package frama-c

  1. Overview
  2. Docs
Legend:
Page
Library
Module
Module type
Parameter
Class
Class type
Source

Source file datascope.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
(**************************************************************************)
(*                                                                        *)
(*  This file is part of Frama-C.                                         *)
(*                                                                        *)
(*  Copyright (C) 2007-2024                                               *)
(*    CEA (Commissariat à l'énergie atomique et aux énergies              *)
(*         alternatives)                                                  *)
(*                                                                        *)
(*  you can redistribute it and/or modify it under the terms of the GNU   *)
(*  Lesser General Public License as published by the Free Software       *)
(*  Foundation, version 2.1.                                              *)
(*                                                                        *)
(*  It is distributed in the hope that it will be useful,                 *)
(*  but WITHOUT ANY WARRANTY; without even the implied warranty of        *)
(*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *)
(*  GNU Lesser General Public License for more details.                   *)
(*                                                                        *)
(*  See the GNU Lesser General Public License version 2.1                 *)
(*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
(*                                                                        *)
(**************************************************************************)

(** The aim here is to select the statements where a data D
 * has the same value then a given starting program point L. *)

open Cil_types

let name = "scope"

module R =
  Plugin.Register
    (struct
      let name = name
      let shortname = name
      let help = "data dependencies higher level functions"
    end)

let cat_rm_asserts = R.register_category "rm_asserts"
let () = R.add_debug_keys cat_rm_asserts

(** {2 Computing a mapping between zones and modifying statements}
    We first go through all the function statements in other to build
    a mapping between each zone and the statements that are modifying it.
 **)

(** Statement identifier *)
module StmtDefault = struct
  include Cil_datatype.Stmt
  let id s = s.sid
end

(** set of values to store for each data *)
module StmtSetLattice = struct

  include Abstract_interp.Make_Hashconsed_Lattice_Set(StmtDefault)(Cil_datatype.Stmt.Hptset)

  let default: t = empty

  let single s = inject_singleton s

end

(** A place to map each data to the state of statements that modify it. *)
module InitSid = struct
  module LM = Lmap_bitwise.Make_bitwise (StmtSetLattice)
  (* Clear the (non-project compliant) internal caches each time the ast
     changes, which includes every time we switch project. *)
  let () = Ast.add_hook_on_update LM.clear_caches

  let empty = LM.empty
  let find = LM.find

  let add_zone lmap zone sid =
    let new_val = StmtSetLattice.single sid in
    LM.add_binding ~exact:false lmap zone new_val

  let pretty fmt lmap =
    Format.fprintf fmt "Lmap = %a@\n" LM.pretty lmap
end

let get_writes stmt lval =
  Eva.Results.(before stmt |> eval_address ~for_writing:true lval |> as_zone)

(** Add to [stmt] to [lmap] for all the locations modified by the statement.
 * Something to do only for calls and assignments.
 * *)
let register_modified_zones lmap stmt =
  let register lmap zone = InitSid.add_zone lmap zone stmt in
  let aux_out out kf =
    let inout= Inout.get_precise_inout ~stmt kf in
    Locations.Zone.join out inout.Inout_type.over_outputs
  in
  match stmt.skind with
  | Instr (Set (lval, _, _)) ->
    let zone = get_writes stmt lval in
    register lmap zone
  | Instr (Local_init(v, i, _)) ->
    let zone = get_writes stmt (Cil.var v) in
    let lmap_init = register lmap zone in
    (match i with
     | AssignInit _ -> lmap_init
     | ConsInit(f,_,_) ->
       let kf = Globals.Functions.get f in
       let out = aux_out Locations.Zone.bottom kf in
       register lmap_init out)
  | Instr (Call (dst,funcexp,_args,_)) ->
    begin
      let lmap = match dst with
        | None -> lmap
        | Some lval ->
          let zone = get_writes stmt lval in
          register lmap zone
      in
      let kfs =
        Eva.Results.(before stmt |> eval_callee funcexp |> default [])
      in
      let out =
        List.fold_left aux_out Locations.Zone.bottom kfs
      in
      register lmap out
    end
  | _ -> lmap


(** compute the mapping for the function
 * @raise Kernel_function.No_Definition if [kf] has no definition
*)
let compute kf =
  let open Current_loc.Operators in
  R.debug ~level:1 "computing for function %a" Kernel_function.pretty kf;
  let f = Kernel_function.get_definition kf in
  let do_stmt lmap s =
    let<> UpdatedCurrentLoc = Cil_datatype.Stmt.loc s in
    if Eva.Results.is_reachable s
    then register_modified_zones lmap s
    else lmap
  in
  let f_datas = List.fold_left do_stmt InitSid.empty f.sallstmts in
  R.debug ~level:2 "data init stmts : %a" InitSid.pretty f_datas;
  f.sallstmts, f_datas (* TODO : store it ! *)

(** {2 Computing Scopes} *)

module State = struct

  (* The algorithm starts by defining the "modified" function, that
     tells for each statement if it changes the lvalue under
     consideration. We want to add a "temporal" information on top of
     modified, i.e. we want to know for each statement s', whether for
     each path from the starting statement s to s', the lvalue has
     been modified. To make this computable, we overapproximate, and
     the dataflow computes if the statement may have been modified
     (Modif) or has not been modified in any case (SameVal).

     The simple boolean lattice with Modif and SameVal does not
     suffice: if we initialized the dataflow with "SameVal" for all
     statements, "join_and_is_included" would return true and the
     dataflow could stop before having visited all statements. This
     explains why a value of Bottom is needed, to distinguish
     statements not yet visited (or unreachable) from the others.

     Now another problem in the dataflow is the representation of
     loop. In a program such has:

     while(1) {
     s1;
     s2;
     s3;
     s4;
     }

     Where "modified" is false except for s4. We start the forward
     dataflow on s2. We would compute that s2 is not modified, then s3
     is not modified, then s4 is modified, then s1 is modified... but
     then we would compute that s3 and s4 are modified (and indeed,
     they are in further iterations of the loop). To cope with this
     problem, s2 is initialized to the Start state. The Start state is
     not propagated (transfer Start = SameVal), and cannot be removed
     from s2 (Start = Top). Thus the Hasse diagram of the lattice is simply:

     :  Start = Top
     :    |
     :  Modif
     :    |
     :  SameVal
     :    |
     :  NotSeen = Bottom
  *)

  type t = Start | NotSeen | Modif | SameVal

  let pretty fmt b = Format.fprintf fmt "%s" (match b with
      | Start -> "Start"
      | NotSeen -> "NotSeen"
      | Modif -> "Modif"
      | SameVal -> "SameVal")

  let bottom = NotSeen

  (* Just compute the "max" between elements of the lattice. *)
  let merge b1 b2 =
    let b = match b1, b2 with
      | Start, _ | _, Start -> Start
      | NotSeen, b | b, NotSeen -> b
      | Modif, _ | _, Modif -> Modif
      | SameVal, SameVal -> SameVal
    in b
  let join = merge;;

  let equal (b1 : t) (b2: t) = (b1 = b2)

  let join_and_is_included a b =
    let j = join a b in
    (j, equal j b)

  let is_included a b = snd (join_and_is_included a b)

  (* Note: the transfer function "if m = Start then SameVal else if
     modif then Modif else m" suits better visualisation by scope,
     since it does not consider the "current statement" as
     "modifying". But this gives incorrect results for
     remove-redundant-alarms. *)
  let transfer modif m =
    if modif then Modif else if m = Start then SameVal else m

end

module BackwardScope (X : sig val modified : stmt -> bool end ) = struct

  let transfer_stmt stmt state = match stmt.skind  with
    | Instr _ -> State.transfer (X.modified stmt) state
    | _ -> state

  include State

end

let backward_data_scope modif_stmts s kf =
  let modified s = StmtSetLattice.mem s modif_stmts in
  let module Fenv = (val Dataflows.function_env kf: Dataflows.FUNCTION_ENV) in
  let module Arg = struct
    include BackwardScope(struct let modified = modified end)
    let init = [(s,State.Start)];;
  end in
  let module Compute = Dataflows.Simple_backward(Fenv)(Arg) in
  Compute.pre_state
;;

module ForwardScope (X : sig
    (* Effects of the statement itself *)
    val modified : stmt -> bool
    (* Effects of scope change *)
    val modified_by_edge: stmt -> stmt -> bool
  end) =
struct
  include State;;

  let transfer_stmt s state =
    let map_on_all_succs new_state =
      let do_succ s' =
        (s', State.transfer (X.modified_by_edge s s') new_state)
      in
      List.map do_succ s.succs
    in
    match s.skind with
    | Instr _ -> map_on_all_succs (State.transfer (X.modified s) state)
    | If _ | Switch _ -> map_on_all_succs (State.transfer false state)

    | Return _ | Throw _ -> []

    | UnspecifiedSequence _ | Loop _ | Block _
    | Goto _ | Break _ | Continue _
    | TryExcept _ | TryFinally _ | TryCatch _
      -> map_on_all_succs state
  ;;

end

let forward_data_scope modif_stmts modif_edge s kf =
  let modified s = StmtSetLattice.mem s modif_stmts in
  let module Fenv = (val Dataflows.function_env kf: Dataflows.FUNCTION_ENV) in
  let module Arg = struct
    include ForwardScope(struct
        let modified = modified
        let modified_by_edge = modif_edge
      end)
    let init = [(s,State.Start)];;
  end in
  let module Compute = Dataflows.Simple_forward(Fenv)(Arg) in
  Compute.pre_state, Compute.post_state
;;

(* Add only 'simple' statements. *)
let add_s s acc =
  match s.skind with
  | Instr _ | Return _ | Continue _ | Break _ | Goto _ | Throw _
    -> Cil_datatype.Stmt.Hptset.add s acc
  | Block _ | Switch _ | If _ | UnspecifiedSequence _ | Loop _
  | TryExcept _ | TryFinally _ | TryCatch _
    -> acc

(** Do backward and then forward propagations and compute the 3 statement sets :
 * - forward only,
 * - forward and backward,
 * - backward only.
*)
let find_scope allstmts modif_stmts modif_edge s kf =
  (* Add only statements for which the lvalue certainly did not change. *)
  let add get_state acc s =
    match get_state s with
    | State.Start | State.SameVal -> add_s s acc
    | _ -> acc
  in
  let _, fw_post = forward_data_scope modif_stmts modif_edge s kf in
  let fw = List.fold_left (add fw_post) Cil_datatype.Stmt.Hptset.empty allstmts in
  let bw_pre = backward_data_scope modif_stmts s kf in
  let bw = List.fold_left (add bw_pre)  Cil_datatype.Stmt.Hptset.empty allstmts in
  let fb = Cil_datatype.Stmt.Hptset.inter bw fw in
  let fw = Cil_datatype.Stmt.Hptset.diff fw fb in
  let bw = Cil_datatype.Stmt.Hptset.diff bw fb in
  fw, fb, bw

(* Computes the memory zones that points to a base in [escaping] in a state. *)
let gather_escaping_zones escaping = function
  | Cvalue.Model.Top -> Locations.Zone.top
  | Cvalue.Model.Bottom -> Locations.Zone.bottom
  | Cvalue.Model.Map m ->
    let aux base offsm zone =
      let test b = Base.Hptset.mem b escaping in
      let gather (_, _ as itv) (v, _, _) acc =
        let v = Cvalue.V_Or_Uninitialized.get_v v in
        if Cvalue.V.contains_addresses_of_locals test v
        then
          let z = Locations.Zone.inject base (Int_Intervals.inject_itv itv) in
          Locations.Zone.join acc z
        else acc
      in
      Cvalue.V_Offsetmap.fold gather offsm zone
    in
    Cvalue.Model.fold aux m Locations.Zone.bottom

(* compute the memory zones that are changed into ESCAPING ADDRESS
   when taking the cfg edge s1->s2 *)
let compute_escaping_zones s1 s2 =
  let closed_blocks = Kernel_function.blocks_closed_by_edge s1 s2 in
  let locals = List.flatten (List.map (fun b -> b.blocals) closed_blocks) in
  let filter acc v =
    if v.vtemp || not v.vreferenced
    then acc else Base.Hptset.add (Base.of_varinfo v) acc
  in
  let bases = List.fold_left filter Base.Hptset.empty locals in
  if Base.Hptset.is_empty bases
  then Locations.Zone.bottom
  else
    let cvalue_state = Eva.Results.(before s1 |> get_cvalue_model) in
    gather_escaping_zones bases cvalue_state

(* type pair_stmts = stmt * stmt *)
module PairStmts =
  Datatype.Pair_with_collections
    (Cil_datatype.Stmt)(Cil_datatype.Stmt)
    (struct let module_name = "Scope.Datascope.PairStmts" end)

(* Hashtbl from pairs of stmts to zone. Used as maps from Cfg edges to the
   memory zones that are 'modified' by thescope change. *)
module HashPairStmtsZone =
  PairStmts.Hashtbl.Make(Locations.Zone)
type modified_by_edge = HashPairStmtsZone.t

(* compute the {!modified_by_edge} hashtbl for the fundec [fdec] *)
let compute_modif_edge fdec : modified_by_edge =
  let modifs_edge = PairStmts.Hashtbl.create 17 in
  let do_stmt stmt =
    let do_succ stmt' =
      let z = compute_escaping_zones stmt stmt' in
      PairStmts.Hashtbl.add modifs_edge (stmt, stmt') z
    in
    List.iter do_succ stmt.succs
  in
  List.iter do_stmt fdec.sallstmts;
  modifs_edge

module ModifEdge =
  Cil_state_builder.Kernel_function_hashtbl(HashPairStmtsZone)
    (struct
      let name = "Scope.Datatscope.ModifsEdge"
      let dependencies = [Eva.Analysis.self]
      let size = 16
    end)

let modified_by_edge_kf =
  ModifEdge.memo
    (fun kf -> compute_modif_edge (Kernel_function.get_definition kf))

(* Does the Cfg edge [s1->s2] has an effect on [z]? *)
let is_modified_by_edge kf z s1 s2 =
  let modifs_edge = modified_by_edge_kf kf in
  Locations.Zone.intersects z (PairStmts.Hashtbl.find modifs_edge (s1, s2))

(** Try to find the statement set where [data] has the same value than
 * before [stmt].
 * @raise Kernel_function.No_Definition if [kf] has no definition
*)
let get_data_scope_at_stmt kf stmt lval =
  let zone = Eva.Results.(before stmt |> lval_deps lval) in
  let allstmts, info = compute kf in
  let modif_stmts = InitSid.find info zone in
  let modifs_edge = is_modified_by_edge kf zone in
  let (f_scope, fb_scope, b_scope) =
    find_scope allstmts modif_stmts modifs_edge stmt kf
  in
  R.debug
    "@[<hv 4>get_data_scope_at_stmt %a at %d @\n\
     modified by = %a@\n\
     f = %a@\nfb = %a@\nb = %a@]"
    (* stmt at *)
    Locations.Zone.pretty zone stmt.sid
    (* modified by *)
    (Pretty_utils.pp_iter
       StmtSetLattice.iter ~sep:",@ " Cil_datatype.Stmt.pretty_sid)
    modif_stmts
    (* scope *)
    Cil_datatype.Stmt.Hptset.pretty f_scope
    Cil_datatype.Stmt.Hptset.pretty fb_scope
    Cil_datatype.Stmt.Hptset.pretty b_scope;
  (f_scope, (fb_scope, b_scope))

exception ToDo

let get_annot_zone kf stmt annot =
  let add_zone z info =
    let s = info.Logic_deps.ki in
    let before = info.Logic_deps.before in
    let zone = info.Logic_deps.zone in
    R.debug ~level:2 "[forward_prop_scope] need %a %s stmt %d@."
      Locations.Zone.pretty zone
      (if before then "before" else "after") s.sid;
    if before && stmt.sid = s.sid then
      Locations.Zone.join zone z
    else (* TODO *)
      raise ToDo
  in
  let (info, _), _ = Logic_deps.from_stmt_annot annot (stmt, kf) in
  match info with
  | None -> raise ToDo
  | Some info ->
    let zone = List.fold_left add_zone Locations.Zone.bottom info in
    R.debug "[get_annot_zone] need %a" Locations.Zone.pretty zone ;
    zone


module CA_Map = Cil_datatype.Code_annotation.Map

type proven = (stmt * code_annotation * stmt) CA_Map.t
(** Type of the properties proven so far. A binding
    [ca -> (stmt_ca, ca_because, stmt_because)] must be read as "[ca] at
    statement [stmt_ca] is a logical consequence of [ca_because] at statement
    [stmt_because]".
    Currently, [ca] and [ca_because] are always exactly the same ACSL assertion,
    although this may be extended in the future. *)

(** Assertions proven so far, as a list *)
let list_proven (m:proven) =
  CA_Map.fold (fun ca _ acc -> ca :: acc) m []

(** [add_proven_annot proven because] add the fact that [proven] is proven
    thanks to [because]. This function also returns a boolean indicating
    that [proven] was not already proven. *)
let add_proven_annot (ca, stmt_ca) (ca_because, stmt_because) acc =
  if CA_Map.mem ca acc then
    (* already proven *)
    acc, false
  else
    CA_Map.add ca (stmt_ca, ca_because, stmt_because) acc, true

(** Check if an assertion at [stmt] is identical to [ca] (itself emitted
    at [stmt_ca]). Add them to acc if any *)
let check_stmt_annots (ca, stmt_ca) stmt acc =
  let check _ annot acc =
    match ca.annot_content, annot.annot_content with
    | AAssert (_, p'), AAssert (_, p)
      when p'.tp_kind <> Check && p.tp_kind <> Admit ->
      let p = p.tp_statement.pred_content in
      let p' = p'.tp_statement.pred_content in
      if Logic_utils.is_same_predicate_node p p' then
        let acc, added = add_proven_annot (annot, stmt) (ca, stmt_ca) acc in
        if added then
          R.debug "annot at stmt %d could be removed: %a"
            stmt.sid Printer.pp_code_annotation annot;
        acc
      else
        acc
    | _ -> acc
  in
  Annotations.fold_code_annot check stmt acc

exception VolatileFound

(* This visitor detects the presence of a volatile logic l-value. Such a
   l-value may evaluate differently at different program point. *)
class containsVolatile = object
  inherit Visitor.frama_c_inplace

  method! vterm t =
    match t.term_node with
    | TLval tlv -> if Cil.isVolatileTermLval tlv then raise VolatileFound ;
      Cil.DoChildren
    | _ -> Cil.DoChildren

end

let code_annot_is_volatile ca =
  let vis = new containsVolatile in
  try ignore (Visitor.visitFramacCodeAnnotation vis ca); false
  with VolatileFound -> true

(** Return the set of stmts ([scope]) where [annot] has the same value
    as at [stmt], and adds to [proven] the annotations that are identical to
    [annot] at statements that are both in [scope] and dominated by [stmt].
    [stmt] is not added to the set, and [annot] is not added to [proven]. *)
let get_prop_scope_at_stmt ~warn kf stmt ?(proven=CA_Map.empty) annot =
  R.debug "[get_prop_scope_at_stmt] at stmt %d in %a : %a"
    stmt.sid Kernel_function.pretty kf
    Printer.pp_code_annotation annot;
  let acc = (Cil_datatype.Stmt.Hptset.empty, proven) in
  if code_annot_is_volatile annot then acc
  else
    try
      let zone =  get_annot_zone kf stmt annot in
      let allstmts, info = compute kf in
      let modif_stmts = InitSid.find info zone in
      let modifs_edge = is_modified_by_edge kf zone in
      let pre_state, _ = forward_data_scope modif_stmts modifs_edge stmt kf in
      begin match annot.annot_content with
        | AAssert _ -> ()
        | _ -> R.abort "only 'assert' are handled by get_prop_scope_at_stmt"
      end;
      let add ((acc_scope, acc_to_be_rm) as acc) s = match pre_state s with
        | State.SameVal ->
          if Dominators.dominates stmt s && not (Cil_datatype.Stmt.equal stmt s)
          then
            let acc_scope = add_s s acc_scope in
            let acc_to_be_rm = check_stmt_annots (annot, stmt) s acc_to_be_rm in
            (acc_scope, acc_to_be_rm)
          else acc
        | _ -> acc
      in
      List.fold_left add acc allstmts
    with ToDo ->
      if warn then
        R.warning ~current:true ~once:true
          "[get_annot_zone] don't know how to compute zone: skip this annotation";
      acc

(** Collect the annotations that can be removed because they are redundant. *)
class check_annot_visitor = object(self)

  inherit Visitor.frama_c_inplace

  val mutable proven = CA_Map.empty

  method proven () = proven

  method! vcode_annot annot =
    let kf = Option.get self#current_kf in
    let stmt =
      Visitor_behavior.Get_orig.stmt
        self#behavior (Option.get self#current_stmt)
    in
    begin match annot.annot_content with
      | AAssert _ ->
        R.debug ~level:2 "[check] annot %d at stmt %d in %a : %a@."
          annot.annot_id stmt.sid Kernel_function.pretty kf
          Printer.pp_code_annotation annot;
        let _scope, proven' =
          get_prop_scope_at_stmt ~warn:false kf stmt ~proven annot
        in
        proven <- proven'
      | _ -> ()
    end;
    Cil.SkipChildren

  method! vglob_aux g = match g with
    | GFun _ when Eva.Results.are_available (Option.get self#current_kf) ->
      Cil.DoChildren
    | _ -> Cil.SkipChildren

  method! vexpr _ = Cil.SkipChildren

end (* class check_annot_visitor *)

let redundant_assertions () =
  let visitor = new check_annot_visitor in
  ignore (Visitor.visitFramacFile
            (visitor:>Visitor.frama_c_visitor)
            (Ast.get ()));
  visitor#proven ()

let check_asserts () =
  R.feedback "check if there are some redundant assertions...";
  let to_be_removed = redundant_assertions () in
  let n = CA_Map.cardinal to_be_removed in
  R.result "[check_asserts] %d assertion(s) could be removed@." n;
  (list_proven to_be_removed)

(* erasing optional arguments, plus return a list*)
let get_prop_scope_at_stmt kf stmt annot =
  let s, m = get_prop_scope_at_stmt ~warn:true kf stmt annot in
  s, list_proven m

(* Currently lazy, because we need to define it after Value has been registered
   in Db *)
let emitter = lazy (
  let conv = List.map Typed_parameter.get in
  let correctness = conv (Emitter.correctness_parameters Eva.Analysis.emitter) in
  let tuning = conv (Emitter.tuning_parameters Eva.Analysis.emitter) in
  Emitter.create "RedundantAlarms" [Emitter.Property_status]
    ~correctness ~tuning)

(** Mark as proved the annotations collected by [check_asserts]. *)
let rm_asserts () =
  let to_be_removed = redundant_assertions () in
  let n = CA_Map.cardinal to_be_removed in
  if n > 0 then begin
    R.feedback ~dkey:cat_rm_asserts "removing %d assertion(s)@." n;
    let aux ca (stmt_ca, ca_because, stmt_because) =
      let loc = Cil_datatype.Stmt.loc stmt_ca in
      R.result ~source:(fst loc) ~dkey:cat_rm_asserts ~level:2
        "@[removing redundant@ %a@]" Printer.pp_code_annotation ca;
      let kf = Kernel_function.find_englobing_kf stmt_ca in
      let ip_ca = Property.ip_of_code_annot_single kf stmt_ca ca in
      let ip_because =
        Property.ip_of_code_annot_single kf stmt_because ca_because
      in
      let e = Lazy.force emitter in
      Property_status.emit e ~hyps:[ip_because] ip_ca Property_status.True
    in
    CA_Map.iter aux to_be_removed
  end

let rm_asserts =
  Dynamic.register
    ~comment:"Remove redundant alarms. Used by the Eva plugin."
    ~plugin:name
    "rm_asserts"
    Datatype.(func unit unit)
    rm_asserts

(*
Local Variables:
compile-command: "make -C ../../.."
End:
*)
OCaml

Innovation. Community. Security.