summaryrefslogtreecommitdiff
path: root/js/xpconnect/src/XPCWrappedNativeJSOps.cpp
blob: 737638af98cccf63abee879be37f6cd549d4269b (plain)
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
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* JavaScript JSClasses and JSOps for our Wrapped Native JS Objects. */

#include "xpcprivate.h"
#include "xpc_make_class.h"
#include "jsprf.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/Preferences.h"
#include "nsIAddonInterposition.h"
#include "AddonWrapper.h"
#include "js/Class.h"
#include "nsContentUtils.h"

using namespace mozilla;
using namespace JS;

/***************************************************************************/

// All of the exceptions thrown into JS from this file go through here.
// That makes this a nice place to set a breakpoint.

static bool Throw(nsresult errNum, JSContext* cx)
{
    XPCThrower::Throw(errNum, cx);
    return false;
}

// Handy macro used in many callback stub below.

#define THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper)                          \
    PR_BEGIN_MACRO                                                            \
    if (!wrapper)                                                             \
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);                    \
    if (!wrapper->IsValid())                                                  \
        return Throw(NS_ERROR_XPC_HAS_BEEN_SHUTDOWN, cx);                     \
    PR_END_MACRO

/***************************************************************************/

static bool
ToStringGuts(XPCCallContext& ccx)
{
    char* sz;
    XPCWrappedNative* wrapper = ccx.GetWrapper();

    if (wrapper)
        sz = wrapper->ToString(ccx.GetTearOff());
    else
        sz = JS_smprintf("[xpconnect wrapped native prototype]");

    if (!sz) {
        JS_ReportOutOfMemory(ccx);
        return false;
    }

    JSString* str = JS_NewStringCopyZ(ccx, sz);
    JS_smprintf_free(sz);
    if (!str)
        return false;

    ccx.SetRetVal(JS::StringValue(str));
    return true;
}

/***************************************************************************/

static bool
XPC_WN_Shared_ToString(JSContext* cx, unsigned argc, Value* vp)
{
    CallArgs args = CallArgsFromVp(argc, vp);
    RootedObject obj(cx, JS_THIS_OBJECT(cx, vp));
    if (!obj)
        return false;

    XPCCallContext ccx(cx, obj);
    if (!ccx.IsValid())
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);
    ccx.SetName(ccx.GetContext()->GetStringID(XPCJSContext::IDX_TO_STRING));
    ccx.SetArgsAndResultPtr(args.length(), args.array(), vp);
    return ToStringGuts(ccx);
}

static bool
XPC_WN_Shared_ToSource(JSContext* cx, unsigned argc, Value* vp)
{
    CallArgs args = CallArgsFromVp(argc, vp);
    static const char empty[] = "({})";
    JSString* str = JS_NewStringCopyN(cx, empty, sizeof(empty)-1);
    if (!str)
        return false;
    args.rval().setString(str);

    return true;
}

static bool
XPC_WN_Shared_toPrimitive(JSContext* cx, unsigned argc, Value* vp)
{
    CallArgs args = CallArgsFromVp(argc, vp);

    RootedObject obj(cx);
    if (!JS_ValueToObject(cx, args.thisv(), &obj))
        return false;
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    JSType hint;
    if (!GetFirstArgumentAsTypeHint(cx, args, &hint))
        return false;

    if (hint == JSTYPE_NUMBER) {
        args.rval().set(JS_GetNaNValue(cx));
        return true;
    }

    MOZ_ASSERT(hint == JSTYPE_STRING || hint == JSTYPE_VOID);
    ccx.SetName(ccx.GetContext()->GetStringID(XPCJSContext::IDX_TO_STRING));
    ccx.SetArgsAndResultPtr(0, nullptr, args.rval().address());

    XPCNativeMember* member = ccx.GetMember();
    if (member && member->IsMethod()) {
        if (!XPCWrappedNative::CallMethod(ccx))
            return false;

        if (args.rval().isPrimitive())
            return true;
    }

    // else...
    return ToStringGuts(ccx);
}

/***************************************************************************/

// A "double wrapped object" is a user JSObject that has been wrapped as a
// wrappedJS in order to be used by native code and then re-wrapped by a
// wrappedNative wrapper to be used by JS code. One might think of it as:
//    wrappedNative(wrappedJS(underlying_JSObject))
// This is done (as opposed to just unwrapping the wrapped JS and automatically
// returning the underlying JSObject) so that JS callers will see what looks
// Like any other xpcom object - and be limited to use its interfaces.
//
// See the comment preceding nsIXPCWrappedJSObjectGetter in nsIXPConnect.idl.

static JSObject*
GetDoubleWrappedJSObject(XPCCallContext& ccx, XPCWrappedNative* wrapper)
{
    RootedObject obj(ccx);
    nsCOMPtr<nsIXPConnectWrappedJS>
        underware = do_QueryInterface(wrapper->GetIdentityObject());
    if (underware) {
        RootedObject mainObj(ccx, underware->GetJSObject());
        if (mainObj) {
            RootedId id(ccx, ccx.GetContext()->
                            GetStringID(XPCJSContext::IDX_WRAPPED_JSOBJECT));

            JSAutoCompartment ac(ccx, mainObj);

            RootedValue val(ccx);
            if (JS_GetPropertyById(ccx, mainObj, id, &val) &&
                !val.isPrimitive()) {
                obj = val.toObjectOrNull();
            }
        }
    }
    return obj;
}

// This is the getter native function we use to handle 'wrappedJSObject' for
// double wrapped JSObjects.

static bool
XPC_WN_DoubleWrappedGetter(JSContext* cx, unsigned argc, Value* vp)
{
    CallArgs args = CallArgsFromVp(argc, vp);

    RootedObject obj(cx, JS_THIS_OBJECT(cx, vp));
    if (!obj)
        return false;

    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    MOZ_ASSERT(JS_TypeOfValue(cx, args.calleev()) == JSTYPE_FUNCTION, "bad function");

    RootedObject realObject(cx, GetDoubleWrappedJSObject(ccx, wrapper));
    if (!realObject) {
        // This is pretty unexpected at this point. The object originally
        // responded to this get property call and now gives no object.
        // XXX Should this throw something at the caller?
        args.rval().setNull();
        return true;
    }

    // It is a double wrapped object. This should really never appear in
    // content these days, but addons still do it - see bug 965921.
    if (MOZ_UNLIKELY(!nsContentUtils::IsCallerChrome())) {
        JS_ReportErrorASCII(cx, "Attempt to use .wrappedJSObject in untrusted code");
        return false;
    }
    args.rval().setObject(*realObject);
    return JS_WrapValue(cx, args.rval());
}

/***************************************************************************/

// This is our shared function to define properties on our JSObjects.

/*
 * NOTE:
 * We *never* set the tearoff names (e.g. nsIFoo) as JS_ENUMERATE.
 * We *never* set toString or toSource as JS_ENUMERATE.
 */

static bool
DefinePropertyIfFound(XPCCallContext& ccx,
                      HandleObject obj,
                      HandleId idArg,
                      XPCNativeSet* set,
                      XPCNativeInterface* ifaceArg,
                      XPCNativeMember* member,
                      XPCWrappedNativeScope* scope,
                      bool reflectToStringAndToSource,
                      XPCWrappedNative* wrapperToReflectInterfaceNames,
                      XPCWrappedNative* wrapperToReflectDoubleWrap,
                      XPCNativeScriptableInfo* scriptableInfo,
                      unsigned propFlags,
                      bool* resolved)
{
    RootedId id(ccx, idArg);
    RefPtr<XPCNativeInterface> iface = ifaceArg;
    XPCJSContext* xpccx = ccx.GetContext();
    bool found;
    const char* name;

    propFlags |= JSPROP_RESOLVING;

    if (set) {
        if (iface)
            found = true;
        else
            found = set->FindMember(id, &member, &iface);
    } else
        found = (nullptr != (member = iface->FindMember(id)));

    if (!found) {
        if (reflectToStringAndToSource) {
            JSNative call;
            uint32_t flags = 0;

            if (scriptableInfo) {
                nsCOMPtr<nsIClassInfo> classInfo = do_QueryInterface(
                    scriptableInfo->GetCallback());

                if (classInfo) {
                    nsresult rv = classInfo->GetFlags(&flags);
                    if (NS_FAILED(rv))
                        return Throw(rv, ccx);
                }
            }

            bool overwriteToString = !(flags & nsIClassInfo::DOM_OBJECT)
                || Preferences::GetBool("dom.XPCToStringForDOMClasses", false);

            if(id == xpccx->GetStringID(XPCJSContext::IDX_TO_STRING)
                && overwriteToString)
            {
                call = XPC_WN_Shared_ToString;
                name = xpccx->GetStringName(XPCJSContext::IDX_TO_STRING);
            } else if (id == xpccx->GetStringID(XPCJSContext::IDX_TO_SOURCE)) {
                call = XPC_WN_Shared_ToSource;
                name = xpccx->GetStringName(XPCJSContext::IDX_TO_SOURCE);
            } else if (id == SYMBOL_TO_JSID(
                               JS::GetWellKnownSymbol(ccx, JS::SymbolCode::toPrimitive)))
            {
                call = XPC_WN_Shared_toPrimitive;
                name = "[Symbol.toPrimitive]";
            } else {
                call = nullptr;
            }

            if (call) {
                RootedFunction fun(ccx, JS_NewFunction(ccx, call, 0, 0, name));
                if (!fun) {
                    JS_ReportOutOfMemory(ccx);
                    return false;
                }

                AutoResolveName arn(ccx, id);
                if (resolved)
                    *resolved = true;
                RootedObject value(ccx, JS_GetFunctionObject(fun));
                return JS_DefinePropertyById(ccx, obj, id, value,
                                             propFlags & ~JSPROP_ENUMERATE);
            }
        }
        // This *might* be a tearoff name that is not yet part of our
        // set. Let's lookup the name and see if it is the name of an
        // interface. Then we'll see if the object actually *does* this
        // interface and add a tearoff as necessary.

        if (wrapperToReflectInterfaceNames) {
            JSAutoByteString name;
            RefPtr<XPCNativeInterface> iface2;
            XPCWrappedNativeTearOff* to;
            RootedObject jso(ccx);
            nsresult rv = NS_OK;

            if (JSID_IS_STRING(id) &&
                name.encodeLatin1(ccx, JSID_TO_STRING(id)) &&
                (iface2 = XPCNativeInterface::GetNewOrUsed(name.ptr()), iface2) &&
                nullptr != (to = wrapperToReflectInterfaceNames->
                           FindTearOff(iface2, true, &rv)) &&
                nullptr != (jso = to->GetJSObject()))

            {
                AutoResolveName arn(ccx, id);
                if (resolved)
                    *resolved = true;
                return JS_DefinePropertyById(ccx, obj, id, jso,
                                             propFlags & ~JSPROP_ENUMERATE);
            } else if (NS_FAILED(rv) && rv != NS_ERROR_NO_INTERFACE) {
                return Throw(rv, ccx);
            }
        }

        // This *might* be a double wrapped JSObject
        if (wrapperToReflectDoubleWrap &&
            id == xpccx->GetStringID(XPCJSContext::IDX_WRAPPED_JSOBJECT) &&
            GetDoubleWrappedJSObject(ccx, wrapperToReflectDoubleWrap)) {
            // We build and add a getter function.
            // A security check is done on a per-get basis.

            JSFunction* fun;

            id = xpccx->GetStringID(XPCJSContext::IDX_WRAPPED_JSOBJECT);
            name = xpccx->GetStringName(XPCJSContext::IDX_WRAPPED_JSOBJECT);

            fun = JS_NewFunction(ccx, XPC_WN_DoubleWrappedGetter,
                                 0, 0, name);

            if (!fun)
                return false;

            RootedObject funobj(ccx, JS_GetFunctionObject(fun));
            if (!funobj)
                return false;

            propFlags |= JSPROP_GETTER | JSPROP_SHARED;
            propFlags &= ~JSPROP_ENUMERATE;

            AutoResolveName arn(ccx, id);
            if (resolved)
                *resolved = true;
            return JS_DefinePropertyById(ccx, obj, id, UndefinedHandleValue, propFlags,
                                         JS_DATA_TO_FUNC_PTR(JSNative, funobj.get()),
                                         nullptr);
        }

        if (resolved)
            *resolved = false;
        return true;
    }

    if (!member) {
        if (wrapperToReflectInterfaceNames) {
            XPCWrappedNativeTearOff* to =
              wrapperToReflectInterfaceNames->FindTearOff(iface, true);

            if (!to)
                return false;
            RootedObject jso(ccx, to->GetJSObject());
            if (!jso)
                return false;

            AutoResolveName arn(ccx, id);
            if (resolved)
                *resolved = true;
            return JS_DefinePropertyById(ccx, obj, id, jso,
                                         propFlags & ~JSPROP_ENUMERATE);
        }
        if (resolved)
            *resolved = false;
        return true;
    }

    if (member->IsConstant()) {
        RootedValue val(ccx);
        AutoResolveName arn(ccx, id);
        if (resolved)
            *resolved = true;
        return member->GetConstantValue(ccx, iface, val.address()) &&
               JS_DefinePropertyById(ccx, obj, id, val, propFlags);
    }

    if (scope->HasInterposition()) {
        Rooted<PropertyDescriptor> desc(ccx);
        if (!xpc::InterposeProperty(ccx, obj, iface->GetIID(), id, &desc))
            return false;

        if (desc.object()) {
            AutoResolveName arn(ccx, id);
            if (resolved)
                *resolved = true;
            desc.attributesRef() |= JSPROP_RESOLVING;
            return JS_DefinePropertyById(ccx, obj, id, desc);
        }
    }

    if (id == xpccx->GetStringID(XPCJSContext::IDX_TO_STRING) ||
        id == xpccx->GetStringID(XPCJSContext::IDX_TO_SOURCE) ||
        (scriptableInfo &&
         scriptableInfo->GetFlags().DontEnumQueryInterface() &&
         id == xpccx->GetStringID(XPCJSContext::IDX_QUERY_INTERFACE)))
        propFlags &= ~JSPROP_ENUMERATE;

    RootedValue funval(ccx);
    if (!member->NewFunctionObject(ccx, iface, obj, funval.address()))
        return false;

    if (member->IsMethod()) {
        AutoResolveName arn(ccx, id);
        if (resolved)
            *resolved = true;
        return JS_DefinePropertyById(ccx, obj, id, funval, propFlags);
    }

    // else...

    MOZ_ASSERT(member->IsAttribute(), "way broken!");

    propFlags |= JSPROP_GETTER | JSPROP_SHARED;
    propFlags &= ~JSPROP_READONLY;
    JSObject* funobj = funval.toObjectOrNull();
    JSNative getter = JS_DATA_TO_FUNC_PTR(JSNative, funobj);
    JSNative setter;
    if (member->IsWritableAttribute()) {
        propFlags |= JSPROP_SETTER;
        setter = JS_DATA_TO_FUNC_PTR(JSNative, funobj);
    } else {
        setter = nullptr;
    }

    AutoResolveName arn(ccx, id);
    if (resolved)
        *resolved = true;

    return JS_DefinePropertyById(ccx, obj, id, UndefinedHandleValue, propFlags, getter, setter);
}

/***************************************************************************/
/***************************************************************************/

static bool
XPC_WN_OnlyIWrite_AddPropertyStub(JSContext* cx, HandleObject obj, HandleId id, HandleValue v)
{
    XPCCallContext ccx(cx, obj, nullptr, id);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    // Allow only XPConnect to add/set the property
    if (ccx.GetResolveName() == id)
        return true;

    return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx);
}

bool
XPC_WN_CannotModifyPropertyStub(JSContext* cx, HandleObject obj, HandleId id,
                                HandleValue v)
{
    return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx);
}

bool
XPC_WN_CantDeletePropertyStub(JSContext* cx, HandleObject obj, HandleId id,
                              ObjectOpResult& result)
{
    return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx);
}

bool
XPC_WN_CannotModifySetPropertyStub(JSContext* cx, HandleObject obj, HandleId id,
                                   MutableHandleValue vp, ObjectOpResult& result)
{
    return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx);
}

bool
XPC_WN_Shared_Enumerate(JSContext* cx, HandleObject obj)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    // Since we aren't going to enumerate tearoff names and the prototype
    // handles non-mutated members, we can do this potential short-circuit.
    if (!wrapper->HasMutatedSet())
        return true;

    XPCNativeSet* set = wrapper->GetSet();
    XPCNativeSet* protoSet = wrapper->HasProto() ?
                                wrapper->GetProto()->GetSet() : nullptr;

    uint16_t interface_count = set->GetInterfaceCount();
    XPCNativeInterface** interfaceArray = set->GetInterfaceArray();
    for (uint16_t i = 0; i < interface_count; i++) {
        XPCNativeInterface* iface = interfaceArray[i];
        uint16_t member_count = iface->GetMemberCount();
        for (uint16_t k = 0; k < member_count; k++) {
            XPCNativeMember* member = iface->GetMemberAt(k);
            jsid name = member->GetName();

            // Skip if this member is going to come from the proto.
            uint16_t index;
            if (protoSet &&
                protoSet->FindMember(name, nullptr, &index) && index == i)
                continue;
            if (!xpc_ForcePropertyResolve(cx, obj, name))
                return false;
        }
    }
    return true;
}

/***************************************************************************/

enum WNHelperType {
    WN_NOHELPER,
    WN_HELPER
};

static void
WrappedNativeFinalize(js::FreeOp* fop, JSObject* obj, WNHelperType helperType)
{
    const js::Class* clazz = js::GetObjectClass(obj);
    if (clazz->flags & JSCLASS_DOM_GLOBAL) {
        mozilla::dom::DestroyProtoAndIfaceCache(obj);
    }
    nsISupports* p = static_cast<nsISupports*>(xpc_GetJSPrivate(obj));
    if (!p)
        return;

    XPCWrappedNative* wrapper = static_cast<XPCWrappedNative*>(p);
    if (helperType == WN_HELPER)
        wrapper->GetScriptableCallback()->Finalize(wrapper, js::CastToJSFreeOp(fop), obj);
    wrapper->FlatJSObjectFinalized();
}

static void
WrappedNativeObjectMoved(JSObject* obj, const JSObject* old)
{
    nsISupports* p = static_cast<nsISupports*>(xpc_GetJSPrivate(obj));
    if (!p)
        return;

    XPCWrappedNative* wrapper = static_cast<XPCWrappedNative*>(p);
    wrapper->FlatJSObjectMoved(obj, old);
}

void
XPC_WN_NoHelper_Finalize(js::FreeOp* fop, JSObject* obj)
{
    WrappedNativeFinalize(fop, obj, WN_NOHELPER);
}

/*
 * General comment about XPConnect tracing: Given a C++ object |wrapper| and its
 * corresponding JS object |obj|, calling |wrapper->TraceSelf| will ask the JS
 * engine to mark |obj|. Eventually, this will lead to the trace hook being
 * called for |obj|. The trace hook should call |wrapper->TraceInside|, which
 * should mark any JS objects held by |wrapper| as members.
 */

/* static */ void
XPCWrappedNative::Trace(JSTracer* trc, JSObject* obj)
{
    const js::Class* clazz = js::GetObjectClass(obj);
    if (clazz->flags & JSCLASS_DOM_GLOBAL) {
        mozilla::dom::TraceProtoAndIfaceCache(trc, obj);
    }
    MOZ_ASSERT(IS_WN_CLASS(clazz));

    XPCWrappedNative* wrapper = XPCWrappedNative::Get(obj);
    if (wrapper && wrapper->IsValid())
        wrapper->TraceInside(trc);
}

void
XPCWrappedNative_Trace(JSTracer* trc, JSObject* obj)
{
    XPCWrappedNative::Trace(trc, obj);
}

static bool
XPC_WN_NoHelper_Resolve(JSContext* cx, HandleObject obj, HandleId id, bool* resolvedp)
{
    XPCCallContext ccx(cx, obj, nullptr, id);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    XPCNativeSet* set = ccx.GetSet();
    if (!set)
        return true;

    // Don't resolve properties that are on our prototype.
    if (ccx.GetInterface() && !ccx.GetStaticMemberIsLocal())
        return true;

    return DefinePropertyIfFound(ccx, obj, id,
                                 set, nullptr, nullptr, wrapper->GetScope(),
                                 true, wrapper, wrapper, nullptr,
                                 JSPROP_ENUMERATE |
                                 JSPROP_READONLY |
                                 JSPROP_PERMANENT,
                                 resolvedp);
}

static const js::ClassOps XPC_WN_NoHelper_JSClassOps = {
    XPC_WN_OnlyIWrite_AddPropertyStub, // addProperty
    XPC_WN_CantDeletePropertyStub,     // delProperty
    nullptr,                           // getProperty
    nullptr,                           // setProperty
    XPC_WN_Shared_Enumerate,           // enumerate
    XPC_WN_NoHelper_Resolve,           // resolve
    nullptr,                           // mayResolve
    XPC_WN_NoHelper_Finalize,          // finalize
    nullptr,                           // call
    nullptr,                           // construct
    nullptr,                           // hasInstance
    XPCWrappedNative::Trace,           // trace
};

const js::ClassExtension XPC_WN_JSClassExtension = {
    nullptr, // weakmapKeyDelegateOp
    WrappedNativeObjectMoved
};

const js::Class XPC_WN_NoHelper_JSClass = {
    "XPCWrappedNative_NoHelper",
    XPC_WRAPPER_FLAGS |
    JSCLASS_IS_WRAPPED_NATIVE |
    JSCLASS_PRIVATE_IS_NSISUPPORTS |
    JSCLASS_FOREGROUND_FINALIZE,
    &XPC_WN_NoHelper_JSClassOps,
    JS_NULL_CLASS_SPEC,
    &XPC_WN_JSClassExtension,
    JS_NULL_OBJECT_OPS
};


/***************************************************************************/

bool
XPC_WN_MaybeResolvingPropertyStub(JSContext* cx, HandleObject obj, HandleId id, HandleValue v)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    if (ccx.GetResolvingWrapper() == wrapper)
        return true;
    return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx);
}

bool
XPC_WN_MaybeResolvingSetPropertyStub(JSContext* cx, HandleObject obj, HandleId id,
                                     MutableHandleValue vp, ObjectOpResult& result)
{
    result.succeed();
    return XPC_WN_MaybeResolvingPropertyStub(cx, obj, id, vp);
}

bool
XPC_WN_MaybeResolvingDeletePropertyStub(JSContext* cx, HandleObject obj, HandleId id,
                                        ObjectOpResult& result)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    if (ccx.GetResolvingWrapper() == wrapper) {
        return result.succeed();
    }
    return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx);
}

// macro fun!
#define PRE_HELPER_STUB                                                       \
    /* It's very important for "unwrapped" to be rooted here.  */             \
    RootedObject unwrapped(cx, js::CheckedUnwrap(obj, false));                \
    if (!unwrapped) {                                                         \
        JS_ReportErrorASCII(cx, "Permission denied to operate on object.");   \
        return false;                                                         \
    }                                                                         \
    if (!IS_WN_REFLECTOR(unwrapped)) {                                        \
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);                    \
    }                                                                         \
    XPCWrappedNative* wrapper = XPCWrappedNative::Get(unwrapped);             \
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);                             \
    bool retval = true;                                                       \
    nsresult rv = wrapper->GetScriptableCallback()->

#define POST_HELPER_STUB                                                      \
    if (NS_FAILED(rv))                                                        \
        return Throw(rv, cx);                                                 \
    return retval;

#define POST_HELPER_STUB_WITH_OBJECTOPRESULT(failMethod)                      \
    if (NS_FAILED(rv))                                                        \
        return Throw(rv, cx);                                                 \
    return retval ? result.succeed() : result.failMethod();

bool
XPC_WN_Helper_GetProperty(JSContext* cx, HandleObject obj, HandleId id,
                          MutableHandleValue vp)
{
    PRE_HELPER_STUB
    GetProperty(wrapper, cx, obj, id, vp.address(), &retval);
    POST_HELPER_STUB
}

bool
XPC_WN_Helper_SetProperty(JSContext* cx, HandleObject obj, HandleId id,
                          MutableHandleValue vp, ObjectOpResult& result)
{
    PRE_HELPER_STUB
    SetProperty(wrapper, cx, obj, id, vp.address(), &retval);
    POST_HELPER_STUB_WITH_OBJECTOPRESULT(failReadOnly)
}

bool
XPC_WN_Helper_Call(JSContext* cx, unsigned argc, Value* vp)
{
    JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
    // N.B. we want obj to be the callee, not JS_THIS(cx, vp)
    RootedObject obj(cx, &args.callee());

    XPCCallContext ccx(cx, obj, nullptr, JSID_VOIDHANDLE, args.length(),
                       args.array(), args.rval().address());
    if (!ccx.IsValid())
        return false;

    PRE_HELPER_STUB
    Call(wrapper, cx, obj, args, &retval);
    POST_HELPER_STUB
}

bool
XPC_WN_Helper_Construct(JSContext* cx, unsigned argc, Value* vp)
{
    JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
    RootedObject obj(cx, &args.callee());
    if (!obj)
        return false;

    XPCCallContext ccx(cx, obj, nullptr, JSID_VOIDHANDLE, args.length(),
                       args.array(), args.rval().address());
    if (!ccx.IsValid())
        return false;

    PRE_HELPER_STUB
    Construct(wrapper, cx, obj, args, &retval);
    POST_HELPER_STUB
}

bool
XPC_WN_Helper_HasInstance(JSContext* cx, HandleObject obj, MutableHandleValue valp, bool* bp)
{
    bool retval2;
    PRE_HELPER_STUB
    HasInstance(wrapper, cx, obj, valp, &retval2, &retval);
    *bp = retval2;
    POST_HELPER_STUB
}

void
XPC_WN_Helper_Finalize(js::FreeOp* fop, JSObject* obj)
{
    WrappedNativeFinalize(fop, obj, WN_HELPER);
}

bool
XPC_WN_Helper_Resolve(JSContext* cx, HandleObject obj, HandleId id, bool* resolvedp)
{
    nsresult rv = NS_OK;
    bool retval = true;
    bool resolved = false;
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    RootedId old(cx, ccx.SetResolveName(id));

    XPCNativeScriptableInfo* si = wrapper->GetScriptableInfo();
    if (si && si->GetFlags().WantResolve()) {
        XPCWrappedNative* oldResolvingWrapper;
        bool allowPropMods = si->GetFlags().AllowPropModsDuringResolve();

        if (allowPropMods)
            oldResolvingWrapper = ccx.SetResolvingWrapper(wrapper);

        rv = si->GetCallback()->Resolve(wrapper, cx, obj, id, &resolved, &retval);

        if (allowPropMods)
            (void)ccx.SetResolvingWrapper(oldResolvingWrapper);
    }

    old = ccx.SetResolveName(old);
    MOZ_ASSERT(old == id, "bad nest");

    if (NS_FAILED(rv)) {
        return Throw(rv, cx);
    }

    if (resolved) {
        *resolvedp = true;
    } else if (wrapper->HasMutatedSet()) {
        // We are here if scriptable did not resolve this property and
        // it *might* be in the instance set but not the proto set.

        XPCNativeSet* set = wrapper->GetSet();
        XPCNativeSet* protoSet = wrapper->HasProto() ?
                                    wrapper->GetProto()->GetSet() : nullptr;
        XPCNativeMember* member = nullptr;
        RefPtr<XPCNativeInterface> iface;
        bool IsLocal = false;

        if (set->FindMember(id, &member, &iface, protoSet, &IsLocal) &&
            IsLocal) {
            XPCWrappedNative* oldResolvingWrapper;

            XPCNativeScriptableFlags siFlags(0);
            if (si)
                siFlags = si->GetFlags();

            XPCWrappedNative* wrapperForInterfaceNames =
                siFlags.DontReflectInterfaceNames() ? nullptr : wrapper;

            oldResolvingWrapper = ccx.SetResolvingWrapper(wrapper);
            retval = DefinePropertyIfFound(ccx, obj, id,
                                           set, iface, member,
                                           wrapper->GetScope(),
                                           false,
                                           wrapperForInterfaceNames,
                                           nullptr, si,
                                           JSPROP_ENUMERATE, resolvedp);
            (void)ccx.SetResolvingWrapper(oldResolvingWrapper);
        }
    }

    return retval;
}

bool
XPC_WN_Helper_Enumerate(JSContext* cx, HandleObject obj)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    XPCNativeScriptableInfo* si = wrapper->GetScriptableInfo();
    if (!si || !si->GetFlags().WantEnumerate())
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);

    if (!XPC_WN_Shared_Enumerate(cx, obj))
        return false;

    bool retval = true;
    nsresult rv = si->GetCallback()->Enumerate(wrapper, cx, obj, &retval);
    if (NS_FAILED(rv))
        return Throw(rv, cx);
    return retval;
}

/***************************************************************************/

static bool
XPC_WN_JSOp_Enumerate(JSContext* cx, HandleObject obj, AutoIdVector& properties,
                      bool enumerableOnly)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    XPCNativeScriptableInfo* si = wrapper->GetScriptableInfo();
    if (!si || !si->GetFlags().WantNewEnumerate())
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);

    if (!XPC_WN_Shared_Enumerate(cx, obj))
        return false;

    bool retval = true;
    nsresult rv = si->GetCallback()->NewEnumerate(wrapper, cx, obj, properties, &retval);
    if (NS_FAILED(rv))
        return Throw(rv, cx);
    return retval;
}

/***************************************************************************/

// static
XPCNativeScriptableInfo*
XPCNativeScriptableInfo::Construct(const XPCNativeScriptableCreateInfo* sci)
{
    MOZ_ASSERT(sci, "bad param");
    nsCOMPtr<nsIXPCScriptable> callback = sci->GetCallback();
    MOZ_ASSERT(callback);
    MOZ_ASSERT(callback->GetScriptableFlags() == sci->GetFlags());
    return new XPCNativeScriptableInfo(callback);
}

const js::ObjectOps XPC_WN_ObjectOpsWithEnumerate = {
    nullptr,  // lookupProperty
    nullptr,  // defineProperty
    nullptr,  // hasProperty
    nullptr,  // getProperty
    nullptr,  // setProperty
    nullptr,  // getOwnPropertyDescriptor
    nullptr,  // deleteProperty
    nullptr,  // getElements
    XPC_WN_JSOp_Enumerate,
    nullptr,  // funToString
};

/***************************************************************************/
/***************************************************************************/

// Compatibility hack.
//
// XPConnect used to do all sorts of funny tricks to find the "correct"
// |this| object for a given method (often to the detriment of proper
// call/apply). When these tricks were removed, a fair amount of chrome
// code broke, because it was relying on being able to grab methods off
// some XPCOM object and invoke them without a proper |this|. So, if it's
// quite clear that we're in this situation and about to use a |this|
// argument that just won't work, fix things up.
//
// This hack is only useful for getters/setters if someone sets an XPCOM object
// as the prototype for a vanilla JS object and expects the XPCOM attributes to
// work on the derived object, which we really don't want to support. But we
// handle it anyway, for now, to minimize regression risk on an already-risky
// landing.
//
// This hack is mainly useful for the NoHelper JSClass. We also fix up
// Components.utils because it implements nsIXPCScriptable (giving it a custom
// JSClass) but not nsIClassInfo (which would put the methods on a prototype).

#define IS_NOHELPER_CLASS(clasp) (clasp == &XPC_WN_NoHelper_JSClass)
#define IS_CU_CLASS(clasp) (clasp->name[0] == 'n' && !strcmp(clasp->name, "nsXPCComponents_Utils"))

MOZ_ALWAYS_INLINE JSObject*
FixUpThisIfBroken(JSObject* obj, JSObject* funobj)
{
    if (funobj) {
        JSObject* parentObj =
            &js::GetFunctionNativeReserved(funobj,
                                           XPC_FUNCTION_PARENT_OBJECT_SLOT).toObject();
        const js::Class* parentClass = js::GetObjectClass(parentObj);
        if (MOZ_UNLIKELY((IS_NOHELPER_CLASS(parentClass) || IS_CU_CLASS(parentClass)) &&
                         (js::GetObjectClass(obj) != parentClass)))
        {
            return parentObj;
        }
    }
    return obj;
}

bool
XPC_WN_CallMethod(JSContext* cx, unsigned argc, Value* vp)
{
    JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
    MOZ_ASSERT(JS_TypeOfValue(cx, args.calleev()) == JSTYPE_FUNCTION, "bad function");
    RootedObject funobj(cx, &args.callee());

    RootedObject obj(cx, JS_THIS_OBJECT(cx, vp));
    if (!obj)
        return false;

    obj = FixUpThisIfBroken(obj, funobj);
    XPCCallContext ccx(cx, obj, funobj, JSID_VOIDHANDLE, args.length(),
                       args.array(), vp);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    RefPtr<XPCNativeInterface> iface;
    XPCNativeMember*    member;

    if (!XPCNativeMember::GetCallInfo(funobj, &iface, &member))
        return Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, cx);
    ccx.SetCallInfo(iface, member, false);
    return XPCWrappedNative::CallMethod(ccx);
}

bool
XPC_WN_GetterSetter(JSContext* cx, unsigned argc, Value* vp)
{
    JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
    MOZ_ASSERT(JS_TypeOfValue(cx, args.calleev()) == JSTYPE_FUNCTION, "bad function");
    RootedObject funobj(cx, &args.callee());

    RootedObject obj(cx, JS_THIS_OBJECT(cx, vp));
    if (!obj)
        return false;

    obj = FixUpThisIfBroken(obj, funobj);
    XPCCallContext ccx(cx, obj, funobj, JSID_VOIDHANDLE, args.length(),
                       args.array(), vp);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    RefPtr<XPCNativeInterface> iface;
    XPCNativeMember*    member;

    if (!XPCNativeMember::GetCallInfo(funobj, &iface, &member))
        return Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, cx);

    if (args.length() != 0 && member->IsWritableAttribute()) {
        ccx.SetCallInfo(iface, member, true);
        bool retval = XPCWrappedNative::SetAttribute(ccx);
        if (retval)
            args.rval().set(args[0]);
        return retval;
    }
    // else...

    ccx.SetCallInfo(iface, member, false);
    return XPCWrappedNative::GetAttribute(ccx);
}

/***************************************************************************/

static bool
XPC_WN_Shared_Proto_Enumerate(JSContext* cx, HandleObject obj)
{
    MOZ_ASSERT(js::GetObjectClass(obj) == &XPC_WN_ModsAllowed_Proto_JSClass ||
               js::GetObjectClass(obj) == &XPC_WN_NoMods_Proto_JSClass,
               "bad proto");
    XPCWrappedNativeProto* self =
        (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (!self)
        return false;

    XPCNativeSet* set = self->GetSet();
    if (!set)
        return false;

    XPCCallContext ccx(cx);
    if (!ccx.IsValid())
        return false;

    uint16_t interface_count = set->GetInterfaceCount();
    XPCNativeInterface** interfaceArray = set->GetInterfaceArray();
    for (uint16_t i = 0; i < interface_count; i++) {
        XPCNativeInterface* iface = interfaceArray[i];
        uint16_t member_count = iface->GetMemberCount();

        for (uint16_t k = 0; k < member_count; k++) {
            if (!xpc_ForcePropertyResolve(cx, obj, iface->GetMemberAt(k)->GetName()))
                return false;
        }
    }

    return true;
}

static void
XPC_WN_Shared_Proto_Finalize(js::FreeOp* fop, JSObject* obj)
{
    // This can be null if xpc shutdown has already happened
    XPCWrappedNativeProto* p = (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (p)
        p->JSProtoObjectFinalized(fop, obj);
}

static void
XPC_WN_Shared_Proto_ObjectMoved(JSObject* obj, const JSObject* old)
{
    // This can be null if xpc shutdown has already happened
    XPCWrappedNativeProto* p = (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (p)
        p->JSProtoObjectMoved(obj, old);
}

static void
XPC_WN_Shared_Proto_Trace(JSTracer* trc, JSObject* obj)
{
    // This can be null if xpc shutdown has already happened
    XPCWrappedNativeProto* p =
        (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (p)
        p->TraceInside(trc);
}

/*****************************************************/

static bool
XPC_WN_ModsAllowed_Proto_Resolve(JSContext* cx, HandleObject obj, HandleId id, bool* resolvep)
{
    MOZ_ASSERT(js::GetObjectClass(obj) == &XPC_WN_ModsAllowed_Proto_JSClass,
               "bad proto");

    XPCWrappedNativeProto* self =
        (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (!self)
        return false;

    XPCCallContext ccx(cx);
    if (!ccx.IsValid())
        return false;

    XPCNativeScriptableInfo* si = self->GetScriptableInfo();
    return DefinePropertyIfFound(ccx, obj, id,
                                 self->GetSet(), nullptr, nullptr,
                                 self->GetScope(),
                                 true, nullptr, nullptr, si,
                                 JSPROP_ENUMERATE, resolvep);
}

static const js::ClassOps XPC_WN_ModsAllowed_Proto_JSClassOps = {
    nullptr,                            // addProperty
    nullptr,                            // delProperty
    nullptr,                            // getProperty
    nullptr,                            // setProperty
    XPC_WN_Shared_Proto_Enumerate,      // enumerate
    XPC_WN_ModsAllowed_Proto_Resolve,   // resolve
    nullptr,                            // mayResolve
    XPC_WN_Shared_Proto_Finalize,       // finalize
    nullptr,                            // call
    nullptr,                            // construct
    nullptr,                            // hasInstance
    XPC_WN_Shared_Proto_Trace,          // trace
};

static const js::ClassExtension XPC_WN_Shared_Proto_ClassExtension = {
    nullptr,    /* weakmapKeyDelegateOp */
    XPC_WN_Shared_Proto_ObjectMoved
};

const js::Class XPC_WN_ModsAllowed_Proto_JSClass = {
    "XPC_WN_ModsAllowed_Proto_JSClass",
    XPC_WRAPPER_FLAGS,
    &XPC_WN_ModsAllowed_Proto_JSClassOps,
    JS_NULL_CLASS_SPEC,
    &XPC_WN_Shared_Proto_ClassExtension,
    JS_NULL_OBJECT_OPS
};

/***************************************************************************/

static bool
XPC_WN_OnlyIWrite_Proto_AddPropertyStub(JSContext* cx, HandleObject obj, HandleId id,
                                        HandleValue v)
{
    MOZ_ASSERT(js::GetObjectClass(obj) == &XPC_WN_NoMods_Proto_JSClass,
               "bad proto");

    XPCWrappedNativeProto* self =
        (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (!self)
        return false;

    XPCCallContext ccx(cx);
    if (!ccx.IsValid())
        return false;

    // Allow XPConnect to add the property only
    if (ccx.GetResolveName() == id)
        return true;

    return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);
}

static bool
XPC_WN_NoMods_Proto_Resolve(JSContext* cx, HandleObject obj, HandleId id, bool* resolvedp)
{
    MOZ_ASSERT(js::GetObjectClass(obj) == &XPC_WN_NoMods_Proto_JSClass,
               "bad proto");

    XPCWrappedNativeProto* self =
        (XPCWrappedNativeProto*) xpc_GetJSPrivate(obj);
    if (!self)
        return false;

    XPCCallContext ccx(cx);
    if (!ccx.IsValid())
        return false;

    XPCNativeScriptableInfo* si = self->GetScriptableInfo();

    return DefinePropertyIfFound(ccx, obj, id,
                                 self->GetSet(), nullptr, nullptr,
                                 self->GetScope(),
                                 true, nullptr, nullptr, si,
                                 JSPROP_READONLY |
                                 JSPROP_PERMANENT |
                                 JSPROP_ENUMERATE, resolvedp);
}

static const js::ClassOps XPC_WN_NoMods_Proto_JSClassOps = {
    XPC_WN_OnlyIWrite_Proto_AddPropertyStub,   // addProperty
    XPC_WN_CantDeletePropertyStub,             // delProperty
    nullptr,                                   // getProperty
    nullptr,                                   // setProperty
    XPC_WN_Shared_Proto_Enumerate,             // enumerate
    XPC_WN_NoMods_Proto_Resolve,               // resolve
    nullptr,                                   // mayResolve
    XPC_WN_Shared_Proto_Finalize,              // finalize
    nullptr,                                   // call
    nullptr,                                   // construct
    nullptr,                                   // hasInstance
    XPC_WN_Shared_Proto_Trace,                 // trace
};

const js::Class XPC_WN_NoMods_Proto_JSClass = {
    "XPC_WN_NoMods_Proto_JSClass",
    XPC_WRAPPER_FLAGS,
    &XPC_WN_NoMods_Proto_JSClassOps,
    JS_NULL_CLASS_SPEC,
    &XPC_WN_Shared_Proto_ClassExtension,
    JS_NULL_OBJECT_OPS
};

/***************************************************************************/

static bool
XPC_WN_TearOff_Enumerate(JSContext* cx, HandleObject obj)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    XPCWrappedNativeTearOff* to = ccx.GetTearOff();
    XPCNativeInterface* iface;

    if (!to || nullptr == (iface = to->GetInterface()))
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);

    uint16_t member_count = iface->GetMemberCount();
    for (uint16_t k = 0; k < member_count; k++) {
        if (!xpc_ForcePropertyResolve(cx, obj, iface->GetMemberAt(k)->GetName()))
            return false;
    }

    return true;
}

static bool
XPC_WN_TearOff_Resolve(JSContext* cx, HandleObject obj, HandleId id, bool* resolvedp)
{
    XPCCallContext ccx(cx, obj);
    XPCWrappedNative* wrapper = ccx.GetWrapper();
    THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper);

    XPCWrappedNativeTearOff* to = ccx.GetTearOff();
    XPCNativeInterface* iface;

    if (!to || nullptr == (iface = to->GetInterface()))
        return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx);

    return DefinePropertyIfFound(ccx, obj, id, nullptr, iface, nullptr,
                                 wrapper->GetScope(),
                                 true, nullptr, nullptr, nullptr,
                                 JSPROP_READONLY |
                                 JSPROP_PERMANENT |
                                 JSPROP_ENUMERATE, resolvedp);
}

static void
XPC_WN_TearOff_Finalize(js::FreeOp* fop, JSObject* obj)
{
    XPCWrappedNativeTearOff* p = (XPCWrappedNativeTearOff*)
        xpc_GetJSPrivate(obj);
    if (!p)
        return;
    p->JSObjectFinalized();
}

static void
XPC_WN_TearOff_ObjectMoved(JSObject* obj, const JSObject* old)
{
    XPCWrappedNativeTearOff* p = (XPCWrappedNativeTearOff*)
        xpc_GetJSPrivate(obj);
    if (!p)
        return;
    p->JSObjectMoved(obj, old);
}

// Make sure XPC_WRAPPER_FLAGS has no reserved slots, so our
// XPC_WN_TEAROFF_RESERVED_SLOTS value is OK.

static_assert(((XPC_WRAPPER_FLAGS >> JSCLASS_RESERVED_SLOTS_SHIFT) &
               JSCLASS_RESERVED_SLOTS_MASK) == 0,
              "XPC_WRAPPER_FLAGS should not include any reserved slots");

static const js::ClassOps XPC_WN_Tearoff_JSClassOps = {
    XPC_WN_OnlyIWrite_AddPropertyStub,  // addProperty
    XPC_WN_CantDeletePropertyStub,      // delProperty
    nullptr,                            // getProperty
    nullptr,                            // setProperty
    XPC_WN_TearOff_Enumerate,           // enumerate
    XPC_WN_TearOff_Resolve,             // resolve
    nullptr,                            // mayResolve
    XPC_WN_TearOff_Finalize,            // finalize
    nullptr,                            // call
    nullptr,                            // construct
    nullptr,                            // hasInstance
    nullptr,                            // trace
};

static const js::ClassExtension XPC_WN_Tearoff_JSClassExtension = {
    nullptr,                            // weakmapKeyDelegateOp
    XPC_WN_TearOff_ObjectMoved
};

const js::Class XPC_WN_Tearoff_JSClass = {
    "WrappedNative_TearOff",
    XPC_WRAPPER_FLAGS |
    JSCLASS_HAS_RESERVED_SLOTS(XPC_WN_TEAROFF_RESERVED_SLOTS),
    &XPC_WN_Tearoff_JSClassOps,
    JS_NULL_CLASS_SPEC,
    &XPC_WN_Tearoff_JSClassExtension
};