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.                                                    *)

(*                                                                  *)

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

(* The compilation presented here was first defined in Garoche, Gurfinkel,

   Kahsai, HCSV'14.

   This is a modified version that handle reset

*)

open Format

open LustreSpec

open Corelang

open Machine_code

open Horn_backend_common

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

(*                    Instruction Printing functions                                        *)

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

let pp_horn_var m fmt id =

  if Types.is_array_type id.var_type

  then

    assert false (* no arrays in Horn output *)

  else

    fprintf fmt "%s" id.var_id

(* Used to print boolean constants *)

let pp_horn_tag fmt t =

  pp_print_string fmt (if t = tag_true then "true" else if t = tag_false then "false" else t)

(* Prints a constant value *)

let rec pp_horn_const fmt c =

  match c with

    | Const_int i    -> pp_print_int fmt i

    | Const_real (_,_,s)   -> pp_print_string fmt s

    | Const_tag t    -> pp_horn_tag fmt t

    | _              -> assert false

(* Prints a value expression [v], with internal function calls only.

   [pp_var] is a printer for variables (typically [pp_c_var_read]),

   but an offset suffix may be added for array variables

*)

let rec pp_horn_val ?(is_lhs=false) self pp_var fmt v =

  match v.value_desc with

    | Cst c         -> pp_horn_const fmt c

    | Array _

    | Access _ -> assert false (* no arrays *)

    | Power (v, n)  -> assert false

    | LocalVar v    -> pp_var fmt (rename_machine self v)

    | StateVar v    ->

      if Types.is_array_type v.var_type

      then assert false

      else pp_var fmt (rename_machine self ((if is_lhs then rename_next else rename_current) (* self *) v))

    | Fun (n, vl)   -> fprintf fmt "%a" (Basic_library.pp_horn n (pp_horn_val self pp_var)) vl

(* Prints a [value] indexed by the suffix list [loop_vars] *)

let rec pp_value_suffix self pp_value fmt value =

 match value.value_desc with

 | Fun (n, vl)  ->

   Basic_library.pp_horn n (pp_value_suffix self pp_value) fmt vl

 |  _            ->

   pp_horn_val self pp_value fmt value

(* type_directed assignment: array vs. statically sized type

   - [var_type]: type of variable to be assigned

   - [var_name]: name of variable to be assigned

   - [value]: assigned value

   - [pp_var]: printer for variables

*)

let pp_assign m pp_var fmt var_name value =

  let self = m.mname.node_id in

  fprintf fmt "(= %a %a)" 

    (pp_horn_val ~is_lhs:true self pp_var) var_name

    (pp_value_suffix self pp_var) value

(* In case of no reset call, we define mid_mem = current_mem *)

let pp_no_reset machines m fmt i =

  let (n,_) = List.assoc i m.minstances in

  let target_machine = List.find (fun m  -> m.mname.node_id = (node_name n)) machines in

  let m_list = 

    rename_machine_list

      (concat m.mname.node_id i)

      (rename_mid_list (full_memory_vars machines target_machine))

  in

  let c_list =

    rename_machine_list

      (concat m.mname.node_id i)

      (rename_current_list (full_memory_vars machines target_machine))

  in

  match c_list, m_list with

  | [chd], [mhd] ->

    fprintf fmt "(= %a %a)"

      (pp_horn_var m) mhd

      (pp_horn_var m) chd

  | _ -> (

    fprintf fmt "@[<v 0>(and @[<v 0>";

    List.iter2 (fun mhd chd -> 

      fprintf fmt "(= %a %a)@ "

      (pp_horn_var m) mhd

      (pp_horn_var m) chd

    )

      m_list

      c_list      ;

    fprintf fmt ")@]@ @]"

  )

let pp_instance_reset machines m fmt i =

  let (n,_) = List.assoc i m.minstances in

  let target_machine = List.find (fun m  -> m.mname.node_id = (node_name n)) machines in

  fprintf fmt "(%a @[<v 0>%a)@]"

    pp_machine_reset_name (node_name n)

    (Utils.fprintf_list ~sep:"@ " (pp_horn_var m)) 

    (

      (rename_machine_list

	 (concat m.mname.node_id i)

	 (rename_current_list (full_memory_vars machines target_machine))

      ) 

      @

	(rename_machine_list

	   (concat m.mname.node_id i)

	   (rename_mid_list (full_memory_vars machines target_machine))

	)

    )

let pp_instance_call machines reset_instances m fmt i inputs outputs =

  let self = m.mname.node_id in

  try (* stateful node instance *)

    begin

      let (n,_) = List.assoc i m.minstances in

      let target_machine = List.find (fun m  -> m.mname.node_id = node_name n) machines in

      (* Checking whether this specific instances has been reset yet *)

      if not (List.mem i reset_instances) then

	(* If not, declare mem_m = mem_c *)

	pp_no_reset machines m fmt i;

      let mems = full_memory_vars machines target_machine in

      let rename_mems f = rename_machine_list (concat m.mname.node_id i) (f mems) in

      let mid_mems = rename_mems rename_mid_list in

      let next_mems = rename_mems rename_next_list in

      match node_name n, inputs, outputs, mid_mems, next_mems with

      | "_arrow", [i1; i2], [o], [mem_m], [mem_x] -> begin

	fprintf fmt "@[<v 5>(and ";

	fprintf fmt "(= %a (ite %a %a %a))"

	  (pp_horn_val ~is_lhs:true self (pp_horn_var m)) (mk_val (LocalVar o) o.var_type) (* output var *)

	  (pp_horn_var m) mem_m 

	  (pp_horn_val self (pp_horn_var m)) i1

	  (pp_horn_val self (pp_horn_var m)) i2

	;

	fprintf fmt "@ ";

	fprintf fmt "(= %a false)" (pp_horn_var m) mem_x;

	fprintf fmt ")@]"

      end

      | node_name_n -> begin

	fprintf fmt "(%a @[<v 0>%a%t%a%t%a)@]"

	  pp_machine_step_name (node_name n)

	  (Utils.fprintf_list ~sep:"@ " (pp_horn_val self (pp_horn_var m))) inputs

	  (Utils.pp_final_char_if_non_empty "@ " inputs)

	  (Utils.fprintf_list ~sep:"@ " (pp_horn_val self (pp_horn_var m)))

	  (List.map (fun v -> mk_val (LocalVar v) v.var_type) outputs)

	  (Utils.pp_final_char_if_non_empty "@ " outputs)

	  (Utils.fprintf_list ~sep:"@ " (pp_horn_var m)) (mid_mems@next_mems)

      end

    end

  with Not_found -> ( (* stateless node instance *)

    let (n,_) = List.assoc i m.mcalls in

    fprintf fmt "(%s @[<v 0>%a%t%a)@]"

      (node_name n)

      (Utils.fprintf_list ~sep:"@ " (pp_horn_val self (pp_horn_var m)))

      inputs

      (Utils.pp_final_char_if_non_empty "@ " inputs)

      (Utils.fprintf_list ~sep:"@ " (pp_horn_val self (pp_horn_var m)))

      (List.map (fun v -> mk_val (LocalVar v) v.var_type) outputs)

  )

(* Print the instruction and update the set of reset instances *)

let rec pp_machine_instr machines reset_instances (m: machine_t) fmt instr : ident list =

  match instr with

  | MNoReset i -> (* we assign middle_mem with mem_m. And declare i as reset *)

    pp_no_reset machines m fmt i;

    i::reset_instances

  | MReset i -> (* we assign middle_mem with reset: reset(mem_m) *)

    pp_instance_reset machines m fmt i;

    i::reset_instances

  | MLocalAssign (i,v) ->

    pp_assign

      m (pp_horn_var m) fmt

      (mk_val (LocalVar i) i.var_type) v;

    reset_instances

  | MStateAssign (i,v) ->

    pp_assign

      m (pp_horn_var m) fmt

      (mk_val (StateVar i) i.var_type) v;

    reset_instances

  | MStep ([i0], i, vl) when Basic_library.is_internal_fun i (List.map (fun v -> v.value_type) vl) ->

    assert false (* This should not happen anymore *)

  | MStep (il, i, vl) ->

    (* if reset instance, just print the call over mem_m , otherwise declare mem_m =

       mem_c and print the call to mem_m *)

    pp_instance_call machines reset_instances m fmt i vl il;

    reset_instances (* Since this instance call will only happen once, we

		       don't have to update reset_instances *)

  | MBranch (g,hl) -> (* (g = tag1 => expr1) and (g = tag2 => expr2) ...

			 should not be produced yet. Later, we will have to

			 compare the reset_instances of each branch and

			 introduced the mem_m = mem_c for branches to do not

			 address it while other did. Am I clear ? *)

    (* For each branch we obtain the logical encoding, and the information

       whether a sub node has been reset or not. If a node has been reset in one

       of the branch, then all others have to have the mem_m = mem_c

       statement. *)

    let self = m.mname.node_id in

    let pp_branch fmt (tag, instrs) =

      fprintf fmt 

	"@[<v 3>(or (not (= %a %s))@ " 

	(*"@[<v 3>(=> (= %a %s)@ "*)  (* Issues with some versions of Z3. It

					  seems that => within Horn predicate

					  may cause trouble. I have hard time

					  producing a MWE, so I'll just keep the

					  fix here as (not a) or b *)

	(pp_horn_val self (pp_horn_var m)) g

	tag;

      let rs = pp_machine_instrs machines reset_instances m fmt instrs in

      fprintf fmt "@])";

      () (* rs *)

    in

    pp_conj pp_branch fmt hl;

    reset_instances 

and pp_machine_instrs machines reset_instances m fmt instrs = 

  let ppi rs fmt i = pp_machine_instr machines rs m fmt i in

  match instrs with

  | [x] -> ppi reset_instances fmt x 

  | _::_ ->

    fprintf fmt "(and @[<v 0>";

    let rs = List.fold_left (fun rs i -> 

      let rs = ppi rs fmt i in

      fprintf fmt "@ ";

      rs

    )

      reset_instances instrs 

    in

    fprintf fmt "@])";

    rs

  | [] -> fprintf fmt "true"; reset_instances

let pp_machine_reset machines fmt m =

  let locals = local_memory_vars machines m in

  fprintf fmt "@[<v 5>(and @ ";

  (* print "x_m = x_c" for each local memory *)

  (Utils.fprintf_list ~sep:"@ " (fun fmt v -> 

    fprintf fmt "(= %a %a)"

      (pp_horn_var m) (rename_mid v)

      (pp_horn_var m) (rename_current v)

   )) fmt locals;

  fprintf fmt "@ ";

  (* print "child_reset ( associated vars _ {c,m} )" for each subnode.

     Special treatment for _arrow: _first = true

  *)

  (Utils.fprintf_list ~sep:"@ " (fun fmt (id, (n, _)) ->

    let name = node_name n in

    if name = "_arrow" then ( 

      fprintf fmt "(= %s._arrow._first_m true)"

	(concat m.mname.node_id id)  

    ) else (

      let machine_n = get_machine machines name in 

      fprintf fmt "(%s_reset @[<hov 0>%a@])" 

	name

	(Utils.fprintf_list ~sep:"@ " (pp_horn_var m)) 

	(rename_machine_list (concat m.mname.node_id id) (reset_vars machines machine_n))

    )

   )) fmt m.minstances;

  fprintf fmt "@]@ )"

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

let is_stateless m = m.minstances = [] && m.mmemory = []

(* Print the machine m:

   two functions: m_init and m_step

   - m_init is a predicate over m memories

   - m_step is a predicate over old_memories, inputs, new_memories, outputs

   We first declare all variables then the two /rules/.

*)

let print_machine machines fmt m =

  if m.mname.node_id = arrow_id then

    (* We don't print arrow function *)

    ()

  else

    begin

      fprintf fmt "; %s@." m.mname.node_id;

      (* Printing variables *)

      Utils.fprintf_list ~sep:"@." pp_decl_var fmt

	(

	  (inout_vars machines m)@

	    (rename_current_list (full_memory_vars machines m)) @

	    (rename_mid_list (full_memory_vars machines m)) @

	    (rename_next_list (full_memory_vars machines m)) @

	    (rename_machine_list m.mname.node_id m.mstep.step_locals)

	);

      pp_print_newline fmt ();

      if is_stateless m then

	begin

	  (* Declaring single predicate *)

	  fprintf fmt "(declare-rel %a (%a))@."

	    pp_machine_stateless_name m.mname.node_id

	    (Utils.fprintf_list ~sep:" " pp_type)

	    (List.map (fun v -> v.var_type) (inout_vars machines m));

	  (* Rule for single predicate *)

	  fprintf fmt "@[<v 2>(rule (=> @ ";

	  ignore (pp_machine_instrs machines ([] (* No reset info for stateless nodes *) )  m fmt m.mstep.step_instrs);

	  fprintf fmt "@ (%a %a)@]@.))@.@."

	    pp_machine_stateless_name m.mname.node_id

	    (Utils.fprintf_list ~sep:" " (pp_horn_var m)) (inout_vars machines m);

	end

      else

	begin

	  (* Declaring predicate *)

	  fprintf fmt "(declare-rel %a (%a))@."

	    pp_machine_reset_name m.mname.node_id

	    (Utils.fprintf_list ~sep:" " pp_type)

	    (List.map (fun v -> v.var_type) (reset_vars machines m));

	  fprintf fmt "(declare-rel %a (%a))@."

	    pp_machine_step_name m.mname.node_id

	    (Utils.fprintf_list ~sep:" " pp_type)

	    (List.map (fun v -> v.var_type) (step_vars machines m));

	  pp_print_newline fmt ();

	  (* Rule for reset *)

	  fprintf fmt "@[<v 2>(rule (=> @ %a@ (%a @[<v 0>%a)@]@]@.))@.@."

	    (pp_machine_reset machines) m 

	    pp_machine_reset_name m.mname.node_id

	    (Utils.fprintf_list ~sep:"@ " (pp_horn_var m)) (reset_vars machines m);

          match m.mstep.step_asserts with

	  | [] ->

	    begin

	      (* Rule for step*)

	      fprintf fmt "@[<v 2>(rule (=> @ ";

	      ignore (pp_machine_instrs machines [] m fmt m.mstep.step_instrs);

	      fprintf fmt "@ (%a @[<v 0>%a)@]@]@.))@.@."

		pp_machine_step_name m.mname.node_id

		(Utils.fprintf_list ~sep:"@ " (pp_horn_var m)) (step_vars machines m);

	    end

	  | assertsl -> 

	    begin

	      let pp_val = pp_horn_val ~is_lhs:true m.mname.node_id (pp_horn_var m) in

	      (* print_string pp_val; *)

	      fprintf fmt "; with Assertions @.";

	      (*Rule for step*)

	      fprintf fmt "@[<v 2>(rule (=> @ (and @ ";

	      ignore (pp_machine_instrs machines [] m fmt m.mstep.step_instrs);

	      fprintf fmt "@. %a)(%a @[<v 0>%a)@]@]@.))@.@." (pp_conj pp_val) assertsl

		pp_machine_step_name m.mname.node_id

		(Utils.fprintf_list ~sep:" " (pp_horn_var m)) (step_vars machines m);

	    end

	end

    end

(* Local Variables: *)

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

(* End: *)