CristalCaveGem » LustreC

(********************************************************************)

(*                                                                  *)

(*  The LustreC compiler toolset   /  The LustreC Development Team  *)

(*  Copyright 2012 -    --   ONERA - CNRS - INPT                    *)

(*                                                                  *)

(*  LustreC is free software, distributed WITHOUT ANY WARRANTY      *)

(*  under the terms of the GNU Lesser General Public License        *)

(*  version 2.1.                                                    *)

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open LustreSpec

open Corelang

type error =

| Stateful_kwd   of ident

| Stateful_imp   of ident

| Stateful_ext_C of ident

exception Error of Location.t * error

let rec check_expr expr =

  match expr.expr_desc with

  | Expr_const _ 

  | Expr_ident _ -> true

  | Expr_tuple el

  | Expr_array el -> List.for_all check_expr el

  | Expr_access (e1, _)

  | Expr_power (e1, _) -> check_expr e1

  | Expr_ite (c, t, e) -> check_expr c && check_expr t && check_expr e

  | Expr_arrow _

  | Expr_fby _

  | Expr_pre _ -> false

  | Expr_when (e', i, l)-> check_expr e'

  | Expr_merge (i, hl) -> List.for_all (fun (t, h) -> check_expr h) hl 

  | Expr_appl (i, e', i') ->

    check_expr e' &&

      (Basic_library.is_stateless_fun i || check_node (node_from_name i))

and compute_node nd =

 List.for_all (fun eq -> check_expr eq.eq_rhs) (get_node_eqs nd)

and check_node td =

  match td.top_decl_desc with 

  | Node nd         -> (

    match nd.node_stateless with

    | None     -> 

      begin

	let stateless = compute_node nd in

	nd.node_stateless <- Some stateless;

	if nd.node_dec_stateless && (not stateless)

	then raise (Error (td.top_decl_loc, Stateful_kwd nd.node_id))

	else (nd.node_dec_stateless <- stateless; stateless)

      end

    | Some stl -> stl)

  | ImportedNode nd ->

     begin

       (if nd.nodei_prototype = Some "C" && not nd.nodei_stateless

	then raise (Error (td.top_decl_loc, Stateful_ext_C nd.nodei_id)));

       nd.nodei_stateless

     end

  | _ -> true

let check_prog decls =

  List.iter (fun td -> ignore (check_node td)) decls

let force_prog decls =

  let force_node td =

    match td.top_decl_desc with 

    | Node nd         -> (

      nd.node_dec_stateless <- false;

      nd.node_stateless <- Some false)

    | _ -> ()

  in

  List.iter (fun td -> ignore (force_node td)) decls

let check_compat_decl decl =

 match decl.top_decl_desc with

 | ImportedNode nd ->

   let td = Corelang.node_from_name nd.nodei_id in

   (match td.top_decl_desc with

   | Node nd' -> let stateless = check_node td in

		 if nd.nodei_stateless && (not stateless)

		 then raise (Error (td.top_decl_loc, Stateful_imp nd.nodei_id))

		 else nd'.node_dec_stateless <- nd.nodei_stateless

   | _        -> assert false)

 | Node _          -> assert false

 | _               -> ()

let check_compat header =

  List.iter check_compat_decl header

let pp_error fmt err =

  match err with

  | Stateful_kwd nd ->

     Format.fprintf fmt

       "node %s should be stateless but is actually stateful.@."

       nd

  | Stateful_imp nd ->

     Format.fprintf fmt

       "node %s is declared stateless but is actually stateful.@."

       nd

  | Stateful_ext_C nd ->

     Format.fprintf fmt

       "node %s with declared prototype C cannot be stateful, it has to be a function.@."

       nd

(* Local Variables: *)

(* compile-command:"make -C .." *)

(* End: *)