CristalCaveGem » LustreC

open Lustre_types

open Corelang

open Log

module IdSet = Set.Make (struct

  type t = expr * int

  let compare = compare

end)

let inout_vars = ref []

(* This was used to add inout variables in the final signature. May have to be

   reactivated later *)

(* let print_tautology_var fmt v = *)

(*   match (Types.repr v.var_type).Types.tdesc with *)

(*   | Types.Tbool -> Format.fprintf fmt "(%s or not %s)" v.var_id v.var_id *)

(* | Types.Tint -> Format.fprintf fmt "(%s > 0 or %s <= 0)" v.var_id v.var_id *)

(* | Types.Treal -> Format.fprintf fmt "(%s > 0 or %s <= 0)" v.var_id v.var_id *)

(* | _ -> Format.fprintf fmt "(true)" *)

(* let print_path arg = match !inout_vars with *)

(*   | [] -> Format.printf "%t@." arg   *)

(* | l -> Format.printf "%t and %a@." arg (Utils.fprintf_list ~sep:" and " (fun

   fmt elem -> print_tautology_var fmt elem)) l *)

let rel_op = [ "="; "!="; "<"; "<="; ">"; ">=" ]

(* Used when we were printing the expression directly. Now we are constructing

   them as regular expressions.

   let rec print_pre fmt nb_pre = if nb_pre <= 0 then () else ( Format.fprintf

   fmt "pre "; print_pre fmt (nb_pre-1) ) *)

let mk_pre n e = if n <= 0 then e else mkexpr e.expr_loc (Expr_pre e)

(* let combine2 f sub1 sub2 = let elem_e1 = List.fold_right IdSet.add (List.map

   fst sub1) IdSet.empty in let elem_e2 = List.fold_right IdSet.add (List.map

   fst sub2) IdSet.empty in let common = IdSet.inter elem_e1 elem_e2 in let

   sub1_filtered = List.filter (fun (v, _) -> not (IdSet.mem v common)) sub1 in

   let sub2_filtered = List.filter (fun (v, _) -> not (IdSet.mem v common)) sub2

   in (List.map (fun (v, negv) -> (v, f negv e2)) sub1_filtered) @ (List.map

   (fun (v, negv) -> (v, f e1 negv)) sub2_filtered) @ (List.map (fun v -> (v,

   {expr with expr_desc = Expr_arrow(List.assoc v sub1, List.assoc v sub2)})

   (IdSet.elements common)) ) *)

let rec select (v : expr * int) (active : bool list)

    (modified : ((expr * int) * expr) list list) (orig : expr list) =

  match active, modified, orig with

  | true :: active_tl, e :: modified_tl, _ :: orig_tl ->

    List.assoc v e :: select v active_tl modified_tl orig_tl

  | false :: active_tl, _ :: modified_tl, e :: orig_tl ->

    e :: select v active_tl modified_tl orig_tl

  | [], [], [] ->

    []

  | _ ->

    assert false

let combine (f : expr list -> expr) subs orig : ((expr * int) * expr) list =

  let elems =

    List.map

      (fun sub_i -> List.fold_right IdSet.add (List.map fst sub_i) IdSet.empty)

      subs

  in

  let all = List.fold_right IdSet.union elems IdSet.empty in

  List.map

    (fun v ->

      let active_subs = List.map (IdSet.mem v) elems in

      v, f (select v active_subs subs orig))

    (IdSet.elements all)

(* In a previous version, the printer was introducing fake description, ie

   tautologies, over inout variables to make sure they were not suppresed by

   some other algorithms *)

(* Takes the variable on which these coverage criteria will apply, as well as

   the expression and its negated version. Returns the expr and the variable

   expression, as well as the two new boolean expressions descibing the two

   associated modes. *)

let mcdc_var vi_as_expr nb_elems expr expr_neg_vi =

  let loc = expr.expr_loc in

  let not_vi_as_expr = mkpredef_call loc "not" [ vi_as_expr ] in

  let expr1, expr2 =

    if nb_elems > 1 then

      let changed_expr = mkpredef_call loc "!=" [ expr; expr_neg_vi ] in

      let expr1 = mkpredef_call loc "&&" [ vi_as_expr; changed_expr ] in

      let expr2 = mkpredef_call loc "&&" [ not_vi_as_expr; changed_expr ] in

      expr1, expr2

    else vi_as_expr, not_vi_as_expr

  in

  (expr, vi_as_expr), [ true, expr1; false, expr2 ]

(* expr1 corresponds to atom true while expr2 corresponds to atom false *)

(* Format.printf "%a@." Printers.pp_expr expr1;  *)

(* print_path (fun fmt -> Format.fprintf fmt "%a and (%a != %a)" *)

(*   Printers.pp_expr vi_as_expr *)

(*   Printers.pp_expr expr (\*v*\) *)

(*   Printers.pp_expr expr_neg_vi); *)

(* Format.printf "%a@." Printers.pp_expr expr2;  *)

(* print_path (fun fmt -> Format.fprintf fmt "(not %a) and (%a != %a)" *)

(*   Printers.pp_expr vi_as_expr *)

(*   Printers.pp_expr expr (\*v*\) *)

(*   Printers.pp_expr expr_neg_vi) *)

let rec compute_neg_expr cpt_pre (expr : Lustre_types.expr) =

  let neg_list l =

    List.fold_right

      (fun e (vl, el) ->

        let vl', e' = compute_neg_expr cpt_pre e in

        vl' @ vl, e' :: el)

      l ([], [])

  in

  match expr.expr_desc with

  | Expr_tuple l ->

    let vl, neg = neg_list l in

    vl, combine (fun l' -> { expr with expr_desc = Expr_tuple l' }) neg l

  | Expr_ite (i, t, e) when Types.is_bool_type t.expr_type ->

    let list = [ i; t; e ] in

    let vl, neg = neg_list list in

    ( vl,

      combine

        (fun l ->

          match l with

          | [ i'; t'; e' ] ->

            { expr with expr_desc = Expr_ite (i', t', e') }

          | _ ->

            assert false)

        neg list )

  | Expr_ite (i, t, e) ->

    (* We return the guard as a new guard *)

    let vl = gen_mcdc_cond_guard i in

    let list = [ i; t; e ] in

    let vl', neg = neg_list list in

    ( vl @ vl',

      combine

        (fun l ->

          match l with

          | [ i'; t'; e' ] ->

            { expr with expr_desc = Expr_ite (i', t', e') }

          | _ ->

            assert false)

        neg list )

  | Expr_arrow (e1, e2) ->

    let vl1, e1' = compute_neg_expr cpt_pre e1 in

    let vl2, e2' = compute_neg_expr cpt_pre e2 in

    ( vl1 @ vl2,

      combine

        (fun l ->

          match l with

          | [ x; y ] ->

            { expr with expr_desc = Expr_arrow (x, y) }

          | _ ->

            assert false)

        [ e1'; e2' ] [ e1; e2 ] )

  | Expr_pre e ->

    let vl, e' = compute_neg_expr (cpt_pre + 1) e in

    ( vl,

      List.map (fun (v, negv) -> v, { expr with expr_desc = Expr_pre negv }) e'

    )

  | Expr_appl (op_name, _, _) when List.mem op_name rel_op ->

    [], [ (expr, cpt_pre), mkpredef_call expr.expr_loc "not" [ expr ] ]

  | Expr_appl (op_name, args, r) ->

    let vl, args' = compute_neg_expr cpt_pre args in

    ( vl,

      List.map

        (fun (v, negv) ->

          v, { expr with expr_desc = Expr_appl (op_name, negv, r) })

        args' )

  | Expr_ident _ when Types.is_bool_type expr.expr_type ->

    [], [ (expr, cpt_pre), mkpredef_call expr.expr_loc "not" [ expr ] ]

  | _ ->

    [] (* empty vars *), []

and gen_mcdc_cond_var v expr =

  report ~level:1 (fun fmt ->

      Format.fprintf fmt

        ".. Generating MC/DC cond for boolean flow %s and expression %a@." v

        Printers.pp_expr expr);

  let vl, leafs_n_neg_expr = compute_neg_expr 0 expr in

  let len = List.length leafs_n_neg_expr in

  if len >= 1 then

    List.fold_left

      (fun accu ((vi, nb_pre), expr_neg_vi) ->

        mcdc_var (mk_pre nb_pre vi) len expr expr_neg_vi :: accu)

      vl leafs_n_neg_expr

  else vl

and gen_mcdc_cond_guard expr =

  report ~level:1 (fun fmt ->

      Format.fprintf fmt ".. Generating MC/DC cond for guard %a@."

        Printers.pp_expr expr);

  let vl, leafs_n_neg_expr = compute_neg_expr 0 expr in

  let len = List.length leafs_n_neg_expr in

  if len >= 1 then

    List.fold_left

      (fun accu ((vi, nb_pre), expr_neg_vi) ->

        mcdc_var (mk_pre nb_pre vi) len expr expr_neg_vi :: accu)

      vl leafs_n_neg_expr

  else vl

let rec mcdc_expr cpt_pre expr =

  match expr.expr_desc with

  | Expr_tuple l ->

    let vl =

      List.fold_right

        (fun e accu_v ->

          let vl = mcdc_expr cpt_pre e in

          vl @ accu_v)

        l []

    in

    vl

  | Expr_ite (i, t, e) ->

    let vl_i = gen_mcdc_cond_guard i in

    let vl_t = mcdc_expr cpt_pre t in

    let vl_e = mcdc_expr cpt_pre e in

    vl_i @ vl_t @ vl_e

  | Expr_arrow (e1, e2) ->

    let vl1 = mcdc_expr cpt_pre e1 in

    let vl2 = mcdc_expr cpt_pre e2 in

    vl1 @ vl2

  | Expr_pre e ->

    let vl = mcdc_expr (cpt_pre + 1) e in

    vl

  | Expr_appl (_, args, _) ->

    let vl = mcdc_expr cpt_pre args in

    vl

  | _ ->

    []

let mcdc_var_def v expr =

  if Types.is_bool_type expr.expr_type then

    let vl = gen_mcdc_cond_var v expr in

    vl

  else

    let vl = mcdc_expr 0 expr in

    vl

let mcdc_node_eq eq =

  let vl =

    match

      ( eq.eq_lhs,

        Types.is_bool_type eq.eq_rhs.expr_type,

        (Types.repr eq.eq_rhs.expr_type).Types.tdesc,

        eq.eq_rhs.expr_desc )

    with

    | [ lhs ], true, _, _ ->

      gen_mcdc_cond_var lhs eq.eq_rhs

    | _ :: _, false, Types.Ttuple _, Expr_tuple rhs ->

      (* We iterate trough pairs, but accumulate variables aside. The resulting

         expression shall remain a tuple defintion *)

      let vl =

        List.fold_right2

          (fun lhs rhs accu ->

            let v = mcdc_var_def lhs rhs in

            (* we don't care about the expression it. We focus on the coverage

               expressions in v *)

            v @ accu)

          eq.eq_lhs rhs []

      in

      vl

    | _ ->

      mcdc_expr 0 eq.eq_rhs

  in

  vl

let mcdc_node_stmt stmt =

  match stmt with

  | Eq eq ->

    let vl = mcdc_node_eq eq in

    vl

  | Aut _ ->

    assert false

let mcdc_top_decl td =

  match td.top_decl_desc with

  | Node nd ->

    let new_coverage_exprs =

      List.fold_right

        (fun s accu_v ->

          let vl' = mcdc_node_stmt s in

          vl' @ accu_v)

        nd.node_stmts []

    in

    (* We add coverage vars as boolean internal flows. *)

    let fresh_cov_defs =

      List.flatten

        (List.map

           (fun ((_, atom), expr_l) ->

             List.map (fun (atom_valid, case) -> atom, atom_valid, case) expr_l)

           new_coverage_exprs)

    in

    let nb_total = List.length fresh_cov_defs in

    let fresh_cov_vars =

      List.mapi

        (fun i (atom, atom_valid, cov_expr) ->

          let loc = cov_expr.expr_loc in

          Format.fprintf Format.str_formatter "__cov_%i_%i" i nb_total;

          let cov_id = Format.flush_str_formatter () in

          let cov_var =

            mkvar_decl loc

              ( cov_id,

                mktyp loc Tydec_bool,

                mkclock loc Ckdec_any,

                false,

                None,

                None )

          in

          let cov_def = Eq (mkeq loc ([ cov_id ], cov_expr)) in

          cov_var, cov_def, atom, atom_valid)

        fresh_cov_defs

    in

    let fresh_vars, fresh_eqs =

      List.fold_right

        (fun (v, eq, _, _) (accuv, accueq) -> v :: accuv, eq :: accueq)

        fresh_cov_vars ([], [])

    in

    let fresh_annots =

      (* We produce two sets of annotations: PROPERTY ones for kind2, and

         regular ones to keep track of the nature of the annotations. *)

      List.map

        (fun (v, _, atom, atom_valid) ->

          let e = expr_of_vdecl v in

          let neg_ee = expr_to_eexpr (mkpredef_call e.expr_loc "not" [ e ]) in

          {

            annots =

              [

                [ "PROPERTY" ], neg_ee;

                (* Using negated property to force model-checker to produce a

                   suitable covering trace *)

                (let loc = Location.dummy_loc in

                 let valid_e =

                   let open Corelang in

                   mkexpr loc (Expr_const (const_of_bool atom_valid))

                 in

                 ( [ "coverage"; "mcdc"; v.var_id ],

                   expr_to_eexpr

                     (Corelang.expr_of_expr_list loc [ e; atom; valid_e ]) ));

              ];

            annot_loc = v.var_loc;

          })

        fresh_cov_vars

    in

    Format.printf "%i coverage criteria generated for node %s@ " nb_total

      nd.node_id;

    (* And add them as annotations --%PROPERTY: var TODO *)

    {

      td with

      top_decl_desc =

        Node

          {

            nd with

            node_locals = nd.node_locals @ fresh_vars;

            node_stmts = nd.node_stmts @ fresh_eqs;

            node_annot = nd.node_annot @ fresh_annots;

          };

    }

  | _ ->

    td

let mcdc prog =

  (* If main node is provided add silly constraints to show in/out variables in

     the path condition *)

  (if !Options.main_node <> "" then

   inout_vars :=

     let top =

       List.find

         (fun td ->

           match td.top_decl_desc with

           | Node nd when nd.node_id = !Options.main_node ->

             true

           | _ ->

             false)

         prog

     in

     match top.top_decl_desc with

     | Node nd ->

       nd.node_inputs @ nd.node_outputs

     | _ ->

       assert false);

  List.map mcdc_top_decl prog

(* Local Variables: *)

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

(* End: *)