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/base/smart-pointers.h"
15 #include "src/builtins.h"
16 #include "src/checks.h"
17 #include "src/elements-kind.h"
18 #include "src/field-index.h"
19 #include "src/flags.h"
21 #include "src/property-details.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
82 // - CompilationCacheTable
83 // - CodeCacheHashTable
89 // - TypeFeedbackVector
92 // - ScriptContextTable
103 // - ExternalOneByteString
104 // - ExternalTwoByteString
105 // - InternalizedString
106 // - SeqInternalizedString
107 // - SeqOneByteInternalizedString
108 // - SeqTwoByteInternalizedString
109 // - ConsInternalizedString
110 // - ExternalInternalizedString
111 // - ExternalOneByteInternalizedString
112 // - ExternalTwoByteInternalizedString
129 // - SharedFunctionInfo
133 // - ExecutableAccessorInfo
139 // - FunctionTemplateInfo
140 // - 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 TypeofMode { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
185 enum ExternalArrayType {
186 kExternalInt8Array = 1,
189 kExternalUint16Array,
191 kExternalUint32Array,
192 kExternalFloat32Array,
193 kExternalFloat64Array,
194 kExternalUint8ClampedArray,
198 static const int kGrowICDelta = STORE_AND_GROW_NO_TRANSITION -
200 STATIC_ASSERT(STANDARD_STORE == 0);
201 STATIC_ASSERT(kGrowICDelta ==
202 STORE_AND_GROW_TRANSITION_SMI_TO_OBJECT -
203 STORE_TRANSITION_SMI_TO_OBJECT);
204 STATIC_ASSERT(kGrowICDelta ==
205 STORE_AND_GROW_TRANSITION_SMI_TO_DOUBLE -
206 STORE_TRANSITION_SMI_TO_DOUBLE);
207 STATIC_ASSERT(kGrowICDelta ==
208 STORE_AND_GROW_TRANSITION_DOUBLE_TO_OBJECT -
209 STORE_TRANSITION_DOUBLE_TO_OBJECT);
212 static inline KeyedAccessStoreMode GetGrowStoreMode(
213 KeyedAccessStoreMode store_mode) {
214 if (store_mode < STORE_AND_GROW_NO_TRANSITION) {
215 store_mode = static_cast<KeyedAccessStoreMode>(
216 static_cast<int>(store_mode) + kGrowICDelta);
222 static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) {
223 return store_mode > STANDARD_STORE &&
224 store_mode <= STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT &&
225 store_mode != STORE_AND_GROW_NO_TRANSITION;
229 static inline KeyedAccessStoreMode GetNonTransitioningStoreMode(
230 KeyedAccessStoreMode store_mode) {
231 if (store_mode >= STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
234 if (store_mode >= STORE_AND_GROW_NO_TRANSITION) {
235 return STORE_AND_GROW_NO_TRANSITION;
237 return STANDARD_STORE;
241 static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
242 return store_mode >= STORE_AND_GROW_NO_TRANSITION &&
243 store_mode <= STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT;
247 enum IcCheckType { ELEMENT, PROPERTY };
250 // SKIP_WRITE_BARRIER skips the write barrier.
251 // UPDATE_WEAK_WRITE_BARRIER skips the marking part of the write barrier and
252 // only performs the generational part.
253 // UPDATE_WRITE_BARRIER is doing the full barrier, marking and generational.
254 enum WriteBarrierMode {
256 UPDATE_WEAK_WRITE_BARRIER,
261 // Indicates whether a value can be loaded as a constant.
262 enum StoreMode { ALLOW_IN_DESCRIPTOR, FORCE_FIELD };
265 // PropertyNormalizationMode is used to specify whether to keep
266 // inobject properties when normalizing properties of a JSObject.
267 enum PropertyNormalizationMode {
268 CLEAR_INOBJECT_PROPERTIES,
269 KEEP_INOBJECT_PROPERTIES
273 // Indicates how aggressively the prototype should be optimized. FAST_PROTOTYPE
274 // will give the fastest result by tailoring the map to the prototype, but that
275 // will cause polymorphism with other objects. REGULAR_PROTOTYPE is to be used
276 // (at least for now) when dynamically modifying the prototype chain of an
277 // object using __proto__ or Object.setPrototypeOf.
278 enum PrototypeOptimizationMode { REGULAR_PROTOTYPE, FAST_PROTOTYPE };
281 // Indicates whether transitions can be added to a source map or not.
282 enum TransitionFlag {
288 // Indicates whether the transition is simple: the target map of the transition
289 // either extends the current map with a new property, or it modifies the
290 // property that was added last to the current map.
291 enum SimpleTransitionFlag {
292 SIMPLE_PROPERTY_TRANSITION,
298 // Indicates whether we are only interested in the descriptors of a particular
299 // map, or in all descriptors in the descriptor array.
300 enum DescriptorFlag {
305 // The GC maintains a bit of information, the MarkingParity, which toggles
306 // from odd to even and back every time marking is completed. Incremental
307 // marking can visit an object twice during a marking phase, so algorithms that
308 // that piggy-back on marking can use the parity to ensure that they only
309 // perform an operation on an object once per marking phase: they record the
310 // MarkingParity when they visit an object, and only re-visit the object when it
311 // is marked again and the MarkingParity changes.
318 // ICs store extra state in a Code object. The default extra state is
320 typedef int ExtraICState;
321 static const ExtraICState kNoExtraICState = 0;
323 // Instance size sentinel for objects of variable size.
324 const int kVariableSizeSentinel = 0;
326 // We may store the unsigned bit field as signed Smi value and do not
328 const int kStubMajorKeyBits = 7;
329 const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
331 // All Maps have a field instance_type containing a InstanceType.
332 // It describes the type of the instances.
334 // As an example, a JavaScript object is a heap object and its map
335 // instance_type is JS_OBJECT_TYPE.
337 // The names of the string instance types are intended to systematically
338 // mirror their encoding in the instance_type field of the map. The default
339 // encoding is considered TWO_BYTE. It is not mentioned in the name. ONE_BYTE
340 // encoding is mentioned explicitly in the name. Likewise, the default
341 // representation is considered sequential. It is not mentioned in the
342 // name. The other representations (e.g. CONS, EXTERNAL) are explicitly
343 // mentioned. Finally, the string is either a STRING_TYPE (if it is a normal
344 // string) or a INTERNALIZED_STRING_TYPE (if it is a internalized string).
346 // NOTE: The following things are some that depend on the string types having
347 // instance_types that are less than those of all other types:
348 // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and
351 // NOTE: Everything following JS_VALUE_TYPE is considered a
352 // JSObject for GC purposes. The first four entries here have typeof
353 // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'.
354 #define INSTANCE_TYPE_LIST(V) \
356 V(ONE_BYTE_STRING_TYPE) \
357 V(CONS_STRING_TYPE) \
358 V(CONS_ONE_BYTE_STRING_TYPE) \
359 V(SLICED_STRING_TYPE) \
360 V(SLICED_ONE_BYTE_STRING_TYPE) \
361 V(EXTERNAL_STRING_TYPE) \
362 V(EXTERNAL_ONE_BYTE_STRING_TYPE) \
363 V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
364 V(SHORT_EXTERNAL_STRING_TYPE) \
365 V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE) \
366 V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
368 V(INTERNALIZED_STRING_TYPE) \
369 V(ONE_BYTE_INTERNALIZED_STRING_TYPE) \
370 V(EXTERNAL_INTERNALIZED_STRING_TYPE) \
371 V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
372 V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
373 V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE) \
374 V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
375 V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
378 V(SIMD128_VALUE_TYPE) \
384 V(PROPERTY_CELL_TYPE) \
386 V(HEAP_NUMBER_TYPE) \
387 V(MUTABLE_HEAP_NUMBER_TYPE) \
390 V(BYTECODE_ARRAY_TYPE) \
393 V(FIXED_INT8_ARRAY_TYPE) \
394 V(FIXED_UINT8_ARRAY_TYPE) \
395 V(FIXED_INT16_ARRAY_TYPE) \
396 V(FIXED_UINT16_ARRAY_TYPE) \
397 V(FIXED_INT32_ARRAY_TYPE) \
398 V(FIXED_UINT32_ARRAY_TYPE) \
399 V(FIXED_FLOAT32_ARRAY_TYPE) \
400 V(FIXED_FLOAT64_ARRAY_TYPE) \
401 V(FIXED_UINT8_CLAMPED_ARRAY_TYPE) \
405 V(DECLARED_ACCESSOR_DESCRIPTOR_TYPE) \
406 V(DECLARED_ACCESSOR_INFO_TYPE) \
407 V(EXECUTABLE_ACCESSOR_INFO_TYPE) \
408 V(ACCESSOR_PAIR_TYPE) \
409 V(ACCESS_CHECK_INFO_TYPE) \
410 V(INTERCEPTOR_INFO_TYPE) \
411 V(CALL_HANDLER_INFO_TYPE) \
412 V(FUNCTION_TEMPLATE_INFO_TYPE) \
413 V(OBJECT_TEMPLATE_INFO_TYPE) \
414 V(SIGNATURE_INFO_TYPE) \
415 V(TYPE_SWITCH_INFO_TYPE) \
416 V(ALLOCATION_MEMENTO_TYPE) \
417 V(ALLOCATION_SITE_TYPE) \
420 V(POLYMORPHIC_CODE_CACHE_TYPE) \
421 V(TYPE_FEEDBACK_INFO_TYPE) \
422 V(ALIASED_ARGUMENTS_ENTRY_TYPE) \
424 V(PROTOTYPE_INFO_TYPE) \
426 V(FIXED_ARRAY_TYPE) \
427 V(FIXED_DOUBLE_ARRAY_TYPE) \
428 V(SHARED_FUNCTION_INFO_TYPE) \
431 V(JS_MESSAGE_OBJECT_TYPE) \
436 V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \
437 V(JS_GENERATOR_OBJECT_TYPE) \
439 V(JS_GLOBAL_OBJECT_TYPE) \
440 V(JS_BUILTINS_OBJECT_TYPE) \
441 V(JS_GLOBAL_PROXY_TYPE) \
443 V(JS_ARRAY_BUFFER_TYPE) \
444 V(JS_TYPED_ARRAY_TYPE) \
445 V(JS_DATA_VIEW_TYPE) \
449 V(JS_SET_ITERATOR_TYPE) \
450 V(JS_MAP_ITERATOR_TYPE) \
451 V(JS_WEAK_MAP_TYPE) \
452 V(JS_WEAK_SET_TYPE) \
455 V(JS_FUNCTION_TYPE) \
456 V(JS_FUNCTION_PROXY_TYPE) \
458 V(BREAK_POINT_INFO_TYPE)
461 // Since string types are not consecutive, this macro is used to
462 // iterate over them.
463 #define STRING_TYPE_LIST(V) \
464 V(STRING_TYPE, kVariableSizeSentinel, string, String) \
465 V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string, \
467 V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString) \
468 V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string, \
470 V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString) \
471 V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string, \
472 SlicedOneByteString) \
473 V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string, \
475 V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize, \
476 external_one_byte_string, ExternalOneByteString) \
477 V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize, \
478 external_string_with_one_byte_data, ExternalStringWithOneByteData) \
479 V(SHORT_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kShortSize, \
480 short_external_string, ShortExternalString) \
481 V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kShortSize, \
482 short_external_one_byte_string, ShortExternalOneByteString) \
483 V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, \
484 ExternalTwoByteString::kShortSize, \
485 short_external_string_with_one_byte_data, \
486 ShortExternalStringWithOneByteData) \
488 V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string, \
489 InternalizedString) \
490 V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, \
491 one_byte_internalized_string, OneByteInternalizedString) \
492 V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize, \
493 external_internalized_string, ExternalInternalizedString) \
494 V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize, \
495 external_one_byte_internalized_string, ExternalOneByteInternalizedString) \
496 V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
497 ExternalTwoByteString::kSize, \
498 external_internalized_string_with_one_byte_data, \
499 ExternalInternalizedStringWithOneByteData) \
500 V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE, \
501 ExternalTwoByteString::kShortSize, short_external_internalized_string, \
502 ShortExternalInternalizedString) \
503 V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, \
504 ExternalOneByteString::kShortSize, \
505 short_external_one_byte_internalized_string, \
506 ShortExternalOneByteInternalizedString) \
507 V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
508 ExternalTwoByteString::kShortSize, \
509 short_external_internalized_string_with_one_byte_data, \
510 ShortExternalInternalizedStringWithOneByteData)
512 // A struct is a simple object a set of object-valued fields. Including an
513 // object type in this causes the compiler to generate most of the boilerplate
514 // code for the class including allocation and garbage collection routines,
515 // casts and predicates. All you need to define is the class, methods and
516 // object verification routines. Easy, no?
518 // Note that for subtle reasons related to the ordering or numerical values of
519 // type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST
521 #define STRUCT_LIST(V) \
523 V(EXECUTABLE_ACCESSOR_INFO, ExecutableAccessorInfo, \
524 executable_accessor_info) \
525 V(ACCESSOR_PAIR, AccessorPair, accessor_pair) \
526 V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \
527 V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \
528 V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \
529 V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \
530 V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \
531 V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info) \
532 V(SCRIPT, Script, script) \
533 V(ALLOCATION_SITE, AllocationSite, allocation_site) \
534 V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento) \
535 V(CODE_CACHE, CodeCache, code_cache) \
536 V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) \
537 V(TYPE_FEEDBACK_INFO, TypeFeedbackInfo, type_feedback_info) \
538 V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \
539 V(DEBUG_INFO, DebugInfo, debug_info) \
540 V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) \
541 V(PROTOTYPE_INFO, PrototypeInfo, prototype_info)
543 // We use the full 8 bits of the instance_type field to encode heap object
544 // instance types. The high-order bit (bit 7) is set if the object is not a
545 // string, and cleared if it is a string.
546 const uint32_t kIsNotStringMask = 0x80;
547 const uint32_t kStringTag = 0x0;
548 const uint32_t kNotStringTag = 0x80;
550 // Bit 6 indicates that the object is an internalized string (if set) or not.
551 // Bit 7 has to be clear as well.
552 const uint32_t kIsNotInternalizedMask = 0x40;
553 const uint32_t kNotInternalizedTag = 0x40;
554 const uint32_t kInternalizedTag = 0x0;
556 // If bit 7 is clear then bit 2 indicates whether the string consists of
557 // two-byte characters or one-byte characters.
558 const uint32_t kStringEncodingMask = 0x4;
559 const uint32_t kTwoByteStringTag = 0x0;
560 const uint32_t kOneByteStringTag = 0x4;
562 // If bit 7 is clear, the low-order 2 bits indicate the representation
564 const uint32_t kStringRepresentationMask = 0x03;
565 enum StringRepresentationTag {
567 kConsStringTag = 0x1,
568 kExternalStringTag = 0x2,
569 kSlicedStringTag = 0x3
571 const uint32_t kIsIndirectStringMask = 0x1;
572 const uint32_t kIsIndirectStringTag = 0x1;
573 STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); // NOLINT
574 STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); // NOLINT
575 STATIC_ASSERT((kConsStringTag &
576 kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
577 STATIC_ASSERT((kSlicedStringTag &
578 kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
580 // Use this mask to distinguish between cons and slice only after making
581 // sure that the string is one of the two (an indirect string).
582 const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag;
583 STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask));
585 // If bit 7 is clear, then bit 3 indicates whether this two-byte
586 // string actually contains one byte data.
587 const uint32_t kOneByteDataHintMask = 0x08;
588 const uint32_t kOneByteDataHintTag = 0x08;
590 // If bit 7 is clear and string representation indicates an external string,
591 // then bit 4 indicates whether the data pointer is cached.
592 const uint32_t kShortExternalStringMask = 0x10;
593 const uint32_t kShortExternalStringTag = 0x10;
596 // A ConsString with an empty string as the right side is a candidate
597 // for being shortcut by the garbage collector. We don't allocate any
598 // non-flat internalized strings, so we do not shortcut them thereby
599 // avoiding turning internalized strings into strings. The bit-masks
600 // below contain the internalized bit as additional safety.
601 // See heap.cc, mark-compact.cc and objects-visiting.cc.
602 const uint32_t kShortcutTypeMask =
604 kIsNotInternalizedMask |
605 kStringRepresentationMask;
606 const uint32_t kShortcutTypeTag = kConsStringTag | kNotInternalizedTag;
608 static inline bool IsShortcutCandidate(int type) {
609 return ((type & kShortcutTypeMask) == kShortcutTypeTag);
615 INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kSeqStringTag |
616 kInternalizedTag, // FIRST_PRIMITIVE_TYPE
617 ONE_BYTE_INTERNALIZED_STRING_TYPE =
618 kOneByteStringTag | kSeqStringTag | kInternalizedTag,
619 EXTERNAL_INTERNALIZED_STRING_TYPE =
620 kTwoByteStringTag | kExternalStringTag | kInternalizedTag,
621 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
622 kOneByteStringTag | kExternalStringTag | kInternalizedTag,
623 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
624 EXTERNAL_INTERNALIZED_STRING_TYPE | kOneByteDataHintTag |
626 SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE |
627 kShortExternalStringTag |
629 SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
630 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kShortExternalStringTag |
632 SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
633 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
634 kShortExternalStringTag | kInternalizedTag,
635 STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
636 ONE_BYTE_STRING_TYPE =
637 ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
638 CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag | kNotInternalizedTag,
639 CONS_ONE_BYTE_STRING_TYPE =
640 kOneByteStringTag | kConsStringTag | kNotInternalizedTag,
642 kTwoByteStringTag | kSlicedStringTag | kNotInternalizedTag,
643 SLICED_ONE_BYTE_STRING_TYPE =
644 kOneByteStringTag | kSlicedStringTag | kNotInternalizedTag,
645 EXTERNAL_STRING_TYPE =
646 EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
647 EXTERNAL_ONE_BYTE_STRING_TYPE =
648 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
649 EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
650 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
652 SHORT_EXTERNAL_STRING_TYPE =
653 SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
654 SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE =
655 SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
656 SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
657 SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
661 SYMBOL_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE
663 // Other primitives (cannot contain non-map-word pointers to heap objects).
666 ODDBALL_TYPE, // LAST_PRIMITIVE_TYPE
668 // Objects allocated in their own spaces (never in new space).
672 // "Data", objects that cannot contain non-map-word pointers to heap
674 MUTABLE_HEAP_NUMBER_TYPE,
679 FIXED_INT8_ARRAY_TYPE, // FIRST_FIXED_TYPED_ARRAY_TYPE
680 FIXED_UINT8_ARRAY_TYPE,
681 FIXED_INT16_ARRAY_TYPE,
682 FIXED_UINT16_ARRAY_TYPE,
683 FIXED_INT32_ARRAY_TYPE,
684 FIXED_UINT32_ARRAY_TYPE,
685 FIXED_FLOAT32_ARRAY_TYPE,
686 FIXED_FLOAT64_ARRAY_TYPE,
687 FIXED_UINT8_CLAMPED_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE
688 FIXED_DOUBLE_ARRAY_TYPE,
689 FILLER_TYPE, // LAST_DATA_TYPE
692 DECLARED_ACCESSOR_DESCRIPTOR_TYPE,
693 DECLARED_ACCESSOR_INFO_TYPE,
694 EXECUTABLE_ACCESSOR_INFO_TYPE,
696 ACCESS_CHECK_INFO_TYPE,
697 INTERCEPTOR_INFO_TYPE,
698 CALL_HANDLER_INFO_TYPE,
699 FUNCTION_TEMPLATE_INFO_TYPE,
700 OBJECT_TEMPLATE_INFO_TYPE,
702 TYPE_SWITCH_INFO_TYPE,
703 ALLOCATION_SITE_TYPE,
704 ALLOCATION_MEMENTO_TYPE,
707 POLYMORPHIC_CODE_CACHE_TYPE,
708 TYPE_FEEDBACK_INFO_TYPE,
709 ALIASED_ARGUMENTS_ENTRY_TYPE,
712 BREAK_POINT_INFO_TYPE,
714 SHARED_FUNCTION_INFO_TYPE,
720 // All the following types are subtypes of JSReceiver, which corresponds to
721 // objects in the JS sense. The first and the last type in this range are
722 // the two forms of function. This organization enables using the same
723 // compares for checking the JS_RECEIVER/SPEC_OBJECT range and the
724 // NONCALLABLE_JS_OBJECT range.
725 JS_FUNCTION_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE, FIRST_JS_PROXY_TYPE
726 JS_PROXY_TYPE, // LAST_JS_PROXY_TYPE
727 JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE
728 JS_MESSAGE_OBJECT_TYPE,
731 JS_CONTEXT_EXTENSION_OBJECT_TYPE,
732 JS_GENERATOR_OBJECT_TYPE,
734 JS_GLOBAL_OBJECT_TYPE,
735 JS_BUILTINS_OBJECT_TYPE,
736 JS_GLOBAL_PROXY_TYPE,
738 JS_ARRAY_BUFFER_TYPE,
743 JS_SET_ITERATOR_TYPE,
744 JS_MAP_ITERATOR_TYPE,
748 JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
752 LAST_TYPE = JS_FUNCTION_TYPE,
753 FIRST_NAME_TYPE = FIRST_TYPE,
754 LAST_NAME_TYPE = SYMBOL_TYPE,
755 FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
756 LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
757 FIRST_NONSTRING_TYPE = SYMBOL_TYPE,
758 FIRST_PRIMITIVE_TYPE = FIRST_NAME_TYPE,
759 LAST_PRIMITIVE_TYPE = ODDBALL_TYPE,
760 // Boundaries for testing for a fixed typed array.
761 FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE,
762 LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_UINT8_CLAMPED_ARRAY_TYPE,
763 // Boundary for promotion to old space.
764 LAST_DATA_TYPE = FILLER_TYPE,
765 // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy).
766 // Note that there is no range for JSObject or JSProxy, since their subtypes
767 // are not continuous in this enum! The enum ranges instead reflect the
768 // external class names, where proxies are treated as either ordinary objects,
770 FIRST_JS_RECEIVER_TYPE = JS_FUNCTION_PROXY_TYPE,
771 LAST_JS_RECEIVER_TYPE = LAST_TYPE,
772 // Boundaries for testing the types represented as JSObject
773 FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE,
774 LAST_JS_OBJECT_TYPE = LAST_TYPE,
775 // Boundaries for testing the types represented as JSProxy
776 FIRST_JS_PROXY_TYPE = JS_FUNCTION_PROXY_TYPE,
777 LAST_JS_PROXY_TYPE = JS_PROXY_TYPE,
778 // Boundaries for testing whether the type is a JavaScript object.
779 FIRST_SPEC_OBJECT_TYPE = FIRST_JS_RECEIVER_TYPE,
780 LAST_SPEC_OBJECT_TYPE = LAST_JS_RECEIVER_TYPE,
781 // Boundaries for testing the types for which typeof is "object".
782 FIRST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_PROXY_TYPE,
783 LAST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_REGEXP_TYPE,
784 // Note that the types for which typeof is "function" are not continuous.
785 // Define this so that we can put assertions on discrete checks.
786 NUM_OF_CALLABLE_SPEC_OBJECT_TYPES = 2
789 STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
790 STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType);
791 STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType);
792 STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType);
795 #define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
796 V(FAST_ELEMENTS_SUB_TYPE) \
797 V(DICTIONARY_ELEMENTS_SUB_TYPE) \
798 V(FAST_PROPERTIES_SUB_TYPE) \
799 V(DICTIONARY_PROPERTIES_SUB_TYPE) \
800 V(MAP_CODE_CACHE_SUB_TYPE) \
801 V(SCOPE_INFO_SUB_TYPE) \
802 V(STRING_TABLE_SUB_TYPE) \
803 V(DESCRIPTOR_ARRAY_SUB_TYPE) \
804 V(TRANSITION_ARRAY_SUB_TYPE)
806 enum FixedArraySubInstanceType {
807 #define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
808 FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
809 #undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
810 LAST_FIXED_ARRAY_SUB_TYPE = TRANSITION_ARRAY_SUB_TYPE
823 #define DECL_BOOLEAN_ACCESSORS(name) \
824 inline bool name() const; \
825 inline void set_##name(bool value); \
828 #define DECL_ACCESSORS(name, type) \
829 inline type* name() const; \
830 inline void set_##name(type* value, \
831 WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \
834 #define DECLARE_CAST(type) \
835 INLINE(static type* cast(Object* object)); \
836 INLINE(static const type* cast(const Object* object));
840 class AllocationSite;
841 class AllocationSiteCreationContext;
842 class AllocationSiteUsageContext;
845 class ElementsAccessor;
846 class FixedArrayBase;
847 class FunctionLiteral;
849 class JSBuiltinsObject;
850 class LayoutDescriptor;
851 class LookupIterator;
852 class ObjectHashTable;
855 class SafepointEntry;
856 class SharedFunctionInfo;
858 class TypeFeedbackInfo;
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) \
907 V(ExternalTwoByteString) \
908 V(ExternalOneByteString) \
909 V(SeqTwoByteString) \
910 V(SeqOneByteString) \
911 V(InternalizedString) \
914 V(FixedTypedArrayBase) \
917 V(FixedUint16Array) \
919 V(FixedUint32Array) \
921 V(FixedFloat32Array) \
922 V(FixedFloat64Array) \
923 V(FixedUint8ClampedArray) \
929 V(JSContextExtensionObject) \
930 V(JSGeneratorObject) \
932 V(LayoutDescriptor) \
936 V(TypeFeedbackVector) \
937 V(DeoptimizationInputData) \
938 V(DeoptimizationOutputData) \
942 V(FixedDoubleArray) \
946 V(ScriptContextTable) \
952 V(SharedFunctionInfo) \
961 V(JSArrayBufferView) \
970 V(JSWeakCollection) \
977 V(NormalizedMapCache) \
978 V(CompilationCacheTable) \
979 V(CodeCacheHashTable) \
980 V(PolymorphicCodeCacheHashTable) \
985 V(JSBuiltinsObject) \
987 V(UndetectableObject) \
988 V(AccessCheckNeeded) \
994 V(WeakValueHashTable) \
997 // Object is the abstract superclass for all classes in the
999 // Object does not use any virtual functions to avoid the
1000 // allocation of the C++ vtable.
1001 // Since both Smi and HeapObject are subclasses of Object no
1002 // data members can be present in Object.
1006 bool IsObject() const { return true; }
1008 #define IS_TYPE_FUNCTION_DECL(type_) INLINE(bool Is##type_() const);
1009 OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
1010 HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
1011 #undef IS_TYPE_FUNCTION_DECL
1013 // A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
1014 // a keyed store is of the form a[expression] = foo.
1015 enum StoreFromKeyed {
1016 MAY_BE_STORE_FROM_KEYED,
1017 CERTAINLY_NOT_STORE_FROM_KEYED
1020 INLINE(bool IsFixedArrayBase() const);
1021 INLINE(bool IsExternal() const);
1022 INLINE(bool IsAccessorInfo() const);
1024 INLINE(bool IsStruct() const);
1025 #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \
1026 INLINE(bool Is##Name() const);
1027 STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
1028 #undef DECLARE_STRUCT_PREDICATE
1030 INLINE(bool IsSpecObject()) const;
1031 INLINE(bool IsSpecFunction()) const;
1032 INLINE(bool IsTemplateInfo()) const;
1033 INLINE(bool IsNameDictionary() const);
1034 INLINE(bool IsGlobalDictionary() const);
1035 INLINE(bool IsSeededNumberDictionary() const);
1036 INLINE(bool IsUnseededNumberDictionary() const);
1037 INLINE(bool IsOrderedHashSet() const);
1038 INLINE(bool IsOrderedHashMap() const);
1039 bool IsCallable() const;
1040 static bool IsPromise(Handle<Object> object);
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();
1064 inline ElementsKind OptimalElementsKind();
1066 inline bool FitsRepresentation(Representation representation);
1068 // Checks whether two valid primitive encodings of a property name resolve to
1069 // the same logical property. E.g., the smi 1, the string "1" and the double
1070 // 1 all refer to the same property, so this helper will return true.
1071 inline bool KeyEquals(Object* other);
1073 Handle<HeapType> OptimalType(Isolate* isolate, Representation representation);
1075 inline static Handle<Object> NewStorageFor(Isolate* isolate,
1076 Handle<Object> object,
1077 Representation representation);
1079 inline static Handle<Object> WrapForRead(Isolate* isolate,
1080 Handle<Object> object,
1081 Representation representation);
1083 // Returns true if the object is of the correct type to be used as a
1084 // implementation of a JSObject's elements.
1085 inline bool HasValidElements();
1087 inline bool HasSpecificClassOf(String* name);
1089 bool BooleanValue(); // ECMA-262 9.2.
1091 // Convert to a JSObject if needed.
1092 // native_context is used when creating wrapper object.
1093 static inline MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1094 Handle<Object> object);
1095 static MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1096 Handle<Object> object,
1097 Handle<Context> context);
1099 MUST_USE_RESULT static MaybeHandle<Object> GetProperty(
1100 LookupIterator* it, LanguageMode language_mode = SLOPPY);
1102 // Implementation of [[Put]], ECMA-262 5th edition, section 8.12.5.
1103 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1104 Handle<Object> object, Handle<Name> name, Handle<Object> value,
1105 LanguageMode language_mode,
1106 StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
1108 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1109 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1110 StoreFromKeyed store_mode);
1112 MUST_USE_RESULT static MaybeHandle<Object> SetSuperProperty(
1113 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1114 StoreFromKeyed store_mode);
1116 MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty(
1117 LookupIterator* it, LanguageMode language_mode);
1118 MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty(
1119 Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
1120 LanguageMode language_mode);
1121 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1122 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
1123 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1124 Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
1125 Handle<Object> value, LanguageMode language_mode);
1126 MUST_USE_RESULT static MaybeHandle<Object> RedefineNonconfigurableProperty(
1127 Isolate* isolate, Handle<Object> name, Handle<Object> value,
1128 LanguageMode language_mode);
1129 MUST_USE_RESULT static MaybeHandle<Object> SetDataProperty(
1130 LookupIterator* it, Handle<Object> value);
1131 MUST_USE_RESULT static MaybeHandle<Object> AddDataProperty(
1132 LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
1133 LanguageMode language_mode, StoreFromKeyed store_mode);
1134 MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
1135 Handle<Object> object, Handle<Name> name,
1136 LanguageMode language_mode = SLOPPY);
1137 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1138 Isolate* isolate, Handle<Object> object, const char* key,
1139 LanguageMode language_mode = SLOPPY);
1140 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1141 Handle<Object> object, Handle<Name> name,
1142 LanguageMode language_mode = SLOPPY);
1144 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
1145 LookupIterator* it, LanguageMode language_mode);
1146 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithAccessor(
1147 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
1149 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter(
1150 Handle<Object> receiver,
1151 Handle<JSReceiver> getter);
1152 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithDefinedSetter(
1153 Handle<Object> receiver,
1154 Handle<JSReceiver> setter,
1155 Handle<Object> value);
1157 MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
1158 Isolate* isolate, Handle<Object> object, uint32_t index,
1159 LanguageMode language_mode = SLOPPY);
1161 MUST_USE_RESULT static inline MaybeHandle<Object> SetElement(
1162 Isolate* isolate, Handle<Object> object, uint32_t index,
1163 Handle<Object> value, LanguageMode language_mode);
1165 static inline Handle<Object> GetPrototypeSkipHiddenPrototypes(
1166 Isolate* isolate, Handle<Object> receiver);
1168 // Returns the permanent hash code associated with this object. May return
1169 // undefined if not yet created.
1172 // Returns undefined for JSObjects, but returns the hash code for simple
1173 // objects. This avoids a double lookup in the cases where we know we will
1174 // add the hash to the JSObject if it does not already exist.
1175 Object* GetSimpleHash();
1177 // Returns the permanent hash code associated with this object depending on
1178 // the actual object type. May create and store a hash code if needed and none
1180 static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object);
1182 // Checks whether this object has the same value as the given one. This
1183 // function is implemented according to ES5, section 9.12 and can be used
1184 // to implement the Harmony "egal" function.
1185 bool SameValue(Object* other);
1187 // Checks whether this object has the same value as the given one.
1188 // +0 and -0 are treated equal. Everything else is the same as SameValue.
1189 // This function is implemented according to ES6, section 7.2.4 and is used
1190 // by ES6 Map and Set.
1191 bool SameValueZero(Object* other);
1193 // Tries to convert an object to an array length. Returns true and sets the
1194 // output parameter if it succeeds.
1195 inline bool ToArrayLength(uint32_t* index);
1197 // Tries to convert an object to an array index. Returns true and sets the
1198 // output parameter if it succeeds. Equivalent to ToArrayLength, but does not
1199 // allow kMaxUInt32.
1200 inline bool ToArrayIndex(uint32_t* index);
1202 // Returns true if this is a JSValue containing a string and the index is
1203 // < the length of the string. Used to implement [] on strings.
1204 inline bool IsStringObjectWithCharacterAt(uint32_t index);
1206 DECLARE_VERIFIER(Object)
1208 // Verify a pointer is a valid object pointer.
1209 static void VerifyPointer(Object* p);
1212 inline void VerifyApiCallResultType();
1214 // Prints this object without details.
1215 void ShortPrint(FILE* out = stdout);
1217 // Prints this object without details to a message accumulator.
1218 void ShortPrint(StringStream* accumulator);
1220 void ShortPrint(std::ostream& os); // NOLINT
1222 DECLARE_CAST(Object)
1224 // Layout description.
1225 static const int kHeaderSize = 0; // Object does not take up any space.
1228 // For our gdb macros, we should perhaps change these in the future.
1231 // Prints this object with details.
1232 void Print(std::ostream& os); // NOLINT
1234 void Print() { ShortPrint(); }
1235 void Print(std::ostream& os) { ShortPrint(os); } // NOLINT
1239 friend class LookupIterator;
1240 friend class PrototypeIterator;
1242 // Return the map of the root of object's prototype chain.
1243 Map* GetRootMap(Isolate* isolate);
1245 // Helper for SetProperty and SetSuperProperty.
1246 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyInternal(
1247 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1248 StoreFromKeyed store_mode, bool* found);
1250 DISALLOW_IMPLICIT_CONSTRUCTORS(Object);
1255 explicit Brief(const Object* const v) : value(v) {}
1256 const Object* value;
1260 std::ostream& operator<<(std::ostream& os, const Brief& v);
1263 // Smi represents integer Numbers that can be stored in 31 bits.
1264 // Smis are immediate which means they are NOT allocated in the heap.
1265 // The this pointer has the following format: [31 bit signed int] 0
1266 // For long smis it has the following format:
1267 // [32 bit signed int] [31 bits zero padding] 0
1268 // Smi stands for small integer.
1269 class Smi: public Object {
1271 // Returns the integer value.
1272 inline int value() const { return Internals::SmiValue(this); }
1274 // Convert a value to a Smi object.
1275 static inline Smi* FromInt(int value) {
1276 DCHECK(Smi::IsValid(value));
1277 return reinterpret_cast<Smi*>(Internals::IntToSmi(value));
1280 static inline Smi* FromIntptr(intptr_t value) {
1281 DCHECK(Smi::IsValid(value));
1282 int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
1283 return reinterpret_cast<Smi*>((value << smi_shift_bits) | kSmiTag);
1286 // Returns whether value can be represented in a Smi.
1287 static inline bool IsValid(intptr_t value) {
1288 bool result = Internals::IsValidSmi(value);
1289 DCHECK_EQ(result, value >= kMinValue && value <= kMaxValue);
1295 // Dispatched behavior.
1296 void SmiPrint(std::ostream& os) const; // NOLINT
1297 DECLARE_VERIFIER(Smi)
1299 static const int kMinValue =
1300 (static_cast<unsigned int>(-1)) << (kSmiValueSize - 1);
1301 static const int kMaxValue = -(kMinValue + 1);
1304 DISALLOW_IMPLICIT_CONSTRUCTORS(Smi);
1308 // Heap objects typically have a map pointer in their first word. However,
1309 // during GC other data (e.g. mark bits, forwarding addresses) is sometimes
1310 // encoded in the first word. The class MapWord is an abstraction of the
1311 // value in a heap object's first word.
1312 class MapWord BASE_EMBEDDED {
1314 // Normal state: the map word contains a map pointer.
1316 // Create a map word from a map pointer.
1317 static inline MapWord FromMap(const Map* map);
1319 // View this map word as a map pointer.
1320 inline Map* ToMap();
1323 // Scavenge collection: the map word of live objects in the from space
1324 // contains a forwarding address (a heap object pointer in the to space).
1326 // True if this map word is a forwarding address for a scavenge
1327 // collection. Only valid during a scavenge collection (specifically,
1328 // when all map words are heap object pointers, i.e. not during a full GC).
1329 inline bool IsForwardingAddress();
1331 // Create a map word from a forwarding address.
1332 static inline MapWord FromForwardingAddress(HeapObject* object);
1334 // View this map word as a forwarding address.
1335 inline HeapObject* ToForwardingAddress();
1337 static inline MapWord FromRawValue(uintptr_t value) {
1338 return MapWord(value);
1341 inline uintptr_t ToRawValue() {
1346 // HeapObject calls the private constructor and directly reads the value.
1347 friend class HeapObject;
1349 explicit MapWord(uintptr_t value) : value_(value) {}
1355 // The content of an heap object (except for the map pointer). kTaggedValues
1356 // objects can contain both heap pointers and Smis, kMixedValues can contain
1357 // heap pointers, Smis, and raw values (e.g. doubles or strings), and kRawValues
1358 // objects can contain raw values and Smis.
1359 enum class HeapObjectContents { kTaggedValues, kMixedValues, kRawValues };
1362 // HeapObject is the superclass for all classes describing heap allocated
1364 class HeapObject: public Object {
1366 // [map]: Contains a map which contains the object's reflective
1368 inline Map* map() const;
1369 inline void set_map(Map* value);
1370 // The no-write-barrier version. This is OK if the object is white and in
1371 // new space, or if the value is an immortal immutable object, like the maps
1372 // of primitive (non-JS) objects like strings, heap numbers etc.
1373 inline void set_map_no_write_barrier(Map* value);
1375 // Get the map using acquire load.
1376 inline Map* synchronized_map();
1377 inline MapWord synchronized_map_word() const;
1379 // Set the map using release store
1380 inline void synchronized_set_map(Map* value);
1381 inline void synchronized_set_map_no_write_barrier(Map* value);
1382 inline void synchronized_set_map_word(MapWord map_word);
1384 // During garbage collection, the map word of a heap object does not
1385 // necessarily contain a map pointer.
1386 inline MapWord map_word() const;
1387 inline void set_map_word(MapWord map_word);
1389 // The Heap the object was allocated in. Used also to access Isolate.
1390 inline Heap* GetHeap() const;
1392 // Convenience method to get current isolate.
1393 inline Isolate* GetIsolate() const;
1395 // Converts an address to a HeapObject pointer.
1396 static inline HeapObject* FromAddress(Address address) {
1397 DCHECK_TAG_ALIGNED(address);
1398 return reinterpret_cast<HeapObject*>(address + kHeapObjectTag);
1401 // Returns the address of this HeapObject.
1402 inline Address address() {
1403 return reinterpret_cast<Address>(this) - kHeapObjectTag;
1406 // Iterates over pointers contained in the object (including the Map)
1407 void Iterate(ObjectVisitor* v);
1409 // Iterates over all pointers contained in the object except the
1410 // first map pointer. The object type is given in the first
1411 // parameter. This function does not access the map pointer in the
1412 // object, and so is safe to call while the map pointer is modified.
1413 void IterateBody(InstanceType type, int object_size, ObjectVisitor* v);
1415 // Returns the heap object's size in bytes
1418 // Indicates what type of values this heap object may contain.
1419 inline HeapObjectContents ContentType();
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 AllocationAlignment RequiredAlignment();
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 // The Simd128Value class describes heap allocated 128 bit SIMD values.
1582 class Simd128Value : public HeapObject {
1584 DECLARE_CAST(Simd128Value)
1586 DECLARE_PRINTER(Simd128Value)
1587 DECLARE_VERIFIER(Simd128Value)
1589 // Checks that another instance is bit-wise equal.
1590 bool BitwiseEquals(const Simd128Value* other) const;
1591 // Computes a hash from the 128 bit value, viewed as 4 32-bit integers.
1592 uint32_t Hash() const;
1593 // Copies the 16 bytes of SIMD data to the destination address.
1594 void CopyBits(void* destination) const;
1596 // Layout description.
1597 static const int kValueOffset = HeapObject::kHeaderSize;
1598 static const int kSize = kValueOffset + kSimd128Size;
1601 DISALLOW_IMPLICIT_CONSTRUCTORS(Simd128Value);
1605 // V has parameters (TYPE, Type, type, lane count, lane type)
1606 #define SIMD128_TYPES(V) \
1607 V(FLOAT32X4, Float32x4, float32x4, 4, float) \
1608 V(INT32X4, Int32x4, int32x4, 4, int32_t) \
1609 V(BOOL32X4, Bool32x4, bool32x4, 4, bool) \
1610 V(INT16X8, Int16x8, int16x8, 8, int16_t) \
1611 V(BOOL16X8, Bool16x8, bool16x8, 8, bool) \
1612 V(INT8X16, Int8x16, int8x16, 16, int8_t) \
1613 V(BOOL8X16, Bool8x16, bool8x16, 16, bool)
1615 #define SIMD128_VALUE_CLASS(TYPE, Type, type, lane_count, lane_type) \
1616 class Type final : public Simd128Value { \
1618 inline lane_type get_lane(int lane) const; \
1619 inline void set_lane(int lane, lane_type value); \
1621 DECLARE_CAST(Type) \
1623 DECLARE_PRINTER(Type) \
1626 DISALLOW_IMPLICIT_CONSTRUCTORS(Type); \
1628 SIMD128_TYPES(SIMD128_VALUE_CLASS)
1629 #undef SIMD128_VALUE_CLASS
1632 enum EnsureElementsMode {
1633 DONT_ALLOW_DOUBLE_ELEMENTS,
1634 ALLOW_COPIED_DOUBLE_ELEMENTS,
1635 ALLOW_CONVERTED_DOUBLE_ELEMENTS
1639 // Indicator for one component of an AccessorPair.
1640 enum AccessorComponent {
1646 // JSReceiver includes types on which properties can be defined, i.e.,
1647 // JSObject and JSProxy.
1648 class JSReceiver: public HeapObject {
1650 DECLARE_CAST(JSReceiver)
1652 // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
1653 MUST_USE_RESULT static inline Maybe<bool> HasProperty(
1654 Handle<JSReceiver> object, Handle<Name> name);
1655 MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty(Handle<JSReceiver>,
1657 MUST_USE_RESULT static inline Maybe<bool> HasElement(
1658 Handle<JSReceiver> object, uint32_t index);
1659 MUST_USE_RESULT static inline Maybe<bool> HasOwnElement(
1660 Handle<JSReceiver> object, uint32_t index);
1662 // Implementation of [[Delete]], ECMA-262 5th edition, section 8.12.7.
1663 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyOrElement(
1664 Handle<JSReceiver> object, Handle<Name> name,
1665 LanguageMode language_mode = SLOPPY);
1666 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
1667 Handle<JSReceiver> object, Handle<Name> name,
1668 LanguageMode language_mode = SLOPPY);
1669 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
1670 LookupIterator* it, LanguageMode language_mode);
1671 MUST_USE_RESULT static MaybeHandle<Object> DeleteElement(
1672 Handle<JSReceiver> object, uint32_t index,
1673 LanguageMode language_mode = SLOPPY);
1675 // Tests for the fast common case for property enumeration.
1676 bool IsSimpleEnum();
1678 // Returns the class name ([[Class]] property in the specification).
1679 String* class_name();
1681 // Returns the constructor name (the name (possibly, inferred name) of the
1682 // function that was used to instantiate the object).
1683 String* constructor_name();
1685 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes(
1686 Handle<JSReceiver> object, Handle<Name> name);
1687 MUST_USE_RESULT static inline Maybe<PropertyAttributes>
1688 GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
1690 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetElementAttributes(
1691 Handle<JSReceiver> object, uint32_t index);
1692 MUST_USE_RESULT static inline Maybe<PropertyAttributes>
1693 GetOwnElementAttributes(Handle<JSReceiver> object, uint32_t index);
1695 MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
1696 LookupIterator* it);
1699 static Handle<Object> GetDataProperty(Handle<JSReceiver> object,
1701 static Handle<Object> GetDataProperty(LookupIterator* it);
1704 // Retrieves a permanent object identity hash code. The undefined value might
1705 // be returned in case no hash was created yet.
1706 inline Object* GetIdentityHash();
1708 // Retrieves a permanent object identity hash code. May create and store a
1709 // hash code if needed and none exists.
1710 inline static Handle<Smi> GetOrCreateIdentityHash(
1711 Handle<JSReceiver> object);
1713 enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS };
1715 // Computes the enumerable keys for a JSObject. Used for implementing
1716 // "for (n in object) { }".
1717 MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys(
1718 Handle<JSReceiver> object,
1719 KeyCollectionType type);
1722 DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
1726 // The JSObject describes real heap allocated JavaScript objects with
1728 // Note that the map of JSObject changes during execution to enable inline
1730 class JSObject: public JSReceiver {
1732 // [properties]: Backing storage for properties.
1733 // properties is a FixedArray in the fast case and a Dictionary in the
1735 DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties.
1736 inline void initialize_properties();
1737 inline bool HasFastProperties();
1738 // Gets slow properties for non-global objects.
1739 inline NameDictionary* property_dictionary();
1740 // Gets global object properties.
1741 inline GlobalDictionary* global_dictionary();
1743 // [elements]: The elements (properties with names that are integers).
1745 // Elements can be in two general modes: fast and slow. Each mode
1746 // corrensponds to a set of object representations of elements that
1747 // have something in common.
1749 // In the fast mode elements is a FixedArray and so each element can
1750 // be quickly accessed. This fact is used in the generated code. The
1751 // elements array can have one of three maps in this mode:
1752 // fixed_array_map, sloppy_arguments_elements_map or
1753 // fixed_cow_array_map (for copy-on-write arrays). In the latter case
1754 // the elements array may be shared by a few objects and so before
1755 // writing to any element the array must be copied. Use
1756 // EnsureWritableFastElements in this case.
1758 // In the slow mode the elements is either a NumberDictionary, a
1759 // FixedArray parameter map for a (sloppy) arguments object.
1760 DECL_ACCESSORS(elements, FixedArrayBase)
1761 inline void initialize_elements();
1762 static void ResetElements(Handle<JSObject> object);
1763 static inline void SetMapAndElements(Handle<JSObject> object,
1765 Handle<FixedArrayBase> elements);
1766 inline ElementsKind GetElementsKind();
1767 ElementsAccessor* GetElementsAccessor();
1768 // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
1769 inline bool HasFastSmiElements();
1770 // Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
1771 inline bool HasFastObjectElements();
1772 // Returns true if an object has elements of FAST_ELEMENTS or
1773 // FAST_SMI_ONLY_ELEMENTS.
1774 inline bool HasFastSmiOrObjectElements();
1775 // Returns true if an object has any of the fast elements kinds.
1776 inline bool HasFastElements();
1777 // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
1779 inline bool HasFastDoubleElements();
1780 // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
1782 inline bool HasFastHoleyElements();
1783 inline bool HasSloppyArgumentsElements();
1784 inline bool HasDictionaryElements();
1786 inline bool HasFixedTypedArrayElements();
1788 inline bool HasFixedUint8ClampedElements();
1789 inline bool HasFixedArrayElements();
1790 inline bool HasFixedInt8Elements();
1791 inline bool HasFixedUint8Elements();
1792 inline bool HasFixedInt16Elements();
1793 inline bool HasFixedUint16Elements();
1794 inline bool HasFixedInt32Elements();
1795 inline bool HasFixedUint32Elements();
1796 inline bool HasFixedFloat32Elements();
1797 inline bool HasFixedFloat64Elements();
1799 inline bool HasFastArgumentsElements();
1800 inline bool HasSlowArgumentsElements();
1801 inline SeededNumberDictionary* element_dictionary(); // Gets slow elements.
1803 // Requires: HasFastElements().
1804 static Handle<FixedArray> EnsureWritableFastElements(
1805 Handle<JSObject> object);
1807 // Collects elements starting at index 0.
1808 // Undefined values are placed after non-undefined values.
1809 // Returns the number of non-undefined values.
1810 static Handle<Object> PrepareElementsForSort(Handle<JSObject> object,
1812 // As PrepareElementsForSort, but only on objects where elements is
1813 // a dictionary, and it will stay a dictionary. Collates undefined and
1814 // unexisting elements below limit from position zero of the elements.
1815 static Handle<Object> PrepareSlowElementsForSort(Handle<JSObject> object,
1818 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithInterceptor(
1819 LookupIterator* it, Handle<Object> value);
1821 // SetLocalPropertyIgnoreAttributes converts callbacks to fields. We need to
1822 // grant an exemption to ExecutableAccessor callbacks in some cases.
1823 enum ExecutableAccessorInfoHandling { DEFAULT_HANDLING, DONT_FORCE_FIELD };
1825 MUST_USE_RESULT static MaybeHandle<Object> DefineOwnPropertyIgnoreAttributes(
1826 LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
1827 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1829 MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes(
1830 Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
1831 PropertyAttributes attributes,
1832 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1834 MUST_USE_RESULT static MaybeHandle<Object> SetOwnElementIgnoreAttributes(
1835 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1836 PropertyAttributes attributes,
1837 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1839 // Equivalent to one of the above depending on whether |name| can be converted
1840 // to an array index.
1841 MUST_USE_RESULT static MaybeHandle<Object>
1842 DefinePropertyOrElementIgnoreAttributes(
1843 Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
1844 PropertyAttributes attributes = NONE,
1845 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1847 // Adds or reconfigures a property to attributes NONE. It will fail when it
1849 MUST_USE_RESULT static Maybe<bool> CreateDataProperty(LookupIterator* it,
1850 Handle<Object> value);
1852 static void AddProperty(Handle<JSObject> object, Handle<Name> name,
1853 Handle<Object> value, PropertyAttributes attributes);
1855 MUST_USE_RESULT static MaybeHandle<Object> AddDataElement(
1856 Handle<JSObject> receiver, uint32_t index, Handle<Object> value,
1857 PropertyAttributes attributes);
1859 // Extend the receiver with a single fast property appeared first in the
1860 // passed map. This also extends the property backing store if necessary.
1861 static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
1863 // Migrates the given object to a map whose field representations are the
1864 // lowest upper bound of all known representations for that field.
1865 static void MigrateInstance(Handle<JSObject> instance);
1867 // Migrates the given object only if the target map is already available,
1868 // or returns false if such a map is not yet available.
1869 static bool TryMigrateInstance(Handle<JSObject> instance);
1871 // Sets the property value in a normalized object given (key, value, details).
1872 // Handles the special representation of JS global objects.
1873 static void SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name,
1874 Handle<Object> value,
1875 PropertyDetails details);
1876 static void SetDictionaryElement(Handle<JSObject> object, uint32_t index,
1877 Handle<Object> value,
1878 PropertyAttributes attributes);
1879 static void SetDictionaryArgumentsElement(Handle<JSObject> object,
1881 Handle<Object> value,
1882 PropertyAttributes attributes);
1884 static void OptimizeAsPrototype(Handle<JSObject> object,
1885 PrototypeOptimizationMode mode);
1886 static void ReoptimizeIfPrototype(Handle<JSObject> object);
1887 static void LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate);
1888 static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate);
1889 static void InvalidatePrototypeChains(Map* map);
1891 // Alternative implementation of WeakFixedArray::NullCallback.
1892 class PrototypeRegistryCompactionCallback {
1894 static void Callback(Object* value, int old_index, int new_index);
1897 // Retrieve interceptors.
1898 InterceptorInfo* GetNamedInterceptor();
1899 InterceptorInfo* GetIndexedInterceptor();
1901 // Used from JSReceiver.
1902 MUST_USE_RESULT static Maybe<PropertyAttributes>
1903 GetPropertyAttributesWithInterceptor(LookupIterator* it);
1904 MUST_USE_RESULT static Maybe<PropertyAttributes>
1905 GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
1907 // Retrieves an AccessorPair property from the given object. Might return
1908 // undefined if the property doesn't exist or is of a different kind.
1909 MUST_USE_RESULT static MaybeHandle<Object> GetAccessor(
1910 Handle<JSObject> object,
1912 AccessorComponent component);
1914 // Defines an AccessorPair property on the given object.
1915 // TODO(mstarzinger): Rename to SetAccessor().
1916 static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
1918 Handle<Object> getter,
1919 Handle<Object> setter,
1920 PropertyAttributes attributes);
1922 // Defines an AccessorInfo property on the given object.
1923 MUST_USE_RESULT static MaybeHandle<Object> SetAccessor(
1924 Handle<JSObject> object,
1925 Handle<AccessorInfo> info);
1927 // The result must be checked first for exceptions. If there's no exception,
1928 // the output parameter |done| indicates whether the interceptor has a result
1930 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
1931 LookupIterator* it, bool* done);
1933 // Accessors for hidden properties object.
1935 // Hidden properties are not own properties of the object itself.
1936 // Instead they are stored in an auxiliary structure kept as an own
1937 // property with a special name Heap::hidden_string(). But if the
1938 // receiver is a JSGlobalProxy then the auxiliary object is a property
1939 // of its prototype, and if it's a detached proxy, then you can't have
1940 // hidden properties.
1942 // Sets a hidden property on this object. Returns this object if successful,
1943 // undefined if called on a detached proxy.
1944 static Handle<Object> SetHiddenProperty(Handle<JSObject> object,
1946 Handle<Object> value);
1947 // Gets the value of a hidden property with the given key. Returns the hole
1948 // if the property doesn't exist (or if called on a detached proxy),
1949 // otherwise returns the value set for the key.
1950 Object* GetHiddenProperty(Handle<Name> key);
1951 // Deletes a hidden property. Deleting a non-existing property is
1952 // considered successful.
1953 static void DeleteHiddenProperty(Handle<JSObject> object,
1955 // Returns true if the object has a property with the hidden string as name.
1956 static bool HasHiddenProperties(Handle<JSObject> object);
1958 static void SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash);
1960 static void ValidateElements(Handle<JSObject> object);
1962 // Makes sure that this object can contain HeapObject as elements.
1963 static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
1965 // Makes sure that this object can contain the specified elements.
1966 static inline void EnsureCanContainElements(
1967 Handle<JSObject> object,
1970 EnsureElementsMode mode);
1971 static inline void EnsureCanContainElements(
1972 Handle<JSObject> object,
1973 Handle<FixedArrayBase> elements,
1975 EnsureElementsMode mode);
1976 static void EnsureCanContainElements(
1977 Handle<JSObject> object,
1978 Arguments* arguments,
1981 EnsureElementsMode mode);
1983 // Would we convert a fast elements array to dictionary mode given
1984 // an access at key?
1985 bool WouldConvertToSlowElements(uint32_t index);
1987 // Computes the new capacity when expanding the elements of a JSObject.
1988 static uint32_t NewElementsCapacity(uint32_t old_capacity) {
1989 // (old_capacity + 50%) + 16
1990 return old_capacity + (old_capacity >> 1) + 16;
1993 // These methods do not perform access checks!
1994 static void UpdateAllocationSite(Handle<JSObject> object,
1995 ElementsKind to_kind);
1997 // Lookup interceptors are used for handling properties controlled by host
1999 inline bool HasNamedInterceptor();
2000 inline bool HasIndexedInterceptor();
2002 // Computes the enumerable keys from interceptors. Used for debug mirrors and
2003 // by JSReceiver::GetKeys.
2004 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForNamedInterceptor(
2005 Handle<JSObject> object,
2006 Handle<JSReceiver> receiver);
2007 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForIndexedInterceptor(
2008 Handle<JSObject> object,
2009 Handle<JSReceiver> receiver);
2011 // Support functions for v8 api (needed for correct interceptor behavior).
2012 MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
2013 Handle<JSObject> object, Handle<Name> name);
2014 MUST_USE_RESULT static Maybe<bool> HasRealElementProperty(
2015 Handle<JSObject> object, uint32_t index);
2016 MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
2017 Handle<JSObject> object, Handle<Name> name);
2019 // Get the header size for a JSObject. Used to compute the index of
2020 // internal fields as well as the number of internal fields.
2021 inline int GetHeaderSize();
2023 inline int GetInternalFieldCount();
2024 inline int GetInternalFieldOffset(int index);
2025 inline Object* GetInternalField(int index);
2026 inline void SetInternalField(int index, Object* value);
2027 inline void SetInternalField(int index, Smi* value);
2029 // Returns the number of properties on this object filtering out properties
2030 // with the specified attributes (ignoring interceptors).
2031 int NumberOfOwnProperties(PropertyAttributes filter = NONE);
2032 // Fill in details for properties into storage starting at the specified
2033 // index. Returns the number of properties added.
2034 int GetOwnPropertyNames(FixedArray* storage, int index,
2035 PropertyAttributes filter = NONE);
2037 // Returns the number of properties on this object filtering out properties
2038 // with the specified attributes (ignoring interceptors).
2039 int NumberOfOwnElements(PropertyAttributes filter);
2040 // Returns the number of enumerable elements (ignoring interceptors).
2041 int NumberOfEnumElements();
2042 // Returns the number of elements on this object filtering out elements
2043 // with the specified attributes (ignoring interceptors).
2044 int GetOwnElementKeys(FixedArray* storage, PropertyAttributes filter);
2045 // Count and fill in the enumerable elements into storage.
2046 // (storage->length() == NumberOfEnumElements()).
2047 // If storage is NULL, will count the elements without adding
2048 // them to any storage.
2049 // Returns the number of enumerable elements.
2050 int GetEnumElementKeys(FixedArray* storage);
2052 static Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object,
2055 // Returns a new map with all transitions dropped from the object's current
2056 // map and the ElementsKind set.
2057 static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
2058 ElementsKind to_kind);
2059 static void TransitionElementsKind(Handle<JSObject> object,
2060 ElementsKind to_kind);
2062 // Always use this to migrate an object to a new map.
2063 // |expected_additional_properties| is only used for fast-to-slow transitions
2064 // and ignored otherwise.
2065 static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map,
2066 int expected_additional_properties = 0);
2068 // Convert the object to use the canonical dictionary
2069 // representation. If the object is expected to have additional properties
2070 // added this number can be indicated to have the backing store allocated to
2071 // an initial capacity for holding these properties.
2072 static void NormalizeProperties(Handle<JSObject> object,
2073 PropertyNormalizationMode mode,
2074 int expected_additional_properties,
2075 const char* reason);
2077 // Convert and update the elements backing store to be a
2078 // SeededNumberDictionary dictionary. Returns the backing after conversion.
2079 static Handle<SeededNumberDictionary> NormalizeElements(
2080 Handle<JSObject> object);
2082 void RequireSlowElements(SeededNumberDictionary* dictionary);
2084 // Transform slow named properties to fast variants.
2085 static void MigrateSlowToFast(Handle<JSObject> object,
2086 int unused_property_fields, const char* reason);
2088 inline bool IsUnboxedDoubleField(FieldIndex index);
2090 // Access fast-case object properties at index.
2091 static Handle<Object> FastPropertyAt(Handle<JSObject> object,
2092 Representation representation,
2094 inline Object* RawFastPropertyAt(FieldIndex index);
2095 inline double RawFastDoublePropertyAt(FieldIndex index);
2097 inline void FastPropertyAtPut(FieldIndex index, Object* value);
2098 inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
2099 inline void RawFastDoublePropertyAtPut(FieldIndex index, double value);
2100 inline void WriteToField(int descriptor, Object* value);
2102 // Access to in object properties.
2103 inline int GetInObjectPropertyOffset(int index);
2104 inline Object* InObjectPropertyAt(int index);
2105 inline Object* InObjectPropertyAtPut(int index,
2107 WriteBarrierMode mode
2108 = UPDATE_WRITE_BARRIER);
2110 // Set the object's prototype (only JSReceiver and null are allowed values).
2111 MUST_USE_RESULT static MaybeHandle<Object> SetPrototype(
2112 Handle<JSObject> object, Handle<Object> value, bool from_javascript);
2114 // Initializes the body after properties slot, properties slot is
2115 // initialized by set_properties. Fill the pre-allocated fields with
2116 // pre_allocated_value and the rest with filler_value.
2117 // Note: this call does not update write barrier, the caller is responsible
2118 // to ensure that |filler_value| can be collected without WB here.
2119 inline void InitializeBody(Map* map,
2120 Object* pre_allocated_value,
2121 Object* filler_value);
2123 // Check whether this object references another object
2124 bool ReferencesObject(Object* obj);
2126 // Disalow further properties to be added to the oject.
2127 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensions(
2128 Handle<JSObject> object);
2130 bool IsExtensible();
2133 MUST_USE_RESULT static MaybeHandle<Object> Seal(Handle<JSObject> object);
2135 // ES5 Object.freeze
2136 MUST_USE_RESULT static MaybeHandle<Object> Freeze(Handle<JSObject> object);
2138 // Called the first time an object is observed with ES7 Object.observe.
2139 static void SetObserved(Handle<JSObject> object);
2142 enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 };
2144 MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy(
2145 Handle<JSObject> object,
2146 AllocationSiteUsageContext* site_context,
2147 DeepCopyHints hints = kNoHints);
2148 MUST_USE_RESULT static MaybeHandle<JSObject> DeepWalk(
2149 Handle<JSObject> object,
2150 AllocationSiteCreationContext* site_context);
2152 DECLARE_CAST(JSObject)
2154 // Dispatched behavior.
2155 void JSObjectShortPrint(StringStream* accumulator);
2156 DECLARE_PRINTER(JSObject)
2157 DECLARE_VERIFIER(JSObject)
2159 void PrintProperties(std::ostream& os); // NOLINT
2160 void PrintElements(std::ostream& os); // NOLINT
2162 #if defined(DEBUG) || defined(OBJECT_PRINT)
2163 void PrintTransitions(std::ostream& os); // NOLINT
2166 static void PrintElementsTransition(
2167 FILE* file, Handle<JSObject> object,
2168 ElementsKind from_kind, Handle<FixedArrayBase> from_elements,
2169 ElementsKind to_kind, Handle<FixedArrayBase> to_elements);
2171 void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
2174 // Structure for collecting spill information about JSObjects.
2175 class SpillInformation {
2179 int number_of_objects_;
2180 int number_of_objects_with_fast_properties_;
2181 int number_of_objects_with_fast_elements_;
2182 int number_of_fast_used_fields_;
2183 int number_of_fast_unused_fields_;
2184 int number_of_slow_used_properties_;
2185 int number_of_slow_unused_properties_;
2186 int number_of_fast_used_elements_;
2187 int number_of_fast_unused_elements_;
2188 int number_of_slow_used_elements_;
2189 int number_of_slow_unused_elements_;
2192 void IncrementSpillStatistics(SpillInformation* info);
2196 // If a GC was caused while constructing this object, the elements pointer
2197 // may point to a one pointer filler map. The object won't be rooted, but
2198 // our heap verification code could stumble across it.
2199 bool ElementsAreSafeToExamine();
2202 Object* SlowReverseLookup(Object* value);
2204 // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
2205 // Also maximal value of JSArray's length property.
2206 static const uint32_t kMaxElementCount = 0xffffffffu;
2208 // Constants for heuristics controlling conversion of fast elements
2209 // to slow elements.
2211 // Maximal gap that can be introduced by adding an element beyond
2212 // the current elements length.
2213 static const uint32_t kMaxGap = 1024;
2215 // Maximal length of fast elements array that won't be checked for
2216 // being dense enough on expansion.
2217 static const int kMaxUncheckedFastElementsLength = 5000;
2219 // Same as above but for old arrays. This limit is more strict. We
2220 // don't want to be wasteful with long lived objects.
2221 static const int kMaxUncheckedOldFastElementsLength = 500;
2223 // Note that Page::kMaxRegularHeapObjectSize puts a limit on
2224 // permissible values (see the DCHECK in heap.cc).
2225 static const int kInitialMaxFastElementArray = 100000;
2227 // This constant applies only to the initial map of "global.Object" and
2228 // not to arbitrary other JSObject maps.
2229 static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
2231 static const int kMaxInstanceSize = 255 * kPointerSize;
2232 // When extending the backing storage for property values, we increase
2233 // its size by more than the 1 entry necessary, so sequentially adding fields
2234 // to the same object requires fewer allocations and copies.
2235 static const int kFieldsAdded = 3;
2237 // Layout description.
2238 static const int kPropertiesOffset = HeapObject::kHeaderSize;
2239 static const int kElementsOffset = kPropertiesOffset + kPointerSize;
2240 static const int kHeaderSize = kElementsOffset + kPointerSize;
2242 STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
2244 class BodyDescriptor : public FlexibleBodyDescriptor<kPropertiesOffset> {
2246 static inline int SizeOf(Map* map, HeapObject* object);
2249 Context* GetCreationContext();
2251 // Enqueue change record for Object.observe. May cause GC.
2252 MUST_USE_RESULT static MaybeHandle<Object> EnqueueChangeRecord(
2253 Handle<JSObject> object, const char* type, Handle<Name> name,
2254 Handle<Object> old_value);
2256 // Gets the number of currently used elements.
2257 int GetFastElementsUsage();
2259 // Deletes an existing named property in a normalized object.
2260 static void DeleteNormalizedProperty(Handle<JSObject> object,
2261 Handle<Name> name, int entry);
2263 static bool AllCanRead(LookupIterator* it);
2264 static bool AllCanWrite(LookupIterator* it);
2267 friend class JSReceiver;
2268 friend class Object;
2270 static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map);
2271 static void MigrateFastToSlow(Handle<JSObject> object,
2272 Handle<Map> new_map,
2273 int expected_additional_properties);
2275 // Used from Object::GetProperty().
2276 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
2277 LookupIterator* it);
2279 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithFailedAccessCheck(
2280 LookupIterator* it, Handle<Object> value);
2282 // Add a property to a slow-case object.
2283 static void AddSlowProperty(Handle<JSObject> object,
2285 Handle<Object> value,
2286 PropertyAttributes attributes);
2288 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithInterceptor(
2289 LookupIterator* it);
2291 bool ReferencesObjectFromElements(FixedArray* elements,
2295 // Return the hash table backing store or the inline stored identity hash,
2296 // whatever is found.
2297 MUST_USE_RESULT Object* GetHiddenPropertiesHashTable();
2299 // Return the hash table backing store for hidden properties. If there is no
2300 // backing store, allocate one.
2301 static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable(
2302 Handle<JSObject> object);
2304 // Set the hidden property backing store to either a hash table or
2305 // the inline-stored identity hash.
2306 static Handle<Object> SetHiddenPropertiesHashTable(
2307 Handle<JSObject> object,
2308 Handle<Object> value);
2310 MUST_USE_RESULT Object* GetIdentityHash();
2312 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSObject> object);
2314 static Handle<SeededNumberDictionary> GetNormalizedElementDictionary(
2315 Handle<JSObject> object, Handle<FixedArrayBase> elements);
2317 // Helper for fast versions of preventExtensions, seal, and freeze.
2318 // attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
2319 template <PropertyAttributes attrs>
2320 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensionsWithTransition(
2321 Handle<JSObject> object);
2323 DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
2327 // Common superclass for FixedArrays that allow implementations to share
2328 // common accessors and some code paths.
2329 class FixedArrayBase: public HeapObject {
2331 // [length]: length of the array.
2332 inline int length() const;
2333 inline void set_length(int value);
2335 // Get and set the length using acquire loads and release stores.
2336 inline int synchronized_length() const;
2337 inline void synchronized_set_length(int value);
2339 DECLARE_CAST(FixedArrayBase)
2341 // Layout description.
2342 // Length is smi tagged when it is stored.
2343 static const int kLengthOffset = HeapObject::kHeaderSize;
2344 static const int kHeaderSize = kLengthOffset + kPointerSize;
2348 class FixedDoubleArray;
2349 class IncrementalMarking;
2352 // FixedArray describes fixed-sized arrays with element type Object*.
2353 class FixedArray: public FixedArrayBase {
2355 // Setter and getter for elements.
2356 inline Object* get(int index) const;
2357 void SetValue(uint32_t index, Object* value);
2358 static inline Handle<Object> get(Handle<FixedArray> array, int index);
2359 // Setter that uses write barrier.
2360 inline void set(int index, Object* value);
2361 inline bool is_the_hole(int index);
2363 // Setter that doesn't need write barrier.
2364 inline void set(int index, Smi* value);
2365 // Setter with explicit barrier mode.
2366 inline void set(int index, Object* value, WriteBarrierMode mode);
2368 // Setters for frequently used oddballs located in old space.
2369 inline void set_undefined(int index);
2370 inline void set_null(int index);
2371 inline void set_the_hole(int index);
2373 inline Object** GetFirstElementAddress();
2374 inline bool ContainsOnlySmisOrHoles();
2376 // Gives access to raw memory which stores the array's data.
2377 inline Object** data_start();
2379 inline void FillWithHoles(int from, int to);
2381 // Shrink length and insert filler objects.
2382 void Shrink(int length);
2384 enum KeyFilter { ALL_KEYS, NON_SYMBOL_KEYS };
2386 // Add the elements of a JSArray to this FixedArray.
2387 MUST_USE_RESULT static MaybeHandle<FixedArray> AddKeysFromArrayLike(
2388 Handle<FixedArray> content, Handle<JSObject> array,
2389 KeyFilter filter = ALL_KEYS);
2391 // Computes the union of keys and return the result.
2392 // Used for implementing "for (n in object) { }"
2393 MUST_USE_RESULT static MaybeHandle<FixedArray> UnionOfKeys(
2394 Handle<FixedArray> first,
2395 Handle<FixedArray> second);
2397 // Copy a sub array from the receiver to dest.
2398 void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
2400 // Garbage collection support.
2401 static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
2403 // Code Generation support.
2404 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2406 // Garbage collection support.
2407 inline Object** RawFieldOfElementAt(int index);
2409 DECLARE_CAST(FixedArray)
2411 // Maximal allowed size, in bytes, of a single FixedArray.
2412 // Prevents overflowing size computations, as well as extreme memory
2414 static const int kMaxSize = 128 * MB * kPointerSize;
2415 // Maximally allowed length of a FixedArray.
2416 static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
2418 // Dispatched behavior.
2419 DECLARE_PRINTER(FixedArray)
2420 DECLARE_VERIFIER(FixedArray)
2422 // Checks if two FixedArrays have identical contents.
2423 bool IsEqualTo(FixedArray* other);
2426 // Swap two elements in a pair of arrays. If this array and the
2427 // numbers array are the same object, the elements are only swapped
2429 void SwapPairs(FixedArray* numbers, int i, int j);
2431 // Sort prefix of this array and the numbers array as pairs wrt. the
2432 // numbers. If the numbers array and the this array are the same
2433 // object, the prefix of this array is sorted.
2434 void SortPairs(FixedArray* numbers, uint32_t len);
2436 class BodyDescriptor : public FlexibleBodyDescriptor<kHeaderSize> {
2438 static inline int SizeOf(Map* map, HeapObject* object);
2442 // Set operation on FixedArray without using write barriers. Can
2443 // only be used for storing old space objects or smis.
2444 static inline void NoWriteBarrierSet(FixedArray* array,
2448 // Set operation on FixedArray without incremental write barrier. Can
2449 // only be used if the object is guaranteed to be white (whiteness witness
2451 static inline void NoIncrementalWriteBarrierSet(FixedArray* array,
2456 STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);
2458 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray);
2462 // FixedDoubleArray describes fixed-sized arrays with element type double.
2463 class FixedDoubleArray: public FixedArrayBase {
2465 // Setter and getter for elements.
2466 inline double get_scalar(int index);
2467 inline uint64_t get_representation(int index);
2468 static inline Handle<Object> get(Handle<FixedDoubleArray> array, int index);
2469 // This accessor has to get a Number as |value|.
2470 void SetValue(uint32_t index, Object* value);
2471 inline void set(int index, double value);
2472 inline void set_the_hole(int index);
2474 // Checking for the hole.
2475 inline bool is_the_hole(int index);
2477 // Garbage collection support.
2478 inline static int SizeFor(int length) {
2479 return kHeaderSize + length * kDoubleSize;
2482 // Gives access to raw memory which stores the array's data.
2483 inline double* data_start();
2485 inline void FillWithHoles(int from, int to);
2487 // Code Generation support.
2488 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2490 DECLARE_CAST(FixedDoubleArray)
2492 // Maximal allowed size, in bytes, of a single FixedDoubleArray.
2493 // Prevents overflowing size computations, as well as extreme memory
2495 static const int kMaxSize = 512 * MB;
2496 // Maximally allowed length of a FixedArray.
2497 static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
2499 // Dispatched behavior.
2500 DECLARE_PRINTER(FixedDoubleArray)
2501 DECLARE_VERIFIER(FixedDoubleArray)
2504 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
2508 class WeakFixedArray : public FixedArray {
2510 // If |maybe_array| is not a WeakFixedArray, a fresh one will be allocated.
2511 // This function does not check if the value exists already, callers must
2512 // ensure this themselves if necessary.
2513 static Handle<WeakFixedArray> Add(Handle<Object> maybe_array,
2514 Handle<HeapObject> value,
2515 int* assigned_index = NULL);
2517 // Returns true if an entry was found and removed.
2518 bool Remove(Handle<HeapObject> value);
2520 class NullCallback {
2522 static void Callback(Object* value, int old_index, int new_index) {}
2525 template <class CompactionCallback>
2528 inline Object* Get(int index) const;
2529 inline void Clear(int index);
2530 inline int Length() const;
2532 inline bool IsEmptySlot(int index) const;
2533 static Object* Empty() { return Smi::FromInt(0); }
2535 DECLARE_CAST(WeakFixedArray)
2538 static const int kLastUsedIndexIndex = 0;
2539 static const int kFirstIndex = 1;
2541 static Handle<WeakFixedArray> Allocate(
2542 Isolate* isolate, int size, Handle<WeakFixedArray> initialize_from);
2544 static void Set(Handle<WeakFixedArray> array, int index,
2545 Handle<HeapObject> value);
2546 inline void clear(int index);
2548 inline int last_used_index() const;
2549 inline void set_last_used_index(int index);
2551 // Disallow inherited setters.
2552 void set(int index, Smi* value);
2553 void set(int index, Object* value);
2554 void set(int index, Object* value, WriteBarrierMode mode);
2555 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
2559 // Generic array grows dynamically with O(1) amortized insertion.
2560 class ArrayList : public FixedArray {
2564 // Use this if GC can delete elements from the array.
2565 kReloadLengthAfterAllocation,
2567 static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj,
2568 AddMode mode = kNone);
2569 static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj1,
2570 Handle<Object> obj2, AddMode = kNone);
2571 inline int Length();
2572 inline void SetLength(int length);
2573 inline Object* Get(int index);
2574 inline Object** Slot(int index);
2575 inline void Set(int index, Object* obj);
2576 inline void Clear(int index, Object* undefined);
2577 DECLARE_CAST(ArrayList)
2580 static Handle<ArrayList> EnsureSpace(Handle<ArrayList> array, int length);
2581 static const int kLengthIndex = 0;
2582 static const int kFirstIndex = 1;
2583 DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
2587 // DescriptorArrays are fixed arrays used to hold instance descriptors.
2588 // The format of the these objects is:
2589 // [0]: Number of descriptors
2590 // [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array:
2591 // [0]: pointer to fixed array with enum cache
2592 // [1]: either Smi(0) or pointer to fixed array with indices
2594 // [2 + number of descriptors * kDescriptorSize]: start of slack
2595 class DescriptorArray: public FixedArray {
2597 // Returns true for both shared empty_descriptor_array and for smis, which the
2598 // map uses to encode additional bit fields when the descriptor array is not
2600 inline bool IsEmpty();
2602 // Returns the number of descriptors in the array.
2603 inline int number_of_descriptors();
2605 inline int number_of_descriptors_storage();
2607 inline int NumberOfSlackDescriptors();
2609 inline void SetNumberOfDescriptors(int number_of_descriptors);
2610 inline int number_of_entries();
2612 inline bool HasEnumCache();
2614 inline void CopyEnumCacheFrom(DescriptorArray* array);
2616 inline FixedArray* GetEnumCache();
2618 inline bool HasEnumIndicesCache();
2620 inline FixedArray* GetEnumIndicesCache();
2622 inline Object** GetEnumCacheSlot();
2624 void ClearEnumCache();
2626 // Initialize or change the enum cache,
2627 // using the supplied storage for the small "bridge".
2628 void SetEnumCache(FixedArray* bridge_storage,
2629 FixedArray* new_cache,
2630 Object* new_index_cache);
2632 bool CanHoldValue(int descriptor, Object* value);
2634 // Accessors for fetching instance descriptor at descriptor number.
2635 inline Name* GetKey(int descriptor_number);
2636 inline Object** GetKeySlot(int descriptor_number);
2637 inline Object* GetValue(int descriptor_number);
2638 inline void SetValue(int descriptor_number, Object* value);
2639 inline Object** GetValueSlot(int descriptor_number);
2640 static inline int GetValueOffset(int descriptor_number);
2641 inline Object** GetDescriptorStartSlot(int descriptor_number);
2642 inline Object** GetDescriptorEndSlot(int descriptor_number);
2643 inline PropertyDetails GetDetails(int descriptor_number);
2644 inline PropertyType GetType(int descriptor_number);
2645 inline int GetFieldIndex(int descriptor_number);
2646 inline HeapType* GetFieldType(int descriptor_number);
2647 inline Object* GetConstant(int descriptor_number);
2648 inline Object* GetCallbacksObject(int descriptor_number);
2649 inline AccessorDescriptor* GetCallbacks(int descriptor_number);
2651 inline Name* GetSortedKey(int descriptor_number);
2652 inline int GetSortedKeyIndex(int descriptor_number);
2653 inline void SetSortedKey(int pointer, int descriptor_number);
2654 inline void SetRepresentation(int descriptor_number,
2655 Representation representation);
2657 // Accessor for complete descriptor.
2658 inline void Get(int descriptor_number, Descriptor* desc);
2659 inline void Set(int descriptor_number, Descriptor* desc);
2660 void Replace(int descriptor_number, Descriptor* descriptor);
2662 // Append automatically sets the enumeration index. This should only be used
2663 // to add descriptors in bulk at the end, followed by sorting the descriptor
2665 inline void Append(Descriptor* desc);
2667 static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc,
2668 int enumeration_index,
2671 static Handle<DescriptorArray> CopyUpToAddAttributes(
2672 Handle<DescriptorArray> desc,
2673 int enumeration_index,
2674 PropertyAttributes attributes,
2677 // Sort the instance descriptors by the hash codes of their keys.
2680 // Search the instance descriptors for given name.
2681 INLINE(int Search(Name* name, int number_of_own_descriptors));
2683 // As the above, but uses DescriptorLookupCache and updates it when
2685 INLINE(int SearchWithCache(Name* name, Map* map));
2687 // Allocates a DescriptorArray, but returns the singleton
2688 // empty descriptor array object if number_of_descriptors is 0.
2689 static Handle<DescriptorArray> Allocate(Isolate* isolate,
2690 int number_of_descriptors,
2693 DECLARE_CAST(DescriptorArray)
2695 // Constant for denoting key was not found.
2696 static const int kNotFound = -1;
2698 static const int kDescriptorLengthIndex = 0;
2699 static const int kEnumCacheIndex = 1;
2700 static const int kFirstIndex = 2;
2702 // The length of the "bridge" to the enum cache.
2703 static const int kEnumCacheBridgeLength = 2;
2704 static const int kEnumCacheBridgeCacheIndex = 0;
2705 static const int kEnumCacheBridgeIndicesCacheIndex = 1;
2707 // Layout description.
2708 static const int kDescriptorLengthOffset = FixedArray::kHeaderSize;
2709 static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize;
2710 static const int kFirstOffset = kEnumCacheOffset + kPointerSize;
2712 // Layout description for the bridge array.
2713 static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize;
2715 // Layout of descriptor.
2716 static const int kDescriptorKey = 0;
2717 static const int kDescriptorDetails = 1;
2718 static const int kDescriptorValue = 2;
2719 static const int kDescriptorSize = 3;
2721 #if defined(DEBUG) || defined(OBJECT_PRINT)
2722 // For our gdb macros, we should perhaps change these in the future.
2725 // Print all the descriptors.
2726 void PrintDescriptors(std::ostream& os); // NOLINT
2730 // Is the descriptor array sorted and without duplicates?
2731 bool IsSortedNoDuplicates(int valid_descriptors = -1);
2733 // Is the descriptor array consistent with the back pointers in targets?
2734 bool IsConsistentWithBackPointers(Map* current_map);
2736 // Are two DescriptorArrays equal?
2737 bool IsEqualTo(DescriptorArray* other);
2740 // Returns the fixed array length required to hold number_of_descriptors
2742 static int LengthFor(int number_of_descriptors) {
2743 return ToKeyIndex(number_of_descriptors);
2747 // WhitenessWitness is used to prove that a descriptor array is white
2748 // (unmarked), so incremental write barriers can be skipped because the
2749 // marking invariant cannot be broken and slots pointing into evacuation
2750 // candidates will be discovered when the object is scanned. A witness is
2751 // always stack-allocated right after creating an array. By allocating a
2752 // witness, incremental marking is globally disabled. The witness is then
2753 // passed along wherever needed to statically prove that the array is known to
2755 class WhitenessWitness {
2757 inline explicit WhitenessWitness(DescriptorArray* array);
2758 inline ~WhitenessWitness();
2761 IncrementalMarking* marking_;
2764 // An entry in a DescriptorArray, represented as an (array, index) pair.
2767 inline explicit Entry(DescriptorArray* descs, int index) :
2768 descs_(descs), index_(index) { }
2770 inline PropertyType type();
2771 inline Object* GetCallbackObject();
2774 DescriptorArray* descs_;
2778 // Conversion from descriptor number to array indices.
2779 static int ToKeyIndex(int descriptor_number) {
2780 return kFirstIndex +
2781 (descriptor_number * kDescriptorSize) +
2785 static int ToDetailsIndex(int descriptor_number) {
2786 return kFirstIndex +
2787 (descriptor_number * kDescriptorSize) +
2791 static int ToValueIndex(int descriptor_number) {
2792 return kFirstIndex +
2793 (descriptor_number * kDescriptorSize) +
2797 // Transfer a complete descriptor from the src descriptor array to this
2798 // descriptor array.
2799 void CopyFrom(int index, DescriptorArray* src, const WhitenessWitness&);
2801 inline void Set(int descriptor_number,
2803 const WhitenessWitness&);
2805 // Swap first and second descriptor.
2806 inline void SwapSortedKeys(int first, int second);
2808 DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
2812 enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
2814 template <SearchMode search_mode, typename T>
2815 inline int Search(T* array, Name* name, int valid_entries = 0,
2816 int* out_insertion_index = NULL);
2819 // HashTable is a subclass of FixedArray that implements a hash table
2820 // that uses open addressing and quadratic probing.
2822 // In order for the quadratic probing to work, elements that have not
2823 // yet been used and elements that have been deleted are
2824 // distinguished. Probing continues when deleted elements are
2825 // encountered and stops when unused elements are encountered.
2827 // - Elements with key == undefined have not been used yet.
2828 // - Elements with key == the_hole have been deleted.
2830 // The hash table class is parameterized with a Shape and a Key.
2831 // Shape must be a class with the following interface:
2832 // class ExampleShape {
2834 // // Tells whether key matches other.
2835 // static bool IsMatch(Key key, Object* other);
2836 // // Returns the hash value for key.
2837 // static uint32_t Hash(Key key);
2838 // // Returns the hash value for object.
2839 // static uint32_t HashForObject(Key key, Object* object);
2840 // // Convert key to an object.
2841 // static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
2842 // // The prefix size indicates number of elements in the beginning
2843 // // of the backing storage.
2844 // static const int kPrefixSize = ..;
2845 // // The Element size indicates number of elements per entry.
2846 // static const int kEntrySize = ..;
2848 // The prefix size indicates an amount of memory in the
2849 // beginning of the backing storage that can be used for non-element
2850 // information by subclasses.
2852 template<typename Key>
2855 static const bool UsesSeed = false;
2856 static uint32_t Hash(Key key) { return 0; }
2857 static uint32_t SeededHash(Key key, uint32_t seed) {
2861 static uint32_t HashForObject(Key key, Object* object) { return 0; }
2862 static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) {
2864 return HashForObject(key, object);
2869 class HashTableBase : public FixedArray {
2871 // Returns the number of elements in the hash table.
2872 inline int NumberOfElements();
2874 // Returns the number of deleted elements in the hash table.
2875 inline int NumberOfDeletedElements();
2877 // Returns the capacity of the hash table.
2878 inline int Capacity();
2880 // ElementAdded should be called whenever an element is added to a
2882 inline void ElementAdded();
2884 // ElementRemoved should be called whenever an element is removed from
2886 inline void ElementRemoved();
2887 inline void ElementsRemoved(int n);
2889 // Computes the required capacity for a table holding the given
2890 // number of elements. May be more than HashTable::kMaxCapacity.
2891 static inline int ComputeCapacity(int at_least_space_for);
2893 // Tells whether k is a real key. The hole and undefined are not allowed
2894 // as keys and can be used to indicate missing or deleted elements.
2895 inline bool IsKey(Object* k);
2897 // Compute the probe offset (quadratic probing).
2898 INLINE(static uint32_t GetProbeOffset(uint32_t n)) {
2899 return (n + n * n) >> 1;
2902 static const int kNumberOfElementsIndex = 0;
2903 static const int kNumberOfDeletedElementsIndex = 1;
2904 static const int kCapacityIndex = 2;
2905 static const int kPrefixStartIndex = 3;
2907 // Constant used for denoting a absent entry.
2908 static const int kNotFound = -1;
2911 // Update the number of elements in the hash table.
2912 inline void SetNumberOfElements(int nof);
2914 // Update the number of deleted elements in the hash table.
2915 inline void SetNumberOfDeletedElements(int nod);
2917 // Returns probe entry.
2918 static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) {
2919 DCHECK(base::bits::IsPowerOfTwo32(size));
2920 return (hash + GetProbeOffset(number)) & (size - 1);
2923 inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) {
2924 return hash & (size - 1);
2927 inline static uint32_t NextProbe(
2928 uint32_t last, uint32_t number, uint32_t size) {
2929 return (last + number) & (size - 1);
2934 template <typename Derived, typename Shape, typename Key>
2935 class HashTable : public HashTableBase {
2938 inline uint32_t Hash(Key key) {
2939 if (Shape::UsesSeed) {
2940 return Shape::SeededHash(key, GetHeap()->HashSeed());
2942 return Shape::Hash(key);
2946 inline uint32_t HashForObject(Key key, Object* object) {
2947 if (Shape::UsesSeed) {
2948 return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object);
2950 return Shape::HashForObject(key, object);
2954 // Returns a new HashTable object.
2955 MUST_USE_RESULT static Handle<Derived> New(
2956 Isolate* isolate, int at_least_space_for,
2957 MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
2958 PretenureFlag pretenure = NOT_TENURED);
2960 DECLARE_CAST(HashTable)
2962 // Garbage collection support.
2963 void IteratePrefix(ObjectVisitor* visitor);
2964 void IterateElements(ObjectVisitor* visitor);
2966 // Find entry for key otherwise return kNotFound.
2967 inline int FindEntry(Key key);
2968 inline int FindEntry(Isolate* isolate, Key key, int32_t hash);
2969 int FindEntry(Isolate* isolate, Key key);
2971 // Rehashes the table in-place.
2972 void Rehash(Key key);
2974 // Returns the key at entry.
2975 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
2977 static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize;
2978 static const int kEntrySize = Shape::kEntrySize;
2979 static const int kElementsStartOffset =
2980 kHeaderSize + kElementsStartIndex * kPointerSize;
2981 static const int kCapacityOffset =
2982 kHeaderSize + kCapacityIndex * kPointerSize;
2984 // Returns the index for an entry (of the key)
2985 static inline int EntryToIndex(int entry) {
2986 return (entry * kEntrySize) + kElementsStartIndex;
2990 friend class ObjectHashTable;
2992 // Find the entry at which to insert element with the given key that
2993 // has the given hash value.
2994 uint32_t FindInsertionEntry(uint32_t hash);
2996 // Attempt to shrink hash table after removal of key.
2997 MUST_USE_RESULT static Handle<Derived> Shrink(Handle<Derived> table, Key key);
2999 // Ensure enough space for n additional elements.
3000 MUST_USE_RESULT static Handle<Derived> EnsureCapacity(
3001 Handle<Derived> table,
3004 PretenureFlag pretenure = NOT_TENURED);
3006 // Sets the capacity of the hash table.
3007 void SetCapacity(int capacity) {
3008 // To scale a computed hash code to fit within the hash table, we
3009 // use bit-wise AND with a mask, so the capacity must be positive
3011 DCHECK(capacity > 0);
3012 DCHECK(capacity <= kMaxCapacity);
3013 set(kCapacityIndex, Smi::FromInt(capacity));
3016 // Maximal capacity of HashTable. Based on maximal length of underlying
3017 // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex
3019 static const int kMaxCapacity =
3020 (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize;
3023 // Returns _expected_ if one of entries given by the first _probe_ probes is
3024 // equal to _expected_. Otherwise, returns the entry given by the probe
3026 uint32_t EntryForProbe(Key key, Object* k, int probe, uint32_t expected);
3028 void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode);
3030 // Rehashes this hash-table into the new table.
3031 void Rehash(Handle<Derived> new_table, Key key);
3035 // HashTableKey is an abstract superclass for virtual key behavior.
3036 class HashTableKey {
3038 // Returns whether the other object matches this key.
3039 virtual bool IsMatch(Object* other) = 0;
3040 // Returns the hash value for this key.
3041 virtual uint32_t Hash() = 0;
3042 // Returns the hash value for object.
3043 virtual uint32_t HashForObject(Object* key) = 0;
3044 // Returns the key object for storing into the hash table.
3045 MUST_USE_RESULT virtual Handle<Object> AsHandle(Isolate* isolate) = 0;
3047 virtual ~HashTableKey() {}
3051 class StringTableShape : public BaseShape<HashTableKey*> {
3053 static inline bool IsMatch(HashTableKey* key, Object* value) {
3054 return key->IsMatch(value);
3057 static inline uint32_t Hash(HashTableKey* key) {
3061 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
3062 return key->HashForObject(object);
3065 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
3067 static const int kPrefixSize = 0;
3068 static const int kEntrySize = 1;
3071 class SeqOneByteString;
3075 // No special elements in the prefix and the element size is 1
3076 // because only the string itself (the key) needs to be stored.
3077 class StringTable: public HashTable<StringTable,
3081 // Find string in the string table. If it is not there yet, it is
3082 // added. The return value is the string found.
3083 static Handle<String> LookupString(Isolate* isolate, Handle<String> key);
3084 static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key);
3085 static String* LookupKeyIfExists(Isolate* isolate, HashTableKey* key);
3087 // Tries to internalize given string and returns string handle on success
3088 // or an empty handle otherwise.
3089 MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists(
3091 Handle<String> string);
3093 // Looks up a string that is equal to the given string and returns
3094 // string handle if it is found, or an empty handle otherwise.
3095 MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists(
3097 Handle<String> str);
3098 MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists(
3103 static void EnsureCapacityForDeserialization(Isolate* isolate, int expected);
3105 DECLARE_CAST(StringTable)
3108 template <bool seq_one_byte>
3109 friend class JsonParser;
3111 DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable);
3115 template <typename Derived, typename Shape, typename Key>
3116 class Dictionary: public HashTable<Derived, Shape, Key> {
3117 typedef HashTable<Derived, Shape, Key> DerivedHashTable;
3120 // Returns the value at entry.
3121 Object* ValueAt(int entry) {
3122 return this->get(Derived::EntryToIndex(entry) + 1);
3125 // Set the value for entry.
3126 void ValueAtPut(int entry, Object* value) {
3127 this->set(Derived::EntryToIndex(entry) + 1, value);
3130 // Returns the property details for the property at entry.
3131 PropertyDetails DetailsAt(int entry) {
3132 return Shape::DetailsAt(static_cast<Derived*>(this), entry);
3135 // Set the details for entry.
3136 void DetailsAtPut(int entry, PropertyDetails value) {
3137 Shape::DetailsAtPut(static_cast<Derived*>(this), entry, value);
3140 // Returns true if property at given entry is deleted.
3141 bool IsDeleted(int entry) {
3142 return Shape::IsDeleted(static_cast<Derived*>(this), entry);
3145 // Delete a property from the dictionary.
3146 static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry);
3148 // Attempt to shrink the dictionary after deletion of key.
3149 MUST_USE_RESULT static inline Handle<Derived> Shrink(
3150 Handle<Derived> dictionary,
3152 return DerivedHashTable::Shrink(dictionary, key);
3156 // TODO(dcarney): templatize or move to SeededNumberDictionary
3157 void CopyValuesTo(FixedArray* elements);
3159 // Returns the number of elements in the dictionary filtering out properties
3160 // with the specified attributes.
3161 int NumberOfElementsFilterAttributes(PropertyAttributes filter);
3163 // Returns the number of enumerable elements in the dictionary.
3164 int NumberOfEnumElements() {
3165 return NumberOfElementsFilterAttributes(
3166 static_cast<PropertyAttributes>(DONT_ENUM | SYMBOLIC));
3169 // Returns true if the dictionary contains any elements that are non-writable,
3170 // non-configurable, non-enumerable, or have getters/setters.
3171 bool HasComplexElements();
3173 enum SortMode { UNSORTED, SORTED };
3175 // Fill in details for properties into storage.
3176 // Returns the number of properties added.
3177 int CopyKeysTo(FixedArray* storage, int index, PropertyAttributes filter,
3178 SortMode sort_mode);
3180 // Copies enumerable keys to preallocated fixed array.
3181 void CopyEnumKeysTo(FixedArray* storage);
3183 // Accessors for next enumeration index.
3184 void SetNextEnumerationIndex(int index) {
3186 this->set(kNextEnumerationIndexIndex, Smi::FromInt(index));
3189 int NextEnumerationIndex() {
3190 return Smi::cast(this->get(kNextEnumerationIndexIndex))->value();
3193 // Creates a new dictionary.
3194 MUST_USE_RESULT static Handle<Derived> New(
3196 int at_least_space_for,
3197 PretenureFlag pretenure = NOT_TENURED);
3199 // Ensure enough space for n additional elements.
3200 static Handle<Derived> EnsureCapacity(Handle<Derived> obj, int n, Key key);
3203 void Print(std::ostream& os); // NOLINT
3205 // Returns the key (slow).
3206 Object* SlowReverseLookup(Object* value);
3208 // Sets the entry to (key, value) pair.
3209 inline void SetEntry(int entry,
3211 Handle<Object> value);
3212 inline void SetEntry(int entry,
3214 Handle<Object> value,
3215 PropertyDetails details);
3217 MUST_USE_RESULT static Handle<Derived> Add(
3218 Handle<Derived> dictionary,
3220 Handle<Object> value,
3221 PropertyDetails details);
3223 // Returns iteration indices array for the |dictionary|.
3224 // Values are direct indices in the |HashTable| array.
3225 static Handle<FixedArray> BuildIterationIndicesArray(
3226 Handle<Derived> dictionary);
3229 // Generic at put operation.
3230 MUST_USE_RESULT static Handle<Derived> AtPut(
3231 Handle<Derived> dictionary,
3233 Handle<Object> value);
3235 // Add entry to dictionary.
3236 static void AddEntry(
3237 Handle<Derived> dictionary,
3239 Handle<Object> value,
3240 PropertyDetails details,
3243 // Generate new enumeration indices to avoid enumeration index overflow.
3244 // Returns iteration indices array for the |dictionary|.
3245 static Handle<FixedArray> GenerateNewEnumerationIndices(
3246 Handle<Derived> dictionary);
3247 static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex;
3248 static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
3252 template <typename Derived, typename Shape>
3253 class NameDictionaryBase : public Dictionary<Derived, Shape, Handle<Name> > {
3254 typedef Dictionary<Derived, Shape, Handle<Name> > DerivedDictionary;
3257 // Find entry for key, otherwise return kNotFound. Optimized version of
3258 // HashTable::FindEntry.
3259 int FindEntry(Handle<Name> key);
3263 template <typename Key>
3264 class BaseDictionaryShape : public BaseShape<Key> {
3266 template <typename Dictionary>
3267 static inline PropertyDetails DetailsAt(Dictionary* dict, int entry) {
3268 STATIC_ASSERT(Dictionary::kEntrySize == 3);
3269 DCHECK(entry >= 0); // Not found is -1, which is not caught by get().
3270 return PropertyDetails(
3271 Smi::cast(dict->get(Dictionary::EntryToIndex(entry) + 2)));
3274 template <typename Dictionary>
3275 static inline void DetailsAtPut(Dictionary* dict, int entry,
3276 PropertyDetails value) {
3277 STATIC_ASSERT(Dictionary::kEntrySize == 3);
3278 dict->set(Dictionary::EntryToIndex(entry) + 2, value.AsSmi());
3281 template <typename Dictionary>
3282 static bool IsDeleted(Dictionary* dict, int entry) {
3286 template <typename Dictionary>
3287 static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key,
3288 Handle<Object> value, PropertyDetails details);
3292 class NameDictionaryShape : public BaseDictionaryShape<Handle<Name> > {
3294 static inline bool IsMatch(Handle<Name> key, Object* other);
3295 static inline uint32_t Hash(Handle<Name> key);
3296 static inline uint32_t HashForObject(Handle<Name> key, Object* object);
3297 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
3298 static const int kPrefixSize = 2;
3299 static const int kEntrySize = 3;
3300 static const bool kIsEnumerable = true;
3304 class NameDictionary
3305 : public NameDictionaryBase<NameDictionary, NameDictionaryShape> {
3306 typedef NameDictionaryBase<NameDictionary, NameDictionaryShape>
3310 DECLARE_CAST(NameDictionary)
3312 inline static Handle<FixedArray> DoGenerateNewEnumerationIndices(
3313 Handle<NameDictionary> dictionary);
3317 class GlobalDictionaryShape : public NameDictionaryShape {
3319 static const int kEntrySize = 2; // Overrides NameDictionaryShape::kEntrySize
3321 template <typename Dictionary>
3322 static inline PropertyDetails DetailsAt(Dictionary* dict, int entry);
3324 template <typename Dictionary>
3325 static inline void DetailsAtPut(Dictionary* dict, int entry,
3326 PropertyDetails value);
3328 template <typename Dictionary>
3329 static bool IsDeleted(Dictionary* dict, int entry);
3331 template <typename Dictionary>
3332 static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key,
3333 Handle<Object> value, PropertyDetails details);
3337 class GlobalDictionary
3338 : public NameDictionaryBase<GlobalDictionary, GlobalDictionaryShape> {
3340 DECLARE_CAST(GlobalDictionary)
3344 class NumberDictionaryShape : public BaseDictionaryShape<uint32_t> {
3346 static inline bool IsMatch(uint32_t key, Object* other);
3347 static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key);
3348 static const int kEntrySize = 3;
3349 static const bool kIsEnumerable = false;
3353 class SeededNumberDictionaryShape : public NumberDictionaryShape {
3355 static const bool UsesSeed = true;
3356 static const int kPrefixSize = 2;
3358 static inline uint32_t SeededHash(uint32_t key, uint32_t seed);
3359 static inline uint32_t SeededHashForObject(uint32_t key,
3365 class UnseededNumberDictionaryShape : public NumberDictionaryShape {
3367 static const int kPrefixSize = 0;
3369 static inline uint32_t Hash(uint32_t key);
3370 static inline uint32_t HashForObject(uint32_t key, Object* object);
3374 class SeededNumberDictionary
3375 : public Dictionary<SeededNumberDictionary,
3376 SeededNumberDictionaryShape,
3379 DECLARE_CAST(SeededNumberDictionary)
3381 // Type specific at put (default NONE attributes is used when adding).
3382 MUST_USE_RESULT static Handle<SeededNumberDictionary> AtNumberPut(
3383 Handle<SeededNumberDictionary> dictionary, uint32_t key,
3384 Handle<Object> value, bool used_as_prototype);
3385 MUST_USE_RESULT static Handle<SeededNumberDictionary> AddNumberEntry(
3386 Handle<SeededNumberDictionary> dictionary, uint32_t key,
3387 Handle<Object> value, PropertyDetails details, bool used_as_prototype);
3389 // Set an existing entry or add a new one if needed.
3390 // Return the updated dictionary.
3391 MUST_USE_RESULT static Handle<SeededNumberDictionary> Set(
3392 Handle<SeededNumberDictionary> dictionary, uint32_t key,
3393 Handle<Object> value, PropertyDetails details, bool used_as_prototype);
3395 void UpdateMaxNumberKey(uint32_t key, bool used_as_prototype);
3397 // If slow elements are required we will never go back to fast-case
3398 // for the elements kept in this dictionary. We require slow
3399 // elements if an element has been added at an index larger than
3400 // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called
3401 // when defining a getter or setter with a number key.
3402 inline bool requires_slow_elements();
3403 inline void set_requires_slow_elements();
3405 // Get the value of the max number key that has been added to this
3406 // dictionary. max_number_key can only be called if
3407 // requires_slow_elements returns false.
3408 inline uint32_t max_number_key();
3411 static const int kRequiresSlowElementsMask = 1;
3412 static const int kRequiresSlowElementsTagSize = 1;
3413 static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1;
3417 class UnseededNumberDictionary
3418 : public Dictionary<UnseededNumberDictionary,
3419 UnseededNumberDictionaryShape,
3422 DECLARE_CAST(UnseededNumberDictionary)
3424 // Type specific at put (default NONE attributes is used when adding).
3425 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AtNumberPut(
3426 Handle<UnseededNumberDictionary> dictionary,
3428 Handle<Object> value);
3429 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AddNumberEntry(
3430 Handle<UnseededNumberDictionary> dictionary,
3432 Handle<Object> value);
3434 // Set an existing entry or add a new one if needed.
3435 // Return the updated dictionary.
3436 MUST_USE_RESULT static Handle<UnseededNumberDictionary> Set(
3437 Handle<UnseededNumberDictionary> dictionary,
3439 Handle<Object> value);
3443 class ObjectHashTableShape : public BaseShape<Handle<Object> > {
3445 static inline bool IsMatch(Handle<Object> key, Object* other);
3446 static inline uint32_t Hash(Handle<Object> key);
3447 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
3448 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
3449 static const int kPrefixSize = 0;
3450 static const int kEntrySize = 2;
3454 // ObjectHashTable maps keys that are arbitrary objects to object values by
3455 // using the identity hash of the key for hashing purposes.
3456 class ObjectHashTable: public HashTable<ObjectHashTable,
3457 ObjectHashTableShape,
3460 ObjectHashTable, ObjectHashTableShape, Handle<Object> > DerivedHashTable;
3462 DECLARE_CAST(ObjectHashTable)
3464 // Attempt to shrink hash table after removal of key.
3465 MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink(
3466 Handle<ObjectHashTable> table,
3467 Handle<Object> key);
3469 // Looks up the value associated with the given key. The hole value is
3470 // returned in case the key is not present.
3471 Object* Lookup(Handle<Object> key);
3472 Object* Lookup(Handle<Object> key, int32_t hash);
3473 Object* Lookup(Isolate* isolate, Handle<Object> key, int32_t hash);
3475 // Adds (or overwrites) the value associated with the given key.
3476 static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
3478 Handle<Object> value);
3479 static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
3480 Handle<Object> key, Handle<Object> value,
3483 // Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
3484 static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
3487 static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
3488 Handle<Object> key, bool* was_present,
3492 friend class MarkCompactCollector;
3494 void AddEntry(int entry, Object* key, Object* value);
3495 void RemoveEntry(int entry);
3497 // Returns the index to the value of an entry.
3498 static inline int EntryToValueIndex(int entry) {
3499 return EntryToIndex(entry) + 1;
3504 // OrderedHashTable is a HashTable with Object keys that preserves
3505 // insertion order. There are Map and Set interfaces (OrderedHashMap
3506 // and OrderedHashTable, below). It is meant to be used by JSMap/JSSet.
3508 // Only Object* keys are supported, with Object::SameValueZero() used as the
3509 // equality operator and Object::GetHash() for the hash function.
3511 // Based on the "Deterministic Hash Table" as described by Jason Orendorff at
3512 // https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables
3513 // Originally attributed to Tyler Close.
3516 // [0]: bucket count
3517 // [1]: element count
3518 // [2]: deleted element count
3519 // [3..(3 + NumberOfBuckets() - 1)]: "hash table", where each item is an
3520 // offset into the data table (see below) where the
3521 // first item in this bucket is stored.
3522 // [3 + NumberOfBuckets()..length]: "data table", an array of length
3523 // Capacity() * kEntrySize, where the first entrysize
3524 // items are handled by the derived class and the
3525 // item at kChainOffset is another entry into the
3526 // data table indicating the next entry in this hash
3529 // When we transition the table to a new version we obsolete it and reuse parts
3530 // of the memory to store information how to transition an iterator to the new
3533 // Memory layout for obsolete table:
3534 // [0]: bucket count
3535 // [1]: Next newer table
3536 // [2]: Number of removed holes or -1 when the table was cleared.
3537 // [3..(3 + NumberOfRemovedHoles() - 1)]: The indexes of the removed holes.
3538 // [3 + NumberOfRemovedHoles()..length]: Not used
3540 template<class Derived, class Iterator, int entrysize>
3541 class OrderedHashTable: public FixedArray {
3543 // Returns an OrderedHashTable with a capacity of at least |capacity|.
3544 static Handle<Derived> Allocate(
3545 Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED);
3547 // Returns an OrderedHashTable (possibly |table|) with enough space
3548 // to add at least one new element.
3549 static Handle<Derived> EnsureGrowable(Handle<Derived> table);
3551 // Returns an OrderedHashTable (possibly |table|) that's shrunken
3553 static Handle<Derived> Shrink(Handle<Derived> table);
3555 // Returns a new empty OrderedHashTable and records the clearing so that
3556 // exisiting iterators can be updated.
3557 static Handle<Derived> Clear(Handle<Derived> table);
3559 int NumberOfElements() {
3560 return Smi::cast(get(kNumberOfElementsIndex))->value();
3563 int NumberOfDeletedElements() {
3564 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
3567 int UsedCapacity() { return NumberOfElements() + NumberOfDeletedElements(); }
3569 int NumberOfBuckets() {
3570 return Smi::cast(get(kNumberOfBucketsIndex))->value();
3573 // Returns an index into |this| for the given entry.
3574 int EntryToIndex(int entry) {
3575 return kHashTableStartIndex + NumberOfBuckets() + (entry * kEntrySize);
3578 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
3581 return !get(kNextTableIndex)->IsSmi();
3584 // The next newer table. This is only valid if the table is obsolete.
3585 Derived* NextTable() {
3586 return Derived::cast(get(kNextTableIndex));
3589 // When the table is obsolete we store the indexes of the removed holes.
3590 int RemovedIndexAt(int index) {
3591 return Smi::cast(get(kRemovedHolesIndex + index))->value();
3594 static const int kNotFound = -1;
3595 static const int kMinCapacity = 4;
3597 static const int kNumberOfBucketsIndex = 0;
3598 static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1;
3599 static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
3600 static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1;
3601 static const int kNextTableIndex = kNumberOfElementsIndex;
3603 static const int kNumberOfBucketsOffset =
3604 kHeaderSize + kNumberOfBucketsIndex * kPointerSize;
3605 static const int kNumberOfElementsOffset =
3606 kHeaderSize + kNumberOfElementsIndex * kPointerSize;
3607 static const int kNumberOfDeletedElementsOffset =
3608 kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize;
3609 static const int kHashTableStartOffset =
3610 kHeaderSize + kHashTableStartIndex * kPointerSize;
3611 static const int kNextTableOffset =
3612 kHeaderSize + kNextTableIndex * kPointerSize;
3614 static const int kEntrySize = entrysize + 1;
3615 static const int kChainOffset = entrysize;
3617 static const int kLoadFactor = 2;
3619 // NumberOfDeletedElements is set to kClearedTableSentinel when
3620 // the table is cleared, which allows iterator transitions to
3621 // optimize that case.
3622 static const int kClearedTableSentinel = -1;
3625 static Handle<Derived> Rehash(Handle<Derived> table, int new_capacity);
3627 void SetNumberOfBuckets(int num) {
3628 set(kNumberOfBucketsIndex, Smi::FromInt(num));
3631 void SetNumberOfElements(int num) {
3632 set(kNumberOfElementsIndex, Smi::FromInt(num));
3635 void SetNumberOfDeletedElements(int num) {
3636 set(kNumberOfDeletedElementsIndex, Smi::FromInt(num));
3640 return NumberOfBuckets() * kLoadFactor;
3643 void SetNextTable(Derived* next_table) {
3644 set(kNextTableIndex, next_table);
3647 void SetRemovedIndexAt(int index, int removed_index) {
3648 return set(kRemovedHolesIndex + index, Smi::FromInt(removed_index));
3651 static const int kRemovedHolesIndex = kHashTableStartIndex;
3653 static const int kMaxCapacity =
3654 (FixedArray::kMaxLength - kHashTableStartIndex)
3655 / (1 + (kEntrySize * kLoadFactor));
3659 class JSSetIterator;
3662 class OrderedHashSet: public OrderedHashTable<
3663 OrderedHashSet, JSSetIterator, 1> {
3665 DECLARE_CAST(OrderedHashSet)
3669 class JSMapIterator;
3672 class OrderedHashMap
3673 : public OrderedHashTable<OrderedHashMap, JSMapIterator, 2> {
3675 DECLARE_CAST(OrderedHashMap)
3677 inline Object* ValueAt(int entry);
3679 static const int kValueOffset = 1;
3683 template <int entrysize>
3684 class WeakHashTableShape : public BaseShape<Handle<Object> > {
3686 static inline bool IsMatch(Handle<Object> key, Object* other);
3687 static inline uint32_t Hash(Handle<Object> key);
3688 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
3689 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
3690 static const int kPrefixSize = 0;
3691 static const int kEntrySize = entrysize;
3695 // WeakHashTable maps keys that are arbitrary heap objects to heap object
3696 // values. The table wraps the keys in weak cells and store values directly.
3697 // Thus it references keys weakly and values strongly.
3698 class WeakHashTable: public HashTable<WeakHashTable,
3699 WeakHashTableShape<2>,
3702 WeakHashTable, WeakHashTableShape<2>, Handle<Object> > DerivedHashTable;
3704 DECLARE_CAST(WeakHashTable)
3706 // Looks up the value associated with the given key. The hole value is
3707 // returned in case the key is not present.
3708 Object* Lookup(Handle<HeapObject> key);
3710 // Adds (or overwrites) the value associated with the given key. Mapping a
3711 // key to the hole value causes removal of the whole entry.
3712 MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table,
3713 Handle<HeapObject> key,
3714 Handle<HeapObject> value);
3716 static Handle<FixedArray> GetValues(Handle<WeakHashTable> table);
3719 friend class MarkCompactCollector;
3721 void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value);
3723 // Returns the index to the value of an entry.
3724 static inline int EntryToValueIndex(int entry) {
3725 return EntryToIndex(entry) + 1;
3730 class WeakValueHashTable : public ObjectHashTable {
3732 DECLARE_CAST(WeakValueHashTable)
3735 // Looks up the value associated with the given key. The hole value is
3736 // returned in case the key is not present.
3737 Object* LookupWeak(Handle<Object> key);
3740 // Adds (or overwrites) the value associated with the given key. Mapping a
3741 // key to the hole value causes removal of the whole entry.
3742 MUST_USE_RESULT static Handle<WeakValueHashTable> PutWeak(
3743 Handle<WeakValueHashTable> table, Handle<Object> key,
3744 Handle<HeapObject> value);
3746 static Handle<FixedArray> GetWeakValues(Handle<WeakValueHashTable> table);
3750 // ScopeInfo represents information about different scopes of a source
3751 // program and the allocation of the scope's variables. Scope information
3752 // is stored in a compressed form in ScopeInfo objects and is used
3753 // at runtime (stack dumps, deoptimization, etc.).
3755 // This object provides quick access to scope info details for runtime
3757 class ScopeInfo : public FixedArray {
3759 DECLARE_CAST(ScopeInfo)
3761 // Return the type of this scope.
3762 ScopeType scope_type();
3764 // Does this scope call eval?
3767 // Return the language mode of this scope.
3768 LanguageMode language_mode();
3770 // Does this scope make a sloppy eval call?
3771 bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); }
3773 // Return the total number of locals allocated on the stack and in the
3774 // context. This includes the parameters that are allocated in the context.
3777 // Return the number of stack slots for code. This number consists of two
3779 // 1. One stack slot per stack allocated local.
3780 // 2. One stack slot for the function name if it is stack allocated.
3781 int StackSlotCount();
3783 // Return the number of context slots for code if a context is allocated. This
3784 // number consists of three parts:
3785 // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS
3786 // 2. One context slot per context allocated local.
3787 // 3. One context slot for the function name if it is context allocated.
3788 // Parameters allocated in the context count as context allocated locals. If
3789 // no contexts are allocated for this scope ContextLength returns 0.
3790 int ContextLength();
3792 // Does this scope declare a "this" binding?
3795 // Does this scope declare a "this" binding, and the "this" binding is stack-
3796 // or context-allocated?
3797 bool HasAllocatedReceiver();
3799 // Is this scope the scope of a named function expression?
3800 bool HasFunctionName();
3802 // Return if this has context allocated locals.
3803 bool HasHeapAllocatedLocals();
3805 // Return if contexts are allocated for this scope.
3808 // Return if this is a function scope with "use asm".
3809 inline bool IsAsmModule();
3811 // Return if this is a nested function within an asm module scope.
3812 inline bool IsAsmFunction();
3814 inline bool HasSimpleParameters();
3816 // Return the function_name if present.
3817 String* FunctionName();
3819 // Return the name of the given parameter.
3820 String* ParameterName(int var);
3822 // Return the name of the given local.
3823 String* LocalName(int var);
3825 // Return the name of the given stack local.
3826 String* StackLocalName(int var);
3828 // Return the name of the given stack local.
3829 int StackLocalIndex(int var);
3831 // Return the name of the given context local.
3832 String* ContextLocalName(int var);
3834 // Return the mode of the given context local.
3835 VariableMode ContextLocalMode(int var);
3837 // Return the initialization flag of the given context local.
3838 InitializationFlag ContextLocalInitFlag(int var);
3840 // Return the initialization flag of the given context local.
3841 MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var);
3843 // Return true if this local was introduced by the compiler, and should not be
3844 // exposed to the user in a debugger.
3845 bool LocalIsSynthetic(int var);
3847 String* StrongModeFreeVariableName(int var);
3848 int StrongModeFreeVariableStartPosition(int var);
3849 int StrongModeFreeVariableEndPosition(int var);
3851 // Lookup support for serialized scope info. Returns the
3852 // the stack slot index for a given slot name if the slot is
3853 // present; otherwise returns a value < 0. The name must be an internalized
3855 int StackSlotIndex(String* name);
3857 // Lookup support for serialized scope info. Returns the
3858 // context slot index for a given slot name if the slot is present; otherwise
3859 // returns a value < 0. The name must be an internalized string.
3860 // If the slot is present and mode != NULL, sets *mode to the corresponding
3861 // mode for that variable.
3862 static int ContextSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name,
3863 VariableMode* mode, VariableLocation* location,
3864 InitializationFlag* init_flag,
3865 MaybeAssignedFlag* maybe_assigned_flag);
3867 // Lookup the name of a certain context slot by its index.
3868 String* ContextSlotName(int slot_index);
3870 // Lookup support for serialized scope info. Returns the
3871 // parameter index for a given parameter name if the parameter is present;
3872 // otherwise returns a value < 0. The name must be an internalized string.
3873 int ParameterIndex(String* name);
3875 // Lookup support for serialized scope info. Returns the function context
3876 // slot index if the function name is present and context-allocated (named
3877 // function expressions, only), otherwise returns a value < 0. The name
3878 // must be an internalized string.
3879 int FunctionContextSlotIndex(String* name, VariableMode* mode);
3881 // Lookup support for serialized scope info. Returns the receiver context
3882 // slot index if scope has a "this" binding, and the binding is
3883 // context-allocated. Otherwise returns a value < 0.
3884 int ReceiverContextSlotIndex();
3886 FunctionKind function_kind();
3888 static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope);
3889 static Handle<ScopeInfo> CreateGlobalThisBinding(Isolate* isolate);
3891 // Serializes empty scope info.
3892 static ScopeInfo* Empty(Isolate* isolate);
3898 // The layout of the static part of a ScopeInfo is as follows. Each entry is
3899 // numeric and occupies one array slot.
3900 // 1. A set of properties of the scope
3901 // 2. The number of parameters. This only applies to function scopes. For
3902 // non-function scopes this is 0.
3903 // 3. The number of non-parameter variables allocated on the stack.
3904 // 4. The number of non-parameter and parameter variables allocated in the
3906 #define FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(V) \
3909 V(StackLocalCount) \
3910 V(ContextLocalCount) \
3911 V(ContextGlobalCount) \
3912 V(StrongModeFreeVariableCount)
3914 #define FIELD_ACCESSORS(name) \
3915 inline void Set##name(int value); \
3917 FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(FIELD_ACCESSORS)
3918 #undef FIELD_ACCESSORS
3922 #define DECL_INDEX(name) k##name,
3923 FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(DECL_INDEX)
3928 // The layout of the variable part of a ScopeInfo is as follows:
3929 // 1. ParameterEntries:
3930 // This part stores the names of the parameters for function scopes. One
3931 // slot is used per parameter, so in total this part occupies
3932 // ParameterCount() slots in the array. For other scopes than function
3933 // scopes ParameterCount() is 0.
3934 // 2. StackLocalFirstSlot:
3935 // Index of a first stack slot for stack local. Stack locals belonging to
3936 // this scope are located on a stack at slots starting from this index.
3937 // 3. StackLocalEntries:
3938 // Contains the names of local variables that are allocated on the stack,
3939 // in increasing order of the stack slot index. First local variable has
3940 // a stack slot index defined in StackLocalFirstSlot (point 2 above).
3941 // One slot is used per stack local, so in total this part occupies
3942 // StackLocalCount() slots in the array.
3943 // 4. ContextLocalNameEntries:
3944 // Contains the names of local variables and parameters that are allocated
3945 // in the context. They are stored in increasing order of the context slot
3946 // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
3947 // context local, so in total this part occupies ContextLocalCount() slots
3949 // 5. ContextLocalInfoEntries:
3950 // Contains the variable modes and initialization flags corresponding to
3951 // the context locals in ContextLocalNameEntries. One slot is used per
3952 // context local, so in total this part occupies ContextLocalCount()
3953 // slots in the array.
3954 // 6. StrongModeFreeVariableNameEntries:
3955 // Stores the names of strong mode free variables.
3956 // 7. StrongModeFreeVariablePositionEntries:
3957 // Stores the locations (start and end position) of strong mode free
3959 // 8. RecieverEntryIndex:
3960 // If the scope binds a "this" value, one slot is reserved to hold the
3961 // context or stack slot index for the variable.
3962 // 9. FunctionNameEntryIndex:
3963 // If the scope belongs to a named function expression this part contains
3964 // information about the function variable. It always occupies two array
3965 // slots: a. The name of the function variable.
3966 // b. The context or stack slot index for the variable.
3967 int ParameterEntriesIndex();
3968 int StackLocalFirstSlotIndex();
3969 int StackLocalEntriesIndex();
3970 int ContextLocalNameEntriesIndex();
3971 int ContextGlobalNameEntriesIndex();
3972 int ContextLocalInfoEntriesIndex();
3973 int ContextGlobalInfoEntriesIndex();
3974 int StrongModeFreeVariableNameEntriesIndex();
3975 int StrongModeFreeVariablePositionEntriesIndex();
3976 int ReceiverEntryIndex();
3977 int FunctionNameEntryIndex();
3979 int Lookup(Handle<String> name, int start, int end, VariableMode* mode,
3980 VariableLocation* location, InitializationFlag* init_flag,
3981 MaybeAssignedFlag* maybe_assigned_flag);
3983 // Used for the function name variable for named function expressions, and for
3985 enum VariableAllocationInfo { NONE, STACK, CONTEXT, UNUSED };
3987 // Properties of scopes.
3988 class ScopeTypeField : public BitField<ScopeType, 0, 4> {};
3989 class CallsEvalField : public BitField<bool, ScopeTypeField::kNext, 1> {};
3990 STATIC_ASSERT(LANGUAGE_END == 3);
3991 class LanguageModeField
3992 : public BitField<LanguageMode, CallsEvalField::kNext, 2> {};
3993 class ReceiverVariableField
3994 : public BitField<VariableAllocationInfo, LanguageModeField::kNext, 2> {};
3995 class FunctionVariableField
3996 : public BitField<VariableAllocationInfo, ReceiverVariableField::kNext,
3998 class FunctionVariableMode
3999 : public BitField<VariableMode, FunctionVariableField::kNext, 3> {};
4000 class AsmModuleField : public BitField<bool, FunctionVariableMode::kNext, 1> {
4002 class AsmFunctionField : public BitField<bool, AsmModuleField::kNext, 1> {};
4003 class HasSimpleParametersField
4004 : public BitField<bool, AsmFunctionField::kNext, 1> {};
4005 class FunctionKindField
4006 : public BitField<FunctionKind, HasSimpleParametersField::kNext, 8> {};
4008 // BitFields representing the encoded information for context locals in the
4009 // ContextLocalInfoEntries part.
4010 class ContextLocalMode: public BitField<VariableMode, 0, 3> {};
4011 class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {};
4012 class ContextLocalMaybeAssignedFlag
4013 : public BitField<MaybeAssignedFlag, 4, 1> {};
4015 friend class ScopeIterator;
4019 // The cache for maps used by normalized (dictionary mode) objects.
4020 // Such maps do not have property descriptors, so a typical program
4021 // needs very limited number of distinct normalized maps.
4022 class NormalizedMapCache: public FixedArray {
4024 static Handle<NormalizedMapCache> New(Isolate* isolate);
4026 MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
4027 PropertyNormalizationMode mode);
4028 void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
4032 DECLARE_CAST(NormalizedMapCache)
4034 static inline bool IsNormalizedMapCache(const Object* obj);
4036 DECLARE_VERIFIER(NormalizedMapCache)
4038 static const int kEntries = 64;
4040 static inline int GetIndex(Handle<Map> map);
4042 // The following declarations hide base class methods.
4043 Object* get(int index);
4044 void set(int index, Object* value);
4048 // ByteArray represents fixed sized byte arrays. Used for the relocation info
4049 // that is attached to code objects.
4050 class ByteArray: public FixedArrayBase {
4054 // Setter and getter.
4055 inline byte get(int index);
4056 inline void set(int index, byte value);
4058 // Treat contents as an int array.
4059 inline int get_int(int index);
4061 static int SizeFor(int length) {
4062 return OBJECT_POINTER_ALIGN(kHeaderSize + length);
4064 // We use byte arrays for free blocks in the heap. Given a desired size in
4065 // bytes that is a multiple of the word size and big enough to hold a byte
4066 // array, this function returns the number of elements a byte array should
4068 static int LengthFor(int size_in_bytes) {
4069 DCHECK(IsAligned(size_in_bytes, kPointerSize));
4070 DCHECK(size_in_bytes >= kHeaderSize);
4071 return size_in_bytes - kHeaderSize;
4074 // Returns data start address.
4075 inline Address GetDataStartAddress();
4077 // Returns a pointer to the ByteArray object for a given data start address.
4078 static inline ByteArray* FromDataStartAddress(Address address);
4080 DECLARE_CAST(ByteArray)
4082 // Dispatched behavior.
4083 inline int ByteArraySize();
4084 DECLARE_PRINTER(ByteArray)
4085 DECLARE_VERIFIER(ByteArray)
4087 // Layout description.
4088 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4090 // Maximal memory consumption for a single ByteArray.
4091 static const int kMaxSize = 512 * MB;
4092 // Maximal length of a single ByteArray.
4093 static const int kMaxLength = kMaxSize - kHeaderSize;
4096 DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
4100 // BytecodeArray represents a sequence of interpreter bytecodes.
4101 class BytecodeArray : public FixedArrayBase {
4103 static int SizeFor(int length) {
4104 return OBJECT_POINTER_ALIGN(kHeaderSize + length);
4107 // Setter and getter
4108 inline byte get(int index);
4109 inline void set(int index, byte value);
4111 // Returns data start address.
4112 inline Address GetFirstBytecodeAddress();
4114 // Accessors for frame size and the number of locals
4115 inline int frame_size() const;
4116 inline void set_frame_size(int value);
4118 DECLARE_CAST(BytecodeArray)
4120 // Dispatched behavior.
4121 inline int BytecodeArraySize();
4123 DECLARE_PRINTER(BytecodeArray)
4124 DECLARE_VERIFIER(BytecodeArray)
4126 void Disassemble(std::ostream& os);
4128 // Layout description.
4129 static const int kFrameSizeOffset = FixedArrayBase::kHeaderSize;
4130 static const int kHeaderSize = kFrameSizeOffset + kIntSize;
4132 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4134 // Maximal memory consumption for a single BytecodeArray.
4135 static const int kMaxSize = 512 * MB;
4136 // Maximal length of a single BytecodeArray.
4137 static const int kMaxLength = kMaxSize - kHeaderSize;
4140 DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArray);
4144 // FreeSpace are fixed-size free memory blocks used by the heap and GC.
4145 // They look like heap objects (are heap object tagged and have a map) so that
4146 // the heap remains iterable. They have a size and a next pointer.
4147 // The next pointer is the raw address of the next FreeSpace object (or NULL)
4148 // in the free list.
4149 class FreeSpace: public HeapObject {
4151 // [size]: size of the free space including the header.
4152 inline int size() const;
4153 inline void set_size(int value);
4155 inline int nobarrier_size() const;
4156 inline void nobarrier_set_size(int value);
4160 // Accessors for the next field.
4161 inline FreeSpace* next();
4162 inline FreeSpace** next_address();
4163 inline void set_next(FreeSpace* next);
4165 inline static FreeSpace* cast(HeapObject* obj);
4167 // Dispatched behavior.
4168 DECLARE_PRINTER(FreeSpace)
4169 DECLARE_VERIFIER(FreeSpace)
4171 // Layout description.
4172 // Size is smi tagged when it is stored.
4173 static const int kSizeOffset = HeapObject::kHeaderSize;
4174 static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize);
4177 DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
4181 // V has parameters (Type, type, TYPE, C type, element_size)
4182 #define TYPED_ARRAYS(V) \
4183 V(Uint8, uint8, UINT8, uint8_t, 1) \
4184 V(Int8, int8, INT8, int8_t, 1) \
4185 V(Uint16, uint16, UINT16, uint16_t, 2) \
4186 V(Int16, int16, INT16, int16_t, 2) \
4187 V(Uint32, uint32, UINT32, uint32_t, 4) \
4188 V(Int32, int32, INT32, int32_t, 4) \
4189 V(Float32, float32, FLOAT32, float, 4) \
4190 V(Float64, float64, FLOAT64, double, 8) \
4191 V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1)
4194 class FixedTypedArrayBase: public FixedArrayBase {
4196 // [base_pointer]: Either points to the FixedTypedArrayBase itself or nullptr.
4197 DECL_ACCESSORS(base_pointer, Object)
4199 // [external_pointer]: Contains the offset between base_pointer and the start
4200 // of the data. If the base_pointer is a nullptr, the external_pointer
4201 // therefore points to the actual backing store.
4202 DECL_ACCESSORS(external_pointer, void)
4204 // Dispatched behavior.
4205 inline void FixedTypedArrayBaseIterateBody(ObjectVisitor* v);
4207 template <typename StaticVisitor>
4208 inline void FixedTypedArrayBaseIterateBody();
4210 DECLARE_CAST(FixedTypedArrayBase)
4212 static const int kBasePointerOffset = FixedArrayBase::kHeaderSize;
4213 static const int kExternalPointerOffset = kBasePointerOffset + kPointerSize;
4214 static const int kHeaderSize =
4215 DOUBLE_POINTER_ALIGN(kExternalPointerOffset + kPointerSize);
4217 static const int kDataOffset = kHeaderSize;
4221 static inline int TypedArraySize(InstanceType type, int length);
4222 inline int TypedArraySize(InstanceType type);
4224 // Use with care: returns raw pointer into heap.
4225 inline void* DataPtr();
4227 inline int DataSize();
4230 static inline int ElementSize(InstanceType type);
4232 inline int DataSize(InstanceType type);
4234 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase);
4238 template <class Traits>
4239 class FixedTypedArray: public FixedTypedArrayBase {
4241 typedef typename Traits::ElementType ElementType;
4242 static const InstanceType kInstanceType = Traits::kInstanceType;
4244 DECLARE_CAST(FixedTypedArray<Traits>)
4246 inline ElementType get_scalar(int index);
4247 static inline Handle<Object> get(Handle<FixedTypedArray> array, int index);
4248 inline void set(int index, ElementType value);
4250 static inline ElementType from_int(int value);
4251 static inline ElementType from_double(double value);
4253 // This accessor applies the correct conversion from Smi, HeapNumber
4255 void SetValue(uint32_t index, Object* value);
4257 DECLARE_PRINTER(FixedTypedArray)
4258 DECLARE_VERIFIER(FixedTypedArray)
4261 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray);
4264 #define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType, size) \
4265 class Type##ArrayTraits { \
4266 public: /* NOLINT */ \
4267 typedef elementType ElementType; \
4268 static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE; \
4269 static const char* Designator() { return #type " array"; } \
4270 static inline Handle<Object> ToHandle(Isolate* isolate, \
4271 elementType scalar); \
4272 static inline elementType defaultValue(); \
4275 typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array;
4277 TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS)
4279 #undef FIXED_TYPED_ARRAY_TRAITS
4282 // DeoptimizationInputData is a fixed array used to hold the deoptimization
4283 // data for code generated by the Hydrogen/Lithium compiler. It also
4284 // contains information about functions that were inlined. If N different
4285 // functions were inlined then first N elements of the literal array will
4286 // contain these functions.
4289 class DeoptimizationInputData: public FixedArray {
4291 // Layout description. Indices in the array.
4292 static const int kTranslationByteArrayIndex = 0;
4293 static const int kInlinedFunctionCountIndex = 1;
4294 static const int kLiteralArrayIndex = 2;
4295 static const int kOsrAstIdIndex = 3;
4296 static const int kOsrPcOffsetIndex = 4;
4297 static const int kOptimizationIdIndex = 5;
4298 static const int kSharedFunctionInfoIndex = 6;
4299 static const int kWeakCellCacheIndex = 7;
4300 static const int kFirstDeoptEntryIndex = 8;
4302 // Offsets of deopt entry elements relative to the start of the entry.
4303 static const int kAstIdRawOffset = 0;
4304 static const int kTranslationIndexOffset = 1;
4305 static const int kArgumentsStackHeightOffset = 2;
4306 static const int kPcOffset = 3;
4307 static const int kDeoptEntrySize = 4;
4309 // Simple element accessors.
4310 #define DECLARE_ELEMENT_ACCESSORS(name, type) \
4311 inline type* name(); \
4312 inline void Set##name(type* value);
4314 DECLARE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray)
4315 DECLARE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi)
4316 DECLARE_ELEMENT_ACCESSORS(LiteralArray, FixedArray)
4317 DECLARE_ELEMENT_ACCESSORS(OsrAstId, Smi)
4318 DECLARE_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
4319 DECLARE_ELEMENT_ACCESSORS(OptimizationId, Smi)
4320 DECLARE_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
4321 DECLARE_ELEMENT_ACCESSORS(WeakCellCache, Object)
4323 #undef DECLARE_ELEMENT_ACCESSORS
4325 // Accessors for elements of the ith deoptimization entry.
4326 #define DECLARE_ENTRY_ACCESSORS(name, type) \
4327 inline type* name(int i); \
4328 inline void Set##name(int i, type* value);
4330 DECLARE_ENTRY_ACCESSORS(AstIdRaw, Smi)
4331 DECLARE_ENTRY_ACCESSORS(TranslationIndex, Smi)
4332 DECLARE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi)
4333 DECLARE_ENTRY_ACCESSORS(Pc, Smi)
4335 #undef DECLARE_ENTRY_ACCESSORS
4337 inline BailoutId AstId(int i);
4339 inline void SetAstId(int i, BailoutId value);
4341 inline int DeoptCount();
4343 // Allocates a DeoptimizationInputData.
4344 static Handle<DeoptimizationInputData> New(Isolate* isolate,
4345 int deopt_entry_count,
4346 PretenureFlag pretenure);
4348 DECLARE_CAST(DeoptimizationInputData)
4350 #ifdef ENABLE_DISASSEMBLER
4351 void DeoptimizationInputDataPrint(std::ostream& os); // NOLINT
4355 static int IndexForEntry(int i) {
4356 return kFirstDeoptEntryIndex + (i * kDeoptEntrySize);
4360 static int LengthFor(int entry_count) { return IndexForEntry(entry_count); }
4364 // DeoptimizationOutputData is a fixed array used to hold the deoptimization
4365 // data for code generated by the full compiler.
4366 // The format of the these objects is
4367 // [i * 2]: Ast ID for ith deoptimization.
4368 // [i * 2 + 1]: PC and state of ith deoptimization
4369 class DeoptimizationOutputData: public FixedArray {
4371 inline int DeoptPoints();
4373 inline BailoutId AstId(int index);
4375 inline void SetAstId(int index, BailoutId id);
4377 inline Smi* PcAndState(int index);
4378 inline void SetPcAndState(int index, Smi* offset);
4380 static int LengthOfFixedArray(int deopt_points) {
4381 return deopt_points * 2;
4384 // Allocates a DeoptimizationOutputData.
4385 static Handle<DeoptimizationOutputData> New(Isolate* isolate,
4386 int number_of_deopt_points,
4387 PretenureFlag pretenure);
4389 DECLARE_CAST(DeoptimizationOutputData)
4391 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
4392 void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT
4397 // HandlerTable is a fixed array containing entries for exception handlers in
4398 // the code object it is associated with. The tables comes in two flavors:
4399 // 1) Based on ranges: Used for unoptimized code. Contains one entry per
4400 // exception handler and a range representing the try-block covered by that
4401 // handler. Layout looks as follows:
4402 // [ range-start , range-end , handler-offset , stack-depth ]
4403 // 2) Based on return addresses: Used for turbofanned code. Contains one entry
4404 // per call-site that could throw an exception. Layout looks as follows:
4405 // [ return-address-offset , handler-offset ]
4406 class HandlerTable : public FixedArray {
4408 // Conservative prediction whether a given handler will locally catch an
4409 // exception or cause a re-throw to outside the code boundary. Since this is
4410 // undecidable it is merely an approximation (e.g. useful for debugger).
4411 enum CatchPrediction { UNCAUGHT, CAUGHT };
4413 // Accessors for handler table based on ranges.
4414 inline void SetRangeStart(int index, int value);
4415 inline void SetRangeEnd(int index, int value);
4416 inline void SetRangeHandler(int index, int offset, CatchPrediction pred);
4417 inline void SetRangeDepth(int index, int value);
4419 // Accessors for handler table based on return addresses.
4420 inline void SetReturnOffset(int index, int value);
4421 inline void SetReturnHandler(int index, int offset, CatchPrediction pred);
4423 // Lookup handler in a table based on ranges.
4424 int LookupRange(int pc_offset, int* stack_depth, CatchPrediction* prediction);
4426 // Lookup handler in a table based on return addresses.
4427 int LookupReturn(int pc_offset, CatchPrediction* prediction);
4429 // Returns the required length of the underlying fixed array.
4430 static int LengthForRange(int entries) { return entries * kRangeEntrySize; }
4431 static int LengthForReturn(int entries) { return entries * kReturnEntrySize; }
4433 DECLARE_CAST(HandlerTable)
4435 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
4436 void HandlerTableRangePrint(std::ostream& os); // NOLINT
4437 void HandlerTableReturnPrint(std::ostream& os); // NOLINT
4441 // Layout description for handler table based on ranges.
4442 static const int kRangeStartIndex = 0;
4443 static const int kRangeEndIndex = 1;
4444 static const int kRangeHandlerIndex = 2;
4445 static const int kRangeDepthIndex = 3;
4446 static const int kRangeEntrySize = 4;
4448 // Layout description for handler table based on return addresses.
4449 static const int kReturnOffsetIndex = 0;
4450 static const int kReturnHandlerIndex = 1;
4451 static const int kReturnEntrySize = 2;
4453 // Encoding of the {handler} field.
4454 class HandlerPredictionField : public BitField<CatchPrediction, 0, 1> {};
4455 class HandlerOffsetField : public BitField<int, 1, 30> {};
4459 // Code describes objects with on-the-fly generated machine code.
4460 class Code: public HeapObject {
4462 // Opaque data type for encapsulating code flags like kind, inline
4463 // cache state, and arguments count.
4464 typedef uint32_t Flags;
4466 #define NON_IC_KIND_LIST(V) \
4468 V(OPTIMIZED_FUNCTION) \
4474 #define IC_KIND_LIST(V) \
4485 #define CODE_KIND_LIST(V) \
4486 NON_IC_KIND_LIST(V) \
4490 #define DEFINE_CODE_KIND_ENUM(name) name,
4491 CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM)
4492 #undef DEFINE_CODE_KIND_ENUM
4496 // No more than 16 kinds. The value is currently encoded in four bits in
4498 STATIC_ASSERT(NUMBER_OF_KINDS <= 16);
4500 static const char* Kind2String(Kind kind);
4508 static const int kPrologueOffsetNotSet = -1;
4510 #ifdef ENABLE_DISASSEMBLER
4512 static const char* ICState2String(InlineCacheState state);
4513 static const char* StubType2String(StubType type);
4514 static void PrintExtraICState(std::ostream& os, // NOLINT
4515 Kind kind, ExtraICState extra);
4516 void Disassemble(const char* name, std::ostream& os); // NOLINT
4517 #endif // ENABLE_DISASSEMBLER
4519 // [instruction_size]: Size of the native instructions
4520 inline int instruction_size() const;
4521 inline void set_instruction_size(int value);
4523 // [relocation_info]: Code relocation information
4524 DECL_ACCESSORS(relocation_info, ByteArray)
4525 void InvalidateRelocation();
4526 void InvalidateEmbeddedObjects();
4528 // [handler_table]: Fixed array containing offsets of exception handlers.
4529 DECL_ACCESSORS(handler_table, FixedArray)
4531 // [deoptimization_data]: Array containing data for deopt.
4532 DECL_ACCESSORS(deoptimization_data, FixedArray)
4534 // [raw_type_feedback_info]: This field stores various things, depending on
4535 // the kind of the code object.
4536 // FUNCTION => type feedback information.
4537 // STUB and ICs => major/minor key as Smi.
4538 DECL_ACCESSORS(raw_type_feedback_info, Object)
4539 inline Object* type_feedback_info();
4540 inline void set_type_feedback_info(
4541 Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
4542 inline uint32_t stub_key();
4543 inline void set_stub_key(uint32_t key);
4545 // [next_code_link]: Link for lists of optimized or deoptimized code.
4546 // Note that storage for this field is overlapped with typefeedback_info.
4547 DECL_ACCESSORS(next_code_link, Object)
4549 // [gc_metadata]: Field used to hold GC related metadata. The contents of this
4550 // field does not have to be traced during garbage collection since
4551 // it is only used by the garbage collector itself.
4552 DECL_ACCESSORS(gc_metadata, Object)
4554 // [ic_age]: Inline caching age: the value of the Heap::global_ic_age
4555 // at the moment when this object was created.
4556 inline void set_ic_age(int count);
4557 inline int ic_age() const;
4559 // [prologue_offset]: Offset of the function prologue, used for aging
4560 // FUNCTIONs and OPTIMIZED_FUNCTIONs.
4561 inline int prologue_offset() const;
4562 inline void set_prologue_offset(int offset);
4564 // [constant_pool offset]: Offset of the constant pool.
4565 // Valid for FLAG_enable_embedded_constant_pool only
4566 inline int constant_pool_offset() const;
4567 inline void set_constant_pool_offset(int offset);
4569 // Unchecked accessors to be used during GC.
4570 inline ByteArray* unchecked_relocation_info();
4572 inline int relocation_size();
4574 // [flags]: Various code flags.
4575 inline Flags flags();
4576 inline void set_flags(Flags flags);
4578 // [flags]: Access to specific code flags.
4580 inline InlineCacheState ic_state(); // Only valid for IC stubs.
4581 inline ExtraICState extra_ic_state(); // Only valid for IC stubs.
4583 inline StubType type(); // Only valid for monomorphic IC stubs.
4585 // Testers for IC stub kinds.
4586 inline bool is_inline_cache_stub();
4587 inline bool is_debug_stub();
4588 inline bool is_handler();
4589 inline bool is_load_stub();
4590 inline bool is_keyed_load_stub();
4591 inline bool is_store_stub();
4592 inline bool is_keyed_store_stub();
4593 inline bool is_call_stub();
4594 inline bool is_binary_op_stub();
4595 inline bool is_compare_ic_stub();
4596 inline bool is_compare_nil_ic_stub();
4597 inline bool is_to_boolean_ic_stub();
4598 inline bool is_keyed_stub();
4599 inline bool is_optimized_code();
4600 inline bool embeds_maps_weakly();
4602 inline bool IsCodeStubOrIC();
4604 inline void set_raw_kind_specific_flags1(int value);
4605 inline void set_raw_kind_specific_flags2(int value);
4607 // [is_crankshafted]: For kind STUB or ICs, tells whether or not a code
4608 // object was generated by either the hydrogen or the TurboFan optimizing
4609 // compiler (but it may not be an optimized function).
4610 inline bool is_crankshafted();
4611 inline bool is_hydrogen_stub(); // Crankshafted, but not a function.
4612 inline void set_is_crankshafted(bool value);
4614 // [is_turbofanned]: For kind STUB or OPTIMIZED_FUNCTION, tells whether the
4615 // code object was generated by the TurboFan optimizing compiler.
4616 inline bool is_turbofanned();
4617 inline void set_is_turbofanned(bool value);
4619 // [can_have_weak_objects]: For kind OPTIMIZED_FUNCTION, tells whether the
4620 // embedded objects in code should be treated weakly.
4621 inline bool can_have_weak_objects();
4622 inline void set_can_have_weak_objects(bool value);
4624 // [has_deoptimization_support]: For FUNCTION kind, tells if it has
4625 // deoptimization support.
4626 inline bool has_deoptimization_support();
4627 inline void set_has_deoptimization_support(bool value);
4629 // [has_debug_break_slots]: For FUNCTION kind, tells if it has
4630 // been compiled with debug break slots.
4631 inline bool has_debug_break_slots();
4632 inline void set_has_debug_break_slots(bool value);
4634 // [has_reloc_info_for_serialization]: For FUNCTION kind, tells if its
4635 // reloc info includes runtime and external references to support
4636 // serialization/deserialization.
4637 inline bool has_reloc_info_for_serialization();
4638 inline void set_has_reloc_info_for_serialization(bool value);
4640 // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for
4641 // how long the function has been marked for OSR and therefore which
4642 // level of loop nesting we are willing to do on-stack replacement
4644 inline void set_allow_osr_at_loop_nesting_level(int level);
4645 inline int allow_osr_at_loop_nesting_level();
4647 // [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks
4648 // the code object was seen on the stack with no IC patching going on.
4649 inline int profiler_ticks();
4650 inline void set_profiler_ticks(int ticks);
4652 // [builtin_index]: For BUILTIN kind, tells which builtin index it has.
4653 // For builtins, tells which builtin index it has.
4654 // Note that builtins can have a code kind other than BUILTIN, which means
4655 // that for arbitrary code objects, this index value may be random garbage.
4656 // To verify in that case, compare the code object to the indexed builtin.
4657 inline int builtin_index();
4658 inline void set_builtin_index(int id);
4660 // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots
4661 // reserved in the code prologue.
4662 inline unsigned stack_slots();
4663 inline void set_stack_slots(unsigned slots);
4665 // [safepoint_table_start]: For kind OPTIMIZED_FUNCTION, the offset in
4666 // the instruction stream where the safepoint table starts.
4667 inline unsigned safepoint_table_offset();
4668 inline void set_safepoint_table_offset(unsigned offset);
4670 // [back_edge_table_start]: For kind FUNCTION, the offset in the
4671 // instruction stream where the back edge table starts.
4672 inline unsigned back_edge_table_offset();
4673 inline void set_back_edge_table_offset(unsigned offset);
4675 inline bool back_edges_patched_for_osr();
4677 // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in.
4678 inline uint16_t to_boolean_state();
4680 // [has_function_cache]: For kind STUB tells whether there is a function
4681 // cache is passed to the stub.
4682 inline bool has_function_cache();
4683 inline void set_has_function_cache(bool flag);
4686 // [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether
4687 // the code is going to be deoptimized because of dead embedded maps.
4688 inline bool marked_for_deoptimization();
4689 inline void set_marked_for_deoptimization(bool flag);
4691 // [constant_pool]: The constant pool for this function.
4692 inline Address constant_pool();
4694 // Get the safepoint entry for the given pc.
4695 SafepointEntry GetSafepointEntry(Address pc);
4697 // Find an object in a stub with a specified map
4698 Object* FindNthObject(int n, Map* match_map);
4700 // Find the first allocation site in an IC stub.
4701 AllocationSite* FindFirstAllocationSite();
4703 // Find the first map in an IC stub.
4704 Map* FindFirstMap();
4705 void FindAllMaps(MapHandleList* maps);
4707 // Find the first handler in an IC stub.
4708 Code* FindFirstHandler();
4710 // Find |length| handlers and put them into |code_list|. Returns false if not
4711 // enough handlers can be found.
4712 bool FindHandlers(CodeHandleList* code_list, int length = -1);
4714 // Find the handler for |map|.
4715 MaybeHandle<Code> FindHandlerForMap(Map* map);
4717 // Find the first name in an IC stub.
4718 Name* FindFirstName();
4720 class FindAndReplacePattern;
4721 // For each (map-to-find, object-to-replace) pair in the pattern, this
4722 // function replaces the corresponding placeholder in the code with the
4723 // object-to-replace. The function assumes that pairs in the pattern come in
4724 // the same order as the placeholders in the code.
4725 // If the placeholder is a weak cell, then the value of weak cell is matched
4726 // against the map-to-find.
4727 void FindAndReplace(const FindAndReplacePattern& pattern);
4729 // The entire code object including its header is copied verbatim to the
4730 // snapshot so that it can be written in one, fast, memcpy during
4731 // deserialization. The deserializer will overwrite some pointers, rather
4732 // like a runtime linker, but the random allocation addresses used in the
4733 // mksnapshot process would still be present in the unlinked snapshot data,
4734 // which would make snapshot production non-reproducible. This method wipes
4735 // out the to-be-overwritten header data for reproducible snapshots.
4736 inline void WipeOutHeader();
4738 // Flags operations.
4739 static inline Flags ComputeFlags(
4740 Kind kind, InlineCacheState ic_state = UNINITIALIZED,
4741 ExtraICState extra_ic_state = kNoExtraICState, StubType type = NORMAL,
4742 CacheHolderFlag holder = kCacheOnReceiver);
4744 static inline Flags ComputeMonomorphicFlags(
4745 Kind kind, ExtraICState extra_ic_state = kNoExtraICState,
4746 CacheHolderFlag holder = kCacheOnReceiver, StubType type = NORMAL);
4748 static inline Flags ComputeHandlerFlags(
4749 Kind handler_kind, StubType type = NORMAL,
4750 CacheHolderFlag holder = kCacheOnReceiver);
4752 static inline InlineCacheState ExtractICStateFromFlags(Flags flags);
4753 static inline StubType ExtractTypeFromFlags(Flags flags);
4754 static inline CacheHolderFlag ExtractCacheHolderFromFlags(Flags flags);
4755 static inline Kind ExtractKindFromFlags(Flags flags);
4756 static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags);
4758 static inline Flags RemoveTypeFromFlags(Flags flags);
4759 static inline Flags RemoveTypeAndHolderFromFlags(Flags flags);
4761 // Convert a target address into a code object.
4762 static inline Code* GetCodeFromTargetAddress(Address address);
4764 // Convert an entry address into an object.
4765 static inline Object* GetObjectFromEntryAddress(Address location_of_address);
4767 // Returns the address of the first instruction.
4768 inline byte* instruction_start();
4770 // Returns the address right after the last instruction.
4771 inline byte* instruction_end();
4773 // Returns the size of the instructions, padding, and relocation information.
4774 inline int body_size();
4776 // Returns the address of the first relocation info (read backwards!).
4777 inline byte* relocation_start();
4779 // Code entry point.
4780 inline byte* entry();
4782 // Returns true if pc is inside this object's instructions.
4783 inline bool contains(byte* pc);
4785 // Relocate the code by delta bytes. Called to signal that this code
4786 // object has been moved by delta bytes.
4787 void Relocate(intptr_t delta);
4789 // Migrate code described by desc.
4790 void CopyFrom(const CodeDesc& desc);
4792 // Returns the object size for a given body (used for allocation).
4793 static int SizeFor(int body_size) {
4794 DCHECK_SIZE_TAG_ALIGNED(body_size);
4795 return RoundUp(kHeaderSize + body_size, kCodeAlignment);
4798 // Calculate the size of the code object to report for log events. This takes
4799 // the layout of the code object into account.
4800 inline int ExecutableSize();
4802 // Locating source position.
4803 int SourcePosition(Address pc);
4804 int SourceStatementPosition(Address pc);
4808 // Dispatched behavior.
4809 inline int CodeSize();
4810 inline void CodeIterateBody(ObjectVisitor* v);
4812 template<typename StaticVisitor>
4813 inline void CodeIterateBody(Heap* heap);
4815 DECLARE_PRINTER(Code)
4816 DECLARE_VERIFIER(Code)
4818 void ClearInlineCaches();
4819 void ClearInlineCaches(Kind kind);
4821 BailoutId TranslatePcOffsetToAstId(uint32_t pc_offset);
4822 uint32_t TranslateAstIdToPcOffset(BailoutId ast_id);
4824 #define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
4826 kToBeExecutedOnceCodeAge = -3,
4827 kNotExecutedCodeAge = -2,
4828 kExecutedOnceCodeAge = -1,
4830 CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
4832 kFirstCodeAge = kToBeExecutedOnceCodeAge,
4833 kLastCodeAge = kAfterLastCodeAge - 1,
4834 kCodeAgeCount = kAfterLastCodeAge - kFirstCodeAge - 1,
4835 kIsOldCodeAge = kSexagenarianCodeAge,
4836 kPreAgedCodeAge = kIsOldCodeAge - 1
4838 #undef DECLARE_CODE_AGE_ENUM
4840 // Code aging. Indicates how many full GCs this code has survived without
4841 // being entered through the prologue. Used to determine when it is
4842 // relatively safe to flush this code object and replace it with the lazy
4843 // compilation stub.
4844 static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate);
4845 static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate);
4846 void MakeYoung(Isolate* isolate);
4847 void MarkToBeExecutedOnce(Isolate* isolate);
4848 void MakeOlder(MarkingParity);
4849 static bool IsYoungSequence(Isolate* isolate, byte* sequence);
4852 static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) {
4853 return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY);
4856 void PrintDeoptLocation(FILE* out, Address pc);
4857 bool CanDeoptAt(Address pc);
4860 void VerifyEmbeddedObjectsDependency();
4864 enum VerifyMode { kNoContextSpecificPointers, kNoContextRetainingPointers };
4865 void VerifyEmbeddedObjects(VerifyMode mode = kNoContextRetainingPointers);
4866 static void VerifyRecompiledCode(Code* old_code, Code* new_code);
4869 inline bool CanContainWeakObjects();
4871 inline bool IsWeakObject(Object* object);
4873 static inline bool IsWeakObjectInOptimizedCode(Object* object);
4875 static Handle<WeakCell> WeakCellFor(Handle<Code> code);
4876 WeakCell* CachedWeakCell();
4878 // Max loop nesting marker used to postpose OSR. We don't take loop
4879 // nesting that is deeper than 5 levels into account.
4880 static const int kMaxLoopNestingMarker = 6;
4882 static const int kConstantPoolSize =
4883 FLAG_enable_embedded_constant_pool ? kIntSize : 0;
4885 // Layout description.
4886 static const int kRelocationInfoOffset = HeapObject::kHeaderSize;
4887 static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
4888 static const int kDeoptimizationDataOffset =
4889 kHandlerTableOffset + kPointerSize;
4890 // For FUNCTION kind, we store the type feedback info here.
4891 static const int kTypeFeedbackInfoOffset =
4892 kDeoptimizationDataOffset + kPointerSize;
4893 static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
4894 static const int kGCMetadataOffset = kNextCodeLinkOffset + kPointerSize;
4895 static const int kInstructionSizeOffset = kGCMetadataOffset + kPointerSize;
4896 static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
4897 static const int kFlagsOffset = kICAgeOffset + kIntSize;
4898 static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
4899 static const int kKindSpecificFlags2Offset =
4900 kKindSpecificFlags1Offset + kIntSize;
4901 // Note: We might be able to squeeze this into the flags above.
4902 static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
4903 static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
4904 static const int kHeaderPaddingStart =
4905 kConstantPoolOffset + kConstantPoolSize;
4907 // Add padding to align the instruction start following right after
4908 // the Code object header.
4909 static const int kHeaderSize =
4910 (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
4912 // Byte offsets within kKindSpecificFlags1Offset.
4913 static const int kFullCodeFlags = kKindSpecificFlags1Offset;
4914 class FullCodeFlagsHasDeoptimizationSupportField:
4915 public BitField<bool, 0, 1> {}; // NOLINT
4916 class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {};
4917 class FullCodeFlagsHasRelocInfoForSerialization
4918 : public BitField<bool, 2, 1> {};
4919 // Bit 3 in this bitfield is unused.
4920 class ProfilerTicksField : public BitField<int, 4, 28> {};
4922 // Flags layout. BitField<type, shift, size>.
4923 class ICStateField : public BitField<InlineCacheState, 0, 4> {};
4924 class TypeField : public BitField<StubType, 4, 1> {};
4925 class CacheHolderField : public BitField<CacheHolderFlag, 5, 2> {};
4926 class KindField : public BitField<Kind, 7, 4> {};
4927 class ExtraICStateField: public BitField<ExtraICState, 11,
4928 PlatformSmiTagging::kSmiValueSize - 11 + 1> {}; // NOLINT
4930 // KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
4931 static const int kStackSlotsFirstBit = 0;
4932 static const int kStackSlotsBitCount = 24;
4933 static const int kHasFunctionCacheBit =
4934 kStackSlotsFirstBit + kStackSlotsBitCount;
4935 static const int kMarkedForDeoptimizationBit = kHasFunctionCacheBit + 1;
4936 static const int kIsTurbofannedBit = kMarkedForDeoptimizationBit + 1;
4937 static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1;
4939 STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32);
4940 STATIC_ASSERT(kCanHaveWeakObjects + 1 <= 32);
4942 class StackSlotsField: public BitField<int,
4943 kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT
4944 class HasFunctionCacheField : public BitField<bool, kHasFunctionCacheBit, 1> {
4946 class MarkedForDeoptimizationField
4947 : public BitField<bool, kMarkedForDeoptimizationBit, 1> {}; // NOLINT
4948 class IsTurbofannedField : public BitField<bool, kIsTurbofannedBit, 1> {
4950 class CanHaveWeakObjectsField
4951 : public BitField<bool, kCanHaveWeakObjects, 1> {}; // NOLINT
4953 // KindSpecificFlags2 layout (ALL)
4954 static const int kIsCrankshaftedBit = 0;
4955 class IsCrankshaftedField: public BitField<bool,
4956 kIsCrankshaftedBit, 1> {}; // NOLINT
4958 // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
4959 static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1;
4960 static const int kSafepointTableOffsetBitCount = 30;
4962 STATIC_ASSERT(kSafepointTableOffsetFirstBit +
4963 kSafepointTableOffsetBitCount <= 32);
4964 STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32);
4966 class SafepointTableOffsetField: public BitField<int,
4967 kSafepointTableOffsetFirstBit,
4968 kSafepointTableOffsetBitCount> {}; // NOLINT
4970 // KindSpecificFlags2 layout (FUNCTION)
4971 class BackEdgeTableOffsetField: public BitField<int,
4972 kIsCrankshaftedBit + 1, 27> {}; // NOLINT
4973 class AllowOSRAtLoopNestingLevelField: public BitField<int,
4974 kIsCrankshaftedBit + 1 + 27, 4> {}; // NOLINT
4975 STATIC_ASSERT(AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker);
4977 static const int kArgumentsBits = 16;
4978 static const int kMaxArguments = (1 << kArgumentsBits) - 1;
4980 // This constant should be encodable in an ARM instruction.
4981 static const int kFlagsNotUsedInLookup =
4982 TypeField::kMask | CacheHolderField::kMask;
4985 friend class RelocIterator;
4986 friend class Deoptimizer; // For FindCodeAgeSequence.
4988 void ClearInlineCaches(Kind* kind);
4991 byte* FindCodeAgeSequence();
4992 static void GetCodeAgeAndParity(Code* code, Age* age,
4993 MarkingParity* parity);
4994 static void GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
4995 MarkingParity* parity);
4996 static Code* GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity);
4998 // Code aging -- platform-specific
4999 static void PatchPlatformCodeAge(Isolate* isolate,
5000 byte* sequence, Age age,
5001 MarkingParity parity);
5003 DISALLOW_IMPLICIT_CONSTRUCTORS(Code);
5007 // This class describes the layout of dependent codes array of a map. The
5008 // array is partitioned into several groups of dependent codes. Each group
5009 // contains codes with the same dependency on the map. The array has the
5010 // following layout for n dependency groups:
5012 // +----+----+-----+----+---------+----------+-----+---------+-----------+
5013 // | C1 | C2 | ... | Cn | group 1 | group 2 | ... | group n | undefined |
5014 // +----+----+-----+----+---------+----------+-----+---------+-----------+
5016 // The first n elements are Smis, each of them specifies the number of codes
5017 // in the corresponding group. The subsequent elements contain grouped code
5018 // objects in weak cells. The suffix of the array can be filled with the
5019 // undefined value if the number of codes is less than the length of the
5020 // array. The order of the code objects within a group is not preserved.
5022 // All code indexes used in the class are counted starting from the first
5023 // code object of the first group. In other words, code index 0 corresponds
5024 // to array index n = kCodesStartIndex.
5026 class DependentCode: public FixedArray {
5028 enum DependencyGroup {
5029 // Group of code that weakly embed this map and depend on being
5030 // deoptimized when the map is garbage collected.
5032 // Group of code that embed a transition to this map, and depend on being
5033 // deoptimized when the transition is replaced by a new version.
5035 // Group of code that omit run-time prototype checks for prototypes
5036 // described by this map. The group is deoptimized whenever an object
5037 // described by this map changes shape (and transitions to a new map),
5038 // possibly invalidating the assumptions embedded in the code.
5039 kPrototypeCheckGroup,
5040 // Group of code that depends on global property values in property cells
5041 // not being changed.
5042 kPropertyCellChangedGroup,
5043 // Group of code that omit run-time type checks for the field(s) introduced
5046 // Group of code that omit run-time type checks for initial maps of
5048 kInitialMapChangedGroup,
5049 // Group of code that depends on tenuring information in AllocationSites
5050 // not being changed.
5051 kAllocationSiteTenuringChangedGroup,
5052 // Group of code that depends on element transition information in
5053 // AllocationSites not being changed.
5054 kAllocationSiteTransitionChangedGroup
5057 static const int kGroupCount = kAllocationSiteTransitionChangedGroup + 1;
5059 // Array for holding the index of the first code object of each group.
5060 // The last element stores the total number of code objects.
5061 class GroupStartIndexes {
5063 explicit GroupStartIndexes(DependentCode* entries);
5064 void Recompute(DependentCode* entries);
5065 int at(int i) { return start_indexes_[i]; }
5066 int number_of_entries() { return start_indexes_[kGroupCount]; }
5068 int start_indexes_[kGroupCount + 1];
5071 bool Contains(DependencyGroup group, WeakCell* code_cell);
5073 static Handle<DependentCode> InsertCompilationDependencies(
5074 Handle<DependentCode> entries, DependencyGroup group,
5075 Handle<Foreign> info);
5077 static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries,
5078 DependencyGroup group,
5079 Handle<WeakCell> code_cell);
5081 void UpdateToFinishedCode(DependencyGroup group, Foreign* info,
5082 WeakCell* code_cell);
5084 void RemoveCompilationDependencies(DependentCode::DependencyGroup group,
5087 void DeoptimizeDependentCodeGroup(Isolate* isolate,
5088 DependentCode::DependencyGroup group);
5090 bool MarkCodeForDeoptimization(Isolate* isolate,
5091 DependentCode::DependencyGroup group);
5093 // The following low-level accessors should only be used by this class
5094 // and the mark compact collector.
5095 inline int number_of_entries(DependencyGroup group);
5096 inline void set_number_of_entries(DependencyGroup group, int value);
5097 inline Object* object_at(int i);
5098 inline void set_object_at(int i, Object* object);
5099 inline void clear_at(int i);
5100 inline void copy(int from, int to);
5101 DECLARE_CAST(DependentCode)
5103 static const char* DependencyGroupName(DependencyGroup group);
5104 static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
5107 static Handle<DependentCode> Insert(Handle<DependentCode> entries,
5108 DependencyGroup group,
5109 Handle<Object> object);
5110 static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries);
5111 // Make a room at the end of the given group by moving out the first
5112 // code objects of the subsequent groups.
5113 inline void ExtendGroup(DependencyGroup group);
5114 // Compact by removing cleared weak cells and return true if there was
5115 // any cleared weak cell.
5117 static int Grow(int number_of_entries) {
5118 if (number_of_entries < 5) return number_of_entries + 1;
5119 return number_of_entries * 5 / 4;
5121 static const int kCodesStartIndex = kGroupCount;
5125 class PrototypeInfo;
5128 // All heap objects have a Map that describes their structure.
5129 // A Map contains information about:
5130 // - Size information about the object
5131 // - How to iterate over an object (for garbage collection)
5132 class Map: public HeapObject {
5135 // Size in bytes or kVariableSizeSentinel if instances do not have
5137 inline int instance_size();
5138 inline void set_instance_size(int value);
5140 // Only to clear an unused byte, remove once byte is used.
5141 inline void clear_unused();
5143 // [inobject_properties_or_constructor_function_index]: Provides access
5144 // to the inobject properties in case of JSObject maps, or the constructor
5145 // function index in case of primitive maps.
5146 inline int inobject_properties_or_constructor_function_index();
5147 inline void set_inobject_properties_or_constructor_function_index(int value);
5148 // Count of properties allocated in the object (JSObject only).
5149 inline int GetInObjectProperties();
5150 inline void SetInObjectProperties(int value);
5151 // Index of the constructor function in the native context (primitives only),
5152 // or the special sentinel value to indicate that there is no object wrapper
5153 // for the primitive (i.e. in case of null or undefined).
5154 static const int kNoConstructorFunctionIndex = 0;
5155 inline int GetConstructorFunctionIndex();
5156 inline void SetConstructorFunctionIndex(int value);
5159 inline InstanceType instance_type();
5160 inline void set_instance_type(InstanceType value);
5162 // Tells how many unused property fields are available in the
5163 // instance (only used for JSObject in fast mode).
5164 inline int unused_property_fields();
5165 inline void set_unused_property_fields(int value);
5168 inline byte bit_field() const;
5169 inline void set_bit_field(byte value);
5172 inline byte bit_field2() const;
5173 inline void set_bit_field2(byte value);
5176 inline uint32_t bit_field3() const;
5177 inline void set_bit_field3(uint32_t bits);
5179 class EnumLengthBits: public BitField<int,
5180 0, kDescriptorIndexBitCount> {}; // NOLINT
5181 class NumberOfOwnDescriptorsBits: public BitField<int,
5182 kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT
5183 STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
5184 class DictionaryMap : public BitField<bool, 20, 1> {};
5185 class OwnsDescriptors : public BitField<bool, 21, 1> {};
5186 class HasInstanceCallHandler : public BitField<bool, 22, 1> {};
5187 class Deprecated : public BitField<bool, 23, 1> {};
5188 class IsUnstable : public BitField<bool, 24, 1> {};
5189 class IsMigrationTarget : public BitField<bool, 25, 1> {};
5190 class IsStrong : public BitField<bool, 26, 1> {};
5193 // Keep this bit field at the very end for better code in
5194 // Builtins::kJSConstructStubGeneric stub.
5195 // This counter is used for in-object slack tracking and for map aging.
5196 // The in-object slack tracking is considered enabled when the counter is
5197 // in the range [kSlackTrackingCounterStart, kSlackTrackingCounterEnd].
5198 class Counter : public BitField<int, 28, 4> {};
5199 static const int kSlackTrackingCounterStart = 14;
5200 static const int kSlackTrackingCounterEnd = 8;
5201 static const int kRetainingCounterStart = kSlackTrackingCounterEnd - 1;
5202 static const int kRetainingCounterEnd = 0;
5204 // Tells whether the object in the prototype property will be used
5205 // for instances created from this function. If the prototype
5206 // property is set to a value that is not a JSObject, the prototype
5207 // property will not be used to create instances of the function.
5208 // See ECMA-262, 13.2.2.
5209 inline void set_non_instance_prototype(bool value);
5210 inline bool has_non_instance_prototype();
5212 // Tells whether function has special prototype property. If not, prototype
5213 // property will not be created when accessed (will return undefined),
5214 // and construction from this function will not be allowed.
5215 inline void set_function_with_prototype(bool value);
5216 inline bool function_with_prototype();
5218 // Tells whether the instance with this map should be ignored by the
5219 // Object.getPrototypeOf() function and the __proto__ accessor.
5220 inline void set_is_hidden_prototype();
5221 inline bool is_hidden_prototype();
5223 // Records and queries whether the instance has a named interceptor.
5224 inline void set_has_named_interceptor();
5225 inline bool has_named_interceptor();
5227 // Records and queries whether the instance has an indexed interceptor.
5228 inline void set_has_indexed_interceptor();
5229 inline bool has_indexed_interceptor();
5231 // Tells whether the instance is undetectable.
5232 // An undetectable object is a special class of JSObject: 'typeof' operator
5233 // returns undefined, ToBoolean returns false. Otherwise it behaves like
5234 // a normal JS object. It is useful for implementing undetectable
5235 // document.all in Firefox & Safari.
5236 // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
5237 inline void set_is_undetectable();
5238 inline bool is_undetectable();
5240 // Tells whether the instance has a call-as-function handler.
5241 inline void set_is_observed();
5242 inline bool is_observed();
5244 inline void set_is_strong();
5245 inline bool is_strong();
5246 inline void set_is_extensible(bool value);
5247 inline bool is_extensible();
5248 inline void set_is_prototype_map(bool value);
5249 inline bool is_prototype_map() const;
5251 inline void set_elements_kind(ElementsKind elements_kind);
5252 inline ElementsKind elements_kind();
5254 // Tells whether the instance has fast elements that are only Smis.
5255 inline bool has_fast_smi_elements();
5257 // Tells whether the instance has fast elements.
5258 inline bool has_fast_object_elements();
5259 inline bool has_fast_smi_or_object_elements();
5260 inline bool has_fast_double_elements();
5261 inline bool has_fast_elements();
5262 inline bool has_sloppy_arguments_elements();
5263 inline bool has_fixed_typed_array_elements();
5264 inline bool has_dictionary_elements();
5266 static bool IsValidElementsTransition(ElementsKind from_kind,
5267 ElementsKind to_kind);
5269 // Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
5270 // map with DICTIONARY_ELEMENTS was found in the prototype chain.
5271 bool DictionaryElementsInPrototypeChainOnly();
5273 inline Map* ElementsTransitionMap();
5275 inline FixedArrayBase* GetInitialElements();
5277 // [raw_transitions]: Provides access to the transitions storage field.
5278 // Don't call set_raw_transitions() directly to overwrite transitions, use
5279 // the TransitionArray::ReplaceTransitions() wrapper instead!
5280 DECL_ACCESSORS(raw_transitions, Object)
5281 // [prototype_info]: Per-prototype metadata. Aliased with transitions
5282 // (which prototype maps don't have).
5283 DECL_ACCESSORS(prototype_info, Object)
5284 // PrototypeInfo is created lazily using this helper (which installs it on
5285 // the given prototype's map).
5286 static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
5287 Handle<JSObject> prototype, Isolate* isolate);
5288 static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
5289 Handle<Map> prototype_map, Isolate* isolate);
5291 // [prototype chain validity cell]: Associated with a prototype object,
5292 // stored in that object's map's PrototypeInfo, indicates that prototype
5293 // chains through this object are currently valid. The cell will be
5294 // invalidated and replaced when the prototype chain changes.
5295 static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map,
5297 static const int kPrototypeChainValid = 0;
5298 static const int kPrototypeChainInvalid = 1;
5301 Map* FindFieldOwner(int descriptor);
5303 inline int GetInObjectPropertyOffset(int index);
5305 int NumberOfFields();
5307 // TODO(ishell): candidate with JSObject::MigrateToMap().
5308 bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
5309 int target_inobject, int target_unused,
5310 int* old_number_of_fields);
5311 // TODO(ishell): moveit!
5312 static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map);
5313 MUST_USE_RESULT static Handle<HeapType> GeneralizeFieldType(
5314 Handle<HeapType> type1,
5315 Handle<HeapType> type2,
5317 static void GeneralizeFieldType(Handle<Map> map, int modify_index,
5318 Representation new_representation,
5319 Handle<HeapType> new_field_type);
5320 static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
5321 PropertyKind new_kind,
5322 PropertyAttributes new_attributes,
5323 Representation new_representation,
5324 Handle<HeapType> new_field_type,
5325 StoreMode store_mode);
5326 static Handle<Map> CopyGeneralizeAllRepresentations(
5327 Handle<Map> map, int modify_index, StoreMode store_mode,
5328 PropertyKind kind, PropertyAttributes attributes, const char* reason);
5330 static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
5331 int descriptor_number,
5332 Handle<Object> value);
5334 static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
5335 const char* reason);
5337 // Returns the constructor name (the name (possibly, inferred name) of the
5338 // function that was used to instantiate the object).
5339 String* constructor_name();
5341 // Tells whether the map is used for JSObjects in dictionary mode (ie
5342 // normalized objects, ie objects for which HasFastProperties returns false).
5343 // A map can never be used for both dictionary mode and fast mode JSObjects.
5344 // False by default and for HeapObjects that are not JSObjects.
5345 inline void set_dictionary_map(bool value);
5346 inline bool is_dictionary_map();
5348 // Tells whether the instance needs security checks when accessing its
5350 inline void set_is_access_check_needed(bool access_check_needed);
5351 inline bool is_access_check_needed();
5353 // Returns true if map has a non-empty stub code cache.
5354 inline bool has_code_cache();
5356 // [prototype]: implicit prototype object.
5357 DECL_ACCESSORS(prototype, Object)
5358 // TODO(jkummerow): make set_prototype private.
5359 static void SetPrototype(
5360 Handle<Map> map, Handle<Object> prototype,
5361 PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
5363 // [constructor]: points back to the function responsible for this map.
5364 // The field overlaps with the back pointer. All maps in a transition tree
5365 // have the same constructor, so maps with back pointers can walk the
5366 // back pointer chain until they find the map holding their constructor.
5367 DECL_ACCESSORS(constructor_or_backpointer, Object)
5368 inline Object* GetConstructor() const;
5369 inline void SetConstructor(Object* constructor,
5370 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5371 // [back pointer]: points back to the parent map from which a transition
5372 // leads to this map. The field overlaps with the constructor (see above).
5373 inline Object* GetBackPointer();
5374 inline void SetBackPointer(Object* value,
5375 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5377 // [instance descriptors]: describes the object.
5378 DECL_ACCESSORS(instance_descriptors, DescriptorArray)
5380 // [layout descriptor]: describes the object layout.
5381 DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
5382 // |layout descriptor| accessor which can be used from GC.
5383 inline LayoutDescriptor* layout_descriptor_gc_safe();
5384 inline bool HasFastPointerLayout() const;
5386 // |layout descriptor| accessor that is safe to call even when
5387 // FLAG_unbox_double_fields is disabled (in this case Map does not contain
5388 // |layout_descriptor| field at all).
5389 inline LayoutDescriptor* GetLayoutDescriptor();
5391 inline void UpdateDescriptors(DescriptorArray* descriptors,
5392 LayoutDescriptor* layout_descriptor);
5393 inline void InitializeDescriptors(DescriptorArray* descriptors,
5394 LayoutDescriptor* layout_descriptor);
5396 // [stub cache]: contains stubs compiled for this map.
5397 DECL_ACCESSORS(code_cache, Object)
5399 // [dependent code]: list of optimized codes that weakly embed this map.
5400 DECL_ACCESSORS(dependent_code, DependentCode)
5402 // [weak cell cache]: cache that stores a weak cell pointing to this map.
5403 DECL_ACCESSORS(weak_cell_cache, Object)
5405 inline PropertyDetails GetLastDescriptorDetails();
5407 inline int LastAdded();
5409 inline int NumberOfOwnDescriptors();
5410 inline void SetNumberOfOwnDescriptors(int number);
5412 inline Cell* RetrieveDescriptorsPointer();
5414 inline int EnumLength();
5415 inline void SetEnumLength(int length);
5417 inline bool owns_descriptors();
5418 inline void set_owns_descriptors(bool owns_descriptors);
5419 inline bool has_instance_call_handler();
5420 inline void set_has_instance_call_handler();
5421 inline void mark_unstable();
5422 inline bool is_stable();
5423 inline void set_migration_target(bool value);
5424 inline bool is_migration_target();
5425 inline void set_counter(int value);
5426 inline int counter();
5427 inline void deprecate();
5428 inline bool is_deprecated();
5429 inline bool CanBeDeprecated();
5430 // Returns a non-deprecated version of the input. If the input was not
5431 // deprecated, it is directly returned. Otherwise, the non-deprecated version
5432 // is found by re-transitioning from the root of the transition tree using the
5433 // descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
5435 static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
5437 // Returns a non-deprecated version of the input. This method may deprecate
5438 // existing maps along the way if encodings conflict. Not for use while
5439 // gathering type feedback. Use TryUpdate in those cases instead.
5440 static Handle<Map> Update(Handle<Map> map);
5442 static Handle<Map> CopyDropDescriptors(Handle<Map> map);
5443 static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
5444 Descriptor* descriptor,
5445 TransitionFlag flag);
5447 MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
5450 Handle<HeapType> type,
5451 PropertyAttributes attributes,
5452 Representation representation,
5453 TransitionFlag flag);
5455 MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
5458 Handle<Object> constant,
5459 PropertyAttributes attributes,
5460 TransitionFlag flag);
5462 // Returns a new map with all transitions dropped from the given map and
5463 // the ElementsKind set.
5464 static Handle<Map> TransitionElementsTo(Handle<Map> map,
5465 ElementsKind to_kind);
5467 static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
5469 static Handle<Map> CopyAsElementsKind(Handle<Map> map,
5471 TransitionFlag flag);
5473 static Handle<Map> CopyForObserved(Handle<Map> map);
5475 static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
5476 PropertyAttributes attrs_to_add,
5477 Handle<Symbol> transition_marker,
5478 const char* reason);
5480 static Handle<Map> FixProxy(Handle<Map> map, InstanceType type, int size);
5483 // Maximal number of fast properties. Used to restrict the number of map
5484 // transitions to avoid an explosion in the number of maps for objects used as
5486 inline bool TooManyFastProperties(StoreFromKeyed store_mode);
5487 static Handle<Map> TransitionToDataProperty(Handle<Map> map,
5489 Handle<Object> value,
5490 PropertyAttributes attributes,
5491 StoreFromKeyed store_mode);
5492 static Handle<Map> TransitionToAccessorProperty(
5493 Handle<Map> map, Handle<Name> name, AccessorComponent component,
5494 Handle<Object> accessor, PropertyAttributes attributes);
5495 static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
5498 PropertyAttributes attributes);
5500 inline void AppendDescriptor(Descriptor* desc);
5502 // Returns a copy of the map, prepared for inserting into the transition
5503 // tree (if the |map| owns descriptors then the new one will share
5504 // descriptors with |map|).
5505 static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
5507 // Returns a copy of the map, with all transitions dropped from the
5508 // instance descriptors.
5509 static Handle<Map> Copy(Handle<Map> map, const char* reason);
5510 static Handle<Map> Create(Isolate* isolate, int inobject_properties);
5512 // Returns the next free property index (only valid for FAST MODE).
5513 int NextFreePropertyIndex();
5515 // Returns the number of properties described in instance_descriptors
5516 // filtering out properties with the specified attributes.
5517 int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
5518 PropertyAttributes filter = NONE);
5522 // Code cache operations.
5524 // Clears the code cache.
5525 inline void ClearCodeCache(Heap* heap);
5527 // Update code cache.
5528 static void UpdateCodeCache(Handle<Map> map,
5532 // Extend the descriptor array of the map with the list of descriptors.
5533 // In case of duplicates, the latest descriptor is used.
5534 static void AppendCallbackDescriptors(Handle<Map> map,
5535 Handle<Object> descriptors);
5537 static inline int SlackForArraySize(int old_size, int size_limit);
5539 static void EnsureDescriptorSlack(Handle<Map> map, int slack);
5541 // Returns the found code or undefined if absent.
5542 Object* FindInCodeCache(Name* name, Code::Flags flags);
5544 // Returns the non-negative index of the code object if it is in the
5545 // cache and -1 otherwise.
5546 int IndexInCodeCache(Object* name, Code* code);
5548 // Removes a code object from the code cache at the given index.
5549 void RemoveFromCodeCache(Name* name, Code* code, int index);
5551 // Computes a hash value for this map, to be used in HashTables and such.
5554 // Returns the map that this map transitions to if its elements_kind
5555 // is changed to |elements_kind|, or NULL if no such map is cached yet.
5556 // |safe_to_add_transitions| is set to false if adding transitions is not
5558 Map* LookupElementsTransitionMap(ElementsKind elements_kind);
5560 // Returns the transitioned map for this map with the most generic
5561 // elements_kind that's found in |candidates|, or null handle if no match is
5563 static Handle<Map> FindTransitionedMap(Handle<Map> map,
5564 MapHandleList* candidates);
5566 inline bool CanTransition();
5568 inline bool IsPrimitiveMap();
5569 inline bool IsJSObjectMap();
5570 inline bool IsJSArrayMap();
5571 inline bool IsStringMap();
5572 inline bool IsJSProxyMap();
5573 inline bool IsJSGlobalProxyMap();
5574 inline bool IsJSGlobalObjectMap();
5575 inline bool IsGlobalObjectMap();
5577 inline bool CanOmitMapChecks();
5579 static void AddDependentCode(Handle<Map> map,
5580 DependentCode::DependencyGroup group,
5583 bool IsMapInArrayPrototypeChain();
5585 static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
5587 // Dispatched behavior.
5588 DECLARE_PRINTER(Map)
5589 DECLARE_VERIFIER(Map)
5592 void DictionaryMapVerify();
5593 void VerifyOmittedMapChecks();
5596 inline int visitor_id();
5597 inline void set_visitor_id(int visitor_id);
5599 static Handle<Map> TransitionToPrototype(Handle<Map> map,
5600 Handle<Object> prototype,
5601 PrototypeOptimizationMode mode);
5603 static const int kMaxPreAllocatedPropertyFields = 255;
5605 // Layout description.
5606 static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
5607 static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
5608 static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
5609 static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
5610 static const int kConstructorOrBackPointerOffset =
5611 kPrototypeOffset + kPointerSize;
5612 // When there is only one transition, it is stored directly in this field;
5613 // otherwise a transition array is used.
5614 // For prototype maps, this slot is used to store this map's PrototypeInfo
5616 static const int kTransitionsOrPrototypeInfoOffset =
5617 kConstructorOrBackPointerOffset + kPointerSize;
5618 static const int kDescriptorsOffset =
5619 kTransitionsOrPrototypeInfoOffset + kPointerSize;
5620 #if V8_DOUBLE_FIELDS_UNBOXING
5621 static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize;
5622 static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize;
5624 static const int kLayoutDecriptorOffset = 1; // Must not be ever accessed.
5625 static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
5627 static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
5628 static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
5629 static const int kSize = kWeakCellCacheOffset + kPointerSize;
5631 // Layout of pointer fields. Heap iteration code relies on them
5632 // being continuously allocated.
5633 static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
5634 static const int kPointerFieldsEndOffset = kSize;
5636 // Byte offsets within kInstanceSizesOffset.
5637 static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
5638 static const int kInObjectPropertiesOrConstructorFunctionIndexByte = 1;
5639 static const int kInObjectPropertiesOrConstructorFunctionIndexOffset =
5640 kInstanceSizesOffset + kInObjectPropertiesOrConstructorFunctionIndexByte;
5641 // Note there is one byte available for use here.
5642 static const int kUnusedByte = 2;
5643 static const int kUnusedOffset = kInstanceSizesOffset + kUnusedByte;
5644 static const int kVisitorIdByte = 3;
5645 static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
5647 // Byte offsets within kInstanceAttributesOffset attributes.
5648 #if V8_TARGET_LITTLE_ENDIAN
5649 // Order instance type and bit field together such that they can be loaded
5650 // together as a 16-bit word with instance type in the lower 8 bits regardless
5651 // of endianess. Also provide endian-independent offset to that 16-bit word.
5652 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
5653 static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
5655 static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
5656 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
5658 static const int kInstanceTypeAndBitFieldOffset =
5659 kInstanceAttributesOffset + 0;
5660 static const int kBitField2Offset = kInstanceAttributesOffset + 2;
5661 static const int kUnusedPropertyFieldsByte = 3;
5662 static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
5664 STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
5665 Internals::kMapInstanceTypeAndBitFieldOffset);
5667 // Bit positions for bit field.
5668 static const int kHasNonInstancePrototype = 0;
5669 static const int kIsHiddenPrototype = 1;
5670 static const int kHasNamedInterceptor = 2;
5671 static const int kHasIndexedInterceptor = 3;
5672 static const int kIsUndetectable = 4;
5673 static const int kIsObserved = 5;
5674 static const int kIsAccessCheckNeeded = 6;
5675 class FunctionWithPrototype: public BitField<bool, 7, 1> {};
5677 // Bit positions for bit field 2
5678 static const int kIsExtensible = 0;
5679 static const int kStringWrapperSafeForDefaultValueOf = 1;
5680 class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
5681 class ElementsKindBits: public BitField<ElementsKind, 3, 5> {};
5683 // Derived values from bit field 2
5684 static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
5685 (FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1;
5686 static const int8_t kMaximumBitField2FastSmiElementValue =
5687 static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
5688 Map::ElementsKindBits::kShift) - 1;
5689 static const int8_t kMaximumBitField2FastHoleyElementValue =
5690 static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
5691 Map::ElementsKindBits::kShift) - 1;
5692 static const int8_t kMaximumBitField2FastHoleySmiElementValue =
5693 static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
5694 Map::ElementsKindBits::kShift) - 1;
5696 typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
5697 kPointerFieldsEndOffset,
5698 kSize> BodyDescriptor;
5700 // Compares this map to another to see if they describe equivalent objects.
5701 // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
5702 // it had exactly zero inobject properties.
5703 // The "shared" flags of both this map and |other| are ignored.
5704 bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
5706 // Returns true if given field is unboxed double.
5707 inline bool IsUnboxedDoubleField(FieldIndex index);
5710 static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
5711 static void TraceAllTransitions(Map* map);
5714 static inline Handle<Map> CopyInstallDescriptorsForTesting(
5715 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
5716 Handle<LayoutDescriptor> layout_descriptor);
5719 static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
5720 Handle<Name> name, SimpleTransitionFlag flag);
5722 bool EquivalentToForTransition(Map* other);
5723 static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
5724 static Handle<Map> ShareDescriptor(Handle<Map> map,
5725 Handle<DescriptorArray> descriptors,
5726 Descriptor* descriptor);
5727 static Handle<Map> CopyInstallDescriptors(
5728 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
5729 Handle<LayoutDescriptor> layout_descriptor);
5730 static Handle<Map> CopyAddDescriptor(Handle<Map> map,
5731 Descriptor* descriptor,
5732 TransitionFlag flag);
5733 static Handle<Map> CopyReplaceDescriptors(
5734 Handle<Map> map, Handle<DescriptorArray> descriptors,
5735 Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
5736 MaybeHandle<Name> maybe_name, const char* reason,
5737 SimpleTransitionFlag simple_flag);
5739 static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
5740 Handle<DescriptorArray> descriptors,
5741 Descriptor* descriptor,
5743 TransitionFlag flag);
5744 static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
5745 Handle<Map> map, int descriptor, PropertyKind kind,
5746 PropertyAttributes attributes, const char** reason);
5748 static Handle<Map> CopyNormalized(Handle<Map> map,
5749 PropertyNormalizationMode mode);
5751 // Fires when the layout of an object with a leaf map changes.
5752 // This includes adding transitions to the leaf map or changing
5753 // the descriptor array.
5754 inline void NotifyLeafMapLayoutChange();
5756 void DeprecateTransitionTree();
5757 bool DeprecateTarget(PropertyKind kind, Name* key,
5758 PropertyAttributes attributes,
5759 DescriptorArray* new_descriptors,
5760 LayoutDescriptor* new_layout_descriptor);
5762 Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
5764 // Update field type of the given descriptor to new representation and new
5765 // type. The type must be prepared for storing in descriptor array:
5766 // it must be either a simple type or a map wrapped in a weak cell.
5767 void UpdateFieldType(int descriptor_number, Handle<Name> name,
5768 Representation new_representation,
5769 Handle<Object> new_wrapped_type);
5771 void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
5772 PropertyAttributes attributes);
5773 void PrintGeneralization(FILE* file,
5778 bool constant_to_field,
5779 Representation old_representation,
5780 Representation new_representation,
5781 HeapType* old_field_type,
5782 HeapType* new_field_type);
5784 static const int kFastPropertiesSoftLimit = 12;
5785 static const int kMaxFastProperties = 128;
5787 DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
5791 // An abstract superclass, a marker class really, for simple structure classes.
5792 // It doesn't carry much functionality but allows struct classes to be
5793 // identified in the type system.
5794 class Struct: public HeapObject {
5796 inline void InitializeBody(int object_size);
5797 DECLARE_CAST(Struct)
5801 // A simple one-element struct, useful where smis need to be boxed.
5802 class Box : public Struct {
5804 // [value]: the boxed contents.
5805 DECL_ACCESSORS(value, Object)
5809 // Dispatched behavior.
5810 DECLARE_PRINTER(Box)
5811 DECLARE_VERIFIER(Box)
5813 static const int kValueOffset = HeapObject::kHeaderSize;
5814 static const int kSize = kValueOffset + kPointerSize;
5817 DISALLOW_IMPLICIT_CONSTRUCTORS(Box);
5821 // Container for metadata stored on each prototype map.
5822 class PrototypeInfo : public Struct {
5824 static const int UNREGISTERED = -1;
5826 // [prototype_users]: WeakFixedArray containing maps using this prototype,
5827 // or Smi(0) if uninitialized.
5828 DECL_ACCESSORS(prototype_users, Object)
5829 // [registry_slot]: Slot in prototype's user registry where this user
5830 // is stored. Returns UNREGISTERED if this prototype has not been registered.
5831 inline int registry_slot() const;
5832 inline void set_registry_slot(int slot);
5833 // [validity_cell]: Cell containing the validity bit for prototype chains
5834 // going through this object, or Smi(0) if uninitialized.
5835 DECL_ACCESSORS(validity_cell, Object)
5836 // [constructor_name]: User-friendly name of the original constructor.
5837 DECL_ACCESSORS(constructor_name, Object)
5839 DECLARE_CAST(PrototypeInfo)
5841 // Dispatched behavior.
5842 DECLARE_PRINTER(PrototypeInfo)
5843 DECLARE_VERIFIER(PrototypeInfo)
5845 static const int kPrototypeUsersOffset = HeapObject::kHeaderSize;
5846 static const int kRegistrySlotOffset = kPrototypeUsersOffset + kPointerSize;
5847 static const int kValidityCellOffset = kRegistrySlotOffset + kPointerSize;
5848 static const int kConstructorNameOffset = kValidityCellOffset + kPointerSize;
5849 static const int kSize = kConstructorNameOffset + kPointerSize;
5852 DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeInfo);
5856 // Script describes a script which has been added to the VM.
5857 class Script: public Struct {
5866 // Script compilation types.
5867 enum CompilationType {
5868 COMPILATION_TYPE_HOST = 0,
5869 COMPILATION_TYPE_EVAL = 1
5872 // Script compilation state.
5873 enum CompilationState {
5874 COMPILATION_STATE_INITIAL = 0,
5875 COMPILATION_STATE_COMPILED = 1
5878 // [source]: the script source.
5879 DECL_ACCESSORS(source, Object)
5881 // [name]: the script name.
5882 DECL_ACCESSORS(name, Object)
5884 // [id]: the script id.
5885 DECL_ACCESSORS(id, Smi)
5887 // [line_offset]: script line offset in resource from where it was extracted.
5888 DECL_ACCESSORS(line_offset, Smi)
5890 // [column_offset]: script column offset in resource from where it was
5892 DECL_ACCESSORS(column_offset, Smi)
5894 // [context_data]: context data for the context this script was compiled in.
5895 DECL_ACCESSORS(context_data, Object)
5897 // [wrapper]: the wrapper cache. This is either undefined or a WeakCell.
5898 DECL_ACCESSORS(wrapper, HeapObject)
5900 // [type]: the script type.
5901 DECL_ACCESSORS(type, Smi)
5903 // [line_ends]: FixedArray of line ends positions.
5904 DECL_ACCESSORS(line_ends, Object)
5906 // [eval_from_shared]: for eval scripts the shared funcion info for the
5907 // function from which eval was called.
5908 DECL_ACCESSORS(eval_from_shared, Object)
5910 // [eval_from_instructions_offset]: the instruction offset in the code for the
5911 // function from which eval was called where eval was called.
5912 DECL_ACCESSORS(eval_from_instructions_offset, Smi)
5914 // [shared_function_infos]: weak fixed array containing all shared
5915 // function infos created from this script.
5916 DECL_ACCESSORS(shared_function_infos, Object)
5918 // [flags]: Holds an exciting bitfield.
5919 DECL_ACCESSORS(flags, Smi)
5921 // [source_url]: sourceURL from magic comment
5922 DECL_ACCESSORS(source_url, Object)
5924 // [source_url]: sourceMappingURL magic comment
5925 DECL_ACCESSORS(source_mapping_url, Object)
5927 // [compilation_type]: how the the script was compiled. Encoded in the
5929 inline CompilationType compilation_type();
5930 inline void set_compilation_type(CompilationType type);
5932 // [compilation_state]: determines whether the script has already been
5933 // compiled. Encoded in the 'flags' field.
5934 inline CompilationState compilation_state();
5935 inline void set_compilation_state(CompilationState state);
5937 // [origin_options]: optional attributes set by the embedder via ScriptOrigin,
5938 // and used by the embedder to make decisions about the script. V8 just passes
5939 // this through. Encoded in the 'flags' field.
5940 inline v8::ScriptOriginOptions origin_options();
5941 inline void set_origin_options(ScriptOriginOptions origin_options);
5943 DECLARE_CAST(Script)
5945 // If script source is an external string, check that the underlying
5946 // resource is accessible. Otherwise, always return true.
5947 inline bool HasValidSource();
5949 // Convert code position into column number.
5950 static int GetColumnNumber(Handle<Script> script, int code_pos);
5952 // Convert code position into (zero-based) line number.
5953 // The non-handlified version does not allocate, but may be much slower.
5954 static int GetLineNumber(Handle<Script> script, int code_pos);
5955 int GetLineNumber(int code_pos);
5957 static Handle<Object> GetNameOrSourceURL(Handle<Script> script);
5959 // Init line_ends array with code positions of line ends inside script source.
5960 static void InitLineEnds(Handle<Script> script);
5962 // Get the JS object wrapping the given script; create it if none exists.
5963 static Handle<JSObject> GetWrapper(Handle<Script> script);
5965 // Look through the list of existing shared function infos to find one
5966 // that matches the function literal. Return empty handle if not found.
5967 MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(FunctionLiteral* fun);
5969 // Dispatched behavior.
5970 DECLARE_PRINTER(Script)
5971 DECLARE_VERIFIER(Script)
5973 static const int kSourceOffset = HeapObject::kHeaderSize;
5974 static const int kNameOffset = kSourceOffset + kPointerSize;
5975 static const int kLineOffsetOffset = kNameOffset + kPointerSize;
5976 static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
5977 static const int kContextOffset = kColumnOffsetOffset + kPointerSize;
5978 static const int kWrapperOffset = kContextOffset + kPointerSize;
5979 static const int kTypeOffset = kWrapperOffset + kPointerSize;
5980 static const int kLineEndsOffset = kTypeOffset + kPointerSize;
5981 static const int kIdOffset = kLineEndsOffset + kPointerSize;
5982 static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
5983 static const int kEvalFrominstructionsOffsetOffset =
5984 kEvalFromSharedOffset + kPointerSize;
5985 static const int kSharedFunctionInfosOffset =
5986 kEvalFrominstructionsOffsetOffset + kPointerSize;
5987 static const int kFlagsOffset = kSharedFunctionInfosOffset + kPointerSize;
5988 static const int kSourceUrlOffset = kFlagsOffset + kPointerSize;
5989 static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
5990 static const int kSize = kSourceMappingUrlOffset + kPointerSize;
5993 int GetLineNumberWithArray(int code_pos);
5995 // Bit positions in the flags field.
5996 static const int kCompilationTypeBit = 0;
5997 static const int kCompilationStateBit = 1;
5998 static const int kOriginOptionsShift = 2;
5999 static const int kOriginOptionsSize = 3;
6000 static const int kOriginOptionsMask = ((1 << kOriginOptionsSize) - 1)
6001 << kOriginOptionsShift;
6003 DISALLOW_IMPLICIT_CONSTRUCTORS(Script);
6007 // List of builtin functions we want to identify to improve code
6010 // Each entry has a name of a global object property holding an object
6011 // optionally followed by ".prototype", a name of a builtin function
6012 // on the object (the one the id is set for), and a label.
6014 // Installation of ids for the selected builtin functions is handled
6015 // by the bootstrapper.
6016 #define FUNCTIONS_WITH_ID_LIST(V) \
6017 V(Array.prototype, indexOf, ArrayIndexOf) \
6018 V(Array.prototype, lastIndexOf, ArrayLastIndexOf) \
6019 V(Array.prototype, push, ArrayPush) \
6020 V(Array.prototype, pop, ArrayPop) \
6021 V(Array.prototype, shift, ArrayShift) \
6022 V(Function.prototype, apply, FunctionApply) \
6023 V(Function.prototype, call, FunctionCall) \
6024 V(String.prototype, charCodeAt, StringCharCodeAt) \
6025 V(String.prototype, charAt, StringCharAt) \
6026 V(String, fromCharCode, StringFromCharCode) \
6027 V(Math, random, MathRandom) \
6028 V(Math, floor, MathFloor) \
6029 V(Math, round, MathRound) \
6030 V(Math, ceil, MathCeil) \
6031 V(Math, abs, MathAbs) \
6032 V(Math, log, MathLog) \
6033 V(Math, exp, MathExp) \
6034 V(Math, sqrt, MathSqrt) \
6035 V(Math, pow, MathPow) \
6036 V(Math, max, MathMax) \
6037 V(Math, min, MathMin) \
6038 V(Math, cos, MathCos) \
6039 V(Math, sin, MathSin) \
6040 V(Math, tan, MathTan) \
6041 V(Math, acos, MathAcos) \
6042 V(Math, asin, MathAsin) \
6043 V(Math, atan, MathAtan) \
6044 V(Math, atan2, MathAtan2) \
6045 V(Math, imul, MathImul) \
6046 V(Math, clz32, MathClz32) \
6047 V(Math, fround, MathFround)
6049 #define ATOMIC_FUNCTIONS_WITH_ID_LIST(V) \
6050 V(Atomics, load, AtomicsLoad) \
6051 V(Atomics, store, AtomicsStore)
6053 enum BuiltinFunctionId {
6055 #define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \
6057 FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
6058 ATOMIC_FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
6059 #undef DECLARE_FUNCTION_ID
6060 // Fake id for a special case of Math.pow. Note, it continues the
6061 // list of math functions.
6066 // Result of searching in an optimized code map of a SharedFunctionInfo. Note
6067 // that both {code} and {literals} can be NULL to pass search result status.
6068 struct CodeAndLiterals {
6069 Code* code; // Cached optimized code.
6070 FixedArray* literals; // Cached literals array.
6074 // SharedFunctionInfo describes the JSFunction information that can be
6075 // shared by multiple instances of the function.
6076 class SharedFunctionInfo: public HeapObject {
6078 // [name]: Function name.
6079 DECL_ACCESSORS(name, Object)
6081 // [code]: Function code.
6082 DECL_ACCESSORS(code, Code)
6083 inline void ReplaceCode(Code* code);
6085 // [optimized_code_map]: Map from native context to optimized code
6086 // and a shared literals array or Smi(0) if none.
6087 DECL_ACCESSORS(optimized_code_map, Object)
6089 // Returns entry from optimized code map for specified context and OSR entry.
6090 // Note that {code == nullptr} indicates no matching entry has been found,
6091 // whereas {literals == nullptr} indicates the code is context-independent.
6092 CodeAndLiterals SearchOptimizedCodeMap(Context* native_context,
6093 BailoutId osr_ast_id);
6095 // Clear optimized code map.
6096 void ClearOptimizedCodeMap();
6098 // Removed a specific optimized code object from the optimized code map.
6099 void EvictFromOptimizedCodeMap(Code* optimized_code, const char* reason);
6101 // Trims the optimized code map after entries have been removed.
6102 void TrimOptimizedCodeMap(int shrink_by);
6104 // Add a new entry to the optimized code map for context-independent code.
6105 static void AddSharedCodeToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
6108 // Add a new entry to the optimized code map for context-dependent code.
6109 static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
6110 Handle<Context> native_context,
6112 Handle<FixedArray> literals,
6113 BailoutId osr_ast_id);
6115 // Set up the link between shared function info and the script. The shared
6116 // function info is added to the list on the script.
6117 static void SetScript(Handle<SharedFunctionInfo> shared,
6118 Handle<Object> script_object);
6120 // Layout description of the optimized code map.
6121 static const int kNextMapIndex = 0;
6122 static const int kSharedCodeIndex = 1;
6123 static const int kEntriesStart = 2;
6124 static const int kContextOffset = 0;
6125 static const int kCachedCodeOffset = 1;
6126 static const int kLiteralsOffset = 2;
6127 static const int kOsrAstIdOffset = 3;
6128 static const int kEntryLength = 4;
6129 static const int kInitialLength = kEntriesStart + kEntryLength;
6131 // [scope_info]: Scope info.
6132 DECL_ACCESSORS(scope_info, ScopeInfo)
6134 // [construct stub]: Code stub for constructing instances of this function.
6135 DECL_ACCESSORS(construct_stub, Code)
6137 // Returns if this function has been compiled to native code yet.
6138 inline bool is_compiled();
6140 // [length]: The function length - usually the number of declared parameters.
6141 // Use up to 2^30 parameters.
6142 inline int length() const;
6143 inline void set_length(int value);
6145 // [internal formal parameter count]: The declared number of parameters.
6146 // For subclass constructors, also includes new.target.
6147 // The size of function's frame is internal_formal_parameter_count + 1.
6148 inline int internal_formal_parameter_count() const;
6149 inline void set_internal_formal_parameter_count(int value);
6151 // Set the formal parameter count so the function code will be
6152 // called without using argument adaptor frames.
6153 inline void DontAdaptArguments();
6155 // [expected_nof_properties]: Expected number of properties for the function.
6156 inline int expected_nof_properties() const;
6157 inline void set_expected_nof_properties(int value);
6159 // [feedback_vector] - accumulates ast node feedback from full-codegen and
6160 // (increasingly) from crankshafted code where sufficient feedback isn't
6162 DECL_ACCESSORS(feedback_vector, TypeFeedbackVector)
6164 // Unconditionally clear the type feedback vector (including vector ICs).
6165 void ClearTypeFeedbackInfo();
6167 // Clear the type feedback vector with a more subtle policy at GC time.
6168 void ClearTypeFeedbackInfoAtGCTime();
6171 // [unique_id] - For --trace-maps purposes, an identifier that's persistent
6172 // even if the GC moves this SharedFunctionInfo.
6173 inline int unique_id() const;
6174 inline void set_unique_id(int value);
6177 // [instance class name]: class name for instances.
6178 DECL_ACCESSORS(instance_class_name, Object)
6180 // [function data]: This field holds some additional data for function.
6181 // Currently it has one of:
6182 // - a FunctionTemplateInfo to make benefit the API [IsApiFunction()].
6183 // - a Smi identifying a builtin function [HasBuiltinFunctionId()].
6184 // - a BytecodeArray for the interpreter [HasBytecodeArray()].
6185 // In the long run we don't want all functions to have this field but
6186 // we can fix that when we have a better model for storing hidden data
6188 DECL_ACCESSORS(function_data, Object)
6190 inline bool IsApiFunction();
6191 inline FunctionTemplateInfo* get_api_func_data();
6192 inline bool HasBuiltinFunctionId();
6193 inline BuiltinFunctionId builtin_function_id();
6194 inline bool HasBytecodeArray();
6195 inline BytecodeArray* bytecode_array();
6197 // [script info]: Script from which the function originates.
6198 DECL_ACCESSORS(script, Object)
6200 // [num_literals]: Number of literals used by this function.
6201 inline int num_literals() const;
6202 inline void set_num_literals(int value);
6204 // [start_position_and_type]: Field used to store both the source code
6205 // position, whether or not the function is a function expression,
6206 // and whether or not the function is a toplevel function. The two
6207 // least significants bit indicates whether the function is an
6208 // expression and the rest contains the source code position.
6209 inline int start_position_and_type() const;
6210 inline void set_start_position_and_type(int value);
6212 // The function is subject to debugging if a debug info is attached.
6213 inline bool HasDebugInfo();
6214 inline DebugInfo* GetDebugInfo();
6216 // A function has debug code if the compiled code has debug break slots.
6217 inline bool HasDebugCode();
6219 // [debug info]: Debug information.
6220 DECL_ACCESSORS(debug_info, Object)
6222 // [inferred name]: Name inferred from variable or property
6223 // assignment of this function. Used to facilitate debugging and
6224 // profiling of JavaScript code written in OO style, where almost
6225 // all functions are anonymous but are assigned to object
6227 DECL_ACCESSORS(inferred_name, String)
6229 // The function's name if it is non-empty, otherwise the inferred name.
6230 String* DebugName();
6232 // Position of the 'function' token in the script source.
6233 inline int function_token_position() const;
6234 inline void set_function_token_position(int function_token_position);
6236 // Position of this function in the script source.
6237 inline int start_position() const;
6238 inline void set_start_position(int start_position);
6240 // End position of this function in the script source.
6241 inline int end_position() const;
6242 inline void set_end_position(int end_position);
6244 // Is this function a function expression in the source code.
6245 DECL_BOOLEAN_ACCESSORS(is_expression)
6247 // Is this function a top-level function (scripts, evals).
6248 DECL_BOOLEAN_ACCESSORS(is_toplevel)
6250 // Bit field containing various information collected by the compiler to
6251 // drive optimization.
6252 inline int compiler_hints() const;
6253 inline void set_compiler_hints(int value);
6255 inline int ast_node_count() const;
6256 inline void set_ast_node_count(int count);
6258 inline int profiler_ticks() const;
6259 inline void set_profiler_ticks(int ticks);
6261 // Inline cache age is used to infer whether the function survived a context
6262 // disposal or not. In the former case we reset the opt_count.
6263 inline int ic_age();
6264 inline void set_ic_age(int age);
6266 // Indicates if this function can be lazy compiled.
6267 // This is used to determine if we can safely flush code from a function
6268 // when doing GC if we expect that the function will no longer be used.
6269 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation)
6271 // Indicates if this function can be lazy compiled without a context.
6272 // This is used to determine if we can force compilation without reaching
6273 // the function through program execution but through other means (e.g. heap
6274 // iteration by the debugger).
6275 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context)
6277 // Indicates whether optimizations have been disabled for this
6278 // shared function info. If a function is repeatedly optimized or if
6279 // we cannot optimize the function we disable optimization to avoid
6280 // spending time attempting to optimize it again.
6281 DECL_BOOLEAN_ACCESSORS(optimization_disabled)
6283 // Indicates the language mode.
6284 inline LanguageMode language_mode();
6285 inline void set_language_mode(LanguageMode language_mode);
6287 // False if the function definitely does not allocate an arguments object.
6288 DECL_BOOLEAN_ACCESSORS(uses_arguments)
6290 // Indicates that this function uses a super property (or an eval that may
6291 // use a super property).
6292 // This is needed to set up the [[HomeObject]] on the function instance.
6293 DECL_BOOLEAN_ACCESSORS(needs_home_object)
6295 // True if the function has any duplicated parameter names.
6296 DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
6298 // Indicates whether the function is a native function.
6299 // These needs special treatment in .call and .apply since
6300 // null passed as the receiver should not be translated to the
6302 DECL_BOOLEAN_ACCESSORS(native)
6304 // Indicate that this function should always be inlined in optimized code.
6305 DECL_BOOLEAN_ACCESSORS(force_inline)
6307 // Indicates that the function was created by the Function function.
6308 // Though it's anonymous, toString should treat it as if it had the name
6309 // "anonymous". We don't set the name itself so that the system does not
6310 // see a binding for it.
6311 DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous)
6313 // Indicates whether the function is a bound function created using
6314 // the bind function.
6315 DECL_BOOLEAN_ACCESSORS(bound)
6317 // Indicates that the function is anonymous (the name field can be set
6318 // through the API, which does not change this flag).
6319 DECL_BOOLEAN_ACCESSORS(is_anonymous)
6321 // Is this a function or top-level/eval code.
6322 DECL_BOOLEAN_ACCESSORS(is_function)
6324 // Indicates that code for this function cannot be compiled with Crankshaft.
6325 DECL_BOOLEAN_ACCESSORS(dont_crankshaft)
6327 // Indicates that code for this function cannot be flushed.
6328 DECL_BOOLEAN_ACCESSORS(dont_flush)
6330 // Indicates that this function is a generator.
6331 DECL_BOOLEAN_ACCESSORS(is_generator)
6333 // Indicates that this function is an arrow function.
6334 DECL_BOOLEAN_ACCESSORS(is_arrow)
6336 // Indicates that this function is a concise method.
6337 DECL_BOOLEAN_ACCESSORS(is_concise_method)
6339 // Indicates that this function is an accessor (getter or setter).
6340 DECL_BOOLEAN_ACCESSORS(is_accessor_function)
6342 // Indicates that this function is a default constructor.
6343 DECL_BOOLEAN_ACCESSORS(is_default_constructor)
6345 // Indicates that this function is an asm function.
6346 DECL_BOOLEAN_ACCESSORS(asm_function)
6348 // Indicates that the the shared function info is deserialized from cache.
6349 DECL_BOOLEAN_ACCESSORS(deserialized)
6351 // Indicates that the the shared function info has never been compiled before.
6352 DECL_BOOLEAN_ACCESSORS(never_compiled)
6354 inline FunctionKind kind();
6355 inline void set_kind(FunctionKind kind);
6357 // Indicates whether or not the code in the shared function support
6359 inline bool has_deoptimization_support();
6361 // Enable deoptimization support through recompiled code.
6362 void EnableDeoptimizationSupport(Code* recompiled);
6364 // Disable (further) attempted optimization of all functions sharing this
6365 // shared function info.
6366 void DisableOptimization(BailoutReason reason);
6368 inline BailoutReason disable_optimization_reason();
6370 // Lookup the bailout ID and DCHECK that it exists in the non-optimized
6371 // code, returns whether it asserted (i.e., always true if assertions are
6373 bool VerifyBailoutId(BailoutId id);
6375 // [source code]: Source code for the function.
6376 bool HasSourceCode() const;
6377 Handle<Object> GetSourceCode();
6379 // Number of times the function was optimized.
6380 inline int opt_count();
6381 inline void set_opt_count(int opt_count);
6383 // Number of times the function was deoptimized.
6384 inline void set_deopt_count(int value);
6385 inline int deopt_count();
6386 inline void increment_deopt_count();
6388 // Number of time we tried to re-enable optimization after it
6389 // was disabled due to high number of deoptimizations.
6390 inline void set_opt_reenable_tries(int value);
6391 inline int opt_reenable_tries();
6393 inline void TryReenableOptimization();
6395 // Stores deopt_count, opt_reenable_tries and ic_age as bit-fields.
6396 inline void set_counters(int value);
6397 inline int counters() const;
6399 // Stores opt_count and bailout_reason as bit-fields.
6400 inline void set_opt_count_and_bailout_reason(int value);
6401 inline int opt_count_and_bailout_reason() const;
6403 inline void set_disable_optimization_reason(BailoutReason reason);
6405 // Tells whether this function should be subject to debugging.
6406 inline bool IsSubjectToDebugging();
6408 // Check whether or not this function is inlineable.
6409 bool IsInlineable();
6411 // Source size of this function.
6414 // Calculate the instance size.
6415 int CalculateInstanceSize();
6417 // Calculate the number of in-object properties.
6418 int CalculateInObjectProperties();
6420 inline bool has_simple_parameters();
6422 // Initialize a SharedFunctionInfo from a parsed function literal.
6423 static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info,
6424 FunctionLiteral* lit);
6426 // Dispatched behavior.
6427 DECLARE_PRINTER(SharedFunctionInfo)
6428 DECLARE_VERIFIER(SharedFunctionInfo)
6430 void ResetForNewContext(int new_ic_age);
6432 DECLARE_CAST(SharedFunctionInfo)
6435 static const int kDontAdaptArgumentsSentinel = -1;
6437 // Layout description.
6439 static const int kNameOffset = HeapObject::kHeaderSize;
6440 static const int kCodeOffset = kNameOffset + kPointerSize;
6441 static const int kOptimizedCodeMapOffset = kCodeOffset + kPointerSize;
6442 static const int kScopeInfoOffset = kOptimizedCodeMapOffset + kPointerSize;
6443 static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize;
6444 static const int kInstanceClassNameOffset =
6445 kConstructStubOffset + kPointerSize;
6446 static const int kFunctionDataOffset =
6447 kInstanceClassNameOffset + kPointerSize;
6448 static const int kScriptOffset = kFunctionDataOffset + kPointerSize;
6449 static const int kDebugInfoOffset = kScriptOffset + kPointerSize;
6450 static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize;
6451 static const int kFeedbackVectorOffset =
6452 kInferredNameOffset + kPointerSize;
6454 static const int kUniqueIdOffset = kFeedbackVectorOffset + kPointerSize;
6455 static const int kLastPointerFieldOffset = kUniqueIdOffset;
6457 // Just to not break the postmortrem support with conditional offsets
6458 static const int kUniqueIdOffset = kFeedbackVectorOffset;
6459 static const int kLastPointerFieldOffset = kFeedbackVectorOffset;
6462 #if V8_HOST_ARCH_32_BIT
6464 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
6465 static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize;
6466 static const int kExpectedNofPropertiesOffset =
6467 kFormalParameterCountOffset + kPointerSize;
6468 static const int kNumLiteralsOffset =
6469 kExpectedNofPropertiesOffset + kPointerSize;
6470 static const int kStartPositionAndTypeOffset =
6471 kNumLiteralsOffset + kPointerSize;
6472 static const int kEndPositionOffset =
6473 kStartPositionAndTypeOffset + kPointerSize;
6474 static const int kFunctionTokenPositionOffset =
6475 kEndPositionOffset + kPointerSize;
6476 static const int kCompilerHintsOffset =
6477 kFunctionTokenPositionOffset + kPointerSize;
6478 static const int kOptCountAndBailoutReasonOffset =
6479 kCompilerHintsOffset + kPointerSize;
6480 static const int kCountersOffset =
6481 kOptCountAndBailoutReasonOffset + kPointerSize;
6482 static const int kAstNodeCountOffset =
6483 kCountersOffset + kPointerSize;
6484 static const int kProfilerTicksOffset =
6485 kAstNodeCountOffset + kPointerSize;
6488 static const int kSize = kProfilerTicksOffset + kPointerSize;
6490 // The only reason to use smi fields instead of int fields
6491 // is to allow iteration without maps decoding during
6492 // garbage collections.
6493 // To avoid wasting space on 64-bit architectures we use
6494 // the following trick: we group integer fields into pairs
6495 // The least significant integer in each pair is shifted left by 1.
6496 // By doing this we guarantee that LSB of each kPointerSize aligned
6497 // word is not set and thus this word cannot be treated as pointer
6498 // to HeapObject during old space traversal.
6499 #if V8_TARGET_LITTLE_ENDIAN
6500 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
6501 static const int kFormalParameterCountOffset =
6502 kLengthOffset + kIntSize;
6504 static const int kExpectedNofPropertiesOffset =
6505 kFormalParameterCountOffset + kIntSize;
6506 static const int kNumLiteralsOffset =
6507 kExpectedNofPropertiesOffset + kIntSize;
6509 static const int kEndPositionOffset =
6510 kNumLiteralsOffset + kIntSize;
6511 static const int kStartPositionAndTypeOffset =
6512 kEndPositionOffset + kIntSize;
6514 static const int kFunctionTokenPositionOffset =
6515 kStartPositionAndTypeOffset + kIntSize;
6516 static const int kCompilerHintsOffset =
6517 kFunctionTokenPositionOffset + kIntSize;
6519 static const int kOptCountAndBailoutReasonOffset =
6520 kCompilerHintsOffset + kIntSize;
6521 static const int kCountersOffset =
6522 kOptCountAndBailoutReasonOffset + kIntSize;
6524 static const int kAstNodeCountOffset =
6525 kCountersOffset + kIntSize;
6526 static const int kProfilerTicksOffset =
6527 kAstNodeCountOffset + kIntSize;
6530 static const int kSize = kProfilerTicksOffset + kIntSize;
6532 #elif V8_TARGET_BIG_ENDIAN
6533 static const int kFormalParameterCountOffset =
6534 kLastPointerFieldOffset + kPointerSize;
6535 static const int kLengthOffset = kFormalParameterCountOffset + kIntSize;
6537 static const int kNumLiteralsOffset = kLengthOffset + kIntSize;
6538 static const int kExpectedNofPropertiesOffset = kNumLiteralsOffset + kIntSize;
6540 static const int kStartPositionAndTypeOffset =
6541 kExpectedNofPropertiesOffset + kIntSize;
6542 static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize;
6544 static const int kCompilerHintsOffset = kEndPositionOffset + kIntSize;
6545 static const int kFunctionTokenPositionOffset =
6546 kCompilerHintsOffset + kIntSize;
6548 static const int kCountersOffset = kFunctionTokenPositionOffset + kIntSize;
6549 static const int kOptCountAndBailoutReasonOffset = kCountersOffset + kIntSize;
6551 static const int kProfilerTicksOffset =
6552 kOptCountAndBailoutReasonOffset + kIntSize;
6553 static const int kAstNodeCountOffset = kProfilerTicksOffset + kIntSize;
6556 static const int kSize = kAstNodeCountOffset + kIntSize;
6559 #error Unknown byte ordering
6560 #endif // Big endian
6564 static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
6566 typedef FixedBodyDescriptor<kNameOffset,
6567 kLastPointerFieldOffset + kPointerSize,
6568 kSize> BodyDescriptor;
6570 // Bit positions in start_position_and_type.
6571 // The source code start position is in the 30 most significant bits of
6572 // the start_position_and_type field.
6573 static const int kIsExpressionBit = 0;
6574 static const int kIsTopLevelBit = 1;
6575 static const int kStartPositionShift = 2;
6576 static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1);
6578 // Bit positions in compiler_hints.
6579 enum CompilerHints {
6580 kAllowLazyCompilation,
6581 kAllowLazyCompilationWithoutContext,
6582 kOptimizationDisabled,
6583 kStrictModeFunction,
6584 kStrongModeFunction,
6587 kHasDuplicateParameters,
6592 kNameShouldPrintAsAnonymous,
6599 kIsAccessorFunction,
6600 kIsDefaultConstructor,
6601 kIsSubclassConstructor,
6607 kCompilerHintsCount // Pseudo entry
6609 // Add hints for other modes when they're added.
6610 STATIC_ASSERT(LANGUAGE_END == 3);
6612 class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 8> {};
6614 class DeoptCountBits : public BitField<int, 0, 4> {};
6615 class OptReenableTriesBits : public BitField<int, 4, 18> {};
6616 class ICAgeBits : public BitField<int, 22, 8> {};
6618 class OptCountBits : public BitField<int, 0, 22> {};
6619 class DisabledOptimizationReasonBits : public BitField<int, 22, 8> {};
6622 #if V8_HOST_ARCH_32_BIT
6623 // On 32 bit platforms, compiler hints is a smi.
6624 static const int kCompilerHintsSmiTagSize = kSmiTagSize;
6625 static const int kCompilerHintsSize = kPointerSize;
6627 // On 64 bit platforms, compiler hints is not a smi, see comment above.
6628 static const int kCompilerHintsSmiTagSize = 0;
6629 static const int kCompilerHintsSize = kIntSize;
6632 STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <=
6633 SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte);
6636 // Constants for optimizing codegen for strict mode function and
6638 // Allows to use byte-width instructions.
6639 static const int kStrictModeBitWithinByte =
6640 (kStrictModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte;
6641 static const int kStrongModeBitWithinByte =
6642 (kStrongModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte;
6644 static const int kNativeBitWithinByte =
6645 (kNative + kCompilerHintsSmiTagSize) % kBitsPerByte;
6647 #if defined(V8_TARGET_LITTLE_ENDIAN)
6648 static const int kStrictModeByteOffset = kCompilerHintsOffset +
6649 (kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte;
6650 static const int kStrongModeByteOffset =
6651 kCompilerHintsOffset +
6652 (kStrongModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte;
6653 static const int kNativeByteOffset = kCompilerHintsOffset +
6654 (kNative + kCompilerHintsSmiTagSize) / kBitsPerByte;
6655 #elif defined(V8_TARGET_BIG_ENDIAN)
6656 static const int kStrictModeByteOffset = kCompilerHintsOffset +
6657 (kCompilerHintsSize - 1) -
6658 ((kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte);
6659 static const int kStrongModeByteOffset =
6660 kCompilerHintsOffset + (kCompilerHintsSize - 1) -
6661 ((kStrongModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte);
6662 static const int kNativeByteOffset = kCompilerHintsOffset +
6663 (kCompilerHintsSize - 1) -
6664 ((kNative + kCompilerHintsSmiTagSize) / kBitsPerByte);
6666 #error Unknown byte ordering
6670 DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo);
6674 // Printing support.
6675 struct SourceCodeOf {
6676 explicit SourceCodeOf(SharedFunctionInfo* v, int max = -1)
6677 : value(v), max_length(max) {}
6678 const SharedFunctionInfo* value;
6683 std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v);
6686 class JSGeneratorObject: public JSObject {
6688 // [function]: The function corresponding to this generator object.
6689 DECL_ACCESSORS(function, JSFunction)
6691 // [context]: The context of the suspended computation.
6692 DECL_ACCESSORS(context, Context)
6694 // [receiver]: The receiver of the suspended computation.
6695 DECL_ACCESSORS(receiver, Object)
6697 // [continuation]: Offset into code of continuation.
6699 // A positive offset indicates a suspended generator. The special
6700 // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
6701 // cannot be resumed.
6702 inline int continuation() const;
6703 inline void set_continuation(int continuation);
6704 inline bool is_closed();
6705 inline bool is_executing();
6706 inline bool is_suspended();
6708 // [operand_stack]: Saved operand stack.
6709 DECL_ACCESSORS(operand_stack, FixedArray)
6711 DECLARE_CAST(JSGeneratorObject)
6713 // Dispatched behavior.
6714 DECLARE_PRINTER(JSGeneratorObject)
6715 DECLARE_VERIFIER(JSGeneratorObject)
6717 // Magic sentinel values for the continuation.
6718 static const int kGeneratorExecuting = -1;
6719 static const int kGeneratorClosed = 0;
6721 // Layout description.
6722 static const int kFunctionOffset = JSObject::kHeaderSize;
6723 static const int kContextOffset = kFunctionOffset + kPointerSize;
6724 static const int kReceiverOffset = kContextOffset + kPointerSize;
6725 static const int kContinuationOffset = kReceiverOffset + kPointerSize;
6726 static const int kOperandStackOffset = kContinuationOffset + kPointerSize;
6727 static const int kSize = kOperandStackOffset + kPointerSize;
6729 // Resume mode, for use by runtime functions.
6730 enum ResumeMode { NEXT, THROW };
6732 // Yielding from a generator returns an object with the following inobject
6733 // properties. See Context::iterator_result_map() for the map.
6734 static const int kResultValuePropertyIndex = 0;
6735 static const int kResultDonePropertyIndex = 1;
6736 static const int kResultPropertyCount = 2;
6738 static const int kResultValuePropertyOffset = JSObject::kHeaderSize;
6739 static const int kResultDonePropertyOffset =
6740 kResultValuePropertyOffset + kPointerSize;
6741 static const int kResultSize = kResultDonePropertyOffset + kPointerSize;
6744 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
6748 // Representation for module instance objects.
6749 class JSModule: public JSObject {
6751 // [context]: the context holding the module's locals, or undefined if none.
6752 DECL_ACCESSORS(context, Object)
6754 // [scope_info]: Scope info.
6755 DECL_ACCESSORS(scope_info, ScopeInfo)
6757 DECLARE_CAST(JSModule)
6759 // Dispatched behavior.
6760 DECLARE_PRINTER(JSModule)
6761 DECLARE_VERIFIER(JSModule)
6763 // Layout description.
6764 static const int kContextOffset = JSObject::kHeaderSize;
6765 static const int kScopeInfoOffset = kContextOffset + kPointerSize;
6766 static const int kSize = kScopeInfoOffset + kPointerSize;
6769 DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule);
6773 // JSFunction describes JavaScript functions.
6774 class JSFunction: public JSObject {
6776 // [prototype_or_initial_map]:
6777 DECL_ACCESSORS(prototype_or_initial_map, Object)
6779 // [shared]: The information about the function that
6780 // can be shared by instances.
6781 DECL_ACCESSORS(shared, SharedFunctionInfo)
6783 // [context]: The context for this function.
6784 inline Context* context();
6785 inline void set_context(Object* context);
6786 inline JSObject* global_proxy();
6788 // [code]: The generated code object for this function. Executed
6789 // when the function is invoked, e.g. foo() or new foo(). See
6790 // [[Call]] and [[Construct]] description in ECMA-262, section
6792 inline Code* code();
6793 inline void set_code(Code* code);
6794 inline void set_code_no_write_barrier(Code* code);
6795 inline void ReplaceCode(Code* code);
6797 // Tells whether this function is builtin.
6798 inline bool IsBuiltin();
6800 // Tells whether this function inlines the given shared function info.
6801 bool Inlines(SharedFunctionInfo* candidate);
6803 // Tells whether this function should be subject to debugging.
6804 inline bool IsSubjectToDebugging();
6806 // Tells whether or not the function needs arguments adaption.
6807 inline bool NeedsArgumentsAdaption();
6809 // Tells whether or not this function has been optimized.
6810 inline bool IsOptimized();
6812 // Mark this function for lazy recompilation. The function will be
6813 // recompiled the next time it is executed.
6814 void MarkForOptimization();
6815 void AttemptConcurrentOptimization();
6817 // Tells whether or not the function is already marked for lazy
6819 inline bool IsMarkedForOptimization();
6820 inline bool IsMarkedForConcurrentOptimization();
6822 // Tells whether or not the function is on the concurrent recompilation queue.
6823 inline bool IsInOptimizationQueue();
6825 // Inobject slack tracking is the way to reclaim unused inobject space.
6827 // The instance size is initially determined by adding some slack to
6828 // expected_nof_properties (to allow for a few extra properties added
6829 // after the constructor). There is no guarantee that the extra space
6830 // will not be wasted.
6832 // Here is the algorithm to reclaim the unused inobject space:
6833 // - Detect the first constructor call for this JSFunction.
6834 // When it happens enter the "in progress" state: initialize construction
6835 // counter in the initial_map.
6836 // - While the tracking is in progress create objects filled with
6837 // one_pointer_filler_map instead of undefined_value. This way they can be
6838 // resized quickly and safely.
6839 // - Once enough objects have been created compute the 'slack'
6840 // (traverse the map transition tree starting from the
6841 // initial_map and find the lowest value of unused_property_fields).
6842 // - Traverse the transition tree again and decrease the instance size
6843 // of every map. Existing objects will resize automatically (they are
6844 // filled with one_pointer_filler_map). All further allocations will
6845 // use the adjusted instance size.
6846 // - SharedFunctionInfo's expected_nof_properties left unmodified since
6847 // allocations made using different closures could actually create different
6848 // kind of objects (see prototype inheritance pattern).
6850 // Important: inobject slack tracking is not attempted during the snapshot
6853 // True if the initial_map is set and the object constructions countdown
6854 // counter is not zero.
6855 static const int kGenerousAllocationCount =
6856 Map::kSlackTrackingCounterStart - Map::kSlackTrackingCounterEnd + 1;
6857 inline bool IsInobjectSlackTrackingInProgress();
6859 // Starts the tracking.
6860 // Initializes object constructions countdown counter in the initial map.
6861 void StartInobjectSlackTracking();
6863 // Completes the tracking.
6864 void CompleteInobjectSlackTracking();
6866 // [literals_or_bindings]: Fixed array holding either
6867 // the materialized literals or the bindings of a bound function.
6869 // If the function contains object, regexp or array literals, the
6870 // literals array prefix contains the object, regexp, and array
6871 // function to be used when creating these literals. This is
6872 // necessary so that we do not dynamically lookup the object, regexp
6873 // or array functions. Performing a dynamic lookup, we might end up
6874 // using the functions from a new context that we should not have
6877 // On bound functions, the array is a (copy-on-write) fixed-array containing
6878 // the function that was bound, bound this-value and any bound
6879 // arguments. Bound functions never contain literals.
6880 DECL_ACCESSORS(literals_or_bindings, FixedArray)
6882 inline FixedArray* literals();
6883 inline void set_literals(FixedArray* literals);
6885 inline FixedArray* function_bindings();
6886 inline void set_function_bindings(FixedArray* bindings);
6888 // The initial map for an object created by this constructor.
6889 inline Map* initial_map();
6890 static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
6891 Handle<Object> prototype);
6892 inline bool has_initial_map();
6893 static void EnsureHasInitialMap(Handle<JSFunction> function);
6895 // Get and set the prototype property on a JSFunction. If the
6896 // function has an initial map the prototype is set on the initial
6897 // map. Otherwise, the prototype is put in the initial map field
6898 // until an initial map is needed.
6899 inline bool has_prototype();
6900 inline bool has_instance_prototype();
6901 inline Object* prototype();
6902 inline Object* instance_prototype();
6903 static void SetPrototype(Handle<JSFunction> function,
6904 Handle<Object> value);
6905 static void SetInstancePrototype(Handle<JSFunction> function,
6906 Handle<Object> value);
6908 // Creates a new closure for the fucntion with the same bindings,
6909 // bound values, and prototype. An equivalent of spec operations
6910 // ``CloneMethod`` and ``CloneBoundFunction``.
6911 static Handle<JSFunction> CloneClosure(Handle<JSFunction> function);
6913 // After prototype is removed, it will not be created when accessed, and
6914 // [[Construct]] from this function will not be allowed.
6915 bool RemovePrototype();
6916 inline bool should_have_prototype();
6918 // Accessor for this function's initial map's [[class]]
6919 // property. This is primarily used by ECMA native functions. This
6920 // method sets the class_name field of this function's initial map
6921 // to a given value. It creates an initial map if this function does
6922 // not have one. Note that this method does not copy the initial map
6923 // if it has one already, but simply replaces it with the new value.
6924 // Instances created afterwards will have a map whose [[class]] is
6925 // set to 'value', but there is no guarantees on instances created
6927 void SetInstanceClassName(String* name);
6929 // Returns if this function has been compiled to native code yet.
6930 inline bool is_compiled();
6932 // Returns `false` if formal parameters include rest parameters, optional
6933 // parameters, or destructuring parameters.
6934 // TODO(caitp): make this a flag set during parsing
6935 inline bool has_simple_parameters();
6937 // [next_function_link]: Links functions into various lists, e.g. the list
6938 // of optimized functions hanging off the native_context. The CodeFlusher
6939 // uses this link to chain together flushing candidates. Treated weakly
6940 // by the garbage collector.
6941 DECL_ACCESSORS(next_function_link, Object)
6943 // Prints the name of the function using PrintF.
6944 void PrintName(FILE* out = stdout);
6946 DECLARE_CAST(JSFunction)
6948 // Iterates the objects, including code objects indirectly referenced
6949 // through pointers to the first instruction in the code object.
6950 void JSFunctionIterateBody(int object_size, ObjectVisitor* v);
6952 // Dispatched behavior.
6953 DECLARE_PRINTER(JSFunction)
6954 DECLARE_VERIFIER(JSFunction)
6956 // Returns the number of allocated literals.
6957 inline int NumberOfLiterals();
6959 // Used for flags such as --hydrogen-filter.
6960 bool PassesFilter(const char* raw_filter);
6962 // The function's name if it is configured, otherwise shared function info
6964 static Handle<String> GetDebugName(Handle<JSFunction> function);
6966 // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
6967 // kSize) is weak and has special handling during garbage collection.
6968 static const int kCodeEntryOffset = JSObject::kHeaderSize;
6969 static const int kPrototypeOrInitialMapOffset =
6970 kCodeEntryOffset + kPointerSize;
6971 static const int kSharedFunctionInfoOffset =
6972 kPrototypeOrInitialMapOffset + kPointerSize;
6973 static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize;
6974 static const int kLiteralsOffset = kContextOffset + kPointerSize;
6975 static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize;
6976 static const int kNextFunctionLinkOffset = kNonWeakFieldsEndOffset;
6977 static const int kSize = kNextFunctionLinkOffset + kPointerSize;
6979 // Layout of the bound-function binding array.
6980 static const int kBoundFunctionIndex = 0;
6981 static const int kBoundThisIndex = 1;
6982 static const int kBoundArgumentsStartIndex = 2;
6985 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
6989 // JSGlobalProxy's prototype must be a JSGlobalObject or null,
6990 // and the prototype is hidden. JSGlobalProxy always delegates
6991 // property accesses to its prototype if the prototype is not null.
6993 // A JSGlobalProxy can be reinitialized which will preserve its identity.
6995 // Accessing a JSGlobalProxy requires security check.
6997 class JSGlobalProxy : public JSObject {
6999 // [native_context]: the owner native context of this global proxy object.
7000 // It is null value if this object is not used by any context.
7001 DECL_ACCESSORS(native_context, Object)
7003 // [hash]: The hash code property (undefined if not initialized yet).
7004 DECL_ACCESSORS(hash, Object)
7006 DECLARE_CAST(JSGlobalProxy)
7008 inline bool IsDetachedFrom(GlobalObject* global) const;
7010 // Dispatched behavior.
7011 DECLARE_PRINTER(JSGlobalProxy)
7012 DECLARE_VERIFIER(JSGlobalProxy)
7014 // Layout description.
7015 static const int kNativeContextOffset = JSObject::kHeaderSize;
7016 static const int kHashOffset = kNativeContextOffset + kPointerSize;
7017 static const int kSize = kHashOffset + kPointerSize;
7020 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
7024 // Common super class for JavaScript global objects and the special
7025 // builtins global objects.
7026 class GlobalObject: public JSObject {
7028 // [builtins]: the object holding the runtime routines written in JS.
7029 DECL_ACCESSORS(builtins, JSBuiltinsObject)
7031 // [native context]: the natives corresponding to this global object.
7032 DECL_ACCESSORS(native_context, Context)
7034 // [global proxy]: the global proxy object of the context
7035 DECL_ACCESSORS(global_proxy, JSObject)
7037 DECLARE_CAST(GlobalObject)
7039 static void InvalidatePropertyCell(Handle<GlobalObject> object,
7041 // Ensure that the global object has a cell for the given property name.
7042 static Handle<PropertyCell> EnsurePropertyCell(Handle<GlobalObject> global,
7045 // Layout description.
7046 static const int kBuiltinsOffset = JSObject::kHeaderSize;
7047 static const int kNativeContextOffset = kBuiltinsOffset + kPointerSize;
7048 static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
7049 static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
7052 DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject);
7056 // JavaScript global object.
7057 class JSGlobalObject: public GlobalObject {
7059 DECLARE_CAST(JSGlobalObject)
7061 inline bool IsDetached();
7063 // Dispatched behavior.
7064 DECLARE_PRINTER(JSGlobalObject)
7065 DECLARE_VERIFIER(JSGlobalObject)
7067 // Layout description.
7068 static const int kSize = GlobalObject::kHeaderSize;
7071 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
7075 // Builtins global object which holds the runtime routines written in
7077 class JSBuiltinsObject: public GlobalObject {
7079 // Accessors for the runtime routines written in JavaScript.
7080 inline Object* javascript_builtin(Builtins::JavaScript id);
7081 inline void set_javascript_builtin(Builtins::JavaScript id, Object* value);
7083 DECLARE_CAST(JSBuiltinsObject)
7085 // Dispatched behavior.
7086 DECLARE_PRINTER(JSBuiltinsObject)
7087 DECLARE_VERIFIER(JSBuiltinsObject)
7089 // Layout description. The size of the builtins object includes
7090 // room for two pointers per runtime routine written in javascript
7091 // (function and code object).
7092 static const int kJSBuiltinsCount = Builtins::id_count;
7093 static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize;
7094 static const int kSize =
7095 GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize);
7097 static int OffsetOfFunctionWithId(Builtins::JavaScript id) {
7098 return kJSBuiltinsOffset + id * kPointerSize;
7102 DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject);
7106 // Representation for JS Wrapper objects, String, Number, Boolean, etc.
7107 class JSValue: public JSObject {
7109 // [value]: the object being wrapped.
7110 DECL_ACCESSORS(value, Object)
7112 DECLARE_CAST(JSValue)
7114 // Dispatched behavior.
7115 DECLARE_PRINTER(JSValue)
7116 DECLARE_VERIFIER(JSValue)
7118 // Layout description.
7119 static const int kValueOffset = JSObject::kHeaderSize;
7120 static const int kSize = kValueOffset + kPointerSize;
7123 DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
7129 // Representation for JS date objects.
7130 class JSDate: public JSObject {
7132 // If one component is NaN, all of them are, indicating a NaN time value.
7133 // [value]: the time value.
7134 DECL_ACCESSORS(value, Object)
7135 // [year]: caches year. Either undefined, smi, or NaN.
7136 DECL_ACCESSORS(year, Object)
7137 // [month]: caches month. Either undefined, smi, or NaN.
7138 DECL_ACCESSORS(month, Object)
7139 // [day]: caches day. Either undefined, smi, or NaN.
7140 DECL_ACCESSORS(day, Object)
7141 // [weekday]: caches day of week. Either undefined, smi, or NaN.
7142 DECL_ACCESSORS(weekday, Object)
7143 // [hour]: caches hours. Either undefined, smi, or NaN.
7144 DECL_ACCESSORS(hour, Object)
7145 // [min]: caches minutes. Either undefined, smi, or NaN.
7146 DECL_ACCESSORS(min, Object)
7147 // [sec]: caches seconds. Either undefined, smi, or NaN.
7148 DECL_ACCESSORS(sec, Object)
7149 // [cache stamp]: sample of the date cache stamp at the
7150 // moment when chached fields were cached.
7151 DECL_ACCESSORS(cache_stamp, Object)
7153 DECLARE_CAST(JSDate)
7155 // Returns the date field with the specified index.
7156 // See FieldIndex for the list of date fields.
7157 static Object* GetField(Object* date, Smi* index);
7159 void SetValue(Object* value, bool is_value_nan);
7162 // Dispatched behavior.
7163 DECLARE_PRINTER(JSDate)
7164 DECLARE_VERIFIER(JSDate)
7166 // The order is important. It must be kept in sync with date macros
7177 kFirstUncachedField,
7178 kMillisecond = kFirstUncachedField,
7182 kYearUTC = kFirstUTCField,
7195 // Layout description.
7196 static const int kValueOffset = JSObject::kHeaderSize;
7197 static const int kYearOffset = kValueOffset + kPointerSize;
7198 static const int kMonthOffset = kYearOffset + kPointerSize;
7199 static const int kDayOffset = kMonthOffset + kPointerSize;
7200 static const int kWeekdayOffset = kDayOffset + kPointerSize;
7201 static const int kHourOffset = kWeekdayOffset + kPointerSize;
7202 static const int kMinOffset = kHourOffset + kPointerSize;
7203 static const int kSecOffset = kMinOffset + kPointerSize;
7204 static const int kCacheStampOffset = kSecOffset + kPointerSize;
7205 static const int kSize = kCacheStampOffset + kPointerSize;
7208 inline Object* DoGetField(FieldIndex index);
7210 Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
7212 // Computes and caches the cacheable fields of the date.
7213 inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
7216 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
7220 // Representation of message objects used for error reporting through
7221 // the API. The messages are formatted in JavaScript so this object is
7222 // a real JavaScript object. The information used for formatting the
7223 // error messages are not directly accessible from JavaScript to
7224 // prevent leaking information to user code called during error
7226 class JSMessageObject: public JSObject {
7228 // [type]: the type of error message.
7229 inline int type() const;
7230 inline void set_type(int value);
7232 // [arguments]: the arguments for formatting the error message.
7233 DECL_ACCESSORS(argument, Object)
7235 // [script]: the script from which the error message originated.
7236 DECL_ACCESSORS(script, Object)
7238 // [stack_frames]: an array of stack frames for this error object.
7239 DECL_ACCESSORS(stack_frames, Object)
7241 // [start_position]: the start position in the script for the error message.
7242 inline int start_position() const;
7243 inline void set_start_position(int value);
7245 // [end_position]: the end position in the script for the error message.
7246 inline int end_position() const;
7247 inline void set_end_position(int value);
7249 DECLARE_CAST(JSMessageObject)
7251 // Dispatched behavior.
7252 DECLARE_PRINTER(JSMessageObject)
7253 DECLARE_VERIFIER(JSMessageObject)
7255 // Layout description.
7256 static const int kTypeOffset = JSObject::kHeaderSize;
7257 static const int kArgumentsOffset = kTypeOffset + kPointerSize;
7258 static const int kScriptOffset = kArgumentsOffset + kPointerSize;
7259 static const int kStackFramesOffset = kScriptOffset + kPointerSize;
7260 static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
7261 static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
7262 static const int kSize = kEndPositionOffset + kPointerSize;
7264 typedef FixedBodyDescriptor<HeapObject::kMapOffset,
7265 kStackFramesOffset + kPointerSize,
7266 kSize> BodyDescriptor;
7270 // Regular expressions
7271 // The regular expression holds a single reference to a FixedArray in
7272 // the kDataOffset field.
7273 // The FixedArray contains the following data:
7274 // - tag : type of regexp implementation (not compiled yet, atom or irregexp)
7275 // - reference to the original source string
7276 // - reference to the original flag string
7277 // If it is an atom regexp
7278 // - a reference to a literal string to search for
7279 // If it is an irregexp regexp:
7280 // - a reference to code for Latin1 inputs (bytecode or compiled), or a smi
7281 // used for tracking the last usage (used for code flushing).
7282 // - a reference to code for UC16 inputs (bytecode or compiled), or a smi
7283 // used for tracking the last usage (used for code flushing)..
7284 // - max number of registers used by irregexp implementations.
7285 // - number of capture registers (output values) of the regexp.
7286 class JSRegExp: public JSObject {
7289 // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet.
7290 // ATOM: A simple string to match against using an indexOf operation.
7291 // IRREGEXP: Compiled with Irregexp.
7292 // IRREGEXP_NATIVE: Compiled to native code with Irregexp.
7293 enum Type { NOT_COMPILED, ATOM, IRREGEXP };
7300 UNICODE_ESCAPES = 16
7305 explicit Flags(uint32_t value) : value_(value) { }
7306 bool is_global() { return (value_ & GLOBAL) != 0; }
7307 bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; }
7308 bool is_multiline() { return (value_ & MULTILINE) != 0; }
7309 bool is_sticky() { return (value_ & STICKY) != 0; }
7310 bool is_unicode() { return (value_ & UNICODE_ESCAPES) != 0; }
7311 uint32_t value() { return value_; }
7316 DECL_ACCESSORS(data, Object)
7318 inline Type TypeTag();
7319 inline int CaptureCount();
7320 inline Flags GetFlags();
7321 inline String* Pattern();
7322 inline Object* DataAt(int index);
7323 // Set implementation data after the object has been prepared.
7324 inline void SetDataAt(int index, Object* value);
7326 static int code_index(bool is_latin1) {
7328 return kIrregexpLatin1CodeIndex;
7330 return kIrregexpUC16CodeIndex;
7334 static int saved_code_index(bool is_latin1) {
7336 return kIrregexpLatin1CodeSavedIndex;
7338 return kIrregexpUC16CodeSavedIndex;
7342 DECLARE_CAST(JSRegExp)
7344 // Dispatched behavior.
7345 DECLARE_VERIFIER(JSRegExp)
7347 static const int kDataOffset = JSObject::kHeaderSize;
7348 static const int kSize = kDataOffset + kPointerSize;
7350 // Indices in the data array.
7351 static const int kTagIndex = 0;
7352 static const int kSourceIndex = kTagIndex + 1;
7353 static const int kFlagsIndex = kSourceIndex + 1;
7354 static const int kDataIndex = kFlagsIndex + 1;
7355 // The data fields are used in different ways depending on the
7356 // value of the tag.
7357 // Atom regexps (literal strings).
7358 static const int kAtomPatternIndex = kDataIndex;
7360 static const int kAtomDataSize = kAtomPatternIndex + 1;
7362 // Irregexp compiled code or bytecode for Latin1. If compilation
7363 // fails, this fields hold an exception object that should be
7364 // thrown if the regexp is used again.
7365 static const int kIrregexpLatin1CodeIndex = kDataIndex;
7366 // Irregexp compiled code or bytecode for UC16. If compilation
7367 // fails, this fields hold an exception object that should be
7368 // thrown if the regexp is used again.
7369 static const int kIrregexpUC16CodeIndex = kDataIndex + 1;
7371 // Saved instance of Irregexp compiled code or bytecode for Latin1 that
7372 // is a potential candidate for flushing.
7373 static const int kIrregexpLatin1CodeSavedIndex = kDataIndex + 2;
7374 // Saved instance of Irregexp compiled code or bytecode for UC16 that is
7375 // a potential candidate for flushing.
7376 static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3;
7378 // Maximal number of registers used by either Latin1 or UC16.
7379 // Only used to check that there is enough stack space
7380 static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4;
7381 // Number of captures in the compiled regexp.
7382 static const int kIrregexpCaptureCountIndex = kDataIndex + 5;
7384 static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1;
7386 // Offsets directly into the data fixed array.
7387 static const int kDataTagOffset =
7388 FixedArray::kHeaderSize + kTagIndex * kPointerSize;
7389 static const int kDataOneByteCodeOffset =
7390 FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize;
7391 static const int kDataUC16CodeOffset =
7392 FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize;
7393 static const int kIrregexpCaptureCountOffset =
7394 FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize;
7396 // In-object fields.
7397 static const int kSourceFieldIndex = 0;
7398 static const int kGlobalFieldIndex = 1;
7399 static const int kIgnoreCaseFieldIndex = 2;
7400 static const int kMultilineFieldIndex = 3;
7401 static const int kLastIndexFieldIndex = 4;
7402 static const int kInObjectFieldCount = 5;
7404 // The uninitialized value for a regexp code object.
7405 static const int kUninitializedValue = -1;
7407 // The compilation error value for the regexp code object. The real error
7408 // object is in the saved code field.
7409 static const int kCompilationErrorValue = -2;
7411 // When we store the sweep generation at which we moved the code from the
7412 // code index to the saved code index we mask it of to be in the [0:255]
7414 static const int kCodeAgeMask = 0xff;
7418 class CompilationCacheShape : public BaseShape<HashTableKey*> {
7420 static inline bool IsMatch(HashTableKey* key, Object* value) {
7421 return key->IsMatch(value);
7424 static inline uint32_t Hash(HashTableKey* key) {
7428 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
7429 return key->HashForObject(object);
7432 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
7434 static const int kPrefixSize = 0;
7435 static const int kEntrySize = 2;
7439 // This cache is used in two different variants. For regexp caching, it simply
7440 // maps identifying info of the regexp to the cached regexp object. Scripts and
7441 // eval code only gets cached after a second probe for the code object. To do
7442 // so, on first "put" only a hash identifying the source is entered into the
7443 // cache, mapping it to a lifetime count of the hash. On each call to Age all
7444 // such lifetimes get reduced, and removed once they reach zero. If a second put
7445 // is called while such a hash is live in the cache, the hash gets replaced by
7446 // an actual cache entry. Age also removes stale live entries from the cache.
7447 // Such entries are identified by SharedFunctionInfos pointing to either the
7448 // recompilation stub, or to "old" code. This avoids memory leaks due to
7449 // premature caching of scripts and eval strings that are never needed later.
7450 class CompilationCacheTable: public HashTable<CompilationCacheTable,
7451 CompilationCacheShape,
7454 // Find cached value for a string key, otherwise return null.
7455 Handle<Object> Lookup(
7456 Handle<String> src, Handle<Context> context, LanguageMode language_mode);
7457 Handle<Object> LookupEval(
7458 Handle<String> src, Handle<SharedFunctionInfo> shared,
7459 LanguageMode language_mode, int scope_position);
7460 Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags);
7461 static Handle<CompilationCacheTable> Put(
7462 Handle<CompilationCacheTable> cache, Handle<String> src,
7463 Handle<Context> context, LanguageMode language_mode,
7464 Handle<Object> value);
7465 static Handle<CompilationCacheTable> PutEval(
7466 Handle<CompilationCacheTable> cache, Handle<String> src,
7467 Handle<SharedFunctionInfo> context, Handle<SharedFunctionInfo> value,
7468 int scope_position);
7469 static Handle<CompilationCacheTable> PutRegExp(
7470 Handle<CompilationCacheTable> cache, Handle<String> src,
7471 JSRegExp::Flags flags, Handle<FixedArray> value);
7472 void Remove(Object* value);
7474 static const int kHashGenerations = 10;
7476 DECLARE_CAST(CompilationCacheTable)
7479 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable);
7483 class CodeCache: public Struct {
7485 DECL_ACCESSORS(default_cache, FixedArray)
7486 DECL_ACCESSORS(normal_type_cache, Object)
7488 // Add the code object to the cache.
7490 Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code);
7492 // Lookup code object in the cache. Returns code object if found and undefined
7494 Object* Lookup(Name* name, Code::Flags flags);
7496 // Get the internal index of a code object in the cache. Returns -1 if the
7497 // code object is not in that cache. This index can be used to later call
7498 // RemoveByIndex. The cache cannot be modified between a call to GetIndex and
7500 int GetIndex(Object* name, Code* code);
7502 // Remove an object from the cache with the provided internal index.
7503 void RemoveByIndex(Object* name, Code* code, int index);
7505 DECLARE_CAST(CodeCache)
7507 // Dispatched behavior.
7508 DECLARE_PRINTER(CodeCache)
7509 DECLARE_VERIFIER(CodeCache)
7511 static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
7512 static const int kNormalTypeCacheOffset =
7513 kDefaultCacheOffset + kPointerSize;
7514 static const int kSize = kNormalTypeCacheOffset + kPointerSize;
7517 static void UpdateDefaultCache(
7518 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
7519 static void UpdateNormalTypeCache(
7520 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
7521 Object* LookupDefaultCache(Name* name, Code::Flags flags);
7522 Object* LookupNormalTypeCache(Name* name, Code::Flags flags);
7524 // Code cache layout of the default cache. Elements are alternating name and
7525 // code objects for non normal load/store/call IC's.
7526 static const int kCodeCacheEntrySize = 2;
7527 static const int kCodeCacheEntryNameOffset = 0;
7528 static const int kCodeCacheEntryCodeOffset = 1;
7530 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
7534 class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
7536 static inline bool IsMatch(HashTableKey* key, Object* value) {
7537 return key->IsMatch(value);
7540 static inline uint32_t Hash(HashTableKey* key) {
7544 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
7545 return key->HashForObject(object);
7548 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
7550 static const int kPrefixSize = 0;
7551 static const int kEntrySize = 2;
7555 class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
7556 CodeCacheHashTableShape,
7559 Object* Lookup(Name* name, Code::Flags flags);
7560 static Handle<CodeCacheHashTable> Put(
7561 Handle<CodeCacheHashTable> table,
7565 int GetIndex(Name* name, Code::Flags flags);
7566 void RemoveByIndex(int index);
7568 DECLARE_CAST(CodeCacheHashTable)
7570 // Initial size of the fixed array backing the hash table.
7571 static const int kInitialSize = 64;
7574 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
7578 class PolymorphicCodeCache: public Struct {
7580 DECL_ACCESSORS(cache, Object)
7582 static void Update(Handle<PolymorphicCodeCache> cache,
7583 MapHandleList* maps,
7588 // Returns an undefined value if the entry is not found.
7589 Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags);
7591 DECLARE_CAST(PolymorphicCodeCache)
7593 // Dispatched behavior.
7594 DECLARE_PRINTER(PolymorphicCodeCache)
7595 DECLARE_VERIFIER(PolymorphicCodeCache)
7597 static const int kCacheOffset = HeapObject::kHeaderSize;
7598 static const int kSize = kCacheOffset + kPointerSize;
7601 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache);
7605 class PolymorphicCodeCacheHashTable
7606 : public HashTable<PolymorphicCodeCacheHashTable,
7607 CodeCacheHashTableShape,
7610 Object* Lookup(MapHandleList* maps, int code_kind);
7612 static Handle<PolymorphicCodeCacheHashTable> Put(
7613 Handle<PolymorphicCodeCacheHashTable> hash_table,
7614 MapHandleList* maps,
7618 DECLARE_CAST(PolymorphicCodeCacheHashTable)
7620 static const int kInitialSize = 64;
7622 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable);
7626 class TypeFeedbackInfo: public Struct {
7628 inline int ic_total_count();
7629 inline void set_ic_total_count(int count);
7631 inline int ic_with_type_info_count();
7632 inline void change_ic_with_type_info_count(int delta);
7634 inline int ic_generic_count();
7635 inline void change_ic_generic_count(int delta);
7637 inline void initialize_storage();
7639 inline void change_own_type_change_checksum();
7640 inline int own_type_change_checksum();
7642 inline void set_inlined_type_change_checksum(int checksum);
7643 inline bool matches_inlined_type_change_checksum(int checksum);
7645 DECLARE_CAST(TypeFeedbackInfo)
7647 // Dispatched behavior.
7648 DECLARE_PRINTER(TypeFeedbackInfo)
7649 DECLARE_VERIFIER(TypeFeedbackInfo)
7651 static const int kStorage1Offset = HeapObject::kHeaderSize;
7652 static const int kStorage2Offset = kStorage1Offset + kPointerSize;
7653 static const int kStorage3Offset = kStorage2Offset + kPointerSize;
7654 static const int kSize = kStorage3Offset + kPointerSize;
7657 static const int kTypeChangeChecksumBits = 7;
7659 class ICTotalCountField: public BitField<int, 0,
7660 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
7661 class OwnTypeChangeChecksum: public BitField<int,
7662 kSmiValueSize - kTypeChangeChecksumBits,
7663 kTypeChangeChecksumBits> {}; // NOLINT
7664 class ICsWithTypeInfoCountField: public BitField<int, 0,
7665 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
7666 class InlinedTypeChangeChecksum: public BitField<int,
7667 kSmiValueSize - kTypeChangeChecksumBits,
7668 kTypeChangeChecksumBits> {}; // NOLINT
7670 DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo);
7674 enum AllocationSiteMode {
7675 DONT_TRACK_ALLOCATION_SITE,
7676 TRACK_ALLOCATION_SITE,
7677 LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE
7681 class AllocationSite: public Struct {
7683 static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
7684 static const double kPretenureRatio;
7685 static const int kPretenureMinimumCreated = 100;
7687 // Values for pretenure decision field.
7688 enum PretenureDecision {
7694 kLastPretenureDecisionValue = kZombie
7697 const char* PretenureDecisionName(PretenureDecision decision);
7699 DECL_ACCESSORS(transition_info, Object)
7700 // nested_site threads a list of sites that represent nested literals
7701 // walked in a particular order. So [[1, 2], 1, 2] will have one
7702 // nested_site, but [[1, 2], 3, [4]] will have a list of two.
7703 DECL_ACCESSORS(nested_site, Object)
7704 DECL_ACCESSORS(pretenure_data, Smi)
7705 DECL_ACCESSORS(pretenure_create_count, Smi)
7706 DECL_ACCESSORS(dependent_code, DependentCode)
7707 DECL_ACCESSORS(weak_next, Object)
7709 inline void Initialize();
7711 // This method is expensive, it should only be called for reporting.
7712 bool IsNestedSite();
7714 // transition_info bitfields, for constructed array transition info.
7715 class ElementsKindBits: public BitField<ElementsKind, 0, 15> {};
7716 class UnusedBits: public BitField<int, 15, 14> {};
7717 class DoNotInlineBit: public BitField<bool, 29, 1> {};
7719 // Bitfields for pretenure_data
7720 class MementoFoundCountBits: public BitField<int, 0, 26> {};
7721 class PretenureDecisionBits: public BitField<PretenureDecision, 26, 3> {};
7722 class DeoptDependentCodeBit: public BitField<bool, 29, 1> {};
7723 STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
7725 // Increments the mementos found counter and returns true when the first
7726 // memento was found for a given allocation site.
7727 inline bool IncrementMementoFoundCount();
7729 inline void IncrementMementoCreateCount();
7731 PretenureFlag GetPretenureMode();
7733 void ResetPretenureDecision();
7735 inline PretenureDecision pretenure_decision();
7736 inline void set_pretenure_decision(PretenureDecision decision);
7738 inline bool deopt_dependent_code();
7739 inline void set_deopt_dependent_code(bool deopt);
7741 inline int memento_found_count();
7742 inline void set_memento_found_count(int count);
7744 inline int memento_create_count();
7745 inline void set_memento_create_count(int count);
7747 // The pretenuring decision is made during gc, and the zombie state allows
7748 // us to recognize when an allocation site is just being kept alive because
7749 // a later traversal of new space may discover AllocationMementos that point
7750 // to this AllocationSite.
7751 inline bool IsZombie();
7753 inline bool IsMaybeTenure();
7755 inline void MarkZombie();
7757 inline bool MakePretenureDecision(PretenureDecision current_decision,
7759 bool maximum_size_scavenge);
7761 inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
7763 inline ElementsKind GetElementsKind();
7764 inline void SetElementsKind(ElementsKind kind);
7766 inline bool CanInlineCall();
7767 inline void SetDoNotInlineCall();
7769 inline bool SitePointsToLiteral();
7771 static void DigestTransitionFeedback(Handle<AllocationSite> site,
7772 ElementsKind to_kind);
7774 DECLARE_PRINTER(AllocationSite)
7775 DECLARE_VERIFIER(AllocationSite)
7777 DECLARE_CAST(AllocationSite)
7778 static inline AllocationSiteMode GetMode(
7779 ElementsKind boilerplate_elements_kind);
7780 static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to);
7781 static inline bool CanTrack(InstanceType type);
7783 static const int kTransitionInfoOffset = HeapObject::kHeaderSize;
7784 static const int kNestedSiteOffset = kTransitionInfoOffset + kPointerSize;
7785 static const int kPretenureDataOffset = kNestedSiteOffset + kPointerSize;
7786 static const int kPretenureCreateCountOffset =
7787 kPretenureDataOffset + kPointerSize;
7788 static const int kDependentCodeOffset =
7789 kPretenureCreateCountOffset + kPointerSize;
7790 static const int kWeakNextOffset = kDependentCodeOffset + kPointerSize;
7791 static const int kSize = kWeakNextOffset + kPointerSize;
7793 // During mark compact we need to take special care for the dependent code
7795 static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
7796 static const int kPointerFieldsEndOffset = kWeakNextOffset;
7798 // For other visitors, use the fixed body descriptor below.
7799 typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
7800 kDependentCodeOffset + kPointerSize,
7801 kSize> BodyDescriptor;
7804 inline bool PretenuringDecisionMade();
7806 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
7810 class AllocationMemento: public Struct {
7812 static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
7813 static const int kSize = kAllocationSiteOffset + kPointerSize;
7815 DECL_ACCESSORS(allocation_site, Object)
7817 inline bool IsValid();
7818 inline AllocationSite* GetAllocationSite();
7820 DECLARE_PRINTER(AllocationMemento)
7821 DECLARE_VERIFIER(AllocationMemento)
7823 DECLARE_CAST(AllocationMemento)
7826 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
7830 // Representation of a slow alias as part of a sloppy arguments objects.
7831 // For fast aliases (if HasSloppyArgumentsElements()):
7832 // - the parameter map contains an index into the context
7833 // - all attributes of the element have default values
7834 // For slow aliases (if HasDictionaryArgumentsElements()):
7835 // - the parameter map contains no fast alias mapping (i.e. the hole)
7836 // - this struct (in the slow backing store) contains an index into the context
7837 // - all attributes are available as part if the property details
7838 class AliasedArgumentsEntry: public Struct {
7840 inline int aliased_context_slot() const;
7841 inline void set_aliased_context_slot(int count);
7843 DECLARE_CAST(AliasedArgumentsEntry)
7845 // Dispatched behavior.
7846 DECLARE_PRINTER(AliasedArgumentsEntry)
7847 DECLARE_VERIFIER(AliasedArgumentsEntry)
7849 static const int kAliasedContextSlot = HeapObject::kHeaderSize;
7850 static const int kSize = kAliasedContextSlot + kPointerSize;
7853 DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry);
7857 enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
7858 enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};
7861 class StringHasher {
7863 explicit inline StringHasher(int length, uint32_t seed);
7865 template <typename schar>
7866 static inline uint32_t HashSequentialString(const schar* chars,
7870 // Reads all the data, even for long strings and computes the utf16 length.
7871 static uint32_t ComputeUtf8Hash(Vector<const char> chars,
7873 int* utf16_length_out);
7875 // Calculated hash value for a string consisting of 1 to
7876 // String::kMaxArrayIndexSize digits with no leading zeros (except "0").
7877 // value is represented decimal value.
7878 static uint32_t MakeArrayIndexHash(uint32_t value, int length);
7880 // No string is allowed to have a hash of zero. That value is reserved
7881 // for internal properties. If the hash calculation yields zero then we
7883 static const int kZeroHash = 27;
7885 // Reusable parts of the hashing algorithm.
7886 INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
7887 INLINE(static uint32_t GetHashCore(uint32_t running_hash));
7888 INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
7889 const uc16* chars, int length));
7890 INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
7895 // Returns the value to store in the hash field of a string with
7896 // the given length and contents.
7897 uint32_t GetHashField();
7898 // Returns true if the hash of this string can be computed without
7899 // looking at the contents.
7900 inline bool has_trivial_hash();
7901 // Adds a block of characters to the hash.
7902 template<typename Char>
7903 inline void AddCharacters(const Char* chars, int len);
7906 // Add a character to the hash.
7907 inline void AddCharacter(uint16_t c);
7908 // Update index. Returns true if string is still an index.
7909 inline bool UpdateIndex(uint16_t c);
7912 uint32_t raw_running_hash_;
7913 uint32_t array_index_;
7914 bool is_array_index_;
7915 bool is_first_char_;
7916 DISALLOW_COPY_AND_ASSIGN(StringHasher);
7920 class IteratingStringHasher : public StringHasher {
7922 static inline uint32_t Hash(String* string, uint32_t seed);
7923 inline void VisitOneByteString(const uint8_t* chars, int length);
7924 inline void VisitTwoByteString(const uint16_t* chars, int length);
7927 inline IteratingStringHasher(int len, uint32_t seed);
7928 void VisitConsString(ConsString* cons_string);
7929 DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
7933 // The characteristics of a string are stored in its map. Retrieving these
7934 // few bits of information is moderately expensive, involving two memory
7935 // loads where the second is dependent on the first. To improve efficiency
7936 // the shape of the string is given its own class so that it can be retrieved
7937 // once and used for several string operations. A StringShape is small enough
7938 // to be passed by value and is immutable, but be aware that flattening a
7939 // string can potentially alter its shape. Also be aware that a GC caused by
7940 // something else can alter the shape of a string due to ConsString
7941 // shortcutting. Keeping these restrictions in mind has proven to be error-
7942 // prone and so we no longer put StringShapes in variables unless there is a
7943 // concrete performance benefit at that particular point in the code.
7944 class StringShape BASE_EMBEDDED {
7946 inline explicit StringShape(const String* s);
7947 inline explicit StringShape(Map* s);
7948 inline explicit StringShape(InstanceType t);
7949 inline bool IsSequential();
7950 inline bool IsExternal();
7951 inline bool IsCons();
7952 inline bool IsSliced();
7953 inline bool IsIndirect();
7954 inline bool IsExternalOneByte();
7955 inline bool IsExternalTwoByte();
7956 inline bool IsSequentialOneByte();
7957 inline bool IsSequentialTwoByte();
7958 inline bool IsInternalized();
7959 inline StringRepresentationTag representation_tag();
7960 inline uint32_t encoding_tag();
7961 inline uint32_t full_representation_tag();
7962 inline uint32_t size_tag();
7964 inline uint32_t type() { return type_; }
7965 inline void invalidate() { valid_ = false; }
7966 inline bool valid() { return valid_; }
7968 inline void invalidate() { }
7974 inline void set_valid() { valid_ = true; }
7977 inline void set_valid() { }
7982 // The Name abstract class captures anything that can be used as a property
7983 // name, i.e., strings and symbols. All names store a hash value.
7984 class Name: public HeapObject {
7986 // Get and set the hash field of the name.
7987 inline uint32_t hash_field();
7988 inline void set_hash_field(uint32_t value);
7990 // Tells whether the hash code has been computed.
7991 inline bool HasHashCode();
7993 // Returns a hash value used for the property table
7994 inline uint32_t Hash();
7996 // Equality operations.
7997 inline bool Equals(Name* other);
7998 inline static bool Equals(Handle<Name> one, Handle<Name> two);
8001 inline bool AsArrayIndex(uint32_t* index);
8003 // If the name is private, it can only name own properties.
8004 inline bool IsPrivate();
8006 // If the name is a non-flat string, this method returns a flat version of the
8007 // string. Otherwise it'll just return the input.
8008 static inline Handle<Name> Flatten(Handle<Name> name,
8009 PretenureFlag pretenure = NOT_TENURED);
8013 DECLARE_PRINTER(Name)
8015 void NameShortPrint();
8016 int NameShortPrint(Vector<char> str);
8019 // Layout description.
8020 static const int kHashFieldSlot = HeapObject::kHeaderSize;
8021 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
8022 static const int kHashFieldOffset = kHashFieldSlot;
8024 static const int kHashFieldOffset = kHashFieldSlot + kIntSize;
8026 static const int kSize = kHashFieldSlot + kPointerSize;
8028 // Mask constant for checking if a name has a computed hash code
8029 // and if it is a string that is an array index. The least significant bit
8030 // indicates whether a hash code has been computed. If the hash code has
8031 // been computed the 2nd bit tells whether the string can be used as an
8033 static const int kHashNotComputedMask = 1;
8034 static const int kIsNotArrayIndexMask = 1 << 1;
8035 static const int kNofHashBitFields = 2;
8037 // Shift constant retrieving hash code from hash field.
8038 static const int kHashShift = kNofHashBitFields;
8040 // Only these bits are relevant in the hash, since the top two are shifted
8042 static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift;
8044 // Array index strings this short can keep their index in the hash field.
8045 static const int kMaxCachedArrayIndexLength = 7;
8047 // For strings which are array indexes the hash value has the string length
8048 // mixed into the hash, mainly to avoid a hash value of zero which would be
8049 // the case for the string '0'. 24 bits are used for the array index value.
8050 static const int kArrayIndexValueBits = 24;
8051 static const int kArrayIndexLengthBits =
8052 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8054 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8056 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8057 kArrayIndexValueBits> {}; // NOLINT
8058 class ArrayIndexLengthBits : public BitField<unsigned int,
8059 kNofHashBitFields + kArrayIndexValueBits,
8060 kArrayIndexLengthBits> {}; // NOLINT
8062 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8063 // could use a mask to test if the length of string is less than or equal to
8064 // kMaxCachedArrayIndexLength.
8065 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8067 static const unsigned int kContainsCachedArrayIndexMask =
8068 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8069 << ArrayIndexLengthBits::kShift) |
8070 kIsNotArrayIndexMask;
8072 // Value of empty hash field indicating that the hash is not computed.
8073 static const int kEmptyHashField =
8074 kIsNotArrayIndexMask | kHashNotComputedMask;
8077 static inline bool IsHashFieldComputed(uint32_t field);
8080 DISALLOW_IMPLICIT_CONSTRUCTORS(Name);
8085 class Symbol: public Name {
8087 // [name]: The print name of a symbol, or undefined if none.
8088 DECL_ACCESSORS(name, Object)
8090 DECL_ACCESSORS(flags, Smi)
8092 // [is_private]: Whether this is a private symbol. Private symbols can only
8093 // be used to designate own properties of objects.
8094 DECL_BOOLEAN_ACCESSORS(is_private)
8096 DECLARE_CAST(Symbol)
8098 // Dispatched behavior.
8099 DECLARE_PRINTER(Symbol)
8100 DECLARE_VERIFIER(Symbol)
8102 // Layout description.
8103 static const int kNameOffset = Name::kSize;
8104 static const int kFlagsOffset = kNameOffset + kPointerSize;
8105 static const int kSize = kFlagsOffset + kPointerSize;
8107 typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
8109 void SymbolShortPrint(std::ostream& os);
8112 static const int kPrivateBit = 0;
8114 const char* PrivateSymbolToName() const;
8117 friend class Name; // For PrivateSymbolToName.
8120 DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol);
8126 // The String abstract class captures JavaScript string values:
8129 // 4.3.16 String Value
8130 // A string value is a member of the type String and is a finite
8131 // ordered sequence of zero or more 16-bit unsigned integer values.
8133 // All string values have a length field.
8134 class String: public Name {
8136 enum Encoding { ONE_BYTE_ENCODING, TWO_BYTE_ENCODING };
8138 // Array index strings this short can keep their index in the hash field.
8139 static const int kMaxCachedArrayIndexLength = 7;
8141 // For strings which are array indexes the hash value has the string length
8142 // mixed into the hash, mainly to avoid a hash value of zero which would be
8143 // the case for the string '0'. 24 bits are used for the array index value.
8144 static const int kArrayIndexValueBits = 24;
8145 static const int kArrayIndexLengthBits =
8146 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8148 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8150 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8151 kArrayIndexValueBits> {}; // NOLINT
8152 class ArrayIndexLengthBits : public BitField<unsigned int,
8153 kNofHashBitFields + kArrayIndexValueBits,
8154 kArrayIndexLengthBits> {}; // NOLINT
8156 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8157 // could use a mask to test if the length of string is less than or equal to
8158 // kMaxCachedArrayIndexLength.
8159 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8161 static const unsigned int kContainsCachedArrayIndexMask =
8162 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8163 << ArrayIndexLengthBits::kShift) |
8164 kIsNotArrayIndexMask;
8166 class SubStringRange {
8168 explicit inline SubStringRange(String* string, int first = 0,
8171 inline iterator begin();
8172 inline iterator end();
8180 // Representation of the flat content of a String.
8181 // A non-flat string doesn't have flat content.
8182 // A flat string has content that's encoded as a sequence of either
8183 // one-byte chars or two-byte UC16.
8184 // Returned by String::GetFlatContent().
8187 // Returns true if the string is flat and this structure contains content.
8188 bool IsFlat() { return state_ != NON_FLAT; }
8189 // Returns true if the structure contains one-byte content.
8190 bool IsOneByte() { return state_ == ONE_BYTE; }
8191 // Returns true if the structure contains two-byte content.
8192 bool IsTwoByte() { return state_ == TWO_BYTE; }
8194 // Return the one byte content of the string. Only use if IsOneByte()
8196 Vector<const uint8_t> ToOneByteVector() {
8197 DCHECK_EQ(ONE_BYTE, state_);
8198 return Vector<const uint8_t>(onebyte_start, length_);
8200 // Return the two-byte content of the string. Only use if IsTwoByte()
8202 Vector<const uc16> ToUC16Vector() {
8203 DCHECK_EQ(TWO_BYTE, state_);
8204 return Vector<const uc16>(twobyte_start, length_);
8208 DCHECK(i < length_);
8209 DCHECK(state_ != NON_FLAT);
8210 if (state_ == ONE_BYTE) return onebyte_start[i];
8211 return twobyte_start[i];
8214 bool UsesSameString(const FlatContent& other) const {
8215 return onebyte_start == other.onebyte_start;
8219 enum State { NON_FLAT, ONE_BYTE, TWO_BYTE };
8221 // Constructors only used by String::GetFlatContent().
8222 explicit FlatContent(const uint8_t* start, int length)
8223 : onebyte_start(start), length_(length), state_(ONE_BYTE) {}
8224 explicit FlatContent(const uc16* start, int length)
8225 : twobyte_start(start), length_(length), state_(TWO_BYTE) { }
8226 FlatContent() : onebyte_start(NULL), length_(0), state_(NON_FLAT) { }
8229 const uint8_t* onebyte_start;
8230 const uc16* twobyte_start;
8235 friend class String;
8236 friend class IterableSubString;
8239 template <typename Char>
8240 INLINE(Vector<const Char> GetCharVector());
8242 // Get and set the length of the string.
8243 inline int length() const;
8244 inline void set_length(int value);
8246 // Get and set the length of the string using acquire loads and release
8248 inline int synchronized_length() const;
8249 inline void synchronized_set_length(int value);
8251 // Returns whether this string has only one-byte chars, i.e. all of them can
8252 // be one-byte encoded. This might be the case even if the string is
8253 // two-byte. Such strings may appear when the embedder prefers
8254 // two-byte external representations even for one-byte data.
8255 inline bool IsOneByteRepresentation() const;
8256 inline bool IsTwoByteRepresentation() const;
8258 // Cons and slices have an encoding flag that may not represent the actual
8259 // encoding of the underlying string. This is taken into account here.
8260 // Requires: this->IsFlat()
8261 inline bool IsOneByteRepresentationUnderneath();
8262 inline bool IsTwoByteRepresentationUnderneath();
8264 // NOTE: this should be considered only a hint. False negatives are
8266 inline bool HasOnlyOneByteChars();
8268 // Get and set individual two byte chars in the string.
8269 inline void Set(int index, uint16_t value);
8270 // Get individual two byte char in the string. Repeated calls
8271 // to this method are not efficient unless the string is flat.
8272 INLINE(uint16_t Get(int index));
8274 // Flattens the string. Checks first inline to see if it is
8275 // necessary. Does nothing if the string is not a cons string.
8276 // Flattening allocates a sequential string with the same data as
8277 // the given string and mutates the cons string to a degenerate
8278 // form, where the first component is the new sequential string and
8279 // the second component is the empty string. If allocation fails,
8280 // this function returns a failure. If flattening succeeds, this
8281 // function returns the sequential string that is now the first
8282 // component of the cons string.
8284 // Degenerate cons strings are handled specially by the garbage
8285 // collector (see IsShortcutCandidate).
8287 static inline Handle<String> Flatten(Handle<String> string,
8288 PretenureFlag pretenure = NOT_TENURED);
8290 // Tries to return the content of a flat string as a structure holding either
8291 // a flat vector of char or of uc16.
8292 // If the string isn't flat, and therefore doesn't have flat content, the
8293 // returned structure will report so, and can't provide a vector of either
8295 FlatContent GetFlatContent();
8297 // Returns the parent of a sliced string or first part of a flat cons string.
8298 // Requires: StringShape(this).IsIndirect() && this->IsFlat()
8299 inline String* GetUnderlying();
8301 // String equality operations.
8302 inline bool Equals(String* other);
8303 inline static bool Equals(Handle<String> one, Handle<String> two);
8304 bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
8305 bool IsOneByteEqualTo(Vector<const uint8_t> str);
8306 bool IsTwoByteEqualTo(Vector<const uc16> str);
8308 // Return a UTF8 representation of the string. The string is null
8309 // terminated but may optionally contain nulls. Length is returned
8310 // in length_output if length_output is not a null pointer The string
8311 // should be nearly flat, otherwise the performance of this method may
8312 // be very slow (quadratic in the length). Setting robustness_flag to
8313 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
8314 // handles unexpected data without causing assert failures and it does not
8315 // do any heap allocations. This is useful when printing stack traces.
8316 base::SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls,
8317 RobustnessFlag robustness_flag,
8318 int offset, int length,
8319 int* length_output = 0);
8320 base::SmartArrayPointer<char> ToCString(
8321 AllowNullsFlag allow_nulls = DISALLOW_NULLS,
8322 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL,
8323 int* length_output = 0);
8325 // Return a 16 bit Unicode representation of the string.
8326 // The string should be nearly flat, otherwise the performance of
8327 // of this method may be very bad. Setting robustness_flag to
8328 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
8329 // handles unexpected data without causing assert failures and it does not
8330 // do any heap allocations. This is useful when printing stack traces.
8331 base::SmartArrayPointer<uc16> ToWideCString(
8332 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL);
8334 bool ComputeArrayIndex(uint32_t* index);
8337 bool MakeExternal(v8::String::ExternalStringResource* resource);
8338 bool MakeExternal(v8::String::ExternalOneByteStringResource* resource);
8341 inline bool AsArrayIndex(uint32_t* index);
8343 DECLARE_CAST(String)
8345 void PrintOn(FILE* out);
8347 // For use during stack traces. Performs rudimentary sanity check.
8350 // Dispatched behavior.
8351 void StringShortPrint(StringStream* accumulator);
8352 void PrintUC16(std::ostream& os, int start = 0, int end = -1); // NOLINT
8353 #if defined(DEBUG) || defined(OBJECT_PRINT)
8354 char* ToAsciiArray();
8356 DECLARE_PRINTER(String)
8357 DECLARE_VERIFIER(String)
8359 inline bool IsFlat();
8361 // Layout description.
8362 static const int kLengthOffset = Name::kSize;
8363 static const int kSize = kLengthOffset + kPointerSize;
8365 // Maximum number of characters to consider when trying to convert a string
8366 // value into an array index.
8367 static const int kMaxArrayIndexSize = 10;
8368 STATIC_ASSERT(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits));
8371 static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar;
8372 static const uint32_t kMaxOneByteCharCodeU = unibrow::Latin1::kMaxChar;
8373 static const int kMaxUtf16CodeUnit = 0xffff;
8374 static const uint32_t kMaxUtf16CodeUnitU = kMaxUtf16CodeUnit;
8376 // Value of hash field containing computed hash equal to zero.
8377 static const int kEmptyStringHash = kIsNotArrayIndexMask;
8379 // Maximal string length.
8380 static const int kMaxLength = (1 << 28) - 16;
8382 // Max length for computing hash. For strings longer than this limit the
8383 // string length is used as the hash value.
8384 static const int kMaxHashCalcLength = 16383;
8386 // Limit for truncation in short printing.
8387 static const int kMaxShortPrintLength = 1024;
8389 // Support for regular expressions.
8390 const uc16* GetTwoByteData(unsigned start);
8392 // Helper function for flattening strings.
8393 template <typename sinkchar>
8394 static void WriteToFlat(String* source,
8399 // The return value may point to the first aligned word containing the first
8400 // non-one-byte character, rather than directly to the non-one-byte character.
8401 // If the return value is >= the passed length, the entire string was
8403 static inline int NonAsciiStart(const char* chars, int length) {
8404 const char* start = chars;
8405 const char* limit = chars + length;
8407 if (length >= kIntptrSize) {
8408 // Check unaligned bytes.
8409 while (!IsAligned(reinterpret_cast<intptr_t>(chars), sizeof(uintptr_t))) {
8410 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
8411 return static_cast<int>(chars - start);
8415 // Check aligned words.
8416 DCHECK(unibrow::Utf8::kMaxOneByteChar == 0x7F);
8417 const uintptr_t non_one_byte_mask = kUintptrAllBitsSet / 0xFF * 0x80;
8418 while (chars + sizeof(uintptr_t) <= limit) {
8419 if (*reinterpret_cast<const uintptr_t*>(chars) & non_one_byte_mask) {
8420 return static_cast<int>(chars - start);
8422 chars += sizeof(uintptr_t);
8425 // Check remaining unaligned bytes.
8426 while (chars < limit) {
8427 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
8428 return static_cast<int>(chars - start);
8433 return static_cast<int>(chars - start);
8436 static inline bool IsAscii(const char* chars, int length) {
8437 return NonAsciiStart(chars, length) >= length;
8440 static inline bool IsAscii(const uint8_t* chars, int length) {
8442 NonAsciiStart(reinterpret_cast<const char*>(chars), length) >= length;
8445 static inline int NonOneByteStart(const uc16* chars, int length) {
8446 const uc16* limit = chars + length;
8447 const uc16* start = chars;
8448 while (chars < limit) {
8449 if (*chars > kMaxOneByteCharCodeU) return static_cast<int>(chars - start);
8452 return static_cast<int>(chars - start);
8455 static inline bool IsOneByte(const uc16* chars, int length) {
8456 return NonOneByteStart(chars, length) >= length;
8459 template<class Visitor>
8460 static inline ConsString* VisitFlat(Visitor* visitor,
8464 static Handle<FixedArray> CalculateLineEnds(Handle<String> string,
8465 bool include_ending_line);
8467 // Use the hash field to forward to the canonical internalized string
8468 // when deserializing an internalized string.
8469 inline void SetForwardedInternalizedString(String* string);
8470 inline String* GetForwardedInternalizedString();
8474 friend class StringTableInsertionKey;
8476 static Handle<String> SlowFlatten(Handle<ConsString> cons,
8477 PretenureFlag tenure);
8479 // Slow case of String::Equals. This implementation works on any strings
8480 // but it is most efficient on strings that are almost flat.
8481 bool SlowEquals(String* other);
8483 static bool SlowEquals(Handle<String> one, Handle<String> two);
8485 // Slow case of AsArrayIndex.
8486 bool SlowAsArrayIndex(uint32_t* index);
8488 // Compute and set the hash code.
8489 uint32_t ComputeAndSetHash();
8491 DISALLOW_IMPLICIT_CONSTRUCTORS(String);
8495 // The SeqString abstract class captures sequential string values.
8496 class SeqString: public String {
8498 DECLARE_CAST(SeqString)
8500 // Layout description.
8501 static const int kHeaderSize = String::kSize;
8503 // Truncate the string in-place if possible and return the result.
8504 // In case of new_length == 0, the empty string is returned without
8505 // truncating the original string.
8506 MUST_USE_RESULT static Handle<String> Truncate(Handle<SeqString> string,
8509 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString);
8513 // The OneByteString class captures sequential one-byte string objects.
8514 // Each character in the OneByteString is an one-byte character.
8515 class SeqOneByteString: public SeqString {
8517 static const bool kHasOneByteEncoding = true;
8519 // Dispatched behavior.
8520 inline uint16_t SeqOneByteStringGet(int index);
8521 inline void SeqOneByteStringSet(int index, uint16_t value);
8523 // Get the address of the characters in this string.
8524 inline Address GetCharsAddress();
8526 inline uint8_t* GetChars();
8528 DECLARE_CAST(SeqOneByteString)
8530 // Garbage collection support. This method is called by the
8531 // garbage collector to compute the actual size of an OneByteString
8533 inline int SeqOneByteStringSize(InstanceType instance_type);
8535 // Computes the size for an OneByteString instance of a given length.
8536 static int SizeFor(int length) {
8537 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize);
8540 // Maximal memory usage for a single sequential one-byte string.
8541 static const int kMaxSize = 512 * MB - 1;
8542 STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength);
8545 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
8549 // The TwoByteString class captures sequential unicode string objects.
8550 // Each character in the TwoByteString is a two-byte uint16_t.
8551 class SeqTwoByteString: public SeqString {
8553 static const bool kHasOneByteEncoding = false;
8555 // Dispatched behavior.
8556 inline uint16_t SeqTwoByteStringGet(int index);
8557 inline void SeqTwoByteStringSet(int index, uint16_t value);
8559 // Get the address of the characters in this string.
8560 inline Address GetCharsAddress();
8562 inline uc16* GetChars();
8565 const uint16_t* SeqTwoByteStringGetData(unsigned start);
8567 DECLARE_CAST(SeqTwoByteString)
8569 // Garbage collection support. This method is called by the
8570 // garbage collector to compute the actual size of a TwoByteString
8572 inline int SeqTwoByteStringSize(InstanceType instance_type);
8574 // Computes the size for a TwoByteString instance of a given length.
8575 static int SizeFor(int length) {
8576 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize);
8579 // Maximal memory usage for a single sequential two-byte string.
8580 static const int kMaxSize = 512 * MB - 1;
8581 STATIC_ASSERT(static_cast<int>((kMaxSize - kHeaderSize)/sizeof(uint16_t)) >=
8582 String::kMaxLength);
8585 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString);
8589 // The ConsString class describes string values built by using the
8590 // addition operator on strings. A ConsString is a pair where the
8591 // first and second components are pointers to other string values.
8592 // One or both components of a ConsString can be pointers to other
8593 // ConsStrings, creating a binary tree of ConsStrings where the leaves
8594 // are non-ConsString string values. The string value represented by
8595 // a ConsString can be obtained by concatenating the leaf string
8596 // values in a left-to-right depth-first traversal of the tree.
8597 class ConsString: public String {
8599 // First string of the cons cell.
8600 inline String* first();
8601 // Doesn't check that the result is a string, even in debug mode. This is
8602 // useful during GC where the mark bits confuse the checks.
8603 inline Object* unchecked_first();
8604 inline void set_first(String* first,
8605 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
8607 // Second string of the cons cell.
8608 inline String* second();
8609 // Doesn't check that the result is a string, even in debug mode. This is
8610 // useful during GC where the mark bits confuse the checks.
8611 inline Object* unchecked_second();
8612 inline void set_second(String* second,
8613 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
8615 // Dispatched behavior.
8616 uint16_t ConsStringGet(int index);
8618 DECLARE_CAST(ConsString)
8620 // Layout description.
8621 static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize);
8622 static const int kSecondOffset = kFirstOffset + kPointerSize;
8623 static const int kSize = kSecondOffset + kPointerSize;
8625 // Minimum length for a cons string.
8626 static const int kMinLength = 13;
8628 typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize>
8631 DECLARE_VERIFIER(ConsString)
8634 DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString);
8638 // The Sliced String class describes strings that are substrings of another
8639 // sequential string. The motivation is to save time and memory when creating
8640 // a substring. A Sliced String is described as a pointer to the parent,
8641 // the offset from the start of the parent string and the length. Using
8642 // a Sliced String therefore requires unpacking of the parent string and
8643 // adding the offset to the start address. A substring of a Sliced String
8644 // are not nested since the double indirection is simplified when creating
8645 // such a substring.
8646 // Currently missing features are:
8647 // - handling externalized parent strings
8648 // - external strings as parent
8649 // - truncating sliced string to enable otherwise unneeded parent to be GC'ed.
8650 class SlicedString: public String {
8652 inline String* parent();
8653 inline void set_parent(String* parent,
8654 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
8655 inline int offset() const;
8656 inline void set_offset(int offset);
8658 // Dispatched behavior.
8659 uint16_t SlicedStringGet(int index);
8661 DECLARE_CAST(SlicedString)
8663 // Layout description.
8664 static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize);
8665 static const int kOffsetOffset = kParentOffset + kPointerSize;
8666 static const int kSize = kOffsetOffset + kPointerSize;
8668 // Minimum length for a sliced string.
8669 static const int kMinLength = 13;
8671 typedef FixedBodyDescriptor<kParentOffset,
8672 kOffsetOffset + kPointerSize, kSize>
8675 DECLARE_VERIFIER(SlicedString)
8678 DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString);
8682 // The ExternalString class describes string values that are backed by
8683 // a string resource that lies outside the V8 heap. ExternalStrings
8684 // consist of the length field common to all strings, a pointer to the
8685 // external resource. It is important to ensure (externally) that the
8686 // resource is not deallocated while the ExternalString is live in the
8689 // The API expects that all ExternalStrings are created through the
8690 // API. Therefore, ExternalStrings should not be used internally.
8691 class ExternalString: public String {
8693 DECLARE_CAST(ExternalString)
8695 // Layout description.
8696 static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
8697 static const int kShortSize = kResourceOffset + kPointerSize;
8698 static const int kResourceDataOffset = kResourceOffset + kPointerSize;
8699 static const int kSize = kResourceDataOffset + kPointerSize;
8701 static const int kMaxShortLength =
8702 (kShortSize - SeqString::kHeaderSize) / kCharSize;
8704 // Return whether external string is short (data pointer is not cached).
8705 inline bool is_short();
8707 STATIC_ASSERT(kResourceOffset == Internals::kStringResourceOffset);
8710 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString);
8714 // The ExternalOneByteString class is an external string backed by an
8716 class ExternalOneByteString : public ExternalString {
8718 static const bool kHasOneByteEncoding = true;
8720 typedef v8::String::ExternalOneByteStringResource Resource;
8722 // The underlying resource.
8723 inline const Resource* resource();
8724 inline void set_resource(const Resource* buffer);
8726 // Update the pointer cache to the external character array.
8727 // The cached pointer is always valid, as the external character array does =
8728 // not move during lifetime. Deserialization is the only exception, after
8729 // which the pointer cache has to be refreshed.
8730 inline void update_data_cache();
8732 inline const uint8_t* GetChars();
8734 // Dispatched behavior.
8735 inline uint16_t ExternalOneByteStringGet(int index);
8737 DECLARE_CAST(ExternalOneByteString)
8739 // Garbage collection support.
8740 inline void ExternalOneByteStringIterateBody(ObjectVisitor* v);
8742 template <typename StaticVisitor>
8743 inline void ExternalOneByteStringIterateBody();
8746 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString);
8750 // The ExternalTwoByteString class is an external string backed by a UTF-16
8752 class ExternalTwoByteString: public ExternalString {
8754 static const bool kHasOneByteEncoding = false;
8756 typedef v8::String::ExternalStringResource Resource;
8758 // The underlying string resource.
8759 inline const Resource* resource();
8760 inline void set_resource(const Resource* buffer);
8762 // Update the pointer cache to the external character array.
8763 // The cached pointer is always valid, as the external character array does =
8764 // not move during lifetime. Deserialization is the only exception, after
8765 // which the pointer cache has to be refreshed.
8766 inline void update_data_cache();
8768 inline const uint16_t* GetChars();
8770 // Dispatched behavior.
8771 inline uint16_t ExternalTwoByteStringGet(int index);
8774 inline const uint16_t* ExternalTwoByteStringGetData(unsigned start);
8776 DECLARE_CAST(ExternalTwoByteString)
8778 // Garbage collection support.
8779 inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v);
8781 template<typename StaticVisitor>
8782 inline void ExternalTwoByteStringIterateBody();
8785 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString);
8789 // Utility superclass for stack-allocated objects that must be updated
8790 // on gc. It provides two ways for the gc to update instances, either
8791 // iterating or updating after gc.
8792 class Relocatable BASE_EMBEDDED {
8794 explicit inline Relocatable(Isolate* isolate);
8795 inline virtual ~Relocatable();
8796 virtual void IterateInstance(ObjectVisitor* v) { }
8797 virtual void PostGarbageCollection() { }
8799 static void PostGarbageCollectionProcessing(Isolate* isolate);
8800 static int ArchiveSpacePerThread();
8801 static char* ArchiveState(Isolate* isolate, char* to);
8802 static char* RestoreState(Isolate* isolate, char* from);
8803 static void Iterate(Isolate* isolate, ObjectVisitor* v);
8804 static void Iterate(ObjectVisitor* v, Relocatable* top);
8805 static char* Iterate(ObjectVisitor* v, char* t);
8813 // A flat string reader provides random access to the contents of a
8814 // string independent of the character width of the string. The handle
8815 // must be valid as long as the reader is being used.
8816 class FlatStringReader : public Relocatable {
8818 FlatStringReader(Isolate* isolate, Handle<String> str);
8819 FlatStringReader(Isolate* isolate, Vector<const char> input);
8820 void PostGarbageCollection();
8821 inline uc32 Get(int index);
8822 template <typename Char>
8823 inline Char Get(int index);
8824 int length() { return length_; }
8833 // This maintains an off-stack representation of the stack frames required
8834 // to traverse a ConsString, allowing an entirely iterative and restartable
8835 // traversal of the entire string
8836 class ConsStringIterator {
8838 inline ConsStringIterator() {}
8839 inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) {
8840 Reset(cons_string, offset);
8842 inline void Reset(ConsString* cons_string, int offset = 0) {
8844 // Next will always return NULL.
8845 if (cons_string == NULL) return;
8846 Initialize(cons_string, offset);
8848 // Returns NULL when complete.
8849 inline String* Next(int* offset_out) {
8851 if (depth_ == 0) return NULL;
8852 return Continue(offset_out);
8856 static const int kStackSize = 32;
8857 // Use a mask instead of doing modulo operations for stack wrapping.
8858 static const int kDepthMask = kStackSize-1;
8859 STATIC_ASSERT(IS_POWER_OF_TWO(kStackSize));
8860 static inline int OffsetForDepth(int depth);
8862 inline void PushLeft(ConsString* string);
8863 inline void PushRight(ConsString* string);
8864 inline void AdjustMaximumDepth();
8866 inline bool StackBlown() { return maximum_depth_ - depth_ == kStackSize; }
8867 void Initialize(ConsString* cons_string, int offset);
8868 String* Continue(int* offset_out);
8869 String* NextLeaf(bool* blew_stack);
8870 String* Search(int* offset_out);
8872 // Stack must always contain only frames for which right traversal
8873 // has not yet been performed.
8874 ConsString* frames_[kStackSize];
8879 DISALLOW_COPY_AND_ASSIGN(ConsStringIterator);
8883 class StringCharacterStream {
8885 inline StringCharacterStream(String* string,
8887 inline uint16_t GetNext();
8888 inline bool HasMore();
8889 inline void Reset(String* string, int offset = 0);
8890 inline void VisitOneByteString(const uint8_t* chars, int length);
8891 inline void VisitTwoByteString(const uint16_t* chars, int length);
8894 ConsStringIterator iter_;
8897 const uint8_t* buffer8_;
8898 const uint16_t* buffer16_;
8900 const uint8_t* end_;
8901 DISALLOW_COPY_AND_ASSIGN(StringCharacterStream);
8905 template <typename T>
8906 class VectorIterator {
8908 VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { }
8909 explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { }
8910 T GetNext() { return data_[index_++]; }
8911 bool has_more() { return index_ < data_.length(); }
8913 Vector<const T> data_;
8918 // The Oddball describes objects null, undefined, true, and false.
8919 class Oddball: public HeapObject {
8921 // [to_string]: Cached to_string computed at startup.
8922 DECL_ACCESSORS(to_string, String)
8924 // [to_number]: Cached to_number computed at startup.
8925 DECL_ACCESSORS(to_number, Object)
8927 // [typeof]: Cached type_of computed at startup.
8928 DECL_ACCESSORS(type_of, String)
8930 inline byte kind() const;
8931 inline void set_kind(byte kind);
8933 DECLARE_CAST(Oddball)
8935 // Dispatched behavior.
8936 DECLARE_VERIFIER(Oddball)
8938 // Initialize the fields.
8939 static void Initialize(Isolate* isolate, Handle<Oddball> oddball,
8940 const char* to_string, Handle<Object> to_number,
8941 const char* type_of, byte kind);
8943 // Layout description.
8944 static const int kToStringOffset = HeapObject::kHeaderSize;
8945 static const int kToNumberOffset = kToStringOffset + kPointerSize;
8946 static const int kTypeOfOffset = kToNumberOffset + kPointerSize;
8947 static const int kKindOffset = kTypeOfOffset + kPointerSize;
8948 static const int kSize = kKindOffset + kPointerSize;
8950 static const byte kFalse = 0;
8951 static const byte kTrue = 1;
8952 static const byte kNotBooleanMask = ~1;
8953 static const byte kTheHole = 2;
8954 static const byte kNull = 3;
8955 static const byte kArgumentMarker = 4;
8956 static const byte kUndefined = 5;
8957 static const byte kUninitialized = 6;
8958 static const byte kOther = 7;
8959 static const byte kException = 8;
8961 typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize,
8962 kSize> BodyDescriptor;
8964 STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
8965 STATIC_ASSERT(kNull == Internals::kNullOddballKind);
8966 STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind);
8969 DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
8973 class Cell: public HeapObject {
8975 // [value]: value of the cell.
8976 DECL_ACCESSORS(value, Object)
8980 static inline Cell* FromValueAddress(Address value) {
8981 Object* result = FromAddress(value - kValueOffset);
8982 return static_cast<Cell*>(result);
8985 inline Address ValueAddress() {
8986 return address() + kValueOffset;
8989 // Dispatched behavior.
8990 DECLARE_PRINTER(Cell)
8991 DECLARE_VERIFIER(Cell)
8993 // Layout description.
8994 static const int kValueOffset = HeapObject::kHeaderSize;
8995 static const int kSize = kValueOffset + kPointerSize;
8997 typedef FixedBodyDescriptor<kValueOffset,
8998 kValueOffset + kPointerSize,
8999 kSize> BodyDescriptor;
9002 DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
9006 class PropertyCell : public HeapObject {
9008 // [property_details]: details of the global property.
9009 DECL_ACCESSORS(property_details_raw, Object)
9010 // [value]: value of the global property.
9011 DECL_ACCESSORS(value, Object)
9012 // [dependent_code]: dependent code that depends on the type of the global
9014 DECL_ACCESSORS(dependent_code, DependentCode)
9016 inline PropertyDetails property_details();
9017 inline void set_property_details(PropertyDetails details);
9019 PropertyCellConstantType GetConstantType();
9021 // Computes the new type of the cell's contents for the given value, but
9022 // without actually modifying the details.
9023 static PropertyCellType UpdatedType(Handle<PropertyCell> cell,
9024 Handle<Object> value,
9025 PropertyDetails details);
9026 static void UpdateCell(Handle<GlobalDictionary> dictionary, int entry,
9027 Handle<Object> value, PropertyDetails details);
9029 static Handle<PropertyCell> InvalidateEntry(
9030 Handle<GlobalDictionary> dictionary, int entry);
9032 static void SetValueWithInvalidation(Handle<PropertyCell> cell,
9033 Handle<Object> new_value);
9035 DECLARE_CAST(PropertyCell)
9037 // Dispatched behavior.
9038 DECLARE_PRINTER(PropertyCell)
9039 DECLARE_VERIFIER(PropertyCell)
9041 // Layout description.
9042 static const int kDetailsOffset = HeapObject::kHeaderSize;
9043 static const int kValueOffset = kDetailsOffset + kPointerSize;
9044 static const int kDependentCodeOffset = kValueOffset + kPointerSize;
9045 static const int kSize = kDependentCodeOffset + kPointerSize;
9047 static const int kPointerFieldsBeginOffset = kValueOffset;
9048 static const int kPointerFieldsEndOffset = kSize;
9050 typedef FixedBodyDescriptor<kValueOffset,
9052 kSize> BodyDescriptor;
9055 DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
9059 class WeakCell : public HeapObject {
9061 inline Object* value() const;
9063 // This should not be called by anyone except GC.
9064 inline void clear();
9066 // This should not be called by anyone except allocator.
9067 inline void initialize(HeapObject* value);
9069 inline bool cleared() const;
9071 DECL_ACCESSORS(next, Object)
9073 inline void clear_next(Heap* heap);
9075 inline bool next_cleared();
9077 DECLARE_CAST(WeakCell)
9079 DECLARE_PRINTER(WeakCell)
9080 DECLARE_VERIFIER(WeakCell)
9082 // Layout description.
9083 static const int kValueOffset = HeapObject::kHeaderSize;
9084 static const int kNextOffset = kValueOffset + kPointerSize;
9085 static const int kSize = kNextOffset + kPointerSize;
9087 typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor;
9090 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCell);
9094 // The JSProxy describes EcmaScript Harmony proxies
9095 class JSProxy: public JSReceiver {
9097 // [handler]: The handler property.
9098 DECL_ACCESSORS(handler, Object)
9100 // [hash]: The hash code property (undefined if not initialized yet).
9101 DECL_ACCESSORS(hash, Object)
9103 DECLARE_CAST(JSProxy)
9105 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithHandler(
9106 Handle<JSProxy> proxy,
9107 Handle<Object> receiver,
9110 // If the handler defines an accessor property with a setter, invoke it.
9111 // If it defines an accessor property without a setter, or a data property
9112 // that is read-only, throw. In all these cases set '*done' to true,
9113 // otherwise set it to false.
9115 static MaybeHandle<Object> SetPropertyViaPrototypesWithHandler(
9116 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9117 Handle<Object> value, LanguageMode language_mode, bool* done);
9119 MUST_USE_RESULT static Maybe<PropertyAttributes>
9120 GetPropertyAttributesWithHandler(Handle<JSProxy> proxy,
9121 Handle<Object> receiver,
9123 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithHandler(
9124 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9125 Handle<Object> value, LanguageMode language_mode);
9127 // Turn the proxy into an (empty) JSObject.
9128 static void Fix(Handle<JSProxy> proxy);
9130 // Initializes the body after the handler slot.
9131 inline void InitializeBody(int object_size, Object* value);
9133 // Invoke a trap by name. If the trap does not exist on this's handler,
9134 // but derived_trap is non-NULL, invoke that instead. May cause GC.
9135 MUST_USE_RESULT static MaybeHandle<Object> CallTrap(
9136 Handle<JSProxy> proxy,
9138 Handle<Object> derived_trap,
9140 Handle<Object> args[]);
9142 // Dispatched behavior.
9143 DECLARE_PRINTER(JSProxy)
9144 DECLARE_VERIFIER(JSProxy)
9146 // Layout description. We add padding so that a proxy has the same
9147 // size as a virgin JSObject. This is essential for becoming a JSObject
9149 static const int kHandlerOffset = HeapObject::kHeaderSize;
9150 static const int kHashOffset = kHandlerOffset + kPointerSize;
9151 static const int kPaddingOffset = kHashOffset + kPointerSize;
9152 static const int kSize = JSObject::kHeaderSize;
9153 static const int kHeaderSize = kPaddingOffset;
9154 static const int kPaddingSize = kSize - kPaddingOffset;
9156 STATIC_ASSERT(kPaddingSize >= 0);
9158 typedef FixedBodyDescriptor<kHandlerOffset,
9160 kSize> BodyDescriptor;
9163 friend class JSReceiver;
9165 MUST_USE_RESULT static Maybe<bool> HasPropertyWithHandler(
9166 Handle<JSProxy> proxy, Handle<Name> name);
9168 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithHandler(
9169 Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode);
9171 MUST_USE_RESULT Object* GetIdentityHash();
9173 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy);
9175 DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy);
9179 class JSFunctionProxy: public JSProxy {
9181 // [call_trap]: The call trap.
9182 DECL_ACCESSORS(call_trap, Object)
9184 // [construct_trap]: The construct trap.
9185 DECL_ACCESSORS(construct_trap, Object)
9187 DECLARE_CAST(JSFunctionProxy)
9189 // Dispatched behavior.
9190 DECLARE_PRINTER(JSFunctionProxy)
9191 DECLARE_VERIFIER(JSFunctionProxy)
9193 // Layout description.
9194 static const int kCallTrapOffset = JSProxy::kPaddingOffset;
9195 static const int kConstructTrapOffset = kCallTrapOffset + kPointerSize;
9196 static const int kPaddingOffset = kConstructTrapOffset + kPointerSize;
9197 static const int kSize = JSFunction::kSize;
9198 static const int kPaddingSize = kSize - kPaddingOffset;
9200 STATIC_ASSERT(kPaddingSize >= 0);
9202 typedef FixedBodyDescriptor<kHandlerOffset,
9203 kConstructTrapOffset + kPointerSize,
9204 kSize> BodyDescriptor;
9207 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunctionProxy);
9211 class JSCollection : public JSObject {
9213 // [table]: the backing hash table
9214 DECL_ACCESSORS(table, Object)
9216 static const int kTableOffset = JSObject::kHeaderSize;
9217 static const int kSize = kTableOffset + kPointerSize;
9220 DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollection);
9224 // The JSSet describes EcmaScript Harmony sets
9225 class JSSet : public JSCollection {
9229 // Dispatched behavior.
9230 DECLARE_PRINTER(JSSet)
9231 DECLARE_VERIFIER(JSSet)
9234 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet);
9238 // The JSMap describes EcmaScript Harmony maps
9239 class JSMap : public JSCollection {
9243 // Dispatched behavior.
9244 DECLARE_PRINTER(JSMap)
9245 DECLARE_VERIFIER(JSMap)
9248 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
9252 // OrderedHashTableIterator is an iterator that iterates over the keys and
9253 // values of an OrderedHashTable.
9255 // The iterator has a reference to the underlying OrderedHashTable data,
9256 // [table], as well as the current [index] the iterator is at.
9258 // When the OrderedHashTable is rehashed it adds a reference from the old table
9259 // to the new table as well as storing enough data about the changes so that the
9260 // iterator [index] can be adjusted accordingly.
9262 // When the [Next] result from the iterator is requested, the iterator checks if
9263 // there is a newer table that it needs to transition to.
9264 template<class Derived, class TableType>
9265 class OrderedHashTableIterator: public JSObject {
9267 // [table]: the backing hash table mapping keys to values.
9268 DECL_ACCESSORS(table, Object)
9270 // [index]: The index into the data table.
9271 DECL_ACCESSORS(index, Object)
9273 // [kind]: The kind of iteration this is. One of the [Kind] enum values.
9274 DECL_ACCESSORS(kind, Object)
9277 void OrderedHashTableIteratorPrint(std::ostream& os); // NOLINT
9280 static const int kTableOffset = JSObject::kHeaderSize;
9281 static const int kIndexOffset = kTableOffset + kPointerSize;
9282 static const int kKindOffset = kIndexOffset + kPointerSize;
9283 static const int kSize = kKindOffset + kPointerSize;
9291 // Whether the iterator has more elements. This needs to be called before
9292 // calling |CurrentKey| and/or |CurrentValue|.
9295 // Move the index forward one.
9297 set_index(Smi::FromInt(Smi::cast(index())->value() + 1));
9300 // Populates the array with the next key and value and then moves the iterator
9302 // This returns the |kind| or 0 if the iterator is already at the end.
9303 Smi* Next(JSArray* value_array);
9305 // Returns the current key of the iterator. This should only be called when
9306 // |HasMore| returns true.
9307 inline Object* CurrentKey();
9310 // Transitions the iterator to the non obsolete backing store. This is a NOP
9311 // if the [table] is not obsolete.
9314 DISALLOW_IMPLICIT_CONSTRUCTORS(OrderedHashTableIterator);
9318 class JSSetIterator: public OrderedHashTableIterator<JSSetIterator,
9321 // Dispatched behavior.
9322 DECLARE_PRINTER(JSSetIterator)
9323 DECLARE_VERIFIER(JSSetIterator)
9325 DECLARE_CAST(JSSetIterator)
9327 // Called by |Next| to populate the array. This allows the subclasses to
9328 // populate the array differently.
9329 inline void PopulateValueArray(FixedArray* array);
9332 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSetIterator);
9336 class JSMapIterator: public OrderedHashTableIterator<JSMapIterator,
9339 // Dispatched behavior.
9340 DECLARE_PRINTER(JSMapIterator)
9341 DECLARE_VERIFIER(JSMapIterator)
9343 DECLARE_CAST(JSMapIterator)
9345 // Called by |Next| to populate the array. This allows the subclasses to
9346 // populate the array differently.
9347 inline void PopulateValueArray(FixedArray* array);
9350 // Returns the current value of the iterator. This should only be called when
9351 // |HasMore| returns true.
9352 inline Object* CurrentValue();
9354 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMapIterator);
9358 // Base class for both JSWeakMap and JSWeakSet
9359 class JSWeakCollection: public JSObject {
9361 // [table]: the backing hash table mapping keys to values.
9362 DECL_ACCESSORS(table, Object)
9364 // [next]: linked list of encountered weak maps during GC.
9365 DECL_ACCESSORS(next, Object)
9367 static const int kTableOffset = JSObject::kHeaderSize;
9368 static const int kNextOffset = kTableOffset + kPointerSize;
9369 static const int kSize = kNextOffset + kPointerSize;
9372 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection);
9376 // The JSWeakMap describes EcmaScript Harmony weak maps
9377 class JSWeakMap: public JSWeakCollection {
9379 DECLARE_CAST(JSWeakMap)
9381 // Dispatched behavior.
9382 DECLARE_PRINTER(JSWeakMap)
9383 DECLARE_VERIFIER(JSWeakMap)
9386 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
9390 // The JSWeakSet describes EcmaScript Harmony weak sets
9391 class JSWeakSet: public JSWeakCollection {
9393 DECLARE_CAST(JSWeakSet)
9395 // Dispatched behavior.
9396 DECLARE_PRINTER(JSWeakSet)
9397 DECLARE_VERIFIER(JSWeakSet)
9400 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet);
9404 // Whether a JSArrayBuffer is a SharedArrayBuffer or not.
9405 enum class SharedFlag { kNotShared, kShared };
9408 class JSArrayBuffer: public JSObject {
9410 // [backing_store]: backing memory for this array
9411 DECL_ACCESSORS(backing_store, void)
9413 // [byte_length]: length in bytes
9414 DECL_ACCESSORS(byte_length, Object)
9416 inline uint32_t bit_field() const;
9417 inline void set_bit_field(uint32_t bits);
9419 inline bool is_external();
9420 inline void set_is_external(bool value);
9422 inline bool is_neuterable();
9423 inline void set_is_neuterable(bool value);
9425 inline bool was_neutered();
9426 inline void set_was_neutered(bool value);
9428 inline bool is_shared();
9429 inline void set_is_shared(bool value);
9431 DECLARE_CAST(JSArrayBuffer)
9435 // Dispatched behavior.
9436 DECLARE_PRINTER(JSArrayBuffer)
9437 DECLARE_VERIFIER(JSArrayBuffer)
9439 static const int kBackingStoreOffset = JSObject::kHeaderSize;
9440 static const int kByteLengthOffset = kBackingStoreOffset + kPointerSize;
9441 static const int kBitFieldSlot = kByteLengthOffset + kPointerSize;
9442 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
9443 static const int kBitFieldOffset = kBitFieldSlot;
9445 static const int kBitFieldOffset = kBitFieldSlot + kIntSize;
9447 static const int kSize = kBitFieldSlot + kPointerSize;
9449 static const int kSizeWithInternalFields =
9450 kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
9452 class IsExternal : public BitField<bool, 1, 1> {};
9453 class IsNeuterable : public BitField<bool, 2, 1> {};
9454 class WasNeutered : public BitField<bool, 3, 1> {};
9455 class IsShared : public BitField<bool, 4, 1> {};
9458 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
9462 class JSArrayBufferView: public JSObject {
9464 // [buffer]: ArrayBuffer that this typed array views.
9465 DECL_ACCESSORS(buffer, Object)
9467 // [byte_offset]: offset of typed array in bytes.
9468 DECL_ACCESSORS(byte_offset, Object)
9470 // [byte_length]: length of typed array in bytes.
9471 DECL_ACCESSORS(byte_length, Object)
9473 DECLARE_CAST(JSArrayBufferView)
9475 DECLARE_VERIFIER(JSArrayBufferView)
9477 inline bool WasNeutered() const;
9479 static const int kBufferOffset = JSObject::kHeaderSize;
9480 static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
9481 static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
9482 static const int kViewSize = kByteLengthOffset + kPointerSize;
9486 DECL_ACCESSORS(raw_byte_offset, Object)
9487 DECL_ACCESSORS(raw_byte_length, Object)
9490 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
9494 class JSTypedArray: public JSArrayBufferView {
9496 // [length]: length of typed array in elements.
9497 DECL_ACCESSORS(length, Object)
9498 inline uint32_t length_value() const;
9500 DECLARE_CAST(JSTypedArray)
9502 ExternalArrayType type();
9503 size_t element_size();
9505 Handle<JSArrayBuffer> GetBuffer();
9507 // Dispatched behavior.
9508 DECLARE_PRINTER(JSTypedArray)
9509 DECLARE_VERIFIER(JSTypedArray)
9511 static const int kLengthOffset = kViewSize + kPointerSize;
9512 static const int kSize = kLengthOffset + kPointerSize;
9514 static const int kSizeWithInternalFields =
9515 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
9518 static Handle<JSArrayBuffer> MaterializeArrayBuffer(
9519 Handle<JSTypedArray> typed_array);
9521 DECL_ACCESSORS(raw_length, Object)
9524 DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
9528 class JSDataView: public JSArrayBufferView {
9530 DECLARE_CAST(JSDataView)
9532 // Dispatched behavior.
9533 DECLARE_PRINTER(JSDataView)
9534 DECLARE_VERIFIER(JSDataView)
9536 static const int kSize = kViewSize;
9538 static const int kSizeWithInternalFields =
9539 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
9542 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
9546 // Foreign describes objects pointing from JavaScript to C structures.
9547 class Foreign: public HeapObject {
9549 // [address]: field containing the address.
9550 inline Address foreign_address();
9551 inline void set_foreign_address(Address value);
9553 DECLARE_CAST(Foreign)
9555 // Dispatched behavior.
9556 inline void ForeignIterateBody(ObjectVisitor* v);
9558 template<typename StaticVisitor>
9559 inline void ForeignIterateBody();
9561 // Dispatched behavior.
9562 DECLARE_PRINTER(Foreign)
9563 DECLARE_VERIFIER(Foreign)
9565 // Layout description.
9567 static const int kForeignAddressOffset = HeapObject::kHeaderSize;
9568 static const int kSize = kForeignAddressOffset + kPointerSize;
9570 STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
9573 DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
9577 // The JSArray describes JavaScript Arrays
9578 // Such an array can be in one of two modes:
9579 // - fast, backing storage is a FixedArray and length <= elements.length();
9580 // Please note: push and pop can be used to grow and shrink the array.
9581 // - slow, backing storage is a HashTable with numbers as keys.
9582 class JSArray: public JSObject {
9584 // [length]: The length property.
9585 DECL_ACCESSORS(length, Object)
9587 // Overload the length setter to skip write barrier when the length
9588 // is set to a smi. This matches the set function on FixedArray.
9589 inline void set_length(Smi* length);
9591 static bool HasReadOnlyLength(Handle<JSArray> array);
9592 static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index);
9593 static MaybeHandle<Object> ReadOnlyLengthError(Handle<JSArray> array);
9595 // Initialize the array with the given capacity. The function may
9596 // fail due to out-of-memory situations, but only if the requested
9597 // capacity is non-zero.
9598 static void Initialize(Handle<JSArray> array, int capacity, int length = 0);
9600 // If the JSArray has fast elements, and new_length would result in
9601 // normalization, returns true.
9602 bool SetLengthWouldNormalize(uint32_t new_length);
9603 static inline bool SetLengthWouldNormalize(Heap* heap, uint32_t new_length);
9605 // Initializes the array to a certain length.
9606 inline bool AllowsSetLength();
9608 static void SetLength(Handle<JSArray> array, uint32_t length);
9609 // Same as above but will also queue splice records if |array| is observed.
9610 static MaybeHandle<Object> ObservableSetLength(Handle<JSArray> array,
9613 // Set the content of the array to the content of storage.
9614 static inline void SetContent(Handle<JSArray> array,
9615 Handle<FixedArrayBase> storage);
9617 DECLARE_CAST(JSArray)
9619 // Dispatched behavior.
9620 DECLARE_PRINTER(JSArray)
9621 DECLARE_VERIFIER(JSArray)
9623 // Number of element slots to pre-allocate for an empty array.
9624 static const int kPreallocatedArrayElements = 4;
9626 // Layout description.
9627 static const int kLengthOffset = JSObject::kHeaderSize;
9628 static const int kSize = kLengthOffset + kPointerSize;
9631 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray);
9635 Handle<Object> CacheInitialJSArrayMaps(Handle<Context> native_context,
9636 Handle<Map> initial_map);
9639 // JSRegExpResult is just a JSArray with a specific initial map.
9640 // This initial map adds in-object properties for "index" and "input"
9641 // properties, as assigned by RegExp.prototype.exec, which allows
9642 // faster creation of RegExp exec results.
9643 // This class just holds constants used when creating the result.
9644 // After creation the result must be treated as a JSArray in all regards.
9645 class JSRegExpResult: public JSArray {
9647 // Offsets of object fields.
9648 static const int kIndexOffset = JSArray::kSize;
9649 static const int kInputOffset = kIndexOffset + kPointerSize;
9650 static const int kSize = kInputOffset + kPointerSize;
9651 // Indices of in-object properties.
9652 static const int kIndexIndex = 0;
9653 static const int kInputIndex = 1;
9655 DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
9659 class AccessorInfo: public Struct {
9661 DECL_ACCESSORS(name, Object)
9662 DECL_ACCESSORS(flag, Smi)
9663 DECL_ACCESSORS(expected_receiver_type, Object)
9665 inline bool all_can_read();
9666 inline void set_all_can_read(bool value);
9668 inline bool all_can_write();
9669 inline void set_all_can_write(bool value);
9671 inline bool is_special_data_property();
9672 inline void set_is_special_data_property(bool value);
9674 inline PropertyAttributes property_attributes();
9675 inline void set_property_attributes(PropertyAttributes attributes);
9677 // Checks whether the given receiver is compatible with this accessor.
9678 static bool IsCompatibleReceiverMap(Isolate* isolate,
9679 Handle<AccessorInfo> info,
9681 inline bool IsCompatibleReceiver(Object* receiver);
9683 DECLARE_CAST(AccessorInfo)
9685 // Dispatched behavior.
9686 DECLARE_VERIFIER(AccessorInfo)
9688 // Append all descriptors to the array that are not already there.
9689 // Return number added.
9690 static int AppendUnique(Handle<Object> descriptors,
9691 Handle<FixedArray> array,
9692 int valid_descriptors);
9694 static const int kNameOffset = HeapObject::kHeaderSize;
9695 static const int kFlagOffset = kNameOffset + kPointerSize;
9696 static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
9697 static const int kSize = kExpectedReceiverTypeOffset + kPointerSize;
9700 inline bool HasExpectedReceiverType();
9702 // Bit positions in flag.
9703 static const int kAllCanReadBit = 0;
9704 static const int kAllCanWriteBit = 1;
9705 static const int kSpecialDataProperty = 2;
9706 class AttributesField : public BitField<PropertyAttributes, 3, 3> {};
9708 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo);
9712 // An accessor must have a getter, but can have no setter.
9714 // When setting a property, V8 searches accessors in prototypes.
9715 // If an accessor was found and it does not have a setter,
9716 // the request is ignored.
9718 // If the accessor in the prototype has the READ_ONLY property attribute, then
9719 // a new value is added to the derived object when the property is set.
9720 // This shadows the accessor in the prototype.
9721 class ExecutableAccessorInfo: public AccessorInfo {
9723 DECL_ACCESSORS(getter, Object)
9724 DECL_ACCESSORS(setter, Object)
9725 DECL_ACCESSORS(data, Object)
9727 DECLARE_CAST(ExecutableAccessorInfo)
9729 // Dispatched behavior.
9730 DECLARE_PRINTER(ExecutableAccessorInfo)
9731 DECLARE_VERIFIER(ExecutableAccessorInfo)
9733 static const int kGetterOffset = AccessorInfo::kSize;
9734 static const int kSetterOffset = kGetterOffset + kPointerSize;
9735 static const int kDataOffset = kSetterOffset + kPointerSize;
9736 static const int kSize = kDataOffset + kPointerSize;
9738 static void ClearSetter(Handle<ExecutableAccessorInfo> info);
9741 DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutableAccessorInfo);
9745 // Support for JavaScript accessors: A pair of a getter and a setter. Each
9746 // accessor can either be
9747 // * a pointer to a JavaScript function or proxy: a real accessor
9748 // * undefined: considered an accessor by the spec, too, strangely enough
9749 // * the hole: an accessor which has not been set
9750 // * a pointer to a map: a transition used to ensure map sharing
9751 class AccessorPair: public Struct {
9753 DECL_ACCESSORS(getter, Object)
9754 DECL_ACCESSORS(setter, Object)
9756 DECLARE_CAST(AccessorPair)
9758 static Handle<AccessorPair> Copy(Handle<AccessorPair> pair);
9760 inline Object* get(AccessorComponent component);
9761 inline void set(AccessorComponent component, Object* value);
9763 // Note: Returns undefined instead in case of a hole.
9764 Object* GetComponent(AccessorComponent component);
9766 // Set both components, skipping arguments which are a JavaScript null.
9767 inline void SetComponents(Object* getter, Object* setter);
9769 inline bool Equals(AccessorPair* pair);
9770 inline bool Equals(Object* getter_value, Object* setter_value);
9772 inline bool ContainsAccessor();
9774 // Dispatched behavior.
9775 DECLARE_PRINTER(AccessorPair)
9776 DECLARE_VERIFIER(AccessorPair)
9778 static const int kGetterOffset = HeapObject::kHeaderSize;
9779 static const int kSetterOffset = kGetterOffset + kPointerSize;
9780 static const int kSize = kSetterOffset + kPointerSize;
9783 // Strangely enough, in addition to functions and harmony proxies, the spec
9784 // requires us to consider undefined as a kind of accessor, too:
9786 // Object.defineProperty(obj, "foo", {get: undefined});
9787 // assertTrue("foo" in obj);
9788 inline bool IsJSAccessor(Object* obj);
9790 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
9794 class AccessCheckInfo: public Struct {
9796 DECL_ACCESSORS(named_callback, Object)
9797 DECL_ACCESSORS(indexed_callback, Object)
9798 DECL_ACCESSORS(data, Object)
9800 DECLARE_CAST(AccessCheckInfo)
9802 // Dispatched behavior.
9803 DECLARE_PRINTER(AccessCheckInfo)
9804 DECLARE_VERIFIER(AccessCheckInfo)
9806 static const int kNamedCallbackOffset = HeapObject::kHeaderSize;
9807 static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize;
9808 static const int kDataOffset = kIndexedCallbackOffset + kPointerSize;
9809 static const int kSize = kDataOffset + kPointerSize;
9812 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo);
9816 class InterceptorInfo: public Struct {
9818 DECL_ACCESSORS(getter, Object)
9819 DECL_ACCESSORS(setter, Object)
9820 DECL_ACCESSORS(query, Object)
9821 DECL_ACCESSORS(deleter, Object)
9822 DECL_ACCESSORS(enumerator, Object)
9823 DECL_ACCESSORS(data, Object)
9824 DECL_BOOLEAN_ACCESSORS(can_intercept_symbols)
9825 DECL_BOOLEAN_ACCESSORS(all_can_read)
9826 DECL_BOOLEAN_ACCESSORS(non_masking)
9828 inline int flags() const;
9829 inline void set_flags(int flags);
9831 DECLARE_CAST(InterceptorInfo)
9833 // Dispatched behavior.
9834 DECLARE_PRINTER(InterceptorInfo)
9835 DECLARE_VERIFIER(InterceptorInfo)
9837 static const int kGetterOffset = HeapObject::kHeaderSize;
9838 static const int kSetterOffset = kGetterOffset + kPointerSize;
9839 static const int kQueryOffset = kSetterOffset + kPointerSize;
9840 static const int kDeleterOffset = kQueryOffset + kPointerSize;
9841 static const int kEnumeratorOffset = kDeleterOffset + kPointerSize;
9842 static const int kDataOffset = kEnumeratorOffset + kPointerSize;
9843 static const int kFlagsOffset = kDataOffset + kPointerSize;
9844 static const int kSize = kFlagsOffset + kPointerSize;
9846 static const int kCanInterceptSymbolsBit = 0;
9847 static const int kAllCanReadBit = 1;
9848 static const int kNonMasking = 2;
9851 DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo);
9855 class CallHandlerInfo: public Struct {
9857 DECL_ACCESSORS(callback, Object)
9858 DECL_ACCESSORS(data, Object)
9860 DECLARE_CAST(CallHandlerInfo)
9862 // Dispatched behavior.
9863 DECLARE_PRINTER(CallHandlerInfo)
9864 DECLARE_VERIFIER(CallHandlerInfo)
9866 static const int kCallbackOffset = HeapObject::kHeaderSize;
9867 static const int kDataOffset = kCallbackOffset + kPointerSize;
9868 static const int kSize = kDataOffset + kPointerSize;
9871 DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo);
9875 class TemplateInfo: public Struct {
9877 DECL_ACCESSORS(tag, Object)
9878 inline int number_of_properties() const;
9879 inline void set_number_of_properties(int value);
9880 DECL_ACCESSORS(property_list, Object)
9881 DECL_ACCESSORS(property_accessors, Object)
9883 DECLARE_VERIFIER(TemplateInfo)
9885 static const int kTagOffset = HeapObject::kHeaderSize;
9886 static const int kNumberOfProperties = kTagOffset + kPointerSize;
9887 static const int kPropertyListOffset = kNumberOfProperties + kPointerSize;
9888 static const int kPropertyAccessorsOffset =
9889 kPropertyListOffset + kPointerSize;
9890 static const int kHeaderSize = kPropertyAccessorsOffset + kPointerSize;
9893 DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo);
9897 class FunctionTemplateInfo: public TemplateInfo {
9899 DECL_ACCESSORS(serial_number, Object)
9900 DECL_ACCESSORS(call_code, Object)
9901 DECL_ACCESSORS(prototype_template, Object)
9902 DECL_ACCESSORS(parent_template, Object)
9903 DECL_ACCESSORS(named_property_handler, Object)
9904 DECL_ACCESSORS(indexed_property_handler, Object)
9905 DECL_ACCESSORS(instance_template, Object)
9906 DECL_ACCESSORS(class_name, Object)
9907 DECL_ACCESSORS(signature, Object)
9908 DECL_ACCESSORS(instance_call_handler, Object)
9909 DECL_ACCESSORS(access_check_info, Object)
9910 DECL_ACCESSORS(flag, Smi)
9912 inline int length() const;
9913 inline void set_length(int value);
9915 // Following properties use flag bits.
9916 DECL_BOOLEAN_ACCESSORS(hidden_prototype)
9917 DECL_BOOLEAN_ACCESSORS(undetectable)
9918 // If the bit is set, object instances created by this function
9919 // requires access check.
9920 DECL_BOOLEAN_ACCESSORS(needs_access_check)
9921 DECL_BOOLEAN_ACCESSORS(read_only_prototype)
9922 DECL_BOOLEAN_ACCESSORS(remove_prototype)
9923 DECL_BOOLEAN_ACCESSORS(do_not_cache)
9924 DECL_BOOLEAN_ACCESSORS(instantiated)
9925 DECL_BOOLEAN_ACCESSORS(accept_any_receiver)
9927 DECLARE_CAST(FunctionTemplateInfo)
9929 // Dispatched behavior.
9930 DECLARE_PRINTER(FunctionTemplateInfo)
9931 DECLARE_VERIFIER(FunctionTemplateInfo)
9933 static const int kSerialNumberOffset = TemplateInfo::kHeaderSize;
9934 static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize;
9935 static const int kPrototypeTemplateOffset =
9936 kCallCodeOffset + kPointerSize;
9937 static const int kParentTemplateOffset =
9938 kPrototypeTemplateOffset + kPointerSize;
9939 static const int kNamedPropertyHandlerOffset =
9940 kParentTemplateOffset + kPointerSize;
9941 static const int kIndexedPropertyHandlerOffset =
9942 kNamedPropertyHandlerOffset + kPointerSize;
9943 static const int kInstanceTemplateOffset =
9944 kIndexedPropertyHandlerOffset + kPointerSize;
9945 static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize;
9946 static const int kSignatureOffset = kClassNameOffset + kPointerSize;
9947 static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize;
9948 static const int kAccessCheckInfoOffset =
9949 kInstanceCallHandlerOffset + kPointerSize;
9950 static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize;
9951 static const int kLengthOffset = kFlagOffset + kPointerSize;
9952 static const int kSize = kLengthOffset + kPointerSize;
9954 // Returns true if |object| is an instance of this function template.
9955 bool IsTemplateFor(Object* object);
9956 bool IsTemplateFor(Map* map);
9958 // Returns the holder JSObject if the function can legally be called with this
9959 // receiver. Returns Heap::null_value() if the call is illegal.
9960 Object* GetCompatibleReceiver(Isolate* isolate, Object* receiver);
9963 // Bit position in the flag, from least significant bit position.
9964 static const int kHiddenPrototypeBit = 0;
9965 static const int kUndetectableBit = 1;
9966 static const int kNeedsAccessCheckBit = 2;
9967 static const int kReadOnlyPrototypeBit = 3;
9968 static const int kRemovePrototypeBit = 4;
9969 static const int kDoNotCacheBit = 5;
9970 static const int kInstantiatedBit = 6;
9971 static const int kAcceptAnyReceiver = 7;
9973 DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo);
9977 class ObjectTemplateInfo: public TemplateInfo {
9979 DECL_ACCESSORS(constructor, Object)
9980 DECL_ACCESSORS(internal_field_count, Object)
9982 DECLARE_CAST(ObjectTemplateInfo)
9984 // Dispatched behavior.
9985 DECLARE_PRINTER(ObjectTemplateInfo)
9986 DECLARE_VERIFIER(ObjectTemplateInfo)
9988 static const int kConstructorOffset = TemplateInfo::kHeaderSize;
9989 static const int kInternalFieldCountOffset =
9990 kConstructorOffset + kPointerSize;
9991 static const int kSize = kInternalFieldCountOffset + kPointerSize;
9995 class TypeSwitchInfo: public Struct {
9997 DECL_ACCESSORS(types, Object)
9999 DECLARE_CAST(TypeSwitchInfo)
10001 // Dispatched behavior.
10002 DECLARE_PRINTER(TypeSwitchInfo)
10003 DECLARE_VERIFIER(TypeSwitchInfo)
10005 static const int kTypesOffset = Struct::kHeaderSize;
10006 static const int kSize = kTypesOffset + kPointerSize;
10010 // The DebugInfo class holds additional information for a function being
10012 class DebugInfo: public Struct {
10014 // The shared function info for the source being debugged.
10015 DECL_ACCESSORS(shared, SharedFunctionInfo)
10016 // Code object for the patched code. This code object is the code object
10017 // currently active for the function.
10018 DECL_ACCESSORS(code, Code)
10019 // Fixed array holding status information for each active break point.
10020 DECL_ACCESSORS(break_points, FixedArray)
10022 // Check if there is a break point at a code position.
10023 bool HasBreakPoint(int code_position);
10024 // Get the break point info object for a code position.
10025 Object* GetBreakPointInfo(int code_position);
10026 // Clear a break point.
10027 static void ClearBreakPoint(Handle<DebugInfo> debug_info,
10029 Handle<Object> break_point_object);
10030 // Set a break point.
10031 static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position,
10032 int source_position, int statement_position,
10033 Handle<Object> break_point_object);
10034 // Get the break point objects for a code position.
10035 Handle<Object> GetBreakPointObjects(int code_position);
10036 // Find the break point info holding this break point object.
10037 static Handle<Object> FindBreakPointInfo(Handle<DebugInfo> debug_info,
10038 Handle<Object> break_point_object);
10039 // Get the number of break points for this function.
10040 int GetBreakPointCount();
10042 DECLARE_CAST(DebugInfo)
10044 // Dispatched behavior.
10045 DECLARE_PRINTER(DebugInfo)
10046 DECLARE_VERIFIER(DebugInfo)
10048 static const int kSharedFunctionInfoIndex = Struct::kHeaderSize;
10049 static const int kCodeIndex = kSharedFunctionInfoIndex + kPointerSize;
10050 static const int kBreakPointsStateIndex = kCodeIndex + kPointerSize;
10051 static const int kSize = kBreakPointsStateIndex + kPointerSize;
10053 static const int kEstimatedNofBreakPointsInFunction = 16;
10056 static const int kNoBreakPointInfo = -1;
10058 // Lookup the index in the break_points array for a code position.
10059 int GetBreakPointInfoIndex(int code_position);
10061 DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo);
10065 // The BreakPointInfo class holds information for break points set in a
10066 // function. The DebugInfo object holds a BreakPointInfo object for each code
10067 // position with one or more break points.
10068 class BreakPointInfo: public Struct {
10070 // The position in the code for the break point.
10071 DECL_ACCESSORS(code_position, Smi)
10072 // The position in the source for the break position.
10073 DECL_ACCESSORS(source_position, Smi)
10074 // The position in the source for the last statement before this break
10076 DECL_ACCESSORS(statement_position, Smi)
10077 // List of related JavaScript break points.
10078 DECL_ACCESSORS(break_point_objects, Object)
10080 // Removes a break point.
10081 static void ClearBreakPoint(Handle<BreakPointInfo> info,
10082 Handle<Object> break_point_object);
10083 // Set a break point.
10084 static void SetBreakPoint(Handle<BreakPointInfo> info,
10085 Handle<Object> break_point_object);
10086 // Check if break point info has this break point object.
10087 static bool HasBreakPointObject(Handle<BreakPointInfo> info,
10088 Handle<Object> break_point_object);
10089 // Get the number of break points for this code position.
10090 int GetBreakPointCount();
10092 DECLARE_CAST(BreakPointInfo)
10094 // Dispatched behavior.
10095 DECLARE_PRINTER(BreakPointInfo)
10096 DECLARE_VERIFIER(BreakPointInfo)
10098 static const int kCodePositionIndex = Struct::kHeaderSize;
10099 static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize;
10100 static const int kStatementPositionIndex =
10101 kSourcePositionIndex + kPointerSize;
10102 static const int kBreakPointObjectsIndex =
10103 kStatementPositionIndex + kPointerSize;
10104 static const int kSize = kBreakPointObjectsIndex + kPointerSize;
10107 DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo);
10111 #undef DECL_BOOLEAN_ACCESSORS
10112 #undef DECL_ACCESSORS
10113 #undef DECLARE_CAST
10114 #undef DECLARE_VERIFIER
10116 #define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \
10117 V(kStringTable, "string_table", "(Internalized strings)") \
10118 V(kExternalStringsTable, "external_strings_table", "(External strings)") \
10119 V(kStrongRootList, "strong_root_list", "(Strong roots)") \
10120 V(kSmiRootList, "smi_root_list", "(Smi roots)") \
10121 V(kInternalizedString, "internalized_string", "(Internal string)") \
10122 V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \
10123 V(kTop, "top", "(Isolate)") \
10124 V(kRelocatable, "relocatable", "(Relocatable)") \
10125 V(kDebug, "debug", "(Debugger)") \
10126 V(kCompilationCache, "compilationcache", "(Compilation cache)") \
10127 V(kHandleScope, "handlescope", "(Handle scope)") \
10128 V(kBuiltins, "builtins", "(Builtins)") \
10129 V(kGlobalHandles, "globalhandles", "(Global handles)") \
10130 V(kEternalHandles, "eternalhandles", "(Eternal handles)") \
10131 V(kThreadManager, "threadmanager", "(Thread manager)") \
10132 V(kStrongRoots, "strong roots", "(Strong roots)") \
10133 V(kExtensions, "Extensions", "(Extensions)")
10135 class VisitorSynchronization : public AllStatic {
10137 #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item,
10139 VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM)
10142 #undef DECLARE_ENUM
10144 static const char* const kTags[kNumberOfSyncTags];
10145 static const char* const kTagNames[kNumberOfSyncTags];
10148 // Abstract base class for visiting, and optionally modifying, the
10149 // pointers contained in Objects. Used in GC and serialization/deserialization.
10150 class ObjectVisitor BASE_EMBEDDED {
10152 virtual ~ObjectVisitor() {}
10154 // Visits a contiguous arrays of pointers in the half-open range
10155 // [start, end). Any or all of the values may be modified on return.
10156 virtual void VisitPointers(Object** start, Object** end) = 0;
10158 // Handy shorthand for visiting a single pointer.
10159 virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
10161 // Visit weak next_code_link in Code object.
10162 virtual void VisitNextCodeLink(Object** p) { VisitPointers(p, p + 1); }
10164 // To allow lazy clearing of inline caches the visitor has
10165 // a rich interface for iterating over Code objects..
10167 // Visits a code target in the instruction stream.
10168 virtual void VisitCodeTarget(RelocInfo* rinfo);
10170 // Visits a code entry in a JS function.
10171 virtual void VisitCodeEntry(Address entry_address);
10173 // Visits a global property cell reference in the instruction stream.
10174 virtual void VisitCell(RelocInfo* rinfo);
10176 // Visits a runtime entry in the instruction stream.
10177 virtual void VisitRuntimeEntry(RelocInfo* rinfo) {}
10179 // Visits the resource of an one-byte or two-byte string.
10180 virtual void VisitExternalOneByteString(
10181 v8::String::ExternalOneByteStringResource** resource) {}
10182 virtual void VisitExternalTwoByteString(
10183 v8::String::ExternalStringResource** resource) {}
10185 // Visits a debug call target in the instruction stream.
10186 virtual void VisitDebugTarget(RelocInfo* rinfo);
10188 // Visits the byte sequence in a function's prologue that contains information
10189 // about the code's age.
10190 virtual void VisitCodeAgeSequence(RelocInfo* rinfo);
10192 // Visit pointer embedded into a code object.
10193 virtual void VisitEmbeddedPointer(RelocInfo* rinfo);
10195 // Visits an external reference embedded into a code object.
10196 virtual void VisitExternalReference(RelocInfo* rinfo);
10198 // Visits an external reference.
10199 virtual void VisitExternalReference(Address* p) {}
10201 // Visits an (encoded) internal reference.
10202 virtual void VisitInternalReference(RelocInfo* rinfo) {}
10204 // Visits a handle that has an embedder-assigned class ID.
10205 virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {}
10207 // Intended for serialization/deserialization checking: insert, or
10208 // check for the presence of, a tag at this position in the stream.
10209 // Also used for marking up GC roots in heap snapshots.
10210 virtual void Synchronize(VisitorSynchronization::SyncTag tag) {}
10214 class StructBodyDescriptor : public
10215 FlexibleBodyDescriptor<HeapObject::kHeaderSize> {
10217 static inline int SizeOf(Map* map, HeapObject* object);
10221 // BooleanBit is a helper class for setting and getting a bit in an
10223 class BooleanBit : public AllStatic {
10225 static inline bool get(Smi* smi, int bit_position) {
10226 return get(smi->value(), bit_position);
10229 static inline bool get(int value, int bit_position) {
10230 return (value & (1 << bit_position)) != 0;
10233 static inline Smi* set(Smi* smi, int bit_position, bool v) {
10234 return Smi::FromInt(set(smi->value(), bit_position, v));
10237 static inline int set(int value, int bit_position, bool v) {
10239 value |= (1 << bit_position);
10241 value &= ~(1 << bit_position);
10247 } } // namespace v8::internal
10249 #endif // V8_OBJECTS_H_