heptagon/minils/analysis/init.ml

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(**************************************************************************)
(* *)
(* Heptagon *)
(* *)
(* Author : Marc Pouzet *)
(* Organization : Demons, LRI, University of Paris-Sud, Orsay *)
(* *)
(**************************************************************************)
(* simple initialization analysis. This is almost trivial since *)
(* input/outputs of a node are forced to be initialized *)
(* add a special treatment of clock state variables whose initial *)
(* values are known. This allows to accept code generated *)
(* for automata *)
(* if [clock c = C fby ec] then [merge c (C -> e) ...] is initialized *)
(* if [e] is initialized only *)
open Misc
open Names
open Ident
open Minils
open Location
open Format
open Types
type typ = | Iproduct of typ list | Ileaf of init
and init = { mutable i_desc : init_desc; mutable i_index : int}
and init_desc = | Izero | Ione | Ivar | Imax of init * init | Ilink of init
type typ_env =
{ t_init : init; (* its initialisation type *) t_value : longname option }
(* its initial value *)
(* typing errors *)
exception Unify
let index = ref 0
let gen_index () = (incr index; !index)
let new_var () = { i_desc = Ivar; i_index = gen_index (); }
let izero = { i_desc = Izero; i_index = gen_index (); }
let ione = { i_desc = Ione; i_index = gen_index (); }
let imax i1 i2 = { i_desc = Imax (i1, i2); i_index = gen_index (); }
let product l = Iproduct l
let leaf i = Ileaf i
(* basic operation on initialization values *)
let rec irepr i =
match i.i_desc with
| Ilink i_son ->
let i_son = irepr i_son in (i.i_desc <- Ilink i_son; i_son)
| _ -> i
(** Simplification rules for max. Nothing fancy here *)
let max i1 i2 =
let i1 = irepr i1 in
let i2 = irepr i2
in
match ((i1.i_desc), (i2.i_desc)) with
| (Izero, Izero) -> izero
| (Izero, _) -> i2
| (_, Izero) -> i1
| (_, Ione) | (Ione, _) -> ione
| _ -> imax i1 i2
let rec itype =
function | Iproduct ty_list -> itype_list ty_list | Ileaf i -> i
and itype_list ty_list =
List.fold_left (fun acc ty -> max acc (itype ty)) izero ty_list
(* saturate an initialization type. Every element must be initialized *)
let rec initialized i =
let i = irepr i
in
match i.i_desc with
| Izero -> ()
| Ivar -> i.i_desc <- Ilink izero
| Imax (i1, i2) -> (initialized i1; initialized i2)
| Ilink i -> initialized i
| Ione -> raise Unify
(* build an initialization type from a type *)
let rec skeleton i =
function
| Tprod ty_list -> product (List.map (skeleton i) ty_list)
| Tarray _ | Tid _ -> leaf i
(* sub-typing *)
let rec less left_ty right_ty =
if left_ty == right_ty
then ()
else
(match (left_ty, right_ty) with
| (Iproduct l1, Iproduct l2) -> List.iter2 less l1 l2
| (Ileaf i1, Ileaf i2) -> iless i1 i2
| _ -> raise Unify)
and iless left_i right_i =
if left_i == right_i
then ()
else
(let left_i = irepr left_i in
let right_i = irepr right_i
in
if left_i == right_i
then ()
else
(match ((left_i.i_desc), (right_i.i_desc)) with
| (Izero, _) | (_, Ione) -> ()
| (_, Izero) -> initialized left_i
| (Imax (i1, i2), _) -> (iless i1 right_i; iless i2 right_i)
| (_, Ivar) ->
let left_i = occur_check right_i.i_index left_i
in right_i.i_desc <- Ilink left_i
| (_, Imax (i1, i2)) ->
let i1 = occur_check left_i.i_index i1 in
let i2 = occur_check left_i.i_index i2
in right_i.i_desc <- Ilink (imax left_i (imax i1 i2))
| _ -> raise Unify))
and (* an inequation [a < t[a]] becomes [a = t[0]] *) occur_check index i =
match i.i_desc with
| Izero | Ione -> i
| Ivar -> if i.i_index = index then izero else i
| Imax (i1, i2) -> max (occur_check index i1) (occur_check index i2)
| Ilink i -> occur_check index i
(* computes the initialization type of a merge *)
let merge opt_c c_i_list =
let rec search c c_i_list =
match c_i_list with
| [] -> izero
| (c0, i) :: c_i_list -> if c = c0 then i else search c c_i_list
in
match opt_c with
| None -> List.fold_left (fun acc (_, i) -> max acc i) izero c_i_list
| Some c -> search c c_i_list
module Printer =
struct
open Format
let rec print_list_r print po sep pf ff =
function
| [] -> ()
| x :: l ->
(fprintf ff "@[%s%a" po print x;
List.iter (fprintf ff "%s@]@ @[%a" sep print) l;
fprintf ff "%s@]" pf)
let rec fprint_init ff i =
match i.i_desc with
| Izero -> fprintf ff "0"
| Ione -> fprintf ff "1"
| Ivar -> fprintf ff "0"
| Imax (i1, i2) ->
fprintf ff "@[%a\\/%a@]" fprint_init i1 fprint_init i2
| Ilink i -> fprint_init ff i
let rec fprint_typ ff =
function
| Ileaf i -> fprint_init ff i
| Iproduct ty_list ->
fprintf ff "@[%a@]" (print_list_r fprint_typ "(" " *" ")") ty_list
let output_typ oc ty =
let ff = formatter_of_out_channel oc
in (fprintf ff "@["; fprint_typ ff ty; fprintf ff "@?@]")
end
module Error =
struct
open Location
type error = | Eclash of typ * typ
exception Error of location * error
let error loc kind = raise (Error (loc, kind))
let message loc kind =
((match kind with
| Eclash (left_ty, right_ty) ->
Printf.eprintf
"%aInitialization error: this expression has type \
%a, \n\
but is expected to have type %a\n"
output_location loc Printer.output_typ left_ty Printer.
output_typ right_ty);
raise Misc.Error)
end
let less_exp e actual_ty expected_ty =
try less actual_ty expected_ty
with
| Unify -> Error.message e.e_loc (Error.Eclash (actual_ty, expected_ty))
let rec typing h e =
match e.e_desc with
| Econst c -> leaf izero
| Evar x -> let { t_init = i } = Env.find x h in leaf i
| Efby (None, e) -> (expect h e (skeleton izero e.e_ty); leaf ione)
| Efby ((Some _), e) -> (expect h e (skeleton izero e.e_ty); leaf izero)
| Etuple e_list -> product (List.map (typing h) e_list)
(*TODO traitement singulier et emp<6D>che reset d'un 'op'*)
| Ecall (op, e_list, None) when op.op_kind = Eop ->
let i = List.fold_left (fun acc e -> itype (typing h e)) izero e_list
in skeleton i e.e_ty
| Ecall (op, e_list, reset) when op.op_kind = Enode ->
List.iter (fun e -> expect h e (skeleton izero e.e_ty)) e_list;
let i = match reset with
| None -> izero
| Some(n) -> let { t_init = i } = Env.find n h in i
in skeleton i e.e_ty
| Ewhen (e, c, n) ->
let { t_init = i1 } = Env.find n h in
let i2 = itype (typing h e) in skeleton (max i1 i2) e.e_ty
| Eifthenelse (e1, e2, e3) ->
let i1 = itype (typing h e1) in
let i2 = itype (typing h e2) in
let i3 = itype (typing h e3) in
let i = max i1 (max i2 i3) in skeleton i e.e_ty
| Emerge (n, c_e_list) ->
let { t_init = i; t_value = opt_c } = Env.find n h in
let i =
merge opt_c
(List.map (fun (c, e) -> (c, (itype (typing h e)))) c_e_list)
in skeleton i e.e_ty
| Efield (e1, n) -> let i = itype (typing h e1) in skeleton i e.e_ty
| Estruct l ->
let i =
List.fold_left (fun acc (_, e) -> max acc (itype (typing h e))) izero
l
in skeleton i e.e_ty
| Efield_update _ | Econstvar _ | Earray _ | Earray_op _ ->
leaf izero (* TODO FIXME array_op dans init *)
and expect h e expected_ty =
let actual_ty = typing h e in less_exp e actual_ty expected_ty
let rec typing_pat h =
function
| Evarpat x -> let { t_init = i } = Env.find x h in leaf i
| Etuplepat pat_list -> product (List.map (typing_pat h) pat_list)
let typing_eqs h eq_list =
List.iter
(fun { eq_lhs = pat; eq_rhs = e } ->
let ty_pat = typing_pat h pat in expect h e ty_pat)
eq_list
let build h eq_list =
let rec build_pat h =
function
| Evarpat x -> Env.add x { t_init = new_var (); t_value = None; } h
| Etuplepat pat_list -> List.fold_left build_pat h pat_list in
let build_equation h { eq_lhs = pat; eq_rhs = e } =
match (pat, (e.e_desc)) with
| (Evarpat x, Efby ((Some (Cconstr c)), _)) ->
(* we keep the initial value of state variables *)
Env.add x { t_init = new_var (); t_value = Some c; } h
| _ -> build_pat h pat
in List.fold_left build_equation h eq_list
let sbuild h dec =
List.fold_left
(fun h { v_name = n } -> Env.add n { t_init = izero; t_value = None; } h)
h dec
let typing_contract h contract =
match contract with
| None -> h
| Some
{
c_local = l_list;
c_eq = eq_list;
c_assume = e_a;
c_enforce = e_g;
c_controllables = c_list
} ->
let h = sbuild h c_list in
let h' = build h eq_list
in
(* assumption *)
(* property *)
(typing_eqs h' eq_list;
expect h' e_a (skeleton izero e_a.e_ty);
expect h' e_g (skeleton izero e_g.e_ty);
h)
let typing_node {
n_name = f;
n_input = i_list;
n_output = o_list;
n_contract = contract;
n_local = l_list;
n_equs = eq_list
} =
let h = sbuild Env.empty i_list in
let h = sbuild h o_list in
let h = typing_contract h contract in
let h = build h eq_list in typing_eqs h eq_list
let program (({ p_nodes = p_node_list } as p)) =
(List.iter typing_node p_node_list; p)