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.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_TO_OBJECT,
159 STORE_TRANSITION_TO_DOUBLE,
160 STORE_AND_GROW_NO_TRANSITION,
161 STORE_AND_GROW_TRANSITION_TO_OBJECT,
162 STORE_AND_GROW_TRANSITION_TO_DOUBLE,
163 STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS,
164 STORE_NO_TRANSITION_HANDLE_COW
168 enum TypeofMode { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
177 enum ExternalArrayType {
178 kExternalInt8Array = 1,
181 kExternalUint16Array,
183 kExternalUint32Array,
184 kExternalFloat32Array,
185 kExternalFloat64Array,
186 kExternalUint8ClampedArray,
190 static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) {
191 return store_mode == STORE_TRANSITION_TO_OBJECT ||
192 store_mode == STORE_TRANSITION_TO_DOUBLE ||
193 store_mode == STORE_AND_GROW_TRANSITION_TO_OBJECT ||
194 store_mode == STORE_AND_GROW_TRANSITION_TO_DOUBLE;
198 static inline KeyedAccessStoreMode GetNonTransitioningStoreMode(
199 KeyedAccessStoreMode store_mode) {
200 if (store_mode >= STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
203 if (store_mode >= STORE_AND_GROW_NO_TRANSITION) {
204 return STORE_AND_GROW_NO_TRANSITION;
206 return STANDARD_STORE;
210 static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
211 return store_mode >= STORE_AND_GROW_NO_TRANSITION &&
212 store_mode <= STORE_AND_GROW_TRANSITION_TO_DOUBLE;
216 enum IcCheckType { ELEMENT, PROPERTY };
219 // SKIP_WRITE_BARRIER skips the write barrier.
220 // UPDATE_WEAK_WRITE_BARRIER skips the marking part of the write barrier and
221 // only performs the generational part.
222 // UPDATE_WRITE_BARRIER is doing the full barrier, marking and generational.
223 enum WriteBarrierMode {
225 UPDATE_WEAK_WRITE_BARRIER,
230 // Indicates whether a value can be loaded as a constant.
231 enum StoreMode { ALLOW_IN_DESCRIPTOR, FORCE_FIELD };
234 // PropertyNormalizationMode is used to specify whether to keep
235 // inobject properties when normalizing properties of a JSObject.
236 enum PropertyNormalizationMode {
237 CLEAR_INOBJECT_PROPERTIES,
238 KEEP_INOBJECT_PROPERTIES
242 // Indicates how aggressively the prototype should be optimized. FAST_PROTOTYPE
243 // will give the fastest result by tailoring the map to the prototype, but that
244 // will cause polymorphism with other objects. REGULAR_PROTOTYPE is to be used
245 // (at least for now) when dynamically modifying the prototype chain of an
246 // object using __proto__ or Object.setPrototypeOf.
247 enum PrototypeOptimizationMode { REGULAR_PROTOTYPE, FAST_PROTOTYPE };
250 // Indicates whether transitions can be added to a source map or not.
251 enum TransitionFlag {
257 // Indicates whether the transition is simple: the target map of the transition
258 // either extends the current map with a new property, or it modifies the
259 // property that was added last to the current map.
260 enum SimpleTransitionFlag {
261 SIMPLE_PROPERTY_TRANSITION,
267 // Indicates whether we are only interested in the descriptors of a particular
268 // map, or in all descriptors in the descriptor array.
269 enum DescriptorFlag {
274 // The GC maintains a bit of information, the MarkingParity, which toggles
275 // from odd to even and back every time marking is completed. Incremental
276 // marking can visit an object twice during a marking phase, so algorithms that
277 // that piggy-back on marking can use the parity to ensure that they only
278 // perform an operation on an object once per marking phase: they record the
279 // MarkingParity when they visit an object, and only re-visit the object when it
280 // is marked again and the MarkingParity changes.
287 // ICs store extra state in a Code object. The default extra state is
289 typedef int ExtraICState;
290 static const ExtraICState kNoExtraICState = 0;
292 // Instance size sentinel for objects of variable size.
293 const int kVariableSizeSentinel = 0;
295 // We may store the unsigned bit field as signed Smi value and do not
297 const int kStubMajorKeyBits = 7;
298 const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
300 // All Maps have a field instance_type containing a InstanceType.
301 // It describes the type of the instances.
303 // As an example, a JavaScript object is a heap object and its map
304 // instance_type is JS_OBJECT_TYPE.
306 // The names of the string instance types are intended to systematically
307 // mirror their encoding in the instance_type field of the map. The default
308 // encoding is considered TWO_BYTE. It is not mentioned in the name. ONE_BYTE
309 // encoding is mentioned explicitly in the name. Likewise, the default
310 // representation is considered sequential. It is not mentioned in the
311 // name. The other representations (e.g. CONS, EXTERNAL) are explicitly
312 // mentioned. Finally, the string is either a STRING_TYPE (if it is a normal
313 // string) or a INTERNALIZED_STRING_TYPE (if it is a internalized string).
315 // NOTE: The following things are some that depend on the string types having
316 // instance_types that are less than those of all other types:
317 // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and
320 // NOTE: Everything following JS_VALUE_TYPE is considered a
321 // JSObject for GC purposes. The first four entries here have typeof
322 // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'.
323 #define INSTANCE_TYPE_LIST(V) \
325 V(ONE_BYTE_STRING_TYPE) \
326 V(CONS_STRING_TYPE) \
327 V(CONS_ONE_BYTE_STRING_TYPE) \
328 V(SLICED_STRING_TYPE) \
329 V(SLICED_ONE_BYTE_STRING_TYPE) \
330 V(EXTERNAL_STRING_TYPE) \
331 V(EXTERNAL_ONE_BYTE_STRING_TYPE) \
332 V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
333 V(SHORT_EXTERNAL_STRING_TYPE) \
334 V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE) \
335 V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
337 V(INTERNALIZED_STRING_TYPE) \
338 V(ONE_BYTE_INTERNALIZED_STRING_TYPE) \
339 V(EXTERNAL_INTERNALIZED_STRING_TYPE) \
340 V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
341 V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
342 V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE) \
343 V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
344 V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
347 V(SIMD128_VALUE_TYPE) \
353 V(PROPERTY_CELL_TYPE) \
355 V(HEAP_NUMBER_TYPE) \
356 V(MUTABLE_HEAP_NUMBER_TYPE) \
359 V(BYTECODE_ARRAY_TYPE) \
362 V(FIXED_INT8_ARRAY_TYPE) \
363 V(FIXED_UINT8_ARRAY_TYPE) \
364 V(FIXED_INT16_ARRAY_TYPE) \
365 V(FIXED_UINT16_ARRAY_TYPE) \
366 V(FIXED_INT32_ARRAY_TYPE) \
367 V(FIXED_UINT32_ARRAY_TYPE) \
368 V(FIXED_FLOAT32_ARRAY_TYPE) \
369 V(FIXED_FLOAT64_ARRAY_TYPE) \
370 V(FIXED_UINT8_CLAMPED_ARRAY_TYPE) \
374 V(DECLARED_ACCESSOR_DESCRIPTOR_TYPE) \
375 V(DECLARED_ACCESSOR_INFO_TYPE) \
376 V(EXECUTABLE_ACCESSOR_INFO_TYPE) \
377 V(ACCESSOR_PAIR_TYPE) \
378 V(ACCESS_CHECK_INFO_TYPE) \
379 V(INTERCEPTOR_INFO_TYPE) \
380 V(CALL_HANDLER_INFO_TYPE) \
381 V(FUNCTION_TEMPLATE_INFO_TYPE) \
382 V(OBJECT_TEMPLATE_INFO_TYPE) \
383 V(SIGNATURE_INFO_TYPE) \
384 V(TYPE_SWITCH_INFO_TYPE) \
385 V(ALLOCATION_MEMENTO_TYPE) \
386 V(ALLOCATION_SITE_TYPE) \
389 V(POLYMORPHIC_CODE_CACHE_TYPE) \
390 V(TYPE_FEEDBACK_INFO_TYPE) \
391 V(ALIASED_ARGUMENTS_ENTRY_TYPE) \
393 V(PROTOTYPE_INFO_TYPE) \
395 V(FIXED_ARRAY_TYPE) \
396 V(FIXED_DOUBLE_ARRAY_TYPE) \
397 V(SHARED_FUNCTION_INFO_TYPE) \
400 V(JS_MESSAGE_OBJECT_TYPE) \
405 V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \
406 V(JS_GENERATOR_OBJECT_TYPE) \
408 V(JS_GLOBAL_OBJECT_TYPE) \
409 V(JS_BUILTINS_OBJECT_TYPE) \
410 V(JS_GLOBAL_PROXY_TYPE) \
412 V(JS_ARRAY_BUFFER_TYPE) \
413 V(JS_TYPED_ARRAY_TYPE) \
414 V(JS_DATA_VIEW_TYPE) \
418 V(JS_SET_ITERATOR_TYPE) \
419 V(JS_MAP_ITERATOR_TYPE) \
420 V(JS_WEAK_MAP_TYPE) \
421 V(JS_WEAK_SET_TYPE) \
424 V(JS_FUNCTION_TYPE) \
425 V(JS_FUNCTION_PROXY_TYPE) \
427 V(BREAK_POINT_INFO_TYPE)
430 // Since string types are not consecutive, this macro is used to
431 // iterate over them.
432 #define STRING_TYPE_LIST(V) \
433 V(STRING_TYPE, kVariableSizeSentinel, string, String) \
434 V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string, \
436 V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString) \
437 V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string, \
439 V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString) \
440 V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string, \
441 SlicedOneByteString) \
442 V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string, \
444 V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize, \
445 external_one_byte_string, ExternalOneByteString) \
446 V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize, \
447 external_string_with_one_byte_data, ExternalStringWithOneByteData) \
448 V(SHORT_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kShortSize, \
449 short_external_string, ShortExternalString) \
450 V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kShortSize, \
451 short_external_one_byte_string, ShortExternalOneByteString) \
452 V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, \
453 ExternalTwoByteString::kShortSize, \
454 short_external_string_with_one_byte_data, \
455 ShortExternalStringWithOneByteData) \
457 V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string, \
458 InternalizedString) \
459 V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, \
460 one_byte_internalized_string, OneByteInternalizedString) \
461 V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize, \
462 external_internalized_string, ExternalInternalizedString) \
463 V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize, \
464 external_one_byte_internalized_string, ExternalOneByteInternalizedString) \
465 V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
466 ExternalTwoByteString::kSize, \
467 external_internalized_string_with_one_byte_data, \
468 ExternalInternalizedStringWithOneByteData) \
469 V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE, \
470 ExternalTwoByteString::kShortSize, short_external_internalized_string, \
471 ShortExternalInternalizedString) \
472 V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, \
473 ExternalOneByteString::kShortSize, \
474 short_external_one_byte_internalized_string, \
475 ShortExternalOneByteInternalizedString) \
476 V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
477 ExternalTwoByteString::kShortSize, \
478 short_external_internalized_string_with_one_byte_data, \
479 ShortExternalInternalizedStringWithOneByteData)
481 // A struct is a simple object a set of object-valued fields. Including an
482 // object type in this causes the compiler to generate most of the boilerplate
483 // code for the class including allocation and garbage collection routines,
484 // casts and predicates. All you need to define is the class, methods and
485 // object verification routines. Easy, no?
487 // Note that for subtle reasons related to the ordering or numerical values of
488 // type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST
490 #define STRUCT_LIST(V) \
492 V(EXECUTABLE_ACCESSOR_INFO, ExecutableAccessorInfo, \
493 executable_accessor_info) \
494 V(ACCESSOR_PAIR, AccessorPair, accessor_pair) \
495 V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \
496 V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \
497 V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \
498 V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \
499 V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \
500 V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info) \
501 V(SCRIPT, Script, script) \
502 V(ALLOCATION_SITE, AllocationSite, allocation_site) \
503 V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento) \
504 V(CODE_CACHE, CodeCache, code_cache) \
505 V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) \
506 V(TYPE_FEEDBACK_INFO, TypeFeedbackInfo, type_feedback_info) \
507 V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \
508 V(DEBUG_INFO, DebugInfo, debug_info) \
509 V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) \
510 V(PROTOTYPE_INFO, PrototypeInfo, prototype_info)
512 // We use the full 8 bits of the instance_type field to encode heap object
513 // instance types. The high-order bit (bit 7) is set if the object is not a
514 // string, and cleared if it is a string.
515 const uint32_t kIsNotStringMask = 0x80;
516 const uint32_t kStringTag = 0x0;
517 const uint32_t kNotStringTag = 0x80;
519 // Bit 6 indicates that the object is an internalized string (if set) or not.
520 // Bit 7 has to be clear as well.
521 const uint32_t kIsNotInternalizedMask = 0x40;
522 const uint32_t kNotInternalizedTag = 0x40;
523 const uint32_t kInternalizedTag = 0x0;
525 // If bit 7 is clear then bit 2 indicates whether the string consists of
526 // two-byte characters or one-byte characters.
527 const uint32_t kStringEncodingMask = 0x4;
528 const uint32_t kTwoByteStringTag = 0x0;
529 const uint32_t kOneByteStringTag = 0x4;
531 // If bit 7 is clear, the low-order 2 bits indicate the representation
533 const uint32_t kStringRepresentationMask = 0x03;
534 enum StringRepresentationTag {
536 kConsStringTag = 0x1,
537 kExternalStringTag = 0x2,
538 kSlicedStringTag = 0x3
540 const uint32_t kIsIndirectStringMask = 0x1;
541 const uint32_t kIsIndirectStringTag = 0x1;
542 STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); // NOLINT
543 STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); // NOLINT
544 STATIC_ASSERT((kConsStringTag &
545 kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
546 STATIC_ASSERT((kSlicedStringTag &
547 kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
549 // Use this mask to distinguish between cons and slice only after making
550 // sure that the string is one of the two (an indirect string).
551 const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag;
552 STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask));
554 // If bit 7 is clear, then bit 3 indicates whether this two-byte
555 // string actually contains one byte data.
556 const uint32_t kOneByteDataHintMask = 0x08;
557 const uint32_t kOneByteDataHintTag = 0x08;
559 // If bit 7 is clear and string representation indicates an external string,
560 // then bit 4 indicates whether the data pointer is cached.
561 const uint32_t kShortExternalStringMask = 0x10;
562 const uint32_t kShortExternalStringTag = 0x10;
565 // A ConsString with an empty string as the right side is a candidate
566 // for being shortcut by the garbage collector. We don't allocate any
567 // non-flat internalized strings, so we do not shortcut them thereby
568 // avoiding turning internalized strings into strings. The bit-masks
569 // below contain the internalized bit as additional safety.
570 // See heap.cc, mark-compact.cc and objects-visiting.cc.
571 const uint32_t kShortcutTypeMask =
573 kIsNotInternalizedMask |
574 kStringRepresentationMask;
575 const uint32_t kShortcutTypeTag = kConsStringTag | kNotInternalizedTag;
577 static inline bool IsShortcutCandidate(int type) {
578 return ((type & kShortcutTypeMask) == kShortcutTypeTag);
584 INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kSeqStringTag |
585 kInternalizedTag, // FIRST_PRIMITIVE_TYPE
586 ONE_BYTE_INTERNALIZED_STRING_TYPE =
587 kOneByteStringTag | kSeqStringTag | kInternalizedTag,
588 EXTERNAL_INTERNALIZED_STRING_TYPE =
589 kTwoByteStringTag | kExternalStringTag | kInternalizedTag,
590 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
591 kOneByteStringTag | kExternalStringTag | kInternalizedTag,
592 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
593 EXTERNAL_INTERNALIZED_STRING_TYPE | kOneByteDataHintTag |
595 SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE |
596 kShortExternalStringTag |
598 SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
599 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kShortExternalStringTag |
601 SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
602 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
603 kShortExternalStringTag | kInternalizedTag,
604 STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
605 ONE_BYTE_STRING_TYPE =
606 ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
607 CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag | kNotInternalizedTag,
608 CONS_ONE_BYTE_STRING_TYPE =
609 kOneByteStringTag | kConsStringTag | kNotInternalizedTag,
611 kTwoByteStringTag | kSlicedStringTag | kNotInternalizedTag,
612 SLICED_ONE_BYTE_STRING_TYPE =
613 kOneByteStringTag | kSlicedStringTag | kNotInternalizedTag,
614 EXTERNAL_STRING_TYPE =
615 EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
616 EXTERNAL_ONE_BYTE_STRING_TYPE =
617 EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
618 EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
619 EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
621 SHORT_EXTERNAL_STRING_TYPE =
622 SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
623 SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE =
624 SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
625 SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
626 SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
630 SYMBOL_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE
632 // Other primitives (cannot contain non-map-word pointers to heap objects).
635 ODDBALL_TYPE, // LAST_PRIMITIVE_TYPE
637 // Objects allocated in their own spaces (never in new space).
641 // "Data", objects that cannot contain non-map-word pointers to heap
643 MUTABLE_HEAP_NUMBER_TYPE,
648 FIXED_INT8_ARRAY_TYPE, // FIRST_FIXED_TYPED_ARRAY_TYPE
649 FIXED_UINT8_ARRAY_TYPE,
650 FIXED_INT16_ARRAY_TYPE,
651 FIXED_UINT16_ARRAY_TYPE,
652 FIXED_INT32_ARRAY_TYPE,
653 FIXED_UINT32_ARRAY_TYPE,
654 FIXED_FLOAT32_ARRAY_TYPE,
655 FIXED_FLOAT64_ARRAY_TYPE,
656 FIXED_UINT8_CLAMPED_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE
657 FIXED_DOUBLE_ARRAY_TYPE,
658 FILLER_TYPE, // LAST_DATA_TYPE
661 DECLARED_ACCESSOR_DESCRIPTOR_TYPE,
662 DECLARED_ACCESSOR_INFO_TYPE,
663 EXECUTABLE_ACCESSOR_INFO_TYPE,
665 ACCESS_CHECK_INFO_TYPE,
666 INTERCEPTOR_INFO_TYPE,
667 CALL_HANDLER_INFO_TYPE,
668 FUNCTION_TEMPLATE_INFO_TYPE,
669 OBJECT_TEMPLATE_INFO_TYPE,
671 TYPE_SWITCH_INFO_TYPE,
672 ALLOCATION_SITE_TYPE,
673 ALLOCATION_MEMENTO_TYPE,
676 POLYMORPHIC_CODE_CACHE_TYPE,
677 TYPE_FEEDBACK_INFO_TYPE,
678 ALIASED_ARGUMENTS_ENTRY_TYPE,
681 BREAK_POINT_INFO_TYPE,
683 SHARED_FUNCTION_INFO_TYPE,
689 // All the following types are subtypes of JSReceiver, which corresponds to
690 // objects in the JS sense. The first and the last type in this range are
691 // the two forms of function. This organization enables using the same
692 // compares for checking the JS_RECEIVER/SPEC_OBJECT range and the
693 // NONCALLABLE_JS_OBJECT range.
694 JS_FUNCTION_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE, FIRST_JS_PROXY_TYPE
695 JS_PROXY_TYPE, // LAST_JS_PROXY_TYPE
696 JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE
697 JS_MESSAGE_OBJECT_TYPE,
700 JS_CONTEXT_EXTENSION_OBJECT_TYPE,
701 JS_GENERATOR_OBJECT_TYPE,
703 JS_GLOBAL_OBJECT_TYPE,
704 JS_BUILTINS_OBJECT_TYPE,
705 JS_GLOBAL_PROXY_TYPE,
707 JS_ARRAY_BUFFER_TYPE,
712 JS_SET_ITERATOR_TYPE,
713 JS_MAP_ITERATOR_TYPE,
717 JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
721 LAST_TYPE = JS_FUNCTION_TYPE,
722 FIRST_NAME_TYPE = FIRST_TYPE,
723 LAST_NAME_TYPE = SYMBOL_TYPE,
724 FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
725 LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
726 FIRST_NONSTRING_TYPE = SYMBOL_TYPE,
727 FIRST_PRIMITIVE_TYPE = FIRST_NAME_TYPE,
728 LAST_PRIMITIVE_TYPE = ODDBALL_TYPE,
729 // Boundaries for testing for a fixed typed array.
730 FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE,
731 LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_UINT8_CLAMPED_ARRAY_TYPE,
732 // Boundary for promotion to old space.
733 LAST_DATA_TYPE = FILLER_TYPE,
734 // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy).
735 // Note that there is no range for JSObject or JSProxy, since their subtypes
736 // are not continuous in this enum! The enum ranges instead reflect the
737 // external class names, where proxies are treated as either ordinary objects,
739 FIRST_JS_RECEIVER_TYPE = JS_FUNCTION_PROXY_TYPE,
740 LAST_JS_RECEIVER_TYPE = LAST_TYPE,
741 // Boundaries for testing the types represented as JSObject
742 FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE,
743 LAST_JS_OBJECT_TYPE = LAST_TYPE,
744 // Boundaries for testing the types represented as JSProxy
745 FIRST_JS_PROXY_TYPE = JS_FUNCTION_PROXY_TYPE,
746 LAST_JS_PROXY_TYPE = JS_PROXY_TYPE,
747 // Boundaries for testing whether the type is a JavaScript object.
748 FIRST_SPEC_OBJECT_TYPE = FIRST_JS_RECEIVER_TYPE,
749 LAST_SPEC_OBJECT_TYPE = LAST_JS_RECEIVER_TYPE,
750 // Boundaries for testing the types for which typeof is "object".
751 FIRST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_PROXY_TYPE,
752 LAST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_REGEXP_TYPE,
753 // Note that the types for which typeof is "function" are not continuous.
754 // Define this so that we can put assertions on discrete checks.
755 NUM_OF_CALLABLE_SPEC_OBJECT_TYPES = 2
758 STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
759 STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType);
760 STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType);
761 STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType);
764 #define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
765 V(FAST_ELEMENTS_SUB_TYPE) \
766 V(DICTIONARY_ELEMENTS_SUB_TYPE) \
767 V(FAST_PROPERTIES_SUB_TYPE) \
768 V(DICTIONARY_PROPERTIES_SUB_TYPE) \
769 V(MAP_CODE_CACHE_SUB_TYPE) \
770 V(SCOPE_INFO_SUB_TYPE) \
771 V(STRING_TABLE_SUB_TYPE) \
772 V(DESCRIPTOR_ARRAY_SUB_TYPE) \
773 V(TRANSITION_ARRAY_SUB_TYPE)
775 enum FixedArraySubInstanceType {
776 #define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
777 FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
778 #undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
779 LAST_FIXED_ARRAY_SUB_TYPE = TRANSITION_ARRAY_SUB_TYPE
792 #define DECL_BOOLEAN_ACCESSORS(name) \
793 inline bool name() const; \
794 inline void set_##name(bool value); \
797 #define DECL_ACCESSORS(name, type) \
798 inline type* name() const; \
799 inline void set_##name(type* value, \
800 WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \
803 #define DECLARE_CAST(type) \
804 INLINE(static type* cast(Object* object)); \
805 INLINE(static const type* cast(const Object* object));
809 class AllocationSite;
810 class AllocationSiteCreationContext;
811 class AllocationSiteUsageContext;
814 class ElementsAccessor;
815 class FixedArrayBase;
816 class FunctionLiteral;
818 class JSBuiltinsObject;
819 class LayoutDescriptor;
820 class LookupIterator;
821 class ObjectHashTable;
824 class SafepointEntry;
825 class SharedFunctionInfo;
827 class TypeFeedbackInfo;
828 class TypeFeedbackVector;
831 // We cannot just say "class HeapType;" if it is created from a template... =8-?
832 template<class> class TypeImpl;
833 struct HeapTypeConfig;
834 typedef TypeImpl<HeapTypeConfig> HeapType;
837 // A template-ized version of the IsXXX functions.
838 template <class C> inline bool Is(Object* obj);
841 #define DECLARE_VERIFIER(Name) void Name##Verify();
843 #define DECLARE_VERIFIER(Name)
847 #define DECLARE_PRINTER(Name) void Name##Print(std::ostream& os); // NOLINT
849 #define DECLARE_PRINTER(Name)
853 #define OBJECT_TYPE_LIST(V) \
858 #define HEAP_OBJECT_TYPE_LIST(V) \
860 V(MutableHeapNumber) \
876 V(ExternalTwoByteString) \
877 V(ExternalOneByteString) \
878 V(SeqTwoByteString) \
879 V(SeqOneByteString) \
880 V(InternalizedString) \
883 V(FixedTypedArrayBase) \
886 V(FixedUint16Array) \
888 V(FixedUint32Array) \
890 V(FixedFloat32Array) \
891 V(FixedFloat64Array) \
892 V(FixedUint8ClampedArray) \
898 V(JSContextExtensionObject) \
899 V(JSGeneratorObject) \
901 V(LayoutDescriptor) \
905 V(TypeFeedbackVector) \
906 V(DeoptimizationInputData) \
907 V(DeoptimizationOutputData) \
911 V(FixedDoubleArray) \
915 V(ScriptContextTable) \
921 V(SharedFunctionInfo) \
930 V(JSArrayBufferView) \
939 V(JSWeakCollection) \
946 V(NormalizedMapCache) \
947 V(CompilationCacheTable) \
948 V(CodeCacheHashTable) \
949 V(PolymorphicCodeCacheHashTable) \
954 V(JSBuiltinsObject) \
956 V(UndetectableObject) \
957 V(AccessCheckNeeded) \
965 // Object is the abstract superclass for all classes in the
967 // Object does not use any virtual functions to avoid the
968 // allocation of the C++ vtable.
969 // Since both Smi and HeapObject are subclasses of Object no
970 // data members can be present in Object.
974 bool IsObject() const { return true; }
976 #define IS_TYPE_FUNCTION_DECL(type_) INLINE(bool Is##type_() const);
977 OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
978 HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
979 #undef IS_TYPE_FUNCTION_DECL
981 // A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
982 // a keyed store is of the form a[expression] = foo.
983 enum StoreFromKeyed {
984 MAY_BE_STORE_FROM_KEYED,
985 CERTAINLY_NOT_STORE_FROM_KEYED
988 INLINE(bool IsFixedArrayBase() const);
989 INLINE(bool IsExternal() const);
990 INLINE(bool IsAccessorInfo() const);
992 INLINE(bool IsStruct() const);
993 #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \
994 INLINE(bool Is##Name() const);
995 STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
996 #undef DECLARE_STRUCT_PREDICATE
998 INLINE(bool IsSpecObject()) const;
999 INLINE(bool IsSpecFunction()) const;
1000 INLINE(bool IsTemplateInfo()) const;
1001 INLINE(bool IsNameDictionary() const);
1002 INLINE(bool IsGlobalDictionary() const);
1003 INLINE(bool IsSeededNumberDictionary() const);
1004 INLINE(bool IsUnseededNumberDictionary() const);
1005 INLINE(bool IsOrderedHashSet() const);
1006 INLINE(bool IsOrderedHashMap() const);
1007 bool IsCallable() const;
1008 static bool IsPromise(Handle<Object> object);
1011 INLINE(bool IsUndefined() const);
1012 INLINE(bool IsNull() const);
1013 INLINE(bool IsTheHole() const);
1014 INLINE(bool IsException() const);
1015 INLINE(bool IsUninitialized() const);
1016 INLINE(bool IsTrue() const);
1017 INLINE(bool IsFalse() const);
1018 INLINE(bool IsArgumentsMarker() const);
1020 // Filler objects (fillers and free space objects).
1021 INLINE(bool IsFiller() const);
1023 // Extract the number.
1024 inline double Number();
1025 INLINE(bool IsNaN() const);
1026 INLINE(bool IsMinusZero() const);
1027 bool ToInt32(int32_t* value);
1028 bool ToUint32(uint32_t* value);
1030 inline Representation OptimalRepresentation();
1032 inline ElementsKind OptimalElementsKind();
1034 inline bool FitsRepresentation(Representation representation);
1036 // Checks whether two valid primitive encodings of a property name resolve to
1037 // the same logical property. E.g., the smi 1, the string "1" and the double
1038 // 1 all refer to the same property, so this helper will return true.
1039 inline bool KeyEquals(Object* other);
1041 Handle<HeapType> OptimalType(Isolate* isolate, Representation representation);
1043 inline static Handle<Object> NewStorageFor(Isolate* isolate,
1044 Handle<Object> object,
1045 Representation representation);
1047 inline static Handle<Object> WrapForRead(Isolate* isolate,
1048 Handle<Object> object,
1049 Representation representation);
1051 // Returns true if the object is of the correct type to be used as a
1052 // implementation of a JSObject's elements.
1053 inline bool HasValidElements();
1055 inline bool HasSpecificClassOf(String* name);
1057 bool BooleanValue(); // ECMA-262 9.2.
1059 // ES6 section 7.2.13 Strict Equality Comparison
1060 bool StrictEquals(Object* that);
1062 // Convert to a JSObject if needed.
1063 // native_context is used when creating wrapper object.
1064 static inline MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1065 Handle<Object> object);
1066 static MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
1067 Handle<Object> object,
1068 Handle<Context> context);
1070 MUST_USE_RESULT static MaybeHandle<Object> GetProperty(
1071 LookupIterator* it, LanguageMode language_mode = SLOPPY);
1073 // Implementation of [[Put]], ECMA-262 5th edition, section 8.12.5.
1074 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1075 Handle<Object> object, Handle<Name> name, Handle<Object> value,
1076 LanguageMode language_mode,
1077 StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
1079 MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
1080 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1081 StoreFromKeyed store_mode);
1083 MUST_USE_RESULT static MaybeHandle<Object> SetSuperProperty(
1084 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1085 StoreFromKeyed store_mode);
1087 MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty(
1088 LookupIterator* it, LanguageMode language_mode);
1089 MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty(
1090 Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
1091 LanguageMode language_mode);
1092 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1093 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
1094 MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
1095 Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
1096 Handle<Object> value, LanguageMode language_mode);
1097 MUST_USE_RESULT static MaybeHandle<Object> RedefineNonconfigurableProperty(
1098 Isolate* isolate, Handle<Object> name, Handle<Object> value,
1099 LanguageMode language_mode);
1100 MUST_USE_RESULT static MaybeHandle<Object> SetDataProperty(
1101 LookupIterator* it, Handle<Object> value);
1102 MUST_USE_RESULT static MaybeHandle<Object> AddDataProperty(
1103 LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
1104 LanguageMode language_mode, StoreFromKeyed store_mode);
1105 MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
1106 Handle<Object> object, Handle<Name> name,
1107 LanguageMode language_mode = SLOPPY);
1108 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1109 Isolate* isolate, Handle<Object> object, const char* key,
1110 LanguageMode language_mode = SLOPPY);
1111 MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
1112 Handle<Object> object, Handle<Name> name,
1113 LanguageMode language_mode = SLOPPY);
1115 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
1116 LookupIterator* it, LanguageMode language_mode);
1117 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithAccessor(
1118 LookupIterator* it, Handle<Object> value, LanguageMode language_mode);
1120 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter(
1121 Handle<Object> receiver,
1122 Handle<JSReceiver> getter);
1123 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithDefinedSetter(
1124 Handle<Object> receiver,
1125 Handle<JSReceiver> setter,
1126 Handle<Object> value);
1128 MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
1129 Isolate* isolate, Handle<Object> object, uint32_t index,
1130 LanguageMode language_mode = SLOPPY);
1132 MUST_USE_RESULT static inline MaybeHandle<Object> SetElement(
1133 Isolate* isolate, Handle<Object> object, uint32_t index,
1134 Handle<Object> value, LanguageMode language_mode);
1136 static inline Handle<Object> GetPrototypeSkipHiddenPrototypes(
1137 Isolate* isolate, Handle<Object> receiver);
1139 bool HasInPrototypeChain(Isolate* isolate, Object* object);
1141 // Returns the permanent hash code associated with this object. May return
1142 // undefined if not yet created.
1145 // Returns undefined for JSObjects, but returns the hash code for simple
1146 // objects. This avoids a double lookup in the cases where we know we will
1147 // add the hash to the JSObject if it does not already exist.
1148 Object* GetSimpleHash();
1150 // Returns the permanent hash code associated with this object depending on
1151 // the actual object type. May create and store a hash code if needed and none
1153 static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object);
1155 // Checks whether this object has the same value as the given one. This
1156 // function is implemented according to ES5, section 9.12 and can be used
1157 // to implement the Harmony "egal" function.
1158 bool SameValue(Object* other);
1160 // Checks whether this object has the same value as the given one.
1161 // +0 and -0 are treated equal. Everything else is the same as SameValue.
1162 // This function is implemented according to ES6, section 7.2.4 and is used
1163 // by ES6 Map and Set.
1164 bool SameValueZero(Object* other);
1166 // Tries to convert an object to an array length. Returns true and sets the
1167 // output parameter if it succeeds.
1168 inline bool ToArrayLength(uint32_t* index);
1170 // Tries to convert an object to an array index. Returns true and sets the
1171 // output parameter if it succeeds. Equivalent to ToArrayLength, but does not
1172 // allow kMaxUInt32.
1173 inline bool ToArrayIndex(uint32_t* index);
1175 // Returns true if this is a JSValue containing a string and the index is
1176 // < the length of the string. Used to implement [] on strings.
1177 inline bool IsStringObjectWithCharacterAt(uint32_t index);
1179 DECLARE_VERIFIER(Object)
1181 // Verify a pointer is a valid object pointer.
1182 static void VerifyPointer(Object* p);
1185 inline void VerifyApiCallResultType();
1187 // Prints this object without details.
1188 void ShortPrint(FILE* out = stdout);
1190 // Prints this object without details to a message accumulator.
1191 void ShortPrint(StringStream* accumulator);
1193 void ShortPrint(std::ostream& os); // NOLINT
1195 DECLARE_CAST(Object)
1197 // Layout description.
1198 static const int kHeaderSize = 0; // Object does not take up any space.
1201 // For our gdb macros, we should perhaps change these in the future.
1204 // Prints this object with details.
1205 void Print(std::ostream& os); // NOLINT
1207 void Print() { ShortPrint(); }
1208 void Print(std::ostream& os) { ShortPrint(os); } // NOLINT
1212 friend class LookupIterator;
1213 friend class PrototypeIterator;
1215 // Return the map of the root of object's prototype chain.
1216 Map* GetRootMap(Isolate* isolate);
1218 // Helper for SetProperty and SetSuperProperty.
1219 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyInternal(
1220 LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
1221 StoreFromKeyed store_mode, bool* found);
1223 DISALLOW_IMPLICIT_CONSTRUCTORS(Object);
1227 // In objects.h to be usable without objects-inl.h inclusion.
1228 bool Object::IsSmi() const { return HAS_SMI_TAG(this); }
1229 bool Object::IsHeapObject() const { return Internals::HasHeapObjectTag(this); }
1233 explicit Brief(const Object* const v) : value(v) {}
1234 const Object* value;
1238 std::ostream& operator<<(std::ostream& os, const Brief& v);
1241 // Smi represents integer Numbers that can be stored in 31 bits.
1242 // Smis are immediate which means they are NOT allocated in the heap.
1243 // The this pointer has the following format: [31 bit signed int] 0
1244 // For long smis it has the following format:
1245 // [32 bit signed int] [31 bits zero padding] 0
1246 // Smi stands for small integer.
1247 class Smi: public Object {
1249 // Returns the integer value.
1250 inline int value() const { return Internals::SmiValue(this); }
1252 // Convert a value to a Smi object.
1253 static inline Smi* FromInt(int value) {
1254 DCHECK(Smi::IsValid(value));
1255 return reinterpret_cast<Smi*>(Internals::IntToSmi(value));
1258 static inline Smi* FromIntptr(intptr_t value) {
1259 DCHECK(Smi::IsValid(value));
1260 int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
1261 return reinterpret_cast<Smi*>((value << smi_shift_bits) | kSmiTag);
1264 // Returns whether value can be represented in a Smi.
1265 static inline bool IsValid(intptr_t value) {
1266 bool result = Internals::IsValidSmi(value);
1267 DCHECK_EQ(result, value >= kMinValue && value <= kMaxValue);
1273 // Dispatched behavior.
1274 void SmiPrint(std::ostream& os) const; // NOLINT
1275 DECLARE_VERIFIER(Smi)
1277 static const int kMinValue =
1278 (static_cast<unsigned int>(-1)) << (kSmiValueSize - 1);
1279 static const int kMaxValue = -(kMinValue + 1);
1282 DISALLOW_IMPLICIT_CONSTRUCTORS(Smi);
1286 // Heap objects typically have a map pointer in their first word. However,
1287 // during GC other data (e.g. mark bits, forwarding addresses) is sometimes
1288 // encoded in the first word. The class MapWord is an abstraction of the
1289 // value in a heap object's first word.
1290 class MapWord BASE_EMBEDDED {
1292 // Normal state: the map word contains a map pointer.
1294 // Create a map word from a map pointer.
1295 static inline MapWord FromMap(const Map* map);
1297 // View this map word as a map pointer.
1298 inline Map* ToMap();
1301 // Scavenge collection: the map word of live objects in the from space
1302 // contains a forwarding address (a heap object pointer in the to space).
1304 // True if this map word is a forwarding address for a scavenge
1305 // collection. Only valid during a scavenge collection (specifically,
1306 // when all map words are heap object pointers, i.e. not during a full GC).
1307 inline bool IsForwardingAddress();
1309 // Create a map word from a forwarding address.
1310 static inline MapWord FromForwardingAddress(HeapObject* object);
1312 // View this map word as a forwarding address.
1313 inline HeapObject* ToForwardingAddress();
1315 static inline MapWord FromRawValue(uintptr_t value) {
1316 return MapWord(value);
1319 inline uintptr_t ToRawValue() {
1324 // HeapObject calls the private constructor and directly reads the value.
1325 friend class HeapObject;
1327 explicit MapWord(uintptr_t value) : value_(value) {}
1333 // The content of an heap object (except for the map pointer). kTaggedValues
1334 // objects can contain both heap pointers and Smis, kMixedValues can contain
1335 // heap pointers, Smis, and raw values (e.g. doubles or strings), and kRawValues
1336 // objects can contain raw values and Smis.
1337 enum class HeapObjectContents { kTaggedValues, kMixedValues, kRawValues };
1340 // HeapObject is the superclass for all classes describing heap allocated
1342 class HeapObject: public Object {
1344 // [map]: Contains a map which contains the object's reflective
1346 inline Map* map() const;
1347 inline void set_map(Map* value);
1348 // The no-write-barrier version. This is OK if the object is white and in
1349 // new space, or if the value is an immortal immutable object, like the maps
1350 // of primitive (non-JS) objects like strings, heap numbers etc.
1351 inline void set_map_no_write_barrier(Map* value);
1353 // Get the map using acquire load.
1354 inline Map* synchronized_map();
1355 inline MapWord synchronized_map_word() const;
1357 // Set the map using release store
1358 inline void synchronized_set_map(Map* value);
1359 inline void synchronized_set_map_no_write_barrier(Map* value);
1360 inline void synchronized_set_map_word(MapWord map_word);
1362 // During garbage collection, the map word of a heap object does not
1363 // necessarily contain a map pointer.
1364 inline MapWord map_word() const;
1365 inline void set_map_word(MapWord map_word);
1367 // The Heap the object was allocated in. Used also to access Isolate.
1368 inline Heap* GetHeap() const;
1370 // Convenience method to get current isolate.
1371 inline Isolate* GetIsolate() const;
1373 // Converts an address to a HeapObject pointer.
1374 static inline HeapObject* FromAddress(Address address) {
1375 DCHECK_TAG_ALIGNED(address);
1376 return reinterpret_cast<HeapObject*>(address + kHeapObjectTag);
1379 // Returns the address of this HeapObject.
1380 inline Address address() {
1381 return reinterpret_cast<Address>(this) - kHeapObjectTag;
1384 // Iterates over pointers contained in the object (including the Map)
1385 void Iterate(ObjectVisitor* v);
1387 // Iterates over all pointers contained in the object except the
1388 // first map pointer. The object type is given in the first
1389 // parameter. This function does not access the map pointer in the
1390 // object, and so is safe to call while the map pointer is modified.
1391 void IterateBody(InstanceType type, int object_size, ObjectVisitor* v);
1393 // Returns the heap object's size in bytes
1396 // Indicates what type of values this heap object may contain.
1397 inline HeapObjectContents ContentType();
1399 // Given a heap object's map pointer, returns the heap size in bytes
1400 // Useful when the map pointer field is used for other purposes.
1402 inline int SizeFromMap(Map* map);
1404 // Returns the field at offset in obj, as a read/write Object* reference.
1405 // Does no checking, and is safe to use during GC, while maps are invalid.
1406 // Does not invoke write barrier, so should only be assigned to
1407 // during marking GC.
1408 static inline Object** RawField(HeapObject* obj, int offset);
1410 // Adds the |code| object related to |name| to the code cache of this map. If
1411 // this map is a dictionary map that is shared, the map copied and installed
1413 static void UpdateMapCodeCache(Handle<HeapObject> object,
1417 DECLARE_CAST(HeapObject)
1419 // Return the write barrier mode for this. Callers of this function
1420 // must be able to present a reference to an DisallowHeapAllocation
1421 // object as a sign that they are not going to use this function
1422 // from code that allocates and thus invalidates the returned write
1424 inline WriteBarrierMode GetWriteBarrierMode(
1425 const DisallowHeapAllocation& promise);
1427 // Dispatched behavior.
1428 void HeapObjectShortPrint(std::ostream& os); // NOLINT
1430 void PrintHeader(std::ostream& os, const char* id); // NOLINT
1432 DECLARE_PRINTER(HeapObject)
1433 DECLARE_VERIFIER(HeapObject)
1435 inline void VerifyObjectField(int offset);
1436 inline void VerifySmiField(int offset);
1438 // Verify a pointer is a valid HeapObject pointer that points to object
1439 // areas in the heap.
1440 static void VerifyHeapPointer(Object* p);
1443 inline AllocationAlignment RequiredAlignment();
1445 // Layout description.
1446 // First field in a heap object is map.
1447 static const int kMapOffset = Object::kHeaderSize;
1448 static const int kHeaderSize = kMapOffset + kPointerSize;
1450 STATIC_ASSERT(kMapOffset == Internals::kHeapObjectMapOffset);
1453 // helpers for calling an ObjectVisitor to iterate over pointers in the
1454 // half-open range [start, end) specified as integer offsets
1455 inline void IteratePointers(ObjectVisitor* v, int start, int end);
1456 // as above, for the single element at "offset"
1457 inline void IteratePointer(ObjectVisitor* v, int offset);
1458 // as above, for the next code link of a code object.
1459 inline void IterateNextCodeLink(ObjectVisitor* v, int offset);
1462 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject);
1466 // This class describes a body of an object of a fixed size
1467 // in which all pointer fields are located in the [start_offset, end_offset)
1469 template<int start_offset, int end_offset, int size>
1470 class FixedBodyDescriptor {
1472 static const int kStartOffset = start_offset;
1473 static const int kEndOffset = end_offset;
1474 static const int kSize = size;
1476 static inline void IterateBody(HeapObject* obj, ObjectVisitor* v);
1478 template<typename StaticVisitor>
1479 static inline void IterateBody(HeapObject* obj) {
1480 StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
1481 HeapObject::RawField(obj, end_offset));
1486 // This class describes a body of an object of a variable size
1487 // in which all pointer fields are located in the [start_offset, object_size)
1489 template<int start_offset>
1490 class FlexibleBodyDescriptor {
1492 static const int kStartOffset = start_offset;
1494 static inline void IterateBody(HeapObject* obj,
1498 template<typename StaticVisitor>
1499 static inline void IterateBody(HeapObject* obj, int object_size) {
1500 StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
1501 HeapObject::RawField(obj, object_size));
1506 // The HeapNumber class describes heap allocated numbers that cannot be
1507 // represented in a Smi (small integer)
1508 class HeapNumber: public HeapObject {
1510 // [value]: number value.
1511 inline double value() const;
1512 inline void set_value(double value);
1514 DECLARE_CAST(HeapNumber)
1516 // Dispatched behavior.
1517 bool HeapNumberBooleanValue();
1519 void HeapNumberPrint(std::ostream& os); // NOLINT
1520 DECLARE_VERIFIER(HeapNumber)
1522 inline int get_exponent();
1523 inline int get_sign();
1525 // Layout description.
1526 static const int kValueOffset = HeapObject::kHeaderSize;
1527 // IEEE doubles are two 32 bit words. The first is just mantissa, the second
1528 // is a mixture of sign, exponent and mantissa. The offsets of two 32 bit
1529 // words within double numbers are endian dependent and they are set
1531 #if defined(V8_TARGET_LITTLE_ENDIAN)
1532 static const int kMantissaOffset = kValueOffset;
1533 static const int kExponentOffset = kValueOffset + 4;
1534 #elif defined(V8_TARGET_BIG_ENDIAN)
1535 static const int kMantissaOffset = kValueOffset + 4;
1536 static const int kExponentOffset = kValueOffset;
1538 #error Unknown byte ordering
1541 static const int kSize = kValueOffset + kDoubleSize;
1542 static const uint32_t kSignMask = 0x80000000u;
1543 static const uint32_t kExponentMask = 0x7ff00000u;
1544 static const uint32_t kMantissaMask = 0xfffffu;
1545 static const int kMantissaBits = 52;
1546 static const int kExponentBits = 11;
1547 static const int kExponentBias = 1023;
1548 static const int kExponentShift = 20;
1549 static const int kInfinityOrNanExponent =
1550 (kExponentMask >> kExponentShift) - kExponentBias;
1551 static const int kMantissaBitsInTopWord = 20;
1552 static const int kNonMantissaBitsInTopWord = 12;
1555 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber);
1559 // The Simd128Value class describes heap allocated 128 bit SIMD values.
1560 class Simd128Value : public HeapObject {
1562 DECLARE_CAST(Simd128Value)
1564 DECLARE_PRINTER(Simd128Value)
1565 DECLARE_VERIFIER(Simd128Value)
1567 // Equality operations.
1568 inline bool Equals(Simd128Value* that);
1570 // Checks that another instance is bit-wise equal.
1571 bool BitwiseEquals(const Simd128Value* other) const;
1572 // Computes a hash from the 128 bit value, viewed as 4 32-bit integers.
1573 uint32_t Hash() const;
1574 // Copies the 16 bytes of SIMD data to the destination address.
1575 void CopyBits(void* destination) const;
1577 // Layout description.
1578 static const int kValueOffset = HeapObject::kHeaderSize;
1579 static const int kSize = kValueOffset + kSimd128Size;
1582 DISALLOW_IMPLICIT_CONSTRUCTORS(Simd128Value);
1586 // V has parameters (TYPE, Type, type, lane count, lane type)
1587 #define SIMD128_TYPES(V) \
1588 V(FLOAT32X4, Float32x4, float32x4, 4, float) \
1589 V(INT32X4, Int32x4, int32x4, 4, int32_t) \
1590 V(BOOL32X4, Bool32x4, bool32x4, 4, bool) \
1591 V(INT16X8, Int16x8, int16x8, 8, int16_t) \
1592 V(BOOL16X8, Bool16x8, bool16x8, 8, bool) \
1593 V(INT8X16, Int8x16, int8x16, 16, int8_t) \
1594 V(BOOL8X16, Bool8x16, bool8x16, 16, bool)
1596 #define SIMD128_VALUE_CLASS(TYPE, Type, type, lane_count, lane_type) \
1597 class Type final : public Simd128Value { \
1599 inline lane_type get_lane(int lane) const; \
1600 inline void set_lane(int lane, lane_type value); \
1602 DECLARE_CAST(Type) \
1604 DECLARE_PRINTER(Type) \
1606 inline bool Equals(Type* that); \
1609 DISALLOW_IMPLICIT_CONSTRUCTORS(Type); \
1611 SIMD128_TYPES(SIMD128_VALUE_CLASS)
1612 #undef SIMD128_VALUE_CLASS
1615 enum EnsureElementsMode {
1616 DONT_ALLOW_DOUBLE_ELEMENTS,
1617 ALLOW_COPIED_DOUBLE_ELEMENTS,
1618 ALLOW_CONVERTED_DOUBLE_ELEMENTS
1622 // Indicator for one component of an AccessorPair.
1623 enum AccessorComponent {
1629 // JSReceiver includes types on which properties can be defined, i.e.,
1630 // JSObject and JSProxy.
1631 class JSReceiver: public HeapObject {
1633 DECLARE_CAST(JSReceiver)
1635 // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
1636 MUST_USE_RESULT static inline Maybe<bool> HasProperty(
1637 Handle<JSReceiver> object, Handle<Name> name);
1638 MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty(Handle<JSReceiver>,
1640 MUST_USE_RESULT static inline Maybe<bool> HasElement(
1641 Handle<JSReceiver> object, uint32_t index);
1642 MUST_USE_RESULT static inline Maybe<bool> HasOwnElement(
1643 Handle<JSReceiver> object, uint32_t index);
1645 // Implementation of [[Delete]], ECMA-262 5th edition, section 8.12.7.
1646 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyOrElement(
1647 Handle<JSReceiver> object, Handle<Name> name,
1648 LanguageMode language_mode = SLOPPY);
1649 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
1650 Handle<JSReceiver> object, Handle<Name> name,
1651 LanguageMode language_mode = SLOPPY);
1652 MUST_USE_RESULT static MaybeHandle<Object> DeleteProperty(
1653 LookupIterator* it, LanguageMode language_mode);
1654 MUST_USE_RESULT static MaybeHandle<Object> DeleteElement(
1655 Handle<JSReceiver> object, uint32_t index,
1656 LanguageMode language_mode = SLOPPY);
1658 // Tests for the fast common case for property enumeration.
1659 bool IsSimpleEnum();
1661 // Returns the class name ([[Class]] property in the specification).
1662 String* class_name();
1664 // Returns the constructor name (the name (possibly, inferred name) of the
1665 // function that was used to instantiate the object).
1666 String* constructor_name();
1668 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes(
1669 Handle<JSReceiver> object, Handle<Name> name);
1670 MUST_USE_RESULT static inline Maybe<PropertyAttributes>
1671 GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
1673 MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetElementAttributes(
1674 Handle<JSReceiver> object, uint32_t index);
1675 MUST_USE_RESULT static inline Maybe<PropertyAttributes>
1676 GetOwnElementAttributes(Handle<JSReceiver> object, uint32_t index);
1678 MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
1679 LookupIterator* it);
1682 static Handle<Object> GetDataProperty(Handle<JSReceiver> object,
1684 static Handle<Object> GetDataProperty(LookupIterator* it);
1687 // Retrieves a permanent object identity hash code. The undefined value might
1688 // be returned in case no hash was created yet.
1689 inline Object* GetIdentityHash();
1691 // Retrieves a permanent object identity hash code. May create and store a
1692 // hash code if needed and none exists.
1693 inline static Handle<Smi> GetOrCreateIdentityHash(
1694 Handle<JSReceiver> object);
1696 enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS };
1698 // Computes the enumerable keys for a JSObject. Used for implementing
1699 // "for (n in object) { }".
1700 MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys(
1701 Handle<JSReceiver> object,
1702 KeyCollectionType type);
1705 DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
1709 // The JSObject describes real heap allocated JavaScript objects with
1711 // Note that the map of JSObject changes during execution to enable inline
1713 class JSObject: public JSReceiver {
1715 // [properties]: Backing storage for properties.
1716 // properties is a FixedArray in the fast case and a Dictionary in the
1718 DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties.
1719 inline void initialize_properties();
1720 inline bool HasFastProperties();
1721 // Gets slow properties for non-global objects.
1722 inline NameDictionary* property_dictionary();
1723 // Gets global object properties.
1724 inline GlobalDictionary* global_dictionary();
1726 // [elements]: The elements (properties with names that are integers).
1728 // Elements can be in two general modes: fast and slow. Each mode
1729 // corrensponds to a set of object representations of elements that
1730 // have something in common.
1732 // In the fast mode elements is a FixedArray and so each element can
1733 // be quickly accessed. This fact is used in the generated code. The
1734 // elements array can have one of three maps in this mode:
1735 // fixed_array_map, sloppy_arguments_elements_map or
1736 // fixed_cow_array_map (for copy-on-write arrays). In the latter case
1737 // the elements array may be shared by a few objects and so before
1738 // writing to any element the array must be copied. Use
1739 // EnsureWritableFastElements in this case.
1741 // In the slow mode the elements is either a NumberDictionary, a
1742 // FixedArray parameter map for a (sloppy) arguments object.
1743 DECL_ACCESSORS(elements, FixedArrayBase)
1744 inline void initialize_elements();
1745 static void ResetElements(Handle<JSObject> object);
1746 static inline void SetMapAndElements(Handle<JSObject> object,
1748 Handle<FixedArrayBase> elements);
1749 inline ElementsKind GetElementsKind();
1750 ElementsAccessor* GetElementsAccessor();
1751 // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
1752 inline bool HasFastSmiElements();
1753 // Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
1754 inline bool HasFastObjectElements();
1755 // Returns true if an object has elements of FAST_ELEMENTS or
1756 // FAST_SMI_ONLY_ELEMENTS.
1757 inline bool HasFastSmiOrObjectElements();
1758 // Returns true if an object has any of the fast elements kinds.
1759 inline bool HasFastElements();
1760 // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
1762 inline bool HasFastDoubleElements();
1763 // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
1765 inline bool HasFastHoleyElements();
1766 inline bool HasSloppyArgumentsElements();
1767 inline bool HasDictionaryElements();
1769 inline bool HasFixedTypedArrayElements();
1771 inline bool HasFixedUint8ClampedElements();
1772 inline bool HasFixedArrayElements();
1773 inline bool HasFixedInt8Elements();
1774 inline bool HasFixedUint8Elements();
1775 inline bool HasFixedInt16Elements();
1776 inline bool HasFixedUint16Elements();
1777 inline bool HasFixedInt32Elements();
1778 inline bool HasFixedUint32Elements();
1779 inline bool HasFixedFloat32Elements();
1780 inline bool HasFixedFloat64Elements();
1782 inline bool HasFastArgumentsElements();
1783 inline bool HasSlowArgumentsElements();
1784 inline SeededNumberDictionary* element_dictionary(); // Gets slow elements.
1786 // Requires: HasFastElements().
1787 static Handle<FixedArray> EnsureWritableFastElements(
1788 Handle<JSObject> object);
1790 // Collects elements starting at index 0.
1791 // Undefined values are placed after non-undefined values.
1792 // Returns the number of non-undefined values.
1793 static Handle<Object> PrepareElementsForSort(Handle<JSObject> object,
1795 // As PrepareElementsForSort, but only on objects where elements is
1796 // a dictionary, and it will stay a dictionary. Collates undefined and
1797 // unexisting elements below limit from position zero of the elements.
1798 static Handle<Object> PrepareSlowElementsForSort(Handle<JSObject> object,
1801 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithInterceptor(
1802 LookupIterator* it, Handle<Object> value);
1804 // SetLocalPropertyIgnoreAttributes converts callbacks to fields. We need to
1805 // grant an exemption to ExecutableAccessor callbacks in some cases.
1806 enum ExecutableAccessorInfoHandling { DEFAULT_HANDLING, DONT_FORCE_FIELD };
1808 MUST_USE_RESULT static MaybeHandle<Object> DefineOwnPropertyIgnoreAttributes(
1809 LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
1810 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1812 MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes(
1813 Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
1814 PropertyAttributes attributes,
1815 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1817 MUST_USE_RESULT static MaybeHandle<Object> SetOwnElementIgnoreAttributes(
1818 Handle<JSObject> object, uint32_t index, Handle<Object> value,
1819 PropertyAttributes attributes,
1820 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1822 // Equivalent to one of the above depending on whether |name| can be converted
1823 // to an array index.
1824 MUST_USE_RESULT static MaybeHandle<Object>
1825 DefinePropertyOrElementIgnoreAttributes(
1826 Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
1827 PropertyAttributes attributes = NONE,
1828 ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
1830 // Adds or reconfigures a property to attributes NONE. It will fail when it
1832 MUST_USE_RESULT static Maybe<bool> CreateDataProperty(LookupIterator* it,
1833 Handle<Object> value);
1835 static void AddProperty(Handle<JSObject> object, Handle<Name> name,
1836 Handle<Object> value, PropertyAttributes attributes);
1838 MUST_USE_RESULT static MaybeHandle<Object> AddDataElement(
1839 Handle<JSObject> receiver, uint32_t index, Handle<Object> value,
1840 PropertyAttributes attributes);
1842 // Extend the receiver with a single fast property appeared first in the
1843 // passed map. This also extends the property backing store if necessary.
1844 static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
1846 // Migrates the given object to a map whose field representations are the
1847 // lowest upper bound of all known representations for that field.
1848 static void MigrateInstance(Handle<JSObject> instance);
1850 // Migrates the given object only if the target map is already available,
1851 // or returns false if such a map is not yet available.
1852 static bool TryMigrateInstance(Handle<JSObject> instance);
1854 // Sets the property value in a normalized object given (key, value, details).
1855 // Handles the special representation of JS global objects.
1856 static void SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name,
1857 Handle<Object> value,
1858 PropertyDetails details);
1859 static void SetDictionaryElement(Handle<JSObject> object, uint32_t index,
1860 Handle<Object> value,
1861 PropertyAttributes attributes);
1862 static void SetDictionaryArgumentsElement(Handle<JSObject> object,
1864 Handle<Object> value,
1865 PropertyAttributes attributes);
1867 static void OptimizeAsPrototype(Handle<JSObject> object,
1868 PrototypeOptimizationMode mode);
1869 static void ReoptimizeIfPrototype(Handle<JSObject> object);
1870 static void LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate);
1871 static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate);
1872 static void InvalidatePrototypeChains(Map* map);
1874 // Alternative implementation of WeakFixedArray::NullCallback.
1875 class PrototypeRegistryCompactionCallback {
1877 static void Callback(Object* value, int old_index, int new_index);
1880 // Retrieve interceptors.
1881 InterceptorInfo* GetNamedInterceptor();
1882 InterceptorInfo* GetIndexedInterceptor();
1884 // Used from JSReceiver.
1885 MUST_USE_RESULT static Maybe<PropertyAttributes>
1886 GetPropertyAttributesWithInterceptor(LookupIterator* it);
1887 MUST_USE_RESULT static Maybe<PropertyAttributes>
1888 GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
1890 // Retrieves an AccessorPair property from the given object. Might return
1891 // undefined if the property doesn't exist or is of a different kind.
1892 MUST_USE_RESULT static MaybeHandle<Object> GetAccessor(
1893 Handle<JSObject> object,
1895 AccessorComponent component);
1897 // Defines an AccessorPair property on the given object.
1898 // TODO(mstarzinger): Rename to SetAccessor().
1899 static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
1901 Handle<Object> getter,
1902 Handle<Object> setter,
1903 PropertyAttributes attributes);
1905 // Defines an AccessorInfo property on the given object.
1906 MUST_USE_RESULT static MaybeHandle<Object> SetAccessor(
1907 Handle<JSObject> object,
1908 Handle<AccessorInfo> info);
1910 // The result must be checked first for exceptions. If there's no exception,
1911 // the output parameter |done| indicates whether the interceptor has a result
1913 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
1914 LookupIterator* it, bool* done);
1916 // Accessors for hidden properties object.
1918 // Hidden properties are not own properties of the object itself.
1919 // Instead they are stored in an auxiliary structure kept as an own
1920 // property with a special name Heap::hidden_string(). But if the
1921 // receiver is a JSGlobalProxy then the auxiliary object is a property
1922 // of its prototype, and if it's a detached proxy, then you can't have
1923 // hidden properties.
1925 // Sets a hidden property on this object. Returns this object if successful,
1926 // undefined if called on a detached proxy.
1927 static Handle<Object> SetHiddenProperty(Handle<JSObject> object,
1929 Handle<Object> value);
1930 // Gets the value of a hidden property with the given key. Returns the hole
1931 // if the property doesn't exist (or if called on a detached proxy),
1932 // otherwise returns the value set for the key.
1933 Object* GetHiddenProperty(Handle<Name> key);
1934 // Deletes a hidden property. Deleting a non-existing property is
1935 // considered successful.
1936 static void DeleteHiddenProperty(Handle<JSObject> object,
1938 // Returns true if the object has a property with the hidden string as name.
1939 static bool HasHiddenProperties(Handle<JSObject> object);
1941 static void SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash);
1943 static void ValidateElements(Handle<JSObject> object);
1945 // Makes sure that this object can contain HeapObject as elements.
1946 static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
1948 // Makes sure that this object can contain the specified elements.
1949 static inline void EnsureCanContainElements(
1950 Handle<JSObject> object,
1953 EnsureElementsMode mode);
1954 static inline void EnsureCanContainElements(
1955 Handle<JSObject> object,
1956 Handle<FixedArrayBase> elements,
1958 EnsureElementsMode mode);
1959 static void EnsureCanContainElements(
1960 Handle<JSObject> object,
1961 Arguments* arguments,
1964 EnsureElementsMode mode);
1966 // Would we convert a fast elements array to dictionary mode given
1967 // an access at key?
1968 bool WouldConvertToSlowElements(uint32_t index);
1970 // Computes the new capacity when expanding the elements of a JSObject.
1971 static uint32_t NewElementsCapacity(uint32_t old_capacity) {
1972 // (old_capacity + 50%) + 16
1973 return old_capacity + (old_capacity >> 1) + 16;
1976 // These methods do not perform access checks!
1977 static void UpdateAllocationSite(Handle<JSObject> object,
1978 ElementsKind to_kind);
1980 // Lookup interceptors are used for handling properties controlled by host
1982 inline bool HasNamedInterceptor();
1983 inline bool HasIndexedInterceptor();
1985 // Computes the enumerable keys from interceptors. Used for debug mirrors and
1986 // by JSReceiver::GetKeys.
1987 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForNamedInterceptor(
1988 Handle<JSObject> object,
1989 Handle<JSReceiver> receiver);
1990 MUST_USE_RESULT static MaybeHandle<JSObject> GetKeysForIndexedInterceptor(
1991 Handle<JSObject> object,
1992 Handle<JSReceiver> receiver);
1994 // Support functions for v8 api (needed for correct interceptor behavior).
1995 MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
1996 Handle<JSObject> object, Handle<Name> name);
1997 MUST_USE_RESULT static Maybe<bool> HasRealElementProperty(
1998 Handle<JSObject> object, uint32_t index);
1999 MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
2000 Handle<JSObject> object, Handle<Name> name);
2002 // Get the header size for a JSObject. Used to compute the index of
2003 // internal fields as well as the number of internal fields.
2004 inline int GetHeaderSize();
2006 inline int GetInternalFieldCount();
2007 inline int GetInternalFieldOffset(int index);
2008 inline Object* GetInternalField(int index);
2009 inline void SetInternalField(int index, Object* value);
2010 inline void SetInternalField(int index, Smi* value);
2012 // Returns the number of properties on this object filtering out properties
2013 // with the specified attributes (ignoring interceptors).
2014 int NumberOfOwnProperties(PropertyAttributes filter = NONE);
2015 // Fill in details for properties into storage starting at the specified
2016 // index. Returns the number of properties added.
2017 int GetOwnPropertyNames(FixedArray* storage, int index,
2018 PropertyAttributes filter = NONE);
2020 // Returns the number of properties on this object filtering out properties
2021 // with the specified attributes (ignoring interceptors).
2022 int NumberOfOwnElements(PropertyAttributes filter);
2023 // Returns the number of enumerable elements (ignoring interceptors).
2024 int NumberOfEnumElements();
2025 // Returns the number of elements on this object filtering out elements
2026 // with the specified attributes (ignoring interceptors).
2027 int GetOwnElementKeys(FixedArray* storage, PropertyAttributes filter);
2028 // Count and fill in the enumerable elements into storage.
2029 // (storage->length() == NumberOfEnumElements()).
2030 // If storage is NULL, will count the elements without adding
2031 // them to any storage.
2032 // Returns the number of enumerable elements.
2033 int GetEnumElementKeys(FixedArray* storage);
2035 static Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object,
2038 // Returns a new map with all transitions dropped from the object's current
2039 // map and the ElementsKind set.
2040 static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
2041 ElementsKind to_kind);
2042 static void TransitionElementsKind(Handle<JSObject> object,
2043 ElementsKind to_kind);
2045 // Always use this to migrate an object to a new map.
2046 // |expected_additional_properties| is only used for fast-to-slow transitions
2047 // and ignored otherwise.
2048 static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map,
2049 int expected_additional_properties = 0);
2051 // Convert the object to use the canonical dictionary
2052 // representation. If the object is expected to have additional properties
2053 // added this number can be indicated to have the backing store allocated to
2054 // an initial capacity for holding these properties.
2055 static void NormalizeProperties(Handle<JSObject> object,
2056 PropertyNormalizationMode mode,
2057 int expected_additional_properties,
2058 const char* reason);
2060 // Convert and update the elements backing store to be a
2061 // SeededNumberDictionary dictionary. Returns the backing after conversion.
2062 static Handle<SeededNumberDictionary> NormalizeElements(
2063 Handle<JSObject> object);
2065 void RequireSlowElements(SeededNumberDictionary* dictionary);
2067 // Transform slow named properties to fast variants.
2068 static void MigrateSlowToFast(Handle<JSObject> object,
2069 int unused_property_fields, const char* reason);
2071 inline bool IsUnboxedDoubleField(FieldIndex index);
2073 // Access fast-case object properties at index.
2074 static Handle<Object> FastPropertyAt(Handle<JSObject> object,
2075 Representation representation,
2077 inline Object* RawFastPropertyAt(FieldIndex index);
2078 inline double RawFastDoublePropertyAt(FieldIndex index);
2080 inline void FastPropertyAtPut(FieldIndex index, Object* value);
2081 inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
2082 inline void RawFastDoublePropertyAtPut(FieldIndex index, double value);
2083 inline void WriteToField(int descriptor, Object* value);
2085 // Access to in object properties.
2086 inline int GetInObjectPropertyOffset(int index);
2087 inline Object* InObjectPropertyAt(int index);
2088 inline Object* InObjectPropertyAtPut(int index,
2090 WriteBarrierMode mode
2091 = UPDATE_WRITE_BARRIER);
2093 // Set the object's prototype (only JSReceiver and null are allowed values).
2094 MUST_USE_RESULT static MaybeHandle<Object> SetPrototype(
2095 Handle<JSObject> object, Handle<Object> value, bool from_javascript);
2097 // Initializes the body after properties slot, properties slot is
2098 // initialized by set_properties. Fill the pre-allocated fields with
2099 // pre_allocated_value and the rest with filler_value.
2100 // Note: this call does not update write barrier, the caller is responsible
2101 // to ensure that |filler_value| can be collected without WB here.
2102 inline void InitializeBody(Map* map,
2103 Object* pre_allocated_value,
2104 Object* filler_value);
2106 // Check whether this object references another object
2107 bool ReferencesObject(Object* obj);
2109 // Disalow further properties to be added to the oject.
2110 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensions(
2111 Handle<JSObject> object);
2113 bool IsExtensible();
2116 MUST_USE_RESULT static MaybeHandle<Object> Seal(Handle<JSObject> object);
2118 // ES5 Object.freeze
2119 MUST_USE_RESULT static MaybeHandle<Object> Freeze(Handle<JSObject> object);
2121 // Called the first time an object is observed with ES7 Object.observe.
2122 static void SetObserved(Handle<JSObject> object);
2125 enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 };
2127 MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy(
2128 Handle<JSObject> object,
2129 AllocationSiteUsageContext* site_context,
2130 DeepCopyHints hints = kNoHints);
2131 MUST_USE_RESULT static MaybeHandle<JSObject> DeepWalk(
2132 Handle<JSObject> object,
2133 AllocationSiteCreationContext* site_context);
2135 DECLARE_CAST(JSObject)
2137 // Dispatched behavior.
2138 void JSObjectShortPrint(StringStream* accumulator);
2139 DECLARE_PRINTER(JSObject)
2140 DECLARE_VERIFIER(JSObject)
2142 void PrintProperties(std::ostream& os); // NOLINT
2143 void PrintElements(std::ostream& os); // NOLINT
2145 #if defined(DEBUG) || defined(OBJECT_PRINT)
2146 void PrintTransitions(std::ostream& os); // NOLINT
2149 static void PrintElementsTransition(
2150 FILE* file, Handle<JSObject> object,
2151 ElementsKind from_kind, Handle<FixedArrayBase> from_elements,
2152 ElementsKind to_kind, Handle<FixedArrayBase> to_elements);
2154 void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
2157 // Structure for collecting spill information about JSObjects.
2158 class SpillInformation {
2162 int number_of_objects_;
2163 int number_of_objects_with_fast_properties_;
2164 int number_of_objects_with_fast_elements_;
2165 int number_of_fast_used_fields_;
2166 int number_of_fast_unused_fields_;
2167 int number_of_slow_used_properties_;
2168 int number_of_slow_unused_properties_;
2169 int number_of_fast_used_elements_;
2170 int number_of_fast_unused_elements_;
2171 int number_of_slow_used_elements_;
2172 int number_of_slow_unused_elements_;
2175 void IncrementSpillStatistics(SpillInformation* info);
2179 // If a GC was caused while constructing this object, the elements pointer
2180 // may point to a one pointer filler map. The object won't be rooted, but
2181 // our heap verification code could stumble across it.
2182 bool ElementsAreSafeToExamine();
2185 Object* SlowReverseLookup(Object* value);
2187 // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
2188 // Also maximal value of JSArray's length property.
2189 static const uint32_t kMaxElementCount = 0xffffffffu;
2191 // Constants for heuristics controlling conversion of fast elements
2192 // to slow elements.
2194 // Maximal gap that can be introduced by adding an element beyond
2195 // the current elements length.
2196 static const uint32_t kMaxGap = 1024;
2198 // Maximal length of fast elements array that won't be checked for
2199 // being dense enough on expansion.
2200 static const int kMaxUncheckedFastElementsLength = 5000;
2202 // Same as above but for old arrays. This limit is more strict. We
2203 // don't want to be wasteful with long lived objects.
2204 static const int kMaxUncheckedOldFastElementsLength = 500;
2206 // Note that Page::kMaxRegularHeapObjectSize puts a limit on
2207 // permissible values (see the DCHECK in heap.cc).
2208 static const int kInitialMaxFastElementArray = 100000;
2210 // This constant applies only to the initial map of "global.Object" and
2211 // not to arbitrary other JSObject maps.
2212 static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
2214 static const int kMaxInstanceSize = 255 * kPointerSize;
2215 // When extending the backing storage for property values, we increase
2216 // its size by more than the 1 entry necessary, so sequentially adding fields
2217 // to the same object requires fewer allocations and copies.
2218 static const int kFieldsAdded = 3;
2220 // Layout description.
2221 static const int kPropertiesOffset = HeapObject::kHeaderSize;
2222 static const int kElementsOffset = kPropertiesOffset + kPointerSize;
2223 static const int kHeaderSize = kElementsOffset + kPointerSize;
2225 STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
2227 class BodyDescriptor : public FlexibleBodyDescriptor<kPropertiesOffset> {
2229 static inline int SizeOf(Map* map, HeapObject* object);
2232 Context* GetCreationContext();
2234 // Enqueue change record for Object.observe. May cause GC.
2235 MUST_USE_RESULT static MaybeHandle<Object> EnqueueChangeRecord(
2236 Handle<JSObject> object, const char* type, Handle<Name> name,
2237 Handle<Object> old_value);
2239 // Gets the number of currently used elements.
2240 int GetFastElementsUsage();
2242 // Deletes an existing named property in a normalized object.
2243 static void DeleteNormalizedProperty(Handle<JSObject> object,
2244 Handle<Name> name, int entry);
2246 static bool AllCanRead(LookupIterator* it);
2247 static bool AllCanWrite(LookupIterator* it);
2250 friend class JSReceiver;
2251 friend class Object;
2253 static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map);
2254 static void MigrateFastToSlow(Handle<JSObject> object,
2255 Handle<Map> new_map,
2256 int expected_additional_properties);
2258 // Used from Object::GetProperty().
2259 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
2260 LookupIterator* it);
2262 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithFailedAccessCheck(
2263 LookupIterator* it, Handle<Object> value);
2265 // Add a property to a slow-case object.
2266 static void AddSlowProperty(Handle<JSObject> object,
2268 Handle<Object> value,
2269 PropertyAttributes attributes);
2271 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithInterceptor(
2272 LookupIterator* it);
2274 bool ReferencesObjectFromElements(FixedArray* elements,
2278 // Return the hash table backing store or the inline stored identity hash,
2279 // whatever is found.
2280 MUST_USE_RESULT Object* GetHiddenPropertiesHashTable();
2282 // Return the hash table backing store for hidden properties. If there is no
2283 // backing store, allocate one.
2284 static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable(
2285 Handle<JSObject> object);
2287 // Set the hidden property backing store to either a hash table or
2288 // the inline-stored identity hash.
2289 static Handle<Object> SetHiddenPropertiesHashTable(
2290 Handle<JSObject> object,
2291 Handle<Object> value);
2293 MUST_USE_RESULT Object* GetIdentityHash();
2295 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSObject> object);
2297 static Handle<SeededNumberDictionary> GetNormalizedElementDictionary(
2298 Handle<JSObject> object, Handle<FixedArrayBase> elements);
2300 // Helper for fast versions of preventExtensions, seal, and freeze.
2301 // attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
2302 template <PropertyAttributes attrs>
2303 MUST_USE_RESULT static MaybeHandle<Object> PreventExtensionsWithTransition(
2304 Handle<JSObject> object);
2306 DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
2310 // Common superclass for FixedArrays that allow implementations to share
2311 // common accessors and some code paths.
2312 class FixedArrayBase: public HeapObject {
2314 // [length]: length of the array.
2315 inline int length() const;
2316 inline void set_length(int value);
2318 // Get and set the length using acquire loads and release stores.
2319 inline int synchronized_length() const;
2320 inline void synchronized_set_length(int value);
2322 DECLARE_CAST(FixedArrayBase)
2324 // Layout description.
2325 // Length is smi tagged when it is stored.
2326 static const int kLengthOffset = HeapObject::kHeaderSize;
2327 static const int kHeaderSize = kLengthOffset + kPointerSize;
2331 class FixedDoubleArray;
2332 class IncrementalMarking;
2335 // FixedArray describes fixed-sized arrays with element type Object*.
2336 class FixedArray: public FixedArrayBase {
2338 // Setter and getter for elements.
2339 inline Object* get(int index) const;
2340 void SetValue(uint32_t index, Object* value);
2341 static inline Handle<Object> get(Handle<FixedArray> array, int index);
2342 // Setter that uses write barrier.
2343 inline void set(int index, Object* value);
2344 inline bool is_the_hole(int index);
2346 // Setter that doesn't need write barrier.
2347 inline void set(int index, Smi* value);
2348 // Setter with explicit barrier mode.
2349 inline void set(int index, Object* value, WriteBarrierMode mode);
2351 // Setters for frequently used oddballs located in old space.
2352 inline void set_undefined(int index);
2353 inline void set_null(int index);
2354 inline void set_the_hole(int index);
2356 inline Object** GetFirstElementAddress();
2357 inline bool ContainsOnlySmisOrHoles();
2359 // Gives access to raw memory which stores the array's data.
2360 inline Object** data_start();
2362 inline void FillWithHoles(int from, int to);
2364 // Shrink length and insert filler objects.
2365 void Shrink(int length);
2367 enum KeyFilter { ALL_KEYS, NON_SYMBOL_KEYS };
2369 // Add the elements of a JSArray to this FixedArray.
2370 MUST_USE_RESULT static MaybeHandle<FixedArray> AddKeysFromArrayLike(
2371 Handle<FixedArray> content, Handle<JSObject> array,
2372 KeyFilter filter = ALL_KEYS);
2374 // Computes the union of keys and return the result.
2375 // Used for implementing "for (n in object) { }"
2376 MUST_USE_RESULT static MaybeHandle<FixedArray> UnionOfKeys(
2377 Handle<FixedArray> first,
2378 Handle<FixedArray> second);
2380 // Copy a sub array from the receiver to dest.
2381 void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
2383 // Garbage collection support.
2384 static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
2386 // Code Generation support.
2387 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2389 // Garbage collection support.
2390 inline Object** RawFieldOfElementAt(int index);
2392 DECLARE_CAST(FixedArray)
2394 // Maximal allowed size, in bytes, of a single FixedArray.
2395 // Prevents overflowing size computations, as well as extreme memory
2397 static const int kMaxSize = 128 * MB * kPointerSize;
2398 // Maximally allowed length of a FixedArray.
2399 static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
2401 // Dispatched behavior.
2402 DECLARE_PRINTER(FixedArray)
2403 DECLARE_VERIFIER(FixedArray)
2405 // Checks if two FixedArrays have identical contents.
2406 bool IsEqualTo(FixedArray* other);
2409 // Swap two elements in a pair of arrays. If this array and the
2410 // numbers array are the same object, the elements are only swapped
2412 void SwapPairs(FixedArray* numbers, int i, int j);
2414 // Sort prefix of this array and the numbers array as pairs wrt. the
2415 // numbers. If the numbers array and the this array are the same
2416 // object, the prefix of this array is sorted.
2417 void SortPairs(FixedArray* numbers, uint32_t len);
2419 class BodyDescriptor : public FlexibleBodyDescriptor<kHeaderSize> {
2421 static inline int SizeOf(Map* map, HeapObject* object);
2425 // Set operation on FixedArray without using write barriers. Can
2426 // only be used for storing old space objects or smis.
2427 static inline void NoWriteBarrierSet(FixedArray* array,
2431 // Set operation on FixedArray without incremental write barrier. Can
2432 // only be used if the object is guaranteed to be white (whiteness witness
2434 static inline void NoIncrementalWriteBarrierSet(FixedArray* array,
2439 STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);
2441 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray);
2445 // FixedDoubleArray describes fixed-sized arrays with element type double.
2446 class FixedDoubleArray: public FixedArrayBase {
2448 // Setter and getter for elements.
2449 inline double get_scalar(int index);
2450 inline uint64_t get_representation(int index);
2451 static inline Handle<Object> get(Handle<FixedDoubleArray> array, int index);
2452 // This accessor has to get a Number as |value|.
2453 void SetValue(uint32_t index, Object* value);
2454 inline void set(int index, double value);
2455 inline void set_the_hole(int index);
2457 // Checking for the hole.
2458 inline bool is_the_hole(int index);
2460 // Garbage collection support.
2461 inline static int SizeFor(int length) {
2462 return kHeaderSize + length * kDoubleSize;
2465 // Gives access to raw memory which stores the array's data.
2466 inline double* data_start();
2468 inline void FillWithHoles(int from, int to);
2470 // Code Generation support.
2471 static int OffsetOfElementAt(int index) { return SizeFor(index); }
2473 DECLARE_CAST(FixedDoubleArray)
2475 // Maximal allowed size, in bytes, of a single FixedDoubleArray.
2476 // Prevents overflowing size computations, as well as extreme memory
2478 static const int kMaxSize = 512 * MB;
2479 // Maximally allowed length of a FixedArray.
2480 static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
2482 // Dispatched behavior.
2483 DECLARE_PRINTER(FixedDoubleArray)
2484 DECLARE_VERIFIER(FixedDoubleArray)
2487 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
2491 class WeakFixedArray : public FixedArray {
2493 // If |maybe_array| is not a WeakFixedArray, a fresh one will be allocated.
2494 // This function does not check if the value exists already, callers must
2495 // ensure this themselves if necessary.
2496 static Handle<WeakFixedArray> Add(Handle<Object> maybe_array,
2497 Handle<HeapObject> value,
2498 int* assigned_index = NULL);
2500 // Returns true if an entry was found and removed.
2501 bool Remove(Handle<HeapObject> value);
2503 class NullCallback {
2505 static void Callback(Object* value, int old_index, int new_index) {}
2508 template <class CompactionCallback>
2511 inline Object* Get(int index) const;
2512 inline void Clear(int index);
2513 inline int Length() const;
2515 inline bool IsEmptySlot(int index) const;
2516 static Object* Empty() { return Smi::FromInt(0); }
2520 explicit Iterator(Object* maybe_array) : list_(NULL) { Reset(maybe_array); }
2521 void Reset(Object* maybe_array);
2528 WeakFixedArray* list_;
2530 int last_used_index_;
2531 DisallowHeapAllocation no_gc_;
2533 DISALLOW_COPY_AND_ASSIGN(Iterator);
2536 DECLARE_CAST(WeakFixedArray)
2539 static const int kLastUsedIndexIndex = 0;
2540 static const int kFirstIndex = 1;
2542 static Handle<WeakFixedArray> Allocate(
2543 Isolate* isolate, int size, Handle<WeakFixedArray> initialize_from);
2545 static void Set(Handle<WeakFixedArray> array, int index,
2546 Handle<HeapObject> value);
2547 inline void clear(int index);
2549 inline int last_used_index() const;
2550 inline void set_last_used_index(int index);
2552 // Disallow inherited setters.
2553 void set(int index, Smi* value);
2554 void set(int index, Object* value);
2555 void set(int index, Object* value, WriteBarrierMode mode);
2556 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
2560 // Generic array grows dynamically with O(1) amortized insertion.
2561 class ArrayList : public FixedArray {
2565 // Use this if GC can delete elements from the array.
2566 kReloadLengthAfterAllocation,
2568 static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj,
2569 AddMode mode = kNone);
2570 static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj1,
2571 Handle<Object> obj2, AddMode = kNone);
2572 inline int Length();
2573 inline void SetLength(int length);
2574 inline Object* Get(int index);
2575 inline Object** Slot(int index);
2576 inline void Set(int index, Object* obj);
2577 inline void Clear(int index, Object* undefined);
2578 DECLARE_CAST(ArrayList)
2581 static Handle<ArrayList> EnsureSpace(Handle<ArrayList> array, int length);
2582 static const int kLengthIndex = 0;
2583 static const int kFirstIndex = 1;
2584 DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
2588 // DescriptorArrays are fixed arrays used to hold instance descriptors.
2589 // The format of the these objects is:
2590 // [0]: Number of descriptors
2591 // [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array:
2592 // [0]: pointer to fixed array with enum cache
2593 // [1]: either Smi(0) or pointer to fixed array with indices
2595 // [2 + number of descriptors * kDescriptorSize]: start of slack
2596 class DescriptorArray: public FixedArray {
2598 // Returns true for both shared empty_descriptor_array and for smis, which the
2599 // map uses to encode additional bit fields when the descriptor array is not
2601 inline bool IsEmpty();
2603 // Returns the number of descriptors in the array.
2604 inline int number_of_descriptors();
2606 inline int number_of_descriptors_storage();
2608 inline int NumberOfSlackDescriptors();
2610 inline void SetNumberOfDescriptors(int number_of_descriptors);
2611 inline int number_of_entries();
2613 inline bool HasEnumCache();
2615 inline void CopyEnumCacheFrom(DescriptorArray* array);
2617 inline FixedArray* GetEnumCache();
2619 inline bool HasEnumIndicesCache();
2621 inline FixedArray* GetEnumIndicesCache();
2623 inline Object** GetEnumCacheSlot();
2625 void ClearEnumCache();
2627 // Initialize or change the enum cache,
2628 // using the supplied storage for the small "bridge".
2629 void SetEnumCache(FixedArray* bridge_storage,
2630 FixedArray* new_cache,
2631 Object* new_index_cache);
2633 bool CanHoldValue(int descriptor, Object* value);
2635 // Accessors for fetching instance descriptor at descriptor number.
2636 inline Name* GetKey(int descriptor_number);
2637 inline Object** GetKeySlot(int descriptor_number);
2638 inline Object* GetValue(int descriptor_number);
2639 inline void SetValue(int descriptor_number, Object* value);
2640 inline Object** GetValueSlot(int descriptor_number);
2641 static inline int GetValueOffset(int descriptor_number);
2642 inline Object** GetDescriptorStartSlot(int descriptor_number);
2643 inline Object** GetDescriptorEndSlot(int descriptor_number);
2644 inline PropertyDetails GetDetails(int descriptor_number);
2645 inline PropertyType GetType(int descriptor_number);
2646 inline int GetFieldIndex(int descriptor_number);
2647 inline HeapType* GetFieldType(int descriptor_number);
2648 inline Object* GetConstant(int descriptor_number);
2649 inline Object* GetCallbacksObject(int descriptor_number);
2650 inline AccessorDescriptor* GetCallbacks(int descriptor_number);
2652 inline Name* GetSortedKey(int descriptor_number);
2653 inline int GetSortedKeyIndex(int descriptor_number);
2654 inline void SetSortedKey(int pointer, int descriptor_number);
2655 inline void SetRepresentation(int descriptor_number,
2656 Representation representation);
2658 // Accessor for complete descriptor.
2659 inline void Get(int descriptor_number, Descriptor* desc);
2660 inline void Set(int descriptor_number, Descriptor* desc);
2661 void Replace(int descriptor_number, Descriptor* descriptor);
2663 // Append automatically sets the enumeration index. This should only be used
2664 // to add descriptors in bulk at the end, followed by sorting the descriptor
2666 inline void Append(Descriptor* desc);
2668 static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc,
2669 int enumeration_index,
2672 static Handle<DescriptorArray> CopyUpToAddAttributes(
2673 Handle<DescriptorArray> desc,
2674 int enumeration_index,
2675 PropertyAttributes attributes,
2678 // Sort the instance descriptors by the hash codes of their keys.
2681 // Search the instance descriptors for given name.
2682 INLINE(int Search(Name* name, int number_of_own_descriptors));
2684 // As the above, but uses DescriptorLookupCache and updates it when
2686 INLINE(int SearchWithCache(Name* name, Map* map));
2688 // Allocates a DescriptorArray, but returns the singleton
2689 // empty descriptor array object if number_of_descriptors is 0.
2690 static Handle<DescriptorArray> Allocate(Isolate* isolate,
2691 int number_of_descriptors,
2694 DECLARE_CAST(DescriptorArray)
2696 // Constant for denoting key was not found.
2697 static const int kNotFound = -1;
2699 static const int kDescriptorLengthIndex = 0;
2700 static const int kEnumCacheIndex = 1;
2701 static const int kFirstIndex = 2;
2703 // The length of the "bridge" to the enum cache.
2704 static const int kEnumCacheBridgeLength = 2;
2705 static const int kEnumCacheBridgeCacheIndex = 0;
2706 static const int kEnumCacheBridgeIndicesCacheIndex = 1;
2708 // Layout description.
2709 static const int kDescriptorLengthOffset = FixedArray::kHeaderSize;
2710 static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize;
2711 static const int kFirstOffset = kEnumCacheOffset + kPointerSize;
2713 // Layout description for the bridge array.
2714 static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize;
2716 // Layout of descriptor.
2717 static const int kDescriptorKey = 0;
2718 static const int kDescriptorDetails = 1;
2719 static const int kDescriptorValue = 2;
2720 static const int kDescriptorSize = 3;
2722 #if defined(DEBUG) || defined(OBJECT_PRINT)
2723 // For our gdb macros, we should perhaps change these in the future.
2726 // Print all the descriptors.
2727 void PrintDescriptors(std::ostream& os); // NOLINT
2731 // Is the descriptor array sorted and without duplicates?
2732 bool IsSortedNoDuplicates(int valid_descriptors = -1);
2734 // Is the descriptor array consistent with the back pointers in targets?
2735 bool IsConsistentWithBackPointers(Map* current_map);
2737 // Are two DescriptorArrays equal?
2738 bool IsEqualTo(DescriptorArray* other);
2741 // Returns the fixed array length required to hold number_of_descriptors
2743 static int LengthFor(int number_of_descriptors) {
2744 return ToKeyIndex(number_of_descriptors);
2748 // WhitenessWitness is used to prove that a descriptor array is white
2749 // (unmarked), so incremental write barriers can be skipped because the
2750 // marking invariant cannot be broken and slots pointing into evacuation
2751 // candidates will be discovered when the object is scanned. A witness is
2752 // always stack-allocated right after creating an array. By allocating a
2753 // witness, incremental marking is globally disabled. The witness is then
2754 // passed along wherever needed to statically prove that the array is known to
2756 class WhitenessWitness {
2758 inline explicit WhitenessWitness(DescriptorArray* array);
2759 inline ~WhitenessWitness();
2762 IncrementalMarking* marking_;
2765 // An entry in a DescriptorArray, represented as an (array, index) pair.
2768 inline explicit Entry(DescriptorArray* descs, int index) :
2769 descs_(descs), index_(index) { }
2771 inline PropertyType type();
2772 inline Object* GetCallbackObject();
2775 DescriptorArray* descs_;
2779 // Conversion from descriptor number to array indices.
2780 static int ToKeyIndex(int descriptor_number) {
2781 return kFirstIndex +
2782 (descriptor_number * kDescriptorSize) +
2786 static int ToDetailsIndex(int descriptor_number) {
2787 return kFirstIndex +
2788 (descriptor_number * kDescriptorSize) +
2792 static int ToValueIndex(int descriptor_number) {
2793 return kFirstIndex +
2794 (descriptor_number * kDescriptorSize) +
2798 // Transfer a complete descriptor from the src descriptor array to this
2799 // descriptor array.
2800 void CopyFrom(int index, DescriptorArray* src, const WhitenessWitness&);
2802 inline void Set(int descriptor_number,
2804 const WhitenessWitness&);
2806 // Swap first and second descriptor.
2807 inline void SwapSortedKeys(int first, int second);
2809 DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
2813 enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
2815 template <SearchMode search_mode, typename T>
2816 inline int Search(T* array, Name* name, int valid_entries = 0,
2817 int* out_insertion_index = NULL);
2820 // HashTable is a subclass of FixedArray that implements a hash table
2821 // that uses open addressing and quadratic probing.
2823 // In order for the quadratic probing to work, elements that have not
2824 // yet been used and elements that have been deleted are
2825 // distinguished. Probing continues when deleted elements are
2826 // encountered and stops when unused elements are encountered.
2828 // - Elements with key == undefined have not been used yet.
2829 // - Elements with key == the_hole have been deleted.
2831 // The hash table class is parameterized with a Shape and a Key.
2832 // Shape must be a class with the following interface:
2833 // class ExampleShape {
2835 // // Tells whether key matches other.
2836 // static bool IsMatch(Key key, Object* other);
2837 // // Returns the hash value for key.
2838 // static uint32_t Hash(Key key);
2839 // // Returns the hash value for object.
2840 // static uint32_t HashForObject(Key key, Object* object);
2841 // // Convert key to an object.
2842 // static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
2843 // // The prefix size indicates number of elements in the beginning
2844 // // of the backing storage.
2845 // static const int kPrefixSize = ..;
2846 // // The Element size indicates number of elements per entry.
2847 // static const int kEntrySize = ..;
2849 // The prefix size indicates an amount of memory in the
2850 // beginning of the backing storage that can be used for non-element
2851 // information by subclasses.
2853 template<typename Key>
2856 static const bool UsesSeed = false;
2857 static uint32_t Hash(Key key) { return 0; }
2858 static uint32_t SeededHash(Key key, uint32_t seed) {
2862 static uint32_t HashForObject(Key key, Object* object) { return 0; }
2863 static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) {
2865 return HashForObject(key, object);
2870 class HashTableBase : public FixedArray {
2872 // Returns the number of elements in the hash table.
2873 inline int NumberOfElements();
2875 // Returns the number of deleted elements in the hash table.
2876 inline int NumberOfDeletedElements();
2878 // Returns the capacity of the hash table.
2879 inline int Capacity();
2881 // ElementAdded should be called whenever an element is added to a
2883 inline void ElementAdded();
2885 // ElementRemoved should be called whenever an element is removed from
2887 inline void ElementRemoved();
2888 inline void ElementsRemoved(int n);
2890 // Computes the required capacity for a table holding the given
2891 // number of elements. May be more than HashTable::kMaxCapacity.
2892 static inline int ComputeCapacity(int at_least_space_for);
2894 // Tells whether k is a real key. The hole and undefined are not allowed
2895 // as keys and can be used to indicate missing or deleted elements.
2896 inline bool IsKey(Object* k);
2898 // Compute the probe offset (quadratic probing).
2899 INLINE(static uint32_t GetProbeOffset(uint32_t n)) {
2900 return (n + n * n) >> 1;
2903 static const int kNumberOfElementsIndex = 0;
2904 static const int kNumberOfDeletedElementsIndex = 1;
2905 static const int kCapacityIndex = 2;
2906 static const int kPrefixStartIndex = 3;
2908 // Constant used for denoting a absent entry.
2909 static const int kNotFound = -1;
2912 // Update the number of elements in the hash table.
2913 inline void SetNumberOfElements(int nof);
2915 // Update the number of deleted elements in the hash table.
2916 inline void SetNumberOfDeletedElements(int nod);
2918 // Returns probe entry.
2919 static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) {
2920 DCHECK(base::bits::IsPowerOfTwo32(size));
2921 return (hash + GetProbeOffset(number)) & (size - 1);
2924 inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) {
2925 return hash & (size - 1);
2928 inline static uint32_t NextProbe(
2929 uint32_t last, uint32_t number, uint32_t size) {
2930 return (last + number) & (size - 1);
2935 template <typename Derived, typename Shape, typename Key>
2936 class HashTable : public HashTableBase {
2939 inline uint32_t Hash(Key key) {
2940 if (Shape::UsesSeed) {
2941 return Shape::SeededHash(key, GetHeap()->HashSeed());
2943 return Shape::Hash(key);
2947 inline uint32_t HashForObject(Key key, Object* object) {
2948 if (Shape::UsesSeed) {
2949 return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object);
2951 return Shape::HashForObject(key, object);
2955 // Returns a new HashTable object.
2956 MUST_USE_RESULT static Handle<Derived> New(
2957 Isolate* isolate, int at_least_space_for,
2958 MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
2959 PretenureFlag pretenure = NOT_TENURED);
2961 DECLARE_CAST(HashTable)
2963 // Garbage collection support.
2964 void IteratePrefix(ObjectVisitor* visitor);
2965 void IterateElements(ObjectVisitor* visitor);
2967 // Find entry for key otherwise return kNotFound.
2968 inline int FindEntry(Key key);
2969 inline int FindEntry(Isolate* isolate, Key key, int32_t hash);
2970 int FindEntry(Isolate* isolate, Key key);
2972 // Rehashes the table in-place.
2973 void Rehash(Key key);
2975 // Returns the key at entry.
2976 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
2978 static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize;
2979 static const int kEntrySize = Shape::kEntrySize;
2980 static const int kElementsStartOffset =
2981 kHeaderSize + kElementsStartIndex * kPointerSize;
2982 static const int kCapacityOffset =
2983 kHeaderSize + kCapacityIndex * kPointerSize;
2985 // Returns the index for an entry (of the key)
2986 static inline int EntryToIndex(int entry) {
2987 return (entry * kEntrySize) + kElementsStartIndex;
2991 friend class ObjectHashTable;
2993 // Find the entry at which to insert element with the given key that
2994 // has the given hash value.
2995 uint32_t FindInsertionEntry(uint32_t hash);
2997 // Attempt to shrink hash table after removal of key.
2998 MUST_USE_RESULT static Handle<Derived> Shrink(Handle<Derived> table, Key key);
3000 // Ensure enough space for n additional elements.
3001 MUST_USE_RESULT static Handle<Derived> EnsureCapacity(
3002 Handle<Derived> table,
3005 PretenureFlag pretenure = NOT_TENURED);
3007 // Sets the capacity of the hash table.
3008 void SetCapacity(int capacity) {
3009 // To scale a computed hash code to fit within the hash table, we
3010 // use bit-wise AND with a mask, so the capacity must be positive
3012 DCHECK(capacity > 0);
3013 DCHECK(capacity <= kMaxCapacity);
3014 set(kCapacityIndex, Smi::FromInt(capacity));
3017 // Maximal capacity of HashTable. Based on maximal length of underlying
3018 // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex
3020 static const int kMaxCapacity =
3021 (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize;
3024 // Returns _expected_ if one of entries given by the first _probe_ probes is
3025 // equal to _expected_. Otherwise, returns the entry given by the probe
3027 uint32_t EntryForProbe(Key key, Object* k, int probe, uint32_t expected);
3029 void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode);
3031 // Rehashes this hash-table into the new table.
3032 void Rehash(Handle<Derived> new_table, Key key);
3036 // HashTableKey is an abstract superclass for virtual key behavior.
3037 class HashTableKey {
3039 // Returns whether the other object matches this key.
3040 virtual bool IsMatch(Object* other) = 0;
3041 // Returns the hash value for this key.
3042 virtual uint32_t Hash() = 0;
3043 // Returns the hash value for object.
3044 virtual uint32_t HashForObject(Object* key) = 0;
3045 // Returns the key object for storing into the hash table.
3046 MUST_USE_RESULT virtual Handle<Object> AsHandle(Isolate* isolate) = 0;
3048 virtual ~HashTableKey() {}
3052 class StringTableShape : public BaseShape<HashTableKey*> {
3054 static inline bool IsMatch(HashTableKey* key, Object* value) {
3055 return key->IsMatch(value);
3058 static inline uint32_t Hash(HashTableKey* key) {
3062 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
3063 return key->HashForObject(object);
3066 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
3068 static const int kPrefixSize = 0;
3069 static const int kEntrySize = 1;
3072 class SeqOneByteString;
3076 // No special elements in the prefix and the element size is 1
3077 // because only the string itself (the key) needs to be stored.
3078 class StringTable: public HashTable<StringTable,
3082 // Find string in the string table. If it is not there yet, it is
3083 // added. The return value is the string found.
3084 static Handle<String> LookupString(Isolate* isolate, Handle<String> key);
3085 static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key);
3086 static String* LookupKeyIfExists(Isolate* isolate, HashTableKey* key);
3088 // Tries to internalize given string and returns string handle on success
3089 // or an empty handle otherwise.
3090 MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists(
3092 Handle<String> string);
3094 // Looks up a string that is equal to the given string and returns
3095 // string handle if it is found, or an empty handle otherwise.
3096 MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists(
3098 Handle<String> str);
3099 MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists(
3104 static void EnsureCapacityForDeserialization(Isolate* isolate, int expected);
3106 DECLARE_CAST(StringTable)
3109 template <bool seq_one_byte>
3110 friend class JsonParser;
3112 DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable);
3116 template <typename Derived, typename Shape, typename Key>
3117 class Dictionary: public HashTable<Derived, Shape, Key> {
3118 typedef HashTable<Derived, Shape, Key> DerivedHashTable;
3121 // Returns the value at entry.
3122 Object* ValueAt(int entry) {
3123 return this->get(Derived::EntryToIndex(entry) + 1);
3126 // Set the value for entry.
3127 void ValueAtPut(int entry, Object* value) {
3128 this->set(Derived::EntryToIndex(entry) + 1, value);
3131 // Returns the property details for the property at entry.
3132 PropertyDetails DetailsAt(int entry) {
3133 return Shape::DetailsAt(static_cast<Derived*>(this), entry);
3136 // Set the details for entry.
3137 void DetailsAtPut(int entry, PropertyDetails value) {
3138 Shape::DetailsAtPut(static_cast<Derived*>(this), entry, value);
3141 // Returns true if property at given entry is deleted.
3142 bool IsDeleted(int entry) {
3143 return Shape::IsDeleted(static_cast<Derived*>(this), entry);
3146 // Delete a property from the dictionary.
3147 static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry);
3149 // Attempt to shrink the dictionary after deletion of key.
3150 MUST_USE_RESULT static inline Handle<Derived> Shrink(
3151 Handle<Derived> dictionary,
3153 return DerivedHashTable::Shrink(dictionary, key);
3157 // TODO(dcarney): templatize or move to SeededNumberDictionary
3158 void CopyValuesTo(FixedArray* elements);
3160 // Returns the number of elements in the dictionary filtering out properties
3161 // with the specified attributes.
3162 int NumberOfElementsFilterAttributes(PropertyAttributes filter);
3164 // Returns the number of enumerable elements in the dictionary.
3165 int NumberOfEnumElements() {
3166 return NumberOfElementsFilterAttributes(
3167 static_cast<PropertyAttributes>(DONT_ENUM | SYMBOLIC));
3170 // Returns true if the dictionary contains any elements that are non-writable,
3171 // non-configurable, non-enumerable, or have getters/setters.
3172 bool HasComplexElements();
3174 enum SortMode { UNSORTED, SORTED };
3176 // Fill in details for properties into storage.
3177 // Returns the number of properties added.
3178 int CopyKeysTo(FixedArray* storage, int index, PropertyAttributes filter,
3179 SortMode sort_mode);
3181 // Copies enumerable keys to preallocated fixed array.
3182 void CopyEnumKeysTo(FixedArray* storage);
3184 // Accessors for next enumeration index.
3185 void SetNextEnumerationIndex(int index) {
3187 this->set(kNextEnumerationIndexIndex, Smi::FromInt(index));
3190 int NextEnumerationIndex() {
3191 return Smi::cast(this->get(kNextEnumerationIndexIndex))->value();
3194 // Creates a new dictionary.
3195 MUST_USE_RESULT static Handle<Derived> New(
3197 int at_least_space_for,
3198 PretenureFlag pretenure = NOT_TENURED);
3200 // Ensure enough space for n additional elements.
3201 static Handle<Derived> EnsureCapacity(Handle<Derived> obj, int n, Key key);
3204 void Print(std::ostream& os); // NOLINT
3206 // Returns the key (slow).
3207 Object* SlowReverseLookup(Object* value);
3209 // Sets the entry to (key, value) pair.
3210 inline void SetEntry(int entry,
3212 Handle<Object> value);
3213 inline void SetEntry(int entry,
3215 Handle<Object> value,
3216 PropertyDetails details);
3218 MUST_USE_RESULT static Handle<Derived> Add(
3219 Handle<Derived> dictionary,
3221 Handle<Object> value,
3222 PropertyDetails details);
3224 // Returns iteration indices array for the |dictionary|.
3225 // Values are direct indices in the |HashTable| array.
3226 static Handle<FixedArray> BuildIterationIndicesArray(
3227 Handle<Derived> dictionary);
3230 // Generic at put operation.
3231 MUST_USE_RESULT static Handle<Derived> AtPut(
3232 Handle<Derived> dictionary,
3234 Handle<Object> value);
3236 // Add entry to dictionary.
3237 static void AddEntry(
3238 Handle<Derived> dictionary,
3240 Handle<Object> value,
3241 PropertyDetails details,
3244 // Generate new enumeration indices to avoid enumeration index overflow.
3245 // Returns iteration indices array for the |dictionary|.
3246 static Handle<FixedArray> GenerateNewEnumerationIndices(
3247 Handle<Derived> dictionary);
3248 static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex;
3249 static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
3253 template <typename Derived, typename Shape>
3254 class NameDictionaryBase : public Dictionary<Derived, Shape, Handle<Name> > {
3255 typedef Dictionary<Derived, Shape, Handle<Name> > DerivedDictionary;
3258 // Find entry for key, otherwise return kNotFound. Optimized version of
3259 // HashTable::FindEntry.
3260 int FindEntry(Handle<Name> key);
3264 template <typename Key>
3265 class BaseDictionaryShape : public BaseShape<Key> {
3267 template <typename Dictionary>
3268 static inline PropertyDetails DetailsAt(Dictionary* dict, int entry) {
3269 STATIC_ASSERT(Dictionary::kEntrySize == 3);
3270 DCHECK(entry >= 0); // Not found is -1, which is not caught by get().
3271 return PropertyDetails(
3272 Smi::cast(dict->get(Dictionary::EntryToIndex(entry) + 2)));
3275 template <typename Dictionary>
3276 static inline void DetailsAtPut(Dictionary* dict, int entry,
3277 PropertyDetails value) {
3278 STATIC_ASSERT(Dictionary::kEntrySize == 3);
3279 dict->set(Dictionary::EntryToIndex(entry) + 2, value.AsSmi());
3282 template <typename Dictionary>
3283 static bool IsDeleted(Dictionary* dict, int entry) {
3287 template <typename Dictionary>
3288 static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key,
3289 Handle<Object> value, PropertyDetails details);
3293 class NameDictionaryShape : public BaseDictionaryShape<Handle<Name> > {
3295 static inline bool IsMatch(Handle<Name> key, Object* other);
3296 static inline uint32_t Hash(Handle<Name> key);
3297 static inline uint32_t HashForObject(Handle<Name> key, Object* object);
3298 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
3299 static const int kPrefixSize = 2;
3300 static const int kEntrySize = 3;
3301 static const bool kIsEnumerable = true;
3305 class NameDictionary
3306 : public NameDictionaryBase<NameDictionary, NameDictionaryShape> {
3307 typedef NameDictionaryBase<NameDictionary, NameDictionaryShape>
3311 DECLARE_CAST(NameDictionary)
3313 inline static Handle<FixedArray> DoGenerateNewEnumerationIndices(
3314 Handle<NameDictionary> dictionary);
3318 class GlobalDictionaryShape : public NameDictionaryShape {
3320 static const int kEntrySize = 2; // Overrides NameDictionaryShape::kEntrySize
3322 template <typename Dictionary>
3323 static inline PropertyDetails DetailsAt(Dictionary* dict, int entry);
3325 template <typename Dictionary>
3326 static inline void DetailsAtPut(Dictionary* dict, int entry,
3327 PropertyDetails value);
3329 template <typename Dictionary>
3330 static bool IsDeleted(Dictionary* dict, int entry);
3332 template <typename Dictionary>
3333 static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key,
3334 Handle<Object> value, PropertyDetails details);
3338 class GlobalDictionary
3339 : public NameDictionaryBase<GlobalDictionary, GlobalDictionaryShape> {
3341 DECLARE_CAST(GlobalDictionary)
3345 class NumberDictionaryShape : public BaseDictionaryShape<uint32_t> {
3347 static inline bool IsMatch(uint32_t key, Object* other);
3348 static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key);
3349 static const int kEntrySize = 3;
3350 static const bool kIsEnumerable = false;
3354 class SeededNumberDictionaryShape : public NumberDictionaryShape {
3356 static const bool UsesSeed = true;
3357 static const int kPrefixSize = 2;
3359 static inline uint32_t SeededHash(uint32_t key, uint32_t seed);
3360 static inline uint32_t SeededHashForObject(uint32_t key,
3366 class UnseededNumberDictionaryShape : public NumberDictionaryShape {
3368 static const int kPrefixSize = 0;
3370 static inline uint32_t Hash(uint32_t key);
3371 static inline uint32_t HashForObject(uint32_t key, Object* object);
3375 class SeededNumberDictionary
3376 : public Dictionary<SeededNumberDictionary,
3377 SeededNumberDictionaryShape,
3380 DECLARE_CAST(SeededNumberDictionary)
3382 // Type specific at put (default NONE attributes is used when adding).
3383 MUST_USE_RESULT static Handle<SeededNumberDictionary> AtNumberPut(
3384 Handle<SeededNumberDictionary> dictionary, uint32_t key,
3385 Handle<Object> value, bool used_as_prototype);
3386 MUST_USE_RESULT static Handle<SeededNumberDictionary> AddNumberEntry(
3387 Handle<SeededNumberDictionary> dictionary, uint32_t key,
3388 Handle<Object> value, PropertyDetails details, bool used_as_prototype);
3390 // Set an existing entry or add a new one if needed.
3391 // Return the updated dictionary.
3392 MUST_USE_RESULT static Handle<SeededNumberDictionary> Set(
3393 Handle<SeededNumberDictionary> dictionary, uint32_t key,
3394 Handle<Object> value, PropertyDetails details, bool used_as_prototype);
3396 void UpdateMaxNumberKey(uint32_t key, bool used_as_prototype);
3398 // If slow elements are required we will never go back to fast-case
3399 // for the elements kept in this dictionary. We require slow
3400 // elements if an element has been added at an index larger than
3401 // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called
3402 // when defining a getter or setter with a number key.
3403 inline bool requires_slow_elements();
3404 inline void set_requires_slow_elements();
3406 // Get the value of the max number key that has been added to this
3407 // dictionary. max_number_key can only be called if
3408 // requires_slow_elements returns false.
3409 inline uint32_t max_number_key();
3412 static const int kRequiresSlowElementsMask = 1;
3413 static const int kRequiresSlowElementsTagSize = 1;
3414 static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1;
3418 class UnseededNumberDictionary
3419 : public Dictionary<UnseededNumberDictionary,
3420 UnseededNumberDictionaryShape,
3423 DECLARE_CAST(UnseededNumberDictionary)
3425 // Type specific at put (default NONE attributes is used when adding).
3426 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AtNumberPut(
3427 Handle<UnseededNumberDictionary> dictionary,
3429 Handle<Object> value);
3430 MUST_USE_RESULT static Handle<UnseededNumberDictionary> AddNumberEntry(
3431 Handle<UnseededNumberDictionary> dictionary,
3433 Handle<Object> value);
3435 // Set an existing entry or add a new one if needed.
3436 // Return the updated dictionary.
3437 MUST_USE_RESULT static Handle<UnseededNumberDictionary> Set(
3438 Handle<UnseededNumberDictionary> dictionary,
3440 Handle<Object> value);
3444 class ObjectHashTableShape : public BaseShape<Handle<Object> > {
3446 static inline bool IsMatch(Handle<Object> key, Object* other);
3447 static inline uint32_t Hash(Handle<Object> key);
3448 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
3449 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
3450 static const int kPrefixSize = 0;
3451 static const int kEntrySize = 2;
3455 // ObjectHashTable maps keys that are arbitrary objects to object values by
3456 // using the identity hash of the key for hashing purposes.
3457 class ObjectHashTable: public HashTable<ObjectHashTable,
3458 ObjectHashTableShape,
3461 ObjectHashTable, ObjectHashTableShape, Handle<Object> > DerivedHashTable;
3463 DECLARE_CAST(ObjectHashTable)
3465 // Attempt to shrink hash table after removal of key.
3466 MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink(
3467 Handle<ObjectHashTable> table,
3468 Handle<Object> key);
3470 // Looks up the value associated with the given key. The hole value is
3471 // returned in case the key is not present.
3472 Object* Lookup(Handle<Object> key);
3473 Object* Lookup(Handle<Object> key, int32_t hash);
3474 Object* Lookup(Isolate* isolate, Handle<Object> key, int32_t hash);
3476 // Adds (or overwrites) the value associated with the given key.
3477 static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
3479 Handle<Object> value);
3480 static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
3481 Handle<Object> key, Handle<Object> value,
3484 // Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
3485 static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
3488 static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
3489 Handle<Object> key, bool* was_present,
3493 friend class MarkCompactCollector;
3495 void AddEntry(int entry, Object* key, Object* value);
3496 void RemoveEntry(int entry);
3498 // Returns the index to the value of an entry.
3499 static inline int EntryToValueIndex(int entry) {
3500 return EntryToIndex(entry) + 1;
3505 // OrderedHashTable is a HashTable with Object keys that preserves
3506 // insertion order. There are Map and Set interfaces (OrderedHashMap
3507 // and OrderedHashTable, below). It is meant to be used by JSMap/JSSet.
3509 // Only Object* keys are supported, with Object::SameValueZero() used as the
3510 // equality operator and Object::GetHash() for the hash function.
3512 // Based on the "Deterministic Hash Table" as described by Jason Orendorff at
3513 // https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables
3514 // Originally attributed to Tyler Close.
3517 // [0]: bucket count
3518 // [1]: element count
3519 // [2]: deleted element count
3520 // [3..(3 + NumberOfBuckets() - 1)]: "hash table", where each item is an
3521 // offset into the data table (see below) where the
3522 // first item in this bucket is stored.
3523 // [3 + NumberOfBuckets()..length]: "data table", an array of length
3524 // Capacity() * kEntrySize, where the first entrysize
3525 // items are handled by the derived class and the
3526 // item at kChainOffset is another entry into the
3527 // data table indicating the next entry in this hash
3530 // When we transition the table to a new version we obsolete it and reuse parts
3531 // of the memory to store information how to transition an iterator to the new
3534 // Memory layout for obsolete table:
3535 // [0]: bucket count
3536 // [1]: Next newer table
3537 // [2]: Number of removed holes or -1 when the table was cleared.
3538 // [3..(3 + NumberOfRemovedHoles() - 1)]: The indexes of the removed holes.
3539 // [3 + NumberOfRemovedHoles()..length]: Not used
3541 template<class Derived, class Iterator, int entrysize>
3542 class OrderedHashTable: public FixedArray {
3544 // Returns an OrderedHashTable with a capacity of at least |capacity|.
3545 static Handle<Derived> Allocate(
3546 Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED);
3548 // Returns an OrderedHashTable (possibly |table|) with enough space
3549 // to add at least one new element.
3550 static Handle<Derived> EnsureGrowable(Handle<Derived> table);
3552 // Returns an OrderedHashTable (possibly |table|) that's shrunken
3554 static Handle<Derived> Shrink(Handle<Derived> table);
3556 // Returns a new empty OrderedHashTable and records the clearing so that
3557 // exisiting iterators can be updated.
3558 static Handle<Derived> Clear(Handle<Derived> table);
3560 int NumberOfElements() {
3561 return Smi::cast(get(kNumberOfElementsIndex))->value();
3564 int NumberOfDeletedElements() {
3565 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
3568 int UsedCapacity() { return NumberOfElements() + NumberOfDeletedElements(); }
3570 int NumberOfBuckets() {
3571 return Smi::cast(get(kNumberOfBucketsIndex))->value();
3574 // Returns an index into |this| for the given entry.
3575 int EntryToIndex(int entry) {
3576 return kHashTableStartIndex + NumberOfBuckets() + (entry * kEntrySize);
3579 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
3582 return !get(kNextTableIndex)->IsSmi();
3585 // The next newer table. This is only valid if the table is obsolete.
3586 Derived* NextTable() {
3587 return Derived::cast(get(kNextTableIndex));
3590 // When the table is obsolete we store the indexes of the removed holes.
3591 int RemovedIndexAt(int index) {
3592 return Smi::cast(get(kRemovedHolesIndex + index))->value();
3595 static const int kNotFound = -1;
3596 static const int kMinCapacity = 4;
3598 static const int kNumberOfBucketsIndex = 0;
3599 static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1;
3600 static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
3601 static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1;
3602 static const int kNextTableIndex = kNumberOfElementsIndex;
3604 static const int kNumberOfBucketsOffset =
3605 kHeaderSize + kNumberOfBucketsIndex * kPointerSize;
3606 static const int kNumberOfElementsOffset =
3607 kHeaderSize + kNumberOfElementsIndex * kPointerSize;
3608 static const int kNumberOfDeletedElementsOffset =
3609 kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize;
3610 static const int kHashTableStartOffset =
3611 kHeaderSize + kHashTableStartIndex * kPointerSize;
3612 static const int kNextTableOffset =
3613 kHeaderSize + kNextTableIndex * kPointerSize;
3615 static const int kEntrySize = entrysize + 1;
3616 static const int kChainOffset = entrysize;
3618 static const int kLoadFactor = 2;
3620 // NumberOfDeletedElements is set to kClearedTableSentinel when
3621 // the table is cleared, which allows iterator transitions to
3622 // optimize that case.
3623 static const int kClearedTableSentinel = -1;
3626 static Handle<Derived> Rehash(Handle<Derived> table, int new_capacity);
3628 void SetNumberOfBuckets(int num) {
3629 set(kNumberOfBucketsIndex, Smi::FromInt(num));
3632 void SetNumberOfElements(int num) {
3633 set(kNumberOfElementsIndex, Smi::FromInt(num));
3636 void SetNumberOfDeletedElements(int num) {
3637 set(kNumberOfDeletedElementsIndex, Smi::FromInt(num));
3641 return NumberOfBuckets() * kLoadFactor;
3644 void SetNextTable(Derived* next_table) {
3645 set(kNextTableIndex, next_table);
3648 void SetRemovedIndexAt(int index, int removed_index) {
3649 return set(kRemovedHolesIndex + index, Smi::FromInt(removed_index));
3652 static const int kRemovedHolesIndex = kHashTableStartIndex;
3654 static const int kMaxCapacity =
3655 (FixedArray::kMaxLength - kHashTableStartIndex)
3656 / (1 + (kEntrySize * kLoadFactor));
3660 class JSSetIterator;
3663 class OrderedHashSet: public OrderedHashTable<
3664 OrderedHashSet, JSSetIterator, 1> {
3666 DECLARE_CAST(OrderedHashSet)
3670 class JSMapIterator;
3673 class OrderedHashMap
3674 : public OrderedHashTable<OrderedHashMap, JSMapIterator, 2> {
3676 DECLARE_CAST(OrderedHashMap)
3678 inline Object* ValueAt(int entry);
3680 static const int kValueOffset = 1;
3684 template <int entrysize>
3685 class WeakHashTableShape : public BaseShape<Handle<Object> > {
3687 static inline bool IsMatch(Handle<Object> key, Object* other);
3688 static inline uint32_t Hash(Handle<Object> key);
3689 static inline uint32_t HashForObject(Handle<Object> key, Object* object);
3690 static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
3691 static const int kPrefixSize = 0;
3692 static const int kEntrySize = entrysize;
3696 // WeakHashTable maps keys that are arbitrary heap objects to heap object
3697 // values. The table wraps the keys in weak cells and store values directly.
3698 // Thus it references keys weakly and values strongly.
3699 class WeakHashTable: public HashTable<WeakHashTable,
3700 WeakHashTableShape<2>,
3703 WeakHashTable, WeakHashTableShape<2>, Handle<Object> > DerivedHashTable;
3705 DECLARE_CAST(WeakHashTable)
3707 // Looks up the value associated with the given key. The hole value is
3708 // returned in case the key is not present.
3709 Object* Lookup(Handle<HeapObject> key);
3711 // Adds (or overwrites) the value associated with the given key. Mapping a
3712 // key to the hole value causes removal of the whole entry.
3713 MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table,
3714 Handle<HeapObject> key,
3715 Handle<HeapObject> value);
3717 static Handle<FixedArray> GetValues(Handle<WeakHashTable> table);
3720 friend class MarkCompactCollector;
3722 void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value);
3724 // Returns the index to the value of an entry.
3725 static inline int EntryToValueIndex(int entry) {
3726 return EntryToIndex(entry) + 1;
3731 // ScopeInfo represents information about different scopes of a source
3732 // program and the allocation of the scope's variables. Scope information
3733 // is stored in a compressed form in ScopeInfo objects and is used
3734 // at runtime (stack dumps, deoptimization, etc.).
3736 // This object provides quick access to scope info details for runtime
3738 class ScopeInfo : public FixedArray {
3740 DECLARE_CAST(ScopeInfo)
3742 // Return the type of this scope.
3743 ScopeType scope_type();
3745 // Does this scope call eval?
3748 // Return the language mode of this scope.
3749 LanguageMode language_mode();
3751 // Does this scope make a sloppy eval call?
3752 bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); }
3754 // Return the total number of locals allocated on the stack and in the
3755 // context. This includes the parameters that are allocated in the context.
3758 // Return the number of stack slots for code. This number consists of two
3760 // 1. One stack slot per stack allocated local.
3761 // 2. One stack slot for the function name if it is stack allocated.
3762 int StackSlotCount();
3764 // Return the number of context slots for code if a context is allocated. This
3765 // number consists of three parts:
3766 // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS
3767 // 2. One context slot per context allocated local.
3768 // 3. One context slot for the function name if it is context allocated.
3769 // Parameters allocated in the context count as context allocated locals. If
3770 // no contexts are allocated for this scope ContextLength returns 0.
3771 int ContextLength();
3773 // Does this scope declare a "this" binding?
3776 // Does this scope declare a "this" binding, and the "this" binding is stack-
3777 // or context-allocated?
3778 bool HasAllocatedReceiver();
3780 // Is this scope the scope of a named function expression?
3781 bool HasFunctionName();
3783 // Return if this has context allocated locals.
3784 bool HasHeapAllocatedLocals();
3786 // Return if contexts are allocated for this scope.
3789 // Return if this is a function scope with "use asm".
3790 inline bool IsAsmModule();
3792 // Return if this is a nested function within an asm module scope.
3793 inline bool IsAsmFunction();
3795 inline bool HasSimpleParameters();
3797 // Return the function_name if present.
3798 String* FunctionName();
3800 // Return the name of the given parameter.
3801 String* ParameterName(int var);
3803 // Return the name of the given local.
3804 String* LocalName(int var);
3806 // Return the name of the given stack local.
3807 String* StackLocalName(int var);
3809 // Return the name of the given stack local.
3810 int StackLocalIndex(int var);
3812 // Return the name of the given context local.
3813 String* ContextLocalName(int var);
3815 // Return the mode of the given context local.
3816 VariableMode ContextLocalMode(int var);
3818 // Return the initialization flag of the given context local.
3819 InitializationFlag ContextLocalInitFlag(int var);
3821 // Return the initialization flag of the given context local.
3822 MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var);
3824 // Return true if this local was introduced by the compiler, and should not be
3825 // exposed to the user in a debugger.
3826 bool LocalIsSynthetic(int var);
3828 String* StrongModeFreeVariableName(int var);
3829 int StrongModeFreeVariableStartPosition(int var);
3830 int StrongModeFreeVariableEndPosition(int var);
3832 // Lookup support for serialized scope info. Returns the
3833 // the stack slot index for a given slot name if the slot is
3834 // present; otherwise returns a value < 0. The name must be an internalized
3836 int StackSlotIndex(String* name);
3838 // Lookup support for serialized scope info. Returns the
3839 // context slot index for a given slot name if the slot is present; otherwise
3840 // returns a value < 0. The name must be an internalized string.
3841 // If the slot is present and mode != NULL, sets *mode to the corresponding
3842 // mode for that variable.
3843 static int ContextSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name,
3844 VariableMode* mode, VariableLocation* location,
3845 InitializationFlag* init_flag,
3846 MaybeAssignedFlag* maybe_assigned_flag);
3848 // Lookup the name of a certain context slot by its index.
3849 String* ContextSlotName(int slot_index);
3851 // Lookup support for serialized scope info. Returns the
3852 // parameter index for a given parameter name if the parameter is present;
3853 // otherwise returns a value < 0. The name must be an internalized string.
3854 int ParameterIndex(String* name);
3856 // Lookup support for serialized scope info. Returns the function context
3857 // slot index if the function name is present and context-allocated (named
3858 // function expressions, only), otherwise returns a value < 0. The name
3859 // must be an internalized string.
3860 int FunctionContextSlotIndex(String* name, VariableMode* mode);
3862 // Lookup support for serialized scope info. Returns the receiver context
3863 // slot index if scope has a "this" binding, and the binding is
3864 // context-allocated. Otherwise returns a value < 0.
3865 int ReceiverContextSlotIndex();
3867 FunctionKind function_kind();
3869 static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope);
3870 static Handle<ScopeInfo> CreateGlobalThisBinding(Isolate* isolate);
3872 // Serializes empty scope info.
3873 static ScopeInfo* Empty(Isolate* isolate);
3879 // The layout of the static part of a ScopeInfo is as follows. Each entry is
3880 // numeric and occupies one array slot.
3881 // 1. A set of properties of the scope
3882 // 2. The number of parameters. This only applies to function scopes. For
3883 // non-function scopes this is 0.
3884 // 3. The number of non-parameter variables allocated on the stack.
3885 // 4. The number of non-parameter and parameter variables allocated in the
3887 #define FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(V) \
3890 V(StackLocalCount) \
3891 V(ContextLocalCount) \
3892 V(ContextGlobalCount) \
3893 V(StrongModeFreeVariableCount)
3895 #define FIELD_ACCESSORS(name) \
3896 inline void Set##name(int value); \
3898 FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(FIELD_ACCESSORS)
3899 #undef FIELD_ACCESSORS
3903 #define DECL_INDEX(name) k##name,
3904 FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(DECL_INDEX)
3909 // The layout of the variable part of a ScopeInfo is as follows:
3910 // 1. ParameterEntries:
3911 // This part stores the names of the parameters for function scopes. One
3912 // slot is used per parameter, so in total this part occupies
3913 // ParameterCount() slots in the array. For other scopes than function
3914 // scopes ParameterCount() is 0.
3915 // 2. StackLocalFirstSlot:
3916 // Index of a first stack slot for stack local. Stack locals belonging to
3917 // this scope are located on a stack at slots starting from this index.
3918 // 3. StackLocalEntries:
3919 // Contains the names of local variables that are allocated on the stack,
3920 // in increasing order of the stack slot index. First local variable has
3921 // a stack slot index defined in StackLocalFirstSlot (point 2 above).
3922 // One slot is used per stack local, so in total this part occupies
3923 // StackLocalCount() slots in the array.
3924 // 4. ContextLocalNameEntries:
3925 // Contains the names of local variables and parameters that are allocated
3926 // in the context. They are stored in increasing order of the context slot
3927 // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
3928 // context local, so in total this part occupies ContextLocalCount() slots
3930 // 5. ContextLocalInfoEntries:
3931 // Contains the variable modes and initialization flags corresponding to
3932 // the context locals in ContextLocalNameEntries. One slot is used per
3933 // context local, so in total this part occupies ContextLocalCount()
3934 // slots in the array.
3935 // 6. StrongModeFreeVariableNameEntries:
3936 // Stores the names of strong mode free variables.
3937 // 7. StrongModeFreeVariablePositionEntries:
3938 // Stores the locations (start and end position) of strong mode free
3940 // 8. RecieverEntryIndex:
3941 // If the scope binds a "this" value, one slot is reserved to hold the
3942 // context or stack slot index for the variable.
3943 // 9. FunctionNameEntryIndex:
3944 // If the scope belongs to a named function expression this part contains
3945 // information about the function variable. It always occupies two array
3946 // slots: a. The name of the function variable.
3947 // b. The context or stack slot index for the variable.
3948 int ParameterEntriesIndex();
3949 int StackLocalFirstSlotIndex();
3950 int StackLocalEntriesIndex();
3951 int ContextLocalNameEntriesIndex();
3952 int ContextGlobalNameEntriesIndex();
3953 int ContextLocalInfoEntriesIndex();
3954 int ContextGlobalInfoEntriesIndex();
3955 int StrongModeFreeVariableNameEntriesIndex();
3956 int StrongModeFreeVariablePositionEntriesIndex();
3957 int ReceiverEntryIndex();
3958 int FunctionNameEntryIndex();
3960 int Lookup(Handle<String> name, int start, int end, VariableMode* mode,
3961 VariableLocation* location, InitializationFlag* init_flag,
3962 MaybeAssignedFlag* maybe_assigned_flag);
3964 // Used for the function name variable for named function expressions, and for
3966 enum VariableAllocationInfo { NONE, STACK, CONTEXT, UNUSED };
3968 // Properties of scopes.
3969 class ScopeTypeField : public BitField<ScopeType, 0, 4> {};
3970 class CallsEvalField : public BitField<bool, ScopeTypeField::kNext, 1> {};
3971 STATIC_ASSERT(LANGUAGE_END == 3);
3972 class LanguageModeField
3973 : public BitField<LanguageMode, CallsEvalField::kNext, 2> {};
3974 class ReceiverVariableField
3975 : public BitField<VariableAllocationInfo, LanguageModeField::kNext, 2> {};
3976 class FunctionVariableField
3977 : public BitField<VariableAllocationInfo, ReceiverVariableField::kNext,
3979 class FunctionVariableMode
3980 : public BitField<VariableMode, FunctionVariableField::kNext, 3> {};
3981 class AsmModuleField : public BitField<bool, FunctionVariableMode::kNext, 1> {
3983 class AsmFunctionField : public BitField<bool, AsmModuleField::kNext, 1> {};
3984 class HasSimpleParametersField
3985 : public BitField<bool, AsmFunctionField::kNext, 1> {};
3986 class FunctionKindField
3987 : public BitField<FunctionKind, HasSimpleParametersField::kNext, 8> {};
3989 // BitFields representing the encoded information for context locals in the
3990 // ContextLocalInfoEntries part.
3991 class ContextLocalMode: public BitField<VariableMode, 0, 3> {};
3992 class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {};
3993 class ContextLocalMaybeAssignedFlag
3994 : public BitField<MaybeAssignedFlag, 4, 1> {};
3996 friend class ScopeIterator;
4000 // The cache for maps used by normalized (dictionary mode) objects.
4001 // Such maps do not have property descriptors, so a typical program
4002 // needs very limited number of distinct normalized maps.
4003 class NormalizedMapCache: public FixedArray {
4005 static Handle<NormalizedMapCache> New(Isolate* isolate);
4007 MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
4008 PropertyNormalizationMode mode);
4009 void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
4013 DECLARE_CAST(NormalizedMapCache)
4015 static inline bool IsNormalizedMapCache(const Object* obj);
4017 DECLARE_VERIFIER(NormalizedMapCache)
4019 static const int kEntries = 64;
4021 static inline int GetIndex(Handle<Map> map);
4023 // The following declarations hide base class methods.
4024 Object* get(int index);
4025 void set(int index, Object* value);
4029 // ByteArray represents fixed sized byte arrays. Used for the relocation info
4030 // that is attached to code objects.
4031 class ByteArray: public FixedArrayBase {
4035 // Setter and getter.
4036 inline byte get(int index);
4037 inline void set(int index, byte value);
4039 // Treat contents as an int array.
4040 inline int get_int(int index);
4042 static int SizeFor(int length) {
4043 return OBJECT_POINTER_ALIGN(kHeaderSize + length);
4045 // We use byte arrays for free blocks in the heap. Given a desired size in
4046 // bytes that is a multiple of the word size and big enough to hold a byte
4047 // array, this function returns the number of elements a byte array should
4049 static int LengthFor(int size_in_bytes) {
4050 DCHECK(IsAligned(size_in_bytes, kPointerSize));
4051 DCHECK(size_in_bytes >= kHeaderSize);
4052 return size_in_bytes - kHeaderSize;
4055 // Returns data start address.
4056 inline Address GetDataStartAddress();
4058 // Returns a pointer to the ByteArray object for a given data start address.
4059 static inline ByteArray* FromDataStartAddress(Address address);
4061 DECLARE_CAST(ByteArray)
4063 // Dispatched behavior.
4064 inline int ByteArraySize();
4065 DECLARE_PRINTER(ByteArray)
4066 DECLARE_VERIFIER(ByteArray)
4068 // Layout description.
4069 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4071 // Maximal memory consumption for a single ByteArray.
4072 static const int kMaxSize = 512 * MB;
4073 // Maximal length of a single ByteArray.
4074 static const int kMaxLength = kMaxSize - kHeaderSize;
4077 DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
4081 // BytecodeArray represents a sequence of interpreter bytecodes.
4082 class BytecodeArray : public FixedArrayBase {
4084 static int SizeFor(int length) {
4085 return OBJECT_POINTER_ALIGN(kHeaderSize + length);
4088 // Setter and getter
4089 inline byte get(int index);
4090 inline void set(int index, byte value);
4092 // Returns data start address.
4093 inline Address GetFirstBytecodeAddress();
4095 // Accessors for frame size and the number of locals
4096 inline int frame_size() const;
4097 inline void set_frame_size(int value);
4099 DECLARE_CAST(BytecodeArray)
4101 // Dispatched behavior.
4102 inline int BytecodeArraySize();
4104 DECLARE_PRINTER(BytecodeArray)
4105 DECLARE_VERIFIER(BytecodeArray)
4107 void Disassemble(std::ostream& os);
4109 // Layout description.
4110 static const int kFrameSizeOffset = FixedArrayBase::kHeaderSize;
4111 static const int kHeaderSize = kFrameSizeOffset + kIntSize;
4113 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
4115 // Maximal memory consumption for a single BytecodeArray.
4116 static const int kMaxSize = 512 * MB;
4117 // Maximal length of a single BytecodeArray.
4118 static const int kMaxLength = kMaxSize - kHeaderSize;
4121 DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArray);
4125 // FreeSpace are fixed-size free memory blocks used by the heap and GC.
4126 // They look like heap objects (are heap object tagged and have a map) so that
4127 // the heap remains iterable. They have a size and a next pointer.
4128 // The next pointer is the raw address of the next FreeSpace object (or NULL)
4129 // in the free list.
4130 class FreeSpace: public HeapObject {
4132 // [size]: size of the free space including the header.
4133 inline int size() const;
4134 inline void set_size(int value);
4136 inline int nobarrier_size() const;
4137 inline void nobarrier_set_size(int value);
4141 // Accessors for the next field.
4142 inline FreeSpace* next();
4143 inline FreeSpace** next_address();
4144 inline void set_next(FreeSpace* next);
4146 inline static FreeSpace* cast(HeapObject* obj);
4148 // Dispatched behavior.
4149 DECLARE_PRINTER(FreeSpace)
4150 DECLARE_VERIFIER(FreeSpace)
4152 // Layout description.
4153 // Size is smi tagged when it is stored.
4154 static const int kSizeOffset = HeapObject::kHeaderSize;
4155 static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize);
4158 DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
4162 // V has parameters (Type, type, TYPE, C type, element_size)
4163 #define TYPED_ARRAYS(V) \
4164 V(Uint8, uint8, UINT8, uint8_t, 1) \
4165 V(Int8, int8, INT8, int8_t, 1) \
4166 V(Uint16, uint16, UINT16, uint16_t, 2) \
4167 V(Int16, int16, INT16, int16_t, 2) \
4168 V(Uint32, uint32, UINT32, uint32_t, 4) \
4169 V(Int32, int32, INT32, int32_t, 4) \
4170 V(Float32, float32, FLOAT32, float, 4) \
4171 V(Float64, float64, FLOAT64, double, 8) \
4172 V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1)
4175 class FixedTypedArrayBase: public FixedArrayBase {
4177 // [base_pointer]: Either points to the FixedTypedArrayBase itself or nullptr.
4178 DECL_ACCESSORS(base_pointer, Object)
4180 // [external_pointer]: Contains the offset between base_pointer and the start
4181 // of the data. If the base_pointer is a nullptr, the external_pointer
4182 // therefore points to the actual backing store.
4183 DECL_ACCESSORS(external_pointer, void)
4185 // Dispatched behavior.
4186 inline void FixedTypedArrayBaseIterateBody(ObjectVisitor* v);
4188 template <typename StaticVisitor>
4189 inline void FixedTypedArrayBaseIterateBody();
4191 DECLARE_CAST(FixedTypedArrayBase)
4193 static const int kBasePointerOffset = FixedArrayBase::kHeaderSize;
4194 static const int kExternalPointerOffset = kBasePointerOffset + kPointerSize;
4195 static const int kHeaderSize =
4196 DOUBLE_POINTER_ALIGN(kExternalPointerOffset + kPointerSize);
4198 static const int kDataOffset = kHeaderSize;
4202 static inline int TypedArraySize(InstanceType type, int length);
4203 inline int TypedArraySize(InstanceType type);
4205 // Use with care: returns raw pointer into heap.
4206 inline void* DataPtr();
4208 inline int DataSize();
4211 static inline int ElementSize(InstanceType type);
4213 inline int DataSize(InstanceType type);
4215 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase);
4219 template <class Traits>
4220 class FixedTypedArray: public FixedTypedArrayBase {
4222 typedef typename Traits::ElementType ElementType;
4223 static const InstanceType kInstanceType = Traits::kInstanceType;
4225 DECLARE_CAST(FixedTypedArray<Traits>)
4227 inline ElementType get_scalar(int index);
4228 static inline Handle<Object> get(Handle<FixedTypedArray> array, int index);
4229 inline void set(int index, ElementType value);
4231 static inline ElementType from_int(int value);
4232 static inline ElementType from_double(double value);
4234 // This accessor applies the correct conversion from Smi, HeapNumber
4236 void SetValue(uint32_t index, Object* value);
4238 DECLARE_PRINTER(FixedTypedArray)
4239 DECLARE_VERIFIER(FixedTypedArray)
4242 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray);
4245 #define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType, size) \
4246 class Type##ArrayTraits { \
4247 public: /* NOLINT */ \
4248 typedef elementType ElementType; \
4249 static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE; \
4250 static const char* Designator() { return #type " array"; } \
4251 static inline Handle<Object> ToHandle(Isolate* isolate, \
4252 elementType scalar); \
4253 static inline elementType defaultValue(); \
4256 typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array;
4258 TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS)
4260 #undef FIXED_TYPED_ARRAY_TRAITS
4263 // DeoptimizationInputData is a fixed array used to hold the deoptimization
4264 // data for code generated by the Hydrogen/Lithium compiler. It also
4265 // contains information about functions that were inlined. If N different
4266 // functions were inlined then first N elements of the literal array will
4267 // contain these functions.
4270 class DeoptimizationInputData: public FixedArray {
4272 // Layout description. Indices in the array.
4273 static const int kTranslationByteArrayIndex = 0;
4274 static const int kInlinedFunctionCountIndex = 1;
4275 static const int kLiteralArrayIndex = 2;
4276 static const int kOsrAstIdIndex = 3;
4277 static const int kOsrPcOffsetIndex = 4;
4278 static const int kOptimizationIdIndex = 5;
4279 static const int kSharedFunctionInfoIndex = 6;
4280 static const int kWeakCellCacheIndex = 7;
4281 static const int kFirstDeoptEntryIndex = 8;
4283 // Offsets of deopt entry elements relative to the start of the entry.
4284 static const int kAstIdRawOffset = 0;
4285 static const int kTranslationIndexOffset = 1;
4286 static const int kArgumentsStackHeightOffset = 2;
4287 static const int kPcOffset = 3;
4288 static const int kDeoptEntrySize = 4;
4290 // Simple element accessors.
4291 #define DECLARE_ELEMENT_ACCESSORS(name, type) \
4292 inline type* name(); \
4293 inline void Set##name(type* value);
4295 DECLARE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray)
4296 DECLARE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi)
4297 DECLARE_ELEMENT_ACCESSORS(LiteralArray, FixedArray)
4298 DECLARE_ELEMENT_ACCESSORS(OsrAstId, Smi)
4299 DECLARE_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
4300 DECLARE_ELEMENT_ACCESSORS(OptimizationId, Smi)
4301 DECLARE_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
4302 DECLARE_ELEMENT_ACCESSORS(WeakCellCache, Object)
4304 #undef DECLARE_ELEMENT_ACCESSORS
4306 // Accessors for elements of the ith deoptimization entry.
4307 #define DECLARE_ENTRY_ACCESSORS(name, type) \
4308 inline type* name(int i); \
4309 inline void Set##name(int i, type* value);
4311 DECLARE_ENTRY_ACCESSORS(AstIdRaw, Smi)
4312 DECLARE_ENTRY_ACCESSORS(TranslationIndex, Smi)
4313 DECLARE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi)
4314 DECLARE_ENTRY_ACCESSORS(Pc, Smi)
4316 #undef DECLARE_ENTRY_ACCESSORS
4318 inline BailoutId AstId(int i);
4320 inline void SetAstId(int i, BailoutId value);
4322 inline int DeoptCount();
4324 // Allocates a DeoptimizationInputData.
4325 static Handle<DeoptimizationInputData> New(Isolate* isolate,
4326 int deopt_entry_count,
4327 PretenureFlag pretenure);
4329 DECLARE_CAST(DeoptimizationInputData)
4331 #ifdef ENABLE_DISASSEMBLER
4332 void DeoptimizationInputDataPrint(std::ostream& os); // NOLINT
4336 static int IndexForEntry(int i) {
4337 return kFirstDeoptEntryIndex + (i * kDeoptEntrySize);
4341 static int LengthFor(int entry_count) { return IndexForEntry(entry_count); }
4345 // DeoptimizationOutputData is a fixed array used to hold the deoptimization
4346 // data for code generated by the full compiler.
4347 // The format of the these objects is
4348 // [i * 2]: Ast ID for ith deoptimization.
4349 // [i * 2 + 1]: PC and state of ith deoptimization
4350 class DeoptimizationOutputData: public FixedArray {
4352 inline int DeoptPoints();
4354 inline BailoutId AstId(int index);
4356 inline void SetAstId(int index, BailoutId id);
4358 inline Smi* PcAndState(int index);
4359 inline void SetPcAndState(int index, Smi* offset);
4361 static int LengthOfFixedArray(int deopt_points) {
4362 return deopt_points * 2;
4365 // Allocates a DeoptimizationOutputData.
4366 static Handle<DeoptimizationOutputData> New(Isolate* isolate,
4367 int number_of_deopt_points,
4368 PretenureFlag pretenure);
4370 DECLARE_CAST(DeoptimizationOutputData)
4372 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
4373 void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT
4378 // HandlerTable is a fixed array containing entries for exception handlers in
4379 // the code object it is associated with. The tables comes in two flavors:
4380 // 1) Based on ranges: Used for unoptimized code. Contains one entry per
4381 // exception handler and a range representing the try-block covered by that
4382 // handler. Layout looks as follows:
4383 // [ range-start , range-end , handler-offset , stack-depth ]
4384 // 2) Based on return addresses: Used for turbofanned code. Contains one entry
4385 // per call-site that could throw an exception. Layout looks as follows:
4386 // [ return-address-offset , handler-offset ]
4387 class HandlerTable : public FixedArray {
4389 // Conservative prediction whether a given handler will locally catch an
4390 // exception or cause a re-throw to outside the code boundary. Since this is
4391 // undecidable it is merely an approximation (e.g. useful for debugger).
4392 enum CatchPrediction { UNCAUGHT, CAUGHT };
4394 // Accessors for handler table based on ranges.
4395 inline void SetRangeStart(int index, int value);
4396 inline void SetRangeEnd(int index, int value);
4397 inline void SetRangeHandler(int index, int offset, CatchPrediction pred);
4398 inline void SetRangeDepth(int index, int value);
4400 // Accessors for handler table based on return addresses.
4401 inline void SetReturnOffset(int index, int value);
4402 inline void SetReturnHandler(int index, int offset, CatchPrediction pred);
4404 // Lookup handler in a table based on ranges.
4405 int LookupRange(int pc_offset, int* stack_depth, CatchPrediction* prediction);
4407 // Lookup handler in a table based on return addresses.
4408 int LookupReturn(int pc_offset, CatchPrediction* prediction);
4410 // Returns the required length of the underlying fixed array.
4411 static int LengthForRange(int entries) { return entries * kRangeEntrySize; }
4412 static int LengthForReturn(int entries) { return entries * kReturnEntrySize; }
4414 DECLARE_CAST(HandlerTable)
4416 #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
4417 void HandlerTableRangePrint(std::ostream& os); // NOLINT
4418 void HandlerTableReturnPrint(std::ostream& os); // NOLINT
4422 // Layout description for handler table based on ranges.
4423 static const int kRangeStartIndex = 0;
4424 static const int kRangeEndIndex = 1;
4425 static const int kRangeHandlerIndex = 2;
4426 static const int kRangeDepthIndex = 3;
4427 static const int kRangeEntrySize = 4;
4429 // Layout description for handler table based on return addresses.
4430 static const int kReturnOffsetIndex = 0;
4431 static const int kReturnHandlerIndex = 1;
4432 static const int kReturnEntrySize = 2;
4434 // Encoding of the {handler} field.
4435 class HandlerPredictionField : public BitField<CatchPrediction, 0, 1> {};
4436 class HandlerOffsetField : public BitField<int, 1, 30> {};
4440 // Code describes objects with on-the-fly generated machine code.
4441 class Code: public HeapObject {
4443 // Opaque data type for encapsulating code flags like kind, inline
4444 // cache state, and arguments count.
4445 typedef uint32_t Flags;
4447 #define NON_IC_KIND_LIST(V) \
4449 V(OPTIMIZED_FUNCTION) \
4455 #define IC_KIND_LIST(V) \
4466 #define CODE_KIND_LIST(V) \
4467 NON_IC_KIND_LIST(V) \
4471 #define DEFINE_CODE_KIND_ENUM(name) name,
4472 CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM)
4473 #undef DEFINE_CODE_KIND_ENUM
4477 // No more than 16 kinds. The value is currently encoded in four bits in
4479 STATIC_ASSERT(NUMBER_OF_KINDS <= 16);
4481 static const char* Kind2String(Kind kind);
4489 static const int kPrologueOffsetNotSet = -1;
4491 #ifdef ENABLE_DISASSEMBLER
4493 static const char* ICState2String(InlineCacheState state);
4494 static const char* StubType2String(StubType type);
4495 static void PrintExtraICState(std::ostream& os, // NOLINT
4496 Kind kind, ExtraICState extra);
4497 void Disassemble(const char* name, std::ostream& os); // NOLINT
4498 #endif // ENABLE_DISASSEMBLER
4500 // [instruction_size]: Size of the native instructions
4501 inline int instruction_size() const;
4502 inline void set_instruction_size(int value);
4504 // [relocation_info]: Code relocation information
4505 DECL_ACCESSORS(relocation_info, ByteArray)
4506 void InvalidateRelocation();
4507 void InvalidateEmbeddedObjects();
4509 // [handler_table]: Fixed array containing offsets of exception handlers.
4510 DECL_ACCESSORS(handler_table, FixedArray)
4512 // [deoptimization_data]: Array containing data for deopt.
4513 DECL_ACCESSORS(deoptimization_data, FixedArray)
4515 // [raw_type_feedback_info]: This field stores various things, depending on
4516 // the kind of the code object.
4517 // FUNCTION => type feedback information.
4518 // STUB and ICs => major/minor key as Smi.
4519 DECL_ACCESSORS(raw_type_feedback_info, Object)
4520 inline Object* type_feedback_info();
4521 inline void set_type_feedback_info(
4522 Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
4523 inline uint32_t stub_key();
4524 inline void set_stub_key(uint32_t key);
4526 // [next_code_link]: Link for lists of optimized or deoptimized code.
4527 // Note that storage for this field is overlapped with typefeedback_info.
4528 DECL_ACCESSORS(next_code_link, Object)
4530 // [gc_metadata]: Field used to hold GC related metadata. The contents of this
4531 // field does not have to be traced during garbage collection since
4532 // it is only used by the garbage collector itself.
4533 DECL_ACCESSORS(gc_metadata, Object)
4535 // [ic_age]: Inline caching age: the value of the Heap::global_ic_age
4536 // at the moment when this object was created.
4537 inline void set_ic_age(int count);
4538 inline int ic_age() const;
4540 // [prologue_offset]: Offset of the function prologue, used for aging
4541 // FUNCTIONs and OPTIMIZED_FUNCTIONs.
4542 inline int prologue_offset() const;
4543 inline void set_prologue_offset(int offset);
4545 // [constant_pool offset]: Offset of the constant pool.
4546 // Valid for FLAG_enable_embedded_constant_pool only
4547 inline int constant_pool_offset() const;
4548 inline void set_constant_pool_offset(int offset);
4550 // Unchecked accessors to be used during GC.
4551 inline ByteArray* unchecked_relocation_info();
4553 inline int relocation_size();
4555 // [flags]: Various code flags.
4556 inline Flags flags();
4557 inline void set_flags(Flags flags);
4559 // [flags]: Access to specific code flags.
4561 inline InlineCacheState ic_state(); // Only valid for IC stubs.
4562 inline ExtraICState extra_ic_state(); // Only valid for IC stubs.
4564 inline StubType type(); // Only valid for monomorphic IC stubs.
4566 // Testers for IC stub kinds.
4567 inline bool is_inline_cache_stub();
4568 inline bool is_debug_stub();
4569 inline bool is_handler();
4570 inline bool is_load_stub();
4571 inline bool is_keyed_load_stub();
4572 inline bool is_store_stub();
4573 inline bool is_keyed_store_stub();
4574 inline bool is_call_stub();
4575 inline bool is_binary_op_stub();
4576 inline bool is_compare_ic_stub();
4577 inline bool is_compare_nil_ic_stub();
4578 inline bool is_to_boolean_ic_stub();
4579 inline bool is_keyed_stub();
4580 inline bool is_optimized_code();
4581 inline bool embeds_maps_weakly();
4583 inline bool IsCodeStubOrIC();
4584 inline bool IsJavaScriptCode();
4586 inline void set_raw_kind_specific_flags1(int value);
4587 inline void set_raw_kind_specific_flags2(int value);
4589 // [is_crankshafted]: For kind STUB or ICs, tells whether or not a code
4590 // object was generated by either the hydrogen or the TurboFan optimizing
4591 // compiler (but it may not be an optimized function).
4592 inline bool is_crankshafted();
4593 inline bool is_hydrogen_stub(); // Crankshafted, but not a function.
4594 inline void set_is_crankshafted(bool value);
4596 // [is_turbofanned]: For kind STUB or OPTIMIZED_FUNCTION, tells whether the
4597 // code object was generated by the TurboFan optimizing compiler.
4598 inline bool is_turbofanned();
4599 inline void set_is_turbofanned(bool value);
4601 // [can_have_weak_objects]: For kind OPTIMIZED_FUNCTION, tells whether the
4602 // embedded objects in code should be treated weakly.
4603 inline bool can_have_weak_objects();
4604 inline void set_can_have_weak_objects(bool value);
4606 // [has_deoptimization_support]: For FUNCTION kind, tells if it has
4607 // deoptimization support.
4608 inline bool has_deoptimization_support();
4609 inline void set_has_deoptimization_support(bool value);
4611 // [has_debug_break_slots]: For FUNCTION kind, tells if it has
4612 // been compiled with debug break slots.
4613 inline bool has_debug_break_slots();
4614 inline void set_has_debug_break_slots(bool value);
4616 // [has_reloc_info_for_serialization]: For FUNCTION kind, tells if its
4617 // reloc info includes runtime and external references to support
4618 // serialization/deserialization.
4619 inline bool has_reloc_info_for_serialization();
4620 inline void set_has_reloc_info_for_serialization(bool value);
4622 // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for
4623 // how long the function has been marked for OSR and therefore which
4624 // level of loop nesting we are willing to do on-stack replacement
4626 inline void set_allow_osr_at_loop_nesting_level(int level);
4627 inline int allow_osr_at_loop_nesting_level();
4629 // [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks
4630 // the code object was seen on the stack with no IC patching going on.
4631 inline int profiler_ticks();
4632 inline void set_profiler_ticks(int ticks);
4634 // [builtin_index]: For BUILTIN kind, tells which builtin index it has.
4635 // For builtins, tells which builtin index it has.
4636 // Note that builtins can have a code kind other than BUILTIN, which means
4637 // that for arbitrary code objects, this index value may be random garbage.
4638 // To verify in that case, compare the code object to the indexed builtin.
4639 inline int builtin_index();
4640 inline void set_builtin_index(int id);
4642 // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots
4643 // reserved in the code prologue.
4644 inline unsigned stack_slots();
4645 inline void set_stack_slots(unsigned slots);
4647 // [safepoint_table_start]: For kind OPTIMIZED_FUNCTION, the offset in
4648 // the instruction stream where the safepoint table starts.
4649 inline unsigned safepoint_table_offset();
4650 inline void set_safepoint_table_offset(unsigned offset);
4652 // [back_edge_table_start]: For kind FUNCTION, the offset in the
4653 // instruction stream where the back edge table starts.
4654 inline unsigned back_edge_table_offset();
4655 inline void set_back_edge_table_offset(unsigned offset);
4657 inline bool back_edges_patched_for_osr();
4659 // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in.
4660 inline uint16_t to_boolean_state();
4662 // [has_function_cache]: For kind STUB tells whether there is a function
4663 // cache is passed to the stub.
4664 inline bool has_function_cache();
4665 inline void set_has_function_cache(bool flag);
4668 // [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether
4669 // the code is going to be deoptimized because of dead embedded maps.
4670 inline bool marked_for_deoptimization();
4671 inline void set_marked_for_deoptimization(bool flag);
4673 // [constant_pool]: The constant pool for this function.
4674 inline Address constant_pool();
4676 // Get the safepoint entry for the given pc.
4677 SafepointEntry GetSafepointEntry(Address pc);
4679 // Find an object in a stub with a specified map
4680 Object* FindNthObject(int n, Map* match_map);
4682 // Find the first allocation site in an IC stub.
4683 AllocationSite* FindFirstAllocationSite();
4685 // Find the first map in an IC stub.
4686 Map* FindFirstMap();
4687 void FindAllMaps(MapHandleList* maps);
4689 // Find the first handler in an IC stub.
4690 Code* FindFirstHandler();
4692 // Find |length| handlers and put them into |code_list|. Returns false if not
4693 // enough handlers can be found.
4694 bool FindHandlers(CodeHandleList* code_list, int length = -1);
4696 // Find the handler for |map|.
4697 MaybeHandle<Code> FindHandlerForMap(Map* map);
4699 // Find the first name in an IC stub.
4700 Name* FindFirstName();
4702 class FindAndReplacePattern;
4703 // For each (map-to-find, object-to-replace) pair in the pattern, this
4704 // function replaces the corresponding placeholder in the code with the
4705 // object-to-replace. The function assumes that pairs in the pattern come in
4706 // the same order as the placeholders in the code.
4707 // If the placeholder is a weak cell, then the value of weak cell is matched
4708 // against the map-to-find.
4709 void FindAndReplace(const FindAndReplacePattern& pattern);
4711 // The entire code object including its header is copied verbatim to the
4712 // snapshot so that it can be written in one, fast, memcpy during
4713 // deserialization. The deserializer will overwrite some pointers, rather
4714 // like a runtime linker, but the random allocation addresses used in the
4715 // mksnapshot process would still be present in the unlinked snapshot data,
4716 // which would make snapshot production non-reproducible. This method wipes
4717 // out the to-be-overwritten header data for reproducible snapshots.
4718 inline void WipeOutHeader();
4720 // Flags operations.
4721 static inline Flags ComputeFlags(
4722 Kind kind, InlineCacheState ic_state = UNINITIALIZED,
4723 ExtraICState extra_ic_state = kNoExtraICState, StubType type = NORMAL,
4724 CacheHolderFlag holder = kCacheOnReceiver);
4726 static inline Flags ComputeMonomorphicFlags(
4727 Kind kind, ExtraICState extra_ic_state = kNoExtraICState,
4728 CacheHolderFlag holder = kCacheOnReceiver, StubType type = NORMAL);
4730 static inline Flags ComputeHandlerFlags(
4731 Kind handler_kind, StubType type = NORMAL,
4732 CacheHolderFlag holder = kCacheOnReceiver);
4734 static inline InlineCacheState ExtractICStateFromFlags(Flags flags);
4735 static inline StubType ExtractTypeFromFlags(Flags flags);
4736 static inline CacheHolderFlag ExtractCacheHolderFromFlags(Flags flags);
4737 static inline Kind ExtractKindFromFlags(Flags flags);
4738 static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags);
4740 static inline Flags RemoveTypeFromFlags(Flags flags);
4741 static inline Flags RemoveTypeAndHolderFromFlags(Flags flags);
4743 // Convert a target address into a code object.
4744 static inline Code* GetCodeFromTargetAddress(Address address);
4746 // Convert an entry address into an object.
4747 static inline Object* GetObjectFromEntryAddress(Address location_of_address);
4749 // Returns the address of the first instruction.
4750 inline byte* instruction_start();
4752 // Returns the address right after the last instruction.
4753 inline byte* instruction_end();
4755 // Returns the size of the instructions, padding, and relocation information.
4756 inline int body_size();
4758 // Returns the address of the first relocation info (read backwards!).
4759 inline byte* relocation_start();
4761 // Code entry point.
4762 inline byte* entry();
4764 // Returns true if pc is inside this object's instructions.
4765 inline bool contains(byte* pc);
4767 // Relocate the code by delta bytes. Called to signal that this code
4768 // object has been moved by delta bytes.
4769 void Relocate(intptr_t delta);
4771 // Migrate code described by desc.
4772 void CopyFrom(const CodeDesc& desc);
4774 // Returns the object size for a given body (used for allocation).
4775 static int SizeFor(int body_size) {
4776 DCHECK_SIZE_TAG_ALIGNED(body_size);
4777 return RoundUp(kHeaderSize + body_size, kCodeAlignment);
4780 // Calculate the size of the code object to report for log events. This takes
4781 // the layout of the code object into account.
4782 inline int ExecutableSize();
4784 // Locating source position.
4785 int SourcePosition(Address pc);
4786 int SourceStatementPosition(Address pc);
4790 // Dispatched behavior.
4791 inline int CodeSize();
4792 inline void CodeIterateBody(ObjectVisitor* v);
4794 template<typename StaticVisitor>
4795 inline void CodeIterateBody(Heap* heap);
4797 DECLARE_PRINTER(Code)
4798 DECLARE_VERIFIER(Code)
4800 void ClearInlineCaches();
4801 void ClearInlineCaches(Kind kind);
4803 BailoutId TranslatePcOffsetToAstId(uint32_t pc_offset);
4804 uint32_t TranslateAstIdToPcOffset(BailoutId ast_id);
4806 #define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
4808 kToBeExecutedOnceCodeAge = -3,
4809 kNotExecutedCodeAge = -2,
4810 kExecutedOnceCodeAge = -1,
4812 CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
4814 kFirstCodeAge = kToBeExecutedOnceCodeAge,
4815 kLastCodeAge = kAfterLastCodeAge - 1,
4816 kCodeAgeCount = kAfterLastCodeAge - kFirstCodeAge - 1,
4817 kIsOldCodeAge = kSexagenarianCodeAge,
4818 kPreAgedCodeAge = kIsOldCodeAge - 1
4820 #undef DECLARE_CODE_AGE_ENUM
4822 // Code aging. Indicates how many full GCs this code has survived without
4823 // being entered through the prologue. Used to determine when it is
4824 // relatively safe to flush this code object and replace it with the lazy
4825 // compilation stub.
4826 static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate);
4827 static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate);
4828 void MakeYoung(Isolate* isolate);
4829 void MarkToBeExecutedOnce(Isolate* isolate);
4830 void MakeOlder(MarkingParity);
4831 static bool IsYoungSequence(Isolate* isolate, byte* sequence);
4834 static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) {
4835 return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY);
4838 void PrintDeoptLocation(FILE* out, Address pc);
4839 bool CanDeoptAt(Address pc);
4842 void VerifyEmbeddedObjectsDependency();
4846 enum VerifyMode { kNoContextSpecificPointers, kNoContextRetainingPointers };
4847 void VerifyEmbeddedObjects(VerifyMode mode = kNoContextRetainingPointers);
4848 static void VerifyRecompiledCode(Code* old_code, Code* new_code);
4851 inline bool CanContainWeakObjects();
4853 inline bool IsWeakObject(Object* object);
4855 static inline bool IsWeakObjectInOptimizedCode(Object* object);
4857 static Handle<WeakCell> WeakCellFor(Handle<Code> code);
4858 WeakCell* CachedWeakCell();
4860 // Max loop nesting marker used to postpose OSR. We don't take loop
4861 // nesting that is deeper than 5 levels into account.
4862 static const int kMaxLoopNestingMarker = 6;
4864 static const int kConstantPoolSize =
4865 FLAG_enable_embedded_constant_pool ? kIntSize : 0;
4867 // Layout description.
4868 static const int kRelocationInfoOffset = HeapObject::kHeaderSize;
4869 static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
4870 static const int kDeoptimizationDataOffset =
4871 kHandlerTableOffset + kPointerSize;
4872 // For FUNCTION kind, we store the type feedback info here.
4873 static const int kTypeFeedbackInfoOffset =
4874 kDeoptimizationDataOffset + kPointerSize;
4875 static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
4876 static const int kGCMetadataOffset = kNextCodeLinkOffset + kPointerSize;
4877 static const int kInstructionSizeOffset = kGCMetadataOffset + kPointerSize;
4878 static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
4879 static const int kFlagsOffset = kICAgeOffset + kIntSize;
4880 static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
4881 static const int kKindSpecificFlags2Offset =
4882 kKindSpecificFlags1Offset + kIntSize;
4883 // Note: We might be able to squeeze this into the flags above.
4884 static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
4885 static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
4886 static const int kHeaderPaddingStart =
4887 kConstantPoolOffset + kConstantPoolSize;
4889 // Add padding to align the instruction start following right after
4890 // the Code object header.
4891 static const int kHeaderSize =
4892 (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
4894 // Byte offsets within kKindSpecificFlags1Offset.
4895 static const int kFullCodeFlags = kKindSpecificFlags1Offset;
4896 class FullCodeFlagsHasDeoptimizationSupportField:
4897 public BitField<bool, 0, 1> {}; // NOLINT
4898 class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {};
4899 class FullCodeFlagsHasRelocInfoForSerialization
4900 : public BitField<bool, 2, 1> {};
4901 // Bit 3 in this bitfield is unused.
4902 class ProfilerTicksField : public BitField<int, 4, 28> {};
4904 // Flags layout. BitField<type, shift, size>.
4905 class ICStateField : public BitField<InlineCacheState, 0, 4> {};
4906 class TypeField : public BitField<StubType, 4, 1> {};
4907 class CacheHolderField : public BitField<CacheHolderFlag, 5, 2> {};
4908 class KindField : public BitField<Kind, 7, 4> {};
4909 class ExtraICStateField: public BitField<ExtraICState, 11,
4910 PlatformSmiTagging::kSmiValueSize - 11 + 1> {}; // NOLINT
4912 // KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
4913 static const int kStackSlotsFirstBit = 0;
4914 static const int kStackSlotsBitCount = 24;
4915 static const int kHasFunctionCacheBit =
4916 kStackSlotsFirstBit + kStackSlotsBitCount;
4917 static const int kMarkedForDeoptimizationBit = kHasFunctionCacheBit + 1;
4918 static const int kIsTurbofannedBit = kMarkedForDeoptimizationBit + 1;
4919 static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1;
4921 STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32);
4922 STATIC_ASSERT(kCanHaveWeakObjects + 1 <= 32);
4924 class StackSlotsField: public BitField<int,
4925 kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT
4926 class HasFunctionCacheField : public BitField<bool, kHasFunctionCacheBit, 1> {
4928 class MarkedForDeoptimizationField
4929 : public BitField<bool, kMarkedForDeoptimizationBit, 1> {}; // NOLINT
4930 class IsTurbofannedField : public BitField<bool, kIsTurbofannedBit, 1> {
4932 class CanHaveWeakObjectsField
4933 : public BitField<bool, kCanHaveWeakObjects, 1> {}; // NOLINT
4935 // KindSpecificFlags2 layout (ALL)
4936 static const int kIsCrankshaftedBit = 0;
4937 class IsCrankshaftedField: public BitField<bool,
4938 kIsCrankshaftedBit, 1> {}; // NOLINT
4940 // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
4941 static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1;
4942 static const int kSafepointTableOffsetBitCount = 30;
4944 STATIC_ASSERT(kSafepointTableOffsetFirstBit +
4945 kSafepointTableOffsetBitCount <= 32);
4946 STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32);
4948 class SafepointTableOffsetField: public BitField<int,
4949 kSafepointTableOffsetFirstBit,
4950 kSafepointTableOffsetBitCount> {}; // NOLINT
4952 // KindSpecificFlags2 layout (FUNCTION)
4953 class BackEdgeTableOffsetField: public BitField<int,
4954 kIsCrankshaftedBit + 1, 27> {}; // NOLINT
4955 class AllowOSRAtLoopNestingLevelField: public BitField<int,
4956 kIsCrankshaftedBit + 1 + 27, 4> {}; // NOLINT
4957 STATIC_ASSERT(AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker);
4959 static const int kArgumentsBits = 16;
4960 static const int kMaxArguments = (1 << kArgumentsBits) - 1;
4962 // This constant should be encodable in an ARM instruction.
4963 static const int kFlagsNotUsedInLookup =
4964 TypeField::kMask | CacheHolderField::kMask;
4967 friend class RelocIterator;
4968 friend class Deoptimizer; // For FindCodeAgeSequence.
4970 void ClearInlineCaches(Kind* kind);
4973 byte* FindCodeAgeSequence();
4974 static void GetCodeAgeAndParity(Code* code, Age* age,
4975 MarkingParity* parity);
4976 static void GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
4977 MarkingParity* parity);
4978 static Code* GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity);
4980 // Code aging -- platform-specific
4981 static void PatchPlatformCodeAge(Isolate* isolate,
4982 byte* sequence, Age age,
4983 MarkingParity parity);
4985 DISALLOW_IMPLICIT_CONSTRUCTORS(Code);
4989 // This class describes the layout of dependent codes array of a map. The
4990 // array is partitioned into several groups of dependent codes. Each group
4991 // contains codes with the same dependency on the map. The array has the
4992 // following layout for n dependency groups:
4994 // +----+----+-----+----+---------+----------+-----+---------+-----------+
4995 // | C1 | C2 | ... | Cn | group 1 | group 2 | ... | group n | undefined |
4996 // +----+----+-----+----+---------+----------+-----+---------+-----------+
4998 // The first n elements are Smis, each of them specifies the number of codes
4999 // in the corresponding group. The subsequent elements contain grouped code
5000 // objects in weak cells. The suffix of the array can be filled with the
5001 // undefined value if the number of codes is less than the length of the
5002 // array. The order of the code objects within a group is not preserved.
5004 // All code indexes used in the class are counted starting from the first
5005 // code object of the first group. In other words, code index 0 corresponds
5006 // to array index n = kCodesStartIndex.
5008 class DependentCode: public FixedArray {
5010 enum DependencyGroup {
5011 // Group of code that weakly embed this map and depend on being
5012 // deoptimized when the map is garbage collected.
5014 // Group of code that embed a transition to this map, and depend on being
5015 // deoptimized when the transition is replaced by a new version.
5017 // Group of code that omit run-time prototype checks for prototypes
5018 // described by this map. The group is deoptimized whenever an object
5019 // described by this map changes shape (and transitions to a new map),
5020 // possibly invalidating the assumptions embedded in the code.
5021 kPrototypeCheckGroup,
5022 // Group of code that depends on global property values in property cells
5023 // not being changed.
5024 kPropertyCellChangedGroup,
5025 // Group of code that omit run-time type checks for the field(s) introduced
5028 // Group of code that omit run-time type checks for initial maps of
5030 kInitialMapChangedGroup,
5031 // Group of code that depends on tenuring information in AllocationSites
5032 // not being changed.
5033 kAllocationSiteTenuringChangedGroup,
5034 // Group of code that depends on element transition information in
5035 // AllocationSites not being changed.
5036 kAllocationSiteTransitionChangedGroup
5039 static const int kGroupCount = kAllocationSiteTransitionChangedGroup + 1;
5041 // Array for holding the index of the first code object of each group.
5042 // The last element stores the total number of code objects.
5043 class GroupStartIndexes {
5045 explicit GroupStartIndexes(DependentCode* entries);
5046 void Recompute(DependentCode* entries);
5047 int at(int i) { return start_indexes_[i]; }
5048 int number_of_entries() { return start_indexes_[kGroupCount]; }
5050 int start_indexes_[kGroupCount + 1];
5053 bool Contains(DependencyGroup group, WeakCell* code_cell);
5055 static Handle<DependentCode> InsertCompilationDependencies(
5056 Handle<DependentCode> entries, DependencyGroup group,
5057 Handle<Foreign> info);
5059 static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries,
5060 DependencyGroup group,
5061 Handle<WeakCell> code_cell);
5063 void UpdateToFinishedCode(DependencyGroup group, Foreign* info,
5064 WeakCell* code_cell);
5066 void RemoveCompilationDependencies(DependentCode::DependencyGroup group,
5069 void DeoptimizeDependentCodeGroup(Isolate* isolate,
5070 DependentCode::DependencyGroup group);
5072 bool MarkCodeForDeoptimization(Isolate* isolate,
5073 DependentCode::DependencyGroup group);
5075 // The following low-level accessors should only be used by this class
5076 // and the mark compact collector.
5077 inline int number_of_entries(DependencyGroup group);
5078 inline void set_number_of_entries(DependencyGroup group, int value);
5079 inline Object* object_at(int i);
5080 inline void set_object_at(int i, Object* object);
5081 inline void clear_at(int i);
5082 inline void copy(int from, int to);
5083 DECLARE_CAST(DependentCode)
5085 static const char* DependencyGroupName(DependencyGroup group);
5086 static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
5089 static Handle<DependentCode> Insert(Handle<DependentCode> entries,
5090 DependencyGroup group,
5091 Handle<Object> object);
5092 static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries);
5093 // Make a room at the end of the given group by moving out the first
5094 // code objects of the subsequent groups.
5095 inline void ExtendGroup(DependencyGroup group);
5096 // Compact by removing cleared weak cells and return true if there was
5097 // any cleared weak cell.
5099 static int Grow(int number_of_entries) {
5100 if (number_of_entries < 5) return number_of_entries + 1;
5101 return number_of_entries * 5 / 4;
5103 static const int kCodesStartIndex = kGroupCount;
5107 class PrototypeInfo;
5110 // All heap objects have a Map that describes their structure.
5111 // A Map contains information about:
5112 // - Size information about the object
5113 // - How to iterate over an object (for garbage collection)
5114 class Map: public HeapObject {
5117 // Size in bytes or kVariableSizeSentinel if instances do not have
5119 inline int instance_size();
5120 inline void set_instance_size(int value);
5122 // Only to clear an unused byte, remove once byte is used.
5123 inline void clear_unused();
5125 // [inobject_properties_or_constructor_function_index]: Provides access
5126 // to the inobject properties in case of JSObject maps, or the constructor
5127 // function index in case of primitive maps.
5128 inline int inobject_properties_or_constructor_function_index();
5129 inline void set_inobject_properties_or_constructor_function_index(int value);
5130 // Count of properties allocated in the object (JSObject only).
5131 inline int GetInObjectProperties();
5132 inline void SetInObjectProperties(int value);
5133 // Index of the constructor function in the native context (primitives only),
5134 // or the special sentinel value to indicate that there is no object wrapper
5135 // for the primitive (i.e. in case of null or undefined).
5136 static const int kNoConstructorFunctionIndex = 0;
5137 inline int GetConstructorFunctionIndex();
5138 inline void SetConstructorFunctionIndex(int value);
5141 inline InstanceType instance_type();
5142 inline void set_instance_type(InstanceType value);
5144 // Tells how many unused property fields are available in the
5145 // instance (only used for JSObject in fast mode).
5146 inline int unused_property_fields();
5147 inline void set_unused_property_fields(int value);
5150 inline byte bit_field() const;
5151 inline void set_bit_field(byte value);
5154 inline byte bit_field2() const;
5155 inline void set_bit_field2(byte value);
5158 inline uint32_t bit_field3() const;
5159 inline void set_bit_field3(uint32_t bits);
5161 class EnumLengthBits: public BitField<int,
5162 0, kDescriptorIndexBitCount> {}; // NOLINT
5163 class NumberOfOwnDescriptorsBits: public BitField<int,
5164 kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT
5165 STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
5166 class DictionaryMap : public BitField<bool, 20, 1> {};
5167 class OwnsDescriptors : public BitField<bool, 21, 1> {};
5168 class HasInstanceCallHandler : public BitField<bool, 22, 1> {};
5169 class Deprecated : public BitField<bool, 23, 1> {};
5170 class IsUnstable : public BitField<bool, 24, 1> {};
5171 class IsMigrationTarget : public BitField<bool, 25, 1> {};
5172 class IsStrong : public BitField<bool, 26, 1> {};
5175 // Keep this bit field at the very end for better code in
5176 // Builtins::kJSConstructStubGeneric stub.
5177 // This counter is used for in-object slack tracking and for map aging.
5178 // The in-object slack tracking is considered enabled when the counter is
5179 // in the range [kSlackTrackingCounterStart, kSlackTrackingCounterEnd].
5180 class Counter : public BitField<int, 28, 4> {};
5181 static const int kSlackTrackingCounterStart = 14;
5182 static const int kSlackTrackingCounterEnd = 8;
5183 static const int kRetainingCounterStart = kSlackTrackingCounterEnd - 1;
5184 static const int kRetainingCounterEnd = 0;
5186 // Tells whether the object in the prototype property will be used
5187 // for instances created from this function. If the prototype
5188 // property is set to a value that is not a JSObject, the prototype
5189 // property will not be used to create instances of the function.
5190 // See ECMA-262, 13.2.2.
5191 inline void set_non_instance_prototype(bool value);
5192 inline bool has_non_instance_prototype();
5194 // Tells whether function has special prototype property. If not, prototype
5195 // property will not be created when accessed (will return undefined),
5196 // and construction from this function will not be allowed.
5197 inline void set_function_with_prototype(bool value);
5198 inline bool function_with_prototype();
5200 // Tells whether the instance with this map should be ignored by the
5201 // Object.getPrototypeOf() function and the __proto__ accessor.
5202 inline void set_is_hidden_prototype();
5203 inline bool is_hidden_prototype();
5205 // Records and queries whether the instance has a named interceptor.
5206 inline void set_has_named_interceptor();
5207 inline bool has_named_interceptor();
5209 // Records and queries whether the instance has an indexed interceptor.
5210 inline void set_has_indexed_interceptor();
5211 inline bool has_indexed_interceptor();
5213 // Tells whether the instance is undetectable.
5214 // An undetectable object is a special class of JSObject: 'typeof' operator
5215 // returns undefined, ToBoolean returns false. Otherwise it behaves like
5216 // a normal JS object. It is useful for implementing undetectable
5217 // document.all in Firefox & Safari.
5218 // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
5219 inline void set_is_undetectable();
5220 inline bool is_undetectable();
5222 // Tells whether the instance has a call-as-function handler.
5223 inline void set_is_observed();
5224 inline bool is_observed();
5226 inline void set_is_strong();
5227 inline bool is_strong();
5228 inline void set_is_extensible(bool value);
5229 inline bool is_extensible();
5230 inline void set_is_prototype_map(bool value);
5231 inline bool is_prototype_map() const;
5233 inline void set_elements_kind(ElementsKind elements_kind);
5234 inline ElementsKind elements_kind();
5236 // Tells whether the instance has fast elements that are only Smis.
5237 inline bool has_fast_smi_elements();
5239 // Tells whether the instance has fast elements.
5240 inline bool has_fast_object_elements();
5241 inline bool has_fast_smi_or_object_elements();
5242 inline bool has_fast_double_elements();
5243 inline bool has_fast_elements();
5244 inline bool has_sloppy_arguments_elements();
5245 inline bool has_fixed_typed_array_elements();
5246 inline bool has_dictionary_elements();
5248 static bool IsValidElementsTransition(ElementsKind from_kind,
5249 ElementsKind to_kind);
5251 // Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
5252 // map with DICTIONARY_ELEMENTS was found in the prototype chain.
5253 bool DictionaryElementsInPrototypeChainOnly();
5255 inline Map* ElementsTransitionMap();
5257 inline FixedArrayBase* GetInitialElements();
5259 // [raw_transitions]: Provides access to the transitions storage field.
5260 // Don't call set_raw_transitions() directly to overwrite transitions, use
5261 // the TransitionArray::ReplaceTransitions() wrapper instead!
5262 DECL_ACCESSORS(raw_transitions, Object)
5263 // [prototype_info]: Per-prototype metadata. Aliased with transitions
5264 // (which prototype maps don't have).
5265 DECL_ACCESSORS(prototype_info, Object)
5266 // PrototypeInfo is created lazily using this helper (which installs it on
5267 // the given prototype's map).
5268 static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
5269 Handle<JSObject> prototype, Isolate* isolate);
5270 static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
5271 Handle<Map> prototype_map, Isolate* isolate);
5273 // [prototype chain validity cell]: Associated with a prototype object,
5274 // stored in that object's map's PrototypeInfo, indicates that prototype
5275 // chains through this object are currently valid. The cell will be
5276 // invalidated and replaced when the prototype chain changes.
5277 static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map,
5279 static const int kPrototypeChainValid = 0;
5280 static const int kPrototypeChainInvalid = 1;
5283 Map* FindFieldOwner(int descriptor);
5285 inline int GetInObjectPropertyOffset(int index);
5287 int NumberOfFields();
5289 // TODO(ishell): candidate with JSObject::MigrateToMap().
5290 bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
5291 int target_inobject, int target_unused,
5292 int* old_number_of_fields);
5293 // TODO(ishell): moveit!
5294 static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map);
5295 MUST_USE_RESULT static Handle<HeapType> GeneralizeFieldType(
5296 Handle<HeapType> type1,
5297 Handle<HeapType> type2,
5299 static void GeneralizeFieldType(Handle<Map> map, int modify_index,
5300 Representation new_representation,
5301 Handle<HeapType> new_field_type);
5302 static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
5303 PropertyKind new_kind,
5304 PropertyAttributes new_attributes,
5305 Representation new_representation,
5306 Handle<HeapType> new_field_type,
5307 StoreMode store_mode);
5308 static Handle<Map> CopyGeneralizeAllRepresentations(
5309 Handle<Map> map, int modify_index, StoreMode store_mode,
5310 PropertyKind kind, PropertyAttributes attributes, const char* reason);
5312 static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
5313 int descriptor_number,
5314 Handle<Object> value);
5316 static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
5317 const char* reason);
5319 // Returns the constructor name (the name (possibly, inferred name) of the
5320 // function that was used to instantiate the object).
5321 String* constructor_name();
5323 // Tells whether the map is used for JSObjects in dictionary mode (ie
5324 // normalized objects, ie objects for which HasFastProperties returns false).
5325 // A map can never be used for both dictionary mode and fast mode JSObjects.
5326 // False by default and for HeapObjects that are not JSObjects.
5327 inline void set_dictionary_map(bool value);
5328 inline bool is_dictionary_map();
5330 // Tells whether the instance needs security checks when accessing its
5332 inline void set_is_access_check_needed(bool access_check_needed);
5333 inline bool is_access_check_needed();
5335 // Returns true if map has a non-empty stub code cache.
5336 inline bool has_code_cache();
5338 // [prototype]: implicit prototype object.
5339 DECL_ACCESSORS(prototype, Object)
5340 // TODO(jkummerow): make set_prototype private.
5341 static void SetPrototype(
5342 Handle<Map> map, Handle<Object> prototype,
5343 PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
5345 // [constructor]: points back to the function responsible for this map.
5346 // The field overlaps with the back pointer. All maps in a transition tree
5347 // have the same constructor, so maps with back pointers can walk the
5348 // back pointer chain until they find the map holding their constructor.
5349 DECL_ACCESSORS(constructor_or_backpointer, Object)
5350 inline Object* GetConstructor() const;
5351 inline void SetConstructor(Object* constructor,
5352 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5353 // [back pointer]: points back to the parent map from which a transition
5354 // leads to this map. The field overlaps with the constructor (see above).
5355 inline Object* GetBackPointer();
5356 inline void SetBackPointer(Object* value,
5357 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
5359 // [instance descriptors]: describes the object.
5360 DECL_ACCESSORS(instance_descriptors, DescriptorArray)
5362 // [layout descriptor]: describes the object layout.
5363 DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
5364 // |layout descriptor| accessor which can be used from GC.
5365 inline LayoutDescriptor* layout_descriptor_gc_safe();
5366 inline bool HasFastPointerLayout() const;
5368 // |layout descriptor| accessor that is safe to call even when
5369 // FLAG_unbox_double_fields is disabled (in this case Map does not contain
5370 // |layout_descriptor| field at all).
5371 inline LayoutDescriptor* GetLayoutDescriptor();
5373 inline void UpdateDescriptors(DescriptorArray* descriptors,
5374 LayoutDescriptor* layout_descriptor);
5375 inline void InitializeDescriptors(DescriptorArray* descriptors,
5376 LayoutDescriptor* layout_descriptor);
5378 // [stub cache]: contains stubs compiled for this map.
5379 DECL_ACCESSORS(code_cache, Object)
5381 // [dependent code]: list of optimized codes that weakly embed this map.
5382 DECL_ACCESSORS(dependent_code, DependentCode)
5384 // [weak cell cache]: cache that stores a weak cell pointing to this map.
5385 DECL_ACCESSORS(weak_cell_cache, Object)
5387 inline PropertyDetails GetLastDescriptorDetails();
5389 inline int LastAdded();
5391 inline int NumberOfOwnDescriptors();
5392 inline void SetNumberOfOwnDescriptors(int number);
5394 inline Cell* RetrieveDescriptorsPointer();
5396 inline int EnumLength();
5397 inline void SetEnumLength(int length);
5399 inline bool owns_descriptors();
5400 inline void set_owns_descriptors(bool owns_descriptors);
5401 inline bool has_instance_call_handler();
5402 inline void set_has_instance_call_handler();
5403 inline void mark_unstable();
5404 inline bool is_stable();
5405 inline void set_migration_target(bool value);
5406 inline bool is_migration_target();
5407 inline void set_counter(int value);
5408 inline int counter();
5409 inline void deprecate();
5410 inline bool is_deprecated();
5411 inline bool CanBeDeprecated();
5412 // Returns a non-deprecated version of the input. If the input was not
5413 // deprecated, it is directly returned. Otherwise, the non-deprecated version
5414 // is found by re-transitioning from the root of the transition tree using the
5415 // descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
5417 static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
5419 // Returns a non-deprecated version of the input. This method may deprecate
5420 // existing maps along the way if encodings conflict. Not for use while
5421 // gathering type feedback. Use TryUpdate in those cases instead.
5422 static Handle<Map> Update(Handle<Map> map);
5424 static Handle<Map> CopyDropDescriptors(Handle<Map> map);
5425 static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
5426 Descriptor* descriptor,
5427 TransitionFlag flag);
5429 MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
5432 Handle<HeapType> type,
5433 PropertyAttributes attributes,
5434 Representation representation,
5435 TransitionFlag flag);
5437 MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
5440 Handle<Object> constant,
5441 PropertyAttributes attributes,
5442 TransitionFlag flag);
5444 // Returns a new map with all transitions dropped from the given map and
5445 // the ElementsKind set.
5446 static Handle<Map> TransitionElementsTo(Handle<Map> map,
5447 ElementsKind to_kind);
5449 static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
5451 static Handle<Map> CopyAsElementsKind(Handle<Map> map,
5453 TransitionFlag flag);
5455 static Handle<Map> CopyForObserved(Handle<Map> map);
5457 static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
5458 PropertyAttributes attrs_to_add,
5459 Handle<Symbol> transition_marker,
5460 const char* reason);
5462 static Handle<Map> FixProxy(Handle<Map> map, InstanceType type, int size);
5465 // Maximal number of fast properties. Used to restrict the number of map
5466 // transitions to avoid an explosion in the number of maps for objects used as
5468 inline bool TooManyFastProperties(StoreFromKeyed store_mode);
5469 static Handle<Map> TransitionToDataProperty(Handle<Map> map,
5471 Handle<Object> value,
5472 PropertyAttributes attributes,
5473 StoreFromKeyed store_mode);
5474 static Handle<Map> TransitionToAccessorProperty(
5475 Handle<Map> map, Handle<Name> name, AccessorComponent component,
5476 Handle<Object> accessor, PropertyAttributes attributes);
5477 static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
5480 PropertyAttributes attributes);
5482 inline void AppendDescriptor(Descriptor* desc);
5484 // Returns a copy of the map, prepared for inserting into the transition
5485 // tree (if the |map| owns descriptors then the new one will share
5486 // descriptors with |map|).
5487 static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
5489 // Returns a copy of the map, with all transitions dropped from the
5490 // instance descriptors.
5491 static Handle<Map> Copy(Handle<Map> map, const char* reason);
5492 static Handle<Map> Create(Isolate* isolate, int inobject_properties);
5494 // Returns the next free property index (only valid for FAST MODE).
5495 int NextFreePropertyIndex();
5497 // Returns the number of properties described in instance_descriptors
5498 // filtering out properties with the specified attributes.
5499 int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
5500 PropertyAttributes filter = NONE);
5504 // Code cache operations.
5506 // Clears the code cache.
5507 inline void ClearCodeCache(Heap* heap);
5509 // Update code cache.
5510 static void UpdateCodeCache(Handle<Map> map,
5514 // Extend the descriptor array of the map with the list of descriptors.
5515 // In case of duplicates, the latest descriptor is used.
5516 static void AppendCallbackDescriptors(Handle<Map> map,
5517 Handle<Object> descriptors);
5519 static inline int SlackForArraySize(int old_size, int size_limit);
5521 static void EnsureDescriptorSlack(Handle<Map> map, int slack);
5523 // Returns the found code or undefined if absent.
5524 Object* FindInCodeCache(Name* name, Code::Flags flags);
5526 // Returns the non-negative index of the code object if it is in the
5527 // cache and -1 otherwise.
5528 int IndexInCodeCache(Object* name, Code* code);
5530 // Removes a code object from the code cache at the given index.
5531 void RemoveFromCodeCache(Name* name, Code* code, int index);
5533 // Computes a hash value for this map, to be used in HashTables and such.
5536 // Returns the map that this map transitions to if its elements_kind
5537 // is changed to |elements_kind|, or NULL if no such map is cached yet.
5538 // |safe_to_add_transitions| is set to false if adding transitions is not
5540 Map* LookupElementsTransitionMap(ElementsKind elements_kind);
5542 // Returns the transitioned map for this map with the most generic
5543 // elements_kind that's found in |candidates|, or null handle if no match is
5545 static Handle<Map> FindTransitionedMap(Handle<Map> map,
5546 MapHandleList* candidates);
5548 inline bool CanTransition();
5550 inline bool IsPrimitiveMap();
5551 inline bool IsJSObjectMap();
5552 inline bool IsJSArrayMap();
5553 inline bool IsStringMap();
5554 inline bool IsJSProxyMap();
5555 inline bool IsJSGlobalProxyMap();
5556 inline bool IsJSGlobalObjectMap();
5557 inline bool IsGlobalObjectMap();
5559 inline bool CanOmitMapChecks();
5561 static void AddDependentCode(Handle<Map> map,
5562 DependentCode::DependencyGroup group,
5565 bool IsMapInArrayPrototypeChain();
5567 static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
5569 // Dispatched behavior.
5570 DECLARE_PRINTER(Map)
5571 DECLARE_VERIFIER(Map)
5574 void DictionaryMapVerify();
5575 void VerifyOmittedMapChecks();
5578 inline int visitor_id();
5579 inline void set_visitor_id(int visitor_id);
5581 static Handle<Map> TransitionToPrototype(Handle<Map> map,
5582 Handle<Object> prototype,
5583 PrototypeOptimizationMode mode);
5585 static const int kMaxPreAllocatedPropertyFields = 255;
5587 // Layout description.
5588 static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
5589 static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
5590 static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
5591 static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
5592 static const int kConstructorOrBackPointerOffset =
5593 kPrototypeOffset + kPointerSize;
5594 // When there is only one transition, it is stored directly in this field;
5595 // otherwise a transition array is used.
5596 // For prototype maps, this slot is used to store this map's PrototypeInfo
5598 static const int kTransitionsOrPrototypeInfoOffset =
5599 kConstructorOrBackPointerOffset + kPointerSize;
5600 static const int kDescriptorsOffset =
5601 kTransitionsOrPrototypeInfoOffset + kPointerSize;
5602 #if V8_DOUBLE_FIELDS_UNBOXING
5603 static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize;
5604 static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize;
5606 static const int kLayoutDecriptorOffset = 1; // Must not be ever accessed.
5607 static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
5609 static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
5610 static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
5611 static const int kSize = kWeakCellCacheOffset + kPointerSize;
5613 // Layout of pointer fields. Heap iteration code relies on them
5614 // being continuously allocated.
5615 static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
5616 static const int kPointerFieldsEndOffset = kSize;
5618 // Byte offsets within kInstanceSizesOffset.
5619 static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
5620 static const int kInObjectPropertiesOrConstructorFunctionIndexByte = 1;
5621 static const int kInObjectPropertiesOrConstructorFunctionIndexOffset =
5622 kInstanceSizesOffset + kInObjectPropertiesOrConstructorFunctionIndexByte;
5623 // Note there is one byte available for use here.
5624 static const int kUnusedByte = 2;
5625 static const int kUnusedOffset = kInstanceSizesOffset + kUnusedByte;
5626 static const int kVisitorIdByte = 3;
5627 static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
5629 // Byte offsets within kInstanceAttributesOffset attributes.
5630 #if V8_TARGET_LITTLE_ENDIAN
5631 // Order instance type and bit field together such that they can be loaded
5632 // together as a 16-bit word with instance type in the lower 8 bits regardless
5633 // of endianess. Also provide endian-independent offset to that 16-bit word.
5634 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
5635 static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
5637 static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
5638 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
5640 static const int kInstanceTypeAndBitFieldOffset =
5641 kInstanceAttributesOffset + 0;
5642 static const int kBitField2Offset = kInstanceAttributesOffset + 2;
5643 static const int kUnusedPropertyFieldsByte = 3;
5644 static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
5646 STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
5647 Internals::kMapInstanceTypeAndBitFieldOffset);
5649 // Bit positions for bit field.
5650 static const int kHasNonInstancePrototype = 0;
5651 static const int kIsHiddenPrototype = 1;
5652 static const int kHasNamedInterceptor = 2;
5653 static const int kHasIndexedInterceptor = 3;
5654 static const int kIsUndetectable = 4;
5655 static const int kIsObserved = 5;
5656 static const int kIsAccessCheckNeeded = 6;
5657 class FunctionWithPrototype: public BitField<bool, 7, 1> {};
5659 // Bit positions for bit field 2
5660 static const int kIsExtensible = 0;
5661 static const int kStringWrapperSafeForDefaultValueOf = 1;
5662 class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
5663 class ElementsKindBits: public BitField<ElementsKind, 3, 5> {};
5665 // Derived values from bit field 2
5666 static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
5667 (FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1;
5668 static const int8_t kMaximumBitField2FastSmiElementValue =
5669 static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
5670 Map::ElementsKindBits::kShift) - 1;
5671 static const int8_t kMaximumBitField2FastHoleyElementValue =
5672 static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
5673 Map::ElementsKindBits::kShift) - 1;
5674 static const int8_t kMaximumBitField2FastHoleySmiElementValue =
5675 static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
5676 Map::ElementsKindBits::kShift) - 1;
5678 typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
5679 kPointerFieldsEndOffset,
5680 kSize> BodyDescriptor;
5682 // Compares this map to another to see if they describe equivalent objects.
5683 // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
5684 // it had exactly zero inobject properties.
5685 // The "shared" flags of both this map and |other| are ignored.
5686 bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
5688 // Returns true if given field is unboxed double.
5689 inline bool IsUnboxedDoubleField(FieldIndex index);
5692 static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
5693 static void TraceAllTransitions(Map* map);
5696 static inline Handle<Map> CopyInstallDescriptorsForTesting(
5697 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
5698 Handle<LayoutDescriptor> layout_descriptor);
5701 static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
5702 Handle<Name> name, SimpleTransitionFlag flag);
5704 bool EquivalentToForTransition(Map* other);
5705 static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
5706 static Handle<Map> ShareDescriptor(Handle<Map> map,
5707 Handle<DescriptorArray> descriptors,
5708 Descriptor* descriptor);
5709 static Handle<Map> CopyInstallDescriptors(
5710 Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
5711 Handle<LayoutDescriptor> layout_descriptor);
5712 static Handle<Map> CopyAddDescriptor(Handle<Map> map,
5713 Descriptor* descriptor,
5714 TransitionFlag flag);
5715 static Handle<Map> CopyReplaceDescriptors(
5716 Handle<Map> map, Handle<DescriptorArray> descriptors,
5717 Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
5718 MaybeHandle<Name> maybe_name, const char* reason,
5719 SimpleTransitionFlag simple_flag);
5721 static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
5722 Handle<DescriptorArray> descriptors,
5723 Descriptor* descriptor,
5725 TransitionFlag flag);
5726 static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
5727 Handle<Map> map, int descriptor, PropertyKind kind,
5728 PropertyAttributes attributes, const char** reason);
5730 static Handle<Map> CopyNormalized(Handle<Map> map,
5731 PropertyNormalizationMode mode);
5733 // Fires when the layout of an object with a leaf map changes.
5734 // This includes adding transitions to the leaf map or changing
5735 // the descriptor array.
5736 inline void NotifyLeafMapLayoutChange();
5738 void DeprecateTransitionTree();
5739 bool DeprecateTarget(PropertyKind kind, Name* key,
5740 PropertyAttributes attributes,
5741 DescriptorArray* new_descriptors,
5742 LayoutDescriptor* new_layout_descriptor);
5744 Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
5746 // Update field type of the given descriptor to new representation and new
5747 // type. The type must be prepared for storing in descriptor array:
5748 // it must be either a simple type or a map wrapped in a weak cell.
5749 void UpdateFieldType(int descriptor_number, Handle<Name> name,
5750 Representation new_representation,
5751 Handle<Object> new_wrapped_type);
5753 void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
5754 PropertyAttributes attributes);
5755 void PrintGeneralization(FILE* file,
5760 bool constant_to_field,
5761 Representation old_representation,
5762 Representation new_representation,
5763 HeapType* old_field_type,
5764 HeapType* new_field_type);
5766 static const int kFastPropertiesSoftLimit = 12;
5767 static const int kMaxFastProperties = 128;
5769 DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
5773 // An abstract superclass, a marker class really, for simple structure classes.
5774 // It doesn't carry much functionality but allows struct classes to be
5775 // identified in the type system.
5776 class Struct: public HeapObject {
5778 inline void InitializeBody(int object_size);
5779 DECLARE_CAST(Struct)
5783 // A simple one-element struct, useful where smis need to be boxed.
5784 class Box : public Struct {
5786 // [value]: the boxed contents.
5787 DECL_ACCESSORS(value, Object)
5791 // Dispatched behavior.
5792 DECLARE_PRINTER(Box)
5793 DECLARE_VERIFIER(Box)
5795 static const int kValueOffset = HeapObject::kHeaderSize;
5796 static const int kSize = kValueOffset + kPointerSize;
5799 DISALLOW_IMPLICIT_CONSTRUCTORS(Box);
5803 // Container for metadata stored on each prototype map.
5804 class PrototypeInfo : public Struct {
5806 static const int UNREGISTERED = -1;
5808 // [prototype_users]: WeakFixedArray containing maps using this prototype,
5809 // or Smi(0) if uninitialized.
5810 DECL_ACCESSORS(prototype_users, Object)
5811 // [registry_slot]: Slot in prototype's user registry where this user
5812 // is stored. Returns UNREGISTERED if this prototype has not been registered.
5813 inline int registry_slot() const;
5814 inline void set_registry_slot(int slot);
5815 // [validity_cell]: Cell containing the validity bit for prototype chains
5816 // going through this object, or Smi(0) if uninitialized.
5817 DECL_ACCESSORS(validity_cell, Object)
5818 // [constructor_name]: User-friendly name of the original constructor.
5819 DECL_ACCESSORS(constructor_name, Object)
5821 DECLARE_CAST(PrototypeInfo)
5823 // Dispatched behavior.
5824 DECLARE_PRINTER(PrototypeInfo)
5825 DECLARE_VERIFIER(PrototypeInfo)
5827 static const int kPrototypeUsersOffset = HeapObject::kHeaderSize;
5828 static const int kRegistrySlotOffset = kPrototypeUsersOffset + kPointerSize;
5829 static const int kValidityCellOffset = kRegistrySlotOffset + kPointerSize;
5830 static const int kConstructorNameOffset = kValidityCellOffset + kPointerSize;
5831 static const int kSize = kConstructorNameOffset + kPointerSize;
5834 DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeInfo);
5838 // Script describes a script which has been added to the VM.
5839 class Script: public Struct {
5848 // Script compilation types.
5849 enum CompilationType {
5850 COMPILATION_TYPE_HOST = 0,
5851 COMPILATION_TYPE_EVAL = 1
5854 // Script compilation state.
5855 enum CompilationState {
5856 COMPILATION_STATE_INITIAL = 0,
5857 COMPILATION_STATE_COMPILED = 1
5860 // [source]: the script source.
5861 DECL_ACCESSORS(source, Object)
5863 // [name]: the script name.
5864 DECL_ACCESSORS(name, Object)
5866 // [id]: the script id.
5867 DECL_ACCESSORS(id, Smi)
5869 // [line_offset]: script line offset in resource from where it was extracted.
5870 DECL_ACCESSORS(line_offset, Smi)
5872 // [column_offset]: script column offset in resource from where it was
5874 DECL_ACCESSORS(column_offset, Smi)
5876 // [context_data]: context data for the context this script was compiled in.
5877 DECL_ACCESSORS(context_data, Object)
5879 // [wrapper]: the wrapper cache. This is either undefined or a WeakCell.
5880 DECL_ACCESSORS(wrapper, HeapObject)
5882 // [type]: the script type.
5883 DECL_ACCESSORS(type, Smi)
5885 // [line_ends]: FixedArray of line ends positions.
5886 DECL_ACCESSORS(line_ends, Object)
5888 // [eval_from_shared]: for eval scripts the shared funcion info for the
5889 // function from which eval was called.
5890 DECL_ACCESSORS(eval_from_shared, Object)
5892 // [eval_from_instructions_offset]: the instruction offset in the code for the
5893 // function from which eval was called where eval was called.
5894 DECL_ACCESSORS(eval_from_instructions_offset, Smi)
5896 // [shared_function_infos]: weak fixed array containing all shared
5897 // function infos created from this script.
5898 DECL_ACCESSORS(shared_function_infos, Object)
5900 // [flags]: Holds an exciting bitfield.
5901 DECL_ACCESSORS(flags, Smi)
5903 // [source_url]: sourceURL from magic comment
5904 DECL_ACCESSORS(source_url, Object)
5906 // [source_url]: sourceMappingURL magic comment
5907 DECL_ACCESSORS(source_mapping_url, Object)
5909 // [compilation_type]: how the the script was compiled. Encoded in the
5911 inline CompilationType compilation_type();
5912 inline void set_compilation_type(CompilationType type);
5914 // [compilation_state]: determines whether the script has already been
5915 // compiled. Encoded in the 'flags' field.
5916 inline CompilationState compilation_state();
5917 inline void set_compilation_state(CompilationState state);
5919 // [origin_options]: optional attributes set by the embedder via ScriptOrigin,
5920 // and used by the embedder to make decisions about the script. V8 just passes
5921 // this through. Encoded in the 'flags' field.
5922 inline v8::ScriptOriginOptions origin_options();
5923 inline void set_origin_options(ScriptOriginOptions origin_options);
5925 DECLARE_CAST(Script)
5927 // If script source is an external string, check that the underlying
5928 // resource is accessible. Otherwise, always return true.
5929 inline bool HasValidSource();
5931 // Convert code position into column number.
5932 static int GetColumnNumber(Handle<Script> script, int code_pos);
5934 // Convert code position into (zero-based) line number.
5935 // The non-handlified version does not allocate, but may be much slower.
5936 static int GetLineNumber(Handle<Script> script, int code_pos);
5937 int GetLineNumber(int code_pos);
5939 static Handle<Object> GetNameOrSourceURL(Handle<Script> script);
5941 // Init line_ends array with code positions of line ends inside script source.
5942 static void InitLineEnds(Handle<Script> script);
5944 // Get the JS object wrapping the given script; create it if none exists.
5945 static Handle<JSObject> GetWrapper(Handle<Script> script);
5947 // Look through the list of existing shared function infos to find one
5948 // that matches the function literal. Return empty handle if not found.
5949 MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(FunctionLiteral* fun);
5951 // Iterate over all script objects on the heap.
5954 explicit Iterator(Isolate* isolate);
5958 WeakFixedArray::Iterator iterator_;
5959 DISALLOW_COPY_AND_ASSIGN(Iterator);
5962 // Dispatched behavior.
5963 DECLARE_PRINTER(Script)
5964 DECLARE_VERIFIER(Script)
5966 static const int kSourceOffset = HeapObject::kHeaderSize;
5967 static const int kNameOffset = kSourceOffset + kPointerSize;
5968 static const int kLineOffsetOffset = kNameOffset + kPointerSize;
5969 static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
5970 static const int kContextOffset = kColumnOffsetOffset + kPointerSize;
5971 static const int kWrapperOffset = kContextOffset + kPointerSize;
5972 static const int kTypeOffset = kWrapperOffset + kPointerSize;
5973 static const int kLineEndsOffset = kTypeOffset + kPointerSize;
5974 static const int kIdOffset = kLineEndsOffset + kPointerSize;
5975 static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
5976 static const int kEvalFrominstructionsOffsetOffset =
5977 kEvalFromSharedOffset + kPointerSize;
5978 static const int kSharedFunctionInfosOffset =
5979 kEvalFrominstructionsOffsetOffset + kPointerSize;
5980 static const int kFlagsOffset = kSharedFunctionInfosOffset + kPointerSize;
5981 static const int kSourceUrlOffset = kFlagsOffset + kPointerSize;
5982 static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
5983 static const int kSize = kSourceMappingUrlOffset + kPointerSize;
5986 int GetLineNumberWithArray(int code_pos);
5988 // Bit positions in the flags field.
5989 static const int kCompilationTypeBit = 0;
5990 static const int kCompilationStateBit = 1;
5991 static const int kOriginOptionsShift = 2;
5992 static const int kOriginOptionsSize = 3;
5993 static const int kOriginOptionsMask = ((1 << kOriginOptionsSize) - 1)
5994 << kOriginOptionsShift;
5996 DISALLOW_IMPLICIT_CONSTRUCTORS(Script);
6000 // List of builtin functions we want to identify to improve code
6003 // Each entry has a name of a global object property holding an object
6004 // optionally followed by ".prototype", a name of a builtin function
6005 // on the object (the one the id is set for), and a label.
6007 // Installation of ids for the selected builtin functions is handled
6008 // by the bootstrapper.
6009 #define FUNCTIONS_WITH_ID_LIST(V) \
6010 V(Array.prototype, indexOf, ArrayIndexOf) \
6011 V(Array.prototype, lastIndexOf, ArrayLastIndexOf) \
6012 V(Array.prototype, push, ArrayPush) \
6013 V(Array.prototype, pop, ArrayPop) \
6014 V(Array.prototype, shift, ArrayShift) \
6015 V(Function.prototype, apply, FunctionApply) \
6016 V(Function.prototype, call, FunctionCall) \
6017 V(String.prototype, charCodeAt, StringCharCodeAt) \
6018 V(String.prototype, charAt, StringCharAt) \
6019 V(String, fromCharCode, StringFromCharCode) \
6020 V(Math, random, MathRandom) \
6021 V(Math, floor, MathFloor) \
6022 V(Math, round, MathRound) \
6023 V(Math, ceil, MathCeil) \
6024 V(Math, abs, MathAbs) \
6025 V(Math, log, MathLog) \
6026 V(Math, exp, MathExp) \
6027 V(Math, sqrt, MathSqrt) \
6028 V(Math, pow, MathPow) \
6029 V(Math, max, MathMax) \
6030 V(Math, min, MathMin) \
6031 V(Math, cos, MathCos) \
6032 V(Math, sin, MathSin) \
6033 V(Math, tan, MathTan) \
6034 V(Math, acos, MathAcos) \
6035 V(Math, asin, MathAsin) \
6036 V(Math, atan, MathAtan) \
6037 V(Math, atan2, MathAtan2) \
6038 V(Math, imul, MathImul) \
6039 V(Math, clz32, MathClz32) \
6040 V(Math, fround, MathFround)
6042 #define ATOMIC_FUNCTIONS_WITH_ID_LIST(V) \
6043 V(Atomics, load, AtomicsLoad) \
6044 V(Atomics, store, AtomicsStore)
6046 enum BuiltinFunctionId {
6048 #define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \
6050 FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
6051 ATOMIC_FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
6052 #undef DECLARE_FUNCTION_ID
6053 // Fake id for a special case of Math.pow. Note, it continues the
6054 // list of math functions.
6059 // Result of searching in an optimized code map of a SharedFunctionInfo. Note
6060 // that both {code} and {literals} can be NULL to pass search result status.
6061 struct CodeAndLiterals {
6062 Code* code; // Cached optimized code.
6063 FixedArray* literals; // Cached literals array.
6067 // SharedFunctionInfo describes the JSFunction information that can be
6068 // shared by multiple instances of the function.
6069 class SharedFunctionInfo: public HeapObject {
6071 // [name]: Function name.
6072 DECL_ACCESSORS(name, Object)
6074 // [code]: Function code.
6075 DECL_ACCESSORS(code, Code)
6076 inline void ReplaceCode(Code* code);
6078 // [optimized_code_map]: Map from native context to optimized code
6079 // and a shared literals array or Smi(0) if none.
6080 DECL_ACCESSORS(optimized_code_map, Object)
6082 // Returns entry from optimized code map for specified context and OSR entry.
6083 // Note that {code == nullptr} indicates no matching entry has been found,
6084 // whereas {literals == nullptr} indicates the code is context-independent.
6085 CodeAndLiterals SearchOptimizedCodeMap(Context* native_context,
6086 BailoutId osr_ast_id);
6088 // Clear optimized code map.
6089 void ClearOptimizedCodeMap();
6091 // Removed a specific optimized code object from the optimized code map.
6092 void EvictFromOptimizedCodeMap(Code* optimized_code, const char* reason);
6094 // Trims the optimized code map after entries have been removed.
6095 void TrimOptimizedCodeMap(int shrink_by);
6097 // Add a new entry to the optimized code map for context-independent code.
6098 static void AddSharedCodeToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
6101 // Add a new entry to the optimized code map for context-dependent code.
6102 static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
6103 Handle<Context> native_context,
6105 Handle<FixedArray> literals,
6106 BailoutId osr_ast_id);
6108 // Set up the link between shared function info and the script. The shared
6109 // function info is added to the list on the script.
6110 static void SetScript(Handle<SharedFunctionInfo> shared,
6111 Handle<Object> script_object);
6113 // Layout description of the optimized code map.
6114 static const int kNextMapIndex = 0;
6115 static const int kSharedCodeIndex = 1;
6116 static const int kEntriesStart = 2;
6117 static const int kContextOffset = 0;
6118 static const int kCachedCodeOffset = 1;
6119 static const int kLiteralsOffset = 2;
6120 static const int kOsrAstIdOffset = 3;
6121 static const int kEntryLength = 4;
6122 static const int kInitialLength = kEntriesStart + kEntryLength;
6124 // [scope_info]: Scope info.
6125 DECL_ACCESSORS(scope_info, ScopeInfo)
6127 // [construct stub]: Code stub for constructing instances of this function.
6128 DECL_ACCESSORS(construct_stub, Code)
6130 // Returns if this function has been compiled to native code yet.
6131 inline bool is_compiled();
6133 // [length]: The function length - usually the number of declared parameters.
6134 // Use up to 2^30 parameters.
6135 inline int length() const;
6136 inline void set_length(int value);
6138 // [internal formal parameter count]: The declared number of parameters.
6139 // For subclass constructors, also includes new.target.
6140 // The size of function's frame is internal_formal_parameter_count + 1.
6141 inline int internal_formal_parameter_count() const;
6142 inline void set_internal_formal_parameter_count(int value);
6144 // Set the formal parameter count so the function code will be
6145 // called without using argument adaptor frames.
6146 inline void DontAdaptArguments();
6148 // [expected_nof_properties]: Expected number of properties for the function.
6149 inline int expected_nof_properties() const;
6150 inline void set_expected_nof_properties(int value);
6152 // [feedback_vector] - accumulates ast node feedback from full-codegen and
6153 // (increasingly) from crankshafted code where sufficient feedback isn't
6155 DECL_ACCESSORS(feedback_vector, TypeFeedbackVector)
6157 // Unconditionally clear the type feedback vector (including vector ICs).
6158 void ClearTypeFeedbackInfo();
6160 // Clear the type feedback vector with a more subtle policy at GC time.
6161 void ClearTypeFeedbackInfoAtGCTime();
6164 // [unique_id] - For --trace-maps purposes, an identifier that's persistent
6165 // even if the GC moves this SharedFunctionInfo.
6166 inline int unique_id() const;
6167 inline void set_unique_id(int value);
6170 // [instance class name]: class name for instances.
6171 DECL_ACCESSORS(instance_class_name, Object)
6173 // [function data]: This field holds some additional data for function.
6174 // Currently it has one of:
6175 // - a FunctionTemplateInfo to make benefit the API [IsApiFunction()].
6176 // - a Smi identifying a builtin function [HasBuiltinFunctionId()].
6177 // - a BytecodeArray for the interpreter [HasBytecodeArray()].
6178 // In the long run we don't want all functions to have this field but
6179 // we can fix that when we have a better model for storing hidden data
6181 DECL_ACCESSORS(function_data, Object)
6183 inline bool IsApiFunction();
6184 inline FunctionTemplateInfo* get_api_func_data();
6185 inline bool HasBuiltinFunctionId();
6186 inline BuiltinFunctionId builtin_function_id();
6187 inline bool HasBytecodeArray();
6188 inline BytecodeArray* bytecode_array();
6190 // [script info]: Script from which the function originates.
6191 DECL_ACCESSORS(script, Object)
6193 // [num_literals]: Number of literals used by this function.
6194 inline int num_literals() const;
6195 inline void set_num_literals(int value);
6197 // [start_position_and_type]: Field used to store both the source code
6198 // position, whether or not the function is a function expression,
6199 // and whether or not the function is a toplevel function. The two
6200 // least significants bit indicates whether the function is an
6201 // expression and the rest contains the source code position.
6202 inline int start_position_and_type() const;
6203 inline void set_start_position_and_type(int value);
6205 // The function is subject to debugging if a debug info is attached.
6206 inline bool HasDebugInfo();
6207 inline DebugInfo* GetDebugInfo();
6209 // A function has debug code if the compiled code has debug break slots.
6210 inline bool HasDebugCode();
6212 // [debug info]: Debug information.
6213 DECL_ACCESSORS(debug_info, Object)
6215 // [inferred name]: Name inferred from variable or property
6216 // assignment of this function. Used to facilitate debugging and
6217 // profiling of JavaScript code written in OO style, where almost
6218 // all functions are anonymous but are assigned to object
6220 DECL_ACCESSORS(inferred_name, String)
6222 // The function's name if it is non-empty, otherwise the inferred name.
6223 String* DebugName();
6225 // Position of the 'function' token in the script source.
6226 inline int function_token_position() const;
6227 inline void set_function_token_position(int function_token_position);
6229 // Position of this function in the script source.
6230 inline int start_position() const;
6231 inline void set_start_position(int start_position);
6233 // End position of this function in the script source.
6234 inline int end_position() const;
6235 inline void set_end_position(int end_position);
6237 // Is this function a function expression in the source code.
6238 DECL_BOOLEAN_ACCESSORS(is_expression)
6240 // Is this function a top-level function (scripts, evals).
6241 DECL_BOOLEAN_ACCESSORS(is_toplevel)
6243 // Bit field containing various information collected by the compiler to
6244 // drive optimization.
6245 inline int compiler_hints() const;
6246 inline void set_compiler_hints(int value);
6248 inline int ast_node_count() const;
6249 inline void set_ast_node_count(int count);
6251 inline int profiler_ticks() const;
6252 inline void set_profiler_ticks(int ticks);
6254 // Inline cache age is used to infer whether the function survived a context
6255 // disposal or not. In the former case we reset the opt_count.
6256 inline int ic_age();
6257 inline void set_ic_age(int age);
6259 // Indicates if this function can be lazy compiled.
6260 // This is used to determine if we can safely flush code from a function
6261 // when doing GC if we expect that the function will no longer be used.
6262 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation)
6264 // Indicates if this function can be lazy compiled without a context.
6265 // This is used to determine if we can force compilation without reaching
6266 // the function through program execution but through other means (e.g. heap
6267 // iteration by the debugger).
6268 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context)
6270 // Indicates whether optimizations have been disabled for this
6271 // shared function info. If a function is repeatedly optimized or if
6272 // we cannot optimize the function we disable optimization to avoid
6273 // spending time attempting to optimize it again.
6274 DECL_BOOLEAN_ACCESSORS(optimization_disabled)
6276 // Indicates the language mode.
6277 inline LanguageMode language_mode();
6278 inline void set_language_mode(LanguageMode language_mode);
6280 // False if the function definitely does not allocate an arguments object.
6281 DECL_BOOLEAN_ACCESSORS(uses_arguments)
6283 // Indicates that this function uses a super property (or an eval that may
6284 // use a super property).
6285 // This is needed to set up the [[HomeObject]] on the function instance.
6286 DECL_BOOLEAN_ACCESSORS(needs_home_object)
6288 // True if the function has any duplicated parameter names.
6289 DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
6291 // Indicates whether the function is a native function.
6292 // These needs special treatment in .call and .apply since
6293 // null passed as the receiver should not be translated to the
6295 DECL_BOOLEAN_ACCESSORS(native)
6297 // Indicate that this function should always be inlined in optimized code.
6298 DECL_BOOLEAN_ACCESSORS(force_inline)
6300 // Indicates that the function was created by the Function function.
6301 // Though it's anonymous, toString should treat it as if it had the name
6302 // "anonymous". We don't set the name itself so that the system does not
6303 // see a binding for it.
6304 DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous)
6306 // Indicates whether the function is a bound function created using
6307 // the bind function.
6308 DECL_BOOLEAN_ACCESSORS(bound)
6310 // Indicates that the function is anonymous (the name field can be set
6311 // through the API, which does not change this flag).
6312 DECL_BOOLEAN_ACCESSORS(is_anonymous)
6314 // Is this a function or top-level/eval code.
6315 DECL_BOOLEAN_ACCESSORS(is_function)
6317 // Indicates that code for this function cannot be compiled with Crankshaft.
6318 DECL_BOOLEAN_ACCESSORS(dont_crankshaft)
6320 // Indicates that code for this function cannot be flushed.
6321 DECL_BOOLEAN_ACCESSORS(dont_flush)
6323 // Indicates that this function is a generator.
6324 DECL_BOOLEAN_ACCESSORS(is_generator)
6326 // Indicates that this function is an arrow function.
6327 DECL_BOOLEAN_ACCESSORS(is_arrow)
6329 // Indicates that this function is a concise method.
6330 DECL_BOOLEAN_ACCESSORS(is_concise_method)
6332 // Indicates that this function is an accessor (getter or setter).
6333 DECL_BOOLEAN_ACCESSORS(is_accessor_function)
6335 // Indicates that this function is a default constructor.
6336 DECL_BOOLEAN_ACCESSORS(is_default_constructor)
6338 // Indicates that this function is an asm function.
6339 DECL_BOOLEAN_ACCESSORS(asm_function)
6341 // Indicates that the the shared function info is deserialized from cache.
6342 DECL_BOOLEAN_ACCESSORS(deserialized)
6344 // Indicates that the the shared function info has never been compiled before.
6345 DECL_BOOLEAN_ACCESSORS(never_compiled)
6347 inline FunctionKind kind();
6348 inline void set_kind(FunctionKind kind);
6350 // Indicates whether or not the code in the shared function support
6352 inline bool has_deoptimization_support();
6354 // Enable deoptimization support through recompiled code.
6355 void EnableDeoptimizationSupport(Code* recompiled);
6357 // Disable (further) attempted optimization of all functions sharing this
6358 // shared function info.
6359 void DisableOptimization(BailoutReason reason);
6361 inline BailoutReason disable_optimization_reason();
6363 // Lookup the bailout ID and DCHECK that it exists in the non-optimized
6364 // code, returns whether it asserted (i.e., always true if assertions are
6366 bool VerifyBailoutId(BailoutId id);
6368 // [source code]: Source code for the function.
6369 bool HasSourceCode() const;
6370 Handle<Object> GetSourceCode();
6372 // Number of times the function was optimized.
6373 inline int opt_count();
6374 inline void set_opt_count(int opt_count);
6376 // Number of times the function was deoptimized.
6377 inline void set_deopt_count(int value);
6378 inline int deopt_count();
6379 inline void increment_deopt_count();
6381 // Number of time we tried to re-enable optimization after it
6382 // was disabled due to high number of deoptimizations.
6383 inline void set_opt_reenable_tries(int value);
6384 inline int opt_reenable_tries();
6386 inline void TryReenableOptimization();
6388 // Stores deopt_count, opt_reenable_tries and ic_age as bit-fields.
6389 inline void set_counters(int value);
6390 inline int counters() const;
6392 // Stores opt_count and bailout_reason as bit-fields.
6393 inline void set_opt_count_and_bailout_reason(int value);
6394 inline int opt_count_and_bailout_reason() const;
6396 inline void set_disable_optimization_reason(BailoutReason reason);
6398 // Tells whether this function should be subject to debugging.
6399 inline bool IsSubjectToDebugging();
6401 // Check whether or not this function is inlineable.
6402 bool IsInlineable();
6404 // Source size of this function.
6407 // Calculate the instance size.
6408 int CalculateInstanceSize();
6410 // Calculate the number of in-object properties.
6411 int CalculateInObjectProperties();
6413 inline bool has_simple_parameters();
6415 // Initialize a SharedFunctionInfo from a parsed function literal.
6416 static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info,
6417 FunctionLiteral* lit);
6419 // Dispatched behavior.
6420 DECLARE_PRINTER(SharedFunctionInfo)
6421 DECLARE_VERIFIER(SharedFunctionInfo)
6423 void ResetForNewContext(int new_ic_age);
6425 // Iterate over all shared function infos that are created from a script.
6426 // That excludes shared function infos created for API functions and C++
6430 explicit Iterator(Isolate* isolate);
6431 SharedFunctionInfo* Next();
6436 Script::Iterator script_iterator_;
6437 WeakFixedArray::Iterator sfi_iterator_;
6438 DisallowHeapAllocation no_gc_;
6439 DISALLOW_COPY_AND_ASSIGN(Iterator);
6442 DECLARE_CAST(SharedFunctionInfo)
6445 static const int kDontAdaptArgumentsSentinel = -1;
6447 // Layout description.
6449 static const int kNameOffset = HeapObject::kHeaderSize;
6450 static const int kCodeOffset = kNameOffset + kPointerSize;
6451 static const int kOptimizedCodeMapOffset = kCodeOffset + kPointerSize;
6452 static const int kScopeInfoOffset = kOptimizedCodeMapOffset + kPointerSize;
6453 static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize;
6454 static const int kInstanceClassNameOffset =
6455 kConstructStubOffset + kPointerSize;
6456 static const int kFunctionDataOffset =
6457 kInstanceClassNameOffset + kPointerSize;
6458 static const int kScriptOffset = kFunctionDataOffset + kPointerSize;
6459 static const int kDebugInfoOffset = kScriptOffset + kPointerSize;
6460 static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize;
6461 static const int kFeedbackVectorOffset =
6462 kInferredNameOffset + kPointerSize;
6464 static const int kUniqueIdOffset = kFeedbackVectorOffset + kPointerSize;
6465 static const int kLastPointerFieldOffset = kUniqueIdOffset;
6467 // Just to not break the postmortrem support with conditional offsets
6468 static const int kUniqueIdOffset = kFeedbackVectorOffset;
6469 static const int kLastPointerFieldOffset = kFeedbackVectorOffset;
6472 #if V8_HOST_ARCH_32_BIT
6474 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
6475 static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize;
6476 static const int kExpectedNofPropertiesOffset =
6477 kFormalParameterCountOffset + kPointerSize;
6478 static const int kNumLiteralsOffset =
6479 kExpectedNofPropertiesOffset + kPointerSize;
6480 static const int kStartPositionAndTypeOffset =
6481 kNumLiteralsOffset + kPointerSize;
6482 static const int kEndPositionOffset =
6483 kStartPositionAndTypeOffset + kPointerSize;
6484 static const int kFunctionTokenPositionOffset =
6485 kEndPositionOffset + kPointerSize;
6486 static const int kCompilerHintsOffset =
6487 kFunctionTokenPositionOffset + kPointerSize;
6488 static const int kOptCountAndBailoutReasonOffset =
6489 kCompilerHintsOffset + kPointerSize;
6490 static const int kCountersOffset =
6491 kOptCountAndBailoutReasonOffset + kPointerSize;
6492 static const int kAstNodeCountOffset =
6493 kCountersOffset + kPointerSize;
6494 static const int kProfilerTicksOffset =
6495 kAstNodeCountOffset + kPointerSize;
6498 static const int kSize = kProfilerTicksOffset + kPointerSize;
6500 // The only reason to use smi fields instead of int fields
6501 // is to allow iteration without maps decoding during
6502 // garbage collections.
6503 // To avoid wasting space on 64-bit architectures we use
6504 // the following trick: we group integer fields into pairs
6505 // The least significant integer in each pair is shifted left by 1.
6506 // By doing this we guarantee that LSB of each kPointerSize aligned
6507 // word is not set and thus this word cannot be treated as pointer
6508 // to HeapObject during old space traversal.
6509 #if V8_TARGET_LITTLE_ENDIAN
6510 static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
6511 static const int kFormalParameterCountOffset =
6512 kLengthOffset + kIntSize;
6514 static const int kExpectedNofPropertiesOffset =
6515 kFormalParameterCountOffset + kIntSize;
6516 static const int kNumLiteralsOffset =
6517 kExpectedNofPropertiesOffset + kIntSize;
6519 static const int kEndPositionOffset =
6520 kNumLiteralsOffset + kIntSize;
6521 static const int kStartPositionAndTypeOffset =
6522 kEndPositionOffset + kIntSize;
6524 static const int kFunctionTokenPositionOffset =
6525 kStartPositionAndTypeOffset + kIntSize;
6526 static const int kCompilerHintsOffset =
6527 kFunctionTokenPositionOffset + kIntSize;
6529 static const int kOptCountAndBailoutReasonOffset =
6530 kCompilerHintsOffset + kIntSize;
6531 static const int kCountersOffset =
6532 kOptCountAndBailoutReasonOffset + kIntSize;
6534 static const int kAstNodeCountOffset =
6535 kCountersOffset + kIntSize;
6536 static const int kProfilerTicksOffset =
6537 kAstNodeCountOffset + kIntSize;
6540 static const int kSize = kProfilerTicksOffset + kIntSize;
6542 #elif V8_TARGET_BIG_ENDIAN
6543 static const int kFormalParameterCountOffset =
6544 kLastPointerFieldOffset + kPointerSize;
6545 static const int kLengthOffset = kFormalParameterCountOffset + kIntSize;
6547 static const int kNumLiteralsOffset = kLengthOffset + kIntSize;
6548 static const int kExpectedNofPropertiesOffset = kNumLiteralsOffset + kIntSize;
6550 static const int kStartPositionAndTypeOffset =
6551 kExpectedNofPropertiesOffset + kIntSize;
6552 static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize;
6554 static const int kCompilerHintsOffset = kEndPositionOffset + kIntSize;
6555 static const int kFunctionTokenPositionOffset =
6556 kCompilerHintsOffset + kIntSize;
6558 static const int kCountersOffset = kFunctionTokenPositionOffset + kIntSize;
6559 static const int kOptCountAndBailoutReasonOffset = kCountersOffset + kIntSize;
6561 static const int kProfilerTicksOffset =
6562 kOptCountAndBailoutReasonOffset + kIntSize;
6563 static const int kAstNodeCountOffset = kProfilerTicksOffset + kIntSize;
6566 static const int kSize = kAstNodeCountOffset + kIntSize;
6569 #error Unknown byte ordering
6570 #endif // Big endian
6574 static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
6576 typedef FixedBodyDescriptor<kNameOffset,
6577 kLastPointerFieldOffset + kPointerSize,
6578 kSize> BodyDescriptor;
6580 // Bit positions in start_position_and_type.
6581 // The source code start position is in the 30 most significant bits of
6582 // the start_position_and_type field.
6583 static const int kIsExpressionBit = 0;
6584 static const int kIsTopLevelBit = 1;
6585 static const int kStartPositionShift = 2;
6586 static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1);
6588 // Bit positions in compiler_hints.
6589 enum CompilerHints {
6590 kAllowLazyCompilation,
6591 kAllowLazyCompilationWithoutContext,
6592 kOptimizationDisabled,
6593 kStrictModeFunction,
6594 kStrongModeFunction,
6597 kHasDuplicateParameters,
6602 kNameShouldPrintAsAnonymous,
6609 kIsAccessorFunction,
6610 kIsDefaultConstructor,
6611 kIsSubclassConstructor,
6617 kCompilerHintsCount // Pseudo entry
6619 // Add hints for other modes when they're added.
6620 STATIC_ASSERT(LANGUAGE_END == 3);
6622 class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 8> {};
6624 class DeoptCountBits : public BitField<int, 0, 4> {};
6625 class OptReenableTriesBits : public BitField<int, 4, 18> {};
6626 class ICAgeBits : public BitField<int, 22, 8> {};
6628 class OptCountBits : public BitField<int, 0, 22> {};
6629 class DisabledOptimizationReasonBits : public BitField<int, 22, 8> {};
6632 #if V8_HOST_ARCH_32_BIT
6633 // On 32 bit platforms, compiler hints is a smi.
6634 static const int kCompilerHintsSmiTagSize = kSmiTagSize;
6635 static const int kCompilerHintsSize = kPointerSize;
6637 // On 64 bit platforms, compiler hints is not a smi, see comment above.
6638 static const int kCompilerHintsSmiTagSize = 0;
6639 static const int kCompilerHintsSize = kIntSize;
6642 STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <=
6643 SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte);
6646 // Constants for optimizing codegen for strict mode function and
6648 // Allows to use byte-width instructions.
6649 static const int kStrictModeBitWithinByte =
6650 (kStrictModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte;
6651 static const int kStrongModeBitWithinByte =
6652 (kStrongModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte;
6654 static const int kNativeBitWithinByte =
6655 (kNative + kCompilerHintsSmiTagSize) % kBitsPerByte;
6657 #if defined(V8_TARGET_LITTLE_ENDIAN)
6658 static const int kStrictModeByteOffset = kCompilerHintsOffset +
6659 (kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte;
6660 static const int kStrongModeByteOffset =
6661 kCompilerHintsOffset +
6662 (kStrongModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte;
6663 static const int kNativeByteOffset = kCompilerHintsOffset +
6664 (kNative + kCompilerHintsSmiTagSize) / kBitsPerByte;
6665 #elif defined(V8_TARGET_BIG_ENDIAN)
6666 static const int kStrictModeByteOffset = kCompilerHintsOffset +
6667 (kCompilerHintsSize - 1) -
6668 ((kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte);
6669 static const int kStrongModeByteOffset =
6670 kCompilerHintsOffset + (kCompilerHintsSize - 1) -
6671 ((kStrongModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte);
6672 static const int kNativeByteOffset = kCompilerHintsOffset +
6673 (kCompilerHintsSize - 1) -
6674 ((kNative + kCompilerHintsSmiTagSize) / kBitsPerByte);
6676 #error Unknown byte ordering
6680 DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo);
6684 // Printing support.
6685 struct SourceCodeOf {
6686 explicit SourceCodeOf(SharedFunctionInfo* v, int max = -1)
6687 : value(v), max_length(max) {}
6688 const SharedFunctionInfo* value;
6693 std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v);
6696 class JSGeneratorObject: public JSObject {
6698 // [function]: The function corresponding to this generator object.
6699 DECL_ACCESSORS(function, JSFunction)
6701 // [context]: The context of the suspended computation.
6702 DECL_ACCESSORS(context, Context)
6704 // [receiver]: The receiver of the suspended computation.
6705 DECL_ACCESSORS(receiver, Object)
6707 // [continuation]: Offset into code of continuation.
6709 // A positive offset indicates a suspended generator. The special
6710 // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
6711 // cannot be resumed.
6712 inline int continuation() const;
6713 inline void set_continuation(int continuation);
6714 inline bool is_closed();
6715 inline bool is_executing();
6716 inline bool is_suspended();
6718 // [operand_stack]: Saved operand stack.
6719 DECL_ACCESSORS(operand_stack, FixedArray)
6721 DECLARE_CAST(JSGeneratorObject)
6723 // Dispatched behavior.
6724 DECLARE_PRINTER(JSGeneratorObject)
6725 DECLARE_VERIFIER(JSGeneratorObject)
6727 // Magic sentinel values for the continuation.
6728 static const int kGeneratorExecuting = -1;
6729 static const int kGeneratorClosed = 0;
6731 // Layout description.
6732 static const int kFunctionOffset = JSObject::kHeaderSize;
6733 static const int kContextOffset = kFunctionOffset + kPointerSize;
6734 static const int kReceiverOffset = kContextOffset + kPointerSize;
6735 static const int kContinuationOffset = kReceiverOffset + kPointerSize;
6736 static const int kOperandStackOffset = kContinuationOffset + kPointerSize;
6737 static const int kSize = kOperandStackOffset + kPointerSize;
6739 // Resume mode, for use by runtime functions.
6740 enum ResumeMode { NEXT, THROW };
6742 // Yielding from a generator returns an object with the following inobject
6743 // properties. See Context::iterator_result_map() for the map.
6744 static const int kResultValuePropertyIndex = 0;
6745 static const int kResultDonePropertyIndex = 1;
6746 static const int kResultPropertyCount = 2;
6748 static const int kResultValuePropertyOffset = JSObject::kHeaderSize;
6749 static const int kResultDonePropertyOffset =
6750 kResultValuePropertyOffset + kPointerSize;
6751 static const int kResultSize = kResultDonePropertyOffset + kPointerSize;
6754 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
6758 // Representation for module instance objects.
6759 class JSModule: public JSObject {
6761 // [context]: the context holding the module's locals, or undefined if none.
6762 DECL_ACCESSORS(context, Object)
6764 // [scope_info]: Scope info.
6765 DECL_ACCESSORS(scope_info, ScopeInfo)
6767 DECLARE_CAST(JSModule)
6769 // Dispatched behavior.
6770 DECLARE_PRINTER(JSModule)
6771 DECLARE_VERIFIER(JSModule)
6773 // Layout description.
6774 static const int kContextOffset = JSObject::kHeaderSize;
6775 static const int kScopeInfoOffset = kContextOffset + kPointerSize;
6776 static const int kSize = kScopeInfoOffset + kPointerSize;
6779 DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule);
6783 // JSFunction describes JavaScript functions.
6784 class JSFunction: public JSObject {
6786 // [prototype_or_initial_map]:
6787 DECL_ACCESSORS(prototype_or_initial_map, Object)
6789 // [shared]: The information about the function that
6790 // can be shared by instances.
6791 DECL_ACCESSORS(shared, SharedFunctionInfo)
6793 // [context]: The context for this function.
6794 inline Context* context();
6795 inline void set_context(Object* context);
6796 inline JSObject* global_proxy();
6798 // [code]: The generated code object for this function. Executed
6799 // when the function is invoked, e.g. foo() or new foo(). See
6800 // [[Call]] and [[Construct]] description in ECMA-262, section
6802 inline Code* code();
6803 inline void set_code(Code* code);
6804 inline void set_code_no_write_barrier(Code* code);
6805 inline void ReplaceCode(Code* code);
6807 // Tells whether this function is builtin.
6808 inline bool IsBuiltin();
6810 // Tells whether this function inlines the given shared function info.
6811 bool Inlines(SharedFunctionInfo* candidate);
6813 // Tells whether this function should be subject to debugging.
6814 inline bool IsSubjectToDebugging();
6816 // Tells whether or not the function needs arguments adaption.
6817 inline bool NeedsArgumentsAdaption();
6819 // Tells whether or not this function has been optimized.
6820 inline bool IsOptimized();
6822 // Mark this function for lazy recompilation. The function will be
6823 // recompiled the next time it is executed.
6824 void MarkForOptimization();
6825 void AttemptConcurrentOptimization();
6827 // Tells whether or not the function is already marked for lazy
6829 inline bool IsMarkedForOptimization();
6830 inline bool IsMarkedForConcurrentOptimization();
6832 // Tells whether or not the function is on the concurrent recompilation queue.
6833 inline bool IsInOptimizationQueue();
6835 // Inobject slack tracking is the way to reclaim unused inobject space.
6837 // The instance size is initially determined by adding some slack to
6838 // expected_nof_properties (to allow for a few extra properties added
6839 // after the constructor). There is no guarantee that the extra space
6840 // will not be wasted.
6842 // Here is the algorithm to reclaim the unused inobject space:
6843 // - Detect the first constructor call for this JSFunction.
6844 // When it happens enter the "in progress" state: initialize construction
6845 // counter in the initial_map.
6846 // - While the tracking is in progress create objects filled with
6847 // one_pointer_filler_map instead of undefined_value. This way they can be
6848 // resized quickly and safely.
6849 // - Once enough objects have been created compute the 'slack'
6850 // (traverse the map transition tree starting from the
6851 // initial_map and find the lowest value of unused_property_fields).
6852 // - Traverse the transition tree again and decrease the instance size
6853 // of every map. Existing objects will resize automatically (they are
6854 // filled with one_pointer_filler_map). All further allocations will
6855 // use the adjusted instance size.
6856 // - SharedFunctionInfo's expected_nof_properties left unmodified since
6857 // allocations made using different closures could actually create different
6858 // kind of objects (see prototype inheritance pattern).
6860 // Important: inobject slack tracking is not attempted during the snapshot
6863 // True if the initial_map is set and the object constructions countdown
6864 // counter is not zero.
6865 static const int kGenerousAllocationCount =
6866 Map::kSlackTrackingCounterStart - Map::kSlackTrackingCounterEnd + 1;
6867 inline bool IsInobjectSlackTrackingInProgress();
6869 // Starts the tracking.
6870 // Initializes object constructions countdown counter in the initial map.
6871 void StartInobjectSlackTracking();
6873 // Completes the tracking.
6874 void CompleteInobjectSlackTracking();
6876 // [literals_or_bindings]: Fixed array holding either
6877 // the materialized literals or the bindings of a bound function.
6879 // If the function contains object, regexp or array literals, the
6880 // literals array prefix contains the object, regexp, and array
6881 // function to be used when creating these literals. This is
6882 // necessary so that we do not dynamically lookup the object, regexp
6883 // or array functions. Performing a dynamic lookup, we might end up
6884 // using the functions from a new context that we should not have
6887 // On bound functions, the array is a (copy-on-write) fixed-array containing
6888 // the function that was bound, bound this-value and any bound
6889 // arguments. Bound functions never contain literals.
6890 DECL_ACCESSORS(literals_or_bindings, FixedArray)
6892 inline FixedArray* literals();
6893 inline void set_literals(FixedArray* literals);
6895 inline FixedArray* function_bindings();
6896 inline void set_function_bindings(FixedArray* bindings);
6898 // The initial map for an object created by this constructor.
6899 inline Map* initial_map();
6900 static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
6901 Handle<Object> prototype);
6902 inline bool has_initial_map();
6903 static void EnsureHasInitialMap(Handle<JSFunction> function);
6905 // Get and set the prototype property on a JSFunction. If the
6906 // function has an initial map the prototype is set on the initial
6907 // map. Otherwise, the prototype is put in the initial map field
6908 // until an initial map is needed.
6909 inline bool has_prototype();
6910 inline bool has_instance_prototype();
6911 inline Object* prototype();
6912 inline Object* instance_prototype();
6913 static void SetPrototype(Handle<JSFunction> function,
6914 Handle<Object> value);
6915 static void SetInstancePrototype(Handle<JSFunction> function,
6916 Handle<Object> value);
6918 // Creates a new closure for the fucntion with the same bindings,
6919 // bound values, and prototype. An equivalent of spec operations
6920 // ``CloneMethod`` and ``CloneBoundFunction``.
6921 static Handle<JSFunction> CloneClosure(Handle<JSFunction> function);
6923 // After prototype is removed, it will not be created when accessed, and
6924 // [[Construct]] from this function will not be allowed.
6925 bool RemovePrototype();
6926 inline bool should_have_prototype();
6928 // Accessor for this function's initial map's [[class]]
6929 // property. This is primarily used by ECMA native functions. This
6930 // method sets the class_name field of this function's initial map
6931 // to a given value. It creates an initial map if this function does
6932 // not have one. Note that this method does not copy the initial map
6933 // if it has one already, but simply replaces it with the new value.
6934 // Instances created afterwards will have a map whose [[class]] is
6935 // set to 'value', but there is no guarantees on instances created
6937 void SetInstanceClassName(String* name);
6939 // Returns if this function has been compiled to native code yet.
6940 inline bool is_compiled();
6942 // Returns `false` if formal parameters include rest parameters, optional
6943 // parameters, or destructuring parameters.
6944 // TODO(caitp): make this a flag set during parsing
6945 inline bool has_simple_parameters();
6947 // [next_function_link]: Links functions into various lists, e.g. the list
6948 // of optimized functions hanging off the native_context. The CodeFlusher
6949 // uses this link to chain together flushing candidates. Treated weakly
6950 // by the garbage collector.
6951 DECL_ACCESSORS(next_function_link, Object)
6953 // Prints the name of the function using PrintF.
6954 void PrintName(FILE* out = stdout);
6956 DECLARE_CAST(JSFunction)
6958 // Iterates the objects, including code objects indirectly referenced
6959 // through pointers to the first instruction in the code object.
6960 void JSFunctionIterateBody(int object_size, ObjectVisitor* v);
6962 // Dispatched behavior.
6963 DECLARE_PRINTER(JSFunction)
6964 DECLARE_VERIFIER(JSFunction)
6966 // Returns the number of allocated literals.
6967 inline int NumberOfLiterals();
6969 // Used for flags such as --hydrogen-filter.
6970 bool PassesFilter(const char* raw_filter);
6972 // The function's name if it is configured, otherwise shared function info
6974 static Handle<String> GetDebugName(Handle<JSFunction> function);
6976 // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
6977 // kSize) is weak and has special handling during garbage collection.
6978 static const int kCodeEntryOffset = JSObject::kHeaderSize;
6979 static const int kPrototypeOrInitialMapOffset =
6980 kCodeEntryOffset + kPointerSize;
6981 static const int kSharedFunctionInfoOffset =
6982 kPrototypeOrInitialMapOffset + kPointerSize;
6983 static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize;
6984 static const int kLiteralsOffset = kContextOffset + kPointerSize;
6985 static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize;
6986 static const int kNextFunctionLinkOffset = kNonWeakFieldsEndOffset;
6987 static const int kSize = kNextFunctionLinkOffset + kPointerSize;
6989 // Layout of the bound-function binding array.
6990 static const int kBoundFunctionIndex = 0;
6991 static const int kBoundThisIndex = 1;
6992 static const int kBoundArgumentsStartIndex = 2;
6995 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
6999 // JSGlobalProxy's prototype must be a JSGlobalObject or null,
7000 // and the prototype is hidden. JSGlobalProxy always delegates
7001 // property accesses to its prototype if the prototype is not null.
7003 // A JSGlobalProxy can be reinitialized which will preserve its identity.
7005 // Accessing a JSGlobalProxy requires security check.
7007 class JSGlobalProxy : public JSObject {
7009 // [native_context]: the owner native context of this global proxy object.
7010 // It is null value if this object is not used by any context.
7011 DECL_ACCESSORS(native_context, Object)
7013 // [hash]: The hash code property (undefined if not initialized yet).
7014 DECL_ACCESSORS(hash, Object)
7016 DECLARE_CAST(JSGlobalProxy)
7018 inline bool IsDetachedFrom(GlobalObject* global) const;
7020 // Dispatched behavior.
7021 DECLARE_PRINTER(JSGlobalProxy)
7022 DECLARE_VERIFIER(JSGlobalProxy)
7024 // Layout description.
7025 static const int kNativeContextOffset = JSObject::kHeaderSize;
7026 static const int kHashOffset = kNativeContextOffset + kPointerSize;
7027 static const int kSize = kHashOffset + kPointerSize;
7030 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
7034 // Common super class for JavaScript global objects and the special
7035 // builtins global objects.
7036 class GlobalObject: public JSObject {
7038 // [builtins]: the object holding the runtime routines written in JS.
7039 DECL_ACCESSORS(builtins, JSBuiltinsObject)
7041 // [native context]: the natives corresponding to this global object.
7042 DECL_ACCESSORS(native_context, Context)
7044 // [global proxy]: the global proxy object of the context
7045 DECL_ACCESSORS(global_proxy, JSObject)
7047 DECLARE_CAST(GlobalObject)
7049 static void InvalidatePropertyCell(Handle<GlobalObject> object,
7051 // Ensure that the global object has a cell for the given property name.
7052 static Handle<PropertyCell> EnsurePropertyCell(Handle<GlobalObject> global,
7055 // Layout description.
7056 static const int kBuiltinsOffset = JSObject::kHeaderSize;
7057 static const int kNativeContextOffset = kBuiltinsOffset + kPointerSize;
7058 static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
7059 static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
7062 DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject);
7066 // JavaScript global object.
7067 class JSGlobalObject: public GlobalObject {
7069 DECLARE_CAST(JSGlobalObject)
7071 inline bool IsDetached();
7073 // Dispatched behavior.
7074 DECLARE_PRINTER(JSGlobalObject)
7075 DECLARE_VERIFIER(JSGlobalObject)
7077 // Layout description.
7078 static const int kSize = GlobalObject::kHeaderSize;
7081 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
7085 // Builtins global object which holds the runtime routines written in
7087 class JSBuiltinsObject: public GlobalObject {
7089 // Accessors for the runtime routines written in JavaScript.
7090 inline Object* javascript_builtin(Builtins::JavaScript id);
7091 inline void set_javascript_builtin(Builtins::JavaScript id, Object* value);
7093 DECLARE_CAST(JSBuiltinsObject)
7095 // Dispatched behavior.
7096 DECLARE_PRINTER(JSBuiltinsObject)
7097 DECLARE_VERIFIER(JSBuiltinsObject)
7099 // Layout description. The size of the builtins object includes
7100 // room for two pointers per runtime routine written in javascript
7101 // (function and code object).
7102 static const int kJSBuiltinsCount = Builtins::id_count;
7103 static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize;
7104 static const int kSize =
7105 GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize);
7107 static int OffsetOfFunctionWithId(Builtins::JavaScript id) {
7108 return kJSBuiltinsOffset + id * kPointerSize;
7112 DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject);
7116 // Representation for JS Wrapper objects, String, Number, Boolean, etc.
7117 class JSValue: public JSObject {
7119 // [value]: the object being wrapped.
7120 DECL_ACCESSORS(value, Object)
7122 DECLARE_CAST(JSValue)
7124 // Dispatched behavior.
7125 DECLARE_PRINTER(JSValue)
7126 DECLARE_VERIFIER(JSValue)
7128 // Layout description.
7129 static const int kValueOffset = JSObject::kHeaderSize;
7130 static const int kSize = kValueOffset + kPointerSize;
7133 DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
7139 // Representation for JS date objects.
7140 class JSDate: public JSObject {
7142 // If one component is NaN, all of them are, indicating a NaN time value.
7143 // [value]: the time value.
7144 DECL_ACCESSORS(value, Object)
7145 // [year]: caches year. Either undefined, smi, or NaN.
7146 DECL_ACCESSORS(year, Object)
7147 // [month]: caches month. Either undefined, smi, or NaN.
7148 DECL_ACCESSORS(month, Object)
7149 // [day]: caches day. Either undefined, smi, or NaN.
7150 DECL_ACCESSORS(day, Object)
7151 // [weekday]: caches day of week. Either undefined, smi, or NaN.
7152 DECL_ACCESSORS(weekday, Object)
7153 // [hour]: caches hours. Either undefined, smi, or NaN.
7154 DECL_ACCESSORS(hour, Object)
7155 // [min]: caches minutes. Either undefined, smi, or NaN.
7156 DECL_ACCESSORS(min, Object)
7157 // [sec]: caches seconds. Either undefined, smi, or NaN.
7158 DECL_ACCESSORS(sec, Object)
7159 // [cache stamp]: sample of the date cache stamp at the
7160 // moment when chached fields were cached.
7161 DECL_ACCESSORS(cache_stamp, Object)
7163 DECLARE_CAST(JSDate)
7165 // Returns the date field with the specified index.
7166 // See FieldIndex for the list of date fields.
7167 static Object* GetField(Object* date, Smi* index);
7169 void SetValue(Object* value, bool is_value_nan);
7172 // Dispatched behavior.
7173 DECLARE_PRINTER(JSDate)
7174 DECLARE_VERIFIER(JSDate)
7176 // The order is important. It must be kept in sync with date macros
7187 kFirstUncachedField,
7188 kMillisecond = kFirstUncachedField,
7192 kYearUTC = kFirstUTCField,
7205 // Layout description.
7206 static const int kValueOffset = JSObject::kHeaderSize;
7207 static const int kYearOffset = kValueOffset + kPointerSize;
7208 static const int kMonthOffset = kYearOffset + kPointerSize;
7209 static const int kDayOffset = kMonthOffset + kPointerSize;
7210 static const int kWeekdayOffset = kDayOffset + kPointerSize;
7211 static const int kHourOffset = kWeekdayOffset + kPointerSize;
7212 static const int kMinOffset = kHourOffset + kPointerSize;
7213 static const int kSecOffset = kMinOffset + kPointerSize;
7214 static const int kCacheStampOffset = kSecOffset + kPointerSize;
7215 static const int kSize = kCacheStampOffset + kPointerSize;
7218 inline Object* DoGetField(FieldIndex index);
7220 Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
7222 // Computes and caches the cacheable fields of the date.
7223 inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
7226 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
7230 // Representation of message objects used for error reporting through
7231 // the API. The messages are formatted in JavaScript so this object is
7232 // a real JavaScript object. The information used for formatting the
7233 // error messages are not directly accessible from JavaScript to
7234 // prevent leaking information to user code called during error
7236 class JSMessageObject: public JSObject {
7238 // [type]: the type of error message.
7239 inline int type() const;
7240 inline void set_type(int value);
7242 // [arguments]: the arguments for formatting the error message.
7243 DECL_ACCESSORS(argument, Object)
7245 // [script]: the script from which the error message originated.
7246 DECL_ACCESSORS(script, Object)
7248 // [stack_frames]: an array of stack frames for this error object.
7249 DECL_ACCESSORS(stack_frames, Object)
7251 // [start_position]: the start position in the script for the error message.
7252 inline int start_position() const;
7253 inline void set_start_position(int value);
7255 // [end_position]: the end position in the script for the error message.
7256 inline int end_position() const;
7257 inline void set_end_position(int value);
7259 DECLARE_CAST(JSMessageObject)
7261 // Dispatched behavior.
7262 DECLARE_PRINTER(JSMessageObject)
7263 DECLARE_VERIFIER(JSMessageObject)
7265 // Layout description.
7266 static const int kTypeOffset = JSObject::kHeaderSize;
7267 static const int kArgumentsOffset = kTypeOffset + kPointerSize;
7268 static const int kScriptOffset = kArgumentsOffset + kPointerSize;
7269 static const int kStackFramesOffset = kScriptOffset + kPointerSize;
7270 static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
7271 static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
7272 static const int kSize = kEndPositionOffset + kPointerSize;
7274 typedef FixedBodyDescriptor<HeapObject::kMapOffset,
7275 kStackFramesOffset + kPointerSize,
7276 kSize> BodyDescriptor;
7280 // Regular expressions
7281 // The regular expression holds a single reference to a FixedArray in
7282 // the kDataOffset field.
7283 // The FixedArray contains the following data:
7284 // - tag : type of regexp implementation (not compiled yet, atom or irregexp)
7285 // - reference to the original source string
7286 // - reference to the original flag string
7287 // If it is an atom regexp
7288 // - a reference to a literal string to search for
7289 // If it is an irregexp regexp:
7290 // - a reference to code for Latin1 inputs (bytecode or compiled), or a smi
7291 // used for tracking the last usage (used for code flushing).
7292 // - a reference to code for UC16 inputs (bytecode or compiled), or a smi
7293 // used for tracking the last usage (used for code flushing)..
7294 // - max number of registers used by irregexp implementations.
7295 // - number of capture registers (output values) of the regexp.
7296 class JSRegExp: public JSObject {
7299 // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet.
7300 // ATOM: A simple string to match against using an indexOf operation.
7301 // IRREGEXP: Compiled with Irregexp.
7302 // IRREGEXP_NATIVE: Compiled to native code with Irregexp.
7303 enum Type { NOT_COMPILED, ATOM, IRREGEXP };
7310 UNICODE_ESCAPES = 16
7315 explicit Flags(uint32_t value) : value_(value) { }
7316 bool is_global() { return (value_ & GLOBAL) != 0; }
7317 bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; }
7318 bool is_multiline() { return (value_ & MULTILINE) != 0; }
7319 bool is_sticky() { return (value_ & STICKY) != 0; }
7320 bool is_unicode() { return (value_ & UNICODE_ESCAPES) != 0; }
7321 uint32_t value() { return value_; }
7326 DECL_ACCESSORS(data, Object)
7328 inline Type TypeTag();
7329 inline int CaptureCount();
7330 inline Flags GetFlags();
7331 inline String* Pattern();
7332 inline Object* DataAt(int index);
7333 // Set implementation data after the object has been prepared.
7334 inline void SetDataAt(int index, Object* value);
7336 static int code_index(bool is_latin1) {
7338 return kIrregexpLatin1CodeIndex;
7340 return kIrregexpUC16CodeIndex;
7344 static int saved_code_index(bool is_latin1) {
7346 return kIrregexpLatin1CodeSavedIndex;
7348 return kIrregexpUC16CodeSavedIndex;
7352 DECLARE_CAST(JSRegExp)
7354 // Dispatched behavior.
7355 DECLARE_VERIFIER(JSRegExp)
7357 static const int kDataOffset = JSObject::kHeaderSize;
7358 static const int kSize = kDataOffset + kPointerSize;
7360 // Indices in the data array.
7361 static const int kTagIndex = 0;
7362 static const int kSourceIndex = kTagIndex + 1;
7363 static const int kFlagsIndex = kSourceIndex + 1;
7364 static const int kDataIndex = kFlagsIndex + 1;
7365 // The data fields are used in different ways depending on the
7366 // value of the tag.
7367 // Atom regexps (literal strings).
7368 static const int kAtomPatternIndex = kDataIndex;
7370 static const int kAtomDataSize = kAtomPatternIndex + 1;
7372 // Irregexp compiled code or bytecode for Latin1. If compilation
7373 // fails, this fields hold an exception object that should be
7374 // thrown if the regexp is used again.
7375 static const int kIrregexpLatin1CodeIndex = kDataIndex;
7376 // Irregexp compiled code or bytecode for UC16. If compilation
7377 // fails, this fields hold an exception object that should be
7378 // thrown if the regexp is used again.
7379 static const int kIrregexpUC16CodeIndex = kDataIndex + 1;
7381 // Saved instance of Irregexp compiled code or bytecode for Latin1 that
7382 // is a potential candidate for flushing.
7383 static const int kIrregexpLatin1CodeSavedIndex = kDataIndex + 2;
7384 // Saved instance of Irregexp compiled code or bytecode for UC16 that is
7385 // a potential candidate for flushing.
7386 static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3;
7388 // Maximal number of registers used by either Latin1 or UC16.
7389 // Only used to check that there is enough stack space
7390 static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4;
7391 // Number of captures in the compiled regexp.
7392 static const int kIrregexpCaptureCountIndex = kDataIndex + 5;
7394 static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1;
7396 // Offsets directly into the data fixed array.
7397 static const int kDataTagOffset =
7398 FixedArray::kHeaderSize + kTagIndex * kPointerSize;
7399 static const int kDataOneByteCodeOffset =
7400 FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize;
7401 static const int kDataUC16CodeOffset =
7402 FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize;
7403 static const int kIrregexpCaptureCountOffset =
7404 FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize;
7406 // In-object fields.
7407 static const int kSourceFieldIndex = 0;
7408 static const int kGlobalFieldIndex = 1;
7409 static const int kIgnoreCaseFieldIndex = 2;
7410 static const int kMultilineFieldIndex = 3;
7411 static const int kLastIndexFieldIndex = 4;
7412 static const int kInObjectFieldCount = 5;
7414 // The uninitialized value for a regexp code object.
7415 static const int kUninitializedValue = -1;
7417 // The compilation error value for the regexp code object. The real error
7418 // object is in the saved code field.
7419 static const int kCompilationErrorValue = -2;
7421 // When we store the sweep generation at which we moved the code from the
7422 // code index to the saved code index we mask it of to be in the [0:255]
7424 static const int kCodeAgeMask = 0xff;
7428 class CompilationCacheShape : public BaseShape<HashTableKey*> {
7430 static inline bool IsMatch(HashTableKey* key, Object* value) {
7431 return key->IsMatch(value);
7434 static inline uint32_t Hash(HashTableKey* key) {
7438 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
7439 return key->HashForObject(object);
7442 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
7444 static const int kPrefixSize = 0;
7445 static const int kEntrySize = 2;
7449 // This cache is used in two different variants. For regexp caching, it simply
7450 // maps identifying info of the regexp to the cached regexp object. Scripts and
7451 // eval code only gets cached after a second probe for the code object. To do
7452 // so, on first "put" only a hash identifying the source is entered into the
7453 // cache, mapping it to a lifetime count of the hash. On each call to Age all
7454 // such lifetimes get reduced, and removed once they reach zero. If a second put
7455 // is called while such a hash is live in the cache, the hash gets replaced by
7456 // an actual cache entry. Age also removes stale live entries from the cache.
7457 // Such entries are identified by SharedFunctionInfos pointing to either the
7458 // recompilation stub, or to "old" code. This avoids memory leaks due to
7459 // premature caching of scripts and eval strings that are never needed later.
7460 class CompilationCacheTable: public HashTable<CompilationCacheTable,
7461 CompilationCacheShape,
7464 // Find cached value for a string key, otherwise return null.
7465 Handle<Object> Lookup(
7466 Handle<String> src, Handle<Context> context, LanguageMode language_mode);
7467 Handle<Object> LookupEval(
7468 Handle<String> src, Handle<SharedFunctionInfo> shared,
7469 LanguageMode language_mode, int scope_position);
7470 Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags);
7471 static Handle<CompilationCacheTable> Put(
7472 Handle<CompilationCacheTable> cache, Handle<String> src,
7473 Handle<Context> context, LanguageMode language_mode,
7474 Handle<Object> value);
7475 static Handle<CompilationCacheTable> PutEval(
7476 Handle<CompilationCacheTable> cache, Handle<String> src,
7477 Handle<SharedFunctionInfo> context, Handle<SharedFunctionInfo> value,
7478 int scope_position);
7479 static Handle<CompilationCacheTable> PutRegExp(
7480 Handle<CompilationCacheTable> cache, Handle<String> src,
7481 JSRegExp::Flags flags, Handle<FixedArray> value);
7482 void Remove(Object* value);
7484 static const int kHashGenerations = 10;
7486 DECLARE_CAST(CompilationCacheTable)
7489 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable);
7493 class CodeCache: public Struct {
7495 DECL_ACCESSORS(default_cache, FixedArray)
7496 DECL_ACCESSORS(normal_type_cache, Object)
7498 // Add the code object to the cache.
7500 Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code);
7502 // Lookup code object in the cache. Returns code object if found and undefined
7504 Object* Lookup(Name* name, Code::Flags flags);
7506 // Get the internal index of a code object in the cache. Returns -1 if the
7507 // code object is not in that cache. This index can be used to later call
7508 // RemoveByIndex. The cache cannot be modified between a call to GetIndex and
7510 int GetIndex(Object* name, Code* code);
7512 // Remove an object from the cache with the provided internal index.
7513 void RemoveByIndex(Object* name, Code* code, int index);
7515 DECLARE_CAST(CodeCache)
7517 // Dispatched behavior.
7518 DECLARE_PRINTER(CodeCache)
7519 DECLARE_VERIFIER(CodeCache)
7521 static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
7522 static const int kNormalTypeCacheOffset =
7523 kDefaultCacheOffset + kPointerSize;
7524 static const int kSize = kNormalTypeCacheOffset + kPointerSize;
7527 static void UpdateDefaultCache(
7528 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
7529 static void UpdateNormalTypeCache(
7530 Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
7531 Object* LookupDefaultCache(Name* name, Code::Flags flags);
7532 Object* LookupNormalTypeCache(Name* name, Code::Flags flags);
7534 // Code cache layout of the default cache. Elements are alternating name and
7535 // code objects for non normal load/store/call IC's.
7536 static const int kCodeCacheEntrySize = 2;
7537 static const int kCodeCacheEntryNameOffset = 0;
7538 static const int kCodeCacheEntryCodeOffset = 1;
7540 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
7544 class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
7546 static inline bool IsMatch(HashTableKey* key, Object* value) {
7547 return key->IsMatch(value);
7550 static inline uint32_t Hash(HashTableKey* key) {
7554 static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
7555 return key->HashForObject(object);
7558 static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
7560 static const int kPrefixSize = 0;
7561 static const int kEntrySize = 2;
7565 class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
7566 CodeCacheHashTableShape,
7569 Object* Lookup(Name* name, Code::Flags flags);
7570 static Handle<CodeCacheHashTable> Put(
7571 Handle<CodeCacheHashTable> table,
7575 int GetIndex(Name* name, Code::Flags flags);
7576 void RemoveByIndex(int index);
7578 DECLARE_CAST(CodeCacheHashTable)
7580 // Initial size of the fixed array backing the hash table.
7581 static const int kInitialSize = 64;
7584 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
7588 class PolymorphicCodeCache: public Struct {
7590 DECL_ACCESSORS(cache, Object)
7592 static void Update(Handle<PolymorphicCodeCache> cache,
7593 MapHandleList* maps,
7598 // Returns an undefined value if the entry is not found.
7599 Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags);
7601 DECLARE_CAST(PolymorphicCodeCache)
7603 // Dispatched behavior.
7604 DECLARE_PRINTER(PolymorphicCodeCache)
7605 DECLARE_VERIFIER(PolymorphicCodeCache)
7607 static const int kCacheOffset = HeapObject::kHeaderSize;
7608 static const int kSize = kCacheOffset + kPointerSize;
7611 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache);
7615 class PolymorphicCodeCacheHashTable
7616 : public HashTable<PolymorphicCodeCacheHashTable,
7617 CodeCacheHashTableShape,
7620 Object* Lookup(MapHandleList* maps, int code_kind);
7622 static Handle<PolymorphicCodeCacheHashTable> Put(
7623 Handle<PolymorphicCodeCacheHashTable> hash_table,
7624 MapHandleList* maps,
7628 DECLARE_CAST(PolymorphicCodeCacheHashTable)
7630 static const int kInitialSize = 64;
7632 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable);
7636 class TypeFeedbackInfo: public Struct {
7638 inline int ic_total_count();
7639 inline void set_ic_total_count(int count);
7641 inline int ic_with_type_info_count();
7642 inline void change_ic_with_type_info_count(int delta);
7644 inline int ic_generic_count();
7645 inline void change_ic_generic_count(int delta);
7647 inline void initialize_storage();
7649 inline void change_own_type_change_checksum();
7650 inline int own_type_change_checksum();
7652 inline void set_inlined_type_change_checksum(int checksum);
7653 inline bool matches_inlined_type_change_checksum(int checksum);
7655 DECLARE_CAST(TypeFeedbackInfo)
7657 // Dispatched behavior.
7658 DECLARE_PRINTER(TypeFeedbackInfo)
7659 DECLARE_VERIFIER(TypeFeedbackInfo)
7661 static const int kStorage1Offset = HeapObject::kHeaderSize;
7662 static const int kStorage2Offset = kStorage1Offset + kPointerSize;
7663 static const int kStorage3Offset = kStorage2Offset + kPointerSize;
7664 static const int kSize = kStorage3Offset + kPointerSize;
7667 static const int kTypeChangeChecksumBits = 7;
7669 class ICTotalCountField: public BitField<int, 0,
7670 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
7671 class OwnTypeChangeChecksum: public BitField<int,
7672 kSmiValueSize - kTypeChangeChecksumBits,
7673 kTypeChangeChecksumBits> {}; // NOLINT
7674 class ICsWithTypeInfoCountField: public BitField<int, 0,
7675 kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
7676 class InlinedTypeChangeChecksum: public BitField<int,
7677 kSmiValueSize - kTypeChangeChecksumBits,
7678 kTypeChangeChecksumBits> {}; // NOLINT
7680 DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo);
7684 enum AllocationSiteMode {
7685 DONT_TRACK_ALLOCATION_SITE,
7686 TRACK_ALLOCATION_SITE,
7687 LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE
7691 class AllocationSite: public Struct {
7693 static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
7694 static const double kPretenureRatio;
7695 static const int kPretenureMinimumCreated = 100;
7697 // Values for pretenure decision field.
7698 enum PretenureDecision {
7704 kLastPretenureDecisionValue = kZombie
7707 const char* PretenureDecisionName(PretenureDecision decision);
7709 DECL_ACCESSORS(transition_info, Object)
7710 // nested_site threads a list of sites that represent nested literals
7711 // walked in a particular order. So [[1, 2], 1, 2] will have one
7712 // nested_site, but [[1, 2], 3, [4]] will have a list of two.
7713 DECL_ACCESSORS(nested_site, Object)
7714 DECL_ACCESSORS(pretenure_data, Smi)
7715 DECL_ACCESSORS(pretenure_create_count, Smi)
7716 DECL_ACCESSORS(dependent_code, DependentCode)
7717 DECL_ACCESSORS(weak_next, Object)
7719 inline void Initialize();
7721 // This method is expensive, it should only be called for reporting.
7722 bool IsNestedSite();
7724 // transition_info bitfields, for constructed array transition info.
7725 class ElementsKindBits: public BitField<ElementsKind, 0, 15> {};
7726 class UnusedBits: public BitField<int, 15, 14> {};
7727 class DoNotInlineBit: public BitField<bool, 29, 1> {};
7729 // Bitfields for pretenure_data
7730 class MementoFoundCountBits: public BitField<int, 0, 26> {};
7731 class PretenureDecisionBits: public BitField<PretenureDecision, 26, 3> {};
7732 class DeoptDependentCodeBit: public BitField<bool, 29, 1> {};
7733 STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
7735 // Increments the mementos found counter and returns true when the first
7736 // memento was found for a given allocation site.
7737 inline bool IncrementMementoFoundCount();
7739 inline void IncrementMementoCreateCount();
7741 PretenureFlag GetPretenureMode();
7743 void ResetPretenureDecision();
7745 inline PretenureDecision pretenure_decision();
7746 inline void set_pretenure_decision(PretenureDecision decision);
7748 inline bool deopt_dependent_code();
7749 inline void set_deopt_dependent_code(bool deopt);
7751 inline int memento_found_count();
7752 inline void set_memento_found_count(int count);
7754 inline int memento_create_count();
7755 inline void set_memento_create_count(int count);
7757 // The pretenuring decision is made during gc, and the zombie state allows
7758 // us to recognize when an allocation site is just being kept alive because
7759 // a later traversal of new space may discover AllocationMementos that point
7760 // to this AllocationSite.
7761 inline bool IsZombie();
7763 inline bool IsMaybeTenure();
7765 inline void MarkZombie();
7767 inline bool MakePretenureDecision(PretenureDecision current_decision,
7769 bool maximum_size_scavenge);
7771 inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
7773 inline ElementsKind GetElementsKind();
7774 inline void SetElementsKind(ElementsKind kind);
7776 inline bool CanInlineCall();
7777 inline void SetDoNotInlineCall();
7779 inline bool SitePointsToLiteral();
7781 static void DigestTransitionFeedback(Handle<AllocationSite> site,
7782 ElementsKind to_kind);
7784 DECLARE_PRINTER(AllocationSite)
7785 DECLARE_VERIFIER(AllocationSite)
7787 DECLARE_CAST(AllocationSite)
7788 static inline AllocationSiteMode GetMode(
7789 ElementsKind boilerplate_elements_kind);
7790 static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to);
7791 static inline bool CanTrack(InstanceType type);
7793 static const int kTransitionInfoOffset = HeapObject::kHeaderSize;
7794 static const int kNestedSiteOffset = kTransitionInfoOffset + kPointerSize;
7795 static const int kPretenureDataOffset = kNestedSiteOffset + kPointerSize;
7796 static const int kPretenureCreateCountOffset =
7797 kPretenureDataOffset + kPointerSize;
7798 static const int kDependentCodeOffset =
7799 kPretenureCreateCountOffset + kPointerSize;
7800 static const int kWeakNextOffset = kDependentCodeOffset + kPointerSize;
7801 static const int kSize = kWeakNextOffset + kPointerSize;
7803 // During mark compact we need to take special care for the dependent code
7805 static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
7806 static const int kPointerFieldsEndOffset = kWeakNextOffset;
7808 // For other visitors, use the fixed body descriptor below.
7809 typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
7810 kDependentCodeOffset + kPointerSize,
7811 kSize> BodyDescriptor;
7814 inline bool PretenuringDecisionMade();
7816 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
7820 class AllocationMemento: public Struct {
7822 static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
7823 static const int kSize = kAllocationSiteOffset + kPointerSize;
7825 DECL_ACCESSORS(allocation_site, Object)
7827 inline bool IsValid();
7828 inline AllocationSite* GetAllocationSite();
7830 DECLARE_PRINTER(AllocationMemento)
7831 DECLARE_VERIFIER(AllocationMemento)
7833 DECLARE_CAST(AllocationMemento)
7836 DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
7840 // Representation of a slow alias as part of a sloppy arguments objects.
7841 // For fast aliases (if HasSloppyArgumentsElements()):
7842 // - the parameter map contains an index into the context
7843 // - all attributes of the element have default values
7844 // For slow aliases (if HasDictionaryArgumentsElements()):
7845 // - the parameter map contains no fast alias mapping (i.e. the hole)
7846 // - this struct (in the slow backing store) contains an index into the context
7847 // - all attributes are available as part if the property details
7848 class AliasedArgumentsEntry: public Struct {
7850 inline int aliased_context_slot() const;
7851 inline void set_aliased_context_slot(int count);
7853 DECLARE_CAST(AliasedArgumentsEntry)
7855 // Dispatched behavior.
7856 DECLARE_PRINTER(AliasedArgumentsEntry)
7857 DECLARE_VERIFIER(AliasedArgumentsEntry)
7859 static const int kAliasedContextSlot = HeapObject::kHeaderSize;
7860 static const int kSize = kAliasedContextSlot + kPointerSize;
7863 DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry);
7867 enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
7868 enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};
7871 class StringHasher {
7873 explicit inline StringHasher(int length, uint32_t seed);
7875 template <typename schar>
7876 static inline uint32_t HashSequentialString(const schar* chars,
7880 // Reads all the data, even for long strings and computes the utf16 length.
7881 static uint32_t ComputeUtf8Hash(Vector<const char> chars,
7883 int* utf16_length_out);
7885 // Calculated hash value for a string consisting of 1 to
7886 // String::kMaxArrayIndexSize digits with no leading zeros (except "0").
7887 // value is represented decimal value.
7888 static uint32_t MakeArrayIndexHash(uint32_t value, int length);
7890 // No string is allowed to have a hash of zero. That value is reserved
7891 // for internal properties. If the hash calculation yields zero then we
7893 static const int kZeroHash = 27;
7895 // Reusable parts of the hashing algorithm.
7896 INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
7897 INLINE(static uint32_t GetHashCore(uint32_t running_hash));
7898 INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
7899 const uc16* chars, int length));
7900 INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
7905 // Returns the value to store in the hash field of a string with
7906 // the given length and contents.
7907 uint32_t GetHashField();
7908 // Returns true if the hash of this string can be computed without
7909 // looking at the contents.
7910 inline bool has_trivial_hash();
7911 // Adds a block of characters to the hash.
7912 template<typename Char>
7913 inline void AddCharacters(const Char* chars, int len);
7916 // Add a character to the hash.
7917 inline void AddCharacter(uint16_t c);
7918 // Update index. Returns true if string is still an index.
7919 inline bool UpdateIndex(uint16_t c);
7922 uint32_t raw_running_hash_;
7923 uint32_t array_index_;
7924 bool is_array_index_;
7925 bool is_first_char_;
7926 DISALLOW_COPY_AND_ASSIGN(StringHasher);
7930 class IteratingStringHasher : public StringHasher {
7932 static inline uint32_t Hash(String* string, uint32_t seed);
7933 inline void VisitOneByteString(const uint8_t* chars, int length);
7934 inline void VisitTwoByteString(const uint16_t* chars, int length);
7937 inline IteratingStringHasher(int len, uint32_t seed);
7938 void VisitConsString(ConsString* cons_string);
7939 DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
7943 // The characteristics of a string are stored in its map. Retrieving these
7944 // few bits of information is moderately expensive, involving two memory
7945 // loads where the second is dependent on the first. To improve efficiency
7946 // the shape of the string is given its own class so that it can be retrieved
7947 // once and used for several string operations. A StringShape is small enough
7948 // to be passed by value and is immutable, but be aware that flattening a
7949 // string can potentially alter its shape. Also be aware that a GC caused by
7950 // something else can alter the shape of a string due to ConsString
7951 // shortcutting. Keeping these restrictions in mind has proven to be error-
7952 // prone and so we no longer put StringShapes in variables unless there is a
7953 // concrete performance benefit at that particular point in the code.
7954 class StringShape BASE_EMBEDDED {
7956 inline explicit StringShape(const String* s);
7957 inline explicit StringShape(Map* s);
7958 inline explicit StringShape(InstanceType t);
7959 inline bool IsSequential();
7960 inline bool IsExternal();
7961 inline bool IsCons();
7962 inline bool IsSliced();
7963 inline bool IsIndirect();
7964 inline bool IsExternalOneByte();
7965 inline bool IsExternalTwoByte();
7966 inline bool IsSequentialOneByte();
7967 inline bool IsSequentialTwoByte();
7968 inline bool IsInternalized();
7969 inline StringRepresentationTag representation_tag();
7970 inline uint32_t encoding_tag();
7971 inline uint32_t full_representation_tag();
7972 inline uint32_t size_tag();
7974 inline uint32_t type() { return type_; }
7975 inline void invalidate() { valid_ = false; }
7976 inline bool valid() { return valid_; }
7978 inline void invalidate() { }
7984 inline void set_valid() { valid_ = true; }
7987 inline void set_valid() { }
7992 // The Name abstract class captures anything that can be used as a property
7993 // name, i.e., strings and symbols. All names store a hash value.
7994 class Name: public HeapObject {
7996 // Get and set the hash field of the name.
7997 inline uint32_t hash_field();
7998 inline void set_hash_field(uint32_t value);
8000 // Tells whether the hash code has been computed.
8001 inline bool HasHashCode();
8003 // Returns a hash value used for the property table
8004 inline uint32_t Hash();
8006 // Equality operations.
8007 inline bool Equals(Name* other);
8008 inline static bool Equals(Handle<Name> one, Handle<Name> two);
8011 inline bool AsArrayIndex(uint32_t* index);
8013 // If the name is private, it can only name own properties.
8014 inline bool IsPrivate();
8016 // If the name is a non-flat string, this method returns a flat version of the
8017 // string. Otherwise it'll just return the input.
8018 static inline Handle<Name> Flatten(Handle<Name> name,
8019 PretenureFlag pretenure = NOT_TENURED);
8023 DECLARE_PRINTER(Name)
8025 void NameShortPrint();
8026 int NameShortPrint(Vector<char> str);
8029 // Layout description.
8030 static const int kHashFieldSlot = HeapObject::kHeaderSize;
8031 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
8032 static const int kHashFieldOffset = kHashFieldSlot;
8034 static const int kHashFieldOffset = kHashFieldSlot + kIntSize;
8036 static const int kSize = kHashFieldSlot + kPointerSize;
8038 // Mask constant for checking if a name has a computed hash code
8039 // and if it is a string that is an array index. The least significant bit
8040 // indicates whether a hash code has been computed. If the hash code has
8041 // been computed the 2nd bit tells whether the string can be used as an
8043 static const int kHashNotComputedMask = 1;
8044 static const int kIsNotArrayIndexMask = 1 << 1;
8045 static const int kNofHashBitFields = 2;
8047 // Shift constant retrieving hash code from hash field.
8048 static const int kHashShift = kNofHashBitFields;
8050 // Only these bits are relevant in the hash, since the top two are shifted
8052 static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift;
8054 // Array index strings this short can keep their index in the hash field.
8055 static const int kMaxCachedArrayIndexLength = 7;
8057 // For strings which are array indexes the hash value has the string length
8058 // mixed into the hash, mainly to avoid a hash value of zero which would be
8059 // the case for the string '0'. 24 bits are used for the array index value.
8060 static const int kArrayIndexValueBits = 24;
8061 static const int kArrayIndexLengthBits =
8062 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8064 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8066 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8067 kArrayIndexValueBits> {}; // NOLINT
8068 class ArrayIndexLengthBits : public BitField<unsigned int,
8069 kNofHashBitFields + kArrayIndexValueBits,
8070 kArrayIndexLengthBits> {}; // NOLINT
8072 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8073 // could use a mask to test if the length of string is less than or equal to
8074 // kMaxCachedArrayIndexLength.
8075 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8077 static const unsigned int kContainsCachedArrayIndexMask =
8078 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8079 << ArrayIndexLengthBits::kShift) |
8080 kIsNotArrayIndexMask;
8082 // Value of empty hash field indicating that the hash is not computed.
8083 static const int kEmptyHashField =
8084 kIsNotArrayIndexMask | kHashNotComputedMask;
8087 static inline bool IsHashFieldComputed(uint32_t field);
8090 DISALLOW_IMPLICIT_CONSTRUCTORS(Name);
8095 class Symbol: public Name {
8097 // [name]: The print name of a symbol, or undefined if none.
8098 DECL_ACCESSORS(name, Object)
8100 DECL_ACCESSORS(flags, Smi)
8102 // [is_private]: Whether this is a private symbol. Private symbols can only
8103 // be used to designate own properties of objects.
8104 DECL_BOOLEAN_ACCESSORS(is_private)
8106 DECLARE_CAST(Symbol)
8108 // Dispatched behavior.
8109 DECLARE_PRINTER(Symbol)
8110 DECLARE_VERIFIER(Symbol)
8112 // Layout description.
8113 static const int kNameOffset = Name::kSize;
8114 static const int kFlagsOffset = kNameOffset + kPointerSize;
8115 static const int kSize = kFlagsOffset + kPointerSize;
8117 typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
8119 void SymbolShortPrint(std::ostream& os);
8122 static const int kPrivateBit = 0;
8124 const char* PrivateSymbolToName() const;
8127 friend class Name; // For PrivateSymbolToName.
8130 DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol);
8136 // The String abstract class captures JavaScript string values:
8139 // 4.3.16 String Value
8140 // A string value is a member of the type String and is a finite
8141 // ordered sequence of zero or more 16-bit unsigned integer values.
8143 // All string values have a length field.
8144 class String: public Name {
8146 enum Encoding { ONE_BYTE_ENCODING, TWO_BYTE_ENCODING };
8148 // Array index strings this short can keep their index in the hash field.
8149 static const int kMaxCachedArrayIndexLength = 7;
8151 // For strings which are array indexes the hash value has the string length
8152 // mixed into the hash, mainly to avoid a hash value of zero which would be
8153 // the case for the string '0'. 24 bits are used for the array index value.
8154 static const int kArrayIndexValueBits = 24;
8155 static const int kArrayIndexLengthBits =
8156 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
8158 STATIC_ASSERT((kArrayIndexLengthBits > 0));
8160 class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
8161 kArrayIndexValueBits> {}; // NOLINT
8162 class ArrayIndexLengthBits : public BitField<unsigned int,
8163 kNofHashBitFields + kArrayIndexValueBits,
8164 kArrayIndexLengthBits> {}; // NOLINT
8166 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
8167 // could use a mask to test if the length of string is less than or equal to
8168 // kMaxCachedArrayIndexLength.
8169 STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
8171 static const unsigned int kContainsCachedArrayIndexMask =
8172 (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
8173 << ArrayIndexLengthBits::kShift) |
8174 kIsNotArrayIndexMask;
8176 class SubStringRange {
8178 explicit inline SubStringRange(String* string, int first = 0,
8181 inline iterator begin();
8182 inline iterator end();
8190 // Representation of the flat content of a String.
8191 // A non-flat string doesn't have flat content.
8192 // A flat string has content that's encoded as a sequence of either
8193 // one-byte chars or two-byte UC16.
8194 // Returned by String::GetFlatContent().
8197 // Returns true if the string is flat and this structure contains content.
8198 bool IsFlat() { return state_ != NON_FLAT; }
8199 // Returns true if the structure contains one-byte content.
8200 bool IsOneByte() { return state_ == ONE_BYTE; }
8201 // Returns true if the structure contains two-byte content.
8202 bool IsTwoByte() { return state_ == TWO_BYTE; }
8204 // Return the one byte content of the string. Only use if IsOneByte()
8206 Vector<const uint8_t> ToOneByteVector() {
8207 DCHECK_EQ(ONE_BYTE, state_);
8208 return Vector<const uint8_t>(onebyte_start, length_);
8210 // Return the two-byte content of the string. Only use if IsTwoByte()
8212 Vector<const uc16> ToUC16Vector() {
8213 DCHECK_EQ(TWO_BYTE, state_);
8214 return Vector<const uc16>(twobyte_start, length_);
8218 DCHECK(i < length_);
8219 DCHECK(state_ != NON_FLAT);
8220 if (state_ == ONE_BYTE) return onebyte_start[i];
8221 return twobyte_start[i];
8224 bool UsesSameString(const FlatContent& other) const {
8225 return onebyte_start == other.onebyte_start;
8229 enum State { NON_FLAT, ONE_BYTE, TWO_BYTE };
8231 // Constructors only used by String::GetFlatContent().
8232 explicit FlatContent(const uint8_t* start, int length)
8233 : onebyte_start(start), length_(length), state_(ONE_BYTE) {}
8234 explicit FlatContent(const uc16* start, int length)
8235 : twobyte_start(start), length_(length), state_(TWO_BYTE) { }
8236 FlatContent() : onebyte_start(NULL), length_(0), state_(NON_FLAT) { }
8239 const uint8_t* onebyte_start;
8240 const uc16* twobyte_start;
8245 friend class String;
8246 friend class IterableSubString;
8249 template <typename Char>
8250 INLINE(Vector<const Char> GetCharVector());
8252 // Get and set the length of the string.
8253 inline int length() const;
8254 inline void set_length(int value);
8256 // Get and set the length of the string using acquire loads and release
8258 inline int synchronized_length() const;
8259 inline void synchronized_set_length(int value);
8261 // Returns whether this string has only one-byte chars, i.e. all of them can
8262 // be one-byte encoded. This might be the case even if the string is
8263 // two-byte. Such strings may appear when the embedder prefers
8264 // two-byte external representations even for one-byte data.
8265 inline bool IsOneByteRepresentation() const;
8266 inline bool IsTwoByteRepresentation() const;
8268 // Cons and slices have an encoding flag that may not represent the actual
8269 // encoding of the underlying string. This is taken into account here.
8270 // Requires: this->IsFlat()
8271 inline bool IsOneByteRepresentationUnderneath();
8272 inline bool IsTwoByteRepresentationUnderneath();
8274 // NOTE: this should be considered only a hint. False negatives are
8276 inline bool HasOnlyOneByteChars();
8278 // Get and set individual two byte chars in the string.
8279 inline void Set(int index, uint16_t value);
8280 // Get individual two byte char in the string. Repeated calls
8281 // to this method are not efficient unless the string is flat.
8282 INLINE(uint16_t Get(int index));
8284 // Flattens the string. Checks first inline to see if it is
8285 // necessary. Does nothing if the string is not a cons string.
8286 // Flattening allocates a sequential string with the same data as
8287 // the given string and mutates the cons string to a degenerate
8288 // form, where the first component is the new sequential string and
8289 // the second component is the empty string. If allocation fails,
8290 // this function returns a failure. If flattening succeeds, this
8291 // function returns the sequential string that is now the first
8292 // component of the cons string.
8294 // Degenerate cons strings are handled specially by the garbage
8295 // collector (see IsShortcutCandidate).
8297 static inline Handle<String> Flatten(Handle<String> string,
8298 PretenureFlag pretenure = NOT_TENURED);
8300 // Tries to return the content of a flat string as a structure holding either
8301 // a flat vector of char or of uc16.
8302 // If the string isn't flat, and therefore doesn't have flat content, the
8303 // returned structure will report so, and can't provide a vector of either
8305 FlatContent GetFlatContent();
8307 // Returns the parent of a sliced string or first part of a flat cons string.
8308 // Requires: StringShape(this).IsIndirect() && this->IsFlat()
8309 inline String* GetUnderlying();
8311 // String equality operations.
8312 inline bool Equals(String* other);
8313 inline static bool Equals(Handle<String> one, Handle<String> two);
8314 bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
8315 bool IsOneByteEqualTo(Vector<const uint8_t> str);
8316 bool IsTwoByteEqualTo(Vector<const uc16> str);
8318 // Return a UTF8 representation of the string. The string is null
8319 // terminated but may optionally contain nulls. Length is returned
8320 // in length_output if length_output is not a null pointer The string
8321 // should be nearly flat, otherwise the performance of this method may
8322 // be very slow (quadratic in the length). Setting robustness_flag to
8323 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
8324 // handles unexpected data without causing assert failures and it does not
8325 // do any heap allocations. This is useful when printing stack traces.
8326 base::SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls,
8327 RobustnessFlag robustness_flag,
8328 int offset, int length,
8329 int* length_output = 0);
8330 base::SmartArrayPointer<char> ToCString(
8331 AllowNullsFlag allow_nulls = DISALLOW_NULLS,
8332 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL,
8333 int* length_output = 0);
8335 // Return a 16 bit Unicode representation of the string.
8336 // The string should be nearly flat, otherwise the performance of
8337 // of this method may be very bad. Setting robustness_flag to
8338 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
8339 // handles unexpected data without causing assert failures and it does not
8340 // do any heap allocations. This is useful when printing stack traces.
8341 base::SmartArrayPointer<uc16> ToWideCString(
8342 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL);
8344 bool ComputeArrayIndex(uint32_t* index);
8347 bool MakeExternal(v8::String::ExternalStringResource* resource);
8348 bool MakeExternal(v8::String::ExternalOneByteStringResource* resource);
8351 inline bool AsArrayIndex(uint32_t* index);
8353 DECLARE_CAST(String)
8355 void PrintOn(FILE* out);
8357 // For use during stack traces. Performs rudimentary sanity check.
8360 // Dispatched behavior.
8361 void StringShortPrint(StringStream* accumulator);
8362 void PrintUC16(std::ostream& os, int start = 0, int end = -1); // NOLINT
8363 #if defined(DEBUG) || defined(OBJECT_PRINT)
8364 char* ToAsciiArray();
8366 DECLARE_PRINTER(String)
8367 DECLARE_VERIFIER(String)
8369 inline bool IsFlat();
8371 // Layout description.
8372 static const int kLengthOffset = Name::kSize;
8373 static const int kSize = kLengthOffset + kPointerSize;
8375 // Maximum number of characters to consider when trying to convert a string
8376 // value into an array index.
8377 static const int kMaxArrayIndexSize = 10;
8378 STATIC_ASSERT(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits));
8381 static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar;
8382 static const uint32_t kMaxOneByteCharCodeU = unibrow::Latin1::kMaxChar;
8383 static const int kMaxUtf16CodeUnit = 0xffff;
8384 static const uint32_t kMaxUtf16CodeUnitU = kMaxUtf16CodeUnit;
8386 // Value of hash field containing computed hash equal to zero.
8387 static const int kEmptyStringHash = kIsNotArrayIndexMask;
8389 // Maximal string length.
8390 static const int kMaxLength = (1 << 28) - 16;
8392 // Max length for computing hash. For strings longer than this limit the
8393 // string length is used as the hash value.
8394 static const int kMaxHashCalcLength = 16383;
8396 // Limit for truncation in short printing.
8397 static const int kMaxShortPrintLength = 1024;
8399 // Support for regular expressions.
8400 const uc16* GetTwoByteData(unsigned start);
8402 // Helper function for flattening strings.
8403 template <typename sinkchar>
8404 static void WriteToFlat(String* source,
8409 // The return value may point to the first aligned word containing the first
8410 // non-one-byte character, rather than directly to the non-one-byte character.
8411 // If the return value is >= the passed length, the entire string was
8413 static inline int NonAsciiStart(const char* chars, int length) {
8414 const char* start = chars;
8415 const char* limit = chars + length;
8417 if (length >= kIntptrSize) {
8418 // Check unaligned bytes.
8419 while (!IsAligned(reinterpret_cast<intptr_t>(chars), sizeof(uintptr_t))) {
8420 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
8421 return static_cast<int>(chars - start);
8425 // Check aligned words.
8426 DCHECK(unibrow::Utf8::kMaxOneByteChar == 0x7F);
8427 const uintptr_t non_one_byte_mask = kUintptrAllBitsSet / 0xFF * 0x80;
8428 while (chars + sizeof(uintptr_t) <= limit) {
8429 if (*reinterpret_cast<const uintptr_t*>(chars) & non_one_byte_mask) {
8430 return static_cast<int>(chars - start);
8432 chars += sizeof(uintptr_t);
8435 // Check remaining unaligned bytes.
8436 while (chars < limit) {
8437 if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
8438 return static_cast<int>(chars - start);
8443 return static_cast<int>(chars - start);
8446 static inline bool IsAscii(const char* chars, int length) {
8447 return NonAsciiStart(chars, length) >= length;
8450 static inline bool IsAscii(const uint8_t* chars, int length) {
8452 NonAsciiStart(reinterpret_cast<const char*>(chars), length) >= length;
8455 static inline int NonOneByteStart(const uc16* chars, int length) {
8456 const uc16* limit = chars + length;
8457 const uc16* start = chars;
8458 while (chars < limit) {
8459 if (*chars > kMaxOneByteCharCodeU) return static_cast<int>(chars - start);
8462 return static_cast<int>(chars - start);
8465 static inline bool IsOneByte(const uc16* chars, int length) {
8466 return NonOneByteStart(chars, length) >= length;
8469 template<class Visitor>
8470 static inline ConsString* VisitFlat(Visitor* visitor,
8474 static Handle<FixedArray> CalculateLineEnds(Handle<String> string,
8475 bool include_ending_line);
8477 // Use the hash field to forward to the canonical internalized string
8478 // when deserializing an internalized string.
8479 inline void SetForwardedInternalizedString(String* string);
8480 inline String* GetForwardedInternalizedString();
8484 friend class StringTableInsertionKey;
8486 static Handle<String> SlowFlatten(Handle<ConsString> cons,
8487 PretenureFlag tenure);
8489 // Slow case of String::Equals. This implementation works on any strings
8490 // but it is most efficient on strings that are almost flat.
8491 bool SlowEquals(String* other);
8493 static bool SlowEquals(Handle<String> one, Handle<String> two);
8495 // Slow case of AsArrayIndex.
8496 bool SlowAsArrayIndex(uint32_t* index);
8498 // Compute and set the hash code.
8499 uint32_t ComputeAndSetHash();
8501 DISALLOW_IMPLICIT_CONSTRUCTORS(String);
8505 // The SeqString abstract class captures sequential string values.
8506 class SeqString: public String {
8508 DECLARE_CAST(SeqString)
8510 // Layout description.
8511 static const int kHeaderSize = String::kSize;
8513 // Truncate the string in-place if possible and return the result.
8514 // In case of new_length == 0, the empty string is returned without
8515 // truncating the original string.
8516 MUST_USE_RESULT static Handle<String> Truncate(Handle<SeqString> string,
8519 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString);
8523 // The OneByteString class captures sequential one-byte string objects.
8524 // Each character in the OneByteString is an one-byte character.
8525 class SeqOneByteString: public SeqString {
8527 static const bool kHasOneByteEncoding = true;
8529 // Dispatched behavior.
8530 inline uint16_t SeqOneByteStringGet(int index);
8531 inline void SeqOneByteStringSet(int index, uint16_t value);
8533 // Get the address of the characters in this string.
8534 inline Address GetCharsAddress();
8536 inline uint8_t* GetChars();
8538 DECLARE_CAST(SeqOneByteString)
8540 // Garbage collection support. This method is called by the
8541 // garbage collector to compute the actual size of an OneByteString
8543 inline int SeqOneByteStringSize(InstanceType instance_type);
8545 // Computes the size for an OneByteString instance of a given length.
8546 static int SizeFor(int length) {
8547 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize);
8550 // Maximal memory usage for a single sequential one-byte string.
8551 static const int kMaxSize = 512 * MB - 1;
8552 STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength);
8555 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
8559 // The TwoByteString class captures sequential unicode string objects.
8560 // Each character in the TwoByteString is a two-byte uint16_t.
8561 class SeqTwoByteString: public SeqString {
8563 static const bool kHasOneByteEncoding = false;
8565 // Dispatched behavior.
8566 inline uint16_t SeqTwoByteStringGet(int index);
8567 inline void SeqTwoByteStringSet(int index, uint16_t value);
8569 // Get the address of the characters in this string.
8570 inline Address GetCharsAddress();
8572 inline uc16* GetChars();
8575 const uint16_t* SeqTwoByteStringGetData(unsigned start);
8577 DECLARE_CAST(SeqTwoByteString)
8579 // Garbage collection support. This method is called by the
8580 // garbage collector to compute the actual size of a TwoByteString
8582 inline int SeqTwoByteStringSize(InstanceType instance_type);
8584 // Computes the size for a TwoByteString instance of a given length.
8585 static int SizeFor(int length) {
8586 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize);
8589 // Maximal memory usage for a single sequential two-byte string.
8590 static const int kMaxSize = 512 * MB - 1;
8591 STATIC_ASSERT(static_cast<int>((kMaxSize - kHeaderSize)/sizeof(uint16_t)) >=
8592 String::kMaxLength);
8595 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString);
8599 // The ConsString class describes string values built by using the
8600 // addition operator on strings. A ConsString is a pair where the
8601 // first and second components are pointers to other string values.
8602 // One or both components of a ConsString can be pointers to other
8603 // ConsStrings, creating a binary tree of ConsStrings where the leaves
8604 // are non-ConsString string values. The string value represented by
8605 // a ConsString can be obtained by concatenating the leaf string
8606 // values in a left-to-right depth-first traversal of the tree.
8607 class ConsString: public String {
8609 // First string of the cons cell.
8610 inline String* first();
8611 // Doesn't check that the result is a string, even in debug mode. This is
8612 // useful during GC where the mark bits confuse the checks.
8613 inline Object* unchecked_first();
8614 inline void set_first(String* first,
8615 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
8617 // Second string of the cons cell.
8618 inline String* second();
8619 // Doesn't check that the result is a string, even in debug mode. This is
8620 // useful during GC where the mark bits confuse the checks.
8621 inline Object* unchecked_second();
8622 inline void set_second(String* second,
8623 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
8625 // Dispatched behavior.
8626 uint16_t ConsStringGet(int index);
8628 DECLARE_CAST(ConsString)
8630 // Layout description.
8631 static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize);
8632 static const int kSecondOffset = kFirstOffset + kPointerSize;
8633 static const int kSize = kSecondOffset + kPointerSize;
8635 // Minimum length for a cons string.
8636 static const int kMinLength = 13;
8638 typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize>
8641 DECLARE_VERIFIER(ConsString)
8644 DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString);
8648 // The Sliced String class describes strings that are substrings of another
8649 // sequential string. The motivation is to save time and memory when creating
8650 // a substring. A Sliced String is described as a pointer to the parent,
8651 // the offset from the start of the parent string and the length. Using
8652 // a Sliced String therefore requires unpacking of the parent string and
8653 // adding the offset to the start address. A substring of a Sliced String
8654 // are not nested since the double indirection is simplified when creating
8655 // such a substring.
8656 // Currently missing features are:
8657 // - handling externalized parent strings
8658 // - external strings as parent
8659 // - truncating sliced string to enable otherwise unneeded parent to be GC'ed.
8660 class SlicedString: public String {
8662 inline String* parent();
8663 inline void set_parent(String* parent,
8664 WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
8665 inline int offset() const;
8666 inline void set_offset(int offset);
8668 // Dispatched behavior.
8669 uint16_t SlicedStringGet(int index);
8671 DECLARE_CAST(SlicedString)
8673 // Layout description.
8674 static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize);
8675 static const int kOffsetOffset = kParentOffset + kPointerSize;
8676 static const int kSize = kOffsetOffset + kPointerSize;
8678 // Minimum length for a sliced string.
8679 static const int kMinLength = 13;
8681 typedef FixedBodyDescriptor<kParentOffset,
8682 kOffsetOffset + kPointerSize, kSize>
8685 DECLARE_VERIFIER(SlicedString)
8688 DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString);
8692 // The ExternalString class describes string values that are backed by
8693 // a string resource that lies outside the V8 heap. ExternalStrings
8694 // consist of the length field common to all strings, a pointer to the
8695 // external resource. It is important to ensure (externally) that the
8696 // resource is not deallocated while the ExternalString is live in the
8699 // The API expects that all ExternalStrings are created through the
8700 // API. Therefore, ExternalStrings should not be used internally.
8701 class ExternalString: public String {
8703 DECLARE_CAST(ExternalString)
8705 // Layout description.
8706 static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
8707 static const int kShortSize = kResourceOffset + kPointerSize;
8708 static const int kResourceDataOffset = kResourceOffset + kPointerSize;
8709 static const int kSize = kResourceDataOffset + kPointerSize;
8711 static const int kMaxShortLength =
8712 (kShortSize - SeqString::kHeaderSize) / kCharSize;
8714 // Return whether external string is short (data pointer is not cached).
8715 inline bool is_short();
8717 STATIC_ASSERT(kResourceOffset == Internals::kStringResourceOffset);
8720 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString);
8724 // The ExternalOneByteString class is an external string backed by an
8726 class ExternalOneByteString : public ExternalString {
8728 static const bool kHasOneByteEncoding = true;
8730 typedef v8::String::ExternalOneByteStringResource Resource;
8732 // The underlying resource.
8733 inline const Resource* resource();
8734 inline void set_resource(const Resource* buffer);
8736 // Update the pointer cache to the external character array.
8737 // The cached pointer is always valid, as the external character array does =
8738 // not move during lifetime. Deserialization is the only exception, after
8739 // which the pointer cache has to be refreshed.
8740 inline void update_data_cache();
8742 inline const uint8_t* GetChars();
8744 // Dispatched behavior.
8745 inline uint16_t ExternalOneByteStringGet(int index);
8747 DECLARE_CAST(ExternalOneByteString)
8749 // Garbage collection support.
8750 inline void ExternalOneByteStringIterateBody(ObjectVisitor* v);
8752 template <typename StaticVisitor>
8753 inline void ExternalOneByteStringIterateBody();
8756 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString);
8760 // The ExternalTwoByteString class is an external string backed by a UTF-16
8762 class ExternalTwoByteString: public ExternalString {
8764 static const bool kHasOneByteEncoding = false;
8766 typedef v8::String::ExternalStringResource Resource;
8768 // The underlying string resource.
8769 inline const Resource* resource();
8770 inline void set_resource(const Resource* buffer);
8772 // Update the pointer cache to the external character array.
8773 // The cached pointer is always valid, as the external character array does =
8774 // not move during lifetime. Deserialization is the only exception, after
8775 // which the pointer cache has to be refreshed.
8776 inline void update_data_cache();
8778 inline const uint16_t* GetChars();
8780 // Dispatched behavior.
8781 inline uint16_t ExternalTwoByteStringGet(int index);
8784 inline const uint16_t* ExternalTwoByteStringGetData(unsigned start);
8786 DECLARE_CAST(ExternalTwoByteString)
8788 // Garbage collection support.
8789 inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v);
8791 template<typename StaticVisitor>
8792 inline void ExternalTwoByteStringIterateBody();
8795 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString);
8799 // Utility superclass for stack-allocated objects that must be updated
8800 // on gc. It provides two ways for the gc to update instances, either
8801 // iterating or updating after gc.
8802 class Relocatable BASE_EMBEDDED {
8804 explicit inline Relocatable(Isolate* isolate);
8805 inline virtual ~Relocatable();
8806 virtual void IterateInstance(ObjectVisitor* v) { }
8807 virtual void PostGarbageCollection() { }
8809 static void PostGarbageCollectionProcessing(Isolate* isolate);
8810 static int ArchiveSpacePerThread();
8811 static char* ArchiveState(Isolate* isolate, char* to);
8812 static char* RestoreState(Isolate* isolate, char* from);
8813 static void Iterate(Isolate* isolate, ObjectVisitor* v);
8814 static void Iterate(ObjectVisitor* v, Relocatable* top);
8815 static char* Iterate(ObjectVisitor* v, char* t);
8823 // A flat string reader provides random access to the contents of a
8824 // string independent of the character width of the string. The handle
8825 // must be valid as long as the reader is being used.
8826 class FlatStringReader : public Relocatable {
8828 FlatStringReader(Isolate* isolate, Handle<String> str);
8829 FlatStringReader(Isolate* isolate, Vector<const char> input);
8830 void PostGarbageCollection();
8831 inline uc32 Get(int index);
8832 template <typename Char>
8833 inline Char Get(int index);
8834 int length() { return length_; }
8843 // This maintains an off-stack representation of the stack frames required
8844 // to traverse a ConsString, allowing an entirely iterative and restartable
8845 // traversal of the entire string
8846 class ConsStringIterator {
8848 inline ConsStringIterator() {}
8849 inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) {
8850 Reset(cons_string, offset);
8852 inline void Reset(ConsString* cons_string, int offset = 0) {
8854 // Next will always return NULL.
8855 if (cons_string == NULL) return;
8856 Initialize(cons_string, offset);
8858 // Returns NULL when complete.
8859 inline String* Next(int* offset_out) {
8861 if (depth_ == 0) return NULL;
8862 return Continue(offset_out);
8866 static const int kStackSize = 32;
8867 // Use a mask instead of doing modulo operations for stack wrapping.
8868 static const int kDepthMask = kStackSize-1;
8869 STATIC_ASSERT(IS_POWER_OF_TWO(kStackSize));
8870 static inline int OffsetForDepth(int depth);
8872 inline void PushLeft(ConsString* string);
8873 inline void PushRight(ConsString* string);
8874 inline void AdjustMaximumDepth();
8876 inline bool StackBlown() { return maximum_depth_ - depth_ == kStackSize; }
8877 void Initialize(ConsString* cons_string, int offset);
8878 String* Continue(int* offset_out);
8879 String* NextLeaf(bool* blew_stack);
8880 String* Search(int* offset_out);
8882 // Stack must always contain only frames for which right traversal
8883 // has not yet been performed.
8884 ConsString* frames_[kStackSize];
8889 DISALLOW_COPY_AND_ASSIGN(ConsStringIterator);
8893 class StringCharacterStream {
8895 inline StringCharacterStream(String* string,
8897 inline uint16_t GetNext();
8898 inline bool HasMore();
8899 inline void Reset(String* string, int offset = 0);
8900 inline void VisitOneByteString(const uint8_t* chars, int length);
8901 inline void VisitTwoByteString(const uint16_t* chars, int length);
8904 ConsStringIterator iter_;
8907 const uint8_t* buffer8_;
8908 const uint16_t* buffer16_;
8910 const uint8_t* end_;
8911 DISALLOW_COPY_AND_ASSIGN(StringCharacterStream);
8915 template <typename T>
8916 class VectorIterator {
8918 VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { }
8919 explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { }
8920 T GetNext() { return data_[index_++]; }
8921 bool has_more() { return index_ < data_.length(); }
8923 Vector<const T> data_;
8928 // The Oddball describes objects null, undefined, true, and false.
8929 class Oddball: public HeapObject {
8931 // [to_string]: Cached to_string computed at startup.
8932 DECL_ACCESSORS(to_string, String)
8934 // [to_number]: Cached to_number computed at startup.
8935 DECL_ACCESSORS(to_number, Object)
8937 // [typeof]: Cached type_of computed at startup.
8938 DECL_ACCESSORS(type_of, String)
8940 inline byte kind() const;
8941 inline void set_kind(byte kind);
8943 DECLARE_CAST(Oddball)
8945 // Dispatched behavior.
8946 DECLARE_VERIFIER(Oddball)
8948 // Initialize the fields.
8949 static void Initialize(Isolate* isolate, Handle<Oddball> oddball,
8950 const char* to_string, Handle<Object> to_number,
8951 const char* type_of, byte kind);
8953 // Layout description.
8954 static const int kToStringOffset = HeapObject::kHeaderSize;
8955 static const int kToNumberOffset = kToStringOffset + kPointerSize;
8956 static const int kTypeOfOffset = kToNumberOffset + kPointerSize;
8957 static const int kKindOffset = kTypeOfOffset + kPointerSize;
8958 static const int kSize = kKindOffset + kPointerSize;
8960 static const byte kFalse = 0;
8961 static const byte kTrue = 1;
8962 static const byte kNotBooleanMask = ~1;
8963 static const byte kTheHole = 2;
8964 static const byte kNull = 3;
8965 static const byte kArgumentMarker = 4;
8966 static const byte kUndefined = 5;
8967 static const byte kUninitialized = 6;
8968 static const byte kOther = 7;
8969 static const byte kException = 8;
8971 typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize,
8972 kSize> BodyDescriptor;
8974 STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
8975 STATIC_ASSERT(kNull == Internals::kNullOddballKind);
8976 STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind);
8979 DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
8983 class Cell: public HeapObject {
8985 // [value]: value of the cell.
8986 DECL_ACCESSORS(value, Object)
8990 static inline Cell* FromValueAddress(Address value) {
8991 Object* result = FromAddress(value - kValueOffset);
8992 return static_cast<Cell*>(result);
8995 inline Address ValueAddress() {
8996 return address() + kValueOffset;
8999 // Dispatched behavior.
9000 DECLARE_PRINTER(Cell)
9001 DECLARE_VERIFIER(Cell)
9003 // Layout description.
9004 static const int kValueOffset = HeapObject::kHeaderSize;
9005 static const int kSize = kValueOffset + kPointerSize;
9007 typedef FixedBodyDescriptor<kValueOffset,
9008 kValueOffset + kPointerSize,
9009 kSize> BodyDescriptor;
9012 DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
9016 class PropertyCell : public HeapObject {
9018 // [property_details]: details of the global property.
9019 DECL_ACCESSORS(property_details_raw, Object)
9020 // [value]: value of the global property.
9021 DECL_ACCESSORS(value, Object)
9022 // [dependent_code]: dependent code that depends on the type of the global
9024 DECL_ACCESSORS(dependent_code, DependentCode)
9026 inline PropertyDetails property_details();
9027 inline void set_property_details(PropertyDetails details);
9029 PropertyCellConstantType GetConstantType();
9031 // Computes the new type of the cell's contents for the given value, but
9032 // without actually modifying the details.
9033 static PropertyCellType UpdatedType(Handle<PropertyCell> cell,
9034 Handle<Object> value,
9035 PropertyDetails details);
9036 static void UpdateCell(Handle<GlobalDictionary> dictionary, int entry,
9037 Handle<Object> value, PropertyDetails details);
9039 static Handle<PropertyCell> InvalidateEntry(
9040 Handle<GlobalDictionary> dictionary, int entry);
9042 static void SetValueWithInvalidation(Handle<PropertyCell> cell,
9043 Handle<Object> new_value);
9045 DECLARE_CAST(PropertyCell)
9047 // Dispatched behavior.
9048 DECLARE_PRINTER(PropertyCell)
9049 DECLARE_VERIFIER(PropertyCell)
9051 // Layout description.
9052 static const int kDetailsOffset = HeapObject::kHeaderSize;
9053 static const int kValueOffset = kDetailsOffset + kPointerSize;
9054 static const int kDependentCodeOffset = kValueOffset + kPointerSize;
9055 static const int kSize = kDependentCodeOffset + kPointerSize;
9057 static const int kPointerFieldsBeginOffset = kValueOffset;
9058 static const int kPointerFieldsEndOffset = kSize;
9060 typedef FixedBodyDescriptor<kValueOffset,
9062 kSize> BodyDescriptor;
9065 DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
9069 class WeakCell : public HeapObject {
9071 inline Object* value() const;
9073 // This should not be called by anyone except GC.
9074 inline void clear();
9076 // This should not be called by anyone except allocator.
9077 inline void initialize(HeapObject* value);
9079 inline bool cleared() const;
9081 DECL_ACCESSORS(next, Object)
9083 inline void clear_next(Heap* heap);
9085 inline bool next_cleared();
9087 DECLARE_CAST(WeakCell)
9089 DECLARE_PRINTER(WeakCell)
9090 DECLARE_VERIFIER(WeakCell)
9092 // Layout description.
9093 static const int kValueOffset = HeapObject::kHeaderSize;
9094 static const int kNextOffset = kValueOffset + kPointerSize;
9095 static const int kSize = kNextOffset + kPointerSize;
9097 typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor;
9100 DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCell);
9104 // The JSProxy describes EcmaScript Harmony proxies
9105 class JSProxy: public JSReceiver {
9107 // [handler]: The handler property.
9108 DECL_ACCESSORS(handler, Object)
9110 // [hash]: The hash code property (undefined if not initialized yet).
9111 DECL_ACCESSORS(hash, Object)
9113 DECLARE_CAST(JSProxy)
9115 MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithHandler(
9116 Handle<JSProxy> proxy,
9117 Handle<Object> receiver,
9120 // If the handler defines an accessor property with a setter, invoke it.
9121 // If it defines an accessor property without a setter, or a data property
9122 // that is read-only, throw. In all these cases set '*done' to true,
9123 // otherwise set it to false.
9125 static MaybeHandle<Object> SetPropertyViaPrototypesWithHandler(
9126 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9127 Handle<Object> value, LanguageMode language_mode, bool* done);
9129 MUST_USE_RESULT static Maybe<PropertyAttributes>
9130 GetPropertyAttributesWithHandler(Handle<JSProxy> proxy,
9131 Handle<Object> receiver,
9133 MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithHandler(
9134 Handle<JSProxy> proxy, Handle<Object> receiver, Handle<Name> name,
9135 Handle<Object> value, LanguageMode language_mode);
9137 // Turn the proxy into an (empty) JSObject.
9138 static void Fix(Handle<JSProxy> proxy);
9140 // Initializes the body after the handler slot.
9141 inline void InitializeBody(int object_size, Object* value);
9143 // Invoke a trap by name. If the trap does not exist on this's handler,
9144 // but derived_trap is non-NULL, invoke that instead. May cause GC.
9145 MUST_USE_RESULT static MaybeHandle<Object> CallTrap(
9146 Handle<JSProxy> proxy,
9148 Handle<Object> derived_trap,
9150 Handle<Object> args[]);
9152 // Dispatched behavior.
9153 DECLARE_PRINTER(JSProxy)
9154 DECLARE_VERIFIER(JSProxy)
9156 // Layout description. We add padding so that a proxy has the same
9157 // size as a virgin JSObject. This is essential for becoming a JSObject
9159 static const int kHandlerOffset = HeapObject::kHeaderSize;
9160 static const int kHashOffset = kHandlerOffset + kPointerSize;
9161 static const int kPaddingOffset = kHashOffset + kPointerSize;
9162 static const int kSize = JSObject::kHeaderSize;
9163 static const int kHeaderSize = kPaddingOffset;
9164 static const int kPaddingSize = kSize - kPaddingOffset;
9166 STATIC_ASSERT(kPaddingSize >= 0);
9168 typedef FixedBodyDescriptor<kHandlerOffset,
9170 kSize> BodyDescriptor;
9173 friend class JSReceiver;
9175 MUST_USE_RESULT static Maybe<bool> HasPropertyWithHandler(
9176 Handle<JSProxy> proxy, Handle<Name> name);
9178 MUST_USE_RESULT static MaybeHandle<Object> DeletePropertyWithHandler(
9179 Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode);
9181 MUST_USE_RESULT Object* GetIdentityHash();
9183 static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy);
9185 DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy);
9189 class JSFunctionProxy: public JSProxy {
9191 // [call_trap]: The call trap.
9192 DECL_ACCESSORS(call_trap, Object)
9194 // [construct_trap]: The construct trap.
9195 DECL_ACCESSORS(construct_trap, Object)
9197 DECLARE_CAST(JSFunctionProxy)
9199 // Dispatched behavior.
9200 DECLARE_PRINTER(JSFunctionProxy)
9201 DECLARE_VERIFIER(JSFunctionProxy)
9203 // Layout description.
9204 static const int kCallTrapOffset = JSProxy::kPaddingOffset;
9205 static const int kConstructTrapOffset = kCallTrapOffset + kPointerSize;
9206 static const int kPaddingOffset = kConstructTrapOffset + kPointerSize;
9207 static const int kSize = JSFunction::kSize;
9208 static const int kPaddingSize = kSize - kPaddingOffset;
9210 STATIC_ASSERT(kPaddingSize >= 0);
9212 typedef FixedBodyDescriptor<kHandlerOffset,
9213 kConstructTrapOffset + kPointerSize,
9214 kSize> BodyDescriptor;
9217 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunctionProxy);
9221 class JSCollection : public JSObject {
9223 // [table]: the backing hash table
9224 DECL_ACCESSORS(table, Object)
9226 static const int kTableOffset = JSObject::kHeaderSize;
9227 static const int kSize = kTableOffset + kPointerSize;
9230 DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollection);
9234 // The JSSet describes EcmaScript Harmony sets
9235 class JSSet : public JSCollection {
9239 // Dispatched behavior.
9240 DECLARE_PRINTER(JSSet)
9241 DECLARE_VERIFIER(JSSet)
9244 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet);
9248 // The JSMap describes EcmaScript Harmony maps
9249 class JSMap : public JSCollection {
9253 // Dispatched behavior.
9254 DECLARE_PRINTER(JSMap)
9255 DECLARE_VERIFIER(JSMap)
9258 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
9262 // OrderedHashTableIterator is an iterator that iterates over the keys and
9263 // values of an OrderedHashTable.
9265 // The iterator has a reference to the underlying OrderedHashTable data,
9266 // [table], as well as the current [index] the iterator is at.
9268 // When the OrderedHashTable is rehashed it adds a reference from the old table
9269 // to the new table as well as storing enough data about the changes so that the
9270 // iterator [index] can be adjusted accordingly.
9272 // When the [Next] result from the iterator is requested, the iterator checks if
9273 // there is a newer table that it needs to transition to.
9274 template<class Derived, class TableType>
9275 class OrderedHashTableIterator: public JSObject {
9277 // [table]: the backing hash table mapping keys to values.
9278 DECL_ACCESSORS(table, Object)
9280 // [index]: The index into the data table.
9281 DECL_ACCESSORS(index, Object)
9283 // [kind]: The kind of iteration this is. One of the [Kind] enum values.
9284 DECL_ACCESSORS(kind, Object)
9287 void OrderedHashTableIteratorPrint(std::ostream& os); // NOLINT
9290 static const int kTableOffset = JSObject::kHeaderSize;
9291 static const int kIndexOffset = kTableOffset + kPointerSize;
9292 static const int kKindOffset = kIndexOffset + kPointerSize;
9293 static const int kSize = kKindOffset + kPointerSize;
9301 // Whether the iterator has more elements. This needs to be called before
9302 // calling |CurrentKey| and/or |CurrentValue|.
9305 // Move the index forward one.
9307 set_index(Smi::FromInt(Smi::cast(index())->value() + 1));
9310 // Populates the array with the next key and value and then moves the iterator
9312 // This returns the |kind| or 0 if the iterator is already at the end.
9313 Smi* Next(JSArray* value_array);
9315 // Returns the current key of the iterator. This should only be called when
9316 // |HasMore| returns true.
9317 inline Object* CurrentKey();
9320 // Transitions the iterator to the non obsolete backing store. This is a NOP
9321 // if the [table] is not obsolete.
9324 DISALLOW_IMPLICIT_CONSTRUCTORS(OrderedHashTableIterator);
9328 class JSSetIterator: public OrderedHashTableIterator<JSSetIterator,
9331 // Dispatched behavior.
9332 DECLARE_PRINTER(JSSetIterator)
9333 DECLARE_VERIFIER(JSSetIterator)
9335 DECLARE_CAST(JSSetIterator)
9337 // Called by |Next| to populate the array. This allows the subclasses to
9338 // populate the array differently.
9339 inline void PopulateValueArray(FixedArray* array);
9342 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSetIterator);
9346 class JSMapIterator: public OrderedHashTableIterator<JSMapIterator,
9349 // Dispatched behavior.
9350 DECLARE_PRINTER(JSMapIterator)
9351 DECLARE_VERIFIER(JSMapIterator)
9353 DECLARE_CAST(JSMapIterator)
9355 // Called by |Next| to populate the array. This allows the subclasses to
9356 // populate the array differently.
9357 inline void PopulateValueArray(FixedArray* array);
9360 // Returns the current value of the iterator. This should only be called when
9361 // |HasMore| returns true.
9362 inline Object* CurrentValue();
9364 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMapIterator);
9368 // Base class for both JSWeakMap and JSWeakSet
9369 class JSWeakCollection: public JSObject {
9371 // [table]: the backing hash table mapping keys to values.
9372 DECL_ACCESSORS(table, Object)
9374 // [next]: linked list of encountered weak maps during GC.
9375 DECL_ACCESSORS(next, Object)
9377 static const int kTableOffset = JSObject::kHeaderSize;
9378 static const int kNextOffset = kTableOffset + kPointerSize;
9379 static const int kSize = kNextOffset + kPointerSize;
9382 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection);
9386 // The JSWeakMap describes EcmaScript Harmony weak maps
9387 class JSWeakMap: public JSWeakCollection {
9389 DECLARE_CAST(JSWeakMap)
9391 // Dispatched behavior.
9392 DECLARE_PRINTER(JSWeakMap)
9393 DECLARE_VERIFIER(JSWeakMap)
9396 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
9400 // The JSWeakSet describes EcmaScript Harmony weak sets
9401 class JSWeakSet: public JSWeakCollection {
9403 DECLARE_CAST(JSWeakSet)
9405 // Dispatched behavior.
9406 DECLARE_PRINTER(JSWeakSet)
9407 DECLARE_VERIFIER(JSWeakSet)
9410 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet);
9414 // Whether a JSArrayBuffer is a SharedArrayBuffer or not.
9415 enum class SharedFlag { kNotShared, kShared };
9418 class JSArrayBuffer: public JSObject {
9420 // [backing_store]: backing memory for this array
9421 DECL_ACCESSORS(backing_store, void)
9423 // [byte_length]: length in bytes
9424 DECL_ACCESSORS(byte_length, Object)
9426 inline uint32_t bit_field() const;
9427 inline void set_bit_field(uint32_t bits);
9429 inline bool is_external();
9430 inline void set_is_external(bool value);
9432 inline bool is_neuterable();
9433 inline void set_is_neuterable(bool value);
9435 inline bool was_neutered();
9436 inline void set_was_neutered(bool value);
9438 inline bool is_shared();
9439 inline void set_is_shared(bool value);
9441 DECLARE_CAST(JSArrayBuffer)
9445 // Dispatched behavior.
9446 DECLARE_PRINTER(JSArrayBuffer)
9447 DECLARE_VERIFIER(JSArrayBuffer)
9449 static const int kBackingStoreOffset = JSObject::kHeaderSize;
9450 static const int kByteLengthOffset = kBackingStoreOffset + kPointerSize;
9451 static const int kBitFieldSlot = kByteLengthOffset + kPointerSize;
9452 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
9453 static const int kBitFieldOffset = kBitFieldSlot;
9455 static const int kBitFieldOffset = kBitFieldSlot + kIntSize;
9457 static const int kSize = kBitFieldSlot + kPointerSize;
9459 static const int kSizeWithInternalFields =
9460 kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
9462 class IsExternal : public BitField<bool, 1, 1> {};
9463 class IsNeuterable : public BitField<bool, 2, 1> {};
9464 class WasNeutered : public BitField<bool, 3, 1> {};
9465 class IsShared : public BitField<bool, 4, 1> {};
9468 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
9472 class JSArrayBufferView: public JSObject {
9474 // [buffer]: ArrayBuffer that this typed array views.
9475 DECL_ACCESSORS(buffer, Object)
9477 // [byte_offset]: offset of typed array in bytes.
9478 DECL_ACCESSORS(byte_offset, Object)
9480 // [byte_length]: length of typed array in bytes.
9481 DECL_ACCESSORS(byte_length, Object)
9483 DECLARE_CAST(JSArrayBufferView)
9485 DECLARE_VERIFIER(JSArrayBufferView)
9487 inline bool WasNeutered() const;
9489 static const int kBufferOffset = JSObject::kHeaderSize;
9490 static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
9491 static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
9492 static const int kViewSize = kByteLengthOffset + kPointerSize;
9496 DECL_ACCESSORS(raw_byte_offset, Object)
9497 DECL_ACCESSORS(raw_byte_length, Object)
9500 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
9504 class JSTypedArray: public JSArrayBufferView {
9506 // [length]: length of typed array in elements.
9507 DECL_ACCESSORS(length, Object)
9508 inline uint32_t length_value() const;
9510 DECLARE_CAST(JSTypedArray)
9512 ExternalArrayType type();
9513 size_t element_size();
9515 Handle<JSArrayBuffer> GetBuffer();
9517 // Dispatched behavior.
9518 DECLARE_PRINTER(JSTypedArray)
9519 DECLARE_VERIFIER(JSTypedArray)
9521 static const int kLengthOffset = kViewSize + kPointerSize;
9522 static const int kSize = kLengthOffset + kPointerSize;
9524 static const int kSizeWithInternalFields =
9525 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
9528 static Handle<JSArrayBuffer> MaterializeArrayBuffer(
9529 Handle<JSTypedArray> typed_array);
9531 DECL_ACCESSORS(raw_length, Object)
9534 DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
9538 class JSDataView: public JSArrayBufferView {
9540 DECLARE_CAST(JSDataView)
9542 // Dispatched behavior.
9543 DECLARE_PRINTER(JSDataView)
9544 DECLARE_VERIFIER(JSDataView)
9546 static const int kSize = kViewSize;
9548 static const int kSizeWithInternalFields =
9549 kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
9552 DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
9556 // Foreign describes objects pointing from JavaScript to C structures.
9557 class Foreign: public HeapObject {
9559 // [address]: field containing the address.
9560 inline Address foreign_address();
9561 inline void set_foreign_address(Address value);
9563 DECLARE_CAST(Foreign)
9565 // Dispatched behavior.
9566 inline void ForeignIterateBody(ObjectVisitor* v);
9568 template<typename StaticVisitor>
9569 inline void ForeignIterateBody();
9571 // Dispatched behavior.
9572 DECLARE_PRINTER(Foreign)
9573 DECLARE_VERIFIER(Foreign)
9575 // Layout description.
9577 static const int kForeignAddressOffset = HeapObject::kHeaderSize;
9578 static const int kSize = kForeignAddressOffset + kPointerSize;
9580 STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
9583 DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
9587 // The JSArray describes JavaScript Arrays
9588 // Such an array can be in one of two modes:
9589 // - fast, backing storage is a FixedArray and length <= elements.length();
9590 // Please note: push and pop can be used to grow and shrink the array.
9591 // - slow, backing storage is a HashTable with numbers as keys.
9592 class JSArray: public JSObject {
9594 // [length]: The length property.
9595 DECL_ACCESSORS(length, Object)
9597 // Overload the length setter to skip write barrier when the length
9598 // is set to a smi. This matches the set function on FixedArray.
9599 inline void set_length(Smi* length);
9601 static bool HasReadOnlyLength(Handle<JSArray> array);
9602 static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index);
9603 static MaybeHandle<Object> ReadOnlyLengthError(Handle<JSArray> array);
9605 // Initialize the array with the given capacity. The function may
9606 // fail due to out-of-memory situations, but only if the requested
9607 // capacity is non-zero.
9608 static void Initialize(Handle<JSArray> array, int capacity, int length = 0);
9610 // If the JSArray has fast elements, and new_length would result in
9611 // normalization, returns true.
9612 bool SetLengthWouldNormalize(uint32_t new_length);
9613 static inline bool SetLengthWouldNormalize(Heap* heap, uint32_t new_length);
9615 // Initializes the array to a certain length.
9616 inline bool AllowsSetLength();
9618 static void SetLength(Handle<JSArray> array, uint32_t length);
9619 // Same as above but will also queue splice records if |array| is observed.
9620 static MaybeHandle<Object> ObservableSetLength(Handle<JSArray> array,
9623 // Set the content of the array to the content of storage.
9624 static inline void SetContent(Handle<JSArray> array,
9625 Handle<FixedArrayBase> storage);
9627 DECLARE_CAST(JSArray)
9629 // Dispatched behavior.
9630 DECLARE_PRINTER(JSArray)
9631 DECLARE_VERIFIER(JSArray)
9633 // Number of element slots to pre-allocate for an empty array.
9634 static const int kPreallocatedArrayElements = 4;
9636 // Layout description.
9637 static const int kLengthOffset = JSObject::kHeaderSize;
9638 static const int kSize = kLengthOffset + kPointerSize;
9641 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray);
9645 Handle<Object> CacheInitialJSArrayMaps(Handle<Context> native_context,
9646 Handle<Map> initial_map);
9649 // JSRegExpResult is just a JSArray with a specific initial map.
9650 // This initial map adds in-object properties for "index" and "input"
9651 // properties, as assigned by RegExp.prototype.exec, which allows
9652 // faster creation of RegExp exec results.
9653 // This class just holds constants used when creating the result.
9654 // After creation the result must be treated as a JSArray in all regards.
9655 class JSRegExpResult: public JSArray {
9657 // Offsets of object fields.
9658 static const int kIndexOffset = JSArray::kSize;
9659 static const int kInputOffset = kIndexOffset + kPointerSize;
9660 static const int kSize = kInputOffset + kPointerSize;
9661 // Indices of in-object properties.
9662 static const int kIndexIndex = 0;
9663 static const int kInputIndex = 1;
9665 DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
9669 class AccessorInfo: public Struct {
9671 DECL_ACCESSORS(name, Object)
9672 DECL_ACCESSORS(flag, Smi)
9673 DECL_ACCESSORS(expected_receiver_type, Object)
9675 inline bool all_can_read();
9676 inline void set_all_can_read(bool value);
9678 inline bool all_can_write();
9679 inline void set_all_can_write(bool value);
9681 inline bool is_special_data_property();
9682 inline void set_is_special_data_property(bool value);
9684 inline PropertyAttributes property_attributes();
9685 inline void set_property_attributes(PropertyAttributes attributes);
9687 // Checks whether the given receiver is compatible with this accessor.
9688 static bool IsCompatibleReceiverMap(Isolate* isolate,
9689 Handle<AccessorInfo> info,
9691 inline bool IsCompatibleReceiver(Object* receiver);
9693 DECLARE_CAST(AccessorInfo)
9695 // Dispatched behavior.
9696 DECLARE_VERIFIER(AccessorInfo)
9698 // Append all descriptors to the array that are not already there.
9699 // Return number added.
9700 static int AppendUnique(Handle<Object> descriptors,
9701 Handle<FixedArray> array,
9702 int valid_descriptors);
9704 static const int kNameOffset = HeapObject::kHeaderSize;
9705 static const int kFlagOffset = kNameOffset + kPointerSize;
9706 static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
9707 static const int kSize = kExpectedReceiverTypeOffset + kPointerSize;
9710 inline bool HasExpectedReceiverType();
9712 // Bit positions in flag.
9713 static const int kAllCanReadBit = 0;
9714 static const int kAllCanWriteBit = 1;
9715 static const int kSpecialDataProperty = 2;
9716 class AttributesField : public BitField<PropertyAttributes, 3, 3> {};
9718 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo);
9722 // An accessor must have a getter, but can have no setter.
9724 // When setting a property, V8 searches accessors in prototypes.
9725 // If an accessor was found and it does not have a setter,
9726 // the request is ignored.
9728 // If the accessor in the prototype has the READ_ONLY property attribute, then
9729 // a new value is added to the derived object when the property is set.
9730 // This shadows the accessor in the prototype.
9731 class ExecutableAccessorInfo: public AccessorInfo {
9733 DECL_ACCESSORS(getter, Object)
9734 DECL_ACCESSORS(setter, Object)
9735 DECL_ACCESSORS(data, Object)
9737 DECLARE_CAST(ExecutableAccessorInfo)
9739 // Dispatched behavior.
9740 DECLARE_PRINTER(ExecutableAccessorInfo)
9741 DECLARE_VERIFIER(ExecutableAccessorInfo)
9743 static const int kGetterOffset = AccessorInfo::kSize;
9744 static const int kSetterOffset = kGetterOffset + kPointerSize;
9745 static const int kDataOffset = kSetterOffset + kPointerSize;
9746 static const int kSize = kDataOffset + kPointerSize;
9748 static void ClearSetter(Handle<ExecutableAccessorInfo> info);
9751 DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutableAccessorInfo);
9755 // Support for JavaScript accessors: A pair of a getter and a setter. Each
9756 // accessor can either be
9757 // * a pointer to a JavaScript function or proxy: a real accessor
9758 // * undefined: considered an accessor by the spec, too, strangely enough
9759 // * the hole: an accessor which has not been set
9760 // * a pointer to a map: a transition used to ensure map sharing
9761 class AccessorPair: public Struct {
9763 DECL_ACCESSORS(getter, Object)
9764 DECL_ACCESSORS(setter, Object)
9766 DECLARE_CAST(AccessorPair)
9768 static Handle<AccessorPair> Copy(Handle<AccessorPair> pair);
9770 inline Object* get(AccessorComponent component);
9771 inline void set(AccessorComponent component, Object* value);
9773 // Note: Returns undefined instead in case of a hole.
9774 Object* GetComponent(AccessorComponent component);
9776 // Set both components, skipping arguments which are a JavaScript null.
9777 inline void SetComponents(Object* getter, Object* setter);
9779 inline bool Equals(AccessorPair* pair);
9780 inline bool Equals(Object* getter_value, Object* setter_value);
9782 inline bool ContainsAccessor();
9784 // Dispatched behavior.
9785 DECLARE_PRINTER(AccessorPair)
9786 DECLARE_VERIFIER(AccessorPair)
9788 static const int kGetterOffset = HeapObject::kHeaderSize;
9789 static const int kSetterOffset = kGetterOffset + kPointerSize;
9790 static const int kSize = kSetterOffset + kPointerSize;
9793 // Strangely enough, in addition to functions and harmony proxies, the spec
9794 // requires us to consider undefined as a kind of accessor, too:
9796 // Object.defineProperty(obj, "foo", {get: undefined});
9797 // assertTrue("foo" in obj);
9798 inline bool IsJSAccessor(Object* obj);
9800 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
9804 class AccessCheckInfo: public Struct {
9806 DECL_ACCESSORS(named_callback, Object)
9807 DECL_ACCESSORS(indexed_callback, Object)
9808 DECL_ACCESSORS(data, Object)
9810 DECLARE_CAST(AccessCheckInfo)
9812 // Dispatched behavior.
9813 DECLARE_PRINTER(AccessCheckInfo)
9814 DECLARE_VERIFIER(AccessCheckInfo)
9816 static const int kNamedCallbackOffset = HeapObject::kHeaderSize;
9817 static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize;
9818 static const int kDataOffset = kIndexedCallbackOffset + kPointerSize;
9819 static const int kSize = kDataOffset + kPointerSize;
9822 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo);
9826 class InterceptorInfo: public Struct {
9828 DECL_ACCESSORS(getter, Object)
9829 DECL_ACCESSORS(setter, Object)
9830 DECL_ACCESSORS(query, Object)
9831 DECL_ACCESSORS(deleter, Object)
9832 DECL_ACCESSORS(enumerator, Object)
9833 DECL_ACCESSORS(data, Object)
9834 DECL_BOOLEAN_ACCESSORS(can_intercept_symbols)
9835 DECL_BOOLEAN_ACCESSORS(all_can_read)
9836 DECL_BOOLEAN_ACCESSORS(non_masking)
9838 inline int flags() const;
9839 inline void set_flags(int flags);
9841 DECLARE_CAST(InterceptorInfo)
9843 // Dispatched behavior.
9844 DECLARE_PRINTER(InterceptorInfo)
9845 DECLARE_VERIFIER(InterceptorInfo)
9847 static const int kGetterOffset = HeapObject::kHeaderSize;
9848 static const int kSetterOffset = kGetterOffset + kPointerSize;
9849 static const int kQueryOffset = kSetterOffset + kPointerSize;
9850 static const int kDeleterOffset = kQueryOffset + kPointerSize;
9851 static const int kEnumeratorOffset = kDeleterOffset + kPointerSize;
9852 static const int kDataOffset = kEnumeratorOffset + kPointerSize;
9853 static const int kFlagsOffset = kDataOffset + kPointerSize;
9854 static const int kSize = kFlagsOffset + kPointerSize;
9856 static const int kCanInterceptSymbolsBit = 0;
9857 static const int kAllCanReadBit = 1;
9858 static const int kNonMasking = 2;
9861 DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo);
9865 class CallHandlerInfo: public Struct {
9867 DECL_ACCESSORS(callback, Object)
9868 DECL_ACCESSORS(data, Object)
9870 DECLARE_CAST(CallHandlerInfo)
9872 // Dispatched behavior.
9873 DECLARE_PRINTER(CallHandlerInfo)
9874 DECLARE_VERIFIER(CallHandlerInfo)
9876 static const int kCallbackOffset = HeapObject::kHeaderSize;
9877 static const int kDataOffset = kCallbackOffset + kPointerSize;
9878 static const int kSize = kDataOffset + kPointerSize;
9881 DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo);
9885 class TemplateInfo: public Struct {
9887 DECL_ACCESSORS(tag, Object)
9888 inline int number_of_properties() const;
9889 inline void set_number_of_properties(int value);
9890 DECL_ACCESSORS(property_list, Object)
9891 DECL_ACCESSORS(property_accessors, Object)
9893 DECLARE_VERIFIER(TemplateInfo)
9895 static const int kTagOffset = HeapObject::kHeaderSize;
9896 static const int kNumberOfProperties = kTagOffset + kPointerSize;
9897 static const int kPropertyListOffset = kNumberOfProperties + kPointerSize;
9898 static const int kPropertyAccessorsOffset =
9899 kPropertyListOffset + kPointerSize;
9900 static const int kHeaderSize = kPropertyAccessorsOffset + kPointerSize;
9903 DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo);
9907 class FunctionTemplateInfo: public TemplateInfo {
9909 DECL_ACCESSORS(serial_number, Object)
9910 DECL_ACCESSORS(call_code, Object)
9911 DECL_ACCESSORS(prototype_template, Object)
9912 DECL_ACCESSORS(parent_template, Object)
9913 DECL_ACCESSORS(named_property_handler, Object)
9914 DECL_ACCESSORS(indexed_property_handler, Object)
9915 DECL_ACCESSORS(instance_template, Object)
9916 DECL_ACCESSORS(class_name, Object)
9917 DECL_ACCESSORS(signature, Object)
9918 DECL_ACCESSORS(instance_call_handler, Object)
9919 DECL_ACCESSORS(access_check_info, Object)
9920 DECL_ACCESSORS(flag, Smi)
9922 inline int length() const;
9923 inline void set_length(int value);
9925 // Following properties use flag bits.
9926 DECL_BOOLEAN_ACCESSORS(hidden_prototype)
9927 DECL_BOOLEAN_ACCESSORS(undetectable)
9928 // If the bit is set, object instances created by this function
9929 // requires access check.
9930 DECL_BOOLEAN_ACCESSORS(needs_access_check)
9931 DECL_BOOLEAN_ACCESSORS(read_only_prototype)
9932 DECL_BOOLEAN_ACCESSORS(remove_prototype)
9933 DECL_BOOLEAN_ACCESSORS(do_not_cache)
9934 DECL_BOOLEAN_ACCESSORS(instantiated)
9935 DECL_BOOLEAN_ACCESSORS(accept_any_receiver)
9937 DECLARE_CAST(FunctionTemplateInfo)
9939 // Dispatched behavior.
9940 DECLARE_PRINTER(FunctionTemplateInfo)
9941 DECLARE_VERIFIER(FunctionTemplateInfo)
9943 static const int kSerialNumberOffset = TemplateInfo::kHeaderSize;
9944 static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize;
9945 static const int kPrototypeTemplateOffset =
9946 kCallCodeOffset + kPointerSize;
9947 static const int kParentTemplateOffset =
9948 kPrototypeTemplateOffset + kPointerSize;
9949 static const int kNamedPropertyHandlerOffset =
9950 kParentTemplateOffset + kPointerSize;
9951 static const int kIndexedPropertyHandlerOffset =
9952 kNamedPropertyHandlerOffset + kPointerSize;
9953 static const int kInstanceTemplateOffset =
9954 kIndexedPropertyHandlerOffset + kPointerSize;
9955 static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize;
9956 static const int kSignatureOffset = kClassNameOffset + kPointerSize;
9957 static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize;
9958 static const int kAccessCheckInfoOffset =
9959 kInstanceCallHandlerOffset + kPointerSize;
9960 static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize;
9961 static const int kLengthOffset = kFlagOffset + kPointerSize;
9962 static const int kSize = kLengthOffset + kPointerSize;
9964 // Returns true if |object| is an instance of this function template.
9965 bool IsTemplateFor(Object* object);
9966 bool IsTemplateFor(Map* map);
9968 // Returns the holder JSObject if the function can legally be called with this
9969 // receiver. Returns Heap::null_value() if the call is illegal.
9970 Object* GetCompatibleReceiver(Isolate* isolate, Object* receiver);
9973 // Bit position in the flag, from least significant bit position.
9974 static const int kHiddenPrototypeBit = 0;
9975 static const int kUndetectableBit = 1;
9976 static const int kNeedsAccessCheckBit = 2;
9977 static const int kReadOnlyPrototypeBit = 3;
9978 static const int kRemovePrototypeBit = 4;
9979 static const int kDoNotCacheBit = 5;
9980 static const int kInstantiatedBit = 6;
9981 static const int kAcceptAnyReceiver = 7;
9983 DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo);
9987 class ObjectTemplateInfo: public TemplateInfo {
9989 DECL_ACCESSORS(constructor, Object)
9990 DECL_ACCESSORS(internal_field_count, Object)
9992 DECLARE_CAST(ObjectTemplateInfo)
9994 // Dispatched behavior.
9995 DECLARE_PRINTER(ObjectTemplateInfo)
9996 DECLARE_VERIFIER(ObjectTemplateInfo)
9998 static const int kConstructorOffset = TemplateInfo::kHeaderSize;
9999 static const int kInternalFieldCountOffset =
10000 kConstructorOffset + kPointerSize;
10001 static const int kSize = kInternalFieldCountOffset + kPointerSize;
10005 class TypeSwitchInfo: public Struct {
10007 DECL_ACCESSORS(types, Object)
10009 DECLARE_CAST(TypeSwitchInfo)
10011 // Dispatched behavior.
10012 DECLARE_PRINTER(TypeSwitchInfo)
10013 DECLARE_VERIFIER(TypeSwitchInfo)
10015 static const int kTypesOffset = Struct::kHeaderSize;
10016 static const int kSize = kTypesOffset + kPointerSize;
10020 // The DebugInfo class holds additional information for a function being
10022 class DebugInfo: public Struct {
10024 // The shared function info for the source being debugged.
10025 DECL_ACCESSORS(shared, SharedFunctionInfo)
10026 // Code object for the patched code. This code object is the code object
10027 // currently active for the function.
10028 DECL_ACCESSORS(code, Code)
10029 // Fixed array holding status information for each active break point.
10030 DECL_ACCESSORS(break_points, FixedArray)
10032 // Check if there is a break point at a code position.
10033 bool HasBreakPoint(int code_position);
10034 // Get the break point info object for a code position.
10035 Object* GetBreakPointInfo(int code_position);
10036 // Clear a break point.
10037 static void ClearBreakPoint(Handle<DebugInfo> debug_info,
10039 Handle<Object> break_point_object);
10040 // Set a break point.
10041 static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position,
10042 int source_position, int statement_position,
10043 Handle<Object> break_point_object);
10044 // Get the break point objects for a code position.
10045 Handle<Object> GetBreakPointObjects(int code_position);
10046 // Find the break point info holding this break point object.
10047 static Handle<Object> FindBreakPointInfo(Handle<DebugInfo> debug_info,
10048 Handle<Object> break_point_object);
10049 // Get the number of break points for this function.
10050 int GetBreakPointCount();
10052 DECLARE_CAST(DebugInfo)
10054 // Dispatched behavior.
10055 DECLARE_PRINTER(DebugInfo)
10056 DECLARE_VERIFIER(DebugInfo)
10058 static const int kSharedFunctionInfoIndex = Struct::kHeaderSize;
10059 static const int kCodeIndex = kSharedFunctionInfoIndex + kPointerSize;
10060 static const int kBreakPointsStateIndex = kCodeIndex + kPointerSize;
10061 static const int kSize = kBreakPointsStateIndex + kPointerSize;
10063 static const int kEstimatedNofBreakPointsInFunction = 16;
10066 static const int kNoBreakPointInfo = -1;
10068 // Lookup the index in the break_points array for a code position.
10069 int GetBreakPointInfoIndex(int code_position);
10071 DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo);
10075 // The BreakPointInfo class holds information for break points set in a
10076 // function. The DebugInfo object holds a BreakPointInfo object for each code
10077 // position with one or more break points.
10078 class BreakPointInfo: public Struct {
10080 // The position in the code for the break point.
10081 DECL_ACCESSORS(code_position, Smi)
10082 // The position in the source for the break position.
10083 DECL_ACCESSORS(source_position, Smi)
10084 // The position in the source for the last statement before this break
10086 DECL_ACCESSORS(statement_position, Smi)
10087 // List of related JavaScript break points.
10088 DECL_ACCESSORS(break_point_objects, Object)
10090 // Removes a break point.
10091 static void ClearBreakPoint(Handle<BreakPointInfo> info,
10092 Handle<Object> break_point_object);
10093 // Set a break point.
10094 static void SetBreakPoint(Handle<BreakPointInfo> info,
10095 Handle<Object> break_point_object);
10096 // Check if break point info has this break point object.
10097 static bool HasBreakPointObject(Handle<BreakPointInfo> info,
10098 Handle<Object> break_point_object);
10099 // Get the number of break points for this code position.
10100 int GetBreakPointCount();
10102 DECLARE_CAST(BreakPointInfo)
10104 // Dispatched behavior.
10105 DECLARE_PRINTER(BreakPointInfo)
10106 DECLARE_VERIFIER(BreakPointInfo)
10108 static const int kCodePositionIndex = Struct::kHeaderSize;
10109 static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize;
10110 static const int kStatementPositionIndex =
10111 kSourcePositionIndex + kPointerSize;
10112 static const int kBreakPointObjectsIndex =
10113 kStatementPositionIndex + kPointerSize;
10114 static const int kSize = kBreakPointObjectsIndex + kPointerSize;
10117 DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo);
10121 #undef DECL_BOOLEAN_ACCESSORS
10122 #undef DECL_ACCESSORS
10123 #undef DECLARE_CAST
10124 #undef DECLARE_VERIFIER
10126 #define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \
10127 V(kStringTable, "string_table", "(Internalized strings)") \
10128 V(kExternalStringsTable, "external_strings_table", "(External strings)") \
10129 V(kStrongRootList, "strong_root_list", "(Strong roots)") \
10130 V(kSmiRootList, "smi_root_list", "(Smi roots)") \
10131 V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \
10132 V(kTop, "top", "(Isolate)") \
10133 V(kRelocatable, "relocatable", "(Relocatable)") \
10134 V(kDebug, "debug", "(Debugger)") \
10135 V(kCompilationCache, "compilationcache", "(Compilation cache)") \
10136 V(kHandleScope, "handlescope", "(Handle scope)") \
10137 V(kBuiltins, "builtins", "(Builtins)") \
10138 V(kGlobalHandles, "globalhandles", "(Global handles)") \
10139 V(kEternalHandles, "eternalhandles", "(Eternal handles)") \
10140 V(kThreadManager, "threadmanager", "(Thread manager)") \
10141 V(kStrongRoots, "strong roots", "(Strong roots)") \
10142 V(kExtensions, "Extensions", "(Extensions)")
10144 class VisitorSynchronization : public AllStatic {
10146 #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item,
10148 VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM)
10151 #undef DECLARE_ENUM
10153 static const char* const kTags[kNumberOfSyncTags];
10154 static const char* const kTagNames[kNumberOfSyncTags];
10157 // Abstract base class for visiting, and optionally modifying, the
10158 // pointers contained in Objects. Used in GC and serialization/deserialization.
10159 class ObjectVisitor BASE_EMBEDDED {
10161 virtual ~ObjectVisitor() {}
10163 // Visits a contiguous arrays of pointers in the half-open range
10164 // [start, end). Any or all of the values may be modified on return.
10165 virtual void VisitPointers(Object** start, Object** end) = 0;
10167 // Handy shorthand for visiting a single pointer.
10168 virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
10170 // Visit weak next_code_link in Code object.
10171 virtual void VisitNextCodeLink(Object** p) { VisitPointers(p, p + 1); }
10173 // To allow lazy clearing of inline caches the visitor has
10174 // a rich interface for iterating over Code objects..
10176 // Visits a code target in the instruction stream.
10177 virtual void VisitCodeTarget(RelocInfo* rinfo);
10179 // Visits a code entry in a JS function.
10180 virtual void VisitCodeEntry(Address entry_address);
10182 // Visits a global property cell reference in the instruction stream.
10183 virtual void VisitCell(RelocInfo* rinfo);
10185 // Visits a runtime entry in the instruction stream.
10186 virtual void VisitRuntimeEntry(RelocInfo* rinfo) {}
10188 // Visits the resource of an one-byte or two-byte string.
10189 virtual void VisitExternalOneByteString(
10190 v8::String::ExternalOneByteStringResource** resource) {}
10191 virtual void VisitExternalTwoByteString(
10192 v8::String::ExternalStringResource** resource) {}
10194 // Visits a debug call target in the instruction stream.
10195 virtual void VisitDebugTarget(RelocInfo* rinfo);
10197 // Visits the byte sequence in a function's prologue that contains information
10198 // about the code's age.
10199 virtual void VisitCodeAgeSequence(RelocInfo* rinfo);
10201 // Visit pointer embedded into a code object.
10202 virtual void VisitEmbeddedPointer(RelocInfo* rinfo);
10204 // Visits an external reference embedded into a code object.
10205 virtual void VisitExternalReference(RelocInfo* rinfo);
10207 // Visits an external reference.
10208 virtual void VisitExternalReference(Address* p) {}
10210 // Visits an (encoded) internal reference.
10211 virtual void VisitInternalReference(RelocInfo* rinfo) {}
10213 // Visits a handle that has an embedder-assigned class ID.
10214 virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {}
10216 // Intended for serialization/deserialization checking: insert, or
10217 // check for the presence of, a tag at this position in the stream.
10218 // Also used for marking up GC roots in heap snapshots.
10219 virtual void Synchronize(VisitorSynchronization::SyncTag tag) {}
10223 class StructBodyDescriptor : public
10224 FlexibleBodyDescriptor<HeapObject::kHeaderSize> {
10226 static inline int SizeOf(Map* map, HeapObject* object);
10230 // BooleanBit is a helper class for setting and getting a bit in an
10232 class BooleanBit : public AllStatic {
10234 static inline bool get(Smi* smi, int bit_position) {
10235 return get(smi->value(), bit_position);
10238 static inline bool get(int value, int bit_position) {
10239 return (value & (1 << bit_position)) != 0;
10242 static inline Smi* set(Smi* smi, int bit_position, bool v) {
10243 return Smi::FromInt(set(smi->value(), bit_position, v));
10246 static inline int set(int value, int bit_position, bool v) {
10248 value |= (1 << bit_position);
10250 value &= ~(1 << bit_position);
10256 } } // namespace v8::internal
10258 #endif // V8_OBJECTS_H_