expr_type <- typ_out;
535
    typ_out
536
  | Expr_uclock (e,k) | Expr_dclock (e,k) ->
537
      let ty = type_expr env in_main const e in
538
      expr.expr_type <- ty;
539
      ty
540
  | Expr_phclock (e,q) ->
541
      let ty = type_expr env in_main const e in
542
      expr.expr_type <- ty;
543
      ty
544
  in (*Format.eprintf "typing %B %a at %a = %a@." const Printers.pp_expr expr Location.pp_loc expr.expr_loc Types.print_ty res;*) res
545

    
546
and type_branches env in_main loc const hl =
547
  let typ_in = new_var () in
548
  let typ_out = new_var () in
549
  try
550
    let used_labels =
551
      List.fold_left (fun accu (t, h) ->
552
	unify typ_in (type_const loc (Const_tag t));
553
	type_subtyping_arg env in_main const h typ_out;
554
	if List.mem t accu
555
	then raise (Error (loc, Already_bound t))
556
	else t :: accu) [] hl in
557
    let type_labels = get_enum_type_tags (coretype_type typ_in) in
558
    if List.sort compare used_labels <> List.sort compare type_labels
559
    then let unbound_tag = List.find (fun t -> not (List.mem t used_labels)) type_labels in
560
	 raise (Error (loc, Unbound_value ("branching tag " ^ unbound_tag)))
561
    else (typ_in, typ_out)
562
  with Unify (t1, t2) ->
563
    raise (Error (loc, Type_clash (t1,t2)))
564

    
565
and update_clock env in_main id loc typ =
566
 (*Log.report ~level:1 (fun fmt -> Format.fprintf fmt "update_clock %s with %a@ " id print_ty typ);*)
567
 try
568
   let vdecl = List.find (fun v -> v.var_id = id) (snd env)
569
   in vdecl.var_type <- typ
570
 with
571
   Not_found ->
572
   raise (Error (loc, Unbound_value ("clock " ^ id)))
573

    
574
(** [type_eq env eq] types equation [eq] in environment [env] *)
575
let type_eq env in_main undefined_vars eq =
576
  (* Check undefined variables, type lhs *)
577
  let expr_lhs = expr_of_expr_list eq.eq_loc (List.map (fun v -> expr_of_ident v eq.eq_loc) eq.eq_lhs) in
578
  let ty_lhs = type_expr env in_main false expr_lhs in
579
  (* Check multiple variable definitions *)
580
  let define_var id uvars =
581
    try
582
      ignore(IMap.find id uvars);
583
      IMap.remove id uvars
584
    with Not_found ->
585
      raise (Error (eq.eq_loc, Already_defined id))
586
  in
587
  let undefined_vars =
588
    List.fold_left (fun uvars v -> define_var v uvars) undefined_vars eq.eq_lhs in
589
  (* Type rhs wrt to lhs type with subtyping, i.e. a constant rhs value may be assigned
590
     to a (always non-constant) lhs variable *)
591
  type_subtyping_arg env in_main false eq.eq_rhs ty_lhs;
592
  undefined_vars
593

    
594

    
595
(* [type_coreclock env ck id loc] types the type clock declaration [ck]
596
   in environment [env] *)
597
let type_coreclock env ck id loc =
598
  match ck.ck_dec_desc with
599
  | Ckdec_any | Ckdec_pclock (_,_) -> ()
600
  | Ckdec_bool cl ->
601
      let dummy_id_expr = expr_of_ident id loc in
602
      let when_expr =
603
        List.fold_left
604
          (fun expr (x, l) ->
605
                {expr_tag = new_tag ();
606
                 expr_desc= Expr_when (expr,x,l);
607
                 expr_type = new_var ();
608
                 expr_clock = Clocks.new_var true;
609
                 expr_delay = Delay.new_var ();
610
                 expr_loc=loc;
611
		 expr_annot = None})
612
          dummy_id_expr cl
613
      in
614
      ignore (type_expr env false false when_expr)
615

    
616
let rec check_type_declaration loc cty =
617
 match cty with
618
 | Tydec_clock ty
619
 | Tydec_array (_, ty) -> check_type_declaration loc ty
620
 | Tydec_const tname   ->
621
   if not (Hashtbl.mem type_table cty)
622
   then raise (Error (loc, Unbound_type tname));
623
 | _                   -> ()
624

    
625
let type_var_decl vd_env env vdecl =
626
  check_type_declaration vdecl.var_loc vdecl.var_dec_type.ty_dec_desc;
627
  let eval_const id = Types.get_static_value (Env.lookup_value env id) in
628
  let type_dim d =
629
    begin
630
      type_subtyping_arg (env, vd_env) false true (expr_of_dimension d) Type_predef.type_int;
631
      Dimension.eval Basic_library.eval_env eval_const d;
632
    end in
633
  let ty = type_coretype type_dim vdecl.var_dec_type.ty_dec_desc in
634
  let ty_status =
635
    if vdecl.var_dec_const
636
    then Type_predef.type_static (Dimension.mkdim_var ()) ty
637
    else ty in
638
  let new_env = Env.add_value env vdecl.var_id ty_status in
639
  type_coreclock (new_env,vd_env) vdecl.var_dec_clock vdecl.var_id vdecl.var_loc;
640
  vdecl.var_type <- ty_status;
641
  new_env
642

    
643
let type_var_decl_list vd_env env l =
644
  List.fold_left (type_var_decl vd_env) env l
645

    
646
let type_of_vlist vars =
647
  let tyl = List.map (fun v -> v.var_type) vars in
648
  type_of_type_list tyl
649

    
650
let add_vdecl vd_env vdecl =
651
 if List.exists (fun v -> v.var_id = vdecl.var_id) vd_env
652
 then raise (Error (vdecl.var_loc, Already_bound vdecl.var_id))
653
 else vdecl::vd_env
654

    
655
let check_vd_env vd_env =
656
  ignore (List.fold_left add_vdecl [] vd_env)
657

    
658
(** [type_node env nd loc] types node [nd] in environment env. The
659
    location is used for error reports. *)
660
let type_node env nd loc =
661
  let is_main = nd.node_id = !Options.main_node in
662
  let vd_env_ol = nd.node_outputs@nd.node_locals in
663
  let vd_env =  nd.node_inputs@vd_env_ol in
664
  check_vd_env vd_env;
665
  let init_env = env in
666
  let delta_env = type_var_decl_list vd_env init_env nd.node_inputs in
667
  let delta_env = type_var_decl_list vd_env delta_env nd.node_outputs in
668
  let delta_env = type_var_decl_list vd_env delta_env nd.node_locals in
669
  let new_env = Env.overwrite env delta_env in
670
  let undefined_vars_init =
671
    List.fold_left
672
      (fun uvs v -> IMap.add v.var_id () uvs)
673
      IMap.empty vd_env_ol in
674
  let undefined_vars =
675
    List.fold_left (type_eq (new_env, vd_env) is_main) undefined_vars_init nd.node_eqs
676
  in
677
  (* check that table is empty *)
678
  if (not (IMap.is_empty undefined_vars)) then
679
    raise (Error (loc, Undefined_var undefined_vars));
680
  let ty_ins = type_of_vlist nd.node_inputs in
681
  let ty_outs = type_of_vlist nd.node_outputs in
682
  let ty_node = new_ty (Tarrow (ty_ins,ty_outs)) in
683
  generalize ty_node;
684
  (* TODO ? Check that no node in the hierarchy remains polymorphic ? *)
685
  nd.node_type <- ty_node;
686
  Env.add_value env nd.node_id ty_node
687

    
688
let type_imported_node env nd loc =
689
  let new_env = type_var_decl_list nd.nodei_inputs env nd.nodei_inputs in
690
  let vd_env = nd.nodei_inputs@nd.nodei_outputs in
691
  check_vd_env vd_env;
692
  ignore(type_var_decl_list vd_env new_env nd.nodei_outputs);
693
  let ty_ins = type_of_vlist nd.nodei_inputs in
694
  let ty_outs = type_of_vlist nd.nodei_outputs in
695
  let ty_node = new_ty (Tarrow (ty_ins,ty_outs)) in
696
  generalize ty_node;
697
(*
698
  if (is_polymorphic ty_node) then
699
    raise (Error (loc, Poly_imported_node nd.nodei_id));
700
*)
701
  let new_env = Env.add_value env nd.nodei_id ty_node in
702
  nd.nodei_type <- ty_node;
703
  new_env
704

    
705
let type_top_consts env clist =
706
  List.fold_left (fun env cdecl ->
707
    let ty = type_const cdecl.const_loc cdecl.const_value in
708
    let d =
709
      if is_dimension_type ty
710
      then dimension_of_const cdecl.const_loc cdecl.const_value
711
      else Dimension.mkdim_var () in
712
    let ty = Type_predef.type_static d ty in
713
    let new_env = Env.add_value env cdecl.const_id ty in
714
    cdecl.const_type <- ty;
715
    new_env) env clist
716

    
717
let type_top_decl env decl =
718
  match decl.top_decl_desc with
719
  | Node nd -> (
720
      try
721
	type_node env nd decl.top_decl_loc
722
      with Error (loc, err) as exc -> (
723
	if !Options.global_inline then
724
	  Format.eprintf "Type error: failing node@.%a@.@?"
725
	    Printers.pp_node nd
726
	;
727
	raise exc)
728
  )
729
  | ImportedNode nd ->
730
      type_imported_node env nd decl.top_decl_loc
731
  | Consts clist ->
732
      type_top_consts env clist
733
  | Open _  -> env
734

    
735
let type_prog env decls =
736
try
737
  List.fold_left type_top_decl env decls
738
with Failure _ as exc -> raise exc
739

    
740
(* Once the Lustre program is fully typed,
741
   we must get back to the original description of dimensions,
742
   with constant parameters, instead of unifiable internal variables. *)
743

    
744
(* The following functions aims at 'unevaluating' dimension expressions occuring in array types,
745
   i.e. replacing unifiable second_order variables with the original static parameters.
746
   Once restored in this formulation, dimensions may be meaningfully printed.
747
*)
748
let uneval_vdecl_generics vdecl =
749
 if vdecl.var_dec_const
750
 then
751
   match get_static_value vdecl.var_type with
752
   | None   -> (Format.eprintf "internal error: %a@." Types.print_ty vdecl.var_type; assert false)
753
   | Some d -> Dimension.uneval vdecl.var_id d
754

    
755
let uneval_node_generics vdecls =
756
  List.iter uneval_vdecl_generics vdecls
757

    
758
let uneval_top_generics decl =
759
  match decl.top_decl_desc with
760
  | Node nd ->
761
      uneval_node_generics (nd.node_inputs @ nd.node_outputs)
762
  | ImportedNode nd ->
763
      uneval_node_generics (nd.nodei_inputs @ nd.nodei_outputs)
764
  | Consts clist -> ()
765
  | Open _  -> ()
766

    
767
let uneval_prog_generics prog =
768
 List.iter uneval_top_generics prog
769

    
770
let rec get_imported_node decls id =
771
  match decls with
772
  | [] -> assert false
773
  | decl::q ->
774
     (match decl.top_decl_desc with
775
      | ImportedNode nd when id = nd.nodei_id -> decl
776
      | _ -> get_imported_node q id)
777

    
778
let check_env_compat header declared computed = 
779
  uneval_prog_generics header;
780
  Env.iter declared (fun k decl_type_k -> 
781
    let computed_t = instantiate (ref []) (ref []) 
782
				 (try Env.lookup_value computed k
783
				  with Not_found ->
784
				    let loc = (get_imported_node header k).top_decl_loc in 
785
				    raise (Error (loc, Declared_but_undefined k))) in
786
    (*Types.print_ty Format.std_formatter decl_type_k;
787
    Types.print_ty Format.std_formatter computed_t;*)
788
    try_semi_unify decl_type_k computed_t Location.dummy_loc
789
		    )
790

    
791
(* Local Variables: *)
792
(* compile-command:"make -C .." *)
793
(* End: *)