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chromium / v8 / v8 / 76968a2ff31b6540dfd5aefc771a5a962383d333 / . / src / objects.h
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// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_OBJECTS_H_
#define V8_OBJECTS_H_
#include <iosfwd>
#include <memory>
#include "include/v8-internal.h"
#include "include/v8.h"
#include "include/v8config.h"
#include "src/assert-scope.h"
#include "src/base/bits.h"
#include "src/base/build_config.h"
#include "src/base/flags.h"
#include "src/base/logging.h"
#include "src/checks.h"
#include "src/elements-kind.h"
#include "src/field-index.h"
#include "src/flags.h"
#include "src/message-template.h"
#include "src/objects-definitions.h"
#include "src/property-details.h"
#include "src/roots.h"
#include "src/utils.h"
#if V8_TARGET_ARCH_ARM
#include "src/arm/constants-arm.h" // NOLINT
#elif V8_TARGET_ARCH_ARM64
#include "src/arm64/constants-arm64.h" // NOLINT
#elif V8_TARGET_ARCH_MIPS
#include "src/mips/constants-mips.h" // NOLINT
#elif V8_TARGET_ARCH_MIPS64
#include "src/mips64/constants-mips64.h" // NOLINT
#elif V8_TARGET_ARCH_PPC
#include "src/ppc/constants-ppc.h" // NOLINT
#elif V8_TARGET_ARCH_S390
#include "src/s390/constants-s390.h" // NOLINT
#endif
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
//
// Most object types in the V8 JavaScript are described in this file.
//
// Inheritance hierarchy:
// - Object
// - Smi (immediate small integer)
// - HeapObject (superclass for everything allocated in the heap)
// - JSReceiver (suitable for property access)
// - JSObject
// - JSArray
// - JSArrayBuffer
// - JSArrayBufferView
// - JSTypedArray
// - JSDataView
// - JSBoundFunction
// - JSCollection
// - JSSet
// - JSMap
// - JSStringIterator
// - JSSetIterator
// - JSMapIterator
// - JSWeakCollection
// - JSWeakMap
// - JSWeakSet
// - JSRegExp
// - JSFunction
// - JSGeneratorObject
// - JSGlobalObject
// - JSGlobalProxy
// - JSValue
// - JSDate
// - JSMessageObject
// - JSModuleNamespace
// - JSV8BreakIterator // If V8_INTL_SUPPORT enabled.
// - JSCollator // If V8_INTL_SUPPORT enabled.
// - JSDateTimeFormat // If V8_INTL_SUPPORT enabled.
// - JSListFormat // If V8_INTL_SUPPORT enabled.
// - JSLocale // If V8_INTL_SUPPORT enabled.
// - JSNumberFormat // If V8_INTL_SUPPORT enabled.
// - JSPluralRules // If V8_INTL_SUPPORT enabled.
// - JSRelativeTimeFormat // If V8_INTL_SUPPORT enabled.
// - JSSegmentIterator // If V8_INTL_SUPPORT enabled.
// - JSSegmenter // If V8_INTL_SUPPORT enabled.
// - WasmExceptionObject
// - WasmGlobalObject
// - WasmInstanceObject
// - WasmMemoryObject
// - WasmModuleObject
// - WasmTableObject
// - JSProxy
// - FixedArrayBase
// - ByteArray
// - BytecodeArray
// - FixedArray
// - DescriptorArray
// - FrameArray
// - HashTable
// - Dictionary
// - StringTable
// - StringSet
// - CompilationCacheTable
// - MapCache
// - OrderedHashTable
// - OrderedHashSet
// - OrderedHashMap
// - Context
// - FeedbackMetadata
// - TemplateList
// - TransitionArray
// - ScopeInfo
// - ModuleInfo
// - ScriptContextTable
// - FixedDoubleArray
// - Name
// - String
// - SeqString
// - SeqOneByteString
// - SeqTwoByteString
// - SlicedString
// - ConsString
// - ThinString
// - ExternalString
// - ExternalOneByteString
// - ExternalTwoByteString
// - InternalizedString
// - SeqInternalizedString
// - SeqOneByteInternalizedString
// - SeqTwoByteInternalizedString
// - ConsInternalizedString
// - ExternalInternalizedString
// - ExternalOneByteInternalizedString
// - ExternalTwoByteInternalizedString
// - Symbol
// - HeapNumber
// - BigInt
// - Cell
// - PropertyCell
// - PropertyArray
// - Code
// - AbstractCode, a wrapper around Code or BytecodeArray
// - Map
// - Oddball
// - Foreign
// - SmallOrderedHashTable
// - SmallOrderedHashMap
// - SmallOrderedHashSet
// - SharedFunctionInfo
// - Struct
// - AccessorInfo
// - PromiseReaction
// - PromiseCapability
// - AccessorPair
// - AccessCheckInfo
// - InterceptorInfo
// - CallHandlerInfo
// - EnumCache
// - TemplateInfo
// - FunctionTemplateInfo
// - ObjectTemplateInfo
// - Script
// - DebugInfo
// - BreakPoint
// - BreakPointInfo
// - StackFrameInfo
// - SourcePositionTableWithFrameCache
// - CodeCache
// - PrototypeInfo
// - Microtask
// - CallbackTask
// - CallableTask
// - PromiseReactionJobTask
// - PromiseFulfillReactionJobTask
// - PromiseRejectReactionJobTask
// - PromiseResolveThenableJobTask
// - MicrotaskQueue
// - Module
// - ModuleInfoEntry
// - FeedbackCell
// - FeedbackVector
// - PreParsedScopeData
// - UncompiledData
// - UncompiledDataWithoutPreParsedScope
// - UncompiledDataWithPreParsedScope
//
// Formats of Object*:
// Smi: [31 bit signed int] 0
// HeapObject: [32 bit direct pointer] (4 byte aligned) | 01
namespace v8 {
namespace internal {
struct InliningPosition;
class PropertyDescriptorObject;
// SKIP_WRITE_BARRIER skips the write barrier.
// UPDATE_WEAK_WRITE_BARRIER skips the marking part of the write barrier and
// only performs the generational part.
// UPDATE_WRITE_BARRIER is doing the full barrier, marking and generational.
enum WriteBarrierMode {
SKIP_WRITE_BARRIER,
UPDATE_WEAK_WRITE_BARRIER,
UPDATE_WRITE_BARRIER
};
// PropertyNormalizationMode is used to specify whether to keep
// inobject properties when normalizing properties of a JSObject.
enum PropertyNormalizationMode {
CLEAR_INOBJECT_PROPERTIES,
KEEP_INOBJECT_PROPERTIES
};
// Indicates whether transitions can be added to a source map or not.
enum TransitionFlag {
INSERT_TRANSITION,
OMIT_TRANSITION
};
// Indicates whether the transition is simple: the target map of the transition
// either extends the current map with a new property, or it modifies the
// property that was added last to the current map.
enum SimpleTransitionFlag {
SIMPLE_PROPERTY_TRANSITION,
PROPERTY_TRANSITION,
SPECIAL_TRANSITION
};
// Indicates whether we are only interested in the descriptors of a particular
// map, or in all descriptors in the descriptor array.
enum DescriptorFlag {
ALL_DESCRIPTORS,
OWN_DESCRIPTORS
};
// Instance size sentinel for objects of variable size.
const int kVariableSizeSentinel = 0;
// We may store the unsigned bit field as signed Smi value and do not
// use the sign bit.
const int kStubMajorKeyBits = 8;
const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
// We use the full 16 bits of the instance_type field to encode heap object
// instance types. All the high-order bits (bit 7-15) are cleared if the object
// is a string, and contain set bits if it is not a string.
const uint32_t kIsNotStringMask = 0xff80;
const uint32_t kStringTag = 0x0;
// Bit 6 indicates that the object is an internalized string (if set) or not.
// Bit 7 has to be clear as well.
const uint32_t kIsNotInternalizedMask = 0x40;
const uint32_t kNotInternalizedTag = 0x40;
const uint32_t kInternalizedTag = 0x0;
// If bit 7 is clear then bit 3 indicates whether the string consists of
// two-byte characters or one-byte characters.
const uint32_t kStringEncodingMask = 0x8;
const uint32_t kTwoByteStringTag = 0x0;
const uint32_t kOneByteStringTag = 0x8;
// If bit 7 is clear, the low-order 3 bits indicate the representation
// of the string.
const uint32_t kStringRepresentationMask = 0x07;
enum StringRepresentationTag {
kSeqStringTag = 0x0,
kConsStringTag = 0x1,
kExternalStringTag = 0x2,
kSlicedStringTag = 0x3,
kThinStringTag = 0x5
};
const uint32_t kIsIndirectStringMask = 0x1;
const uint32_t kIsIndirectStringTag = 0x1;
STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); // NOLINT
STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); // NOLINT
STATIC_ASSERT((kConsStringTag &
kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
STATIC_ASSERT((kSlicedStringTag &
kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT
STATIC_ASSERT((kThinStringTag & kIsIndirectStringMask) == kIsIndirectStringTag);
// If bit 7 is clear, then bit 4 indicates whether this two-byte
// string actually contains one byte data.
const uint32_t kOneByteDataHintMask = 0x10;
const uint32_t kOneByteDataHintTag = 0x10;
// If bit 7 is clear and string representation indicates an external string,
// then bit 5 indicates whether the data pointer is cached.
const uint32_t kUncachedExternalStringMask = 0x20;
const uint32_t kUncachedExternalStringTag = 0x20;
// A ConsString with an empty string as the right side is a candidate
// for being shortcut by the garbage collector. We don't allocate any
// non-flat internalized strings, so we do not shortcut them thereby
// avoiding turning internalized strings into strings. The bit-masks
// below contain the internalized bit as additional safety.
// See heap.cc, mark-compact.cc and objects-visiting.cc.
const uint32_t kShortcutTypeMask =
kIsNotStringMask |
kIsNotInternalizedMask |
kStringRepresentationMask;
const uint32_t kShortcutTypeTag = kConsStringTag | kNotInternalizedTag;
static inline bool IsShortcutCandidate(int type) {
return ((type & kShortcutTypeMask) == kShortcutTypeTag);
}
enum InstanceType : uint16_t {
// String types.
INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kSeqStringTag |
kInternalizedTag, // FIRST_PRIMITIVE_TYPE
ONE_BYTE_INTERNALIZED_STRING_TYPE =
kOneByteStringTag | kSeqStringTag | kInternalizedTag,
EXTERNAL_INTERNALIZED_STRING_TYPE =
kTwoByteStringTag | kExternalStringTag | kInternalizedTag,
EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
kOneByteStringTag | kExternalStringTag | kInternalizedTag,
EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
EXTERNAL_INTERNALIZED_STRING_TYPE | kOneByteDataHintTag |
kInternalizedTag,
UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE =
EXTERNAL_INTERNALIZED_STRING_TYPE | kUncachedExternalStringTag |
kInternalizedTag,
UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kUncachedExternalStringTag |
kInternalizedTag,
UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
kUncachedExternalStringTag | kInternalizedTag,
STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
ONE_BYTE_STRING_TYPE =
ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag | kNotInternalizedTag,
CONS_ONE_BYTE_STRING_TYPE =
kOneByteStringTag | kConsStringTag | kNotInternalizedTag,
SLICED_STRING_TYPE =
kTwoByteStringTag | kSlicedStringTag | kNotInternalizedTag,
SLICED_ONE_BYTE_STRING_TYPE =
kOneByteStringTag | kSlicedStringTag | kNotInternalizedTag,
EXTERNAL_STRING_TYPE =
EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
EXTERNAL_ONE_BYTE_STRING_TYPE =
EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
kNotInternalizedTag,
UNCACHED_EXTERNAL_STRING_TYPE =
UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE =
UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
kNotInternalizedTag,
THIN_STRING_TYPE = kTwoByteStringTag | kThinStringTag | kNotInternalizedTag,
THIN_ONE_BYTE_STRING_TYPE =
kOneByteStringTag | kThinStringTag | kNotInternalizedTag,
// Non-string names
SYMBOL_TYPE =
1 + (kIsNotInternalizedMask | kUncachedExternalStringMask |
kOneByteDataHintMask | kStringEncodingMask |
kStringRepresentationMask), // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE
// Other primitives (cannot contain non-map-word pointers to heap objects).
HEAP_NUMBER_TYPE,
BIGINT_TYPE,
ODDBALL_TYPE, // LAST_PRIMITIVE_TYPE
// Objects allocated in their own spaces (never in new space).
MAP_TYPE,
CODE_TYPE,
// "Data", objects that cannot contain non-map-word pointers to heap
// objects.
MUTABLE_HEAP_NUMBER_TYPE,
FOREIGN_TYPE,
BYTE_ARRAY_TYPE,
BYTECODE_ARRAY_TYPE,
FREE_SPACE_TYPE,
FIXED_INT8_ARRAY_TYPE, // FIRST_FIXED_TYPED_ARRAY_TYPE
FIXED_UINT8_ARRAY_TYPE,
FIXED_INT16_ARRAY_TYPE,
FIXED_UINT16_ARRAY_TYPE,
FIXED_INT32_ARRAY_TYPE,
FIXED_UINT32_ARRAY_TYPE,
FIXED_FLOAT32_ARRAY_TYPE,
FIXED_FLOAT64_ARRAY_TYPE,
FIXED_UINT8_CLAMPED_ARRAY_TYPE,
FIXED_BIGINT64_ARRAY_TYPE,
FIXED_BIGUINT64_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE
FIXED_DOUBLE_ARRAY_TYPE,
FEEDBACK_METADATA_TYPE,
FILLER_TYPE, // LAST_DATA_TYPE
// Structs.
ACCESS_CHECK_INFO_TYPE,
ACCESSOR_INFO_TYPE,
ACCESSOR_PAIR_TYPE,
ALIASED_ARGUMENTS_ENTRY_TYPE,
ALLOCATION_MEMENTO_TYPE,
ASYNC_GENERATOR_REQUEST_TYPE,
DEBUG_INFO_TYPE,
FUNCTION_TEMPLATE_INFO_TYPE,
INTERCEPTOR_INFO_TYPE,
INTERPRETER_DATA_TYPE,
MODULE_INFO_ENTRY_TYPE,
MODULE_TYPE,
OBJECT_TEMPLATE_INFO_TYPE,
PROMISE_CAPABILITY_TYPE,
PROMISE_REACTION_TYPE,
PROTOTYPE_INFO_TYPE,
SCRIPT_TYPE,
STACK_FRAME_INFO_TYPE,
TUPLE2_TYPE,
TUPLE3_TYPE,
ARRAY_BOILERPLATE_DESCRIPTION_TYPE,
WASM_DEBUG_INFO_TYPE,
WASM_EXPORTED_FUNCTION_DATA_TYPE,
CALLABLE_TASK_TYPE, // FIRST_MICROTASK_TYPE
CALLBACK_TASK_TYPE,
PROMISE_FULFILL_REACTION_JOB_TASK_TYPE,
PROMISE_REJECT_REACTION_JOB_TASK_TYPE,
PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE, // LAST_MICROTASK_TYPE
MICROTASK_QUEUE_TYPE,
ALLOCATION_SITE_TYPE,
// FixedArrays.
FIXED_ARRAY_TYPE, // FIRST_FIXED_ARRAY_TYPE
OBJECT_BOILERPLATE_DESCRIPTION_TYPE,
HASH_TABLE_TYPE, // FIRST_HASH_TABLE_TYPE
ORDERED_HASH_MAP_TYPE, // FIRST_DICTIONARY_TYPE
ORDERED_HASH_SET_TYPE,
NAME_DICTIONARY_TYPE,
GLOBAL_DICTIONARY_TYPE,
NUMBER_DICTIONARY_TYPE,
SIMPLE_NUMBER_DICTIONARY_TYPE, // LAST_DICTIONARY_TYPE
STRING_TABLE_TYPE, // LAST_HASH_TABLE_TYPE
EPHEMERON_HASH_TABLE_TYPE,
SCOPE_INFO_TYPE,
SCRIPT_CONTEXT_TABLE_TYPE,
AWAIT_CONTEXT_TYPE, // FIRST_CONTEXT_TYPE
BLOCK_CONTEXT_TYPE,
CATCH_CONTEXT_TYPE,
DEBUG_EVALUATE_CONTEXT_TYPE,
EVAL_CONTEXT_TYPE,
FUNCTION_CONTEXT_TYPE,
MODULE_CONTEXT_TYPE,
NATIVE_CONTEXT_TYPE,
SCRIPT_CONTEXT_TYPE,
WITH_CONTEXT_TYPE, // LAST_FIXED_ARRAY_TYPE, LAST_CONTEXT_TYPE
WEAK_FIXED_ARRAY_TYPE, // FIRST_WEAK_FIXED_ARRAY_TYPE
DESCRIPTOR_ARRAY_TYPE,
TRANSITION_ARRAY_TYPE, // LAST_WEAK_FIXED_ARRAY_TYPE
// Misc.
CALL_HANDLER_INFO_TYPE,
CELL_TYPE,
CODE_DATA_CONTAINER_TYPE,
FEEDBACK_CELL_TYPE,
FEEDBACK_VECTOR_TYPE,
LOAD_HANDLER_TYPE,
PRE_PARSED_SCOPE_DATA_TYPE,
PROPERTY_ARRAY_TYPE,
PROPERTY_CELL_TYPE,
SHARED_FUNCTION_INFO_TYPE,
SMALL_ORDERED_HASH_MAP_TYPE,
SMALL_ORDERED_HASH_SET_TYPE,
STORE_HANDLER_TYPE,
UNCOMPILED_DATA_WITHOUT_PRE_PARSED_SCOPE_TYPE,
UNCOMPILED_DATA_WITH_PRE_PARSED_SCOPE_TYPE,
WEAK_ARRAY_LIST_TYPE,
// All the following types are subtypes of JSReceiver, which corresponds to
// objects in the JS sense. The first and the last type in this range are
// the two forms of function. This organization enables using the same
// compares for checking the JS_RECEIVER and the NONCALLABLE_JS_OBJECT range.
// Some of the following instance types are exposed in v8.h, so to not
// unnecessarily change the ABI when we introduce new instance types in the
// future, we leave some space between instance types.
JS_PROXY_TYPE = 0x0400, // FIRST_JS_RECEIVER_TYPE
JS_GLOBAL_OBJECT_TYPE, // FIRST_JS_OBJECT_TYPE
JS_GLOBAL_PROXY_TYPE,
JS_MODULE_NAMESPACE_TYPE,
// Like JS_API_OBJECT_TYPE, but requires access checks and/or has
// interceptors.
JS_SPECIAL_API_OBJECT_TYPE = 0x0410, // LAST_SPECIAL_RECEIVER_TYPE
JS_VALUE_TYPE, // LAST_CUSTOM_ELEMENTS_RECEIVER
// Like JS_OBJECT_TYPE, but created from API function.
JS_API_OBJECT_TYPE = 0x0420,
JS_OBJECT_TYPE,
JS_ARGUMENTS_TYPE,
JS_ARRAY_BUFFER_TYPE,
JS_ARRAY_ITERATOR_TYPE,
JS_ARRAY_TYPE,
JS_ASYNC_FROM_SYNC_ITERATOR_TYPE,
JS_ASYNC_FUNCTION_OBJECT_TYPE,
JS_ASYNC_GENERATOR_OBJECT_TYPE,
JS_CONTEXT_EXTENSION_OBJECT_TYPE,
JS_DATE_TYPE,
JS_ERROR_TYPE,
JS_GENERATOR_OBJECT_TYPE,
JS_MAP_TYPE,
JS_MAP_KEY_ITERATOR_TYPE,
JS_MAP_KEY_VALUE_ITERATOR_TYPE,
JS_MAP_VALUE_ITERATOR_TYPE,
JS_MESSAGE_OBJECT_TYPE,
JS_PROMISE_TYPE,
JS_REGEXP_TYPE,
JS_REGEXP_STRING_ITERATOR_TYPE,
JS_SET_TYPE,
JS_SET_KEY_VALUE_ITERATOR_TYPE,
JS_SET_VALUE_ITERATOR_TYPE,
JS_STRING_ITERATOR_TYPE,
JS_WEAK_CELL_TYPE,
JS_WEAK_FACTORY_CLEANUP_ITERATOR_TYPE,
JS_WEAK_FACTORY_TYPE,
JS_WEAK_MAP_TYPE,
JS_WEAK_SET_TYPE,
JS_TYPED_ARRAY_TYPE,
JS_DATA_VIEW_TYPE,
#ifdef V8_INTL_SUPPORT
JS_INTL_V8_BREAK_ITERATOR_TYPE,
JS_INTL_COLLATOR_TYPE,
JS_INTL_DATE_TIME_FORMAT_TYPE,
JS_INTL_LIST_FORMAT_TYPE,
JS_INTL_LOCALE_TYPE,
JS_INTL_NUMBER_FORMAT_TYPE,
JS_INTL_PLURAL_RULES_TYPE,
JS_INTL_RELATIVE_TIME_FORMAT_TYPE,
JS_INTL_SEGMENT_ITERATOR_TYPE,
JS_INTL_SEGMENTER_TYPE,
#endif // V8_INTL_SUPPORT
WASM_EXCEPTION_TYPE,
WASM_GLOBAL_TYPE,
WASM_INSTANCE_TYPE,
WASM_MEMORY_TYPE,
WASM_MODULE_TYPE,
WASM_TABLE_TYPE,
JS_BOUND_FUNCTION_TYPE,
JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
// Pseudo-types
FIRST_TYPE = 0x0,
LAST_TYPE = JS_FUNCTION_TYPE,
FIRST_NAME_TYPE = FIRST_TYPE,
LAST_NAME_TYPE = SYMBOL_TYPE,
FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
FIRST_NONSTRING_TYPE = SYMBOL_TYPE,
FIRST_PRIMITIVE_TYPE = FIRST_NAME_TYPE,
LAST_PRIMITIVE_TYPE = ODDBALL_TYPE,
FIRST_FUNCTION_TYPE = JS_BOUND_FUNCTION_TYPE,
LAST_FUNCTION_TYPE = JS_FUNCTION_TYPE,
// Boundaries for testing if given HeapObject is a subclass of FixedArray.
FIRST_FIXED_ARRAY_TYPE = FIXED_ARRAY_TYPE,
LAST_FIXED_ARRAY_TYPE = WITH_CONTEXT_TYPE,
// Boundaries for testing if given HeapObject is a subclass of HashTable
FIRST_HASH_TABLE_TYPE = HASH_TABLE_TYPE,
LAST_HASH_TABLE_TYPE = STRING_TABLE_TYPE,
// Boundaries for testing if given HeapObject is a subclass of Dictionary
FIRST_DICTIONARY_TYPE = ORDERED_HASH_MAP_TYPE,
LAST_DICTIONARY_TYPE = SIMPLE_NUMBER_DICTIONARY_TYPE,
// Boundaries for testing if given HeapObject is a subclass of WeakFixedArray.
FIRST_WEAK_FIXED_ARRAY_TYPE = WEAK_FIXED_ARRAY_TYPE,
LAST_WEAK_FIXED_ARRAY_TYPE = TRANSITION_ARRAY_TYPE,
// Boundaries for testing if given HeapObject is a Context
FIRST_CONTEXT_TYPE = AWAIT_CONTEXT_TYPE,
LAST_CONTEXT_TYPE = WITH_CONTEXT_TYPE,
// Boundaries for testing if given HeapObject is a subclass of Microtask.
FIRST_MICROTASK_TYPE = CALLABLE_TASK_TYPE,
LAST_MICROTASK_TYPE = PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE,
// Boundaries for testing for a fixed typed array.
FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE,
LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_BIGUINT64_ARRAY_TYPE,
// Boundary for promotion to old space.
LAST_DATA_TYPE = FILLER_TYPE,
// Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy).
// Note that there is no range for JSObject or JSProxy, since their subtypes
// are not continuous in this enum! The enum ranges instead reflect the
// external class names, where proxies are treated as either ordinary objects,
// or functions.
FIRST_JS_RECEIVER_TYPE = JS_PROXY_TYPE,
LAST_JS_RECEIVER_TYPE = LAST_TYPE,
// Boundaries for testing the types represented as JSObject
FIRST_JS_OBJECT_TYPE = JS_GLOBAL_OBJECT_TYPE,
LAST_JS_OBJECT_TYPE = LAST_TYPE,
// Boundary for testing JSReceivers that need special property lookup handling
LAST_SPECIAL_RECEIVER_TYPE = JS_SPECIAL_API_OBJECT_TYPE,
// Boundary case for testing JSReceivers that may have elements while having
// an empty fixed array as elements backing store. This is true for string
// wrappers.
LAST_CUSTOM_ELEMENTS_RECEIVER = JS_VALUE_TYPE,
FIRST_SET_ITERATOR_TYPE = JS_SET_KEY_VALUE_ITERATOR_TYPE,
LAST_SET_ITERATOR_TYPE = JS_SET_VALUE_ITERATOR_TYPE,
FIRST_MAP_ITERATOR_TYPE = JS_MAP_KEY_ITERATOR_TYPE,
LAST_MAP_ITERATOR_TYPE = JS_MAP_VALUE_ITERATOR_TYPE,
};
STATIC_ASSERT((FIRST_NONSTRING_TYPE & kIsNotStringMask) != kStringTag);
STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
STATIC_ASSERT(JS_API_OBJECT_TYPE == Internals::kJSApiObjectType);
STATIC_ASSERT(JS_SPECIAL_API_OBJECT_TYPE == Internals::kJSSpecialApiObjectType);
STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType);
STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType);
STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType);
V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
InstanceType instance_type);
// Result of an abstract relational comparison of x and y, implemented according
// to ES6 section 7.2.11 Abstract Relational Comparison.
enum class ComparisonResult {
kLessThan, // x < y
kEqual, // x = y
kGreaterThan, // x > y
kUndefined // at least one of x or y was undefined or NaN
};
// (Returns false whenever {result} is kUndefined.)
bool ComparisonResultToBool(Operation op, ComparisonResult result);
enum class OnNonExistent { kThrowReferenceError, kReturnUndefined };
class AbstractCode;
class AccessorPair;
class AccessCheckInfo;
class AllocationSite;
class ByteArray;
class Cell;
class ConsString;
class DependentCode;
class ElementsAccessor;
class EnumCache;
class FixedArrayBase;
class PropertyArray;
class FunctionLiteral;
class FunctionTemplateInfo;
class KeyAccumulator;
class LayoutDescriptor;
class LookupIterator;
class FieldType;
class MaybeObjectSlot;
class MicrotaskQueue;
class Module;
class ModuleInfoEntry;
class ObjectHashTable;
class ObjectTemplateInfo;
class ObjectVisitor;
class PreParsedScopeData;
class PropertyCell;
class PropertyDescriptor;
class RootVisitor;
class SafepointEntry;
class SharedFunctionInfo;
class StringStream;
class FeedbackCell;
class FeedbackMetadata;
class FeedbackVector;
class UncompiledData;
class TemplateInfo;
class TransitionArray;
class TemplateList;
template <typename T>
class ZoneForwardList;
#ifdef OBJECT_PRINT
#define DECL_PRINTER(Name) void Name##Print(std::ostream& os); // NOLINT
#else
#define DECL_PRINTER(Name)
#endif
#define OBJECT_TYPE_LIST(V) \
V(Smi) \
V(LayoutDescriptor) \
V(HeapObject) \
V(Primitive) \
V(Number) \
V(Numeric)
#define HEAP_OBJECT_ORDINARY_TYPE_LIST_BASE(V) \
V(AbstractCode) \
V(AccessCheckNeeded) \
V(AllocationSite) \
V(ArrayList) \
V(BigInt) \
V(BigIntWrapper) \
V(ObjectBoilerplateDescription) \
V(Boolean) \
V(BooleanWrapper) \
V(BreakPoint) \
V(BreakPointInfo) \
V(ByteArray) \
V(BytecodeArray) \
V(CallHandlerInfo) \
V(Callable) \
V(Cell) \
V(ClassBoilerplate) \
V(Code) \
V(CodeDataContainer) \
V(CompilationCacheTable) \
V(ConsString) \
V(Constructor) \
V(Context) \
V(CoverageInfo) \
V(DataHandler) \
V(DeoptimizationData) \
V(DependentCode) \
V(DescriptorArray) \
V(EphemeronHashTable) \
V(EnumCache) \
V(ExternalOneByteString) \
V(ExternalString) \
V(ExternalTwoByteString) \
V(FeedbackCell) \
V(FeedbackMetadata) \
V(FeedbackVector) \
V(Filler) \
V(FixedArray) \
V(FixedArrayBase) \
V(FixedArrayExact) \
V(FixedBigInt64Array) \
V(FixedBigUint64Array) \
V(FixedDoubleArray) \
V(FixedFloat32Array) \
V(FixedFloat64Array) \
V(FixedInt16Array) \
V(FixedInt32Array) \
V(FixedInt8Array) \
V(FixedTypedArrayBase) \
V(FixedUint16Array) \
V(FixedUint32Array) \
V(FixedUint8Array) \
V(FixedUint8ClampedArray) \
V(Foreign) \
V(FrameArray) \
V(FreeSpace) \
V(Function) \
V(GlobalDictionary) \
V(HandlerTable) \
V(HeapNumber) \
V(InternalizedString) \
V(JSArgumentsObject) \
V(JSArray) \
V(JSArrayBuffer) \
V(JSArrayBufferView) \
V(JSArrayIterator) \
V(JSAsyncFromSyncIterator) \
V(JSAsyncFunctionObject) \
V(JSAsyncGeneratorObject) \
V(JSBoundFunction) \
V(JSCollection) \
V(JSContextExtensionObject) \
V(JSDataView) \
V(JSDate) \
V(JSError) \
V(JSFunction) \
V(JSGeneratorObject) \
V(JSGlobalObject) \
V(JSGlobalProxy) \
V(JSMap) \
V(JSMapIterator) \
V(JSMessageObject) \
V(JSModuleNamespace) \
V(JSObject) \
V(JSPromise) \
V(JSProxy) \
V(JSReceiver) \
V(JSRegExp) \
V(JSRegExpResult) \
V(JSRegExpStringIterator) \
V(JSSet) \
V(JSSetIterator) \
V(JSSloppyArgumentsObject) \
V(JSStringIterator) \
V(JSTypedArray) \
V(JSValue) \
V(JSWeakCell) \
V(JSWeakCollection) \
V(JSWeakFactory) \
V(JSWeakFactoryCleanupIterator) \
V(JSWeakMap) \
V(JSWeakSet) \
V(LoadHandler) \
V(Map) \
V(MapCache) \
V(Microtask) \
V(ModuleInfo) \
V(MutableHeapNumber) \
V(Name) \
V(NameDictionary) \
V(NativeContext) \
V(NormalizedMapCache) \
V(NumberDictionary) \
V(NumberWrapper) \
V(ObjectHashSet) \
V(ObjectHashTable) \
V(Oddball) \
V(OrderedHashMap) \
V(OrderedHashSet) \
V(PreParsedScopeData) \
V(PromiseReactionJobTask) \
V(PropertyArray) \
V(PropertyCell) \
V(PropertyDescriptorObject) \
V(RegExpMatchInfo) \
V(ScopeInfo) \
V(ScriptContextTable) \
V(ScriptWrapper) \
V(SeqOneByteString) \
V(SeqString) \
V(SeqTwoByteString) \
V(SharedFunctionInfo) \
V(SimpleNumberDictionary) \
V(SlicedString) \
V(SloppyArgumentsElements) \
V(SmallOrderedHashMap) \
V(SmallOrderedHashSet) \
V(SourcePositionTableWithFrameCache) \
V(StoreHandler) \
V(String) \
V(StringSet) \
V(StringTable) \
V(StringWrapper) \
V(Struct) \
V(Symbol) \
V(SymbolWrapper) \
V(TemplateInfo) \
V(TemplateList) \
V(TemplateObjectDescription) \
V(ThinString) \
V(TransitionArray) \
V(UncompiledData) \
V(UncompiledDataWithPreParsedScope) \
V(UncompiledDataWithoutPreParsedScope) \
V(Undetectable) \
V(UniqueName) \
V(WasmExceptionObject) \
V(WasmGlobalObject) \
V(WasmInstanceObject) \
V(WasmMemoryObject) \
V(WasmModuleObject) \
V(WasmTableObject) \
V(WeakFixedArray) \
V(WeakArrayList)
#ifdef V8_INTL_SUPPORT
#define HEAP_OBJECT_ORDINARY_TYPE_LIST(V) \
HEAP_OBJECT_ORDINARY_TYPE_LIST_BASE(V) \
V(JSV8BreakIterator) \
V(JSCollator) \
V(JSDateTimeFormat) \
V(JSListFormat) \
V(JSLocale) \
V(JSNumberFormat) \
V(JSPluralRules) \
V(JSRelativeTimeFormat) \
V(JSSegmentIterator) \
V(JSSegmenter)
#else
#define HEAP_OBJECT_ORDINARY_TYPE_LIST(V) HEAP_OBJECT_ORDINARY_TYPE_LIST_BASE(V)
#endif // V8_INTL_SUPPORT
#define HEAP_OBJECT_TEMPLATE_TYPE_LIST(V) \
V(Dictionary) \
V(HashTable)
#define HEAP_OBJECT_TYPE_LIST(V) \
HEAP_OBJECT_ORDINARY_TYPE_LIST(V) \
HEAP_OBJECT_TEMPLATE_TYPE_LIST(V)
#define ODDBALL_LIST(V) \
V(Undefined, undefined_value) \
V(Null, null_value) \
V(TheHole, the_hole_value) \
V(Exception, exception) \
V(Uninitialized, uninitialized_value) \
V(True, true_value) \
V(False, false_value) \
V(ArgumentsMarker, arguments_marker) \
V(OptimizedOut, optimized_out) \
V(StaleRegister, stale_register)
// List of object types that have a single unique instance type.
#define INSTANCE_TYPE_CHECKERS_SINGLE_BASE(V) \
V(AllocationSite, ALLOCATION_SITE_TYPE) \
V(BigInt, BIGINT_TYPE) \
V(ObjectBoilerplateDescription, OBJECT_BOILERPLATE_DESCRIPTION_TYPE) \
V(BreakPoint, TUPLE2_TYPE) \
V(BreakPointInfo, TUPLE2_TYPE) \
V(ByteArray, BYTE_ARRAY_TYPE) \
V(BytecodeArray, BYTECODE_ARRAY_TYPE) \
V(CallHandlerInfo, CALL_HANDLER_INFO_TYPE) \
V(Cell, CELL_TYPE) \
V(Code, CODE_TYPE) \
V(CodeDataContainer, CODE_DATA_CONTAINER_TYPE) \
V(CoverageInfo, FIXED_ARRAY_TYPE) \
V(DescriptorArray, DESCRIPTOR_ARRAY_TYPE) \
V(EphemeronHashTable, EPHEMERON_HASH_TABLE_TYPE) \
V(FeedbackCell, FEEDBACK_CELL_TYPE) \
V(FeedbackMetadata, FEEDBACK_METADATA_TYPE) \
V(FeedbackVector, FEEDBACK_VECTOR_TYPE) \
V(FixedArrayExact, FIXED_ARRAY_TYPE) \
V(FixedDoubleArray, FIXED_DOUBLE_ARRAY_TYPE) \
V(Foreign, FOREIGN_TYPE) \
V(FreeSpace, FREE_SPACE_TYPE) \
V(GlobalDictionary, GLOBAL_DICTIONARY_TYPE) \
V(HeapNumber, HEAP_NUMBER_TYPE) \
V(JSArgumentsObject, JS_ARGUMENTS_TYPE) \
V(JSArray, JS_ARRAY_TYPE) \
V(JSArrayBuffer, JS_ARRAY_BUFFER_TYPE) \
V(JSArrayIterator, JS_ARRAY_ITERATOR_TYPE) \
V(JSAsyncFromSyncIterator, JS_ASYNC_FROM_SYNC_ITERATOR_TYPE) \
V(JSAsyncFunctionObject, JS_ASYNC_FUNCTION_OBJECT_TYPE) \
V(JSAsyncGeneratorObject, JS_ASYNC_GENERATOR_OBJECT_TYPE) \
V(JSBoundFunction, JS_BOUND_FUNCTION_TYPE) \
V(JSContextExtensionObject, JS_CONTEXT_EXTENSION_OBJECT_TYPE) \
V(JSDataView, JS_DATA_VIEW_TYPE) \
V(JSDate, JS_DATE_TYPE) \
V(JSError, JS_ERROR_TYPE) \
V(JSFunction, JS_FUNCTION_TYPE) \
V(JSGlobalObject, JS_GLOBAL_OBJECT_TYPE) \
V(JSGlobalProxy, JS_GLOBAL_PROXY_TYPE) \
V(JSMap, JS_MAP_TYPE) \
V(JSMessageObject, JS_MESSAGE_OBJECT_TYPE) \
V(JSModuleNamespace, JS_MODULE_NAMESPACE_TYPE) \
V(JSPromise, JS_PROMISE_TYPE) \
V(JSProxy, JS_PROXY_TYPE) \
V(JSRegExp, JS_REGEXP_TYPE) \
V(JSRegExpResult, JS_ARRAY_TYPE) \
V(JSRegExpStringIterator, JS_REGEXP_STRING_ITERATOR_TYPE) \
V(JSSet, JS_SET_TYPE) \
V(JSStringIterator, JS_STRING_ITERATOR_TYPE) \
V(JSTypedArray, JS_TYPED_ARRAY_TYPE) \
V(JSValue, JS_VALUE_TYPE) \
V(JSWeakCell, JS_WEAK_CELL_TYPE) \
V(JSWeakFactory, JS_WEAK_FACTORY_TYPE) \
V(JSWeakFactoryCleanupIterator, JS_WEAK_FACTORY_CLEANUP_ITERATOR_TYPE) \
V(JSWeakMap, JS_WEAK_MAP_TYPE) \
V(JSWeakSet, JS_WEAK_SET_TYPE) \
V(LoadHandler, LOAD_HANDLER_TYPE) \
V(Map, MAP_TYPE) \
V(MutableHeapNumber, MUTABLE_HEAP_NUMBER_TYPE) \
V(NameDictionary, NAME_DICTIONARY_TYPE) \
V(NativeContext, NATIVE_CONTEXT_TYPE) \
V(NumberDictionary, NUMBER_DICTIONARY_TYPE) \
V(Oddball, ODDBALL_TYPE) \
V(OrderedHashMap, ORDERED_HASH_MAP_TYPE) \
V(OrderedHashSet, ORDERED_HASH_SET_TYPE) \
V(PreParsedScopeData, PRE_PARSED_SCOPE_DATA_TYPE) \
V(PropertyArray, PROPERTY_ARRAY_TYPE) \
V(PropertyCell, PROPERTY_CELL_TYPE) \
V(PropertyDescriptorObject, FIXED_ARRAY_TYPE) \
V(ScopeInfo, SCOPE_INFO_TYPE) \
V(ScriptContextTable, SCRIPT_CONTEXT_TABLE_TYPE) \
V(SharedFunctionInfo, SHARED_FUNCTION_INFO_TYPE) \
V(SimpleNumberDictionary, SIMPLE_NUMBER_DICTIONARY_TYPE) \
V(SmallOrderedHashMap, SMALL_ORDERED_HASH_MAP_TYPE) \
V(SmallOrderedHashSet, SMALL_ORDERED_HASH_SET_TYPE) \
V(SourcePositionTableWithFrameCache, TUPLE2_TYPE) \
V(StoreHandler, STORE_HANDLER_TYPE) \
V(StringTable, STRING_TABLE_TYPE) \
V(Symbol, SYMBOL_TYPE) \
V(TemplateObjectDescription, TUPLE2_TYPE) \
V(TransitionArray, TRANSITION_ARRAY_TYPE) \
V(UncompiledDataWithoutPreParsedScope, \
UNCOMPILED_DATA_WITHOUT_PRE_PARSED_SCOPE_TYPE) \
V(UncompiledDataWithPreParsedScope, \
UNCOMPILED_DATA_WITH_PRE_PARSED_SCOPE_TYPE) \
V(WasmExceptionObject, WASM_EXCEPTION_TYPE) \
V(WasmGlobalObject, WASM_GLOBAL_TYPE) \
V(WasmInstanceObject, WASM_INSTANCE_TYPE) \
V(WasmMemoryObject, WASM_MEMORY_TYPE) \
V(WasmModuleObject, WASM_MODULE_TYPE) \
V(WasmTableObject, WASM_TABLE_TYPE) \
V(WeakArrayList, WEAK_ARRAY_LIST_TYPE)
#ifdef V8_INTL_SUPPORT
#define INSTANCE_TYPE_CHECKERS_SINGLE(V) \
INSTANCE_TYPE_CHECKERS_SINGLE_BASE(V) \
V(JSV8BreakIterator, JS_INTL_V8_BREAK_ITERATOR_TYPE) \
V(JSCollator, JS_INTL_COLLATOR_TYPE) \
V(JSDateTimeFormat, JS_INTL_DATE_TIME_FORMAT_TYPE) \
V(JSListFormat, JS_INTL_LIST_FORMAT_TYPE) \
V(JSLocale, JS_INTL_LOCALE_TYPE) \
V(JSNumberFormat, JS_INTL_NUMBER_FORMAT_TYPE) \
V(JSPluralRules, JS_INTL_PLURAL_RULES_TYPE) \
V(JSRelativeTimeFormat, JS_INTL_RELATIVE_TIME_FORMAT_TYPE) \
V(JSSegmentIterator, JS_INTL_SEGMENT_ITERATOR_TYPE) \
V(JSSegmenter, JS_INTL_SEGMENTER_TYPE)
#else
#define INSTANCE_TYPE_CHECKERS_SINGLE(V) INSTANCE_TYPE_CHECKERS_SINGLE_BASE(V)
#endif // V8_INTL_SUPPORT
#define INSTANCE_TYPE_CHECKERS_RANGE(V) \
V(Context, FIRST_CONTEXT_TYPE, LAST_CONTEXT_TYPE) \
V(Dictionary, FIRST_DICTIONARY_TYPE, LAST_DICTIONARY_TYPE) \
V(FixedArray, FIRST_FIXED_ARRAY_TYPE, LAST_FIXED_ARRAY_TYPE) \
V(FixedTypedArrayBase, FIRST_FIXED_TYPED_ARRAY_TYPE, \
LAST_FIXED_TYPED_ARRAY_TYPE) \
V(HashTable, FIRST_HASH_TABLE_TYPE, LAST_HASH_TABLE_TYPE) \
V(JSMapIterator, FIRST_MAP_ITERATOR_TYPE, LAST_MAP_ITERATOR_TYPE) \
V(JSSetIterator, FIRST_SET_ITERATOR_TYPE, LAST_SET_ITERATOR_TYPE) \
V(Microtask, FIRST_MICROTASK_TYPE, LAST_MICROTASK_TYPE) \
V(Name, FIRST_TYPE, LAST_NAME_TYPE) \
V(String, FIRST_TYPE, FIRST_NONSTRING_TYPE - 1) \
V(WeakFixedArray, FIRST_WEAK_FIXED_ARRAY_TYPE, LAST_WEAK_FIXED_ARRAY_TYPE)
#define INSTANCE_TYPE_CHECKERS_CUSTOM(V) \
V(FixedArrayBase) \
V(InternalizedString) \
V(JSObject) \
V(JSReceiver)
#define INSTANCE_TYPE_CHECKERS(V) \
INSTANCE_TYPE_CHECKERS_SINGLE(V) \
INSTANCE_TYPE_CHECKERS_RANGE(V) \
INSTANCE_TYPE_CHECKERS_CUSTOM(V)
namespace InstanceTypeChecker {
#define IS_TYPE_FUNCTION_DECL(Type, ...) \
V8_INLINE bool Is##Type(InstanceType instance_type);
INSTANCE_TYPE_CHECKERS(IS_TYPE_FUNCTION_DECL)
#define TYPED_ARRAY_IS_TYPE_FUNCTION_DECL(Type, ...) \
IS_TYPE_FUNCTION_DECL(Fixed##Type##Array)
TYPED_ARRAYS(TYPED_ARRAY_IS_TYPE_FUNCTION_DECL)
#undef TYPED_ARRAY_IS_TYPE_FUNCTION_DECL
#define STRUCT_IS_TYPE_FUNCTION_DECL(NAME, Name, name) \
IS_TYPE_FUNCTION_DECL(Name)
STRUCT_LIST(STRUCT_IS_TYPE_FUNCTION_DECL)
#undef STRUCT_IS_TYPE_FUNCTION_DECL
#undef IS_TYPE_FUNCTION_DECL
} // namespace InstanceTypeChecker
// The element types selection for CreateListFromArrayLike.
enum class ElementTypes { kAll, kStringAndSymbol };
// Object is the abstract superclass for all classes in the
// object hierarchy.
// Object does not use any virtual functions to avoid the
// allocation of the C++ vtable.
// Since both Smi and HeapObject are subclasses of Object no
// data members can be present in Object.
class Object {
public:
// Type testing.
bool IsObject() const { return true; }
// Syntax compatibility with ObjectPtr, so the same macros can consume
// arguments of either type.
Address ptr() const { return reinterpret_cast<Address>(this); }
#define IS_TYPE_FUNCTION_DECL(Type) V8_INLINE bool Is##Type() const;
OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
#undef IS_TYPE_FUNCTION_DECL
V8_INLINE bool IsExternal(Isolate* isolate) const;
// Oddball checks are faster when they are raw pointer comparisons, so the
// isolate/read-only roots overloads should be preferred where possible.
#define IS_TYPE_FUNCTION_DECL(Type, Value) \
V8_INLINE bool Is##Type(Isolate* isolate) const; \
V8_INLINE bool Is##Type(ReadOnlyRoots roots) const; \
V8_INLINE bool Is##Type() const;
ODDBALL_LIST(IS_TYPE_FUNCTION_DECL)
#undef IS_TYPE_FUNCTION_DECL
V8_INLINE bool IsNullOrUndefined(Isolate* isolate) const;
V8_INLINE bool IsNullOrUndefined(ReadOnlyRoots roots) const;
V8_INLINE bool IsNullOrUndefined() const;
enum class Conversion { kToNumber, kToNumeric };
#define RETURN_FAILURE(isolate, should_throw, call) \
do { \
if ((should_throw) == kDontThrow) { \
return Just(false); \
} else { \
isolate->Throw(*isolate->factory()->call); \
return Nothing<bool>(); \
} \
} while (false)
#define MAYBE_RETURN(call, value) \
do { \
if ((call).IsNothing()) return value; \
} while (false)
#define MAYBE_RETURN_NULL(call) MAYBE_RETURN(call, MaybeHandle<Object>())
#define MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, dst, call) \
do { \
Isolate* __isolate__ = (isolate); \
if (!(call).To(&dst)) { \
DCHECK(__isolate__->has_pending_exception()); \
return ReadOnlyRoots(__isolate__).exception(); \
} \
} while (false)
#define DECL_STRUCT_PREDICATE(NAME, Name, name) V8_INLINE bool Is##Name() const;
STRUCT_LIST(DECL_STRUCT_PREDICATE)
#undef DECL_STRUCT_PREDICATE
// ES6, #sec-isarray. NOT to be confused with %_IsArray.
V8_INLINE
V8_WARN_UNUSED_RESULT static Maybe<bool> IsArray(Handle<Object> object);
V8_INLINE bool IsSmallOrderedHashTable() const;
// Extract the number.
inline double Number() const;
V8_INLINE bool IsNaN() const;
V8_INLINE bool IsMinusZero() const;
V8_EXPORT_PRIVATE bool ToInt32(int32_t* value);
inline bool ToUint32(uint32_t* value) const;
inline Representation OptimalRepresentation();
inline ElementsKind OptimalElementsKind();
inline bool FitsRepresentation(Representation representation);
// Checks whether two valid primitive encodings of a property name resolve to
// the same logical property. E.g., the smi 1, the string "1" and the double
// 1 all refer to the same property, so this helper will return true.
inline bool KeyEquals(Object* other);
inline bool FilterKey(PropertyFilter filter);
Handle<FieldType> OptimalType(Isolate* isolate,
Representation representation);
inline static Handle<Object> NewStorageFor(Isolate* isolate,
Handle<Object> object,
Representation representation);
inline static Handle<Object> WrapForRead(Isolate* isolate,
Handle<Object> object,
Representation representation);
// Returns true if the object is of the correct type to be used as a
// implementation of a JSObject's elements.
inline bool HasValidElements();
// ECMA-262 9.2.
bool BooleanValue(Isolate* isolate);
// ES6 section 7.2.11 Abstract Relational Comparison
V8_WARN_UNUSED_RESULT static Maybe<ComparisonResult> Compare(
Isolate* isolate, Handle<Object> x, Handle<Object> y);
// ES6 section 7.2.12 Abstract Equality Comparison
V8_WARN_UNUSED_RESULT static Maybe<bool> Equals(Isolate* isolate,
Handle<Object> x,
Handle<Object> y);
// ES6 section 7.2.13 Strict Equality Comparison
bool StrictEquals(Object* that);
// ES6 section 7.1.13 ToObject
// Convert to a JSObject if needed.
// native_context is used when creating wrapper object.
//
// Passing a non-null method_name allows us to give a more informative
// error message for those cases where ToObject is being called on
// the receiver of a built-in method.
V8_WARN_UNUSED_RESULT static inline MaybeHandle<JSReceiver> ToObject(
Isolate* isolate, Handle<Object> object,
const char* method_name = nullptr);
V8_WARN_UNUSED_RESULT static MaybeHandle<JSReceiver> ToObject(
Isolate* isolate, Handle<Object> object, Handle<Context> native_context,
const char* method_name = nullptr);
// ES6 section 9.2.1.2, OrdinaryCallBindThis for sloppy callee.
V8_WARN_UNUSED_RESULT static MaybeHandle<JSReceiver> ConvertReceiver(
Isolate* isolate, Handle<Object> object);
// ES6 section 7.1.14 ToPropertyKey
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Name> ToName(
Isolate* isolate, Handle<Object> input);
// ES6 section 7.1.1 ToPrimitive
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToPrimitive(
Handle<Object> input, ToPrimitiveHint hint = ToPrimitiveHint::kDefault);
// ES6 section 7.1.3 ToNumber
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToNumber(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToNumeric(
Isolate* isolate, Handle<Object> input);
// ES6 section 7.1.4 ToInteger
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToInteger(
Isolate* isolate, Handle<Object> input);
// ES6 section 7.1.5 ToInt32
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToInt32(
Isolate* isolate, Handle<Object> input);
// ES6 section 7.1.6 ToUint32
V8_WARN_UNUSED_RESULT inline static MaybeHandle<Object> ToUint32(
Isolate* isolate, Handle<Object> input);
// ES6 section 7.1.12 ToString
V8_WARN_UNUSED_RESULT static inline MaybeHandle<String> ToString(
Isolate* isolate, Handle<Object> input);
static Handle<String> NoSideEffectsToString(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.1.14 ToPropertyKey
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToPropertyKey(
Isolate* isolate, Handle<Object> value);
// ES6 section 7.1.15 ToLength
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToLength(
Isolate* isolate, Handle<Object> input);
// ES6 section 7.1.17 ToIndex
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> ToIndex(
Isolate* isolate, Handle<Object> input, MessageTemplate error_index);
// ES6 section 7.3.9 GetMethod
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetMethod(
Handle<JSReceiver> receiver, Handle<Name> name);
// ES6 section 7.3.17 CreateListFromArrayLike
V8_WARN_UNUSED_RESULT static MaybeHandle<FixedArray> CreateListFromArrayLike(
Isolate* isolate, Handle<Object> object, ElementTypes element_types);
// Get length property and apply ToLength.
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetLengthFromArrayLike(
Isolate* isolate, Handle<JSReceiver> object);
// ES6 section 12.5.6 The typeof Operator
static Handle<String> TypeOf(Isolate* isolate, Handle<Object> object);
// ES6 section 12.7 Additive Operators
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> Add(Isolate* isolate,
Handle<Object> lhs,
Handle<Object> rhs);
// ES6 section 12.9 Relational Operators
V8_WARN_UNUSED_RESULT static inline Maybe<bool> GreaterThan(Isolate* isolate,
Handle<Object> x,
Handle<Object> y);
V8_WARN_UNUSED_RESULT static inline Maybe<bool> GreaterThanOrEqual(
Isolate* isolate, Handle<Object> x, Handle<Object> y);
V8_WARN_UNUSED_RESULT static inline Maybe<bool> LessThan(Isolate* isolate,
Handle<Object> x,
Handle<Object> y);
V8_WARN_UNUSED_RESULT static inline Maybe<bool> LessThanOrEqual(
Isolate* isolate, Handle<Object> x, Handle<Object> y);
// ES6 section 7.3.19 OrdinaryHasInstance (C, O).
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> OrdinaryHasInstance(
Isolate* isolate, Handle<Object> callable, Handle<Object> object);
// ES6 section 12.10.4 Runtime Semantics: InstanceofOperator(O, C)
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> InstanceOf(
Isolate* isolate, Handle<Object> object, Handle<Object> callable);
V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
GetProperty(LookupIterator* it,
OnNonExistent on_non_existent = OnNonExistent::kReturnUndefined);
// ES6 [[Set]] (when passed kDontThrow)
// Invariants for this and related functions (unless stated otherwise):
// 1) When the result is Nothing, an exception is pending.
// 2) When passed kThrowOnError, the result is never Just(false).
// In some cases, an exception is thrown regardless of the ShouldThrow
// argument. These cases are either in accordance with the spec or not
// covered by it (eg., concerning API callbacks).
V8_WARN_UNUSED_RESULT static Maybe<bool> SetProperty(
LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
StoreOrigin store_origin);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> SetProperty(
Isolate* isolate, Handle<Object> object, Handle<Name> name,
Handle<Object> value, LanguageMode language_mode,
StoreOrigin store_origin = StoreOrigin::kMaybeKeyed);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> SetPropertyOrElement(
Isolate* isolate, Handle<Object> object, Handle<Name> name,
Handle<Object> value, LanguageMode language_mode,
StoreOrigin store_origin = StoreOrigin::kMaybeKeyed);
V8_WARN_UNUSED_RESULT static Maybe<bool> SetSuperProperty(
LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
StoreOrigin store_origin);
V8_WARN_UNUSED_RESULT static Maybe<bool> CannotCreateProperty(
Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
Handle<Object> value, ShouldThrow should_throw);
V8_WARN_UNUSED_RESULT static Maybe<bool> WriteToReadOnlyProperty(
LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
V8_WARN_UNUSED_RESULT static Maybe<bool> WriteToReadOnlyProperty(
Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
Handle<Object> value, ShouldThrow should_throw);
V8_WARN_UNUSED_RESULT static Maybe<bool> RedefineIncompatibleProperty(
Isolate* isolate, Handle<Object> name, Handle<Object> value,
ShouldThrow should_throw);
V8_WARN_UNUSED_RESULT static Maybe<bool> SetDataProperty(
LookupIterator* it, Handle<Object> value);
V8_WARN_UNUSED_RESULT static Maybe<bool> AddDataProperty(
LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
ShouldThrow should_throw, StoreOrigin store_origin);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
Isolate* isolate, Handle<Object> object, Handle<Name> name);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
Handle<Object> receiver, Handle<Name> name, Handle<JSReceiver> holder);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetProperty(
Isolate* isolate, Handle<Object> object, Handle<Name> name);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
LookupIterator* it);
V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyWithAccessor(
LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter(
Handle<Object> receiver, Handle<JSReceiver> getter);
V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyWithDefinedSetter(
Handle<Object> receiver, Handle<JSReceiver> setter, Handle<Object> value,
ShouldThrow should_throw);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetElement(
Isolate* isolate, Handle<Object> object, uint32_t index);
V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> SetElement(
Isolate* isolate, Handle<Object> object, uint32_t index,
Handle<Object> value, LanguageMode language_mode);
// Returns the permanent hash code associated with this object. May return
// undefined if not yet created.
inline Object* GetHash();
// Returns the permanent hash code associated with this object depending on
// the actual object type. May create and store a hash code if needed and none
// exists.
Smi* GetOrCreateHash(Isolate* isolate);
static Smi* GetOrCreateHash(Isolate* isolate, Object* key);
// Checks whether this object has the same value as the given one. This
// function is implemented according to ES5, section 9.12 and can be used
// to implement the Object.is function.
V8_EXPORT_PRIVATE bool SameValue(Object* other);
// Checks whether this object has the same value as the given one.
// +0 and -0 are treated equal. Everything else is the same as SameValue.
// This function is implemented according to ES6, section 7.2.4 and is used
// by ES6 Map and Set.
bool SameValueZero(Object* other);
// ES6 section 9.4.2.3 ArraySpeciesCreate (part of it)
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ArraySpeciesConstructor(
Isolate* isolate, Handle<Object> original_array);
// ES6 section 7.3.20 SpeciesConstructor ( O, defaultConstructor )
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> SpeciesConstructor(
Isolate* isolate, Handle<JSReceiver> recv,
Handle<JSFunction> default_ctor);
// Tries to convert an object to an array length. Returns true and sets the
// output parameter if it succeeds.
inline bool ToArrayLength(uint32_t* index) const;
// Tries to convert an object to an array index. Returns true and sets the
// output parameter if it succeeds. Equivalent to ToArrayLength, but does not
// allow kMaxUInt32.
V8_WARN_UNUSED_RESULT inline bool ToArrayIndex(uint32_t* index) const;
// Returns true if the result of iterating over the object is the same
// (including observable effects) as simply accessing the properties between 0
// and length.
bool IterationHasObservableEffects();
DECL_VERIFIER(Object)
#ifdef VERIFY_HEAP
// Verify a pointer is a valid object pointer.
static void VerifyPointer(Isolate* isolate, Object* p);
#endif
inline void VerifyApiCallResultType();
// Prints this object without details.
void ShortPrint(FILE* out = stdout);
// Prints this object without details to a message accumulator.
void ShortPrint(StringStream* accumulator);
void ShortPrint(std::ostream& os); // NOLINT
DECL_CAST(Object)
// Layout description.
static const int kHeaderSize = 0; // Object does not take up any space.
#ifdef OBJECT_PRINT
// For our gdb macros, we should perhaps change these in the future.
void Print();
// Prints this object with details.
void Print(std::ostream& os); // NOLINT
#else
void Print() { ShortPrint(); }
void Print(std::ostream& os) { ShortPrint(os); } // NOLINT
#endif
private:
friend class LookupIterator;
friend class StringStream;
// Return the map of the root of object's prototype chain.
Map* GetPrototypeChainRootMap(Isolate* isolate) const;
// Returns a non-SMI for JSReceivers, but returns the hash code for
// simple objects. This avoids a double lookup in the cases where
// we know we will add the hash to the JSReceiver if it does not
// already exist.
//
// Despite its size, this needs to be inlined for performance
// reasons.
static inline Object* GetSimpleHash(Object* object);
// Helper for SetProperty and SetSuperProperty.
// Return value is only meaningful if [found] is set to true on return.
V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyInternal(
LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
StoreOrigin store_origin, bool* found);
V8_WARN_UNUSED_RESULT static MaybeHandle<Name> ConvertToName(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToPropertyKey(
Isolate* isolate, Handle<Object> value);
V8_WARN_UNUSED_RESULT static MaybeHandle<String> ConvertToString(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToNumberOrNumeric(
Isolate* isolate, Handle<Object> input, Conversion mode);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToInteger(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToInt32(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToUint32(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToLength(
Isolate* isolate, Handle<Object> input);
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToIndex(
Isolate* isolate, Handle<Object> input, MessageTemplate error_index);
DISALLOW_IMPLICIT_CONSTRUCTORS(Object);
};
// In objects.h to be usable without objects-inl.h inclusion.
bool Object::IsSmi() const { return HAS_SMI_TAG(this); }
bool Object::IsHeapObject() const {
DCHECK_EQ(!IsSmi(),
Internals::HasHeapObjectTag(reinterpret_cast<Address>(this)));
return !IsSmi();
}
struct Brief {
V8_EXPORT_PRIVATE explicit Brief(const Object* v);
explicit Brief(const MaybeObject* v) : value(v) {}
const MaybeObject* value;
};
V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, const Brief& v);
// Smi represents integer Numbers that can be stored in 31 bits.
// Smis are immediate which means they are NOT allocated in the heap.
// The this pointer has the following format: [31 bit signed int] 0
// For long smis it has the following format:
// [32 bit signed int] [31 bits zero padding] 0
// Smi stands for small integer.
class Smi: public Object {
public:
// Returns the integer value.
inline int value() const {
return Internals::SmiValue(reinterpret_cast<Address>(this));
}
inline Smi* ToUint32Smi() {
if (value() <= 0) return Smi::kZero;
return Smi::FromInt(static_cast<uint32_t>(value()));
}
// Convert a Smi object to an int.
static inline int ToInt(const Object* object);
// Convert a value to a Smi object.
static inline Smi* FromInt(int value) {
DCHECK(Smi::IsValid(value));
return reinterpret_cast<Smi*>(Internals::IntToSmi(value));
}
static inline Smi* FromIntptr(intptr_t value) {
DCHECK(Smi::IsValid(value));
int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
return reinterpret_cast<Smi*>((value << smi_shift_bits) | kSmiTag);
}
template <typename E,
typename = typename std::enable_if<std::is_enum<E>::value>::type>
static inline Smi* FromEnum(E value) {
STATIC_ASSERT(sizeof(E) <= sizeof(int));
return FromInt(static_cast<int>(value));
}
// Returns whether value can be represented in a Smi.
static inline bool IsValid(intptr_t value) {
bool result = Internals::IsValidSmi(value);
DCHECK_EQ(result, value >= kMinValue && value <= kMaxValue);
return result;
}
// Compare two Smis x, y as if they were converted to strings and then
// compared lexicographically. Returns:
// -1 if x < y.
// 0 if x == y.
// 1 if x > y.
static Smi* LexicographicCompare(Isolate* isolate, Smi* x, Smi* y);
DECL_CAST(Smi)
// Dispatched behavior.
V8_EXPORT_PRIVATE void SmiPrint(std::ostream& os) const; // NOLINT
DECL_VERIFIER(Smi)
static constexpr Smi* const kZero = nullptr;
static const int kMinValue = kSmiMinValue;
static const int kMaxValue = kSmiMaxValue;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Smi);
};
// Heap objects typically have a map pointer in their first word. However,
// during GC other data (e.g. mark bits, forwarding addresses) is sometimes
// encoded in the first word. The class MapWord is an abstraction of the
// value in a heap object's first word.
class MapWord {
public:
// Normal state: the map word contains a map pointer.
// Create a map word from a map pointer.
static inline MapWord FromMap(const Map* map);
// View this map word as a map pointer.
inline Map* ToMap() const;
// Scavenge collection: the map word of live objects in the from space
// contains a forwarding address (a heap object pointer in the to space).
// True if this map word is a forwarding address for a scavenge
// collection. Only valid during a scavenge collection (specifically,
// when all map words are heap object pointers, i.e. not during a full GC).
inline bool IsForwardingAddress() const;
// Create a map word from a forwarding address.
static inline MapWord FromForwardingAddress(HeapObject* object);
// View this map word as a forwarding address.
inline HeapObject* ToForwardingAddress();
static inline MapWord FromRawValue(uintptr_t value) {
return MapWord(value);
}
inline uintptr_t ToRawValue() {
return value_;
}
private:
// HeapObject calls the private constructor and directly reads the value.
friend class HeapObject;
explicit MapWord(uintptr_t value) : value_(value) {}
uintptr_t value_;
};
// HeapObject is the superclass for all classes describing heap allocated
// objects.
class HeapObject: public Object {
public:
// [map]: Contains a map which contains the object's reflective
// information.
inline Map* map() const;
inline void set_map(Map* value);
inline ObjectSlot map_slot();
// The no-write-barrier version. This is OK if the object is white and in
// new space, or if the value is an immortal immutable object, like the maps
// of primitive (non-JS) objects like strings, heap numbers etc.
inline void set_map_no_write_barrier(Map* value);
// Get the map using acquire load.
inline Map* synchronized_map() const;
inline MapWord synchronized_map_word() const;
// Set the map using release store
inline void synchronized_set_map(Map* value);
inline void synchronized_set_map_word(MapWord map_word);
// Initialize the map immediately after the object is allocated.
// Do not use this outside Heap.
inline void set_map_after_allocation(
Map* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// During garbage collection, the map word of a heap object does not
// necessarily contain a map pointer.
inline MapWord map_word() const;
inline void set_map_word(MapWord map_word);
// TODO(v8:7464): Once RO_SPACE is shared between isolates, this method can be
// removed as ReadOnlyRoots will be accessible from a global variable. For now
// this method exists to help remove GetIsolate/GetHeap from HeapObject, in a
// way that doesn't require passing Isolate/Heap down huge call chains or to
// places where it might not be safe to access it.
inline ReadOnlyRoots GetReadOnlyRoots() const;
#define IS_TYPE_FUNCTION_DECL(Type) V8_INLINE bool Is##Type() const;
HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL)
#undef IS_TYPE_FUNCTION_DECL
V8_INLINE bool IsExternal(Isolate* isolate) const;
// Oddball checks are faster when they are raw pointer comparisons, so the
// isolate/read-only roots overloads should be preferred where possible.
#define IS_TYPE_FUNCTION_DECL(Type, Value) \
V8_INLINE bool Is##Type(Isolate* isolate) const; \
V8_INLINE bool Is##Type(ReadOnlyRoots roots) const; \
V8_INLINE bool Is##Type() const;
ODDBALL_LIST(IS_TYPE_FUNCTION_DECL)
#undef IS_TYPE_FUNCTION_DECL
V8_INLINE bool IsNullOrUndefined(Isolate* isolate) const;
V8_INLINE bool IsNullOrUndefined(ReadOnlyRoots roots) const;
V8_INLINE bool IsNullOrUndefined() const;
#define DECL_STRUCT_PREDICATE(NAME, Name, name) V8_INLINE bool Is##Name() const;
STRUCT_LIST(DECL_STRUCT_PREDICATE)
#undef DECL_STRUCT_PREDICATE
// Converts an address to a HeapObject pointer.
static inline HeapObject* FromAddress(Address address) {
DCHECK_TAG_ALIGNED(address);
return reinterpret_cast<HeapObject*>(address + kHeapObjectTag);
}
// Returns the address of this HeapObject.
inline Address address() const {
return reinterpret_cast<Address>(this) - kHeapObjectTag;
}
// Iterates over pointers contained in the object (including the Map).
// If it's not performance critical iteration use the non-templatized
// version.
void Iterate(ObjectVisitor* v);
template <typename ObjectVisitor>
inline void IterateFast(ObjectVisitor* v);
// Iterates over all pointers contained in the object except the
// first map pointer. The object type is given in the first
// parameter. This function does not access the map pointer in the
// object, and so is safe to call while the map pointer is modified.
// If it's not performance critical iteration use the non-templatized
// version.
void IterateBody(ObjectVisitor* v);
void IterateBody(Map* map, int object_size, ObjectVisitor* v);
template <typename ObjectVisitor>
inline void IterateBodyFast(ObjectVisitor* v);
template <typename ObjectVisitor>
inline void IterateBodyFast(Map* map, int object_size, ObjectVisitor* v);
// Returns true if the object contains a tagged value at given offset.
// It is used for invalid slots filtering. If the offset points outside
// of the object or to the map word, the result is UNDEFINED (!!!).
bool IsValidSlot(Map* map, int offset);
// Returns the heap object's size in bytes
inline int Size() const;
// Given a heap object's map pointer, returns the heap size in bytes
// Useful when the map pointer field is used for other purposes.
// GC internal.
inline int SizeFromMap(Map* map) const;
// Returns the field at offset in obj, as a read/write Object* reference.
// Does no checking, and is safe to use during GC, while maps are invalid.
// Does not invoke write barrier, so should only be assigned to
// during marking GC.
inline ObjectSlot RawField(int byte_offset) const;
static inline ObjectSlot RawField(const HeapObject* obj, int offset);
inline MaybeObjectSlot RawMaybeWeakField(int byte_offset) const;
static inline MaybeObjectSlot RawMaybeWeakField(HeapObject* obj, int offset);
DECL_CAST(HeapObject)
// Return the write barrier mode for this. Callers of this function
// must be able to present a reference to an DisallowHeapAllocation
// object as a sign that they are not going to use this function
// from code that allocates and thus invalidates the returned write
// barrier mode.
inline WriteBarrierMode GetWriteBarrierMode(
const DisallowHeapAllocation& promise);
// Dispatched behavior.
void HeapObjectShortPrint(std::ostream& os); // NOLINT
#ifdef OBJECT_PRINT
void PrintHeader(std::ostream& os, const char* id); // NOLINT
#endif
DECL_PRINTER(HeapObject)
DECL_VERIFIER(HeapObject)
#ifdef VERIFY_HEAP
inline void VerifyObjectField(Isolate* isolate, int offset);
inline void VerifySmiField(int offset);
inline void VerifyMaybeObjectField(Isolate* isolate, int offset);
// Verify a pointer is a valid HeapObject pointer that points to object
// areas in the heap.
static void VerifyHeapPointer(Isolate* isolate, Object* p);
#endif
static inline AllocationAlignment RequiredAlignment(Map* map);
// Whether the object needs rehashing. That is the case if the object's
// content depends on FLAG_hash_seed. When the object is deserialized into
// a heap with a different hash seed, these objects need to adapt.
inline bool NeedsRehashing() const;
// Rehashing support is not implemented for all objects that need rehashing.
// With objects that need rehashing but cannot be rehashed, rehashing has to
// be disabled.
bool CanBeRehashed() const;
// Rehash the object based on the layout inferred from its map.
void RehashBasedOnMap(Isolate* isolate);
// Layout description.
// First field in a heap object is map.
static const int kMapOffset = Object::kHeaderSize;
static const int kHeaderSize = kMapOffset + kPointerSize;
STATIC_ASSERT(kMapOffset == Internals::kHeapObjectMapOffset);
inline Address GetFieldAddress(int field_offset) const;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject);
};
// Mixin class for objects that can never be in RO space.
// TODO(leszeks): Add checks in the factory that we never allocate these objects
// in RO space.
class NeverReadOnlySpaceObject {
public:
// The Heap the object was allocated in. Used also to access Isolate.
inline Heap* GetHeap() const;
// Convenience method to get current isolate.
inline Isolate* GetIsolate() const;
};
template <int start_offset, int end_offset, int size>
class FixedBodyDescriptor;
template <int start_offset>
class FlexibleBodyDescriptor;
template <class ParentBodyDescriptor, class ChildBodyDescriptor>
class SubclassBodyDescriptor;
// The HeapNumber class describes heap allocated numbers that cannot be
// represented in a Smi (small integer). MutableHeapNumber is the same, but its
// number value can change over time (it is used only as property storage).
// HeapNumberBase merely exists to avoid code duplication.
class HeapNumberBase : public HeapObject {
public:
// [value]: number value.
inline double value() const;
inline void set_value(double value);
inline uint64_t value_as_bits() const;
inline void set_value_as_bits(uint64_t bits);
inline int get_exponent();
inline int get_sign();
// Layout description.
static const int kValueOffset = HeapObject::kHeaderSize;
// IEEE doubles are two 32 bit words. The first is just mantissa, the second
// is a mixture of sign, exponent and mantissa. The offsets of two 32 bit
// words within double numbers are endian dependent and they are set
// accordingly.
#if defined(V8_TARGET_LITTLE_ENDIAN)
static const int kMantissaOffset = kValueOffset;
static const int kExponentOffset = kValueOffset + 4;
#elif defined(V8_TARGET_BIG_ENDIAN)
static const int kMantissaOffset = kValueOffset + 4;
static const int kExponentOffset = kValueOffset;
#else
#error Unknown byte ordering
#endif
static const int kSize = kValueOffset + kDoubleSize;
static const uint32_t kSignMask = 0x80000000u;
static const uint32_t kExponentMask = 0x7ff00000u;
static const uint32_t kMantissaMask = 0xfffffu;
static const int kMantissaBits = 52;
static const int kExponentBits = 11;
static const int kExponentBias = 1023;
static const int kExponentShift = 20;
static const int kInfinityOrNanExponent =
(kExponentMask >> kExponentShift) - kExponentBias;
static const int kMantissaBitsInTopWord = 20;
static const int kNonMantissaBitsInTopWord = 12;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumberBase)
};
class HeapNumber : public HeapNumberBase {
public:
DECL_CAST(HeapNumber)
V8_EXPORT_PRIVATE void HeapNumberPrint(std::ostream& os);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber)
};
class MutableHeapNumber : public HeapNumberBase {
public:
DECL_CAST(MutableHeapNumber)
V8_EXPORT_PRIVATE void MutableHeapNumberPrint(std::ostream& os);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(MutableHeapNumber)
};
enum EnsureElementsMode {
DONT_ALLOW_DOUBLE_ELEMENTS,
ALLOW_COPIED_DOUBLE_ELEMENTS,
ALLOW_CONVERTED_DOUBLE_ELEMENTS
};
// Indicator for one component of an AccessorPair.
enum AccessorComponent {
ACCESSOR_GETTER,
ACCESSOR_SETTER
};
enum class GetKeysConversion {
kKeepNumbers = static_cast<int>(v8::KeyConversionMode::kKeepNumbers),
kConvertToString = static_cast<int>(v8::KeyConversionMode::kConvertToString)
};
enum class KeyCollectionMode {
kOwnOnly = static_cast<int>(v8::KeyCollectionMode::kOwnOnly),
kIncludePrototypes =
static_cast<int>(v8::KeyCollectionMode::kIncludePrototypes)
};
// FreeSpace are fixed-size free memory blocks used by the heap and GC.
// They look like heap objects (are heap object tagged and have a map) so that
// the heap remains iterable. They have a size and a next pointer.
// The next pointer is the raw address of the next FreeSpace object (or NULL)
// in the free list.
class FreeSpace: public HeapObject {
public:
// [size]: size of the free space including the header.
inline int size() const;
inline void set_size(int value);
inline int relaxed_read_size() const;
inline void relaxed_write_size(int value);
inline int Size();
// Accessors for the next field.
inline FreeSpace* next();
inline void set_next(FreeSpace* next);
inline static FreeSpace* cast(HeapObject* obj);
// Dispatched behavior.
DECL_PRINTER(FreeSpace)
DECL_VERIFIER(FreeSpace)
// Layout description.
// Size is smi tagged when it is stored.
static const int kSizeOffset = HeapObject::kHeaderSize;
static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize);
static const int kSize = kNextOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
};
class PrototypeInfo;
// An abstract superclass, a marker class really, for simple structure classes.
// It doesn't carry much functionality but allows struct classes to be
// identified in the type system.
class Struct: public HeapObject {
public:
inline void InitializeBody(int object_size);
DECL_CAST(Struct)
void BriefPrintDetails(std::ostream& os);
};
class Tuple2 : public Struct {
public:
DECL_ACCESSORS(value1, Object)
DECL_ACCESSORS(value2, Object)
DECL_CAST(Tuple2)
// Dispatched behavior.
DECL_PRINTER(Tuple2)
DECL_VERIFIER(Tuple2)
void BriefPrintDetails(std::ostream& os);
static const int kValue1Offset = HeapObject::kHeaderSize;
static const int kValue2Offset = kValue1Offset + kPointerSize;
static const int kSize = kValue2Offset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple2);
};
class Tuple3 : public Tuple2 {
public:
DECL_ACCESSORS(value3, Object)
DECL_CAST(Tuple3)
// Dispatched behavior.
DECL_PRINTER(Tuple3)
DECL_VERIFIER(Tuple3)
void BriefPrintDetails(std::ostream& os);
static const int kValue3Offset = Tuple2::kSize;
static const int kSize = kValue3Offset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple3);
};
class AsyncGeneratorRequest : public Struct {
public:
// Holds an AsyncGeneratorRequest, or Undefined.
DECL_ACCESSORS(next, Object)
DECL_INT_ACCESSORS(resume_mode)
DECL_ACCESSORS(value, Object)
DECL_ACCESSORS(promise, Object)
static const int kNextOffset = Struct::kHeaderSize;
static const int kResumeModeOffset = kNextOffset + kPointerSize;
static const int kValueOffset = kResumeModeOffset + kPointerSize;
static const int kPromiseOffset = kValueOffset + kPointerSize;
static const int kSize = kPromiseOffset + kPointerSize;
DECL_CAST(AsyncGeneratorRequest)
DECL_PRINTER(AsyncGeneratorRequest)
DECL_VERIFIER(AsyncGeneratorRequest)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(AsyncGeneratorRequest);
};
// Utility superclass for stack-allocated objects that must be updated
// on gc. It provides two ways for the gc to update instances, either
// iterating or updating after gc.
class Relocatable {
public:
explicit inline Relocatable(Isolate* isolate);
inline virtual ~Relocatable();
virtual void IterateInstance(RootVisitor* v) {}
virtual void PostGarbageCollection() { }
static void PostGarbageCollectionProcessing(Isolate* isolate);
static int ArchiveSpacePerThread();
static char* ArchiveState(Isolate* isolate, char* to);
static char* RestoreState(Isolate* isolate, char* from);
static void Iterate(Isolate* isolate, RootVisitor* v);
static void Iterate(RootVisitor* v, Relocatable* top);
static char* Iterate(RootVisitor* v, char* t);
private:
Isolate* isolate_;
Relocatable* prev_;
};
// The Oddball describes objects null, undefined, true, and false.
class Oddball: public HeapObject {
public:
// [to_number_raw]: Cached raw to_number computed at startup.
inline double to_number_raw() const;
inline void set_to_number_raw(double value);
inline void set_to_number_raw_as_bits(uint64_t bits);
// [to_string]: Cached to_string computed at startup.
DECL_ACCESSORS(to_string, String)
// [to_number]: Cached to_number computed at startup.
DECL_ACCESSORS(to_number, Object)
// [typeof]: Cached type_of computed at startup.
DECL_ACCESSORS(type_of, String)
inline byte kind() const;
inline void set_kind(byte kind);
// ES6 section 7.1.3 ToNumber for Boolean, Null, Undefined.
V8_WARN_UNUSED_RESULT static inline Handle<Object> ToNumber(
Isolate* isolate, Handle<Oddball> input);
DECL_CAST(Oddball)
// Dispatched behavior.
DECL_VERIFIER(Oddball)
// Initialize the fields.
static void Initialize(Isolate* isolate, Handle<Oddball> oddball,
const char* to_string, Handle<Object> to_number,
const char* type_of, byte kind);
// Layout description.
static const int kToNumberRawOffset = HeapObject::kHeaderSize;
static const int kToStringOffset = kToNumberRawOffset + kDoubleSize;
static const int kToNumberOffset = kToStringOffset + kPointerSize;
static const int kTypeOfOffset = kToNumberOffset + kPointerSize;
static const int kKindOffset = kTypeOfOffset + kPointerSize;
static const int kSize = kKindOffset + kPointerSize;
static const byte kFalse = 0;
static const byte kTrue = 1;
static const byte kNotBooleanMask = static_cast<byte>(~1);
static const byte kTheHole = 2;
static const byte kNull = 3;
static const byte kArgumentsMarker = 4;
static const byte kUndefined = 5;
static const byte kUninitialized = 6;
static const byte kOther = 7;
static const byte kException = 8;
static const byte kOptimizedOut = 9;
static const byte kStaleRegister = 10;
static const byte kSelfReferenceMarker = 10;
typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize,
kSize> BodyDescriptor;
STATIC_ASSERT(kToNumberRawOffset == HeapNumber::kValueOffset);
STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
STATIC_ASSERT(kNull == Internals::kNullOddballKind);
STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
};
class Cell: public HeapObject {
public:
// [value]: value of the cell.
DECL_ACCESSORS(value, Object)
DECL_CAST(Cell)
static inline Cell* FromValueAddress(Address value) {
Object* result = FromAddress(value - kValueOffset);
return static_cast<Cell*>(result);
}
inline Address ValueAddress() {
return address() + kValueOffset;
}
// Dispatched behavior.
DECL_PRINTER(Cell)
DECL_VERIFIER(Cell)
// Layout description.
static const int kValueOffset = HeapObject::kHeaderSize;
static const int kSize = kValueOffset + kPointerSize;
typedef FixedBodyDescriptor<kValueOffset,
kValueOffset + kPointerSize,
kSize> BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
};
// This is a special cell used to maintain both the link between a
// closure and it's feedback vector, as well as a way to count the
// number of closures created for a certain function per native
// context. There's at most one FeedbackCell for each function in
// a native context.
class FeedbackCell : public Struct {
public:
// [value]: value of the cell.
DECL_ACCESSORS(value, HeapObject)
DECL_CAST(FeedbackCell)
// Dispatched behavior.
DECL_PRINTER(FeedbackCell)
DECL_VERIFIER(FeedbackCell)
static const int kValueOffset = HeapObject::kHeaderSize;
static const int kSize = kValueOffset + kPointerSize;
typedef FixedBodyDescriptor<kValueOffset, kValueOffset + kPointerSize, kSize>
BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FeedbackCell);
};
class PropertyCell : public HeapObject {
public:
// [name]: the name of the global property.
DECL_ACCESSORS(name, Name)
// [property_details]: details of the global property.
DECL_ACCESSORS(property_details_raw, Object)
// [value]: value of the global property.
DECL_ACCESSORS(value, Object)
// [dependent_code]: dependent code that depends on the type of the global
// property.
DECL_ACCESSORS(dependent_code, DependentCode)
inline PropertyDetails property_details() const;
inline void set_property_details(PropertyDetails details);
PropertyCellConstantType GetConstantType();
// Computes the new type of the cell's contents for the given value, but
// without actually modifying the details.
static PropertyCellType UpdatedType(Isolate* isolate,
Handle<PropertyCell> cell,
Handle<Object> value,
PropertyDetails details);
// Prepares property cell at given entry for receiving given value.
// As a result the old cell could be invalidated and/or dependent code could
// be deoptimized. Returns the prepared property cell.
static Handle<PropertyCell> PrepareForValue(
Isolate* isolate, Handle<GlobalDictionary> dictionary, int entry,
Handle<Object> value, PropertyDetails details);
static Handle<PropertyCell> InvalidateEntry(
Isolate* isolate, Handle<GlobalDictionary> dictionary, int entry);
static void SetValueWithInvalidation(Isolate* isolate,
Handle<PropertyCell> cell,
Handle<Object> new_value);
DECL_CAST(PropertyCell)
// Dispatched behavior.
DECL_PRINTER(PropertyCell)
DECL_VERIFIER(PropertyCell)
// Layout description.
static const int kDetailsOffset = HeapObject::kHeaderSize;
static const int kNameOffset = kDetailsOffset + kPointerSize;
static const int kValueOffset = kNameOffset + kPointerSize;
static const int kDependentCodeOffset = kValueOffset + kPointerSize;
static const int kSize = kDependentCodeOffset + kPointerSize;
typedef FixedBodyDescriptor<kNameOffset, kSize, kSize> BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
};
// Foreign describes objects pointing from JavaScript to C structures.
class Foreign: public HeapObject {
public:
// [address]: field containing the address.
inline Address foreign_address();
static inline bool IsNormalized(Object* object);
DECL_CAST(Foreign)
// Dispatched behavior.
DECL_PRINTER(Foreign)
DECL_VERIFIER(Foreign)
// Layout description.
static const int kForeignAddressOffset = HeapObject::kHeaderSize;
static const int kSize = kForeignAddressOffset + kPointerSize;
STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
class BodyDescriptor;
private:
friend class Factory;
friend class SerializerDeserializer;
friend class StartupSerializer;
inline void set_foreign_address(Address value);
DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
};
// Support for JavaScript accessors: A pair of a getter and a setter. Each
// accessor can either be
// * a JavaScript function or proxy: a real accessor
// * a FunctionTemplateInfo: a real (lazy) accessor
// * undefined: considered an accessor by the spec, too, strangely enough
// * null: an accessor which has not been set
class AccessorPair: public Struct {
public:
DECL_ACCESSORS(getter, Object)
DECL_ACCESSORS(setter, Object)
DECL_CAST(AccessorPair)
static Handle<AccessorPair> Copy(Isolate* isolate, Handle<AccessorPair> pair);
inline Object* get(AccessorComponent component);
inline void set(AccessorComponent component, Object* value);
// Note: Returns undefined if the component is not set.
static Handle<Object> GetComponent(Isolate* isolate,
Handle<AccessorPair> accessor_pair,
AccessorComponent component);
// Set both components, skipping arguments which are a JavaScript null.
inline void SetComponents(Object* getter, Object* setter);
inline bool Equals(AccessorPair* pair);
inline bool Equals(Object* getter_value, Object* setter_value);
inline bool ContainsAccessor();
// Dispatched behavior.
DECL_PRINTER(AccessorPair)
DECL_VERIFIER(AccessorPair)
static const int kGetterOffset = HeapObject::kHeaderSize;
static const int kSetterOffset = kGetterOffset + kPointerSize;
static const int kSize = kSetterOffset + kPointerSize;
private:
// Strangely enough, in addition to functions and harmony proxies, the spec
// requires us to consider undefined as a kind of accessor, too:
// var obj = {};
// Object.defineProperty(obj, "foo", {get: undefined});
// assertTrue("foo" in obj);
inline bool IsJSAccessor(Object* obj);
DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
};
// BooleanBit is a helper class for setting and getting a bit in an integer.
class BooleanBit : public AllStatic {
public:
static inline bool get(int value, int bit_position) {
return (value & (1 << bit_position)) != 0;
}
static inline int set(int value, int bit_position, bool v) {
if (v) {
value |= (1 << bit_position);
} else {
value &= ~(1 << bit_position);
}
return value;
}
};
} // NOLINT, false-positive due to second-order macros.
} // NOLINT, false-positive due to second-order macros.
#include "src/objects/object-macros-undef.h"
#endif // V8_OBJECTS_H_