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).
666 // "Data", objects that cannot contain non-map-word pointers to heap
669 MUTABLE_HEAP_NUMBER_TYPE,
673 EXTERNAL_INT8_ARRAY_TYPE, // FIRST_EXTERNAL_ARRAY_TYPE
674 EXTERNAL_UINT8_ARRAY_TYPE,
675 EXTERNAL_INT16_ARRAY_TYPE,
676 EXTERNAL_UINT16_ARRAY_TYPE,
677 EXTERNAL_INT32_ARRAY_TYPE,
678 EXTERNAL_UINT32_ARRAY_TYPE,
679 EXTERNAL_FLOAT32_ARRAY_TYPE,
680 EXTERNAL_FLOAT64_ARRAY_TYPE,
681 EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE, // LAST_EXTERNAL_ARRAY_TYPE
682 FIXED_INT8_ARRAY_TYPE, // FIRST_FIXED_TYPED_ARRAY_TYPE
683 FIXED_UINT8_ARRAY_TYPE,
684 FIXED_INT16_ARRAY_TYPE,
685 FIXED_UINT16_ARRAY_TYPE,
686 FIXED_INT32_ARRAY_TYPE,
687 FIXED_UINT32_ARRAY_TYPE,
688 FIXED_FLOAT32_ARRAY_TYPE,
689 FIXED_FLOAT64_ARRAY_TYPE,
690 FIXED_UINT8_CLAMPED_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE
691 FIXED_DOUBLE_ARRAY_TYPE,
692 FILLER_TYPE, // LAST_DATA_TYPE
695 DECLARED_ACCESSOR_DESCRIPTOR_TYPE,
696 DECLARED_ACCESSOR_INFO_TYPE,
697 EXECUTABLE_ACCESSOR_INFO_TYPE,
699 ACCESS_CHECK_INFO_TYPE,
700 INTERCEPTOR_INFO_TYPE,
701 CALL_HANDLER_INFO_TYPE,
702 FUNCTION_TEMPLATE_INFO_TYPE,
703 OBJECT_TEMPLATE_INFO_TYPE,
705 TYPE_SWITCH_INFO_TYPE,
706 ALLOCATION_SITE_TYPE,
707 ALLOCATION_MEMENTO_TYPE,
710 POLYMORPHIC_CODE_CACHE_TYPE,
711 TYPE_FEEDBACK_INFO_TYPE,
712 ALIASED_ARGUMENTS_ENTRY_TYPE,
715 BREAK_POINT_INFO_TYPE,
717 CONSTANT_POOL_ARRAY_TYPE,
718 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) \
943 V(FixedDoubleArray) \
946 V(ConstantPoolArray) \
948 V(ScriptContextTable) \
954 V(SharedFunctionInfo) \
963 V(JSArrayBufferView) \
972 V(JSWeakCollection) \
979 V(JSFunctionResultCache) \
980 V(NormalizedMapCache) \
981 V(CompilationCacheTable) \
982 V(CodeCacheHashTable) \
983 V(PolymorphicCodeCacheHashTable) \
988 V(JSBuiltinsObject) \
990 V(UndetectableObject) \
991 V(AccessCheckNeeded) \
999 // Object is the abstract superclass for all classes in the
1000 // object hierarchy.
1001 // Object does not use any virtual functions to avoid the
1002 // allocation of the C++ vtable.
1003 // Since both Smi and HeapObject are subclasses of Object no
1004 // data members can be present in Object.
1008 bool IsObject() const { return true; }
1010 #define IS_TYPE_FUNCTION_DECL(type_) INLINE(bool Is##type_() const);
1011 OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
1012 HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
1013 #undef IS_TYPE_FUNCTION_DECL
1015 // A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
1016 // a keyed store is of the form a[expression] = foo.
1017 enum StoreFromKeyed {
1018 MAY_BE_STORE_FROM_KEYED,
1019 CERTAINLY_NOT_STORE_FROM_KEYED
1022 INLINE(bool IsFixedArrayBase() const);
1023 INLINE(bool IsExternal() const);
1024 INLINE(bool IsAccessorInfo() const);
1026 INLINE(bool IsStruct() const);
1027 #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \
1028 INLINE(bool Is##Name() const);
1029 STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
1030 #undef DECLARE_STRUCT_PREDICATE
1032 INLINE(bool IsSpecObject()) const;
1033 INLINE(bool IsSpecFunction()) const;
1034 INLINE(bool IsTemplateInfo()) const;
1035 INLINE(bool IsNameDictionary() const);
1036 INLINE(bool IsSeededNumberDictionary() const);
1037 INLINE(bool IsUnseededNumberDictionary() const);
1038 INLINE(bool IsOrderedHashSet() const);
1039 INLINE(bool IsOrderedHashMap() const);
1040 bool IsCallable() const;
1043 INLINE(bool IsUndefined() const);
1044 INLINE(bool IsNull() const);
1045 INLINE(bool IsTheHole() const);
1046 INLINE(bool IsException() const);
1047 INLINE(bool IsUninitialized() const);
1048 INLINE(bool IsTrue() const);
1049 INLINE(bool IsFalse() const);
1050 INLINE(bool IsArgumentsMarker() const);
1052 // Filler objects (fillers and free space objects).
1053 INLINE(bool IsFiller() const);
1055 // Extract the number.
1056 inline double Number();
1057 INLINE(bool IsNaN() const);
1058 INLINE(bool IsMinusZero() const);
1059 bool ToInt32(int32_t* value);
1060 bool ToUint32(uint32_t* value);
1062 inline Representation OptimalRepresentation() {
1063 if (!FLAG_track_fields) return Representation::Tagged();
1065 return Representation::Smi();
1066 } else if (FLAG_track_double_fields && IsHeapNumber()) {
1067 return Representation::Double();
1068 } else if (FLAG_track_computed_fields && IsUninitialized()) {
1069 return Representation::None();
1070 } else if (FLAG_track_heap_object_fields) {
1071 DCHECK(IsHeapObject());
1072 return Representation::HeapObject();
1074 return Representation::Tagged();
1078 inline bool FitsRepresentation(Representation representation) {
1079 if (FLAG_track_fields && representation.IsNone()) {
1081 } else if (FLAG_track_fields && representation.IsSmi()) {
1083 } else if (FLAG_track_double_fields && representation.IsDouble()) {
1084 return IsMutableHeapNumber() || IsNumber();
1085 } else if (FLAG_track_heap_object_fields && representation.IsHeapObject()) {
1086 return IsHeapObject();
1091 Handle<HeapType> OptimalType(Isolate* isolate, Representation representation);
1093 inline static Handle<Object> NewStorageFor(Isolate* isolate,
1094 Handle<Object> object,
1095 Representation representation);
1097 inline static Handle<Object> WrapForRead(Isolate* isolate,
1098 Handle<Object> object,
1099 Representation representation);
1101 // Returns true if the object is of the correct type to be used as a
1102 // implementation of a JSObject's elements.
1103 inline bool HasValidElements();
1105 inline bool HasSpecificClassOf(String* name);
1107 bool BooleanValue(); // ECMA-262 9.2.
1109 // Convert to a JSObject if needed.
1110 // native_context is used when creating wrapper object.
1111 static inline MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1112 Handle<Object> object);
1113 static MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1114 Handle<Object> object,
1115 Handle<Context> context);
1117 // Converts this to a Smi if possible.
1118 MUST_USE_RESULT static inline MaybeHandle<Smi> ToSmi(Isolate* isolate,
1119 Handle<Object> object);
1121 MUST_USE_RESULT static MaybeHandle<Object> GetProperty(LookupIterator* it);
1123 // Implementation of [[Put]], ECMA-262 5th edition, section 8.12.5.
1124 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1125 Handle<Object> object, Handle<Name> key, Handle<Object> value,
1126 LanguageMode language_mode,
1127 StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
1129 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1130 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1131 StoreFromKeyed store_mode);
1133 MUST_USE_RESULT static MaybeHandle<Object> SetSuperProperty(
1134 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1135 StoreFromKeyed store_mode);
1137 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1138 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
1139 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1140 Isolate* isolate, Handle<Object> reciever, Handle<Object> name,
1141 Handle<Object> value, LanguageMode language_mode);
1142 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyElement(
1143 Isolate* isolate, Handle<Object> receiver, uint32_t index,
1144 Handle<Object> value, LanguageMode language_mode);
1145 MUST_USE_RESULT static MaybeHandle<Object> RedefineNonconfigurableProperty(
1146 Isolate* isolate, Handle<Object> name, Handle<Object> value,
1147 LanguageMode language_mode);
1148 MUST_USE_RESULT static MaybeHandle<Object> SetDataProperty(
1149 LookupIterator* it, Handle<Object> value);
1150 MUST_USE_RESULT static MaybeHandle<Object> AddDataProperty(
1151 LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
1152 LanguageMode language_mode, StoreFromKeyed store_mode);
1153 MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
1154 Handle<Object> object,
1156 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1158 Handle<Object> object,
1160 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1161 Handle<Object> object,
1164 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
1165 Handle<Object> receiver,
1167 Handle<JSObject> holder,
1168 Handle<Object> structure);
1169 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithAccessor(
1170 Handle<Object> receiver, Handle<Name> name, Handle<Object> value,
1171 Handle<JSObject> holder, Handle<Object> structure,
1172 LanguageMode language_mode);
1174 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter(
1175 Handle<Object> receiver,
1176 Handle<JSReceiver> getter);
1177 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithDefinedSetter(
1178 Handle<Object> receiver,
1179 Handle<JSReceiver> setter,
1180 Handle<Object> value);
1182 MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
1184 Handle<Object> object,
1187 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithReceiver(
1189 Handle<Object> object,
1190 Handle<Object> receiver,
1193 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithReceiver(
1194 Isolate* isolate, Handle<Object> object, Handle<Object> receiver,
1195 uint32_t index, Handle<Object> value, LanguageMode language_mode);
1197 static inline Handle<Object> GetPrototypeSkipHiddenPrototypes(
1198 Isolate* isolate, Handle<Object> receiver);
1200 // Returns the permanent hash code associated with this object. May return
1201 // undefined if not yet created.
1204 // Returns the permanent hash code associated with this object depending on
1205 // the actual object type. May create and store a hash code if needed and none
1207 static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object);
1209 // Checks whether this object has the same value as the given one. This
1210 // function is implemented according to ES5, section 9.12 and can be used
1211 // to implement the Harmony "egal" function.
1212 bool SameValue(Object* other);
1214 // Checks whether this object has the same value as the given one.
1215 // +0 and -0 are treated equal. Everything else is the same as SameValue.
1216 // This function is implemented according to ES6, section 7.2.4 and is used
1217 // by ES6 Map and Set.
1218 bool SameValueZero(Object* other);
1220 // Tries to convert an object to an array index. Returns true and sets
1221 // the output parameter if it succeeds.
1222 inline bool ToArrayIndex(uint32_t* index);
1224 // Returns true if this is a JSValue containing a string and the index is
1225 // < the length of the string. Used to implement [] on strings.
1226 inline bool IsStringObjectWithCharacterAt(uint32_t index);
1228 DECLARE_VERIFIER(Object)
1230 // Verify a pointer is a valid object pointer.
1231 static void VerifyPointer(Object* p);
1234 inline void VerifyApiCallResultType();
1236 // Prints this object without details.
1237 void ShortPrint(FILE* out = stdout);
1239 // Prints this object without details to a message accumulator.
1240 void ShortPrint(StringStream* accumulator);
1242 void ShortPrint(std::ostream& os); // NOLINT
1244 DECLARE_CAST(Object)
1246 // Layout description.
1247 static const int kHeaderSize = 0; // Object does not take up any space.
1250 // For our gdb macros, we should perhaps change these in the future.
1253 // Prints this object with details.
1254 void Print(std::ostream& os); // NOLINT
1256 void Print() { ShortPrint(); }
1257 void Print(std::ostream& os) { ShortPrint(os); } // NOLINT
1261 friend class LookupIterator;
1262 friend class PrototypeIterator;
1264 // Return the map of the root of object's prototype chain.
1265 Map* GetRootMap(Isolate* isolate);
1267 // Helper for SetProperty and SetSuperProperty.
1268 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyInternal(
1269 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1270 StoreFromKeyed store_mode, bool* found);
1272 DISALLOW_IMPLICIT_CONSTRUCTORS(Object);
1277 explicit Brief(const Object* const v) : value(v) {}
1278 const Object* value;
1282 std::ostream& operator<<(std::ostream& os, const Brief& v);
1285 // Smi represents integer Numbers that can be stored in 31 bits.
1286 // Smis are immediate which means they are NOT allocated in the heap.
1287 // The this pointer has the following format: [31 bit signed int] 0
1288 // For long smis it has the following format:
1289 // [32 bit signed int] [31 bits zero padding] 0
1290 // Smi stands for small integer.
1291 class Smi: public Object {
1293 // Returns the integer value.
1294 inline int value() const;
1296 // Convert a value to a Smi object.
1297 static inline Smi* FromInt(int value);
1299 static inline Smi* FromIntptr(intptr_t value);
1301 // Returns whether value can be represented in a Smi.
1302 static inline bool IsValid(intptr_t value);
1306 // Dispatched behavior.
1307 void SmiPrint(std::ostream& os) const; // NOLINT
1308 DECLARE_VERIFIER(Smi)
1310 static const int kMinValue =
1311 (static_cast<unsigned int>(-1)) << (kSmiValueSize - 1);
1312 static const int kMaxValue = -(kMinValue + 1);
1315 DISALLOW_IMPLICIT_CONSTRUCTORS(Smi);
1319 // Heap objects typically have a map pointer in their first word. However,
1320 // during GC other data (e.g. mark bits, forwarding addresses) is sometimes
1321 // encoded in the first word. The class MapWord is an abstraction of the
1322 // value in a heap object's first word.
1323 class MapWord BASE_EMBEDDED {
1325 // Normal state: the map word contains a map pointer.
1327 // Create a map word from a map pointer.
1328 static inline MapWord FromMap(const Map* map);
1330 // View this map word as a map pointer.
1331 inline Map* ToMap();
1334 // Scavenge collection: the map word of live objects in the from space
1335 // contains a forwarding address (a heap object pointer in the to space).
1337 // True if this map word is a forwarding address for a scavenge
1338 // collection. Only valid during a scavenge collection (specifically,
1339 // when all map words are heap object pointers, i.e. not during a full GC).
1340 inline bool IsForwardingAddress();
1342 // Create a map word from a forwarding address.
1343 static inline MapWord FromForwardingAddress(HeapObject* object);
1345 // View this map word as a forwarding address.
1346 inline HeapObject* ToForwardingAddress();
1348 static inline MapWord FromRawValue(uintptr_t value) {
1349 return MapWord(value);
1352 inline uintptr_t ToRawValue() {
1357 // HeapObject calls the private constructor and directly reads the value.
1358 friend class HeapObject;
1360 explicit MapWord(uintptr_t value) : value_(value) {}
1366 // HeapObject is the superclass for all classes describing heap allocated
1368 class HeapObject: public Object {
1370 // [map]: Contains a map which contains the object's reflective
1372 inline Map* map() const;
1373 inline void set_map(Map* value);
1374 // The no-write-barrier version. This is OK if the object is white and in
1375 // new space, or if the value is an immortal immutable object, like the maps
1376 // of primitive (non-JS) objects like strings, heap numbers etc.
1377 inline void set_map_no_write_barrier(Map* value);
1379 // Get the map using acquire load.
1380 inline Map* synchronized_map();
1381 inline MapWord synchronized_map_word() const;
1383 // Set the map using release store
1384 inline void synchronized_set_map(Map* value);
1385 inline void synchronized_set_map_no_write_barrier(Map* value);
1386 inline void synchronized_set_map_word(MapWord map_word);
1388 // During garbage collection, the map word of a heap object does not
1389 // necessarily contain a map pointer.
1390 inline MapWord map_word() const;
1391 inline void set_map_word(MapWord map_word);
1393 // The Heap the object was allocated in. Used also to access Isolate.
1394 inline Heap* GetHeap() const;
1396 // Convenience method to get current isolate.
1397 inline Isolate* GetIsolate() const;
1399 // Converts an address to a HeapObject pointer.
1400 static inline HeapObject* FromAddress(Address address);
1402 // Returns the address of this HeapObject.
1403 inline Address address();
1405 // Iterates over pointers contained in the object (including the Map)
1406 void Iterate(ObjectVisitor* v);
1408 // Iterates over all pointers contained in the object except the
1409 // first map pointer. The object type is given in the first
1410 // parameter. This function does not access the map pointer in the
1411 // object, and so is safe to call while the map pointer is modified.
1412 void IterateBody(InstanceType type, int object_size, ObjectVisitor* v);
1414 // Returns the heap object's size in bytes
1417 // Returns true if this heap object may contain raw values, i.e., values that
1418 // look like pointers to heap objects.
1419 inline bool MayContainRawValues();
1421 // Given a heap object's map pointer, returns the heap size in bytes
1422 // Useful when the map pointer field is used for other purposes.
1424 inline int SizeFromMap(Map* map);
1426 // Returns the field at offset in obj, as a read/write Object* reference.
1427 // Does no checking, and is safe to use during GC, while maps are invalid.
1428 // Does not invoke write barrier, so should only be assigned to
1429 // during marking GC.
1430 static inline Object** RawField(HeapObject* obj, int offset);
1432 // Adds the |code| object related to |name| to the code cache of this map. If
1433 // this map is a dictionary map that is shared, the map copied and installed
1435 static void UpdateMapCodeCache(Handle<HeapObject> object,
1439 DECLARE_CAST(HeapObject)
1441 // Return the write barrier mode for this. Callers of this function
1442 // must be able to present a reference to an DisallowHeapAllocation
1443 // object as a sign that they are not going to use this function
1444 // from code that allocates and thus invalidates the returned write
1446 inline WriteBarrierMode GetWriteBarrierMode(
1447 const DisallowHeapAllocation& promise);
1449 // Dispatched behavior.
1450 void HeapObjectShortPrint(std::ostream& os); // NOLINT
1452 void PrintHeader(std::ostream& os, const char* id); // NOLINT
1454 DECLARE_PRINTER(HeapObject)
1455 DECLARE_VERIFIER(HeapObject)
1457 inline void VerifyObjectField(int offset);
1458 inline void VerifySmiField(int offset);
1460 // Verify a pointer is a valid HeapObject pointer that points to object
1461 // areas in the heap.
1462 static void VerifyHeapPointer(Object* p);
1465 inline bool NeedsToEnsureDoubleAlignment();
1467 // Layout description.
1468 // First field in a heap object is map.
1469 static const int kMapOffset = Object::kHeaderSize;
1470 static const int kHeaderSize = kMapOffset + kPointerSize;
1472 STATIC_ASSERT(kMapOffset == Internals::kHeapObjectMapOffset);
1475 // helpers for calling an ObjectVisitor to iterate over pointers in the
1476 // half-open range [start, end) specified as integer offsets
1477 inline void IteratePointers(ObjectVisitor* v, int start, int end);
1478 // as above, for the single element at "offset"
1479 inline void IteratePointer(ObjectVisitor* v, int offset);
1480 // as above, for the next code link of a code object.
1481 inline void IterateNextCodeLink(ObjectVisitor* v, int offset);
1484 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject);
1488 // This class describes a body of an object of a fixed size
1489 // in which all pointer fields are located in the [start_offset, end_offset)
1491 template<int start_offset, int end_offset, int size>
1492 class FixedBodyDescriptor {
1494 static const int kStartOffset = start_offset;
1495 static const int kEndOffset = end_offset;
1496 static const int kSize = size;
1498 static inline void IterateBody(HeapObject* obj, ObjectVisitor* v);
1500 template<typename StaticVisitor>
1501 static inline void IterateBody(HeapObject* obj) {
1502 StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
1503 HeapObject::RawField(obj, end_offset));
1508 // This class describes a body of an object of a variable size
1509 // in which all pointer fields are located in the [start_offset, object_size)
1511 template<int start_offset>
1512 class FlexibleBodyDescriptor {
1514 static const int kStartOffset = start_offset;
1516 static inline void IterateBody(HeapObject* obj,
1520 template<typename StaticVisitor>
1521 static inline void IterateBody(HeapObject* obj, int object_size) {
1522 StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
1523 HeapObject::RawField(obj, object_size));
1528 // The HeapNumber class describes heap allocated numbers that cannot be
1529 // represented in a Smi (small integer)
1530 class HeapNumber: public HeapObject {
1532 // [value]: number value.
1533 inline double value() const;
1534 inline void set_value(double value);
1536 DECLARE_CAST(HeapNumber)
1538 // Dispatched behavior.
1539 bool HeapNumberBooleanValue();
1541 void HeapNumberPrint(std::ostream& os); // NOLINT
1542 DECLARE_VERIFIER(HeapNumber)
1544 inline int get_exponent();
1545 inline int get_sign();
1547 // Layout description.
1548 static const int kValueOffset = HeapObject::kHeaderSize;
1549 // IEEE doubles are two 32 bit words. The first is just mantissa, the second
1550 // is a mixture of sign, exponent and mantissa. The offsets of two 32 bit
1551 // words within double numbers are endian dependent and they are set
1553 #if defined(V8_TARGET_LITTLE_ENDIAN)
1554 static const int kMantissaOffset = kValueOffset;
1555 static const int kExponentOffset = kValueOffset + 4;
1556 #elif defined(V8_TARGET_BIG_ENDIAN)
1557 static const int kMantissaOffset = kValueOffset + 4;
1558 static const int kExponentOffset = kValueOffset;
1560 #error Unknown byte ordering
1563 static const int kSize = kValueOffset + kDoubleSize;
1564 static const uint32_t kSignMask = 0x80000000u;
1565 static const uint32_t kExponentMask = 0x7ff00000u;
1566 static const uint32_t kMantissaMask = 0xfffffu;
1567 static const int kMantissaBits = 52;
1568 static const int kExponentBits = 11;
1569 static const int kExponentBias = 1023;
1570 static const int kExponentShift = 20;
1571 static const int kInfinityOrNanExponent =
1572 (kExponentMask >> kExponentShift) - kExponentBias;
1573 static const int kMantissaBitsInTopWord = 20;
1574 static const int kNonMantissaBitsInTopWord = 12;
1577 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber);
1581 enum EnsureElementsMode {
1582 DONT_ALLOW_DOUBLE_ELEMENTS,
1583 ALLOW_COPIED_DOUBLE_ELEMENTS,
1584 ALLOW_CONVERTED_DOUBLE_ELEMENTS
1588 // Indicates whether a property should be set or (re)defined. Setting of a
1589 // property causes attributes to remain unchanged, writability to be checked
1590 // and callbacks to be called. Defining of a property causes attributes to
1591 // be updated and callbacks to be overridden.
1592 enum SetPropertyMode {
1598 // Indicator for one component of an AccessorPair.
1599 enum AccessorComponent {
1605 // JSReceiver includes types on which properties can be defined, i.e.,
1606 // JSObject and JSProxy.
1607 class JSReceiver: public HeapObject {
1609 DECLARE_CAST(JSReceiver)
1611 MUST_USE_RESULT static MaybeHandle<Object> SetElement(
1612 Handle<JSReceiver> object, uint32_t index, Handle<Object> value,
1613 PropertyAttributes attributes, LanguageMode language_mode);
1615 // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
1616 MUST_USE_RESULT static inline Maybe<bool> HasProperty(
1617 Handle<JSReceiver> object, Handle<Name> name);
1618 MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty(Handle<JSReceiver>,
1620 MUST_USE_RESULT static inline Maybe<bool> HasElement(
1621 Handle<JSReceiver> object, uint32_t index);
1622 MUST_USE_RESULT static inline Maybe<bool> HasOwnElement(
1623 Handle<JSReceiver> object, uint32_t index);
1625 // Implementation of [[Delete]], ECMA-262 5th edition, section 8.12.7.
1626 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
1627 Handle<JSReceiver> object, Handle<Name> name,
1628 LanguageMode language_mode = SLOPPY);
1629 MUST_USE_RESULT static MaybeHandle<Object> DeleteElement(
1630 Handle<JSReceiver> object, uint32_t index,
1631 LanguageMode language_mode = SLOPPY);
1633 // Tests for the fast common case for property enumeration.
1634 bool IsSimpleEnum();
1636 // Returns the class name ([[Class]] property in the specification).
1637 String* class_name();
1639 // Returns the constructor name (the name (possibly, inferred name) of the
1640 // function that was used to instantiate the object).
1641 String* constructor_name();
1643 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes(
1644 Handle<JSReceiver> object, Handle<Name> name);
1645 MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
1646 LookupIterator* it);
1647 MUST_USE_RESULT static Maybe<PropertyAttributes> GetOwnPropertyAttributes(
1648 Handle<JSReceiver> object, Handle<Name> name);
1650 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetElementAttribute(
1651 Handle<JSReceiver> object, uint32_t index);
1652 MUST_USE_RESULT static inline Maybe<PropertyAttributes>
1653 GetOwnElementAttribute(Handle<JSReceiver> object, uint32_t index);
1655 // Retrieves a permanent object identity hash code. The undefined value might
1656 // be returned in case no hash was created yet.
1657 inline Object* GetIdentityHash();
1659 // Retrieves a permanent object identity hash code. May create and store a
1660 // hash code if needed and none exists.
1661 inline static Handle<Smi> GetOrCreateIdentityHash(
1662 Handle<JSReceiver> object);
1664 enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS };
1666 // Computes the enumerable keys for a JSObject. Used for implementing
1667 // "for (n in object) { }".
1668 MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys(
1669 Handle<JSReceiver> object,
1670 KeyCollectionType type);
1673 DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
1676 // Forward declaration for JSObject::GetOrCreateHiddenPropertiesHashTable.
1677 class ObjectHashTable;
1679 // Forward declaration for JSObject::Copy.
1680 class AllocationSite;
1683 // The JSObject describes real heap allocated JavaScript objects with
1685 // Note that the map of JSObject changes during execution to enable inline
1687 class JSObject: public JSReceiver {
1689 // [properties]: Backing storage for properties.
1690 // properties is a FixedArray in the fast case and a Dictionary in the
1692 DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties.
1693 inline void initialize_properties();
1694 inline bool HasFastProperties();
1695 inline NameDictionary* property_dictionary(); // Gets slow properties.
1697 // [elements]: The elements (properties with names that are integers).
1699 // Elements can be in two general modes: fast and slow. Each mode
1700 // corrensponds to a set of object representations of elements that
1701 // have something in common.
1703 // In the fast mode elements is a FixedArray and so each element can
1704 // be quickly accessed. This fact is used in the generated code. The
1705 // elements array can have one of three maps in this mode:
1706 // fixed_array_map, sloppy_arguments_elements_map or
1707 // fixed_cow_array_map (for copy-on-write arrays). In the latter case
1708 // the elements array may be shared by a few objects and so before
1709 // writing to any element the array must be copied. Use
1710 // EnsureWritableFastElements in this case.
1712 // In the slow mode the elements is either a NumberDictionary, an
1713 // ExternalArray, or a FixedArray parameter map for a (sloppy)
1714 // arguments object.
1715 DECL_ACCESSORS(elements, FixedArrayBase)
1716 inline void initialize_elements();
1717 static void ResetElements(Handle<JSObject> object);
1718 static inline void SetMapAndElements(Handle<JSObject> object,
1720 Handle<FixedArrayBase> elements);
1721 inline ElementsKind GetElementsKind();
1722 inline ElementsAccessor* GetElementsAccessor();
1723 // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
1724 inline bool HasFastSmiElements();
1725 // Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
1726 inline bool HasFastObjectElements();
1727 // Returns true if an object has elements of FAST_ELEMENTS or
1728 // FAST_SMI_ONLY_ELEMENTS.
1729 inline bool HasFastSmiOrObjectElements();
1730 // Returns true if an object has any of the fast elements kinds.
1731 inline bool HasFastElements();
1732 // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
1734 inline bool HasFastDoubleElements();
1735 // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
1737 inline bool HasFastHoleyElements();
1738 inline bool HasSloppyArgumentsElements();
1739 inline bool HasDictionaryElements();
1741 inline bool HasExternalUint8ClampedElements();
1742 inline bool HasExternalArrayElements();
1743 inline bool HasExternalInt8Elements();
1744 inline bool HasExternalUint8Elements();
1745 inline bool HasExternalInt16Elements();
1746 inline bool HasExternalUint16Elements();
1747 inline bool HasExternalInt32Elements();
1748 inline bool HasExternalUint32Elements();
1749 inline bool HasExternalFloat32Elements();
1750 inline bool HasExternalFloat64Elements();
1752 inline bool HasFixedTypedArrayElements();
1754 inline bool HasFixedUint8ClampedElements();
1755 inline bool HasFixedArrayElements();
1756 inline bool HasFixedInt8Elements();
1757 inline bool HasFixedUint8Elements();
1758 inline bool HasFixedInt16Elements();
1759 inline bool HasFixedUint16Elements();
1760 inline bool HasFixedInt32Elements();
1761 inline bool HasFixedUint32Elements();
1762 inline bool HasFixedFloat32Elements();
1763 inline bool HasFixedFloat64Elements();
1765 bool HasFastArgumentsElements();
1766 bool HasDictionaryArgumentsElements();
1767 inline SeededNumberDictionary* element_dictionary(); // Gets slow elements.
1769 // Requires: HasFastElements().
1770 static Handle<FixedArray> EnsureWritableFastElements(
1771 Handle<JSObject> object);
1773 // Collects elements starting at index 0.
1774 // Undefined values are placed after non-undefined values.
1775 // Returns the number of non-undefined values.
1776 static Handle<Object> PrepareElementsForSort(Handle<JSObject> object,
1778 // As PrepareElementsForSort, but only on objects where elements is
1779 // a dictionary, and it will stay a dictionary. Collates undefined and
1780 // unexisting elements below limit from position zero of the elements.
1781 static Handle<Object> PrepareSlowElementsForSort(Handle<JSObject> object,
1784 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithInterceptor(
1785 LookupIterator* it, Handle<Object> value);
1787 // SetLocalPropertyIgnoreAttributes converts callbacks to fields. We need to
1788 // grant an exemption to ExecutableAccessor callbacks in some cases.
1789 enum ExecutableAccessorInfoHandling {
1794 MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes(
1795 Handle<JSObject> object,
1797 Handle<Object> value,
1798 PropertyAttributes attributes,
1799 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1801 static void AddProperty(Handle<JSObject> object, Handle<Name> key,
1802 Handle<Object> value, PropertyAttributes attributes);
1804 // Extend the receiver with a single fast property appeared first in the
1805 // passed map. This also extends the property backing store if necessary.
1806 static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
1808 // Migrates the given object to a map whose field representations are the
1809 // lowest upper bound of all known representations for that field.
1810 static void MigrateInstance(Handle<JSObject> instance);
1812 // Migrates the given object only if the target map is already available,
1813 // or returns false if such a map is not yet available.
1814 static bool TryMigrateInstance(Handle<JSObject> instance);
1816 // Sets the property value in a normalized object given (key, value, details).
1817 // Handles the special representation of JS global objects.
1818 static void SetNormalizedProperty(Handle<JSObject> object,
1820 Handle<Object> value,
1821 PropertyDetails details);
1823 static void OptimizeAsPrototype(Handle<JSObject> object,
1824 PrototypeOptimizationMode mode);
1825 static void ReoptimizeIfPrototype(Handle<JSObject> object);
1826 static void RegisterPrototypeUser(Handle<JSObject> prototype,
1827 Handle<HeapObject> user);
1828 static void UnregisterPrototypeUser(Handle<JSObject> prototype,
1829 Handle<HeapObject> user);
1831 // Retrieve interceptors.
1832 InterceptorInfo* GetNamedInterceptor();
1833 InterceptorInfo* GetIndexedInterceptor();
1835 // Used from JSReceiver.
1836 MUST_USE_RESULT static Maybe<PropertyAttributes>
1837 GetPropertyAttributesWithInterceptor(Handle<JSObject> holder,
1838 Handle<Object> receiver,
1840 MUST_USE_RESULT static Maybe<PropertyAttributes>
1841 GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
1842 MUST_USE_RESULT static Maybe<PropertyAttributes>
1843 GetElementAttributeWithReceiver(Handle<JSObject> object,
1844 Handle<JSReceiver> receiver,
1845 uint32_t index, bool check_prototype);
1847 // Retrieves an AccessorPair property from the given object. Might return
1848 // undefined if the property doesn't exist or is of a different kind.
1849 MUST_USE_RESULT static MaybeHandle<Object> GetAccessor(
1850 Handle<JSObject> object,
1852 AccessorComponent component);
1854 // Defines an AccessorPair property on the given object.
1855 // TODO(mstarzinger): Rename to SetAccessor().
1856 static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
1858 Handle<Object> getter,
1859 Handle<Object> setter,
1860 PropertyAttributes attributes);
1862 // Defines an AccessorInfo property on the given object.
1863 MUST_USE_RESULT static MaybeHandle<Object> SetAccessor(
1864 Handle<JSObject> object,
1865 Handle<AccessorInfo> info);
1867 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
1868 Handle<JSObject> object,
1869 Handle<Object> receiver,
1872 // Accessors for hidden properties object.
1874 // Hidden properties are not own properties of the object itself.
1875 // Instead they are stored in an auxiliary structure kept as an own
1876 // property with a special name Heap::hidden_string(). But if the
1877 // receiver is a JSGlobalProxy then the auxiliary object is a property
1878 // of its prototype, and if it's a detached proxy, then you can't have
1879 // hidden properties.
1881 // Sets a hidden property on this object. Returns this object if successful,
1882 // undefined if called on a detached proxy.
1883 static Handle<Object> SetHiddenProperty(Handle<JSObject> object,
1885 Handle<Object> value);
1886 // Gets the value of a hidden property with the given key. Returns the hole
1887 // if the property doesn't exist (or if called on a detached proxy),
1888 // otherwise returns the value set for the key.
1889 Object* GetHiddenProperty(Handle<Name> key);
1890 // Deletes a hidden property. Deleting a non-existing property is
1891 // considered successful.
1892 static void DeleteHiddenProperty(Handle<JSObject> object,
1894 // Returns true if the object has a property with the hidden string as name.
1895 static bool HasHiddenProperties(Handle<JSObject> object);
1897 static void SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash);
1899 static inline void ValidateElements(Handle<JSObject> object);
1901 // Makes sure that this object can contain HeapObject as elements.
1902 static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
1904 // Makes sure that this object can contain the specified elements.
1905 static inline void EnsureCanContainElements(
1906 Handle<JSObject> object,
1909 EnsureElementsMode mode);
1910 static inline void EnsureCanContainElements(
1911 Handle<JSObject> object,
1912 Handle<FixedArrayBase> elements,
1914 EnsureElementsMode mode);
1915 static void EnsureCanContainElements(
1916 Handle<JSObject> object,
1917 Arguments* arguments,
1920 EnsureElementsMode mode);
1922 // Would we convert a fast elements array to dictionary mode given
1923 // an access at key?
1924 bool WouldConvertToSlowElements(Handle<Object> key);
1925 // Do we want to keep the elements in fast case when increasing the
1927 bool ShouldConvertToSlowElements(int new_capacity);
1928 // Returns true if the backing storage for the slow-case elements of
1929 // this object takes up nearly as much space as a fast-case backing
1930 // storage would. In that case the JSObject should have fast
1932 bool ShouldConvertToFastElements();
1933 // Returns true if the elements of JSObject contains only values that can be
1934 // represented in a FixedDoubleArray and has at least one value that can only
1935 // be represented as a double and not a Smi.
1936 bool ShouldConvertToFastDoubleElements(bool* has_smi_only_elements);
1938 // Computes the new capacity when expanding the elements of a JSObject.
1939 static int NewElementsCapacity(int old_capacity) {
1940 // (old_capacity + 50%) + 16
1941 return old_capacity + (old_capacity >> 1) + 16;
1944 // These methods do not perform access checks!
1945 MUST_USE_RESULT static MaybeHandle<AccessorPair> GetOwnElementAccessorPair(
1946 Handle<JSObject> object, uint32_t index);
1948 MUST_USE_RESULT static MaybeHandle<Object> SetFastElement(
1949 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1950 LanguageMode language_mode, bool check_prototype);
1952 MUST_USE_RESULT static inline MaybeHandle<Object> SetOwnElement(
1953 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1954 LanguageMode language_mode);
1956 MUST_USE_RESULT static MaybeHandle<Object> SetOwnElement(
1957 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1958 PropertyAttributes attributes, LanguageMode language_mode);
1960 // Empty handle is returned if the element cannot be set to the given value.
1961 MUST_USE_RESULT static MaybeHandle<Object> SetElement(
1962 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1963 PropertyAttributes attributes, LanguageMode language_mode,
1964 bool check_prototype = true, SetPropertyMode set_mode = SET_PROPERTY);
1966 // Returns the index'th element.
1967 // The undefined object if index is out of bounds.
1968 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithInterceptor(
1969 Handle<JSObject> object, Handle<Object> receiver, uint32_t index,
1970 bool check_prototype);
1972 enum SetFastElementsCapacitySmiMode {
1975 kDontAllowSmiElements
1978 // Replace the elements' backing store with fast elements of the given
1979 // capacity. Update the length for JSArrays. Returns the new backing
1981 static Handle<FixedArray> SetFastElementsCapacityAndLength(
1982 Handle<JSObject> object,
1985 SetFastElementsCapacitySmiMode smi_mode);
1986 static void SetFastDoubleElementsCapacityAndLength(
1987 Handle<JSObject> object,
1991 // Lookup interceptors are used for handling properties controlled by host
1993 inline bool HasNamedInterceptor();
1994 inline bool HasIndexedInterceptor();
1996 // Computes the enumerable keys from interceptors. Used for debug mirrors and
1997 // by JSReceiver::GetKeys.
1998 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForNamedInterceptor(
1999 Handle<JSObject> object,
2000 Handle<JSReceiver> receiver);
2001 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForIndexedInterceptor(
2002 Handle<JSObject> object,
2003 Handle<JSReceiver> receiver);
2005 // Support functions for v8 api (needed for correct interceptor behavior).
2006 MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
2007 Handle<JSObject> object, Handle<Name> key);
2008 MUST_USE_RESULT static Maybe<bool> HasRealElementProperty(
2009 Handle<JSObject> object, uint32_t index);
2010 MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
2011 Handle<JSObject> object, Handle<Name> key);
2013 // Get the header size for a JSObject. Used to compute the index of
2014 // internal fields as well as the number of internal fields.
2015 inline int GetHeaderSize();
2017 inline int GetInternalFieldCount();
2018 inline int GetInternalFieldOffset(int index);
2019 inline Object* GetInternalField(int index);
2020 inline void SetInternalField(int index, Object* value);
2021 inline void SetInternalField(int index, Smi* value);
2023 // Returns the number of properties on this object filtering out properties
2024 // with the specified attributes (ignoring interceptors).
2025 int NumberOfOwnProperties(PropertyAttributes filter = NONE);
2026 // Fill in details for properties into storage starting at the specified
2028 void GetOwnPropertyNames(
2029 FixedArray* storage, int index, PropertyAttributes filter = NONE);
2031 // Returns the number of properties on this object filtering out properties
2032 // with the specified attributes (ignoring interceptors).
2033 int NumberOfOwnElements(PropertyAttributes filter);
2034 // Returns the number of enumerable elements (ignoring interceptors).
2035 int NumberOfEnumElements();
2036 // Returns the number of elements on this object filtering out elements
2037 // with the specified attributes (ignoring interceptors).
2038 int GetOwnElementKeys(FixedArray* storage, PropertyAttributes filter);
2039 // Count and fill in the enumerable elements into storage.
2040 // (storage->length() == NumberOfEnumElements()).
2041 // If storage is NULL, will count the elements without adding
2042 // them to any storage.
2043 // Returns the number of enumerable elements.
2044 int GetEnumElementKeys(FixedArray* storage);
2046 // Returns a new map with all transitions dropped from the object's current
2047 // map and the ElementsKind set.
2048 static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
2049 ElementsKind to_kind);
2050 static void TransitionElementsKind(Handle<JSObject> object,
2051 ElementsKind to_kind);
2053 static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map);
2055 // Convert the object to use the canonical dictionary
2056 // representation. If the object is expected to have additional properties
2057 // added this number can be indicated to have the backing store allocated to
2058 // an initial capacity for holding these properties.
2059 static void NormalizeProperties(Handle<JSObject> object,
2060 PropertyNormalizationMode mode,
2061 int expected_additional_properties,
2062 const char* reason);
2064 // Convert and update the elements backing store to be a
2065 // SeededNumberDictionary dictionary. Returns the backing after conversion.
2066 static Handle<SeededNumberDictionary> NormalizeElements(
2067 Handle<JSObject> object);
2069 // Transform slow named properties to fast variants.
2070 static void MigrateSlowToFast(Handle<JSObject> object,
2071 int unused_property_fields, const char* reason);
2073 inline bool IsUnboxedDoubleField(FieldIndex index);
2075 // Access fast-case object properties at index.
2076 static Handle<Object> FastPropertyAt(Handle<JSObject> object,
2077 Representation representation,
2079 inline Object* RawFastPropertyAt(FieldIndex index);
2080 inline double RawFastDoublePropertyAt(FieldIndex index);
2082 inline void FastPropertyAtPut(FieldIndex index, Object* value);
2083 inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
2084 inline void RawFastDoublePropertyAtPut(FieldIndex index, double value);
2085 inline void WriteToField(int descriptor, Object* value);
2087 // Access to in object properties.
2088 inline int GetInObjectPropertyOffset(int index);
2089 inline Object* InObjectPropertyAt(int index);
2090 inline Object* InObjectPropertyAtPut(int index,
2092 WriteBarrierMode mode
2093 = UPDATE_WRITE_BARRIER);
2095 // Set the object's prototype (only JSReceiver and null are allowed values).
2096 MUST_USE_RESULT static MaybeHandle<Object> SetPrototype(
2097 Handle<JSObject> object, Handle<Object> value, bool from_javascript);
2099 // Initializes the body after properties slot, properties slot is
2100 // initialized by set_properties. Fill the pre-allocated fields with
2101 // pre_allocated_value and the rest with filler_value.
2102 // Note: this call does not update write barrier, the caller is responsible
2103 // to ensure that |filler_value| can be collected without WB here.
2104 inline void InitializeBody(Map* map,
2105 Object* pre_allocated_value,
2106 Object* filler_value);
2108 // Check whether this object references another object
2109 bool ReferencesObject(Object* obj);
2111 // Disalow further properties to be added to the object.
2112 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensions(
2113 Handle<JSObject> object);
2116 MUST_USE_RESULT static MaybeHandle<Object> Seal(Handle<JSObject> object);
2118 // ES5 Object.freeze
2119 MUST_USE_RESULT static MaybeHandle<Object> Freeze(Handle<JSObject> object);
2121 // Called the first time an object is observed with ES7 Object.observe.
2122 static void SetObserved(Handle<JSObject> object);
2125 enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 };
2127 static Handle<JSObject> Copy(Handle<JSObject> object);
2128 MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy(
2129 Handle<JSObject> object,
2130 AllocationSiteUsageContext* site_context,
2131 DeepCopyHints hints = kNoHints);
2132 MUST_USE_RESULT static MaybeHandle<JSObject> DeepWalk(
2133 Handle<JSObject> object,
2134 AllocationSiteCreationContext* site_context);
2136 static Handle<Object> GetDataProperty(Handle<JSObject> object,
2138 static Handle<Object> GetDataProperty(LookupIterator* it);
2140 DECLARE_CAST(JSObject)
2142 // Dispatched behavior.
2143 void JSObjectShortPrint(StringStream* accumulator);
2144 DECLARE_PRINTER(JSObject)
2145 DECLARE_VERIFIER(JSObject)
2147 void PrintProperties(std::ostream& os); // NOLINT
2148 void PrintElements(std::ostream& os); // NOLINT
2150 #if defined(DEBUG) || defined(OBJECT_PRINT)
2151 void PrintTransitions(std::ostream& os); // NOLINT
2154 static void PrintElementsTransition(
2155 FILE* file, Handle<JSObject> object,
2156 ElementsKind from_kind, Handle<FixedArrayBase> from_elements,
2157 ElementsKind to_kind, Handle<FixedArrayBase> to_elements);
2159 void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
2162 // Structure for collecting spill information about JSObjects.
2163 class SpillInformation {
2167 int number_of_objects_;
2168 int number_of_objects_with_fast_properties_;
2169 int number_of_objects_with_fast_elements_;
2170 int number_of_fast_used_fields_;
2171 int number_of_fast_unused_fields_;
2172 int number_of_slow_used_properties_;
2173 int number_of_slow_unused_properties_;
2174 int number_of_fast_used_elements_;
2175 int number_of_fast_unused_elements_;
2176 int number_of_slow_used_elements_;
2177 int number_of_slow_unused_elements_;
2180 void IncrementSpillStatistics(SpillInformation* info);
2184 // If a GC was caused while constructing this object, the elements pointer
2185 // may point to a one pointer filler map. The object won't be rooted, but
2186 // our heap verification code could stumble across it.
2187 bool ElementsAreSafeToExamine();
2190 Object* SlowReverseLookup(Object* value);
2192 // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
2193 // Also maximal value of JSArray's length property.
2194 static const uint32_t kMaxElementCount = 0xffffffffu;
2196 // Constants for heuristics controlling conversion of fast elements
2197 // to slow elements.
2199 // Maximal gap that can be introduced by adding an element beyond
2200 // the current elements length.
2201 static const uint32_t kMaxGap = 1024;
2203 // Maximal length of fast elements array that won't be checked for
2204 // being dense enough on expansion.
2205 static const int kMaxUncheckedFastElementsLength = 5000;
2207 // Same as above but for old arrays. This limit is more strict. We
2208 // don't want to be wasteful with long lived objects.
2209 static const int kMaxUncheckedOldFastElementsLength = 500;
2211 // Note that Page::kMaxRegularHeapObjectSize puts a limit on
2212 // permissible values (see the DCHECK in heap.cc).
2213 static const int kInitialMaxFastElementArray = 100000;
2215 // This constant applies only to the initial map of "$Object" aka
2216 // "global.Object" and not to arbitrary other JSObject maps.
2217 static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
2219 static const int kMaxInstanceSize = 255 * kPointerSize;
2220 // When extending the backing storage for property values, we increase
2221 // its size by more than the 1 entry necessary, so sequentially adding fields
2222 // to the same object requires fewer allocations and copies.
2223 static const int kFieldsAdded = 3;
2225 // Layout description.
2226 static const int kPropertiesOffset = HeapObject::kHeaderSize;
2227 static const int kElementsOffset = kPropertiesOffset + kPointerSize;
2228 static const int kHeaderSize = kElementsOffset + kPointerSize;
2230 STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
2232 class BodyDescriptor : public FlexibleBodyDescriptor<kPropertiesOffset> {
2234 static inline int SizeOf(Map* map, HeapObject* object);
2237 Context* GetCreationContext();
2239 // Enqueue change record for Object.observe. May cause GC.
2240 MUST_USE_RESULT static MaybeHandle<Object> EnqueueChangeRecord(
2241 Handle<JSObject> object, const char* type, Handle<Name> name,
2242 Handle<Object> old_value);
2245 friend class DictionaryElementsAccessor;
2246 friend class JSReceiver;
2247 friend class Object;
2249 static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map);
2250 static void MigrateFastToSlow(Handle<JSObject> object,
2251 Handle<Map> new_map,
2252 int expected_additional_properties);
2254 static void UpdateAllocationSite(Handle<JSObject> object,
2255 ElementsKind to_kind);
2257 // Used from Object::GetProperty().
2258 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
2259 LookupIterator* it);
2261 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithCallback(
2262 Handle<JSObject> object,
2263 Handle<Object> receiver,
2264 Handle<Object> structure,
2266 Handle<Object> holder);
2268 MUST_USE_RESULT static Maybe<PropertyAttributes>
2269 GetElementAttributeWithInterceptor(Handle<JSObject> object,
2270 Handle<JSReceiver> receiver,
2271 uint32_t index, bool continue_search);
2273 // Queries indexed interceptor on an object for property attributes.
2275 // We determine property attributes as follows:
2276 // - if interceptor has a query callback, then the property attributes are
2277 // the result of query callback for index.
2278 // - otherwise if interceptor has a getter callback and it returns
2279 // non-empty value on index, then the property attributes is NONE
2280 // (property is present, and it is enumerable, configurable, writable)
2281 // - otherwise there are no property attributes that can be inferred for
2282 // interceptor, and this function returns ABSENT.
2283 MUST_USE_RESULT static Maybe<PropertyAttributes>
2284 GetElementAttributeFromInterceptor(Handle<JSObject> object,
2285 Handle<Object> receiver,
2288 MUST_USE_RESULT static Maybe<PropertyAttributes>
2289 GetElementAttributeWithoutInterceptor(Handle<JSObject> object,
2290 Handle<JSReceiver> receiver,
2292 bool continue_search);
2293 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithCallback(
2294 Handle<Object> object, Handle<Object> structure, uint32_t index,
2295 Handle<Object> value, Handle<JSObject> holder,
2296 LanguageMode language_mode);
2297 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithInterceptor(
2298 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2299 PropertyAttributes attributes, LanguageMode language_mode,
2300 bool check_prototype, SetPropertyMode set_mode);
2301 MUST_USE_RESULT static MaybeHandle<Object> SetElementWithoutInterceptor(
2302 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2303 PropertyAttributes attributes, LanguageMode language_mode,
2304 bool check_prototype, SetPropertyMode set_mode);
2306 static MaybeHandle<Object> SetElementWithCallbackSetterInPrototypes(
2307 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2308 bool* found, LanguageMode language_mode);
2309 MUST_USE_RESULT static MaybeHandle<Object> SetDictionaryElement(
2310 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2311 PropertyAttributes attributes, LanguageMode language_mode,
2312 bool check_prototype, SetPropertyMode set_mode = SET_PROPERTY);
2313 MUST_USE_RESULT static MaybeHandle<Object> SetFastDoubleElement(
2314 Handle<JSObject> object, uint32_t index, Handle<Object> value,
2315 LanguageMode language_mode, bool check_prototype = true);
2316 MUST_USE_RESULT static MaybeHandle<Object> GetElementWithFailedAccessCheck(
2317 Isolate* isolate, Handle<JSObject> object, Handle<Object> receiver,
2319 MUST_USE_RESULT static Maybe<PropertyAttributes>
2320 GetElementAttributesWithFailedAccessCheck(Isolate* isolate,
2321 Handle<JSObject> object,
2322 Handle<Object> receiver,
2325 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithFailedAccessCheck(
2326 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
2328 // Add a property to a slow-case object.
2329 static void AddSlowProperty(Handle<JSObject> object,
2331 Handle<Object> value,
2332 PropertyAttributes attributes);
2334 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
2335 Handle<JSObject> object, Handle<Name> name, LanguageMode language_mode);
2336 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithInterceptor(
2337 Handle<JSObject> holder, Handle<JSObject> receiver, Handle<Name> name);
2339 // Deletes an existing named property in a normalized object.
2340 static void DeleteNormalizedProperty(Handle<JSObject> object,
2343 MUST_USE_RESULT static MaybeHandle<Object> DeleteElement(
2344 Handle<JSObject> object, uint32_t index, LanguageMode language_mode);
2345 MUST_USE_RESULT static MaybeHandle<Object> DeleteElementWithInterceptor(
2346 Handle<JSObject> object,
2349 bool ReferencesObjectFromElements(FixedArray* elements,
2353 // Returns true if most of the elements backing storage is used.
2354 bool HasDenseElements();
2356 // Gets the current elements capacity and the number of used elements.
2357 void GetElementsCapacityAndUsage(int* capacity, int* used);
2359 static bool CanSetCallback(Handle<JSObject> object, Handle<Name> name);
2360 static void SetElementCallback(Handle<JSObject> object,
2362 Handle<Object> structure,
2363 PropertyAttributes attributes);
2364 static void SetPropertyCallback(Handle<JSObject> object,
2366 Handle<Object> structure,
2367 PropertyAttributes attributes);
2368 static void DefineElementAccessor(Handle<JSObject> object,
2370 Handle<Object> getter,
2371 Handle<Object> setter,
2372 PropertyAttributes attributes);
2374 // Return the hash table backing store or the inline stored identity hash,
2375 // whatever is found.
2376 MUST_USE_RESULT Object* GetHiddenPropertiesHashTable();
2378 // Return the hash table backing store for hidden properties. If there is no
2379 // backing store, allocate one.
2380 static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable(
2381 Handle<JSObject> object);
2383 // Set the hidden property backing store to either a hash table or
2384 // the inline-stored identity hash.
2385 static Handle<Object> SetHiddenPropertiesHashTable(
2386 Handle<JSObject> object,
2387 Handle<Object> value);
2389 MUST_USE_RESULT Object* GetIdentityHash();
2391 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSObject> object);
2393 static Handle<SeededNumberDictionary> GetNormalizedElementDictionary(
2394 Handle<JSObject> object);
2396 // Helper for fast versions of preventExtensions, seal, and freeze.
2397 // attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
2398 template <PropertyAttributes attrs>
2399 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensionsWithTransition(
2400 Handle<JSObject> object);
2402 DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
2406 // Common superclass for FixedArrays that allow implementations to share
2407 // common accessors and some code paths.
2408 class FixedArrayBase: public HeapObject {
2410 // [length]: length of the array.
2411 inline int length() const;
2412 inline void set_length(int value);
2414 // Get and set the length using acquire loads and release stores.
2415 inline int synchronized_length() const;
2416 inline void synchronized_set_length(int value);
2418 DECLARE_CAST(FixedArrayBase)
2420 // Layout description.
2421 // Length is smi tagged when it is stored.
2422 static const int kLengthOffset = HeapObject::kHeaderSize;
2423 static const int kHeaderSize = kLengthOffset + kPointerSize;
2427 class FixedDoubleArray;
2428 class IncrementalMarking;
2431 // FixedArray describes fixed-sized arrays with element type Object*.
2432 class FixedArray: public FixedArrayBase {
2434 // Setter and getter for elements.
2435 inline Object* get(int index) const;
2436 static inline Handle<Object> get(Handle<FixedArray> array, int index);
2437 // Setter that uses write barrier.
2438 inline void set(int index, Object* value);
2439 inline bool is_the_hole(int index);
2441 // Setter that doesn't need write barrier.
2442 inline void set(int index, Smi* value);
2443 // Setter with explicit barrier mode.
2444 inline void set(int index, Object* value, WriteBarrierMode mode);
2446 // Setters for frequently used oddballs located in old space.
2447 inline void set_undefined(int index);
2448 inline void set_null(int index);
2449 inline void set_the_hole(int index);
2451 inline Object** GetFirstElementAddress();
2452 inline bool ContainsOnlySmisOrHoles();
2454 // Gives access to raw memory which stores the array's data.
2455 inline Object** data_start();
2457 inline void FillWithHoles(int from, int to);
2459 // Shrink length and insert filler objects.
2460 void Shrink(int length);
2463 static Handle<FixedArray> CopySize(Handle<FixedArray> array,
2465 PretenureFlag pretenure = NOT_TENURED);
2467 enum KeyFilter { ALL_KEYS, NON_SYMBOL_KEYS };
2469 // Add the elements of a JSArray to this FixedArray.
2470 MUST_USE_RESULT static MaybeHandle<FixedArray> AddKeysFromArrayLike(
2471 Handle<FixedArray> content, Handle<JSObject> array,
2472 KeyFilter filter = ALL_KEYS);
2474 // Computes the union of keys and return the result.
2475 // Used for implementing "for (n in object) { }"
2476 MUST_USE_RESULT static MaybeHandle<FixedArray> UnionOfKeys(
2477 Handle<FixedArray> first,
2478 Handle<FixedArray> second);
2480 // Copy a sub array from the receiver to dest.
2481 void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
2483 // Garbage collection support.
2484 static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
2486 // Code Generation support.
2487 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2489 // Garbage collection support.
2490 Object** RawFieldOfElementAt(int index) {
2491 return HeapObject::RawField(this, OffsetOfElementAt(index));
2494 DECLARE_CAST(FixedArray)
2496 // Maximal allowed size, in bytes, of a single FixedArray.
2497 // Prevents overflowing size computations, as well as extreme memory
2499 static const int kMaxSize = 128 * MB * kPointerSize;
2500 // Maximally allowed length of a FixedArray.
2501 static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
2503 // Dispatched behavior.
2504 DECLARE_PRINTER(FixedArray)
2505 DECLARE_VERIFIER(FixedArray)
2507 // Checks if two FixedArrays have identical contents.
2508 bool IsEqualTo(FixedArray* other);
2511 // Swap two elements in a pair of arrays. If this array and the
2512 // numbers array are the same object, the elements are only swapped
2514 void SwapPairs(FixedArray* numbers, int i, int j);
2516 // Sort prefix of this array and the numbers array as pairs wrt. the
2517 // numbers. If the numbers array and the this array are the same
2518 // object, the prefix of this array is sorted.
2519 void SortPairs(FixedArray* numbers, uint32_t len);
2521 class BodyDescriptor : public FlexibleBodyDescriptor<kHeaderSize> {
2523 static inline int SizeOf(Map* map, HeapObject* object) {
2524 return SizeFor(reinterpret_cast<FixedArray*>(object)->length());
2529 // Set operation on FixedArray without using write barriers. Can
2530 // only be used for storing old space objects or smis.
2531 static inline void NoWriteBarrierSet(FixedArray* array,
2535 // Set operation on FixedArray without incremental write barrier. Can
2536 // only be used if the object is guaranteed to be white (whiteness witness
2538 static inline void NoIncrementalWriteBarrierSet(FixedArray* array,
2543 STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);
2545 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray);
2549 // FixedDoubleArray describes fixed-sized arrays with element type double.
2550 class FixedDoubleArray: public FixedArrayBase {
2552 // Setter and getter for elements.
2553 inline double get_scalar(int index);
2554 inline uint64_t get_representation(int index);
2555 static inline Handle<Object> get(Handle<FixedDoubleArray> array, int index);
2556 inline void set(int index, double value);
2557 inline void set_the_hole(int index);
2559 // Checking for the hole.
2560 inline bool is_the_hole(int index);
2562 // Garbage collection support.
2563 inline static int SizeFor(int length) {
2564 return kHeaderSize + length * kDoubleSize;
2567 // Gives access to raw memory which stores the array's data.
2568 inline double* data_start();
2570 inline void FillWithHoles(int from, int to);
2572 // Code Generation support.
2573 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2575 DECLARE_CAST(FixedDoubleArray)
2577 // Maximal allowed size, in bytes, of a single FixedDoubleArray.
2578 // Prevents overflowing size computations, as well as extreme memory
2580 static const int kMaxSize = 512 * MB;
2581 // Maximally allowed length of a FixedArray.
2582 static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
2584 // Dispatched behavior.
2585 DECLARE_PRINTER(FixedDoubleArray)
2586 DECLARE_VERIFIER(FixedDoubleArray)
2589 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
2593 class WeakFixedArray : public FixedArray {
2595 enum SearchForDuplicates { kAlwaysAdd, kAddIfNotFound };
2597 // If |maybe_array| is not a WeakFixedArray, a fresh one will be allocated.
2598 static Handle<WeakFixedArray> Add(
2599 Handle<Object> maybe_array, Handle<HeapObject> value,
2600 SearchForDuplicates search_for_duplicates = kAlwaysAdd);
2602 void Remove(Handle<HeapObject> value);
2604 inline Object* Get(int index) const;
2605 inline int Length() const;
2607 DECLARE_CAST(WeakFixedArray)
2610 static const int kLastUsedIndexIndex = 0;
2611 static const int kFirstIndex = 1;
2613 static Handle<WeakFixedArray> Allocate(
2614 Isolate* isolate, int size, Handle<WeakFixedArray> initialize_from);
2616 static void Set(Handle<WeakFixedArray> array, int index,
2617 Handle<HeapObject> value);
2618 inline void clear(int index);
2619 inline bool IsEmptySlot(int index) const;
2621 inline int last_used_index() const;
2622 inline void set_last_used_index(int index);
2624 // Disallow inherited setters.
2625 void set(int index, Smi* value);
2626 void set(int index, Object* value);
2627 void set(int index, Object* value, WriteBarrierMode mode);
2628 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
2632 // Generic array grows dynamically with O(1) amortized insertion.
2633 class ArrayList : public FixedArray {
2637 // Use this if GC can delete elements from the array.
2638 kReloadLengthAfterAllocation,
2640 static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj,
2641 AddMode mode = kNone);
2642 static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj1,
2643 Handle<Object> obj2, AddMode = kNone);
2644 inline int Length();
2645 inline void SetLength(int length);
2646 inline Object* Get(int index);
2647 inline Object** Slot(int index);
2648 inline void Set(int index, Object* obj);
2649 inline void Clear(int index, Object* undefined);
2650 DECLARE_CAST(ArrayList)
2653 static Handle<ArrayList> EnsureSpace(Handle<ArrayList> array, int length);
2654 static const int kLengthIndex = 0;
2655 static const int kFirstIndex = 1;
2656 DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
2660 // ConstantPoolArray describes a fixed-sized array containing constant pool
2663 // A ConstantPoolArray can be structured in two different ways depending upon
2664 // whether it is extended or small. The is_extended_layout() method can be used
2665 // to discover which layout the constant pool has.
2667 // The format of a small constant pool is:
2668 // [kSmallLayout1Offset] : Small section layout bitmap 1
2669 // [kSmallLayout2Offset] : Small section layout bitmap 2
2670 // [first_index(INT64, SMALL_SECTION)] : 64 bit entries
2672 // [first_index(CODE_PTR, SMALL_SECTION)] : code pointer entries
2674 // [first_index(HEAP_PTR, SMALL_SECTION)] : heap pointer entries
2676 // [first_index(INT32, SMALL_SECTION)] : 32 bit entries
2679 // If the constant pool has an extended layout, the extended section constant
2680 // pool also contains an extended section, which has the following format at
2681 // location get_extended_section_header_offset():
2682 // [kExtendedInt64CountOffset] : count of extended 64 bit entries
2683 // [kExtendedCodePtrCountOffset] : count of extended code pointers
2684 // [kExtendedHeapPtrCountOffset] : count of extended heap pointers
2685 // [kExtendedInt32CountOffset] : count of extended 32 bit entries
2686 // [first_index(INT64, EXTENDED_SECTION)] : 64 bit entries
2688 // [first_index(CODE_PTR, EXTENDED_SECTION)]: code pointer entries
2690 // [first_index(HEAP_PTR, EXTENDED_SECTION)]: heap pointer entries
2692 // [first_index(INT32, EXTENDED_SECTION)] : 32 bit entries
2695 class ConstantPoolArray: public HeapObject {
2697 enum WeakObjectState { NO_WEAK_OBJECTS, WEAK_OBJECTS_IN_OPTIMIZED_CODE };
2704 // Number of types stored by the ConstantPoolArrays.
2710 enum LayoutSection {
2713 NUMBER_OF_LAYOUT_SECTIONS
2716 class NumberOfEntries BASE_EMBEDDED {
2718 inline NumberOfEntries() {
2719 for (int i = 0; i < NUMBER_OF_TYPES; i++) {
2720 element_counts_[i] = 0;
2724 inline NumberOfEntries(int int64_count, int code_ptr_count,
2725 int heap_ptr_count, int int32_count) {
2726 element_counts_[INT64] = int64_count;
2727 element_counts_[CODE_PTR] = code_ptr_count;
2728 element_counts_[HEAP_PTR] = heap_ptr_count;
2729 element_counts_[INT32] = int32_count;
2732 inline NumberOfEntries(ConstantPoolArray* array, LayoutSection section) {
2733 element_counts_[INT64] = array->number_of_entries(INT64, section);
2734 element_counts_[CODE_PTR] = array->number_of_entries(CODE_PTR, section);
2735 element_counts_[HEAP_PTR] = array->number_of_entries(HEAP_PTR, section);
2736 element_counts_[INT32] = array->number_of_entries(INT32, section);
2739 inline void increment(Type type);
2740 inline int equals(const NumberOfEntries& other) const;
2741 inline bool is_empty() const;
2742 inline int count_of(Type type) const;
2743 inline int base_of(Type type) const;
2744 inline int total_count() const;
2745 inline int are_in_range(int min, int max) const;
2748 int element_counts_[NUMBER_OF_TYPES];
2751 class Iterator BASE_EMBEDDED {
2753 inline Iterator(ConstantPoolArray* array, Type type)
2756 final_section_(array->final_section()),
2757 current_section_(SMALL_SECTION),
2758 next_index_(array->first_index(type, SMALL_SECTION)) {
2762 inline Iterator(ConstantPoolArray* array, Type type, LayoutSection section)
2765 final_section_(section),
2766 current_section_(section),
2767 next_index_(array->first_index(type, section)) {
2771 inline int next_index();
2772 inline bool is_finished();
2775 inline void update_section();
2776 ConstantPoolArray* array_;
2778 const LayoutSection final_section_;
2780 LayoutSection current_section_;
2784 // Getters for the first index, the last index and the count of entries of
2785 // a given type for a given layout section.
2786 inline int first_index(Type type, LayoutSection layout_section);
2787 inline int last_index(Type type, LayoutSection layout_section);
2788 inline int number_of_entries(Type type, LayoutSection layout_section);
2790 // Returns the type of the entry at the given index.
2791 inline Type get_type(int index);
2792 inline bool offset_is_type(int offset, Type type);
2794 // Setter and getter for pool elements.
2795 inline Address get_code_ptr_entry(int index);
2796 inline Object* get_heap_ptr_entry(int index);
2797 inline int64_t get_int64_entry(int index);
2798 inline int32_t get_int32_entry(int index);
2799 inline double get_int64_entry_as_double(int index);
2801 inline void set(int index, Address value);
2802 inline void set(int index, Object* value);
2803 inline void set(int index, int64_t value);
2804 inline void set(int index, double value);
2805 inline void set(int index, int32_t value);
2807 // Setters which take a raw offset rather than an index (for code generation).
2808 inline void set_at_offset(int offset, int32_t value);
2809 inline void set_at_offset(int offset, int64_t value);
2810 inline void set_at_offset(int offset, double value);
2811 inline void set_at_offset(int offset, Address value);
2812 inline void set_at_offset(int offset, Object* value);
2814 // Setter and getter for weak objects state
2815 inline void set_weak_object_state(WeakObjectState state);
2816 inline WeakObjectState get_weak_object_state();
2818 // Returns true if the constant pool has an extended layout, false if it has
2819 // only the small layout.
2820 inline bool is_extended_layout();
2822 // Returns the last LayoutSection in this constant pool array.
2823 inline LayoutSection final_section();
2825 // Set up initial state for a small layout constant pool array.
2826 inline void Init(const NumberOfEntries& small);
2828 // Set up initial state for an extended layout constant pool array.
2829 inline void InitExtended(const NumberOfEntries& small,
2830 const NumberOfEntries& extended);
2832 // Clears the pointer entries with GC safe values.
2833 void ClearPtrEntries(Isolate* isolate);
2835 // returns the total number of entries in the constant pool array.
2836 inline int length();
2838 // Garbage collection support.
2842 inline static int MaxInt64Offset(int number_of_int64) {
2843 return kFirstEntryOffset + (number_of_int64 * kInt64Size);
2846 inline static int SizeFor(const NumberOfEntries& small) {
2847 int size = kFirstEntryOffset +
2848 (small.count_of(INT64) * kInt64Size) +
2849 (small.count_of(CODE_PTR) * kPointerSize) +
2850 (small.count_of(HEAP_PTR) * kPointerSize) +
2851 (small.count_of(INT32) * kInt32Size);
2852 return RoundUp(size, kPointerSize);
2855 inline static int SizeForExtended(const NumberOfEntries& small,
2856 const NumberOfEntries& extended) {
2857 int size = SizeFor(small);
2858 size = RoundUp(size, kInt64Size); // Align extended header to 64 bits.
2859 size += kExtendedFirstOffset +
2860 (extended.count_of(INT64) * kInt64Size) +
2861 (extended.count_of(CODE_PTR) * kPointerSize) +
2862 (extended.count_of(HEAP_PTR) * kPointerSize) +
2863 (extended.count_of(INT32) * kInt32Size);
2864 return RoundUp(size, kPointerSize);
2867 inline static int entry_size(Type type) {
2875 return kPointerSize;
2882 // Code Generation support.
2883 inline int OffsetOfElementAt(int index) {
2885 LayoutSection section;
2886 if (is_extended_layout() && index >= first_extended_section_index()) {
2887 section = EXTENDED_SECTION;
2888 offset = get_extended_section_header_offset() + kExtendedFirstOffset;
2890 section = SMALL_SECTION;
2891 offset = kFirstEntryOffset;
2894 // Add offsets for the preceding type sections.
2895 DCHECK(index <= last_index(LAST_TYPE, section));
2896 for (Type type = FIRST_TYPE; index > last_index(type, section);
2897 type = next_type(type)) {
2898 offset += entry_size(type) * number_of_entries(type, section);
2901 // Add offset for the index in it's type.
2902 Type type = get_type(index);
2903 offset += entry_size(type) * (index - first_index(type, section));
2907 DECLARE_CAST(ConstantPoolArray)
2909 // Garbage collection support.
2910 Object** RawFieldOfElementAt(int index) {
2911 return HeapObject::RawField(this, OffsetOfElementAt(index));
2914 // Small Layout description.
2915 static const int kSmallLayout1Offset = HeapObject::kHeaderSize;
2916 static const int kSmallLayout2Offset = kSmallLayout1Offset + kInt32Size;
2917 static const int kHeaderSize = kSmallLayout2Offset + kInt32Size;
2918 static const int kFirstEntryOffset = ROUND_UP(kHeaderSize, kInt64Size);
2920 static const int kSmallLayoutCountBits = 10;
2921 static const int kMaxSmallEntriesPerType = (1 << kSmallLayoutCountBits) - 1;
2923 // Fields in kSmallLayout1Offset.
2924 class Int64CountField: public BitField<int, 1, kSmallLayoutCountBits> {};
2925 class CodePtrCountField: public BitField<int, 11, kSmallLayoutCountBits> {};
2926 class HeapPtrCountField: public BitField<int, 21, kSmallLayoutCountBits> {};
2927 class IsExtendedField: public BitField<bool, 31, 1> {};
2929 // Fields in kSmallLayout2Offset.
2930 class Int32CountField: public BitField<int, 1, kSmallLayoutCountBits> {};
2931 class TotalCountField: public BitField<int, 11, 12> {};
2932 class WeakObjectStateField: public BitField<WeakObjectState, 23, 2> {};
2934 // Extended layout description, which starts at
2935 // get_extended_section_header_offset().
2936 static const int kExtendedInt64CountOffset = 0;
2937 static const int kExtendedCodePtrCountOffset =
2938 kExtendedInt64CountOffset + kInt32Size;
2939 static const int kExtendedHeapPtrCountOffset =
2940 kExtendedCodePtrCountOffset + kInt32Size;
2941 static const int kExtendedInt32CountOffset =
2942 kExtendedHeapPtrCountOffset + kInt32Size;
2943 static const int kExtendedFirstOffset =
2944 kExtendedInt32CountOffset + kInt32Size;
2946 // Dispatched behavior.
2947 void ConstantPoolIterateBody(ObjectVisitor* v);
2949 DECLARE_PRINTER(ConstantPoolArray)
2950 DECLARE_VERIFIER(ConstantPoolArray)
2953 inline int first_extended_section_index();
2954 inline int get_extended_section_header_offset();
2956 inline static Type next_type(Type type) {
2957 DCHECK(type >= FIRST_TYPE && type < NUMBER_OF_TYPES);
2958 int type_int = static_cast<int>(type);
2959 return static_cast<Type>(++type_int);
2962 DISALLOW_IMPLICIT_CONSTRUCTORS(ConstantPoolArray);
2966 // DescriptorArrays are fixed arrays used to hold instance descriptors.
2967 // The format of the these objects is:
2968 // [0]: Number of descriptors
2969 // [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array:
2970 // [0]: pointer to fixed array with enum cache
2971 // [1]: either Smi(0) or pointer to fixed array with indices
2973 // [2 + number of descriptors * kDescriptorSize]: start of slack
2974 class DescriptorArray: public FixedArray {
2976 // Returns true for both shared empty_descriptor_array and for smis, which the
2977 // map uses to encode additional bit fields when the descriptor array is not
2979 inline bool IsEmpty();
2981 // Returns the number of descriptors in the array.
2982 int number_of_descriptors() {
2983 DCHECK(length() >= kFirstIndex || IsEmpty());
2985 return len == 0 ? 0 : Smi::cast(get(kDescriptorLengthIndex))->value();
2988 int number_of_descriptors_storage() {
2990 return len == 0 ? 0 : (len - kFirstIndex) / kDescriptorSize;
2993 int NumberOfSlackDescriptors() {
2994 return number_of_descriptors_storage() - number_of_descriptors();
2997 inline void SetNumberOfDescriptors(int number_of_descriptors);
2998 inline int number_of_entries() { return number_of_descriptors(); }
3000 bool HasEnumCache() {
3001 return !IsEmpty() && !get(kEnumCacheIndex)->IsSmi();
3004 void CopyEnumCacheFrom(DescriptorArray* array) {
3005 set(kEnumCacheIndex, array->get(kEnumCacheIndex));
3008 FixedArray* GetEnumCache() {
3009 DCHECK(HasEnumCache());
3010 FixedArray* bridge = FixedArray::cast(get(kEnumCacheIndex));
3011 return FixedArray::cast(bridge->get(kEnumCacheBridgeCacheIndex));
3014 bool HasEnumIndicesCache() {
3015 if (IsEmpty()) return false;
3016 Object* object = get(kEnumCacheIndex);
3017 if (object->IsSmi()) return false;
3018 FixedArray* bridge = FixedArray::cast(object);
3019 return !bridge->get(kEnumCacheBridgeIndicesCacheIndex)->IsSmi();
3022 FixedArray* GetEnumIndicesCache() {
3023 DCHECK(HasEnumIndicesCache());
3024 FixedArray* bridge = FixedArray::cast(get(kEnumCacheIndex));
3025 return FixedArray::cast(bridge->get(kEnumCacheBridgeIndicesCacheIndex));
3028 Object** GetEnumCacheSlot() {
3029 DCHECK(HasEnumCache());
3030 return HeapObject::RawField(reinterpret_cast<HeapObject*>(this),
3034 void ClearEnumCache();
3036 // Initialize or change the enum cache,
3037 // using the supplied storage for the small "bridge".
3038 void SetEnumCache(FixedArray* bridge_storage,
3039 FixedArray* new_cache,
3040 Object* new_index_cache);
3042 bool CanHoldValue(int descriptor, Object* value);
3044 // Accessors for fetching instance descriptor at descriptor number.
3045 inline Name* GetKey(int descriptor_number);
3046 inline Object** GetKeySlot(int descriptor_number);
3047 inline Object* GetValue(int descriptor_number);
3048 inline void SetValue(int descriptor_number, Object* value);
3049 inline Object** GetValueSlot(int descriptor_number);
3050 static inline int GetValueOffset(int descriptor_number);
3051 inline Object** GetDescriptorStartSlot(int descriptor_number);
3052 inline Object** GetDescriptorEndSlot(int descriptor_number);
3053 inline PropertyDetails GetDetails(int descriptor_number);
3054 inline PropertyType GetType(int descriptor_number);
3055 inline int GetFieldIndex(int descriptor_number);
3056 inline HeapType* GetFieldType(int descriptor_number);
3057 inline Object* GetConstant(int descriptor_number);
3058 inline Object* GetCallbacksObject(int descriptor_number);
3059 inline AccessorDescriptor* GetCallbacks(int descriptor_number);
3061 inline Name* GetSortedKey(int descriptor_number);
3062 inline int GetSortedKeyIndex(int descriptor_number);
3063 inline void SetSortedKey(int pointer, int descriptor_number);
3064 inline void SetRepresentation(int descriptor_number,
3065 Representation representation);
3067 // Accessor for complete descriptor.
3068 inline void Get(int descriptor_number, Descriptor* desc);
3069 inline void Set(int descriptor_number, Descriptor* desc);
3070 void Replace(int descriptor_number, Descriptor* descriptor);
3072 // Append automatically sets the enumeration index. This should only be used
3073 // to add descriptors in bulk at the end, followed by sorting the descriptor
3075 inline void Append(Descriptor* desc);
3077 static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc,
3078 int enumeration_index,
3081 static Handle<DescriptorArray> CopyUpToAddAttributes(
3082 Handle<DescriptorArray> desc,
3083 int enumeration_index,
3084 PropertyAttributes attributes,
3087 // Sort the instance descriptors by the hash codes of their keys.
3090 // Search the instance descriptors for given name.
3091 INLINE(int Search(Name* name, int number_of_own_descriptors));
3093 // As the above, but uses DescriptorLookupCache and updates it when
3095 INLINE(int SearchWithCache(Name* name, Map* map));
3097 // Allocates a DescriptorArray, but returns the singleton
3098 // empty descriptor array object if number_of_descriptors is 0.
3099 static Handle<DescriptorArray> Allocate(Isolate* isolate,
3100 int number_of_descriptors,
3103 DECLARE_CAST(DescriptorArray)
3105 // Constant for denoting key was not found.
3106 static const int kNotFound = -1;
3108 static const int kDescriptorLengthIndex = 0;
3109 static const int kEnumCacheIndex = 1;
3110 static const int kFirstIndex = 2;
3112 // The length of the "bridge" to the enum cache.
3113 static const int kEnumCacheBridgeLength = 2;
3114 static const int kEnumCacheBridgeCacheIndex = 0;
3115 static const int kEnumCacheBridgeIndicesCacheIndex = 1;
3117 // Layout description.
3118 static const int kDescriptorLengthOffset = FixedArray::kHeaderSize;
3119 static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize;
3120 static const int kFirstOffset = kEnumCacheOffset + kPointerSize;
3122 // Layout description for the bridge array.
3123 static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize;
3125 // Layout of descriptor.
3126 static const int kDescriptorKey = 0;
3127 static const int kDescriptorDetails = 1;
3128 static const int kDescriptorValue = 2;
3129 static const int kDescriptorSize = 3;
3131 #if defined(DEBUG) || defined(OBJECT_PRINT)
3132 // For our gdb macros, we should perhaps change these in the future.
3135 // Print all the descriptors.
3136 void PrintDescriptors(std::ostream& os); // NOLINT
3140 // Is the descriptor array sorted and without duplicates?
3141 bool IsSortedNoDuplicates(int valid_descriptors = -1);
3143 // Is the descriptor array consistent with the back pointers in targets?
3144 bool IsConsistentWithBackPointers(Map* current_map);
3146 // Are two DescriptorArrays equal?
3147 bool IsEqualTo(DescriptorArray* other);
3150 // Returns the fixed array length required to hold number_of_descriptors
3152 static int LengthFor(int number_of_descriptors) {
3153 return ToKeyIndex(number_of_descriptors);
3157 // WhitenessWitness is used to prove that a descriptor array is white
3158 // (unmarked), so incremental write barriers can be skipped because the
3159 // marking invariant cannot be broken and slots pointing into evacuation
3160 // candidates will be discovered when the object is scanned. A witness is
3161 // always stack-allocated right after creating an array. By allocating a
3162 // witness, incremental marking is globally disabled. The witness is then
3163 // passed along wherever needed to statically prove that the array is known to
3165 class WhitenessWitness {
3167 inline explicit WhitenessWitness(DescriptorArray* array);
3168 inline ~WhitenessWitness();
3171 IncrementalMarking* marking_;
3174 // An entry in a DescriptorArray, represented as an (array, index) pair.
3177 inline explicit Entry(DescriptorArray* descs, int index) :
3178 descs_(descs), index_(index) { }
3180 inline PropertyType type() { return descs_->GetType(index_); }
3181 inline Object* GetCallbackObject() { return descs_->GetValue(index_); }
3184 DescriptorArray* descs_;
3188 // Conversion from descriptor number to array indices.
3189 static int ToKeyIndex(int descriptor_number) {
3190 return kFirstIndex +
3191 (descriptor_number * kDescriptorSize) +
3195 static int ToDetailsIndex(int descriptor_number) {
3196 return kFirstIndex +
3197 (descriptor_number * kDescriptorSize) +
3201 static int ToValueIndex(int descriptor_number) {
3202 return kFirstIndex +
3203 (descriptor_number * kDescriptorSize) +
3207 // Transfer a complete descriptor from the src descriptor array to this
3208 // descriptor array.
3209 void CopyFrom(int index, DescriptorArray* src, const WhitenessWitness&);
3211 inline void Set(int descriptor_number,
3213 const WhitenessWitness&);
3215 // Swap first and second descriptor.
3216 inline void SwapSortedKeys(int first, int second);
3218 DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
3222 enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
3224 template <SearchMode search_mode, typename T>
3225 inline int Search(T* array, Name* name, int valid_entries = 0,
3226 int* out_insertion_index = NULL);
3229 // HashTable is a subclass of FixedArray that implements a hash table
3230 // that uses open addressing and quadratic probing.
3232 // In order for the quadratic probing to work, elements that have not
3233 // yet been used and elements that have been deleted are
3234 // distinguished. Probing continues when deleted elements are
3235 // encountered and stops when unused elements are encountered.
3237 // - Elements with key == undefined have not been used yet.
3238 // - Elements with key == the_hole have been deleted.
3240 // The hash table class is parameterized with a Shape and a Key.
3241 // Shape must be a class with the following interface:
3242 // class ExampleShape {
3244 // // Tells whether key matches other.
3245 // static bool IsMatch(Key key, Object* other);
3246 // // Returns the hash value for key.
3247 // static uint32_t Hash(Key key);
3248 // // Returns the hash value for object.
3249 // static uint32_t HashForObject(Key key, Object* object);
3250 // // Convert key to an object.
3251 // static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
3252 // // The prefix size indicates number of elements in the beginning
3253 // // of the backing storage.
3254 // static const int kPrefixSize = ..;
3255 // // The Element size indicates number of elements per entry.
3256 // static const int kEntrySize = ..;
3258 // The prefix size indicates an amount of memory in the
3259 // beginning of the backing storage that can be used for non-element
3260 // information by subclasses.
3262 template<typename Key>
3265 static const bool UsesSeed = false;
3266 static uint32_t Hash(Key key) { return 0; }
3267 static uint32_t SeededHash(Key key, uint32_t seed) {
3271 static uint32_t HashForObject(Key key, Object* object) { return 0; }
3272 static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) {
3274 return HashForObject(key, object);
3278 template<typename Derived, typename Shape, typename Key>
3279 class HashTable: public FixedArray {
3282 inline uint32_t Hash(Key key) {
3283 if (Shape::UsesSeed) {
3284 return Shape::SeededHash(key, GetHeap()->HashSeed());
3286 return Shape::Hash(key);
3290 inline uint32_t HashForObject(Key key, Object* object) {
3291 if (Shape::UsesSeed) {
3292 return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object);
3294 return Shape::HashForObject(key, object);
3298 // Returns the number of elements in the hash table.
3299 int NumberOfElements() {
3300 return Smi::cast(get(kNumberOfElementsIndex))->value();
3303 // Returns the number of deleted elements in the hash table.
3304 int NumberOfDeletedElements() {
3305 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
3308 // Returns the capacity of the hash table.
3310 return Smi::cast(get(kCapacityIndex))->value();
3313 // ElementAdded should be called whenever an element is added to a
3315 void ElementAdded() { SetNumberOfElements(NumberOfElements() + 1); }
3317 // ElementRemoved should be called whenever an element is removed from
3319 void ElementRemoved() {
3320 SetNumberOfElements(NumberOfElements() - 1);
3321 SetNumberOfDeletedElements(NumberOfDeletedElements() + 1);
3323 void ElementsRemoved(int n) {
3324 SetNumberOfElements(NumberOfElements() - n);
3325 SetNumberOfDeletedElements(NumberOfDeletedElements() + n);
3328 // Returns a new HashTable object.
3329 MUST_USE_RESULT static Handle<Derived> New(
3331 int at_least_space_for,
3332 MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
3333 PretenureFlag pretenure = NOT_TENURED);
3335 // Computes the required capacity for a table holding the given
3336 // number of elements. May be more than HashTable::kMaxCapacity.
3337 static int ComputeCapacity(int at_least_space_for);
3339 // Returns the key at entry.
3340 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
3342 // Tells whether k is a real key. The hole and undefined are not allowed
3343 // as keys and can be used to indicate missing or deleted elements.
3344 bool IsKey(Object* k) {
3345 return !k->IsTheHole() && !k->IsUndefined();
3348 // Garbage collection support.
3349 void IteratePrefix(ObjectVisitor* visitor);
3350 void IterateElements(ObjectVisitor* visitor);
3352 DECLARE_CAST(HashTable)
3354 // Compute the probe offset (quadratic probing).
3355 INLINE(static uint32_t GetProbeOffset(uint32_t n)) {
3356 return (n + n * n) >> 1;
3359 static const int kNumberOfElementsIndex = 0;
3360 static const int kNumberOfDeletedElementsIndex = 1;
3361 static const int kCapacityIndex = 2;
3362 static const int kPrefixStartIndex = 3;
3363 static const int kElementsStartIndex =
3364 kPrefixStartIndex + Shape::kPrefixSize;
3365 static const int kEntrySize = Shape::kEntrySize;
3366 static const int kElementsStartOffset =
3367 kHeaderSize + kElementsStartIndex * kPointerSize;
3368 static const int kCapacityOffset =
3369 kHeaderSize + kCapacityIndex * kPointerSize;
3371 // Constant used for denoting a absent entry.
3372 static const int kNotFound = -1;
3374 // Maximal capacity of HashTable. Based on maximal length of underlying
3375 // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex
3377 static const int kMaxCapacity =
3378 (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize;
3380 // Find entry for key otherwise return kNotFound.
3381 inline int FindEntry(Key key);
3382 int FindEntry(Isolate* isolate, Key key);
3384 // Rehashes the table in-place.
3385 void Rehash(Key key);
3388 friend class ObjectHashTable;
3390 // Find the entry at which to insert element with the given key that
3391 // has the given hash value.
3392 uint32_t FindInsertionEntry(uint32_t hash);
3394 // Returns the index for an entry (of the key)
3395 static inline int EntryToIndex(int entry) {
3396 return (entry * kEntrySize) + kElementsStartIndex;
3399 // Update the number of elements in the hash table.
3400 void SetNumberOfElements(int nof) {
3401 set(kNumberOfElementsIndex, Smi::FromInt(nof));
3404 // Update the number of deleted elements in the hash table.
3405 void SetNumberOfDeletedElements(int nod) {
3406 set(kNumberOfDeletedElementsIndex, Smi::FromInt(nod));
3409 // Sets the capacity of the hash table.
3410 void SetCapacity(int capacity) {
3411 // To scale a computed hash code to fit within the hash table, we
3412 // use bit-wise AND with a mask, so the capacity must be positive
3414 DCHECK(capacity > 0);
3415 DCHECK(capacity <= kMaxCapacity);
3416 set(kCapacityIndex, Smi::FromInt(capacity));
3420 // Returns probe entry.
3421 static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) {
3422 DCHECK(base::bits::IsPowerOfTwo32(size));
3423 return (hash + GetProbeOffset(number)) & (size - 1);
3426 inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) {
3427 return hash & (size - 1);
3430 inline static uint32_t NextProbe(
3431 uint32_t last, uint32_t number, uint32_t size) {
3432 return (last + number) & (size - 1);
3435 // Attempt to shrink hash table after removal of key.
3436 MUST_USE_RESULT static Handle<Derived> Shrink(Handle<Derived> table, Key key);
3438 // Ensure enough space for n additional elements.
3439 MUST_USE_RESULT static Handle<Derived> EnsureCapacity(
3440 Handle<Derived> table,
3443 PretenureFlag pretenure = NOT_TENURED);
3446 // Returns _expected_ if one of entries given by the first _probe_ probes is
3447 // equal to _expected_. Otherwise, returns the entry given by the probe
3449 uint32_t EntryForProbe(Key key, Object* k, int probe, uint32_t expected);
3451 void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode);
3453 // Rehashes this hash-table into the new table.
3454 void Rehash(Handle<Derived> new_table, Key key);
3458 // HashTableKey is an abstract superclass for virtual key behavior.
3459 class HashTableKey {
3461 // Returns whether the other object matches this key.
3462 virtual bool IsMatch(Object* other) = 0;
3463 // Returns the hash value for this key.
3464 virtual uint32_t Hash() = 0;
3465 // Returns the hash value for object.
3466 virtual uint32_t HashForObject(Object* key) = 0;
3467 // Returns the key object for storing into the hash table.
3468 MUST_USE_RESULT virtual Handle<Object> AsHandle(Isolate* isolate) = 0;
3470 virtual ~HashTableKey() {}
3474 class StringTableShape : public BaseShape<HashTableKey*> {
3476 static inline bool IsMatch(HashTableKey* key, Object* value) {
3477 return key->IsMatch(value);
3480 static inline uint32_t Hash(HashTableKey* key) {
3484 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
3485 return key->HashForObject(object);
3488 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
3490 static const int kPrefixSize = 0;
3491 static const int kEntrySize = 1;
3494 class SeqOneByteString;
3498 // No special elements in the prefix and the element size is 1
3499 // because only the string itself (the key) needs to be stored.
3500 class StringTable: public HashTable<StringTable,
3504 // Find string in the string table. If it is not there yet, it is
3505 // added. The return value is the string found.
3506 static Handle<String> LookupString(Isolate* isolate, Handle<String> key);
3507 static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key);
3509 // Tries to internalize given string and returns string handle on success
3510 // or an empty handle otherwise.
3511 MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists(
3513 Handle<String> string);
3515 // Looks up a string that is equal to the given string and returns
3516 // string handle if it is found, or an empty handle otherwise.
3517 MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists(
3519 Handle<String> str);
3520 MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists(
3525 static void EnsureCapacityForDeserialization(Isolate* isolate, int expected);
3527 DECLARE_CAST(StringTable)
3530 template <bool seq_one_byte>
3531 friend class JsonParser;
3533 DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable);
3537 enum class DictionaryEntryType { kObjects, kCells };
3540 template <typename Derived, typename Shape, typename Key>
3541 class Dictionary: public HashTable<Derived, Shape, Key> {
3543 typedef HashTable<Derived, Shape, Key> DerivedHashTable;
3546 // Returns the value at entry.
3547 Object* ValueAt(int entry) {
3548 return this->get(DerivedHashTable::EntryToIndex(entry) + 1);
3551 // Set the value for entry.
3552 void ValueAtPut(int entry, Object* value) {
3553 this->set(DerivedHashTable::EntryToIndex(entry) + 1, value);
3556 // Returns the property details for the property at entry.
3557 PropertyDetails DetailsAt(int entry) {
3558 DCHECK(entry >= 0); // Not found is -1, which is not caught by get().
3559 return PropertyDetails(
3560 Smi::cast(this->get(DerivedHashTable::EntryToIndex(entry) + 2)));
3563 // Set the details for entry.
3564 void DetailsAtPut(int entry, PropertyDetails value) {
3565 this->set(DerivedHashTable::EntryToIndex(entry) + 2, value.AsSmi());
3568 // Delete a property from the dictionary.
3569 static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry);
3571 // Attempt to shrink the dictionary after deletion of key.
3572 MUST_USE_RESULT static inline Handle<Derived> Shrink(
3573 Handle<Derived> dictionary,
3575 return DerivedHashTable::Shrink(dictionary, key);
3579 // TODO(dcarney): templatize or move to SeededNumberDictionary
3580 void CopyValuesTo(FixedArray* elements);
3582 // Returns the number of elements in the dictionary filtering out properties
3583 // with the specified attributes.
3584 template <DictionaryEntryType type>
3585 int NumberOfElementsFilterAttributes(PropertyAttributes filter);
3586 int NumberOfElementsFilterAttributes(Object* holder,
3587 PropertyAttributes filter) {
3588 if (holder->IsGlobalObject()) {
3589 return NumberOfElementsFilterAttributes<DictionaryEntryType::kCells>(
3592 return NumberOfElementsFilterAttributes<DictionaryEntryType::kObjects>(
3597 // Returns the number of enumerable elements in the dictionary.
3598 template <DictionaryEntryType type>
3599 int NumberOfEnumElements() {
3600 return NumberOfElementsFilterAttributes<type>(
3601 static_cast<PropertyAttributes>(DONT_ENUM | SYMBOLIC));
3603 int NumberOfEnumElements(Object* holder) {
3604 if (holder->IsGlobalObject()) {
3605 return NumberOfEnumElements<DictionaryEntryType::kCells>();
3607 return NumberOfEnumElements<DictionaryEntryType::kObjects>();
3611 // Returns true if the dictionary contains any elements that are non-writable,
3612 // non-configurable, non-enumerable, or have getters/setters.
3613 template <DictionaryEntryType type>
3614 bool HasComplexElements();
3615 bool HasComplexElements(Object* holder) {
3616 if (holder->IsGlobalObject()) {
3617 return HasComplexElements<DictionaryEntryType::kCells>();
3619 return HasComplexElements<DictionaryEntryType::kObjects>();
3623 enum SortMode { UNSORTED, SORTED };
3625 // Copies keys to preallocated fixed array.
3626 template <DictionaryEntryType type>
3627 void CopyKeysTo(FixedArray* storage, PropertyAttributes filter,
3628 SortMode sort_mode);
3629 void CopyKeysTo(Object* holder, FixedArray* storage,
3630 PropertyAttributes filter, SortMode sort_mode) {
3631 if (holder->IsGlobalObject()) {
3632 return CopyKeysTo<DictionaryEntryType::kCells>(storage, filter,
3635 return CopyKeysTo<DictionaryEntryType::kObjects>(storage, filter,
3640 // Fill in details for properties into storage.
3641 template <DictionaryEntryType type>
3642 void CopyKeysTo(FixedArray* storage, int index, PropertyAttributes filter,
3643 SortMode sort_mode);
3644 void CopyKeysTo(Object* holder, FixedArray* storage, int index,
3645 PropertyAttributes filter, SortMode sort_mode) {
3646 if (holder->IsGlobalObject()) {
3647 return CopyKeysTo<DictionaryEntryType::kCells>(storage, index, filter,
3650 return CopyKeysTo<DictionaryEntryType::kObjects>(storage, index, filter,
3655 // Accessors for next enumeration index.
3656 void SetNextEnumerationIndex(int index) {
3658 this->set(kNextEnumerationIndexIndex, Smi::FromInt(index));
3661 int NextEnumerationIndex() {
3662 return Smi::cast(this->get(kNextEnumerationIndexIndex))->value();
3665 // Creates a new dictionary.
3666 MUST_USE_RESULT static Handle<Derived> New(
3668 int at_least_space_for,
3669 PretenureFlag pretenure = NOT_TENURED);
3671 // Ensure enough space for n additional elements.
3672 static Handle<Derived> EnsureCapacity(Handle<Derived> obj, int n, Key key);
3675 void Print(std::ostream& os); // NOLINT
3677 // Returns the key (slow).
3678 Object* SlowReverseLookup(Object* value);
3680 // Sets the entry to (key, value) pair.
3681 inline void SetEntry(int entry,
3683 Handle<Object> value);
3684 inline void SetEntry(int entry,
3686 Handle<Object> value,
3687 PropertyDetails details);
3689 MUST_USE_RESULT static Handle<Derived> Add(
3690 Handle<Derived> dictionary,
3692 Handle<Object> value,
3693 PropertyDetails details);
3695 // Returns iteration indices array for the |dictionary|.
3696 // Values are direct indices in the |HashTable| array.
3697 static Handle<FixedArray> BuildIterationIndicesArray(
3698 Handle<Derived> dictionary);
3701 // Generic at put operation.
3702 MUST_USE_RESULT static Handle<Derived> AtPut(
3703 Handle<Derived> dictionary,
3705 Handle<Object> value);
3707 // Add entry to dictionary.
3708 static void AddEntry(
3709 Handle<Derived> dictionary,
3711 Handle<Object> value,
3712 PropertyDetails details,
3715 // Generate new enumeration indices to avoid enumeration index overflow.
3716 // Returns iteration indices array for the |dictionary|.
3717 static Handle<FixedArray> GenerateNewEnumerationIndices(
3718 Handle<Derived> dictionary);
3719 static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex;
3720 static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
3724 class NameDictionaryShape : public BaseShape<Handle<Name> > {
3726 static inline bool IsMatch(Handle<Name> key, Object* other);
3727 static inline uint32_t Hash(Handle<Name> key);
3728 static inline uint32_t HashForObject(Handle<Name> key, Object* object);
3729 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
3730 static const int kPrefixSize = 2;
3731 static const int kEntrySize = 3;
3732 static const bool kIsEnumerable = true;
3736 class NameDictionary: public Dictionary<NameDictionary,
3737 NameDictionaryShape,
3740 NameDictionary, NameDictionaryShape, Handle<Name> > DerivedDictionary;
3743 DECLARE_CAST(NameDictionary)
3745 // Copies enumerable keys to preallocated fixed array.
3746 template <DictionaryEntryType type>
3747 void CopyEnumKeysTo(FixedArray* storage);
3748 void CopyEnumKeysTo(Object* holder, FixedArray* storage) {
3749 if (holder->IsGlobalObject()) {
3750 return CopyEnumKeysTo<DictionaryEntryType::kCells>(storage);
3752 return CopyEnumKeysTo<DictionaryEntryType::kObjects>(storage);
3756 inline static Handle<FixedArray> DoGenerateNewEnumerationIndices(
3757 Handle<NameDictionary> dictionary);
3759 // Find entry for key, otherwise return kNotFound. Optimized version of
3760 // HashTable::FindEntry.
3761 int FindEntry(Handle<Name> key);
3765 class NumberDictionaryShape : public BaseShape<uint32_t> {
3767 static inline bool IsMatch(uint32_t key, Object* other);
3768 static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key);
3769 static const int kEntrySize = 3;
3770 static const bool kIsEnumerable = false;
3774 class SeededNumberDictionaryShape : public NumberDictionaryShape {
3776 static const bool UsesSeed = true;
3777 static const int kPrefixSize = 2;
3779 static inline uint32_t SeededHash(uint32_t key, uint32_t seed);
3780 static inline uint32_t SeededHashForObject(uint32_t key,
3786 class UnseededNumberDictionaryShape : public NumberDictionaryShape {
3788 static const int kPrefixSize = 0;
3790 static inline uint32_t Hash(uint32_t key);
3791 static inline uint32_t HashForObject(uint32_t key, Object* object);
3795 class SeededNumberDictionary
3796 : public Dictionary<SeededNumberDictionary,
3797 SeededNumberDictionaryShape,
3800 DECLARE_CAST(SeededNumberDictionary)
3802 // Type specific at put (default NONE attributes is used when adding).
3803 MUST_USE_RESULT static Handle<SeededNumberDictionary> AtNumberPut(
3804 Handle<SeededNumberDictionary> dictionary,
3806 Handle<Object> value);
3807 MUST_USE_RESULT static Handle<SeededNumberDictionary> AddNumberEntry(
3808 Handle<SeededNumberDictionary> dictionary,
3810 Handle<Object> value,
3811 PropertyDetails details);
3813 // Set an existing entry or add a new one if needed.
3814 // Return the updated dictionary.
3815 MUST_USE_RESULT static Handle<SeededNumberDictionary> Set(
3816 Handle<SeededNumberDictionary> dictionary,
3818 Handle<Object> value,
3819 PropertyDetails details);
3821 void UpdateMaxNumberKey(uint32_t key);
3823 // If slow elements are required we will never go back to fast-case
3824 // for the elements kept in this dictionary. We require slow
3825 // elements if an element has been added at an index larger than
3826 // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called
3827 // when defining a getter or setter with a number key.
3828 inline bool requires_slow_elements();
3829 inline void set_requires_slow_elements();
3831 // Get the value of the max number key that has been added to this
3832 // dictionary. max_number_key can only be called if
3833 // requires_slow_elements returns false.
3834 inline uint32_t max_number_key();
3837 static const int kRequiresSlowElementsMask = 1;
3838 static const int kRequiresSlowElementsTagSize = 1;
3839 static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1;
3843 class UnseededNumberDictionary
3844 : public Dictionary<UnseededNumberDictionary,
3845 UnseededNumberDictionaryShape,
3848 DECLARE_CAST(UnseededNumberDictionary)
3850 // Type specific at put (default NONE attributes is used when adding).
3851 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AtNumberPut(
3852 Handle<UnseededNumberDictionary> dictionary,
3854 Handle<Object> value);
3855 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AddNumberEntry(
3856 Handle<UnseededNumberDictionary> dictionary,
3858 Handle<Object> value);
3860 // Set an existing entry or add a new one if needed.
3861 // Return the updated dictionary.
3862 MUST_USE_RESULT static Handle<UnseededNumberDictionary> Set(
3863 Handle<UnseededNumberDictionary> dictionary,
3865 Handle<Object> value);
3869 class ObjectHashTableShape : public BaseShape<Handle<Object> > {
3871 static inline bool IsMatch(Handle<Object> key, Object* other);
3872 static inline uint32_t Hash(Handle<Object> key);
3873 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
3874 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
3875 static const int kPrefixSize = 0;
3876 static const int kEntrySize = 2;
3880 // ObjectHashTable maps keys that are arbitrary objects to object values by
3881 // using the identity hash of the key for hashing purposes.
3882 class ObjectHashTable: public HashTable<ObjectHashTable,
3883 ObjectHashTableShape,
3886 ObjectHashTable, ObjectHashTableShape, Handle<Object> > DerivedHashTable;
3888 DECLARE_CAST(ObjectHashTable)
3890 // Attempt to shrink hash table after removal of key.
3891 MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink(
3892 Handle<ObjectHashTable> table,
3893 Handle<Object> key);
3895 // Looks up the value associated with the given key. The hole value is
3896 // returned in case the key is not present.
3897 Object* Lookup(Handle<Object> key);
3899 // Adds (or overwrites) the value associated with the given key.
3900 static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
3902 Handle<Object> value);
3904 // Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
3905 static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
3910 friend class MarkCompactCollector;
3912 void AddEntry(int entry, Object* key, Object* value);
3913 void RemoveEntry(int entry);
3915 // Returns the index to the value of an entry.
3916 static inline int EntryToValueIndex(int entry) {
3917 return EntryToIndex(entry) + 1;
3922 // OrderedHashTable is a HashTable with Object keys that preserves
3923 // insertion order. There are Map and Set interfaces (OrderedHashMap
3924 // and OrderedHashTable, below). It is meant to be used by JSMap/JSSet.
3926 // Only Object* keys are supported, with Object::SameValueZero() used as the
3927 // equality operator and Object::GetHash() for the hash function.
3929 // Based on the "Deterministic Hash Table" as described by Jason Orendorff at
3930 // https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables
3931 // Originally attributed to Tyler Close.
3934 // [0]: bucket count
3935 // [1]: element count
3936 // [2]: deleted element count
3937 // [3..(3 + NumberOfBuckets() - 1)]: "hash table", where each item is an
3938 // offset into the data table (see below) where the
3939 // first item in this bucket is stored.
3940 // [3 + NumberOfBuckets()..length]: "data table", an array of length
3941 // Capacity() * kEntrySize, where the first entrysize
3942 // items are handled by the derived class and the
3943 // item at kChainOffset is another entry into the
3944 // data table indicating the next entry in this hash
3947 // When we transition the table to a new version we obsolete it and reuse parts
3948 // of the memory to store information how to transition an iterator to the new
3951 // Memory layout for obsolete table:
3952 // [0]: bucket count
3953 // [1]: Next newer table
3954 // [2]: Number of removed holes or -1 when the table was cleared.
3955 // [3..(3 + NumberOfRemovedHoles() - 1)]: The indexes of the removed holes.
3956 // [3 + NumberOfRemovedHoles()..length]: Not used
3958 template<class Derived, class Iterator, int entrysize>
3959 class OrderedHashTable: public FixedArray {
3961 // Returns an OrderedHashTable with a capacity of at least |capacity|.
3962 static Handle<Derived> Allocate(
3963 Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED);
3965 // Returns an OrderedHashTable (possibly |table|) with enough space
3966 // to add at least one new element.
3967 static Handle<Derived> EnsureGrowable(Handle<Derived> table);
3969 // Returns an OrderedHashTable (possibly |table|) that's shrunken
3971 static Handle<Derived> Shrink(Handle<Derived> table);
3973 // Returns a new empty OrderedHashTable and records the clearing so that
3974 // exisiting iterators can be updated.
3975 static Handle<Derived> Clear(Handle<Derived> table);
3977 // Returns an OrderedHashTable (possibly |table|) where |key| has been
3979 static Handle<Derived> Remove(Handle<Derived> table, Handle<Object> key,
3982 // Returns kNotFound if the key isn't present.
3983 int FindEntry(Handle<Object> key, int hash);
3985 // Like the above, but doesn't require the caller to provide a hash.
3986 int FindEntry(Handle<Object> key);
3988 int NumberOfElements() {
3989 return Smi::cast(get(kNumberOfElementsIndex))->value();
3992 int NumberOfDeletedElements() {
3993 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
3996 int UsedCapacity() { return NumberOfElements() + NumberOfDeletedElements(); }
3998 int NumberOfBuckets() {
3999 return Smi::cast(get(kNumberOfBucketsIndex))->value();
4002 // Returns the index into the data table where the new entry
4003 // should be placed. The table is assumed to have enough space
4005 int AddEntry(int hash);
4007 // Removes the entry, and puts the_hole in entrysize pointers
4008 // (leaving the hash table chain intact).
4009 void RemoveEntry(int entry);
4011 // Returns an index into |this| for the given entry.
4012 int EntryToIndex(int entry) {
4013 return kHashTableStartIndex + NumberOfBuckets() + (entry * kEntrySize);
4016 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
4019 return !get(kNextTableIndex)->IsSmi();
4022 // The next newer table. This is only valid if the table is obsolete.
4023 Derived* NextTable() {
4024 return Derived::cast(get(kNextTableIndex));
4027 // When the table is obsolete we store the indexes of the removed holes.
4028 int RemovedIndexAt(int index) {
4029 return Smi::cast(get(kRemovedHolesIndex + index))->value();
4032 static const int kNotFound = -1;
4033 static const int kMinCapacity = 4;
4035 static const int kNumberOfBucketsIndex = 0;
4036 static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1;
4037 static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
4038 static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1;
4039 static const int kNextTableIndex = kNumberOfElementsIndex;
4041 static const int kNumberOfBucketsOffset =
4042 kHeaderSize + kNumberOfBucketsIndex * kPointerSize;
4043 static const int kNumberOfElementsOffset =
4044 kHeaderSize + kNumberOfElementsIndex * kPointerSize;
4045 static const int kNumberOfDeletedElementsOffset =
4046 kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize;
4047 static const int kHashTableStartOffset =
4048 kHeaderSize + kHashTableStartIndex * kPointerSize;
4049 static const int kNextTableOffset =
4050 kHeaderSize + kNextTableIndex * kPointerSize;
4052 static const int kEntrySize = entrysize + 1;
4053 static const int kChainOffset = entrysize;
4055 static const int kLoadFactor = 2;
4057 // NumberOfDeletedElements is set to kClearedTableSentinel when
4058 // the table is cleared, which allows iterator transitions to
4059 // optimize that case.
4060 static const int kClearedTableSentinel = -1;
4063 static Handle<Derived> Rehash(Handle<Derived> table, int new_capacity);
4065 void SetNumberOfBuckets(int num) {
4066 set(kNumberOfBucketsIndex, Smi::FromInt(num));
4069 void SetNumberOfElements(int num) {
4070 set(kNumberOfElementsIndex, Smi::FromInt(num));
4073 void SetNumberOfDeletedElements(int num) {
4074 set(kNumberOfDeletedElementsIndex, Smi::FromInt(num));
4078 return NumberOfBuckets() * kLoadFactor;
4081 // Returns the next entry for the given entry.
4082 int ChainAt(int entry) {
4083 return Smi::cast(get(EntryToIndex(entry) + kChainOffset))->value();
4086 int HashToBucket(int hash) {
4087 return hash & (NumberOfBuckets() - 1);
4090 int HashToEntry(int hash) {
4091 int bucket = HashToBucket(hash);
4092 return Smi::cast(get(kHashTableStartIndex + bucket))->value();
4095 void SetNextTable(Derived* next_table) {
4096 set(kNextTableIndex, next_table);
4099 void SetRemovedIndexAt(int index, int removed_index) {
4100 return set(kRemovedHolesIndex + index, Smi::FromInt(removed_index));
4103 static const int kRemovedHolesIndex = kHashTableStartIndex;
4105 static const int kMaxCapacity =
4106 (FixedArray::kMaxLength - kHashTableStartIndex)
4107 / (1 + (kEntrySize * kLoadFactor));
4111 class JSSetIterator;
4114 class OrderedHashSet: public OrderedHashTable<
4115 OrderedHashSet, JSSetIterator, 1> {
4117 DECLARE_CAST(OrderedHashSet)
4119 bool Contains(Handle<Object> key);
4120 static Handle<OrderedHashSet> Add(
4121 Handle<OrderedHashSet> table, Handle<Object> key);
4125 class JSMapIterator;
4128 class OrderedHashMap:public OrderedHashTable<
4129 OrderedHashMap, JSMapIterator, 2> {
4131 DECLARE_CAST(OrderedHashMap)
4133 Object* Lookup(Handle<Object> key);
4134 static Handle<OrderedHashMap> Put(
4135 Handle<OrderedHashMap> table,
4137 Handle<Object> value);
4139 Object* ValueAt(int entry) {
4140 return get(EntryToIndex(entry) + kValueOffset);
4143 static const int kValueOffset = 1;
4147 template <int entrysize>
4148 class WeakHashTableShape : public BaseShape<Handle<Object> > {
4150 static inline bool IsMatch(Handle<Object> key, Object* other);
4151 static inline uint32_t Hash(Handle<Object> key);
4152 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
4153 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
4154 static const int kPrefixSize = 0;
4155 static const int kEntrySize = entrysize;
4159 // WeakHashTable maps keys that are arbitrary heap objects to heap object
4160 // values. The table wraps the keys in weak cells and store values directly.
4161 // Thus it references keys weakly and values strongly.
4162 class WeakHashTable: public HashTable<WeakHashTable,
4163 WeakHashTableShape<2>,
4166 WeakHashTable, WeakHashTableShape<2>, Handle<Object> > DerivedHashTable;
4168 DECLARE_CAST(WeakHashTable)
4170 // Looks up the value associated with the given key. The hole value is
4171 // returned in case the key is not present.
4172 Object* Lookup(Handle<HeapObject> key);
4174 // Adds (or overwrites) the value associated with the given key. Mapping a
4175 // key to the hole value causes removal of the whole entry.
4176 MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table,
4177 Handle<HeapObject> key,
4178 Handle<HeapObject> value);
4181 friend class MarkCompactCollector;
4183 void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value);
4185 // Returns the index to the value of an entry.
4186 static inline int EntryToValueIndex(int entry) {
4187 return EntryToIndex(entry) + 1;
4192 // JSFunctionResultCache caches results of some JSFunction invocation.
4193 // It is a fixed array with fixed structure:
4194 // [0]: factory function
4195 // [1]: finger index
4196 // [2]: current cache size
4197 // [3]: dummy field.
4198 // The rest of array are key/value pairs.
4199 class JSFunctionResultCache: public FixedArray {
4201 static const int kFactoryIndex = 0;
4202 static const int kFingerIndex = kFactoryIndex + 1;
4203 static const int kCacheSizeIndex = kFingerIndex + 1;
4204 static const int kDummyIndex = kCacheSizeIndex + 1;
4205 static const int kEntriesIndex = kDummyIndex + 1;
4207 static const int kEntrySize = 2; // key + value
4209 static const int kFactoryOffset = kHeaderSize;
4210 static const int kFingerOffset = kFactoryOffset + kPointerSize;
4211 static const int kCacheSizeOffset = kFingerOffset + kPointerSize;
4213 inline void MakeZeroSize();
4214 inline void Clear();
4217 inline void set_size(int size);
4218 inline int finger_index();
4219 inline void set_finger_index(int finger_index);
4221 DECLARE_CAST(JSFunctionResultCache)
4223 DECLARE_VERIFIER(JSFunctionResultCache)
4227 // ScopeInfo represents information about different scopes of a source
4228 // program and the allocation of the scope's variables. Scope information
4229 // is stored in a compressed form in ScopeInfo objects and is used
4230 // at runtime (stack dumps, deoptimization, etc.).
4232 // This object provides quick access to scope info details for runtime
4234 class ScopeInfo : public FixedArray {
4236 DECLARE_CAST(ScopeInfo)
4238 // Return the type of this scope.
4239 ScopeType scope_type();
4241 // Does this scope call eval?
4244 // Return the language mode of this scope.
4245 LanguageMode language_mode();
4247 // Does this scope make a sloppy eval call?
4248 bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); }
4250 // Return the total number of locals allocated on the stack and in the
4251 // context. This includes the parameters that are allocated in the context.
4254 // Return the number of stack slots for code. This number consists of two
4256 // 1. One stack slot per stack allocated local.
4257 // 2. One stack slot for the function name if it is stack allocated.
4258 int StackSlotCount();
4260 // Return the number of context slots for code if a context is allocated. This
4261 // number consists of three parts:
4262 // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS
4263 // 2. One context slot per context allocated local.
4264 // 3. One context slot for the function name if it is context allocated.
4265 // Parameters allocated in the context count as context allocated locals. If
4266 // no contexts are allocated for this scope ContextLength returns 0.
4267 int ContextLength();
4269 // Is this scope the scope of a named function expression?
4270 bool HasFunctionName();
4272 // Return if this has context allocated locals.
4273 bool HasHeapAllocatedLocals();
4275 // Return if contexts are allocated for this scope.
4278 // Return if this is a function scope with "use asm".
4279 bool IsAsmModule() { return AsmModuleField::decode(Flags()); }
4281 // Return if this is a nested function within an asm module scope.
4282 bool IsAsmFunction() { return AsmFunctionField::decode(Flags()); }
4284 bool IsSimpleParameterList() {
4285 return IsSimpleParameterListField::decode(Flags());
4288 // Return the function_name if present.
4289 String* FunctionName();
4291 // Return the name of the given parameter.
4292 String* ParameterName(int var);
4294 // Return the name of the given local.
4295 String* LocalName(int var);
4297 // Return the name of the given stack local.
4298 String* StackLocalName(int var);
4300 // Return the name of the given context local.
4301 String* ContextLocalName(int var);
4303 // Return the mode of the given context local.
4304 VariableMode ContextLocalMode(int var);
4306 // Return the initialization flag of the given context local.
4307 InitializationFlag ContextLocalInitFlag(int var);
4309 // Return the initialization flag of the given context local.
4310 MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var);
4312 // Return true if this local was introduced by the compiler, and should not be
4313 // exposed to the user in a debugger.
4314 bool LocalIsSynthetic(int var);
4316 String* StrongModeFreeVariableName(int var);
4317 int StrongModeFreeVariableStartPosition(int var);
4318 int StrongModeFreeVariableEndPosition(int var);
4320 // Lookup support for serialized scope info. Returns the
4321 // the stack slot index for a given slot name if the slot is
4322 // present; otherwise returns a value < 0. The name must be an internalized
4324 int StackSlotIndex(String* name);
4326 // Lookup support for serialized scope info. Returns the
4327 // context slot index for a given slot name if the slot is present; otherwise
4328 // returns a value < 0. The name must be an internalized string.
4329 // If the slot is present and mode != NULL, sets *mode to the corresponding
4330 // mode for that variable.
4331 static int ContextSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name,
4332 VariableMode* mode, InitializationFlag* init_flag,
4333 MaybeAssignedFlag* maybe_assigned_flag);
4335 // Lookup support for serialized scope info. Returns the
4336 // parameter index for a given parameter name if the parameter is present;
4337 // otherwise returns a value < 0. The name must be an internalized string.
4338 int ParameterIndex(String* name);
4340 // Lookup support for serialized scope info. Returns the function context
4341 // slot index if the function name is present and context-allocated (named
4342 // function expressions, only), otherwise returns a value < 0. The name
4343 // must be an internalized string.
4344 int FunctionContextSlotIndex(String* name, VariableMode* mode);
4346 bool block_scope_is_class_scope();
4347 FunctionKind function_kind();
4349 // Copies all the context locals into an object used to materialize a scope.
4350 static bool CopyContextLocalsToScopeObject(Handle<ScopeInfo> scope_info,
4351 Handle<Context> context,
4352 Handle<JSObject> scope_object);
4355 static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope);
4357 // Serializes empty scope info.
4358 static ScopeInfo* Empty(Isolate* isolate);
4364 // The layout of the static part of a ScopeInfo is as follows. Each entry is
4365 // numeric and occupies one array slot.
4366 // 1. A set of properties of the scope
4367 // 2. The number of parameters. This only applies to function scopes. For
4368 // non-function scopes this is 0.
4369 // 3. The number of non-parameter variables allocated on the stack.
4370 // 4. The number of non-parameter and parameter variables allocated in the
4372 #define FOR_EACH_NUMERIC_FIELD(V) \
4375 V(StackLocalCount) \
4376 V(ContextLocalCount) \
4377 V(StrongModeFreeVariableCount)
4379 #define FIELD_ACCESSORS(name) \
4380 void Set##name(int value) { \
4381 set(k##name, Smi::FromInt(value)); \
4384 if (length() > 0) { \
4385 return Smi::cast(get(k##name))->value(); \
4390 FOR_EACH_NUMERIC_FIELD(FIELD_ACCESSORS)
4391 #undef FIELD_ACCESSORS
4395 #define DECL_INDEX(name) k##name,
4396 FOR_EACH_NUMERIC_FIELD(DECL_INDEX)
4398 #undef FOR_EACH_NUMERIC_FIELD
4402 // The layout of the variable part of a ScopeInfo is as follows:
4403 // 1. ParameterEntries:
4404 // This part stores the names of the parameters for function scopes. One
4405 // slot is used per parameter, so in total this part occupies
4406 // ParameterCount() slots in the array. For other scopes than function
4407 // scopes ParameterCount() is 0.
4408 // 2. StackLocalEntries:
4409 // Contains the names of local variables that are allocated on the stack,
4410 // in increasing order of the stack slot index. One slot is used per stack
4411 // local, so in total this part occupies StackLocalCount() slots in the
4413 // 3. ContextLocalNameEntries:
4414 // Contains the names of local variables and parameters that are allocated
4415 // in the context. They are stored in increasing order of the context slot
4416 // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
4417 // context local, so in total this part occupies ContextLocalCount() slots
4419 // 4. ContextLocalInfoEntries:
4420 // Contains the variable modes and initialization flags corresponding to
4421 // the context locals in ContextLocalNameEntries. One slot is used per
4422 // context local, so in total this part occupies ContextLocalCount()
4423 // slots in the array.
4424 // 5. StrongModeFreeVariableNameEntries:
4425 // Stores the names of strong mode free variables.
4426 // 6. StrongModeFreeVariablePositionEntries:
4427 // Stores the locations (start and end position) of strong mode free
4429 // 7. FunctionNameEntryIndex:
4430 // If the scope belongs to a named function expression this part contains
4431 // information about the function variable. It always occupies two array
4432 // slots: a. The name of the function variable.
4433 // b. The context or stack slot index for the variable.
4434 int ParameterEntriesIndex();
4435 int StackLocalEntriesIndex();
4436 int ContextLocalNameEntriesIndex();
4437 int ContextLocalInfoEntriesIndex();
4438 int StrongModeFreeVariableNameEntriesIndex();
4439 int StrongModeFreeVariablePositionEntriesIndex();
4440 int FunctionNameEntryIndex();
4442 // Location of the function variable for named function expressions.
4443 enum FunctionVariableInfo {
4444 NONE, // No function name present.
4450 // Properties of scopes.
4451 class ScopeTypeField : public BitField<ScopeType, 0, 4> {};
4452 class CallsEvalField : public BitField<bool, 4, 1> {};
4453 STATIC_ASSERT(LANGUAGE_END == 3);
4454 class LanguageModeField : public BitField<LanguageMode, 5, 2> {};
4455 class FunctionVariableField : public BitField<FunctionVariableInfo, 7, 2> {};
4456 class FunctionVariableMode : public BitField<VariableMode, 9, 3> {};
4457 class AsmModuleField : public BitField<bool, 12, 1> {};
4458 class AsmFunctionField : public BitField<bool, 13, 1> {};
4459 class IsSimpleParameterListField
4460 : public BitField<bool, AsmFunctionField::kNext, 1> {};
4461 class BlockScopeIsClassScopeField
4462 : public BitField<bool, IsSimpleParameterListField::kNext, 1> {};
4463 class FunctionKindField
4464 : public BitField<FunctionKind, BlockScopeIsClassScopeField::kNext, 8> {};
4466 // BitFields representing the encoded information for context locals in the
4467 // ContextLocalInfoEntries part.
4468 class ContextLocalMode: public BitField<VariableMode, 0, 3> {};
4469 class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {};
4470 class ContextLocalMaybeAssignedFlag
4471 : public BitField<MaybeAssignedFlag, 4, 1> {};
4475 // The cache for maps used by normalized (dictionary mode) objects.
4476 // Such maps do not have property descriptors, so a typical program
4477 // needs very limited number of distinct normalized maps.
4478 class NormalizedMapCache: public FixedArray {
4480 static Handle<NormalizedMapCache> New(Isolate* isolate);
4482 MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
4483 PropertyNormalizationMode mode);
4484 void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
4488 DECLARE_CAST(NormalizedMapCache)
4490 static inline bool IsNormalizedMapCache(const Object* obj);
4492 DECLARE_VERIFIER(NormalizedMapCache)
4494 static const int kEntries = 64;
4496 static inline int GetIndex(Handle<Map> map);
4498 // The following declarations hide base class methods.
4499 Object* get(int index);
4500 void set(int index, Object* value);
4504 // ByteArray represents fixed sized byte arrays. Used for the relocation info
4505 // that is attached to code objects.
4506 class ByteArray: public FixedArrayBase {
4508 inline int Size() { return RoundUp(length() + kHeaderSize, kPointerSize); }
4510 // Setter and getter.
4511 inline byte get(int index);
4512 inline void set(int index, byte value);
4514 // Treat contents as an int array.
4515 inline int get_int(int index);
4517 static int SizeFor(int length) {
4518 return OBJECT_POINTER_ALIGN(kHeaderSize + length);
4520 // We use byte arrays for free blocks in the heap. Given a desired size in
4521 // bytes that is a multiple of the word size and big enough to hold a byte
4522 // array, this function returns the number of elements a byte array should
4524 static int LengthFor(int size_in_bytes) {
4525 DCHECK(IsAligned(size_in_bytes, kPointerSize));
4526 DCHECK(size_in_bytes >= kHeaderSize);
4527 return size_in_bytes - kHeaderSize;
4530 // Returns data start address.
4531 inline Address GetDataStartAddress();
4533 // Returns a pointer to the ByteArray object for a given data start address.
4534 static inline ByteArray* FromDataStartAddress(Address address);
4536 DECLARE_CAST(ByteArray)
4538 // Dispatched behavior.
4539 inline int ByteArraySize() {
4540 return SizeFor(this->length());
4542 DECLARE_PRINTER(ByteArray)
4543 DECLARE_VERIFIER(ByteArray)
4545 // Layout description.
4546 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4548 // Maximal memory consumption for a single ByteArray.
4549 static const int kMaxSize = 512 * MB;
4550 // Maximal length of a single ByteArray.
4551 static const int kMaxLength = kMaxSize - kHeaderSize;
4554 DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
4558 // FreeSpace are fixed-size free memory blocks used by the heap and GC.
4559 // They look like heap objects (are heap object tagged and have a map) so that
4560 // the heap remains iterable. They have a size and a next pointer.
4561 // The next pointer is the raw address of the next FreeSpace object (or NULL)
4562 // in the free list.
4563 class FreeSpace: public HeapObject {
4565 // [size]: size of the free space including the header.
4566 inline int size() const;
4567 inline void set_size(int value);
4569 inline int nobarrier_size() const;
4570 inline void nobarrier_set_size(int value);
4572 inline int Size() { return size(); }
4574 // Accessors for the next field.
4575 inline FreeSpace* next();
4576 inline FreeSpace** next_address();
4577 inline void set_next(FreeSpace* next);
4579 inline static FreeSpace* cast(HeapObject* obj);
4581 // Dispatched behavior.
4582 DECLARE_PRINTER(FreeSpace)
4583 DECLARE_VERIFIER(FreeSpace)
4585 // Layout description.
4586 // Size is smi tagged when it is stored.
4587 static const int kSizeOffset = HeapObject::kHeaderSize;
4588 static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize);
4591 DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
4595 // V has parameters (Type, type, TYPE, C type, element_size)
4596 #define TYPED_ARRAYS(V) \
4597 V(Uint8, uint8, UINT8, uint8_t, 1) \
4598 V(Int8, int8, INT8, int8_t, 1) \
4599 V(Uint16, uint16, UINT16, uint16_t, 2) \
4600 V(Int16, int16, INT16, int16_t, 2) \
4601 V(Uint32, uint32, UINT32, uint32_t, 4) \
4602 V(Int32, int32, INT32, int32_t, 4) \
4603 V(Float32, float32, FLOAT32, float, 4) \
4604 V(Float64, float64, FLOAT64, double, 8) \
4605 V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1)
4609 // An ExternalArray represents a fixed-size array of primitive values
4610 // which live outside the JavaScript heap. Its subclasses are used to
4611 // implement the CanvasArray types being defined in the WebGL
4612 // specification. As of this writing the first public draft is not yet
4613 // available, but Khronos members can access the draft at:
4614 // https://cvs.khronos.org/svn/repos/3dweb/trunk/doc/spec/WebGL-spec.html
4616 // The semantics of these arrays differ from CanvasPixelArray.
4617 // Out-of-range values passed to the setter are converted via a C
4618 // cast, not clamping. Out-of-range indices cause exceptions to be
4619 // raised rather than being silently ignored.
4620 class ExternalArray: public FixedArrayBase {
4622 inline bool is_the_hole(int index) { return false; }
4624 // [external_pointer]: The pointer to the external memory area backing this
4626 DECL_ACCESSORS(external_pointer, void) // Pointer to the data store.
4628 DECLARE_CAST(ExternalArray)
4630 // Maximal acceptable length for an external array.
4631 static const int kMaxLength = 0x3fffffff;
4633 // ExternalArray headers are not quadword aligned.
4634 static const int kExternalPointerOffset =
4635 POINTER_SIZE_ALIGN(FixedArrayBase::kLengthOffset + kPointerSize);
4636 static const int kHeaderSize = kExternalPointerOffset + kPointerSize;
4637 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4640 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalArray);
4644 // A ExternalUint8ClampedArray represents a fixed-size byte array with special
4645 // semantics used for implementing the CanvasPixelArray object. Please see the
4646 // specification at:
4648 // http://www.whatwg.org/specs/web-apps/current-work/
4649 // multipage/the-canvas-element.html#canvaspixelarray
4650 // In particular, write access clamps the value written to 0 or 255 if the
4651 // value written is outside this range.
4652 class ExternalUint8ClampedArray: public ExternalArray {
4654 inline uint8_t* external_uint8_clamped_pointer();
4656 // Setter and getter.
4657 inline uint8_t get_scalar(int index);
4658 static inline Handle<Object> get(Handle<ExternalUint8ClampedArray> array,
4660 inline void set(int index, uint8_t value);
4662 // This accessor applies the correct conversion from Smi, HeapNumber
4663 // and undefined and clamps the converted value between 0 and 255.
4664 static Handle<Object> SetValue(Handle<ExternalUint8ClampedArray> array,
4666 Handle<Object> value);
4668 DECLARE_CAST(ExternalUint8ClampedArray)
4670 // Dispatched behavior.
4671 DECLARE_PRINTER(ExternalUint8ClampedArray)
4672 DECLARE_VERIFIER(ExternalUint8ClampedArray)
4675 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint8ClampedArray);
4679 class ExternalInt8Array: public ExternalArray {
4681 // Setter and getter.
4682 inline int8_t get_scalar(int index);
4683 static inline Handle<Object> get(Handle<ExternalInt8Array> array, int index);
4684 inline void set(int index, int8_t value);
4686 // This accessor applies the correct conversion from Smi, HeapNumber
4688 static Handle<Object> SetValue(Handle<ExternalInt8Array> array,
4690 Handle<Object> value);
4692 DECLARE_CAST(ExternalInt8Array)
4694 // Dispatched behavior.
4695 DECLARE_PRINTER(ExternalInt8Array)
4696 DECLARE_VERIFIER(ExternalInt8Array)
4699 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt8Array);
4703 class ExternalUint8Array: public ExternalArray {
4705 // Setter and getter.
4706 inline uint8_t get_scalar(int index);
4707 static inline Handle<Object> get(Handle<ExternalUint8Array> array, int index);
4708 inline void set(int index, uint8_t value);
4710 // This accessor applies the correct conversion from Smi, HeapNumber
4712 static Handle<Object> SetValue(Handle<ExternalUint8Array> array,
4714 Handle<Object> value);
4716 DECLARE_CAST(ExternalUint8Array)
4718 // Dispatched behavior.
4719 DECLARE_PRINTER(ExternalUint8Array)
4720 DECLARE_VERIFIER(ExternalUint8Array)
4723 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint8Array);
4727 class ExternalInt16Array: public ExternalArray {
4729 // Setter and getter.
4730 inline int16_t get_scalar(int index);
4731 static inline Handle<Object> get(Handle<ExternalInt16Array> array, int index);
4732 inline void set(int index, int16_t value);
4734 // This accessor applies the correct conversion from Smi, HeapNumber
4736 static Handle<Object> SetValue(Handle<ExternalInt16Array> array,
4738 Handle<Object> value);
4740 DECLARE_CAST(ExternalInt16Array)
4742 // Dispatched behavior.
4743 DECLARE_PRINTER(ExternalInt16Array)
4744 DECLARE_VERIFIER(ExternalInt16Array)
4747 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt16Array);
4751 class ExternalUint16Array: public ExternalArray {
4753 // Setter and getter.
4754 inline uint16_t get_scalar(int index);
4755 static inline Handle<Object> get(Handle<ExternalUint16Array> array,
4757 inline void set(int index, uint16_t value);
4759 // This accessor applies the correct conversion from Smi, HeapNumber
4761 static Handle<Object> SetValue(Handle<ExternalUint16Array> array,
4763 Handle<Object> value);
4765 DECLARE_CAST(ExternalUint16Array)
4767 // Dispatched behavior.
4768 DECLARE_PRINTER(ExternalUint16Array)
4769 DECLARE_VERIFIER(ExternalUint16Array)
4772 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint16Array);
4776 class ExternalInt32Array: public ExternalArray {
4778 // Setter and getter.
4779 inline int32_t get_scalar(int index);
4780 static inline Handle<Object> get(Handle<ExternalInt32Array> array, int index);
4781 inline void set(int index, int32_t value);
4783 // This accessor applies the correct conversion from Smi, HeapNumber
4785 static Handle<Object> SetValue(Handle<ExternalInt32Array> array,
4787 Handle<Object> value);
4789 DECLARE_CAST(ExternalInt32Array)
4791 // Dispatched behavior.
4792 DECLARE_PRINTER(ExternalInt32Array)
4793 DECLARE_VERIFIER(ExternalInt32Array)
4796 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt32Array);
4800 class ExternalUint32Array: public ExternalArray {
4802 // Setter and getter.
4803 inline uint32_t get_scalar(int index);
4804 static inline Handle<Object> get(Handle<ExternalUint32Array> array,
4806 inline void set(int index, uint32_t value);
4808 // This accessor applies the correct conversion from Smi, HeapNumber
4810 static Handle<Object> SetValue(Handle<ExternalUint32Array> array,
4812 Handle<Object> value);
4814 DECLARE_CAST(ExternalUint32Array)
4816 // Dispatched behavior.
4817 DECLARE_PRINTER(ExternalUint32Array)
4818 DECLARE_VERIFIER(ExternalUint32Array)
4821 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint32Array);
4825 class ExternalFloat32Array: public ExternalArray {
4827 // Setter and getter.
4828 inline float get_scalar(int index);
4829 static inline Handle<Object> get(Handle<ExternalFloat32Array> array,
4831 inline void set(int index, float value);
4833 // This accessor applies the correct conversion from Smi, HeapNumber
4835 static Handle<Object> SetValue(Handle<ExternalFloat32Array> array,
4837 Handle<Object> value);
4839 DECLARE_CAST(ExternalFloat32Array)
4841 // Dispatched behavior.
4842 DECLARE_PRINTER(ExternalFloat32Array)
4843 DECLARE_VERIFIER(ExternalFloat32Array)
4846 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloat32Array);
4850 class ExternalFloat64Array: public ExternalArray {
4852 // Setter and getter.
4853 inline double get_scalar(int index);
4854 static inline Handle<Object> get(Handle<ExternalFloat64Array> array,
4856 inline void set(int index, double value);
4858 // This accessor applies the correct conversion from Smi, HeapNumber
4860 static Handle<Object> SetValue(Handle<ExternalFloat64Array> array,
4862 Handle<Object> value);
4864 DECLARE_CAST(ExternalFloat64Array)
4866 // Dispatched behavior.
4867 DECLARE_PRINTER(ExternalFloat64Array)
4868 DECLARE_VERIFIER(ExternalFloat64Array)
4871 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloat64Array);
4875 class FixedTypedArrayBase: public FixedArrayBase {
4877 DECLARE_CAST(FixedTypedArrayBase)
4879 static const int kDataOffset = kHeaderSize;
4883 static inline int TypedArraySize(InstanceType type, int length);
4884 inline int TypedArraySize(InstanceType type);
4886 // Use with care: returns raw pointer into heap.
4887 inline void* DataPtr();
4889 inline int DataSize();
4892 static inline int ElementSize(InstanceType type);
4894 inline int DataSize(InstanceType type);
4896 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase);
4900 template <class Traits>
4901 class FixedTypedArray: public FixedTypedArrayBase {
4903 typedef typename Traits::ElementType ElementType;
4904 static const InstanceType kInstanceType = Traits::kInstanceType;
4906 DECLARE_CAST(FixedTypedArray<Traits>)
4908 static inline int ElementOffset(int index) {
4909 return kDataOffset + index * sizeof(ElementType);
4912 static inline int SizeFor(int length) {
4913 return ElementOffset(length);
4916 inline ElementType get_scalar(int index);
4917 static inline Handle<Object> get(Handle<FixedTypedArray> array, int index);
4918 inline void set(int index, ElementType value);
4920 static inline ElementType from_int(int value);
4921 static inline ElementType from_double(double value);
4923 // This accessor applies the correct conversion from Smi, HeapNumber
4925 static Handle<Object> SetValue(Handle<FixedTypedArray<Traits> > array,
4927 Handle<Object> value);
4929 DECLARE_PRINTER(FixedTypedArray)
4930 DECLARE_VERIFIER(FixedTypedArray)
4933 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray);
4936 #define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType, size) \
4937 class Type##ArrayTraits { \
4938 public: /* NOLINT */ \
4939 typedef elementType ElementType; \
4940 static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE; \
4941 static const char* Designator() { return #type " array"; } \
4942 static inline Handle<Object> ToHandle(Isolate* isolate, \
4943 elementType scalar); \
4944 static inline elementType defaultValue(); \
4947 typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array;
4949 TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS)
4951 #undef FIXED_TYPED_ARRAY_TRAITS
4954 // DeoptimizationInputData is a fixed array used to hold the deoptimization
4955 // data for code generated by the Hydrogen/Lithium compiler. It also
4956 // contains information about functions that were inlined. If N different
4957 // functions were inlined then first N elements of the literal array will
4958 // contain these functions.
4961 class DeoptimizationInputData: public FixedArray {
4963 // Layout description. Indices in the array.
4964 static const int kTranslationByteArrayIndex = 0;
4965 static const int kInlinedFunctionCountIndex = 1;
4966 static const int kLiteralArrayIndex = 2;
4967 static const int kOsrAstIdIndex = 3;
4968 static const int kOsrPcOffsetIndex = 4;
4969 static const int kOptimizationIdIndex = 5;
4970 static const int kSharedFunctionInfoIndex = 6;
4971 static const int kWeakCellCacheIndex = 7;
4972 static const int kFirstDeoptEntryIndex = 8;
4974 // Offsets of deopt entry elements relative to the start of the entry.
4975 static const int kAstIdRawOffset = 0;
4976 static const int kTranslationIndexOffset = 1;
4977 static const int kArgumentsStackHeightOffset = 2;
4978 static const int kPcOffset = 3;
4979 static const int kDeoptEntrySize = 4;
4981 // Simple element accessors.
4982 #define DEFINE_ELEMENT_ACCESSORS(name, type) \
4984 return type::cast(get(k##name##Index)); \
4986 void Set##name(type* value) { \
4987 set(k##name##Index, value); \
4990 DEFINE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray)
4991 DEFINE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi)
4992 DEFINE_ELEMENT_ACCESSORS(LiteralArray, FixedArray)
4993 DEFINE_ELEMENT_ACCESSORS(OsrAstId, Smi)
4994 DEFINE_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
4995 DEFINE_ELEMENT_ACCESSORS(OptimizationId, Smi)
4996 DEFINE_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
4997 DEFINE_ELEMENT_ACCESSORS(WeakCellCache, Object)
4999 #undef DEFINE_ELEMENT_ACCESSORS
5001 // Accessors for elements of the ith deoptimization entry.
5002 #define DEFINE_ENTRY_ACCESSORS(name, type) \
5003 type* name(int i) { \
5004 return type::cast(get(IndexForEntry(i) + k##name##Offset)); \
5006 void Set##name(int i, type* value) { \
5007 set(IndexForEntry(i) + k##name##Offset, value); \
5010 DEFINE_ENTRY_ACCESSORS(AstIdRaw, Smi)
5011 DEFINE_ENTRY_ACCESSORS(TranslationIndex, Smi)
5012 DEFINE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi)
5013 DEFINE_ENTRY_ACCESSORS(Pc, Smi)
5015 #undef DEFINE_DEOPT_ENTRY_ACCESSORS
5017 BailoutId AstId(int i) {
5018 return BailoutId(AstIdRaw(i)->value());
5021 void SetAstId(int i, BailoutId value) {
5022 SetAstIdRaw(i, Smi::FromInt(value.ToInt()));
5026 return (length() - kFirstDeoptEntryIndex) / kDeoptEntrySize;
5029 // Allocates a DeoptimizationInputData.
5030 static Handle<DeoptimizationInputData> New(Isolate* isolate,
5031 int deopt_entry_count,
5032 PretenureFlag pretenure);
5034 DECLARE_CAST(DeoptimizationInputData)
5036 #ifdef ENABLE_DISASSEMBLER
5037 void DeoptimizationInputDataPrint(std::ostream& os); // NOLINT
5041 static int IndexForEntry(int i) {
5042 return kFirstDeoptEntryIndex + (i * kDeoptEntrySize);
5046 static int LengthFor(int entry_count) { return IndexForEntry(entry_count); }
5050 // DeoptimizationOutputData is a fixed array used to hold the deoptimization
5051 // data for code generated by the full compiler.
5052 // The format of the these objects is
5053 // [i * 2]: Ast ID for ith deoptimization.
5054 // [i * 2 + 1]: PC and state of ith deoptimization
5055 class DeoptimizationOutputData: public FixedArray {
5057 int DeoptPoints() { return length() / 2; }
5059 BailoutId AstId(int index) {
5060 return BailoutId(Smi::cast(get(index * 2))->value());
5063 void SetAstId(int index, BailoutId id) {
5064 set(index * 2, Smi::FromInt(id.ToInt()));
5067 Smi* PcAndState(int index) { return Smi::cast(get(1 + index * 2)); }
5068 void SetPcAndState(int index, Smi* offset) { set(1 + index * 2, offset); }
5070 static int LengthOfFixedArray(int deopt_points) {
5071 return deopt_points * 2;
5074 // Allocates a DeoptimizationOutputData.
5075 static Handle<DeoptimizationOutputData> New(Isolate* isolate,
5076 int number_of_deopt_points,
5077 PretenureFlag pretenure);
5079 DECLARE_CAST(DeoptimizationOutputData)
5081 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
5082 void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT
5087 // HandlerTable is a fixed array containing entries for exception handlers in
5088 // the code object it is associated with. The tables comes in two flavors:
5089 // 1) Based on ranges: Used for unoptimized code. Contains one entry per
5090 // exception handler and a range representing the try-block covered by that
5091 // handler. Layout looks as follows:
5092 // [ range-start , range-end , handler-offset , stack-depth ]
5093 // 2) Based on return addresses: Used for turbofanned code. Contains one entry
5094 // per call-site that could throw an exception. Layout looks as follows:
5095 // [ return-address-offset , handler-offset ]
5096 class HandlerTable : public FixedArray {
5098 // Accessors for handler table based on ranges.
5099 void SetRangeStart(int index, int value) {
5100 set(index * kRangeEntrySize + kRangeStartIndex, Smi::FromInt(value));
5102 void SetRangeEnd(int index, int value) {
5103 set(index * kRangeEntrySize + kRangeEndIndex, Smi::FromInt(value));
5105 void SetRangeHandler(int index, int value) {
5106 set(index * kRangeEntrySize + kRangeHandlerIndex, Smi::FromInt(value));
5108 void SetRangeDepth(int index, int value) {
5109 set(index * kRangeEntrySize + kRangeDepthIndex, Smi::FromInt(value));
5112 // Accessors for handler table based on return addresses.
5113 void SetReturnOffset(int index, int value) {
5114 set(index * kReturnEntrySize + kReturnOffsetIndex, Smi::FromInt(value));
5116 void SetReturnHandler(int index, int value) {
5117 set(index * kReturnEntrySize + kReturnHandlerIndex, Smi::FromInt(value));
5120 // Lookup handler in a table based on ranges.
5121 int LookupRange(int pc_offset, int* stack_depth);
5123 // Lookup handler in a table based on return addresses.
5124 int LookupReturn(int pc_offset);
5126 // Returns the required length of the underlying fixed array.
5127 static int LengthForRange(int entries) { return entries * kRangeEntrySize; }
5128 static int LengthForReturn(int entries) { return entries * kReturnEntrySize; }
5130 DECLARE_CAST(HandlerTable)
5132 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
5133 void HandlerTableRangePrint(std::ostream& os); // NOLINT
5134 void HandlerTableReturnPrint(std::ostream& os); // NOLINT
5138 // Layout description for handler table based on ranges.
5139 static const int kRangeStartIndex = 0;
5140 static const int kRangeEndIndex = 1;
5141 static const int kRangeHandlerIndex = 2;
5142 static const int kRangeDepthIndex = 3;
5143 static const int kRangeEntrySize = 4;
5145 // Layout description for handler table based on return addresses.
5146 static const int kReturnOffsetIndex = 0;
5147 static const int kReturnHandlerIndex = 1;
5148 static const int kReturnEntrySize = 2;
5152 // Forward declaration.
5155 class SafepointEntry;
5156 class TypeFeedbackInfo;
5158 // Code describes objects with on-the-fly generated machine code.
5159 class Code: public HeapObject {
5161 // Opaque data type for encapsulating code flags like kind, inline
5162 // cache state, and arguments count.
5163 typedef uint32_t Flags;
5165 #define NON_IC_KIND_LIST(V) \
5167 V(OPTIMIZED_FUNCTION) \
5173 #define IC_KIND_LIST(V) \
5184 #define CODE_KIND_LIST(V) \
5185 NON_IC_KIND_LIST(V) \
5189 #define DEFINE_CODE_KIND_ENUM(name) name,
5190 CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM)
5191 #undef DEFINE_CODE_KIND_ENUM
5195 // No more than 16 kinds. The value is currently encoded in four bits in
5197 STATIC_ASSERT(NUMBER_OF_KINDS <= 16);
5199 static const char* Kind2String(Kind kind);
5207 static const int kPrologueOffsetNotSet = -1;
5209 #ifdef ENABLE_DISASSEMBLER
5211 static const char* ICState2String(InlineCacheState state);
5212 static const char* StubType2String(StubType type);
5213 static void PrintExtraICState(std::ostream& os, // NOLINT
5214 Kind kind, ExtraICState extra);
5215 void Disassemble(const char* name, std::ostream& os); // NOLINT
5216 #endif // ENABLE_DISASSEMBLER
5218 // [instruction_size]: Size of the native instructions
5219 inline int instruction_size() const;
5220 inline void set_instruction_size(int value);
5222 // [relocation_info]: Code relocation information
5223 DECL_ACCESSORS(relocation_info, ByteArray)
5224 void InvalidateRelocation();
5225 void InvalidateEmbeddedObjects();
5227 // [handler_table]: Fixed array containing offsets of exception handlers.
5228 DECL_ACCESSORS(handler_table, FixedArray)
5230 // [deoptimization_data]: Array containing data for deopt.
5231 DECL_ACCESSORS(deoptimization_data, FixedArray)
5233 // [raw_type_feedback_info]: This field stores various things, depending on
5234 // the kind of the code object.
5235 // FUNCTION => type feedback information.
5236 // STUB and ICs => major/minor key as Smi.
5237 DECL_ACCESSORS(raw_type_feedback_info, Object)
5238 inline Object* type_feedback_info();
5239 inline void set_type_feedback_info(
5240 Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5241 inline uint32_t stub_key();
5242 inline void set_stub_key(uint32_t key);
5244 // [next_code_link]: Link for lists of optimized or deoptimized code.
5245 // Note that storage for this field is overlapped with typefeedback_info.
5246 DECL_ACCESSORS(next_code_link, Object)
5248 // [gc_metadata]: Field used to hold GC related metadata. The contents of this
5249 // field does not have to be traced during garbage collection since
5250 // it is only used by the garbage collector itself.
5251 DECL_ACCESSORS(gc_metadata, Object)
5253 // [ic_age]: Inline caching age: the value of the Heap::global_ic_age
5254 // at the moment when this object was created.
5255 inline void set_ic_age(int count);
5256 inline int ic_age() const;
5258 // [prologue_offset]: Offset of the function prologue, used for aging
5259 // FUNCTIONs and OPTIMIZED_FUNCTIONs.
5260 inline int prologue_offset() const;
5261 inline void set_prologue_offset(int offset);
5263 // Unchecked accessors to be used during GC.
5264 inline ByteArray* unchecked_relocation_info();
5266 inline int relocation_size();
5268 // [flags]: Various code flags.
5269 inline Flags flags();
5270 inline void set_flags(Flags flags);
5272 // [flags]: Access to specific code flags.
5274 inline InlineCacheState ic_state(); // Only valid for IC stubs.
5275 inline ExtraICState extra_ic_state(); // Only valid for IC stubs.
5277 inline StubType type(); // Only valid for monomorphic IC stubs.
5279 // Testers for IC stub kinds.
5280 inline bool is_inline_cache_stub();
5281 inline bool is_debug_stub();
5282 inline bool is_handler() { return kind() == HANDLER; }
5283 inline bool is_load_stub() { return kind() == LOAD_IC; }
5284 inline bool is_keyed_load_stub() { return kind() == KEYED_LOAD_IC; }
5285 inline bool is_store_stub() { return kind() == STORE_IC; }
5286 inline bool is_keyed_store_stub() { return kind() == KEYED_STORE_IC; }
5287 inline bool is_call_stub() { return kind() == CALL_IC; }
5288 inline bool is_binary_op_stub() { return kind() == BINARY_OP_IC; }
5289 inline bool is_compare_ic_stub() { return kind() == COMPARE_IC; }
5290 inline bool is_compare_nil_ic_stub() { return kind() == COMPARE_NIL_IC; }
5291 inline bool is_to_boolean_ic_stub() { return kind() == TO_BOOLEAN_IC; }
5292 inline bool is_keyed_stub();
5293 inline bool is_optimized_code() { return kind() == OPTIMIZED_FUNCTION; }
5294 inline bool embeds_maps_weakly() {
5296 return (k == LOAD_IC || k == STORE_IC || k == KEYED_LOAD_IC ||
5297 k == KEYED_STORE_IC || k == COMPARE_NIL_IC) &&
5298 ic_state() == MONOMORPHIC;
5301 inline bool IsCodeStubOrIC();
5303 inline void set_raw_kind_specific_flags1(int value);
5304 inline void set_raw_kind_specific_flags2(int value);
5306 // [is_crankshafted]: For kind STUB or ICs, tells whether or not a code
5307 // object was generated by either the hydrogen or the TurboFan optimizing
5308 // compiler (but it may not be an optimized function).
5309 inline bool is_crankshafted();
5310 inline bool is_hydrogen_stub(); // Crankshafted, but not a function.
5311 inline void set_is_crankshafted(bool value);
5313 // [is_turbofanned]: For kind STUB or OPTIMIZED_FUNCTION, tells whether the
5314 // code object was generated by the TurboFan optimizing compiler.
5315 inline bool is_turbofanned();
5316 inline void set_is_turbofanned(bool value);
5318 // [can_have_weak_objects]: For kind OPTIMIZED_FUNCTION, tells whether the
5319 // embedded objects in code should be treated weakly.
5320 inline bool can_have_weak_objects();
5321 inline void set_can_have_weak_objects(bool value);
5323 // [optimizable]: For FUNCTION kind, tells if it is optimizable.
5324 inline bool optimizable();
5325 inline void set_optimizable(bool value);
5327 // [has_deoptimization_support]: For FUNCTION kind, tells if it has
5328 // deoptimization support.
5329 inline bool has_deoptimization_support();
5330 inline void set_has_deoptimization_support(bool value);
5332 // [has_debug_break_slots]: For FUNCTION kind, tells if it has
5333 // been compiled with debug break slots.
5334 inline bool has_debug_break_slots();
5335 inline void set_has_debug_break_slots(bool value);
5337 // [compiled_with_optimizing]: For FUNCTION kind, tells if it has
5338 // been compiled with IsOptimizing set to true.
5339 inline bool is_compiled_optimizable();
5340 inline void set_compiled_optimizable(bool value);
5342 // [has_reloc_info_for_serialization]: For FUNCTION kind, tells if its
5343 // reloc info includes runtime and external references to support
5344 // serialization/deserialization.
5345 inline bool has_reloc_info_for_serialization();
5346 inline void set_has_reloc_info_for_serialization(bool value);
5348 // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for
5349 // how long the function has been marked for OSR and therefore which
5350 // level of loop nesting we are willing to do on-stack replacement
5352 inline void set_allow_osr_at_loop_nesting_level(int level);
5353 inline int allow_osr_at_loop_nesting_level();
5355 // [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks
5356 // the code object was seen on the stack with no IC patching going on.
5357 inline int profiler_ticks();
5358 inline void set_profiler_ticks(int ticks);
5360 // [builtin_index]: For BUILTIN kind, tells which builtin index it has.
5361 // For builtins, tells which builtin index it has.
5362 // Note that builtins can have a code kind other than BUILTIN, which means
5363 // that for arbitrary code objects, this index value may be random garbage.
5364 // To verify in that case, compare the code object to the indexed builtin.
5365 inline int builtin_index();
5366 inline void set_builtin_index(int id);
5368 // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots
5369 // reserved in the code prologue.
5370 inline unsigned stack_slots();
5371 inline void set_stack_slots(unsigned slots);
5373 // [safepoint_table_start]: For kind OPTIMIZED_FUNCTION, the offset in
5374 // the instruction stream where the safepoint table starts.
5375 inline unsigned safepoint_table_offset();
5376 inline void set_safepoint_table_offset(unsigned offset);
5378 // [back_edge_table_start]: For kind FUNCTION, the offset in the
5379 // instruction stream where the back edge table starts.
5380 inline unsigned back_edge_table_offset();
5381 inline void set_back_edge_table_offset(unsigned offset);
5383 inline bool back_edges_patched_for_osr();
5385 // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in.
5386 inline byte to_boolean_state();
5388 // [has_function_cache]: For kind STUB tells whether there is a function
5389 // cache is passed to the stub.
5390 inline bool has_function_cache();
5391 inline void set_has_function_cache(bool flag);
5394 // [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether
5395 // the code is going to be deoptimized because of dead embedded maps.
5396 inline bool marked_for_deoptimization();
5397 inline void set_marked_for_deoptimization(bool flag);
5399 // [constant_pool]: The constant pool for this function.
5400 inline ConstantPoolArray* constant_pool();
5401 inline void set_constant_pool(Object* constant_pool);
5403 // Get the safepoint entry for the given pc.
5404 SafepointEntry GetSafepointEntry(Address pc);
5406 // Find an object in a stub with a specified map
5407 Object* FindNthObject(int n, Map* match_map);
5409 // Find the first allocation site in an IC stub.
5410 AllocationSite* FindFirstAllocationSite();
5412 // Find the first map in an IC stub.
5413 Map* FindFirstMap();
5414 void FindAllMaps(MapHandleList* maps);
5416 // Find the first handler in an IC stub.
5417 Code* FindFirstHandler();
5419 // Find |length| handlers and put them into |code_list|. Returns false if not
5420 // enough handlers can be found.
5421 bool FindHandlers(CodeHandleList* code_list, int length = -1);
5423 // Find the handler for |map|.
5424 MaybeHandle<Code> FindHandlerForMap(Map* map);
5426 // Find the first name in an IC stub.
5427 Name* FindFirstName();
5429 class FindAndReplacePattern;
5430 // For each (map-to-find, object-to-replace) pair in the pattern, this
5431 // function replaces the corresponding placeholder in the code with the
5432 // object-to-replace. The function assumes that pairs in the pattern come in
5433 // the same order as the placeholders in the code.
5434 // If the placeholder is a weak cell, then the value of weak cell is matched
5435 // against the map-to-find.
5436 void FindAndReplace(const FindAndReplacePattern& pattern);
5438 // The entire code object including its header is copied verbatim to the
5439 // snapshot so that it can be written in one, fast, memcpy during
5440 // deserialization. The deserializer will overwrite some pointers, rather
5441 // like a runtime linker, but the random allocation addresses used in the
5442 // mksnapshot process would still be present in the unlinked snapshot data,
5443 // which would make snapshot production non-reproducible. This method wipes
5444 // out the to-be-overwritten header data for reproducible snapshots.
5445 inline void WipeOutHeader();
5447 // Flags operations.
5448 static inline Flags ComputeFlags(
5449 Kind kind, InlineCacheState ic_state = UNINITIALIZED,
5450 ExtraICState extra_ic_state = kNoExtraICState, StubType type = NORMAL,
5451 CacheHolderFlag holder = kCacheOnReceiver);
5453 static inline Flags ComputeMonomorphicFlags(
5454 Kind kind, ExtraICState extra_ic_state = kNoExtraICState,
5455 CacheHolderFlag holder = kCacheOnReceiver, StubType type = NORMAL);
5457 static inline Flags ComputeHandlerFlags(
5458 Kind handler_kind, StubType type = NORMAL,
5459 CacheHolderFlag holder = kCacheOnReceiver);
5461 static inline InlineCacheState ExtractICStateFromFlags(Flags flags);
5462 static inline StubType ExtractTypeFromFlags(Flags flags);
5463 static inline CacheHolderFlag ExtractCacheHolderFromFlags(Flags flags);
5464 static inline Kind ExtractKindFromFlags(Flags flags);
5465 static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags);
5467 static inline Flags RemoveTypeFromFlags(Flags flags);
5468 static inline Flags RemoveTypeAndHolderFromFlags(Flags flags);
5470 // Convert a target address into a code object.
5471 static inline Code* GetCodeFromTargetAddress(Address address);
5473 // Convert an entry address into an object.
5474 static inline Object* GetObjectFromEntryAddress(Address location_of_address);
5476 // Returns the address of the first instruction.
5477 inline byte* instruction_start();
5479 // Returns the address right after the last instruction.
5480 inline byte* instruction_end();
5482 // Returns the size of the instructions, padding, and relocation information.
5483 inline int body_size();
5485 // Returns the address of the first relocation info (read backwards!).
5486 inline byte* relocation_start();
5488 // Code entry point.
5489 inline byte* entry();
5491 // Returns true if pc is inside this object's instructions.
5492 inline bool contains(byte* pc);
5494 // Relocate the code by delta bytes. Called to signal that this code
5495 // object has been moved by delta bytes.
5496 void Relocate(intptr_t delta);
5498 // Migrate code described by desc.
5499 void CopyFrom(const CodeDesc& desc);
5501 // Returns the object size for a given body (used for allocation).
5502 static int SizeFor(int body_size) {
5503 DCHECK_SIZE_TAG_ALIGNED(body_size);
5504 return RoundUp(kHeaderSize + body_size, kCodeAlignment);
5507 // Calculate the size of the code object to report for log events. This takes
5508 // the layout of the code object into account.
5509 int ExecutableSize() {
5510 // Check that the assumptions about the layout of the code object holds.
5511 DCHECK_EQ(static_cast<int>(instruction_start() - address()),
5513 return instruction_size() + Code::kHeaderSize;
5516 // Locating source position.
5517 int SourcePosition(Address pc);
5518 int SourceStatementPosition(Address pc);
5522 // Dispatched behavior.
5523 int CodeSize() { return SizeFor(body_size()); }
5524 inline void CodeIterateBody(ObjectVisitor* v);
5526 template<typename StaticVisitor>
5527 inline void CodeIterateBody(Heap* heap);
5529 DECLARE_PRINTER(Code)
5530 DECLARE_VERIFIER(Code)
5532 void ClearInlineCaches();
5533 void ClearInlineCaches(Kind kind);
5535 BailoutId TranslatePcOffsetToAstId(uint32_t pc_offset);
5536 uint32_t TranslateAstIdToPcOffset(BailoutId ast_id);
5538 #define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
5540 kNotExecutedCodeAge = -2,
5541 kExecutedOnceCodeAge = -1,
5543 CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
5545 kFirstCodeAge = kNotExecutedCodeAge,
5546 kLastCodeAge = kAfterLastCodeAge - 1,
5547 kCodeAgeCount = kAfterLastCodeAge - kNotExecutedCodeAge - 1,
5548 kIsOldCodeAge = kSexagenarianCodeAge,
5549 kPreAgedCodeAge = kIsOldCodeAge - 1
5551 #undef DECLARE_CODE_AGE_ENUM
5553 // Code aging. Indicates how many full GCs this code has survived without
5554 // being entered through the prologue. Used to determine when it is
5555 // relatively safe to flush this code object and replace it with the lazy
5556 // compilation stub.
5557 static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate);
5558 static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate);
5559 void MakeYoung(Isolate* isolate);
5560 void MakeOlder(MarkingParity);
5561 static bool IsYoungSequence(Isolate* isolate, byte* sequence);
5564 // Gets the raw code age, including psuedo code-age values such as
5565 // kNotExecutedCodeAge and kExecutedOnceCodeAge.
5567 static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) {
5568 return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY);
5571 void PrintDeoptLocation(FILE* out, Address pc);
5572 bool CanDeoptAt(Address pc);
5575 void VerifyEmbeddedObjectsDependency();
5579 enum VerifyMode { kNoContextSpecificPointers, kNoContextRetainingPointers };
5580 void VerifyEmbeddedObjects(VerifyMode mode = kNoContextRetainingPointers);
5583 inline bool CanContainWeakObjects() {
5584 // is_turbofanned() implies !can_have_weak_objects().
5585 DCHECK(!is_optimized_code() || !is_turbofanned() ||
5586 !can_have_weak_objects());
5587 return is_optimized_code() && can_have_weak_objects();
5590 inline bool IsWeakObject(Object* object) {
5591 return (CanContainWeakObjects() && IsWeakObjectInOptimizedCode(object));
5594 static inline bool IsWeakObjectInOptimizedCode(Object* object);
5596 static Handle<WeakCell> WeakCellFor(Handle<Code> code);
5597 WeakCell* CachedWeakCell();
5599 // Max loop nesting marker used to postpose OSR. We don't take loop
5600 // nesting that is deeper than 5 levels into account.
5601 static const int kMaxLoopNestingMarker = 6;
5603 // Layout description.
5604 static const int kRelocationInfoOffset = HeapObject::kHeaderSize;
5605 static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
5606 static const int kDeoptimizationDataOffset =
5607 kHandlerTableOffset + kPointerSize;
5608 // For FUNCTION kind, we store the type feedback info here.
5609 static const int kTypeFeedbackInfoOffset =
5610 kDeoptimizationDataOffset + kPointerSize;
5611 static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
5612 static const int kGCMetadataOffset = kNextCodeLinkOffset + kPointerSize;
5613 static const int kInstructionSizeOffset = kGCMetadataOffset + kPointerSize;
5614 static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
5615 static const int kFlagsOffset = kICAgeOffset + kIntSize;
5616 static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
5617 static const int kKindSpecificFlags2Offset =
5618 kKindSpecificFlags1Offset + kIntSize;
5619 // Note: We might be able to squeeze this into the flags above.
5620 static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
5621 static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
5623 static const int kHeaderPaddingStart = kConstantPoolOffset + kPointerSize;
5625 // Add padding to align the instruction start following right after
5626 // the Code object header.
5627 static const int kHeaderSize =
5628 (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
5629 // Ensure that the slot for the constant pool pointer is aligned.
5630 STATIC_ASSERT((kConstantPoolOffset & kPointerAlignmentMask) == 0);
5632 // Byte offsets within kKindSpecificFlags1Offset.
5633 static const int kOptimizableOffset = kKindSpecificFlags1Offset;
5635 static const int kFullCodeFlags = kOptimizableOffset + 1;
5636 class FullCodeFlagsHasDeoptimizationSupportField:
5637 public BitField<bool, 0, 1> {}; // NOLINT
5638 class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {};
5639 class FullCodeFlagsIsCompiledOptimizable: public BitField<bool, 2, 1> {};
5640 class FullCodeFlagsHasRelocInfoForSerialization
5641 : public BitField<bool, 3, 1> {};
5643 static const int kProfilerTicksOffset = kFullCodeFlags + 1;
5645 // Flags layout. BitField<type, shift, size>.
5646 class ICStateField : public BitField<InlineCacheState, 0, 4> {};
5647 class TypeField : public BitField<StubType, 4, 1> {};
5648 class CacheHolderField : public BitField<CacheHolderFlag, 5, 2> {};
5649 class KindField : public BitField<Kind, 7, 4> {};
5650 class ExtraICStateField: public BitField<ExtraICState, 11,
5651 PlatformSmiTagging::kSmiValueSize - 11 + 1> {}; // NOLINT
5653 // KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
5654 static const int kStackSlotsFirstBit = 0;
5655 static const int kStackSlotsBitCount = 24;
5656 static const int kHasFunctionCacheBit =
5657 kStackSlotsFirstBit + kStackSlotsBitCount;
5658 static const int kMarkedForDeoptimizationBit = kHasFunctionCacheBit + 1;
5659 static const int kIsTurbofannedBit = kMarkedForDeoptimizationBit + 1;
5660 static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1;
5662 STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32);
5663 STATIC_ASSERT(kCanHaveWeakObjects + 1 <= 32);
5665 class StackSlotsField: public BitField<int,
5666 kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT
5667 class HasFunctionCacheField : public BitField<bool, kHasFunctionCacheBit, 1> {
5669 class MarkedForDeoptimizationField
5670 : public BitField<bool, kMarkedForDeoptimizationBit, 1> {}; // NOLINT
5671 class IsTurbofannedField : public BitField<bool, kIsTurbofannedBit, 1> {
5673 class CanHaveWeakObjectsField
5674 : public BitField<bool, kCanHaveWeakObjects, 1> {}; // NOLINT
5676 // KindSpecificFlags2 layout (ALL)
5677 static const int kIsCrankshaftedBit = 0;
5678 class IsCrankshaftedField: public BitField<bool,
5679 kIsCrankshaftedBit, 1> {}; // NOLINT
5681 // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
5682 static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1;
5683 static const int kSafepointTableOffsetBitCount = 24;
5685 STATIC_ASSERT(kSafepointTableOffsetFirstBit +
5686 kSafepointTableOffsetBitCount <= 32);
5687 STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32);
5689 class SafepointTableOffsetField: public BitField<int,
5690 kSafepointTableOffsetFirstBit,
5691 kSafepointTableOffsetBitCount> {}; // NOLINT
5693 // KindSpecificFlags2 layout (FUNCTION)
5694 class BackEdgeTableOffsetField: public BitField<int,
5695 kIsCrankshaftedBit + 1, 27> {}; // NOLINT
5696 class AllowOSRAtLoopNestingLevelField: public BitField<int,
5697 kIsCrankshaftedBit + 1 + 27, 4> {}; // NOLINT
5698 STATIC_ASSERT(AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker);
5700 static const int kArgumentsBits = 16;
5701 static const int kMaxArguments = (1 << kArgumentsBits) - 1;
5703 // This constant should be encodable in an ARM instruction.
5704 static const int kFlagsNotUsedInLookup =
5705 TypeField::kMask | CacheHolderField::kMask;
5708 friend class RelocIterator;
5709 friend class Deoptimizer; // For FindCodeAgeSequence.
5711 void ClearInlineCaches(Kind* kind);
5714 byte* FindCodeAgeSequence();
5715 static void GetCodeAgeAndParity(Code* code, Age* age,
5716 MarkingParity* parity);
5717 static void GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
5718 MarkingParity* parity);
5719 static Code* GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity);
5721 // Code aging -- platform-specific
5722 static void PatchPlatformCodeAge(Isolate* isolate,
5723 byte* sequence, Age age,
5724 MarkingParity parity);
5726 DISALLOW_IMPLICIT_CONSTRUCTORS(Code);
5730 class CompilationInfo;
5732 // This class describes the layout of dependent codes array of a map. The
5733 // array is partitioned into several groups of dependent codes. Each group
5734 // contains codes with the same dependency on the map. The array has the
5735 // following layout for n dependency groups:
5737 // +----+----+-----+----+---------+----------+-----+---------+-----------+
5738 // | C1 | C2 | ... | Cn | group 1 | group 2 | ... | group n | undefined |
5739 // +----+----+-----+----+---------+----------+-----+---------+-----------+
5741 // The first n elements are Smis, each of them specifies the number of codes
5742 // in the corresponding group. The subsequent elements contain grouped code
5743 // objects in weak cells. The suffix of the array can be filled with the
5744 // undefined value if the number of codes is less than the length of the
5745 // array. The order of the code objects within a group is not preserved.
5747 // All code indexes used in the class are counted starting from the first
5748 // code object of the first group. In other words, code index 0 corresponds
5749 // to array index n = kCodesStartIndex.
5751 class DependentCode: public FixedArray {
5753 enum DependencyGroup {
5754 // Group of code that weakly embed this map and depend on being
5755 // deoptimized when the map is garbage collected.
5757 // Group of code that embed a transition to this map, and depend on being
5758 // deoptimized when the transition is replaced by a new version.
5760 // Group of code that omit run-time prototype checks for prototypes
5761 // described by this map. The group is deoptimized whenever an object
5762 // described by this map changes shape (and transitions to a new map),
5763 // possibly invalidating the assumptions embedded in the code.
5764 kPrototypeCheckGroup,
5765 // Group of code that depends on elements not being added to objects with
5767 kElementsCantBeAddedGroup,
5768 // Group of code that depends on global property values in property cells
5769 // not being changed.
5770 kPropertyCellChangedGroup,
5771 // Group of code that omit run-time type checks for the field(s) introduced
5774 // Group of code that omit run-time type checks for initial maps of
5776 kInitialMapChangedGroup,
5777 // Group of code that depends on tenuring information in AllocationSites
5778 // not being changed.
5779 kAllocationSiteTenuringChangedGroup,
5780 // Group of code that depends on element transition information in
5781 // AllocationSites not being changed.
5782 kAllocationSiteTransitionChangedGroup
5785 static const int kGroupCount = kAllocationSiteTransitionChangedGroup + 1;
5787 // Array for holding the index of the first code object of each group.
5788 // The last element stores the total number of code objects.
5789 class GroupStartIndexes {
5791 explicit GroupStartIndexes(DependentCode* entries);
5792 void Recompute(DependentCode* entries);
5793 int at(int i) { return start_indexes_[i]; }
5794 int number_of_entries() { return start_indexes_[kGroupCount]; }
5796 int start_indexes_[kGroupCount + 1];
5799 bool Contains(DependencyGroup group, WeakCell* code_cell);
5801 static Handle<DependentCode> InsertCompilationInfo(
5802 Handle<DependentCode> entries, DependencyGroup group,
5803 Handle<Foreign> info);
5805 static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries,
5806 DependencyGroup group,
5807 Handle<WeakCell> code_cell);
5809 void UpdateToFinishedCode(DependencyGroup group, Foreign* info,
5810 WeakCell* code_cell);
5812 void RemoveCompilationInfo(DependentCode::DependencyGroup group,
5815 void DeoptimizeDependentCodeGroup(Isolate* isolate,
5816 DependentCode::DependencyGroup group);
5818 bool MarkCodeForDeoptimization(Isolate* isolate,
5819 DependentCode::DependencyGroup group);
5821 // The following low-level accessors should only be used by this class
5822 // and the mark compact collector.
5823 inline int number_of_entries(DependencyGroup group);
5824 inline void set_number_of_entries(DependencyGroup group, int value);
5825 inline Object* object_at(int i);
5826 inline void set_object_at(int i, Object* object);
5827 inline void clear_at(int i);
5828 inline void copy(int from, int to);
5829 DECLARE_CAST(DependentCode)
5831 static DependentCode* ForObject(Handle<HeapObject> object,
5832 DependencyGroup group);
5834 static const char* DependencyGroupName(DependencyGroup group);
5835 static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
5838 static Handle<DependentCode> Insert(Handle<DependentCode> entries,
5839 DependencyGroup group,
5840 Handle<Object> object);
5841 static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries);
5842 // Make a room at the end of the given group by moving out the first
5843 // code objects of the subsequent groups.
5844 inline void ExtendGroup(DependencyGroup group);
5845 // Compact by removing cleared weak cells and return true if there was
5846 // any cleared weak cell.
5848 static int Grow(int number_of_entries) {
5849 if (number_of_entries < 5) return number_of_entries + 1;
5850 return number_of_entries * 5 / 4;
5852 static const int kCodesStartIndex = kGroupCount;
5856 // All heap objects have a Map that describes their structure.
5857 // A Map contains information about:
5858 // - Size information about the object
5859 // - How to iterate over an object (for garbage collection)
5860 class Map: public HeapObject {
5863 // Size in bytes or kVariableSizeSentinel if instances do not have
5865 inline int instance_size();
5866 inline void set_instance_size(int value);
5868 // Count of properties allocated in the object.
5869 inline int inobject_properties();
5870 inline void set_inobject_properties(int value);
5872 // Count of property fields pre-allocated in the object when first allocated.
5873 inline int pre_allocated_property_fields();
5874 inline void set_pre_allocated_property_fields(int value);
5877 inline InstanceType instance_type();
5878 inline void set_instance_type(InstanceType value);
5880 // Tells how many unused property fields are available in the
5881 // instance (only used for JSObject in fast mode).
5882 inline int unused_property_fields();
5883 inline void set_unused_property_fields(int value);
5886 inline byte bit_field();
5887 inline void set_bit_field(byte value);
5890 inline byte bit_field2();
5891 inline void set_bit_field2(byte value);
5894 inline uint32_t bit_field3();
5895 inline void set_bit_field3(uint32_t bits);
5897 class EnumLengthBits: public BitField<int,
5898 0, kDescriptorIndexBitCount> {}; // NOLINT
5899 class NumberOfOwnDescriptorsBits: public BitField<int,
5900 kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT
5901 STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
5902 class DictionaryMap : public BitField<bool, 20, 1> {};
5903 class OwnsDescriptors : public BitField<bool, 21, 1> {};
5904 class HasInstanceCallHandler : public BitField<bool, 22, 1> {};
5905 class Deprecated : public BitField<bool, 23, 1> {};
5906 class IsUnstable : public BitField<bool, 24, 1> {};
5907 class IsMigrationTarget : public BitField<bool, 25, 1> {};
5908 // Bits 26 and 27 are free.
5910 // Keep this bit field at the very end for better code in
5911 // Builtins::kJSConstructStubGeneric stub.
5912 // This counter is used for in-object slack tracking and for map aging.
5913 // The in-object slack tracking is considered enabled when the counter is
5914 // in the range [kSlackTrackingCounterStart, kSlackTrackingCounterEnd].
5915 class Counter : public BitField<int, 28, 4> {};
5916 static const int kSlackTrackingCounterStart = 14;
5917 static const int kSlackTrackingCounterEnd = 8;
5918 static const int kRetainingCounterStart = kSlackTrackingCounterEnd - 1;
5919 static const int kRetainingCounterEnd = 0;
5921 // Tells whether the object in the prototype property will be used
5922 // for instances created from this function. If the prototype
5923 // property is set to a value that is not a JSObject, the prototype
5924 // property will not be used to create instances of the function.
5925 // See ECMA-262, 13.2.2.
5926 inline void set_non_instance_prototype(bool value);
5927 inline bool has_non_instance_prototype();
5929 // Tells whether function has special prototype property. If not, prototype
5930 // property will not be created when accessed (will return undefined),
5931 // and construction from this function will not be allowed.
5932 inline void set_function_with_prototype(bool value);
5933 inline bool function_with_prototype();
5935 // Tells whether the instance with this map should be ignored by the
5936 // Object.getPrototypeOf() function and the __proto__ accessor.
5937 inline void set_is_hidden_prototype() {
5938 set_bit_field(bit_field() | (1 << kIsHiddenPrototype));
5941 inline bool is_hidden_prototype() {
5942 return ((1 << kIsHiddenPrototype) & bit_field()) != 0;
5945 // Records and queries whether the instance has a named interceptor.
5946 inline void set_has_named_interceptor() {
5947 set_bit_field(bit_field() | (1 << kHasNamedInterceptor));
5950 inline bool has_named_interceptor() {
5951 return ((1 << kHasNamedInterceptor) & bit_field()) != 0;
5954 // Records and queries whether the instance has an indexed interceptor.
5955 inline void set_has_indexed_interceptor() {
5956 set_bit_field(bit_field() | (1 << kHasIndexedInterceptor));
5959 inline bool has_indexed_interceptor() {
5960 return ((1 << kHasIndexedInterceptor) & bit_field()) != 0;
5963 // Tells whether the instance is undetectable.
5964 // An undetectable object is a special class of JSObject: 'typeof' operator
5965 // returns undefined, ToBoolean returns false. Otherwise it behaves like
5966 // a normal JS object. It is useful for implementing undetectable
5967 // document.all in Firefox & Safari.
5968 // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
5969 inline void set_is_undetectable() {
5970 set_bit_field(bit_field() | (1 << kIsUndetectable));
5973 inline bool is_undetectable() {
5974 return ((1 << kIsUndetectable) & bit_field()) != 0;
5977 // Tells whether the instance has a call-as-function handler.
5978 inline void set_is_observed() {
5979 set_bit_field(bit_field() | (1 << kIsObserved));
5982 inline bool is_observed() {
5983 return ((1 << kIsObserved) & bit_field()) != 0;
5986 inline void set_is_extensible(bool value);
5987 inline bool is_extensible();
5988 inline void set_is_prototype_map(bool value);
5989 inline bool is_prototype_map();
5991 inline void set_elements_kind(ElementsKind elements_kind) {
5992 DCHECK(static_cast<int>(elements_kind) < kElementsKindCount);
5993 DCHECK(kElementsKindCount <= (1 << Map::ElementsKindBits::kSize));
5994 set_bit_field2(Map::ElementsKindBits::update(bit_field2(), elements_kind));
5995 DCHECK(this->elements_kind() == elements_kind);
5998 inline ElementsKind elements_kind() {
5999 return Map::ElementsKindBits::decode(bit_field2());
6002 // Tells whether the instance has fast elements that are only Smis.
6003 inline bool has_fast_smi_elements() {
6004 return IsFastSmiElementsKind(elements_kind());
6007 // Tells whether the instance has fast elements.
6008 inline bool has_fast_object_elements() {
6009 return IsFastObjectElementsKind(elements_kind());
6012 inline bool has_fast_smi_or_object_elements() {
6013 return IsFastSmiOrObjectElementsKind(elements_kind());
6016 inline bool has_fast_double_elements() {
6017 return IsFastDoubleElementsKind(elements_kind());
6020 inline bool has_fast_elements() {
6021 return IsFastElementsKind(elements_kind());
6024 inline bool has_sloppy_arguments_elements() {
6025 return elements_kind() == SLOPPY_ARGUMENTS_ELEMENTS;
6028 inline bool has_external_array_elements() {
6029 return IsExternalArrayElementsKind(elements_kind());
6032 inline bool has_fixed_typed_array_elements() {
6033 return IsFixedTypedArrayElementsKind(elements_kind());
6036 inline bool has_dictionary_elements() {
6037 return IsDictionaryElementsKind(elements_kind());
6040 inline bool has_slow_elements_kind() {
6041 return elements_kind() == DICTIONARY_ELEMENTS
6042 || elements_kind() == SLOPPY_ARGUMENTS_ELEMENTS;
6045 static bool IsValidElementsTransition(ElementsKind from_kind,
6046 ElementsKind to_kind);
6048 // Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
6049 // map with DICTIONARY_ELEMENTS was found in the prototype chain.
6050 bool DictionaryElementsInPrototypeChainOnly();
6052 inline Map* ElementsTransitionMap();
6054 inline FixedArrayBase* GetInitialElements();
6056 // [raw_transitions]: Provides access to the transitions storage field.
6057 // Don't call set_raw_transitions() directly to overwrite transitions, use
6058 // the TransitionArray::ReplaceTransitions() wrapper instead!
6059 DECL_ACCESSORS(raw_transitions, Object)
6062 Map* FindFieldOwner(int descriptor);
6064 inline int GetInObjectPropertyOffset(int index);
6066 int NumberOfFields();
6068 // TODO(ishell): candidate with JSObject::MigrateToMap().
6069 bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
6070 int target_inobject, int target_unused,
6071 int* old_number_of_fields);
6072 // TODO(ishell): moveit!
6073 static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map);
6074 MUST_USE_RESULT static Handle<HeapType> GeneralizeFieldType(
6075 Handle<HeapType> type1,
6076 Handle<HeapType> type2,
6078 static void GeneralizeFieldType(Handle<Map> map, int modify_index,
6079 Representation new_representation,
6080 Handle<HeapType> new_field_type);
6081 static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
6082 PropertyKind new_kind,
6083 PropertyAttributes new_attributes,
6084 Representation new_representation,
6085 Handle<HeapType> new_field_type,
6086 StoreMode store_mode);
6087 static Handle<Map> CopyGeneralizeAllRepresentations(
6088 Handle<Map> map, int modify_index, StoreMode store_mode,
6089 PropertyKind kind, PropertyAttributes attributes, const char* reason);
6091 static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
6092 int descriptor_number,
6093 Handle<Object> value);
6095 static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
6096 const char* reason);
6098 // Returns the constructor name (the name (possibly, inferred name) of the
6099 // function that was used to instantiate the object).
6100 String* constructor_name();
6102 // Tells whether the map is used for JSObjects in dictionary mode (ie
6103 // normalized objects, ie objects for which HasFastProperties returns false).
6104 // A map can never be used for both dictionary mode and fast mode JSObjects.
6105 // False by default and for HeapObjects that are not JSObjects.
6106 inline void set_dictionary_map(bool value);
6107 inline bool is_dictionary_map();
6109 // Tells whether the instance needs security checks when accessing its
6111 inline void set_is_access_check_needed(bool access_check_needed);
6112 inline bool is_access_check_needed();
6114 // Returns true if map has a non-empty stub code cache.
6115 inline bool has_code_cache();
6117 // [prototype]: implicit prototype object.
6118 DECL_ACCESSORS(prototype, Object)
6119 // TODO(jkummerow): make set_prototype private.
6120 void SetPrototype(Handle<Object> prototype,
6121 PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
6122 bool ShouldRegisterAsPrototypeUser(Handle<JSObject> prototype);
6123 bool CanUseOptimizationsBasedOnPrototypeRegistry();
6125 // [constructor]: points back to the function responsible for this map.
6126 // The field overlaps with the back pointer. All maps in a transition tree
6127 // have the same constructor, so maps with back pointers can walk the
6128 // back pointer chain until they find the map holding their constructor.
6129 DECL_ACCESSORS(constructor_or_backpointer, Object)
6130 inline Object* GetConstructor() const;
6131 inline void SetConstructor(Object* constructor,
6132 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
6133 // [back pointer]: points back to the parent map from which a transition
6134 // leads to this map. The field overlaps with the constructor (see above).
6135 inline Object* GetBackPointer();
6136 inline void SetBackPointer(Object* value,
6137 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
6139 // [instance descriptors]: describes the object.
6140 DECL_ACCESSORS(instance_descriptors, DescriptorArray)
6142 // [layout descriptor]: describes the object layout.
6143 DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
6144 // |layout descriptor| accessor which can be used from GC.
6145 inline LayoutDescriptor* layout_descriptor_gc_safe();
6146 inline bool HasFastPointerLayout() const;
6148 // |layout descriptor| accessor that is safe to call even when
6149 // FLAG_unbox_double_fields is disabled (in this case Map does not contain
6150 // |layout_descriptor| field at all).
6151 inline LayoutDescriptor* GetLayoutDescriptor();
6153 inline void UpdateDescriptors(DescriptorArray* descriptors,
6154 LayoutDescriptor* layout_descriptor);
6155 inline void InitializeDescriptors(DescriptorArray* descriptors,
6156 LayoutDescriptor* layout_descriptor);
6158 // [stub cache]: contains stubs compiled for this map.
6159 DECL_ACCESSORS(code_cache, Object)
6161 // [dependent code]: list of optimized codes that weakly embed this map.
6162 DECL_ACCESSORS(dependent_code, DependentCode)
6164 // [weak cell cache]: cache that stores a weak cell pointing to this map.
6165 DECL_ACCESSORS(weak_cell_cache, Object)
6167 inline PropertyDetails GetLastDescriptorDetails();
6170 int number_of_own_descriptors = NumberOfOwnDescriptors();
6171 DCHECK(number_of_own_descriptors > 0);
6172 return number_of_own_descriptors - 1;
6175 int NumberOfOwnDescriptors() {
6176 return NumberOfOwnDescriptorsBits::decode(bit_field3());
6179 void SetNumberOfOwnDescriptors(int number) {
6180 DCHECK(number <= instance_descriptors()->number_of_descriptors());
6181 set_bit_field3(NumberOfOwnDescriptorsBits::update(bit_field3(), number));
6184 inline Cell* RetrieveDescriptorsPointer();
6187 return EnumLengthBits::decode(bit_field3());
6190 void SetEnumLength(int length) {
6191 if (length != kInvalidEnumCacheSentinel) {
6192 DCHECK(length >= 0);
6193 DCHECK(length == 0 || instance_descriptors()->HasEnumCache());
6194 DCHECK(length <= NumberOfOwnDescriptors());
6196 set_bit_field3(EnumLengthBits::update(bit_field3(), length));
6199 inline bool owns_descriptors();
6200 inline void set_owns_descriptors(bool owns_descriptors);
6201 inline bool has_instance_call_handler();
6202 inline void set_has_instance_call_handler();
6203 inline void mark_unstable();
6204 inline bool is_stable();
6205 inline void set_migration_target(bool value);
6206 inline bool is_migration_target();
6207 inline void set_counter(int value);
6208 inline int counter();
6209 inline void deprecate();
6210 inline bool is_deprecated();
6211 inline bool CanBeDeprecated();
6212 // Returns a non-deprecated version of the input. If the input was not
6213 // deprecated, it is directly returned. Otherwise, the non-deprecated version
6214 // is found by re-transitioning from the root of the transition tree using the
6215 // descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
6217 static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
6219 // Returns a non-deprecated version of the input. This method may deprecate
6220 // existing maps along the way if encodings conflict. Not for use while
6221 // gathering type feedback. Use TryUpdate in those cases instead.
6222 static Handle<Map> Update(Handle<Map> map);
6224 static Handle<Map> CopyDropDescriptors(Handle<Map> map);
6225 static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
6226 Descriptor* descriptor,
6227 TransitionFlag flag);
6229 MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
6232 Handle<HeapType> type,
6233 PropertyAttributes attributes,
6234 Representation representation,
6235 TransitionFlag flag);
6237 MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
6240 Handle<Object> constant,
6241 PropertyAttributes attributes,
6242 TransitionFlag flag);
6244 // Returns a new map with all transitions dropped from the given map and
6245 // the ElementsKind set.
6246 static Handle<Map> TransitionElementsTo(Handle<Map> map,
6247 ElementsKind to_kind);
6249 static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
6251 static Handle<Map> CopyAsElementsKind(Handle<Map> map,
6253 TransitionFlag flag);
6255 static Handle<Map> CopyForObserved(Handle<Map> map);
6257 static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
6258 PropertyAttributes attrs_to_add,
6259 Handle<Symbol> transition_marker,
6260 const char* reason);
6261 // Maximal number of fast properties. Used to restrict the number of map
6262 // transitions to avoid an explosion in the number of maps for objects used as
6264 inline bool TooManyFastProperties(StoreFromKeyed store_mode);
6265 static Handle<Map> TransitionToDataProperty(Handle<Map> map,
6267 Handle<Object> value,
6268 PropertyAttributes attributes,
6269 StoreFromKeyed store_mode);
6270 static Handle<Map> TransitionToAccessorProperty(
6271 Handle<Map> map, Handle<Name> name, AccessorComponent component,
6272 Handle<Object> accessor, PropertyAttributes attributes);
6273 static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
6276 PropertyAttributes attributes);
6278 inline void AppendDescriptor(Descriptor* desc);
6280 // Returns a copy of the map, prepared for inserting into the transition
6281 // tree (if the |map| owns descriptors then the new one will share
6282 // descriptors with |map|).
6283 static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
6285 // Returns a copy of the map, with all transitions dropped from the
6286 // instance descriptors.
6287 static Handle<Map> Copy(Handle<Map> map, const char* reason);
6288 static Handle<Map> Create(Isolate* isolate, int inobject_properties);
6290 // Returns the next free property index (only valid for FAST MODE).
6291 int NextFreePropertyIndex();
6293 // Returns the number of properties described in instance_descriptors
6294 // filtering out properties with the specified attributes.
6295 int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
6296 PropertyAttributes filter = NONE);
6298 // Returns the number of slots allocated for the initial properties
6299 // backing storage for instances of this map.
6300 int InitialPropertiesLength() {
6301 return pre_allocated_property_fields() + unused_property_fields() -
6302 inobject_properties();
6307 // Code cache operations.
6309 // Clears the code cache.
6310 inline void ClearCodeCache(Heap* heap);
6312 // Update code cache.
6313 static void UpdateCodeCache(Handle<Map> map,
6317 // Extend the descriptor array of the map with the list of descriptors.
6318 // In case of duplicates, the latest descriptor is used.
6319 static void AppendCallbackDescriptors(Handle<Map> map,
6320 Handle<Object> descriptors);
6322 static inline int SlackForArraySize(int old_size, int size_limit);
6324 static void EnsureDescriptorSlack(Handle<Map> map, int slack);
6326 // Returns the found code or undefined if absent.
6327 Object* FindInCodeCache(Name* name, Code::Flags flags);
6329 // Returns the non-negative index of the code object if it is in the
6330 // cache and -1 otherwise.
6331 int IndexInCodeCache(Object* name, Code* code);
6333 // Removes a code object from the code cache at the given index.
6334 void RemoveFromCodeCache(Name* name, Code* code, int index);
6336 // Computes a hash value for this map, to be used in HashTables and such.
6339 // Returns the map that this map transitions to if its elements_kind
6340 // is changed to |elements_kind|, or NULL if no such map is cached yet.
6341 // |safe_to_add_transitions| is set to false if adding transitions is not
6343 Map* LookupElementsTransitionMap(ElementsKind elements_kind);
6345 // Returns the transitioned map for this map with the most generic
6346 // elements_kind that's found in |candidates|, or null handle if no match is
6348 Handle<Map> FindTransitionedMap(MapHandleList* candidates);
6350 bool CanTransition() {
6351 // Only JSObject and subtypes have map transitions and back pointers.
6352 STATIC_ASSERT(LAST_TYPE == LAST_JS_OBJECT_TYPE);
6353 return instance_type() >= FIRST_JS_OBJECT_TYPE;
6356 bool IsJSObjectMap() {
6357 return instance_type() >= FIRST_JS_OBJECT_TYPE;
6359 bool IsStringMap() { return instance_type() < FIRST_NONSTRING_TYPE; }
6360 bool IsJSProxyMap() {
6361 InstanceType type = instance_type();
6362 return FIRST_JS_PROXY_TYPE <= type && type <= LAST_JS_PROXY_TYPE;
6364 bool IsJSGlobalProxyMap() {
6365 return instance_type() == JS_GLOBAL_PROXY_TYPE;
6367 bool IsJSGlobalObjectMap() {
6368 return instance_type() == JS_GLOBAL_OBJECT_TYPE;
6370 bool IsGlobalObjectMap() {
6371 const InstanceType type = instance_type();
6372 return type == JS_GLOBAL_OBJECT_TYPE || type == JS_BUILTINS_OBJECT_TYPE;
6375 inline bool CanOmitMapChecks();
6377 static void AddDependentCompilationInfo(Handle<Map> map,
6378 DependentCode::DependencyGroup group,
6379 CompilationInfo* info);
6381 static void AddDependentCode(Handle<Map> map,
6382 DependentCode::DependencyGroup group,
6385 bool IsMapInArrayPrototypeChain();
6387 static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
6389 // Dispatched behavior.
6390 DECLARE_PRINTER(Map)
6391 DECLARE_VERIFIER(Map)
6394 void DictionaryMapVerify();
6395 void VerifyOmittedMapChecks();
6398 inline int visitor_id();
6399 inline void set_visitor_id(int visitor_id);
6401 static Handle<Map> TransitionToPrototype(Handle<Map> map,
6402 Handle<Object> prototype,
6403 PrototypeOptimizationMode mode);
6405 static const int kMaxPreAllocatedPropertyFields = 255;
6407 // Layout description.
6408 static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
6409 static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
6410 static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
6411 static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
6412 static const int kConstructorOrBackPointerOffset =
6413 kPrototypeOffset + kPointerSize;
6414 // When there is only one transition, it is stored directly in this field;
6415 // otherwise a transition array is used.
6416 // For prototype maps, this slot is used to store a pointer to the prototype
6417 // object using this map.
6418 static const int kTransitionsOffset =
6419 kConstructorOrBackPointerOffset + kPointerSize;
6420 static const int kDescriptorsOffset = kTransitionsOffset + kPointerSize;
6421 #if V8_DOUBLE_FIELDS_UNBOXING
6422 static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize;
6423 static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize;
6425 static const int kLayoutDecriptorOffset = 1; // Must not be ever accessed.
6426 static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
6428 static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
6429 static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
6430 static const int kSize = kWeakCellCacheOffset + kPointerSize;
6432 // Layout of pointer fields. Heap iteration code relies on them
6433 // being continuously allocated.
6434 static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
6435 static const int kPointerFieldsEndOffset = kSize;
6437 // Byte offsets within kInstanceSizesOffset.
6438 static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
6439 static const int kInObjectPropertiesByte = 1;
6440 static const int kInObjectPropertiesOffset =
6441 kInstanceSizesOffset + kInObjectPropertiesByte;
6442 static const int kPreAllocatedPropertyFieldsByte = 2;
6443 static const int kPreAllocatedPropertyFieldsOffset =
6444 kInstanceSizesOffset + kPreAllocatedPropertyFieldsByte;
6445 static const int kVisitorIdByte = 3;
6446 static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
6448 // Byte offsets within kInstanceAttributesOffset attributes.
6449 #if V8_TARGET_LITTLE_ENDIAN
6450 // Order instance type and bit field together such that they can be loaded
6451 // together as a 16-bit word with instance type in the lower 8 bits regardless
6452 // of endianess. Also provide endian-independent offset to that 16-bit word.
6453 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
6454 static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
6456 static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
6457 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
6459 static const int kInstanceTypeAndBitFieldOffset =
6460 kInstanceAttributesOffset + 0;
6461 static const int kBitField2Offset = kInstanceAttributesOffset + 2;
6462 static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
6464 STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
6465 Internals::kMapInstanceTypeAndBitFieldOffset);
6467 // Bit positions for bit field.
6468 static const int kHasNonInstancePrototype = 0;
6469 static const int kIsHiddenPrototype = 1;
6470 static const int kHasNamedInterceptor = 2;
6471 static const int kHasIndexedInterceptor = 3;
6472 static const int kIsUndetectable = 4;
6473 static const int kIsObserved = 5;
6474 static const int kIsAccessCheckNeeded = 6;
6475 class FunctionWithPrototype: public BitField<bool, 7, 1> {};
6477 // Bit positions for bit field 2
6478 static const int kIsExtensible = 0;
6479 static const int kStringWrapperSafeForDefaultValueOf = 1;
6480 class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
6481 class ElementsKindBits: public BitField<ElementsKind, 3, 5> {};
6483 // Derived values from bit field 2
6484 static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
6485 (FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1;
6486 static const int8_t kMaximumBitField2FastSmiElementValue =
6487 static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
6488 Map::ElementsKindBits::kShift) - 1;
6489 static const int8_t kMaximumBitField2FastHoleyElementValue =
6490 static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
6491 Map::ElementsKindBits::kShift) - 1;
6492 static const int8_t kMaximumBitField2FastHoleySmiElementValue =
6493 static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
6494 Map::ElementsKindBits::kShift) - 1;
6496 typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
6497 kPointerFieldsEndOffset,
6498 kSize> BodyDescriptor;
6500 // Compares this map to another to see if they describe equivalent objects.
6501 // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
6502 // it had exactly zero inobject properties.
6503 // The "shared" flags of both this map and |other| are ignored.
6504 bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
6506 // Returns true if given field is unboxed double.
6507 inline bool IsUnboxedDoubleField(FieldIndex index);
6510 static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
6511 static void TraceAllTransitions(Map* map);
6514 static inline Handle<Map> CopyInstallDescriptorsForTesting(
6515 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
6516 Handle<LayoutDescriptor> layout_descriptor);
6519 static void ConnectElementsTransition(Handle<Map> parent, Handle<Map> child);
6520 static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
6521 Handle<Name> name, SimpleTransitionFlag flag);
6523 bool EquivalentToForTransition(Map* other);
6524 static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
6525 static Handle<Map> ShareDescriptor(Handle<Map> map,
6526 Handle<DescriptorArray> descriptors,
6527 Descriptor* descriptor);
6528 static Handle<Map> CopyInstallDescriptors(
6529 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
6530 Handle<LayoutDescriptor> layout_descriptor);
6531 static Handle<Map> CopyAddDescriptor(Handle<Map> map,
6532 Descriptor* descriptor,
6533 TransitionFlag flag);
6534 static Handle<Map> CopyReplaceDescriptors(
6535 Handle<Map> map, Handle<DescriptorArray> descriptors,
6536 Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
6537 MaybeHandle<Name> maybe_name, const char* reason,
6538 SimpleTransitionFlag simple_flag);
6540 static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
6541 Handle<DescriptorArray> descriptors,
6542 Descriptor* descriptor,
6544 TransitionFlag flag);
6545 static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
6546 Handle<Map> map, int descriptor, PropertyKind kind,
6547 PropertyAttributes attributes, const char** reason);
6549 static Handle<Map> CopyNormalized(Handle<Map> map,
6550 PropertyNormalizationMode mode);
6552 // Fires when the layout of an object with a leaf map changes.
6553 // This includes adding transitions to the leaf map or changing
6554 // the descriptor array.
6555 inline void NotifyLeafMapLayoutChange();
6557 static Handle<Map> TransitionElementsToSlow(Handle<Map> object,
6558 ElementsKind to_kind);
6560 void DeprecateTransitionTree();
6561 bool DeprecateTarget(PropertyKind kind, Name* key,
6562 PropertyAttributes attributes,
6563 DescriptorArray* new_descriptors,
6564 LayoutDescriptor* new_layout_descriptor);
6566 Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
6568 // Update field type of the given descriptor to new representation and new
6569 // type. The type must be prepared for storing in descriptor array:
6570 // it must be either a simple type or a map wrapped in a weak cell.
6571 void UpdateFieldType(int descriptor_number, Handle<Name> name,
6572 Representation new_representation,
6573 Handle<Object> new_wrapped_type);
6575 void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
6576 PropertyAttributes attributes);
6577 void PrintGeneralization(FILE* file,
6582 bool constant_to_field,
6583 Representation old_representation,
6584 Representation new_representation,
6585 HeapType* old_field_type,
6586 HeapType* new_field_type);
6588 static const int kFastPropertiesSoftLimit = 12;
6589 static const int kMaxFastProperties = 128;
6591 DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
6595 // An abstract superclass, a marker class really, for simple structure classes.
6596 // It doesn't carry much functionality but allows struct classes to be
6597 // identified in the type system.
6598 class Struct: public HeapObject {
6600 inline void InitializeBody(int object_size);
6601 DECLARE_CAST(Struct)
6605 // A simple one-element struct, useful where smis need to be boxed.
6606 class Box : public Struct {
6608 // [value]: the boxed contents.
6609 DECL_ACCESSORS(value, Object)
6613 // Dispatched behavior.
6614 DECLARE_PRINTER(Box)
6615 DECLARE_VERIFIER(Box)
6617 static const int kValueOffset = HeapObject::kHeaderSize;
6618 static const int kSize = kValueOffset + kPointerSize;
6621 DISALLOW_IMPLICIT_CONSTRUCTORS(Box);
6625 // Script describes a script which has been added to the VM.
6626 class Script: public Struct {
6635 // Script compilation types.
6636 enum CompilationType {
6637 COMPILATION_TYPE_HOST = 0,
6638 COMPILATION_TYPE_EVAL = 1
6641 // Script compilation state.
6642 enum CompilationState {
6643 COMPILATION_STATE_INITIAL = 0,
6644 COMPILATION_STATE_COMPILED = 1
6647 // [source]: the script source.
6648 DECL_ACCESSORS(source, Object)
6650 // [name]: the script name.
6651 DECL_ACCESSORS(name, Object)
6653 // [id]: the script id.
6654 DECL_ACCESSORS(id, Smi)
6656 // [line_offset]: script line offset in resource from where it was extracted.
6657 DECL_ACCESSORS(line_offset, Smi)
6659 // [column_offset]: script column offset in resource from where it was
6661 DECL_ACCESSORS(column_offset, Smi)
6663 // [context_data]: context data for the context this script was compiled in.
6664 DECL_ACCESSORS(context_data, Object)
6666 // [wrapper]: the wrapper cache. This is either undefined or a WeakCell.
6667 DECL_ACCESSORS(wrapper, HeapObject)
6669 // [type]: the script type.
6670 DECL_ACCESSORS(type, Smi)
6672 // [line_ends]: FixedArray of line ends positions.
6673 DECL_ACCESSORS(line_ends, Object)
6675 // [eval_from_shared]: for eval scripts the shared funcion info for the
6676 // function from which eval was called.
6677 DECL_ACCESSORS(eval_from_shared, Object)
6679 // [eval_from_instructions_offset]: the instruction offset in the code for the
6680 // function from which eval was called where eval was called.
6681 DECL_ACCESSORS(eval_from_instructions_offset, Smi)
6683 // [flags]: Holds an exciting bitfield.
6684 DECL_ACCESSORS(flags, Smi)
6686 // [source_url]: sourceURL from magic comment
6687 DECL_ACCESSORS(source_url, Object)
6689 // [source_url]: sourceMappingURL magic comment
6690 DECL_ACCESSORS(source_mapping_url, Object)
6692 // [compilation_type]: how the the script was compiled. Encoded in the
6694 inline CompilationType compilation_type();
6695 inline void set_compilation_type(CompilationType type);
6697 // [compilation_state]: determines whether the script has already been
6698 // compiled. Encoded in the 'flags' field.
6699 inline CompilationState compilation_state();
6700 inline void set_compilation_state(CompilationState state);
6702 // [is_embedder_debug_script]: An opaque boolean set by the embedder via
6703 // ScriptOrigin, and used by the embedder to make decisions about the
6704 // script's origin. V8 just passes this through. Encoded in
6705 // the 'flags' field.
6706 DECL_BOOLEAN_ACCESSORS(is_embedder_debug_script)
6708 // [is_shared_cross_origin]: An opaque boolean set by the embedder via
6709 // ScriptOrigin, and used by the embedder to make decisions about the
6710 // script's level of privilege. V8 just passes this through. Encoded in
6711 // the 'flags' field.
6712 DECL_BOOLEAN_ACCESSORS(is_shared_cross_origin)
6714 DECLARE_CAST(Script)
6716 // If script source is an external string, check that the underlying
6717 // resource is accessible. Otherwise, always return true.
6718 inline bool HasValidSource();
6720 // Convert code position into column number.
6721 static int GetColumnNumber(Handle<Script> script, int code_pos);
6723 // Convert code position into (zero-based) line number.
6724 // The non-handlified version does not allocate, but may be much slower.
6725 static int GetLineNumber(Handle<Script> script, int code_pos);
6726 int GetLineNumber(int code_pos);
6728 static Handle<Object> GetNameOrSourceURL(Handle<Script> script);
6730 // Init line_ends array with code positions of line ends inside script source.
6731 static void InitLineEnds(Handle<Script> script);
6733 // Get the JS object wrapping the given script; create it if none exists.
6734 static Handle<JSObject> GetWrapper(Handle<Script> script);
6736 // Dispatched behavior.
6737 DECLARE_PRINTER(Script)
6738 DECLARE_VERIFIER(Script)
6740 static const int kSourceOffset = HeapObject::kHeaderSize;
6741 static const int kNameOffset = kSourceOffset + kPointerSize;
6742 static const int kLineOffsetOffset = kNameOffset + kPointerSize;
6743 static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
6744 static const int kContextOffset = kColumnOffsetOffset + kPointerSize;
6745 static const int kWrapperOffset = kContextOffset + kPointerSize;
6746 static const int kTypeOffset = kWrapperOffset + kPointerSize;
6747 static const int kLineEndsOffset = kTypeOffset + kPointerSize;
6748 static const int kIdOffset = kLineEndsOffset + kPointerSize;
6749 static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
6750 static const int kEvalFrominstructionsOffsetOffset =
6751 kEvalFromSharedOffset + kPointerSize;
6752 static const int kFlagsOffset =
6753 kEvalFrominstructionsOffsetOffset + kPointerSize;
6754 static const int kSourceUrlOffset = kFlagsOffset + kPointerSize;
6755 static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
6756 static const int kSize = kSourceMappingUrlOffset + kPointerSize;
6759 int GetLineNumberWithArray(int code_pos);
6761 // Bit positions in the flags field.
6762 static const int kCompilationTypeBit = 0;
6763 static const int kCompilationStateBit = 1;
6764 static const int kIsEmbedderDebugScriptBit = 2;
6765 static const int kIsSharedCrossOriginBit = 3;
6767 DISALLOW_IMPLICIT_CONSTRUCTORS(Script);
6771 // List of builtin functions we want to identify to improve code
6774 // Each entry has a name of a global object property holding an object
6775 // optionally followed by ".prototype", a name of a builtin function
6776 // on the object (the one the id is set for), and a label.
6778 // Installation of ids for the selected builtin functions is handled
6779 // by the bootstrapper.
6780 #define FUNCTIONS_WITH_ID_LIST(V) \
6781 V(Array.prototype, indexOf, ArrayIndexOf) \
6782 V(Array.prototype, lastIndexOf, ArrayLastIndexOf) \
6783 V(Array.prototype, push, ArrayPush) \
6784 V(Array.prototype, pop, ArrayPop) \
6785 V(Array.prototype, shift, ArrayShift) \
6786 V(Function.prototype, apply, FunctionApply) \
6787 V(Function.prototype, call, FunctionCall) \
6788 V(String.prototype, charCodeAt, StringCharCodeAt) \
6789 V(String.prototype, charAt, StringCharAt) \
6790 V(String, fromCharCode, StringFromCharCode) \
6791 V(Math, random, MathRandom) \
6792 V(Math, floor, MathFloor) \
6793 V(Math, round, MathRound) \
6794 V(Math, ceil, MathCeil) \
6795 V(Math, abs, MathAbs) \
6796 V(Math, log, MathLog) \
6797 V(Math, exp, MathExp) \
6798 V(Math, sqrt, MathSqrt) \
6799 V(Math, pow, MathPow) \
6800 V(Math, max, MathMax) \
6801 V(Math, min, MathMin) \
6802 V(Math, cos, MathCos) \
6803 V(Math, sin, MathSin) \
6804 V(Math, tan, MathTan) \
6805 V(Math, acos, MathAcos) \
6806 V(Math, asin, MathAsin) \
6807 V(Math, atan, MathAtan) \
6808 V(Math, atan2, MathAtan2) \
6809 V(Math, imul, MathImul) \
6810 V(Math, clz32, MathClz32) \
6811 V(Math, fround, MathFround)
6813 enum BuiltinFunctionId {
6815 #define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \
6817 FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
6818 #undef DECLARE_FUNCTION_ID
6819 // Fake id for a special case of Math.pow. Note, it continues the
6820 // list of math functions.
6825 // SharedFunctionInfo describes the JSFunction information that can be
6826 // shared by multiple instances of the function.
6827 class SharedFunctionInfo: public HeapObject {
6829 // [name]: Function name.
6830 DECL_ACCESSORS(name, Object)
6832 // [code]: Function code.
6833 DECL_ACCESSORS(code, Code)
6834 inline void ReplaceCode(Code* code);
6836 // [optimized_code_map]: Map from native context to optimized code
6837 // and a shared literals array or Smi(0) if none.
6838 DECL_ACCESSORS(optimized_code_map, Object)
6840 // Returns index i of the entry with the specified context and OSR entry.
6841 // At position i - 1 is the context, position i the code, and i + 1 the
6842 // literals array. Returns -1 when no matching entry is found.
6843 int SearchOptimizedCodeMap(Context* native_context, BailoutId osr_ast_id);
6845 // Installs optimized code from the code map on the given closure. The
6846 // index has to be consistent with a search result as defined above.
6847 FixedArray* GetLiteralsFromOptimizedCodeMap(int index);
6849 Code* GetCodeFromOptimizedCodeMap(int index);
6851 // Clear optimized code map.
6852 void ClearOptimizedCodeMap();
6854 // Removed a specific optimized code object from the optimized code map.
6855 void EvictFromOptimizedCodeMap(Code* optimized_code, const char* reason);
6857 // Unconditionally clear the type feedback vector (including vector ICs).
6858 void ClearTypeFeedbackInfo();
6860 // Clear the type feedback vector with a more subtle policy at GC time.
6861 void ClearTypeFeedbackInfoAtGCTime();
6863 // Trims the optimized code map after entries have been removed.
6864 void TrimOptimizedCodeMap(int shrink_by);
6866 // Initialize a SharedFunctionInfo from a parsed function literal.
6867 static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info,
6868 FunctionLiteral* lit);
6870 // Add a new entry to the optimized code map.
6871 static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
6872 Handle<Context> native_context,
6874 Handle<FixedArray> literals,
6875 BailoutId osr_ast_id);
6877 // Layout description of the optimized code map.
6878 static const int kNextMapIndex = 0;
6879 static const int kEntriesStart = 1;
6880 static const int kContextOffset = 0;
6881 static const int kCachedCodeOffset = 1;
6882 static const int kLiteralsOffset = 2;
6883 static const int kOsrAstIdOffset = 3;
6884 static const int kEntryLength = 4;
6885 static const int kInitialLength = kEntriesStart + kEntryLength;
6887 // [scope_info]: Scope info.
6888 DECL_ACCESSORS(scope_info, ScopeInfo)
6890 // [construct stub]: Code stub for constructing instances of this function.
6891 DECL_ACCESSORS(construct_stub, Code)
6893 // Returns if this function has been compiled to native code yet.
6894 inline bool is_compiled();
6896 // [length]: The function length - usually the number of declared parameters.
6897 // Use up to 2^30 parameters.
6898 inline int length() const;
6899 inline void set_length(int value);
6901 // [internal formal parameter count]: The declared number of parameters.
6902 // For subclass constructors, also includes new.target.
6903 // The size of function's frame is internal_formal_parameter_count + 1.
6904 inline int internal_formal_parameter_count() const;
6905 inline void set_internal_formal_parameter_count(int value);
6907 // Set the formal parameter count so the function code will be
6908 // called without using argument adaptor frames.
6909 inline void DontAdaptArguments();
6911 // [expected_nof_properties]: Expected number of properties for the function.
6912 inline int expected_nof_properties() const;
6913 inline void set_expected_nof_properties(int value);
6915 // [feedback_vector] - accumulates ast node feedback from full-codegen and
6916 // (increasingly) from crankshafted code where sufficient feedback isn't
6918 DECL_ACCESSORS(feedback_vector, TypeFeedbackVector)
6921 // [unique_id] - For --trace-maps purposes, an identifier that's persistent
6922 // even if the GC moves this SharedFunctionInfo.
6923 inline int unique_id() const;
6924 inline void set_unique_id(int value);
6927 // [instance class name]: class name for instances.
6928 DECL_ACCESSORS(instance_class_name, Object)
6930 // [function data]: This field holds some additional data for function.
6931 // Currently it either has FunctionTemplateInfo to make benefit the API
6932 // or Smi identifying a builtin function.
6933 // In the long run we don't want all functions to have this field but
6934 // we can fix that when we have a better model for storing hidden data
6936 DECL_ACCESSORS(function_data, Object)
6938 inline bool IsApiFunction();
6939 inline FunctionTemplateInfo* get_api_func_data();
6940 inline bool HasBuiltinFunctionId();
6941 inline BuiltinFunctionId builtin_function_id();
6943 // [script info]: Script from which the function originates.
6944 DECL_ACCESSORS(script, Object)
6946 // [num_literals]: Number of literals used by this function.
6947 inline int num_literals() const;
6948 inline void set_num_literals(int value);
6950 // [start_position_and_type]: Field used to store both the source code
6951 // position, whether or not the function is a function expression,
6952 // and whether or not the function is a toplevel function. The two
6953 // least significants bit indicates whether the function is an
6954 // expression and the rest contains the source code position.
6955 inline int start_position_and_type() const;
6956 inline void set_start_position_and_type(int value);
6958 // [debug info]: Debug information.
6959 DECL_ACCESSORS(debug_info, Object)
6961 // [inferred name]: Name inferred from variable or property
6962 // assignment of this function. Used to facilitate debugging and
6963 // profiling of JavaScript code written in OO style, where almost
6964 // all functions are anonymous but are assigned to object
6966 DECL_ACCESSORS(inferred_name, String)
6968 // The function's name if it is non-empty, otherwise the inferred name.
6969 String* DebugName();
6971 // Position of the 'function' token in the script source.
6972 inline int function_token_position() const;
6973 inline void set_function_token_position(int function_token_position);
6975 // Position of this function in the script source.
6976 inline int start_position() const;
6977 inline void set_start_position(int start_position);
6979 // End position of this function in the script source.
6980 inline int end_position() const;
6981 inline void set_end_position(int end_position);
6983 // Is this function a function expression in the source code.
6984 DECL_BOOLEAN_ACCESSORS(is_expression)
6986 // Is this function a top-level function (scripts, evals).
6987 DECL_BOOLEAN_ACCESSORS(is_toplevel)
6989 // Bit field containing various information collected by the compiler to
6990 // drive optimization.
6991 inline int compiler_hints() const;
6992 inline void set_compiler_hints(int value);
6994 inline int ast_node_count() const;
6995 inline void set_ast_node_count(int count);
6997 inline int profiler_ticks() const;
6998 inline void set_profiler_ticks(int ticks);
7000 // Inline cache age is used to infer whether the function survived a context
7001 // disposal or not. In the former case we reset the opt_count.
7002 inline int ic_age();
7003 inline void set_ic_age(int age);
7005 // Indicates if this function can be lazy compiled.
7006 // This is used to determine if we can safely flush code from a function
7007 // when doing GC if we expect that the function will no longer be used.
7008 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation)
7010 // Indicates if this function can be lazy compiled without a context.
7011 // This is used to determine if we can force compilation without reaching
7012 // the function through program execution but through other means (e.g. heap
7013 // iteration by the debugger).
7014 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context)
7016 // Indicates whether optimizations have been disabled for this
7017 // shared function info. If a function is repeatedly optimized or if
7018 // we cannot optimize the function we disable optimization to avoid
7019 // spending time attempting to optimize it again.
7020 DECL_BOOLEAN_ACCESSORS(optimization_disabled)
7022 // Indicates the language mode.
7023 inline LanguageMode language_mode();
7024 inline void set_language_mode(LanguageMode language_mode);
7026 // False if the function definitely does not allocate an arguments object.
7027 DECL_BOOLEAN_ACCESSORS(uses_arguments)
7029 // Indicates that this function uses a super property.
7030 // This is needed to set up the [[HomeObject]] on the function instance.
7031 DECL_BOOLEAN_ACCESSORS(uses_super_property)
7033 // True if the function has any duplicated parameter names.
7034 DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
7036 // Indicates whether the function is a native function.
7037 // These needs special treatment in .call and .apply since
7038 // null passed as the receiver should not be translated to the
7040 DECL_BOOLEAN_ACCESSORS(native)
7042 // Indicate that this builtin needs to be inlined in crankshaft.
7043 DECL_BOOLEAN_ACCESSORS(inline_builtin)
7045 // Indicates that the function was created by the Function function.
7046 // Though it's anonymous, toString should treat it as if it had the name
7047 // "anonymous". We don't set the name itself so that the system does not
7048 // see a binding for it.
7049 DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous)
7051 // Indicates whether the function is a bound function created using
7052 // the bind function.
7053 DECL_BOOLEAN_ACCESSORS(bound)
7055 // Indicates that the function is anonymous (the name field can be set
7056 // through the API, which does not change this flag).
7057 DECL_BOOLEAN_ACCESSORS(is_anonymous)
7059 // Is this a function or top-level/eval code.
7060 DECL_BOOLEAN_ACCESSORS(is_function)
7062 // Indicates that code for this function cannot be cached.
7063 DECL_BOOLEAN_ACCESSORS(dont_cache)
7065 // Indicates that code for this function cannot be flushed.
7066 DECL_BOOLEAN_ACCESSORS(dont_flush)
7068 // Indicates that this function is a generator.
7069 DECL_BOOLEAN_ACCESSORS(is_generator)
7071 // Indicates that this function is an arrow function.
7072 DECL_BOOLEAN_ACCESSORS(is_arrow)
7074 // Indicates that this function is a concise method.
7075 DECL_BOOLEAN_ACCESSORS(is_concise_method)
7077 // Indicates that this function is an accessor (getter or setter).
7078 DECL_BOOLEAN_ACCESSORS(is_accessor_function)
7080 // Indicates that this function is a default constructor.
7081 DECL_BOOLEAN_ACCESSORS(is_default_constructor)
7083 // Indicates that this function is an asm function.
7084 DECL_BOOLEAN_ACCESSORS(asm_function)
7086 // Indicates that the the shared function info is deserialized from cache.
7087 DECL_BOOLEAN_ACCESSORS(deserialized)
7089 inline FunctionKind kind();
7090 inline void set_kind(FunctionKind kind);
7092 // Indicates whether or not the code in the shared function support
7094 inline bool has_deoptimization_support();
7096 // Enable deoptimization support through recompiled code.
7097 void EnableDeoptimizationSupport(Code* recompiled);
7099 // Disable (further) attempted optimization of all functions sharing this
7100 // shared function info.
7101 void DisableOptimization(BailoutReason reason);
7103 inline BailoutReason disable_optimization_reason();
7105 // Lookup the bailout ID and DCHECK that it exists in the non-optimized
7106 // code, returns whether it asserted (i.e., always true if assertions are
7108 bool VerifyBailoutId(BailoutId id);
7110 // [source code]: Source code for the function.
7111 bool HasSourceCode() const;
7112 Handle<Object> GetSourceCode();
7114 // Number of times the function was optimized.
7115 inline int opt_count();
7116 inline void set_opt_count(int opt_count);
7118 // Number of times the function was deoptimized.
7119 inline void set_deopt_count(int value);
7120 inline int deopt_count();
7121 inline void increment_deopt_count();
7123 // Number of time we tried to re-enable optimization after it
7124 // was disabled due to high number of deoptimizations.
7125 inline void set_opt_reenable_tries(int value);
7126 inline int opt_reenable_tries();
7128 inline void TryReenableOptimization();
7130 // Stores deopt_count, opt_reenable_tries and ic_age as bit-fields.
7131 inline void set_counters(int value);
7132 inline int counters() const;
7134 // Stores opt_count and bailout_reason as bit-fields.
7135 inline void set_opt_count_and_bailout_reason(int value);
7136 inline int opt_count_and_bailout_reason() const;
7138 void set_disable_optimization_reason(BailoutReason reason) {
7139 set_opt_count_and_bailout_reason(
7140 DisabledOptimizationReasonBits::update(opt_count_and_bailout_reason(),
7144 // Check whether or not this function is inlineable.
7145 bool IsInlineable();
7147 // Source size of this function.
7150 // Calculate the instance size.
7151 int CalculateInstanceSize();
7153 // Calculate the number of in-object properties.
7154 int CalculateInObjectProperties();
7156 inline bool is_simple_parameter_list();
7158 // Dispatched behavior.
7159 DECLARE_PRINTER(SharedFunctionInfo)
7160 DECLARE_VERIFIER(SharedFunctionInfo)
7162 void ResetForNewContext(int new_ic_age);
7164 DECLARE_CAST(SharedFunctionInfo)
7167 static const int kDontAdaptArgumentsSentinel = -1;
7169 // Layout description.
7171 static const int kNameOffset = HeapObject::kHeaderSize;
7172 static const int kCodeOffset = kNameOffset + kPointerSize;
7173 static const int kOptimizedCodeMapOffset = kCodeOffset + kPointerSize;
7174 static const int kScopeInfoOffset = kOptimizedCodeMapOffset + kPointerSize;
7175 static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize;
7176 static const int kInstanceClassNameOffset =
7177 kConstructStubOffset + kPointerSize;
7178 static const int kFunctionDataOffset =
7179 kInstanceClassNameOffset + kPointerSize;
7180 static const int kScriptOffset = kFunctionDataOffset + kPointerSize;
7181 static const int kDebugInfoOffset = kScriptOffset + kPointerSize;
7182 static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize;
7183 static const int kFeedbackVectorOffset =
7184 kInferredNameOffset + kPointerSize;
7186 static const int kUniqueIdOffset = kFeedbackVectorOffset + kPointerSize;
7187 static const int kLastPointerFieldOffset = kUniqueIdOffset;
7189 // Just to not break the postmortrem support with conditional offsets
7190 static const int kUniqueIdOffset = kFeedbackVectorOffset;
7191 static const int kLastPointerFieldOffset = kFeedbackVectorOffset;
7194 #if V8_HOST_ARCH_32_BIT
7196 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
7197 static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize;
7198 static const int kExpectedNofPropertiesOffset =
7199 kFormalParameterCountOffset + kPointerSize;
7200 static const int kNumLiteralsOffset =
7201 kExpectedNofPropertiesOffset + kPointerSize;
7202 static const int kStartPositionAndTypeOffset =
7203 kNumLiteralsOffset + kPointerSize;
7204 static const int kEndPositionOffset =
7205 kStartPositionAndTypeOffset + kPointerSize;
7206 static const int kFunctionTokenPositionOffset =
7207 kEndPositionOffset + kPointerSize;
7208 static const int kCompilerHintsOffset =
7209 kFunctionTokenPositionOffset + kPointerSize;
7210 static const int kOptCountAndBailoutReasonOffset =
7211 kCompilerHintsOffset + kPointerSize;
7212 static const int kCountersOffset =
7213 kOptCountAndBailoutReasonOffset + kPointerSize;
7214 static const int kAstNodeCountOffset =
7215 kCountersOffset + kPointerSize;
7216 static const int kProfilerTicksOffset =
7217 kAstNodeCountOffset + kPointerSize;
7220 static const int kSize = kProfilerTicksOffset + kPointerSize;
7222 // The only reason to use smi fields instead of int fields
7223 // is to allow iteration without maps decoding during
7224 // garbage collections.
7225 // To avoid wasting space on 64-bit architectures we use
7226 // the following trick: we group integer fields into pairs
7227 // The least significant integer in each pair is shifted left by 1.
7228 // By doing this we guarantee that LSB of each kPointerSize aligned
7229 // word is not set and thus this word cannot be treated as pointer
7230 // to HeapObject during old space traversal.
7231 #if V8_TARGET_LITTLE_ENDIAN
7232 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
7233 static const int kFormalParameterCountOffset =
7234 kLengthOffset + kIntSize;
7236 static const int kExpectedNofPropertiesOffset =
7237 kFormalParameterCountOffset + kIntSize;
7238 static const int kNumLiteralsOffset =
7239 kExpectedNofPropertiesOffset + kIntSize;
7241 static const int kEndPositionOffset =
7242 kNumLiteralsOffset + kIntSize;
7243 static const int kStartPositionAndTypeOffset =
7244 kEndPositionOffset + kIntSize;
7246 static const int kFunctionTokenPositionOffset =
7247 kStartPositionAndTypeOffset + kIntSize;
7248 static const int kCompilerHintsOffset =
7249 kFunctionTokenPositionOffset + kIntSize;
7251 static const int kOptCountAndBailoutReasonOffset =
7252 kCompilerHintsOffset + kIntSize;
7253 static const int kCountersOffset =
7254 kOptCountAndBailoutReasonOffset + kIntSize;
7256 static const int kAstNodeCountOffset =
7257 kCountersOffset + kIntSize;
7258 static const int kProfilerTicksOffset =
7259 kAstNodeCountOffset + kIntSize;
7262 static const int kSize = kProfilerTicksOffset + kIntSize;
7264 #elif V8_TARGET_BIG_ENDIAN
7265 static const int kFormalParameterCountOffset =
7266 kLastPointerFieldOffset + kPointerSize;
7267 static const int kLengthOffset = kFormalParameterCountOffset + kIntSize;
7269 static const int kNumLiteralsOffset = kLengthOffset + kIntSize;
7270 static const int kExpectedNofPropertiesOffset = kNumLiteralsOffset + kIntSize;
7272 static const int kStartPositionAndTypeOffset =
7273 kExpectedNofPropertiesOffset + kIntSize;
7274 static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize;
7276 static const int kCompilerHintsOffset = kEndPositionOffset + kIntSize;
7277 static const int kFunctionTokenPositionOffset =
7278 kCompilerHintsOffset + kIntSize;
7280 static const int kCountersOffset = kFunctionTokenPositionOffset + kIntSize;
7281 static const int kOptCountAndBailoutReasonOffset = kCountersOffset + kIntSize;
7283 static const int kProfilerTicksOffset =
7284 kOptCountAndBailoutReasonOffset + kIntSize;
7285 static const int kAstNodeCountOffset = kProfilerTicksOffset + kIntSize;
7288 static const int kSize = kAstNodeCountOffset + kIntSize;
7291 #error Unknown byte ordering
7292 #endif // Big endian
7296 static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
7298 typedef FixedBodyDescriptor<kNameOffset,
7299 kLastPointerFieldOffset + kPointerSize,
7300 kSize> BodyDescriptor;
7302 // Bit positions in start_position_and_type.
7303 // The source code start position is in the 30 most significant bits of
7304 // the start_position_and_type field.
7305 static const int kIsExpressionBit = 0;
7306 static const int kIsTopLevelBit = 1;
7307 static const int kStartPositionShift = 2;
7308 static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1);
7310 // Bit positions in compiler_hints.
7311 enum CompilerHints {
7312 kAllowLazyCompilation,
7313 kAllowLazyCompilationWithoutContext,
7314 kOptimizationDisabled,
7315 kStrictModeFunction,
7316 kStrongModeFunction,
7319 kHasDuplicateParameters,
7324 kNameShouldPrintAsAnonymous,
7331 kIsAccessorFunction,
7332 kIsDefaultConstructor,
7333 kIsSubclassConstructor,
7338 kCompilerHintsCount // Pseudo entry
7340 // Add hints for other modes when they're added.
7341 STATIC_ASSERT(LANGUAGE_END == 3);
7343 class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 8> {};
7345 class DeoptCountBits : public BitField<int, 0, 4> {};
7346 class OptReenableTriesBits : public BitField<int, 4, 18> {};
7347 class ICAgeBits : public BitField<int, 22, 8> {};
7349 class OptCountBits : public BitField<int, 0, 22> {};
7350 class DisabledOptimizationReasonBits : public BitField<int, 22, 8> {};
7353 #if V8_HOST_ARCH_32_BIT
7354 // On 32 bit platforms, compiler hints is a smi.
7355 static const int kCompilerHintsSmiTagSize = kSmiTagSize;
7356 static const int kCompilerHintsSize = kPointerSize;
7358 // On 64 bit platforms, compiler hints is not a smi, see comment above.
7359 static const int kCompilerHintsSmiTagSize = 0;
7360 static const int kCompilerHintsSize = kIntSize;
7363 STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <=
7364 SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte);
7367 // Constants for optimizing codegen for strict mode function and
7369 // Allows to use byte-width instructions.
7370 static const int kStrictModeBitWithinByte =
7371 (kStrictModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte;
7373 static const int kNativeBitWithinByte =
7374 (kNative + kCompilerHintsSmiTagSize) % kBitsPerByte;
7376 #if defined(V8_TARGET_LITTLE_ENDIAN)
7377 static const int kStrictModeByteOffset = kCompilerHintsOffset +
7378 (kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte;
7379 static const int kNativeByteOffset = kCompilerHintsOffset +
7380 (kNative + kCompilerHintsSmiTagSize) / kBitsPerByte;
7381 #elif defined(V8_TARGET_BIG_ENDIAN)
7382 static const int kStrictModeByteOffset = kCompilerHintsOffset +
7383 (kCompilerHintsSize - 1) -
7384 ((kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte);
7385 static const int kNativeByteOffset = kCompilerHintsOffset +
7386 (kCompilerHintsSize - 1) -
7387 ((kNative + kCompilerHintsSmiTagSize) / kBitsPerByte);
7389 #error Unknown byte ordering
7393 DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo);
7397 // Printing support.
7398 struct SourceCodeOf {
7399 explicit SourceCodeOf(SharedFunctionInfo* v, int max = -1)
7400 : value(v), max_length(max) {}
7401 const SharedFunctionInfo* value;
7406 std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v);
7409 class JSGeneratorObject: public JSObject {
7411 // [function]: The function corresponding to this generator object.
7412 DECL_ACCESSORS(function, JSFunction)
7414 // [context]: The context of the suspended computation.
7415 DECL_ACCESSORS(context, Context)
7417 // [receiver]: The receiver of the suspended computation.
7418 DECL_ACCESSORS(receiver, Object)
7420 // [continuation]: Offset into code of continuation.
7422 // A positive offset indicates a suspended generator. The special
7423 // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
7424 // cannot be resumed.
7425 inline int continuation() const;
7426 inline void set_continuation(int continuation);
7427 inline bool is_closed();
7428 inline bool is_executing();
7429 inline bool is_suspended();
7431 // [operand_stack]: Saved operand stack.
7432 DECL_ACCESSORS(operand_stack, FixedArray)
7434 DECLARE_CAST(JSGeneratorObject)
7436 // Dispatched behavior.
7437 DECLARE_PRINTER(JSGeneratorObject)
7438 DECLARE_VERIFIER(JSGeneratorObject)
7440 // Magic sentinel values for the continuation.
7441 static const int kGeneratorExecuting = -1;
7442 static const int kGeneratorClosed = 0;
7444 // Layout description.
7445 static const int kFunctionOffset = JSObject::kHeaderSize;
7446 static const int kContextOffset = kFunctionOffset + kPointerSize;
7447 static const int kReceiverOffset = kContextOffset + kPointerSize;
7448 static const int kContinuationOffset = kReceiverOffset + kPointerSize;
7449 static const int kOperandStackOffset = kContinuationOffset + kPointerSize;
7450 static const int kSize = kOperandStackOffset + kPointerSize;
7452 // Resume mode, for use by runtime functions.
7453 enum ResumeMode { NEXT, THROW };
7455 // Yielding from a generator returns an object with the following inobject
7456 // properties. See Context::iterator_result_map() for the map.
7457 static const int kResultValuePropertyIndex = 0;
7458 static const int kResultDonePropertyIndex = 1;
7459 static const int kResultPropertyCount = 2;
7461 static const int kResultValuePropertyOffset = JSObject::kHeaderSize;
7462 static const int kResultDonePropertyOffset =
7463 kResultValuePropertyOffset + kPointerSize;
7464 static const int kResultSize = kResultDonePropertyOffset + kPointerSize;
7467 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
7471 // Representation for module instance objects.
7472 class JSModule: public JSObject {
7474 // [context]: the context holding the module's locals, or undefined if none.
7475 DECL_ACCESSORS(context, Object)
7477 // [scope_info]: Scope info.
7478 DECL_ACCESSORS(scope_info, ScopeInfo)
7480 DECLARE_CAST(JSModule)
7482 // Dispatched behavior.
7483 DECLARE_PRINTER(JSModule)
7484 DECLARE_VERIFIER(JSModule)
7486 // Layout description.
7487 static const int kContextOffset = JSObject::kHeaderSize;
7488 static const int kScopeInfoOffset = kContextOffset + kPointerSize;
7489 static const int kSize = kScopeInfoOffset + kPointerSize;
7492 DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule);
7496 // JSFunction describes JavaScript functions.
7497 class JSFunction: public JSObject {
7499 // [prototype_or_initial_map]:
7500 DECL_ACCESSORS(prototype_or_initial_map, Object)
7502 // [shared]: The information about the function that
7503 // can be shared by instances.
7504 DECL_ACCESSORS(shared, SharedFunctionInfo)
7506 // [context]: The context for this function.
7507 inline Context* context();
7508 inline void set_context(Object* context);
7509 inline JSObject* global_proxy();
7511 // [code]: The generated code object for this function. Executed
7512 // when the function is invoked, e.g. foo() or new foo(). See
7513 // [[Call]] and [[Construct]] description in ECMA-262, section
7515 inline Code* code();
7516 inline void set_code(Code* code);
7517 inline void set_code_no_write_barrier(Code* code);
7518 inline void ReplaceCode(Code* code);
7520 // Tells whether this function is builtin.
7521 inline bool IsBuiltin();
7523 // Tells whether this function is defined in a native script.
7524 inline bool IsFromNativeScript();
7526 // Tells whether this function is defined in an extension script.
7527 inline bool IsFromExtensionScript();
7529 // Tells whether or not the function needs arguments adaption.
7530 inline bool NeedsArgumentsAdaption();
7532 // Tells whether or not this function has been optimized.
7533 inline bool IsOptimized();
7535 // Tells whether or not this function can be optimized.
7536 inline bool IsOptimizable();
7538 // Mark this function for lazy recompilation. The function will be
7539 // recompiled the next time it is executed.
7540 void MarkForOptimization();
7541 void AttemptConcurrentOptimization();
7543 // Tells whether or not the function is already marked for lazy
7545 inline bool IsMarkedForOptimization();
7546 inline bool IsMarkedForConcurrentOptimization();
7548 // Tells whether or not the function is on the concurrent recompilation queue.
7549 inline bool IsInOptimizationQueue();
7551 // Inobject slack tracking is the way to reclaim unused inobject space.
7553 // The instance size is initially determined by adding some slack to
7554 // expected_nof_properties (to allow for a few extra properties added
7555 // after the constructor). There is no guarantee that the extra space
7556 // will not be wasted.
7558 // Here is the algorithm to reclaim the unused inobject space:
7559 // - Detect the first constructor call for this JSFunction.
7560 // When it happens enter the "in progress" state: initialize construction
7561 // counter in the initial_map.
7562 // - While the tracking is in progress create objects filled with
7563 // one_pointer_filler_map instead of undefined_value. This way they can be
7564 // resized quickly and safely.
7565 // - Once enough objects have been created compute the 'slack'
7566 // (traverse the map transition tree starting from the
7567 // initial_map and find the lowest value of unused_property_fields).
7568 // - Traverse the transition tree again and decrease the instance size
7569 // of every map. Existing objects will resize automatically (they are
7570 // filled with one_pointer_filler_map). All further allocations will
7571 // use the adjusted instance size.
7572 // - SharedFunctionInfo's expected_nof_properties left unmodified since
7573 // allocations made using different closures could actually create different
7574 // kind of objects (see prototype inheritance pattern).
7576 // Important: inobject slack tracking is not attempted during the snapshot
7579 // True if the initial_map is set and the object constructions countdown
7580 // counter is not zero.
7581 static const int kGenerousAllocationCount =
7582 Map::kSlackTrackingCounterStart - Map::kSlackTrackingCounterEnd + 1;
7583 inline bool IsInobjectSlackTrackingInProgress();
7585 // Starts the tracking.
7586 // Initializes object constructions countdown counter in the initial map.
7587 void StartInobjectSlackTracking();
7589 // Completes the tracking.
7590 void CompleteInobjectSlackTracking();
7592 // [literals_or_bindings]: Fixed array holding either
7593 // the materialized literals or the bindings of a bound function.
7595 // If the function contains object, regexp or array literals, the
7596 // literals array prefix contains the object, regexp, and array
7597 // function to be used when creating these literals. This is
7598 // necessary so that we do not dynamically lookup the object, regexp
7599 // or array functions. Performing a dynamic lookup, we might end up
7600 // using the functions from a new context that we should not have
7603 // On bound functions, the array is a (copy-on-write) fixed-array containing
7604 // the function that was bound, bound this-value and any bound
7605 // arguments. Bound functions never contain literals.
7606 DECL_ACCESSORS(literals_or_bindings, FixedArray)
7608 inline FixedArray* literals();
7609 inline void set_literals(FixedArray* literals);
7611 inline FixedArray* function_bindings();
7612 inline void set_function_bindings(FixedArray* bindings);
7614 // The initial map for an object created by this constructor.
7615 inline Map* initial_map();
7616 static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
7617 Handle<Object> prototype);
7618 inline bool has_initial_map();
7619 static void EnsureHasInitialMap(Handle<JSFunction> function);
7621 // Get and set the prototype property on a JSFunction. If the
7622 // function has an initial map the prototype is set on the initial
7623 // map. Otherwise, the prototype is put in the initial map field
7624 // until an initial map is needed.
7625 inline bool has_prototype();
7626 inline bool has_instance_prototype();
7627 inline Object* prototype();
7628 inline Object* instance_prototype();
7629 static void SetPrototype(Handle<JSFunction> function,
7630 Handle<Object> value);
7631 static void SetInstancePrototype(Handle<JSFunction> function,
7632 Handle<Object> value);
7634 // Creates a new closure for the fucntion with the same bindings,
7635 // bound values, and prototype. An equivalent of spec operations
7636 // ``CloneMethod`` and ``CloneBoundFunction``.
7637 static Handle<JSFunction> CloneClosure(Handle<JSFunction> function);
7639 // After prototype is removed, it will not be created when accessed, and
7640 // [[Construct]] from this function will not be allowed.
7641 bool RemovePrototype();
7642 inline bool should_have_prototype();
7644 // Accessor for this function's initial map's [[class]]
7645 // property. This is primarily used by ECMA native functions. This
7646 // method sets the class_name field of this function's initial map
7647 // to a given value. It creates an initial map if this function does
7648 // not have one. Note that this method does not copy the initial map
7649 // if it has one already, but simply replaces it with the new value.
7650 // Instances created afterwards will have a map whose [[class]] is
7651 // set to 'value', but there is no guarantees on instances created
7653 void SetInstanceClassName(String* name);
7655 // Returns if this function has been compiled to native code yet.
7656 inline bool is_compiled();
7658 // Returns `false` if formal parameters include rest parameters, optional
7659 // parameters, or destructuring parameters.
7660 // TODO(caitp): make this a flag set during parsing
7661 inline bool is_simple_parameter_list();
7663 // [next_function_link]: Links functions into various lists, e.g. the list
7664 // of optimized functions hanging off the native_context. The CodeFlusher
7665 // uses this link to chain together flushing candidates. Treated weakly
7666 // by the garbage collector.
7667 DECL_ACCESSORS(next_function_link, Object)
7669 // Prints the name of the function using PrintF.
7670 void PrintName(FILE* out = stdout);
7672 DECLARE_CAST(JSFunction)
7674 // Iterates the objects, including code objects indirectly referenced
7675 // through pointers to the first instruction in the code object.
7676 void JSFunctionIterateBody(int object_size, ObjectVisitor* v);
7678 // Dispatched behavior.
7679 DECLARE_PRINTER(JSFunction)
7680 DECLARE_VERIFIER(JSFunction)
7682 // Returns the number of allocated literals.
7683 inline int NumberOfLiterals();
7685 // Used for flags such as --hydrogen-filter.
7686 bool PassesFilter(const char* raw_filter);
7688 // The function's name if it is configured, otherwise shared function info
7690 static Handle<String> GetDebugName(Handle<JSFunction> function);
7692 // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
7693 // kSize) is weak and has special handling during garbage collection.
7694 static const int kCodeEntryOffset = JSObject::kHeaderSize;
7695 static const int kPrototypeOrInitialMapOffset =
7696 kCodeEntryOffset + kPointerSize;
7697 static const int kSharedFunctionInfoOffset =
7698 kPrototypeOrInitialMapOffset + kPointerSize;
7699 static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize;
7700 static const int kLiteralsOffset = kContextOffset + kPointerSize;
7701 static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize;
7702 static const int kNextFunctionLinkOffset = kNonWeakFieldsEndOffset;
7703 static const int kSize = kNextFunctionLinkOffset + kPointerSize;
7705 // Layout of the bound-function binding array.
7706 static const int kBoundFunctionIndex = 0;
7707 static const int kBoundThisIndex = 1;
7708 static const int kBoundArgumentsStartIndex = 2;
7711 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
7715 // JSGlobalProxy's prototype must be a JSGlobalObject or null,
7716 // and the prototype is hidden. JSGlobalProxy always delegates
7717 // property accesses to its prototype if the prototype is not null.
7719 // A JSGlobalProxy can be reinitialized which will preserve its identity.
7721 // Accessing a JSGlobalProxy requires security check.
7723 class JSGlobalProxy : public JSObject {
7725 // [native_context]: the owner native context of this global proxy object.
7726 // It is null value if this object is not used by any context.
7727 DECL_ACCESSORS(native_context, Object)
7729 // [hash]: The hash code property (undefined if not initialized yet).
7730 DECL_ACCESSORS(hash, Object)
7732 DECLARE_CAST(JSGlobalProxy)
7734 inline bool IsDetachedFrom(GlobalObject* global) const;
7736 // Dispatched behavior.
7737 DECLARE_PRINTER(JSGlobalProxy)
7738 DECLARE_VERIFIER(JSGlobalProxy)
7740 // Layout description.
7741 static const int kNativeContextOffset = JSObject::kHeaderSize;
7742 static const int kHashOffset = kNativeContextOffset + kPointerSize;
7743 static const int kSize = kHashOffset + kPointerSize;
7746 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
7750 // Forward declaration.
7751 class JSBuiltinsObject;
7753 // Common super class for JavaScript global objects and the special
7754 // builtins global objects.
7755 class GlobalObject: public JSObject {
7757 // [builtins]: the object holding the runtime routines written in JS.
7758 DECL_ACCESSORS(builtins, JSBuiltinsObject)
7760 // [native context]: the natives corresponding to this global object.
7761 DECL_ACCESSORS(native_context, Context)
7763 // [global proxy]: the global proxy object of the context
7764 DECL_ACCESSORS(global_proxy, JSObject)
7766 DECLARE_CAST(GlobalObject)
7768 static void InvalidatePropertyCell(Handle<GlobalObject> object,
7770 // Ensure that the global object has a cell for the given property name.
7771 static Handle<PropertyCell> EnsurePropertyCell(Handle<GlobalObject> global,
7774 // Layout description.
7775 static const int kBuiltinsOffset = JSObject::kHeaderSize;
7776 static const int kNativeContextOffset = kBuiltinsOffset + kPointerSize;
7777 static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
7778 static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
7781 DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject);
7785 // JavaScript global object.
7786 class JSGlobalObject: public GlobalObject {
7788 DECLARE_CAST(JSGlobalObject)
7790 inline bool IsDetached();
7792 // Dispatched behavior.
7793 DECLARE_PRINTER(JSGlobalObject)
7794 DECLARE_VERIFIER(JSGlobalObject)
7796 // Layout description.
7797 static const int kSize = GlobalObject::kHeaderSize;
7800 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
7804 // Builtins global object which holds the runtime routines written in
7806 class JSBuiltinsObject: public GlobalObject {
7808 // Accessors for the runtime routines written in JavaScript.
7809 inline Object* javascript_builtin(Builtins::JavaScript id);
7810 inline void set_javascript_builtin(Builtins::JavaScript id, Object* value);
7812 DECLARE_CAST(JSBuiltinsObject)
7814 // Dispatched behavior.
7815 DECLARE_PRINTER(JSBuiltinsObject)
7816 DECLARE_VERIFIER(JSBuiltinsObject)
7818 // Layout description. The size of the builtins object includes
7819 // room for two pointers per runtime routine written in javascript
7820 // (function and code object).
7821 static const int kJSBuiltinsCount = Builtins::id_count;
7822 static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize;
7823 static const int kSize =
7824 GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize);
7826 static int OffsetOfFunctionWithId(Builtins::JavaScript id) {
7827 return kJSBuiltinsOffset + id * kPointerSize;
7831 DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject);
7835 // Representation for JS Wrapper objects, String, Number, Boolean, etc.
7836 class JSValue: public JSObject {
7838 // [value]: the object being wrapped.
7839 DECL_ACCESSORS(value, Object)
7841 DECLARE_CAST(JSValue)
7843 // Dispatched behavior.
7844 DECLARE_PRINTER(JSValue)
7845 DECLARE_VERIFIER(JSValue)
7847 // Layout description.
7848 static const int kValueOffset = JSObject::kHeaderSize;
7849 static const int kSize = kValueOffset + kPointerSize;
7852 DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
7858 // Representation for JS date objects.
7859 class JSDate: public JSObject {
7861 // If one component is NaN, all of them are, indicating a NaN time value.
7862 // [value]: the time value.
7863 DECL_ACCESSORS(value, Object)
7864 // [year]: caches year. Either undefined, smi, or NaN.
7865 DECL_ACCESSORS(year, Object)
7866 // [month]: caches month. Either undefined, smi, or NaN.
7867 DECL_ACCESSORS(month, Object)
7868 // [day]: caches day. Either undefined, smi, or NaN.
7869 DECL_ACCESSORS(day, Object)
7870 // [weekday]: caches day of week. Either undefined, smi, or NaN.
7871 DECL_ACCESSORS(weekday, Object)
7872 // [hour]: caches hours. Either undefined, smi, or NaN.
7873 DECL_ACCESSORS(hour, Object)
7874 // [min]: caches minutes. Either undefined, smi, or NaN.
7875 DECL_ACCESSORS(min, Object)
7876 // [sec]: caches seconds. Either undefined, smi, or NaN.
7877 DECL_ACCESSORS(sec, Object)
7878 // [cache stamp]: sample of the date cache stamp at the
7879 // moment when chached fields were cached.
7880 DECL_ACCESSORS(cache_stamp, Object)
7882 DECLARE_CAST(JSDate)
7884 // Returns the date field with the specified index.
7885 // See FieldIndex for the list of date fields.
7886 static Object* GetField(Object* date, Smi* index);
7888 void SetValue(Object* value, bool is_value_nan);
7891 // Dispatched behavior.
7892 DECLARE_PRINTER(JSDate)
7893 DECLARE_VERIFIER(JSDate)
7895 // The order is important. It must be kept in sync with date macros
7906 kFirstUncachedField,
7907 kMillisecond = kFirstUncachedField,
7911 kYearUTC = kFirstUTCField,
7924 // Layout description.
7925 static const int kValueOffset = JSObject::kHeaderSize;
7926 static const int kYearOffset = kValueOffset + kPointerSize;
7927 static const int kMonthOffset = kYearOffset + kPointerSize;
7928 static const int kDayOffset = kMonthOffset + kPointerSize;
7929 static const int kWeekdayOffset = kDayOffset + kPointerSize;
7930 static const int kHourOffset = kWeekdayOffset + kPointerSize;
7931 static const int kMinOffset = kHourOffset + kPointerSize;
7932 static const int kSecOffset = kMinOffset + kPointerSize;
7933 static const int kCacheStampOffset = kSecOffset + kPointerSize;
7934 static const int kSize = kCacheStampOffset + kPointerSize;
7937 inline Object* DoGetField(FieldIndex index);
7939 Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
7941 // Computes and caches the cacheable fields of the date.
7942 inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
7945 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
7949 // Representation of message objects used for error reporting through
7950 // the API. The messages are formatted in JavaScript so this object is
7951 // a real JavaScript object. The information used for formatting the
7952 // error messages are not directly accessible from JavaScript to
7953 // prevent leaking information to user code called during error
7955 class JSMessageObject: public JSObject {
7957 // [type]: the type of error message.
7958 DECL_ACCESSORS(type, String)
7960 // [arguments]: the arguments for formatting the error message.
7961 DECL_ACCESSORS(arguments, JSArray)
7963 // [script]: the script from which the error message originated.
7964 DECL_ACCESSORS(script, Object)
7966 // [stack_frames]: an array of stack frames for this error object.
7967 DECL_ACCESSORS(stack_frames, Object)
7969 // [start_position]: the start position in the script for the error message.
7970 inline int start_position() const;
7971 inline void set_start_position(int value);
7973 // [end_position]: the end position in the script for the error message.
7974 inline int end_position() const;
7975 inline void set_end_position(int value);
7977 DECLARE_CAST(JSMessageObject)
7979 // Dispatched behavior.
7980 DECLARE_PRINTER(JSMessageObject)
7981 DECLARE_VERIFIER(JSMessageObject)
7983 // Layout description.
7984 static const int kTypeOffset = JSObject::kHeaderSize;
7985 static const int kArgumentsOffset = kTypeOffset + kPointerSize;
7986 static const int kScriptOffset = kArgumentsOffset + kPointerSize;
7987 static const int kStackFramesOffset = kScriptOffset + kPointerSize;
7988 static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
7989 static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
7990 static const int kSize = kEndPositionOffset + kPointerSize;
7992 typedef FixedBodyDescriptor<HeapObject::kMapOffset,
7993 kStackFramesOffset + kPointerSize,
7994 kSize> BodyDescriptor;
7998 // Regular expressions
7999 // The regular expression holds a single reference to a FixedArray in
8000 // the kDataOffset field.
8001 // The FixedArray contains the following data:
8002 // - tag : type of regexp implementation (not compiled yet, atom or irregexp)
8003 // - reference to the original source string
8004 // - reference to the original flag string
8005 // If it is an atom regexp
8006 // - a reference to a literal string to search for
8007 // If it is an irregexp regexp:
8008 // - a reference to code for Latin1 inputs (bytecode or compiled), or a smi
8009 // used for tracking the last usage (used for code flushing).
8010 // - a reference to code for UC16 inputs (bytecode or compiled), or a smi
8011 // used for tracking the last usage (used for code flushing)..
8012 // - max number of registers used by irregexp implementations.
8013 // - number of capture registers (output values) of the regexp.
8014 class JSRegExp: public JSObject {
8017 // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet.
8018 // ATOM: A simple string to match against using an indexOf operation.
8019 // IRREGEXP: Compiled with Irregexp.
8020 // IRREGEXP_NATIVE: Compiled to native code with Irregexp.
8021 enum Type { NOT_COMPILED, ATOM, IRREGEXP };
8028 UNICODE_ESCAPES = 16
8033 explicit Flags(uint32_t value) : value_(value) { }
8034 bool is_global() { return (value_ & GLOBAL) != 0; }
8035 bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; }
8036 bool is_multiline() { return (value_ & MULTILINE) != 0; }
8037 bool is_sticky() { return (value_ & STICKY) != 0; }
8038 bool is_unicode() { return (value_ & UNICODE_ESCAPES) != 0; }
8039 uint32_t value() { return value_; }
8044 DECL_ACCESSORS(data, Object)
8046 inline Type TypeTag();
8047 inline int CaptureCount();
8048 inline Flags GetFlags();
8049 inline String* Pattern();
8050 inline Object* DataAt(int index);
8051 // Set implementation data after the object has been prepared.
8052 inline void SetDataAt(int index, Object* value);
8054 static int code_index(bool is_latin1) {
8056 return kIrregexpLatin1CodeIndex;
8058 return kIrregexpUC16CodeIndex;
8062 static int saved_code_index(bool is_latin1) {
8064 return kIrregexpLatin1CodeSavedIndex;
8066 return kIrregexpUC16CodeSavedIndex;
8070 DECLARE_CAST(JSRegExp)
8072 // Dispatched behavior.
8073 DECLARE_VERIFIER(JSRegExp)
8075 static const int kDataOffset = JSObject::kHeaderSize;
8076 static const int kSize = kDataOffset + kPointerSize;
8078 // Indices in the data array.
8079 static const int kTagIndex = 0;
8080 static const int kSourceIndex = kTagIndex + 1;
8081 static const int kFlagsIndex = kSourceIndex + 1;
8082 static const int kDataIndex = kFlagsIndex + 1;
8083 // The data fields are used in different ways depending on the
8084 // value of the tag.
8085 // Atom regexps (literal strings).
8086 static const int kAtomPatternIndex = kDataIndex;
8088 static const int kAtomDataSize = kAtomPatternIndex + 1;
8090 // Irregexp compiled code or bytecode for Latin1. If compilation
8091 // fails, this fields hold an exception object that should be
8092 // thrown if the regexp is used again.
8093 static const int kIrregexpLatin1CodeIndex = kDataIndex;
8094 // Irregexp compiled code or bytecode for UC16. If compilation
8095 // fails, this fields hold an exception object that should be
8096 // thrown if the regexp is used again.
8097 static const int kIrregexpUC16CodeIndex = kDataIndex + 1;
8099 // Saved instance of Irregexp compiled code or bytecode for Latin1 that
8100 // is a potential candidate for flushing.
8101 static const int kIrregexpLatin1CodeSavedIndex = kDataIndex + 2;
8102 // Saved instance of Irregexp compiled code or bytecode for UC16 that is
8103 // a potential candidate for flushing.
8104 static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3;
8106 // Maximal number of registers used by either Latin1 or UC16.
8107 // Only used to check that there is enough stack space
8108 static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4;
8109 // Number of captures in the compiled regexp.
8110 static const int kIrregexpCaptureCountIndex = kDataIndex + 5;
8112 static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1;
8114 // Offsets directly into the data fixed array.
8115 static const int kDataTagOffset =
8116 FixedArray::kHeaderSize + kTagIndex * kPointerSize;
8117 static const int kDataOneByteCodeOffset =
8118 FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize;
8119 static const int kDataUC16CodeOffset =
8120 FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize;
8121 static const int kIrregexpCaptureCountOffset =
8122 FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize;
8124 // In-object fields.
8125 static const int kGlobalFieldIndex = 0;
8126 static const int kIgnoreCaseFieldIndex = 1;
8127 static const int kMultilineFieldIndex = 2;
8128 static const int kLastIndexFieldIndex = 3;
8129 static const int kInObjectFieldCount = 4;
8131 // The uninitialized value for a regexp code object.
8132 static const int kUninitializedValue = -1;
8134 // The compilation error value for the regexp code object. The real error
8135 // object is in the saved code field.
8136 static const int kCompilationErrorValue = -2;
8138 // When we store the sweep generation at which we moved the code from the
8139 // code index to the saved code index we mask it of to be in the [0:255]
8141 static const int kCodeAgeMask = 0xff;
8145 class CompilationCacheShape : public BaseShape<HashTableKey*> {
8147 static inline bool IsMatch(HashTableKey* key, Object* value) {
8148 return key->IsMatch(value);
8151 static inline uint32_t Hash(HashTableKey* key) {
8155 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
8156 return key->HashForObject(object);
8159 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
8161 static const int kPrefixSize = 0;
8162 static const int kEntrySize = 2;
8166 // This cache is used in two different variants. For regexp caching, it simply
8167 // maps identifying info of the regexp to the cached regexp object. Scripts and
8168 // eval code only gets cached after a second probe for the code object. To do
8169 // so, on first "put" only a hash identifying the source is entered into the
8170 // cache, mapping it to a lifetime count of the hash. On each call to Age all
8171 // such lifetimes get reduced, and removed once they reach zero. If a second put
8172 // is called while such a hash is live in the cache, the hash gets replaced by
8173 // an actual cache entry. Age also removes stale live entries from the cache.
8174 // Such entries are identified by SharedFunctionInfos pointing to either the
8175 // recompilation stub, or to "old" code. This avoids memory leaks due to
8176 // premature caching of scripts and eval strings that are never needed later.
8177 class CompilationCacheTable: public HashTable<CompilationCacheTable,
8178 CompilationCacheShape,
8181 // Find cached value for a string key, otherwise return null.
8182 Handle<Object> Lookup(
8183 Handle<String> src, Handle<Context> context, LanguageMode language_mode);
8184 Handle<Object> LookupEval(
8185 Handle<String> src, Handle<SharedFunctionInfo> shared,
8186 LanguageMode language_mode, int scope_position);
8187 Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags);
8188 static Handle<CompilationCacheTable> Put(
8189 Handle<CompilationCacheTable> cache, Handle<String> src,
8190 Handle<Context> context, LanguageMode language_mode,
8191 Handle<Object> value);
8192 static Handle<CompilationCacheTable> PutEval(
8193 Handle<CompilationCacheTable> cache, Handle<String> src,
8194 Handle<SharedFunctionInfo> context, Handle<SharedFunctionInfo> value,
8195 int scope_position);
8196 static Handle<CompilationCacheTable> PutRegExp(
8197 Handle<CompilationCacheTable> cache, Handle<String> src,
8198 JSRegExp::Flags flags, Handle<FixedArray> value);
8199 void Remove(Object* value);
8201 static const int kHashGenerations = 10;
8203 DECLARE_CAST(CompilationCacheTable)
8206 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable);
8210 class CodeCache: public Struct {
8212 DECL_ACCESSORS(default_cache, FixedArray)
8213 DECL_ACCESSORS(normal_type_cache, Object)
8215 // Add the code object to the cache.
8217 Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code);
8219 // Lookup code object in the cache. Returns code object if found and undefined
8221 Object* Lookup(Name* name, Code::Flags flags);
8223 // Get the internal index of a code object in the cache. Returns -1 if the
8224 // code object is not in that cache. This index can be used to later call
8225 // RemoveByIndex. The cache cannot be modified between a call to GetIndex and
8227 int GetIndex(Object* name, Code* code);
8229 // Remove an object from the cache with the provided internal index.
8230 void RemoveByIndex(Object* name, Code* code, int index);
8232 DECLARE_CAST(CodeCache)
8234 // Dispatched behavior.
8235 DECLARE_PRINTER(CodeCache)
8236 DECLARE_VERIFIER(CodeCache)
8238 static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
8239 static const int kNormalTypeCacheOffset =
8240 kDefaultCacheOffset + kPointerSize;
8241 static const int kSize = kNormalTypeCacheOffset + kPointerSize;
8244 static void UpdateDefaultCache(
8245 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
8246 static void UpdateNormalTypeCache(
8247 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
8248 Object* LookupDefaultCache(Name* name, Code::Flags flags);
8249 Object* LookupNormalTypeCache(Name* name, Code::Flags flags);
8251 // Code cache layout of the default cache. Elements are alternating name and
8252 // code objects for non normal load/store/call IC's.
8253 static const int kCodeCacheEntrySize = 2;
8254 static const int kCodeCacheEntryNameOffset = 0;
8255 static const int kCodeCacheEntryCodeOffset = 1;
8257 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
8261 class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
8263 static inline bool IsMatch(HashTableKey* key, Object* value) {
8264 return key->IsMatch(value);
8267 static inline uint32_t Hash(HashTableKey* key) {
8271 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
8272 return key->HashForObject(object);
8275 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
8277 static const int kPrefixSize = 0;
8278 static const int kEntrySize = 2;
8282 class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
8283 CodeCacheHashTableShape,
8286 Object* Lookup(Name* name, Code::Flags flags);
8287 static Handle<CodeCacheHashTable> Put(
8288 Handle<CodeCacheHashTable> table,
8292 int GetIndex(Name* name, Code::Flags flags);
8293 void RemoveByIndex(int index);
8295 DECLARE_CAST(CodeCacheHashTable)
8297 // Initial size of the fixed array backing the hash table.
8298 static const int kInitialSize = 64;
8301 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
8305 class PolymorphicCodeCache: public Struct {
8307 DECL_ACCESSORS(cache, Object)
8309 static void Update(Handle<PolymorphicCodeCache> cache,
8310 MapHandleList* maps,
8315 // Returns an undefined value if the entry is not found.
8316 Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags);
8318 DECLARE_CAST(PolymorphicCodeCache)
8320 // Dispatched behavior.
8321 DECLARE_PRINTER(PolymorphicCodeCache)
8322 DECLARE_VERIFIER(PolymorphicCodeCache)
8324 static const int kCacheOffset = HeapObject::kHeaderSize;
8325 static const int kSize = kCacheOffset + kPointerSize;
8328 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache);
8332 class PolymorphicCodeCacheHashTable
8333 : public HashTable<PolymorphicCodeCacheHashTable,
8334 CodeCacheHashTableShape,
8337 Object* Lookup(MapHandleList* maps, int code_kind);
8339 static Handle<PolymorphicCodeCacheHashTable> Put(
8340 Handle<PolymorphicCodeCacheHashTable> hash_table,
8341 MapHandleList* maps,
8345 DECLARE_CAST(PolymorphicCodeCacheHashTable)
8347 static const int kInitialSize = 64;
8349 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable);
8353 class TypeFeedbackInfo: public Struct {
8355 inline int ic_total_count();
8356 inline void set_ic_total_count(int count);
8358 inline int ic_with_type_info_count();
8359 inline void change_ic_with_type_info_count(int delta);
8361 inline int ic_generic_count();
8362 inline void change_ic_generic_count(int delta);
8364 inline void initialize_storage();
8366 inline void change_own_type_change_checksum();
8367 inline int own_type_change_checksum();
8369 inline void set_inlined_type_change_checksum(int checksum);
8370 inline bool matches_inlined_type_change_checksum(int checksum);
8372 DECLARE_CAST(TypeFeedbackInfo)
8374 // Dispatched behavior.
8375 DECLARE_PRINTER(TypeFeedbackInfo)
8376 DECLARE_VERIFIER(TypeFeedbackInfo)
8378 static const int kStorage1Offset = HeapObject::kHeaderSize;
8379 static const int kStorage2Offset = kStorage1Offset + kPointerSize;
8380 static const int kStorage3Offset = kStorage2Offset + kPointerSize;
8381 static const int kSize = kStorage3Offset + kPointerSize;
8384 static const int kTypeChangeChecksumBits = 7;
8386 class ICTotalCountField: public BitField<int, 0,
8387 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
8388 class OwnTypeChangeChecksum: public BitField<int,
8389 kSmiValueSize - kTypeChangeChecksumBits,
8390 kTypeChangeChecksumBits> {}; // NOLINT
8391 class ICsWithTypeInfoCountField: public BitField<int, 0,
8392 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
8393 class InlinedTypeChangeChecksum: public BitField<int,
8394 kSmiValueSize - kTypeChangeChecksumBits,
8395 kTypeChangeChecksumBits> {}; // NOLINT
8397 DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo);
8401 enum AllocationSiteMode {
8402 DONT_TRACK_ALLOCATION_SITE,
8403 TRACK_ALLOCATION_SITE,
8404 LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE
8408 class AllocationSite: public Struct {
8410 static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
8411 static const double kPretenureRatio;
8412 static const int kPretenureMinimumCreated = 100;
8414 // Values for pretenure decision field.
8415 enum PretenureDecision {
8421 kLastPretenureDecisionValue = kZombie
8424 const char* PretenureDecisionName(PretenureDecision decision);
8426 DECL_ACCESSORS(transition_info, Object)
8427 // nested_site threads a list of sites that represent nested literals
8428 // walked in a particular order. So [[1, 2], 1, 2] will have one
8429 // nested_site, but [[1, 2], 3, [4]] will have a list of two.
8430 DECL_ACCESSORS(nested_site, Object)
8431 DECL_ACCESSORS(pretenure_data, Smi)
8432 DECL_ACCESSORS(pretenure_create_count, Smi)
8433 DECL_ACCESSORS(dependent_code, DependentCode)
8434 DECL_ACCESSORS(weak_next, Object)
8436 inline void Initialize();
8438 // This method is expensive, it should only be called for reporting.
8439 bool IsNestedSite();
8441 // transition_info bitfields, for constructed array transition info.
8442 class ElementsKindBits: public BitField<ElementsKind, 0, 15> {};
8443 class UnusedBits: public BitField<int, 15, 14> {};
8444 class DoNotInlineBit: public BitField<bool, 29, 1> {};
8446 // Bitfields for pretenure_data
8447 class MementoFoundCountBits: public BitField<int, 0, 26> {};
8448 class PretenureDecisionBits: public BitField<PretenureDecision, 26, 3> {};
8449 class DeoptDependentCodeBit: public BitField<bool, 29, 1> {};
8450 STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
8452 // Increments the mementos found counter and returns true when the first
8453 // memento was found for a given allocation site.
8454 inline bool IncrementMementoFoundCount();
8456 inline void IncrementMementoCreateCount();
8458 PretenureFlag GetPretenureMode();
8460 void ResetPretenureDecision();
8462 PretenureDecision pretenure_decision() {
8463 int value = pretenure_data()->value();
8464 return PretenureDecisionBits::decode(value);
8467 void set_pretenure_decision(PretenureDecision decision) {
8468 int value = pretenure_data()->value();
8470 Smi::FromInt(PretenureDecisionBits::update(value, decision)),
8471 SKIP_WRITE_BARRIER);
8474 bool deopt_dependent_code() {
8475 int value = pretenure_data()->value();
8476 return DeoptDependentCodeBit::decode(value);
8479 void set_deopt_dependent_code(bool deopt) {
8480 int value = pretenure_data()->value();
8482 Smi::FromInt(DeoptDependentCodeBit::update(value, deopt)),
8483 SKIP_WRITE_BARRIER);
8486 int memento_found_count() {
8487 int value = pretenure_data()->value();
8488 return MementoFoundCountBits::decode(value);
8491 inline void set_memento_found_count(int count);
8493 int memento_create_count() {
8494 return pretenure_create_count()->value();
8497 void set_memento_create_count(int count) {
8498 set_pretenure_create_count(Smi::FromInt(count), SKIP_WRITE_BARRIER);
8501 // The pretenuring decision is made during gc, and the zombie state allows
8502 // us to recognize when an allocation site is just being kept alive because
8503 // a later traversal of new space may discover AllocationMementos that point
8504 // to this AllocationSite.
8506 return pretenure_decision() == kZombie;
8509 bool IsMaybeTenure() {
8510 return pretenure_decision() == kMaybeTenure;
8513 inline void MarkZombie();
8515 inline bool MakePretenureDecision(PretenureDecision current_decision,
8517 bool maximum_size_scavenge);
8519 inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
8521 ElementsKind GetElementsKind() {
8522 DCHECK(!SitePointsToLiteral());
8523 int value = Smi::cast(transition_info())->value();
8524 return ElementsKindBits::decode(value);
8527 void SetElementsKind(ElementsKind kind) {
8528 int value = Smi::cast(transition_info())->value();
8529 set_transition_info(Smi::FromInt(ElementsKindBits::update(value, kind)),
8530 SKIP_WRITE_BARRIER);
8533 bool CanInlineCall() {
8534 int value = Smi::cast(transition_info())->value();
8535 return DoNotInlineBit::decode(value) == 0;
8538 void SetDoNotInlineCall() {
8539 int value = Smi::cast(transition_info())->value();
8540 set_transition_info(Smi::FromInt(DoNotInlineBit::update(value, true)),
8541 SKIP_WRITE_BARRIER);
8544 bool SitePointsToLiteral() {
8545 // If transition_info is a smi, then it represents an ElementsKind
8546 // for a constructed array. Otherwise, it must be a boilerplate
8547 // for an object or array literal.
8548 return transition_info()->IsJSArray() || transition_info()->IsJSObject();
8551 static void DigestTransitionFeedback(Handle<AllocationSite> site,
8552 ElementsKind to_kind);
8554 static void RegisterForDeoptOnTenureChange(Handle<AllocationSite> site,
8555 CompilationInfo* info);
8557 static void RegisterForDeoptOnTransitionChange(Handle<AllocationSite> site,
8558 CompilationInfo* info);
8560 DECLARE_PRINTER(AllocationSite)
8561 DECLARE_VERIFIER(AllocationSite)
8563 DECLARE_CAST(AllocationSite)
8564 static inline AllocationSiteMode GetMode(
8565 ElementsKind boilerplate_elements_kind);
8566 static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to);
8567 static inline bool CanTrack(InstanceType type);
8569 static const int kTransitionInfoOffset = HeapObject::kHeaderSize;
8570 static const int kNestedSiteOffset = kTransitionInfoOffset + kPointerSize;
8571 static const int kPretenureDataOffset = kNestedSiteOffset + kPointerSize;
8572 static const int kPretenureCreateCountOffset =
8573 kPretenureDataOffset + kPointerSize;
8574 static const int kDependentCodeOffset =
8575 kPretenureCreateCountOffset + kPointerSize;
8576 static const int kWeakNextOffset = kDependentCodeOffset + kPointerSize;
8577 static const int kSize = kWeakNextOffset + kPointerSize;
8579 // During mark compact we need to take special care for the dependent code
8581 static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
8582 static const int kPointerFieldsEndOffset = kWeakNextOffset;
8584 // For other visitors, use the fixed body descriptor below.
8585 typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
8586 kDependentCodeOffset + kPointerSize,
8587 kSize> BodyDescriptor;
8590 static void AddDependentCompilationInfo(Handle<AllocationSite> site,
8591 DependentCode::DependencyGroup group,
8592 CompilationInfo* info);
8594 bool PretenuringDecisionMade() {
8595 return pretenure_decision() != kUndecided;
8598 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
8602 class AllocationMemento: public Struct {
8604 static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
8605 static const int kSize = kAllocationSiteOffset + kPointerSize;
8607 DECL_ACCESSORS(allocation_site, Object)
8610 return allocation_site()->IsAllocationSite() &&
8611 !AllocationSite::cast(allocation_site())->IsZombie();
8613 AllocationSite* GetAllocationSite() {
8615 return AllocationSite::cast(allocation_site());
8618 DECLARE_PRINTER(AllocationMemento)
8619 DECLARE_VERIFIER(AllocationMemento)
8621 DECLARE_CAST(AllocationMemento)
8624 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
8628 // Representation of a slow alias as part of a sloppy arguments objects.
8629 // For fast aliases (if HasSloppyArgumentsElements()):
8630 // - the parameter map contains an index into the context
8631 // - all attributes of the element have default values
8632 // For slow aliases (if HasDictionaryArgumentsElements()):
8633 // - the parameter map contains no fast alias mapping (i.e. the hole)
8634 // - this struct (in the slow backing store) contains an index into the context
8635 // - all attributes are available as part if the property details
8636 class AliasedArgumentsEntry: public Struct {
8638 inline int aliased_context_slot() const;
8639 inline void set_aliased_context_slot(int count);
8641 DECLARE_CAST(AliasedArgumentsEntry)
8643 // Dispatched behavior.
8644 DECLARE_PRINTER(AliasedArgumentsEntry)
8645 DECLARE_VERIFIER(AliasedArgumentsEntry)
8647 static const int kAliasedContextSlot = HeapObject::kHeaderSize;
8648 static const int kSize = kAliasedContextSlot + kPointerSize;
8651 DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry);
8655 enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
8656 enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};
8659 class StringHasher {
8661 explicit inline StringHasher(int length, uint32_t seed);
8663 template <typename schar>
8664 static inline uint32_t HashSequentialString(const schar* chars,
8668 // Reads all the data, even for long strings and computes the utf16 length.
8669 static uint32_t ComputeUtf8Hash(Vector<const char> chars,
8671 int* utf16_length_out);
8673 // Calculated hash value for a string consisting of 1 to
8674 // String::kMaxArrayIndexSize digits with no leading zeros (except "0").
8675 // value is represented decimal value.
8676 static uint32_t MakeArrayIndexHash(uint32_t value, int length);
8678 // No string is allowed to have a hash of zero. That value is reserved
8679 // for internal properties. If the hash calculation yields zero then we
8681 static const int kZeroHash = 27;
8683 // Reusable parts of the hashing algorithm.
8684 INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
8685 INLINE(static uint32_t GetHashCore(uint32_t running_hash));
8686 INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
8687 const uc16* chars, int length));
8688 INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
8693 // Returns the value to store in the hash field of a string with
8694 // the given length and contents.
8695 uint32_t GetHashField();
8696 // Returns true if the hash of this string can be computed without
8697 // looking at the contents.
8698 inline bool has_trivial_hash();
8699 // Adds a block of characters to the hash.
8700 template<typename Char>
8701 inline void AddCharacters(const Char* chars, int len);
8704 // Add a character to the hash.
8705 inline void AddCharacter(uint16_t c);
8706 // Update index. Returns true if string is still an index.
8707 inline bool UpdateIndex(uint16_t c);
8710 uint32_t raw_running_hash_;
8711 uint32_t array_index_;
8712 bool is_array_index_;
8713 bool is_first_char_;
8714 DISALLOW_COPY_AND_ASSIGN(StringHasher);
8718 class IteratingStringHasher : public StringHasher {
8720 static inline uint32_t Hash(String* string, uint32_t seed);
8721 inline void VisitOneByteString(const uint8_t* chars, int length);
8722 inline void VisitTwoByteString(const uint16_t* chars, int length);
8725 inline IteratingStringHasher(int len, uint32_t seed)
8726 : StringHasher(len, seed) {}
8727 void VisitConsString(ConsString* cons_string);
8728 DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
8732 // The characteristics of a string are stored in its map. Retrieving these
8733 // few bits of information is moderately expensive, involving two memory
8734 // loads where the second is dependent on the first. To improve efficiency
8735 // the shape of the string is given its own class so that it can be retrieved
8736 // once and used for several string operations. A StringShape is small enough
8737 // to be passed by value and is immutable, but be aware that flattening a
8738 // string can potentially alter its shape. Also be aware that a GC caused by
8739 // something else can alter the shape of a string due to ConsString
8740 // shortcutting. Keeping these restrictions in mind has proven to be error-
8741 // prone and so we no longer put StringShapes in variables unless there is a
8742 // concrete performance benefit at that particular point in the code.
8743 class StringShape BASE_EMBEDDED {
8745 inline explicit StringShape(const String* s);
8746 inline explicit StringShape(Map* s);
8747 inline explicit StringShape(InstanceType t);
8748 inline bool IsSequential();
8749 inline bool IsExternal();
8750 inline bool IsCons();
8751 inline bool IsSliced();
8752 inline bool IsIndirect();
8753 inline bool IsExternalOneByte();
8754 inline bool IsExternalTwoByte();
8755 inline bool IsSequentialOneByte();
8756 inline bool IsSequentialTwoByte();
8757 inline bool IsInternalized();
8758 inline StringRepresentationTag representation_tag();
8759 inline uint32_t encoding_tag();
8760 inline uint32_t full_representation_tag();
8761 inline uint32_t size_tag();
8763 inline uint32_t type() { return type_; }
8764 inline void invalidate() { valid_ = false; }
8765 inline bool valid() { return valid_; }
8767 inline void invalidate() { }
8773 inline void set_valid() { valid_ = true; }
8776 inline void set_valid() { }
8781 // The Name abstract class captures anything that can be used as a property
8782 // name, i.e., strings and symbols. All names store a hash value.
8783 class Name: public HeapObject {
8785 // Get and set the hash field of the name.
8786 inline uint32_t hash_field();
8787 inline void set_hash_field(uint32_t value);
8789 // Tells whether the hash code has been computed.
8790 inline bool HasHashCode();
8792 // Returns a hash value used for the property table
8793 inline uint32_t Hash();
8795 // Equality operations.
8796 inline bool Equals(Name* other);
8797 inline static bool Equals(Handle<Name> one, Handle<Name> two);
8800 inline bool AsArrayIndex(uint32_t* index);
8802 // Whether name can only name own properties.
8803 inline bool IsOwn();
8807 DECLARE_PRINTER(Name)
8809 void NameShortPrint();
8810 int NameShortPrint(Vector<char> str);
8813 // Layout description.
8814 static const int kHashFieldSlot = HeapObject::kHeaderSize;
8815 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
8816 static const int kHashFieldOffset = kHashFieldSlot;
8818 static const int kHashFieldOffset = kHashFieldSlot + kIntSize;
8820 static const int kSize = kHashFieldSlot + kPointerSize;
8822 // Mask constant for checking if a name has a computed hash code
8823 // and if it is a string that is an array index. The least significant bit
8824 // indicates whether a hash code has been computed. If the hash code has
8825 // been computed the 2nd bit tells whether the string can be used as an
8827 static const int kHashNotComputedMask = 1;
8828 static const int kIsNotArrayIndexMask = 1 << 1;
8829 static const int kNofHashBitFields = 2;
8831 // Shift constant retrieving hash code from hash field.
8832 static const int kHashShift = kNofHashBitFields;
8834 // Only these bits are relevant in the hash, since the top two are shifted
8836 static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift;
8838 // Array index strings this short can keep their index in the hash field.
8839 static const int kMaxCachedArrayIndexLength = 7;
8841 // For strings which are array indexes the hash value has the string length
8842 // mixed into the hash, mainly to avoid a hash value of zero which would be
8843 // the case for the string '0'. 24 bits are used for the array index value.
8844 static const int kArrayIndexValueBits = 24;
8845 static const int kArrayIndexLengthBits =
8846 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8848 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8850 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8851 kArrayIndexValueBits> {}; // NOLINT
8852 class ArrayIndexLengthBits : public BitField<unsigned int,
8853 kNofHashBitFields + kArrayIndexValueBits,
8854 kArrayIndexLengthBits> {}; // NOLINT
8856 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8857 // could use a mask to test if the length of string is less than or equal to
8858 // kMaxCachedArrayIndexLength.
8859 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8861 static const unsigned int kContainsCachedArrayIndexMask =
8862 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8863 << ArrayIndexLengthBits::kShift) |
8864 kIsNotArrayIndexMask;
8866 // Value of empty hash field indicating that the hash is not computed.
8867 static const int kEmptyHashField =
8868 kIsNotArrayIndexMask | kHashNotComputedMask;
8871 static inline bool IsHashFieldComputed(uint32_t field);
8874 DISALLOW_IMPLICIT_CONSTRUCTORS(Name);
8879 class Symbol: public Name {
8881 // [name]: the print name of a symbol, or undefined if none.
8882 DECL_ACCESSORS(name, Object)
8884 DECL_ACCESSORS(flags, Smi)
8886 // [is_private]: whether this is a private symbol.
8887 DECL_BOOLEAN_ACCESSORS(is_private)
8889 // [is_own]: whether this is an own symbol, that is, only used to designate
8890 // own properties of objects.
8891 DECL_BOOLEAN_ACCESSORS(is_own)
8893 DECLARE_CAST(Symbol)
8895 // Dispatched behavior.
8896 DECLARE_PRINTER(Symbol)
8897 DECLARE_VERIFIER(Symbol)
8899 // Layout description.
8900 static const int kNameOffset = Name::kSize;
8901 static const int kFlagsOffset = kNameOffset + kPointerSize;
8902 static const int kSize = kFlagsOffset + kPointerSize;
8904 typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
8906 void SymbolShortPrint(std::ostream& os);
8909 static const int kPrivateBit = 0;
8910 static const int kOwnBit = 1;
8912 const char* PrivateSymbolToName() const;
8915 friend class Name; // For PrivateSymbolToName.
8918 DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol);
8924 // The String abstract class captures JavaScript string values:
8927 // 4.3.16 String Value
8928 // A string value is a member of the type String and is a finite
8929 // ordered sequence of zero or more 16-bit unsigned integer values.
8931 // All string values have a length field.
8932 class String: public Name {
8934 enum Encoding { ONE_BYTE_ENCODING, TWO_BYTE_ENCODING };
8936 // Array index strings this short can keep their index in the hash field.
8937 static const int kMaxCachedArrayIndexLength = 7;
8939 // For strings which are array indexes the hash value has the string length
8940 // mixed into the hash, mainly to avoid a hash value of zero which would be
8941 // the case for the string '0'. 24 bits are used for the array index value.
8942 static const int kArrayIndexValueBits = 24;
8943 static const int kArrayIndexLengthBits =
8944 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8946 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8948 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8949 kArrayIndexValueBits> {}; // NOLINT
8950 class ArrayIndexLengthBits : public BitField<unsigned int,
8951 kNofHashBitFields + kArrayIndexValueBits,
8952 kArrayIndexLengthBits> {}; // NOLINT
8954 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8955 // could use a mask to test if the length of string is less than or equal to
8956 // kMaxCachedArrayIndexLength.
8957 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8959 static const unsigned int kContainsCachedArrayIndexMask =
8960 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8961 << ArrayIndexLengthBits::kShift) |
8962 kIsNotArrayIndexMask;
8964 class SubStringRange {
8966 explicit SubStringRange(String* string, int first = 0, int length = -1)
8969 length_(length == -1 ? string->length() : length) {}
8971 inline iterator begin();
8972 inline iterator end();
8980 // Representation of the flat content of a String.
8981 // A non-flat string doesn't have flat content.
8982 // A flat string has content that's encoded as a sequence of either
8983 // one-byte chars or two-byte UC16.
8984 // Returned by String::GetFlatContent().
8987 // Returns true if the string is flat and this structure contains content.
8988 bool IsFlat() { return state_ != NON_FLAT; }
8989 // Returns true if the structure contains one-byte content.
8990 bool IsOneByte() { return state_ == ONE_BYTE; }
8991 // Returns true if the structure contains two-byte content.
8992 bool IsTwoByte() { return state_ == TWO_BYTE; }
8994 // Return the one byte content of the string. Only use if IsOneByte()
8996 Vector<const uint8_t> ToOneByteVector() {
8997 DCHECK_EQ(ONE_BYTE, state_);
8998 return Vector<const uint8_t>(onebyte_start, length_);
9000 // Return the two-byte content of the string. Only use if IsTwoByte()
9002 Vector<const uc16> ToUC16Vector() {
9003 DCHECK_EQ(TWO_BYTE, state_);
9004 return Vector<const uc16>(twobyte_start, length_);
9008 DCHECK(i < length_);
9009 DCHECK(state_ != NON_FLAT);
9010 if (state_ == ONE_BYTE) return onebyte_start[i];
9011 return twobyte_start[i];
9014 bool UsesSameString(const FlatContent& other) const {
9015 return onebyte_start == other.onebyte_start;
9019 enum State { NON_FLAT, ONE_BYTE, TWO_BYTE };
9021 // Constructors only used by String::GetFlatContent().
9022 explicit FlatContent(const uint8_t* start, int length)
9023 : onebyte_start(start), length_(length), state_(ONE_BYTE) {}
9024 explicit FlatContent(const uc16* start, int length)
9025 : twobyte_start(start), length_(length), state_(TWO_BYTE) { }
9026 FlatContent() : onebyte_start(NULL), length_(0), state_(NON_FLAT) { }
9029 const uint8_t* onebyte_start;
9030 const uc16* twobyte_start;
9035 friend class String;
9036 friend class IterableSubString;
9039 template <typename Char>
9040 INLINE(Vector<const Char> GetCharVector());
9042 // Get and set the length of the string.
9043 inline int length() const;
9044 inline void set_length(int value);
9046 // Get and set the length of the string using acquire loads and release
9048 inline int synchronized_length() const;
9049 inline void synchronized_set_length(int value);
9051 // Returns whether this string has only one-byte chars, i.e. all of them can
9052 // be one-byte encoded. This might be the case even if the string is
9053 // two-byte. Such strings may appear when the embedder prefers
9054 // two-byte external representations even for one-byte data.
9055 inline bool IsOneByteRepresentation() const;
9056 inline bool IsTwoByteRepresentation() const;
9058 // Cons and slices have an encoding flag that may not represent the actual
9059 // encoding of the underlying string. This is taken into account here.
9060 // Requires: this->IsFlat()
9061 inline bool IsOneByteRepresentationUnderneath();
9062 inline bool IsTwoByteRepresentationUnderneath();
9064 // NOTE: this should be considered only a hint. False negatives are
9066 inline bool HasOnlyOneByteChars();
9068 // Get and set individual two byte chars in the string.
9069 inline void Set(int index, uint16_t value);
9070 // Get individual two byte char in the string. Repeated calls
9071 // to this method are not efficient unless the string is flat.
9072 INLINE(uint16_t Get(int index));
9074 // Flattens the string. Checks first inline to see if it is
9075 // necessary. Does nothing if the string is not a cons string.
9076 // Flattening allocates a sequential string with the same data as
9077 // the given string and mutates the cons string to a degenerate
9078 // form, where the first component is the new sequential string and
9079 // the second component is the empty string. If allocation fails,
9080 // this function returns a failure. If flattening succeeds, this
9081 // function returns the sequential string that is now the first
9082 // component of the cons string.
9084 // Degenerate cons strings are handled specially by the garbage
9085 // collector (see IsShortcutCandidate).
9087 static inline Handle<String> Flatten(Handle<String> string,
9088 PretenureFlag pretenure = NOT_TENURED);
9090 // Tries to return the content of a flat string as a structure holding either
9091 // a flat vector of char or of uc16.
9092 // If the string isn't flat, and therefore doesn't have flat content, the
9093 // returned structure will report so, and can't provide a vector of either
9095 FlatContent GetFlatContent();
9097 // Returns the parent of a sliced string or first part of a flat cons string.
9098 // Requires: StringShape(this).IsIndirect() && this->IsFlat()
9099 inline String* GetUnderlying();
9101 // String equality operations.
9102 inline bool Equals(String* other);
9103 inline static bool Equals(Handle<String> one, Handle<String> two);
9104 bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
9105 bool IsOneByteEqualTo(Vector<const uint8_t> str);
9106 bool IsTwoByteEqualTo(Vector<const uc16> str);
9108 // Return a UTF8 representation of the string. The string is null
9109 // terminated but may optionally contain nulls. Length is returned
9110 // in length_output if length_output is not a null pointer The string
9111 // should be nearly flat, otherwise the performance of this method may
9112 // be very slow (quadratic in the length). Setting robustness_flag to
9113 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
9114 // handles unexpected data without causing assert failures and it does not
9115 // do any heap allocations. This is useful when printing stack traces.
9116 SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls,
9117 RobustnessFlag robustness_flag,
9120 int* length_output = 0);
9121 SmartArrayPointer<char> ToCString(
9122 AllowNullsFlag allow_nulls = DISALLOW_NULLS,
9123 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL,
9124 int* length_output = 0);
9126 // Return a 16 bit Unicode representation of the string.
9127 // The string should be nearly flat, otherwise the performance of
9128 // of this method may be very bad. Setting robustness_flag to
9129 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
9130 // handles unexpected data without causing assert failures and it does not
9131 // do any heap allocations. This is useful when printing stack traces.
9132 SmartArrayPointer<uc16> ToWideCString(
9133 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL);
9135 bool ComputeArrayIndex(uint32_t* index);
9138 bool MakeExternal(v8::String::ExternalStringResource* resource);
9139 bool MakeExternal(v8::String::ExternalOneByteStringResource* resource);
9142 inline bool AsArrayIndex(uint32_t* index);
9144 DECLARE_CAST(String)
9146 void PrintOn(FILE* out);
9148 // For use during stack traces. Performs rudimentary sanity check.
9151 // Dispatched behavior.
9152 void StringShortPrint(StringStream* accumulator);
9153 void PrintUC16(std::ostream& os, int start = 0, int end = -1); // NOLINT
9154 #if defined(DEBUG) || defined(OBJECT_PRINT)
9155 char* ToAsciiArray();
9157 DECLARE_PRINTER(String)
9158 DECLARE_VERIFIER(String)
9160 inline bool IsFlat();
9162 // Layout description.
9163 static const int kLengthOffset = Name::kSize;
9164 static const int kSize = kLengthOffset + kPointerSize;
9166 // Maximum number of characters to consider when trying to convert a string
9167 // value into an array index.
9168 static const int kMaxArrayIndexSize = 10;
9169 STATIC_ASSERT(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits));
9172 static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar;
9173 static const uint32_t kMaxOneByteCharCodeU = unibrow::Latin1::kMaxChar;
9174 static const int kMaxUtf16CodeUnit = 0xffff;
9175 static const uint32_t kMaxUtf16CodeUnitU = kMaxUtf16CodeUnit;
9177 // Value of hash field containing computed hash equal to zero.
9178 static const int kEmptyStringHash = kIsNotArrayIndexMask;
9180 // Maximal string length.
9181 static const int kMaxLength = (1 << 28) - 16;
9183 // Max length for computing hash. For strings longer than this limit the
9184 // string length is used as the hash value.
9185 static const int kMaxHashCalcLength = 16383;
9187 // Limit for truncation in short printing.
9188 static const int kMaxShortPrintLength = 1024;
9190 // Support for regular expressions.
9191 const uc16* GetTwoByteData(unsigned start);
9193 // Helper function for flattening strings.
9194 template <typename sinkchar>
9195 static void WriteToFlat(String* source,
9200 // The return value may point to the first aligned word containing the first
9201 // non-one-byte character, rather than directly to the non-one-byte character.
9202 // If the return value is >= the passed length, the entire string was
9204 static inline int NonAsciiStart(const char* chars, int length) {
9205 const char* start = chars;
9206 const char* limit = chars + length;
9208 if (length >= kIntptrSize) {
9209 // Check unaligned bytes.
9210 while (!IsAligned(reinterpret_cast<intptr_t>(chars), sizeof(uintptr_t))) {
9211 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
9212 return static_cast<int>(chars - start);
9216 // Check aligned words.
9217 DCHECK(unibrow::Utf8::kMaxOneByteChar == 0x7F);
9218 const uintptr_t non_one_byte_mask = kUintptrAllBitsSet / 0xFF * 0x80;
9219 while (chars + sizeof(uintptr_t) <= limit) {
9220 if (*reinterpret_cast<const uintptr_t*>(chars) & non_one_byte_mask) {
9221 return static_cast<int>(chars - start);
9223 chars += sizeof(uintptr_t);
9226 // Check remaining unaligned bytes.
9227 while (chars < limit) {
9228 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
9229 return static_cast<int>(chars - start);
9234 return static_cast<int>(chars - start);
9237 static inline bool IsAscii(const char* chars, int length) {
9238 return NonAsciiStart(chars, length) >= length;
9241 static inline bool IsAscii(const uint8_t* chars, int length) {
9243 NonAsciiStart(reinterpret_cast<const char*>(chars), length) >= length;
9246 static inline int NonOneByteStart(const uc16* chars, int length) {
9247 const uc16* limit = chars + length;
9248 const uc16* start = chars;
9249 while (chars < limit) {
9250 if (*chars > kMaxOneByteCharCodeU) return static_cast<int>(chars - start);
9253 return static_cast<int>(chars - start);
9256 static inline bool IsOneByte(const uc16* chars, int length) {
9257 return NonOneByteStart(chars, length) >= length;
9260 template<class Visitor>
9261 static inline ConsString* VisitFlat(Visitor* visitor,
9265 static Handle<FixedArray> CalculateLineEnds(Handle<String> string,
9266 bool include_ending_line);
9268 // Use the hash field to forward to the canonical internalized string
9269 // when deserializing an internalized string.
9270 inline void SetForwardedInternalizedString(String* string);
9271 inline String* GetForwardedInternalizedString();
9275 friend class StringTableInsertionKey;
9277 static Handle<String> SlowFlatten(Handle<ConsString> cons,
9278 PretenureFlag tenure);
9280 // Slow case of String::Equals. This implementation works on any strings
9281 // but it is most efficient on strings that are almost flat.
9282 bool SlowEquals(String* other);
9284 static bool SlowEquals(Handle<String> one, Handle<String> two);
9286 // Slow case of AsArrayIndex.
9287 bool SlowAsArrayIndex(uint32_t* index);
9289 // Compute and set the hash code.
9290 uint32_t ComputeAndSetHash();
9292 DISALLOW_IMPLICIT_CONSTRUCTORS(String);
9296 // The SeqString abstract class captures sequential string values.
9297 class SeqString: public String {
9299 DECLARE_CAST(SeqString)
9301 // Layout description.
9302 static const int kHeaderSize = String::kSize;
9304 // Truncate the string in-place if possible and return the result.
9305 // In case of new_length == 0, the empty string is returned without
9306 // truncating the original string.
9307 MUST_USE_RESULT static Handle<String> Truncate(Handle<SeqString> string,
9310 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString);
9314 // The OneByteString class captures sequential one-byte string objects.
9315 // Each character in the OneByteString is an one-byte character.
9316 class SeqOneByteString: public SeqString {
9318 static const bool kHasOneByteEncoding = true;
9320 // Dispatched behavior.
9321 inline uint16_t SeqOneByteStringGet(int index);
9322 inline void SeqOneByteStringSet(int index, uint16_t value);
9324 // Get the address of the characters in this string.
9325 inline Address GetCharsAddress();
9327 inline uint8_t* GetChars();
9329 DECLARE_CAST(SeqOneByteString)
9331 // Garbage collection support. This method is called by the
9332 // garbage collector to compute the actual size of an OneByteString
9334 inline int SeqOneByteStringSize(InstanceType instance_type);
9336 // Computes the size for an OneByteString instance of a given length.
9337 static int SizeFor(int length) {
9338 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize);
9341 // Maximal memory usage for a single sequential one-byte string.
9342 static const int kMaxSize = 512 * MB - 1;
9343 STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength);
9346 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
9350 // The TwoByteString class captures sequential unicode string objects.
9351 // Each character in the TwoByteString is a two-byte uint16_t.
9352 class SeqTwoByteString: public SeqString {
9354 static const bool kHasOneByteEncoding = false;
9356 // Dispatched behavior.
9357 inline uint16_t SeqTwoByteStringGet(int index);
9358 inline void SeqTwoByteStringSet(int index, uint16_t value);
9360 // Get the address of the characters in this string.
9361 inline Address GetCharsAddress();
9363 inline uc16* GetChars();
9366 const uint16_t* SeqTwoByteStringGetData(unsigned start);
9368 DECLARE_CAST(SeqTwoByteString)
9370 // Garbage collection support. This method is called by the
9371 // garbage collector to compute the actual size of a TwoByteString
9373 inline int SeqTwoByteStringSize(InstanceType instance_type);
9375 // Computes the size for a TwoByteString instance of a given length.
9376 static int SizeFor(int length) {
9377 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize);
9380 // Maximal memory usage for a single sequential two-byte string.
9381 static const int kMaxSize = 512 * MB - 1;
9382 STATIC_ASSERT(static_cast<int>((kMaxSize - kHeaderSize)/sizeof(uint16_t)) >=
9383 String::kMaxLength);
9386 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString);
9390 // The ConsString class describes string values built by using the
9391 // addition operator on strings. A ConsString is a pair where the
9392 // first and second components are pointers to other string values.
9393 // One or both components of a ConsString can be pointers to other
9394 // ConsStrings, creating a binary tree of ConsStrings where the leaves
9395 // are non-ConsString string values. The string value represented by
9396 // a ConsString can be obtained by concatenating the leaf string
9397 // values in a left-to-right depth-first traversal of the tree.
9398 class ConsString: public String {
9400 // First string of the cons cell.
9401 inline String* first();
9402 // Doesn't check that the result is a string, even in debug mode. This is
9403 // useful during GC where the mark bits confuse the checks.
9404 inline Object* unchecked_first();
9405 inline void set_first(String* first,
9406 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9408 // Second string of the cons cell.
9409 inline String* second();
9410 // Doesn't check that the result is a string, even in debug mode. This is
9411 // useful during GC where the mark bits confuse the checks.
9412 inline Object* unchecked_second();
9413 inline void set_second(String* second,
9414 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9416 // Dispatched behavior.
9417 uint16_t ConsStringGet(int index);
9419 DECLARE_CAST(ConsString)
9421 // Layout description.
9422 static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize);
9423 static const int kSecondOffset = kFirstOffset + kPointerSize;
9424 static const int kSize = kSecondOffset + kPointerSize;
9426 // Minimum length for a cons string.
9427 static const int kMinLength = 13;
9429 typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize>
9432 DECLARE_VERIFIER(ConsString)
9435 DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString);
9439 // The Sliced String class describes strings that are substrings of another
9440 // sequential string. The motivation is to save time and memory when creating
9441 // a substring. A Sliced String is described as a pointer to the parent,
9442 // the offset from the start of the parent string and the length. Using
9443 // a Sliced String therefore requires unpacking of the parent string and
9444 // adding the offset to the start address. A substring of a Sliced String
9445 // are not nested since the double indirection is simplified when creating
9446 // such a substring.
9447 // Currently missing features are:
9448 // - handling externalized parent strings
9449 // - external strings as parent
9450 // - truncating sliced string to enable otherwise unneeded parent to be GC'ed.
9451 class SlicedString: public String {
9453 inline String* parent();
9454 inline void set_parent(String* parent,
9455 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
9456 inline int offset() const;
9457 inline void set_offset(int offset);
9459 // Dispatched behavior.
9460 uint16_t SlicedStringGet(int index);
9462 DECLARE_CAST(SlicedString)
9464 // Layout description.
9465 static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize);
9466 static const int kOffsetOffset = kParentOffset + kPointerSize;
9467 static const int kSize = kOffsetOffset + kPointerSize;
9469 // Minimum length for a sliced string.
9470 static const int kMinLength = 13;
9472 typedef FixedBodyDescriptor<kParentOffset,
9473 kOffsetOffset + kPointerSize, kSize>
9476 DECLARE_VERIFIER(SlicedString)
9479 DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString);
9483 // The ExternalString class describes string values that are backed by
9484 // a string resource that lies outside the V8 heap. ExternalStrings
9485 // consist of the length field common to all strings, a pointer to the
9486 // external resource. It is important to ensure (externally) that the
9487 // resource is not deallocated while the ExternalString is live in the
9490 // The API expects that all ExternalStrings are created through the
9491 // API. Therefore, ExternalStrings should not be used internally.
9492 class ExternalString: public String {
9494 DECLARE_CAST(ExternalString)
9496 // Layout description.
9497 static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
9498 static const int kShortSize = kResourceOffset + kPointerSize;
9499 static const int kResourceDataOffset = kResourceOffset + kPointerSize;
9500 static const int kSize = kResourceDataOffset + kPointerSize;
9502 static const int kMaxShortLength =
9503 (kShortSize - SeqString::kHeaderSize) / kCharSize;
9505 // Return whether external string is short (data pointer is not cached).
9506 inline bool is_short();
9508 STATIC_ASSERT(kResourceOffset == Internals::kStringResourceOffset);
9511 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString);
9515 // The ExternalOneByteString class is an external string backed by an
9517 class ExternalOneByteString : public ExternalString {
9519 static const bool kHasOneByteEncoding = true;
9521 typedef v8::String::ExternalOneByteStringResource Resource;
9523 // The underlying resource.
9524 inline const Resource* resource();
9525 inline void set_resource(const Resource* buffer);
9527 // Update the pointer cache to the external character array.
9528 // The cached pointer is always valid, as the external character array does =
9529 // not move during lifetime. Deserialization is the only exception, after
9530 // which the pointer cache has to be refreshed.
9531 inline void update_data_cache();
9533 inline const uint8_t* GetChars();
9535 // Dispatched behavior.
9536 inline uint16_t ExternalOneByteStringGet(int index);
9538 DECLARE_CAST(ExternalOneByteString)
9540 // Garbage collection support.
9541 inline void ExternalOneByteStringIterateBody(ObjectVisitor* v);
9543 template <typename StaticVisitor>
9544 inline void ExternalOneByteStringIterateBody();
9547 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString);
9551 // The ExternalTwoByteString class is an external string backed by a UTF-16
9553 class ExternalTwoByteString: public ExternalString {
9555 static const bool kHasOneByteEncoding = false;
9557 typedef v8::String::ExternalStringResource Resource;
9559 // The underlying string resource.
9560 inline const Resource* resource();
9561 inline void set_resource(const Resource* buffer);
9563 // Update the pointer cache to the external character array.
9564 // The cached pointer is always valid, as the external character array does =
9565 // not move during lifetime. Deserialization is the only exception, after
9566 // which the pointer cache has to be refreshed.
9567 inline void update_data_cache();
9569 inline const uint16_t* GetChars();
9571 // Dispatched behavior.
9572 inline uint16_t ExternalTwoByteStringGet(int index);
9575 inline const uint16_t* ExternalTwoByteStringGetData(unsigned start);
9577 DECLARE_CAST(ExternalTwoByteString)
9579 // Garbage collection support.
9580 inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v);
9582 template<typename StaticVisitor>
9583 inline void ExternalTwoByteStringIterateBody();
9586 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString);
9590 // Utility superclass for stack-allocated objects that must be updated
9591 // on gc. It provides two ways for the gc to update instances, either
9592 // iterating or updating after gc.
9593 class Relocatable BASE_EMBEDDED {
9595 explicit inline Relocatable(Isolate* isolate);
9596 inline virtual ~Relocatable();
9597 virtual void IterateInstance(ObjectVisitor* v) { }
9598 virtual void PostGarbageCollection() { }
9600 static void PostGarbageCollectionProcessing(Isolate* isolate);
9601 static int ArchiveSpacePerThread();
9602 static char* ArchiveState(Isolate* isolate, char* to);
9603 static char* RestoreState(Isolate* isolate, char* from);
9604 static void Iterate(Isolate* isolate, ObjectVisitor* v);
9605 static void Iterate(ObjectVisitor* v, Relocatable* top);
9606 static char* Iterate(ObjectVisitor* v, char* t);
9614 // A flat string reader provides random access to the contents of a
9615 // string independent of the character width of the string. The handle
9616 // must be valid as long as the reader is being used.
9617 class FlatStringReader : public Relocatable {
9619 FlatStringReader(Isolate* isolate, Handle<String> str);
9620 FlatStringReader(Isolate* isolate, Vector<const char> input);
9621 void PostGarbageCollection();
9622 inline uc32 Get(int index);
9623 template <typename Char>
9624 inline Char Get(int index);
9625 int length() { return length_; }
9634 // This maintains an off-stack representation of the stack frames required
9635 // to traverse a ConsString, allowing an entirely iterative and restartable
9636 // traversal of the entire string
9637 class ConsStringIterator {
9639 inline ConsStringIterator() {}
9640 inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) {
9641 Reset(cons_string, offset);
9643 inline void Reset(ConsString* cons_string, int offset = 0) {
9645 // Next will always return NULL.
9646 if (cons_string == NULL) return;
9647 Initialize(cons_string, offset);
9649 // Returns NULL when complete.
9650 inline String* Next(int* offset_out) {
9652 if (depth_ == 0) return NULL;
9653 return Continue(offset_out);
9657 static const int kStackSize = 32;
9658 // Use a mask instead of doing modulo operations for stack wrapping.
9659 static const int kDepthMask = kStackSize-1;
9660 STATIC_ASSERT(IS_POWER_OF_TWO(kStackSize));
9661 static inline int OffsetForDepth(int depth);
9663 inline void PushLeft(ConsString* string);
9664 inline void PushRight(ConsString* string);
9665 inline void AdjustMaximumDepth();
9667 inline bool StackBlown() { return maximum_depth_ - depth_ == kStackSize; }
9668 void Initialize(ConsString* cons_string, int offset);
9669 String* Continue(int* offset_out);
9670 String* NextLeaf(bool* blew_stack);
9671 String* Search(int* offset_out);
9673 // Stack must always contain only frames for which right traversal
9674 // has not yet been performed.
9675 ConsString* frames_[kStackSize];
9680 DISALLOW_COPY_AND_ASSIGN(ConsStringIterator);
9684 class StringCharacterStream {
9686 inline StringCharacterStream(String* string,
9688 inline uint16_t GetNext();
9689 inline bool HasMore();
9690 inline void Reset(String* string, int offset = 0);
9691 inline void VisitOneByteString(const uint8_t* chars, int length);
9692 inline void VisitTwoByteString(const uint16_t* chars, int length);
9695 ConsStringIterator iter_;
9698 const uint8_t* buffer8_;
9699 const uint16_t* buffer16_;
9701 const uint8_t* end_;
9702 DISALLOW_COPY_AND_ASSIGN(StringCharacterStream);
9706 template <typename T>
9707 class VectorIterator {
9709 VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { }
9710 explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { }
9711 T GetNext() { return data_[index_++]; }
9712 bool has_more() { return index_ < data_.length(); }
9714 Vector<const T> data_;
9719 // The Oddball describes objects null, undefined, true, and false.
9720 class Oddball: public HeapObject {
9722 // [to_string]: Cached to_string computed at startup.
9723 DECL_ACCESSORS(to_string, String)
9725 // [to_number]: Cached to_number computed at startup.
9726 DECL_ACCESSORS(to_number, Object)
9728 inline byte kind() const;
9729 inline void set_kind(byte kind);
9731 DECLARE_CAST(Oddball)
9733 // Dispatched behavior.
9734 DECLARE_VERIFIER(Oddball)
9736 // Initialize the fields.
9737 static void Initialize(Isolate* isolate,
9738 Handle<Oddball> oddball,
9739 const char* to_string,
9740 Handle<Object> to_number,
9743 // Layout description.
9744 static const int kToStringOffset = HeapObject::kHeaderSize;
9745 static const int kToNumberOffset = kToStringOffset + kPointerSize;
9746 static const int kKindOffset = kToNumberOffset + kPointerSize;
9747 static const int kSize = kKindOffset + kPointerSize;
9749 static const byte kFalse = 0;
9750 static const byte kTrue = 1;
9751 static const byte kNotBooleanMask = ~1;
9752 static const byte kTheHole = 2;
9753 static const byte kNull = 3;
9754 static const byte kArgumentMarker = 4;
9755 static const byte kUndefined = 5;
9756 static const byte kUninitialized = 6;
9757 static const byte kOther = 7;
9758 static const byte kException = 8;
9760 typedef FixedBodyDescriptor<kToStringOffset,
9761 kToNumberOffset + kPointerSize,
9762 kSize> BodyDescriptor;
9764 STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
9765 STATIC_ASSERT(kNull == Internals::kNullOddballKind);
9766 STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind);
9769 DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
9773 class Cell: public HeapObject {
9775 // [value]: value of the cell.
9776 DECL_ACCESSORS(value, Object)
9780 static inline Cell* FromValueAddress(Address value) {
9781 Object* result = FromAddress(value - kValueOffset);
9782 DCHECK(result->IsCell());
9783 return static_cast<Cell*>(result);
9786 inline Address ValueAddress() {
9787 return address() + kValueOffset;
9790 // Dispatched behavior.
9791 DECLARE_PRINTER(Cell)
9792 DECLARE_VERIFIER(Cell)
9794 // Layout description.
9795 static const int kValueOffset = HeapObject::kHeaderSize;
9796 static const int kSize = kValueOffset + kPointerSize;
9798 typedef FixedBodyDescriptor<kValueOffset,
9799 kValueOffset + kPointerSize,
9800 kSize> BodyDescriptor;
9803 DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
9807 class PropertyCell : public HeapObject {
9809 // [value]: value of the global property.
9810 DECL_ACCESSORS(value, Object)
9811 // [dependent_code]: dependent code that depends on the type of the global
9813 DECL_ACCESSORS(dependent_code, DependentCode)
9815 // Computes the new type of the cell's contents for the given value, but
9816 // without actually modifying the details.
9817 static PropertyCellType UpdatedType(Handle<PropertyCell> cell,
9818 Handle<Object> value,
9819 PropertyDetails details);
9820 static Handle<Object> UpdateCell(Handle<NameDictionary> dictionary, int entry,
9821 Handle<Object> value,
9822 PropertyDetails details);
9824 static Handle<PropertyCell> InvalidateEntry(Handle<NameDictionary> dictionary,
9827 static void AddDependentCompilationInfo(Handle<PropertyCell> cell,
9828 CompilationInfo* info);
9830 DECLARE_CAST(PropertyCell)
9832 // Dispatched behavior.
9833 DECLARE_PRINTER(PropertyCell)
9834 DECLARE_VERIFIER(PropertyCell)
9836 // Layout description.
9837 static const int kValueOffset = HeapObject::kHeaderSize;
9838 static const int kDependentCodeOffset = kValueOffset + kPointerSize;
9839 static const int kSize = kDependentCodeOffset + kPointerSize;
9841 static const int kPointerFieldsBeginOffset = kValueOffset;
9842 static const int kPointerFieldsEndOffset = kSize;
9844 typedef FixedBodyDescriptor<kValueOffset,
9846 kSize> BodyDescriptor;
9849 DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
9853 class WeakCell : public HeapObject {
9855 inline Object* value() const;
9857 // This should not be called by anyone except GC.
9858 inline void clear();
9860 // This should not be called by anyone except allocator.
9861 inline void initialize(HeapObject* value);
9863 inline bool cleared() const;
9865 DECL_ACCESSORS(next, Object)
9867 DECLARE_CAST(WeakCell)
9869 DECLARE_PRINTER(WeakCell)
9870 DECLARE_VERIFIER(WeakCell)
9872 // Layout description.
9873 static const int kValueOffset = HeapObject::kHeaderSize;
9874 static const int kNextOffset = kValueOffset + kPointerSize;
9875 static const int kSize = kNextOffset + kPointerSize;
9877 typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor;
9880 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCell);
9884 // The JSProxy describes EcmaScript Harmony proxies
9885 class JSProxy: public JSReceiver {
9887 // [handler]: The handler property.
9888 DECL_ACCESSORS(handler, Object)
9890 // [hash]: The hash code property (undefined if not initialized yet).
9891 DECL_ACCESSORS(hash, Object)
9893 DECLARE_CAST(JSProxy)
9895 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithHandler(
9896 Handle<JSProxy> proxy,
9897 Handle<Object> receiver,
9899 MUST_USE_RESULT static inline MaybeHandle<Object> GetElementWithHandler(
9900 Handle<JSProxy> proxy,
9901 Handle<Object> receiver,
9904 // If the handler defines an accessor property with a setter, invoke it.
9905 // If it defines an accessor property without a setter, or a data property
9906 // that is read-only, throw. In all these cases set '*done' to true,
9907 // otherwise set it to false.
9909 static MaybeHandle<Object> SetPropertyViaPrototypesWithHandler(
9910 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9911 Handle<Object> value, LanguageMode language_mode, bool* done);
9913 MUST_USE_RESULT static Maybe<PropertyAttributes>
9914 GetPropertyAttributesWithHandler(Handle<JSProxy> proxy,
9915 Handle<Object> receiver,
9917 MUST_USE_RESULT static Maybe<PropertyAttributes>
9918 GetElementAttributeWithHandler(Handle<JSProxy> proxy,
9919 Handle<JSReceiver> receiver,
9921 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithHandler(
9922 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9923 Handle<Object> value, LanguageMode language_mode);
9925 // Turn the proxy into an (empty) JSObject.
9926 static void Fix(Handle<JSProxy> proxy);
9928 // Initializes the body after the handler slot.
9929 inline void InitializeBody(int object_size, Object* value);
9931 // Invoke a trap by name. If the trap does not exist on this's handler,
9932 // but derived_trap is non-NULL, invoke that instead. May cause GC.
9933 MUST_USE_RESULT static MaybeHandle<Object> CallTrap(
9934 Handle<JSProxy> proxy,
9936 Handle<Object> derived_trap,
9938 Handle<Object> args[]);
9940 // Dispatched behavior.
9941 DECLARE_PRINTER(JSProxy)
9942 DECLARE_VERIFIER(JSProxy)
9944 // Layout description. We add padding so that a proxy has the same
9945 // size as a virgin JSObject. This is essential for becoming a JSObject
9947 static const int kHandlerOffset = HeapObject::kHeaderSize;
9948 static const int kHashOffset = kHandlerOffset + kPointerSize;
9949 static const int kPaddingOffset = kHashOffset + kPointerSize;
9950 static const int kSize = JSObject::kHeaderSize;
9951 static const int kHeaderSize = kPaddingOffset;
9952 static const int kPaddingSize = kSize - kPaddingOffset;
9954 STATIC_ASSERT(kPaddingSize >= 0);
9956 typedef FixedBodyDescriptor<kHandlerOffset,
9958 kSize> BodyDescriptor;
9961 friend class JSReceiver;
9963 MUST_USE_RESULT static inline MaybeHandle<Object> SetElementWithHandler(
9964 Handle<JSProxy> proxy, Handle<JSReceiver> receiver, uint32_t index,
9965 Handle<Object> value, LanguageMode language_mode);
9967 MUST_USE_RESULT static Maybe<bool> HasPropertyWithHandler(
9968 Handle<JSProxy> proxy, Handle<Name> name);
9969 MUST_USE_RESULT static inline Maybe<bool> HasElementWithHandler(
9970 Handle<JSProxy> proxy, uint32_t index);
9972 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithHandler(
9973 Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode);
9974 MUST_USE_RESULT static MaybeHandle<Object> DeleteElementWithHandler(
9975 Handle<JSProxy> proxy, uint32_t index, LanguageMode language_mode);
9977 MUST_USE_RESULT Object* GetIdentityHash();
9979 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy);
9981 DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy);
9985 class JSFunctionProxy: public JSProxy {
9987 // [call_trap]: The call trap.
9988 DECL_ACCESSORS(call_trap, Object)
9990 // [construct_trap]: The construct trap.
9991 DECL_ACCESSORS(construct_trap, Object)
9993 DECLARE_CAST(JSFunctionProxy)
9995 // Dispatched behavior.
9996 DECLARE_PRINTER(JSFunctionProxy)
9997 DECLARE_VERIFIER(JSFunctionProxy)
9999 // Layout description.
10000 static const int kCallTrapOffset = JSProxy::kPaddingOffset;
10001 static const int kConstructTrapOffset = kCallTrapOffset + kPointerSize;
10002 static const int kPaddingOffset = kConstructTrapOffset + kPointerSize;
10003 static const int kSize = JSFunction::kSize;
10004 static const int kPaddingSize = kSize - kPaddingOffset;
10006 STATIC_ASSERT(kPaddingSize >= 0);
10008 typedef FixedBodyDescriptor<kHandlerOffset,
10009 kConstructTrapOffset + kPointerSize,
10010 kSize> BodyDescriptor;
10013 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunctionProxy);
10017 class JSCollection : public JSObject {
10019 // [table]: the backing hash table
10020 DECL_ACCESSORS(table, Object)
10022 static const int kTableOffset = JSObject::kHeaderSize;
10023 static const int kSize = kTableOffset + kPointerSize;
10026 DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollection);
10030 // The JSSet describes EcmaScript Harmony sets
10031 class JSSet : public JSCollection {
10033 DECLARE_CAST(JSSet)
10035 // Dispatched behavior.
10036 DECLARE_PRINTER(JSSet)
10037 DECLARE_VERIFIER(JSSet)
10040 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet);
10044 // The JSMap describes EcmaScript Harmony maps
10045 class JSMap : public JSCollection {
10047 DECLARE_CAST(JSMap)
10049 // Dispatched behavior.
10050 DECLARE_PRINTER(JSMap)
10051 DECLARE_VERIFIER(JSMap)
10054 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
10058 // OrderedHashTableIterator is an iterator that iterates over the keys and
10059 // values of an OrderedHashTable.
10061 // The iterator has a reference to the underlying OrderedHashTable data,
10062 // [table], as well as the current [index] the iterator is at.
10064 // When the OrderedHashTable is rehashed it adds a reference from the old table
10065 // to the new table as well as storing enough data about the changes so that the
10066 // iterator [index] can be adjusted accordingly.
10068 // When the [Next] result from the iterator is requested, the iterator checks if
10069 // there is a newer table that it needs to transition to.
10070 template<class Derived, class TableType>
10071 class OrderedHashTableIterator: public JSObject {
10073 // [table]: the backing hash table mapping keys to values.
10074 DECL_ACCESSORS(table, Object)
10076 // [index]: The index into the data table.
10077 DECL_ACCESSORS(index, Object)
10079 // [kind]: The kind of iteration this is. One of the [Kind] enum values.
10080 DECL_ACCESSORS(kind, Object)
10082 #ifdef OBJECT_PRINT
10083 void OrderedHashTableIteratorPrint(std::ostream& os); // NOLINT
10086 static const int kTableOffset = JSObject::kHeaderSize;
10087 static const int kIndexOffset = kTableOffset + kPointerSize;
10088 static const int kKindOffset = kIndexOffset + kPointerSize;
10089 static const int kSize = kKindOffset + kPointerSize;
10097 // Whether the iterator has more elements. This needs to be called before
10098 // calling |CurrentKey| and/or |CurrentValue|.
10101 // Move the index forward one.
10103 set_index(Smi::FromInt(Smi::cast(index())->value() + 1));
10106 // Populates the array with the next key and value and then moves the iterator
10108 // This returns the |kind| or 0 if the iterator is already at the end.
10109 Smi* Next(JSArray* value_array);
10111 // Returns the current key of the iterator. This should only be called when
10112 // |HasMore| returns true.
10113 inline Object* CurrentKey();
10116 // Transitions the iterator to the non obsolete backing store. This is a NOP
10117 // if the [table] is not obsolete.
10120 DISALLOW_IMPLICIT_CONSTRUCTORS(OrderedHashTableIterator);
10124 class JSSetIterator: public OrderedHashTableIterator<JSSetIterator,
10127 // Dispatched behavior.
10128 DECLARE_PRINTER(JSSetIterator)
10129 DECLARE_VERIFIER(JSSetIterator)
10131 DECLARE_CAST(JSSetIterator)
10133 // Called by |Next| to populate the array. This allows the subclasses to
10134 // populate the array differently.
10135 inline void PopulateValueArray(FixedArray* array);
10138 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSetIterator);
10142 class JSMapIterator: public OrderedHashTableIterator<JSMapIterator,
10145 // Dispatched behavior.
10146 DECLARE_PRINTER(JSMapIterator)
10147 DECLARE_VERIFIER(JSMapIterator)
10149 DECLARE_CAST(JSMapIterator)
10151 // Called by |Next| to populate the array. This allows the subclasses to
10152 // populate the array differently.
10153 inline void PopulateValueArray(FixedArray* array);
10156 // Returns the current value of the iterator. This should only be called when
10157 // |HasMore| returns true.
10158 inline Object* CurrentValue();
10160 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMapIterator);
10164 // Base class for both JSWeakMap and JSWeakSet
10165 class JSWeakCollection: public JSObject {
10167 // [table]: the backing hash table mapping keys to values.
10168 DECL_ACCESSORS(table, Object)
10170 // [next]: linked list of encountered weak maps during GC.
10171 DECL_ACCESSORS(next, Object)
10173 static const int kTableOffset = JSObject::kHeaderSize;
10174 static const int kNextOffset = kTableOffset + kPointerSize;
10175 static const int kSize = kNextOffset + kPointerSize;
10178 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection);
10182 // The JSWeakMap describes EcmaScript Harmony weak maps
10183 class JSWeakMap: public JSWeakCollection {
10185 DECLARE_CAST(JSWeakMap)
10187 // Dispatched behavior.
10188 DECLARE_PRINTER(JSWeakMap)
10189 DECLARE_VERIFIER(JSWeakMap)
10192 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
10196 // The JSWeakSet describes EcmaScript Harmony weak sets
10197 class JSWeakSet: public JSWeakCollection {
10199 DECLARE_CAST(JSWeakSet)
10201 // Dispatched behavior.
10202 DECLARE_PRINTER(JSWeakSet)
10203 DECLARE_VERIFIER(JSWeakSet)
10206 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet);
10210 class JSArrayBuffer: public JSObject {
10212 // [backing_store]: backing memory for this array
10213 DECL_ACCESSORS(backing_store, void)
10215 // [byte_length]: length in bytes
10216 DECL_ACCESSORS(byte_length, Object)
10219 DECL_ACCESSORS(flag, Smi)
10221 inline bool is_external();
10222 inline void set_is_external(bool value);
10224 inline bool should_be_freed();
10225 inline void set_should_be_freed(bool value);
10227 inline bool is_neuterable();
10228 inline void set_is_neuterable(bool value);
10230 // [weak_next]: linked list of array buffers.
10231 DECL_ACCESSORS(weak_next, Object)
10233 // [weak_first_array]: weak linked list of views.
10234 DECL_ACCESSORS(weak_first_view, Object)
10236 DECLARE_CAST(JSArrayBuffer)
10238 // Neutering. Only neuters the buffer, not associated typed arrays.
10241 // Dispatched behavior.
10242 DECLARE_PRINTER(JSArrayBuffer)
10243 DECLARE_VERIFIER(JSArrayBuffer)
10245 static const int kBackingStoreOffset = JSObject::kHeaderSize;
10246 static const int kByteLengthOffset = kBackingStoreOffset + kPointerSize;
10247 static const int kFlagOffset = kByteLengthOffset + kPointerSize;
10248 static const int kWeakNextOffset = kFlagOffset + kPointerSize;
10249 static const int kWeakFirstViewOffset = kWeakNextOffset + kPointerSize;
10250 static const int kSize = kWeakFirstViewOffset + kPointerSize;
10252 static const int kSizeWithInternalFields =
10253 kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
10256 // Bit position in a flag
10257 static const int kIsExternalBit = 0;
10258 static const int kShouldBeFreed = 1;
10259 static const int kIsNeuterableBit = 2;
10261 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
10265 class JSArrayBufferView: public JSObject {
10267 // [buffer]: ArrayBuffer that this typed array views.
10268 DECL_ACCESSORS(buffer, Object)
10270 // [byte_length]: offset of typed array in bytes.
10271 DECL_ACCESSORS(byte_offset, Object)
10273 // [byte_length]: length of typed array in bytes.
10274 DECL_ACCESSORS(byte_length, Object)
10276 // [weak_next]: linked list of typed arrays over the same array buffer.
10277 DECL_ACCESSORS(weak_next, Object)
10279 DECLARE_CAST(JSArrayBufferView)
10281 DECLARE_VERIFIER(JSArrayBufferView)
10283 static const int kBufferOffset = JSObject::kHeaderSize;
10284 static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
10285 static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
10286 static const int kWeakNextOffset = kByteLengthOffset + kPointerSize;
10287 static const int kViewSize = kWeakNextOffset + kPointerSize;
10293 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
10297 class JSTypedArray: public JSArrayBufferView {
10299 // [length]: length of typed array in elements.
10300 DECL_ACCESSORS(length, Object)
10302 // Neutering. Only neuters this typed array.
10305 DECLARE_CAST(JSTypedArray)
10307 ExternalArrayType type();
10308 size_t element_size();
10310 Handle<JSArrayBuffer> GetBuffer();
10312 // Dispatched behavior.
10313 DECLARE_PRINTER(JSTypedArray)
10314 DECLARE_VERIFIER(JSTypedArray)
10316 static const int kLengthOffset = kViewSize + kPointerSize;
10317 static const int kSize = kLengthOffset + kPointerSize;
10319 static const int kSizeWithInternalFields =
10320 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
10323 static Handle<JSArrayBuffer> MaterializeArrayBuffer(
10324 Handle<JSTypedArray> typed_array);
10326 DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
10330 class JSDataView: public JSArrayBufferView {
10332 // Only neuters this DataView
10335 DECLARE_CAST(JSDataView)
10337 // Dispatched behavior.
10338 DECLARE_PRINTER(JSDataView)
10339 DECLARE_VERIFIER(JSDataView)
10341 static const int kSize = kViewSize;
10343 static const int kSizeWithInternalFields =
10344 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
10347 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
10351 // Foreign describes objects pointing from JavaScript to C structures.
10352 // Since they cannot contain references to JS HeapObjects they can be
10353 // placed in old_data_space.
10354 class Foreign: public HeapObject {
10356 // [address]: field containing the address.
10357 inline Address foreign_address();
10358 inline void set_foreign_address(Address value);
10360 DECLARE_CAST(Foreign)
10362 // Dispatched behavior.
10363 inline void ForeignIterateBody(ObjectVisitor* v);
10365 template<typename StaticVisitor>
10366 inline void ForeignIterateBody();
10368 // Dispatched behavior.
10369 DECLARE_PRINTER(Foreign)
10370 DECLARE_VERIFIER(Foreign)
10372 // Layout description.
10374 static const int kForeignAddressOffset = HeapObject::kHeaderSize;
10375 static const int kSize = kForeignAddressOffset + kPointerSize;
10377 STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
10380 DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
10384 // The JSArray describes JavaScript Arrays
10385 // Such an array can be in one of two modes:
10386 // - fast, backing storage is a FixedArray and length <= elements.length();
10387 // Please note: push and pop can be used to grow and shrink the array.
10388 // - slow, backing storage is a HashTable with numbers as keys.
10389 class JSArray: public JSObject {
10391 // [length]: The length property.
10392 DECL_ACCESSORS(length, Object)
10394 // Overload the length setter to skip write barrier when the length
10395 // is set to a smi. This matches the set function on FixedArray.
10396 inline void set_length(Smi* length);
10398 static void JSArrayUpdateLengthFromIndex(Handle<JSArray> array,
10400 Handle<Object> value);
10402 static bool HasReadOnlyLength(Handle<JSArray> array);
10403 static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index);
10404 static MaybeHandle<Object> ReadOnlyLengthError(Handle<JSArray> array);
10406 // Initialize the array with the given capacity. The function may
10407 // fail due to out-of-memory situations, but only if the requested
10408 // capacity is non-zero.
10409 static void Initialize(Handle<JSArray> array, int capacity, int length = 0);
10411 // Initializes the array to a certain length.
10412 inline bool AllowsSetElementsLength();
10414 MUST_USE_RESULT static MaybeHandle<Object> SetElementsLength(
10415 Handle<JSArray> array,
10416 Handle<Object> length);
10418 // Set the content of the array to the content of storage.
10419 static inline void SetContent(Handle<JSArray> array,
10420 Handle<FixedArrayBase> storage);
10422 DECLARE_CAST(JSArray)
10424 // Ensures that the fixed array backing the JSArray has at
10425 // least the stated size.
10426 static inline void EnsureSize(Handle<JSArray> array,
10427 int minimum_size_of_backing_fixed_array);
10429 // Expand the fixed array backing of a fast-case JSArray to at least
10430 // the requested size.
10431 static void Expand(Handle<JSArray> array,
10432 int minimum_size_of_backing_fixed_array);
10434 // Dispatched behavior.
10435 DECLARE_PRINTER(JSArray)
10436 DECLARE_VERIFIER(JSArray)
10438 // Number of element slots to pre-allocate for an empty array.
10439 static const int kPreallocatedArrayElements = 4;
10441 // Layout description.
10442 static const int kLengthOffset = JSObject::kHeaderSize;
10443 static const int kSize = kLengthOffset + kPointerSize;
10446 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray);
10450 Handle<Object> CacheInitialJSArrayMaps(Handle<Context> native_context,
10451 Handle<Map> initial_map);
10454 // JSRegExpResult is just a JSArray with a specific initial map.
10455 // This initial map adds in-object properties for "index" and "input"
10456 // properties, as assigned by RegExp.prototype.exec, which allows
10457 // faster creation of RegExp exec results.
10458 // This class just holds constants used when creating the result.
10459 // After creation the result must be treated as a JSArray in all regards.
10460 class JSRegExpResult: public JSArray {
10462 // Offsets of object fields.
10463 static const int kIndexOffset = JSArray::kSize;
10464 static const int kInputOffset = kIndexOffset + kPointerSize;
10465 static const int kSize = kInputOffset + kPointerSize;
10466 // Indices of in-object properties.
10467 static const int kIndexIndex = 0;
10468 static const int kInputIndex = 1;
10470 DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
10474 class AccessorInfo: public Struct {
10476 DECL_ACCESSORS(name, Object)
10477 DECL_ACCESSORS(flag, Smi)
10478 DECL_ACCESSORS(expected_receiver_type, Object)
10480 inline bool all_can_read();
10481 inline void set_all_can_read(bool value);
10483 inline bool all_can_write();
10484 inline void set_all_can_write(bool value);
10486 inline PropertyAttributes property_attributes();
10487 inline void set_property_attributes(PropertyAttributes attributes);
10489 // Checks whether the given receiver is compatible with this accessor.
10490 static bool IsCompatibleReceiverMap(Isolate* isolate,
10491 Handle<AccessorInfo> info,
10493 inline bool IsCompatibleReceiver(Object* receiver);
10495 DECLARE_CAST(AccessorInfo)
10497 // Dispatched behavior.
10498 DECLARE_VERIFIER(AccessorInfo)
10500 // Append all descriptors to the array that are not already there.
10501 // Return number added.
10502 static int AppendUnique(Handle<Object> descriptors,
10503 Handle<FixedArray> array,
10504 int valid_descriptors);
10506 static const int kNameOffset = HeapObject::kHeaderSize;
10507 static const int kFlagOffset = kNameOffset + kPointerSize;
10508 static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
10509 static const int kSize = kExpectedReceiverTypeOffset + kPointerSize;
10512 inline bool HasExpectedReceiverType() {
10513 return expected_receiver_type()->IsFunctionTemplateInfo();
10515 // Bit positions in flag.
10516 static const int kAllCanReadBit = 0;
10517 static const int kAllCanWriteBit = 1;
10518 class AttributesField: public BitField<PropertyAttributes, 2, 3> {};
10520 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo);
10524 // An accessor must have a getter, but can have no setter.
10526 // When setting a property, V8 searches accessors in prototypes.
10527 // If an accessor was found and it does not have a setter,
10528 // the request is ignored.
10530 // If the accessor in the prototype has the READ_ONLY property attribute, then
10531 // a new value is added to the derived object when the property is set.
10532 // This shadows the accessor in the prototype.
10533 class ExecutableAccessorInfo: public AccessorInfo {
10535 DECL_ACCESSORS(getter, Object)
10536 DECL_ACCESSORS(setter, Object)
10537 DECL_ACCESSORS(data, Object)
10539 DECLARE_CAST(ExecutableAccessorInfo)
10541 // Dispatched behavior.
10542 DECLARE_PRINTER(ExecutableAccessorInfo)
10543 DECLARE_VERIFIER(ExecutableAccessorInfo)
10545 static const int kGetterOffset = AccessorInfo::kSize;
10546 static const int kSetterOffset = kGetterOffset + kPointerSize;
10547 static const int kDataOffset = kSetterOffset + kPointerSize;
10548 static const int kSize = kDataOffset + kPointerSize;
10550 inline void clear_setter();
10553 DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutableAccessorInfo);
10557 // Support for JavaScript accessors: A pair of a getter and a setter. Each
10558 // accessor can either be
10559 // * a pointer to a JavaScript function or proxy: a real accessor
10560 // * undefined: considered an accessor by the spec, too, strangely enough
10561 // * the hole: an accessor which has not been set
10562 // * a pointer to a map: a transition used to ensure map sharing
10563 class AccessorPair: public Struct {
10565 DECL_ACCESSORS(getter, Object)
10566 DECL_ACCESSORS(setter, Object)
10568 DECLARE_CAST(AccessorPair)
10570 static Handle<AccessorPair> Copy(Handle<AccessorPair> pair);
10572 Object* get(AccessorComponent component) {
10573 return component == ACCESSOR_GETTER ? getter() : setter();
10576 void set(AccessorComponent component, Object* value) {
10577 if (component == ACCESSOR_GETTER) {
10584 // Note: Returns undefined instead in case of a hole.
10585 Object* GetComponent(AccessorComponent component);
10587 // Set both components, skipping arguments which are a JavaScript null.
10588 void SetComponents(Object* getter, Object* setter) {
10589 if (!getter->IsNull()) set_getter(getter);
10590 if (!setter->IsNull()) set_setter(setter);
10593 bool Equals(AccessorPair* pair) {
10594 return (this == pair) || pair->Equals(getter(), setter());
10597 bool Equals(Object* getter_value, Object* setter_value) {
10598 return (getter() == getter_value) && (setter() == setter_value);
10601 bool ContainsAccessor() {
10602 return IsJSAccessor(getter()) || IsJSAccessor(setter());
10605 // Dispatched behavior.
10606 DECLARE_PRINTER(AccessorPair)
10607 DECLARE_VERIFIER(AccessorPair)
10609 static const int kGetterOffset = HeapObject::kHeaderSize;
10610 static const int kSetterOffset = kGetterOffset + kPointerSize;
10611 static const int kSize = kSetterOffset + kPointerSize;
10614 // Strangely enough, in addition to functions and harmony proxies, the spec
10615 // requires us to consider undefined as a kind of accessor, too:
10617 // Object.defineProperty(obj, "foo", {get: undefined});
10618 // assertTrue("foo" in obj);
10619 bool IsJSAccessor(Object* obj) {
10620 return obj->IsSpecFunction() || obj->IsUndefined();
10623 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
10627 class AccessCheckInfo: public Struct {
10629 DECL_ACCESSORS(named_callback, Object)
10630 DECL_ACCESSORS(indexed_callback, Object)
10631 DECL_ACCESSORS(data, Object)
10633 DECLARE_CAST(AccessCheckInfo)
10635 // Dispatched behavior.
10636 DECLARE_PRINTER(AccessCheckInfo)
10637 DECLARE_VERIFIER(AccessCheckInfo)
10639 static const int kNamedCallbackOffset = HeapObject::kHeaderSize;
10640 static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize;
10641 static const int kDataOffset = kIndexedCallbackOffset + kPointerSize;
10642 static const int kSize = kDataOffset + kPointerSize;
10645 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo);
10649 class InterceptorInfo: public Struct {
10651 DECL_ACCESSORS(getter, Object)
10652 DECL_ACCESSORS(setter, Object)
10653 DECL_ACCESSORS(query, Object)
10654 DECL_ACCESSORS(deleter, Object)
10655 DECL_ACCESSORS(enumerator, Object)
10656 DECL_ACCESSORS(data, Object)
10657 DECL_BOOLEAN_ACCESSORS(can_intercept_symbols)
10658 DECL_BOOLEAN_ACCESSORS(all_can_read)
10659 DECL_BOOLEAN_ACCESSORS(non_masking)
10661 inline int flags() const;
10662 inline void set_flags(int flags);
10664 DECLARE_CAST(InterceptorInfo)
10666 // Dispatched behavior.
10667 DECLARE_PRINTER(InterceptorInfo)
10668 DECLARE_VERIFIER(InterceptorInfo)
10670 static const int kGetterOffset = HeapObject::kHeaderSize;
10671 static const int kSetterOffset = kGetterOffset + kPointerSize;
10672 static const int kQueryOffset = kSetterOffset + kPointerSize;
10673 static const int kDeleterOffset = kQueryOffset + kPointerSize;
10674 static const int kEnumeratorOffset = kDeleterOffset + kPointerSize;
10675 static const int kDataOffset = kEnumeratorOffset + kPointerSize;
10676 static const int kFlagsOffset = kDataOffset + kPointerSize;
10677 static const int kSize = kFlagsOffset + kPointerSize;
10679 static const int kCanInterceptSymbolsBit = 0;
10680 static const int kAllCanReadBit = 1;
10681 static const int kNonMasking = 2;
10684 DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo);
10688 class CallHandlerInfo: public Struct {
10690 DECL_ACCESSORS(callback, Object)
10691 DECL_ACCESSORS(data, Object)
10693 DECLARE_CAST(CallHandlerInfo)
10695 // Dispatched behavior.
10696 DECLARE_PRINTER(CallHandlerInfo)
10697 DECLARE_VERIFIER(CallHandlerInfo)
10699 static const int kCallbackOffset = HeapObject::kHeaderSize;
10700 static const int kDataOffset = kCallbackOffset + kPointerSize;
10701 static const int kSize = kDataOffset + kPointerSize;
10704 DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo);
10708 class TemplateInfo: public Struct {
10710 DECL_ACCESSORS(tag, Object)
10711 DECL_ACCESSORS(property_list, Object)
10712 DECL_ACCESSORS(property_accessors, Object)
10714 DECLARE_VERIFIER(TemplateInfo)
10716 static const int kTagOffset = HeapObject::kHeaderSize;
10717 static const int kPropertyListOffset = kTagOffset + kPointerSize;
10718 static const int kPropertyAccessorsOffset =
10719 kPropertyListOffset + kPointerSize;
10720 static const int kHeaderSize = kPropertyAccessorsOffset + kPointerSize;
10723 DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo);
10727 class FunctionTemplateInfo: public TemplateInfo {
10729 DECL_ACCESSORS(serial_number, Object)
10730 DECL_ACCESSORS(call_code, Object)
10731 DECL_ACCESSORS(prototype_template, Object)
10732 DECL_ACCESSORS(parent_template, Object)
10733 DECL_ACCESSORS(named_property_handler, Object)
10734 DECL_ACCESSORS(indexed_property_handler, Object)
10735 DECL_ACCESSORS(instance_template, Object)
10736 DECL_ACCESSORS(class_name, Object)
10737 DECL_ACCESSORS(signature, Object)
10738 DECL_ACCESSORS(instance_call_handler, Object)
10739 DECL_ACCESSORS(access_check_info, Object)
10740 DECL_ACCESSORS(flag, Smi)
10742 inline int length() const;
10743 inline void set_length(int value);
10745 // Following properties use flag bits.
10746 DECL_BOOLEAN_ACCESSORS(hidden_prototype)
10747 DECL_BOOLEAN_ACCESSORS(undetectable)
10748 // If the bit is set, object instances created by this function
10749 // requires access check.
10750 DECL_BOOLEAN_ACCESSORS(needs_access_check)
10751 DECL_BOOLEAN_ACCESSORS(read_only_prototype)
10752 DECL_BOOLEAN_ACCESSORS(remove_prototype)
10753 DECL_BOOLEAN_ACCESSORS(do_not_cache)
10754 DECL_BOOLEAN_ACCESSORS(instantiated)
10755 DECL_BOOLEAN_ACCESSORS(accept_any_receiver)
10757 DECLARE_CAST(FunctionTemplateInfo)
10759 // Dispatched behavior.
10760 DECLARE_PRINTER(FunctionTemplateInfo)
10761 DECLARE_VERIFIER(FunctionTemplateInfo)
10763 static const int kSerialNumberOffset = TemplateInfo::kHeaderSize;
10764 static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize;
10765 static const int kPrototypeTemplateOffset =
10766 kCallCodeOffset + kPointerSize;
10767 static const int kParentTemplateOffset =
10768 kPrototypeTemplateOffset + kPointerSize;
10769 static const int kNamedPropertyHandlerOffset =
10770 kParentTemplateOffset + kPointerSize;
10771 static const int kIndexedPropertyHandlerOffset =
10772 kNamedPropertyHandlerOffset + kPointerSize;
10773 static const int kInstanceTemplateOffset =
10774 kIndexedPropertyHandlerOffset + kPointerSize;
10775 static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize;
10776 static const int kSignatureOffset = kClassNameOffset + kPointerSize;
10777 static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize;
10778 static const int kAccessCheckInfoOffset =
10779 kInstanceCallHandlerOffset + kPointerSize;
10780 static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize;
10781 static const int kLengthOffset = kFlagOffset + kPointerSize;
10782 static const int kSize = kLengthOffset + kPointerSize;
10784 // Returns true if |object| is an instance of this function template.
10785 bool IsTemplateFor(Object* object);
10786 bool IsTemplateFor(Map* map);
10788 // Returns the holder JSObject if the function can legally be called with this
10789 // receiver. Returns Heap::null_value() if the call is illegal.
10790 Object* GetCompatibleReceiver(Isolate* isolate, Object* receiver);
10793 // Bit position in the flag, from least significant bit position.
10794 static const int kHiddenPrototypeBit = 0;
10795 static const int kUndetectableBit = 1;
10796 static const int kNeedsAccessCheckBit = 2;
10797 static const int kReadOnlyPrototypeBit = 3;
10798 static const int kRemovePrototypeBit = 4;
10799 static const int kDoNotCacheBit = 5;
10800 static const int kInstantiatedBit = 6;
10801 static const int kAcceptAnyReceiver = 7;
10803 DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo);
10807 class ObjectTemplateInfo: public TemplateInfo {
10809 DECL_ACCESSORS(constructor, Object)
10810 DECL_ACCESSORS(internal_field_count, Object)
10812 DECLARE_CAST(ObjectTemplateInfo)
10814 // Dispatched behavior.
10815 DECLARE_PRINTER(ObjectTemplateInfo)
10816 DECLARE_VERIFIER(ObjectTemplateInfo)
10818 static const int kConstructorOffset = TemplateInfo::kHeaderSize;
10819 static const int kInternalFieldCountOffset =
10820 kConstructorOffset + kPointerSize;
10821 static const int kSize = kInternalFieldCountOffset + kPointerSize;
10825 class TypeSwitchInfo: public Struct {
10827 DECL_ACCESSORS(types, Object)
10829 DECLARE_CAST(TypeSwitchInfo)
10831 // Dispatched behavior.
10832 DECLARE_PRINTER(TypeSwitchInfo)
10833 DECLARE_VERIFIER(TypeSwitchInfo)
10835 static const int kTypesOffset = Struct::kHeaderSize;
10836 static const int kSize = kTypesOffset + kPointerSize;
10840 // The DebugInfo class holds additional information for a function being
10842 class DebugInfo: public Struct {
10844 // The shared function info for the source being debugged.
10845 DECL_ACCESSORS(shared, SharedFunctionInfo)
10846 // Code object for the original code.
10847 DECL_ACCESSORS(original_code, Code)
10848 // Code object for the patched code. This code object is the code object
10849 // currently active for the function.
10850 DECL_ACCESSORS(code, Code)
10851 // Fixed array holding status information for each active break point.
10852 DECL_ACCESSORS(break_points, FixedArray)
10854 // Check if there is a break point at a code position.
10855 bool HasBreakPoint(int code_position);
10856 // Get the break point info object for a code position.
10857 Object* GetBreakPointInfo(int code_position);
10858 // Clear a break point.
10859 static void ClearBreakPoint(Handle<DebugInfo> debug_info,
10861 Handle<Object> break_point_object);
10862 // Set a break point.
10863 static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position,
10864 int source_position, int statement_position,
10865 Handle<Object> break_point_object);
10866 // Get the break point objects for a code position.
10867 Handle<Object> GetBreakPointObjects(int code_position);
10868 // Find the break point info holding this break point object.
10869 static Handle<Object> FindBreakPointInfo(Handle<DebugInfo> debug_info,
10870 Handle<Object> break_point_object);
10871 // Get the number of break points for this function.
10872 int GetBreakPointCount();
10874 DECLARE_CAST(DebugInfo)
10876 // Dispatched behavior.
10877 DECLARE_PRINTER(DebugInfo)
10878 DECLARE_VERIFIER(DebugInfo)
10880 static const int kSharedFunctionInfoIndex = Struct::kHeaderSize;
10881 static const int kOriginalCodeIndex = kSharedFunctionInfoIndex + kPointerSize;
10882 static const int kPatchedCodeIndex = kOriginalCodeIndex + kPointerSize;
10883 static const int kActiveBreakPointsCountIndex =
10884 kPatchedCodeIndex + kPointerSize;
10885 static const int kBreakPointsStateIndex =
10886 kActiveBreakPointsCountIndex + kPointerSize;
10887 static const int kSize = kBreakPointsStateIndex + kPointerSize;
10889 static const int kEstimatedNofBreakPointsInFunction = 16;
10892 static const int kNoBreakPointInfo = -1;
10894 // Lookup the index in the break_points array for a code position.
10895 int GetBreakPointInfoIndex(int code_position);
10897 DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo);
10901 // The BreakPointInfo class holds information for break points set in a
10902 // function. The DebugInfo object holds a BreakPointInfo object for each code
10903 // position with one or more break points.
10904 class BreakPointInfo: public Struct {
10906 // The position in the code for the break point.
10907 DECL_ACCESSORS(code_position, Smi)
10908 // The position in the source for the break position.
10909 DECL_ACCESSORS(source_position, Smi)
10910 // The position in the source for the last statement before this break
10912 DECL_ACCESSORS(statement_position, Smi)
10913 // List of related JavaScript break points.
10914 DECL_ACCESSORS(break_point_objects, Object)
10916 // Removes a break point.
10917 static void ClearBreakPoint(Handle<BreakPointInfo> info,
10918 Handle<Object> break_point_object);
10919 // Set a break point.
10920 static void SetBreakPoint(Handle<BreakPointInfo> info,
10921 Handle<Object> break_point_object);
10922 // Check if break point info has this break point object.
10923 static bool HasBreakPointObject(Handle<BreakPointInfo> info,
10924 Handle<Object> break_point_object);
10925 // Get the number of break points for this code position.
10926 int GetBreakPointCount();
10928 DECLARE_CAST(BreakPointInfo)
10930 // Dispatched behavior.
10931 DECLARE_PRINTER(BreakPointInfo)
10932 DECLARE_VERIFIER(BreakPointInfo)
10934 static const int kCodePositionIndex = Struct::kHeaderSize;
10935 static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize;
10936 static const int kStatementPositionIndex =
10937 kSourcePositionIndex + kPointerSize;
10938 static const int kBreakPointObjectsIndex =
10939 kStatementPositionIndex + kPointerSize;
10940 static const int kSize = kBreakPointObjectsIndex + kPointerSize;
10943 DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo);
10947 #undef DECL_BOOLEAN_ACCESSORS
10948 #undef DECL_ACCESSORS
10949 #undef DECLARE_CAST
10950 #undef DECLARE_VERIFIER
10952 #define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \
10953 V(kStringTable, "string_table", "(Internalized strings)") \
10954 V(kExternalStringsTable, "external_strings_table", "(External strings)") \
10955 V(kStrongRootList, "strong_root_list", "(Strong roots)") \
10956 V(kSmiRootList, "smi_root_list", "(Smi roots)") \
10957 V(kInternalizedString, "internalized_string", "(Internal string)") \
10958 V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \
10959 V(kTop, "top", "(Isolate)") \
10960 V(kRelocatable, "relocatable", "(Relocatable)") \
10961 V(kDebug, "debug", "(Debugger)") \
10962 V(kCompilationCache, "compilationcache", "(Compilation cache)") \
10963 V(kHandleScope, "handlescope", "(Handle scope)") \
10964 V(kBuiltins, "builtins", "(Builtins)") \
10965 V(kGlobalHandles, "globalhandles", "(Global handles)") \
10966 V(kEternalHandles, "eternalhandles", "(Eternal handles)") \
10967 V(kThreadManager, "threadmanager", "(Thread manager)") \
10968 V(kExtensions, "Extensions", "(Extensions)")
10970 class VisitorSynchronization : public AllStatic {
10972 #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item,
10974 VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM)
10977 #undef DECLARE_ENUM
10979 static const char* const kTags[kNumberOfSyncTags];
10980 static const char* const kTagNames[kNumberOfSyncTags];
10983 // Abstract base class for visiting, and optionally modifying, the
10984 // pointers contained in Objects. Used in GC and serialization/deserialization.
10985 class ObjectVisitor BASE_EMBEDDED {
10987 virtual ~ObjectVisitor() {}
10989 // Visits a contiguous arrays of pointers in the half-open range
10990 // [start, end). Any or all of the values may be modified on return.
10991 virtual void VisitPointers(Object** start, Object** end) = 0;
10993 // Handy shorthand for visiting a single pointer.
10994 virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
10996 // Visit weak next_code_link in Code object.
10997 virtual void VisitNextCodeLink(Object** p) { VisitPointers(p, p + 1); }
10999 // To allow lazy clearing of inline caches the visitor has
11000 // a rich interface for iterating over Code objects..
11002 // Visits a code target in the instruction stream.
11003 virtual void VisitCodeTarget(RelocInfo* rinfo);
11005 // Visits a code entry in a JS function.
11006 virtual void VisitCodeEntry(Address entry_address);
11008 // Visits a global property cell reference in the instruction stream.
11009 virtual void VisitCell(RelocInfo* rinfo);
11011 // Visits a runtime entry in the instruction stream.
11012 virtual void VisitRuntimeEntry(RelocInfo* rinfo) {}
11014 // Visits the resource of an one-byte or two-byte string.
11015 virtual void VisitExternalOneByteString(
11016 v8::String::ExternalOneByteStringResource** resource) {}
11017 virtual void VisitExternalTwoByteString(
11018 v8::String::ExternalStringResource** resource) {}
11020 // Visits a debug call target in the instruction stream.
11021 virtual void VisitDebugTarget(RelocInfo* rinfo);
11023 // Visits the byte sequence in a function's prologue that contains information
11024 // about the code's age.
11025 virtual void VisitCodeAgeSequence(RelocInfo* rinfo);
11027 // Visit pointer embedded into a code object.
11028 virtual void VisitEmbeddedPointer(RelocInfo* rinfo);
11030 // Visits an external reference embedded into a code object.
11031 virtual void VisitExternalReference(RelocInfo* rinfo);
11033 // Visits an external reference.
11034 virtual void VisitExternalReference(Address* p) {}
11036 // Visits an (encoded) internal reference.
11037 virtual void VisitInternalReference(RelocInfo* rinfo) {}
11039 // Visits a handle that has an embedder-assigned class ID.
11040 virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {}
11042 // Intended for serialization/deserialization checking: insert, or
11043 // check for the presence of, a tag at this position in the stream.
11044 // Also used for marking up GC roots in heap snapshots.
11045 virtual void Synchronize(VisitorSynchronization::SyncTag tag) {}
11049 class StructBodyDescriptor : public
11050 FlexibleBodyDescriptor<HeapObject::kHeaderSize> {
11052 static inline int SizeOf(Map* map, HeapObject* object) {
11053 return map->instance_size();
11058 // BooleanBit is a helper class for setting and getting a bit in an
11060 class BooleanBit : public AllStatic {
11062 static inline bool get(Smi* smi, int bit_position) {
11063 return get(smi->value(), bit_position);
11066 static inline bool get(int value, int bit_position) {
11067 return (value & (1 << bit_position)) != 0;
11070 static inline Smi* set(Smi* smi, int bit_position, bool v) {
11071 return Smi::FromInt(set(smi->value(), bit_position, v));
11074 static inline int set(int value, int bit_position, bool v) {
11076 value |= (1 << bit_position);
11078 value &= ~(1 << bit_position);
11084 } } // namespace v8::internal
11086 #endif // V8_OBJECTS_H_