1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
10 #include "src/allocation.h"
11 #include "src/assert-scope.h"
12 #include "src/bailout-reason.h"
13 #include "src/base/bits.h"
14 #include "src/builtins.h"
15 #include "src/checks.h"
16 #include "src/elements-kind.h"
17 #include "src/field-index.h"
18 #include "src/flags.h"
20 #include "src/property-details.h"
21 #include "src/smart-pointers.h"
22 #include "src/unicode-inl.h"
23 #include "src/unicode-decoder.h"
26 #if V8_TARGET_ARCH_ARM
27 #include "src/arm/constants-arm.h" // NOLINT
28 #elif V8_TARGET_ARCH_ARM64
29 #include "src/arm64/constants-arm64.h" // NOLINT
30 #elif V8_TARGET_ARCH_MIPS
31 #include "src/mips/constants-mips.h" // NOLINT
32 #elif V8_TARGET_ARCH_MIPS64
33 #include "src/mips64/constants-mips64.h" // NOLINT
34 #elif V8_TARGET_ARCH_PPC
35 #include "src/ppc/constants-ppc.h" // NOLINT
40 // Most object types in the V8 JavaScript are described in this file.
42 // Inheritance hierarchy:
44 // - Smi (immediate small integer)
45 // - HeapObject (superclass for everything allocated in the heap)
46 // - JSReceiver (suitable for property access)
50 // - JSArrayBufferView
63 // - JSGeneratorObject
81 // - CompilationCacheTable
82 // - CodeCacheHashTable
88 // - TypeFeedbackVector
89 // - JSFunctionResultCache
92 // - ScriptContextTable
96 // - ExternalUint8ClampedArray
97 // - ExternalInt8Array
98 // - ExternalUint8Array
99 // - ExternalInt16Array
100 // - ExternalUint16Array
101 // - ExternalInt32Array
102 // - ExternalUint32Array
103 // - ExternalFloat32Array
107 // - SeqOneByteString
108 // - SeqTwoByteString
112 // - ExternalOneByteString
113 // - ExternalTwoByteString
114 // - InternalizedString
115 // - SeqInternalizedString
116 // - SeqOneByteInternalizedString
117 // - SeqTwoByteInternalizedString
118 // - ConsInternalizedString
119 // - ExternalInternalizedString
120 // - ExternalOneByteInternalizedString
121 // - ExternalTwoByteInternalizedString
130 // - SharedFunctionInfo
134 // - ExecutableAccessorInfo
140 // - FunctionTemplateInfo
141 // - ObjectTemplateInfo
149 // Formats of Object*:
150 // Smi: [31 bit signed int] 0
151 // HeapObject: [32 bit direct pointer] (4 byte aligned) | 01
156 enum KeyedAccessStoreMode {
158 STORE_TRANSITION_SMI_TO_OBJECT,
159 STORE_TRANSITION_SMI_TO_DOUBLE,
160 STORE_TRANSITION_DOUBLE_TO_OBJECT,
161 STORE_TRANSITION_HOLEY_SMI_TO_OBJECT,
162 STORE_TRANSITION_HOLEY_SMI_TO_DOUBLE,
163 STORE_TRANSITION_HOLEY_DOUBLE_TO_OBJECT,
164 STORE_AND_GROW_NO_TRANSITION,
165 STORE_AND_GROW_TRANSITION_SMI_TO_OBJECT,
166 STORE_AND_GROW_TRANSITION_SMI_TO_DOUBLE,
167 STORE_AND_GROW_TRANSITION_DOUBLE_TO_OBJECT,
168 STORE_AND_GROW_TRANSITION_HOLEY_SMI_TO_OBJECT,
169 STORE_AND_GROW_TRANSITION_HOLEY_SMI_TO_DOUBLE,
170 STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT,
171 STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS,
172 STORE_NO_TRANSITION_HANDLE_COW
176 enum ContextualMode {
188 static const int kGrowICDelta = STORE_AND_GROW_NO_TRANSITION -
190 STATIC_ASSERT(STANDARD_STORE == 0);
191 STATIC_ASSERT(kGrowICDelta ==
192 STORE_AND_GROW_TRANSITION_SMI_TO_OBJECT -
193 STORE_TRANSITION_SMI_TO_OBJECT);
194 STATIC_ASSERT(kGrowICDelta ==
195 STORE_AND_GROW_TRANSITION_SMI_TO_DOUBLE -
196 STORE_TRANSITION_SMI_TO_DOUBLE);
197 STATIC_ASSERT(kGrowICDelta ==
198 STORE_AND_GROW_TRANSITION_DOUBLE_TO_OBJECT -
199 STORE_TRANSITION_DOUBLE_TO_OBJECT);
202 static inline KeyedAccessStoreMode GetGrowStoreMode(
203 KeyedAccessStoreMode store_mode) {
204 if (store_mode < STORE_AND_GROW_NO_TRANSITION) {
205 store_mode = static_cast<KeyedAccessStoreMode>(
206 static_cast<int>(store_mode) + kGrowICDelta);
212 static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) {
213 return store_mode > STANDARD_STORE &&
214 store_mode <= STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT &&
215 store_mode != STORE_AND_GROW_NO_TRANSITION;
219 static inline KeyedAccessStoreMode GetNonTransitioningStoreMode(
220 KeyedAccessStoreMode store_mode) {
221 if (store_mode >= STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
224 if (store_mode >= STORE_AND_GROW_NO_TRANSITION) {
225 return STORE_AND_GROW_NO_TRANSITION;
227 return STANDARD_STORE;
231 static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
232 return store_mode >= STORE_AND_GROW_NO_TRANSITION &&
233 store_mode <= STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT;
237 enum IcCheckType { ELEMENT, PROPERTY };
240 // Setter that skips the write barrier if mode is SKIP_WRITE_BARRIER.
241 enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WRITE_BARRIER };
244 // Indicates whether a value can be loaded as a constant.
245 enum StoreMode { ALLOW_IN_DESCRIPTOR, FORCE_FIELD };
248 // PropertyNormalizationMode is used to specify whether to keep
249 // inobject properties when normalizing properties of a JSObject.
250 enum PropertyNormalizationMode {
251 CLEAR_INOBJECT_PROPERTIES,
252 KEEP_INOBJECT_PROPERTIES
256 // Indicates how aggressively the prototype should be optimized. FAST_PROTOTYPE
257 // will give the fastest result by tailoring the map to the prototype, but that
258 // will cause polymorphism with other objects. REGULAR_PROTOTYPE is to be used
259 // (at least for now) when dynamically modifying the prototype chain of an
260 // object using __proto__ or Object.setPrototypeOf.
261 enum PrototypeOptimizationMode { REGULAR_PROTOTYPE, FAST_PROTOTYPE };
264 // Indicates whether transitions can be added to a source map or not.
265 enum TransitionFlag {
271 enum DebugExtraICState {
273 DEBUG_PREPARE_STEP_IN
277 // Indicates whether the transition is simple: the target map of the transition
278 // either extends the current map with a new property, or it modifies the
279 // property that was added last to the current map.
280 enum SimpleTransitionFlag {
281 SIMPLE_PROPERTY_TRANSITION,
287 // Indicates whether we are only interested in the descriptors of a particular
288 // map, or in all descriptors in the descriptor array.
289 enum DescriptorFlag {
294 // The GC maintains a bit of information, the MarkingParity, which toggles
295 // from odd to even and back every time marking is completed. Incremental
296 // marking can visit an object twice during a marking phase, so algorithms that
297 // that piggy-back on marking can use the parity to ensure that they only
298 // perform an operation on an object once per marking phase: they record the
299 // MarkingParity when they visit an object, and only re-visit the object when it
300 // is marked again and the MarkingParity changes.
307 // ICs store extra state in a Code object. The default extra state is
309 typedef int ExtraICState;
310 static const ExtraICState kNoExtraICState = 0;
312 // Instance size sentinel for objects of variable size.
313 const int kVariableSizeSentinel = 0;
315 // We may store the unsigned bit field as signed Smi value and do not
317 const int kStubMajorKeyBits = 7;
318 const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
320 // All Maps have a field instance_type containing a InstanceType.
321 // It describes the type of the instances.
323 // As an example, a JavaScript object is a heap object and its map
324 // instance_type is JS_OBJECT_TYPE.
326 // The names of the string instance types are intended to systematically
327 // mirror their encoding in the instance_type field of the map. The default
328 // encoding is considered TWO_BYTE. It is not mentioned in the name. ONE_BYTE
329 // encoding is mentioned explicitly in the name. Likewise, the default
330 // representation is considered sequential. It is not mentioned in the
331 // name. The other representations (e.g. CONS, EXTERNAL) are explicitly
332 // mentioned. Finally, the string is either a STRING_TYPE (if it is a normal
333 // string) or a INTERNALIZED_STRING_TYPE (if it is a internalized string).
335 // NOTE: The following things are some that depend on the string types having
336 // instance_types that are less than those of all other types:
337 // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and
340 // NOTE: Everything following JS_VALUE_TYPE is considered a
341 // JSObject for GC purposes. The first four entries here have typeof
342 // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'.
343 #define INSTANCE_TYPE_LIST(V) \
345 V(ONE_BYTE_STRING_TYPE) \
346 V(CONS_STRING_TYPE) \
347 V(CONS_ONE_BYTE_STRING_TYPE) \
348 V(SLICED_STRING_TYPE) \
349 V(SLICED_ONE_BYTE_STRING_TYPE) \
350 V(EXTERNAL_STRING_TYPE) \
351 V(EXTERNAL_ONE_BYTE_STRING_TYPE) \
352 V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
353 V(SHORT_EXTERNAL_STRING_TYPE) \
354 V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE) \
355 V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
357 V(INTERNALIZED_STRING_TYPE) \
358 V(ONE_BYTE_INTERNALIZED_STRING_TYPE) \
359 V(EXTERNAL_INTERNALIZED_STRING_TYPE) \
360 V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
361 V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
362 V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE) \
363 V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
364 V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
372 V(PROPERTY_CELL_TYPE) \
374 V(HEAP_NUMBER_TYPE) \
375 V(MUTABLE_HEAP_NUMBER_TYPE) \
379 /* Note: the order of these external array */ \
380 /* types is relied upon in */ \
381 /* Object::IsExternalArray(). */ \
382 V(EXTERNAL_INT8_ARRAY_TYPE) \
383 V(EXTERNAL_UINT8_ARRAY_TYPE) \
384 V(EXTERNAL_INT16_ARRAY_TYPE) \
385 V(EXTERNAL_UINT16_ARRAY_TYPE) \
386 V(EXTERNAL_INT32_ARRAY_TYPE) \
387 V(EXTERNAL_UINT32_ARRAY_TYPE) \
388 V(EXTERNAL_FLOAT32_ARRAY_TYPE) \
389 V(EXTERNAL_FLOAT64_ARRAY_TYPE) \
390 V(EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE) \
392 V(FIXED_INT8_ARRAY_TYPE) \
393 V(FIXED_UINT8_ARRAY_TYPE) \
394 V(FIXED_INT16_ARRAY_TYPE) \
395 V(FIXED_UINT16_ARRAY_TYPE) \
396 V(FIXED_INT32_ARRAY_TYPE) \
397 V(FIXED_UINT32_ARRAY_TYPE) \
398 V(FIXED_FLOAT32_ARRAY_TYPE) \
399 V(FIXED_FLOAT64_ARRAY_TYPE) \
400 V(FIXED_UINT8_CLAMPED_ARRAY_TYPE) \
404 V(DECLARED_ACCESSOR_DESCRIPTOR_TYPE) \
405 V(DECLARED_ACCESSOR_INFO_TYPE) \
406 V(EXECUTABLE_ACCESSOR_INFO_TYPE) \
407 V(ACCESSOR_PAIR_TYPE) \
408 V(ACCESS_CHECK_INFO_TYPE) \
409 V(INTERCEPTOR_INFO_TYPE) \
410 V(CALL_HANDLER_INFO_TYPE) \
411 V(FUNCTION_TEMPLATE_INFO_TYPE) \
412 V(OBJECT_TEMPLATE_INFO_TYPE) \
413 V(SIGNATURE_INFO_TYPE) \
414 V(TYPE_SWITCH_INFO_TYPE) \
415 V(ALLOCATION_MEMENTO_TYPE) \
416 V(ALLOCATION_SITE_TYPE) \
419 V(POLYMORPHIC_CODE_CACHE_TYPE) \
420 V(TYPE_FEEDBACK_INFO_TYPE) \
421 V(ALIASED_ARGUMENTS_ENTRY_TYPE) \
424 V(FIXED_ARRAY_TYPE) \
425 V(FIXED_DOUBLE_ARRAY_TYPE) \
426 V(CONSTANT_POOL_ARRAY_TYPE) \
427 V(SHARED_FUNCTION_INFO_TYPE) \
430 V(JS_MESSAGE_OBJECT_TYPE) \
435 V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \
436 V(JS_GENERATOR_OBJECT_TYPE) \
438 V(JS_GLOBAL_OBJECT_TYPE) \
439 V(JS_BUILTINS_OBJECT_TYPE) \
440 V(JS_GLOBAL_PROXY_TYPE) \
442 V(JS_ARRAY_BUFFER_TYPE) \
443 V(JS_TYPED_ARRAY_TYPE) \
444 V(JS_DATA_VIEW_TYPE) \
448 V(JS_SET_ITERATOR_TYPE) \
449 V(JS_MAP_ITERATOR_TYPE) \
450 V(JS_WEAK_MAP_TYPE) \
451 V(JS_WEAK_SET_TYPE) \
454 V(JS_FUNCTION_TYPE) \
455 V(JS_FUNCTION_PROXY_TYPE) \
457 V(BREAK_POINT_INFO_TYPE)
460 // Since string types are not consecutive, this macro is used to
461 // iterate over them.
462 #define STRING_TYPE_LIST(V) \
463 V(STRING_TYPE, kVariableSizeSentinel, string, String) \
464 V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string, \
466 V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString) \
467 V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string, \
469 V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString) \
470 V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string, \
471 SlicedOneByteString) \
472 V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string, \
474 V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize, \
475 external_one_byte_string, ExternalOneByteString) \
476 V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize, \
477 external_string_with_one_byte_data, ExternalStringWithOneByteData) \
478 V(SHORT_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kShortSize, \
479 short_external_string, ShortExternalString) \
480 V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kShortSize, \
481 short_external_one_byte_string, ShortExternalOneByteString) \
482 V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, \
483 ExternalTwoByteString::kShortSize, \
484 short_external_string_with_one_byte_data, \
485 ShortExternalStringWithOneByteData) \
487 V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string, \
488 InternalizedString) \
489 V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, \
490 one_byte_internalized_string, OneByteInternalizedString) \
491 V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize, \
492 external_internalized_string, ExternalInternalizedString) \
493 V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize, \
494 external_one_byte_internalized_string, ExternalOneByteInternalizedString) \
495 V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
496 ExternalTwoByteString::kSize, \
497 external_internalized_string_with_one_byte_data, \
498 ExternalInternalizedStringWithOneByteData) \
499 V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE, \
500 ExternalTwoByteString::kShortSize, short_external_internalized_string, \
501 ShortExternalInternalizedString) \
502 V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, \
503 ExternalOneByteString::kShortSize, \
504 short_external_one_byte_internalized_string, \
505 ShortExternalOneByteInternalizedString) \
506 V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
507 ExternalTwoByteString::kShortSize, \
508 short_external_internalized_string_with_one_byte_data, \
509 ShortExternalInternalizedStringWithOneByteData)
511 // A struct is a simple object a set of object-valued fields. Including an
512 // object type in this causes the compiler to generate most of the boilerplate
513 // code for the class including allocation and garbage collection routines,
514 // casts and predicates. All you need to define is the class, methods and
515 // object verification routines. Easy, no?
517 // Note that for subtle reasons related to the ordering or numerical values of
518 // type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST
520 #define STRUCT_LIST(V) \
522 V(EXECUTABLE_ACCESSOR_INFO, ExecutableAccessorInfo, executable_accessor_info)\
523 V(ACCESSOR_PAIR, AccessorPair, accessor_pair) \
524 V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \
525 V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \
526 V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \
527 V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \
528 V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \
529 V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info) \
530 V(SCRIPT, Script, script) \
531 V(ALLOCATION_SITE, AllocationSite, allocation_site) \
532 V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento) \
533 V(CODE_CACHE, CodeCache, code_cache) \
534 V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) \
535 V(TYPE_FEEDBACK_INFO, TypeFeedbackInfo, type_feedback_info) \
536 V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \
537 V(DEBUG_INFO, DebugInfo, debug_info) \
538 V(BREAK_POINT_INFO, BreakPointInfo, break_point_info)
540 // We use the full 8 bits of the instance_type field to encode heap object
541 // instance types. The high-order bit (bit 7) is set if the object is not a
542 // string, and cleared if it is a string.
543 const uint32_t kIsNotStringMask = 0x80;
544 const uint32_t kStringTag = 0x0;
545 const uint32_t kNotStringTag = 0x80;
547 // Bit 6 indicates that the object is an internalized string (if set) or not.
548 // Bit 7 has to be clear as well.
549 const uint32_t kIsNotInternalizedMask = 0x40;
550 const uint32_t kNotInternalizedTag = 0x40;
551 const uint32_t kInternalizedTag = 0x0;
553 // If bit 7 is clear then bit 2 indicates whether the string consists of
554 // two-byte characters or one-byte characters.
555 const uint32_t kStringEncodingMask = 0x4;
556 const uint32_t kTwoByteStringTag = 0x0;
557 const uint32_t kOneByteStringTag = 0x4;
559 // If bit 7 is clear, the low-order 2 bits indicate the representation
561 const uint32_t kStringRepresentationMask = 0x03;
562 enum StringRepresentationTag {
564 kConsStringTag = 0x1,
565 kExternalStringTag = 0x2,
566 kSlicedStringTag = 0x3
568 const uint32_t kIsIndirectStringMask = 0x1;
569 const uint32_t kIsIndirectStringTag = 0x1;
570 STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); // NOLINT
571 STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); // NOLINT
572 STATIC_ASSERT((kConsStringTag &
573 kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
574 STATIC_ASSERT((kSlicedStringTag &
575 kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
577 // Use this mask to distinguish between cons and slice only after making
578 // sure that the string is one of the two (an indirect string).
579 const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag;
580 STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask));
582 // If bit 7 is clear, then bit 3 indicates whether this two-byte
583 // string actually contains one byte data.
584 const uint32_t kOneByteDataHintMask = 0x08;
585 const uint32_t kOneByteDataHintTag = 0x08;
587 // If bit 7 is clear and string representation indicates an external string,
588 // then bit 4 indicates whether the data pointer is cached.
589 const uint32_t kShortExternalStringMask = 0x10;
590 const uint32_t kShortExternalStringTag = 0x10;
593 // A ConsString with an empty string as the right side is a candidate
594 // for being shortcut by the garbage collector. We don't allocate any
595 // non-flat internalized strings, so we do not shortcut them thereby
596 // avoiding turning internalized strings into strings. The bit-masks
597 // below contain the internalized bit as additional safety.
598 // See heap.cc, mark-compact.cc and objects-visiting.cc.
599 const uint32_t kShortcutTypeMask =
601 kIsNotInternalizedMask |
602 kStringRepresentationMask;
603 const uint32_t kShortcutTypeTag = kConsStringTag | kNotInternalizedTag;
605 static inline bool IsShortcutCandidate(int type) {
606 return ((type & kShortcutTypeMask) == kShortcutTypeTag);
612 INTERNALIZED_STRING_TYPE =
613 kTwoByteStringTag | kSeqStringTag | kInternalizedTag,
614 ONE_BYTE_INTERNALIZED_STRING_TYPE =
615 kOneByteStringTag | kSeqStringTag | kInternalizedTag,
616 EXTERNAL_INTERNALIZED_STRING_TYPE =
617 kTwoByteStringTag | kExternalStringTag | kInternalizedTag,
618 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
619 kOneByteStringTag | kExternalStringTag | kInternalizedTag,
620 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
621 EXTERNAL_INTERNALIZED_STRING_TYPE | kOneByteDataHintTag |
623 SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE |
624 kShortExternalStringTag |
626 SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
627 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kShortExternalStringTag |
629 SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
630 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
631 kShortExternalStringTag | kInternalizedTag,
632 STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
633 ONE_BYTE_STRING_TYPE =
634 ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
635 CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag | kNotInternalizedTag,
636 CONS_ONE_BYTE_STRING_TYPE =
637 kOneByteStringTag | kConsStringTag | kNotInternalizedTag,
639 kTwoByteStringTag | kSlicedStringTag | kNotInternalizedTag,
640 SLICED_ONE_BYTE_STRING_TYPE =
641 kOneByteStringTag | kSlicedStringTag | kNotInternalizedTag,
642 EXTERNAL_STRING_TYPE =
643 EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
644 EXTERNAL_ONE_BYTE_STRING_TYPE =
645 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
646 EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
647 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
649 SHORT_EXTERNAL_STRING_TYPE =
650 SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
651 SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE =
652 SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
653 SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
654 SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
658 SYMBOL_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE
660 // Objects allocated in their own spaces (never in new space).
667 // "Data", objects that cannot contain non-map-word pointers to heap
670 MUTABLE_HEAP_NUMBER_TYPE,
674 EXTERNAL_INT8_ARRAY_TYPE, // FIRST_EXTERNAL_ARRAY_TYPE
675 EXTERNAL_UINT8_ARRAY_TYPE,
676 EXTERNAL_INT16_ARRAY_TYPE,
677 EXTERNAL_UINT16_ARRAY_TYPE,
678 EXTERNAL_INT32_ARRAY_TYPE,
679 EXTERNAL_UINT32_ARRAY_TYPE,
680 EXTERNAL_FLOAT32_ARRAY_TYPE,
681 EXTERNAL_FLOAT64_ARRAY_TYPE,
682 EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE, // LAST_EXTERNAL_ARRAY_TYPE
683 FIXED_INT8_ARRAY_TYPE, // FIRST_FIXED_TYPED_ARRAY_TYPE
684 FIXED_UINT8_ARRAY_TYPE,
685 FIXED_INT16_ARRAY_TYPE,
686 FIXED_UINT16_ARRAY_TYPE,
687 FIXED_INT32_ARRAY_TYPE,
688 FIXED_UINT32_ARRAY_TYPE,
689 FIXED_FLOAT32_ARRAY_TYPE,
690 FIXED_FLOAT64_ARRAY_TYPE,
691 FIXED_UINT8_CLAMPED_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE
692 FIXED_DOUBLE_ARRAY_TYPE,
693 FILLER_TYPE, // LAST_DATA_TYPE
696 DECLARED_ACCESSOR_DESCRIPTOR_TYPE,
697 DECLARED_ACCESSOR_INFO_TYPE,
698 EXECUTABLE_ACCESSOR_INFO_TYPE,
700 ACCESS_CHECK_INFO_TYPE,
701 INTERCEPTOR_INFO_TYPE,
702 CALL_HANDLER_INFO_TYPE,
703 FUNCTION_TEMPLATE_INFO_TYPE,
704 OBJECT_TEMPLATE_INFO_TYPE,
706 TYPE_SWITCH_INFO_TYPE,
707 ALLOCATION_SITE_TYPE,
708 ALLOCATION_MEMENTO_TYPE,
711 POLYMORPHIC_CODE_CACHE_TYPE,
712 TYPE_FEEDBACK_INFO_TYPE,
713 ALIASED_ARGUMENTS_ENTRY_TYPE,
716 BREAK_POINT_INFO_TYPE,
718 CONSTANT_POOL_ARRAY_TYPE,
719 SHARED_FUNCTION_INFO_TYPE,
722 // All the following types are subtypes of JSReceiver, which corresponds to
723 // objects in the JS sense. The first and the last type in this range are
724 // the two forms of function. This organization enables using the same
725 // compares for checking the JS_RECEIVER/SPEC_OBJECT range and the
726 // NONCALLABLE_JS_OBJECT range.
727 JS_FUNCTION_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE, FIRST_JS_PROXY_TYPE
728 JS_PROXY_TYPE, // LAST_JS_PROXY_TYPE
729 JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE
730 JS_MESSAGE_OBJECT_TYPE,
733 JS_CONTEXT_EXTENSION_OBJECT_TYPE,
734 JS_GENERATOR_OBJECT_TYPE,
736 JS_GLOBAL_OBJECT_TYPE,
737 JS_BUILTINS_OBJECT_TYPE,
738 JS_GLOBAL_PROXY_TYPE,
740 JS_ARRAY_BUFFER_TYPE,
745 JS_SET_ITERATOR_TYPE,
746 JS_MAP_ITERATOR_TYPE,
750 JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
754 LAST_TYPE = JS_FUNCTION_TYPE,
755 FIRST_NAME_TYPE = FIRST_TYPE,
756 LAST_NAME_TYPE = SYMBOL_TYPE,
757 FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
758 LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
759 FIRST_NONSTRING_TYPE = SYMBOL_TYPE,
760 // Boundaries for testing for an external array.
761 FIRST_EXTERNAL_ARRAY_TYPE = EXTERNAL_INT8_ARRAY_TYPE,
762 LAST_EXTERNAL_ARRAY_TYPE = EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE,
763 // Boundaries for testing for a fixed typed array.
764 FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE,
765 LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_UINT8_CLAMPED_ARRAY_TYPE,
766 // Boundary for promotion to old data space/old pointer space.
767 LAST_DATA_TYPE = FILLER_TYPE,
768 // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy).
769 // Note that there is no range for JSObject or JSProxy, since their subtypes
770 // are not continuous in this enum! The enum ranges instead reflect the
771 // external class names, where proxies are treated as either ordinary objects,
773 FIRST_JS_RECEIVER_TYPE = JS_FUNCTION_PROXY_TYPE,
774 LAST_JS_RECEIVER_TYPE = LAST_TYPE,
775 // Boundaries for testing the types represented as JSObject
776 FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE,
777 LAST_JS_OBJECT_TYPE = LAST_TYPE,
778 // Boundaries for testing the types represented as JSProxy
779 FIRST_JS_PROXY_TYPE = JS_FUNCTION_PROXY_TYPE,
780 LAST_JS_PROXY_TYPE = JS_PROXY_TYPE,
781 // Boundaries for testing whether the type is a JavaScript object.
782 FIRST_SPEC_OBJECT_TYPE = FIRST_JS_RECEIVER_TYPE,
783 LAST_SPEC_OBJECT_TYPE = LAST_JS_RECEIVER_TYPE,
784 // Boundaries for testing the types for which typeof is "object".
785 FIRST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_PROXY_TYPE,
786 LAST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_REGEXP_TYPE,
787 // Note that the types for which typeof is "function" are not continuous.
788 // Define this so that we can put assertions on discrete checks.
789 NUM_OF_CALLABLE_SPEC_OBJECT_TYPES = 2
792 const int kExternalArrayTypeCount =
793 LAST_EXTERNAL_ARRAY_TYPE - FIRST_EXTERNAL_ARRAY_TYPE + 1;
795 STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
796 STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType);
797 STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType);
798 STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType);
801 #define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
802 V(FAST_ELEMENTS_SUB_TYPE) \
803 V(DICTIONARY_ELEMENTS_SUB_TYPE) \
804 V(FAST_PROPERTIES_SUB_TYPE) \
805 V(DICTIONARY_PROPERTIES_SUB_TYPE) \
806 V(MAP_CODE_CACHE_SUB_TYPE) \
807 V(SCOPE_INFO_SUB_TYPE) \
808 V(STRING_TABLE_SUB_TYPE) \
809 V(DESCRIPTOR_ARRAY_SUB_TYPE) \
810 V(TRANSITION_ARRAY_SUB_TYPE)
812 enum FixedArraySubInstanceType {
813 #define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
814 FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
815 #undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
816 LAST_FIXED_ARRAY_SUB_TYPE = TRANSITION_ARRAY_SUB_TYPE
829 #define DECL_BOOLEAN_ACCESSORS(name) \
830 inline bool name() const; \
831 inline void set_##name(bool value); \
834 #define DECL_ACCESSORS(name, type) \
835 inline type* name() const; \
836 inline void set_##name(type* value, \
837 WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \
840 #define DECLARE_CAST(type) \
841 INLINE(static type* cast(Object* object)); \
842 INLINE(static const type* cast(const Object* object));
846 class AllocationSite;
847 class AllocationSiteCreationContext;
848 class AllocationSiteUsageContext;
850 class DictionaryElementsAccessor;
851 class ElementsAccessor;
852 class FixedArrayBase;
853 class FunctionLiteral;
855 class LayoutDescriptor;
856 class LookupIterator;
859 class TypeFeedbackVector;
862 // We cannot just say "class HeapType;" if it is created from a template... =8-?
863 template<class> class TypeImpl;
864 struct HeapTypeConfig;
865 typedef TypeImpl<HeapTypeConfig> HeapType;
868 // A template-ized version of the IsXXX functions.
869 template <class C> inline bool Is(Object* obj);
872 #define DECLARE_VERIFIER(Name) void Name##Verify();
874 #define DECLARE_VERIFIER(Name)
878 #define DECLARE_PRINTER(Name) void Name##Print(std::ostream& os); // NOLINT
880 #define DECLARE_PRINTER(Name)
884 #define OBJECT_TYPE_LIST(V) \
889 #define HEAP_OBJECT_TYPE_LIST(V) \
891 V(MutableHeapNumber) \
899 V(ExternalTwoByteString) \
900 V(ExternalOneByteString) \
901 V(SeqTwoByteString) \
902 V(SeqOneByteString) \
903 V(InternalizedString) \
907 V(ExternalInt8Array) \
908 V(ExternalUint8Array) \
909 V(ExternalInt16Array) \
910 V(ExternalUint16Array) \
911 V(ExternalInt32Array) \
912 V(ExternalUint32Array) \
913 V(ExternalFloat32Array) \
914 V(ExternalFloat64Array) \
915 V(ExternalUint8ClampedArray) \
916 V(FixedTypedArrayBase) \
919 V(FixedUint16Array) \
921 V(FixedUint32Array) \
923 V(FixedFloat32Array) \
924 V(FixedFloat64Array) \
925 V(FixedUint8ClampedArray) \
930 V(JSContextExtensionObject) \
931 V(JSGeneratorObject) \
933 V(LayoutDescriptor) \
937 V(TypeFeedbackVector) \
938 V(DeoptimizationInputData) \
939 V(DeoptimizationOutputData) \
942 V(FixedDoubleArray) \
944 V(ConstantPoolArray) \
946 V(ScriptContextTable) \
952 V(SharedFunctionInfo) \
961 V(JSArrayBufferView) \
970 V(JSWeakCollection) \
977 V(JSFunctionResultCache) \
978 V(NormalizedMapCache) \
979 V(CompilationCacheTable) \
980 V(CodeCacheHashTable) \
981 V(PolymorphicCodeCacheHashTable) \
986 V(JSBuiltinsObject) \
988 V(UndetectableObject) \
989 V(AccessCheckNeeded) \
997 // Object is the abstract superclass for all classes in the
999 // Object does not use any virtual functions to avoid the
1000 // allocation of the C++ vtable.
1001 // Since both Smi and HeapObject are subclasses of Object no
1002 // data members can be present in Object.
1006 bool IsObject() const { return true; }
1008 #define IS_TYPE_FUNCTION_DECL(type_) INLINE(bool Is##type_() const);
1009 OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
1010 HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
1011 #undef IS_TYPE_FUNCTION_DECL
1013 // A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
1014 // a keyed store is of the form a[expression] = foo.
1015 enum StoreFromKeyed {
1016 MAY_BE_STORE_FROM_KEYED,
1017 CERTAINLY_NOT_STORE_FROM_KEYED
1020 INLINE(bool IsFixedArrayBase() const);
1021 INLINE(bool IsExternal() const);
1022 INLINE(bool IsAccessorInfo() const);
1024 INLINE(bool IsStruct() const);
1025 #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \
1026 INLINE(bool Is##Name() const);
1027 STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
1028 #undef DECLARE_STRUCT_PREDICATE
1030 INLINE(bool IsSpecObject()) const;
1031 INLINE(bool IsSpecFunction()) const;
1032 INLINE(bool IsTemplateInfo()) const;
1033 INLINE(bool IsNameDictionary() const);
1034 INLINE(bool IsSeededNumberDictionary() const);
1035 INLINE(bool IsUnseededNumberDictionary() const);
1036 INLINE(bool IsOrderedHashSet() const);
1037 INLINE(bool IsOrderedHashMap() const);
1038 bool IsCallable() const;
1041 INLINE(bool IsUndefined() const);
1042 INLINE(bool IsNull() const);
1043 INLINE(bool IsTheHole() const);
1044 INLINE(bool IsException() const);
1045 INLINE(bool IsUninitialized() const);
1046 INLINE(bool IsTrue() const);
1047 INLINE(bool IsFalse() const);
1048 INLINE(bool IsArgumentsMarker() const);
1050 // Filler objects (fillers and free space objects).
1051 INLINE(bool IsFiller() const);
1053 // Extract the number.
1054 inline double Number();
1055 INLINE(bool IsNaN() const);
1056 INLINE(bool IsMinusZero() const);
1057 bool ToInt32(int32_t* value);
1058 bool ToUint32(uint32_t* value);
1060 inline Representation OptimalRepresentation() {
1061 if (!FLAG_track_fields) return Representation::Tagged();
1063 return Representation::Smi();
1064 } else if (FLAG_track_double_fields && IsHeapNumber()) {
1065 return Representation::Double();
1066 } else if (FLAG_track_computed_fields && IsUninitialized()) {
1067 return Representation::None();
1068 } else if (FLAG_track_heap_object_fields) {
1069 DCHECK(IsHeapObject());
1070 return Representation::HeapObject();
1072 return Representation::Tagged();
1076 inline bool FitsRepresentation(Representation representation) {
1077 if (FLAG_track_fields && representation.IsNone()) {
1079 } else if (FLAG_track_fields && representation.IsSmi()) {
1081 } else if (FLAG_track_double_fields && representation.IsDouble()) {
1082 return IsMutableHeapNumber() || IsNumber();
1083 } else if (FLAG_track_heap_object_fields && representation.IsHeapObject()) {
1084 return IsHeapObject();
1089 Handle<HeapType> OptimalType(Isolate* isolate, Representation representation);
1091 inline static Handle<Object> NewStorageFor(Isolate* isolate,
1092 Handle<Object> object,
1093 Representation representation);
1095 inline static Handle<Object> WrapForRead(Isolate* isolate,
1096 Handle<Object> object,
1097 Representation representation);
1099 // Returns true if the object is of the correct type to be used as a
1100 // implementation of a JSObject's elements.
1101 inline bool HasValidElements();
1103 inline bool HasSpecificClassOf(String* name);
1105 bool BooleanValue(); // ECMA-262 9.2.
1107 // Convert to a JSObject if needed.
1108 // native_context is used when creating wrapper object.
1109 static inline MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1110 Handle<Object> object);
1111 static MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1112 Handle<Object> object,
1113 Handle<Context> context);
1115 // Converts this to a Smi if possible.
1116 MUST_USE_RESULT static inline MaybeHandle<Smi> ToSmi(Isolate* isolate,
1117 Handle<Object> object);
1119 MUST_USE_RESULT static MaybeHandle<Object> GetProperty(LookupIterator* it);
1121 // Implementation of [[Put]], ECMA-262 5th edition, section 8.12.5.
1122 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1123 Handle<Object> object, Handle<Name> key, Handle<Object> value,
1124 LanguageMode language_mode,
1125 StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
1127 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1128 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1129 StoreFromKeyed store_mode);
1131 MUST_USE_RESULT static MaybeHandle<Object> SetSuperProperty(
1132 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1133 StoreFromKeyed store_mode);
1135 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1136 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
1137 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1138 Isolate* isolate, Handle<Object> reciever, Handle<Object> name,
1139 Handle<Object> value, LanguageMode language_mode);
1140 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyElement(
1141 Isolate* isolate, Handle<Object> receiver, uint32_t index,
1142 Handle<Object> value, LanguageMode language_mode);
1143 MUST_USE_RESULT static MaybeHandle<Object> RedefineNonconfigurableProperty(
1144 Isolate* isolate, Handle<Object> name, Handle<Object> value,
1145 LanguageMode language_mode);
1146 MUST_USE_RESULT static MaybeHandle<Object> SetDataProperty(
1147 LookupIterator* it, Handle<Object> value);
1148 MUST_USE_RESULT static MaybeHandle<Object> AddDataProperty(
1149 LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
1150 LanguageMode language_mode, StoreFromKeyed store_mode);
1151 MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
1152 Handle<Object> object,
1154 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1156 Handle<Object> object,
1158 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1159 Handle<Object> object,
1162 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
1163 Handle<Object> receiver,
1165 Handle<JSObject> holder,
1166 Handle<Object> structure);
1167 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithAccessor(
1168 Handle<Object> receiver, Handle<Name> name, Handle<Object> value,
1169 Handle<JSObject> holder, Handle<Object> structure,
1170 LanguageMode language_mode);
1172 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter(
1173 Handle<Object> receiver,
1174 Handle<JSReceiver> getter);
1175 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithDefinedSetter(
1176 Handle<Object> receiver,
1177 Handle<JSReceiver> setter,
1178 Handle<Object> value);
1180 MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
1182 Handle<Object> object,
1185 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithReceiver(
1187 Handle<Object> object,
1188 Handle<Object> receiver,
1191 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithReceiver(
1192 Isolate* isolate, Handle<Object> object, Handle<Object> receiver,
1193 uint32_t index, Handle<Object> value, LanguageMode language_mode);
1195 static inline Handle<Object> GetPrototypeSkipHiddenPrototypes(
1196 Isolate* isolate, Handle<Object> receiver);
1198 // Returns the permanent hash code associated with this object. May return
1199 // undefined if not yet created.
1202 // Returns the permanent hash code associated with this object depending on
1203 // the actual object type. May create and store a hash code if needed and none
1205 static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object);
1207 // Checks whether this object has the same value as the given one. This
1208 // function is implemented according to ES5, section 9.12 and can be used
1209 // to implement the Harmony "egal" function.
1210 bool SameValue(Object* other);
1212 // Checks whether this object has the same value as the given one.
1213 // +0 and -0 are treated equal. Everything else is the same as SameValue.
1214 // This function is implemented according to ES6, section 7.2.4 and is used
1215 // by ES6 Map and Set.
1216 bool SameValueZero(Object* other);
1218 // Tries to convert an object to an array index. Returns true and sets
1219 // the output parameter if it succeeds.
1220 inline bool ToArrayIndex(uint32_t* index);
1222 // Returns true if this is a JSValue containing a string and the index is
1223 // < the length of the string. Used to implement [] on strings.
1224 inline bool IsStringObjectWithCharacterAt(uint32_t index);
1226 DECLARE_VERIFIER(Object)
1228 // Verify a pointer is a valid object pointer.
1229 static void VerifyPointer(Object* p);
1232 inline void VerifyApiCallResultType();
1234 // Prints this object without details.
1235 void ShortPrint(FILE* out = stdout);
1237 // Prints this object without details to a message accumulator.
1238 void ShortPrint(StringStream* accumulator);
1240 void ShortPrint(std::ostream& os); // NOLINT
1242 DECLARE_CAST(Object)
1244 // Layout description.
1245 static const int kHeaderSize = 0; // Object does not take up any space.
1248 // For our gdb macros, we should perhaps change these in the future.
1251 // Prints this object with details.
1252 void Print(std::ostream& os); // NOLINT
1254 void Print() { ShortPrint(); }
1255 void Print(std::ostream& os) { ShortPrint(os); } // NOLINT
1259 friend class LookupIterator;
1260 friend class PrototypeIterator;
1262 // Return the map of the root of object's prototype chain.
1263 Map* GetRootMap(Isolate* isolate);
1265 // Helper for SetProperty and SetSuperProperty.
1266 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyInternal(
1267 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1268 StoreFromKeyed store_mode, bool* found);
1270 DISALLOW_IMPLICIT_CONSTRUCTORS(Object);
1275 explicit Brief(const Object* const v) : value(v) {}
1276 const Object* value;
1280 std::ostream& operator<<(std::ostream& os, const Brief& v);
1283 // Smi represents integer Numbers that can be stored in 31 bits.
1284 // Smis are immediate which means they are NOT allocated in the heap.
1285 // The this pointer has the following format: [31 bit signed int] 0
1286 // For long smis it has the following format:
1287 // [32 bit signed int] [31 bits zero padding] 0
1288 // Smi stands for small integer.
1289 class Smi: public Object {
1291 // Returns the integer value.
1292 inline int value() const;
1294 // Convert a value to a Smi object.
1295 static inline Smi* FromInt(int value);
1297 static inline Smi* FromIntptr(intptr_t value);
1299 // Returns whether value can be represented in a Smi.
1300 static inline bool IsValid(intptr_t value);
1304 // Dispatched behavior.
1305 void SmiPrint(std::ostream& os) const; // NOLINT
1306 DECLARE_VERIFIER(Smi)
1308 static const int kMinValue =
1309 (static_cast<unsigned int>(-1)) << (kSmiValueSize - 1);
1310 static const int kMaxValue = -(kMinValue + 1);
1313 DISALLOW_IMPLICIT_CONSTRUCTORS(Smi);
1317 // Heap objects typically have a map pointer in their first word. However,
1318 // during GC other data (e.g. mark bits, forwarding addresses) is sometimes
1319 // encoded in the first word. The class MapWord is an abstraction of the
1320 // value in a heap object's first word.
1321 class MapWord BASE_EMBEDDED {
1323 // Normal state: the map word contains a map pointer.
1325 // Create a map word from a map pointer.
1326 static inline MapWord FromMap(const Map* map);
1328 // View this map word as a map pointer.
1329 inline Map* ToMap();
1332 // Scavenge collection: the map word of live objects in the from space
1333 // contains a forwarding address (a heap object pointer in the to space).
1335 // True if this map word is a forwarding address for a scavenge
1336 // collection. Only valid during a scavenge collection (specifically,
1337 // when all map words are heap object pointers, i.e. not during a full GC).
1338 inline bool IsForwardingAddress();
1340 // Create a map word from a forwarding address.
1341 static inline MapWord FromForwardingAddress(HeapObject* object);
1343 // View this map word as a forwarding address.
1344 inline HeapObject* ToForwardingAddress();
1346 static inline MapWord FromRawValue(uintptr_t value) {
1347 return MapWord(value);
1350 inline uintptr_t ToRawValue() {
1355 // HeapObject calls the private constructor and directly reads the value.
1356 friend class HeapObject;
1358 explicit MapWord(uintptr_t value) : value_(value) {}
1364 // HeapObject is the superclass for all classes describing heap allocated
1366 class HeapObject: public Object {
1368 // [map]: Contains a map which contains the object's reflective
1370 inline Map* map() const;
1371 inline void set_map(Map* value);
1372 // The no-write-barrier version. This is OK if the object is white and in
1373 // new space, or if the value is an immortal immutable object, like the maps
1374 // of primitive (non-JS) objects like strings, heap numbers etc.
1375 inline void set_map_no_write_barrier(Map* value);
1377 // Get the map using acquire load.
1378 inline Map* synchronized_map();
1379 inline MapWord synchronized_map_word() const;
1381 // Set the map using release store
1382 inline void synchronized_set_map(Map* value);
1383 inline void synchronized_set_map_no_write_barrier(Map* value);
1384 inline void synchronized_set_map_word(MapWord map_word);
1386 // During garbage collection, the map word of a heap object does not
1387 // necessarily contain a map pointer.
1388 inline MapWord map_word() const;
1389 inline void set_map_word(MapWord map_word);
1391 // The Heap the object was allocated in. Used also to access Isolate.
1392 inline Heap* GetHeap() const;
1394 // Convenience method to get current isolate.
1395 inline Isolate* GetIsolate() const;
1397 // Converts an address to a HeapObject pointer.
1398 static inline HeapObject* FromAddress(Address address);
1400 // Returns the address of this HeapObject.
1401 inline Address address();
1403 // Iterates over pointers contained in the object (including the Map)
1404 void Iterate(ObjectVisitor* v);
1406 // Iterates over all pointers contained in the object except the
1407 // first map pointer. The object type is given in the first
1408 // parameter. This function does not access the map pointer in the
1409 // object, and so is safe to call while the map pointer is modified.
1410 void IterateBody(InstanceType type, int object_size, ObjectVisitor* v);
1412 // Returns the heap object's size in bytes
1415 // Returns true if this heap object may contain raw values, i.e., values that
1416 // look like pointers to heap objects.
1417 inline bool MayContainRawValues();
1419 // Given a heap object's map pointer, returns the heap size in bytes
1420 // Useful when the map pointer field is used for other purposes.
1422 inline int SizeFromMap(Map* map);
1424 // Returns the field at offset in obj, as a read/write Object* reference.
1425 // Does no checking, and is safe to use during GC, while maps are invalid.
1426 // Does not invoke write barrier, so should only be assigned to
1427 // during marking GC.
1428 static inline Object** RawField(HeapObject* obj, int offset);
1430 // Adds the |code| object related to |name| to the code cache of this map. If
1431 // this map is a dictionary map that is shared, the map copied and installed
1433 static void UpdateMapCodeCache(Handle<HeapObject> object,
1437 DECLARE_CAST(HeapObject)
1439 // Return the write barrier mode for this. Callers of this function
1440 // must be able to present a reference to an DisallowHeapAllocation
1441 // object as a sign that they are not going to use this function
1442 // from code that allocates and thus invalidates the returned write
1444 inline WriteBarrierMode GetWriteBarrierMode(
1445 const DisallowHeapAllocation& promise);
1447 // Dispatched behavior.
1448 void HeapObjectShortPrint(std::ostream& os); // NOLINT
1450 void PrintHeader(std::ostream& os, const char* id); // NOLINT
1452 DECLARE_PRINTER(HeapObject)
1453 DECLARE_VERIFIER(HeapObject)
1455 inline void VerifyObjectField(int offset);
1456 inline void VerifySmiField(int offset);
1458 // Verify a pointer is a valid HeapObject pointer that points to object
1459 // areas in the heap.
1460 static void VerifyHeapPointer(Object* p);
1463 inline bool NeedsToEnsureDoubleAlignment();
1465 // Layout description.
1466 // First field in a heap object is map.
1467 static const int kMapOffset = Object::kHeaderSize;
1468 static const int kHeaderSize = kMapOffset + kPointerSize;
1470 STATIC_ASSERT(kMapOffset == Internals::kHeapObjectMapOffset);
1473 // helpers for calling an ObjectVisitor to iterate over pointers in the
1474 // half-open range [start, end) specified as integer offsets
1475 inline void IteratePointers(ObjectVisitor* v, int start, int end);
1476 // as above, for the single element at "offset"
1477 inline void IteratePointer(ObjectVisitor* v, int offset);
1478 // as above, for the next code link of a code object.
1479 inline void IterateNextCodeLink(ObjectVisitor* v, int offset);
1482 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject);
1486 // This class describes a body of an object of a fixed size
1487 // in which all pointer fields are located in the [start_offset, end_offset)
1489 template<int start_offset, int end_offset, int size>
1490 class FixedBodyDescriptor {
1492 static const int kStartOffset = start_offset;
1493 static const int kEndOffset = end_offset;
1494 static const int kSize = size;
1496 static inline void IterateBody(HeapObject* obj, ObjectVisitor* v);
1498 template<typename StaticVisitor>
1499 static inline void IterateBody(HeapObject* obj) {
1500 StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
1501 HeapObject::RawField(obj, end_offset));
1506 // This class describes a body of an object of a variable size
1507 // in which all pointer fields are located in the [start_offset, object_size)
1509 template<int start_offset>
1510 class FlexibleBodyDescriptor {
1512 static const int kStartOffset = start_offset;
1514 static inline void IterateBody(HeapObject* obj,
1518 template<typename StaticVisitor>
1519 static inline void IterateBody(HeapObject* obj, int object_size) {
1520 StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
1521 HeapObject::RawField(obj, object_size));
1526 // The HeapNumber class describes heap allocated numbers that cannot be
1527 // represented in a Smi (small integer)
1528 class HeapNumber: public HeapObject {
1530 // [value]: number value.
1531 inline double value() const;
1532 inline void set_value(double value);
1534 DECLARE_CAST(HeapNumber)
1536 // Dispatched behavior.
1537 bool HeapNumberBooleanValue();
1539 void HeapNumberPrint(std::ostream& os); // NOLINT
1540 DECLARE_VERIFIER(HeapNumber)
1542 inline int get_exponent();
1543 inline int get_sign();
1545 // Layout description.
1546 static const int kValueOffset = HeapObject::kHeaderSize;
1547 // IEEE doubles are two 32 bit words. The first is just mantissa, the second
1548 // is a mixture of sign, exponent and mantissa. The offsets of two 32 bit
1549 // words within double numbers are endian dependent and they are set
1551 #if defined(V8_TARGET_LITTLE_ENDIAN)
1552 static const int kMantissaOffset = kValueOffset;
1553 static const int kExponentOffset = kValueOffset + 4;
1554 #elif defined(V8_TARGET_BIG_ENDIAN)
1555 static const int kMantissaOffset = kValueOffset + 4;
1556 static const int kExponentOffset = kValueOffset;
1558 #error Unknown byte ordering
1561 static const int kSize = kValueOffset + kDoubleSize;
1562 static const uint32_t kSignMask = 0x80000000u;
1563 static const uint32_t kExponentMask = 0x7ff00000u;
1564 static const uint32_t kMantissaMask = 0xfffffu;
1565 static const int kMantissaBits = 52;
1566 static const int kExponentBits = 11;
1567 static const int kExponentBias = 1023;
1568 static const int kExponentShift = 20;
1569 static const int kInfinityOrNanExponent =
1570 (kExponentMask >> kExponentShift) - kExponentBias;
1571 static const int kMantissaBitsInTopWord = 20;
1572 static const int kNonMantissaBitsInTopWord = 12;
1575 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber);
1579 enum EnsureElementsMode {
1580 DONT_ALLOW_DOUBLE_ELEMENTS,
1581 ALLOW_COPIED_DOUBLE_ELEMENTS,
1582 ALLOW_CONVERTED_DOUBLE_ELEMENTS
1586 // Indicates whether a property should be set or (re)defined. Setting of a
1587 // property causes attributes to remain unchanged, writability to be checked
1588 // and callbacks to be called. Defining of a property causes attributes to
1589 // be updated and callbacks to be overridden.
1590 enum SetPropertyMode {
1596 // Indicator for one component of an AccessorPair.
1597 enum AccessorComponent {
1603 // JSReceiver includes types on which properties can be defined, i.e.,
1604 // JSObject and JSProxy.
1605 class JSReceiver: public HeapObject {
1607 DECLARE_CAST(JSReceiver)
1609 MUST_USE_RESULT static MaybeHandle<Object> SetElement(
1610 Handle<JSReceiver> object, uint32_t index, Handle<Object> value,
1611 PropertyAttributes attributes, LanguageMode language_mode);
1613 // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
1614 MUST_USE_RESULT static inline Maybe<bool> HasProperty(
1615 Handle<JSReceiver> object, Handle<Name> name);
1616 MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty(Handle<JSReceiver>,
1618 MUST_USE_RESULT static inline Maybe<bool> HasElement(
1619 Handle<JSReceiver> object, uint32_t index);
1620 MUST_USE_RESULT static inline Maybe<bool> HasOwnElement(
1621 Handle<JSReceiver> object, uint32_t index);
1623 // Implementation of [[Delete]], ECMA-262 5th edition, section 8.12.7.
1624 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
1625 Handle<JSReceiver> object, Handle<Name> name,
1626 LanguageMode language_mode = SLOPPY);
1627 MUST_USE_RESULT static MaybeHandle<Object> DeleteElement(
1628 Handle<JSReceiver> object, uint32_t index,
1629 LanguageMode language_mode = SLOPPY);
1631 // Tests for the fast common case for property enumeration.
1632 bool IsSimpleEnum();
1634 // Returns the class name ([[Class]] property in the specification).
1635 String* class_name();
1637 // Returns the constructor name (the name (possibly, inferred name) of the
1638 // function that was used to instantiate the object).
1639 String* constructor_name();
1641 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes(
1642 Handle<JSReceiver> object, Handle<Name> name);
1643 MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
1644 LookupIterator* it);
1645 MUST_USE_RESULT static Maybe<PropertyAttributes> GetOwnPropertyAttributes(
1646 Handle<JSReceiver> object, Handle<Name> name);
1648 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetElementAttribute(
1649 Handle<JSReceiver> object, uint32_t index);
1650 MUST_USE_RESULT static inline Maybe<PropertyAttributes>
1651 GetOwnElementAttribute(Handle<JSReceiver> object, uint32_t index);
1653 // Retrieves a permanent object identity hash code. The undefined value might
1654 // be returned in case no hash was created yet.
1655 inline Object* GetIdentityHash();
1657 // Retrieves a permanent object identity hash code. May create and store a
1658 // hash code if needed and none exists.
1659 inline static Handle<Smi> GetOrCreateIdentityHash(
1660 Handle<JSReceiver> object);
1662 enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS };
1664 // Computes the enumerable keys for a JSObject. Used for implementing
1665 // "for (n in object) { }".
1666 MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys(
1667 Handle<JSReceiver> object,
1668 KeyCollectionType type);
1671 DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
1674 // Forward declaration for JSObject::GetOrCreateHiddenPropertiesHashTable.
1675 class ObjectHashTable;
1677 // Forward declaration for JSObject::Copy.
1678 class AllocationSite;
1681 // The JSObject describes real heap allocated JavaScript objects with
1683 // Note that the map of JSObject changes during execution to enable inline
1685 class JSObject: public JSReceiver {
1687 // [properties]: Backing storage for properties.
1688 // properties is a FixedArray in the fast case and a Dictionary in the
1690 DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties.
1691 inline void initialize_properties();
1692 inline bool HasFastProperties();
1693 inline NameDictionary* property_dictionary(); // Gets slow properties.
1695 // [elements]: The elements (properties with names that are integers).
1697 // Elements can be in two general modes: fast and slow. Each mode
1698 // corrensponds to a set of object representations of elements that
1699 // have something in common.
1701 // In the fast mode elements is a FixedArray and so each element can
1702 // be quickly accessed. This fact is used in the generated code. The
1703 // elements array can have one of three maps in this mode:
1704 // fixed_array_map, sloppy_arguments_elements_map or
1705 // fixed_cow_array_map (for copy-on-write arrays). In the latter case
1706 // the elements array may be shared by a few objects and so before
1707 // writing to any element the array must be copied. Use
1708 // EnsureWritableFastElements in this case.
1710 // In the slow mode the elements is either a NumberDictionary, an
1711 // ExternalArray, or a FixedArray parameter map for a (sloppy)
1712 // arguments object.
1713 DECL_ACCESSORS(elements, FixedArrayBase)
1714 inline void initialize_elements();
1715 static void ResetElements(Handle<JSObject> object);
1716 static inline void SetMapAndElements(Handle<JSObject> object,
1718 Handle<FixedArrayBase> elements);
1719 inline ElementsKind GetElementsKind();
1720 inline ElementsAccessor* GetElementsAccessor();
1721 // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
1722 inline bool HasFastSmiElements();
1723 // Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
1724 inline bool HasFastObjectElements();
1725 // Returns true if an object has elements of FAST_ELEMENTS or
1726 // FAST_SMI_ONLY_ELEMENTS.
1727 inline bool HasFastSmiOrObjectElements();
1728 // Returns true if an object has any of the fast elements kinds.
1729 inline bool HasFastElements();
1730 // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
1732 inline bool HasFastDoubleElements();
1733 // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
1735 inline bool HasFastHoleyElements();
1736 inline bool HasSloppyArgumentsElements();
1737 inline bool HasDictionaryElements();
1739 inline bool HasExternalUint8ClampedElements();
1740 inline bool HasExternalArrayElements();
1741 inline bool HasExternalInt8Elements();
1742 inline bool HasExternalUint8Elements();
1743 inline bool HasExternalInt16Elements();
1744 inline bool HasExternalUint16Elements();
1745 inline bool HasExternalInt32Elements();
1746 inline bool HasExternalUint32Elements();
1747 inline bool HasExternalFloat32Elements();
1748 inline bool HasExternalFloat64Elements();
1750 inline bool HasFixedTypedArrayElements();
1752 inline bool HasFixedUint8ClampedElements();
1753 inline bool HasFixedArrayElements();
1754 inline bool HasFixedInt8Elements();
1755 inline bool HasFixedUint8Elements();
1756 inline bool HasFixedInt16Elements();
1757 inline bool HasFixedUint16Elements();
1758 inline bool HasFixedInt32Elements();
1759 inline bool HasFixedUint32Elements();
1760 inline bool HasFixedFloat32Elements();
1761 inline bool HasFixedFloat64Elements();
1763 bool HasFastArgumentsElements();
1764 bool HasDictionaryArgumentsElements();
1765 inline SeededNumberDictionary* element_dictionary(); // Gets slow elements.
1767 // Requires: HasFastElements().
1768 static Handle<FixedArray> EnsureWritableFastElements(
1769 Handle<JSObject> object);
1771 // Collects elements starting at index 0.
1772 // Undefined values are placed after non-undefined values.
1773 // Returns the number of non-undefined values.
1774 static Handle<Object> PrepareElementsForSort(Handle<JSObject> object,
1776 // As PrepareElementsForSort, but only on objects where elements is
1777 // a dictionary, and it will stay a dictionary. Collates undefined and
1778 // unexisting elements below limit from position zero of the elements.
1779 static Handle<Object> PrepareSlowElementsForSort(Handle<JSObject> object,
1782 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithInterceptor(
1783 LookupIterator* it, Handle<Object> value);
1785 // SetLocalPropertyIgnoreAttributes converts callbacks to fields. We need to
1786 // grant an exemption to ExecutableAccessor callbacks in some cases.
1787 enum ExecutableAccessorInfoHandling {
1792 MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes(
1793 Handle<JSObject> object,
1795 Handle<Object> value,
1796 PropertyAttributes attributes,
1797 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1799 static void AddProperty(Handle<JSObject> object, Handle<Name> key,
1800 Handle<Object> value, PropertyAttributes attributes);
1802 // Extend the receiver with a single fast property appeared first in the
1803 // passed map. This also extends the property backing store if necessary.
1804 static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
1806 // Migrates the given object to a map whose field representations are the
1807 // lowest upper bound of all known representations for that field.
1808 static void MigrateInstance(Handle<JSObject> instance);
1810 // Migrates the given object only if the target map is already available,
1811 // or returns false if such a map is not yet available.
1812 static bool TryMigrateInstance(Handle<JSObject> instance);
1814 // Sets the property value in a normalized object given (key, value, details).
1815 // Handles the special representation of JS global objects.
1816 static void SetNormalizedProperty(Handle<JSObject> object,
1818 Handle<Object> value,
1819 PropertyDetails details);
1821 static void OptimizeAsPrototype(Handle<JSObject> object,
1822 PrototypeOptimizationMode mode);
1823 static void ReoptimizeIfPrototype(Handle<JSObject> object);
1824 static void RegisterPrototypeUser(Handle<JSObject> prototype,
1825 Handle<HeapObject> user);
1826 static void UnregisterPrototypeUser(Handle<JSObject> prototype,
1827 Handle<HeapObject> user);
1829 // Retrieve interceptors.
1830 InterceptorInfo* GetNamedInterceptor();
1831 InterceptorInfo* GetIndexedInterceptor();
1833 // Used from JSReceiver.
1834 MUST_USE_RESULT static Maybe<PropertyAttributes>
1835 GetPropertyAttributesWithInterceptor(Handle<JSObject> holder,
1836 Handle<Object> receiver,
1838 MUST_USE_RESULT static Maybe<PropertyAttributes>
1839 GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
1840 MUST_USE_RESULT static Maybe<PropertyAttributes>
1841 GetElementAttributeWithReceiver(Handle<JSObject> object,
1842 Handle<JSReceiver> receiver,
1843 uint32_t index, bool check_prototype);
1845 // Retrieves an AccessorPair property from the given object. Might return
1846 // undefined if the property doesn't exist or is of a different kind.
1847 MUST_USE_RESULT static MaybeHandle<Object> GetAccessor(
1848 Handle<JSObject> object,
1850 AccessorComponent component);
1852 // Defines an AccessorPair property on the given object.
1853 // TODO(mstarzinger): Rename to SetAccessor().
1854 static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
1856 Handle<Object> getter,
1857 Handle<Object> setter,
1858 PropertyAttributes attributes);
1860 // Defines an AccessorInfo property on the given object.
1861 MUST_USE_RESULT static MaybeHandle<Object> SetAccessor(
1862 Handle<JSObject> object,
1863 Handle<AccessorInfo> info);
1865 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
1866 Handle<JSObject> object,
1867 Handle<Object> receiver,
1870 // Accessors for hidden properties object.
1872 // Hidden properties are not own properties of the object itself.
1873 // Instead they are stored in an auxiliary structure kept as an own
1874 // property with a special name Heap::hidden_string(). But if the
1875 // receiver is a JSGlobalProxy then the auxiliary object is a property
1876 // of its prototype, and if it's a detached proxy, then you can't have
1877 // hidden properties.
1879 // Sets a hidden property on this object. Returns this object if successful,
1880 // undefined if called on a detached proxy.
1881 static Handle<Object> SetHiddenProperty(Handle<JSObject> object,
1883 Handle<Object> value);
1884 // Gets the value of a hidden property with the given key. Returns the hole
1885 // if the property doesn't exist (or if called on a detached proxy),
1886 // otherwise returns the value set for the key.
1887 Object* GetHiddenProperty(Handle<Name> key);
1888 // Deletes a hidden property. Deleting a non-existing property is
1889 // considered successful.
1890 static void DeleteHiddenProperty(Handle<JSObject> object,
1892 // Returns true if the object has a property with the hidden string as name.
1893 static bool HasHiddenProperties(Handle<JSObject> object);
1895 static void SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash);
1897 static inline void ValidateElements(Handle<JSObject> object);
1899 // Makes sure that this object can contain HeapObject as elements.
1900 static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
1902 // Makes sure that this object can contain the specified elements.
1903 static inline void EnsureCanContainElements(
1904 Handle<JSObject> object,
1907 EnsureElementsMode mode);
1908 static inline void EnsureCanContainElements(
1909 Handle<JSObject> object,
1910 Handle<FixedArrayBase> elements,
1912 EnsureElementsMode mode);
1913 static void EnsureCanContainElements(
1914 Handle<JSObject> object,
1915 Arguments* arguments,
1918 EnsureElementsMode mode);
1920 // Would we convert a fast elements array to dictionary mode given
1921 // an access at key?
1922 bool WouldConvertToSlowElements(Handle<Object> key);
1923 // Do we want to keep the elements in fast case when increasing the
1925 bool ShouldConvertToSlowElements(int new_capacity);
1926 // Returns true if the backing storage for the slow-case elements of
1927 // this object takes up nearly as much space as a fast-case backing
1928 // storage would. In that case the JSObject should have fast
1930 bool ShouldConvertToFastElements();
1931 // Returns true if the elements of JSObject contains only values that can be
1932 // represented in a FixedDoubleArray and has at least one value that can only
1933 // be represented as a double and not a Smi.
1934 bool ShouldConvertToFastDoubleElements(bool* has_smi_only_elements);
1936 // Computes the new capacity when expanding the elements of a JSObject.
1937 static int NewElementsCapacity(int old_capacity) {
1938 // (old_capacity + 50%) + 16
1939 return old_capacity + (old_capacity >> 1) + 16;
1942 // These methods do not perform access checks!
1943 MUST_USE_RESULT static MaybeHandle<AccessorPair> GetOwnElementAccessorPair(
1944 Handle<JSObject> object, uint32_t index);
1946 MUST_USE_RESULT static MaybeHandle<Object> SetFastElement(
1947 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1948 LanguageMode language_mode, bool check_prototype);
1950 MUST_USE_RESULT static inline MaybeHandle<Object> SetOwnElement(
1951 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1952 LanguageMode language_mode);
1954 MUST_USE_RESULT static MaybeHandle<Object> SetOwnElement(
1955 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1956 PropertyAttributes attributes, LanguageMode language_mode);
1958 // Empty handle is returned if the element cannot be set to the given value.
1959 MUST_USE_RESULT static MaybeHandle<Object> SetElement(
1960 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1961 PropertyAttributes attributes, LanguageMode language_mode,
1962 bool check_prototype = true, SetPropertyMode set_mode = SET_PROPERTY);
1964 // Returns the index'th element.
1965 // The undefined object if index is out of bounds.
1966 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithInterceptor(
1967 Handle<JSObject> object, Handle<Object> receiver, uint32_t index,
1968 bool check_prototype);
1970 enum SetFastElementsCapacitySmiMode {
1973 kDontAllowSmiElements
1976 // Replace the elements' backing store with fast elements of the given
1977 // capacity. Update the length for JSArrays. Returns the new backing
1979 static Handle<FixedArray> SetFastElementsCapacityAndLength(
1980 Handle<JSObject> object,
1983 SetFastElementsCapacitySmiMode smi_mode);
1984 static void SetFastDoubleElementsCapacityAndLength(
1985 Handle<JSObject> object,
1989 // Lookup interceptors are used for handling properties controlled by host
1991 inline bool HasNamedInterceptor();
1992 inline bool HasIndexedInterceptor();
1994 // Computes the enumerable keys from interceptors. Used for debug mirrors and
1995 // by JSReceiver::GetKeys.
1996 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForNamedInterceptor(
1997 Handle<JSObject> object,
1998 Handle<JSReceiver> receiver);
1999 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForIndexedInterceptor(
2000 Handle<JSObject> object,
2001 Handle<JSReceiver> receiver);
2003 // Support functions for v8 api (needed for correct interceptor behavior).
2004 MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
2005 Handle<JSObject> object, Handle<Name> key);
2006 MUST_USE_RESULT static Maybe<bool> HasRealElementProperty(
2007 Handle<JSObject> object, uint32_t index);
2008 MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
2009 Handle<JSObject> object, Handle<Name> key);
2011 // Get the header size for a JSObject. Used to compute the index of
2012 // internal fields as well as the number of internal fields.
2013 inline int GetHeaderSize();
2015 inline int GetInternalFieldCount();
2016 inline int GetInternalFieldOffset(int index);
2017 inline Object* GetInternalField(int index);
2018 inline void SetInternalField(int index, Object* value);
2019 inline void SetInternalField(int index, Smi* value);
2021 // Returns the number of properties on this object filtering out properties
2022 // with the specified attributes (ignoring interceptors).
2023 int NumberOfOwnProperties(PropertyAttributes filter = NONE);
2024 // Fill in details for properties into storage starting at the specified
2026 void GetOwnPropertyNames(
2027 FixedArray* storage, int index, PropertyAttributes filter = NONE);
2029 // Returns the number of properties on this object filtering out properties
2030 // with the specified attributes (ignoring interceptors).
2031 int NumberOfOwnElements(PropertyAttributes filter);
2032 // Returns the number of enumerable elements (ignoring interceptors).
2033 int NumberOfEnumElements();
2034 // Returns the number of elements on this object filtering out elements
2035 // with the specified attributes (ignoring interceptors).
2036 int GetOwnElementKeys(FixedArray* storage, PropertyAttributes filter);
2037 // Count and fill in the enumerable elements into storage.
2038 // (storage->length() == NumberOfEnumElements()).
2039 // If storage is NULL, will count the elements without adding
2040 // them to any storage.
2041 // Returns the number of enumerable elements.
2042 int GetEnumElementKeys(FixedArray* storage);
2044 // Returns a new map with all transitions dropped from the object's current
2045 // map and the ElementsKind set.
2046 static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
2047 ElementsKind to_kind);
2048 static void TransitionElementsKind(Handle<JSObject> object,
2049 ElementsKind to_kind);
2051 static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map);
2053 // Convert the object to use the canonical dictionary
2054 // representation. If the object is expected to have additional properties
2055 // added this number can be indicated to have the backing store allocated to
2056 // an initial capacity for holding these properties.
2057 static void NormalizeProperties(Handle<JSObject> object,
2058 PropertyNormalizationMode mode,
2059 int expected_additional_properties,
2060 const char* reason);
2062 // Convert and update the elements backing store to be a
2063 // SeededNumberDictionary dictionary. Returns the backing after conversion.
2064 static Handle<SeededNumberDictionary> NormalizeElements(
2065 Handle<JSObject> object);
2067 // Transform slow named properties to fast variants.
2068 static void MigrateSlowToFast(Handle<JSObject> object,
2069 int unused_property_fields, const char* reason);
2071 inline bool IsUnboxedDoubleField(FieldIndex index);
2073 // Access fast-case object properties at index.
2074 static Handle<Object> FastPropertyAt(Handle<JSObject> object,
2075 Representation representation,
2077 inline Object* RawFastPropertyAt(FieldIndex index);
2078 inline double RawFastDoublePropertyAt(FieldIndex index);
2080 inline void FastPropertyAtPut(FieldIndex index, Object* value);
2081 inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
2082 inline void RawFastDoublePropertyAtPut(FieldIndex index, double value);
2083 void WriteToField(int descriptor, Object* value);
2085 // Access to in object properties.
2086 inline int GetInObjectPropertyOffset(int index);
2087 inline Object* InObjectPropertyAt(int index);
2088 inline Object* InObjectPropertyAtPut(int index,
2090 WriteBarrierMode mode
2091 = UPDATE_WRITE_BARRIER);
2093 // Set the object's prototype (only JSReceiver and null are allowed values).
2094 MUST_USE_RESULT static MaybeHandle<Object> SetPrototype(
2095 Handle<JSObject> object, Handle<Object> value, bool from_javascript);
2097 // Initializes the body after properties slot, properties slot is
2098 // initialized by set_properties. Fill the pre-allocated fields with
2099 // pre_allocated_value and the rest with filler_value.
2100 // Note: this call does not update write barrier, the caller is responsible
2101 // to ensure that |filler_value| can be collected without WB here.
2102 inline void InitializeBody(Map* map,
2103 Object* pre_allocated_value,
2104 Object* filler_value);
2106 // Check whether this object references another object
2107 bool ReferencesObject(Object* obj);
2109 // Disalow further properties to be added to the object.
2110 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensions(
2111 Handle<JSObject> object);
2114 MUST_USE_RESULT static MaybeHandle<Object> Seal(Handle<JSObject> object);
2116 // ES5 Object.freeze
2117 MUST_USE_RESULT static MaybeHandle<Object> Freeze(Handle<JSObject> object);
2119 // Called the first time an object is observed with ES7 Object.observe.
2120 static void SetObserved(Handle<JSObject> object);
2123 enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 };
2125 static Handle<JSObject> Copy(Handle<JSObject> object);
2126 MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy(
2127 Handle<JSObject> object,
2128 AllocationSiteUsageContext* site_context,
2129 DeepCopyHints hints = kNoHints);
2130 MUST_USE_RESULT static MaybeHandle<JSObject> DeepWalk(
2131 Handle<JSObject> object,
2132 AllocationSiteCreationContext* site_context);
2134 static Handle<Object> GetDataProperty(Handle<JSObject> object,
2136 static Handle<Object> GetDataProperty(LookupIterator* it);
2138 DECLARE_CAST(JSObject)
2140 // Dispatched behavior.
2141 void JSObjectShortPrint(StringStream* accumulator);
2142 DECLARE_PRINTER(JSObject)
2143 DECLARE_VERIFIER(JSObject)
2145 void PrintProperties(std::ostream& os); // NOLINT
2146 void PrintElements(std::ostream& os); // NOLINT
2148 #if defined(DEBUG) || defined(OBJECT_PRINT)
2149 void PrintTransitions(std::ostream& os); // NOLINT
2152 static void PrintElementsTransition(
2153 FILE* file, Handle<JSObject> object,
2154 ElementsKind from_kind, Handle<FixedArrayBase> from_elements,
2155 ElementsKind to_kind, Handle<FixedArrayBase> to_elements);
2157 void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
2160 // Structure for collecting spill information about JSObjects.
2161 class SpillInformation {
2165 int number_of_objects_;
2166 int number_of_objects_with_fast_properties_;
2167 int number_of_objects_with_fast_elements_;
2168 int number_of_fast_used_fields_;
2169 int number_of_fast_unused_fields_;
2170 int number_of_slow_used_properties_;
2171 int number_of_slow_unused_properties_;
2172 int number_of_fast_used_elements_;
2173 int number_of_fast_unused_elements_;
2174 int number_of_slow_used_elements_;
2175 int number_of_slow_unused_elements_;
2178 void IncrementSpillStatistics(SpillInformation* info);
2182 // If a GC was caused while constructing this object, the elements pointer
2183 // may point to a one pointer filler map. The object won't be rooted, but
2184 // our heap verification code could stumble across it.
2185 bool ElementsAreSafeToExamine();
2188 Object* SlowReverseLookup(Object* value);
2190 // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
2191 // Also maximal value of JSArray's length property.
2192 static const uint32_t kMaxElementCount = 0xffffffffu;
2194 // Constants for heuristics controlling conversion of fast elements
2195 // to slow elements.
2197 // Maximal gap that can be introduced by adding an element beyond
2198 // the current elements length.
2199 static const uint32_t kMaxGap = 1024;
2201 // Maximal length of fast elements array that won't be checked for
2202 // being dense enough on expansion.
2203 static const int kMaxUncheckedFastElementsLength = 5000;
2205 // Same as above but for old arrays. This limit is more strict. We
2206 // don't want to be wasteful with long lived objects.
2207 static const int kMaxUncheckedOldFastElementsLength = 500;
2209 // Note that Page::kMaxRegularHeapObjectSize puts a limit on
2210 // permissible values (see the DCHECK in heap.cc).
2211 static const int kInitialMaxFastElementArray = 100000;
2213 // This constant applies only to the initial map of "$Object" aka
2214 // "global.Object" and not to arbitrary other JSObject maps.
2215 static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
2217 static const int kMaxInstanceSize = 255 * kPointerSize;
2218 // When extending the backing storage for property values, we increase
2219 // its size by more than the 1 entry necessary, so sequentially adding fields
2220 // to the same object requires fewer allocations and copies.
2221 static const int kFieldsAdded = 3;
2223 // Layout description.
2224 static const int kPropertiesOffset = HeapObject::kHeaderSize;
2225 static const int kElementsOffset = kPropertiesOffset + kPointerSize;
2226 static const int kHeaderSize = kElementsOffset + kPointerSize;
2228 STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
2230 class BodyDescriptor : public FlexibleBodyDescriptor<kPropertiesOffset> {
2232 static inline int SizeOf(Map* map, HeapObject* object);
2235 Context* GetCreationContext();
2237 // Enqueue change record for Object.observe. May cause GC.
2238 MUST_USE_RESULT static MaybeHandle<Object> EnqueueChangeRecord(
2239 Handle<JSObject> object, const char* type, Handle<Name> name,
2240 Handle<Object> old_value);
2243 friend class DictionaryElementsAccessor;
2244 friend class JSReceiver;
2245 friend class Object;
2247 static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map);
2248 static void MigrateFastToSlow(Handle<JSObject> object,
2249 Handle<Map> new_map,
2250 int expected_additional_properties);
2252 static void UpdateAllocationSite(Handle<JSObject> object,
2253 ElementsKind to_kind);
2255 // Used from Object::GetProperty().
2256 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
2257 LookupIterator* it);
2259 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithCallback(
2260 Handle<JSObject> object,
2261 Handle<Object> receiver,
2262 Handle<Object> structure,
2264 Handle<Object> holder);
2266 MUST_USE_RESULT static Maybe<PropertyAttributes>
2267 GetElementAttributeWithInterceptor(Handle<JSObject> object,
2268 Handle<JSReceiver> receiver,
2269 uint32_t index, bool continue_search);
2271 // Queries indexed interceptor on an object for property attributes.
2273 // We determine property attributes as follows:
2274 // - if interceptor has a query callback, then the property attributes are
2275 // the result of query callback for index.
2276 // - otherwise if interceptor has a getter callback and it returns
2277 // non-empty value on index, then the property attributes is NONE
2278 // (property is present, and it is enumerable, configurable, writable)
2279 // - otherwise there are no property attributes that can be inferred for
2280 // interceptor, and this function returns ABSENT.
2281 MUST_USE_RESULT static Maybe<PropertyAttributes>
2282 GetElementAttributeFromInterceptor(Handle<JSObject> object,
2283 Handle<Object> receiver,
2286 MUST_USE_RESULT static Maybe<PropertyAttributes>
2287 GetElementAttributeWithoutInterceptor(Handle<JSObject> object,
2288 Handle<JSReceiver> receiver,
2290 bool continue_search);
2291 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithCallback(
2292 Handle<Object> object, Handle<Object> structure, uint32_t index,
2293 Handle<Object> value, Handle<JSObject> holder,
2294 LanguageMode language_mode);
2295 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithInterceptor(
2296 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2297 PropertyAttributes attributes, LanguageMode language_mode,
2298 bool check_prototype, SetPropertyMode set_mode);
2299 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithoutInterceptor(
2300 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2301 PropertyAttributes attributes, LanguageMode language_mode,
2302 bool check_prototype, SetPropertyMode set_mode);
2304 static MaybeHandle<Object> SetElementWithCallbackSetterInPrototypes(
2305 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2306 bool* found, LanguageMode language_mode);
2307 MUST_USE_RESULT static MaybeHandle<Object> SetDictionaryElement(
2308 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2309 PropertyAttributes attributes, LanguageMode language_mode,
2310 bool check_prototype, SetPropertyMode set_mode = SET_PROPERTY);
2311 MUST_USE_RESULT static MaybeHandle<Object> SetFastDoubleElement(
2312 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2313 LanguageMode language_mode, bool check_prototype = true);
2314 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithFailedAccessCheck(
2315 Isolate* isolate, Handle<JSObject> object, Handle<Object> receiver,
2317 MUST_USE_RESULT static Maybe<PropertyAttributes>
2318 GetElementAttributesWithFailedAccessCheck(Isolate* isolate,
2319 Handle<JSObject> object,
2320 Handle<Object> receiver,
2323 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithFailedAccessCheck(
2324 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
2326 // Add a property to a slow-case object.
2327 static void AddSlowProperty(Handle<JSObject> object,
2329 Handle<Object> value,
2330 PropertyAttributes attributes);
2332 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
2333 Handle<JSObject> object, Handle<Name> name, LanguageMode language_mode);
2334 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithInterceptor(
2335 Handle<JSObject> holder, Handle<JSObject> receiver, Handle<Name> name);
2337 // Deletes an existing named property in a normalized object.
2338 static void DeleteNormalizedProperty(Handle<JSObject> object,
2341 MUST_USE_RESULT static MaybeHandle<Object> DeleteElement(
2342 Handle<JSObject> object, uint32_t index, LanguageMode language_mode);
2343 MUST_USE_RESULT static MaybeHandle<Object> DeleteElementWithInterceptor(
2344 Handle<JSObject> object,
2347 bool ReferencesObjectFromElements(FixedArray* elements,
2351 // Returns true if most of the elements backing storage is used.
2352 bool HasDenseElements();
2354 // Gets the current elements capacity and the number of used elements.
2355 void GetElementsCapacityAndUsage(int* capacity, int* used);
2357 static bool CanSetCallback(Handle<JSObject> object, Handle<Name> name);
2358 static void SetElementCallback(Handle<JSObject> object,
2360 Handle<Object> structure,
2361 PropertyAttributes attributes);
2362 static void SetPropertyCallback(Handle<JSObject> object,
2364 Handle<Object> structure,
2365 PropertyAttributes attributes);
2366 static void DefineElementAccessor(Handle<JSObject> object,
2368 Handle<Object> getter,
2369 Handle<Object> setter,
2370 PropertyAttributes attributes);
2372 // Return the hash table backing store or the inline stored identity hash,
2373 // whatever is found.
2374 MUST_USE_RESULT Object* GetHiddenPropertiesHashTable();
2376 // Return the hash table backing store for hidden properties. If there is no
2377 // backing store, allocate one.
2378 static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable(
2379 Handle<JSObject> object);
2381 // Set the hidden property backing store to either a hash table or
2382 // the inline-stored identity hash.
2383 static Handle<Object> SetHiddenPropertiesHashTable(
2384 Handle<JSObject> object,
2385 Handle<Object> value);
2387 MUST_USE_RESULT Object* GetIdentityHash();
2389 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSObject> object);
2391 static Handle<SeededNumberDictionary> GetNormalizedElementDictionary(
2392 Handle<JSObject> object);
2394 // Helper for fast versions of preventExtensions, seal, and freeze.
2395 // attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
2396 template <PropertyAttributes attrs>
2397 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensionsWithTransition(
2398 Handle<JSObject> object);
2400 DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
2404 // Common superclass for FixedArrays that allow implementations to share
2405 // common accessors and some code paths.
2406 class FixedArrayBase: public HeapObject {
2408 // [length]: length of the array.
2409 inline int length() const;
2410 inline void set_length(int value);
2412 // Get and set the length using acquire loads and release stores.
2413 inline int synchronized_length() const;
2414 inline void synchronized_set_length(int value);
2416 DECLARE_CAST(FixedArrayBase)
2418 // Layout description.
2419 // Length is smi tagged when it is stored.
2420 static const int kLengthOffset = HeapObject::kHeaderSize;
2421 static const int kHeaderSize = kLengthOffset + kPointerSize;
2425 class FixedDoubleArray;
2426 class IncrementalMarking;
2429 // FixedArray describes fixed-sized arrays with element type Object*.
2430 class FixedArray: public FixedArrayBase {
2432 // Setter and getter for elements.
2433 inline Object* get(int index) const;
2434 static inline Handle<Object> get(Handle<FixedArray> array, int index);
2435 // Setter that uses write barrier.
2436 inline void set(int index, Object* value);
2437 inline bool is_the_hole(int index);
2439 // Setter that doesn't need write barrier.
2440 inline void set(int index, Smi* value);
2441 // Setter with explicit barrier mode.
2442 inline void set(int index, Object* value, WriteBarrierMode mode);
2444 // Setters for frequently used oddballs located in old space.
2445 inline void set_undefined(int index);
2446 inline void set_null(int index);
2447 inline void set_the_hole(int index);
2449 inline Object** GetFirstElementAddress();
2450 inline bool ContainsOnlySmisOrHoles();
2452 // Gives access to raw memory which stores the array's data.
2453 inline Object** data_start();
2455 inline void FillWithHoles(int from, int to);
2457 // Shrink length and insert filler objects.
2458 void Shrink(int length);
2461 static Handle<FixedArray> CopySize(Handle<FixedArray> array,
2463 PretenureFlag pretenure = NOT_TENURED);
2465 enum KeyFilter { ALL_KEYS, NON_SYMBOL_KEYS };
2467 // Add the elements of a JSArray to this FixedArray.
2468 MUST_USE_RESULT static MaybeHandle<FixedArray> AddKeysFromArrayLike(
2469 Handle<FixedArray> content, Handle<JSObject> array,
2470 KeyFilter filter = ALL_KEYS);
2472 // Computes the union of keys and return the result.
2473 // Used for implementing "for (n in object) { }"
2474 MUST_USE_RESULT static MaybeHandle<FixedArray> UnionOfKeys(
2475 Handle<FixedArray> first,
2476 Handle<FixedArray> second);
2478 // Copy a sub array from the receiver to dest.
2479 void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
2481 // Garbage collection support.
2482 static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
2484 // Code Generation support.
2485 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2487 // Garbage collection support.
2488 Object** RawFieldOfElementAt(int index) {
2489 return HeapObject::RawField(this, OffsetOfElementAt(index));
2492 DECLARE_CAST(FixedArray)
2494 // Maximal allowed size, in bytes, of a single FixedArray.
2495 // Prevents overflowing size computations, as well as extreme memory
2497 static const int kMaxSize = 128 * MB * kPointerSize;
2498 // Maximally allowed length of a FixedArray.
2499 static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
2501 // Dispatched behavior.
2502 DECLARE_PRINTER(FixedArray)
2503 DECLARE_VERIFIER(FixedArray)
2505 // Checks if two FixedArrays have identical contents.
2506 bool IsEqualTo(FixedArray* other);
2509 // Swap two elements in a pair of arrays. If this array and the
2510 // numbers array are the same object, the elements are only swapped
2512 void SwapPairs(FixedArray* numbers, int i, int j);
2514 // Sort prefix of this array and the numbers array as pairs wrt. the
2515 // numbers. If the numbers array and the this array are the same
2516 // object, the prefix of this array is sorted.
2517 void SortPairs(FixedArray* numbers, uint32_t len);
2519 class BodyDescriptor : public FlexibleBodyDescriptor<kHeaderSize> {
2521 static inline int SizeOf(Map* map, HeapObject* object) {
2522 return SizeFor(reinterpret_cast<FixedArray*>(object)->length());
2527 // Set operation on FixedArray without using write barriers. Can
2528 // only be used for storing old space objects or smis.
2529 static inline void NoWriteBarrierSet(FixedArray* array,
2533 // Set operation on FixedArray without incremental write barrier. Can
2534 // only be used if the object is guaranteed to be white (whiteness witness
2536 static inline void NoIncrementalWriteBarrierSet(FixedArray* array,
2541 STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);
2543 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray);
2547 // FixedDoubleArray describes fixed-sized arrays with element type double.
2548 class FixedDoubleArray: public FixedArrayBase {
2550 // Setter and getter for elements.
2551 inline double get_scalar(int index);
2552 inline uint64_t get_representation(int index);
2553 static inline Handle<Object> get(Handle<FixedDoubleArray> array, int index);
2554 inline void set(int index, double value);
2555 inline void set_the_hole(int index);
2557 // Checking for the hole.
2558 inline bool is_the_hole(int index);
2560 // Garbage collection support.
2561 inline static int SizeFor(int length) {
2562 return kHeaderSize + length * kDoubleSize;
2565 // Gives access to raw memory which stores the array's data.
2566 inline double* data_start();
2568 inline void FillWithHoles(int from, int to);
2570 // Code Generation support.
2571 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2573 DECLARE_CAST(FixedDoubleArray)
2575 // Maximal allowed size, in bytes, of a single FixedDoubleArray.
2576 // Prevents overflowing size computations, as well as extreme memory
2578 static const int kMaxSize = 512 * MB;
2579 // Maximally allowed length of a FixedArray.
2580 static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
2582 // Dispatched behavior.
2583 DECLARE_PRINTER(FixedDoubleArray)
2584 DECLARE_VERIFIER(FixedDoubleArray)
2587 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
2591 class WeakFixedArray : public FixedArray {
2593 enum SearchForDuplicates { kAlwaysAdd, kAddIfNotFound };
2595 // If |maybe_array| is not a WeakFixedArray, a fresh one will be allocated.
2596 static Handle<WeakFixedArray> Add(
2597 Handle<Object> maybe_array, Handle<HeapObject> value,
2598 SearchForDuplicates search_for_duplicates = kAlwaysAdd);
2600 void Remove(Handle<HeapObject> value);
2602 inline Object* Get(int index) const;
2603 inline int Length() const;
2605 DECLARE_CAST(WeakFixedArray)
2608 static const int kLastUsedIndexIndex = 0;
2609 static const int kFirstIndex = 1;
2611 static Handle<WeakFixedArray> Allocate(
2612 Isolate* isolate, int size, Handle<WeakFixedArray> initialize_from);
2614 static void Set(Handle<WeakFixedArray> array, int index,
2615 Handle<HeapObject> value);
2616 inline void clear(int index);
2617 inline bool IsEmptySlot(int index) const;
2619 inline int last_used_index() const;
2620 inline void set_last_used_index(int index);
2622 // Disallow inherited setters.
2623 void set(int index, Smi* value);
2624 void set(int index, Object* value);
2625 void set(int index, Object* value, WriteBarrierMode mode);
2626 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
2630 // ConstantPoolArray describes a fixed-sized array containing constant pool
2633 // A ConstantPoolArray can be structured in two different ways depending upon
2634 // whether it is extended or small. The is_extended_layout() method can be used
2635 // to discover which layout the constant pool has.
2637 // The format of a small constant pool is:
2638 // [kSmallLayout1Offset] : Small section layout bitmap 1
2639 // [kSmallLayout2Offset] : Small section layout bitmap 2
2640 // [first_index(INT64, SMALL_SECTION)] : 64 bit entries
2642 // [first_index(CODE_PTR, SMALL_SECTION)] : code pointer entries
2644 // [first_index(HEAP_PTR, SMALL_SECTION)] : heap pointer entries
2646 // [first_index(INT32, SMALL_SECTION)] : 32 bit entries
2649 // If the constant pool has an extended layout, the extended section constant
2650 // pool also contains an extended section, which has the following format at
2651 // location get_extended_section_header_offset():
2652 // [kExtendedInt64CountOffset] : count of extended 64 bit entries
2653 // [kExtendedCodePtrCountOffset] : count of extended code pointers
2654 // [kExtendedHeapPtrCountOffset] : count of extended heap pointers
2655 // [kExtendedInt32CountOffset] : count of extended 32 bit entries
2656 // [first_index(INT64, EXTENDED_SECTION)] : 64 bit entries
2658 // [first_index(CODE_PTR, EXTENDED_SECTION)]: code pointer entries
2660 // [first_index(HEAP_PTR, EXTENDED_SECTION)]: heap pointer entries
2662 // [first_index(INT32, EXTENDED_SECTION)] : 32 bit entries
2665 class ConstantPoolArray: public HeapObject {
2667 enum WeakObjectState { NO_WEAK_OBJECTS, WEAK_OBJECTS_IN_OPTIMIZED_CODE };
2674 // Number of types stored by the ConstantPoolArrays.
2680 enum LayoutSection {
2683 NUMBER_OF_LAYOUT_SECTIONS
2686 class NumberOfEntries BASE_EMBEDDED {
2688 inline NumberOfEntries() {
2689 for (int i = 0; i < NUMBER_OF_TYPES; i++) {
2690 element_counts_[i] = 0;
2694 inline NumberOfEntries(int int64_count, int code_ptr_count,
2695 int heap_ptr_count, int int32_count) {
2696 element_counts_[INT64] = int64_count;
2697 element_counts_[CODE_PTR] = code_ptr_count;
2698 element_counts_[HEAP_PTR] = heap_ptr_count;
2699 element_counts_[INT32] = int32_count;
2702 inline NumberOfEntries(ConstantPoolArray* array, LayoutSection section) {
2703 element_counts_[INT64] = array->number_of_entries(INT64, section);
2704 element_counts_[CODE_PTR] = array->number_of_entries(CODE_PTR, section);
2705 element_counts_[HEAP_PTR] = array->number_of_entries(HEAP_PTR, section);
2706 element_counts_[INT32] = array->number_of_entries(INT32, section);
2709 inline void increment(Type type);
2710 inline int equals(const NumberOfEntries& other) const;
2711 inline bool is_empty() const;
2712 inline int count_of(Type type) const;
2713 inline int base_of(Type type) const;
2714 inline int total_count() const;
2715 inline int are_in_range(int min, int max) const;
2718 int element_counts_[NUMBER_OF_TYPES];
2721 class Iterator BASE_EMBEDDED {
2723 inline Iterator(ConstantPoolArray* array, Type type)
2726 final_section_(array->final_section()),
2727 current_section_(SMALL_SECTION),
2728 next_index_(array->first_index(type, SMALL_SECTION)) {
2732 inline Iterator(ConstantPoolArray* array, Type type, LayoutSection section)
2735 final_section_(section),
2736 current_section_(section),
2737 next_index_(array->first_index(type, section)) {
2741 inline int next_index();
2742 inline bool is_finished();
2745 inline void update_section();
2746 ConstantPoolArray* array_;
2748 const LayoutSection final_section_;
2750 LayoutSection current_section_;
2754 // Getters for the first index, the last index and the count of entries of
2755 // a given type for a given layout section.
2756 inline int first_index(Type type, LayoutSection layout_section);
2757 inline int last_index(Type type, LayoutSection layout_section);
2758 inline int number_of_entries(Type type, LayoutSection layout_section);
2760 // Returns the type of the entry at the given index.
2761 inline Type get_type(int index);
2762 inline bool offset_is_type(int offset, Type type);
2764 // Setter and getter for pool elements.
2765 inline Address get_code_ptr_entry(int index);
2766 inline Object* get_heap_ptr_entry(int index);
2767 inline int64_t get_int64_entry(int index);
2768 inline int32_t get_int32_entry(int index);
2769 inline double get_int64_entry_as_double(int index);
2771 inline void set(int index, Address value);
2772 inline void set(int index, Object* value);
2773 inline void set(int index, int64_t value);
2774 inline void set(int index, double value);
2775 inline void set(int index, int32_t value);
2777 // Setters which take a raw offset rather than an index (for code generation).
2778 inline void set_at_offset(int offset, int32_t value);
2779 inline void set_at_offset(int offset, int64_t value);
2780 inline void set_at_offset(int offset, double value);
2781 inline void set_at_offset(int offset, Address value);
2782 inline void set_at_offset(int offset, Object* value);
2784 // Setter and getter for weak objects state
2785 inline void set_weak_object_state(WeakObjectState state);
2786 inline WeakObjectState get_weak_object_state();
2788 // Returns true if the constant pool has an extended layout, false if it has
2789 // only the small layout.
2790 inline bool is_extended_layout();
2792 // Returns the last LayoutSection in this constant pool array.
2793 inline LayoutSection final_section();
2795 // Set up initial state for a small layout constant pool array.
2796 inline void Init(const NumberOfEntries& small);
2798 // Set up initial state for an extended layout constant pool array.
2799 inline void InitExtended(const NumberOfEntries& small,
2800 const NumberOfEntries& extended);
2802 // Clears the pointer entries with GC safe values.
2803 void ClearPtrEntries(Isolate* isolate);
2805 // returns the total number of entries in the constant pool array.
2806 inline int length();
2808 // Garbage collection support.
2812 inline static int MaxInt64Offset(int number_of_int64) {
2813 return kFirstEntryOffset + (number_of_int64 * kInt64Size);
2816 inline static int SizeFor(const NumberOfEntries& small) {
2817 int size = kFirstEntryOffset +
2818 (small.count_of(INT64) * kInt64Size) +
2819 (small.count_of(CODE_PTR) * kPointerSize) +
2820 (small.count_of(HEAP_PTR) * kPointerSize) +
2821 (small.count_of(INT32) * kInt32Size);
2822 return RoundUp(size, kPointerSize);
2825 inline static int SizeForExtended(const NumberOfEntries& small,
2826 const NumberOfEntries& extended) {
2827 int size = SizeFor(small);
2828 size = RoundUp(size, kInt64Size); // Align extended header to 64 bits.
2829 size += kExtendedFirstOffset +
2830 (extended.count_of(INT64) * kInt64Size) +
2831 (extended.count_of(CODE_PTR) * kPointerSize) +
2832 (extended.count_of(HEAP_PTR) * kPointerSize) +
2833 (extended.count_of(INT32) * kInt32Size);
2834 return RoundUp(size, kPointerSize);
2837 inline static int entry_size(Type type) {
2845 return kPointerSize;
2852 // Code Generation support.
2853 inline int OffsetOfElementAt(int index) {
2855 LayoutSection section;
2856 if (is_extended_layout() && index >= first_extended_section_index()) {
2857 section = EXTENDED_SECTION;
2858 offset = get_extended_section_header_offset() + kExtendedFirstOffset;
2860 section = SMALL_SECTION;
2861 offset = kFirstEntryOffset;
2864 // Add offsets for the preceding type sections.
2865 DCHECK(index <= last_index(LAST_TYPE, section));
2866 for (Type type = FIRST_TYPE; index > last_index(type, section);
2867 type = next_type(type)) {
2868 offset += entry_size(type) * number_of_entries(type, section);
2871 // Add offset for the index in it's type.
2872 Type type = get_type(index);
2873 offset += entry_size(type) * (index - first_index(type, section));
2877 DECLARE_CAST(ConstantPoolArray)
2879 // Garbage collection support.
2880 Object** RawFieldOfElementAt(int index) {
2881 return HeapObject::RawField(this, OffsetOfElementAt(index));
2884 // Small Layout description.
2885 static const int kSmallLayout1Offset = HeapObject::kHeaderSize;
2886 static const int kSmallLayout2Offset = kSmallLayout1Offset + kInt32Size;
2887 static const int kHeaderSize = kSmallLayout2Offset + kInt32Size;
2888 static const int kFirstEntryOffset = ROUND_UP(kHeaderSize, kInt64Size);
2890 static const int kSmallLayoutCountBits = 10;
2891 static const int kMaxSmallEntriesPerType = (1 << kSmallLayoutCountBits) - 1;
2893 // Fields in kSmallLayout1Offset.
2894 class Int64CountField: public BitField<int, 1, kSmallLayoutCountBits> {};
2895 class CodePtrCountField: public BitField<int, 11, kSmallLayoutCountBits> {};
2896 class HeapPtrCountField: public BitField<int, 21, kSmallLayoutCountBits> {};
2897 class IsExtendedField: public BitField<bool, 31, 1> {};
2899 // Fields in kSmallLayout2Offset.
2900 class Int32CountField: public BitField<int, 1, kSmallLayoutCountBits> {};
2901 class TotalCountField: public BitField<int, 11, 12> {};
2902 class WeakObjectStateField: public BitField<WeakObjectState, 23, 2> {};
2904 // Extended layout description, which starts at
2905 // get_extended_section_header_offset().
2906 static const int kExtendedInt64CountOffset = 0;
2907 static const int kExtendedCodePtrCountOffset =
2908 kExtendedInt64CountOffset + kInt32Size;
2909 static const int kExtendedHeapPtrCountOffset =
2910 kExtendedCodePtrCountOffset + kInt32Size;
2911 static const int kExtendedInt32CountOffset =
2912 kExtendedHeapPtrCountOffset + kInt32Size;
2913 static const int kExtendedFirstOffset =
2914 kExtendedInt32CountOffset + kInt32Size;
2916 // Dispatched behavior.
2917 void ConstantPoolIterateBody(ObjectVisitor* v);
2919 DECLARE_PRINTER(ConstantPoolArray)
2920 DECLARE_VERIFIER(ConstantPoolArray)
2923 inline int first_extended_section_index();
2924 inline int get_extended_section_header_offset();
2926 inline static Type next_type(Type type) {
2927 DCHECK(type >= FIRST_TYPE && type < NUMBER_OF_TYPES);
2928 int type_int = static_cast<int>(type);
2929 return static_cast<Type>(++type_int);
2932 DISALLOW_IMPLICIT_CONSTRUCTORS(ConstantPoolArray);
2936 // DescriptorArrays are fixed arrays used to hold instance descriptors.
2937 // The format of the these objects is:
2938 // [0]: Number of descriptors
2939 // [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array:
2940 // [0]: pointer to fixed array with enum cache
2941 // [1]: either Smi(0) or pointer to fixed array with indices
2943 // [2 + number of descriptors * kDescriptorSize]: start of slack
2944 class DescriptorArray: public FixedArray {
2946 // Returns true for both shared empty_descriptor_array and for smis, which the
2947 // map uses to encode additional bit fields when the descriptor array is not
2949 inline bool IsEmpty();
2951 // Returns the number of descriptors in the array.
2952 int number_of_descriptors() {
2953 DCHECK(length() >= kFirstIndex || IsEmpty());
2955 return len == 0 ? 0 : Smi::cast(get(kDescriptorLengthIndex))->value();
2958 int number_of_descriptors_storage() {
2960 return len == 0 ? 0 : (len - kFirstIndex) / kDescriptorSize;
2963 int NumberOfSlackDescriptors() {
2964 return number_of_descriptors_storage() - number_of_descriptors();
2967 inline void SetNumberOfDescriptors(int number_of_descriptors);
2968 inline int number_of_entries() { return number_of_descriptors(); }
2970 bool HasEnumCache() {
2971 return !IsEmpty() && !get(kEnumCacheIndex)->IsSmi();
2974 void CopyEnumCacheFrom(DescriptorArray* array) {
2975 set(kEnumCacheIndex, array->get(kEnumCacheIndex));
2978 FixedArray* GetEnumCache() {
2979 DCHECK(HasEnumCache());
2980 FixedArray* bridge = FixedArray::cast(get(kEnumCacheIndex));
2981 return FixedArray::cast(bridge->get(kEnumCacheBridgeCacheIndex));
2984 bool HasEnumIndicesCache() {
2985 if (IsEmpty()) return false;
2986 Object* object = get(kEnumCacheIndex);
2987 if (object->IsSmi()) return false;
2988 FixedArray* bridge = FixedArray::cast(object);
2989 return !bridge->get(kEnumCacheBridgeIndicesCacheIndex)->IsSmi();
2992 FixedArray* GetEnumIndicesCache() {
2993 DCHECK(HasEnumIndicesCache());
2994 FixedArray* bridge = FixedArray::cast(get(kEnumCacheIndex));
2995 return FixedArray::cast(bridge->get(kEnumCacheBridgeIndicesCacheIndex));
2998 Object** GetEnumCacheSlot() {
2999 DCHECK(HasEnumCache());
3000 return HeapObject::RawField(reinterpret_cast<HeapObject*>(this),
3004 void ClearEnumCache();
3006 // Initialize or change the enum cache,
3007 // using the supplied storage for the small "bridge".
3008 void SetEnumCache(FixedArray* bridge_storage,
3009 FixedArray* new_cache,
3010 Object* new_index_cache);
3012 bool CanHoldValue(int descriptor, Object* value);
3014 // Accessors for fetching instance descriptor at descriptor number.
3015 inline Name* GetKey(int descriptor_number);
3016 inline Object** GetKeySlot(int descriptor_number);
3017 inline Object* GetValue(int descriptor_number);
3018 inline void SetValue(int descriptor_number, Object* value);
3019 inline Object** GetValueSlot(int descriptor_number);
3020 static inline int GetValueOffset(int descriptor_number);
3021 inline Object** GetDescriptorStartSlot(int descriptor_number);
3022 inline Object** GetDescriptorEndSlot(int descriptor_number);
3023 inline PropertyDetails GetDetails(int descriptor_number);
3024 inline PropertyType GetType(int descriptor_number);
3025 inline int GetFieldIndex(int descriptor_number);
3026 inline HeapType* GetFieldType(int descriptor_number);
3027 inline Object* GetConstant(int descriptor_number);
3028 inline Object* GetCallbacksObject(int descriptor_number);
3029 inline AccessorDescriptor* GetCallbacks(int descriptor_number);
3031 inline Name* GetSortedKey(int descriptor_number);
3032 inline int GetSortedKeyIndex(int descriptor_number);
3033 inline void SetSortedKey(int pointer, int descriptor_number);
3034 inline void SetRepresentation(int descriptor_number,
3035 Representation representation);
3037 // Accessor for complete descriptor.
3038 inline void Get(int descriptor_number, Descriptor* desc);
3039 inline void Set(int descriptor_number, Descriptor* desc);
3040 void Replace(int descriptor_number, Descriptor* descriptor);
3042 // Append automatically sets the enumeration index. This should only be used
3043 // to add descriptors in bulk at the end, followed by sorting the descriptor
3045 inline void Append(Descriptor* desc);
3047 static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc,
3048 int enumeration_index,
3051 static Handle<DescriptorArray> CopyUpToAddAttributes(
3052 Handle<DescriptorArray> desc,
3053 int enumeration_index,
3054 PropertyAttributes attributes,
3057 // Sort the instance descriptors by the hash codes of their keys.
3060 // Search the instance descriptors for given name.
3061 INLINE(int Search(Name* name, int number_of_own_descriptors));
3063 // As the above, but uses DescriptorLookupCache and updates it when
3065 INLINE(int SearchWithCache(Name* name, Map* map));
3067 // Allocates a DescriptorArray, but returns the singleton
3068 // empty descriptor array object if number_of_descriptors is 0.
3069 static Handle<DescriptorArray> Allocate(Isolate* isolate,
3070 int number_of_descriptors,
3073 DECLARE_CAST(DescriptorArray)
3075 // Constant for denoting key was not found.
3076 static const int kNotFound = -1;
3078 static const int kDescriptorLengthIndex = 0;
3079 static const int kEnumCacheIndex = 1;
3080 static const int kFirstIndex = 2;
3082 // The length of the "bridge" to the enum cache.
3083 static const int kEnumCacheBridgeLength = 2;
3084 static const int kEnumCacheBridgeCacheIndex = 0;
3085 static const int kEnumCacheBridgeIndicesCacheIndex = 1;
3087 // Layout description.
3088 static const int kDescriptorLengthOffset = FixedArray::kHeaderSize;
3089 static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize;
3090 static const int kFirstOffset = kEnumCacheOffset + kPointerSize;
3092 // Layout description for the bridge array.
3093 static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize;
3095 // Layout of descriptor.
3096 static const int kDescriptorKey = 0;
3097 static const int kDescriptorDetails = 1;
3098 static const int kDescriptorValue = 2;
3099 static const int kDescriptorSize = 3;
3101 #if defined(DEBUG) || defined(OBJECT_PRINT)
3102 // For our gdb macros, we should perhaps change these in the future.
3105 // Print all the descriptors.
3106 void PrintDescriptors(std::ostream& os); // NOLINT
3110 // Is the descriptor array sorted and without duplicates?
3111 bool IsSortedNoDuplicates(int valid_descriptors = -1);
3113 // Is the descriptor array consistent with the back pointers in targets?
3114 bool IsConsistentWithBackPointers(Map* current_map);
3116 // Are two DescriptorArrays equal?
3117 bool IsEqualTo(DescriptorArray* other);
3120 // Returns the fixed array length required to hold number_of_descriptors
3122 static int LengthFor(int number_of_descriptors) {
3123 return ToKeyIndex(number_of_descriptors);
3127 // WhitenessWitness is used to prove that a descriptor array is white
3128 // (unmarked), so incremental write barriers can be skipped because the
3129 // marking invariant cannot be broken and slots pointing into evacuation
3130 // candidates will be discovered when the object is scanned. A witness is
3131 // always stack-allocated right after creating an array. By allocating a
3132 // witness, incremental marking is globally disabled. The witness is then
3133 // passed along wherever needed to statically prove that the array is known to
3135 class WhitenessWitness {
3137 inline explicit WhitenessWitness(DescriptorArray* array);
3138 inline ~WhitenessWitness();
3141 IncrementalMarking* marking_;
3144 // An entry in a DescriptorArray, represented as an (array, index) pair.
3147 inline explicit Entry(DescriptorArray* descs, int index) :
3148 descs_(descs), index_(index) { }
3150 inline PropertyType type() { return descs_->GetType(index_); }
3151 inline Object* GetCallbackObject() { return descs_->GetValue(index_); }
3154 DescriptorArray* descs_;
3158 // Conversion from descriptor number to array indices.
3159 static int ToKeyIndex(int descriptor_number) {
3160 return kFirstIndex +
3161 (descriptor_number * kDescriptorSize) +
3165 static int ToDetailsIndex(int descriptor_number) {
3166 return kFirstIndex +
3167 (descriptor_number * kDescriptorSize) +
3171 static int ToValueIndex(int descriptor_number) {
3172 return kFirstIndex +
3173 (descriptor_number * kDescriptorSize) +
3177 // Transfer a complete descriptor from the src descriptor array to this
3178 // descriptor array.
3179 void CopyFrom(int index, DescriptorArray* src, const WhitenessWitness&);
3181 inline void Set(int descriptor_number,
3183 const WhitenessWitness&);
3185 // Swap first and second descriptor.
3186 inline void SwapSortedKeys(int first, int second);
3188 DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
3192 enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
3194 template <SearchMode search_mode, typename T>
3195 inline int Search(T* array, Name* name, int valid_entries = 0,
3196 int* out_insertion_index = NULL);
3199 // HashTable is a subclass of FixedArray that implements a hash table
3200 // that uses open addressing and quadratic probing.
3202 // In order for the quadratic probing to work, elements that have not
3203 // yet been used and elements that have been deleted are
3204 // distinguished. Probing continues when deleted elements are
3205 // encountered and stops when unused elements are encountered.
3207 // - Elements with key == undefined have not been used yet.
3208 // - Elements with key == the_hole have been deleted.
3210 // The hash table class is parameterized with a Shape and a Key.
3211 // Shape must be a class with the following interface:
3212 // class ExampleShape {
3214 // // Tells whether key matches other.
3215 // static bool IsMatch(Key key, Object* other);
3216 // // Returns the hash value for key.
3217 // static uint32_t Hash(Key key);
3218 // // Returns the hash value for object.
3219 // static uint32_t HashForObject(Key key, Object* object);
3220 // // Convert key to an object.
3221 // static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
3222 // // The prefix size indicates number of elements in the beginning
3223 // // of the backing storage.
3224 // static const int kPrefixSize = ..;
3225 // // The Element size indicates number of elements per entry.
3226 // static const int kEntrySize = ..;
3228 // The prefix size indicates an amount of memory in the
3229 // beginning of the backing storage that can be used for non-element
3230 // information by subclasses.
3232 template<typename Key>
3235 static const bool UsesSeed = false;
3236 static uint32_t Hash(Key key) { return 0; }
3237 static uint32_t SeededHash(Key key, uint32_t seed) {
3241 static uint32_t HashForObject(Key key, Object* object) { return 0; }
3242 static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) {
3244 return HashForObject(key, object);
3248 template<typename Derived, typename Shape, typename Key>
3249 class HashTable: public FixedArray {
3252 inline uint32_t Hash(Key key) {
3253 if (Shape::UsesSeed) {
3254 return Shape::SeededHash(key, GetHeap()->HashSeed());
3256 return Shape::Hash(key);
3260 inline uint32_t HashForObject(Key key, Object* object) {
3261 if (Shape::UsesSeed) {
3262 return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object);
3264 return Shape::HashForObject(key, object);
3268 // Returns the number of elements in the hash table.
3269 int NumberOfElements() {
3270 return Smi::cast(get(kNumberOfElementsIndex))->value();
3273 // Returns the number of deleted elements in the hash table.
3274 int NumberOfDeletedElements() {
3275 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
3278 // Returns the capacity of the hash table.
3280 return Smi::cast(get(kCapacityIndex))->value();
3283 // ElementAdded should be called whenever an element is added to a
3285 void ElementAdded() { SetNumberOfElements(NumberOfElements() + 1); }
3287 // ElementRemoved should be called whenever an element is removed from
3289 void ElementRemoved() {
3290 SetNumberOfElements(NumberOfElements() - 1);
3291 SetNumberOfDeletedElements(NumberOfDeletedElements() + 1);
3293 void ElementsRemoved(int n) {
3294 SetNumberOfElements(NumberOfElements() - n);
3295 SetNumberOfDeletedElements(NumberOfDeletedElements() + n);
3298 // Returns a new HashTable object.
3299 MUST_USE_RESULT static Handle<Derived> New(
3301 int at_least_space_for,
3302 MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
3303 PretenureFlag pretenure = NOT_TENURED);
3305 // Computes the required capacity for a table holding the given
3306 // number of elements. May be more than HashTable::kMaxCapacity.
3307 static int ComputeCapacity(int at_least_space_for);
3309 // Returns the key at entry.
3310 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
3312 // Tells whether k is a real key. The hole and undefined are not allowed
3313 // as keys and can be used to indicate missing or deleted elements.
3314 bool IsKey(Object* k) {
3315 return !k->IsTheHole() && !k->IsUndefined();
3318 // Garbage collection support.
3319 void IteratePrefix(ObjectVisitor* visitor);
3320 void IterateElements(ObjectVisitor* visitor);
3322 DECLARE_CAST(HashTable)
3324 // Compute the probe offset (quadratic probing).
3325 INLINE(static uint32_t GetProbeOffset(uint32_t n)) {
3326 return (n + n * n) >> 1;
3329 static const int kNumberOfElementsIndex = 0;
3330 static const int kNumberOfDeletedElementsIndex = 1;
3331 static const int kCapacityIndex = 2;
3332 static const int kPrefixStartIndex = 3;
3333 static const int kElementsStartIndex =
3334 kPrefixStartIndex + Shape::kPrefixSize;
3335 static const int kEntrySize = Shape::kEntrySize;
3336 static const int kElementsStartOffset =
3337 kHeaderSize + kElementsStartIndex * kPointerSize;
3338 static const int kCapacityOffset =
3339 kHeaderSize + kCapacityIndex * kPointerSize;
3341 // Constant used for denoting a absent entry.
3342 static const int kNotFound = -1;
3344 // Maximal capacity of HashTable. Based on maximal length of underlying
3345 // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex
3347 static const int kMaxCapacity =
3348 (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize;
3350 // Find entry for key otherwise return kNotFound.
3351 inline int FindEntry(Key key);
3352 int FindEntry(Isolate* isolate, Key key);
3354 // Rehashes the table in-place.
3355 void Rehash(Key key);
3358 friend class ObjectHashTable;
3360 // Find the entry at which to insert element with the given key that
3361 // has the given hash value.
3362 uint32_t FindInsertionEntry(uint32_t hash);
3364 // Returns the index for an entry (of the key)
3365 static inline int EntryToIndex(int entry) {
3366 return (entry * kEntrySize) + kElementsStartIndex;
3369 // Update the number of elements in the hash table.
3370 void SetNumberOfElements(int nof) {
3371 set(kNumberOfElementsIndex, Smi::FromInt(nof));
3374 // Update the number of deleted elements in the hash table.
3375 void SetNumberOfDeletedElements(int nod) {
3376 set(kNumberOfDeletedElementsIndex, Smi::FromInt(nod));
3379 // Sets the capacity of the hash table.
3380 void SetCapacity(int capacity) {
3381 // To scale a computed hash code to fit within the hash table, we
3382 // use bit-wise AND with a mask, so the capacity must be positive
3384 DCHECK(capacity > 0);
3385 DCHECK(capacity <= kMaxCapacity);
3386 set(kCapacityIndex, Smi::FromInt(capacity));
3390 // Returns probe entry.
3391 static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) {
3392 DCHECK(base::bits::IsPowerOfTwo32(size));
3393 return (hash + GetProbeOffset(number)) & (size - 1);
3396 inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) {
3397 return hash & (size - 1);
3400 inline static uint32_t NextProbe(
3401 uint32_t last, uint32_t number, uint32_t size) {
3402 return (last + number) & (size - 1);
3405 // Attempt to shrink hash table after removal of key.
3406 MUST_USE_RESULT static Handle<Derived> Shrink(Handle<Derived> table, Key key);
3408 // Ensure enough space for n additional elements.
3409 MUST_USE_RESULT static Handle<Derived> EnsureCapacity(
3410 Handle<Derived> table,
3413 PretenureFlag pretenure = NOT_TENURED);
3416 // Returns _expected_ if one of entries given by the first _probe_ probes is
3417 // equal to _expected_. Otherwise, returns the entry given by the probe
3419 uint32_t EntryForProbe(Key key, Object* k, int probe, uint32_t expected);
3421 void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode);
3423 // Rehashes this hash-table into the new table.
3424 void Rehash(Handle<Derived> new_table, Key key);
3428 // HashTableKey is an abstract superclass for virtual key behavior.
3429 class HashTableKey {
3431 // Returns whether the other object matches this key.
3432 virtual bool IsMatch(Object* other) = 0;
3433 // Returns the hash value for this key.
3434 virtual uint32_t Hash() = 0;
3435 // Returns the hash value for object.
3436 virtual uint32_t HashForObject(Object* key) = 0;
3437 // Returns the key object for storing into the hash table.
3438 MUST_USE_RESULT virtual Handle<Object> AsHandle(Isolate* isolate) = 0;
3440 virtual ~HashTableKey() {}
3444 class StringTableShape : public BaseShape<HashTableKey*> {
3446 static inline bool IsMatch(HashTableKey* key, Object* value) {
3447 return key->IsMatch(value);
3450 static inline uint32_t Hash(HashTableKey* key) {
3454 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
3455 return key->HashForObject(object);
3458 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
3460 static const int kPrefixSize = 0;
3461 static const int kEntrySize = 1;
3464 class SeqOneByteString;
3468 // No special elements in the prefix and the element size is 1
3469 // because only the string itself (the key) needs to be stored.
3470 class StringTable: public HashTable<StringTable,
3474 // Find string in the string table. If it is not there yet, it is
3475 // added. The return value is the string found.
3476 static Handle<String> LookupString(Isolate* isolate, Handle<String> key);
3477 static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key);
3479 // Tries to internalize given string and returns string handle on success
3480 // or an empty handle otherwise.
3481 MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists(
3483 Handle<String> string);
3485 // Looks up a string that is equal to the given string and returns
3486 // string handle if it is found, or an empty handle otherwise.
3487 MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists(
3489 Handle<String> str);
3490 MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists(
3495 static void EnsureCapacityForDeserialization(Isolate* isolate, int expected);
3497 DECLARE_CAST(StringTable)
3500 template <bool seq_one_byte>
3501 friend class JsonParser;
3503 DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable);
3507 template <typename Derived, typename Shape, typename Key>
3508 class Dictionary: public HashTable<Derived, Shape, Key> {
3510 typedef HashTable<Derived, Shape, Key> DerivedHashTable;
3513 // Returns the value at entry.
3514 Object* ValueAt(int entry) {
3515 return this->get(DerivedHashTable::EntryToIndex(entry) + 1);
3518 // Set the value for entry.
3519 void ValueAtPut(int entry, Object* value) {
3520 this->set(DerivedHashTable::EntryToIndex(entry) + 1, value);
3523 // Returns the property details for the property at entry.
3524 PropertyDetails DetailsAt(int entry) {
3525 DCHECK(entry >= 0); // Not found is -1, which is not caught by get().
3526 return PropertyDetails(
3527 Smi::cast(this->get(DerivedHashTable::EntryToIndex(entry) + 2)));
3530 // Set the details for entry.
3531 void DetailsAtPut(int entry, PropertyDetails value) {
3532 this->set(DerivedHashTable::EntryToIndex(entry) + 2, value.AsSmi());
3536 void CopyValuesTo(FixedArray* elements);
3538 // Delete a property from the dictionary.
3539 static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry);
3541 // Attempt to shrink the dictionary after deletion of key.
3542 MUST_USE_RESULT static inline Handle<Derived> Shrink(
3543 Handle<Derived> dictionary,
3545 return DerivedHashTable::Shrink(dictionary, key);
3548 // Returns the number of elements in the dictionary filtering out properties
3549 // with the specified attributes.
3550 int NumberOfElementsFilterAttributes(PropertyAttributes filter);
3552 // Returns the number of enumerable elements in the dictionary.
3553 int NumberOfEnumElements();
3555 // Returns true if the dictionary contains any elements that are non-writable,
3556 // non-configurable, non-enumerable, or have getters/setters.
3557 bool HasComplexElements();
3559 enum SortMode { UNSORTED, SORTED };
3560 // Copies keys to preallocated fixed array.
3561 void CopyKeysTo(FixedArray* storage,
3562 PropertyAttributes filter,
3563 SortMode sort_mode);
3564 // Fill in details for properties into storage.
3565 void CopyKeysTo(FixedArray* storage,
3567 PropertyAttributes filter,
3568 SortMode sort_mode);
3570 // Accessors for next enumeration index.
3571 void SetNextEnumerationIndex(int index) {
3573 this->set(kNextEnumerationIndexIndex, Smi::FromInt(index));
3576 int NextEnumerationIndex() {
3577 return Smi::cast(this->get(kNextEnumerationIndexIndex))->value();
3580 // Creates a new dictionary.
3581 MUST_USE_RESULT static Handle<Derived> New(
3583 int at_least_space_for,
3584 PretenureFlag pretenure = NOT_TENURED);
3586 // Ensure enough space for n additional elements.
3587 static Handle<Derived> EnsureCapacity(Handle<Derived> obj, int n, Key key);
3590 void Print(std::ostream& os); // NOLINT
3592 // Returns the key (slow).
3593 Object* SlowReverseLookup(Object* value);
3595 // Sets the entry to (key, value) pair.
3596 inline void SetEntry(int entry,
3598 Handle<Object> value);
3599 inline void SetEntry(int entry,
3601 Handle<Object> value,
3602 PropertyDetails details);
3604 MUST_USE_RESULT static Handle<Derived> Add(
3605 Handle<Derived> dictionary,
3607 Handle<Object> value,
3608 PropertyDetails details);
3610 // Returns iteration indices array for the |dictionary|.
3611 // Values are direct indices in the |HashTable| array.
3612 static Handle<FixedArray> BuildIterationIndicesArray(
3613 Handle<Derived> dictionary);
3616 // Generic at put operation.
3617 MUST_USE_RESULT static Handle<Derived> AtPut(
3618 Handle<Derived> dictionary,
3620 Handle<Object> value);
3622 // Add entry to dictionary.
3623 static void AddEntry(
3624 Handle<Derived> dictionary,
3626 Handle<Object> value,
3627 PropertyDetails details,
3630 // Generate new enumeration indices to avoid enumeration index overflow.
3631 // Returns iteration indices array for the |dictionary|.
3632 static Handle<FixedArray> GenerateNewEnumerationIndices(
3633 Handle<Derived> dictionary);
3634 static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex;
3635 static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
3639 class NameDictionaryShape : public BaseShape<Handle<Name> > {
3641 static inline bool IsMatch(Handle<Name> key, Object* other);
3642 static inline uint32_t Hash(Handle<Name> key);
3643 static inline uint32_t HashForObject(Handle<Name> key, Object* object);
3644 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
3645 static const int kPrefixSize = 2;
3646 static const int kEntrySize = 3;
3647 static const bool kIsEnumerable = true;
3651 class NameDictionary: public Dictionary<NameDictionary,
3652 NameDictionaryShape,
3655 NameDictionary, NameDictionaryShape, Handle<Name> > DerivedDictionary;
3658 DECLARE_CAST(NameDictionary)
3660 // Copies enumerable keys to preallocated fixed array.
3661 void CopyEnumKeysTo(FixedArray* storage);
3662 inline static Handle<FixedArray> DoGenerateNewEnumerationIndices(
3663 Handle<NameDictionary> dictionary);
3665 // Find entry for key, otherwise return kNotFound. Optimized version of
3666 // HashTable::FindEntry.
3667 int FindEntry(Handle<Name> key);
3671 class NumberDictionaryShape : public BaseShape<uint32_t> {
3673 static inline bool IsMatch(uint32_t key, Object* other);
3674 static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key);
3675 static const int kEntrySize = 3;
3676 static const bool kIsEnumerable = false;
3680 class SeededNumberDictionaryShape : public NumberDictionaryShape {
3682 static const bool UsesSeed = true;
3683 static const int kPrefixSize = 2;
3685 static inline uint32_t SeededHash(uint32_t key, uint32_t seed);
3686 static inline uint32_t SeededHashForObject(uint32_t key,
3692 class UnseededNumberDictionaryShape : public NumberDictionaryShape {
3694 static const int kPrefixSize = 0;
3696 static inline uint32_t Hash(uint32_t key);
3697 static inline uint32_t HashForObject(uint32_t key, Object* object);
3701 class SeededNumberDictionary
3702 : public Dictionary<SeededNumberDictionary,
3703 SeededNumberDictionaryShape,
3706 DECLARE_CAST(SeededNumberDictionary)
3708 // Type specific at put (default NONE attributes is used when adding).
3709 MUST_USE_RESULT static Handle<SeededNumberDictionary> AtNumberPut(
3710 Handle<SeededNumberDictionary> dictionary,
3712 Handle<Object> value);
3713 MUST_USE_RESULT static Handle<SeededNumberDictionary> AddNumberEntry(
3714 Handle<SeededNumberDictionary> dictionary,
3716 Handle<Object> value,
3717 PropertyDetails details);
3719 // Set an existing entry or add a new one if needed.
3720 // Return the updated dictionary.
3721 MUST_USE_RESULT static Handle<SeededNumberDictionary> Set(
3722 Handle<SeededNumberDictionary> dictionary,
3724 Handle<Object> value,
3725 PropertyDetails details);
3727 void UpdateMaxNumberKey(uint32_t key);
3729 // If slow elements are required we will never go back to fast-case
3730 // for the elements kept in this dictionary. We require slow
3731 // elements if an element has been added at an index larger than
3732 // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called
3733 // when defining a getter or setter with a number key.
3734 inline bool requires_slow_elements();
3735 inline void set_requires_slow_elements();
3737 // Get the value of the max number key that has been added to this
3738 // dictionary. max_number_key can only be called if
3739 // requires_slow_elements returns false.
3740 inline uint32_t max_number_key();
3743 static const int kRequiresSlowElementsMask = 1;
3744 static const int kRequiresSlowElementsTagSize = 1;
3745 static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1;
3749 class UnseededNumberDictionary
3750 : public Dictionary<UnseededNumberDictionary,
3751 UnseededNumberDictionaryShape,
3754 DECLARE_CAST(UnseededNumberDictionary)
3756 // Type specific at put (default NONE attributes is used when adding).
3757 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AtNumberPut(
3758 Handle<UnseededNumberDictionary> dictionary,
3760 Handle<Object> value);
3761 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AddNumberEntry(
3762 Handle<UnseededNumberDictionary> dictionary,
3764 Handle<Object> value);
3766 // Set an existing entry or add a new one if needed.
3767 // Return the updated dictionary.
3768 MUST_USE_RESULT static Handle<UnseededNumberDictionary> Set(
3769 Handle<UnseededNumberDictionary> dictionary,
3771 Handle<Object> value);
3775 class ObjectHashTableShape : public BaseShape<Handle<Object> > {
3777 static inline bool IsMatch(Handle<Object> key, Object* other);
3778 static inline uint32_t Hash(Handle<Object> key);
3779 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
3780 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
3781 static const int kPrefixSize = 0;
3782 static const int kEntrySize = 2;
3786 // ObjectHashTable maps keys that are arbitrary objects to object values by
3787 // using the identity hash of the key for hashing purposes.
3788 class ObjectHashTable: public HashTable<ObjectHashTable,
3789 ObjectHashTableShape,
3792 ObjectHashTable, ObjectHashTableShape, Handle<Object> > DerivedHashTable;
3794 DECLARE_CAST(ObjectHashTable)
3796 // Attempt to shrink hash table after removal of key.
3797 MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink(
3798 Handle<ObjectHashTable> table,
3799 Handle<Object> key);
3801 // Looks up the value associated with the given key. The hole value is
3802 // returned in case the key is not present.
3803 Object* Lookup(Handle<Object> key);
3805 // Adds (or overwrites) the value associated with the given key.
3806 static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
3808 Handle<Object> value);
3810 // Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
3811 static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
3816 friend class MarkCompactCollector;
3818 void AddEntry(int entry, Object* key, Object* value);
3819 void RemoveEntry(int entry);
3821 // Returns the index to the value of an entry.
3822 static inline int EntryToValueIndex(int entry) {
3823 return EntryToIndex(entry) + 1;
3828 // OrderedHashTable is a HashTable with Object keys that preserves
3829 // insertion order. There are Map and Set interfaces (OrderedHashMap
3830 // and OrderedHashTable, below). It is meant to be used by JSMap/JSSet.
3832 // Only Object* keys are supported, with Object::SameValueZero() used as the
3833 // equality operator and Object::GetHash() for the hash function.
3835 // Based on the "Deterministic Hash Table" as described by Jason Orendorff at
3836 // https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables
3837 // Originally attributed to Tyler Close.
3840 // [0]: bucket count
3841 // [1]: element count
3842 // [2]: deleted element count
3843 // [3..(3 + NumberOfBuckets() - 1)]: "hash table", where each item is an
3844 // offset into the data table (see below) where the
3845 // first item in this bucket is stored.
3846 // [3 + NumberOfBuckets()..length]: "data table", an array of length
3847 // Capacity() * kEntrySize, where the first entrysize
3848 // items are handled by the derived class and the
3849 // item at kChainOffset is another entry into the
3850 // data table indicating the next entry in this hash
3853 // When we transition the table to a new version we obsolete it and reuse parts
3854 // of the memory to store information how to transition an iterator to the new
3857 // Memory layout for obsolete table:
3858 // [0]: bucket count
3859 // [1]: Next newer table
3860 // [2]: Number of removed holes or -1 when the table was cleared.
3861 // [3..(3 + NumberOfRemovedHoles() - 1)]: The indexes of the removed holes.
3862 // [3 + NumberOfRemovedHoles()..length]: Not used
3864 template<class Derived, class Iterator, int entrysize>
3865 class OrderedHashTable: public FixedArray {
3867 // Returns an OrderedHashTable with a capacity of at least |capacity|.
3868 static Handle<Derived> Allocate(
3869 Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED);
3871 // Returns an OrderedHashTable (possibly |table|) with enough space
3872 // to add at least one new element.
3873 static Handle<Derived> EnsureGrowable(Handle<Derived> table);
3875 // Returns an OrderedHashTable (possibly |table|) that's shrunken
3877 static Handle<Derived> Shrink(Handle<Derived> table);
3879 // Returns a new empty OrderedHashTable and records the clearing so that
3880 // exisiting iterators can be updated.
3881 static Handle<Derived> Clear(Handle<Derived> table);
3883 // Returns an OrderedHashTable (possibly |table|) where |key| has been
3885 static Handle<Derived> Remove(Handle<Derived> table, Handle<Object> key,
3888 // Returns kNotFound if the key isn't present.
3889 int FindEntry(Handle<Object> key, int hash);
3891 // Like the above, but doesn't require the caller to provide a hash.
3892 int FindEntry(Handle<Object> key);
3894 int NumberOfElements() {
3895 return Smi::cast(get(kNumberOfElementsIndex))->value();
3898 int NumberOfDeletedElements() {
3899 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
3902 int UsedCapacity() { return NumberOfElements() + NumberOfDeletedElements(); }
3904 int NumberOfBuckets() {
3905 return Smi::cast(get(kNumberOfBucketsIndex))->value();
3908 // Returns the index into the data table where the new entry
3909 // should be placed. The table is assumed to have enough space
3911 int AddEntry(int hash);
3913 // Removes the entry, and puts the_hole in entrysize pointers
3914 // (leaving the hash table chain intact).
3915 void RemoveEntry(int entry);
3917 // Returns an index into |this| for the given entry.
3918 int EntryToIndex(int entry) {
3919 return kHashTableStartIndex + NumberOfBuckets() + (entry * kEntrySize);
3922 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
3925 return !get(kNextTableIndex)->IsSmi();
3928 // The next newer table. This is only valid if the table is obsolete.
3929 Derived* NextTable() {
3930 return Derived::cast(get(kNextTableIndex));
3933 // When the table is obsolete we store the indexes of the removed holes.
3934 int RemovedIndexAt(int index) {
3935 return Smi::cast(get(kRemovedHolesIndex + index))->value();
3938 static const int kNotFound = -1;
3939 static const int kMinCapacity = 4;
3941 static const int kNumberOfBucketsIndex = 0;
3942 static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1;
3943 static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
3944 static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1;
3945 static const int kNextTableIndex = kNumberOfElementsIndex;
3947 static const int kNumberOfBucketsOffset =
3948 kHeaderSize + kNumberOfBucketsIndex * kPointerSize;
3949 static const int kNumberOfElementsOffset =
3950 kHeaderSize + kNumberOfElementsIndex * kPointerSize;
3951 static const int kNumberOfDeletedElementsOffset =
3952 kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize;
3953 static const int kHashTableStartOffset =
3954 kHeaderSize + kHashTableStartIndex * kPointerSize;
3955 static const int kNextTableOffset =
3956 kHeaderSize + kNextTableIndex * kPointerSize;
3958 static const int kEntrySize = entrysize + 1;
3959 static const int kChainOffset = entrysize;
3961 static const int kLoadFactor = 2;
3963 // NumberOfDeletedElements is set to kClearedTableSentinel when
3964 // the table is cleared, which allows iterator transitions to
3965 // optimize that case.
3966 static const int kClearedTableSentinel = -1;
3969 static Handle<Derived> Rehash(Handle<Derived> table, int new_capacity);
3971 void SetNumberOfBuckets(int num) {
3972 set(kNumberOfBucketsIndex, Smi::FromInt(num));
3975 void SetNumberOfElements(int num) {
3976 set(kNumberOfElementsIndex, Smi::FromInt(num));
3979 void SetNumberOfDeletedElements(int num) {
3980 set(kNumberOfDeletedElementsIndex, Smi::FromInt(num));
3984 return NumberOfBuckets() * kLoadFactor;
3987 // Returns the next entry for the given entry.
3988 int ChainAt(int entry) {
3989 return Smi::cast(get(EntryToIndex(entry) + kChainOffset))->value();
3992 int HashToBucket(int hash) {
3993 return hash & (NumberOfBuckets() - 1);
3996 int HashToEntry(int hash) {
3997 int bucket = HashToBucket(hash);
3998 return Smi::cast(get(kHashTableStartIndex + bucket))->value();
4001 void SetNextTable(Derived* next_table) {
4002 set(kNextTableIndex, next_table);
4005 void SetRemovedIndexAt(int index, int removed_index) {
4006 return set(kRemovedHolesIndex + index, Smi::FromInt(removed_index));
4009 static const int kRemovedHolesIndex = kHashTableStartIndex;
4011 static const int kMaxCapacity =
4012 (FixedArray::kMaxLength - kHashTableStartIndex)
4013 / (1 + (kEntrySize * kLoadFactor));
4017 class JSSetIterator;
4020 class OrderedHashSet: public OrderedHashTable<
4021 OrderedHashSet, JSSetIterator, 1> {
4023 DECLARE_CAST(OrderedHashSet)
4025 bool Contains(Handle<Object> key);
4026 static Handle<OrderedHashSet> Add(
4027 Handle<OrderedHashSet> table, Handle<Object> key);
4031 class JSMapIterator;
4034 class OrderedHashMap:public OrderedHashTable<
4035 OrderedHashMap, JSMapIterator, 2> {
4037 DECLARE_CAST(OrderedHashMap)
4039 Object* Lookup(Handle<Object> key);
4040 static Handle<OrderedHashMap> Put(
4041 Handle<OrderedHashMap> table,
4043 Handle<Object> value);
4045 Object* ValueAt(int entry) {
4046 return get(EntryToIndex(entry) + kValueOffset);
4049 static const int kValueOffset = 1;
4053 template <int entrysize>
4054 class WeakHashTableShape : public BaseShape<Handle<Object> > {
4056 static inline bool IsMatch(Handle<Object> key, Object* other);
4057 static inline uint32_t Hash(Handle<Object> key);
4058 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
4059 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
4060 static const int kPrefixSize = 0;
4061 static const int kEntrySize = entrysize;
4065 // WeakHashTable maps keys that are arbitrary heap objects to heap object
4066 // values. The table wraps the keys in weak cells and store values directly.
4067 // Thus it references keys weakly and values strongly.
4068 class WeakHashTable: public HashTable<WeakHashTable,
4069 WeakHashTableShape<2>,
4072 WeakHashTable, WeakHashTableShape<2>, Handle<Object> > DerivedHashTable;
4074 DECLARE_CAST(WeakHashTable)
4076 // Looks up the value associated with the given key. The hole value is
4077 // returned in case the key is not present.
4078 Object* Lookup(Handle<HeapObject> key);
4080 // Adds (or overwrites) the value associated with the given key. Mapping a
4081 // key to the hole value causes removal of the whole entry.
4082 MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table,
4083 Handle<HeapObject> key,
4084 Handle<HeapObject> value);
4087 friend class MarkCompactCollector;
4089 void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value);
4091 // Returns the index to the value of an entry.
4092 static inline int EntryToValueIndex(int entry) {
4093 return EntryToIndex(entry) + 1;
4098 // JSFunctionResultCache caches results of some JSFunction invocation.
4099 // It is a fixed array with fixed structure:
4100 // [0]: factory function
4101 // [1]: finger index
4102 // [2]: current cache size
4103 // [3]: dummy field.
4104 // The rest of array are key/value pairs.
4105 class JSFunctionResultCache: public FixedArray {
4107 static const int kFactoryIndex = 0;
4108 static const int kFingerIndex = kFactoryIndex + 1;
4109 static const int kCacheSizeIndex = kFingerIndex + 1;
4110 static const int kDummyIndex = kCacheSizeIndex + 1;
4111 static const int kEntriesIndex = kDummyIndex + 1;
4113 static const int kEntrySize = 2; // key + value
4115 static const int kFactoryOffset = kHeaderSize;
4116 static const int kFingerOffset = kFactoryOffset + kPointerSize;
4117 static const int kCacheSizeOffset = kFingerOffset + kPointerSize;
4119 inline void MakeZeroSize();
4120 inline void Clear();
4123 inline void set_size(int size);
4124 inline int finger_index();
4125 inline void set_finger_index(int finger_index);
4127 DECLARE_CAST(JSFunctionResultCache)
4129 DECLARE_VERIFIER(JSFunctionResultCache)
4133 // ScopeInfo represents information about different scopes of a source
4134 // program and the allocation of the scope's variables. Scope information
4135 // is stored in a compressed form in ScopeInfo objects and is used
4136 // at runtime (stack dumps, deoptimization, etc.).
4138 // This object provides quick access to scope info details for runtime
4140 class ScopeInfo : public FixedArray {
4142 DECLARE_CAST(ScopeInfo)
4144 // Return the type of this scope.
4145 ScopeType scope_type();
4147 // Does this scope call eval?
4150 // Return the language mode of this scope.
4151 LanguageMode language_mode();
4153 // Does this scope make a sloppy eval call?
4154 bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); }
4156 // Return the total number of locals allocated on the stack and in the
4157 // context. This includes the parameters that are allocated in the context.
4160 // Return the number of stack slots for code. This number consists of two
4162 // 1. One stack slot per stack allocated local.
4163 // 2. One stack slot for the function name if it is stack allocated.
4164 int StackSlotCount();
4166 // Return the number of context slots for code if a context is allocated. This
4167 // number consists of three parts:
4168 // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS
4169 // 2. One context slot per context allocated local.
4170 // 3. One context slot for the function name if it is context allocated.
4171 // Parameters allocated in the context count as context allocated locals. If
4172 // no contexts are allocated for this scope ContextLength returns 0.
4173 int ContextLength();
4175 // Is this scope the scope of a named function expression?
4176 bool HasFunctionName();
4178 // Return if this has context allocated locals.
4179 bool HasHeapAllocatedLocals();
4181 // Return if contexts are allocated for this scope.
4184 // Return if this is a function scope with "use asm".
4185 bool IsAsmModule() { return AsmModuleField::decode(Flags()); }
4187 // Return if this is a nested function within an asm module scope.
4188 bool IsAsmFunction() { return AsmFunctionField::decode(Flags()); }
4190 bool IsSimpleParameterList() {
4191 return IsSimpleParameterListField::decode(Flags());
4194 // Return the function_name if present.
4195 String* FunctionName();
4197 // Return the name of the given parameter.
4198 String* ParameterName(int var);
4200 // Return the name of the given local.
4201 String* LocalName(int var);
4203 // Return the name of the given stack local.
4204 String* StackLocalName(int var);
4206 // Return the name of the given context local.
4207 String* ContextLocalName(int var);
4209 // Return the mode of the given context local.
4210 VariableMode ContextLocalMode(int var);
4212 // Return the initialization flag of the given context local.
4213 InitializationFlag ContextLocalInitFlag(int var);
4215 // Return the initialization flag of the given context local.
4216 MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var);
4218 // Return true if this local was introduced by the compiler, and should not be
4219 // exposed to the user in a debugger.
4220 bool LocalIsSynthetic(int var);
4222 // Lookup support for serialized scope info. Returns the
4223 // the stack slot index for a given slot name if the slot is
4224 // present; otherwise returns a value < 0. The name must be an internalized
4226 int StackSlotIndex(String* name);
4228 // Lookup support for serialized scope info. Returns the
4229 // context slot index for a given slot name if the slot is present; otherwise
4230 // returns a value < 0. The name must be an internalized string.
4231 // If the slot is present and mode != NULL, sets *mode to the corresponding
4232 // mode for that variable.
4233 static int ContextSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name,
4234 VariableMode* mode, InitializationFlag* init_flag,
4235 MaybeAssignedFlag* maybe_assigned_flag);
4237 // Lookup support for serialized scope info. Returns the
4238 // parameter index for a given parameter name if the parameter is present;
4239 // otherwise returns a value < 0. The name must be an internalized string.
4240 int ParameterIndex(String* name);
4242 // Lookup support for serialized scope info. Returns the function context
4243 // slot index if the function name is present and context-allocated (named
4244 // function expressions, only), otherwise returns a value < 0. The name
4245 // must be an internalized string.
4246 int FunctionContextSlotIndex(String* name, VariableMode* mode);
4249 // Copies all the context locals into an object used to materialize a scope.
4250 static bool CopyContextLocalsToScopeObject(Handle<ScopeInfo> scope_info,
4251 Handle<Context> context,
4252 Handle<JSObject> scope_object);
4255 static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope);
4257 // Serializes empty scope info.
4258 static ScopeInfo* Empty(Isolate* isolate);
4264 // The layout of the static part of a ScopeInfo is as follows. Each entry is
4265 // numeric and occupies one array slot.
4266 // 1. A set of properties of the scope
4267 // 2. The number of parameters. This only applies to function scopes. For
4268 // non-function scopes this is 0.
4269 // 3. The number of non-parameter variables allocated on the stack.
4270 // 4. The number of non-parameter and parameter variables allocated in the
4272 #define FOR_EACH_NUMERIC_FIELD(V) \
4275 V(StackLocalCount) \
4276 V(ContextLocalCount)
4278 #define FIELD_ACCESSORS(name) \
4279 void Set##name(int value) { \
4280 set(k##name, Smi::FromInt(value)); \
4283 if (length() > 0) { \
4284 return Smi::cast(get(k##name))->value(); \
4289 FOR_EACH_NUMERIC_FIELD(FIELD_ACCESSORS)
4290 #undef FIELD_ACCESSORS
4294 #define DECL_INDEX(name) k##name,
4295 FOR_EACH_NUMERIC_FIELD(DECL_INDEX)
4297 #undef FOR_EACH_NUMERIC_FIELD
4301 // The layout of the variable part of a ScopeInfo is as follows:
4302 // 1. ParameterEntries:
4303 // This part stores the names of the parameters for function scopes. One
4304 // slot is used per parameter, so in total this part occupies
4305 // ParameterCount() slots in the array. For other scopes than function
4306 // scopes ParameterCount() is 0.
4307 // 2. StackLocalEntries:
4308 // Contains the names of local variables that are allocated on the stack,
4309 // in increasing order of the stack slot index. One slot is used per stack
4310 // local, so in total this part occupies StackLocalCount() slots in the
4312 // 3. ContextLocalNameEntries:
4313 // Contains the names of local variables and parameters that are allocated
4314 // in the context. They are stored in increasing order of the context slot
4315 // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
4316 // context local, so in total this part occupies ContextLocalCount() slots
4318 // 4. ContextLocalInfoEntries:
4319 // Contains the variable modes and initialization flags corresponding to
4320 // the context locals in ContextLocalNameEntries. One slot is used per
4321 // context local, so in total this part occupies ContextLocalCount()
4322 // slots in the array.
4323 // 5. FunctionNameEntryIndex:
4324 // If the scope belongs to a named function expression this part contains
4325 // information about the function variable. It always occupies two array
4326 // slots: a. The name of the function variable.
4327 // b. The context or stack slot index for the variable.
4328 int ParameterEntriesIndex();
4329 int StackLocalEntriesIndex();
4330 int ContextLocalNameEntriesIndex();
4331 int ContextLocalInfoEntriesIndex();
4332 int FunctionNameEntryIndex();
4334 // Location of the function variable for named function expressions.
4335 enum FunctionVariableInfo {
4336 NONE, // No function name present.
4342 // Properties of scopes.
4343 class ScopeTypeField : public BitField<ScopeType, 0, 4> {};
4344 class CallsEvalField : public BitField<bool, 4, 1> {};
4345 STATIC_ASSERT(LANGUAGE_END == 3);
4346 class LanguageModeField : public BitField<LanguageMode, 5, 2> {};
4347 class FunctionVariableField : public BitField<FunctionVariableInfo, 7, 2> {};
4348 class FunctionVariableMode : public BitField<VariableMode, 9, 3> {};
4349 class AsmModuleField : public BitField<bool, 12, 1> {};
4350 class AsmFunctionField : public BitField<bool, 13, 1> {};
4351 class IsSimpleParameterListField
4352 : public BitField<bool, AsmFunctionField::kNext, 1> {};
4354 // BitFields representing the encoded information for context locals in the
4355 // ContextLocalInfoEntries part.
4356 class ContextLocalMode: public BitField<VariableMode, 0, 3> {};
4357 class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {};
4358 class ContextLocalMaybeAssignedFlag
4359 : public BitField<MaybeAssignedFlag, 4, 1> {};
4363 // The cache for maps used by normalized (dictionary mode) objects.
4364 // Such maps do not have property descriptors, so a typical program
4365 // needs very limited number of distinct normalized maps.
4366 class NormalizedMapCache: public FixedArray {
4368 static Handle<NormalizedMapCache> New(Isolate* isolate);
4370 MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
4371 PropertyNormalizationMode mode);
4372 void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
4376 DECLARE_CAST(NormalizedMapCache)
4378 static inline bool IsNormalizedMapCache(const Object* obj);
4380 DECLARE_VERIFIER(NormalizedMapCache)
4382 static const int kEntries = 64;
4384 static inline int GetIndex(Handle<Map> map);
4386 // The following declarations hide base class methods.
4387 Object* get(int index);
4388 void set(int index, Object* value);
4392 // ByteArray represents fixed sized byte arrays. Used for the relocation info
4393 // that is attached to code objects.
4394 class ByteArray: public FixedArrayBase {
4396 inline int Size() { return RoundUp(length() + kHeaderSize, kPointerSize); }
4398 // Setter and getter.
4399 inline byte get(int index);
4400 inline void set(int index, byte value);
4402 // Treat contents as an int array.
4403 inline int get_int(int index);
4405 static int SizeFor(int length) {
4406 return OBJECT_POINTER_ALIGN(kHeaderSize + length);
4408 // We use byte arrays for free blocks in the heap. Given a desired size in
4409 // bytes that is a multiple of the word size and big enough to hold a byte
4410 // array, this function returns the number of elements a byte array should
4412 static int LengthFor(int size_in_bytes) {
4413 DCHECK(IsAligned(size_in_bytes, kPointerSize));
4414 DCHECK(size_in_bytes >= kHeaderSize);
4415 return size_in_bytes - kHeaderSize;
4418 // Returns data start address.
4419 inline Address GetDataStartAddress();
4421 // Returns a pointer to the ByteArray object for a given data start address.
4422 static inline ByteArray* FromDataStartAddress(Address address);
4424 DECLARE_CAST(ByteArray)
4426 // Dispatched behavior.
4427 inline int ByteArraySize() {
4428 return SizeFor(this->length());
4430 DECLARE_PRINTER(ByteArray)
4431 DECLARE_VERIFIER(ByteArray)
4433 // Layout description.
4434 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4436 // Maximal memory consumption for a single ByteArray.
4437 static const int kMaxSize = 512 * MB;
4438 // Maximal length of a single ByteArray.
4439 static const int kMaxLength = kMaxSize - kHeaderSize;
4442 DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
4446 // FreeSpace are fixed-size free memory blocks used by the heap and GC.
4447 // They look like heap objects (are heap object tagged and have a map) so that
4448 // the heap remains iterable. They have a size and a next pointer.
4449 // The next pointer is the raw address of the next FreeSpace object (or NULL)
4450 // in the free list.
4451 class FreeSpace: public HeapObject {
4453 // [size]: size of the free space including the header.
4454 inline int size() const;
4455 inline void set_size(int value);
4457 inline int nobarrier_size() const;
4458 inline void nobarrier_set_size(int value);
4460 inline int Size() { return size(); }
4462 // Accessors for the next field.
4463 inline FreeSpace* next();
4464 inline FreeSpace** next_address();
4465 inline void set_next(FreeSpace* next);
4467 inline static FreeSpace* cast(HeapObject* obj);
4469 // Dispatched behavior.
4470 DECLARE_PRINTER(FreeSpace)
4471 DECLARE_VERIFIER(FreeSpace)
4473 // Layout description.
4474 // Size is smi tagged when it is stored.
4475 static const int kSizeOffset = HeapObject::kHeaderSize;
4476 static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize);
4479 DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
4483 // V has parameters (Type, type, TYPE, C type, element_size)
4484 #define TYPED_ARRAYS(V) \
4485 V(Uint8, uint8, UINT8, uint8_t, 1) \
4486 V(Int8, int8, INT8, int8_t, 1) \
4487 V(Uint16, uint16, UINT16, uint16_t, 2) \
4488 V(Int16, int16, INT16, int16_t, 2) \
4489 V(Uint32, uint32, UINT32, uint32_t, 4) \
4490 V(Int32, int32, INT32, int32_t, 4) \
4491 V(Float32, float32, FLOAT32, float, 4) \
4492 V(Float64, float64, FLOAT64, double, 8) \
4493 V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1)
4497 // An ExternalArray represents a fixed-size array of primitive values
4498 // which live outside the JavaScript heap. Its subclasses are used to
4499 // implement the CanvasArray types being defined in the WebGL
4500 // specification. As of this writing the first public draft is not yet
4501 // available, but Khronos members can access the draft at:
4502 // https://cvs.khronos.org/svn/repos/3dweb/trunk/doc/spec/WebGL-spec.html
4504 // The semantics of these arrays differ from CanvasPixelArray.
4505 // Out-of-range values passed to the setter are converted via a C
4506 // cast, not clamping. Out-of-range indices cause exceptions to be
4507 // raised rather than being silently ignored.
4508 class ExternalArray: public FixedArrayBase {
4510 inline bool is_the_hole(int index) { return false; }
4512 // [external_pointer]: The pointer to the external memory area backing this
4514 DECL_ACCESSORS(external_pointer, void) // Pointer to the data store.
4516 DECLARE_CAST(ExternalArray)
4518 // Maximal acceptable length for an external array.
4519 static const int kMaxLength = 0x3fffffff;
4521 // ExternalArray headers are not quadword aligned.
4522 static const int kExternalPointerOffset =
4523 POINTER_SIZE_ALIGN(FixedArrayBase::kLengthOffset + kPointerSize);
4524 static const int kHeaderSize = kExternalPointerOffset + kPointerSize;
4525 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4528 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalArray);
4532 // A ExternalUint8ClampedArray represents a fixed-size byte array with special
4533 // semantics used for implementing the CanvasPixelArray object. Please see the
4534 // specification at:
4536 // http://www.whatwg.org/specs/web-apps/current-work/
4537 // multipage/the-canvas-element.html#canvaspixelarray
4538 // In particular, write access clamps the value written to 0 or 255 if the
4539 // value written is outside this range.
4540 class ExternalUint8ClampedArray: public ExternalArray {
4542 inline uint8_t* external_uint8_clamped_pointer();
4544 // Setter and getter.
4545 inline uint8_t get_scalar(int index);
4546 static inline Handle<Object> get(Handle<ExternalUint8ClampedArray> array,
4548 inline void set(int index, uint8_t value);
4550 // This accessor applies the correct conversion from Smi, HeapNumber
4551 // and undefined and clamps the converted value between 0 and 255.
4552 static Handle<Object> SetValue(Handle<ExternalUint8ClampedArray> array,
4554 Handle<Object> value);
4556 DECLARE_CAST(ExternalUint8ClampedArray)
4558 // Dispatched behavior.
4559 DECLARE_PRINTER(ExternalUint8ClampedArray)
4560 DECLARE_VERIFIER(ExternalUint8ClampedArray)
4563 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint8ClampedArray);
4567 class ExternalInt8Array: public ExternalArray {
4569 // Setter and getter.
4570 inline int8_t get_scalar(int index);
4571 static inline Handle<Object> get(Handle<ExternalInt8Array> array, int index);
4572 inline void set(int index, int8_t value);
4574 // This accessor applies the correct conversion from Smi, HeapNumber
4576 static Handle<Object> SetValue(Handle<ExternalInt8Array> array,
4578 Handle<Object> value);
4580 DECLARE_CAST(ExternalInt8Array)
4582 // Dispatched behavior.
4583 DECLARE_PRINTER(ExternalInt8Array)
4584 DECLARE_VERIFIER(ExternalInt8Array)
4587 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt8Array);
4591 class ExternalUint8Array: public ExternalArray {
4593 // Setter and getter.
4594 inline uint8_t get_scalar(int index);
4595 static inline Handle<Object> get(Handle<ExternalUint8Array> array, int index);
4596 inline void set(int index, uint8_t value);
4598 // This accessor applies the correct conversion from Smi, HeapNumber
4600 static Handle<Object> SetValue(Handle<ExternalUint8Array> array,
4602 Handle<Object> value);
4604 DECLARE_CAST(ExternalUint8Array)
4606 // Dispatched behavior.
4607 DECLARE_PRINTER(ExternalUint8Array)
4608 DECLARE_VERIFIER(ExternalUint8Array)
4611 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint8Array);
4615 class ExternalInt16Array: public ExternalArray {
4617 // Setter and getter.
4618 inline int16_t get_scalar(int index);
4619 static inline Handle<Object> get(Handle<ExternalInt16Array> array, int index);
4620 inline void set(int index, int16_t value);
4622 // This accessor applies the correct conversion from Smi, HeapNumber
4624 static Handle<Object> SetValue(Handle<ExternalInt16Array> array,
4626 Handle<Object> value);
4628 DECLARE_CAST(ExternalInt16Array)
4630 // Dispatched behavior.
4631 DECLARE_PRINTER(ExternalInt16Array)
4632 DECLARE_VERIFIER(ExternalInt16Array)
4635 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt16Array);
4639 class ExternalUint16Array: public ExternalArray {
4641 // Setter and getter.
4642 inline uint16_t get_scalar(int index);
4643 static inline Handle<Object> get(Handle<ExternalUint16Array> array,
4645 inline void set(int index, uint16_t value);
4647 // This accessor applies the correct conversion from Smi, HeapNumber
4649 static Handle<Object> SetValue(Handle<ExternalUint16Array> array,
4651 Handle<Object> value);
4653 DECLARE_CAST(ExternalUint16Array)
4655 // Dispatched behavior.
4656 DECLARE_PRINTER(ExternalUint16Array)
4657 DECLARE_VERIFIER(ExternalUint16Array)
4660 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint16Array);
4664 class ExternalInt32Array: public ExternalArray {
4666 // Setter and getter.
4667 inline int32_t get_scalar(int index);
4668 static inline Handle<Object> get(Handle<ExternalInt32Array> array, int index);
4669 inline void set(int index, int32_t value);
4671 // This accessor applies the correct conversion from Smi, HeapNumber
4673 static Handle<Object> SetValue(Handle<ExternalInt32Array> array,
4675 Handle<Object> value);
4677 DECLARE_CAST(ExternalInt32Array)
4679 // Dispatched behavior.
4680 DECLARE_PRINTER(ExternalInt32Array)
4681 DECLARE_VERIFIER(ExternalInt32Array)
4684 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt32Array);
4688 class ExternalUint32Array: public ExternalArray {
4690 // Setter and getter.
4691 inline uint32_t get_scalar(int index);
4692 static inline Handle<Object> get(Handle<ExternalUint32Array> array,
4694 inline void set(int index, uint32_t value);
4696 // This accessor applies the correct conversion from Smi, HeapNumber
4698 static Handle<Object> SetValue(Handle<ExternalUint32Array> array,
4700 Handle<Object> value);
4702 DECLARE_CAST(ExternalUint32Array)
4704 // Dispatched behavior.
4705 DECLARE_PRINTER(ExternalUint32Array)
4706 DECLARE_VERIFIER(ExternalUint32Array)
4709 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint32Array);
4713 class ExternalFloat32Array: public ExternalArray {
4715 // Setter and getter.
4716 inline float get_scalar(int index);
4717 static inline Handle<Object> get(Handle<ExternalFloat32Array> array,
4719 inline void set(int index, float value);
4721 // This accessor applies the correct conversion from Smi, HeapNumber
4723 static Handle<Object> SetValue(Handle<ExternalFloat32Array> array,
4725 Handle<Object> value);
4727 DECLARE_CAST(ExternalFloat32Array)
4729 // Dispatched behavior.
4730 DECLARE_PRINTER(ExternalFloat32Array)
4731 DECLARE_VERIFIER(ExternalFloat32Array)
4734 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloat32Array);
4738 class ExternalFloat64Array: public ExternalArray {
4740 // Setter and getter.
4741 inline double get_scalar(int index);
4742 static inline Handle<Object> get(Handle<ExternalFloat64Array> array,
4744 inline void set(int index, double value);
4746 // This accessor applies the correct conversion from Smi, HeapNumber
4748 static Handle<Object> SetValue(Handle<ExternalFloat64Array> array,
4750 Handle<Object> value);
4752 DECLARE_CAST(ExternalFloat64Array)
4754 // Dispatched behavior.
4755 DECLARE_PRINTER(ExternalFloat64Array)
4756 DECLARE_VERIFIER(ExternalFloat64Array)
4759 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloat64Array);
4763 class FixedTypedArrayBase: public FixedArrayBase {
4765 DECLARE_CAST(FixedTypedArrayBase)
4767 static const int kDataOffset = kHeaderSize;
4771 inline int TypedArraySize(InstanceType type);
4773 // Use with care: returns raw pointer into heap.
4774 inline void* DataPtr();
4776 inline int DataSize();
4779 inline int DataSize(InstanceType type);
4781 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase);
4785 template <class Traits>
4786 class FixedTypedArray: public FixedTypedArrayBase {
4788 typedef typename Traits::ElementType ElementType;
4789 static const InstanceType kInstanceType = Traits::kInstanceType;
4791 DECLARE_CAST(FixedTypedArray<Traits>)
4793 static inline int ElementOffset(int index) {
4794 return kDataOffset + index * sizeof(ElementType);
4797 static inline int SizeFor(int length) {
4798 return ElementOffset(length);
4801 inline ElementType get_scalar(int index);
4802 static inline Handle<Object> get(Handle<FixedTypedArray> array, int index);
4803 inline void set(int index, ElementType value);
4805 static inline ElementType from_int(int value);
4806 static inline ElementType from_double(double value);
4808 // This accessor applies the correct conversion from Smi, HeapNumber
4810 static Handle<Object> SetValue(Handle<FixedTypedArray<Traits> > array,
4812 Handle<Object> value);
4814 DECLARE_PRINTER(FixedTypedArray)
4815 DECLARE_VERIFIER(FixedTypedArray)
4818 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray);
4821 #define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType, size) \
4822 class Type##ArrayTraits { \
4823 public: /* NOLINT */ \
4824 typedef elementType ElementType; \
4825 static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE; \
4826 static const char* Designator() { return #type " array"; } \
4827 static inline Handle<Object> ToHandle(Isolate* isolate, \
4828 elementType scalar); \
4829 static inline elementType defaultValue(); \
4832 typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array;
4834 TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS)
4836 #undef FIXED_TYPED_ARRAY_TRAITS
4839 // DeoptimizationInputData is a fixed array used to hold the deoptimization
4840 // data for code generated by the Hydrogen/Lithium compiler. It also
4841 // contains information about functions that were inlined. If N different
4842 // functions were inlined then first N elements of the literal array will
4843 // contain these functions.
4846 class DeoptimizationInputData: public FixedArray {
4848 // Layout description. Indices in the array.
4849 static const int kTranslationByteArrayIndex = 0;
4850 static const int kInlinedFunctionCountIndex = 1;
4851 static const int kLiteralArrayIndex = 2;
4852 static const int kOsrAstIdIndex = 3;
4853 static const int kOsrPcOffsetIndex = 4;
4854 static const int kOptimizationIdIndex = 5;
4855 static const int kSharedFunctionInfoIndex = 6;
4856 static const int kWeakCellCacheIndex = 7;
4857 static const int kFirstDeoptEntryIndex = 8;
4859 // Offsets of deopt entry elements relative to the start of the entry.
4860 static const int kAstIdRawOffset = 0;
4861 static const int kTranslationIndexOffset = 1;
4862 static const int kArgumentsStackHeightOffset = 2;
4863 static const int kPcOffset = 3;
4864 static const int kDeoptEntrySize = 4;
4866 // Simple element accessors.
4867 #define DEFINE_ELEMENT_ACCESSORS(name, type) \
4869 return type::cast(get(k##name##Index)); \
4871 void Set##name(type* value) { \
4872 set(k##name##Index, value); \
4875 DEFINE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray)
4876 DEFINE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi)
4877 DEFINE_ELEMENT_ACCESSORS(LiteralArray, FixedArray)
4878 DEFINE_ELEMENT_ACCESSORS(OsrAstId, Smi)
4879 DEFINE_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
4880 DEFINE_ELEMENT_ACCESSORS(OptimizationId, Smi)
4881 DEFINE_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
4882 DEFINE_ELEMENT_ACCESSORS(WeakCellCache, Object)
4884 #undef DEFINE_ELEMENT_ACCESSORS
4886 // Accessors for elements of the ith deoptimization entry.
4887 #define DEFINE_ENTRY_ACCESSORS(name, type) \
4888 type* name(int i) { \
4889 return type::cast(get(IndexForEntry(i) + k##name##Offset)); \
4891 void Set##name(int i, type* value) { \
4892 set(IndexForEntry(i) + k##name##Offset, value); \
4895 DEFINE_ENTRY_ACCESSORS(AstIdRaw, Smi)
4896 DEFINE_ENTRY_ACCESSORS(TranslationIndex, Smi)
4897 DEFINE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi)
4898 DEFINE_ENTRY_ACCESSORS(Pc, Smi)
4900 #undef DEFINE_DEOPT_ENTRY_ACCESSORS
4902 BailoutId AstId(int i) {
4903 return BailoutId(AstIdRaw(i)->value());
4906 void SetAstId(int i, BailoutId value) {
4907 SetAstIdRaw(i, Smi::FromInt(value.ToInt()));
4911 return (length() - kFirstDeoptEntryIndex) / kDeoptEntrySize;
4914 // Allocates a DeoptimizationInputData.
4915 static Handle<DeoptimizationInputData> New(Isolate* isolate,
4916 int deopt_entry_count,
4917 PretenureFlag pretenure);
4919 DECLARE_CAST(DeoptimizationInputData)
4921 #ifdef ENABLE_DISASSEMBLER
4922 void DeoptimizationInputDataPrint(std::ostream& os); // NOLINT
4926 static int IndexForEntry(int i) {
4927 return kFirstDeoptEntryIndex + (i * kDeoptEntrySize);
4931 static int LengthFor(int entry_count) { return IndexForEntry(entry_count); }
4935 // DeoptimizationOutputData is a fixed array used to hold the deoptimization
4936 // data for code generated by the full compiler.
4937 // The format of the these objects is
4938 // [i * 2]: Ast ID for ith deoptimization.
4939 // [i * 2 + 1]: PC and state of ith deoptimization
4940 class DeoptimizationOutputData: public FixedArray {
4942 int DeoptPoints() { return length() / 2; }
4944 BailoutId AstId(int index) {
4945 return BailoutId(Smi::cast(get(index * 2))->value());
4948 void SetAstId(int index, BailoutId id) {
4949 set(index * 2, Smi::FromInt(id.ToInt()));
4952 Smi* PcAndState(int index) { return Smi::cast(get(1 + index * 2)); }
4953 void SetPcAndState(int index, Smi* offset) { set(1 + index * 2, offset); }
4955 static int LengthOfFixedArray(int deopt_points) {
4956 return deopt_points * 2;
4959 // Allocates a DeoptimizationOutputData.
4960 static Handle<DeoptimizationOutputData> New(Isolate* isolate,
4961 int number_of_deopt_points,
4962 PretenureFlag pretenure);
4964 DECLARE_CAST(DeoptimizationOutputData)
4966 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
4967 void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT
4972 // Forward declaration.
4975 class SafepointEntry;
4976 class TypeFeedbackInfo;
4978 // Code describes objects with on-the-fly generated machine code.
4979 class Code: public HeapObject {
4981 // Opaque data type for encapsulating code flags like kind, inline
4982 // cache state, and arguments count.
4983 typedef uint32_t Flags;
4985 #define NON_IC_KIND_LIST(V) \
4987 V(OPTIMIZED_FUNCTION) \
4993 #define IC_KIND_LIST(V) \
5004 #define CODE_KIND_LIST(V) \
5005 NON_IC_KIND_LIST(V) \
5009 #define DEFINE_CODE_KIND_ENUM(name) name,
5010 CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM)
5011 #undef DEFINE_CODE_KIND_ENUM
5015 // No more than 16 kinds. The value is currently encoded in four bits in
5017 STATIC_ASSERT(NUMBER_OF_KINDS <= 16);
5019 static const char* Kind2String(Kind kind);
5027 static const int kPrologueOffsetNotSet = -1;
5029 #ifdef ENABLE_DISASSEMBLER
5031 static const char* ICState2String(InlineCacheState state);
5032 static const char* StubType2String(StubType type);
5033 static void PrintExtraICState(std::ostream& os, // NOLINT
5034 Kind kind, ExtraICState extra);
5035 void Disassemble(const char* name, std::ostream& os); // NOLINT
5036 #endif // ENABLE_DISASSEMBLER
5038 // [instruction_size]: Size of the native instructions
5039 inline int instruction_size() const;
5040 inline void set_instruction_size(int value);
5042 // [relocation_info]: Code relocation information
5043 DECL_ACCESSORS(relocation_info, ByteArray)
5044 void InvalidateRelocation();
5045 void InvalidateEmbeddedObjects();
5047 // [handler_table]: Fixed array containing offsets of exception handlers.
5048 DECL_ACCESSORS(handler_table, FixedArray)
5050 // [deoptimization_data]: Array containing data for deopt.
5051 DECL_ACCESSORS(deoptimization_data, FixedArray)
5053 // [raw_type_feedback_info]: This field stores various things, depending on
5054 // the kind of the code object.
5055 // FUNCTION => type feedback information.
5056 // STUB and ICs => major/minor key as Smi.
5057 DECL_ACCESSORS(raw_type_feedback_info, Object)
5058 inline Object* type_feedback_info();
5059 inline void set_type_feedback_info(
5060 Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5061 inline uint32_t stub_key();
5062 inline void set_stub_key(uint32_t key);
5064 // [next_code_link]: Link for lists of optimized or deoptimized code.
5065 // Note that storage for this field is overlapped with typefeedback_info.
5066 DECL_ACCESSORS(next_code_link, Object)
5068 // [gc_metadata]: Field used to hold GC related metadata. The contents of this
5069 // field does not have to be traced during garbage collection since
5070 // it is only used by the garbage collector itself.
5071 DECL_ACCESSORS(gc_metadata, Object)
5073 // [ic_age]: Inline caching age: the value of the Heap::global_ic_age
5074 // at the moment when this object was created.
5075 inline void set_ic_age(int count);
5076 inline int ic_age() const;
5078 // [prologue_offset]: Offset of the function prologue, used for aging
5079 // FUNCTIONs and OPTIMIZED_FUNCTIONs.
5080 inline int prologue_offset() const;
5081 inline void set_prologue_offset(int offset);
5083 // Unchecked accessors to be used during GC.
5084 inline ByteArray* unchecked_relocation_info();
5086 inline int relocation_size();
5088 // [flags]: Various code flags.
5089 inline Flags flags();
5090 inline void set_flags(Flags flags);
5092 // [flags]: Access to specific code flags.
5094 inline InlineCacheState ic_state(); // Only valid for IC stubs.
5095 inline ExtraICState extra_ic_state(); // Only valid for IC stubs.
5097 inline StubType type(); // Only valid for monomorphic IC stubs.
5099 // Testers for IC stub kinds.
5100 inline bool is_inline_cache_stub();
5101 inline bool is_debug_stub();
5102 inline bool is_handler() { return kind() == HANDLER; }
5103 inline bool is_load_stub() { return kind() == LOAD_IC; }
5104 inline bool is_keyed_load_stub() { return kind() == KEYED_LOAD_IC; }
5105 inline bool is_store_stub() { return kind() == STORE_IC; }
5106 inline bool is_keyed_store_stub() { return kind() == KEYED_STORE_IC; }
5107 inline bool is_call_stub() { return kind() == CALL_IC; }
5108 inline bool is_binary_op_stub() { return kind() == BINARY_OP_IC; }
5109 inline bool is_compare_ic_stub() { return kind() == COMPARE_IC; }
5110 inline bool is_compare_nil_ic_stub() { return kind() == COMPARE_NIL_IC; }
5111 inline bool is_to_boolean_ic_stub() { return kind() == TO_BOOLEAN_IC; }
5112 inline bool is_keyed_stub();
5113 inline bool is_optimized_code() { return kind() == OPTIMIZED_FUNCTION; }
5114 inline bool embeds_maps_weakly() {
5116 return (k == LOAD_IC || k == STORE_IC || k == KEYED_LOAD_IC ||
5117 k == KEYED_STORE_IC || k == COMPARE_NIL_IC) &&
5118 ic_state() == MONOMORPHIC;
5121 inline bool IsCodeStubOrIC();
5123 inline void set_raw_kind_specific_flags1(int value);
5124 inline void set_raw_kind_specific_flags2(int value);
5126 // [is_crankshafted]: For kind STUB or ICs, tells whether or not a code
5127 // object was generated by either the hydrogen or the TurboFan optimizing
5128 // compiler (but it may not be an optimized function).
5129 inline bool is_crankshafted();
5130 inline bool is_hydrogen_stub(); // Crankshafted, but not a function.
5131 inline void set_is_crankshafted(bool value);
5133 // [is_turbofanned]: For kind STUB or OPTIMIZED_FUNCTION, tells whether the
5134 // code object was generated by the TurboFan optimizing compiler.
5135 inline bool is_turbofanned();
5136 inline void set_is_turbofanned(bool value);
5138 // [can_have_weak_objects]: For kind OPTIMIZED_FUNCTION, tells whether the
5139 // embedded objects in code should be treated weakly.
5140 inline bool can_have_weak_objects();
5141 inline void set_can_have_weak_objects(bool value);
5143 // [optimizable]: For FUNCTION kind, tells if it is optimizable.
5144 inline bool optimizable();
5145 inline void set_optimizable(bool value);
5147 // [has_deoptimization_support]: For FUNCTION kind, tells if it has
5148 // deoptimization support.
5149 inline bool has_deoptimization_support();
5150 inline void set_has_deoptimization_support(bool value);
5152 // [has_debug_break_slots]: For FUNCTION kind, tells if it has
5153 // been compiled with debug break slots.
5154 inline bool has_debug_break_slots();
5155 inline void set_has_debug_break_slots(bool value);
5157 // [compiled_with_optimizing]: For FUNCTION kind, tells if it has
5158 // been compiled with IsOptimizing set to true.
5159 inline bool is_compiled_optimizable();
5160 inline void set_compiled_optimizable(bool value);
5162 // [has_reloc_info_for_serialization]: For FUNCTION kind, tells if its
5163 // reloc info includes runtime and external references to support
5164 // serialization/deserialization.
5165 inline bool has_reloc_info_for_serialization();
5166 inline void set_has_reloc_info_for_serialization(bool value);
5168 // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for
5169 // how long the function has been marked for OSR and therefore which
5170 // level of loop nesting we are willing to do on-stack replacement
5172 inline void set_allow_osr_at_loop_nesting_level(int level);
5173 inline int allow_osr_at_loop_nesting_level();
5175 // [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks
5176 // the code object was seen on the stack with no IC patching going on.
5177 inline int profiler_ticks();
5178 inline void set_profiler_ticks(int ticks);
5180 // [builtin_index]: For BUILTIN kind, tells which builtin index it has.
5181 // For builtins, tells which builtin index it has.
5182 // Note that builtins can have a code kind other than BUILTIN, which means
5183 // that for arbitrary code objects, this index value may be random garbage.
5184 // To verify in that case, compare the code object to the indexed builtin.
5185 inline int builtin_index();
5186 inline void set_builtin_index(int id);
5188 // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots
5189 // reserved in the code prologue.
5190 inline unsigned stack_slots();
5191 inline void set_stack_slots(unsigned slots);
5193 // [safepoint_table_start]: For kind OPTIMIZED_FUNCTION, the offset in
5194 // the instruction stream where the safepoint table starts.
5195 inline unsigned safepoint_table_offset();
5196 inline void set_safepoint_table_offset(unsigned offset);
5198 // [back_edge_table_start]: For kind FUNCTION, the offset in the
5199 // instruction stream where the back edge table starts.
5200 inline unsigned back_edge_table_offset();
5201 inline void set_back_edge_table_offset(unsigned offset);
5203 inline bool back_edges_patched_for_osr();
5205 // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in.
5206 inline byte to_boolean_state();
5208 // [has_function_cache]: For kind STUB tells whether there is a function
5209 // cache is passed to the stub.
5210 inline bool has_function_cache();
5211 inline void set_has_function_cache(bool flag);
5214 // [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether
5215 // the code is going to be deoptimized because of dead embedded maps.
5216 inline bool marked_for_deoptimization();
5217 inline void set_marked_for_deoptimization(bool flag);
5219 // [constant_pool]: The constant pool for this function.
5220 inline ConstantPoolArray* constant_pool();
5221 inline void set_constant_pool(Object* constant_pool);
5223 // Get the safepoint entry for the given pc.
5224 SafepointEntry GetSafepointEntry(Address pc);
5226 // Find an object in a stub with a specified map
5227 Object* FindNthObject(int n, Map* match_map);
5229 // Find the first allocation site in an IC stub.
5230 AllocationSite* FindFirstAllocationSite();
5232 // Find the first map in an IC stub.
5233 Map* FindFirstMap();
5234 void FindAllMaps(MapHandleList* maps);
5236 // Find the first handler in an IC stub.
5237 Code* FindFirstHandler();
5239 // Find |length| handlers and put them into |code_list|. Returns false if not
5240 // enough handlers can be found.
5241 bool FindHandlers(CodeHandleList* code_list, int length = -1);
5243 // Find the handler for |map|.
5244 MaybeHandle<Code> FindHandlerForMap(Map* map);
5246 // Find the first name in an IC stub.
5247 Name* FindFirstName();
5249 class FindAndReplacePattern;
5250 // For each (map-to-find, object-to-replace) pair in the pattern, this
5251 // function replaces the corresponding placeholder in the code with the
5252 // object-to-replace. The function assumes that pairs in the pattern come in
5253 // the same order as the placeholders in the code.
5254 // If the placeholder is a weak cell, then the value of weak cell is matched
5255 // against the map-to-find.
5256 void FindAndReplace(const FindAndReplacePattern& pattern);
5258 // The entire code object including its header is copied verbatim to the
5259 // snapshot so that it can be written in one, fast, memcpy during
5260 // deserialization. The deserializer will overwrite some pointers, rather
5261 // like a runtime linker, but the random allocation addresses used in the
5262 // mksnapshot process would still be present in the unlinked snapshot data,
5263 // which would make snapshot production non-reproducible. This method wipes
5264 // out the to-be-overwritten header data for reproducible snapshots.
5265 inline void WipeOutHeader();
5267 // Flags operations.
5268 static inline Flags ComputeFlags(
5269 Kind kind, InlineCacheState ic_state = UNINITIALIZED,
5270 ExtraICState extra_ic_state = kNoExtraICState, StubType type = NORMAL,
5271 CacheHolderFlag holder = kCacheOnReceiver);
5273 static inline Flags ComputeMonomorphicFlags(
5274 Kind kind, ExtraICState extra_ic_state = kNoExtraICState,
5275 CacheHolderFlag holder = kCacheOnReceiver, StubType type = NORMAL);
5277 static inline Flags ComputeHandlerFlags(
5278 Kind handler_kind, StubType type = NORMAL,
5279 CacheHolderFlag holder = kCacheOnReceiver);
5281 static inline InlineCacheState ExtractICStateFromFlags(Flags flags);
5282 static inline StubType ExtractTypeFromFlags(Flags flags);
5283 static inline CacheHolderFlag ExtractCacheHolderFromFlags(Flags flags);
5284 static inline Kind ExtractKindFromFlags(Flags flags);
5285 static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags);
5287 static inline Flags RemoveTypeFromFlags(Flags flags);
5288 static inline Flags RemoveTypeAndHolderFromFlags(Flags flags);
5290 // Convert a target address into a code object.
5291 static inline Code* GetCodeFromTargetAddress(Address address);
5293 // Convert an entry address into an object.
5294 static inline Object* GetObjectFromEntryAddress(Address location_of_address);
5296 // Returns the address of the first instruction.
5297 inline byte* instruction_start();
5299 // Returns the address right after the last instruction.
5300 inline byte* instruction_end();
5302 // Returns the size of the instructions, padding, and relocation information.
5303 inline int body_size();
5305 // Returns the address of the first relocation info (read backwards!).
5306 inline byte* relocation_start();
5308 // Code entry point.
5309 inline byte* entry();
5311 // Returns true if pc is inside this object's instructions.
5312 inline bool contains(byte* pc);
5314 // Relocate the code by delta bytes. Called to signal that this code
5315 // object has been moved by delta bytes.
5316 void Relocate(intptr_t delta);
5318 // Migrate code described by desc.
5319 void CopyFrom(const CodeDesc& desc);
5321 // Returns the object size for a given body (used for allocation).
5322 static int SizeFor(int body_size) {
5323 DCHECK_SIZE_TAG_ALIGNED(body_size);
5324 return RoundUp(kHeaderSize + body_size, kCodeAlignment);
5327 // Calculate the size of the code object to report for log events. This takes
5328 // the layout of the code object into account.
5329 int ExecutableSize() {
5330 // Check that the assumptions about the layout of the code object holds.
5331 DCHECK_EQ(static_cast<int>(instruction_start() - address()),
5333 return instruction_size() + Code::kHeaderSize;
5336 // Locating source position.
5337 int SourcePosition(Address pc);
5338 int SourceStatementPosition(Address pc);
5342 // Dispatched behavior.
5343 int CodeSize() { return SizeFor(body_size()); }
5344 inline void CodeIterateBody(ObjectVisitor* v);
5346 template<typename StaticVisitor>
5347 inline void CodeIterateBody(Heap* heap);
5349 DECLARE_PRINTER(Code)
5350 DECLARE_VERIFIER(Code)
5352 void ClearInlineCaches();
5353 void ClearInlineCaches(Kind kind);
5355 BailoutId TranslatePcOffsetToAstId(uint32_t pc_offset);
5356 uint32_t TranslateAstIdToPcOffset(BailoutId ast_id);
5358 #define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
5360 kNotExecutedCodeAge = -2,
5361 kExecutedOnceCodeAge = -1,
5363 CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
5365 kFirstCodeAge = kNotExecutedCodeAge,
5366 kLastCodeAge = kAfterLastCodeAge - 1,
5367 kCodeAgeCount = kAfterLastCodeAge - kNotExecutedCodeAge - 1,
5368 kIsOldCodeAge = kSexagenarianCodeAge,
5369 kPreAgedCodeAge = kIsOldCodeAge - 1
5371 #undef DECLARE_CODE_AGE_ENUM
5373 // Code aging. Indicates how many full GCs this code has survived without
5374 // being entered through the prologue. Used to determine when it is
5375 // relatively safe to flush this code object and replace it with the lazy
5376 // compilation stub.
5377 static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate);
5378 static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate);
5379 void MakeYoung(Isolate* isolate);
5380 void MakeOlder(MarkingParity);
5381 static bool IsYoungSequence(Isolate* isolate, byte* sequence);
5384 // Gets the raw code age, including psuedo code-age values such as
5385 // kNotExecutedCodeAge and kExecutedOnceCodeAge.
5387 static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) {
5388 return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY);
5391 void PrintDeoptLocation(FILE* out, int bailout_id);
5392 bool CanDeoptAt(Address pc);
5395 void VerifyEmbeddedObjectsDependency();
5399 enum VerifyMode { kNoContextSpecificPointers, kNoContextRetainingPointers };
5400 void VerifyEmbeddedObjects(VerifyMode mode = kNoContextRetainingPointers);
5403 inline bool CanContainWeakObjects() {
5404 // is_turbofanned() implies !can_have_weak_objects().
5405 DCHECK(!is_optimized_code() || !is_turbofanned() ||
5406 !can_have_weak_objects());
5407 return is_optimized_code() && can_have_weak_objects();
5410 inline bool IsWeakObject(Object* object) {
5411 return (CanContainWeakObjects() && IsWeakObjectInOptimizedCode(object));
5414 static inline bool IsWeakObjectInOptimizedCode(Object* object);
5416 static Handle<WeakCell> WeakCellFor(Handle<Code> code);
5417 WeakCell* CachedWeakCell();
5419 // Max loop nesting marker used to postpose OSR. We don't take loop
5420 // nesting that is deeper than 5 levels into account.
5421 static const int kMaxLoopNestingMarker = 6;
5423 // Layout description.
5424 static const int kRelocationInfoOffset = HeapObject::kHeaderSize;
5425 static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
5426 static const int kDeoptimizationDataOffset =
5427 kHandlerTableOffset + kPointerSize;
5428 // For FUNCTION kind, we store the type feedback info here.
5429 static const int kTypeFeedbackInfoOffset =
5430 kDeoptimizationDataOffset + kPointerSize;
5431 static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
5432 static const int kGCMetadataOffset = kNextCodeLinkOffset + kPointerSize;
5433 static const int kInstructionSizeOffset = kGCMetadataOffset + kPointerSize;
5434 static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
5435 static const int kFlagsOffset = kICAgeOffset + kIntSize;
5436 static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
5437 static const int kKindSpecificFlags2Offset =
5438 kKindSpecificFlags1Offset + kIntSize;
5439 // Note: We might be able to squeeze this into the flags above.
5440 static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
5441 static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
5443 static const int kHeaderPaddingStart = kConstantPoolOffset + kPointerSize;
5445 // Add padding to align the instruction start following right after
5446 // the Code object header.
5447 static const int kHeaderSize =
5448 (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
5449 // Ensure that the slot for the constant pool pointer is aligned.
5450 STATIC_ASSERT((kConstantPoolOffset & kPointerAlignmentMask) == 0);
5452 // Byte offsets within kKindSpecificFlags1Offset.
5453 static const int kOptimizableOffset = kKindSpecificFlags1Offset;
5455 static const int kFullCodeFlags = kOptimizableOffset + 1;
5456 class FullCodeFlagsHasDeoptimizationSupportField:
5457 public BitField<bool, 0, 1> {}; // NOLINT
5458 class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {};
5459 class FullCodeFlagsIsCompiledOptimizable: public BitField<bool, 2, 1> {};
5460 class FullCodeFlagsHasRelocInfoForSerialization
5461 : public BitField<bool, 3, 1> {};
5463 static const int kProfilerTicksOffset = kFullCodeFlags + 1;
5465 // Flags layout. BitField<type, shift, size>.
5466 class ICStateField : public BitField<InlineCacheState, 0, 4> {};
5467 class TypeField : public BitField<StubType, 4, 1> {};
5468 class CacheHolderField : public BitField<CacheHolderFlag, 5, 2> {};
5469 class KindField : public BitField<Kind, 7, 4> {};
5470 class ExtraICStateField: public BitField<ExtraICState, 11,
5471 PlatformSmiTagging::kSmiValueSize - 11 + 1> {}; // NOLINT
5473 // KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
5474 static const int kStackSlotsFirstBit = 0;
5475 static const int kStackSlotsBitCount = 24;
5476 static const int kHasFunctionCacheBit =
5477 kStackSlotsFirstBit + kStackSlotsBitCount;
5478 static const int kMarkedForDeoptimizationBit = kHasFunctionCacheBit + 1;
5479 static const int kIsTurbofannedBit = kMarkedForDeoptimizationBit + 1;
5480 static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1;
5482 STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32);
5483 STATIC_ASSERT(kCanHaveWeakObjects + 1 <= 32);
5485 class StackSlotsField: public BitField<int,
5486 kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT
5487 class HasFunctionCacheField : public BitField<bool, kHasFunctionCacheBit, 1> {
5489 class MarkedForDeoptimizationField
5490 : public BitField<bool, kMarkedForDeoptimizationBit, 1> {}; // NOLINT
5491 class IsTurbofannedField : public BitField<bool, kIsTurbofannedBit, 1> {
5493 class CanHaveWeakObjectsField
5494 : public BitField<bool, kCanHaveWeakObjects, 1> {}; // NOLINT
5496 // KindSpecificFlags2 layout (ALL)
5497 static const int kIsCrankshaftedBit = 0;
5498 class IsCrankshaftedField: public BitField<bool,
5499 kIsCrankshaftedBit, 1> {}; // NOLINT
5501 // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
5502 static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1;
5503 static const int kSafepointTableOffsetBitCount = 24;
5505 STATIC_ASSERT(kSafepointTableOffsetFirstBit +
5506 kSafepointTableOffsetBitCount <= 32);
5507 STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32);
5509 class SafepointTableOffsetField: public BitField<int,
5510 kSafepointTableOffsetFirstBit,
5511 kSafepointTableOffsetBitCount> {}; // NOLINT
5513 // KindSpecificFlags2 layout (FUNCTION)
5514 class BackEdgeTableOffsetField: public BitField<int,
5515 kIsCrankshaftedBit + 1, 27> {}; // NOLINT
5516 class AllowOSRAtLoopNestingLevelField: public BitField<int,
5517 kIsCrankshaftedBit + 1 + 27, 4> {}; // NOLINT
5518 STATIC_ASSERT(AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker);
5520 static const int kArgumentsBits = 16;
5521 static const int kMaxArguments = (1 << kArgumentsBits) - 1;
5523 // This constant should be encodable in an ARM instruction.
5524 static const int kFlagsNotUsedInLookup =
5525 TypeField::kMask | CacheHolderField::kMask;
5528 friend class RelocIterator;
5529 friend class Deoptimizer; // For FindCodeAgeSequence.
5531 void ClearInlineCaches(Kind* kind);
5534 byte* FindCodeAgeSequence();
5535 static void GetCodeAgeAndParity(Code* code, Age* age,
5536 MarkingParity* parity);
5537 static void GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
5538 MarkingParity* parity);
5539 static Code* GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity);
5541 // Code aging -- platform-specific
5542 static void PatchPlatformCodeAge(Isolate* isolate,
5543 byte* sequence, Age age,
5544 MarkingParity parity);
5546 DISALLOW_IMPLICIT_CONSTRUCTORS(Code);
5550 class CompilationInfo;
5552 // This class describes the layout of dependent codes array of a map. The
5553 // array is partitioned into several groups of dependent codes. Each group
5554 // contains codes with the same dependency on the map. The array has the
5555 // following layout for n dependency groups:
5557 // +----+----+-----+----+---------+----------+-----+---------+-----------+
5558 // | C1 | C2 | ... | Cn | group 1 | group 2 | ... | group n | undefined |
5559 // +----+----+-----+----+---------+----------+-----+---------+-----------+
5561 // The first n elements are Smis, each of them specifies the number of codes
5562 // in the corresponding group. The subsequent elements contain grouped code
5563 // objects in weak cells. The suffix of the array can be filled with the
5564 // undefined value if the number of codes is less than the length of the
5565 // array. The order of the code objects within a group is not preserved.
5567 // All code indexes used in the class are counted starting from the first
5568 // code object of the first group. In other words, code index 0 corresponds
5569 // to array index n = kCodesStartIndex.
5571 class DependentCode: public FixedArray {
5573 enum DependencyGroup {
5574 // Group of code that weakly embed this map and depend on being
5575 // deoptimized when the map is garbage collected.
5577 // Group of code that embed a transition to this map, and depend on being
5578 // deoptimized when the transition is replaced by a new version.
5580 // Group of code that omit run-time prototype checks for prototypes
5581 // described by this map. The group is deoptimized whenever an object
5582 // described by this map changes shape (and transitions to a new map),
5583 // possibly invalidating the assumptions embedded in the code.
5584 kPrototypeCheckGroup,
5585 // Group of code that depends on elements not being added to objects with
5587 kElementsCantBeAddedGroup,
5588 // Group of code that depends on global property values in property cells
5589 // not being changed.
5590 kPropertyCellChangedGroup,
5591 // Group of code that omit run-time type checks for the field(s) introduced
5594 // Group of code that omit run-time type checks for initial maps of
5596 kInitialMapChangedGroup,
5597 // Group of code that depends on tenuring information in AllocationSites
5598 // not being changed.
5599 kAllocationSiteTenuringChangedGroup,
5600 // Group of code that depends on element transition information in
5601 // AllocationSites not being changed.
5602 kAllocationSiteTransitionChangedGroup
5605 static const int kGroupCount = kAllocationSiteTransitionChangedGroup + 1;
5607 // Array for holding the index of the first code object of each group.
5608 // The last element stores the total number of code objects.
5609 class GroupStartIndexes {
5611 explicit GroupStartIndexes(DependentCode* entries);
5612 void Recompute(DependentCode* entries);
5613 int at(int i) { return start_indexes_[i]; }
5614 int number_of_entries() { return start_indexes_[kGroupCount]; }
5616 int start_indexes_[kGroupCount + 1];
5619 bool Contains(DependencyGroup group, WeakCell* code_cell);
5621 static Handle<DependentCode> InsertCompilationInfo(
5622 Handle<DependentCode> entries, DependencyGroup group,
5623 Handle<Foreign> info);
5625 static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries,
5626 DependencyGroup group,
5627 Handle<WeakCell> code_cell);
5629 void UpdateToFinishedCode(DependencyGroup group, Foreign* info,
5630 WeakCell* code_cell);
5632 void RemoveCompilationInfo(DependentCode::DependencyGroup group,
5635 void DeoptimizeDependentCodeGroup(Isolate* isolate,
5636 DependentCode::DependencyGroup group);
5638 bool MarkCodeForDeoptimization(Isolate* isolate,
5639 DependentCode::DependencyGroup group);
5641 // The following low-level accessors should only be used by this class
5642 // and the mark compact collector.
5643 inline int number_of_entries(DependencyGroup group);
5644 inline void set_number_of_entries(DependencyGroup group, int value);
5645 inline Object* object_at(int i);
5646 inline void set_object_at(int i, Object* object);
5647 inline void clear_at(int i);
5648 inline void copy(int from, int to);
5649 DECLARE_CAST(DependentCode)
5651 static DependentCode* ForObject(Handle<HeapObject> object,
5652 DependencyGroup group);
5654 static const char* DependencyGroupName(DependencyGroup group);
5655 static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
5658 static Handle<DependentCode> Insert(Handle<DependentCode> entries,
5659 DependencyGroup group,
5660 Handle<Object> object);
5661 static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries);
5662 // Make a room at the end of the given group by moving out the first
5663 // code objects of the subsequent groups.
5664 inline void ExtendGroup(DependencyGroup group);
5665 // Compact by removing cleared weak cells and return true if there was
5666 // any cleared weak cell.
5668 static int Grow(int number_of_entries) {
5669 if (number_of_entries < 5) return number_of_entries + 1;
5670 return number_of_entries * 5 / 4;
5672 static const int kCodesStartIndex = kGroupCount;
5676 // All heap objects have a Map that describes their structure.
5677 // A Map contains information about:
5678 // - Size information about the object
5679 // - How to iterate over an object (for garbage collection)
5680 class Map: public HeapObject {
5683 // Size in bytes or kVariableSizeSentinel if instances do not have
5685 inline int instance_size();
5686 inline void set_instance_size(int value);
5688 // Count of properties allocated in the object.
5689 inline int inobject_properties();
5690 inline void set_inobject_properties(int value);
5692 // Count of property fields pre-allocated in the object when first allocated.
5693 inline int pre_allocated_property_fields();
5694 inline void set_pre_allocated_property_fields(int value);
5697 inline InstanceType instance_type();
5698 inline void set_instance_type(InstanceType value);
5700 // Tells how many unused property fields are available in the
5701 // instance (only used for JSObject in fast mode).
5702 inline int unused_property_fields();
5703 inline void set_unused_property_fields(int value);
5706 inline byte bit_field();
5707 inline void set_bit_field(byte value);
5710 inline byte bit_field2();
5711 inline void set_bit_field2(byte value);
5714 inline uint32_t bit_field3();
5715 inline void set_bit_field3(uint32_t bits);
5717 class EnumLengthBits: public BitField<int,
5718 0, kDescriptorIndexBitCount> {}; // NOLINT
5719 class NumberOfOwnDescriptorsBits: public BitField<int,
5720 kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT
5721 STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
5722 class DictionaryMap : public BitField<bool, 20, 1> {};
5723 class OwnsDescriptors : public BitField<bool, 21, 1> {};
5724 class HasInstanceCallHandler : public BitField<bool, 22, 1> {};
5725 class Deprecated : public BitField<bool, 23, 1> {};
5726 class IsUnstable : public BitField<bool, 24, 1> {};
5727 class IsMigrationTarget : public BitField<bool, 25, 1> {};
5728 // Bits 26 and 27 are free.
5730 // Keep this bit field at the very end for better code in
5731 // Builtins::kJSConstructStubGeneric stub.
5732 // This counter is used for in-object slack tracking and for map aging.
5733 // The in-object slack tracking is considered enabled when the counter is
5734 // in the range [kSlackTrackingCounterStart, kSlackTrackingCounterEnd].
5735 class Counter : public BitField<int, 28, 4> {};
5736 static const int kSlackTrackingCounterStart = 14;
5737 static const int kSlackTrackingCounterEnd = 8;
5738 static const int kRetainingCounterStart = kSlackTrackingCounterEnd - 1;
5739 static const int kRetainingCounterEnd = 0;
5741 // Tells whether the object in the prototype property will be used
5742 // for instances created from this function. If the prototype
5743 // property is set to a value that is not a JSObject, the prototype
5744 // property will not be used to create instances of the function.
5745 // See ECMA-262, 13.2.2.
5746 inline void set_non_instance_prototype(bool value);
5747 inline bool has_non_instance_prototype();
5749 // Tells whether function has special prototype property. If not, prototype
5750 // property will not be created when accessed (will return undefined),
5751 // and construction from this function will not be allowed.
5752 inline void set_function_with_prototype(bool value);
5753 inline bool function_with_prototype();
5755 // Tells whether the instance with this map should be ignored by the
5756 // Object.getPrototypeOf() function and the __proto__ accessor.
5757 inline void set_is_hidden_prototype() {
5758 set_bit_field(bit_field() | (1 << kIsHiddenPrototype));
5761 inline bool is_hidden_prototype() {
5762 return ((1 << kIsHiddenPrototype) & bit_field()) != 0;
5765 // Records and queries whether the instance has a named interceptor.
5766 inline void set_has_named_interceptor() {
5767 set_bit_field(bit_field() | (1 << kHasNamedInterceptor));
5770 inline bool has_named_interceptor() {
5771 return ((1 << kHasNamedInterceptor) & bit_field()) != 0;
5774 // Records and queries whether the instance has an indexed interceptor.
5775 inline void set_has_indexed_interceptor() {
5776 set_bit_field(bit_field() | (1 << kHasIndexedInterceptor));
5779 inline bool has_indexed_interceptor() {
5780 return ((1 << kHasIndexedInterceptor) & bit_field()) != 0;
5783 // Tells whether the instance is undetectable.
5784 // An undetectable object is a special class of JSObject: 'typeof' operator
5785 // returns undefined, ToBoolean returns false. Otherwise it behaves like
5786 // a normal JS object. It is useful for implementing undetectable
5787 // document.all in Firefox & Safari.
5788 // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
5789 inline void set_is_undetectable() {
5790 set_bit_field(bit_field() | (1 << kIsUndetectable));
5793 inline bool is_undetectable() {
5794 return ((1 << kIsUndetectable) & bit_field()) != 0;
5797 // Tells whether the instance has a call-as-function handler.
5798 inline void set_is_observed() {
5799 set_bit_field(bit_field() | (1 << kIsObserved));
5802 inline bool is_observed() {
5803 return ((1 << kIsObserved) & bit_field()) != 0;
5806 inline void set_is_extensible(bool value);
5807 inline bool is_extensible();
5808 inline void set_is_prototype_map(bool value);
5809 inline bool is_prototype_map();
5811 inline void set_elements_kind(ElementsKind elements_kind) {
5812 DCHECK(static_cast<int>(elements_kind) < kElementsKindCount);
5813 DCHECK(kElementsKindCount <= (1 << Map::ElementsKindBits::kSize));
5814 set_bit_field2(Map::ElementsKindBits::update(bit_field2(), elements_kind));
5815 DCHECK(this->elements_kind() == elements_kind);
5818 inline ElementsKind elements_kind() {
5819 return Map::ElementsKindBits::decode(bit_field2());
5822 // Tells whether the instance has fast elements that are only Smis.
5823 inline bool has_fast_smi_elements() {
5824 return IsFastSmiElementsKind(elements_kind());
5827 // Tells whether the instance has fast elements.
5828 inline bool has_fast_object_elements() {
5829 return IsFastObjectElementsKind(elements_kind());
5832 inline bool has_fast_smi_or_object_elements() {
5833 return IsFastSmiOrObjectElementsKind(elements_kind());
5836 inline bool has_fast_double_elements() {
5837 return IsFastDoubleElementsKind(elements_kind());
5840 inline bool has_fast_elements() {
5841 return IsFastElementsKind(elements_kind());
5844 inline bool has_sloppy_arguments_elements() {
5845 return elements_kind() == SLOPPY_ARGUMENTS_ELEMENTS;
5848 inline bool has_external_array_elements() {
5849 return IsExternalArrayElementsKind(elements_kind());
5852 inline bool has_fixed_typed_array_elements() {
5853 return IsFixedTypedArrayElementsKind(elements_kind());
5856 inline bool has_dictionary_elements() {
5857 return IsDictionaryElementsKind(elements_kind());
5860 inline bool has_slow_elements_kind() {
5861 return elements_kind() == DICTIONARY_ELEMENTS
5862 || elements_kind() == SLOPPY_ARGUMENTS_ELEMENTS;
5865 static bool IsValidElementsTransition(ElementsKind from_kind,
5866 ElementsKind to_kind);
5868 // Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
5869 // map with DICTIONARY_ELEMENTS was found in the prototype chain.
5870 bool DictionaryElementsInPrototypeChainOnly();
5872 inline bool HasTransitionArray() const;
5873 inline bool HasElementsTransition();
5874 inline Map* elements_transition_map();
5876 inline Map* GetTransition(int transition_index);
5877 inline int SearchSpecialTransition(Symbol* name);
5878 inline int SearchTransition(PropertyKind kind, Name* name,
5879 PropertyAttributes attributes);
5880 inline FixedArrayBase* GetInitialElements();
5882 DECL_ACCESSORS(transitions, TransitionArray)
5884 static inline Handle<String> ExpectedTransitionKey(Handle<Map> map);
5885 static inline Handle<Map> ExpectedTransitionTarget(Handle<Map> map);
5887 // Try to follow an existing transition to a field with attributes NONE. The
5888 // return value indicates whether the transition was successful.
5889 static inline Handle<Map> FindTransitionToField(Handle<Map> map,
5893 Map* FindFieldOwner(int descriptor);
5895 inline int GetInObjectPropertyOffset(int index);
5897 int NumberOfFields();
5899 // TODO(ishell): candidate with JSObject::MigrateToMap().
5900 bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
5901 int target_inobject, int target_unused,
5902 int* old_number_of_fields);
5903 // TODO(ishell): moveit!
5904 static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map);
5905 MUST_USE_RESULT static Handle<HeapType> GeneralizeFieldType(
5906 Handle<HeapType> type1,
5907 Handle<HeapType> type2,
5909 static void GeneralizeFieldType(Handle<Map> map, int modify_index,
5910 Representation new_representation,
5911 Handle<HeapType> new_field_type);
5912 static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
5913 PropertyKind new_kind,
5914 PropertyAttributes new_attributes,
5915 Representation new_representation,
5916 Handle<HeapType> new_field_type,
5917 StoreMode store_mode);
5918 static Handle<Map> CopyGeneralizeAllRepresentations(
5919 Handle<Map> map, int modify_index, StoreMode store_mode,
5920 PropertyKind kind, PropertyAttributes attributes, const char* reason);
5922 static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
5923 int descriptor_number,
5924 Handle<Object> value);
5926 static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
5927 const char* reason);
5929 // Returns the constructor name (the name (possibly, inferred name) of the
5930 // function that was used to instantiate the object).
5931 String* constructor_name();
5933 // Tells whether the map is used for JSObjects in dictionary mode (ie
5934 // normalized objects, ie objects for which HasFastProperties returns false).
5935 // A map can never be used for both dictionary mode and fast mode JSObjects.
5936 // False by default and for HeapObjects that are not JSObjects.
5937 inline void set_dictionary_map(bool value);
5938 inline bool is_dictionary_map();
5940 // Tells whether the instance needs security checks when accessing its
5942 inline void set_is_access_check_needed(bool access_check_needed);
5943 inline bool is_access_check_needed();
5945 // Returns true if map has a non-empty stub code cache.
5946 inline bool has_code_cache();
5948 // [prototype]: implicit prototype object.
5949 DECL_ACCESSORS(prototype, Object)
5950 // TODO(jkummerow): make set_prototype private.
5951 void SetPrototype(Handle<Object> prototype,
5952 PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
5953 bool ShouldRegisterAsPrototypeUser(Handle<JSObject> prototype);
5954 bool CanUseOptimizationsBasedOnPrototypeRegistry();
5956 // [constructor]: points back to the function responsible for this map.
5957 DECL_ACCESSORS(constructor, Object)
5959 // [instance descriptors]: describes the object.
5960 DECL_ACCESSORS(instance_descriptors, DescriptorArray)
5962 // [layout descriptor]: describes the object layout.
5963 DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
5964 // |layout descriptor| accessor which can be used from GC.
5965 inline LayoutDescriptor* layout_descriptor_gc_safe();
5966 inline bool HasFastPointerLayout() const;
5968 // |layout descriptor| accessor that is safe to call even when
5969 // FLAG_unbox_double_fields is disabled (in this case Map does not contain
5970 // |layout_descriptor| field at all).
5971 inline LayoutDescriptor* GetLayoutDescriptor();
5973 inline void UpdateDescriptors(DescriptorArray* descriptors,
5974 LayoutDescriptor* layout_descriptor);
5975 inline void InitializeDescriptors(DescriptorArray* descriptors,
5976 LayoutDescriptor* layout_descriptor);
5978 // [stub cache]: contains stubs compiled for this map.
5979 DECL_ACCESSORS(code_cache, Object)
5981 // [dependent code]: list of optimized codes that weakly embed this map.
5982 DECL_ACCESSORS(dependent_code, DependentCode)
5984 // [back pointer]: points back to the parent map from which a transition
5985 // leads to this map. The field overlaps with prototype transitions and the
5986 // back pointer will be moved into the prototype transitions array if
5988 inline Object* GetBackPointer();
5989 inline void SetBackPointer(Object* value,
5990 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5991 inline void init_back_pointer(Object* undefined);
5993 // [prototype transitions]: cache of prototype transitions.
5994 // Prototype transition is a transition that happens
5995 // when we change object's prototype to a new one.
5997 // 0: finger - index of the first free cell in the cache
5998 // 1 + i: target map
5999 inline FixedArray* GetPrototypeTransitions();
6000 inline bool HasPrototypeTransitions();
6002 static const int kProtoTransitionNumberOfEntriesOffset = 0;
6003 static const int kProtoTransitionHeaderSize = 1;
6005 inline int NumberOfProtoTransitions() {
6006 FixedArray* cache = GetPrototypeTransitions();
6007 if (cache->length() == 0) return 0;
6009 Smi::cast(cache->get(kProtoTransitionNumberOfEntriesOffset))->value();
6012 inline void SetNumberOfProtoTransitions(int value) {
6013 FixedArray* cache = GetPrototypeTransitions();
6014 DCHECK(cache->length() != 0);
6015 cache->set(kProtoTransitionNumberOfEntriesOffset, Smi::FromInt(value));
6018 inline PropertyDetails GetLastDescriptorDetails();
6020 // The size of transition arrays are limited so they do not end up in large
6021 // object space. Otherwise ClearNonLiveTransitions would leak memory while
6022 // applying in-place right trimming.
6023 inline bool CanHaveMoreTransitions();
6026 int number_of_own_descriptors = NumberOfOwnDescriptors();
6027 DCHECK(number_of_own_descriptors > 0);
6028 return number_of_own_descriptors - 1;
6031 int NumberOfOwnDescriptors() {
6032 return NumberOfOwnDescriptorsBits::decode(bit_field3());
6035 void SetNumberOfOwnDescriptors(int number) {
6036 DCHECK(number <= instance_descriptors()->number_of_descriptors());
6037 set_bit_field3(NumberOfOwnDescriptorsBits::update(bit_field3(), number));
6040 inline Cell* RetrieveDescriptorsPointer();
6043 return EnumLengthBits::decode(bit_field3());
6046 void SetEnumLength(int length) {
6047 if (length != kInvalidEnumCacheSentinel) {
6048 DCHECK(length >= 0);
6049 DCHECK(length == 0 || instance_descriptors()->HasEnumCache());
6050 DCHECK(length <= NumberOfOwnDescriptors());
6052 set_bit_field3(EnumLengthBits::update(bit_field3(), length));
6055 inline bool owns_descriptors();
6056 inline void set_owns_descriptors(bool owns_descriptors);
6057 inline bool has_instance_call_handler();
6058 inline void set_has_instance_call_handler();
6059 inline void mark_unstable();
6060 inline bool is_stable();
6061 inline void set_migration_target(bool value);
6062 inline bool is_migration_target();
6063 inline void set_counter(int value);
6064 inline int counter();
6065 inline void deprecate();
6066 inline bool is_deprecated();
6067 inline bool CanBeDeprecated();
6068 // Returns a non-deprecated version of the input. If the input was not
6069 // deprecated, it is directly returned. Otherwise, the non-deprecated version
6070 // is found by re-transitioning from the root of the transition tree using the
6071 // descriptor array of the map. Returns NULL if no updated map is found.
6072 // This method also applies any pending migrations along the prototype chain.
6073 static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
6074 // Same as above, but does not touch the prototype chain.
6075 static MaybeHandle<Map> TryUpdateInternal(Handle<Map> map)
6078 // Returns a non-deprecated version of the input. This method may deprecate
6079 // existing maps along the way if encodings conflict. Not for use while
6080 // gathering type feedback. Use TryUpdate in those cases instead.
6081 static Handle<Map> Update(Handle<Map> map);
6083 static Handle<Map> CopyDropDescriptors(Handle<Map> map);
6084 static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
6085 Descriptor* descriptor,
6086 TransitionFlag flag);
6088 MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
6091 Handle<HeapType> type,
6092 PropertyAttributes attributes,
6093 Representation representation,
6094 TransitionFlag flag);
6096 MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
6099 Handle<Object> constant,
6100 PropertyAttributes attributes,
6101 TransitionFlag flag);
6103 // Returns a new map with all transitions dropped from the given map and
6104 // the ElementsKind set.
6105 static Handle<Map> TransitionElementsTo(Handle<Map> map,
6106 ElementsKind to_kind);
6108 static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
6110 static Handle<Map> CopyAsElementsKind(Handle<Map> map,
6112 TransitionFlag flag);
6114 static Handle<Map> CopyForObserved(Handle<Map> map);
6116 static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
6117 PropertyAttributes attrs_to_add,
6118 Handle<Symbol> transition_marker,
6119 const char* reason);
6120 // Maximal number of fast properties. Used to restrict the number of map
6121 // transitions to avoid an explosion in the number of maps for objects used as
6123 inline bool TooManyFastProperties(StoreFromKeyed store_mode);
6124 static Handle<Map> TransitionToDataProperty(Handle<Map> map,
6126 Handle<Object> value,
6127 PropertyAttributes attributes,
6128 StoreFromKeyed store_mode);
6129 static Handle<Map> TransitionToAccessorProperty(
6130 Handle<Map> map, Handle<Name> name, AccessorComponent component,
6131 Handle<Object> accessor, PropertyAttributes attributes);
6132 static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
6135 PropertyAttributes attributes);
6137 inline void AppendDescriptor(Descriptor* desc);
6139 // Returns a copy of the map, prepared for inserting into the transition
6140 // tree (if the |map| owns descriptors then the new one will share
6141 // descriptors with |map|).
6142 static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
6144 // Returns a copy of the map, with all transitions dropped from the
6145 // instance descriptors.
6146 static Handle<Map> Copy(Handle<Map> map, const char* reason);
6147 static Handle<Map> Create(Isolate* isolate, int inobject_properties);
6149 // Returns the next free property index (only valid for FAST MODE).
6150 int NextFreePropertyIndex();
6152 // Returns the number of properties described in instance_descriptors
6153 // filtering out properties with the specified attributes.
6154 int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
6155 PropertyAttributes filter = NONE);
6157 // Returns the number of slots allocated for the initial properties
6158 // backing storage for instances of this map.
6159 int InitialPropertiesLength() {
6160 return pre_allocated_property_fields() + unused_property_fields() -
6161 inobject_properties();
6166 // Code cache operations.
6168 // Clears the code cache.
6169 inline void ClearCodeCache(Heap* heap);
6171 // Update code cache.
6172 static void UpdateCodeCache(Handle<Map> map,
6176 // Extend the descriptor array of the map with the list of descriptors.
6177 // In case of duplicates, the latest descriptor is used.
6178 static void AppendCallbackDescriptors(Handle<Map> map,
6179 Handle<Object> descriptors);
6181 static inline int SlackForArraySize(int old_size, int size_limit);
6183 static void EnsureDescriptorSlack(Handle<Map> map, int slack);
6185 // Returns the found code or undefined if absent.
6186 Object* FindInCodeCache(Name* name, Code::Flags flags);
6188 // Returns the non-negative index of the code object if it is in the
6189 // cache and -1 otherwise.
6190 int IndexInCodeCache(Object* name, Code* code);
6192 // Removes a code object from the code cache at the given index.
6193 void RemoveFromCodeCache(Name* name, Code* code, int index);
6195 // Set all map transitions from this map to dead maps to null. Also clear
6196 // back pointers in transition targets so that we do not process this map
6197 // again while following back pointers.
6198 void ClearNonLiveTransitions(Heap* heap);
6200 // Computes a hash value for this map, to be used in HashTables and such.
6203 // Returns the map that this map transitions to if its elements_kind
6204 // is changed to |elements_kind|, or NULL if no such map is cached yet.
6205 // |safe_to_add_transitions| is set to false if adding transitions is not
6207 Map* LookupElementsTransitionMap(ElementsKind elements_kind);
6209 // Returns the transitioned map for this map with the most generic
6210 // elements_kind that's found in |candidates|, or null handle if no match is
6212 Handle<Map> FindTransitionedMap(MapHandleList* candidates);
6214 bool CanTransition() {
6215 // Only JSObject and subtypes have map transitions and back pointers.
6216 STATIC_ASSERT(LAST_TYPE == LAST_JS_OBJECT_TYPE);
6217 return instance_type() >= FIRST_JS_OBJECT_TYPE;
6220 bool IsJSObjectMap() {
6221 return instance_type() >= FIRST_JS_OBJECT_TYPE;
6223 bool IsStringMap() { return instance_type() < FIRST_NONSTRING_TYPE; }
6224 bool IsJSProxyMap() {
6225 InstanceType type = instance_type();
6226 return FIRST_JS_PROXY_TYPE <= type && type <= LAST_JS_PROXY_TYPE;
6228 bool IsJSGlobalProxyMap() {
6229 return instance_type() == JS_GLOBAL_PROXY_TYPE;
6231 bool IsJSGlobalObjectMap() {
6232 return instance_type() == JS_GLOBAL_OBJECT_TYPE;
6234 bool IsGlobalObjectMap() {
6235 const InstanceType type = instance_type();
6236 return type == JS_GLOBAL_OBJECT_TYPE || type == JS_BUILTINS_OBJECT_TYPE;
6239 inline bool CanOmitMapChecks();
6241 static void AddDependentCompilationInfo(Handle<Map> map,
6242 DependentCode::DependencyGroup group,
6243 CompilationInfo* info);
6245 static void AddDependentCode(Handle<Map> map,
6246 DependentCode::DependencyGroup group,
6249 bool IsMapInArrayPrototypeChain();
6251 static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
6253 // Dispatched behavior.
6254 DECLARE_PRINTER(Map)
6255 DECLARE_VERIFIER(Map)
6258 void DictionaryMapVerify();
6259 void VerifyOmittedMapChecks();
6262 inline int visitor_id();
6263 inline void set_visitor_id(int visitor_id);
6265 typedef void (*TraverseCallback)(Map* map, void* data);
6267 void TraverseTransitionTree(TraverseCallback callback, void* data);
6269 // When you set the prototype of an object using the __proto__ accessor you
6270 // need a new map for the object (the prototype is stored in the map). In
6271 // order not to multiply maps unnecessarily we store these as transitions in
6272 // the original map. That way we can transition to the same map if the same
6273 // prototype is set, rather than creating a new map every time. The
6274 // transitions are in the form of a map where the keys are prototype objects
6275 // and the values are the maps they transition to.
6276 static const int kMaxCachedPrototypeTransitions = 256;
6277 static Handle<Map> TransitionToPrototype(Handle<Map> map,
6278 Handle<Object> prototype,
6279 PrototypeOptimizationMode mode);
6281 static const int kMaxPreAllocatedPropertyFields = 255;
6283 // Layout description.
6284 static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
6285 static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
6286 static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
6287 static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
6288 static const int kConstructorOffset = kPrototypeOffset + kPointerSize;
6289 // Storage for the transition array is overloaded to directly contain a back
6290 // pointer if unused. When the map has transitions, the back pointer is
6291 // transferred to the transition array and accessed through an extra
6293 static const int kTransitionsOrBackPointerOffset =
6294 kConstructorOffset + kPointerSize;
6295 static const int kDescriptorsOffset =
6296 kTransitionsOrBackPointerOffset + kPointerSize;
6297 #if V8_DOUBLE_FIELDS_UNBOXING
6298 static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize;
6299 static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize;
6301 static const int kLayoutDecriptorOffset = 1; // Must not be ever accessed.
6302 static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
6304 static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
6305 static const int kSize = kDependentCodeOffset + kPointerSize;
6307 // Layout of pointer fields. Heap iteration code relies on them
6308 // being continuously allocated.
6309 static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
6310 static const int kPointerFieldsEndOffset = kSize;
6312 // Byte offsets within kInstanceSizesOffset.
6313 static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
6314 static const int kInObjectPropertiesByte = 1;
6315 static const int kInObjectPropertiesOffset =
6316 kInstanceSizesOffset + kInObjectPropertiesByte;
6317 static const int kPreAllocatedPropertyFieldsByte = 2;
6318 static const int kPreAllocatedPropertyFieldsOffset =
6319 kInstanceSizesOffset + kPreAllocatedPropertyFieldsByte;
6320 static const int kVisitorIdByte = 3;
6321 static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
6323 // Byte offsets within kInstanceAttributesOffset attributes.
6324 #if V8_TARGET_LITTLE_ENDIAN
6325 // Order instance type and bit field together such that they can be loaded
6326 // together as a 16-bit word with instance type in the lower 8 bits regardless
6327 // of endianess. Also provide endian-independent offset to that 16-bit word.
6328 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
6329 static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
6331 static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
6332 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
6334 static const int kInstanceTypeAndBitFieldOffset =
6335 kInstanceAttributesOffset + 0;
6336 static const int kBitField2Offset = kInstanceAttributesOffset + 2;
6337 static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
6339 STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
6340 Internals::kMapInstanceTypeAndBitFieldOffset);
6342 // Bit positions for bit field.
6343 static const int kHasNonInstancePrototype = 0;
6344 static const int kIsHiddenPrototype = 1;
6345 static const int kHasNamedInterceptor = 2;
6346 static const int kHasIndexedInterceptor = 3;
6347 static const int kIsUndetectable = 4;
6348 static const int kIsObserved = 5;
6349 static const int kIsAccessCheckNeeded = 6;
6350 class FunctionWithPrototype: public BitField<bool, 7, 1> {};
6352 // Bit positions for bit field 2
6353 static const int kIsExtensible = 0;
6354 static const int kStringWrapperSafeForDefaultValueOf = 1;
6355 class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
6356 class ElementsKindBits: public BitField<ElementsKind, 3, 5> {};
6358 // Derived values from bit field 2
6359 static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
6360 (FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1;
6361 static const int8_t kMaximumBitField2FastSmiElementValue =
6362 static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
6363 Map::ElementsKindBits::kShift) - 1;
6364 static const int8_t kMaximumBitField2FastHoleyElementValue =
6365 static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
6366 Map::ElementsKindBits::kShift) - 1;
6367 static const int8_t kMaximumBitField2FastHoleySmiElementValue =
6368 static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
6369 Map::ElementsKindBits::kShift) - 1;
6371 typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
6372 kPointerFieldsEndOffset,
6373 kSize> BodyDescriptor;
6375 // Compares this map to another to see if they describe equivalent objects.
6376 // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
6377 // it had exactly zero inobject properties.
6378 // The "shared" flags of both this map and |other| are ignored.
6379 bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
6381 // Returns true if given field is unboxed double.
6382 inline bool IsUnboxedDoubleField(FieldIndex index);
6385 static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
6386 static void TraceAllTransitions(Map* map);
6389 static inline Handle<Map> CopyInstallDescriptorsForTesting(
6390 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
6391 Handle<LayoutDescriptor> layout_descriptor);
6394 static void ConnectElementsTransition(Handle<Map> parent, Handle<Map> child);
6395 static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
6396 Handle<Name> name, SimpleTransitionFlag flag);
6398 bool EquivalentToForTransition(Map* other);
6399 static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
6400 static Handle<Map> ShareDescriptor(Handle<Map> map,
6401 Handle<DescriptorArray> descriptors,
6402 Descriptor* descriptor);
6403 static Handle<Map> CopyInstallDescriptors(
6404 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
6405 Handle<LayoutDescriptor> layout_descriptor);
6406 static Handle<Map> CopyAddDescriptor(Handle<Map> map,
6407 Descriptor* descriptor,
6408 TransitionFlag flag);
6409 static Handle<Map> CopyReplaceDescriptors(
6410 Handle<Map> map, Handle<DescriptorArray> descriptors,
6411 Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
6412 MaybeHandle<Name> maybe_name, const char* reason,
6413 SimpleTransitionFlag simple_flag);
6415 static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
6416 Handle<DescriptorArray> descriptors,
6417 Descriptor* descriptor,
6419 TransitionFlag flag);
6420 static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
6421 Handle<Map> map, int descriptor, PropertyKind kind,
6422 PropertyAttributes attributes, const char** reason);
6424 static Handle<Map> CopyNormalized(Handle<Map> map,
6425 PropertyNormalizationMode mode);
6427 // Fires when the layout of an object with a leaf map changes.
6428 // This includes adding transitions to the leaf map or changing
6429 // the descriptor array.
6430 inline void NotifyLeafMapLayoutChange();
6432 static Handle<Map> TransitionElementsToSlow(Handle<Map> object,
6433 ElementsKind to_kind);
6435 // Zaps the contents of backing data structures. Note that the
6436 // heap verifier (i.e. VerifyMarkingVisitor) relies on zapping of objects
6437 // holding weak references when incremental marking is used, because it also
6438 // iterates over objects that are otherwise unreachable.
6439 // In general we only want to call these functions in release mode when
6440 // heap verification is turned on.
6441 void ZapPrototypeTransitions();
6442 void ZapTransitions();
6444 void DeprecateTransitionTree();
6445 bool DeprecateTarget(PropertyKind kind, Name* key,
6446 PropertyAttributes attributes,
6447 DescriptorArray* new_descriptors,
6448 LayoutDescriptor* new_layout_descriptor);
6450 Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
6452 void UpdateFieldType(int descriptor_number, Handle<Name> name,
6453 Representation new_representation,
6454 Handle<HeapType> new_type);
6456 void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
6457 PropertyAttributes attributes);
6458 void PrintGeneralization(FILE* file,
6463 bool constant_to_field,
6464 Representation old_representation,
6465 Representation new_representation,
6466 HeapType* old_field_type,
6467 HeapType* new_field_type);
6469 static inline void SetPrototypeTransitions(
6471 Handle<FixedArray> prototype_transitions);
6473 static Handle<Map> GetPrototypeTransition(Handle<Map> map,
6474 Handle<Object> prototype);
6475 static Handle<Map> PutPrototypeTransition(Handle<Map> map,
6476 Handle<Object> prototype,
6477 Handle<Map> target_map);
6479 static const int kFastPropertiesSoftLimit = 12;
6480 static const int kMaxFastProperties = 128;
6482 DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
6486 // An abstract superclass, a marker class really, for simple structure classes.
6487 // It doesn't carry much functionality but allows struct classes to be
6488 // identified in the type system.
6489 class Struct: public HeapObject {
6491 inline void InitializeBody(int object_size);
6492 DECLARE_CAST(Struct)
6496 // A simple one-element struct, useful where smis need to be boxed.
6497 class Box : public Struct {
6499 // [value]: the boxed contents.
6500 DECL_ACCESSORS(value, Object)
6504 // Dispatched behavior.
6505 DECLARE_PRINTER(Box)
6506 DECLARE_VERIFIER(Box)
6508 static const int kValueOffset = HeapObject::kHeaderSize;
6509 static const int kSize = kValueOffset + kPointerSize;
6512 DISALLOW_IMPLICIT_CONSTRUCTORS(Box);
6516 // Script describes a script which has been added to the VM.
6517 class Script: public Struct {
6526 // Script compilation types.
6527 enum CompilationType {
6528 COMPILATION_TYPE_HOST = 0,
6529 COMPILATION_TYPE_EVAL = 1
6532 // Script compilation state.
6533 enum CompilationState {
6534 COMPILATION_STATE_INITIAL = 0,
6535 COMPILATION_STATE_COMPILED = 1
6538 // [source]: the script source.
6539 DECL_ACCESSORS(source, Object)
6541 // [name]: the script name.
6542 DECL_ACCESSORS(name, Object)
6544 // [id]: the script id.
6545 DECL_ACCESSORS(id, Smi)
6547 // [line_offset]: script line offset in resource from where it was extracted.
6548 DECL_ACCESSORS(line_offset, Smi)
6550 // [column_offset]: script column offset in resource from where it was
6552 DECL_ACCESSORS(column_offset, Smi)
6554 // [context_data]: context data for the context this script was compiled in.
6555 DECL_ACCESSORS(context_data, Object)
6557 // [wrapper]: the wrapper cache. This is either undefined or a WeakCell.
6558 DECL_ACCESSORS(wrapper, HeapObject)
6560 // [type]: the script type.
6561 DECL_ACCESSORS(type, Smi)
6563 // [line_ends]: FixedArray of line ends positions.
6564 DECL_ACCESSORS(line_ends, Object)
6566 // [eval_from_shared]: for eval scripts the shared funcion info for the
6567 // function from which eval was called.
6568 DECL_ACCESSORS(eval_from_shared, Object)
6570 // [eval_from_instructions_offset]: the instruction offset in the code for the
6571 // function from which eval was called where eval was called.
6572 DECL_ACCESSORS(eval_from_instructions_offset, Smi)
6574 // [flags]: Holds an exciting bitfield.
6575 DECL_ACCESSORS(flags, Smi)
6577 // [source_url]: sourceURL from magic comment
6578 DECL_ACCESSORS(source_url, Object)
6580 // [source_url]: sourceMappingURL magic comment
6581 DECL_ACCESSORS(source_mapping_url, Object)
6583 // [compilation_type]: how the the script was compiled. Encoded in the
6585 inline CompilationType compilation_type();
6586 inline void set_compilation_type(CompilationType type);
6588 // [compilation_state]: determines whether the script has already been
6589 // compiled. Encoded in the 'flags' field.
6590 inline CompilationState compilation_state();
6591 inline void set_compilation_state(CompilationState state);
6593 // [is_embedder_debug_script]: An opaque boolean set by the embedder via
6594 // ScriptOrigin, and used by the embedder to make decisions about the
6595 // script's origin. V8 just passes this through. Encoded in
6596 // the 'flags' field.
6597 DECL_BOOLEAN_ACCESSORS(is_embedder_debug_script)
6599 // [is_shared_cross_origin]: An opaque boolean set by the embedder via
6600 // ScriptOrigin, and used by the embedder to make decisions about the
6601 // script's level of privilege. V8 just passes this through. Encoded in
6602 // the 'flags' field.
6603 DECL_BOOLEAN_ACCESSORS(is_shared_cross_origin)
6605 DECLARE_CAST(Script)
6607 // If script source is an external string, check that the underlying
6608 // resource is accessible. Otherwise, always return true.
6609 inline bool HasValidSource();
6611 // Convert code position into column number.
6612 static int GetColumnNumber(Handle<Script> script, int code_pos);
6614 // Convert code position into (zero-based) line number.
6615 // The non-handlified version does not allocate, but may be much slower.
6616 static int GetLineNumber(Handle<Script> script, int code_pos);
6617 int GetLineNumber(int code_pos);
6619 static Handle<Object> GetNameOrSourceURL(Handle<Script> script);
6621 // Init line_ends array with code positions of line ends inside script source.
6622 static void InitLineEnds(Handle<Script> script);
6624 // Get the JS object wrapping the given script; create it if none exists.
6625 static Handle<JSObject> GetWrapper(Handle<Script> script);
6627 // Dispatched behavior.
6628 DECLARE_PRINTER(Script)
6629 DECLARE_VERIFIER(Script)
6631 static const int kSourceOffset = HeapObject::kHeaderSize;
6632 static const int kNameOffset = kSourceOffset + kPointerSize;
6633 static const int kLineOffsetOffset = kNameOffset + kPointerSize;
6634 static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
6635 static const int kContextOffset = kColumnOffsetOffset + kPointerSize;
6636 static const int kWrapperOffset = kContextOffset + kPointerSize;
6637 static const int kTypeOffset = kWrapperOffset + kPointerSize;
6638 static const int kLineEndsOffset = kTypeOffset + kPointerSize;
6639 static const int kIdOffset = kLineEndsOffset + kPointerSize;
6640 static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
6641 static const int kEvalFrominstructionsOffsetOffset =
6642 kEvalFromSharedOffset + kPointerSize;
6643 static const int kFlagsOffset =
6644 kEvalFrominstructionsOffsetOffset + kPointerSize;
6645 static const int kSourceUrlOffset = kFlagsOffset + kPointerSize;
6646 static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
6647 static const int kSize = kSourceMappingUrlOffset + kPointerSize;
6650 int GetLineNumberWithArray(int code_pos);
6652 // Bit positions in the flags field.
6653 static const int kCompilationTypeBit = 0;
6654 static const int kCompilationStateBit = 1;
6655 static const int kIsEmbedderDebugScriptBit = 2;
6656 static const int kIsSharedCrossOriginBit = 3;
6658 DISALLOW_IMPLICIT_CONSTRUCTORS(Script);
6662 // List of builtin functions we want to identify to improve code
6665 // Each entry has a name of a global object property holding an object
6666 // optionally followed by ".prototype", a name of a builtin function
6667 // on the object (the one the id is set for), and a label.
6669 // Installation of ids for the selected builtin functions is handled
6670 // by the bootstrapper.
6671 #define FUNCTIONS_WITH_ID_LIST(V) \
6672 V(Array.prototype, indexOf, ArrayIndexOf) \
6673 V(Array.prototype, lastIndexOf, ArrayLastIndexOf) \
6674 V(Array.prototype, push, ArrayPush) \
6675 V(Array.prototype, pop, ArrayPop) \
6676 V(Array.prototype, shift, ArrayShift) \
6677 V(Function.prototype, apply, FunctionApply) \
6678 V(Function.prototype, call, FunctionCall) \
6679 V(String.prototype, charCodeAt, StringCharCodeAt) \
6680 V(String.prototype, charAt, StringCharAt) \
6681 V(String, fromCharCode, StringFromCharCode) \
6682 V(Math, random, MathRandom) \
6683 V(Math, floor, MathFloor) \
6684 V(Math, round, MathRound) \
6685 V(Math, ceil, MathCeil) \
6686 V(Math, abs, MathAbs) \
6687 V(Math, log, MathLog) \
6688 V(Math, exp, MathExp) \
6689 V(Math, sqrt, MathSqrt) \
6690 V(Math, pow, MathPow) \
6691 V(Math, max, MathMax) \
6692 V(Math, min, MathMin) \
6693 V(Math, cos, MathCos) \
6694 V(Math, sin, MathSin) \
6695 V(Math, tan, MathTan) \
6696 V(Math, acos, MathAcos) \
6697 V(Math, asin, MathAsin) \
6698 V(Math, atan, MathAtan) \
6699 V(Math, atan2, MathAtan2) \
6700 V(Math, imul, MathImul) \
6701 V(Math, clz32, MathClz32) \
6702 V(Math, fround, MathFround)
6704 enum BuiltinFunctionId {
6706 #define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \
6708 FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
6709 #undef DECLARE_FUNCTION_ID
6710 // Fake id for a special case of Math.pow. Note, it continues the
6711 // list of math functions.
6716 // SharedFunctionInfo describes the JSFunction information that can be
6717 // shared by multiple instances of the function.
6718 class SharedFunctionInfo: public HeapObject {
6720 // [name]: Function name.
6721 DECL_ACCESSORS(name, Object)
6723 // [code]: Function code.
6724 DECL_ACCESSORS(code, Code)
6725 inline void ReplaceCode(Code* code);
6727 // [optimized_code_map]: Map from native context to optimized code
6728 // and a shared literals array or Smi(0) if none.
6729 DECL_ACCESSORS(optimized_code_map, Object)
6731 // Returns index i of the entry with the specified context and OSR entry.
6732 // At position i - 1 is the context, position i the code, and i + 1 the
6733 // literals array. Returns -1 when no matching entry is found.
6734 int SearchOptimizedCodeMap(Context* native_context, BailoutId osr_ast_id);
6736 // Installs optimized code from the code map on the given closure. The
6737 // index has to be consistent with a search result as defined above.
6738 FixedArray* GetLiteralsFromOptimizedCodeMap(int index);
6740 Code* GetCodeFromOptimizedCodeMap(int index);
6742 // Clear optimized code map.
6743 void ClearOptimizedCodeMap();
6745 // Removed a specific optimized code object from the optimized code map.
6746 void EvictFromOptimizedCodeMap(Code* optimized_code, const char* reason);
6748 // Unconditionally clear the type feedback vector (including vector ICs).
6749 void ClearTypeFeedbackInfo();
6751 // Clear the type feedback vector with a more subtle policy at GC time.
6752 void ClearTypeFeedbackInfoAtGCTime();
6754 // Trims the optimized code map after entries have been removed.
6755 void TrimOptimizedCodeMap(int shrink_by);
6757 // Initialize a SharedFunctionInfo from a parsed function literal.
6758 static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info,
6759 FunctionLiteral* lit);
6761 // Add a new entry to the optimized code map.
6762 static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
6763 Handle<Context> native_context,
6765 Handle<FixedArray> literals,
6766 BailoutId osr_ast_id);
6768 // Layout description of the optimized code map.
6769 static const int kNextMapIndex = 0;
6770 static const int kEntriesStart = 1;
6771 static const int kContextOffset = 0;
6772 static const int kCachedCodeOffset = 1;
6773 static const int kLiteralsOffset = 2;
6774 static const int kOsrAstIdOffset = 3;
6775 static const int kEntryLength = 4;
6776 static const int kInitialLength = kEntriesStart + kEntryLength;
6778 // [scope_info]: Scope info.
6779 DECL_ACCESSORS(scope_info, ScopeInfo)
6781 // [construct stub]: Code stub for constructing instances of this function.
6782 DECL_ACCESSORS(construct_stub, Code)
6784 // Returns if this function has been compiled to native code yet.
6785 inline bool is_compiled();
6787 // [length]: The function length - usually the number of declared parameters.
6788 // Use up to 2^30 parameters.
6789 inline int length() const;
6790 inline void set_length(int value);
6792 // [internal formal parameter count]: The declared number of parameters.
6793 // For subclass constructors, also includes new.target.
6794 // The size of function's frame is internal_formal_parameter_count + 1.
6795 inline int internal_formal_parameter_count() const;
6796 inline void set_internal_formal_parameter_count(int value);
6798 // Set the formal parameter count so the function code will be
6799 // called without using argument adaptor frames.
6800 inline void DontAdaptArguments();
6802 // [expected_nof_properties]: Expected number of properties for the function.
6803 inline int expected_nof_properties() const;
6804 inline void set_expected_nof_properties(int value);
6806 // [feedback_vector] - accumulates ast node feedback from full-codegen and
6807 // (increasingly) from crankshafted code where sufficient feedback isn't
6809 DECL_ACCESSORS(feedback_vector, TypeFeedbackVector)
6812 // [unique_id] - For --trace-maps purposes, an identifier that's persistent
6813 // even if the GC moves this SharedFunctionInfo.
6814 inline int unique_id() const;
6815 inline void set_unique_id(int value);
6818 // [instance class name]: class name for instances.
6819 DECL_ACCESSORS(instance_class_name, Object)
6821 // [function data]: This field holds some additional data for function.
6822 // Currently it either has FunctionTemplateInfo to make benefit the API
6823 // or Smi identifying a builtin function.
6824 // In the long run we don't want all functions to have this field but
6825 // we can fix that when we have a better model for storing hidden data
6827 DECL_ACCESSORS(function_data, Object)
6829 inline bool IsApiFunction();
6830 inline FunctionTemplateInfo* get_api_func_data();
6831 inline bool HasBuiltinFunctionId();
6832 inline BuiltinFunctionId builtin_function_id();
6834 // [script info]: Script from which the function originates.
6835 DECL_ACCESSORS(script, Object)
6837 // [num_literals]: Number of literals used by this function.
6838 inline int num_literals() const;
6839 inline void set_num_literals(int value);
6841 // [start_position_and_type]: Field used to store both the source code
6842 // position, whether or not the function is a function expression,
6843 // and whether or not the function is a toplevel function. The two
6844 // least significants bit indicates whether the function is an
6845 // expression and the rest contains the source code position.
6846 inline int start_position_and_type() const;
6847 inline void set_start_position_and_type(int value);
6849 // [debug info]: Debug information.
6850 DECL_ACCESSORS(debug_info, Object)
6852 // [inferred name]: Name inferred from variable or property
6853 // assignment of this function. Used to facilitate debugging and
6854 // profiling of JavaScript code written in OO style, where almost
6855 // all functions are anonymous but are assigned to object
6857 DECL_ACCESSORS(inferred_name, String)
6859 // The function's name if it is non-empty, otherwise the inferred name.
6860 String* DebugName();
6862 // Position of the 'function' token in the script source.
6863 inline int function_token_position() const;
6864 inline void set_function_token_position(int function_token_position);
6866 // Position of this function in the script source.
6867 inline int start_position() const;
6868 inline void set_start_position(int start_position);
6870 // End position of this function in the script source.
6871 inline int end_position() const;
6872 inline void set_end_position(int end_position);
6874 // Is this function a function expression in the source code.
6875 DECL_BOOLEAN_ACCESSORS(is_expression)
6877 // Is this function a top-level function (scripts, evals).
6878 DECL_BOOLEAN_ACCESSORS(is_toplevel)
6880 // Bit field containing various information collected by the compiler to
6881 // drive optimization.
6882 inline int compiler_hints() const;
6883 inline void set_compiler_hints(int value);
6885 inline int ast_node_count() const;
6886 inline void set_ast_node_count(int count);
6888 inline int profiler_ticks() const;
6889 inline void set_profiler_ticks(int ticks);
6891 // Inline cache age is used to infer whether the function survived a context
6892 // disposal or not. In the former case we reset the opt_count.
6893 inline int ic_age();
6894 inline void set_ic_age(int age);
6896 // Indicates if this function can be lazy compiled.
6897 // This is used to determine if we can safely flush code from a function
6898 // when doing GC if we expect that the function will no longer be used.
6899 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation)
6901 // Indicates if this function can be lazy compiled without a context.
6902 // This is used to determine if we can force compilation without reaching
6903 // the function through program execution but through other means (e.g. heap
6904 // iteration by the debugger).
6905 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context)
6907 // Indicates whether optimizations have been disabled for this
6908 // shared function info. If a function is repeatedly optimized or if
6909 // we cannot optimize the function we disable optimization to avoid
6910 // spending time attempting to optimize it again.
6911 DECL_BOOLEAN_ACCESSORS(optimization_disabled)
6913 // Indicates the language mode.
6914 inline LanguageMode language_mode();
6915 inline void set_language_mode(LanguageMode language_mode);
6917 // False if the function definitely does not allocate an arguments object.
6918 DECL_BOOLEAN_ACCESSORS(uses_arguments)
6920 // Indicates that this function uses a super property.
6921 // This is needed to set up the [[HomeObject]] on the function instance.
6922 DECL_BOOLEAN_ACCESSORS(uses_super_property)
6924 // True if the function has any duplicated parameter names.
6925 DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
6927 // Indicates whether the function is a native function.
6928 // These needs special treatment in .call and .apply since
6929 // null passed as the receiver should not be translated to the
6931 DECL_BOOLEAN_ACCESSORS(native)
6933 // Indicate that this builtin needs to be inlined in crankshaft.
6934 DECL_BOOLEAN_ACCESSORS(inline_builtin)
6936 // Indicates that the function was created by the Function function.
6937 // Though it's anonymous, toString should treat it as if it had the name
6938 // "anonymous". We don't set the name itself so that the system does not
6939 // see a binding for it.
6940 DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous)
6942 // Indicates whether the function is a bound function created using
6943 // the bind function.
6944 DECL_BOOLEAN_ACCESSORS(bound)
6946 // Indicates that the function is anonymous (the name field can be set
6947 // through the API, which does not change this flag).
6948 DECL_BOOLEAN_ACCESSORS(is_anonymous)
6950 // Is this a function or top-level/eval code.
6951 DECL_BOOLEAN_ACCESSORS(is_function)
6953 // Indicates that code for this function cannot be cached.
6954 DECL_BOOLEAN_ACCESSORS(dont_cache)
6956 // Indicates that code for this function cannot be flushed.
6957 DECL_BOOLEAN_ACCESSORS(dont_flush)
6959 // Indicates that this function is a generator.
6960 DECL_BOOLEAN_ACCESSORS(is_generator)
6962 // Indicates that this function is an arrow function.
6963 DECL_BOOLEAN_ACCESSORS(is_arrow)
6965 // Indicates that this function is a concise method.
6966 DECL_BOOLEAN_ACCESSORS(is_concise_method)
6968 // Indicates that this function is an accessor (getter or setter).
6969 DECL_BOOLEAN_ACCESSORS(is_accessor_function)
6971 // Indicates that this function is a default constructor.
6972 DECL_BOOLEAN_ACCESSORS(is_default_constructor)
6974 // Indicates that this function is an asm function.
6975 DECL_BOOLEAN_ACCESSORS(asm_function)
6977 // Indicates that the the shared function info is deserialized from cache.
6978 DECL_BOOLEAN_ACCESSORS(deserialized)
6980 inline FunctionKind kind();
6981 inline void set_kind(FunctionKind kind);
6983 // Indicates whether or not the code in the shared function support
6985 inline bool has_deoptimization_support();
6987 // Enable deoptimization support through recompiled code.
6988 void EnableDeoptimizationSupport(Code* recompiled);
6990 // Disable (further) attempted optimization of all functions sharing this
6991 // shared function info.
6992 void DisableOptimization(BailoutReason reason);
6994 inline BailoutReason disable_optimization_reason();
6996 // Lookup the bailout ID and DCHECK that it exists in the non-optimized
6997 // code, returns whether it asserted (i.e., always true if assertions are
6999 bool VerifyBailoutId(BailoutId id);
7001 // [source code]: Source code for the function.
7002 bool HasSourceCode() const;
7003 Handle<Object> GetSourceCode();
7005 // Number of times the function was optimized.
7006 inline int opt_count();
7007 inline void set_opt_count(int opt_count);
7009 // Number of times the function was deoptimized.
7010 inline void set_deopt_count(int value);
7011 inline int deopt_count();
7012 inline void increment_deopt_count();
7014 // Number of time we tried to re-enable optimization after it
7015 // was disabled due to high number of deoptimizations.
7016 inline void set_opt_reenable_tries(int value);
7017 inline int opt_reenable_tries();
7019 inline void TryReenableOptimization();
7021 // Stores deopt_count, opt_reenable_tries and ic_age as bit-fields.
7022 inline void set_counters(int value);
7023 inline int counters() const;
7025 // Stores opt_count and bailout_reason as bit-fields.
7026 inline void set_opt_count_and_bailout_reason(int value);
7027 inline int opt_count_and_bailout_reason() const;
7029 void set_disable_optimization_reason(BailoutReason reason) {
7030 set_opt_count_and_bailout_reason(
7031 DisabledOptimizationReasonBits::update(opt_count_and_bailout_reason(),
7035 // Check whether or not this function is inlineable.
7036 bool IsInlineable();
7038 // Source size of this function.
7041 // Calculate the instance size.
7042 int CalculateInstanceSize();
7044 // Calculate the number of in-object properties.
7045 int CalculateInObjectProperties();
7047 inline bool is_simple_parameter_list();
7049 // Dispatched behavior.
7050 DECLARE_PRINTER(SharedFunctionInfo)
7051 DECLARE_VERIFIER(SharedFunctionInfo)
7053 void ResetForNewContext(int new_ic_age);
7055 DECLARE_CAST(SharedFunctionInfo)
7058 static const int kDontAdaptArgumentsSentinel = -1;
7060 // Layout description.
7062 static const int kNameOffset = HeapObject::kHeaderSize;
7063 static const int kCodeOffset = kNameOffset + kPointerSize;
7064 static const int kOptimizedCodeMapOffset = kCodeOffset + kPointerSize;
7065 static const int kScopeInfoOffset = kOptimizedCodeMapOffset + kPointerSize;
7066 static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize;
7067 static const int kInstanceClassNameOffset =
7068 kConstructStubOffset + kPointerSize;
7069 static const int kFunctionDataOffset =
7070 kInstanceClassNameOffset + kPointerSize;
7071 static const int kScriptOffset = kFunctionDataOffset + kPointerSize;
7072 static const int kDebugInfoOffset = kScriptOffset + kPointerSize;
7073 static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize;
7074 static const int kFeedbackVectorOffset =
7075 kInferredNameOffset + kPointerSize;
7077 static const int kUniqueIdOffset = kFeedbackVectorOffset + kPointerSize;
7078 static const int kLastPointerFieldOffset = kUniqueIdOffset;
7080 // Just to not break the postmortrem support with conditional offsets
7081 static const int kUniqueIdOffset = kFeedbackVectorOffset;
7082 static const int kLastPointerFieldOffset = kFeedbackVectorOffset;
7085 #if V8_HOST_ARCH_32_BIT
7087 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
7088 static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize;
7089 static const int kExpectedNofPropertiesOffset =
7090 kFormalParameterCountOffset + kPointerSize;
7091 static const int kNumLiteralsOffset =
7092 kExpectedNofPropertiesOffset + kPointerSize;
7093 static const int kStartPositionAndTypeOffset =
7094 kNumLiteralsOffset + kPointerSize;
7095 static const int kEndPositionOffset =
7096 kStartPositionAndTypeOffset + kPointerSize;
7097 static const int kFunctionTokenPositionOffset =
7098 kEndPositionOffset + kPointerSize;
7099 static const int kCompilerHintsOffset =
7100 kFunctionTokenPositionOffset + kPointerSize;
7101 static const int kOptCountAndBailoutReasonOffset =
7102 kCompilerHintsOffset + kPointerSize;
7103 static const int kCountersOffset =
7104 kOptCountAndBailoutReasonOffset + kPointerSize;
7105 static const int kAstNodeCountOffset =
7106 kCountersOffset + kPointerSize;
7107 static const int kProfilerTicksOffset =
7108 kAstNodeCountOffset + kPointerSize;
7111 static const int kSize = kProfilerTicksOffset + kPointerSize;
7113 // The only reason to use smi fields instead of int fields
7114 // is to allow iteration without maps decoding during
7115 // garbage collections.
7116 // To avoid wasting space on 64-bit architectures we use
7117 // the following trick: we group integer fields into pairs
7118 // The least significant integer in each pair is shifted left by 1.
7119 // By doing this we guarantee that LSB of each kPointerSize aligned
7120 // word is not set and thus this word cannot be treated as pointer
7121 // to HeapObject during old space traversal.
7122 #if V8_TARGET_LITTLE_ENDIAN
7123 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
7124 static const int kFormalParameterCountOffset =
7125 kLengthOffset + kIntSize;
7127 static const int kExpectedNofPropertiesOffset =
7128 kFormalParameterCountOffset + kIntSize;
7129 static const int kNumLiteralsOffset =
7130 kExpectedNofPropertiesOffset + kIntSize;
7132 static const int kEndPositionOffset =
7133 kNumLiteralsOffset + kIntSize;
7134 static const int kStartPositionAndTypeOffset =
7135 kEndPositionOffset + kIntSize;
7137 static const int kFunctionTokenPositionOffset =
7138 kStartPositionAndTypeOffset + kIntSize;
7139 static const int kCompilerHintsOffset =
7140 kFunctionTokenPositionOffset + kIntSize;
7142 static const int kOptCountAndBailoutReasonOffset =
7143 kCompilerHintsOffset + kIntSize;
7144 static const int kCountersOffset =
7145 kOptCountAndBailoutReasonOffset + kIntSize;
7147 static const int kAstNodeCountOffset =
7148 kCountersOffset + kIntSize;
7149 static const int kProfilerTicksOffset =
7150 kAstNodeCountOffset + kIntSize;
7153 static const int kSize = kProfilerTicksOffset + kIntSize;
7155 #elif V8_TARGET_BIG_ENDIAN
7156 static const int kFormalParameterCountOffset =
7157 kLastPointerFieldOffset + kPointerSize;
7158 static const int kLengthOffset = kFormalParameterCountOffset + kIntSize;
7160 static const int kNumLiteralsOffset = kLengthOffset + kIntSize;
7161 static const int kExpectedNofPropertiesOffset = kNumLiteralsOffset + kIntSize;
7163 static const int kStartPositionAndTypeOffset =
7164 kExpectedNofPropertiesOffset + kIntSize;
7165 static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize;
7167 static const int kCompilerHintsOffset = kEndPositionOffset + kIntSize;
7168 static const int kFunctionTokenPositionOffset =
7169 kCompilerHintsOffset + kIntSize;
7171 static const int kCountersOffset = kFunctionTokenPositionOffset + kIntSize;
7172 static const int kOptCountAndBailoutReasonOffset = kCountersOffset + kIntSize;
7174 static const int kProfilerTicksOffset =
7175 kOptCountAndBailoutReasonOffset + kIntSize;
7176 static const int kAstNodeCountOffset = kProfilerTicksOffset + kIntSize;
7179 static const int kSize = kAstNodeCountOffset + kIntSize;
7182 #error Unknown byte ordering
7183 #endif // Big endian
7187 static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
7189 typedef FixedBodyDescriptor<kNameOffset,
7190 kLastPointerFieldOffset + kPointerSize,
7191 kSize> BodyDescriptor;
7193 // Bit positions in start_position_and_type.
7194 // The source code start position is in the 30 most significant bits of
7195 // the start_position_and_type field.
7196 static const int kIsExpressionBit = 0;
7197 static const int kIsTopLevelBit = 1;
7198 static const int kStartPositionShift = 2;
7199 static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1);
7201 // Bit positions in compiler_hints.
7202 enum CompilerHints {
7203 kAllowLazyCompilation,
7204 kAllowLazyCompilationWithoutContext,
7205 kOptimizationDisabled,
7206 kStrictModeFunction,
7207 kStrongModeFunction,
7210 kHasDuplicateParameters,
7215 kNameShouldPrintAsAnonymous,
7222 kIsAccessorFunction,
7223 kIsDefaultConstructor,
7225 kIsSubclassConstructor,
7228 kCompilerHintsCount // Pseudo entry
7230 // Add hints for other modes when they're added.
7231 STATIC_ASSERT(LANGUAGE_END == 3);
7233 class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 7> {};
7235 class DeoptCountBits : public BitField<int, 0, 4> {};
7236 class OptReenableTriesBits : public BitField<int, 4, 18> {};
7237 class ICAgeBits : public BitField<int, 22, 8> {};
7239 class OptCountBits : public BitField<int, 0, 22> {};
7240 class DisabledOptimizationReasonBits : public BitField<int, 22, 8> {};
7243 #if V8_HOST_ARCH_32_BIT
7244 // On 32 bit platforms, compiler hints is a smi.
7245 static const int kCompilerHintsSmiTagSize = kSmiTagSize;
7246 static const int kCompilerHintsSize = kPointerSize;
7248 // On 64 bit platforms, compiler hints is not a smi, see comment above.
7249 static const int kCompilerHintsSmiTagSize = 0;
7250 static const int kCompilerHintsSize = kIntSize;
7253 STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <=
7254 SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte);
7257 // Constants for optimizing codegen for strict mode function and
7259 // Allows to use byte-width instructions.
7260 static const int kStrictModeBitWithinByte =
7261 (kStrictModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte;
7263 static const int kNativeBitWithinByte =
7264 (kNative + kCompilerHintsSmiTagSize) % kBitsPerByte;
7266 #if defined(V8_TARGET_LITTLE_ENDIAN)
7267 static const int kStrictModeByteOffset = kCompilerHintsOffset +
7268 (kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte;
7269 static const int kNativeByteOffset = kCompilerHintsOffset +
7270 (kNative + kCompilerHintsSmiTagSize) / kBitsPerByte;
7271 #elif defined(V8_TARGET_BIG_ENDIAN)
7272 static const int kStrictModeByteOffset = kCompilerHintsOffset +
7273 (kCompilerHintsSize - 1) -
7274 ((kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte);
7275 static const int kNativeByteOffset = kCompilerHintsOffset +
7276 (kCompilerHintsSize - 1) -
7277 ((kNative + kCompilerHintsSmiTagSize) / kBitsPerByte);
7279 #error Unknown byte ordering
7283 DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo);
7287 // Printing support.
7288 struct SourceCodeOf {
7289 explicit SourceCodeOf(SharedFunctionInfo* v, int max = -1)
7290 : value(v), max_length(max) {}
7291 const SharedFunctionInfo* value;
7296 std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v);
7299 class JSGeneratorObject: public JSObject {
7301 // [function]: The function corresponding to this generator object.
7302 DECL_ACCESSORS(function, JSFunction)
7304 // [context]: The context of the suspended computation.
7305 DECL_ACCESSORS(context, Context)
7307 // [receiver]: The receiver of the suspended computation.
7308 DECL_ACCESSORS(receiver, Object)
7310 // [continuation]: Offset into code of continuation.
7312 // A positive offset indicates a suspended generator. The special
7313 // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
7314 // cannot be resumed.
7315 inline int continuation() const;
7316 inline void set_continuation(int continuation);
7317 inline bool is_closed();
7318 inline bool is_executing();
7319 inline bool is_suspended();
7321 // [operand_stack]: Saved operand stack.
7322 DECL_ACCESSORS(operand_stack, FixedArray)
7324 // [stack_handler_index]: Index of first stack handler in operand_stack, or -1
7325 // if the captured activation had no stack handler.
7326 inline int stack_handler_index() const;
7327 inline void set_stack_handler_index(int stack_handler_index);
7329 DECLARE_CAST(JSGeneratorObject)
7331 // Dispatched behavior.
7332 DECLARE_PRINTER(JSGeneratorObject)
7333 DECLARE_VERIFIER(JSGeneratorObject)
7335 // Magic sentinel values for the continuation.
7336 static const int kGeneratorExecuting = -1;
7337 static const int kGeneratorClosed = 0;
7339 // Layout description.
7340 static const int kFunctionOffset = JSObject::kHeaderSize;
7341 static const int kContextOffset = kFunctionOffset + kPointerSize;
7342 static const int kReceiverOffset = kContextOffset + kPointerSize;
7343 static const int kContinuationOffset = kReceiverOffset + kPointerSize;
7344 static const int kOperandStackOffset = kContinuationOffset + kPointerSize;
7345 static const int kStackHandlerIndexOffset =
7346 kOperandStackOffset + kPointerSize;
7347 static const int kSize = kStackHandlerIndexOffset + kPointerSize;
7349 // Resume mode, for use by runtime functions.
7350 enum ResumeMode { NEXT, THROW };
7352 // Yielding from a generator returns an object with the following inobject
7353 // properties. See Context::iterator_result_map() for the map.
7354 static const int kResultValuePropertyIndex = 0;
7355 static const int kResultDonePropertyIndex = 1;
7356 static const int kResultPropertyCount = 2;
7358 static const int kResultValuePropertyOffset = JSObject::kHeaderSize;
7359 static const int kResultDonePropertyOffset =
7360 kResultValuePropertyOffset + kPointerSize;
7361 static const int kResultSize = kResultDonePropertyOffset + kPointerSize;
7364 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
7368 // Representation for module instance objects.
7369 class JSModule: public JSObject {
7371 // [context]: the context holding the module's locals, or undefined if none.
7372 DECL_ACCESSORS(context, Object)
7374 // [scope_info]: Scope info.
7375 DECL_ACCESSORS(scope_info, ScopeInfo)
7377 DECLARE_CAST(JSModule)
7379 // Dispatched behavior.
7380 DECLARE_PRINTER(JSModule)
7381 DECLARE_VERIFIER(JSModule)
7383 // Layout description.
7384 static const int kContextOffset = JSObject::kHeaderSize;
7385 static const int kScopeInfoOffset = kContextOffset + kPointerSize;
7386 static const int kSize = kScopeInfoOffset + kPointerSize;
7389 DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule);
7393 // JSFunction describes JavaScript functions.
7394 class JSFunction: public JSObject {
7396 // [prototype_or_initial_map]:
7397 DECL_ACCESSORS(prototype_or_initial_map, Object)
7399 // [shared]: The information about the function that
7400 // can be shared by instances.
7401 DECL_ACCESSORS(shared, SharedFunctionInfo)
7403 // [context]: The context for this function.
7404 inline Context* context();
7405 inline void set_context(Object* context);
7406 inline JSObject* global_proxy();
7408 // [code]: The generated code object for this function. Executed
7409 // when the function is invoked, e.g. foo() or new foo(). See
7410 // [[Call]] and [[Construct]] description in ECMA-262, section
7412 inline Code* code();
7413 inline void set_code(Code* code);
7414 inline void set_code_no_write_barrier(Code* code);
7415 inline void ReplaceCode(Code* code);
7417 // Tells whether this function is builtin.
7418 inline bool IsBuiltin();
7420 // Tells whether this function is defined in a native script.
7421 inline bool IsFromNativeScript();
7423 // Tells whether this function is defined in an extension script.
7424 inline bool IsFromExtensionScript();
7426 // Tells whether or not the function needs arguments adaption.
7427 inline bool NeedsArgumentsAdaption();
7429 // Tells whether or not this function has been optimized.
7430 inline bool IsOptimized();
7432 // Tells whether or not this function can be optimized.
7433 inline bool IsOptimizable();
7435 // Mark this function for lazy recompilation. The function will be
7436 // recompiled the next time it is executed.
7437 void MarkForOptimization();
7438 void AttemptConcurrentOptimization();
7440 // Tells whether or not the function is already marked for lazy
7442 inline bool IsMarkedForOptimization();
7443 inline bool IsMarkedForConcurrentOptimization();
7445 // Tells whether or not the function is on the concurrent recompilation queue.
7446 inline bool IsInOptimizationQueue();
7448 // Inobject slack tracking is the way to reclaim unused inobject space.
7450 // The instance size is initially determined by adding some slack to
7451 // expected_nof_properties (to allow for a few extra properties added
7452 // after the constructor). There is no guarantee that the extra space
7453 // will not be wasted.
7455 // Here is the algorithm to reclaim the unused inobject space:
7456 // - Detect the first constructor call for this JSFunction.
7457 // When it happens enter the "in progress" state: initialize construction
7458 // counter in the initial_map.
7459 // - While the tracking is in progress create objects filled with
7460 // one_pointer_filler_map instead of undefined_value. This way they can be
7461 // resized quickly and safely.
7462 // - Once enough objects have been created compute the 'slack'
7463 // (traverse the map transition tree starting from the
7464 // initial_map and find the lowest value of unused_property_fields).
7465 // - Traverse the transition tree again and decrease the instance size
7466 // of every map. Existing objects will resize automatically (they are
7467 // filled with one_pointer_filler_map). All further allocations will
7468 // use the adjusted instance size.
7469 // - SharedFunctionInfo's expected_nof_properties left unmodified since
7470 // allocations made using different closures could actually create different
7471 // kind of objects (see prototype inheritance pattern).
7473 // Important: inobject slack tracking is not attempted during the snapshot
7476 // True if the initial_map is set and the object constructions countdown
7477 // counter is not zero.
7478 static const int kGenerousAllocationCount =
7479 Map::kSlackTrackingCounterStart - Map::kSlackTrackingCounterEnd + 1;
7480 inline bool IsInobjectSlackTrackingInProgress();
7482 // Starts the tracking.
7483 // Initializes object constructions countdown counter in the initial map.
7484 void StartInobjectSlackTracking();
7486 // Completes the tracking.
7487 void CompleteInobjectSlackTracking();
7489 // [literals_or_bindings]: Fixed array holding either
7490 // the materialized literals or the bindings of a bound function.
7492 // If the function contains object, regexp or array literals, the
7493 // literals array prefix contains the object, regexp, and array
7494 // function to be used when creating these literals. This is
7495 // necessary so that we do not dynamically lookup the object, regexp
7496 // or array functions. Performing a dynamic lookup, we might end up
7497 // using the functions from a new context that we should not have
7500 // On bound functions, the array is a (copy-on-write) fixed-array containing
7501 // the function that was bound, bound this-value and any bound
7502 // arguments. Bound functions never contain literals.
7503 DECL_ACCESSORS(literals_or_bindings, FixedArray)
7505 inline FixedArray* literals();
7506 inline void set_literals(FixedArray* literals);
7508 inline FixedArray* function_bindings();
7509 inline void set_function_bindings(FixedArray* bindings);
7511 // The initial map for an object created by this constructor.
7512 inline Map* initial_map();
7513 static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
7514 Handle<Object> prototype);
7515 inline bool has_initial_map();
7516 static void EnsureHasInitialMap(Handle<JSFunction> function);
7518 // Get and set the prototype property on a JSFunction. If the
7519 // function has an initial map the prototype is set on the initial
7520 // map. Otherwise, the prototype is put in the initial map field
7521 // until an initial map is needed.
7522 inline bool has_prototype();
7523 inline bool has_instance_prototype();
7524 inline Object* prototype();
7525 inline Object* instance_prototype();
7526 static void SetPrototype(Handle<JSFunction> function,
7527 Handle<Object> value);
7528 static void SetInstancePrototype(Handle<JSFunction> function,
7529 Handle<Object> value);
7531 // Creates a new closure for the fucntion with the same bindings,
7532 // bound values, and prototype. An equivalent of spec operations
7533 // ``CloneMethod`` and ``CloneBoundFunction``.
7534 static Handle<JSFunction> CloneClosure(Handle<JSFunction> function);
7536 // After prototype is removed, it will not be created when accessed, and
7537 // [[Construct]] from this function will not be allowed.
7538 bool RemovePrototype();
7539 inline bool should_have_prototype();
7541 // Accessor for this function's initial map's [[class]]
7542 // property. This is primarily used by ECMA native functions. This
7543 // method sets the class_name field of this function's initial map
7544 // to a given value. It creates an initial map if this function does
7545 // not have one. Note that this method does not copy the initial map
7546 // if it has one already, but simply replaces it with the new value.
7547 // Instances created afterwards will have a map whose [[class]] is
7548 // set to 'value', but there is no guarantees on instances created
7550 void SetInstanceClassName(String* name);
7552 // Returns if this function has been compiled to native code yet.
7553 inline bool is_compiled();
7555 // Returns `false` if formal parameters include rest parameters, optional
7556 // parameters, or destructuring parameters.
7557 // TODO(caitp): make this a flag set during parsing
7558 inline bool is_simple_parameter_list();
7560 // [next_function_link]: Links functions into various lists, e.g. the list
7561 // of optimized functions hanging off the native_context. The CodeFlusher
7562 // uses this link to chain together flushing candidates. Treated weakly
7563 // by the garbage collector.
7564 DECL_ACCESSORS(next_function_link, Object)
7566 // Prints the name of the function using PrintF.
7567 void PrintName(FILE* out = stdout);
7569 DECLARE_CAST(JSFunction)
7571 // Iterates the objects, including code objects indirectly referenced
7572 // through pointers to the first instruction in the code object.
7573 void JSFunctionIterateBody(int object_size, ObjectVisitor* v);
7575 // Dispatched behavior.
7576 DECLARE_PRINTER(JSFunction)
7577 DECLARE_VERIFIER(JSFunction)
7579 // Returns the number of allocated literals.
7580 inline int NumberOfLiterals();
7582 // Retrieve the native context from a function's literal array.
7583 static Context* NativeContextFromLiterals(FixedArray* literals);
7585 // Used for flags such as --hydrogen-filter.
7586 bool PassesFilter(const char* raw_filter);
7588 // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
7589 // kSize) is weak and has special handling during garbage collection.
7590 static const int kCodeEntryOffset = JSObject::kHeaderSize;
7591 static const int kPrototypeOrInitialMapOffset =
7592 kCodeEntryOffset + kPointerSize;
7593 static const int kSharedFunctionInfoOffset =
7594 kPrototypeOrInitialMapOffset + kPointerSize;
7595 static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize;
7596 static const int kLiteralsOffset = kContextOffset + kPointerSize;
7597 static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize;
7598 static const int kNextFunctionLinkOffset = kNonWeakFieldsEndOffset;
7599 static const int kSize = kNextFunctionLinkOffset + kPointerSize;
7601 // Layout of the literals array.
7602 static const int kLiteralsPrefixSize = 1;
7603 static const int kLiteralNativeContextIndex = 0;
7605 // Layout of the bound-function binding array.
7606 static const int kBoundFunctionIndex = 0;
7607 static const int kBoundThisIndex = 1;
7608 static const int kBoundArgumentsStartIndex = 2;
7611 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
7615 // JSGlobalProxy's prototype must be a JSGlobalObject or null,
7616 // and the prototype is hidden. JSGlobalProxy always delegates
7617 // property accesses to its prototype if the prototype is not null.
7619 // A JSGlobalProxy can be reinitialized which will preserve its identity.
7621 // Accessing a JSGlobalProxy requires security check.
7623 class JSGlobalProxy : public JSObject {
7625 // [native_context]: the owner native context of this global proxy object.
7626 // It is null value if this object is not used by any context.
7627 DECL_ACCESSORS(native_context, Object)
7629 // [hash]: The hash code property (undefined if not initialized yet).
7630 DECL_ACCESSORS(hash, Object)
7632 DECLARE_CAST(JSGlobalProxy)
7634 inline bool IsDetachedFrom(GlobalObject* global) const;
7636 // Dispatched behavior.
7637 DECLARE_PRINTER(JSGlobalProxy)
7638 DECLARE_VERIFIER(JSGlobalProxy)
7640 // Layout description.
7641 static const int kNativeContextOffset = JSObject::kHeaderSize;
7642 static const int kHashOffset = kNativeContextOffset + kPointerSize;
7643 static const int kSize = kHashOffset + kPointerSize;
7646 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
7650 // Forward declaration.
7651 class JSBuiltinsObject;
7653 // Common super class for JavaScript global objects and the special
7654 // builtins global objects.
7655 class GlobalObject: public JSObject {
7657 // [builtins]: the object holding the runtime routines written in JS.
7658 DECL_ACCESSORS(builtins, JSBuiltinsObject)
7660 // [native context]: the natives corresponding to this global object.
7661 DECL_ACCESSORS(native_context, Context)
7663 // [global proxy]: the global proxy object of the context
7664 DECL_ACCESSORS(global_proxy, JSObject)
7666 DECLARE_CAST(GlobalObject)
7668 static void InvalidatePropertyCell(Handle<GlobalObject> object,
7670 // Ensure that the global object has a cell for the given property name.
7671 static Handle<PropertyCell> EnsurePropertyCell(Handle<GlobalObject> global,
7674 // Layout description.
7675 static const int kBuiltinsOffset = JSObject::kHeaderSize;
7676 static const int kNativeContextOffset = kBuiltinsOffset + kPointerSize;
7677 static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
7678 static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
7681 DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject);
7685 // JavaScript global object.
7686 class JSGlobalObject: public GlobalObject {
7688 DECLARE_CAST(JSGlobalObject)
7690 inline bool IsDetached();
7692 // Dispatched behavior.
7693 DECLARE_PRINTER(JSGlobalObject)
7694 DECLARE_VERIFIER(JSGlobalObject)
7696 // Layout description.
7697 static const int kSize = GlobalObject::kHeaderSize;
7700 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
7704 // Builtins global object which holds the runtime routines written in
7706 class JSBuiltinsObject: public GlobalObject {
7708 // Accessors for the runtime routines written in JavaScript.
7709 inline Object* javascript_builtin(Builtins::JavaScript id);
7710 inline void set_javascript_builtin(Builtins::JavaScript id, Object* value);
7712 // Accessors for code of the runtime routines written in JavaScript.
7713 inline Code* javascript_builtin_code(Builtins::JavaScript id);
7714 inline void set_javascript_builtin_code(Builtins::JavaScript id, Code* value);
7716 DECLARE_CAST(JSBuiltinsObject)
7718 // Dispatched behavior.
7719 DECLARE_PRINTER(JSBuiltinsObject)
7720 DECLARE_VERIFIER(JSBuiltinsObject)
7722 // Layout description. The size of the builtins object includes
7723 // room for two pointers per runtime routine written in javascript
7724 // (function and code object).
7725 static const int kJSBuiltinsCount = Builtins::id_count;
7726 static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize;
7727 static const int kJSBuiltinsCodeOffset =
7728 GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize);
7729 static const int kSize =
7730 kJSBuiltinsCodeOffset + (kJSBuiltinsCount * kPointerSize);
7732 static int OffsetOfFunctionWithId(Builtins::JavaScript id) {
7733 return kJSBuiltinsOffset + id * kPointerSize;
7736 static int OffsetOfCodeWithId(Builtins::JavaScript id) {
7737 return kJSBuiltinsCodeOffset + id * kPointerSize;
7741 DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject);
7745 // Representation for JS Wrapper objects, String, Number, Boolean, etc.
7746 class JSValue: public JSObject {
7748 // [value]: the object being wrapped.
7749 DECL_ACCESSORS(value, Object)
7751 DECLARE_CAST(JSValue)
7753 // Dispatched behavior.
7754 DECLARE_PRINTER(JSValue)
7755 DECLARE_VERIFIER(JSValue)
7757 // Layout description.
7758 static const int kValueOffset = JSObject::kHeaderSize;
7759 static const int kSize = kValueOffset + kPointerSize;
7762 DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
7768 // Representation for JS date objects.
7769 class JSDate: public JSObject {
7771 // If one component is NaN, all of them are, indicating a NaN time value.
7772 // [value]: the time value.
7773 DECL_ACCESSORS(value, Object)
7774 // [year]: caches year. Either undefined, smi, or NaN.
7775 DECL_ACCESSORS(year, Object)
7776 // [month]: caches month. Either undefined, smi, or NaN.
7777 DECL_ACCESSORS(month, Object)
7778 // [day]: caches day. Either undefined, smi, or NaN.
7779 DECL_ACCESSORS(day, Object)
7780 // [weekday]: caches day of week. Either undefined, smi, or NaN.
7781 DECL_ACCESSORS(weekday, Object)
7782 // [hour]: caches hours. Either undefined, smi, or NaN.
7783 DECL_ACCESSORS(hour, Object)
7784 // [min]: caches minutes. Either undefined, smi, or NaN.
7785 DECL_ACCESSORS(min, Object)
7786 // [sec]: caches seconds. Either undefined, smi, or NaN.
7787 DECL_ACCESSORS(sec, Object)
7788 // [cache stamp]: sample of the date cache stamp at the
7789 // moment when chached fields were cached.
7790 DECL_ACCESSORS(cache_stamp, Object)
7792 DECLARE_CAST(JSDate)
7794 // Returns the date field with the specified index.
7795 // See FieldIndex for the list of date fields.
7796 static Object* GetField(Object* date, Smi* index);
7798 void SetValue(Object* value, bool is_value_nan);
7801 // Dispatched behavior.
7802 DECLARE_PRINTER(JSDate)
7803 DECLARE_VERIFIER(JSDate)
7805 // The order is important. It must be kept in sync with date macros
7816 kFirstUncachedField,
7817 kMillisecond = kFirstUncachedField,
7821 kYearUTC = kFirstUTCField,
7834 // Layout description.
7835 static const int kValueOffset = JSObject::kHeaderSize;
7836 static const int kYearOffset = kValueOffset + kPointerSize;
7837 static const int kMonthOffset = kYearOffset + kPointerSize;
7838 static const int kDayOffset = kMonthOffset + kPointerSize;
7839 static const int kWeekdayOffset = kDayOffset + kPointerSize;
7840 static const int kHourOffset = kWeekdayOffset + kPointerSize;
7841 static const int kMinOffset = kHourOffset + kPointerSize;
7842 static const int kSecOffset = kMinOffset + kPointerSize;
7843 static const int kCacheStampOffset = kSecOffset + kPointerSize;
7844 static const int kSize = kCacheStampOffset + kPointerSize;
7847 inline Object* DoGetField(FieldIndex index);
7849 Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
7851 // Computes and caches the cacheable fields of the date.
7852 inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
7855 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
7859 // Representation of message objects used for error reporting through
7860 // the API. The messages are formatted in JavaScript so this object is
7861 // a real JavaScript object. The information used for formatting the
7862 // error messages are not directly accessible from JavaScript to
7863 // prevent leaking information to user code called during error
7865 class JSMessageObject: public JSObject {
7867 // [type]: the type of error message.
7868 DECL_ACCESSORS(type, String)
7870 // [arguments]: the arguments for formatting the error message.
7871 DECL_ACCESSORS(arguments, JSArray)
7873 // [script]: the script from which the error message originated.
7874 DECL_ACCESSORS(script, Object)
7876 // [stack_frames]: an array of stack frames for this error object.
7877 DECL_ACCESSORS(stack_frames, Object)
7879 // [start_position]: the start position in the script for the error message.
7880 inline int start_position() const;
7881 inline void set_start_position(int value);
7883 // [end_position]: the end position in the script for the error message.
7884 inline int end_position() const;
7885 inline void set_end_position(int value);
7887 DECLARE_CAST(JSMessageObject)
7889 // Dispatched behavior.
7890 DECLARE_PRINTER(JSMessageObject)
7891 DECLARE_VERIFIER(JSMessageObject)
7893 // Layout description.
7894 static const int kTypeOffset = JSObject::kHeaderSize;
7895 static const int kArgumentsOffset = kTypeOffset + kPointerSize;
7896 static const int kScriptOffset = kArgumentsOffset + kPointerSize;
7897 static const int kStackFramesOffset = kScriptOffset + kPointerSize;
7898 static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
7899 static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
7900 static const int kSize = kEndPositionOffset + kPointerSize;
7902 typedef FixedBodyDescriptor<HeapObject::kMapOffset,
7903 kStackFramesOffset + kPointerSize,
7904 kSize> BodyDescriptor;
7908 // Regular expressions
7909 // The regular expression holds a single reference to a FixedArray in
7910 // the kDataOffset field.
7911 // The FixedArray contains the following data:
7912 // - tag : type of regexp implementation (not compiled yet, atom or irregexp)
7913 // - reference to the original source string
7914 // - reference to the original flag string
7915 // If it is an atom regexp
7916 // - a reference to a literal string to search for
7917 // If it is an irregexp regexp:
7918 // - a reference to code for Latin1 inputs (bytecode or compiled), or a smi
7919 // used for tracking the last usage (used for code flushing).
7920 // - a reference to code for UC16 inputs (bytecode or compiled), or a smi
7921 // used for tracking the last usage (used for code flushing)..
7922 // - max number of registers used by irregexp implementations.
7923 // - number of capture registers (output values) of the regexp.
7924 class JSRegExp: public JSObject {
7927 // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet.
7928 // ATOM: A simple string to match against using an indexOf operation.
7929 // IRREGEXP: Compiled with Irregexp.
7930 // IRREGEXP_NATIVE: Compiled to native code with Irregexp.
7931 enum Type { NOT_COMPILED, ATOM, IRREGEXP };
7938 UNICODE_ESCAPES = 16
7943 explicit Flags(uint32_t value) : value_(value) { }
7944 bool is_global() { return (value_ & GLOBAL) != 0; }
7945 bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; }
7946 bool is_multiline() { return (value_ & MULTILINE) != 0; }
7947 bool is_sticky() { return (value_ & STICKY) != 0; }
7948 bool is_unicode() { return (value_ & UNICODE_ESCAPES) != 0; }
7949 uint32_t value() { return value_; }
7954 DECL_ACCESSORS(data, Object)
7956 inline Type TypeTag();
7957 inline int CaptureCount();
7958 inline Flags GetFlags();
7959 inline String* Pattern();
7960 inline Object* DataAt(int index);
7961 // Set implementation data after the object has been prepared.
7962 inline void SetDataAt(int index, Object* value);
7964 static int code_index(bool is_latin1) {
7966 return kIrregexpLatin1CodeIndex;
7968 return kIrregexpUC16CodeIndex;
7972 static int saved_code_index(bool is_latin1) {
7974 return kIrregexpLatin1CodeSavedIndex;
7976 return kIrregexpUC16CodeSavedIndex;
7980 DECLARE_CAST(JSRegExp)
7982 // Dispatched behavior.
7983 DECLARE_VERIFIER(JSRegExp)
7985 static const int kDataOffset = JSObject::kHeaderSize;
7986 static const int kSize = kDataOffset + kPointerSize;
7988 // Indices in the data array.
7989 static const int kTagIndex = 0;
7990 static const int kSourceIndex = kTagIndex + 1;
7991 static const int kFlagsIndex = kSourceIndex + 1;
7992 static const int kDataIndex = kFlagsIndex + 1;
7993 // The data fields are used in different ways depending on the
7994 // value of the tag.
7995 // Atom regexps (literal strings).
7996 static const int kAtomPatternIndex = kDataIndex;
7998 static const int kAtomDataSize = kAtomPatternIndex + 1;
8000 // Irregexp compiled code or bytecode for Latin1. If compilation
8001 // fails, this fields hold an exception object that should be
8002 // thrown if the regexp is used again.
8003 static const int kIrregexpLatin1CodeIndex = kDataIndex;
8004 // Irregexp compiled code or bytecode for UC16. If compilation
8005 // fails, this fields hold an exception object that should be
8006 // thrown if the regexp is used again.
8007 static const int kIrregexpUC16CodeIndex = kDataIndex + 1;
8009 // Saved instance of Irregexp compiled code or bytecode for Latin1 that
8010 // is a potential candidate for flushing.
8011 static const int kIrregexpLatin1CodeSavedIndex = kDataIndex + 2;
8012 // Saved instance of Irregexp compiled code or bytecode for UC16 that is
8013 // a potential candidate for flushing.
8014 static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3;
8016 // Maximal number of registers used by either Latin1 or UC16.
8017 // Only used to check that there is enough stack space
8018 static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4;
8019 // Number of captures in the compiled regexp.
8020 static const int kIrregexpCaptureCountIndex = kDataIndex + 5;
8022 static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1;
8024 // Offsets directly into the data fixed array.
8025 static const int kDataTagOffset =
8026 FixedArray::kHeaderSize + kTagIndex * kPointerSize;
8027 static const int kDataOneByteCodeOffset =
8028 FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize;
8029 static const int kDataUC16CodeOffset =
8030 FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize;
8031 static const int kIrregexpCaptureCountOffset =
8032 FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize;
8034 // In-object fields.
8035 static const int kGlobalFieldIndex = 0;
8036 static const int kIgnoreCaseFieldIndex = 1;
8037 static const int kMultilineFieldIndex = 2;
8038 static const int kLastIndexFieldIndex = 3;
8039 static const int kInObjectFieldCount = 4;
8041 // The uninitialized value for a regexp code object.
8042 static const int kUninitializedValue = -1;
8044 // The compilation error value for the regexp code object. The real error
8045 // object is in the saved code field.
8046 static const int kCompilationErrorValue = -2;
8048 // When we store the sweep generation at which we moved the code from the
8049 // code index to the saved code index we mask it of to be in the [0:255]
8051 static const int kCodeAgeMask = 0xff;
8055 class CompilationCacheShape : public BaseShape<HashTableKey*> {
8057 static inline bool IsMatch(HashTableKey* key, Object* value) {
8058 return key->IsMatch(value);
8061 static inline uint32_t Hash(HashTableKey* key) {
8065 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
8066 return key->HashForObject(object);
8069 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
8071 static const int kPrefixSize = 0;
8072 static const int kEntrySize = 2;
8076 // This cache is used in two different variants. For regexp caching, it simply
8077 // maps identifying info of the regexp to the cached regexp object. Scripts and
8078 // eval code only gets cached after a second probe for the code object. To do
8079 // so, on first "put" only a hash identifying the source is entered into the
8080 // cache, mapping it to a lifetime count of the hash. On each call to Age all
8081 // such lifetimes get reduced, and removed once they reach zero. If a second put
8082 // is called while such a hash is live in the cache, the hash gets replaced by
8083 // an actual cache entry. Age also removes stale live entries from the cache.
8084 // Such entries are identified by SharedFunctionInfos pointing to either the
8085 // recompilation stub, or to "old" code. This avoids memory leaks due to
8086 // premature caching of scripts and eval strings that are never needed later.
8087 class CompilationCacheTable: public HashTable<CompilationCacheTable,
8088 CompilationCacheShape,
8091 // Find cached value for a string key, otherwise return null.
8092 Handle<Object> Lookup(
8093 Handle<String> src, Handle<Context> context, LanguageMode language_mode);
8094 Handle<Object> LookupEval(
8095 Handle<String> src, Handle<SharedFunctionInfo> shared,
8096 LanguageMode language_mode, int scope_position);
8097 Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags);
8098 static Handle<CompilationCacheTable> Put(
8099 Handle<CompilationCacheTable> cache, Handle<String> src,
8100 Handle<Context> context, LanguageMode language_mode,
8101 Handle<Object> value);
8102 static Handle<CompilationCacheTable> PutEval(
8103 Handle<CompilationCacheTable> cache, Handle<String> src,
8104 Handle<SharedFunctionInfo> context, Handle<SharedFunctionInfo> value,
8105 int scope_position);
8106 static Handle<CompilationCacheTable> PutRegExp(
8107 Handle<CompilationCacheTable> cache, Handle<String> src,
8108 JSRegExp::Flags flags, Handle<FixedArray> value);
8109 void Remove(Object* value);
8111 static const int kHashGenerations = 10;
8113 DECLARE_CAST(CompilationCacheTable)
8116 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable);
8120 class CodeCache: public Struct {
8122 DECL_ACCESSORS(default_cache, FixedArray)
8123 DECL_ACCESSORS(normal_type_cache, Object)
8124 DECL_ACCESSORS(weak_cell_cache, Object)
8126 // Add the code object to the cache.
8128 Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code);
8130 // Lookup code object in the cache. Returns code object if found and undefined
8132 Object* Lookup(Name* name, Code::Flags flags);
8134 // Get the internal index of a code object in the cache. Returns -1 if the
8135 // code object is not in that cache. This index can be used to later call
8136 // RemoveByIndex. The cache cannot be modified between a call to GetIndex and
8138 int GetIndex(Object* name, Code* code);
8140 // Remove an object from the cache with the provided internal index.
8141 void RemoveByIndex(Object* name, Code* code, int index);
8143 DECLARE_CAST(CodeCache)
8145 // Dispatched behavior.
8146 DECLARE_PRINTER(CodeCache)
8147 DECLARE_VERIFIER(CodeCache)
8149 static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
8150 static const int kNormalTypeCacheOffset =
8151 kDefaultCacheOffset + kPointerSize;
8152 static const int kWeakCellCacheOffset = kNormalTypeCacheOffset + kPointerSize;
8153 static const int kSize = kWeakCellCacheOffset + kPointerSize;
8156 static void UpdateDefaultCache(
8157 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
8158 static void UpdateNormalTypeCache(
8159 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
8160 Object* LookupDefaultCache(Name* name, Code::Flags flags);
8161 Object* LookupNormalTypeCache(Name* name, Code::Flags flags);
8163 // Code cache layout of the default cache. Elements are alternating name and
8164 // code objects for non normal load/store/call IC's.
8165 static const int kCodeCacheEntrySize = 2;
8166 static const int kCodeCacheEntryNameOffset = 0;
8167 static const int kCodeCacheEntryCodeOffset = 1;
8169 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
8173 class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
8175 static inline bool IsMatch(HashTableKey* key, Object* value) {
8176 return key->IsMatch(value);
8179 static inline uint32_t Hash(HashTableKey* key) {
8183 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
8184 return key->HashForObject(object);
8187 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
8189 static const int kPrefixSize = 0;
8190 static const int kEntrySize = 2;
8194 class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
8195 CodeCacheHashTableShape,
8198 Object* Lookup(Name* name, Code::Flags flags);
8199 static Handle<CodeCacheHashTable> Put(
8200 Handle<CodeCacheHashTable> table,
8204 int GetIndex(Name* name, Code::Flags flags);
8205 void RemoveByIndex(int index);
8207 DECLARE_CAST(CodeCacheHashTable)
8209 // Initial size of the fixed array backing the hash table.
8210 static const int kInitialSize = 64;
8213 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
8217 class PolymorphicCodeCache: public Struct {
8219 DECL_ACCESSORS(cache, Object)
8221 static void Update(Handle<PolymorphicCodeCache> cache,
8222 MapHandleList* maps,
8227 // Returns an undefined value if the entry is not found.
8228 Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags);
8230 DECLARE_CAST(PolymorphicCodeCache)
8232 // Dispatched behavior.
8233 DECLARE_PRINTER(PolymorphicCodeCache)
8234 DECLARE_VERIFIER(PolymorphicCodeCache)
8236 static const int kCacheOffset = HeapObject::kHeaderSize;
8237 static const int kSize = kCacheOffset + kPointerSize;
8240 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache);
8244 class PolymorphicCodeCacheHashTable
8245 : public HashTable<PolymorphicCodeCacheHashTable,
8246 CodeCacheHashTableShape,
8249 Object* Lookup(MapHandleList* maps, int code_kind);
8251 static Handle<PolymorphicCodeCacheHashTable> Put(
8252 Handle<PolymorphicCodeCacheHashTable> hash_table,
8253 MapHandleList* maps,
8257 DECLARE_CAST(PolymorphicCodeCacheHashTable)
8259 static const int kInitialSize = 64;
8261 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable);
8265 class TypeFeedbackInfo: public Struct {
8267 inline int ic_total_count();
8268 inline void set_ic_total_count(int count);
8270 inline int ic_with_type_info_count();
8271 inline void change_ic_with_type_info_count(int delta);
8273 inline int ic_generic_count();
8274 inline void change_ic_generic_count(int delta);
8276 inline void initialize_storage();
8278 inline void change_own_type_change_checksum();
8279 inline int own_type_change_checksum();
8281 inline void set_inlined_type_change_checksum(int checksum);
8282 inline bool matches_inlined_type_change_checksum(int checksum);
8284 DECLARE_CAST(TypeFeedbackInfo)
8286 // Dispatched behavior.
8287 DECLARE_PRINTER(TypeFeedbackInfo)
8288 DECLARE_VERIFIER(TypeFeedbackInfo)
8290 static const int kStorage1Offset = HeapObject::kHeaderSize;
8291 static const int kStorage2Offset = kStorage1Offset + kPointerSize;
8292 static const int kStorage3Offset = kStorage2Offset + kPointerSize;
8293 static const int kSize = kStorage3Offset + kPointerSize;
8296 static const int kTypeChangeChecksumBits = 7;
8298 class ICTotalCountField: public BitField<int, 0,
8299 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
8300 class OwnTypeChangeChecksum: public BitField<int,
8301 kSmiValueSize - kTypeChangeChecksumBits,
8302 kTypeChangeChecksumBits> {}; // NOLINT
8303 class ICsWithTypeInfoCountField: public BitField<int, 0,
8304 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
8305 class InlinedTypeChangeChecksum: public BitField<int,
8306 kSmiValueSize - kTypeChangeChecksumBits,
8307 kTypeChangeChecksumBits> {}; // NOLINT
8309 DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo);
8313 enum AllocationSiteMode {
8314 DONT_TRACK_ALLOCATION_SITE,
8315 TRACK_ALLOCATION_SITE,
8316 LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE
8320 class AllocationSite: public Struct {
8322 static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
8323 static const double kPretenureRatio;
8324 static const int kPretenureMinimumCreated = 100;
8326 // Values for pretenure decision field.
8327 enum PretenureDecision {
8333 kLastPretenureDecisionValue = kZombie
8336 const char* PretenureDecisionName(PretenureDecision decision);
8338 DECL_ACCESSORS(transition_info, Object)
8339 // nested_site threads a list of sites that represent nested literals
8340 // walked in a particular order. So [[1, 2], 1, 2] will have one
8341 // nested_site, but [[1, 2], 3, [4]] will have a list of two.
8342 DECL_ACCESSORS(nested_site, Object)
8343 DECL_ACCESSORS(pretenure_data, Smi)
8344 DECL_ACCESSORS(pretenure_create_count, Smi)
8345 DECL_ACCESSORS(dependent_code, DependentCode)
8346 DECL_ACCESSORS(weak_next, Object)
8348 inline void Initialize();
8350 // This method is expensive, it should only be called for reporting.
8351 bool IsNestedSite();
8353 // transition_info bitfields, for constructed array transition info.
8354 class ElementsKindBits: public BitField<ElementsKind, 0, 15> {};
8355 class UnusedBits: public BitField<int, 15, 14> {};
8356 class DoNotInlineBit: public BitField<bool, 29, 1> {};
8358 // Bitfields for pretenure_data
8359 class MementoFoundCountBits: public BitField<int, 0, 26> {};
8360 class PretenureDecisionBits: public BitField<PretenureDecision, 26, 3> {};
8361 class DeoptDependentCodeBit: public BitField<bool, 29, 1> {};
8362 STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
8364 // Increments the mementos found counter and returns true when the first
8365 // memento was found for a given allocation site.
8366 inline bool IncrementMementoFoundCount();
8368 inline void IncrementMementoCreateCount();
8370 PretenureFlag GetPretenureMode();
8372 void ResetPretenureDecision();
8374 PretenureDecision pretenure_decision() {
8375 int value = pretenure_data()->value();
8376 return PretenureDecisionBits::decode(value);
8379 void set_pretenure_decision(PretenureDecision decision) {
8380 int value = pretenure_data()->value();
8382 Smi::FromInt(PretenureDecisionBits::update(value, decision)),
8383 SKIP_WRITE_BARRIER);
8386 bool deopt_dependent_code() {
8387 int value = pretenure_data()->value();
8388 return DeoptDependentCodeBit::decode(value);
8391 void set_deopt_dependent_code(bool deopt) {
8392 int value = pretenure_data()->value();
8394 Smi::FromInt(DeoptDependentCodeBit::update(value, deopt)),
8395 SKIP_WRITE_BARRIER);
8398 int memento_found_count() {
8399 int value = pretenure_data()->value();
8400 return MementoFoundCountBits::decode(value);
8403 inline void set_memento_found_count(int count);
8405 int memento_create_count() {
8406 return pretenure_create_count()->value();
8409 void set_memento_create_count(int count) {
8410 set_pretenure_create_count(Smi::FromInt(count), SKIP_WRITE_BARRIER);
8413 // The pretenuring decision is made during gc, and the zombie state allows
8414 // us to recognize when an allocation site is just being kept alive because
8415 // a later traversal of new space may discover AllocationMementos that point
8416 // to this AllocationSite.
8418 return pretenure_decision() == kZombie;
8421 bool IsMaybeTenure() {
8422 return pretenure_decision() == kMaybeTenure;
8425 inline void MarkZombie();
8427 inline bool MakePretenureDecision(PretenureDecision current_decision,
8429 bool maximum_size_scavenge);
8431 inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
8433 ElementsKind GetElementsKind() {
8434 DCHECK(!SitePointsToLiteral());
8435 int value = Smi::cast(transition_info())->value();
8436 return ElementsKindBits::decode(value);
8439 void SetElementsKind(ElementsKind kind) {
8440 int value = Smi::cast(transition_info())->value();
8441 set_transition_info(Smi::FromInt(ElementsKindBits::update(value, kind)),
8442 SKIP_WRITE_BARRIER);
8445 bool CanInlineCall() {
8446 int value = Smi::cast(transition_info())->value();
8447 return DoNotInlineBit::decode(value) == 0;
8450 void SetDoNotInlineCall() {
8451 int value = Smi::cast(transition_info())->value();
8452 set_transition_info(Smi::FromInt(DoNotInlineBit::update(value, true)),
8453 SKIP_WRITE_BARRIER);
8456 bool SitePointsToLiteral() {
8457 // If transition_info is a smi, then it represents an ElementsKind
8458 // for a constructed array. Otherwise, it must be a boilerplate
8459 // for an object or array literal.
8460 return transition_info()->IsJSArray() || transition_info()->IsJSObject();
8463 static void DigestTransitionFeedback(Handle<AllocationSite> site,
8464 ElementsKind to_kind);
8466 static void RegisterForDeoptOnTenureChange(Handle<AllocationSite> site,
8467 CompilationInfo* info);
8469 static void RegisterForDeoptOnTransitionChange(Handle<AllocationSite> site,
8470 CompilationInfo* info);
8472 DECLARE_PRINTER(AllocationSite)
8473 DECLARE_VERIFIER(AllocationSite)
8475 DECLARE_CAST(AllocationSite)
8476 static inline AllocationSiteMode GetMode(
8477 ElementsKind boilerplate_elements_kind);
8478 static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to);
8479 static inline bool CanTrack(InstanceType type);
8481 static const int kTransitionInfoOffset = HeapObject::kHeaderSize;
8482 static const int kNestedSiteOffset = kTransitionInfoOffset + kPointerSize;
8483 static const int kPretenureDataOffset = kNestedSiteOffset + kPointerSize;
8484 static const int kPretenureCreateCountOffset =
8485 kPretenureDataOffset + kPointerSize;
8486 static const int kDependentCodeOffset =
8487 kPretenureCreateCountOffset + kPointerSize;
8488 static const int kWeakNextOffset = kDependentCodeOffset + kPointerSize;
8489 static const int kSize = kWeakNextOffset + kPointerSize;
8491 // During mark compact we need to take special care for the dependent code
8493 static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
8494 static const int kPointerFieldsEndOffset = kWeakNextOffset;
8496 // For other visitors, use the fixed body descriptor below.
8497 typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
8498 kDependentCodeOffset + kPointerSize,
8499 kSize> BodyDescriptor;
8502 static void AddDependentCompilationInfo(Handle<AllocationSite> site,
8503 DependentCode::DependencyGroup group,
8504 CompilationInfo* info);
8506 bool PretenuringDecisionMade() {
8507 return pretenure_decision() != kUndecided;
8510 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
8514 class AllocationMemento: public Struct {
8516 static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
8517 static const int kSize = kAllocationSiteOffset + kPointerSize;
8519 DECL_ACCESSORS(allocation_site, Object)
8522 return allocation_site()->IsAllocationSite() &&
8523 !AllocationSite::cast(allocation_site())->IsZombie();
8525 AllocationSite* GetAllocationSite() {
8527 return AllocationSite::cast(allocation_site());
8530 DECLARE_PRINTER(AllocationMemento)
8531 DECLARE_VERIFIER(AllocationMemento)
8533 DECLARE_CAST(AllocationMemento)
8536 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
8540 // Representation of a slow alias as part of a sloppy arguments objects.
8541 // For fast aliases (if HasSloppyArgumentsElements()):
8542 // - the parameter map contains an index into the context
8543 // - all attributes of the element have default values
8544 // For slow aliases (if HasDictionaryArgumentsElements()):
8545 // - the parameter map contains no fast alias mapping (i.e. the hole)
8546 // - this struct (in the slow backing store) contains an index into the context
8547 // - all attributes are available as part if the property details
8548 class AliasedArgumentsEntry: public Struct {
8550 inline int aliased_context_slot() const;
8551 inline void set_aliased_context_slot(int count);
8553 DECLARE_CAST(AliasedArgumentsEntry)
8555 // Dispatched behavior.
8556 DECLARE_PRINTER(AliasedArgumentsEntry)
8557 DECLARE_VERIFIER(AliasedArgumentsEntry)
8559 static const int kAliasedContextSlot = HeapObject::kHeaderSize;
8560 static const int kSize = kAliasedContextSlot + kPointerSize;
8563 DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry);
8567 enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
8568 enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};
8571 class StringHasher {
8573 explicit inline StringHasher(int length, uint32_t seed);
8575 template <typename schar>
8576 static inline uint32_t HashSequentialString(const schar* chars,
8580 // Reads all the data, even for long strings and computes the utf16 length.
8581 static uint32_t ComputeUtf8Hash(Vector<const char> chars,
8583 int* utf16_length_out);
8585 // Calculated hash value for a string consisting of 1 to
8586 // String::kMaxArrayIndexSize digits with no leading zeros (except "0").
8587 // value is represented decimal value.
8588 static uint32_t MakeArrayIndexHash(uint32_t value, int length);
8590 // No string is allowed to have a hash of zero. That value is reserved
8591 // for internal properties. If the hash calculation yields zero then we
8593 static const int kZeroHash = 27;
8595 // Reusable parts of the hashing algorithm.
8596 INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
8597 INLINE(static uint32_t GetHashCore(uint32_t running_hash));
8598 INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
8599 const uc16* chars, int length));
8600 INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
8605 // Returns the value to store in the hash field of a string with
8606 // the given length and contents.
8607 uint32_t GetHashField();
8608 // Returns true if the hash of this string can be computed without
8609 // looking at the contents.
8610 inline bool has_trivial_hash();
8611 // Adds a block of characters to the hash.
8612 template<typename Char>
8613 inline void AddCharacters(const Char* chars, int len);
8616 // Add a character to the hash.
8617 inline void AddCharacter(uint16_t c);
8618 // Update index. Returns true if string is still an index.
8619 inline bool UpdateIndex(uint16_t c);
8622 uint32_t raw_running_hash_;
8623 uint32_t array_index_;
8624 bool is_array_index_;
8625 bool is_first_char_;
8626 DISALLOW_COPY_AND_ASSIGN(StringHasher);
8630 class IteratingStringHasher : public StringHasher {
8632 static inline uint32_t Hash(String* string, uint32_t seed);
8633 inline void VisitOneByteString(const uint8_t* chars, int length);
8634 inline void VisitTwoByteString(const uint16_t* chars, int length);
8637 inline IteratingStringHasher(int len, uint32_t seed)
8638 : StringHasher(len, seed) {}
8639 void VisitConsString(ConsString* cons_string);
8640 DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
8644 // The characteristics of a string are stored in its map. Retrieving these
8645 // few bits of information is moderately expensive, involving two memory
8646 // loads where the second is dependent on the first. To improve efficiency
8647 // the shape of the string is given its own class so that it can be retrieved
8648 // once and used for several string operations. A StringShape is small enough
8649 // to be passed by value and is immutable, but be aware that flattening a
8650 // string can potentially alter its shape. Also be aware that a GC caused by
8651 // something else can alter the shape of a string due to ConsString
8652 // shortcutting. Keeping these restrictions in mind has proven to be error-
8653 // prone and so we no longer put StringShapes in variables unless there is a
8654 // concrete performance benefit at that particular point in the code.
8655 class StringShape BASE_EMBEDDED {
8657 inline explicit StringShape(const String* s);
8658 inline explicit StringShape(Map* s);
8659 inline explicit StringShape(InstanceType t);
8660 inline bool IsSequential();
8661 inline bool IsExternal();
8662 inline bool IsCons();
8663 inline bool IsSliced();
8664 inline bool IsIndirect();
8665 inline bool IsExternalOneByte();
8666 inline bool IsExternalTwoByte();
8667 inline bool IsSequentialOneByte();
8668 inline bool IsSequentialTwoByte();
8669 inline bool IsInternalized();
8670 inline StringRepresentationTag representation_tag();
8671 inline uint32_t encoding_tag();
8672 inline uint32_t full_representation_tag();
8673 inline uint32_t size_tag();
8675 inline uint32_t type() { return type_; }
8676 inline void invalidate() { valid_ = false; }
8677 inline bool valid() { return valid_; }
8679 inline void invalidate() { }
8685 inline void set_valid() { valid_ = true; }
8688 inline void set_valid() { }
8693 // The Name abstract class captures anything that can be used as a property
8694 // name, i.e., strings and symbols. All names store a hash value.
8695 class Name: public HeapObject {
8697 // Get and set the hash field of the name.
8698 inline uint32_t hash_field();
8699 inline void set_hash_field(uint32_t value);
8701 // Tells whether the hash code has been computed.
8702 inline bool HasHashCode();
8704 // Returns a hash value used for the property table
8705 inline uint32_t Hash();
8707 // Equality operations.
8708 inline bool Equals(Name* other);
8709 inline static bool Equals(Handle<Name> one, Handle<Name> two);
8712 inline bool AsArrayIndex(uint32_t* index);
8714 // Whether name can only name own properties.
8715 inline bool IsOwn();
8719 DECLARE_PRINTER(Name)
8721 void NameShortPrint();
8722 int NameShortPrint(Vector<char> str);
8725 // Layout description.
8726 static const int kHashFieldSlot = HeapObject::kHeaderSize;
8727 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
8728 static const int kHashFieldOffset = kHashFieldSlot;
8730 static const int kHashFieldOffset = kHashFieldSlot + kIntSize;
8732 static const int kSize = kHashFieldSlot + kPointerSize;
8734 // Mask constant for checking if a name has a computed hash code
8735 // and if it is a string that is an array index. The least significant bit
8736 // indicates whether a hash code has been computed. If the hash code has
8737 // been computed the 2nd bit tells whether the string can be used as an
8739 static const int kHashNotComputedMask = 1;
8740 static const int kIsNotArrayIndexMask = 1 << 1;
8741 static const int kNofHashBitFields = 2;
8743 // Shift constant retrieving hash code from hash field.
8744 static const int kHashShift = kNofHashBitFields;
8746 // Only these bits are relevant in the hash, since the top two are shifted
8748 static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift;
8750 // Array index strings this short can keep their index in the hash field.
8751 static const int kMaxCachedArrayIndexLength = 7;
8753 // For strings which are array indexes the hash value has the string length
8754 // mixed into the hash, mainly to avoid a hash value of zero which would be
8755 // the case for the string '0'. 24 bits are used for the array index value.
8756 static const int kArrayIndexValueBits = 24;
8757 static const int kArrayIndexLengthBits =
8758 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8760 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8762 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8763 kArrayIndexValueBits> {}; // NOLINT
8764 class ArrayIndexLengthBits : public BitField<unsigned int,
8765 kNofHashBitFields + kArrayIndexValueBits,
8766 kArrayIndexLengthBits> {}; // NOLINT
8768 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8769 // could use a mask to test if the length of string is less than or equal to
8770 // kMaxCachedArrayIndexLength.
8771 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8773 static const unsigned int kContainsCachedArrayIndexMask =
8774 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8775 << ArrayIndexLengthBits::kShift) |
8776 kIsNotArrayIndexMask;
8778 // Value of empty hash field indicating that the hash is not computed.
8779 static const int kEmptyHashField =
8780 kIsNotArrayIndexMask | kHashNotComputedMask;
8783 static inline bool IsHashFieldComputed(uint32_t field);
8786 DISALLOW_IMPLICIT_CONSTRUCTORS(Name);
8791 class Symbol: public Name {
8793 // [name]: the print name of a symbol, or undefined if none.
8794 DECL_ACCESSORS(name, Object)
8796 DECL_ACCESSORS(flags, Smi)
8798 // [is_private]: whether this is a private symbol.
8799 DECL_BOOLEAN_ACCESSORS(is_private)
8801 // [is_own]: whether this is an own symbol, that is, only used to designate
8802 // own properties of objects.
8803 DECL_BOOLEAN_ACCESSORS(is_own)
8805 DECLARE_CAST(Symbol)
8807 // Dispatched behavior.
8808 DECLARE_PRINTER(Symbol)
8809 DECLARE_VERIFIER(Symbol)
8811 // Layout description.
8812 static const int kNameOffset = Name::kSize;
8813 static const int kFlagsOffset = kNameOffset + kPointerSize;
8814 static const int kSize = kFlagsOffset + kPointerSize;
8816 typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
8818 void SymbolShortPrint(std::ostream& os);
8821 static const int kPrivateBit = 0;
8822 static const int kOwnBit = 1;
8824 const char* PrivateSymbolToName() const;
8827 friend class Name; // For PrivateSymbolToName.
8830 DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol);
8836 // The String abstract class captures JavaScript string values:
8839 // 4.3.16 String Value
8840 // A string value is a member of the type String and is a finite
8841 // ordered sequence of zero or more 16-bit unsigned integer values.
8843 // All string values have a length field.
8844 class String: public Name {
8846 enum Encoding { ONE_BYTE_ENCODING, TWO_BYTE_ENCODING };
8848 // Array index strings this short can keep their index in the hash field.
8849 static const int kMaxCachedArrayIndexLength = 7;
8851 // For strings which are array indexes the hash value has the string length
8852 // mixed into the hash, mainly to avoid a hash value of zero which would be
8853 // the case for the string '0'. 24 bits are used for the array index value.
8854 static const int kArrayIndexValueBits = 24;
8855 static const int kArrayIndexLengthBits =
8856 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8858 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8860 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8861 kArrayIndexValueBits> {}; // NOLINT
8862 class ArrayIndexLengthBits : public BitField<unsigned int,
8863 kNofHashBitFields + kArrayIndexValueBits,
8864 kArrayIndexLengthBits> {}; // NOLINT
8866 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8867 // could use a mask to test if the length of string is less than or equal to
8868 // kMaxCachedArrayIndexLength.
8869 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8871 static const unsigned int kContainsCachedArrayIndexMask =
8872 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8873 << ArrayIndexLengthBits::kShift) |
8874 kIsNotArrayIndexMask;
8876 class SubStringRange {
8878 explicit SubStringRange(String* string, int first = 0, int length = -1)
8881 length_(length == -1 ? string->length() : length) {}
8883 inline iterator begin();
8884 inline iterator end();
8892 // Representation of the flat content of a String.
8893 // A non-flat string doesn't have flat content.
8894 // A flat string has content that's encoded as a sequence of either
8895 // one-byte chars or two-byte UC16.
8896 // Returned by String::GetFlatContent().
8899 // Returns true if the string is flat and this structure contains content.
8900 bool IsFlat() { return state_ != NON_FLAT; }
8901 // Returns true if the structure contains one-byte content.
8902 bool IsOneByte() { return state_ == ONE_BYTE; }
8903 // Returns true if the structure contains two-byte content.
8904 bool IsTwoByte() { return state_ == TWO_BYTE; }
8906 // Return the one byte content of the string. Only use if IsOneByte()
8908 Vector<const uint8_t> ToOneByteVector() {
8909 DCHECK_EQ(ONE_BYTE, state_);
8910 return Vector<const uint8_t>(onebyte_start, length_);
8912 // Return the two-byte content of the string. Only use if IsTwoByte()
8914 Vector<const uc16> ToUC16Vector() {
8915 DCHECK_EQ(TWO_BYTE, state_);
8916 return Vector<const uc16>(twobyte_start, length_);
8920 DCHECK(i < length_);
8921 DCHECK(state_ != NON_FLAT);
8922 if (state_ == ONE_BYTE) return onebyte_start[i];
8923 return twobyte_start[i];
8926 bool UsesSameString(const FlatContent& other) const {
8927 return onebyte_start == other.onebyte_start;
8931 enum State { NON_FLAT, ONE_BYTE, TWO_BYTE };
8933 // Constructors only used by String::GetFlatContent().
8934 explicit FlatContent(const uint8_t* start, int length)
8935 : onebyte_start(start), length_(length), state_(ONE_BYTE) {}
8936 explicit FlatContent(const uc16* start, int length)
8937 : twobyte_start(start), length_(length), state_(TWO_BYTE) { }
8938 FlatContent() : onebyte_start(NULL), length_(0), state_(NON_FLAT) { }
8941 const uint8_t* onebyte_start;
8942 const uc16* twobyte_start;
8947 friend class String;
8948 friend class IterableSubString;
8951 template <typename Char>
8952 INLINE(Vector<const Char> GetCharVector());
8954 // Get and set the length of the string.
8955 inline int length() const;
8956 inline void set_length(int value);
8958 // Get and set the length of the string using acquire loads and release
8960 inline int synchronized_length() const;
8961 inline void synchronized_set_length(int value);
8963 // Returns whether this string has only one-byte chars, i.e. all of them can
8964 // be one-byte encoded. This might be the case even if the string is
8965 // two-byte. Such strings may appear when the embedder prefers
8966 // two-byte external representations even for one-byte data.
8967 inline bool IsOneByteRepresentation() const;
8968 inline bool IsTwoByteRepresentation() const;
8970 // Cons and slices have an encoding flag that may not represent the actual
8971 // encoding of the underlying string. This is taken into account here.
8972 // Requires: this->IsFlat()
8973 inline bool IsOneByteRepresentationUnderneath();
8974 inline bool IsTwoByteRepresentationUnderneath();
8976 // NOTE: this should be considered only a hint. False negatives are
8978 inline bool HasOnlyOneByteChars();
8980 // Get and set individual two byte chars in the string.
8981 inline void Set(int index, uint16_t value);
8982 // Get individual two byte char in the string. Repeated calls
8983 // to this method are not efficient unless the string is flat.
8984 INLINE(uint16_t Get(int index));
8986 // Flattens the string. Checks first inline to see if it is
8987 // necessary. Does nothing if the string is not a cons string.
8988 // Flattening allocates a sequential string with the same data as
8989 // the given string and mutates the cons string to a degenerate
8990 // form, where the first component is the new sequential string and
8991 // the second component is the empty string. If allocation fails,
8992 // this function returns a failure. If flattening succeeds, this
8993 // function returns the sequential string that is now the first
8994 // component of the cons string.
8996 // Degenerate cons strings are handled specially by the garbage
8997 // collector (see IsShortcutCandidate).
8999 static inline Handle<String> Flatten(Handle<String> string,
9000 PretenureFlag pretenure = NOT_TENURED);
9002 // Tries to return the content of a flat string as a structure holding either
9003 // a flat vector of char or of uc16.
9004 // If the string isn't flat, and therefore doesn't have flat content, the
9005 // returned structure will report so, and can't provide a vector of either
9007 FlatContent GetFlatContent();
9009 // Returns the parent of a sliced string or first part of a flat cons string.
9010 // Requires: StringShape(this).IsIndirect() && this->IsFlat()
9011 inline String* GetUnderlying();
9013 // String equality operations.
9014 inline bool Equals(String* other);
9015 inline static bool Equals(Handle<String> one, Handle<String> two);
9016 bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
9017 bool IsOneByteEqualTo(Vector<const uint8_t> str);
9018 bool IsTwoByteEqualTo(Vector<const uc16> str);
9020 // Return a UTF8 representation of the string. The string is null
9021 // terminated but may optionally contain nulls. Length is returned
9022 // in length_output if length_output is not a null pointer The string
9023 // should be nearly flat, otherwise the performance of this method may
9024 // be very slow (quadratic in the length). Setting robustness_flag to
9025 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
9026 // handles unexpected data without causing assert failures and it does not
9027 // do any heap allocations. This is useful when printing stack traces.
9028 SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls,
9029 RobustnessFlag robustness_flag,
9032 int* length_output = 0);
9033 SmartArrayPointer<char> ToCString(
9034 AllowNullsFlag allow_nulls = DISALLOW_NULLS,
9035 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL,
9036 int* length_output = 0);
9038 // Return a 16 bit Unicode representation of the string.
9039 // The string should be nearly flat, otherwise the performance of
9040 // of this method may be very bad. Setting robustness_flag to
9041 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
9042 // handles unexpected data without causing assert failures and it does not
9043 // do any heap allocations. This is useful when printing stack traces.
9044 SmartArrayPointer<uc16> ToWideCString(
9045 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL);
9047 bool ComputeArrayIndex(uint32_t* index);
9050 bool MakeExternal(v8::String::ExternalStringResource* resource);
9051 bool MakeExternal(v8::String::ExternalOneByteStringResource* resource);
9054 inline bool AsArrayIndex(uint32_t* index);
9056 DECLARE_CAST(String)
9058 void PrintOn(FILE* out);
9060 // For use during stack traces. Performs rudimentary sanity check.
9063 // Dispatched behavior.
9064 void StringShortPrint(StringStream* accumulator);
9065 void PrintUC16(std::ostream& os, int start = 0, int end = -1); // NOLINT
9066 #if defined(DEBUG) || defined(OBJECT_PRINT)
9067 char* ToAsciiArray();
9069 DECLARE_PRINTER(String)
9070 DECLARE_VERIFIER(String)
9072 inline bool IsFlat();
9074 // Layout description.
9075 static const int kLengthOffset = Name::kSize;
9076 static const int kSize = kLengthOffset + kPointerSize;
9078 // Maximum number of characters to consider when trying to convert a string
9079 // value into an array index.
9080 static const int kMaxArrayIndexSize = 10;
9081 STATIC_ASSERT(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits));
9084 static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar;
9085 static const uint32_t kMaxOneByteCharCodeU = unibrow::Latin1::kMaxChar;
9086 static const int kMaxUtf16CodeUnit = 0xffff;
9087 static const uint32_t kMaxUtf16CodeUnitU = kMaxUtf16CodeUnit;
9089 // Value of hash field containing computed hash equal to zero.
9090 static const int kEmptyStringHash = kIsNotArrayIndexMask;
9092 // Maximal string length.
9093 static const int kMaxLength = (1 << 28) - 16;
9095 // Max length for computing hash. For strings longer than this limit the
9096 // string length is used as the hash value.
9097 static const int kMaxHashCalcLength = 16383;
9099 // Limit for truncation in short printing.
9100 static const int kMaxShortPrintLength = 1024;
9102 // Support for regular expressions.
9103 const uc16* GetTwoByteData(unsigned start);
9105 // Helper function for flattening strings.
9106 template <typename sinkchar>
9107 static void WriteToFlat(String* source,
9112 // The return value may point to the first aligned word containing the first
9113 // non-one-byte character, rather than directly to the non-one-byte character.
9114 // If the return value is >= the passed length, the entire string was
9116 static inline int NonAsciiStart(const char* chars, int length) {
9117 const char* start = chars;
9118 const char* limit = chars + length;
9120 if (length >= kIntptrSize) {
9121 // Check unaligned bytes.
9122 while (!IsAligned(reinterpret_cast<intptr_t>(chars), sizeof(uintptr_t))) {
9123 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
9124 return static_cast<int>(chars - start);
9128 // Check aligned words.
9129 DCHECK(unibrow::Utf8::kMaxOneByteChar == 0x7F);
9130 const uintptr_t non_one_byte_mask = kUintptrAllBitsSet / 0xFF * 0x80;
9131 while (chars + sizeof(uintptr_t) <= limit) {
9132 if (*reinterpret_cast<const uintptr_t*>(chars) & non_one_byte_mask) {
9133 return static_cast<int>(chars - start);
9135 chars += sizeof(uintptr_t);
9138 // Check remaining unaligned bytes.
9139 while (chars < limit) {
9140 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
9141 return static_cast<int>(chars - start);
9146 return static_cast<int>(chars - start);
9149 static inline bool IsAscii(const char* chars, int length) {
9150 return NonAsciiStart(chars, length) >= length;
9153 static inline bool IsAscii(const uint8_t* chars, int length) {
9155 NonAsciiStart(reinterpret_cast<const char*>(chars), length) >= length;
9158 static inline int NonOneByteStart(const uc16* chars, int length) {
9159 const uc16* limit = chars + length;
9160 const uc16* start = chars;
9161 while (chars < limit) {
9162 if (*chars > kMaxOneByteCharCodeU) return static_cast<int>(chars - start);
9165 return static_cast<int>(chars - start);
9168 static inline bool IsOneByte(const uc16* chars, int length) {
9169 return NonOneByteStart(chars, length) >= length;
9172 template<class Visitor>
9173 static inline ConsString* VisitFlat(Visitor* visitor,
9177 static Handle<FixedArray> CalculateLineEnds(Handle<String> string,
9178 bool include_ending_line);
9180 // Use the hash field to forward to the canonical internalized string
9181 // when deserializing an internalized string.
9182 inline void SetForwardedInternalizedString(String* string);
9183 inline String* GetForwardedInternalizedString();
9187 friend class StringTableInsertionKey;
9189 static Handle<String> SlowFlatten(Handle<ConsString> cons,
9190 PretenureFlag tenure);
9192 // Slow case of String::Equals. This implementation works on any strings
9193 // but it is most efficient on strings that are almost flat.
9194 bool SlowEquals(String* other);
9196 static bool SlowEquals(Handle<String> one, Handle<String> two);
9198 // Slow case of AsArrayIndex.
9199 bool SlowAsArrayIndex(uint32_t* index);
9201 // Compute and set the hash code.
9202 uint32_t ComputeAndSetHash();
9204 DISALLOW_IMPLICIT_CONSTRUCTORS(String);
9208 // The SeqString abstract class captures sequential string values.
9209 class SeqString: public String {
9211 DECLARE_CAST(SeqString)
9213 // Layout description.
9214 static const int kHeaderSize = String::kSize;
9216 // Truncate the string in-place if possible and return the result.
9217 // In case of new_length == 0, the empty string is returned without
9218 // truncating the original string.
9219 MUST_USE_RESULT static Handle<String> Truncate(Handle<SeqString> string,
9222 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString);
9226 // The OneByteString class captures sequential one-byte string objects.
9227 // Each character in the OneByteString is an one-byte character.
9228 class SeqOneByteString: public SeqString {
9230 static const bool kHasOneByteEncoding = true;
9232 // Dispatched behavior.
9233 inline uint16_t SeqOneByteStringGet(int index);
9234 inline void SeqOneByteStringSet(int index, uint16_t value);
9236 // Get the address of the characters in this string.
9237 inline Address GetCharsAddress();
9239 inline uint8_t* GetChars();
9241 DECLARE_CAST(SeqOneByteString)
9243 // Garbage collection support. This method is called by the
9244 // garbage collector to compute the actual size of an OneByteString
9246 inline int SeqOneByteStringSize(InstanceType instance_type);
9248 // Computes the size for an OneByteString instance of a given length.
9249 static int SizeFor(int length) {
9250 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize);
9253 // Maximal memory usage for a single sequential one-byte string.
9254 static const int kMaxSize = 512 * MB - 1;
9255 STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength);
9258 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
9262 // The TwoByteString class captures sequential unicode string objects.
9263 // Each character in the TwoByteString is a two-byte uint16_t.
9264 class SeqTwoByteString: public SeqString {
9266 static const bool kHasOneByteEncoding = false;
9268 // Dispatched behavior.
9269 inline uint16_t SeqTwoByteStringGet(int index);
9270 inline void SeqTwoByteStringSet(int index, uint16_t value);
9272 // Get the address of the characters in this string.
9273 inline Address GetCharsAddress();
9275 inline uc16* GetChars();
9278 const uint16_t* SeqTwoByteStringGetData(unsigned start);
9280 DECLARE_CAST(SeqTwoByteString)
9282 // Garbage collection support. This method is called by the
9283 // garbage collector to compute the actual size of a TwoByteString
9285 inline int SeqTwoByteStringSize(InstanceType instance_type);
9287 // Computes the size for a TwoByteString instance of a given length.
9288 static int SizeFor(int length) {
9289 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize);
9292 // Maximal memory usage for a single sequential two-byte string.
9293 static const int kMaxSize = 512 * MB - 1;
9294 STATIC_ASSERT(static_cast<int>((kMaxSize - kHeaderSize)/sizeof(uint16_t)) >=
9295 String::kMaxLength);
9298 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString);
9302 // The ConsString class describes string values built by using the
9303 // addition operator on strings. A ConsString is a pair where the
9304 // first and second components are pointers to other string values.
9305 // One or both components of a ConsString can be pointers to other
9306 // ConsStrings, creating a binary tree of ConsStrings where the leaves
9307 // are non-ConsString string values. The string value represented by
9308 // a ConsString can be obtained by concatenating the leaf string
9309 // values in a left-to-right depth-first traversal of the tree.
9310 class ConsString: public String {
9312 // First string of the cons cell.
9313 inline String* first();
9314 // Doesn't check that the result is a string, even in debug mode. This is
9315 // useful during GC where the mark bits confuse the checks.
9316 inline Object* unchecked_first();
9317 inline void set_first(String* first,
9318 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9320 // Second string of the cons cell.
9321 inline String* second();
9322 // Doesn't check that the result is a string, even in debug mode. This is
9323 // useful during GC where the mark bits confuse the checks.
9324 inline Object* unchecked_second();
9325 inline void set_second(String* second,
9326 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9328 // Dispatched behavior.
9329 uint16_t ConsStringGet(int index);
9331 DECLARE_CAST(ConsString)
9333 // Layout description.
9334 static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize);
9335 static const int kSecondOffset = kFirstOffset + kPointerSize;
9336 static const int kSize = kSecondOffset + kPointerSize;
9338 // Minimum length for a cons string.
9339 static const int kMinLength = 13;
9341 typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize>
9344 DECLARE_VERIFIER(ConsString)
9347 DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString);
9351 // The Sliced String class describes strings that are substrings of another
9352 // sequential string. The motivation is to save time and memory when creating
9353 // a substring. A Sliced String is described as a pointer to the parent,
9354 // the offset from the start of the parent string and the length. Using
9355 // a Sliced String therefore requires unpacking of the parent string and
9356 // adding the offset to the start address. A substring of a Sliced String
9357 // are not nested since the double indirection is simplified when creating
9358 // such a substring.
9359 // Currently missing features are:
9360 // - handling externalized parent strings
9361 // - external strings as parent
9362 // - truncating sliced string to enable otherwise unneeded parent to be GC'ed.
9363 class SlicedString: public String {
9365 inline String* parent();
9366 inline void set_parent(String* parent,
9367 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9368 inline int offset() const;
9369 inline void set_offset(int offset);
9371 // Dispatched behavior.
9372 uint16_t SlicedStringGet(int index);
9374 DECLARE_CAST(SlicedString)
9376 // Layout description.
9377 static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize);
9378 static const int kOffsetOffset = kParentOffset + kPointerSize;
9379 static const int kSize = kOffsetOffset + kPointerSize;
9381 // Minimum length for a sliced string.
9382 static const int kMinLength = 13;
9384 typedef FixedBodyDescriptor<kParentOffset,
9385 kOffsetOffset + kPointerSize, kSize>
9388 DECLARE_VERIFIER(SlicedString)
9391 DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString);
9395 // The ExternalString class describes string values that are backed by
9396 // a string resource that lies outside the V8 heap. ExternalStrings
9397 // consist of the length field common to all strings, a pointer to the
9398 // external resource. It is important to ensure (externally) that the
9399 // resource is not deallocated while the ExternalString is live in the
9402 // The API expects that all ExternalStrings are created through the
9403 // API. Therefore, ExternalStrings should not be used internally.
9404 class ExternalString: public String {
9406 DECLARE_CAST(ExternalString)
9408 // Layout description.
9409 static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
9410 static const int kShortSize = kResourceOffset + kPointerSize;
9411 static const int kResourceDataOffset = kResourceOffset + kPointerSize;
9412 static const int kSize = kResourceDataOffset + kPointerSize;
9414 static const int kMaxShortLength =
9415 (kShortSize - SeqString::kHeaderSize) / kCharSize;
9417 // Return whether external string is short (data pointer is not cached).
9418 inline bool is_short();
9420 STATIC_ASSERT(kResourceOffset == Internals::kStringResourceOffset);
9423 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString);
9427 // The ExternalOneByteString class is an external string backed by an
9429 class ExternalOneByteString : public ExternalString {
9431 static const bool kHasOneByteEncoding = true;
9433 typedef v8::String::ExternalOneByteStringResource Resource;
9435 // The underlying resource.
9436 inline const Resource* resource();
9437 inline void set_resource(const Resource* buffer);
9439 // Update the pointer cache to the external character array.
9440 // The cached pointer is always valid, as the external character array does =
9441 // not move during lifetime. Deserialization is the only exception, after
9442 // which the pointer cache has to be refreshed.
9443 inline void update_data_cache();
9445 inline const uint8_t* GetChars();
9447 // Dispatched behavior.
9448 inline uint16_t ExternalOneByteStringGet(int index);
9450 DECLARE_CAST(ExternalOneByteString)
9452 // Garbage collection support.
9453 inline void ExternalOneByteStringIterateBody(ObjectVisitor* v);
9455 template <typename StaticVisitor>
9456 inline void ExternalOneByteStringIterateBody();
9459 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString);
9463 // The ExternalTwoByteString class is an external string backed by a UTF-16
9465 class ExternalTwoByteString: public ExternalString {
9467 static const bool kHasOneByteEncoding = false;
9469 typedef v8::String::ExternalStringResource Resource;
9471 // The underlying string resource.
9472 inline const Resource* resource();
9473 inline void set_resource(const Resource* buffer);
9475 // Update the pointer cache to the external character array.
9476 // The cached pointer is always valid, as the external character array does =
9477 // not move during lifetime. Deserialization is the only exception, after
9478 // which the pointer cache has to be refreshed.
9479 inline void update_data_cache();
9481 inline const uint16_t* GetChars();
9483 // Dispatched behavior.
9484 inline uint16_t ExternalTwoByteStringGet(int index);
9487 inline const uint16_t* ExternalTwoByteStringGetData(unsigned start);
9489 DECLARE_CAST(ExternalTwoByteString)
9491 // Garbage collection support.
9492 inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v);
9494 template<typename StaticVisitor>
9495 inline void ExternalTwoByteStringIterateBody();
9498 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString);
9502 // Utility superclass for stack-allocated objects that must be updated
9503 // on gc. It provides two ways for the gc to update instances, either
9504 // iterating or updating after gc.
9505 class Relocatable BASE_EMBEDDED {
9507 explicit inline Relocatable(Isolate* isolate);
9508 inline virtual ~Relocatable();
9509 virtual void IterateInstance(ObjectVisitor* v) { }
9510 virtual void PostGarbageCollection() { }
9512 static void PostGarbageCollectionProcessing(Isolate* isolate);
9513 static int ArchiveSpacePerThread();
9514 static char* ArchiveState(Isolate* isolate, char* to);
9515 static char* RestoreState(Isolate* isolate, char* from);
9516 static void Iterate(Isolate* isolate, ObjectVisitor* v);
9517 static void Iterate(ObjectVisitor* v, Relocatable* top);
9518 static char* Iterate(ObjectVisitor* v, char* t);
9526 // A flat string reader provides random access to the contents of a
9527 // string independent of the character width of the string. The handle
9528 // must be valid as long as the reader is being used.
9529 class FlatStringReader : public Relocatable {
9531 FlatStringReader(Isolate* isolate, Handle<String> str);
9532 FlatStringReader(Isolate* isolate, Vector<const char> input);
9533 void PostGarbageCollection();
9534 inline uc32 Get(int index);
9535 template <typename Char>
9536 inline Char Get(int index);
9537 int length() { return length_; }
9546 // This maintains an off-stack representation of the stack frames required
9547 // to traverse a ConsString, allowing an entirely iterative and restartable
9548 // traversal of the entire string
9549 class ConsStringIterator {
9551 inline ConsStringIterator() {}
9552 inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) {
9553 Reset(cons_string, offset);
9555 inline void Reset(ConsString* cons_string, int offset = 0) {
9557 // Next will always return NULL.
9558 if (cons_string == NULL) return;
9559 Initialize(cons_string, offset);
9561 // Returns NULL when complete.
9562 inline String* Next(int* offset_out) {
9564 if (depth_ == 0) return NULL;
9565 return Continue(offset_out);
9569 static const int kStackSize = 32;
9570 // Use a mask instead of doing modulo operations for stack wrapping.
9571 static const int kDepthMask = kStackSize-1;
9572 STATIC_ASSERT(IS_POWER_OF_TWO(kStackSize));
9573 static inline int OffsetForDepth(int depth);
9575 inline void PushLeft(ConsString* string);
9576 inline void PushRight(ConsString* string);
9577 inline void AdjustMaximumDepth();
9579 inline bool StackBlown() { return maximum_depth_ - depth_ == kStackSize; }
9580 void Initialize(ConsString* cons_string, int offset);
9581 String* Continue(int* offset_out);
9582 String* NextLeaf(bool* blew_stack);
9583 String* Search(int* offset_out);
9585 // Stack must always contain only frames for which right traversal
9586 // has not yet been performed.
9587 ConsString* frames_[kStackSize];
9592 DISALLOW_COPY_AND_ASSIGN(ConsStringIterator);
9596 class StringCharacterStream {
9598 inline StringCharacterStream(String* string,
9600 inline uint16_t GetNext();
9601 inline bool HasMore();
9602 inline void Reset(String* string, int offset = 0);
9603 inline void VisitOneByteString(const uint8_t* chars, int length);
9604 inline void VisitTwoByteString(const uint16_t* chars, int length);
9607 ConsStringIterator iter_;
9610 const uint8_t* buffer8_;
9611 const uint16_t* buffer16_;
9613 const uint8_t* end_;
9614 DISALLOW_COPY_AND_ASSIGN(StringCharacterStream);
9618 template <typename T>
9619 class VectorIterator {
9621 VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { }
9622 explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { }
9623 T GetNext() { return data_[index_++]; }
9624 bool has_more() { return index_ < data_.length(); }
9626 Vector<const T> data_;
9631 // The Oddball describes objects null, undefined, true, and false.
9632 class Oddball: public HeapObject {
9634 // [to_string]: Cached to_string computed at startup.
9635 DECL_ACCESSORS(to_string, String)
9637 // [to_number]: Cached to_number computed at startup.
9638 DECL_ACCESSORS(to_number, Object)
9640 inline byte kind() const;
9641 inline void set_kind(byte kind);
9643 DECLARE_CAST(Oddball)
9645 // Dispatched behavior.
9646 DECLARE_VERIFIER(Oddball)
9648 // Initialize the fields.
9649 static void Initialize(Isolate* isolate,
9650 Handle<Oddball> oddball,
9651 const char* to_string,
9652 Handle<Object> to_number,
9655 // Layout description.
9656 static const int kToStringOffset = HeapObject::kHeaderSize;
9657 static const int kToNumberOffset = kToStringOffset + kPointerSize;
9658 static const int kKindOffset = kToNumberOffset + kPointerSize;
9659 static const int kSize = kKindOffset + kPointerSize;
9661 static const byte kFalse = 0;
9662 static const byte kTrue = 1;
9663 static const byte kNotBooleanMask = ~1;
9664 static const byte kTheHole = 2;
9665 static const byte kNull = 3;
9666 static const byte kArgumentMarker = 4;
9667 static const byte kUndefined = 5;
9668 static const byte kUninitialized = 6;
9669 static const byte kOther = 7;
9670 static const byte kException = 8;
9672 typedef FixedBodyDescriptor<kToStringOffset,
9673 kToNumberOffset + kPointerSize,
9674 kSize> BodyDescriptor;
9676 STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
9677 STATIC_ASSERT(kNull == Internals::kNullOddballKind);
9678 STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind);
9681 DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
9685 class Cell: public HeapObject {
9687 // [value]: value of the global property.
9688 DECL_ACCESSORS(value, Object)
9692 static inline Cell* FromValueAddress(Address value) {
9693 Object* result = FromAddress(value - kValueOffset);
9694 DCHECK(result->IsCell() || result->IsPropertyCell());
9695 return static_cast<Cell*>(result);
9698 inline Address ValueAddress() {
9699 return address() + kValueOffset;
9702 // Dispatched behavior.
9703 DECLARE_PRINTER(Cell)
9704 DECLARE_VERIFIER(Cell)
9706 // Layout description.
9707 static const int kValueOffset = HeapObject::kHeaderSize;
9708 static const int kSize = kValueOffset + kPointerSize;
9710 typedef FixedBodyDescriptor<kValueOffset,
9711 kValueOffset + kPointerSize,
9712 kSize> BodyDescriptor;
9715 DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
9719 class PropertyCell: public Cell {
9721 // [type]: type of the global property.
9723 void set_type(HeapType* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9725 // [dependent_code]: dependent code that depends on the type of the global
9727 DECL_ACCESSORS(dependent_code, DependentCode)
9729 // Sets the value of the cell and updates the type field to be the union
9730 // of the cell's current type and the value's type. If the change causes
9731 // a change of the type of the cell's contents, code dependent on the cell
9732 // will be deoptimized.
9733 // Usually returns the value that was passed in, but may perform
9734 // non-observable modifications on it, such as internalize strings.
9735 static Handle<Object> SetValueInferType(Handle<PropertyCell> cell,
9736 Handle<Object> value);
9738 // Computes the new type of the cell's contents for the given value, but
9739 // without actually modifying the 'type' field.
9740 static Handle<HeapType> UpdatedType(Handle<PropertyCell> cell,
9741 Handle<Object> value);
9743 static void AddDependentCompilationInfo(Handle<PropertyCell> cell,
9744 CompilationInfo* info);
9746 DECLARE_CAST(PropertyCell)
9748 inline Address TypeAddress() {
9749 return address() + kTypeOffset;
9752 // Dispatched behavior.
9753 DECLARE_PRINTER(PropertyCell)
9754 DECLARE_VERIFIER(PropertyCell)
9756 // Layout description.
9757 static const int kTypeOffset = kValueOffset + kPointerSize;
9758 static const int kDependentCodeOffset = kTypeOffset + kPointerSize;
9759 static const int kSize = kDependentCodeOffset + kPointerSize;
9761 static const int kPointerFieldsBeginOffset = kValueOffset;
9762 static const int kPointerFieldsEndOffset = kSize;
9764 typedef FixedBodyDescriptor<kValueOffset,
9766 kSize> BodyDescriptor;
9769 DECL_ACCESSORS(type_raw, Object)
9770 DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
9774 class WeakCell : public HeapObject {
9776 inline Object* value() const;
9778 // This should not be called by anyone except GC.
9779 inline void clear();
9781 // This should not be called by anyone except allocator.
9782 inline void initialize(HeapObject* value);
9784 inline bool cleared() const;
9786 DECL_ACCESSORS(next, Object)
9788 DECLARE_CAST(WeakCell)
9790 DECLARE_PRINTER(WeakCell)
9791 DECLARE_VERIFIER(WeakCell)
9793 // Layout description.
9794 static const int kValueOffset = HeapObject::kHeaderSize;
9795 static const int kNextOffset = kValueOffset + kPointerSize;
9796 static const int kSize = kNextOffset + kPointerSize;
9798 typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor;
9801 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCell);
9805 // The JSProxy describes EcmaScript Harmony proxies
9806 class JSProxy: public JSReceiver {
9808 // [handler]: The handler property.
9809 DECL_ACCESSORS(handler, Object)
9811 // [hash]: The hash code property (undefined if not initialized yet).
9812 DECL_ACCESSORS(hash, Object)
9814 DECLARE_CAST(JSProxy)
9816 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithHandler(
9817 Handle<JSProxy> proxy,
9818 Handle<Object> receiver,
9820 MUST_USE_RESULT static inline MaybeHandle<Object> GetElementWithHandler(
9821 Handle<JSProxy> proxy,
9822 Handle<Object> receiver,
9825 // If the handler defines an accessor property with a setter, invoke it.
9826 // If it defines an accessor property without a setter, or a data property
9827 // that is read-only, throw. In all these cases set '*done' to true,
9828 // otherwise set it to false.
9830 static MaybeHandle<Object> SetPropertyViaPrototypesWithHandler(
9831 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9832 Handle<Object> value, LanguageMode language_mode, bool* done);
9834 MUST_USE_RESULT static Maybe<PropertyAttributes>
9835 GetPropertyAttributesWithHandler(Handle<JSProxy> proxy,
9836 Handle<Object> receiver,
9838 MUST_USE_RESULT static Maybe<PropertyAttributes>
9839 GetElementAttributeWithHandler(Handle<JSProxy> proxy,
9840 Handle<JSReceiver> receiver,
9842 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithHandler(
9843 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9844 Handle<Object> value, LanguageMode language_mode);
9846 // Turn the proxy into an (empty) JSObject.
9847 static void Fix(Handle<JSProxy> proxy);
9849 // Initializes the body after the handler slot.
9850 inline void InitializeBody(int object_size, Object* value);
9852 // Invoke a trap by name. If the trap does not exist on this's handler,
9853 // but derived_trap is non-NULL, invoke that instead. May cause GC.
9854 MUST_USE_RESULT static MaybeHandle<Object> CallTrap(
9855 Handle<JSProxy> proxy,
9857 Handle<Object> derived_trap,
9859 Handle<Object> args[]);
9861 // Dispatched behavior.
9862 DECLARE_PRINTER(JSProxy)
9863 DECLARE_VERIFIER(JSProxy)
9865 // Layout description. We add padding so that a proxy has the same
9866 // size as a virgin JSObject. This is essential for becoming a JSObject
9868 static const int kHandlerOffset = HeapObject::kHeaderSize;
9869 static const int kHashOffset = kHandlerOffset + kPointerSize;
9870 static const int kPaddingOffset = kHashOffset + kPointerSize;
9871 static const int kSize = JSObject::kHeaderSize;
9872 static const int kHeaderSize = kPaddingOffset;
9873 static const int kPaddingSize = kSize - kPaddingOffset;
9875 STATIC_ASSERT(kPaddingSize >= 0);
9877 typedef FixedBodyDescriptor<kHandlerOffset,
9879 kSize> BodyDescriptor;
9882 friend class JSReceiver;
9884 MUST_USE_RESULT static inline MaybeHandle<Object> SetElementWithHandler(
9885 Handle<JSProxy> proxy, Handle<JSReceiver> receiver, uint32_t index,
9886 Handle<Object> value, LanguageMode language_mode);
9888 MUST_USE_RESULT static Maybe<bool> HasPropertyWithHandler(
9889 Handle<JSProxy> proxy, Handle<Name> name);
9890 MUST_USE_RESULT static inline Maybe<bool> HasElementWithHandler(
9891 Handle<JSProxy> proxy, uint32_t index);
9893 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithHandler(
9894 Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode);
9895 MUST_USE_RESULT static MaybeHandle<Object> DeleteElementWithHandler(
9896 Handle<JSProxy> proxy, uint32_t index, LanguageMode language_mode);
9898 MUST_USE_RESULT Object* GetIdentityHash();
9900 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy);
9902 DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy);
9906 class JSFunctionProxy: public JSProxy {
9908 // [call_trap]: The call trap.
9909 DECL_ACCESSORS(call_trap, Object)
9911 // [construct_trap]: The construct trap.
9912 DECL_ACCESSORS(construct_trap, Object)
9914 DECLARE_CAST(JSFunctionProxy)
9916 // Dispatched behavior.
9917 DECLARE_PRINTER(JSFunctionProxy)
9918 DECLARE_VERIFIER(JSFunctionProxy)
9920 // Layout description.
9921 static const int kCallTrapOffset = JSProxy::kPaddingOffset;
9922 static const int kConstructTrapOffset = kCallTrapOffset + kPointerSize;
9923 static const int kPaddingOffset = kConstructTrapOffset + kPointerSize;
9924 static const int kSize = JSFunction::kSize;
9925 static const int kPaddingSize = kSize - kPaddingOffset;
9927 STATIC_ASSERT(kPaddingSize >= 0);
9929 typedef FixedBodyDescriptor<kHandlerOffset,
9930 kConstructTrapOffset + kPointerSize,
9931 kSize> BodyDescriptor;
9934 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunctionProxy);
9938 class JSCollection : public JSObject {
9940 // [table]: the backing hash table
9941 DECL_ACCESSORS(table, Object)
9943 static const int kTableOffset = JSObject::kHeaderSize;
9944 static const int kSize = kTableOffset + kPointerSize;
9947 DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollection);
9951 // The JSSet describes EcmaScript Harmony sets
9952 class JSSet : public JSCollection {
9956 // Dispatched behavior.
9957 DECLARE_PRINTER(JSSet)
9958 DECLARE_VERIFIER(JSSet)
9961 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet);
9965 // The JSMap describes EcmaScript Harmony maps
9966 class JSMap : public JSCollection {
9970 // Dispatched behavior.
9971 DECLARE_PRINTER(JSMap)
9972 DECLARE_VERIFIER(JSMap)
9975 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
9979 // OrderedHashTableIterator is an iterator that iterates over the keys and
9980 // values of an OrderedHashTable.
9982 // The iterator has a reference to the underlying OrderedHashTable data,
9983 // [table], as well as the current [index] the iterator is at.
9985 // When the OrderedHashTable is rehashed it adds a reference from the old table
9986 // to the new table as well as storing enough data about the changes so that the
9987 // iterator [index] can be adjusted accordingly.
9989 // When the [Next] result from the iterator is requested, the iterator checks if
9990 // there is a newer table that it needs to transition to.
9991 template<class Derived, class TableType>
9992 class OrderedHashTableIterator: public JSObject {
9994 // [table]: the backing hash table mapping keys to values.
9995 DECL_ACCESSORS(table, Object)
9997 // [index]: The index into the data table.
9998 DECL_ACCESSORS(index, Object)
10000 // [kind]: The kind of iteration this is. One of the [Kind] enum values.
10001 DECL_ACCESSORS(kind, Object)
10003 #ifdef OBJECT_PRINT
10004 void OrderedHashTableIteratorPrint(std::ostream& os); // NOLINT
10007 static const int kTableOffset = JSObject::kHeaderSize;
10008 static const int kIndexOffset = kTableOffset + kPointerSize;
10009 static const int kKindOffset = kIndexOffset + kPointerSize;
10010 static const int kSize = kKindOffset + kPointerSize;
10018 // Whether the iterator has more elements. This needs to be called before
10019 // calling |CurrentKey| and/or |CurrentValue|.
10022 // Move the index forward one.
10024 set_index(Smi::FromInt(Smi::cast(index())->value() + 1));
10027 // Populates the array with the next key and value and then moves the iterator
10029 // This returns the |kind| or 0 if the iterator is already at the end.
10030 Smi* Next(JSArray* value_array);
10032 // Returns the current key of the iterator. This should only be called when
10033 // |HasMore| returns true.
10034 inline Object* CurrentKey();
10037 // Transitions the iterator to the non obsolete backing store. This is a NOP
10038 // if the [table] is not obsolete.
10041 DISALLOW_IMPLICIT_CONSTRUCTORS(OrderedHashTableIterator);
10045 class JSSetIterator: public OrderedHashTableIterator<JSSetIterator,
10048 // Dispatched behavior.
10049 DECLARE_PRINTER(JSSetIterator)
10050 DECLARE_VERIFIER(JSSetIterator)
10052 DECLARE_CAST(JSSetIterator)
10054 // Called by |Next| to populate the array. This allows the subclasses to
10055 // populate the array differently.
10056 inline void PopulateValueArray(FixedArray* array);
10059 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSetIterator);
10063 class JSMapIterator: public OrderedHashTableIterator<JSMapIterator,
10066 // Dispatched behavior.
10067 DECLARE_PRINTER(JSMapIterator)
10068 DECLARE_VERIFIER(JSMapIterator)
10070 DECLARE_CAST(JSMapIterator)
10072 // Called by |Next| to populate the array. This allows the subclasses to
10073 // populate the array differently.
10074 inline void PopulateValueArray(FixedArray* array);
10077 // Returns the current value of the iterator. This should only be called when
10078 // |HasMore| returns true.
10079 inline Object* CurrentValue();
10081 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMapIterator);
10085 // Base class for both JSWeakMap and JSWeakSet
10086 class JSWeakCollection: public JSObject {
10088 // [table]: the backing hash table mapping keys to values.
10089 DECL_ACCESSORS(table, Object)
10091 // [next]: linked list of encountered weak maps during GC.
10092 DECL_ACCESSORS(next, Object)
10094 static const int kTableOffset = JSObject::kHeaderSize;
10095 static const int kNextOffset = kTableOffset + kPointerSize;
10096 static const int kSize = kNextOffset + kPointerSize;
10099 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection);
10103 // The JSWeakMap describes EcmaScript Harmony weak maps
10104 class JSWeakMap: public JSWeakCollection {
10106 DECLARE_CAST(JSWeakMap)
10108 // Dispatched behavior.
10109 DECLARE_PRINTER(JSWeakMap)
10110 DECLARE_VERIFIER(JSWeakMap)
10113 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
10117 // The JSWeakSet describes EcmaScript Harmony weak sets
10118 class JSWeakSet: public JSWeakCollection {
10120 DECLARE_CAST(JSWeakSet)
10122 // Dispatched behavior.
10123 DECLARE_PRINTER(JSWeakSet)
10124 DECLARE_VERIFIER(JSWeakSet)
10127 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet);
10131 class JSArrayBuffer: public JSObject {
10133 // [backing_store]: backing memory for this array
10134 DECL_ACCESSORS(backing_store, void)
10136 // [byte_length]: length in bytes
10137 DECL_ACCESSORS(byte_length, Object)
10140 DECL_ACCESSORS(flag, Smi)
10142 inline bool is_external();
10143 inline void set_is_external(bool value);
10145 inline bool should_be_freed();
10146 inline void set_should_be_freed(bool value);
10148 inline bool is_neuterable();
10149 inline void set_is_neuterable(bool value);
10151 // [weak_next]: linked list of array buffers.
10152 DECL_ACCESSORS(weak_next, Object)
10154 // [weak_first_array]: weak linked list of views.
10155 DECL_ACCESSORS(weak_first_view, Object)
10157 DECLARE_CAST(JSArrayBuffer)
10159 // Neutering. Only neuters the buffer, not associated typed arrays.
10162 // Dispatched behavior.
10163 DECLARE_PRINTER(JSArrayBuffer)
10164 DECLARE_VERIFIER(JSArrayBuffer)
10166 static const int kBackingStoreOffset = JSObject::kHeaderSize;
10167 static const int kByteLengthOffset = kBackingStoreOffset + kPointerSize;
10168 static const int kFlagOffset = kByteLengthOffset + kPointerSize;
10169 static const int kWeakNextOffset = kFlagOffset + kPointerSize;
10170 static const int kWeakFirstViewOffset = kWeakNextOffset + kPointerSize;
10171 static const int kSize = kWeakFirstViewOffset + kPointerSize;
10173 static const int kSizeWithInternalFields =
10174 kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
10177 // Bit position in a flag
10178 static const int kIsExternalBit = 0;
10179 static const int kShouldBeFreed = 1;
10180 static const int kIsNeuterableBit = 2;
10182 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
10186 class JSArrayBufferView: public JSObject {
10188 // [buffer]: ArrayBuffer that this typed array views.
10189 DECL_ACCESSORS(buffer, Object)
10191 // [byte_length]: offset of typed array in bytes.
10192 DECL_ACCESSORS(byte_offset, Object)
10194 // [byte_length]: length of typed array in bytes.
10195 DECL_ACCESSORS(byte_length, Object)
10197 // [weak_next]: linked list of typed arrays over the same array buffer.
10198 DECL_ACCESSORS(weak_next, Object)
10200 DECLARE_CAST(JSArrayBufferView)
10202 DECLARE_VERIFIER(JSArrayBufferView)
10204 static const int kBufferOffset = JSObject::kHeaderSize;
10205 static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
10206 static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
10207 static const int kWeakNextOffset = kByteLengthOffset + kPointerSize;
10208 static const int kViewSize = kWeakNextOffset + kPointerSize;
10214 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
10218 class JSTypedArray: public JSArrayBufferView {
10220 // [length]: length of typed array in elements.
10221 DECL_ACCESSORS(length, Object)
10223 // Neutering. Only neuters this typed array.
10226 DECLARE_CAST(JSTypedArray)
10228 ExternalArrayType type();
10229 size_t element_size();
10231 Handle<JSArrayBuffer> GetBuffer();
10233 // Dispatched behavior.
10234 DECLARE_PRINTER(JSTypedArray)
10235 DECLARE_VERIFIER(JSTypedArray)
10237 static const int kLengthOffset = kViewSize + kPointerSize;
10238 static const int kSize = kLengthOffset + kPointerSize;
10240 static const int kSizeWithInternalFields =
10241 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
10244 static Handle<JSArrayBuffer> MaterializeArrayBuffer(
10245 Handle<JSTypedArray> typed_array);
10247 DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
10251 class JSDataView: public JSArrayBufferView {
10253 // Only neuters this DataView
10256 DECLARE_CAST(JSDataView)
10258 // Dispatched behavior.
10259 DECLARE_PRINTER(JSDataView)
10260 DECLARE_VERIFIER(JSDataView)
10262 static const int kSize = kViewSize;
10264 static const int kSizeWithInternalFields =
10265 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
10268 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
10272 // Foreign describes objects pointing from JavaScript to C structures.
10273 // Since they cannot contain references to JS HeapObjects they can be
10274 // placed in old_data_space.
10275 class Foreign: public HeapObject {
10277 // [address]: field containing the address.
10278 inline Address foreign_address();
10279 inline void set_foreign_address(Address value);
10281 DECLARE_CAST(Foreign)
10283 // Dispatched behavior.
10284 inline void ForeignIterateBody(ObjectVisitor* v);
10286 template<typename StaticVisitor>
10287 inline void ForeignIterateBody();
10289 // Dispatched behavior.
10290 DECLARE_PRINTER(Foreign)
10291 DECLARE_VERIFIER(Foreign)
10293 // Layout description.
10295 static const int kForeignAddressOffset = HeapObject::kHeaderSize;
10296 static const int kSize = kForeignAddressOffset + kPointerSize;
10298 STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
10301 DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
10305 // The JSArray describes JavaScript Arrays
10306 // Such an array can be in one of two modes:
10307 // - fast, backing storage is a FixedArray and length <= elements.length();
10308 // Please note: push and pop can be used to grow and shrink the array.
10309 // - slow, backing storage is a HashTable with numbers as keys.
10310 class JSArray: public JSObject {
10312 // [length]: The length property.
10313 DECL_ACCESSORS(length, Object)
10315 // Overload the length setter to skip write barrier when the length
10316 // is set to a smi. This matches the set function on FixedArray.
10317 inline void set_length(Smi* length);
10319 static void JSArrayUpdateLengthFromIndex(Handle<JSArray> array,
10321 Handle<Object> value);
10323 static bool HasReadOnlyLength(Handle<JSArray> array);
10324 static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index);
10325 static MaybeHandle<Object> ReadOnlyLengthError(Handle<JSArray> array);
10327 // Initialize the array with the given capacity. The function may
10328 // fail due to out-of-memory situations, but only if the requested
10329 // capacity is non-zero.
10330 static void Initialize(Handle<JSArray> array, int capacity, int length = 0);
10332 // Initializes the array to a certain length.
10333 inline bool AllowsSetElementsLength();
10335 MUST_USE_RESULT static MaybeHandle<Object> SetElementsLength(
10336 Handle<JSArray> array,
10337 Handle<Object> length);
10339 // Set the content of the array to the content of storage.
10340 static inline void SetContent(Handle<JSArray> array,
10341 Handle<FixedArrayBase> storage);
10343 DECLARE_CAST(JSArray)
10345 // Ensures that the fixed array backing the JSArray has at
10346 // least the stated size.
10347 static inline void EnsureSize(Handle<JSArray> array,
10348 int minimum_size_of_backing_fixed_array);
10350 // Expand the fixed array backing of a fast-case JSArray to at least
10351 // the requested size.
10352 static void Expand(Handle<JSArray> array,
10353 int minimum_size_of_backing_fixed_array);
10355 // Dispatched behavior.
10356 DECLARE_PRINTER(JSArray)
10357 DECLARE_VERIFIER(JSArray)
10359 // Number of element slots to pre-allocate for an empty array.
10360 static const int kPreallocatedArrayElements = 4;
10362 // Layout description.
10363 static const int kLengthOffset = JSObject::kHeaderSize;
10364 static const int kSize = kLengthOffset + kPointerSize;
10367 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray);
10371 Handle<Object> CacheInitialJSArrayMaps(Handle<Context> native_context,
10372 Handle<Map> initial_map);
10375 // JSRegExpResult is just a JSArray with a specific initial map.
10376 // This initial map adds in-object properties for "index" and "input"
10377 // properties, as assigned by RegExp.prototype.exec, which allows
10378 // faster creation of RegExp exec results.
10379 // This class just holds constants used when creating the result.
10380 // After creation the result must be treated as a JSArray in all regards.
10381 class JSRegExpResult: public JSArray {
10383 // Offsets of object fields.
10384 static const int kIndexOffset = JSArray::kSize;
10385 static const int kInputOffset = kIndexOffset + kPointerSize;
10386 static const int kSize = kInputOffset + kPointerSize;
10387 // Indices of in-object properties.
10388 static const int kIndexIndex = 0;
10389 static const int kInputIndex = 1;
10391 DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
10395 class AccessorInfo: public Struct {
10397 DECL_ACCESSORS(name, Object)
10398 DECL_ACCESSORS(flag, Smi)
10399 DECL_ACCESSORS(expected_receiver_type, Object)
10401 inline bool all_can_read();
10402 inline void set_all_can_read(bool value);
10404 inline bool all_can_write();
10405 inline void set_all_can_write(bool value);
10407 inline PropertyAttributes property_attributes();
10408 inline void set_property_attributes(PropertyAttributes attributes);
10410 // Checks whether the given receiver is compatible with this accessor.
10411 static bool IsCompatibleReceiverMap(Isolate* isolate,
10412 Handle<AccessorInfo> info,
10414 inline bool IsCompatibleReceiver(Object* receiver);
10416 DECLARE_CAST(AccessorInfo)
10418 // Dispatched behavior.
10419 DECLARE_VERIFIER(AccessorInfo)
10421 // Append all descriptors to the array that are not already there.
10422 // Return number added.
10423 static int AppendUnique(Handle<Object> descriptors,
10424 Handle<FixedArray> array,
10425 int valid_descriptors);
10427 static const int kNameOffset = HeapObject::kHeaderSize;
10428 static const int kFlagOffset = kNameOffset + kPointerSize;
10429 static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
10430 static const int kSize = kExpectedReceiverTypeOffset + kPointerSize;
10433 inline bool HasExpectedReceiverType() {
10434 return expected_receiver_type()->IsFunctionTemplateInfo();
10436 // Bit positions in flag.
10437 static const int kAllCanReadBit = 0;
10438 static const int kAllCanWriteBit = 1;
10439 class AttributesField: public BitField<PropertyAttributes, 2, 3> {};
10441 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo);
10445 // An accessor must have a getter, but can have no setter.
10447 // When setting a property, V8 searches accessors in prototypes.
10448 // If an accessor was found and it does not have a setter,
10449 // the request is ignored.
10451 // If the accessor in the prototype has the READ_ONLY property attribute, then
10452 // a new value is added to the derived object when the property is set.
10453 // This shadows the accessor in the prototype.
10454 class ExecutableAccessorInfo: public AccessorInfo {
10456 DECL_ACCESSORS(getter, Object)
10457 DECL_ACCESSORS(setter, Object)
10458 DECL_ACCESSORS(data, Object)
10460 DECLARE_CAST(ExecutableAccessorInfo)
10462 // Dispatched behavior.
10463 DECLARE_PRINTER(ExecutableAccessorInfo)
10464 DECLARE_VERIFIER(ExecutableAccessorInfo)
10466 static const int kGetterOffset = AccessorInfo::kSize;
10467 static const int kSetterOffset = kGetterOffset + kPointerSize;
10468 static const int kDataOffset = kSetterOffset + kPointerSize;
10469 static const int kSize = kDataOffset + kPointerSize;
10471 inline void clear_setter();
10474 DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutableAccessorInfo);
10478 // Support for JavaScript accessors: A pair of a getter and a setter. Each
10479 // accessor can either be
10480 // * a pointer to a JavaScript function or proxy: a real accessor
10481 // * undefined: considered an accessor by the spec, too, strangely enough
10482 // * the hole: an accessor which has not been set
10483 // * a pointer to a map: a transition used to ensure map sharing
10484 class AccessorPair: public Struct {
10486 DECL_ACCESSORS(getter, Object)
10487 DECL_ACCESSORS(setter, Object)
10489 DECLARE_CAST(AccessorPair)
10491 static Handle<AccessorPair> Copy(Handle<AccessorPair> pair);
10493 Object* get(AccessorComponent component) {
10494 return component == ACCESSOR_GETTER ? getter() : setter();
10497 void set(AccessorComponent component, Object* value) {
10498 if (component == ACCESSOR_GETTER) {
10505 // Note: Returns undefined instead in case of a hole.
10506 Object* GetComponent(AccessorComponent component);
10508 // Set both components, skipping arguments which are a JavaScript null.
10509 void SetComponents(Object* getter, Object* setter) {
10510 if (!getter->IsNull()) set_getter(getter);
10511 if (!setter->IsNull()) set_setter(setter);
10514 bool Equals(AccessorPair* pair) {
10515 return (this == pair) || pair->Equals(getter(), setter());
10518 bool Equals(Object* getter_value, Object* setter_value) {
10519 return (getter() == getter_value) && (setter() == setter_value);
10522 bool ContainsAccessor() {
10523 return IsJSAccessor(getter()) || IsJSAccessor(setter());
10526 // Dispatched behavior.
10527 DECLARE_PRINTER(AccessorPair)
10528 DECLARE_VERIFIER(AccessorPair)
10530 static const int kGetterOffset = HeapObject::kHeaderSize;
10531 static const int kSetterOffset = kGetterOffset + kPointerSize;
10532 static const int kSize = kSetterOffset + kPointerSize;
10535 // Strangely enough, in addition to functions and harmony proxies, the spec
10536 // requires us to consider undefined as a kind of accessor, too:
10538 // Object.defineProperty(obj, "foo", {get: undefined});
10539 // assertTrue("foo" in obj);
10540 bool IsJSAccessor(Object* obj) {
10541 return obj->IsSpecFunction() || obj->IsUndefined();
10544 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
10548 class AccessCheckInfo: public Struct {
10550 DECL_ACCESSORS(named_callback, Object)
10551 DECL_ACCESSORS(indexed_callback, Object)
10552 DECL_ACCESSORS(data, Object)
10554 DECLARE_CAST(AccessCheckInfo)
10556 // Dispatched behavior.
10557 DECLARE_PRINTER(AccessCheckInfo)
10558 DECLARE_VERIFIER(AccessCheckInfo)
10560 static const int kNamedCallbackOffset = HeapObject::kHeaderSize;
10561 static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize;
10562 static const int kDataOffset = kIndexedCallbackOffset + kPointerSize;
10563 static const int kSize = kDataOffset + kPointerSize;
10566 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo);
10570 class InterceptorInfo: public Struct {
10572 DECL_ACCESSORS(getter, Object)
10573 DECL_ACCESSORS(setter, Object)
10574 DECL_ACCESSORS(query, Object)
10575 DECL_ACCESSORS(deleter, Object)
10576 DECL_ACCESSORS(enumerator, Object)
10577 DECL_ACCESSORS(data, Object)
10578 DECL_BOOLEAN_ACCESSORS(can_intercept_symbols)
10579 DECL_BOOLEAN_ACCESSORS(all_can_read)
10581 inline int flags() const;
10582 inline void set_flags(int flags);
10584 DECLARE_CAST(InterceptorInfo)
10586 // Dispatched behavior.
10587 DECLARE_PRINTER(InterceptorInfo)
10588 DECLARE_VERIFIER(InterceptorInfo)
10590 static const int kGetterOffset = HeapObject::kHeaderSize;
10591 static const int kSetterOffset = kGetterOffset + kPointerSize;
10592 static const int kQueryOffset = kSetterOffset + kPointerSize;
10593 static const int kDeleterOffset = kQueryOffset + kPointerSize;
10594 static const int kEnumeratorOffset = kDeleterOffset + kPointerSize;
10595 static const int kDataOffset = kEnumeratorOffset + kPointerSize;
10596 static const int kFlagsOffset = kDataOffset + kPointerSize;
10597 static const int kSize = kFlagsOffset + kPointerSize;
10599 static const int kCanInterceptSymbolsBit = 0;
10600 static const int kAllCanReadBit = 1;
10603 DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo);
10607 class CallHandlerInfo: public Struct {
10609 DECL_ACCESSORS(callback, Object)
10610 DECL_ACCESSORS(data, Object)
10612 DECLARE_CAST(CallHandlerInfo)
10614 // Dispatched behavior.
10615 DECLARE_PRINTER(CallHandlerInfo)
10616 DECLARE_VERIFIER(CallHandlerInfo)
10618 static const int kCallbackOffset = HeapObject::kHeaderSize;
10619 static const int kDataOffset = kCallbackOffset + kPointerSize;
10620 static const int kSize = kDataOffset + kPointerSize;
10623 DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo);
10627 class TemplateInfo: public Struct {
10629 DECL_ACCESSORS(tag, Object)
10630 DECL_ACCESSORS(property_list, Object)
10631 DECL_ACCESSORS(property_accessors, Object)
10633 DECLARE_VERIFIER(TemplateInfo)
10635 static const int kTagOffset = HeapObject::kHeaderSize;
10636 static const int kPropertyListOffset = kTagOffset + kPointerSize;
10637 static const int kPropertyAccessorsOffset =
10638 kPropertyListOffset + kPointerSize;
10639 static const int kHeaderSize = kPropertyAccessorsOffset + kPointerSize;
10642 DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo);
10646 class FunctionTemplateInfo: public TemplateInfo {
10648 DECL_ACCESSORS(serial_number, Object)
10649 DECL_ACCESSORS(call_code, Object)
10650 DECL_ACCESSORS(prototype_template, Object)
10651 DECL_ACCESSORS(parent_template, Object)
10652 DECL_ACCESSORS(named_property_handler, Object)
10653 DECL_ACCESSORS(indexed_property_handler, Object)
10654 DECL_ACCESSORS(instance_template, Object)
10655 DECL_ACCESSORS(class_name, Object)
10656 DECL_ACCESSORS(signature, Object)
10657 DECL_ACCESSORS(instance_call_handler, Object)
10658 DECL_ACCESSORS(access_check_info, Object)
10659 DECL_ACCESSORS(flag, Smi)
10661 inline int length() const;
10662 inline void set_length(int value);
10664 // Following properties use flag bits.
10665 DECL_BOOLEAN_ACCESSORS(hidden_prototype)
10666 DECL_BOOLEAN_ACCESSORS(undetectable)
10667 // If the bit is set, object instances created by this function
10668 // requires access check.
10669 DECL_BOOLEAN_ACCESSORS(needs_access_check)
10670 DECL_BOOLEAN_ACCESSORS(read_only_prototype)
10671 DECL_BOOLEAN_ACCESSORS(remove_prototype)
10672 DECL_BOOLEAN_ACCESSORS(do_not_cache)
10673 DECL_BOOLEAN_ACCESSORS(instantiated)
10675 DECLARE_CAST(FunctionTemplateInfo)
10677 // Dispatched behavior.
10678 DECLARE_PRINTER(FunctionTemplateInfo)
10679 DECLARE_VERIFIER(FunctionTemplateInfo)
10681 static const int kSerialNumberOffset = TemplateInfo::kHeaderSize;
10682 static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize;
10683 static const int kPrototypeTemplateOffset =
10684 kCallCodeOffset + kPointerSize;
10685 static const int kParentTemplateOffset =
10686 kPrototypeTemplateOffset + kPointerSize;
10687 static const int kNamedPropertyHandlerOffset =
10688 kParentTemplateOffset + kPointerSize;
10689 static const int kIndexedPropertyHandlerOffset =
10690 kNamedPropertyHandlerOffset + kPointerSize;
10691 static const int kInstanceTemplateOffset =
10692 kIndexedPropertyHandlerOffset + kPointerSize;
10693 static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize;
10694 static const int kSignatureOffset = kClassNameOffset + kPointerSize;
10695 static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize;
10696 static const int kAccessCheckInfoOffset =
10697 kInstanceCallHandlerOffset + kPointerSize;
10698 static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize;
10699 static const int kLengthOffset = kFlagOffset + kPointerSize;
10700 static const int kSize = kLengthOffset + kPointerSize;
10702 // Returns true if |object| is an instance of this function template.
10703 bool IsTemplateFor(Object* object);
10704 bool IsTemplateFor(Map* map);
10706 // Returns the holder JSObject if the function can legally be called with this
10707 // receiver. Returns Heap::null_value() if the call is illegal.
10708 Object* GetCompatibleReceiver(Isolate* isolate, Object* receiver);
10711 // Bit position in the flag, from least significant bit position.
10712 static const int kHiddenPrototypeBit = 0;
10713 static const int kUndetectableBit = 1;
10714 static const int kNeedsAccessCheckBit = 2;
10715 static const int kReadOnlyPrototypeBit = 3;
10716 static const int kRemovePrototypeBit = 4;
10717 static const int kDoNotCacheBit = 5;
10718 static const int kInstantiatedBit = 6;
10720 DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo);
10724 class ObjectTemplateInfo: public TemplateInfo {
10726 DECL_ACCESSORS(constructor, Object)
10727 DECL_ACCESSORS(internal_field_count, Object)
10729 DECLARE_CAST(ObjectTemplateInfo)
10731 // Dispatched behavior.
10732 DECLARE_PRINTER(ObjectTemplateInfo)
10733 DECLARE_VERIFIER(ObjectTemplateInfo)
10735 static const int kConstructorOffset = TemplateInfo::kHeaderSize;
10736 static const int kInternalFieldCountOffset =
10737 kConstructorOffset + kPointerSize;
10738 static const int kSize = kInternalFieldCountOffset + kPointerSize;
10742 class TypeSwitchInfo: public Struct {
10744 DECL_ACCESSORS(types, Object)
10746 DECLARE_CAST(TypeSwitchInfo)
10748 // Dispatched behavior.
10749 DECLARE_PRINTER(TypeSwitchInfo)
10750 DECLARE_VERIFIER(TypeSwitchInfo)
10752 static const int kTypesOffset = Struct::kHeaderSize;
10753 static const int kSize = kTypesOffset + kPointerSize;
10757 // The DebugInfo class holds additional information for a function being
10759 class DebugInfo: public Struct {
10761 // The shared function info for the source being debugged.
10762 DECL_ACCESSORS(shared, SharedFunctionInfo)
10763 // Code object for the original code.
10764 DECL_ACCESSORS(original_code, Code)
10765 // Code object for the patched code. This code object is the code object
10766 // currently active for the function.
10767 DECL_ACCESSORS(code, Code)
10768 // Fixed array holding status information for each active break point.
10769 DECL_ACCESSORS(break_points, FixedArray)
10771 // Check if there is a break point at a code position.
10772 bool HasBreakPoint(int code_position);
10773 // Get the break point info object for a code position.
10774 Object* GetBreakPointInfo(int code_position);
10775 // Clear a break point.
10776 static void ClearBreakPoint(Handle<DebugInfo> debug_info,
10778 Handle<Object> break_point_object);
10779 // Set a break point.
10780 static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position,
10781 int source_position, int statement_position,
10782 Handle<Object> break_point_object);
10783 // Get the break point objects for a code position.
10784 Object* GetBreakPointObjects(int code_position);
10785 // Find the break point info holding this break point object.
10786 static Object* FindBreakPointInfo(Handle<DebugInfo> debug_info,
10787 Handle<Object> break_point_object);
10788 // Get the number of break points for this function.
10789 int GetBreakPointCount();
10791 DECLARE_CAST(DebugInfo)
10793 // Dispatched behavior.
10794 DECLARE_PRINTER(DebugInfo)
10795 DECLARE_VERIFIER(DebugInfo)
10797 static const int kSharedFunctionInfoIndex = Struct::kHeaderSize;
10798 static const int kOriginalCodeIndex = kSharedFunctionInfoIndex + kPointerSize;
10799 static const int kPatchedCodeIndex = kOriginalCodeIndex + kPointerSize;
10800 static const int kActiveBreakPointsCountIndex =
10801 kPatchedCodeIndex + kPointerSize;
10802 static const int kBreakPointsStateIndex =
10803 kActiveBreakPointsCountIndex + kPointerSize;
10804 static const int kSize = kBreakPointsStateIndex + kPointerSize;
10806 static const int kEstimatedNofBreakPointsInFunction = 16;
10809 static const int kNoBreakPointInfo = -1;
10811 // Lookup the index in the break_points array for a code position.
10812 int GetBreakPointInfoIndex(int code_position);
10814 DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo);
10818 // The BreakPointInfo class holds information for break points set in a
10819 // function. The DebugInfo object holds a BreakPointInfo object for each code
10820 // position with one or more break points.
10821 class BreakPointInfo: public Struct {
10823 // The position in the code for the break point.
10824 DECL_ACCESSORS(code_position, Smi)
10825 // The position in the source for the break position.
10826 DECL_ACCESSORS(source_position, Smi)
10827 // The position in the source for the last statement before this break
10829 DECL_ACCESSORS(statement_position, Smi)
10830 // List of related JavaScript break points.
10831 DECL_ACCESSORS(break_point_objects, Object)
10833 // Removes a break point.
10834 static void ClearBreakPoint(Handle<BreakPointInfo> info,
10835 Handle<Object> break_point_object);
10836 // Set a break point.
10837 static void SetBreakPoint(Handle<BreakPointInfo> info,
10838 Handle<Object> break_point_object);
10839 // Check if break point info has this break point object.
10840 static bool HasBreakPointObject(Handle<BreakPointInfo> info,
10841 Handle<Object> break_point_object);
10842 // Get the number of break points for this code position.
10843 int GetBreakPointCount();
10845 DECLARE_CAST(BreakPointInfo)
10847 // Dispatched behavior.
10848 DECLARE_PRINTER(BreakPointInfo)
10849 DECLARE_VERIFIER(BreakPointInfo)
10851 static const int kCodePositionIndex = Struct::kHeaderSize;
10852 static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize;
10853 static const int kStatementPositionIndex =
10854 kSourcePositionIndex + kPointerSize;
10855 static const int kBreakPointObjectsIndex =
10856 kStatementPositionIndex + kPointerSize;
10857 static const int kSize = kBreakPointObjectsIndex + kPointerSize;
10860 DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo);
10864 #undef DECL_BOOLEAN_ACCESSORS
10865 #undef DECL_ACCESSORS
10866 #undef DECLARE_CAST
10867 #undef DECLARE_VERIFIER
10869 #define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \
10870 V(kStringTable, "string_table", "(Internalized strings)") \
10871 V(kExternalStringsTable, "external_strings_table", "(External strings)") \
10872 V(kStrongRootList, "strong_root_list", "(Strong roots)") \
10873 V(kSmiRootList, "smi_root_list", "(Smi roots)") \
10874 V(kInternalizedString, "internalized_string", "(Internal string)") \
10875 V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \
10876 V(kTop, "top", "(Isolate)") \
10877 V(kRelocatable, "relocatable", "(Relocatable)") \
10878 V(kDebug, "debug", "(Debugger)") \
10879 V(kCompilationCache, "compilationcache", "(Compilation cache)") \
10880 V(kHandleScope, "handlescope", "(Handle scope)") \
10881 V(kBuiltins, "builtins", "(Builtins)") \
10882 V(kGlobalHandles, "globalhandles", "(Global handles)") \
10883 V(kEternalHandles, "eternalhandles", "(Eternal handles)") \
10884 V(kThreadManager, "threadmanager", "(Thread manager)") \
10885 V(kExtensions, "Extensions", "(Extensions)")
10887 class VisitorSynchronization : public AllStatic {
10889 #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item,
10891 VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM)
10894 #undef DECLARE_ENUM
10896 static const char* const kTags[kNumberOfSyncTags];
10897 static const char* const kTagNames[kNumberOfSyncTags];
10900 // Abstract base class for visiting, and optionally modifying, the
10901 // pointers contained in Objects. Used in GC and serialization/deserialization.
10902 class ObjectVisitor BASE_EMBEDDED {
10904 virtual ~ObjectVisitor() {}
10906 // Visits a contiguous arrays of pointers in the half-open range
10907 // [start, end). Any or all of the values may be modified on return.
10908 virtual void VisitPointers(Object** start, Object** end) = 0;
10910 // Handy shorthand for visiting a single pointer.
10911 virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
10913 // Visit weak next_code_link in Code object.
10914 virtual void VisitNextCodeLink(Object** p) { VisitPointers(p, p + 1); }
10916 // To allow lazy clearing of inline caches the visitor has
10917 // a rich interface for iterating over Code objects..
10919 // Visits a code target in the instruction stream.
10920 virtual void VisitCodeTarget(RelocInfo* rinfo);
10922 // Visits a code entry in a JS function.
10923 virtual void VisitCodeEntry(Address entry_address);
10925 // Visits a global property cell reference in the instruction stream.
10926 virtual void VisitCell(RelocInfo* rinfo);
10928 // Visits a runtime entry in the instruction stream.
10929 virtual void VisitRuntimeEntry(RelocInfo* rinfo) {}
10931 // Visits the resource of an one-byte or two-byte string.
10932 virtual void VisitExternalOneByteString(
10933 v8::String::ExternalOneByteStringResource** resource) {}
10934 virtual void VisitExternalTwoByteString(
10935 v8::String::ExternalStringResource** resource) {}
10937 // Visits a debug call target in the instruction stream.
10938 virtual void VisitDebugTarget(RelocInfo* rinfo);
10940 // Visits the byte sequence in a function's prologue that contains information
10941 // about the code's age.
10942 virtual void VisitCodeAgeSequence(RelocInfo* rinfo);
10944 // Visit pointer embedded into a code object.
10945 virtual void VisitEmbeddedPointer(RelocInfo* rinfo);
10947 // Visits an external reference embedded into a code object.
10948 virtual void VisitExternalReference(RelocInfo* rinfo);
10950 // Visits an external reference. The value may be modified on return.
10951 virtual void VisitExternalReference(Address* p) {}
10953 // Visits a handle that has an embedder-assigned class ID.
10954 virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {}
10956 // Intended for serialization/deserialization checking: insert, or
10957 // check for the presence of, a tag at this position in the stream.
10958 // Also used for marking up GC roots in heap snapshots.
10959 virtual void Synchronize(VisitorSynchronization::SyncTag tag) {}
10963 class StructBodyDescriptor : public
10964 FlexibleBodyDescriptor<HeapObject::kHeaderSize> {
10966 static inline int SizeOf(Map* map, HeapObject* object) {
10967 return map->instance_size();
10972 // BooleanBit is a helper class for setting and getting a bit in an
10974 class BooleanBit : public AllStatic {
10976 static inline bool get(Smi* smi, int bit_position) {
10977 return get(smi->value(), bit_position);
10980 static inline bool get(int value, int bit_position) {
10981 return (value & (1 << bit_position)) != 0;
10984 static inline Smi* set(Smi* smi, int bit_position, bool v) {
10985 return Smi::FromInt(set(smi->value(), bit_position, v));
10988 static inline int set(int value, int bit_position, bool v) {
10990 value |= (1 << bit_position);
10992 value &= ~(1 << bit_position);
10998 } } // namespace v8::internal
11000 #endif // V8_OBJECTS_H_