CristalCaveGem » LustreC

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(*                                                                  *)

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

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

(*                                                                  *)

(*  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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(*  This file was originally from the Prelude compiler              *)

(*                                                                  *) 

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(** Clocks definitions and a few utility functions on clocks. *)

open Utils

open Format

(* type clock_set = *)

(*     CSet_all *)

(*   | CSet_pck of int*rat *)

(* Clock carriers basically correspond to the "c" in "x when c" *)

type carrier_desc =

  | Carry_const of ident

  | Carry_name

  | Carry_var

  | Carry_link of carrier_expr

(* Carriers are scoped, to detect clock extrusion. In other words, we

   check the scope of a clock carrier before generalizing it. *)

and carrier_expr =

    {mutable carrier_desc: carrier_desc;

     mutable carrier_scoped: bool;

     carrier_id: int}

    {mutable cdesc: clock_desc;

     mutable cscoped: bool;

     cid: int}

(* pck stands for periodic clock. Easier not to separate pck from other clocks *)

and clock_desc =

  | Carrow of clock_expr * clock_expr

  | Ctuple of clock_expr list

  | Con of clock_expr * carrier_expr * ident

  (* | Pck_down of clock_expr * int *)

  (* | Pck_phase of clock_expr * rat *)

  (* | Pck_const of int * rat *)

  | Cvar (* of clock_set *) (* Monomorphic clock variable *)

  | Cunivar (* of clock_set *) (* Polymorphic clock variable *)

  | Ccarrying of carrier_expr * clock_expr

type error =

  | Clock_clash of clock_expr * clock_expr

  (* | Clock_set_mismatch of clock_expr * clock_set *)

  | Invalid_imported_clock of clock_expr

  | Invalid_const of clock_expr

  | Factor_zero

  | Carrier_mismatch of carrier_expr * carrier_expr

  | Carrier_extrusion of clock_expr * carrier_expr

  | Clock_extrusion of clock_expr * clock_expr

exception Unify of clock_expr * clock_expr

exception Mismatch of carrier_expr * carrier_expr

exception Scope_carrier of carrier_expr

exception Scope_clock of clock_expr

exception Error of Location.t * error

 (* (if cr.carrier_scoped then fprintf fmt "[%t]" else fprintf fmt "%t") (fun fmt -> *)

  match cr.carrier_desc with

  | Carry_const id -> fprintf fmt "%s" id

  | Carry_name ->

      fprintf fmt "_%s" (name_of_carrier cr.carrier_id)

  | Carry_var ->

    fprintf fmt "'%s" (name_of_carrier cr.carrier_id)

  | Carry_link cr' ->

    print_carrier fmt cr'

(* Simple pretty-printing, performs no simplifications. Linear

   complexity. For debug mainly. *)

let rec print_ck_long fmt ck =

  match ck.cdesc with

  | Carrow (ck1,ck2) ->

    fprintf fmt "(%a)"

      (fprintf_list ~sep:" * " print_ck_long) cklist

  | Con (ck,c,l) ->

    fprintf fmt "%a on %s(%a)" print_ck_long ck l print_carrier c

  | Cunivar -> fprintf fmt "'%i" ck.cid 

    fprintf fmt "link %a" print_ck_long ck'

  | Ccarrying (cr,ck') ->

    fprintf fmt "(%a:%a)" print_carrier cr print_ck_long ck'

  { cdesc = Clink bottom; cid = -666; cscoped = false }

  incr new_id; {cdesc=desc; cid = !new_id; cscoped = scoped}

let new_carrier_id = ref (-1)

let new_carrier desc scoped =

  incr new_carrier_id; {carrier_desc = desc;

                        carrier_id = !new_carrier_id;

                        carrier_scoped = scoped}

let new_carrier_name () =

  new_carrier Carry_name true

let rec repr =

  function

      {cdesc=Clink ck'} ->

        repr ck'

    | ck -> ck

let rec carrier_repr =

  function {carrier_desc = Carry_link cr'} -> carrier_repr cr'

    | cr -> cr

 match (repr ck).cdesc with

 | Ccarrying (cr, _) -> Some cr

 | _                 -> None

  match (carrier_repr cr).carrier_desc with

  | Carry_const id -> { cr with carrier_desc = Carry_const (rename id) }

  | _              -> (Format.eprintf "internal error: Clocks.rename_carrier_static %a@." print_carrier cr; assert false)

let rec rename_static rename ck =

 match (repr ck).cdesc with

 | Ccarrying (cr, ck') -> { ck with cdesc = Ccarrying (rename_carrier_static rename cr, rename_static rename ck') }

 | Con (ck', cr, l)    -> { ck with cdesc = Con (rename_static rename ck', rename_carrier_static rename cr, l) }

 | _                   -> ck

 match ck.cdesc with

 | _                  -> ck

(* Removes all links in a clock. Only used for clocks

   simplification though. *)

  | Carrow (ck1,ck2) ->

  | Cvar | Cunivar -> ck

  | Clink ck' -> simplify ck'

  | Ccarrying (cr,ck') -> new_ck (Ccarrying (cr, simplify ck')) ck.cscoped

(** Splits ck into the [lhs,rhs] of an arrow clock. Expects an arrow clock

    (ensured by language syntax) *)

let split_arrow ck =

  match (repr ck).cdesc with

  | Carrow (cin,cout) -> cin,cout

  | _ -> failwith "Internal error: not an arrow clock"

(** Returns the clock corresponding to a clock list. *)

let clock_of_clock_list ckl =

  if (List.length ckl) > 1 then

    new_ck (Ctuple ckl) true

  else

    List.hd ckl

let clock_list_of_clock ck =

 match (repr ck).cdesc with

 | Ctuple cl -> cl

 | _         -> [ck]

 clock_of_clock_list (List.map (fun ck -> new_ck (Con (ck,cr,l)) true) (clock_list_of_clock ck))

 clock_of_clock_list (List.map (fun ck -> match (repr ck).cdesc with Con(ck',_,_) -> ck' | _ -> assert false) (clock_list_of_clock ck))

  let ck = repr ck in

  match ck.cdesc with

  | Ctuple cklist -> List.hd cklist

  | Ccarrying (_,_) -> ck

(** [is_polymorphic ck] returns true if [ck] is polymorphic. *)

let rec is_polymorphic ck =

  match ck.cdesc with

  | Ctuple ckl -> List.exists (fun c -> is_polymorphic c) ckl

  | Con (ck',_,_) -> is_polymorphic ck'

  | Ccarrying (_,ck') -> is_polymorphic ck'

(** [constrained_vars_of_clock ck] returns the clock variables subject

    to sub-typing constraints appearing in clock [ck]. Removes duplicates *)

(* Used mainly for debug, non-linear complexity. *)

let rec constrained_vars_of_clock ck =

  let rec aux vars ck =

    match ck.cdesc with

        let l = aux vars ck1 in

        aux l ck2

    | Ctuple ckl ->

        List.fold_left

          (fun acc ck' -> aux acc ck') 

          vars ckl

    | Con (ck',_,_) -> aux vars ck'

    | Ccarrying (_,ck') -> aux vars ck'

  in

  aux [] ck

  match (carrier_repr cr1).carrier_desc, (carrier_repr cr2).carrier_desc with

 | Carry_const id1, Carry_const id2 -> id1 = id2

 | _                                -> cr1.carrier_id = cr2.carrier_id

 (repr ck1).cid = (repr ck2).cid

let rec root ck =

  match ck.cdesc with

  | Con (ck',_,_) | Clink ck' | Ccarrying (_,ck') -> root ck'

let rec branch ck =

  let rec branch ck acc =

    match (repr ck).cdesc with

    | Ccarrying (_, ck) -> branch ck acc

    | Con (ck, cr, l)   -> branch ck ((cr, l) :: acc)

    | _                 -> acc

  in branch ck [];;

 List.fold_left (fun ck (cr,l) -> new_ck (Con (ck, cr, l)) true) r br

(* Computes the (longest) common prefix of two branches *)

let rec common_prefix br1 br2 =

 match br1, br2 with

 | []          , _

 | _           , []           -> []

 | (cr1,l1)::q1, (cr2,l2)::q2 ->

   if eq_carrier cr1 cr2 && (l1 = l2)

   then (cr1, l1) :: common_prefix q1 q2

   else []

let rec disjoint_branches br1 br2 =

 match br1, br2 with

 | []          , _

 | _           , []           -> false

(* Disjunction relation between variables based upon their static clocks. *)

let disjoint ck1 ck2 =

  match cvar.cdesc with

      if cvar.cscoped

      then

      else

 *)

      if cvar.cscoped

      then

      else

 *)

  | _ -> failwith "Internal error print_cvar"

(* Nice pretty-printing. Simplifies expressions before printing them. Non-linear

   complexity. *)

let print_ck fmt ck =

  let rec aux fmt ck =

    match ck.cdesc with

    | Carrow (ck1,ck2) ->

      fprintf fmt "(%a)" 

	(fprintf_list ~sep:" * " aux) cklist

    | Con (ck,c,l) ->

      fprintf fmt "%a on %s(%a)" aux ck l print_carrier c

      if ck.cscoped

      then

*)

      if ck.cscoped

      then

        fprintf fmt "['%s]" (name_of_type ck.cid)

      else

*)

        fprintf fmt "'%s" (name_of_type ck.cid)

    | Clink ck' ->

        aux fmt ck'

    | Ccarrying (cr,ck') ->

      fprintf fmt "(%a:%a)" print_carrier cr aux ck'

  in

  let cvars = constrained_vars_of_clock ck in

  aux fmt ck;

  if cvars <> [] then

    fprintf fmt " (where %a)"

      (fprintf_list ~sep:", " print_cvar) cvars

let rec print_ck_suffix fmt ck =

  match ck.cdesc with

  | Carrow _

  | Ctuple _

  | Cunivar    -> ()

       print_ck_suffix fmt ck

     else

       fprintf fmt "%a when %s(%a)" print_ck_suffix ck l print_carrier c

    print_ck_suffix fmt ck'

  | Ccarrying (cr,ck') ->

    fprintf fmt "%a" print_ck_suffix ck'

  | Clock_clash (ck1,ck2) ->

      reset_names ();

      fprintf fmt "Expected clock %a, got clock %a@."

      print_ck ck1

      print_ck ck2

  | Carrier_mismatch (cr1, cr2) ->

     fprintf fmt "Name clash. Expected clock %a, got clock %a@."

       print_carrier cr1

       print_carrier cr2

  | Cannot_be_polymorphic ck ->

      reset_names ();

    fprintf fmt "The main node cannot have a polymorphic clock: %a@."

      print_ck ck

  | Invalid_imported_clock ck ->

      reset_names ();

    fprintf fmt "Not a valid imported node clock: %a@."

      print_ck ck

  | Invalid_const ck ->

      reset_names ();

    fprintf fmt "Clock %a is not a valid periodic clock@."

      print_ck ck;

  | Factor_zero ->

    fprintf fmt "Cannot apply clock transformation with factor 0@."

  | Carrier_extrusion (ck,cr) ->

    fprintf fmt "This node has clock@.%a@.It is invalid as %a escapes its scope@."

      print_ck ck

      print_carrier cr

  | Clock_extrusion (ck_node,ck) ->

    fprintf fmt "This node has clock@.%a@.It is invalid as %a escapes its scope@."

      print_ck ck_node

      print_ck ck

  | Carry_const id -> id

  | Carry_name

  | Carry_var

  | Carry_link _ -> (Format.eprintf "internal error: const_of_carrier %a@." print_carrier cr; assert false) (* TODO check this Xavier *)

  match cr.carrier_desc with

  | Carry_var -> cr.carrier_desc <- Carry_const const

(* Used in rename functions in Corelang. We have to propagate the renaming to

   ids of variables clocking the signals *)

(* Carrier are not renamed. They corresponds to enumerated type constants *)

(*

let rec rename_carrier f c =

  { c with carrier_desc = rename_carrier_desc fvar c.carrier_desc }

and rename_carrier_desc f 

let re = rename_carrier f

  match cd with

  | Carry_const id -> Carry_const (f id)

  | Carry_link ce -> Carry_link (re ce)

  | _ -> cd

*)

let rec rename_clock_expr fvar c =

  { c with cdesc = rename_clock_desc fvar c.cdesc }

and rename_clock_desc fvar cd =

  let re = rename_clock_expr fvar in

  match cd with

  | Carrow (c1, c2) -> Carrow (re c1, re c2)

  | Ctuple cl -> Ctuple (List.map re cl)

  | Con (c1, car, id) -> Con (re c1, car, fvar id)

  | Cvar 

  | Cunivar -> cd

  | Clink c -> Clink (re c)

  | Ccarrying (car, c) -> Ccarrying (car, re c)

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

(* End: *)