summaryrefslogtreecommitdiff
path: root/deps/v8/src/objects/fixed-array.h
blob: 287015ef7c2160578f949c4bd64be348c681e03f (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
// Copyright 2017 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.

#ifndef V8_OBJECTS_FIXED_ARRAY_H_
#define V8_OBJECTS_FIXED_ARRAY_H_

#include "src/maybe-handles.h"
#include "src/objects.h"

// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"

namespace v8 {
namespace internal {

class WeakArrayBodyDescriptor;

#define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V)    \
  V(BYTECODE_ARRAY_CONSTANT_POOL_SUB_TYPE)       \
  V(BYTECODE_ARRAY_HANDLER_TABLE_SUB_TYPE)       \
  V(CODE_STUBS_TABLE_SUB_TYPE)                   \
  V(COMPILATION_CACHE_TABLE_SUB_TYPE)            \
  V(CONTEXT_SUB_TYPE)                            \
  V(COPY_ON_WRITE_SUB_TYPE)                      \
  V(DEOPTIMIZATION_DATA_SUB_TYPE)                \
  V(DESCRIPTOR_ARRAY_SUB_TYPE)                   \
  V(EMBEDDED_OBJECT_SUB_TYPE)                    \
  V(ENUM_CACHE_SUB_TYPE)                         \
  V(ENUM_INDICES_CACHE_SUB_TYPE)                 \
  V(DEPENDENT_CODE_SUB_TYPE)                     \
  V(DICTIONARY_ELEMENTS_SUB_TYPE)                \
  V(DICTIONARY_PROPERTIES_SUB_TYPE)              \
  V(EMPTY_PROPERTIES_DICTIONARY_SUB_TYPE)        \
  V(PACKED_ELEMENTS_SUB_TYPE)                    \
  V(FAST_PROPERTIES_SUB_TYPE)                    \
  V(FAST_TEMPLATE_INSTANTIATIONS_CACHE_SUB_TYPE) \
  V(HANDLER_TABLE_SUB_TYPE)                      \
  V(JS_COLLECTION_SUB_TYPE)                      \
  V(JS_WEAK_COLLECTION_SUB_TYPE)                 \
  V(NOSCRIPT_SHARED_FUNCTION_INFOS_SUB_TYPE)     \
  V(NUMBER_STRING_CACHE_SUB_TYPE)                \
  V(OBJECT_TO_CODE_SUB_TYPE)                     \
  V(OPTIMIZED_CODE_LITERALS_SUB_TYPE)            \
  V(OPTIMIZED_CODE_MAP_SUB_TYPE)                 \
  V(PROTOTYPE_USERS_SUB_TYPE)                    \
  V(REGEXP_MULTIPLE_CACHE_SUB_TYPE)              \
  V(RETAINED_MAPS_SUB_TYPE)                      \
  V(SCOPE_INFO_SUB_TYPE)                         \
  V(SCRIPT_LIST_SUB_TYPE)                        \
  V(SERIALIZED_OBJECTS_SUB_TYPE)                 \
  V(SHARED_FUNCTION_INFOS_SUB_TYPE)              \
  V(SINGLE_CHARACTER_STRING_CACHE_SUB_TYPE)      \
  V(SLOW_TEMPLATE_INSTANTIATIONS_CACHE_SUB_TYPE) \
  V(STRING_SPLIT_CACHE_SUB_TYPE)                 \
  V(STRING_TABLE_SUB_TYPE)                       \
  V(TEMPLATE_INFO_SUB_TYPE)                      \
  V(FEEDBACK_METADATA_SUB_TYPE)                  \
  V(WEAK_NEW_SPACE_OBJECT_TO_CODE_SUB_TYPE)

enum FixedArraySubInstanceType {
#define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
  FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
#undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
      LAST_FIXED_ARRAY_SUB_TYPE = WEAK_NEW_SPACE_OBJECT_TO_CODE_SUB_TYPE
};

// Common superclass for FixedArrays that allow implementations to share
// common accessors and some code paths.
class FixedArrayBase : public HeapObject {
 public:
  // [length]: length of the array.
  inline int length() const;
  inline void set_length(int value);

  // Get and set the length using acquire loads and release stores.
  inline int synchronized_length() const;
  inline void synchronized_set_length(int value);

  inline Object* unchecked_synchronized_length() const;

  DECL_CAST(FixedArrayBase)

  static int GetMaxLengthForNewSpaceAllocation(ElementsKind kind);

  bool IsCowArray() const;

// Maximal allowed size, in bytes, of a single FixedArrayBase.
// Prevents overflowing size computations, as well as extreme memory
// consumption.
#ifdef V8_HOST_ARCH_32_BIT
  static const int kMaxSize = 512 * MB;
#else
  static const int kMaxSize = 1024 * MB;
#endif  // V8_HOST_ARCH_32_BIT

  // Layout description.
  // Length is smi tagged when it is stored.
  static const int kLengthOffset = HeapObject::kHeaderSize;
  static const int kHeaderSize = kLengthOffset + kPointerSize;
};

// FixedArray describes fixed-sized arrays with element type Object*.
class FixedArray : public FixedArrayBase {
 public:
  // Setter and getter for elements.
  inline Object* get(int index) const;
  static inline Handle<Object> get(FixedArray* array, int index,
                                   Isolate* isolate);
  template <class T>
  MaybeHandle<T> GetValue(Isolate* isolate, int index) const;

  template <class T>
  Handle<T> GetValueChecked(Isolate* isolate, int index) const;

  // Return a grown copy if the index is bigger than the array's length.
  static Handle<FixedArray> SetAndGrow(Isolate* isolate,
                                       Handle<FixedArray> array, int index,
                                       Handle<Object> value,
                                       PretenureFlag pretenure = NOT_TENURED);

  // Setter that uses write barrier.
  inline void set(int index, Object* value);
  inline bool is_the_hole(Isolate* isolate, int index);

  // Setter that doesn't need write barrier.
  inline void set(int index, Smi* value);
  // Setter with explicit barrier mode.
  inline void set(int index, Object* value, WriteBarrierMode mode);

  // Setters for frequently used oddballs located in old space.
  inline void set_undefined(int index);
  inline void set_undefined(Isolate* isolate, int index);
  inline void set_null(int index);
  inline void set_null(Isolate* isolate, int index);
  inline void set_the_hole(int index);
  inline void set_the_hole(Isolate* isolate, int index);

  inline Object** GetFirstElementAddress();
  inline bool ContainsOnlySmisOrHoles();
  // Returns true iff the elements are Numbers and sorted ascending.
  bool ContainsSortedNumbers();

  // Gives access to raw memory which stores the array's data.
  inline Object** data_start();

  inline void FillWithHoles(int from, int to);

  // Shrink the array and insert filler objects. {new_length} must be > 0.
  void Shrink(Isolate* isolate, int new_length);
  // If {new_length} is 0, return the canonical empty FixedArray. Otherwise
  // like above.
  static Handle<FixedArray> ShrinkOrEmpty(Isolate* isolate,
                                          Handle<FixedArray> array,
                                          int new_length);

  // Copy a sub array from the receiver to dest.
  void CopyTo(int pos, FixedArray* dest, int dest_pos, int len) const;

  // Garbage collection support.
  static constexpr int SizeFor(int length) {
    return kHeaderSize + length * kPointerSize;
  }

  // Code Generation support.
  static constexpr int OffsetOfElementAt(int index) { return SizeFor(index); }

  // Garbage collection support.
  inline Object** RawFieldOfElementAt(int index);

  DECL_CAST(FixedArray)
  // Maximally allowed length of a FixedArray.
  static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
  static_assert(Internals::IsValidSmi(kMaxLength),
                "FixedArray maxLength not a Smi");

  // Maximally allowed length for regular (non large object space) object.
  STATIC_ASSERT(kMaxRegularHeapObjectSize < kMaxSize);
  static const int kMaxRegularLength =
      (kMaxRegularHeapObjectSize - kHeaderSize) / kPointerSize;

  // Dispatched behavior.
  DECL_PRINTER(FixedArray)
  DECL_VERIFIER(FixedArray)
#ifdef DEBUG
  // Checks if two FixedArrays have identical contents.
  bool IsEqualTo(FixedArray* other);
#endif

  typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor;
  // No weak fields.
  typedef BodyDescriptor BodyDescriptorWeak;

 protected:
  // Set operation on FixedArray without using write barriers. Can
  // only be used for storing old space objects or smis.
  static inline void NoWriteBarrierSet(FixedArray* array, int index,
                                       Object* value);

 private:
  STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);

  inline void set_undefined(ReadOnlyRoots ro_roots, int index);
  inline void set_null(ReadOnlyRoots ro_roots, int index);
  inline void set_the_hole(ReadOnlyRoots ro_roots, int index);

  DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray);
};

// FixedArray alias added only because of IsFixedArrayExact() predicate, which
// checks for the exact instance type FIXED_ARRAY_TYPE instead of a range
// check: [FIRST_FIXED_ARRAY_TYPE, LAST_FIXED_ARRAY_TYPE].
class FixedArrayExact final : public FixedArray {
 public:
  DECL_CAST(FixedArrayExact)
};

// FixedDoubleArray describes fixed-sized arrays with element type double.
class FixedDoubleArray : public FixedArrayBase {
 public:
  // Setter and getter for elements.
  inline double get_scalar(int index);
  inline uint64_t get_representation(int index);
  static inline Handle<Object> get(FixedDoubleArray* array, int index,
                                   Isolate* isolate);
  inline void set(int index, double value);
  inline void set_the_hole(Isolate* isolate, int index);
  inline void set_the_hole(int index);

  // Checking for the hole.
  inline bool is_the_hole(Isolate* isolate, int index);
  inline bool is_the_hole(int index);

  // Garbage collection support.
  inline static int SizeFor(int length) {
    return kHeaderSize + length * kDoubleSize;
  }

  // Gives access to raw memory which stores the array's data.
  inline double* data_start();

  inline void FillWithHoles(int from, int to);

  // Code Generation support.
  static int OffsetOfElementAt(int index) { return SizeFor(index); }

  DECL_CAST(FixedDoubleArray)

  // Maximally allowed length of a FixedArray.
  static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
  static_assert(Internals::IsValidSmi(kMaxLength),
                "FixedDoubleArray maxLength not a Smi");

  // Dispatched behavior.
  DECL_PRINTER(FixedDoubleArray)
  DECL_VERIFIER(FixedDoubleArray)

  class BodyDescriptor;
  // No weak fields.
  typedef BodyDescriptor BodyDescriptorWeak;

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
};

// WeakFixedArray describes fixed-sized arrays with element type
// MaybeObject*.
class WeakFixedArray : public HeapObject {
 public:
  DECL_CAST(WeakFixedArray)

  inline MaybeObject* Get(int index) const;

  // Setter that uses write barrier.
  inline void Set(int index, MaybeObject* value);

  // Setter with explicit barrier mode.
  inline void Set(int index, MaybeObject* value, WriteBarrierMode mode);

  static constexpr int SizeFor(int length) {
    return kHeaderSize + length * kPointerSize;
  }

  DECL_INT_ACCESSORS(length)

  // Get and set the length using acquire loads and release stores.
  inline int synchronized_length() const;
  inline void synchronized_set_length(int value);

  // Gives access to raw memory which stores the array's data.
  inline MaybeObject** data_start();

  inline MaybeObject** RawFieldOfElementAt(int index);

  inline MaybeObject** GetFirstElementAddress();

  DECL_PRINTER(WeakFixedArray)
  DECL_VERIFIER(WeakFixedArray)

  typedef WeakArrayBodyDescriptor BodyDescriptor;
  typedef BodyDescriptor BodyDescriptorWeak;

  static const int kLengthOffset = HeapObject::kHeaderSize;
  static const int kHeaderSize = kLengthOffset + kPointerSize;

  static const int kMaxLength =
      (FixedArray::kMaxSize - kHeaderSize) / kPointerSize;
  static_assert(Internals::IsValidSmi(kMaxLength),
                "WeakFixedArray maxLength not a Smi");

 protected:
  static int OffsetOfElementAt(int index) {
    return kHeaderSize + index * kPointerSize;
  }

 private:
  friend class Heap;

  static const int kFirstIndex = 1;

  DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
};

// WeakArrayList is like a WeakFixedArray with static convenience methods for
// adding more elements. length() returns the number of elements in the list and
// capacity() returns the allocated size. The number of elements is stored at
// kLengthOffset and is updated with every insertion. The array grows
// dynamically with O(1) amortized insertion.
class WeakArrayList : public HeapObject {
 public:
  DECL_CAST(WeakArrayList)
  DECL_VERIFIER(WeakArrayList)
  DECL_PRINTER(WeakArrayList)

  static Handle<WeakArrayList> AddToEnd(Isolate* isolate,
                                        Handle<WeakArrayList> array,
                                        MaybeObjectHandle value);

  inline MaybeObject* Get(int index) const;

  // Set the element at index to obj. The underlying array must be large enough.
  // If you need to grow the WeakArrayList, use the static AddToEnd() method
  // instead.
  inline void Set(int index, MaybeObject* value,
                  WriteBarrierMode mode = UPDATE_WRITE_BARRIER);

  static constexpr int SizeForCapacity(int capacity) {
    return kHeaderSize + capacity * kPointerSize;
  }

  // Gives access to raw memory which stores the array's data.
  inline MaybeObject** data_start();

  bool IsFull();

  DECL_INT_ACCESSORS(capacity)
  DECL_INT_ACCESSORS(length)

  // Get and set the capacity using acquire loads and release stores.
  inline int synchronized_capacity() const;
  inline void synchronized_set_capacity(int value);

  typedef WeakArrayBodyDescriptor BodyDescriptor;
  typedef BodyDescriptor BodyDescriptorWeak;

  static const int kCapacityOffset = HeapObject::kHeaderSize;
  static const int kLengthOffset = kCapacityOffset + kPointerSize;
  static const int kHeaderSize = kLengthOffset + kPointerSize;

  static const int kMaxCapacity =
      (FixedArray::kMaxSize - kHeaderSize) / kPointerSize;

  static Handle<WeakArrayList> EnsureSpace(
      Isolate* isolate, Handle<WeakArrayList> array, int length,
      PretenureFlag pretenure = NOT_TENURED);

  // Returns the number of non-cleaned weak references in the array.
  int CountLiveWeakReferences() const;

  // Returns whether an entry was found and removed. Will move the elements
  // around in the array - this method can only be used in cases where the user
  // doesn't care about the indices! Users should make sure there are no
  // duplicates.
  bool RemoveOne(MaybeObjectHandle value);

  class Iterator {
   public:
    explicit Iterator(WeakArrayList* array) : index_(0), array_(array) {}

    inline HeapObject* Next();

   private:
    int index_;
    WeakArrayList* array_;
#ifdef DEBUG
    DisallowHeapAllocation no_gc_;
#endif  // DEBUG
    DISALLOW_COPY_AND_ASSIGN(Iterator);
  };

 private:
  static int OffsetOfElementAt(int index) {
    return kHeaderSize + index * kPointerSize;
  }

  DISALLOW_IMPLICIT_CONSTRUCTORS(WeakArrayList);
};

// Generic array grows dynamically with O(1) amortized insertion.
//
// ArrayList is a FixedArray with static convenience methods for adding more
// elements. The Length() method returns the number of elements in the list, not
// the allocated size. The number of elements is stored at kLengthIndex and is
// updated with every insertion. The elements of the ArrayList are stored in the
// underlying FixedArray starting at kFirstIndex.
class ArrayList : public FixedArray {
 public:
  static Handle<ArrayList> Add(Isolate* isolate, Handle<ArrayList> array,
                               Handle<Object> obj);
  static Handle<ArrayList> Add(Isolate* isolate, Handle<ArrayList> array,
                               Handle<Object> obj1, Handle<Object> obj2);
  static Handle<ArrayList> New(Isolate* isolate, int size);

  // Returns the number of elements in the list, not the allocated size, which
  // is length(). Lower and upper case length() return different results!
  inline int Length() const;

  // Sets the Length() as used by Elements(). Does not change the underlying
  // storage capacity, i.e., length().
  inline void SetLength(int length);
  inline Object* Get(int index) const;
  inline Object** Slot(int index);

  // Set the element at index to obj. The underlying array must be large enough.
  // If you need to grow the ArrayList, use the static Add() methods instead.
  inline void Set(int index, Object* obj,
                  WriteBarrierMode mode = UPDATE_WRITE_BARRIER);

  // Set the element at index to undefined. This does not change the Length().
  inline void Clear(int index, Object* undefined);

  // Return a copy of the list of size Length() without the first entry. The
  // number returned by Length() is stored in the first entry.
  static Handle<FixedArray> Elements(Isolate* isolate, Handle<ArrayList> array);
  bool IsFull();
  DECL_CAST(ArrayList)

 private:
  static Handle<ArrayList> EnsureSpace(Isolate* isolate,
                                       Handle<ArrayList> array, int length);
  static const int kLengthIndex = 0;
  static const int kFirstIndex = 1;
  DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
};

enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };

template <SearchMode search_mode, typename T>
inline int Search(T* array, Name* name, int valid_entries = 0,
                  int* out_insertion_index = nullptr);

// ByteArray represents fixed sized byte arrays.  Used for the relocation info
// that is attached to code objects.
class ByteArray : public FixedArrayBase {
 public:
  inline int Size();

  // Setter and getter.
  inline byte get(int index) const;
  inline void set(int index, byte value);

  // Copy in / copy out whole byte slices.
  inline void copy_out(int index, byte* buffer, int length);
  inline void copy_in(int index, const byte* buffer, int length);

  // Treat contents as an int array.
  inline int get_int(int index) const;
  inline void set_int(int index, int value);

  inline uint32_t get_uint32(int index) const;
  inline void set_uint32(int index, uint32_t value);

  // Clear uninitialized padding space. This ensures that the snapshot content
  // is deterministic.
  inline void clear_padding();

  static int SizeFor(int length) {
    return OBJECT_POINTER_ALIGN(kHeaderSize + length);
  }
  // We use byte arrays for free blocks in the heap.  Given a desired size in
  // bytes that is a multiple of the word size and big enough to hold a byte
  // array, this function returns the number of elements a byte array should
  // have.
  static int LengthFor(int size_in_bytes) {
    DCHECK(IsAligned(size_in_bytes, kPointerSize));
    DCHECK_GE(size_in_bytes, kHeaderSize);
    return size_in_bytes - kHeaderSize;
  }

  // Returns data start address.
  inline byte* GetDataStartAddress();

  inline int DataSize() const;

  // Returns a pointer to the ByteArray object for a given data start address.
  static inline ByteArray* FromDataStartAddress(Address address);

  DECL_CAST(ByteArray)

  // Dispatched behavior.
  inline int ByteArraySize();
  DECL_PRINTER(ByteArray)
  DECL_VERIFIER(ByteArray)

  // Layout description.
  static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);

  // Maximal length of a single ByteArray.
  static const int kMaxLength = kMaxSize - kHeaderSize;
  static_assert(Internals::IsValidSmi(kMaxLength),
                "ByteArray maxLength not a Smi");

  class BodyDescriptor;
  // No weak fields.
  typedef BodyDescriptor BodyDescriptorWeak;

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
};

// Wrapper class for ByteArray which can store arbitrary C++ classes, as long
// as they can be copied with memcpy.
template <class T>
class PodArray : public ByteArray {
 public:
  static Handle<PodArray<T>> New(Isolate* isolate, int length,
                                 PretenureFlag pretenure = NOT_TENURED);
  void copy_out(int index, T* result) {
    ByteArray::copy_out(index * sizeof(T), reinterpret_cast<byte*>(result),
                        sizeof(T));
  }
  T get(int index) {
    T result;
    copy_out(index, &result);
    return result;
  }
  void set(int index, const T& value) {
    copy_in(index * sizeof(T), reinterpret_cast<const byte*>(&value),
            sizeof(T));
  }
  inline int length();
  DECL_CAST(PodArray<T>)

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(PodArray<T>);
};

class FixedTypedArrayBase : public FixedArrayBase {
 public:
  // [base_pointer]: Either points to the FixedTypedArrayBase itself or nullptr.
  DECL_ACCESSORS(base_pointer, Object)

  // [external_pointer]: Contains the offset between base_pointer and the start
  // of the data. If the base_pointer is a nullptr, the external_pointer
  // therefore points to the actual backing store.
  DECL_ACCESSORS(external_pointer, void)

  // Dispatched behavior.
  DECL_CAST(FixedTypedArrayBase)

  static const int kBasePointerOffset = FixedArrayBase::kHeaderSize;
  static const int kExternalPointerOffset = kBasePointerOffset + kPointerSize;
  static const int kHeaderSize =
      DOUBLE_POINTER_ALIGN(kExternalPointerOffset + kPointerSize);

  static const int kDataOffset = kHeaderSize;

  static const int kMaxElementSize = 8;

#ifdef V8_HOST_ARCH_32_BIT
  static const size_t kMaxByteLength = std::numeric_limits<size_t>::max();
#else
  static const size_t kMaxByteLength =
      static_cast<size_t>(Smi::kMaxValue) * kMaxElementSize;
#endif  // V8_HOST_ARCH_32_BIT

  static const size_t kMaxLength = Smi::kMaxValue;

  class BodyDescriptor;
  // No weak fields.
  typedef BodyDescriptor BodyDescriptorWeak;

  inline int size() const;

  static inline int TypedArraySize(InstanceType type, int length);
  inline int TypedArraySize(InstanceType type) const;

  // Use with care: returns raw pointer into heap.
  inline void* DataPtr();

  inline int DataSize() const;

  inline size_t ByteLength() const;

 private:
  static inline int ElementSize(InstanceType type);

  inline int DataSize(InstanceType type) const;

  DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase);
};

template <class Traits>
class FixedTypedArray : public FixedTypedArrayBase {
 public:
  typedef typename Traits::ElementType ElementType;
  static const InstanceType kInstanceType = Traits::kInstanceType;

  DECL_CAST(FixedTypedArray<Traits>)

  static inline ElementType get_scalar_from_data_ptr(void* data_ptr, int index);
  inline ElementType get_scalar(int index);
  static inline Handle<Object> get(Isolate* isolate, FixedTypedArray* array,
                                   int index);
  inline void set(int index, ElementType value);

  static inline ElementType from(int value);
  static inline ElementType from(uint32_t value);
  static inline ElementType from(double value);
  static inline ElementType from(int64_t value);
  static inline ElementType from(uint64_t value);

  static inline ElementType FromHandle(Handle<Object> value,
                                       bool* lossless = nullptr);

  // This accessor applies the correct conversion from Smi, HeapNumber
  // and undefined.
  inline void SetValue(uint32_t index, Object* value);

  DECL_PRINTER(FixedTypedArray)
  DECL_VERIFIER(FixedTypedArray)

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray);
};

#define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType)               \
  STATIC_ASSERT(sizeof(elementType) <= FixedTypedArrayBase::kMaxElementSize); \
  class Type##ArrayTraits {                                                   \
   public: /* NOLINT */                                                       \
    typedef elementType ElementType;                                          \
    static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE;      \
    static const char* Designator() { return #type " array"; }                \
    static inline Handle<Object> ToHandle(Isolate* isolate,                   \
                                          elementType scalar);                \
    static inline elementType defaultValue();                                 \
  };                                                                          \
                                                                              \
  typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array;

TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS)

#undef FIXED_TYPED_ARRAY_TRAITS

class TemplateList : public FixedArray {
 public:
  static Handle<TemplateList> New(Isolate* isolate, int size);
  inline int length() const;
  inline Object* get(int index) const;
  inline void set(int index, Object* value);
  static Handle<TemplateList> Add(Isolate* isolate, Handle<TemplateList> list,
                                  Handle<Object> value);
  DECL_CAST(TemplateList)
 private:
  static const int kLengthIndex = 0;
  static const int kFirstElementIndex = kLengthIndex + 1;
  DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateList);
};

}  // namespace internal
}  // namespace v8

#include "src/objects/object-macros-undef.h"

#endif  // V8_OBJECTS_FIXED_ARRAY_H_