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(********************************************************************)
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(*                                                                  *)
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(*  The LustreC compiler toolset   /  The LustreC Development Team  *)
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(*  Copyright 2012 -    --   ONERA - CNRS - INPT - LIFL             *)
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(*                                                                  *)
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(*  LustreC is free software, distributed WITHOUT ANY WARRANTY      *)
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(*  under the terms of the GNU Lesser General Public License        *)
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(*  version 2.1.                                                    *)
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(*                                                                  *) 
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(*  This file was originally from the Prelude compiler              *)
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(*                                                                  *) 
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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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      let d = Dimension.copy (ref []) d in
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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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(* [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_coretype_definition tname =
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  try
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    let top = Hashtbl.find type_table (Tydec_const tname) in
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    match top.top_decl_desc with
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    | TypeDef tdef -> tdef.tydef_desc
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    | _ -> assert false
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  with Not_found -> raise (Error (Location.dummy_loc, Unbound_type tname))
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let get_type_definition tname =
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    type_coretype (fun d -> ()) (get_coretype_definition tname)
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(* Equality on ground types only *)
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(* Should be used between local variables which must have a ground type *)
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let rec eq_ground t1 t2 =
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  let t1 = repr t1 in
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  let t2 = repr t2 in
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  t1==t2 ||
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  match t1.tdesc, t2.tdesc with
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  | Tint, Tint | Tbool, Tbool | Trat, Trat | Treal, Treal -> 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, _) ->
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    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', 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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(** [unify t1 t2] unifies types [t1] and [t2]
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    using standard destructive unification.
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    Raises [Unify (t1,t2)] if the types are not unifiable.
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    [t1] is a expected/formal/spec type, [t2] is a computed/real/implem type,
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    so in case of unification error: expected type [t1], got type [t2].
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    If [sub]-typing is allowed, [t2] may be a subtype of [t1].
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    If [semi] unification is required,
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    [t1] should furthermore be an instance of [t2]
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    and constants are handled differently.*)
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let unify ?(sub=false) ?(semi=false) t1 t2 =
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  let rec unif t1 t2 =
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    let t1 = repr t1 in
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    let t2 = repr t2 in
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    if t1==t2 then
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      ()
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    else
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      match t1.tdesc,t2.tdesc with
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      (* strictly subtyping cases first *)
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      | _ , Tclock t2 when sub && (get_clock_base_type t1 = None) ->
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	unif t1 t2
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      | _ , Tstatic (d2, t2) when sub && (get_static_value t1 = None) ->
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	unif t1 t2
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      (* This case is not mandatory 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 semi) && (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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          unif t2 t2';
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	  unif t1' t1
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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 unif tl tl'
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      | Ttuple [t1]        , _                  -> unif t1 t2
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      | _                  , Ttuple [t2]        -> unif t1 t2
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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') -> unif 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', Tclock t2' -> unif t1' t2'
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      | Tint, Tint | Tbool, Tbool | Trat, Trat | Treal, Treal
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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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	unif 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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	unif 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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	let eval_const =
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	  if semi
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	  then (fun c -> Some (Dimension.mkdim_ident Location.dummy_loc c))
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	  else (fun c -> None) in
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	begin
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	  unif t1' t2';
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	  Dimension.eval Basic_library.eval_env eval_const e1;
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	  Dimension.eval Basic_library.eval_env eval_const e2;
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	  Dimension.unify ~semi:semi e1 e2;
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	end
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      | _,_ -> raise (Unify (t1, t2))
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  in unif t1 t2
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(* Expected type ty1, got type ty2 *)
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let try_unify ?(sub=false) ?(semi=false) ty1 ty2 loc =
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  try
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    unify ~sub:sub ~semi:semi ty1 ty2
242
  with
243
  | Unify _ ->
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    raise (Error (loc, Type_clash (ty1,ty2)))
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  | Dimension.Unify _ ->
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    raise (Error (loc, Type_clash (ty1,ty2)))
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248
let rec type_struct_const_field loc (label, c) =
249
  if Hashtbl.mem field_table label
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  then let tydef = Hashtbl.find field_table label in
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       let tydec = (typedef_of_top tydef).tydef_desc in 
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       let tydec_struct = get_struct_type_fields tydec in
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       let ty_label = type_coretype (fun d -> ()) (List.assoc label tydec_struct) in
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       begin
255
	 try_unify ty_label (type_const loc c) loc;
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	 type_coretype (fun d -> ()) tydec
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       end
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  else raise (Error (loc, Unbound_value ("struct field " ^ label)))
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260
and type_const loc c = 
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  match c with
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  | Const_int _     -> Type_predef.type_int
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  | Const_real _    -> Type_predef.type_real
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  | Const_float _   -> Type_predef.type_real
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  | Const_array ca  -> let d = Dimension.mkdim_int loc (List.length ca) in
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		      let ty = new_var () in
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		      List.iter (fun e -> try_unify ty (type_const loc e) loc) ca;
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		      Type_predef.type_array d ty
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  | Const_tag t     ->
270
    if Hashtbl.mem tag_table t
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    then 
272
      let tydef = typedef_of_top (Hashtbl.find tag_table t) in
273
      let tydec =
274
	if is_user_type tydef.tydef_desc
275
	then Tydec_const tydef.tydef_id
276
	else tydef.tydef_desc in
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      type_coretype (fun d -> ()) tydec
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    else raise (Error (loc, Unbound_value ("enum tag " ^ t)))
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  | Const_struct fl ->
280
    let ty_struct = new_var () in
281
    begin
282
      let used =
283
	List.fold_left
284
	  (fun acc (l, c) ->
285
	    if List.mem l acc
286
	    then raise (Error (loc, Already_bound ("struct field " ^ l)))
287
	    else try_unify ty_struct (type_struct_const_field loc (l, c)) loc; l::acc)
288
	  [] fl in
289
      try
290
	let total = List.map fst (get_struct_type_fields (coretype_type ty_struct)) in
291
(*	List.iter (fun l -> Format.eprintf "total: %s@." l) total;
292
	List.iter (fun l -> Format.eprintf "used: %s@." l) used; *)
293
	let undef = List.find (fun l -> not (List.mem l used)) total
294
	in raise (Error (loc, Unbound_value ("struct field " ^ undef)))
295
      with Not_found -> 
296
	ty_struct
297
    end
298
  | Const_string _ -> assert false (* string should only appear in annotations *)
299

    
300
(* The following typing functions take as parameter an environment [env]
301
   and whether the element being typed is expected to be constant [const]. 
302
   [env] is a pair composed of:
303
  - a map from ident to type, associating to each ident, i.e. 
304
    variables, constants and (imported) nodes, its type including whether
305
    it is constant or not. This latter information helps in checking constant 
306
    propagation policy in Lustre.
307
  - a vdecl list, in order to modify types of declared variables that are
308
    later discovered to be clocks during the typing process.
309
*)
310
let check_constant loc const_expected const_real =
311
  if const_expected && not const_real
312
  then raise (Error (loc, Not_a_constant))
313

    
314
let rec type_add_const env const arg targ =
315
(*Format.eprintf "Typing.type_add_const %a %a@." Printers.pp_expr arg Types.print_ty targ;*)
316
  if const
317
  then let d =
318
	 if is_dimension_type targ
319
	 then dimension_of_expr arg
320
	 else Dimension.mkdim_var () in
321
       let eval_const id = Types.get_static_value (Env.lookup_value (fst env) id) in
322
       Dimension.eval Basic_library.eval_env eval_const d;
323
       let real_static_type = Type_predef.type_static d (Types.dynamic_type targ) in
324
       (match Types.get_static_value targ with
325
       | None    -> ()
326
       | Some d' -> try_unify targ real_static_type arg.expr_loc);
327
       real_static_type
328
  else targ
329

    
330
(* emulates a subtyping relation between types t and (d : t),
331
   used during node applications and assignments *)
332
and type_subtyping_arg env in_main ?(sub=true) const real_arg formal_type =
333
  let loc = real_arg.expr_loc in
334
  let const = const || (Types.get_static_value formal_type <> None) in
335
  let real_type = type_add_const env const real_arg (type_expr env in_main const real_arg) in
336
  (*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;*)
337
  try_unify ~sub:sub formal_type real_type loc
338

    
339
and type_ident env in_main loc const id =
340
  type_expr env in_main const (expr_of_ident id loc)
341

    
342
(* typing an application implies:
343
   - checking that const formal parameters match real const (maybe symbolic) arguments
344
   - checking type adequation between formal and real arguments
345
   An application may embed an homomorphic/internal function, in which case we need to split
346
   it in many calls
347
*)
348
and type_appl env in_main loc const f args =
349
  let targs = List.map (type_expr env in_main const) args in
350
  if Basic_library.is_internal_fun f && List.exists is_tuple_type targs
351
  then
352
    try
353
      let targs = Utils.transpose_list (List.map type_list_of_type targs) in
354
      Types.type_of_type_list (List.map (type_simple_call env in_main loc const f) targs)
355
    with
356
      Utils.TransposeError (l, l') -> raise (Error (loc, WrongMorphism (l, l')))
357
  else
358
    type_dependent_call env in_main loc const f (List.combine args targs)
359

    
360
(* type a call with possible dependent types. [targs] is here a list of (argument, type) pairs. *)
361
and type_dependent_call env in_main loc const f targs =
362
(*Format.eprintf "Typing.type_dependent_call %s@." f;*)
363
  let tins, touts = new_var (), new_var () in
364
  let tfun = Type_predef.type_arrow tins touts in
365
  type_subtyping_arg env in_main const (expr_of_ident f loc) tfun;
366
  let tins = type_list_of_type tins in
367
  if List.length targs <> List.length tins then
368
    raise (Error (loc, WrongArity (List.length tins, List.length targs)))
369
  else
370
    begin
371
      List.iter2 (fun (a,t) ti ->
372
	let t' = type_add_const env (const || Types.get_static_value ti <> None) a t
373
	in try_unify ~sub:true ti t' a.expr_loc;
374
      ) targs tins;
375
(*Format.eprintf "Typing.type_dependent_call END@.";*)
376
      touts;
377
    end
378

    
379
(* type a simple call without dependent types 
380
   but possible homomorphic extension.
381
   [targs] is here a list of arguments' types. *)
382
and type_simple_call env in_main loc const f targs =
383
  let tins, touts = new_var (), new_var () in
384
  let tfun = Type_predef.type_arrow tins touts in
385
  type_subtyping_arg env in_main const (expr_of_ident f loc) tfun;
386
  (*Format.eprintf "try unify %a %a@." Types.print_ty tins Types.print_ty (type_of_type_list targs);*)
387
  try_unify ~sub:true tins (type_of_type_list targs) loc;
388
  touts
389

    
390
(** [type_expr env in_main expr] types expression [expr] in environment
391
    [env], expecting it to be [const] or not. *)
392
and type_expr env in_main const expr =
393
  let resulting_ty = 
394
  match expr.expr_desc with
395
  | Expr_const c ->
396
    let ty = type_const expr.expr_loc c in
397
    let ty = Type_predef.type_static (Dimension.mkdim_var ()) ty in
398
    expr.expr_type <- ty;
399
    ty
400
  | Expr_ident v ->
401
    let tyv =
402
      try
403
        Env.lookup_value (fst env) v
404
      with Not_found ->
405
	Format.eprintf "Failure in typing expr %a@." Printers.pp_expr expr;
406
        raise (Error (expr.expr_loc, Unbound_value ("identifier " ^ v)))
407
    in
408
    let ty = instantiate (ref []) (ref []) tyv in
409
    let ty' =
410
      if const
411
      then Type_predef.type_static (Dimension.mkdim_var ()) (new_var ())
412
      else new_var () in
413
    try_unify ty ty' expr.expr_loc;
414
    expr.expr_type <- ty;
415
    ty 
416
  | Expr_array elist ->
417
    let ty_elt = new_var () in
418
    List.iter (fun e -> try_unify ty_elt (type_appl env in_main expr.expr_loc const "uminus" [e]) e.expr_loc) elist;
419
    let d = Dimension.mkdim_int expr.expr_loc (List.length elist) in
420
    let ty = Type_predef.type_array d ty_elt in
421
    expr.expr_type <- ty;
422
    ty
423
  | Expr_access (e1, d) ->
424
    type_subtyping_arg env in_main true (expr_of_dimension d) Type_predef.type_int;
425
    let ty_elt = new_var () in
426
    let d = Dimension.mkdim_var () in
427
    type_subtyping_arg env in_main const e1 (Type_predef.type_array d ty_elt);
428
    expr.expr_type <- ty_elt;
429
    ty_elt
430
  | Expr_power (e1, d) ->
431
    let eval_const id = Types.get_static_value (Env.lookup_value (fst env) id) in
432
    type_subtyping_arg env in_main true (expr_of_dimension d) Type_predef.type_int;
433
    Dimension.eval Basic_library.eval_env eval_const d;
434
    let ty_elt = type_appl env in_main expr.expr_loc const "uminus" [e1] in
435
    let ty = Type_predef.type_array d ty_elt in
436
    expr.expr_type <- ty;
437
    ty
438
  | Expr_tuple elist ->
439
    let ty = new_ty (Ttuple (List.map (type_expr env in_main const) elist)) in
440
    expr.expr_type <- ty;
441
    ty
442
  | Expr_ite (c, t, e) ->
443
    type_subtyping_arg env in_main const c Type_predef.type_bool;
444
    let ty = type_appl env in_main expr.expr_loc const "+" [t; e] in
445
    expr.expr_type <- ty;
446
    ty
447
  | Expr_appl (id, args, r) ->
448
    (* application of non internal function is not legal in a constant
449
       expression *)
450
    (match r with
451
    | None        -> ()
452
    | Some c -> 
453
      check_constant expr.expr_loc const false;	
454
      type_subtyping_arg env in_main const c Type_predef.type_bool);
455
    let touts = type_appl env in_main expr.expr_loc const id (expr_list_of_expr args) in
456
    expr.expr_type <- touts;
457
    touts
458
  | Expr_fby (e1,e2)
459
  | Expr_arrow (e1,e2) ->
460
    (* fby/arrow is not legal in a constant expression *)
461
    check_constant expr.expr_loc const false;
462
    let ty = type_appl env in_main expr.expr_loc const "+" [e1; e2] in
463
    expr.expr_type <- ty;
464
    ty
465
  | Expr_pre e ->
466
    (* pre is not legal in a constant expression *)
467
    check_constant expr.expr_loc const false;
468
    let ty = type_appl env in_main expr.expr_loc const "uminus" [e] in
469
    expr.expr_type <- ty;
470
    ty
471
  | Expr_when (e1,c,l) ->
472
    (* when is not legal in a constant expression *)
473
    check_constant expr.expr_loc const false;
474
    let typ_l = Type_predef.type_clock (type_const expr.expr_loc (Const_tag l)) in
475
    let expr_c = expr_of_ident c expr.expr_loc in
476
    type_subtyping_arg env in_main ~sub:false const expr_c typ_l;
477
    let ty = type_appl env in_main expr.expr_loc const "uminus" [e1] in
478
    expr.expr_type <- ty;
479
    ty
480
  | Expr_merge (c,hl) ->
481
    (* merge is not legal in a constant expression *)
482
    check_constant expr.expr_loc const false;
483
    let typ_in, typ_out = type_branches env in_main expr.expr_loc const hl in
484
    let expr_c = expr_of_ident c expr.expr_loc in
485
    let typ_l = Type_predef.type_clock typ_in in
486
    type_subtyping_arg env in_main ~sub:false const expr_c typ_l;
487
    expr.expr_type <- typ_out;
488
    typ_out
489
  in 
490
  Log.report ~level:3 (fun fmt -> Format.fprintf fmt "Type of expr %a: %a@." Printers.pp_expr expr Types.print_ty resulting_ty);
491
  resulting_ty
492

    
493
and type_branches env in_main loc const hl =
494
  let typ_in = new_var () in
495
  let typ_out = new_var () in
496
  try
497
    let used_labels =
498
      List.fold_left (fun accu (t, h) ->
499
	unify typ_in (type_const loc (Const_tag t));
500
	type_subtyping_arg env in_main const h typ_out;
501
	if List.mem t accu
502
	then raise (Error (loc, Already_bound t))
503
	else t :: accu) [] hl in
504
    let type_labels = get_enum_type_tags (coretype_type typ_in) in
505
    if List.sort compare used_labels <> List.sort compare type_labels
506
    then let unbound_tag = List.find (fun t -> not (List.mem t used_labels)) type_labels in
507
	 raise (Error (loc, Unbound_value ("branching tag " ^ unbound_tag)))
508
    else (typ_in, typ_out)
509
  with Unify (t1, t2) ->
510
    raise (Error (loc, Type_clash (t1,t2)))
511

    
512
(** [type_eq env eq] types equation [eq] in environment [env] *)
513
let type_eq env in_main undefined_vars eq =
514
(*Format.eprintf "Typing.type_eq %a@." Printers.pp_node_eq eq;*)
515
  (* Check undefined variables, type lhs *)
516
  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
517
  let ty_lhs = type_expr env in_main false expr_lhs in
518
  (* Check multiple variable definitions *)
519
  let define_var id uvars =
520
    if ISet.mem id uvars
521
    then ISet.remove id uvars
522
    else raise (Error (eq.eq_loc, Already_defined id))
523
  in
524
  (* check assignment of declared constant, assignment of clock *)
525
  let ty_lhs =
526
    type_of_type_list
527
      (List.map2 (fun ty id ->
528
	if get_static_value ty <> None
529
	then raise (Error (eq.eq_loc, Assigned_constant id)) else
530
	match get_clock_base_type ty with
531
	| None -> ty
532
	| Some ty -> ty)
533
	 (type_list_of_type ty_lhs) eq.eq_lhs) in
534
  let undefined_vars =
535
    List.fold_left (fun uvars v -> define_var v uvars) undefined_vars eq.eq_lhs in
536
  (* Type rhs wrt to lhs type with subtyping, i.e. a constant rhs value may be assigned
537
     to a (always non-constant) lhs variable *)
538
  type_subtyping_arg env in_main false eq.eq_rhs ty_lhs;
539
  undefined_vars
540

    
541

    
542
(* [type_coreclock env ck id loc] types the type clock declaration [ck]
543
   in environment [env] *)
544
let type_coreclock env ck id loc =
545
  match ck.ck_dec_desc with
546
  | Ckdec_any | Ckdec_pclock (_,_) -> ()
547
  | Ckdec_bool cl ->
548
      let dummy_id_expr = expr_of_ident id loc in
549
      let when_expr =
550
        List.fold_left
551
          (fun expr (x, l) ->
552
                {expr_tag = new_tag ();
553
                 expr_desc= Expr_when (expr,x,l);
554
                 expr_type = new_var ();
555
                 expr_clock = Clocks.new_var true;
556
                 expr_delay = Delay.new_var ();
557
                 expr_loc=loc;
558
		 expr_annot = None})
559
          dummy_id_expr cl
560
      in
561
      ignore (type_expr env false false when_expr)
562

    
563
let rec check_type_declaration loc cty =
564
 match cty with
565
 | Tydec_clock ty
566
 | Tydec_array (_, ty) -> check_type_declaration loc ty
567
 | Tydec_const tname   ->
568
   if not (Hashtbl.mem type_table cty)
569
   then raise (Error (loc, Unbound_type tname));
570
 | _                   -> ()
571

    
572
let type_var_decl vd_env env vdecl =
573
(*Format.eprintf "Typing.type_var_decl START %a:%a@." Printers.pp_var vdecl Printers.print_dec_ty vdecl.var_dec_type.ty_dec_desc;*)
574
  check_type_declaration vdecl.var_loc vdecl.var_dec_type.ty_dec_desc;
575
  let eval_const id = Types.get_static_value (Env.lookup_value env id) in
576
  let type_dim d =
577
    begin
578
      type_subtyping_arg (env, vd_env) false true (expr_of_dimension d) Type_predef.type_int;
579

    
580
      Dimension.eval Basic_library.eval_env eval_const d;
581
    end in
582
  let ty = type_coretype type_dim vdecl.var_dec_type.ty_dec_desc in
583

    
584
  let ty_static =
585
    if vdecl.var_dec_const
586
    then  Type_predef.type_static (Dimension.mkdim_var ()) ty
587
    else ty in
588
  (match vdecl.var_dec_value with
589
  | None   -> ()
590
  | Some v -> type_subtyping_arg (env, vd_env) false ~sub:false true v ty_static);
591
  try_unify ty_static vdecl.var_type vdecl.var_loc;
592
  let new_env = Env.add_value env vdecl.var_id ty_static in
593
  type_coreclock (new_env,vd_env) vdecl.var_dec_clock vdecl.var_id vdecl.var_loc;
594
(*Format.eprintf "END %a@." Types.print_ty ty_static;*)
595
  new_env
596

    
597
let type_var_decl_list vd_env env l =
598
  List.fold_left (type_var_decl vd_env) env l
599

    
600
let type_of_vlist vars =
601
  let tyl = List.map (fun v -> v.var_type) vars in
602
  type_of_type_list tyl
603

    
604
let add_vdecl vd_env vdecl =
605
 if List.exists (fun v -> v.var_id = vdecl.var_id) vd_env
606
 then raise (Error (vdecl.var_loc, Already_bound vdecl.var_id))
607
 else vdecl::vd_env
608

    
609
let check_vd_env vd_env =
610
  ignore (List.fold_left add_vdecl [] vd_env)
611

    
612
(** [type_node env nd loc] types node [nd] in environment env. The
613
    location is used for error reports. *)
614
let type_node env nd loc =
615
  let is_main = nd.node_id = !Options.main_node in
616
  let vd_env_ol = nd.node_outputs@nd.node_locals in
617
  let vd_env =  nd.node_inputs@vd_env_ol in
618
  check_vd_env vd_env;
619
  let init_env = env in
620
  let delta_env = type_var_decl_list vd_env init_env nd.node_inputs in
621
  let delta_env = type_var_decl_list vd_env delta_env nd.node_outputs in
622
  let delta_env = type_var_decl_list vd_env delta_env nd.node_locals in
623
  let new_env = Env.overwrite env delta_env in
624
  let undefined_vars_init =
625
    List.fold_left
626
      (fun uvs v -> ISet.add v.var_id uvs)
627
      ISet.empty vd_env_ol in
628
  let undefined_vars =
629
    List.fold_left (type_eq (new_env, vd_env) is_main) undefined_vars_init (get_node_eqs nd)
630
  in
631
  (* Typing asserts *)
632
  List.iter (fun assert_ ->
633
    let assert_expr =  assert_.assert_expr in
634
    type_subtyping_arg (new_env, vd_env) is_main false assert_expr Type_predef.type_bool
635
  )  nd.node_asserts;
636
  
637
  (* check that table is empty *)
638
  let local_consts = List.fold_left (fun res vdecl -> if vdecl.var_dec_const then ISet.add vdecl.var_id res else res) ISet.empty nd.node_locals in
639
  let undefined_vars = ISet.diff undefined_vars local_consts in
640
  if (not (ISet.is_empty undefined_vars)) then
641
    raise (Error (loc, Undefined_var undefined_vars));
642
  let ty_ins = type_of_vlist nd.node_inputs in
643
  let ty_outs = type_of_vlist nd.node_outputs in
644
  let ty_node = new_ty (Tarrow (ty_ins,ty_outs)) in
645
  generalize ty_node;
646
  (* TODO ? Check that no node in the hierarchy remains polymorphic ? *)
647
  nd.node_type <- ty_node;
648
  Env.add_value env nd.node_id ty_node
649

    
650
let type_imported_node env nd loc =
651
  let new_env = type_var_decl_list nd.nodei_inputs env nd.nodei_inputs in
652
  let vd_env = nd.nodei_inputs@nd.nodei_outputs in
653
  check_vd_env vd_env;
654
  ignore(type_var_decl_list vd_env new_env nd.nodei_outputs);
655
  let ty_ins = type_of_vlist nd.nodei_inputs in
656
  let ty_outs = type_of_vlist nd.nodei_outputs in
657
  let ty_node = new_ty (Tarrow (ty_ins,ty_outs)) in
658
  generalize ty_node;
659
(*
660
  if (is_polymorphic ty_node) then
661
    raise (Error (loc, Poly_imported_node nd.nodei_id));
662
*)
663
  let new_env = Env.add_value env nd.nodei_id ty_node in
664
  nd.nodei_type <- ty_node;
665
  new_env
666

    
667
let type_top_const env cdecl =
668
  let ty = type_const cdecl.const_loc cdecl.const_value in
669
  let d =
670
    if is_dimension_type ty
671
    then dimension_of_const cdecl.const_loc cdecl.const_value
672
    else Dimension.mkdim_var () in
673
  let ty = Type_predef.type_static d ty in
674
  let new_env = Env.add_value env cdecl.const_id ty in
675
  cdecl.const_type <- ty;
676
  new_env
677

    
678
let type_top_consts env clist =
679
  List.fold_left type_top_const env clist
680

    
681
let rec type_top_decl env decl =
682
  match decl.top_decl_desc with
683
  | Node nd -> (
684
      try
685
	type_node env nd decl.top_decl_loc
686
      with Error (loc, err) as exc -> (
687
	(*if !Options.global_inline then
688
	  Format.eprintf "Type error: failing node@.%a@.@?"
689
	    Printers.pp_node nd
690
	;*)
691
	raise exc)
692
  )
693
  | ImportedNode nd ->
694
      type_imported_node env nd decl.top_decl_loc
695
  | Const c ->
696
      type_top_const env c
697
  | TypeDef _ -> List.fold_left type_top_decl env (consts_of_enum_type decl)
698
  | Open _  -> env
699

    
700
let type_prog env decls =
701
try
702
  List.fold_left type_top_decl env decls
703
with Failure _ as exc -> raise exc
704

    
705
(* Once the Lustre program is fully typed,
706
   we must get back to the original description of dimensions,
707
   with constant parameters, instead of unifiable internal variables. *)
708

    
709
(* The following functions aims at 'unevaluating' dimension expressions occuring in array types,
710
   i.e. replacing unifiable second_order variables with the original static parameters.
711
   Once restored in this formulation, dimensions may be meaningfully printed.
712
*)
713
let uneval_vdecl_generics vdecl =
714
 if vdecl.var_dec_const
715
 then
716
   match get_static_value vdecl.var_type with
717
   | None   -> (Format.eprintf "internal error: %a@." Types.print_ty vdecl.var_type; assert false)
718
   | Some d -> Dimension.uneval vdecl.var_id d
719

    
720
let uneval_node_generics vdecls =
721
  List.iter uneval_vdecl_generics vdecls
722

    
723
let uneval_top_generics decl =
724
  match decl.top_decl_desc with
725
  | Node nd ->
726
      uneval_node_generics (nd.node_inputs @ nd.node_outputs)
727
  | ImportedNode nd ->
728
      uneval_node_generics (nd.nodei_inputs @ nd.nodei_outputs)
729
  | Const _
730
  | TypeDef _
731
  | Open _  -> ()
732

    
733
let uneval_prog_generics prog =
734
 List.iter uneval_top_generics prog
735

    
736
let rec get_imported_symbol decls id =
737
  match decls with
738
  | [] -> assert false
739
  | decl::q ->
740
     (match decl.top_decl_desc with
741
      | ImportedNode nd when id = nd.nodei_id && decl.top_decl_itf -> decl
742
      | Const c when id = c.const_id && decl.top_decl_itf -> decl
743
      | TypeDef _ -> get_imported_symbol (consts_of_enum_type decl @ q) id
744
      | _ -> get_imported_symbol q id)
745

    
746
let check_env_compat header declared computed = 
747
  uneval_prog_generics header;
748
  Env.iter declared (fun k decl_type_k ->
749
    let loc = (get_imported_symbol header k).top_decl_loc in 
750
    let computed_t =
751
      instantiate (ref []) (ref []) 
752
	(try Env.lookup_value computed k
753
	 with Not_found -> raise (Error (loc, Declared_but_undefined k))) in
754
    (*Types.print_ty Format.std_formatter decl_type_k;
755
      Types.print_ty Format.std_formatter computed_t;*)
756
    try_unify ~sub:true ~semi:true decl_type_k computed_t loc
757
  )
758

    
759
let check_typedef_top decl =
760
(*Format.eprintf "check_typedef %a@." Printers.pp_short_decl decl;*)
761
(*Format.eprintf "%a" Printers.pp_typedef (typedef_of_top decl);*)
762
(*Format.eprintf "%a" Corelang.print_type_table ();*)
763
  match decl.top_decl_desc with
764
  | TypeDef ty ->
765
     let owner = decl.top_decl_owner in
766
     let itf = decl.top_decl_itf in
767
     let decl' =
768
       try Hashtbl.find type_table (Tydec_const (typedef_of_top decl).tydef_id)
769
       with Not_found -> raise (Error (decl.top_decl_loc, Declared_but_undefined ("type "^ ty.tydef_id))) in
770
     let owner' = decl'.top_decl_owner in
771
(*Format.eprintf "def owner = %s@.decl owner = %s@." owner' owner;*)
772
     let itf' = decl'.top_decl_itf in
773
     (match decl'.top_decl_desc with
774
     | Const _ | Node _ | ImportedNode _ -> assert false
775
     | TypeDef ty' when coretype_equal ty'.tydef_desc ty.tydef_desc && owner' = owner && itf && (not itf') -> ()
776
     | _ -> raise (Error (decl.top_decl_loc, Type_mismatch ty.tydef_id)))
777
  | _  -> ()
778

    
779
let check_typedef_compat header =
780
  List.iter check_typedef_top header
781

    
782
(* Local Variables: *)
783
(* compile-command:"make -C .." *)
784
(* End: *)