-
Notifications
You must be signed in to change notification settings - Fork 28.1k
/
keys.cc
1388 lines (1282 loc) · 54.5 KB
/
keys.cc
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
// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/objects/keys.h"
#include "src/api/api-arguments-inl.h"
#include "src/common/globals.h"
#include "src/execution/isolate-inl.h"
#include "src/handles/handles-inl.h"
#include "src/heap/factory.h"
#include "src/objects/api-callbacks.h"
#include "src/objects/elements-inl.h"
#include "src/objects/field-index-inl.h"
#include "src/objects/hash-table-inl.h"
#include "src/objects/module-inl.h"
#include "src/objects/objects-inl.h"
#include "src/objects/ordered-hash-table-inl.h"
#include "src/objects/property-descriptor.h"
#include "src/objects/prototype.h"
#include "src/objects/slots-atomic-inl.h"
#include "src/utils/identity-map.h"
#include "src/zone/zone-hashmap.h"
namespace v8 {
namespace internal {
#define RETURN_NOTHING_IF_NOT_SUCCESSFUL(call) \
do { \
if (!(call)) return Nothing<bool>(); \
} while (false)
#define RETURN_FAILURE_IF_NOT_SUCCESSFUL(call) \
do { \
ExceptionStatus status_enum_result = (call); \
if (!status_enum_result) return status_enum_result; \
} while (false)
namespace {
static bool ContainsOnlyValidKeys(Handle<FixedArray> array) {
int len = array->length();
for (int i = 0; i < len; i++) {
Object e = array->get(i);
if (!(e.IsName() || e.IsNumber())) return false;
}
return true;
}
static int AddKey(Object key, Handle<FixedArray> combined_keys,
Handle<DescriptorArray> descs, int nof_descriptors,
int target) {
for (InternalIndex i : InternalIndex::Range(nof_descriptors)) {
if (descs->GetKey(i) == key) return 0;
}
combined_keys->set(target, key);
return 1;
}
static Handle<FixedArray> CombineKeys(Isolate* isolate,
Handle<FixedArray> own_keys,
Handle<FixedArray> prototype_chain_keys,
Handle<JSReceiver> receiver,
bool may_have_elements) {
int prototype_chain_keys_length = prototype_chain_keys->length();
if (prototype_chain_keys_length == 0) return own_keys;
Map map = receiver->map();
int nof_descriptors = map.NumberOfOwnDescriptors();
if (nof_descriptors == 0 && !may_have_elements) return prototype_chain_keys;
Handle<DescriptorArray> descs(map.instance_descriptors(isolate), isolate);
int own_keys_length = own_keys.is_null() ? 0 : own_keys->length();
Handle<FixedArray> combined_keys = isolate->factory()->NewFixedArray(
own_keys_length + prototype_chain_keys_length);
if (own_keys_length != 0) {
own_keys->CopyTo(0, *combined_keys, 0, own_keys_length);
}
int target_keys_length = own_keys_length;
for (int i = 0; i < prototype_chain_keys_length; i++) {
target_keys_length += AddKey(prototype_chain_keys->get(i), combined_keys,
descs, nof_descriptors, target_keys_length);
}
return FixedArray::ShrinkOrEmpty(isolate, combined_keys, target_keys_length);
}
} // namespace
// static
MaybeHandle<FixedArray> KeyAccumulator::GetKeys(
Isolate* isolate, Handle<JSReceiver> object, KeyCollectionMode mode,
PropertyFilter filter, GetKeysConversion keys_conversion, bool is_for_in,
bool skip_indices) {
FastKeyAccumulator accumulator(isolate, object, mode, filter, is_for_in,
skip_indices);
return accumulator.GetKeys(keys_conversion);
}
Handle<FixedArray> KeyAccumulator::GetKeys(GetKeysConversion convert) {
if (keys_.is_null()) {
return isolate_->factory()->empty_fixed_array();
}
USE(ContainsOnlyValidKeys);
Handle<FixedArray> result =
OrderedHashSet::ConvertToKeysArray(isolate(), keys(), convert);
DCHECK(ContainsOnlyValidKeys(result));
if (try_prototype_info_cache_ && !first_prototype_map_.is_null()) {
PrototypeInfo::cast(first_prototype_map_->prototype_info())
.set_prototype_chain_enum_cache(*result);
Map::GetOrCreatePrototypeChainValidityCell(
Handle<Map>(receiver_->map(), isolate_), isolate_);
DCHECK(first_prototype_map_->IsPrototypeValidityCellValid());
}
return result;
}
Handle<OrderedHashSet> KeyAccumulator::keys() {
return Handle<OrderedHashSet>::cast(keys_);
}
ExceptionStatus KeyAccumulator::AddKey(Object key, AddKeyConversion convert) {
return AddKey(handle(key, isolate_), convert);
}
ExceptionStatus KeyAccumulator::AddKey(Handle<Object> key,
AddKeyConversion convert) {
if (filter_ == PRIVATE_NAMES_ONLY) {
if (!key->IsSymbol()) return ExceptionStatus::kSuccess;
if (!Symbol::cast(*key).is_private_name()) return ExceptionStatus::kSuccess;
} else if (key->IsSymbol()) {
if (filter_ & SKIP_SYMBOLS) return ExceptionStatus::kSuccess;
if (Symbol::cast(*key).is_private()) return ExceptionStatus::kSuccess;
} else if (filter_ & SKIP_STRINGS) {
return ExceptionStatus::kSuccess;
}
if (IsShadowed(key)) return ExceptionStatus::kSuccess;
if (keys_.is_null()) {
keys_ = OrderedHashSet::Allocate(isolate_, 16).ToHandleChecked();
}
uint32_t index;
if (convert == CONVERT_TO_ARRAY_INDEX && key->IsString() &&
Handle<String>::cast(key)->AsArrayIndex(&index)) {
key = isolate_->factory()->NewNumberFromUint(index);
}
MaybeHandle<OrderedHashSet> new_set_candidate =
OrderedHashSet::Add(isolate(), keys(), key);
Handle<OrderedHashSet> new_set;
if (!new_set_candidate.ToHandle(&new_set)) {
THROW_NEW_ERROR_RETURN_VALUE(
isolate_, NewRangeError(MessageTemplate::kTooManyProperties),
ExceptionStatus::kException);
}
if (*new_set != *keys_) {
// The keys_ Set is converted directly to a FixedArray in GetKeys which can
// be left-trimmer. Hence the previous Set should not keep a pointer to the
// new one.
keys_->set(OrderedHashSet::NextTableIndex(), Smi::zero());
keys_ = new_set;
}
return ExceptionStatus::kSuccess;
}
ExceptionStatus KeyAccumulator::AddKeys(Handle<FixedArray> array,
AddKeyConversion convert) {
int add_length = array->length();
for (int i = 0; i < add_length; i++) {
Handle<Object> current(array->get(i), isolate_);
RETURN_FAILURE_IF_NOT_SUCCESSFUL(AddKey(current, convert));
}
return ExceptionStatus::kSuccess;
}
ExceptionStatus KeyAccumulator::AddKeys(Handle<JSObject> array_like,
AddKeyConversion convert) {
DCHECK(array_like->IsJSArray() || array_like->HasSloppyArgumentsElements());
ElementsAccessor* accessor = array_like->GetElementsAccessor();
return accessor->AddElementsToKeyAccumulator(array_like, this, convert);
}
MaybeHandle<FixedArray> FilterProxyKeys(KeyAccumulator* accumulator,
Handle<JSProxy> owner,
Handle<FixedArray> keys,
PropertyFilter filter,
bool skip_indices) {
if (filter == ALL_PROPERTIES) {
// Nothing to do.
return keys;
}
Isolate* isolate = accumulator->isolate();
int store_position = 0;
for (int i = 0; i < keys->length(); ++i) {
Handle<Name> key(Name::cast(keys->get(i)), isolate);
if (key->FilterKey(filter)) continue; // Skip this key.
if (skip_indices) {
uint32_t index;
if (key->AsArrayIndex(&index)) continue; // Skip this key.
}
if (filter & ONLY_ENUMERABLE) {
PropertyDescriptor desc;
Maybe<bool> found =
JSProxy::GetOwnPropertyDescriptor(isolate, owner, key, &desc);
MAYBE_RETURN(found, MaybeHandle<FixedArray>());
if (!found.FromJust()) continue;
if (!desc.enumerable()) {
accumulator->AddShadowingKey(key);
continue;
}
}
// Keep this key.
if (store_position != i) {
keys->set(store_position, *key);
}
store_position++;
}
return FixedArray::ShrinkOrEmpty(isolate, keys, store_position);
}
// Returns "nothing" in case of exception, "true" on success.
Maybe<bool> KeyAccumulator::AddKeysFromJSProxy(Handle<JSProxy> proxy,
Handle<FixedArray> keys) {
// Postpone the enumerable check for for-in to the ForInFilter step.
if (!is_for_in_) {
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, keys,
FilterProxyKeys(this, proxy, keys, filter_, skip_indices_),
Nothing<bool>());
}
// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-ownpropertykeys
// As of 10.5.11.9 says, the keys collected from Proxy should not contain
// any duplicates. And the order of the keys is preserved by the
// OrderedHashTable.
RETURN_NOTHING_IF_NOT_SUCCESSFUL(AddKeys(keys, CONVERT_TO_ARRAY_INDEX));
return Just(true);
}
Maybe<bool> KeyAccumulator::CollectKeys(Handle<JSReceiver> receiver,
Handle<JSReceiver> object) {
// Proxies have no hidden prototype and we should not trigger the
// [[GetPrototypeOf]] trap on the last iteration when using
// AdvanceFollowingProxies.
if (mode_ == KeyCollectionMode::kOwnOnly && object->IsJSProxy()) {
MAYBE_RETURN(CollectOwnJSProxyKeys(receiver, Handle<JSProxy>::cast(object)),
Nothing<bool>());
return Just(true);
}
PrototypeIterator::WhereToEnd end = mode_ == KeyCollectionMode::kOwnOnly
? PrototypeIterator::END_AT_NON_HIDDEN
: PrototypeIterator::END_AT_NULL;
for (PrototypeIterator iter(isolate_, object, kStartAtReceiver, end);
!iter.IsAtEnd();) {
// Start the shadow checks only after the first prototype has added
// shadowing keys.
if (HasShadowingKeys()) skip_shadow_check_ = false;
Handle<JSReceiver> current =
PrototypeIterator::GetCurrent<JSReceiver>(iter);
Maybe<bool> result = Just(false); // Dummy initialization.
if (current->IsJSProxy()) {
result = CollectOwnJSProxyKeys(receiver, Handle<JSProxy>::cast(current));
} else if (current->IsWasmObject()) {
if (mode_ == KeyCollectionMode::kIncludePrototypes) {
RETURN_FAILURE(isolate_, kThrowOnError,
NewTypeError(MessageTemplate::kWasmObjectsAreOpaque));
} else {
DCHECK_EQ(KeyCollectionMode::kOwnOnly, mode_);
DCHECK_EQ(result, Just(false)); // Stop iterating.
}
} else {
DCHECK(current->IsJSObject());
result = CollectOwnKeys(receiver, Handle<JSObject>::cast(current));
}
MAYBE_RETURN(result, Nothing<bool>());
if (!result.FromJust()) break; // |false| means "stop iterating".
// Iterate through proxies but ignore access checks for the ALL_CAN_READ
// case on API objects for OWN_ONLY keys handled in CollectOwnKeys.
if (!iter.AdvanceFollowingProxiesIgnoringAccessChecks()) {
return Nothing<bool>();
}
if (!last_non_empty_prototype_.is_null() &&
*last_non_empty_prototype_ == *current) {
break;
}
}
return Just(true);
}
bool KeyAccumulator::HasShadowingKeys() { return !shadowing_keys_.is_null(); }
bool KeyAccumulator::IsShadowed(Handle<Object> key) {
if (!HasShadowingKeys() || skip_shadow_check_) return false;
return shadowing_keys_->Has(isolate_, key);
}
void KeyAccumulator::AddShadowingKey(Object key,
AllowGarbageCollection* allow_gc) {
if (mode_ == KeyCollectionMode::kOwnOnly) return;
AddShadowingKey(handle(key, isolate_));
}
void KeyAccumulator::AddShadowingKey(Handle<Object> key) {
if (mode_ == KeyCollectionMode::kOwnOnly) return;
if (shadowing_keys_.is_null()) {
shadowing_keys_ = ObjectHashSet::New(isolate_, 16);
}
shadowing_keys_ = ObjectHashSet::Add(isolate(), shadowing_keys_, key);
}
namespace {
void TrySettingEmptyEnumCache(JSReceiver object) {
Map map = object.map();
DCHECK_EQ(kInvalidEnumCacheSentinel, map.EnumLength());
if (!map.OnlyHasSimpleProperties()) return;
if (map.IsJSProxyMap()) return;
if (map.NumberOfEnumerableProperties() > 0) return;
DCHECK(object.IsJSObject());
map.SetEnumLength(0);
}
bool CheckAndInitalizeEmptyEnumCache(JSReceiver object) {
if (object.map().EnumLength() == kInvalidEnumCacheSentinel) {
TrySettingEmptyEnumCache(object);
}
if (object.map().EnumLength() != 0) return false;
DCHECK(object.IsJSObject());
return !JSObject::cast(object).HasEnumerableElements();
}
} // namespace
void FastKeyAccumulator::Prepare() {
DisallowGarbageCollection no_gc;
// Directly go for the fast path for OWN_ONLY keys.
if (mode_ == KeyCollectionMode::kOwnOnly) return;
// Fully walk the prototype chain and find the last prototype with keys.
is_receiver_simple_enum_ = false;
has_empty_prototype_ = true;
only_own_has_simple_elements_ =
!receiver_->map().IsCustomElementsReceiverMap();
JSReceiver last_prototype;
may_have_elements_ = MayHaveElements(*receiver_);
for (PrototypeIterator iter(isolate_, *receiver_); !iter.IsAtEnd();
iter.Advance()) {
JSReceiver current = iter.GetCurrent<JSReceiver>();
if (!may_have_elements_ || only_own_has_simple_elements_) {
if (MayHaveElements(current)) {
may_have_elements_ = true;
only_own_has_simple_elements_ = false;
}
}
bool has_no_properties = CheckAndInitalizeEmptyEnumCache(current);
if (has_no_properties) continue;
last_prototype = current;
has_empty_prototype_ = false;
}
// Check if we should try to create/use prototype info cache.
try_prototype_info_cache_ = TryPrototypeInfoCache(receiver_);
if (has_prototype_info_cache_) return;
if (has_empty_prototype_) {
is_receiver_simple_enum_ =
receiver_->map().EnumLength() != kInvalidEnumCacheSentinel &&
!JSObject::cast(*receiver_).HasEnumerableElements();
} else if (!last_prototype.is_null()) {
last_non_empty_prototype_ = handle(last_prototype, isolate_);
}
}
namespace {
Handle<FixedArray> ReduceFixedArrayTo(Isolate* isolate,
Handle<FixedArray> array, int length) {
DCHECK_LE(length, array->length());
if (array->length() == length) return array;
return isolate->factory()->CopyFixedArrayUpTo(array, length);
}
// Initializes and directly returns the enume cache. Users of this function
// have to make sure to never directly leak the enum cache.
Handle<FixedArray> GetFastEnumPropertyKeys(Isolate* isolate,
Handle<JSObject> object) {
Handle<Map> map(object->map(), isolate);
Handle<FixedArray> keys(
map->instance_descriptors(isolate).enum_cache().keys(), isolate);
// Check if the {map} has a valid enum length, which implies that it
// must have a valid enum cache as well.
int enum_length = map->EnumLength();
if (enum_length != kInvalidEnumCacheSentinel) {
DCHECK(map->OnlyHasSimpleProperties());
DCHECK_LE(enum_length, keys->length());
DCHECK_EQ(enum_length, map->NumberOfEnumerableProperties());
isolate->counters()->enum_cache_hits()->Increment();
return ReduceFixedArrayTo(isolate, keys, enum_length);
}
// Determine the actual number of enumerable properties of the {map}.
enum_length = map->NumberOfEnumerableProperties();
// Check if there's already a shared enum cache on the {map}s
// DescriptorArray with sufficient number of entries.
if (enum_length <= keys->length()) {
if (map->OnlyHasSimpleProperties()) map->SetEnumLength(enum_length);
isolate->counters()->enum_cache_hits()->Increment();
return ReduceFixedArrayTo(isolate, keys, enum_length);
}
Handle<DescriptorArray> descriptors =
Handle<DescriptorArray>(map->instance_descriptors(isolate), isolate);
isolate->counters()->enum_cache_misses()->Increment();
// Create the keys array.
int index = 0;
bool fields_only = true;
keys = isolate->factory()->NewFixedArray(enum_length);
for (InternalIndex i : map->IterateOwnDescriptors()) {
DisallowGarbageCollection no_gc;
PropertyDetails details = descriptors->GetDetails(i);
if (details.IsDontEnum()) continue;
Object key = descriptors->GetKey(i);
if (key.IsSymbol()) continue;
keys->set(index, key);
if (details.location() != PropertyLocation::kField) fields_only = false;
index++;
}
DCHECK_EQ(index, keys->length());
// Optionally also create the indices array.
Handle<FixedArray> indices = isolate->factory()->empty_fixed_array();
if (fields_only) {
indices = isolate->factory()->NewFixedArray(enum_length);
index = 0;
for (InternalIndex i : map->IterateOwnDescriptors()) {
DisallowGarbageCollection no_gc;
PropertyDetails details = descriptors->GetDetails(i);
if (details.IsDontEnum()) continue;
Object key = descriptors->GetKey(i);
if (key.IsSymbol()) continue;
DCHECK_EQ(PropertyKind::kData, details.kind());
DCHECK_EQ(PropertyLocation::kField, details.location());
FieldIndex field_index = FieldIndex::ForDescriptor(*map, i);
indices->set(index, Smi::FromInt(field_index.GetLoadByFieldIndex()));
index++;
}
DCHECK_EQ(index, indices->length());
}
DescriptorArray::InitializeOrChangeEnumCache(descriptors, isolate, keys,
indices);
if (map->OnlyHasSimpleProperties()) map->SetEnumLength(enum_length);
return keys;
}
template <bool fast_properties>
MaybeHandle<FixedArray> GetOwnKeysWithElements(Isolate* isolate,
Handle<JSObject> object,
GetKeysConversion convert,
bool skip_indices) {
Handle<FixedArray> keys;
ElementsAccessor* accessor = object->GetElementsAccessor();
if (fast_properties) {
keys = GetFastEnumPropertyKeys(isolate, object);
} else {
// TODO(cbruni): preallocate big enough array to also hold elements.
keys = KeyAccumulator::GetOwnEnumPropertyKeys(isolate, object);
}
MaybeHandle<FixedArray> result;
if (skip_indices) {
result = keys;
} else {
result = accessor->PrependElementIndices(isolate, object, keys, convert,
ONLY_ENUMERABLE);
}
if (v8_flags.trace_for_in_enumerate) {
PrintF("| strings=%d symbols=0 elements=%u || prototypes>=1 ||\n",
keys->length(), result.ToHandleChecked()->length() - keys->length());
}
return result;
}
} // namespace
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeys(
GetKeysConversion keys_conversion) {
// TODO(v8:9401): We should extend the fast path of KeyAccumulator::GetKeys to
// also use fast path even when filter = SKIP_SYMBOLS. We used to pass wrong
// filter to use fast path in cases where we tried to verify all properties
// are enumerable. However these checks weren't correct and passing the wrong
// filter led to wrong behaviour.
if (filter_ == ENUMERABLE_STRINGS) {
Handle<FixedArray> keys;
if (GetKeysFast(keys_conversion).ToHandle(&keys)) {
return keys;
}
if (isolate_->has_pending_exception()) return MaybeHandle<FixedArray>();
}
if (try_prototype_info_cache_) {
return GetKeysWithPrototypeInfoCache(keys_conversion);
}
return GetKeysSlow(keys_conversion);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysFast(
GetKeysConversion keys_conversion) {
bool own_only = has_empty_prototype_ || mode_ == KeyCollectionMode::kOwnOnly;
Map map = receiver_->map();
if (!own_only || map.IsCustomElementsReceiverMap()) {
return MaybeHandle<FixedArray>();
}
// From this point on we are certain to only collect own keys.
DCHECK(receiver_->IsJSObject());
Handle<JSObject> object = Handle<JSObject>::cast(receiver_);
// Do not try to use the enum-cache for dict-mode objects.
if (map.is_dictionary_map()) {
return GetOwnKeysWithElements<false>(isolate_, object, keys_conversion,
skip_indices_);
}
int enum_length = receiver_->map().EnumLength();
if (enum_length == kInvalidEnumCacheSentinel) {
Handle<FixedArray> keys;
// Try initializing the enum cache and return own properties.
if (GetOwnKeysWithUninitializedEnumCache().ToHandle(&keys)) {
if (v8_flags.trace_for_in_enumerate) {
PrintF("| strings=%d symbols=0 elements=0 || prototypes>=1 ||\n",
keys->length());
}
is_receiver_simple_enum_ =
object->map().EnumLength() != kInvalidEnumCacheSentinel;
return keys;
}
}
// The properties-only case failed because there were probably elements on the
// receiver.
return GetOwnKeysWithElements<true>(isolate_, object, keys_conversion,
skip_indices_);
}
MaybeHandle<FixedArray>
FastKeyAccumulator::GetOwnKeysWithUninitializedEnumCache() {
Handle<JSObject> object = Handle<JSObject>::cast(receiver_);
// Uninitalized enum cache
Map map = object->map();
if (object->elements() != ReadOnlyRoots(isolate_).empty_fixed_array() &&
object->elements() !=
ReadOnlyRoots(isolate_).empty_slow_element_dictionary()) {
// Assume that there are elements.
return MaybeHandle<FixedArray>();
}
int number_of_own_descriptors = map.NumberOfOwnDescriptors();
if (number_of_own_descriptors == 0) {
map.SetEnumLength(0);
return isolate_->factory()->empty_fixed_array();
}
// We have no elements but possibly enumerable property keys, hence we can
// directly initialize the enum cache.
Handle<FixedArray> keys = GetFastEnumPropertyKeys(isolate_, object);
if (is_for_in_) return keys;
// Do not leak the enum cache as it might end up as an elements backing store.
return isolate_->factory()->CopyFixedArray(keys);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysSlow(
GetKeysConversion keys_conversion) {
KeyAccumulator accumulator(isolate_, mode_, filter_);
accumulator.set_is_for_in(is_for_in_);
accumulator.set_skip_indices(skip_indices_);
accumulator.set_last_non_empty_prototype(last_non_empty_prototype_);
accumulator.set_may_have_elements(may_have_elements_);
accumulator.set_first_prototype_map(first_prototype_map_);
accumulator.set_try_prototype_info_cache(try_prototype_info_cache_);
MAYBE_RETURN(accumulator.CollectKeys(receiver_, receiver_),
MaybeHandle<FixedArray>());
return accumulator.GetKeys(keys_conversion);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysWithPrototypeInfoCache(
GetKeysConversion keys_conversion) {
Handle<FixedArray> own_keys;
if (may_have_elements_) {
MaybeHandle<FixedArray> maybe_own_keys;
if (receiver_->map().is_dictionary_map()) {
maybe_own_keys = GetOwnKeysWithElements<false>(
isolate_, Handle<JSObject>::cast(receiver_), keys_conversion,
skip_indices_);
} else {
maybe_own_keys = GetOwnKeysWithElements<true>(
isolate_, Handle<JSObject>::cast(receiver_), keys_conversion,
skip_indices_);
}
ASSIGN_RETURN_ON_EXCEPTION(isolate_, own_keys, maybe_own_keys, FixedArray);
} else {
own_keys = KeyAccumulator::GetOwnEnumPropertyKeys(
isolate_, Handle<JSObject>::cast(receiver_));
}
Handle<FixedArray> prototype_chain_keys;
if (has_prototype_info_cache_) {
prototype_chain_keys =
handle(FixedArray::cast(
PrototypeInfo::cast(first_prototype_map_->prototype_info())
.prototype_chain_enum_cache()),
isolate_);
} else {
KeyAccumulator accumulator(isolate_, mode_, filter_);
accumulator.set_is_for_in(is_for_in_);
accumulator.set_skip_indices(skip_indices_);
accumulator.set_last_non_empty_prototype(last_non_empty_prototype_);
accumulator.set_may_have_elements(may_have_elements_);
accumulator.set_receiver(receiver_);
accumulator.set_first_prototype_map(first_prototype_map_);
accumulator.set_try_prototype_info_cache(try_prototype_info_cache_);
MAYBE_RETURN(accumulator.CollectKeys(first_prototype_, first_prototype_),
MaybeHandle<FixedArray>());
prototype_chain_keys = accumulator.GetKeys(keys_conversion);
}
Handle<FixedArray> result = CombineKeys(
isolate_, own_keys, prototype_chain_keys, receiver_, may_have_elements_);
if (is_for_in_ && own_keys.is_identical_to(result)) {
// Don't leak the enumeration cache without the receiver since it might get
// trimmed otherwise.
return isolate_->factory()->CopyFixedArrayUpTo(result, result->length());
}
return result;
}
bool FastKeyAccumulator::MayHaveElements(JSReceiver receiver) {
if (!receiver.IsJSObject()) return true;
JSObject object = JSObject::cast(receiver);
if (object.HasEnumerableElements()) return true;
if (object.HasIndexedInterceptor()) return true;
return false;
}
bool FastKeyAccumulator::TryPrototypeInfoCache(Handle<JSReceiver> receiver) {
if (may_have_elements_ && !only_own_has_simple_elements_) return false;
Handle<JSObject> object = Handle<JSObject>::cast(receiver);
if (!object->HasFastProperties()) return false;
if (object->HasNamedInterceptor()) return false;
if (object->IsAccessCheckNeeded() &&
!isolate_->MayAccess(handle(isolate_->context(), isolate_), object)) {
return false;
}
HeapObject prototype = receiver->map().prototype();
if (prototype.is_null()) return false;
if (!prototype.map().is_prototype_map() ||
!prototype.map().prototype_info().IsPrototypeInfo()) {
return false;
}
first_prototype_ = handle(JSReceiver::cast(prototype), isolate_);
Handle<Map> map(prototype.map(), isolate_);
first_prototype_map_ = map;
has_prototype_info_cache_ = map->IsPrototypeValidityCellValid() &&
PrototypeInfo::cast(map->prototype_info())
.prototype_chain_enum_cache()
.IsFixedArray();
return true;
}
V8_WARN_UNUSED_RESULT ExceptionStatus
KeyAccumulator::FilterForEnumerableProperties(
Handle<JSReceiver> receiver, Handle<JSObject> object,
Handle<InterceptorInfo> interceptor, Handle<JSObject> result,
IndexedOrNamed type) {
DCHECK(result->IsJSArray() || result->HasSloppyArgumentsElements());
ElementsAccessor* accessor = result->GetElementsAccessor();
size_t length = accessor->GetCapacity(*result, result->elements());
for (InternalIndex entry : InternalIndex::Range(length)) {
if (!accessor->HasEntry(*result, entry)) continue;
// args are invalid after args.Call(), create a new one in every iteration.
// Query callbacks are not expected to have side effects.
PropertyCallbackArguments args(isolate_, interceptor->data(), *receiver,
*object, Just(kDontThrow));
Handle<Object> element = accessor->Get(isolate_, result, entry);
Handle<Object> attributes;
if (type == kIndexed) {
uint32_t number;
CHECK(element->ToUint32(&number));
attributes = args.CallIndexedQuery(interceptor, number);
} else {
CHECK(element->IsName());
attributes =
args.CallNamedQuery(interceptor, Handle<Name>::cast(element));
}
if (!attributes.is_null()) {
int32_t value;
CHECK(attributes->ToInt32(&value));
if ((value & DONT_ENUM) == 0) {
RETURN_FAILURE_IF_NOT_SUCCESSFUL(AddKey(element, DO_NOT_CONVERT));
}
}
}
return ExceptionStatus::kSuccess;
}
// Returns |true| on success, |nothing| on exception.
Maybe<bool> KeyAccumulator::CollectInterceptorKeysInternal(
Handle<JSReceiver> receiver, Handle<JSObject> object,
Handle<InterceptorInfo> interceptor, IndexedOrNamed type) {
PropertyCallbackArguments enum_args(isolate_, interceptor->data(), *receiver,
*object, Just(kDontThrow));
Handle<JSObject> result;
if (!interceptor->enumerator().IsUndefined(isolate_)) {
if (type == kIndexed) {
result = enum_args.CallIndexedEnumerator(interceptor);
} else {
DCHECK_EQ(type, kNamed);
result = enum_args.CallNamedEnumerator(interceptor);
}
}
RETURN_VALUE_IF_SCHEDULED_EXCEPTION_DETECTOR(isolate_, enum_args,
Nothing<bool>());
if (result.is_null()) return Just(true);
// Request was successfully intercepted, so accept potential side effects
// happened up to this point.
enum_args.AcceptSideEffects();
if ((filter_ & ONLY_ENUMERABLE) &&
!interceptor->query().IsUndefined(isolate_)) {
RETURN_NOTHING_IF_NOT_SUCCESSFUL(FilterForEnumerableProperties(
receiver, object, interceptor, result, type));
} else {
RETURN_NOTHING_IF_NOT_SUCCESSFUL(AddKeys(
result, type == kIndexed ? CONVERT_TO_ARRAY_INDEX : DO_NOT_CONVERT));
}
return Just(true);
}
Maybe<bool> KeyAccumulator::CollectInterceptorKeys(Handle<JSReceiver> receiver,
Handle<JSObject> object,
IndexedOrNamed type) {
if (type == kIndexed) {
if (!object->HasIndexedInterceptor()) return Just(true);
} else {
if (!object->HasNamedInterceptor()) return Just(true);
}
Handle<InterceptorInfo> interceptor(type == kIndexed
? object->GetIndexedInterceptor()
: object->GetNamedInterceptor(),
isolate_);
if ((filter() & ONLY_ALL_CAN_READ) && !interceptor->all_can_read()) {
return Just(true);
}
return CollectInterceptorKeysInternal(receiver, object, interceptor, type);
}
Maybe<bool> KeyAccumulator::CollectOwnElementIndices(
Handle<JSReceiver> receiver, Handle<JSObject> object) {
if (filter_ & SKIP_STRINGS || skip_indices_) return Just(true);
ElementsAccessor* accessor = object->GetElementsAccessor();
RETURN_NOTHING_IF_NOT_SUCCESSFUL(
accessor->CollectElementIndices(object, this));
return CollectInterceptorKeys(receiver, object, kIndexed);
}
namespace {
template <bool skip_symbols>
base::Optional<int> CollectOwnPropertyNamesInternal(
Handle<JSObject> object, KeyAccumulator* keys,
Handle<DescriptorArray> descs, int start_index, int limit) {
AllowGarbageCollection allow_gc;
int first_skipped = -1;
PropertyFilter filter = keys->filter();
KeyCollectionMode mode = keys->mode();
for (InternalIndex i : InternalIndex::Range(start_index, limit)) {
bool is_shadowing_key = false;
PropertyDetails details = descs->GetDetails(i);
if ((int{details.attributes()} & filter) != 0) {
if (mode == KeyCollectionMode::kIncludePrototypes) {
is_shadowing_key = true;
} else {
continue;
}
}
if (filter & ONLY_ALL_CAN_READ) {
if (details.kind() != PropertyKind::kAccessor) continue;
Object accessors = descs->GetStrongValue(i);
if (!accessors.IsAccessorInfo()) continue;
if (!AccessorInfo::cast(accessors).all_can_read()) continue;
}
Name key = descs->GetKey(i);
if (skip_symbols == key.IsSymbol()) {
if (first_skipped == -1) first_skipped = i.as_int();
continue;
}
if (key.FilterKey(keys->filter())) continue;
if (is_shadowing_key) {
// This might allocate, but {key} is not used afterwards.
keys->AddShadowingKey(key, &allow_gc);
continue;
} else {
if (keys->AddKey(key, DO_NOT_CONVERT) != ExceptionStatus::kSuccess) {
return base::Optional<int>();
}
}
}
return first_skipped;
}
// Logic shared between different specializations of CopyEnumKeysTo.
template <typename Dictionary>
void CommonCopyEnumKeysTo(Isolate* isolate, Handle<Dictionary> dictionary,
Handle<FixedArray> storage, KeyCollectionMode mode,
KeyAccumulator* accumulator) {
DCHECK_IMPLIES(mode != KeyCollectionMode::kOwnOnly, accumulator != nullptr);
int length = storage->length();
int properties = 0;
ReadOnlyRoots roots(isolate);
AllowGarbageCollection allow_gc;
for (InternalIndex i : dictionary->IterateEntries()) {
Object key;
if (!dictionary->ToKey(roots, i, &key)) continue;
bool is_shadowing_key = false;
if (key.IsSymbol()) continue;
PropertyDetails details = dictionary->DetailsAt(i);
if (details.IsDontEnum()) {
if (mode == KeyCollectionMode::kIncludePrototypes) {
is_shadowing_key = true;
} else {
continue;
}
}
if (is_shadowing_key) {
// This might allocate, but {key} is not used afterwards.
accumulator->AddShadowingKey(key, &allow_gc);
continue;
} else {
if (Dictionary::kIsOrderedDictionaryType) {
storage->set(properties, Name::cast(key));
} else {
// If the dictionary does not store elements in enumeration order,
// we need to sort it afterwards in CopyEnumKeysTo. To enable this we
// need to store indices at this point, rather than the values at the
// given indices.
storage->set(properties, Smi::FromInt(i.as_int()));
}
}
properties++;
if (mode == KeyCollectionMode::kOwnOnly && properties == length) break;
}
CHECK_EQ(length, properties);
}
// Copies enumerable keys to preallocated fixed array.
// Does not throw for uninitialized exports in module namespace objects, so
// this has to be checked separately.
template <typename Dictionary>
void CopyEnumKeysTo(Isolate* isolate, Handle<Dictionary> dictionary,
Handle<FixedArray> storage, KeyCollectionMode mode,
KeyAccumulator* accumulator) {
static_assert(!Dictionary::kIsOrderedDictionaryType);
CommonCopyEnumKeysTo<Dictionary>(isolate, dictionary, storage, mode,
accumulator);
int length = storage->length();
DisallowGarbageCollection no_gc;
Dictionary raw_dictionary = *dictionary;
FixedArray raw_storage = *storage;
EnumIndexComparator<Dictionary> cmp(raw_dictionary);
// Use AtomicSlot wrapper to ensure that std::sort uses atomic load and
// store operations that are safe for concurrent marking.
AtomicSlot start(storage->GetFirstElementAddress());
std::sort(start, start + length, cmp);
for (int i = 0; i < length; i++) {
InternalIndex index(Smi::ToInt(raw_storage.get(i)));
raw_storage.set(i, raw_dictionary.NameAt(index));
}
}
template <>
void CopyEnumKeysTo(Isolate* isolate, Handle<SwissNameDictionary> dictionary,
Handle<FixedArray> storage, KeyCollectionMode mode,
KeyAccumulator* accumulator) {
CommonCopyEnumKeysTo<SwissNameDictionary>(isolate, dictionary, storage, mode,
accumulator);
// No need to sort, as CommonCopyEnumKeysTo on OrderedNameDictionary
// adds entries to |storage| in the dict's insertion order
// Further, the template argument true above means that |storage|
// now contains the actual values from |dictionary|, rather than indices.
}
template <class T>
Handle<FixedArray> GetOwnEnumPropertyDictionaryKeys(Isolate* isolate,
KeyCollectionMode mode,
KeyAccumulator* accumulator,
Handle<JSObject> object,
T raw_dictionary) {
Handle<T> dictionary(raw_dictionary, isolate);
if (dictionary->NumberOfElements() == 0) {
return isolate->factory()->empty_fixed_array();
}
int length = dictionary->NumberOfEnumerableProperties();
Handle<FixedArray> storage = isolate->factory()->NewFixedArray(length);
CopyEnumKeysTo(isolate, dictionary, storage, mode, accumulator);
return storage;
}
// Collect the keys from |dictionary| into |keys|, in ascending chronological
// order of property creation.
template <typename Dictionary>
ExceptionStatus CollectKeysFromDictionary(Handle<Dictionary> dictionary,
KeyAccumulator* keys) {
Isolate* isolate = keys->isolate();
ReadOnlyRoots roots(isolate);
// TODO(jkummerow): Consider using a std::unique_ptr<InternalIndex[]> instead.
Handle<FixedArray> array =
isolate->factory()->NewFixedArray(dictionary->NumberOfElements());
int array_size = 0;
PropertyFilter filter = keys->filter();
// Handle enumerable strings in CopyEnumKeysTo.
DCHECK_NE(keys->filter(), ENUMERABLE_STRINGS);
{
DisallowGarbageCollection no_gc;
for (InternalIndex i : dictionary->IterateEntries()) {
Object key;
Dictionary raw_dictionary = *dictionary;
if (!raw_dictionary.ToKey(roots, i, &key)) continue;
if (key.FilterKey(filter)) continue;
PropertyDetails details = raw_dictionary.DetailsAt(i);
if ((int{details.attributes()} & filter) != 0) {
AllowGarbageCollection gc;
// This might allocate, but {key} is not used afterwards.
keys->AddShadowingKey(key, &gc);
continue;
}
if (filter & ONLY_ALL_CAN_READ) {
if (details.kind() != PropertyKind::kAccessor) continue;
Object accessors = raw_dictionary.ValueAt(i);
if (!accessors.IsAccessorInfo()) continue;
if (!AccessorInfo::cast(accessors).all_can_read()) continue;
}
// TODO(emrich): consider storing keys instead of indices into the array
// in case of ordered dictionary type.
array->set(array_size++, Smi::FromInt(i.as_int()));
}
if (!Dictionary::kIsOrderedDictionaryType) {
// Sorting only needed if it's an unordered dictionary,
// otherwise we traversed elements in insertion order
EnumIndexComparator<Dictionary> cmp(*dictionary);
// Use AtomicSlot wrapper to ensure that std::sort uses atomic load and
// store operations that are safe for concurrent marking.
AtomicSlot start(array->GetFirstElementAddress());
std::sort(start, start + array_size, cmp);
}
}
bool has_seen_symbol = false;
for (int i = 0; i < array_size; i++) {
InternalIndex index(Smi::ToInt(array->get(i)));
Object key = dictionary->NameAt(index);
if (key.IsSymbol()) {
has_seen_symbol = true;
continue;
}
ExceptionStatus status = keys->AddKey(key, DO_NOT_CONVERT);
if (!status) return status;
}
if (has_seen_symbol) {
for (int i = 0; i < array_size; i++) {
InternalIndex index(Smi::ToInt(array->get(i)));
Object key = dictionary->NameAt(index);
if (!key.IsSymbol()) continue;
ExceptionStatus status = keys->AddKey(key, DO_NOT_CONVERT);
if (!status) return status;
}
}
return ExceptionStatus::kSuccess;
}
} // namespace
Maybe<bool> KeyAccumulator::CollectOwnPropertyNames(Handle<JSReceiver> receiver,
Handle<JSObject> object) {
if (filter_ == ENUMERABLE_STRINGS) {
Handle<FixedArray> enum_keys;
if (object->HasFastProperties()) {
enum_keys = KeyAccumulator::GetOwnEnumPropertyKeys(isolate_, object);
// If the number of properties equals the length of enumerable properties