forked from bnoordhuis/smjs
-
Notifications
You must be signed in to change notification settings - Fork 0
/
jsiter.cpp
1809 lines (1568 loc) · 56.5 KB
/
jsiter.cpp
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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=78:
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* JavaScript iterators.
*/
#include "mozilla/Util.h"
#include "jstypes.h"
#include "jsutil.h"
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jsbool.h"
#include "jscntxt.h"
#include "jsversion.h"
#include "jsexn.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsinterp.h"
#include "jsiter.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsproxy.h"
#include "jsscope.h"
#include "jsscript.h"
#if JS_HAS_XML_SUPPORT
#include "jsxml.h"
#endif
#include "ds/Sort.h"
#include "frontend/TokenStream.h"
#include "gc/Marking.h"
#include "vm/GlobalObject.h"
#include "jsinferinlines.h"
#include "jsobjinlines.h"
#include "vm/MethodGuard-inl.h"
#include "vm/Stack-inl.h"
#include "vm/String-inl.h"
using namespace mozilla;
using namespace js;
using namespace js::gc;
static void iterator_finalize(FreeOp *fop, JSObject *obj);
static void iterator_trace(JSTracer *trc, JSObject *obj);
static JSObject *iterator_iterator(JSContext *cx, JSObject *obj, JSBool keysonly);
Class js::IteratorClass = {
"Iterator",
JSCLASS_HAS_PRIVATE | JSCLASS_IMPLEMENTS_BARRIERS |
JSCLASS_HAS_CACHED_PROTO(JSProto_Iterator),
JS_PropertyStub, /* addProperty */
JS_PropertyStub, /* delProperty */
JS_PropertyStub, /* getProperty */
JS_StrictPropertyStub, /* setProperty */
JS_EnumerateStub,
JS_ResolveStub,
JS_ConvertStub,
iterator_finalize,
NULL, /* checkAccess */
NULL, /* call */
NULL, /* construct */
NULL, /* hasInstance */
iterator_trace,
{
NULL, /* equality */
NULL, /* outerObject */
NULL, /* innerObject */
iterator_iterator,
NULL /* unused */
}
};
Class js::ElementIteratorClass = {
"ElementIterator",
JSCLASS_HAS_RESERVED_SLOTS(ElementIteratorObject::NumSlots),
JS_PropertyStub, /* addProperty */
JS_PropertyStub, /* delProperty */
JS_PropertyStub, /* getProperty */
JS_StrictPropertyStub, /* setProperty */
JS_EnumerateStub,
JS_ResolveStub,
JS_ConvertStub,
NULL, /* finalize */
NULL, /* checkAccess */
NULL, /* call */
NULL, /* construct */
NULL, /* hasInstance */
NULL, /* trace */
{
NULL, /* equality */
NULL, /* outerObject */
NULL, /* innerObject */
iterator_iterator,
NULL /* unused */
}
};
static const gc::AllocKind ITERATOR_FINALIZE_KIND = gc::FINALIZE_OBJECT2;
void
NativeIterator::mark(JSTracer *trc)
{
for (HeapPtr<JSFlatString> *str = begin(); str < end(); str++)
MarkString(trc, str, "prop");
if (obj)
MarkObject(trc, &obj, "obj");
}
static void
iterator_finalize(FreeOp *fop, JSObject *obj)
{
JS_ASSERT(obj->isIterator());
NativeIterator *ni = obj->getNativeIterator();
if (ni) {
obj->setPrivate(NULL);
fop->free_(ni);
}
}
static void
iterator_trace(JSTracer *trc, JSObject *obj)
{
NativeIterator *ni = obj->getNativeIterator();
if (ni)
ni->mark(trc);
}
struct IdHashPolicy {
typedef jsid Lookup;
static HashNumber hash(jsid id) {
return JSID_BITS(id);
}
static bool match(jsid id1, jsid id2) {
return id1 == id2;
}
};
typedef HashSet<jsid, IdHashPolicy> IdSet;
static inline bool
NewKeyValuePair(JSContext *cx, jsid id, const Value &val, Value *rval)
{
Value vec[2] = { IdToValue(id), val };
AutoArrayRooter tvr(cx, ArrayLength(vec), vec);
JSObject *aobj = NewDenseCopiedArray(cx, 2, vec);
if (!aobj)
return false;
rval->setObject(*aobj);
return true;
}
static inline bool
Enumerate(JSContext *cx, JSObject *obj, JSObject *pobj, jsid id,
bool enumerable, unsigned flags, IdSet& ht, AutoIdVector *props)
{
JS_ASSERT_IF(flags & JSITER_OWNONLY, obj == pobj);
/*
* We implement __proto__ using a property on |Object.prototype|, but
* because __proto__ is highly deserving of removal, we don't want it to
* show up in property enumeration, even if only for |Object.prototype|
* (think introspection by Prototype-like frameworks that add methods to
* the built-in prototypes). So exclude __proto__ if the object where the
* property was found has no [[Prototype]] and might be |Object.prototype|.
*/
if (JS_UNLIKELY(!pobj->getProto() && JSID_IS_ATOM(id, cx->runtime->atomState.protoAtom)))
return true;
if (!(flags & JSITER_OWNONLY) || pobj->isProxy() || pobj->getOps()->enumerate) {
/* If we've already seen this, we definitely won't add it. */
IdSet::AddPtr p = ht.lookupForAdd(id);
if (JS_UNLIKELY(!!p))
return true;
/*
* It's not necessary to add properties to the hash table at the end of
* the prototype chain, but custom enumeration behaviors might return
* duplicated properties, so always add in such cases.
*/
if ((pobj->getProto() || pobj->isProxy() || pobj->getOps()->enumerate) && !ht.add(p, id))
return false;
}
if (enumerable || (flags & JSITER_HIDDEN))
return props->append(id);
return true;
}
static bool
EnumerateNativeProperties(JSContext *cx, JSObject *obj, JSObject *pobj, unsigned flags, IdSet &ht,
AutoIdVector *props)
{
RootObject objRoot(cx, &obj);
RootObject pobjRoot(cx, &pobj);
size_t initialLength = props->length();
/* Collect all unique properties from this object's scope. */
Shape::Range r = pobj->lastProperty()->all();
Shape::Range::Root root(cx, &r);
for (; !r.empty(); r.popFront()) {
const Shape &shape = r.front();
if (!JSID_IS_DEFAULT_XML_NAMESPACE(shape.propid()) &&
!Enumerate(cx, obj, pobj, shape.propid(), shape.enumerable(), flags, ht, props))
{
return false;
}
}
::Reverse(props->begin() + initialLength, props->end());
return true;
}
static bool
EnumerateDenseArrayProperties(JSContext *cx, JSObject *obj, JSObject *pobj, unsigned flags,
IdSet &ht, AutoIdVector *props)
{
if (!Enumerate(cx, obj, pobj, NameToId(cx->runtime->atomState.lengthAtom), false,
flags, ht, props)) {
return false;
}
if (pobj->getArrayLength() > 0) {
size_t initlen = pobj->getDenseArrayInitializedLength();
const Value *vp = pobj->getDenseArrayElements();
for (size_t i = 0; i < initlen; ++i, ++vp) {
if (!vp->isMagic(JS_ARRAY_HOLE)) {
/* Dense arrays never get so large that i would not fit into an integer id. */
if (!Enumerate(cx, obj, pobj, INT_TO_JSID(i), true, flags, ht, props))
return false;
}
}
}
return true;
}
#ifdef JS_MORE_DETERMINISTIC
struct SortComparatorIds
{
JSContext *const cx;
SortComparatorIds(JSContext *cx)
: cx(cx) {}
bool operator()(jsid a, jsid b, bool *lessOrEqualp)
{
/* Pick an arbitrary total order on jsids that is stable across executions. */
JSString *astr = IdToString(cx, a);
if (!astr)
return false;
JSString *bstr = IdToString(cx, b);
if (!bstr)
return false;
int32_t result;
if (!CompareStrings(cx, astr, bstr, &result))
return false;
*lessOrEqualp = (result <= 0);
return true;
}
};
#endif /* JS_MORE_DETERMINISTIC */
static bool
Snapshot(JSContext *cx, JSObject *obj, unsigned flags, AutoIdVector *props)
{
IdSet ht(cx);
if (!ht.init(32))
return NULL;
RootObject objRoot(cx, &obj);
RootedVarObject pobj(cx);
pobj = obj;
do {
Class *clasp = pobj->getClass();
if (pobj->isNative() &&
!pobj->getOps()->enumerate &&
!(clasp->flags & JSCLASS_NEW_ENUMERATE)) {
if (!clasp->enumerate(cx, pobj))
return false;
if (!EnumerateNativeProperties(cx, obj, pobj, flags, ht, props))
return false;
} else if (pobj->isDenseArray()) {
if (!EnumerateDenseArrayProperties(cx, obj, pobj, flags, ht, props))
return false;
} else {
if (pobj->isProxy()) {
AutoIdVector proxyProps(cx);
if (flags & JSITER_OWNONLY) {
if (flags & JSITER_HIDDEN) {
if (!Proxy::getOwnPropertyNames(cx, pobj, proxyProps))
return false;
} else {
if (!Proxy::keys(cx, pobj, proxyProps))
return false;
}
} else {
if (!Proxy::enumerate(cx, pobj, proxyProps))
return false;
}
for (size_t n = 0, len = proxyProps.length(); n < len; n++) {
if (!Enumerate(cx, obj, pobj, proxyProps[n], true, flags, ht, props))
return false;
}
/* Proxy objects enumerate the prototype on their own, so we are done here. */
break;
}
Value state;
JSIterateOp op = (flags & JSITER_HIDDEN) ? JSENUMERATE_INIT_ALL : JSENUMERATE_INIT;
if (!pobj->enumerate(cx, op, &state, NULL))
return false;
if (state.isMagic(JS_NATIVE_ENUMERATE)) {
if (!EnumerateNativeProperties(cx, obj, pobj, flags, ht, props))
return false;
} else {
while (true) {
jsid id;
if (!pobj->enumerate(cx, JSENUMERATE_NEXT, &state, &id))
return false;
if (state.isNull())
break;
if (!Enumerate(cx, obj, pobj, id, true, flags, ht, props))
return false;
}
}
}
if ((flags & JSITER_OWNONLY) || pobj->isXML())
break;
} while ((pobj = pobj->getProto()) != NULL);
#ifdef JS_MORE_DETERMINISTIC
/*
* In some cases the enumeration order for an object depends on the
* execution mode (interpreter vs. JIT), especially for native objects
* with a class enumerate hook (where resolving a property changes the
* resulting enumeration order). These aren't really bugs, but the
* differences can change the generated output and confuse correctness
* fuzzers, so we sort the ids if such a fuzzer is running.
*
* We don't do this in the general case because (a) doing so is slow,
* and (b) it also breaks the web, which expects enumeration order to
* follow the order in which properties are added, in certain cases.
* Since ECMA does not specify an enumeration order for objects, both
* behaviors are technically correct to do.
*/
jsid *ids = props->begin();
size_t n = props->length();
Vector<jsid> tmp(cx);
if (!tmp.resizeUninitialized(n))
return false;
if (!MergeSort(ids, n, tmp.begin(), SortComparatorIds(cx)))
return false;
#endif /* JS_MORE_DETERMINISTIC */
return true;
}
bool
js::VectorToIdArray(JSContext *cx, AutoIdVector &props, JSIdArray **idap)
{
JS_STATIC_ASSERT(sizeof(JSIdArray) > sizeof(jsid));
size_t len = props.length();
size_t idsz = len * sizeof(jsid);
size_t sz = (sizeof(JSIdArray) - sizeof(jsid)) + idsz;
JSIdArray *ida = static_cast<JSIdArray *>(cx->malloc_(sz));
if (!ida)
return false;
ida->length = static_cast<int>(len);
jsid *v = props.begin();
for (int i = 0; i < ida->length; i++)
ida->vector[i].init(v[i]);
*idap = ida;
return true;
}
JS_FRIEND_API(bool)
js::GetPropertyNames(JSContext *cx, JSObject *obj, unsigned flags, AutoIdVector *props)
{
return Snapshot(cx, obj, flags & (JSITER_OWNONLY | JSITER_HIDDEN), props);
}
size_t sCustomIteratorCount = 0;
static inline bool
GetCustomIterator(JSContext *cx, HandleObject obj, unsigned flags, Value *vp)
{
JS_CHECK_RECURSION(cx, return false);
/*
* for-of iteration does not fall back on __iterator__ or property
* enumeration. This is more conservative than the current proposed spec.
*/
if (flags == JSITER_FOR_OF) {
js_ReportValueErrorFlags(cx, JSREPORT_ERROR, JSMSG_NOT_ITERABLE,
JSDVG_SEARCH_STACK, ObjectValue(*obj), NULL, NULL, NULL);
return false;
}
/* Check whether we have a valid __iterator__ method. */
PropertyName *name = cx->runtime->atomState.iteratorAtom;
if (!js_GetMethod(cx, obj, NameToId(name), 0, vp))
return false;
/* If there is no custom __iterator__ method, we are done here. */
if (!vp->isObject()) {
vp->setUndefined();
return true;
}
if (!cx->runningWithTrustedPrincipals())
++sCustomIteratorCount;
/* Otherwise call it and return that object. */
Value arg = BooleanValue((flags & JSITER_FOREACH) == 0);
if (!Invoke(cx, ObjectValue(*obj), *vp, 1, &arg, vp))
return false;
if (vp->isPrimitive()) {
/*
* We are always coming from js::ValueToIterator, and we are no longer on
* trace, so the object we are iterating over is on top of the stack (-1).
*/
JSAutoByteString bytes;
if (!js_AtomToPrintableString(cx, name, &bytes))
return false;
js_ReportValueError2(cx, JSMSG_BAD_TRAP_RETURN_VALUE,
-1, ObjectValue(*obj), NULL, bytes.ptr());
return false;
}
return true;
}
template <typename T>
static inline bool
Compare(T *a, T *b, size_t c)
{
size_t n = (c + size_t(7)) / size_t(8);
switch (c % 8) {
case 0: do { if (*a++ != *b++) return false;
case 7: if (*a++ != *b++) return false;
case 6: if (*a++ != *b++) return false;
case 5: if (*a++ != *b++) return false;
case 4: if (*a++ != *b++) return false;
case 3: if (*a++ != *b++) return false;
case 2: if (*a++ != *b++) return false;
case 1: if (*a++ != *b++) return false;
} while (--n > 0);
}
return true;
}
static inline JSObject *
NewIteratorObject(JSContext *cx, unsigned flags)
{
if (flags & JSITER_ENUMERATE) {
RootedVarTypeObject type(cx);
type = cx->compartment->getEmptyType(cx);
if (!type)
return NULL;
RootedVarShape emptyEnumeratorShape(cx);
emptyEnumeratorShape = EmptyShape::getInitialShape(cx, &IteratorClass, NULL, NULL,
ITERATOR_FINALIZE_KIND);
if (!emptyEnumeratorShape)
return NULL;
JSObject *obj = JSObject::create(cx, ITERATOR_FINALIZE_KIND,
emptyEnumeratorShape, type, NULL);
if (!obj)
return NULL;
JS_ASSERT(obj->numFixedSlots() == JSObject::ITER_CLASS_NFIXED_SLOTS);
return obj;
}
return NewBuiltinClassInstance(cx, &IteratorClass);
}
NativeIterator *
NativeIterator::allocateIterator(JSContext *cx, uint32_t slength, const AutoIdVector &props)
{
size_t plength = props.length();
NativeIterator *ni = (NativeIterator *)
cx->malloc_(sizeof(NativeIterator)
+ plength * sizeof(JSString *)
+ slength * sizeof(Shape *));
if (!ni)
return NULL;
AutoValueVector strings(cx);
ni->props_array = ni->props_cursor = (HeapPtr<JSFlatString> *) (ni + 1);
ni->props_end = ni->props_array + plength;
if (plength) {
for (size_t i = 0; i < plength; i++) {
JSFlatString *str = IdToString(cx, props[i]);
if (!str || !strings.append(StringValue(str)))
return NULL;
ni->props_array[i].init(str);
}
}
return ni;
}
inline void
NativeIterator::init(JSObject *obj, unsigned flags, uint32_t slength, uint32_t key)
{
this->obj.init(obj);
this->flags = flags;
this->shapes_array = (const Shape **) this->props_end;
this->shapes_length = slength;
this->shapes_key = key;
}
static inline void
RegisterEnumerator(JSContext *cx, JSObject *iterobj, NativeIterator *ni)
{
/* Register non-escaping native enumerators (for-in) with the current context. */
if (ni->flags & JSITER_ENUMERATE) {
ni->next = cx->enumerators;
cx->enumerators = iterobj;
JS_ASSERT(!(ni->flags & JSITER_ACTIVE));
ni->flags |= JSITER_ACTIVE;
}
}
static inline bool
VectorToKeyIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &keys,
uint32_t slength, uint32_t key, Value *vp)
{
JS_ASSERT(!(flags & JSITER_FOREACH));
if (obj) {
if (obj->hasSingletonType() && !obj->setIteratedSingleton(cx))
return false;
types::MarkTypeObjectFlags(cx, obj, types::OBJECT_FLAG_ITERATED);
}
RootedVarObject iterobj(cx, NewIteratorObject(cx, flags));
if (!iterobj)
return false;
NativeIterator *ni = NativeIterator::allocateIterator(cx, slength, keys);
if (!ni)
return false;
ni->init(obj, flags, slength, key);
if (slength) {
/*
* Fill in the shape array from scratch. We can't use the array that was
* computed for the cache lookup earlier, as constructing iterobj could
* have triggered a shape-regenerating GC. Don't bother with regenerating
* the shape key; if such a GC *does* occur, we can only get hits through
* the one-slot lastNativeIterator cache.
*/
JSObject *pobj = obj;
size_t ind = 0;
do {
ni->shapes_array[ind++] = pobj->lastProperty();
pobj = pobj->getProto();
} while (pobj);
JS_ASSERT(ind == slength);
}
iterobj->setNativeIterator(ni);
vp->setObject(*iterobj);
RegisterEnumerator(cx, iterobj, ni);
return true;
}
namespace js {
bool
VectorToKeyIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &props, Value *vp)
{
return VectorToKeyIterator(cx, obj, flags, props, 0, 0, vp);
}
bool
VectorToValueIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &keys,
Value *vp)
{
JS_ASSERT(flags & JSITER_FOREACH);
if (obj) {
if (obj->hasSingletonType() && !obj->setIteratedSingleton(cx))
return false;
types::MarkTypeObjectFlags(cx, obj, types::OBJECT_FLAG_ITERATED);
}
JSObject *iterobj = NewIteratorObject(cx, flags);
if (!iterobj)
return false;
NativeIterator *ni = NativeIterator::allocateIterator(cx, 0, keys);
if (!ni)
return false;
ni->init(obj, flags, 0, 0);
iterobj->setNativeIterator(ni);
vp->setObject(*iterobj);
RegisterEnumerator(cx, iterobj, ni);
return true;
}
bool
EnumeratedIdVectorToIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &props, Value *vp)
{
if (!(flags & JSITER_FOREACH))
return VectorToKeyIterator(cx, obj, flags, props, vp);
return VectorToValueIterator(cx, obj, flags, props, vp);
}
static inline void
UpdateNativeIterator(NativeIterator *ni, JSObject *obj)
{
// Update the object for which the native iterator is associated, so
// SuppressDeletedPropertyHelper will recognize the iterator as a match.
ni->obj = obj;
}
bool
GetIterator(JSContext *cx, HandleObject obj, unsigned flags, Value *vp)
{
Vector<const Shape *, 8> shapes(cx);
uint32_t key = 0;
bool keysOnly = (flags == JSITER_ENUMERATE);
if (obj) {
/* Enumerate Iterator.prototype directly. */
if (JSIteratorOp op = obj->getClass()->ext.iteratorObject) {
/*
* Arrays and other classes representing iterable collections have
* the JSCLASS_FOR_OF_ITERATION flag. This flag means that the
* object responds to all other kinds of enumeration (for-in,
* for-each, Object.keys, Object.getOwnPropertyNames, etc.) in the
* default way, ignoring the hook. The hook is used only when
* iterating in the style of a for-of loop.
*/
if (!(obj->getClass()->flags & JSCLASS_FOR_OF_ITERATION) || flags == JSITER_FOR_OF) {
JSObject *iterobj = op(cx, obj, !(flags & (JSITER_FOREACH | JSITER_FOR_OF)));
if (!iterobj)
return false;
vp->setObject(*iterobj);
types::MarkIteratorUnknown(cx);
return true;
}
}
if (keysOnly) {
/*
* Check to see if this is the same as the most recent object which
* was iterated over. We don't explicitly check for shapeless
* objects here, as they are not inserted into the cache and
* will result in a miss.
*/
JSObject *last = cx->runtime->nativeIterCache.last;
JSObject *proto = obj->getProto();
if (last) {
NativeIterator *lastni = last->getNativeIterator();
if (!(lastni->flags & (JSITER_ACTIVE|JSITER_UNREUSABLE)) &&
obj->isNative() &&
obj->lastProperty() == lastni->shapes_array[0] &&
proto && proto->isNative() &&
proto->lastProperty() == lastni->shapes_array[1] &&
!proto->getProto()) {
vp->setObject(*last);
UpdateNativeIterator(lastni, obj);
RegisterEnumerator(cx, last, lastni);
return true;
}
}
/*
* The iterator object for JSITER_ENUMERATE never escapes, so we
* don't care for the proper parent/proto to be set. This also
* allows us to re-use a previous iterator object that is not
* currently active.
*/
JSObject *pobj = obj;
do {
if (!pobj->isNative() ||
pobj->hasUncacheableProto() ||
obj->getOps()->enumerate ||
pobj->getClass()->enumerate != JS_EnumerateStub) {
shapes.clear();
goto miss;
}
const Shape *shape = pobj->lastProperty();
key = (key + (key << 16)) ^ (uintptr_t(shape) >> 3);
if (!shapes.append((Shape *) shape))
return false;
pobj = pobj->getProto();
} while (pobj);
JSObject *iterobj = cx->runtime->nativeIterCache.get(key);
if (iterobj) {
NativeIterator *ni = iterobj->getNativeIterator();
if (!(ni->flags & (JSITER_ACTIVE|JSITER_UNREUSABLE)) &&
ni->shapes_key == key &&
ni->shapes_length == shapes.length() &&
Compare(ni->shapes_array, shapes.begin(), ni->shapes_length)) {
vp->setObject(*iterobj);
UpdateNativeIterator(ni, obj);
RegisterEnumerator(cx, iterobj, ni);
if (shapes.length() == 2)
cx->runtime->nativeIterCache.last = iterobj;
return true;
}
}
}
miss:
if (obj->isProxy()) {
types::MarkIteratorUnknown(cx);
return Proxy::iterate(cx, obj, flags, vp);
}
if (!GetCustomIterator(cx, obj, flags, vp))
return false;
if (!vp->isUndefined()) {
types::MarkIteratorUnknown(cx);
return true;
}
}
/* NB: for (var p in null) succeeds by iterating over no properties. */
AutoIdVector keys(cx);
if (flags & JSITER_FOREACH) {
if (JS_LIKELY(obj != NULL) && !Snapshot(cx, obj, flags, &keys))
return false;
JS_ASSERT(shapes.empty());
if (!VectorToValueIterator(cx, obj, flags, keys, vp))
return false;
} else {
if (JS_LIKELY(obj != NULL) && !Snapshot(cx, obj, flags, &keys))
return false;
if (!VectorToKeyIterator(cx, obj, flags, keys, shapes.length(), key, vp))
return false;
}
JSObject *iterobj = &vp->toObject();
/* Cache the iterator object if possible. */
if (shapes.length())
cx->runtime->nativeIterCache.set(key, iterobj);
if (shapes.length() == 2)
cx->runtime->nativeIterCache.last = iterobj;
return true;
}
}
static JSObject *
iterator_iterator(JSContext *cx, JSObject *obj, JSBool keysonly)
{
return obj;
}
static JSBool
Iterator(JSContext *cx, unsigned argc, Value *vp)
{
Value *argv = JS_ARGV(cx, vp);
bool keyonly = argc >= 2 ? js_ValueToBoolean(argv[1]) : false;
unsigned flags = JSITER_OWNONLY | (keyonly ? 0 : (JSITER_FOREACH | JSITER_KEYVALUE));
*vp = argc >= 1 ? argv[0] : UndefinedValue();
return ValueToIterator(cx, flags, vp);
}
JSBool
js_ThrowStopIteration(JSContext *cx)
{
Value v;
JS_ASSERT(!JS_IsExceptionPending(cx));
if (js_FindClassObject(cx, NULL, JSProto_StopIteration, &v))
cx->setPendingException(v);
return JS_FALSE;
}
static JSBool
iterator_next(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
bool ok;
RootedVarObject obj(cx, NonGenericMethodGuard(cx, args, iterator_next, &IteratorClass, &ok));
if (!obj)
return ok;
if (!js_IteratorMore(cx, obj, &args.rval()))
return false;
if (!args.rval().toBoolean()) {
js_ThrowStopIteration(cx);
return false;
}
return js_IteratorNext(cx, obj, &args.rval());
}
#define JSPROP_ROPERM (JSPROP_READONLY | JSPROP_PERMANENT)
static JSFunctionSpec iterator_methods[] = {
JS_FN(js_next_str, iterator_next, 0,JSPROP_ROPERM),
JS_FS_END
};
#if JS_HAS_GENERATORS
static JSBool
CloseGenerator(JSContext *cx, JSObject *genobj);
#endif
/*
* Call ToObject(v).__iterator__(keyonly) if ToObject(v).__iterator__ exists.
* Otherwise construct the default iterator.
*/
JSBool
js::ValueToIterator(JSContext *cx, unsigned flags, Value *vp)
{
/* JSITER_KEYVALUE must always come with JSITER_FOREACH */
JS_ASSERT_IF(flags & JSITER_KEYVALUE, flags & JSITER_FOREACH);
/*
* Make sure the more/next state machine doesn't get stuck. A value might be
* left in iterValue when a trace is left due to an operation time-out after
* JSOP_MOREITER but before the value is picked up by FOR*.
*/
cx->iterValue.setMagic(JS_NO_ITER_VALUE);
RootedVarObject obj(cx);
if (vp->isObject()) {
/* Common case. */
obj = &vp->toObject();
} else {
/*
* Enumerating over null and undefined gives an empty enumerator.
* This is contrary to ECMA-262 9.9 ToObject, invoked from step 3 of
* the first production in 12.6.4 and step 4 of the second production,
* but it's "web JS" compatible. ES5 fixed for-in to match this de-facto
* standard.
*/
if ((flags & JSITER_ENUMERATE)) {
if (!js_ValueToObjectOrNull(cx, *vp, obj.address()))
return false;
/* fall through */
} else {
obj = js_ValueToNonNullObject(cx, *vp);
if (!obj)
return false;
}
}
return GetIterator(cx, obj, flags, vp);
}
bool
js::CloseIterator(JSContext *cx, JSObject *obj)
{
cx->iterValue.setMagic(JS_NO_ITER_VALUE);
if (obj->isIterator()) {
/* Remove enumerators from the active list, which is a stack. */
NativeIterator *ni = obj->getNativeIterator();
if (ni->flags & JSITER_ENUMERATE) {
JS_ASSERT(cx->enumerators == obj);
cx->enumerators = ni->next;
JS_ASSERT(ni->flags & JSITER_ACTIVE);
ni->flags &= ~JSITER_ACTIVE;
/*
* Reset the enumerator; it may still be in the cached iterators
* for this thread, and can be reused.
*/
ni->props_cursor = ni->props_array;
}
}
#if JS_HAS_GENERATORS
else if (obj->isGenerator()) {
return CloseGenerator(cx, obj);
}
#endif
return JS_TRUE;
}
bool
js::UnwindIteratorForException(JSContext *cx, JSObject *obj)
{
RootedVarValue v(cx, cx->getPendingException());
cx->clearPendingException();
if (!CloseIterator(cx, obj))
return false;
cx->setPendingException(v);
return true;
}
void
js::UnwindIteratorForUncatchableException(JSContext *cx, JSObject *obj)
{
if (obj->isIterator()) {
NativeIterator *ni = obj->getNativeIterator();
if (ni->flags & JSITER_ENUMERATE) {
JS_ASSERT(cx->enumerators == obj);
cx->enumerators = ni->next;
}
}
}
/*
* Suppress enumeration of deleted properties. This function must be called
* when a property is deleted and there might be active enumerators.
*
* We maintain a list of active non-escaping for-in enumerators. To suppress
* a property, we check whether each active enumerator contains the (obj, id)
* pair and has not yet enumerated |id|. If so, and |id| is the next property,
* we simply advance the cursor. Otherwise, we delete |id| from the list.
*
* We do not suppress enumeration of a property deleted along an object's
* prototype chain. Only direct deletions on the object are handled.
*
* This function can suppress multiple properties at once. The |predicate|
* argument is an object which can be called on an id and returns true or
* false. It also must have a method |matchesAtMostOne| which allows us to
* stop searching after the first deletion if true.
*/
template<typename StringPredicate>
static bool
SuppressDeletedPropertyHelper(JSContext *cx, HandleObject obj, StringPredicate predicate)
{
JSObject *iterobj = cx->enumerators;
while (iterobj) {
again:
NativeIterator *ni = iterobj->getNativeIterator();