Source file senv.ml
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let solvers =
let open Formula_options in
[ Bitwuzla; Boolector; Z3; CVC4; Yices ]
let map =
let open Formula_options in
let open Smt_options in
function
| Auto | Bitwuzla_native -> assert false
| Bitwuzla_smtlib -> Bitwuzla
| Boolector_smtlib -> Boolector
| Z3_smtlib -> Z3
| CVC4_smtlib -> CVC4
| Yices_smtlib -> Yices
let get_solver_factory () =
let open Formula_options in
let open Smt_options in
match Smt_options.SMTSolver.get () with
| (Smt_options.Auto | Smt_options.Bitwuzla_native) when Smt_bitwuzla.available
->
Logger.debug "Use native Bitwuzla binding.";
(module Native_solver.Solver : Solver_sig.FACTORY)
| Auto -> (
try
let solver = List.find Prover.ping solvers in
Logger.info "Found %a in the path." Prover.pp solver;
Solver.set solver;
(module Smt2_solver.Solver : Solver_sig.FACTORY)
with Not_found -> Logger.fatal "No SMT solver found.")
| Bitwuzla_native ->
Logger.fatal "Native bitwuzla binding is required but not available."
| solver when Prover.ping (map solver) ->
Logger.debug "Found %a in the path." Prover.pp (map solver);
Solver.set (map solver);
(module Smt2_solver.Solver : Solver_sig.FACTORY)
| solver ->
Logger.fatal "%a is required but not available in path." Prover.pp
(map solver)
exception Undef = Types.Undef
exception Uninterp = Types.Uninterp
exception Unknown = Types.Unknown
exception Non_unique = Types.Non_unique
exception Non_mergeable = Types.Non_mergeable
type 'a test = 'a Types.test =
| True of 'a
| False of 'a
| Both of { t : 'a; f : 'a }
module BiMap = Basic_types.BigInt.Map
module NiTbl = Basic_types.Int.Htbl
open Sexpr
module BiItM = Imap
module S = Basic_types.String.Map
module I = Basic_types.Int.Map
module R = Basic_types.Int.Htbl
module K = Basic_types.Int.Set
type _ Types.value += Term : Sexpr.Expr.t Types.value
module State
(D : Domains.S)
(F : Solver_sig.FACTORY)
(QS : Types.QUERY_STATISTICS) =
struct
module Uid = struct
type t = Suid.t
let zero = Suid.incr Suid.zero
let succ = Suid.incr
let compare = Suid.compare
end
type t = {
constraints : Expr.t list;
mutable deps : BvSet.t BvMap.t;
mutable domains : D.t BvMap.t;
mutable anchors : K.t;
vsymbols : Expr.t I.t;
varrays : Memory.t S.t;
vmemory : Memory.t;
ilocs : (Z.t * Loader_buf.t) BiItM.t;
alocs : (Z.t * char) list ref;
model : Model.t;
}
module C : Ai.CONTEXT with type t = t and type v := D.t = struct
type nonrec t = t
let add_dependency t ~parent e =
t.deps <-
BvMap.add e
(BvSet.add parent
(try BvMap.find e t.deps with Not_found -> BvSet.empty))
t.deps
let find_dependency t e = BvMap.find e t.deps
let add t e v = t.domains <- BvMap.add e v t.domains
let find t e = BvMap.find e t.domains
end
module Overapprox : Memory_manager.CONTEXT with type t = t and type v := D.t =
struct
include Ai.Make (D) (C)
let anchor t (m : Memory.t) =
match m with
| Root | Symbol _ -> ()
| Layer { id; _ } -> t.anchors <- K.add id t.anchors
let anchored t (m : Memory.t) =
match m with
| Root | Symbol _ -> true
| Layer { id; _ } -> K.mem id t.anchors
end
module MMU = Memory_manager.Make (D) (Overapprox)
let pp ppf state = Model.pp ppf state.model
let empty () =
{
constraints = [];
deps = BvMap.empty;
domains = BvMap.empty;
anchors = K.empty;
vsymbols = I.empty;
varrays = S.empty;
vmemory = Memory.root;
ilocs = BiItM.empty;
alocs = ref [];
model = Model.empty (Kernel_options.Machine.word_size ());
}
let alloc ~array state =
let symbol = Memory.fresh array in
{ state with varrays = S.add array symbol state.varrays }
let assign ({ id; _ } : Types.Var.t) value state =
{ state with vsymbols = I.add id value state.vsymbols }
let write ~addr value dir state =
let vmemory = MMU.write state ~addr value dir state.vmemory in
{ state with vmemory }
let store name ~addr value dir state =
try
let ar = S.find name state.varrays in
let varrays =
S.add name (MMU.write state ~addr value dir ar) state.varrays
in
{ state with varrays }
with Not_found -> raise_notrace (Uninterp name)
let lookup ({ id; _ } as var : Types.Var.t) t =
try I.find id t.vsymbols with Not_found -> raise_notrace (Undef var)
let read ~addr bytes dir state =
let bytes = MMU.read state ~addr bytes dir state.vmemory in
(bytes, state)
let select name ~addr bytes dir state =
try
let array = S.find name state.varrays in
let bytes = MMU.read state ~addr bytes dir array in
(bytes, state)
with Not_found -> raise_notrace (Uninterp name)
let memcpy ~addr len orig state =
let base = Bv.value_of addr in
let ilocs = BiItM.add ~base len (Bv.value_of addr, orig) state.ilocs in
let vmemory =
MMU.source state ~addr:(Expr.constant addr) ~len orig state.vmemory
in
{ state with ilocs; vmemory }
module Engine (Solver : Solver_sig.S) = struct
type result = Unsat | Sat of t
let state =
match Solver.get_array Memory.root with
| (exception Not_found) | [||] -> (BiTbl.create 0, !(state.alocs))
| assignment ->
let memory = BiTbl.create (Array.length assignment) in
let alocs =
Array.fold_left
(fun alocs (addr, value) ->
match BiItM.find addr state.ilocs with
| exception Not_found ->
BiTbl.add memory addr value;
alocs
| base, img ->
let offset = Z.to_int (Z.sub addr base) in
let value' =
Char.unsafe_chr
(if offset < Bigarray.Array1.dim img then
Bigarray.Array1.get img offset
else 0)
in
if value <> value' then (addr, value') :: alocs else alocs)
!(state.alocs) assignment
in
(memory, alocs)
let name =
match Solver.get_array name with
| (exception Not_found) | [||] -> BiTbl.create 0
| assignment ->
let array = BiTbl.create (Array.length assignment) in
Array.iter
(fun (addr, value) -> BiTbl.add array addr value)
assignment;
array
let () =
let arrays = StTbl.create 5 in
Solver.iter_free_arrays (fun name symbol ->
StTbl.add arrays name (extract_array symbol));
arrays
let () =
let vars = StTbl.create 8 and values = BvTbl.create 32 in
Solver.iter_free_variables (fun name bv ->
StTbl.add vars name bv;
BvTbl.add values bv
(Bitvector.create
Solver.(get_value (Solver.get bv))
(Expr.sizeof bv)));
(vars, values)
let rec force_lazy_init alocs state =
if alocs == !(state.alocs) = false then
match alocs with
| [] -> ()
| (addr, value) :: alocs ->
Solver.set_memory ~addr (Z.of_int (Char.code value));
force_lazy_init alocs state
let enumerate =
let rec iter state e expr size n enum =
if n = 0 then enum
else
match Solver.check_sat () with
| Unknown ->
QS.Solver.incr_err ();
raise Unknown
| Unsat ->
QS.Solver.incr_unsat ();
enum
| Sat ->
QS.Solver.incr_sat ();
let memory, alocs = extract_memory state in
if alocs == !(state.alocs) = false then (
force_lazy_init alocs state;
state.alocs := alocs;
iter state e expr size n enum)
else
let x = Solver.get_value expr in
let b = Bv.create x size in
let cond = Expr.equal e (Expr.constant b) in
let vars, values = extract_vars () in
let state' =
{
state with
constraints = cond :: state.constraints;
model =
( vars,
values,
memory,
extract_arrays (),
Kernel_options.Machine.word_size () );
}
in
ignore (Overapprox.eval state' cond);
Overapprox.refine state' cond D.one;
Solver.neq expr x;
iter state e expr size (n - 1) ((b, state') :: enum)
in
fun e ?(n = (1 lsl Expr.sizeof e) - 1) ?(except = []) state ->
let size = Expr.sizeof e in
let expr = Solver.bind Uid.zero e state.constraints in
List.iter
(fun (addr, value) ->
Solver.set_memory ~addr (Z.of_int (Char.code value)))
!(state.alocs);
let d = Overapprox.eval state e in
match D.project ~size d with
| Point z ->
let bv = Bv.create z size in
if List.mem bv except then [] else [ (bv, state) ]
| Top | Seq _ ->
let init =
let bv = Model.eval state.model e in
if List.mem bv except then []
else (
QS.Preprocess.incr_const ();
Solver.neq expr (Bitvector.value_of bv);
let cond = Expr.equal e (Expr.constant bv) in
let state =
{ state with constraints = cond :: state.constraints }
in
ignore (Overapprox.eval state cond);
Overapprox.refine state cond D.one;
[ (bv, state) ])
in
List.iter (fun bv -> Solver.neq expr (Bitvector.value_of bv)) except;
iter state e expr size (n - 1) init
let check_sat =
let rec check_sat_true state =
match Solver.check_sat () with
| Unknown -> raise Unknown
| Unsat -> Unsat
| Sat ->
let memory, alocs = extract_memory state in
if alocs == !(state.alocs) = false then (
force_lazy_init alocs state;
state.alocs := alocs;
check_sat_true state)
else
let vars, values = extract_vars () in
Sat
{
state with
model =
( vars,
values,
memory,
extract_arrays (),
Kernel_options.Machine.word_size () );
}
in
fun state ->
Solver.put Uid.zero state.constraints;
List.iter
(fun (addr, value) ->
Solver.set_memory ~addr (Z.of_int (Char.code value)))
!(state.alocs);
check_sat_true state
let close () = Solver.close ()
end
let assume cond state =
if Expr.is_equal cond Expr.one then (
QS.Preprocess.incr_sat ();
Some state)
else if Expr.is_equal cond Expr.zero then (
QS.Preprocess.incr_unsat ();
None)
else
let d = Overapprox.eval state cond in
if D.included ~size:1 d D.zero then (
QS.Preprocess.incr_unsat ();
None)
else if D.included ~size:1 d D.one then (
QS.Preprocess.incr_sat ();
Some { state with constraints = cond :: state.constraints })
else
let state = { state with constraints = cond :: state.constraints } in
if Bitvector.zero = Model.eval state.model cond then (
QS.Solver.start_timer ();
let open Engine (F ()) in
let r =
match check_sat state with
| exception Unknown ->
QS.Solver.incr_err ();
raise Unknown
| Unsat ->
QS.Solver.incr_unsat ();
None
| Sat state ->
QS.Solver.incr_sat ();
Overapprox.refine state cond D.one;
Some state
in
close ();
QS.Solver.stop_timer ();
r)
else (
QS.Preprocess.incr_sat ();
Overapprox.refine state cond D.one;
Some state)
let test cond state =
if Expr.is_equal cond Expr.one then (
QS.Preprocess.incr_sat ();
True state)
else if Expr.is_equal cond Expr.zero then (
QS.Preprocess.incr_unsat ();
False state)
else
let d = Overapprox.eval state cond in
if D.included ~size:1 d D.zero then (
QS.Preprocess.incr_unsat ();
False state)
else if D.included ~size:1 d D.one then (
QS.Preprocess.incr_sat ();
True state)
else
let t = { state with constraints = cond :: state.constraints } in
let f =
{ state with constraints = Expr.lognot cond :: state.constraints }
in
let e = Model.eval state.model cond in
let s =
if Bv.is_zero e then (
Overapprox.refine f cond D.zero;
t)
else (
Overapprox.refine t cond D.one;
f)
in
QS.Solver.start_timer ();
let open Engine (F ()) in
let r =
match check_sat s with
| exception Unknown ->
QS.Solver.incr_err ();
raise Unknown
| Unsat ->
QS.Solver.incr_unsat ();
if Bv.is_zero e then False f else True t
| Sat state ->
QS.Solver.incr_sat ();
if Bv.is_zero e then (
Overapprox.refine state cond D.one;
Both { t = state; f })
else (
Overapprox.refine state cond D.zero;
Both { t; f = state })
in
close ();
QS.Solver.stop_timer ();
r
let enumerate =
let with_solver e ?n ?except state =
QS.Solver.start_timer ();
let open Engine (F ()) in
let r = enumerate e ?n ?except state in
close ();
QS.Solver.stop_timer ();
r
in
fun e ?n ?(except = []) state ->
match (e, n) with
| Expr.Cst bv, _ when List.mem bv except = false ->
QS.Preprocess.incr_const ();
[ (bv, state) ]
| Expr.Cst _, _ ->
QS.Preprocess.incr_const ();
[]
| _, Some 1 ->
let bv = Model.eval state.model e in
if List.mem bv except then with_solver e ?n ~except state
else (
QS.Preprocess.incr_const ();
let cond = Expr.equal e (Expr.constant bv) in
[
( bv,
{
state with
constraints = cond :: state.constraints ;
} );
])
| _, _ -> with_solver e ?n ~except state
let merge ~parent t t' =
if t == t' then t
else if t.ilocs == t'.ilocs then
match (t.constraints, t'.constraints) with
| c :: constraints, c' :: constraints'
when constraints == constraints' && Expr.is_equal c (Expr.lognot c') ->
let domains = parent.domains
and anchors = K.union t.anchors t'.anchors
and deps =
BvMap.merge
(fun _ o o' ->
match (o, o') with
| None, None -> assert false
| None, Some _ -> o'
| Some _, None -> o
| Some d, Some d' -> Some (BvSet.union d d'))
t.deps t'.deps
and vsymbols =
if t.vsymbols == t'.vsymbols then t.vsymbols
else
I.merge
(fun _ o0 o1 ->
match (o0, o1) with
| Some e0, Some e1 ->
if Expr.is_equal e0 e1 then o0
else Some (Expr.ite c e0 e1)
| (Some _ | None), (Some _ | None) ->
raise_notrace Non_mergeable)
t.vsymbols t'.vsymbols
and varrays =
if t.varrays == t'.varrays then t.varrays
else
S.merge
(fun _ o0 o1 ->
match (o0, o1) with
| Some a0, Some a1 -> Some (MMU.merge parent c a0 a1)
| (Some _ | None), (Some _ | None) ->
raise_notrace Non_mergeable)
t.varrays t'.varrays
and vmemory = MMU.merge parent c t.vmemory t'.vmemory
and ilocs = t.ilocs
and alocs = t.alocs
and model = t.model in
{
constraints;
deps;
domains;
anchors;
vsymbols;
varrays;
vmemory;
ilocs;
alocs;
model;
}
| _ -> raise_notrace Non_mergeable
else raise_notrace Non_mergeable
module Value = struct
type t = Expr.t
let kind = Term
let constant = Expr.constant
let var id name size = Expr.var (name ^ Suid.to_string id) size name
let unary = Expr.unary
let binary = Expr.binary
let ite = Expr.ite
end
let assertions t = t.constraints
let get_value (e : Expr.t) _ =
match e with Cst bv -> bv | _ -> raise_notrace Non_unique
let get_a_value (e : Expr.t) t = Model.eval t.model e
let pp_smt (target : Expr.t Types.target) ppf t =
let module P = Smt2_solver.Printer in
let ctx = P.create ~next_id:Uid.zero () in
List.iter (P.visit_bl ctx) t.constraints;
let defs =
match target with
| Some defs ->
List.iter (fun (e, _) -> P.visit_bv ctx e) defs;
defs
| None ->
P.visit_ax ctx t.vmemory;
List.rev
(I.fold
(fun id expr defs ->
match Dba.Var.from_id id with
| exception Not_found -> defs
| { name; _ } ->
P.visit_bv ctx expr;
(expr, name) :: defs)
t.vsymbols [])
in
Format.pp_open_vbox ppf 0;
P.pp_print_decls ppf ctx;
P.pp_print_defs ppf ctx;
List.iter
(fun (bv, name) ->
Format.fprintf ppf "@[<h>(define-fun %s () (_ BitVec %d)@ " name
(Expr.sizeof bv);
P.pp_print_bv ctx ppf bv;
Format.fprintf ppf ")@]@ ")
defs;
if target = None then
Format.fprintf ppf
"@[<h>(define-fun memory () (Array (_ BitVec %d) (_ BitVec 8))@ %a)@]"
(Kernel_options.Machine.word_size ())
(P.pp_print_ax ctx) t.vmemory;
List.iter
(fun bl ->
Format.pp_open_hbox ppf ();
Format.pp_print_string ppf "(assert ";
P.pp_print_bl ctx ppf bl;
Format.pp_print_char ppf ')';
Format.pp_close_box ppf ();
Format.pp_print_space ppf ())
t.constraints;
Format.pp_close_box ppf ()
let to_formula t =
let module C = Smt2_solver.Cross in
let ctx = C.create ~next_id:Uid.zero () in
List.iter (C.assert_bl ctx) t.constraints;
C.define_ax ctx "memory" t.vmemory;
I.iter
(fun id expr -> C.define_bv ctx (Dba.Var.from_id id).name expr)
t.vsymbols;
C.to_formula ctx
let downcast _ = None
end
type Options.Engine.t += Vanilla
let () =
Options.Engine.register "vanilla" Vanilla (fun () ->
(module State (Domains.Interval) ((val get_solver_factory ()))))