CristalCaveGem » LustreC

open Machine_code_types

open Lustre_types

(*

open Corelang

open Machine_code_common

*)

let is_machine_statefull m = m.mmemory != [] || m.mcalls != []

(** Return true if its the arrow machine

   @param machine the machine to test

*)

let is_arrow machine = String.equal Arrow.arrow_id machine.mname.node_id

(** Extract a node from an instance.

   @param instance the instance

**)

let extract_node instance =

  let (_, (node, _)) = instance in

  match node.top_decl_desc with

    | Node nd         -> nd

    | _ -> assert false (*TODO*)

(** Extract from a machine list the one corresponding to the given instance.

      assume that the machine is in the list.

   @param machines list of all machines

   @param instance instance of a machine

   @return the machine corresponding to hte given instance

**)

let get_machine machines instance =

    let id = (extract_node instance).node_id in

    try

      List.find (function m -> m.mname.node_id=id) machines

    with

      Not_found -> assert false (*TODO*)

(** Test if two types are the same.

   @param typ1 the first type

   @param typ2 the second type

**)

let pp_eq_type typ1 typ2 = 

  let get_basic typ = match (Types.repr typ).Types.tdesc with

    | Types.Tbasic Types.Basic.Tint -> Types.Basic.Tint

    | Types.Tbasic Types.Basic.Treal -> Types.Basic.Treal

    | Types.Tbasic Types.Basic.Tbool -> Types.Basic.Tbool

    | _ -> assert false (*TODO*)

  in

  get_basic typ1 = get_basic typ2

(** Extract all the inputs and outputs.

   @param machine the machine

   @return a list of all the var_decl of a macine

**)

let get_all_vars_machine m =

  m.mmemory@m.mstep.step_inputs@m.mstep.step_outputs@m.mstatic

(** Check if a type is polymorphic.

   @param typ the type

   @return true if its polymorphic

**)

let is_Tunivar typ = (Types.repr typ).tdesc == Types.Tunivar

(** Find all polymorphic type : Types.Tunivar in a machine.

   @param machine the machine

   @return a list of id corresponding to polymorphic type

**)

let find_all_polymorphic_type m =

  let vars = get_all_vars_machine m in

  let extract id = id.var_type.tid in

  let polymorphic_type_vars =

    List.filter (function x-> is_Tunivar x.var_type) vars in

  List.sort_uniq (-) (List.map extract polymorphic_type_vars)

(** Check if a submachine is statefull.

    @param submachine a submachine

    @return true if the submachine is statefull

**)

let is_submachine_statefull submachine =

    not (snd (snd submachine)).mname.node_dec_stateless

(** Find a submachine step call in a list of instructions.

    @param ident submachine instance ident

    @param instr_list List of instruction sto search

    @return a list of pair containing input types and output types for each step call found

**)

let rec find_submachine_step_call ident instr_list =

  let search_instr instruction = 

    match instruction.instr_desc with

      | MStep (il, i, vl) when String.equal i ident -> [

        (List.map (function x-> x.value_type) vl,

            List.map (function x-> x.var_type) il)]

      | MBranch (_, l) -> List.flatten

          (List.map (function x, y -> find_submachine_step_call ident y) l)

      | _ -> []

  in

  List.flatten (List.map search_instr instr_list)

(** Check that two types are the same.

   @param t1 a type

   @param t2 an other type

   @param return true if the two types are Tbasic or Tunivar and equal

**)

let rec check_type_equal (t1:Types.type_expr) (t2:Types.type_expr) =

  match (Types.repr t1).Types.tdesc, (Types.repr t2).Types.tdesc with

    | Types.Tbasic x, Types.Tbasic y -> x = y

    | Types.Tunivar,  Types.Tunivar  -> t1.tid = t2.tid

    | Types.Ttuple l, _ -> assert (List.length l = 1); check_type_equal (List.hd l) t2

    | _, Types.Ttuple l -> assert (List.length l = 1); check_type_equal t1 (List.hd l)

    | Types.Tstatic (_, t), _ -> check_type_equal t t2

    | _, Types.Tstatic (_, t) -> check_type_equal t1 t

    | _ -> assert false

(** Extend a substitution to unify the two given types. Only the

  first type can be polymorphic.

    @param subsitution the base substitution

    @param type_poly the type which can be polymorphic

    @param typ the type to match type_poly with

**)

let unification (substituion:(int*Types.type_expr) list) ((type_poly:Types.type_expr), (typ:Types.type_expr)) =

  assert(not (is_Tunivar typ));

  (* If type_poly is polymorphic *)

  if is_Tunivar type_poly then

    (* If a subsitution exists for it *)

    if List.mem_assoc type_poly.tid substituion then

    begin

      (* We check that the type corresponding to type_poly in the subsitution

         match typ *)

      (try

        assert(check_type_equal (List.assoc type_poly.tid substituion) typ)

      with

        Not_found -> assert false);

      (* We return the original substituion, it is already correct *)

      substituion

    end

    (* If type_poly is not in the subsitution *)

    else

      (* We add it to the substituion *)

      (type_poly.tid, typ)::substituion

  (* iftype_poly is not polymorphic *)

  else

  begin

    (* We check that type_poly and typ are the same *)

    assert(check_type_equal type_poly typ);

    (* We return the original substituion, it is already correct *)

    substituion

  end

(** Check that two calls are equal. A call is

  a pair of list of types, the inputs and the outputs.

   @param calls a list of pair of list of types

   @param return true if the two pairs are equal

**)

let check_call_equal (i1, o1) (i2, o2) =

  (List.for_all2 check_type_equal i1 i2)

    && (List.for_all2 check_type_equal i1 i2)

(** Check that all the elements of list of calls are equal to one.

  A call is a pair of list of types, the inputs and the outputs.

   @param call a pair of list of types

   @param calls a list of pair of list of types

   @param return true if all the elements are equal

**)

let check_calls call calls =

  List.for_all (check_call_equal call) calls

(** Extract from a subinstance that can have polymorphic type the instantiation

    of all its polymorphic type instanciation for a given machine. It searches

    the step calls and extract a substitution for all polymorphic type from

    it.

   @param machine the machine which instantiate the subinstance

   @param ident the identifier of the instance which permits to find the step call

   @param submachine the machine corresponding to the subinstance

   @return the correspondance between polymorphic type id and their instantiation

**)

let get_substitution machine ident submachine =

  (* extract the calls to submachines from the machine *)

  let calls = find_submachine_step_call ident machine.mstep.step_instrs in

  (* extract the first call  *)

  let call = match calls with

              (* assume that there is always one call to a subinstance *)

              | []    -> assert(false)

              | h::t  -> h in

  (* assume that all the calls to a subinstance are using the same type *)

  assert(check_calls call calls);

  (* make a list of all types from input and output vars *)

  let call_types = (fst call)@(snd call) in

  (* extract all the input and output vars from the submachine *)

  let machine_vars = submachine.mstep.step_inputs@submachine.mstep.step_outputs in

  (* keep only the type of vars *)

  let machine_types = List.map (function x-> x.var_type) machine_vars in

  (* assume that there is the same numer of input and output in the submachine

      and the call *)

  assert (List.length machine_types = List.length call_types);

  (* Unify the two lists of types *)

  let substitution = List.fold_left unification [] (List.combine machine_types call_types) in

  (* Assume that our substitution match all the possible

       polymorphic type of the node *)

  let polymorphic_types = find_all_polymorphic_type submachine in

  assert (List.length polymorphic_types = List.length substitution);

  (try

    assert (List.for_all (fun x -> List.mem_assoc x substitution) polymorphic_types)

  with

    Not_found -> assert false);

  substitution

(** Extract from a machine the instance corresponding to the identifier,

      assume that the identifier exists in the instances of the machine.

   @param identifier the instance identifier

   @param machine a machine

   @return the instance of machine.minstances corresponding to identifier

**)

let get_instance identifier typed_submachines =

  try

    List.assoc identifier typed_submachines

  with Not_found -> assert false