heptagon/minils/analysis/init.ml
2010-06-15 14:18:42 +02:00

314 lines
9.2 KiB
OCaml

(**************************************************************************)
(* *)
(* 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 *)
(* $Id: init.ml 615 2009-11-20 17:43:14Z pouzet $ *)
open Misc
open Names
open Ident
open Minils
open Location
open Format
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 ty =
match ty with
| Tbase _ -> leaf i
| Tprod(ty_list) -> product (List.map (skeleton i) ty_list)
(* 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
(* an inequation [a < t[a]] becomes [a = t[0]] *)
and 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 =
begin 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
end;
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)
| Eop(_, e_list) ->
let i = List.fold_left (fun acc e -> itype (typing h e)) izero e_list in
skeleton i e.e_ty
| Eapp(_, e_list) ->
List.iter (fun e -> expect h e (skeleton izero e.e_ty)) e_list;
skeleton izero e.e_ty
| Eevery(_, e_list, n) ->
List.iter (fun e -> expect h e (skeleton izero e.e_ty)) e_list;
let { t_init = i } = Env.find n h 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
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 { p_lhs = pat; p_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 { p_lhs = pat; p_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
typing_eqs h' eq_list;
(* assumption *)
expect h' e_a (skeleton izero e_a.e_ty);
(* property *)
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