// 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 "src/allocation.h"
#include "src/assert-scope.h"
#include "src/bailout-reason.h"
#include "src/base/bits.h"
#include "src/base/flags.h"
#include "src/base/smart-pointers.h"
#include "src/builtins.h"
#include "src/checks.h"
#include "src/elements-kind.h"
#include "src/field-index.h"
#include "src/flags.h"
#include "src/list.h"
#include "src/property-details.h"
#include "src/unicode.h"
#include "src/unicode-decoder.h"
#include "src/zone.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
#endif
//
// 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
// - JSSetIterator
// - JSMapIterator
// - JSWeakCollection
// - JSWeakMap
// - JSWeakSet
// - JSRegExp
// - JSFunction
// - JSGeneratorObject
// - JSModule
// - JSGlobalObject
// - JSGlobalProxy
// - JSValue
// - JSDate
// - JSMessageObject
// - JSProxy
// - FixedArrayBase
// - ByteArray
// - BytecodeArray
// - FixedArray
// - DescriptorArray
// - LiteralsArray
// - HashTable
// - Dictionary
// - StringTable
// - CompilationCacheTable
// - CodeCacheHashTable
// - MapCache
// - OrderedHashTable
// - OrderedHashSet
// - OrderedHashMap
// - Context
// - TypeFeedbackMetadata
// - TypeFeedbackVector
// - ScopeInfo
// - TransitionArray
// - ScriptContextTable
// - WeakFixedArray
// - FixedDoubleArray
// - Name
// - String
// - SeqString
// - SeqOneByteString
// - SeqTwoByteString
// - SlicedString
// - ConsString
// - ExternalString
// - ExternalOneByteString
// - ExternalTwoByteString
// - InternalizedString
// - SeqInternalizedString
// - SeqOneByteInternalizedString
// - SeqTwoByteInternalizedString
// - ConsInternalizedString
// - ExternalInternalizedString
// - ExternalOneByteInternalizedString
// - ExternalTwoByteInternalizedString
// - Symbol
// - HeapNumber
// - Simd128Value
// - Float32x4
// - Int32x4
// - Uint32x4
// - Bool32x4
// - Int16x8
// - Uint16x8
// - Bool16x8
// - Int8x16
// - Uint8x16
// - Bool8x16
// - Cell
// - PropertyCell
// - Code
// - Map
// - Oddball
// - Foreign
// - SharedFunctionInfo
// - Struct
// - Box
// - AccessorInfo
// - ExecutableAccessorInfo
// - AccessorPair
// - AccessCheckInfo
// - InterceptorInfo
// - CallHandlerInfo
// - TemplateInfo
// - FunctionTemplateInfo
// - ObjectTemplateInfo
// - Script
// - DebugInfo
// - BreakPointInfo
// - CodeCache
// - PrototypeInfo
// - WeakCell
//
// Formats of Object*:
// Smi: [31 bit signed int] 0
// HeapObject: [32 bit direct pointer] (4 byte aligned) | 01
namespace v8 {
namespace internal {
enum KeyedAccessStoreMode {
STANDARD_STORE,
STORE_TRANSITION_TO_OBJECT,
STORE_TRANSITION_TO_DOUBLE,
STORE_AND_GROW_NO_TRANSITION,
STORE_AND_GROW_TRANSITION_TO_OBJECT,
STORE_AND_GROW_TRANSITION_TO_DOUBLE,
STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS,
STORE_NO_TRANSITION_HANDLE_COW
};
// Valid hints for the abstract operation ToPrimitive,
// implemented according to ES6, section 7.1.1.
enum class ToPrimitiveHint { kDefault, kNumber, kString };
// Valid hints for the abstract operation OrdinaryToPrimitive,
// implemented according to ES6, section 7.1.1.
enum class OrdinaryToPrimitiveHint { kNumber, kString };
enum TypeofMode : int { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
enum MutableMode {
MUTABLE,
IMMUTABLE
};
enum ExternalArrayType {
kExternalInt8Array = 1,
kExternalUint8Array,
kExternalInt16Array,
kExternalUint16Array,
kExternalInt32Array,
kExternalUint32Array,
kExternalFloat32Array,
kExternalFloat64Array,
kExternalUint8ClampedArray,
};
static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) {
return store_mode == STORE_TRANSITION_TO_OBJECT ||
store_mode == STORE_TRANSITION_TO_DOUBLE ||
store_mode == STORE_AND_GROW_TRANSITION_TO_OBJECT ||
store_mode == STORE_AND_GROW_TRANSITION_TO_DOUBLE;
}
static inline KeyedAccessStoreMode GetNonTransitioningStoreMode(
KeyedAccessStoreMode store_mode) {
if (store_mode >= STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
return store_mode;
}
if (store_mode >= STORE_AND_GROW_NO_TRANSITION) {
return STORE_AND_GROW_NO_TRANSITION;
}
return STANDARD_STORE;
}
static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
return store_mode >= STORE_AND_GROW_NO_TRANSITION &&
store_mode <= STORE_AND_GROW_TRANSITION_TO_DOUBLE;
}
enum IcCheckType { ELEMENT, PROPERTY };
// 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
};
// Indicates whether a value can be loaded as a constant.
enum StoreMode { ALLOW_IN_DESCRIPTOR, FORCE_FIELD };
// 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 how aggressively the prototype should be optimized. FAST_PROTOTYPE
// will give the fastest result by tailoring the map to the prototype, but that
// will cause polymorphism with other objects. REGULAR_PROTOTYPE is to be used
// (at least for now) when dynamically modifying the prototype chain of an
// object using __proto__ or Object.setPrototypeOf.
enum PrototypeOptimizationMode { REGULAR_PROTOTYPE, FAST_PROTOTYPE };
// 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
};
// The GC maintains a bit of information, the MarkingParity, which toggles
// from odd to even and back every time marking is completed. Incremental
// marking can visit an object twice during a marking phase, so algorithms that
// that piggy-back on marking can use the parity to ensure that they only
// perform an operation on an object once per marking phase: they record the
// MarkingParity when they visit an object, and only re-visit the object when it
// is marked again and the MarkingParity changes.
enum MarkingParity {
NO_MARKING_PARITY,
ODD_MARKING_PARITY,
EVEN_MARKING_PARITY
};
// ICs store extra state in a Code object. The default extra state is
// kNoExtraICState.
typedef int ExtraICState;
static const ExtraICState kNoExtraICState = 0;
// 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 = 7;
const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
// All Maps have a field instance_type containing a InstanceType.
// It describes the type of the instances.
//
// As an example, a JavaScript object is a heap object and its map
// instance_type is JS_OBJECT_TYPE.
//
// The names of the string instance types are intended to systematically
// mirror their encoding in the instance_type field of the map. The default
// encoding is considered TWO_BYTE. It is not mentioned in the name. ONE_BYTE
// encoding is mentioned explicitly in the name. Likewise, the default
// representation is considered sequential. It is not mentioned in the
// name. The other representations (e.g. CONS, EXTERNAL) are explicitly
// mentioned. Finally, the string is either a STRING_TYPE (if it is a normal
// string) or a INTERNALIZED_STRING_TYPE (if it is a internalized string).
//
// NOTE: The following things are some that depend on the string types having
// instance_types that are less than those of all other types:
// HeapObject::Size, HeapObject::IterateBody, the typeof operator, and
// Object::IsString.
//
// NOTE: Everything following JS_VALUE_TYPE is considered a
// JSObject for GC purposes. The first four entries here have typeof
// 'object', whereas JS_FUNCTION_TYPE has typeof 'function'.
#define INSTANCE_TYPE_LIST(V) \
V(STRING_TYPE) \
V(ONE_BYTE_STRING_TYPE) \
V(CONS_STRING_TYPE) \
V(CONS_ONE_BYTE_STRING_TYPE) \
V(SLICED_STRING_TYPE) \
V(SLICED_ONE_BYTE_STRING_TYPE) \
V(EXTERNAL_STRING_TYPE) \
V(EXTERNAL_ONE_BYTE_STRING_TYPE) \
V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
V(SHORT_EXTERNAL_STRING_TYPE) \
V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE) \
V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \
\
V(INTERNALIZED_STRING_TYPE) \
V(ONE_BYTE_INTERNALIZED_STRING_TYPE) \
V(EXTERNAL_INTERNALIZED_STRING_TYPE) \
V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE) \
V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \
V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
\
V(SYMBOL_TYPE) \
V(SIMD128_VALUE_TYPE) \
\
V(MAP_TYPE) \
V(CODE_TYPE) \
V(ODDBALL_TYPE) \
V(CELL_TYPE) \
V(PROPERTY_CELL_TYPE) \
\
V(HEAP_NUMBER_TYPE) \
V(MUTABLE_HEAP_NUMBER_TYPE) \
V(FOREIGN_TYPE) \
V(BYTE_ARRAY_TYPE) \
V(BYTECODE_ARRAY_TYPE) \
V(FREE_SPACE_TYPE) \
\
V(FIXED_INT8_ARRAY_TYPE) \
V(FIXED_UINT8_ARRAY_TYPE) \
V(FIXED_INT16_ARRAY_TYPE) \
V(FIXED_UINT16_ARRAY_TYPE) \
V(FIXED_INT32_ARRAY_TYPE) \
V(FIXED_UINT32_ARRAY_TYPE) \
V(FIXED_FLOAT32_ARRAY_TYPE) \
V(FIXED_FLOAT64_ARRAY_TYPE) \
V(FIXED_UINT8_CLAMPED_ARRAY_TYPE) \
\
V(FILLER_TYPE) \
\
V(DECLARED_ACCESSOR_DESCRIPTOR_TYPE) \
V(DECLARED_ACCESSOR_INFO_TYPE) \
V(EXECUTABLE_ACCESSOR_INFO_TYPE) \
V(ACCESSOR_PAIR_TYPE) \
V(ACCESS_CHECK_INFO_TYPE) \
V(INTERCEPTOR_INFO_TYPE) \
V(CALL_HANDLER_INFO_TYPE) \
V(FUNCTION_TEMPLATE_INFO_TYPE) \
V(OBJECT_TEMPLATE_INFO_TYPE) \
V(SIGNATURE_INFO_TYPE) \
V(TYPE_SWITCH_INFO_TYPE) \
V(ALLOCATION_MEMENTO_TYPE) \
V(ALLOCATION_SITE_TYPE) \
V(SCRIPT_TYPE) \
V(CODE_CACHE_TYPE) \
V(POLYMORPHIC_CODE_CACHE_TYPE) \
V(TYPE_FEEDBACK_INFO_TYPE) \
V(ALIASED_ARGUMENTS_ENTRY_TYPE) \
V(BOX_TYPE) \
V(PROTOTYPE_INFO_TYPE) \
V(SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION_TYPE) \
\
V(FIXED_ARRAY_TYPE) \
V(FIXED_DOUBLE_ARRAY_TYPE) \
V(SHARED_FUNCTION_INFO_TYPE) \
V(WEAK_CELL_TYPE) \
V(TRANSITION_ARRAY_TYPE) \
\
V(JS_MESSAGE_OBJECT_TYPE) \
\
V(JS_VALUE_TYPE) \
V(JS_DATE_TYPE) \
V(JS_OBJECT_TYPE) \
V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \
V(JS_GENERATOR_OBJECT_TYPE) \
V(JS_MODULE_TYPE) \
V(JS_GLOBAL_OBJECT_TYPE) \
V(JS_GLOBAL_PROXY_TYPE) \
V(JS_ARRAY_TYPE) \
V(JS_ARRAY_BUFFER_TYPE) \
V(JS_TYPED_ARRAY_TYPE) \
V(JS_DATA_VIEW_TYPE) \
V(JS_PROXY_TYPE) \
V(JS_SET_TYPE) \
V(JS_MAP_TYPE) \
V(JS_SET_ITERATOR_TYPE) \
V(JS_MAP_ITERATOR_TYPE) \
V(JS_ITERATOR_RESULT_TYPE) \
V(JS_WEAK_MAP_TYPE) \
V(JS_WEAK_SET_TYPE) \
V(JS_PROMISE_TYPE) \
V(JS_REGEXP_TYPE) \
\
V(JS_BOUND_FUNCTION_TYPE) \
V(JS_FUNCTION_TYPE) \
V(DEBUG_INFO_TYPE) \
V(BREAK_POINT_INFO_TYPE)
// Since string types are not consecutive, this macro is used to
// iterate over them.
#define STRING_TYPE_LIST(V) \
V(STRING_TYPE, kVariableSizeSentinel, string, String) \
V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string, \
OneByteString) \
V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString) \
V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string, \
ConsOneByteString) \
V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString) \
V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string, \
SlicedOneByteString) \
V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string, \
ExternalString) \
V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize, \
external_one_byte_string, ExternalOneByteString) \
V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize, \
external_string_with_one_byte_data, ExternalStringWithOneByteData) \
V(SHORT_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kShortSize, \
short_external_string, ShortExternalString) \
V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kShortSize, \
short_external_one_byte_string, ShortExternalOneByteString) \
V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, \
ExternalTwoByteString::kShortSize, \
short_external_string_with_one_byte_data, \
ShortExternalStringWithOneByteData) \
\
V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string, \
InternalizedString) \
V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, \
one_byte_internalized_string, OneByteInternalizedString) \
V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize, \
external_internalized_string, ExternalInternalizedString) \
V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize, \
external_one_byte_internalized_string, ExternalOneByteInternalizedString) \
V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
ExternalTwoByteString::kSize, \
external_internalized_string_with_one_byte_data, \
ExternalInternalizedStringWithOneByteData) \
V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE, \
ExternalTwoByteString::kShortSize, short_external_internalized_string, \
ShortExternalInternalizedString) \
V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, \
ExternalOneByteString::kShortSize, \
short_external_one_byte_internalized_string, \
ShortExternalOneByteInternalizedString) \
V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \
ExternalTwoByteString::kShortSize, \
short_external_internalized_string_with_one_byte_data, \
ShortExternalInternalizedStringWithOneByteData)
// A struct is a simple object a set of object-valued fields. Including an
// object type in this causes the compiler to generate most of the boilerplate
// code for the class including allocation and garbage collection routines,
// casts and predicates. All you need to define is the class, methods and
// object verification routines. Easy, no?
//
// Note that for subtle reasons related to the ordering or numerical values of
// type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST
// manually.
#define STRUCT_LIST(V) \
V(BOX, Box, box) \
V(EXECUTABLE_ACCESSOR_INFO, ExecutableAccessorInfo, \
executable_accessor_info) \
V(ACCESSOR_PAIR, AccessorPair, accessor_pair) \
V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \
V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \
V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \
V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \
V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \
V(SCRIPT, Script, script) \
V(ALLOCATION_SITE, AllocationSite, allocation_site) \
V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento) \
V(CODE_CACHE, CodeCache, code_cache) \
V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) \
V(TYPE_FEEDBACK_INFO, TypeFeedbackInfo, type_feedback_info) \
V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \
V(DEBUG_INFO, DebugInfo, debug_info) \
V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) \
V(PROTOTYPE_INFO, PrototypeInfo, prototype_info) \
V(SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION, \
SloppyBlockWithEvalContextExtension, \
sloppy_block_with_eval_context_extension)
// We use the full 8 bits of the instance_type field to encode heap object
// instance types. The high-order bit (bit 7) is set if the object is not a
// string, and cleared if it is a string.
const uint32_t kIsNotStringMask = 0x80;
const uint32_t kStringTag = 0x0;
const uint32_t kNotStringTag = 0x80;
// 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 2 indicates whether the string consists of
// two-byte characters or one-byte characters.
const uint32_t kStringEncodingMask = 0x4;
const uint32_t kTwoByteStringTag = 0x0;
const uint32_t kOneByteStringTag = 0x4;
// If bit 7 is clear, the low-order 2 bits indicate the representation
// of the string.
const uint32_t kStringRepresentationMask = 0x03;
enum StringRepresentationTag {
kSeqStringTag = 0x0,
kConsStringTag = 0x1,
kExternalStringTag = 0x2,
kSlicedStringTag = 0x3
};
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
// Use this mask to distinguish between cons and slice only after making
// sure that the string is one of the two (an indirect string).
const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag;
STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask));
// If bit 7 is clear, then bit 3 indicates whether this two-byte
// string actually contains one byte data.
const uint32_t kOneByteDataHintMask = 0x08;
const uint32_t kOneByteDataHintTag = 0x08;
// If bit 7 is clear and string representation indicates an external string,
// then bit 4 indicates whether the data pointer is cached.
const uint32_t kShortExternalStringMask = 0x10;
const uint32_t kShortExternalStringTag = 0x10;
// 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 {
// 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,
SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE |
kShortExternalStringTag |
kInternalizedTag,
SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kShortExternalStringTag |
kInternalizedTag,
SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
kShortExternalStringTag | 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,
SHORT_EXTERNAL_STRING_TYPE =
SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE =
SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
kNotInternalizedTag,
// Non-string names
SYMBOL_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE
// Other primitives (cannot contain non-map-word pointers to heap objects).
HEAP_NUMBER_TYPE,
SIMD128_VALUE_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, // LAST_FIXED_TYPED_ARRAY_TYPE
FIXED_DOUBLE_ARRAY_TYPE,
FILLER_TYPE, // LAST_DATA_TYPE
// Structs.
DECLARED_ACCESSOR_DESCRIPTOR_TYPE,
DECLARED_ACCESSOR_INFO_TYPE,
EXECUTABLE_ACCESSOR_INFO_TYPE,
ACCESSOR_PAIR_TYPE,
ACCESS_CHECK_INFO_TYPE,
INTERCEPTOR_INFO_TYPE,
CALL_HANDLER_INFO_TYPE,
FUNCTION_TEMPLATE_INFO_TYPE,
OBJECT_TEMPLATE_INFO_TYPE,
SIGNATURE_INFO_TYPE,
TYPE_SWITCH_INFO_TYPE,
ALLOCATION_SITE_TYPE,
ALLOCATION_MEMENTO_TYPE,
SCRIPT_TYPE,
CODE_CACHE_TYPE,
POLYMORPHIC_CODE_CACHE_TYPE,
TYPE_FEEDBACK_INFO_TYPE,
ALIASED_ARGUMENTS_ENTRY_TYPE,
BOX_TYPE,
DEBUG_INFO_TYPE,
BREAK_POINT_INFO_TYPE,
FIXED_ARRAY_TYPE,
SHARED_FUNCTION_INFO_TYPE,
CELL_TYPE,
WEAK_CELL_TYPE,
TRANSITION_ARRAY_TYPE,
PROPERTY_CELL_TYPE,
PROTOTYPE_INFO_TYPE,
SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION_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.
JS_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE
JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE
JS_MESSAGE_OBJECT_TYPE,
JS_DATE_TYPE,
JS_OBJECT_TYPE,
JS_CONTEXT_EXTENSION_OBJECT_TYPE,
JS_GENERATOR_OBJECT_TYPE,
JS_MODULE_TYPE,
JS_GLOBAL_OBJECT_TYPE,
JS_GLOBAL_PROXY_TYPE,
JS_ARRAY_TYPE,
JS_ARRAY_BUFFER_TYPE,
JS_TYPED_ARRAY_TYPE,
JS_DATA_VIEW_TYPE,
JS_SET_TYPE,
JS_MAP_TYPE,
JS_SET_ITERATOR_TYPE,
JS_MAP_ITERATOR_TYPE,
JS_ITERATOR_RESULT_TYPE,
JS_WEAK_MAP_TYPE,
JS_WEAK_SET_TYPE,
JS_PROMISE_TYPE,
JS_REGEXP_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 for a fixed typed array.
FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE,
LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_UINT8_CLAMPED_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_VALUE_TYPE,
LAST_JS_OBJECT_TYPE = LAST_TYPE,
};
STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType);
STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType);
STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType);
std::ostream& operator<<(std::ostream& os, InstanceType instance_type);
#define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
V(FAST_ELEMENTS_SUB_TYPE) \
V(DICTIONARY_ELEMENTS_SUB_TYPE) \
V(FAST_PROPERTIES_SUB_TYPE) \
V(DICTIONARY_PROPERTIES_SUB_TYPE) \
V(MAP_CODE_CACHE_SUB_TYPE) \
V(SCOPE_INFO_SUB_TYPE) \
V(STRING_TABLE_SUB_TYPE) \
V(DESCRIPTOR_ARRAY_SUB_TYPE)
enum FixedArraySubInstanceType {
#define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
#undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
LAST_FIXED_ARRAY_SUB_TYPE = DESCRIPTOR_ARRAY_SUB_TYPE
};
// TODO(bmeurer): Remove this in favor of the ComparisonResult below.
enum CompareResult {
LESS = -1,
EQUAL = 0,
GREATER = 1,
NOT_EQUAL = GREATER
};
// 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
};
#define DECL_BOOLEAN_ACCESSORS(name) \
inline bool name() const; \
inline void set_##name(bool value);
#define DECL_INT_ACCESSORS(name) \
inline int name() const; \
inline void set_##name(int value);
#define DECL_ACCESSORS(name, type) \
inline type* name() const; \
inline void set_##name(type* value, \
WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \
#define DECLARE_CAST(type) \
INLINE(static type* cast(Object* object)); \
INLINE(static const type* cast(const Object* object));
class AccessorPair;
class AllocationSite;
class AllocationSiteCreationContext;
class AllocationSiteUsageContext;
class Cell;
class ConsString;
class ElementsAccessor;
class FixedArrayBase;
class FunctionLiteral;
class JSGlobalObject;
class KeyAccumulator;
class LayoutDescriptor;
class LiteralsArray;
class LookupIterator;
class ObjectHashTable;
class ObjectVisitor;
class PropertyCell;
class PropertyDescriptor;
class SafepointEntry;
class SharedFunctionInfo;
class StringStream;
class TypeFeedbackInfo;
class TypeFeedbackVector;
class WeakCell;
class TransitionArray;
// We cannot just say "class HeapType;" if it is created from a template... =8-?
template<class> class TypeImpl;
struct HeapTypeConfig;
typedef TypeImpl<HeapTypeConfig> HeapType;
// A template-ized version of the IsXXX functions.
template <class C> inline bool Is(Object* obj);
#ifdef VERIFY_HEAP
#define DECLARE_VERIFIER(Name) void Name##Verify();
#else
#define DECLARE_VERIFIER(Name)
#endif
#ifdef OBJECT_PRINT
#define DECLARE_PRINTER(Name) void Name##Print(std::ostream& os); // NOLINT
#else
#define DECLARE_PRINTER(Name)
#endif
#define OBJECT_TYPE_LIST(V) \
V(Smi) \
V(HeapObject) \
V(Number)
#define HEAP_OBJECT_TYPE_LIST(V) \
V(HeapNumber) \
V(MutableHeapNumber) \
V(Simd128Value) \
V(Float32x4) \
V(Int32x4) \
V(Uint32x4) \
V(Bool32x4) \
V(Int16x8) \
V(Uint16x8) \
V(Bool16x8) \
V(Int8x16) \
V(Uint8x16) \
V(Bool8x16) \
V(Name) \
V(UniqueName) \
V(String) \
V(SeqString) \
V(ExternalString) \
V(ConsString) \
V(SlicedString) \
V(ExternalTwoByteString) \
V(ExternalOneByteString) \
V(SeqTwoByteString) \
V(SeqOneByteString) \
V(InternalizedString) \
V(Symbol) \
\
V(FixedTypedArrayBase) \
V(FixedUint8Array) \
V(FixedInt8Array) \
V(FixedUint16Array) \
V(FixedInt16Array) \
V(FixedUint32Array) \
V(FixedInt32Array) \
V(FixedFloat32Array) \
V(FixedFloat64Array) \
V(FixedUint8ClampedArray) \
V(ByteArray) \
V(BytecodeArray) \
V(FreeSpace) \
V(JSReceiver) \
V(JSObject) \
V(JSContextExtensionObject) \
V(JSGeneratorObject) \
V(JSModule) \
V(LayoutDescriptor) \
V(Map) \
V(DescriptorArray) \
V(TransitionArray) \
V(LiteralsArray) \
V(TypeFeedbackMetadata) \
V(TypeFeedbackVector) \
V(DeoptimizationInputData) \
V(DeoptimizationOutputData) \
V(DependentCode) \
V(HandlerTable) \
V(FixedArray) \
V(FixedDoubleArray) \
V(WeakFixedArray) \
V(ArrayList) \
V(Context) \
V(ScriptContextTable) \
V(NativeContext) \
V(ScopeInfo) \
V(JSBoundFunction) \
V(JSFunction) \
V(Code) \
V(Oddball) \
V(SharedFunctionInfo) \
V(JSValue) \
V(JSDate) \
V(JSMessageObject) \
V(StringWrapper) \
V(Foreign) \
V(Boolean) \
V(JSArray) \
V(JSArrayBuffer) \
V(JSArrayBufferView) \
V(JSTypedArray) \
V(JSDataView) \
V(JSProxy) \
V(JSSet) \
V(JSMap) \
V(JSSetIterator) \
V(JSMapIterator) \
V(JSIteratorResult) \
V(JSWeakCollection) \
V(JSWeakMap) \
V(JSWeakSet) \
V(JSRegExp) \
V(HashTable) \
V(Dictionary) \
V(StringTable) \
V(NormalizedMapCache) \
V(CompilationCacheTable) \
V(CodeCacheHashTable) \
V(PolymorphicCodeCacheHashTable) \
V(MapCache) \
V(Primitive) \
V(JSGlobalObject) \
V(JSGlobalProxy) \
V(UndetectableObject) \
V(AccessCheckNeeded) \
V(Cell) \
V(PropertyCell) \
V(WeakCell) \
V(ObjectHashTable) \
V(WeakHashTable) \
V(OrderedHashTable)
// 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; }
#define IS_TYPE_FUNCTION_DECL(type_) 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
// A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
// a keyed store is of the form a[expression] = foo.
enum StoreFromKeyed {
MAY_BE_STORE_FROM_KEYED,
CERTAINLY_NOT_STORE_FROM_KEYED
};
enum ShouldThrow { THROW_ON_ERROR, DONT_THROW };
#define RETURN_FAILURE(isolate, should_throw, call) \
do { \
if ((should_throw) == DONT_THROW) { \
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>())
INLINE(bool IsFixedArrayBase() const);
INLINE(bool IsExternal() const);
INLINE(bool IsAccessorInfo() const);
INLINE(bool IsStruct() const);
#define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \
INLINE(bool Is##Name() const);
STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
#undef DECLARE_STRUCT_PREDICATE
// ES6, section 7.2.2 IsArray. NOT to be confused with %_IsArray.
MUST_USE_RESULT static Maybe<bool> IsArray(Handle<Object> object);
// Test for JSBoundFunction or JSFunction.
INLINE(bool IsFunction() const);
// ES6, section 7.2.3 IsCallable.
INLINE(bool IsCallable() const);
// ES6, section 7.2.4 IsConstructor.
INLINE(bool IsConstructor() const);
INLINE(bool IsTemplateInfo()) const;
INLINE(bool IsNameDictionary() const);
INLINE(bool IsGlobalDictionary() const);
INLINE(bool IsSeededNumberDictionary() const);
INLINE(bool IsUnseededNumberDictionary() const);
INLINE(bool IsOrderedHashSet() const);
INLINE(bool IsOrderedHashMap() const);
static bool IsPromise(Handle<Object> object);
// Oddball testing.
INLINE(bool IsUndefined() const);
INLINE(bool IsNull() const);
INLINE(bool IsTheHole() const);
INLINE(bool IsException() const);
INLINE(bool IsUninitialized() const);
INLINE(bool IsTrue() const);
INLINE(bool IsFalse() const);
INLINE(bool IsArgumentsMarker() const);
// Filler objects (fillers and free space objects).
INLINE(bool IsFiller() const);
// Extract the number.
inline double Number() const;
INLINE(bool IsNaN() const);
INLINE(bool IsMinusZero() const);
bool ToInt32(int32_t* value);
bool ToUint32(uint32_t* value);
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<HeapType> 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();
inline bool HasSpecificClassOf(String* name);
bool BooleanValue(); // ECMA-262 9.2.
// ES6 section 7.2.11 Abstract Relational Comparison
MUST_USE_RESULT static Maybe<ComparisonResult> Compare(
Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK);
// ES6 section 7.2.12 Abstract Equality Comparison
MUST_USE_RESULT static Maybe<bool> Equals(Handle<Object> x, Handle<Object> y);
// ES6 section 7.2.13 Strict Equality Comparison
bool StrictEquals(Object* that);
// Convert to a JSObject if needed.
// native_context is used when creating wrapper object.
static inline MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
Handle<Object> object);
MUST_USE_RESULT static MaybeHandle<JSReceiver> ToObject(
Isolate* isolate, Handle<Object> object, Handle<Context> context);
// ES6 section 7.1.14 ToPropertyKey
MUST_USE_RESULT static MaybeHandle<Name> ToName(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.1.1 ToPrimitive
MUST_USE_RESULT static inline MaybeHandle<Object> ToPrimitive(
Handle<Object> input, ToPrimitiveHint hint = ToPrimitiveHint::kDefault);
// ES6 section 7.1.3 ToNumber
MUST_USE_RESULT static MaybeHandle<Object> ToNumber(Handle<Object> input);
// ES6 section 7.1.4 ToInteger
MUST_USE_RESULT static MaybeHandle<Object> ToInteger(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.1.5 ToInt32
MUST_USE_RESULT static MaybeHandle<Object> ToInt32(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.1.6 ToUint32
MUST_USE_RESULT static MaybeHandle<Object> ToUint32(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.1.12 ToString
MUST_USE_RESULT static MaybeHandle<String> ToString(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.1.15 ToLength
MUST_USE_RESULT static MaybeHandle<Object> ToLength(Isolate* isolate,
Handle<Object> input);
// ES6 section 7.3.9 GetMethod
MUST_USE_RESULT static MaybeHandle<Object> GetMethod(
Handle<JSReceiver> receiver, Handle<Name> name);
// ES6 section 7.3.17 CreateListFromArrayLike
MUST_USE_RESULT static MaybeHandle<FixedArray> CreateListFromArrayLike(
Isolate* isolate, Handle<Object> object, ElementTypes element_types);
// Check whether |object| is an instance of Error or NativeError.
static bool IsErrorObject(Isolate* isolate, Handle<Object> object);
// ES6 section 12.5.6 The typeof Operator
static Handle<String> TypeOf(Isolate* isolate, Handle<Object> object);
// ES6 section 12.6 Multiplicative Operators
MUST_USE_RESULT static MaybeHandle<Object> Multiply(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> Divide(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> Modulus(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
// ES6 section 12.7 Additive Operators
MUST_USE_RESULT static MaybeHandle<Object> Add(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> Subtract(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
// ES6 section 12.8 Bitwise Shift Operators
MUST_USE_RESULT static MaybeHandle<Object> ShiftLeft(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> ShiftRight(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> ShiftRightLogical(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
// ES6 section 12.9 Relational Operators
MUST_USE_RESULT static inline Maybe<bool> GreaterThan(
Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK);
MUST_USE_RESULT static inline Maybe<bool> GreaterThanOrEqual(
Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK);
MUST_USE_RESULT static inline Maybe<bool> LessThan(
Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK);
MUST_USE_RESULT static inline Maybe<bool> LessThanOrEqual(
Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK);
// ES6 section 12.11 Binary Bitwise Operators
MUST_USE_RESULT static MaybeHandle<Object> BitwiseAnd(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> BitwiseOr(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> BitwiseXor(
Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs,
Strength strength = Strength::WEAK);
MUST_USE_RESULT static MaybeHandle<Object> GetProperty(
LookupIterator* it, LanguageMode language_mode = SLOPPY);
// ES6 [[Set]] (when passed DONT_THROW)
// Invariants for this and related functions (unless stated otherwise):
// 1) When the result is Nothing, an exception is pending.
// 2) When passed THROW_ON_ERROR, 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).
MUST_USE_RESULT static Maybe<bool> SetProperty(LookupIterator* it,
Handle<Object> value,
LanguageMode language_mode,
StoreFromKeyed store_mode);
MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
Handle<Object> object, Handle<Name> name, Handle<Object> value,
LanguageMode language_mode,
StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
MUST_USE_RESULT static Maybe<bool> SetSuperProperty(
LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
StoreFromKeyed store_mode);
MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty(
LookupIterator* it, LanguageMode language_mode);
MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty(
Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
LanguageMode language_mode);
MUST_USE_RESULT static Maybe<bool> CannotCreateProperty(
Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
Handle<Object> value, ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> WriteToReadOnlyProperty(
LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> WriteToReadOnlyProperty(
Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
Handle<Object> value, ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> RedefineIncompatibleProperty(
Isolate* isolate, Handle<Object> name, Handle<Object> value,
ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> SetDataProperty(LookupIterator* it,
Handle<Object> value);
MUST_USE_RESULT static Maybe<bool> AddDataProperty(
LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
ShouldThrow should_throw, StoreFromKeyed store_mode);
MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
Handle<Object> object, Handle<Name> name,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
Handle<JSReceiver> holder, Handle<Name> name, Handle<Object> receiver,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
Isolate* isolate, Handle<Object> object, const char* key,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty(
Handle<Object> object, Handle<Name> name,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor(
LookupIterator* it, LanguageMode language_mode);
MUST_USE_RESULT static Maybe<bool> SetPropertyWithAccessor(
LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter(
Handle<Object> receiver,
Handle<JSReceiver> getter);
MUST_USE_RESULT static Maybe<bool> SetPropertyWithDefinedSetter(
Handle<Object> receiver, Handle<JSReceiver> setter, Handle<Object> value,
ShouldThrow should_throw);
MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
Isolate* isolate, Handle<Object> object, uint32_t index,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static inline MaybeHandle<Object> SetElement(
Isolate* isolate, Handle<Object> object, uint32_t index,
Handle<Object> value, LanguageMode language_mode);
// Get the first non-hidden prototype.
static inline MaybeHandle<Object> GetPrototype(Isolate* isolate,
Handle<Object> receiver);
MUST_USE_RESULT static Maybe<bool> HasInPrototypeChain(Isolate* isolate,
Handle<Object> object,
Handle<Object> proto);
// Returns the permanent hash code associated with this object. May return
// undefined if not yet created.
Object* GetHash();
// Returns undefined for JSObjects, 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 JSObject if it does not already exist.
Object* GetSimpleHash();
// 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.
static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object);
// 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 Harmony "egal" function.
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)
MUST_USE_RESULT static MaybeHandle<Object> ArraySpeciesConstructor(
Isolate* isolate, Handle<Object> original_array);
// 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);
// 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.
inline bool ToArrayIndex(uint32_t* index);
// Returns true if this is a JSValue containing a string and the index is
// < the length of the string. Used to implement [] on strings.
inline bool IsStringObjectWithCharacterAt(uint32_t index);
DECLARE_VERIFIER(Object)
#ifdef VERIFY_HEAP
// Verify a pointer is a valid object pointer.
static void VerifyPointer(Object* p);
#endif
inline void VerifyApiCallResultType();
// ES6 19.1.3.6 Object.prototype.toString
MUST_USE_RESULT static MaybeHandle<String> ObjectProtoToString(
Isolate* isolate, Handle<Object> object);
// 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
DECLARE_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 PrototypeIterator;
// Return the map of the root of object's prototype chain.
Map* GetRootMap(Isolate* isolate);
// Helper for SetProperty and SetSuperProperty.
// Return value is only meaningful if [found] is set to true on return.
MUST_USE_RESULT static Maybe<bool> SetPropertyInternal(
LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
StoreFromKeyed store_mode, bool* found);
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 { return Internals::HasHeapObjectTag(this); }
struct Brief {
explicit Brief(const Object* const v) : value(v) {}
const Object* value;
};
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(this); }
// 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);
}
// 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;
}
DECLARE_CAST(Smi)
// Dispatched behavior.
void SmiPrint(std::ostream& os) const; // NOLINT
DECLARE_VERIFIER(Smi)
static const int kMinValue =
(static_cast<unsigned int>(-1)) << (kSmiValueSize - 1);
static const int kMaxValue = -(kMinValue + 1);
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 BASE_EMBEDDED {
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();
// 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();
// 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);
// 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();
inline MapWord synchronized_map_word() const;
// Set the map using release store
inline void synchronized_set_map(Map* value);
inline void synchronized_set_map_no_write_barrier(Map* value);
inline void synchronized_set_map_word(MapWord map_word);
// 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);
// 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;
// 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() {
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(InstanceType type, int object_size, ObjectVisitor* v);
template <typename ObjectVisitor>
inline void IterateBodyFast(ObjectVisitor* v);
template <typename ObjectVisitor>
inline void IterateBodyFast(InstanceType type, 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(int offset);
// Returns the heap object's size in bytes
inline int Size();
// 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);
// 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.
static inline Object** RawField(HeapObject* obj, int offset);
// Adds the |code| object related to |name| to the code cache of this map. If
// this map is a dictionary map that is shared, the map copied and installed
// onto the object.
static void UpdateMapCodeCache(Handle<HeapObject> object,
Handle<Name> name,
Handle<Code> code);
DECLARE_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
DECLARE_PRINTER(HeapObject)
DECLARE_VERIFIER(HeapObject)
#ifdef VERIFY_HEAP
inline void VerifyObjectField(int offset);
inline void VerifySmiField(int offset);
// Verify a pointer is a valid HeapObject pointer that points to object
// areas in the heap.
static void VerifyHeapPointer(Object* p);
#endif
inline AllocationAlignment RequiredAlignment();
// 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);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject);
};
template <int start_offset, int end_offset, int size>
class FixedBodyDescriptor;
template <int start_offset>
class FlexibleBodyDescriptor;
// The HeapNumber class describes heap allocated numbers that cannot be
// represented in a Smi (small integer)
class HeapNumber: public HeapObject {
public:
// [value]: number value.
inline double value() const;
inline void set_value(double value);
DECLARE_CAST(HeapNumber)
// Dispatched behavior.
bool HeapNumberBooleanValue();
void HeapNumberPrint(std::ostream& os); // NOLINT
DECLARE_VERIFIER(HeapNumber)
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(HeapNumber);
};
// The Simd128Value class describes heap allocated 128 bit SIMD values.
class Simd128Value : public HeapObject {
public:
DECLARE_CAST(Simd128Value)
DECLARE_PRINTER(Simd128Value)
DECLARE_VERIFIER(Simd128Value)
static Handle<String> ToString(Handle<Simd128Value> input);
// Equality operations.
inline bool Equals(Simd128Value* that);
static inline bool Equals(Handle<Simd128Value> one, Handle<Simd128Value> two);
// Checks that another instance is bit-wise equal.
bool BitwiseEquals(const Simd128Value* other) const;
// Computes a hash from the 128 bit value, viewed as 4 32-bit integers.
uint32_t Hash() const;
// Copies the 16 bytes of SIMD data to the destination address.
void CopyBits(void* destination) const;
// Layout description.
static const int kValueOffset = HeapObject::kHeaderSize;
static const int kSize = kValueOffset + kSimd128Size;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Simd128Value);
};
// V has parameters (TYPE, Type, type, lane count, lane type)
#define SIMD128_TYPES(V) \
V(FLOAT32X4, Float32x4, float32x4, 4, float) \
V(INT32X4, Int32x4, int32x4, 4, int32_t) \
V(UINT32X4, Uint32x4, uint32x4, 4, uint32_t) \
V(BOOL32X4, Bool32x4, bool32x4, 4, bool) \
V(INT16X8, Int16x8, int16x8, 8, int16_t) \
V(UINT16X8, Uint16x8, uint16x8, 8, uint16_t) \
V(BOOL16X8, Bool16x8, bool16x8, 8, bool) \
V(INT8X16, Int8x16, int8x16, 16, int8_t) \
V(UINT8X16, Uint8x16, uint8x16, 16, uint8_t) \
V(BOOL8X16, Bool8x16, bool8x16, 16, bool)
#define SIMD128_VALUE_CLASS(TYPE, Type, type, lane_count, lane_type) \
class Type final : public Simd128Value { \
public: \
inline lane_type get_lane(int lane) const; \
inline void set_lane(int lane, lane_type value); \
\
DECLARE_CAST(Type) \
\
DECLARE_PRINTER(Type) \
\
static Handle<String> ToString(Handle<Type> input); \
\
inline bool Equals(Type* that); \
\
private: \
DISALLOW_IMPLICIT_CONSTRUCTORS(Type); \
};
SIMD128_TYPES(SIMD128_VALUE_CLASS)
#undef SIMD128_VALUE_CLASS
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 GetKeysConversion { KEEP_NUMBERS, CONVERT_TO_STRING };
// JSReceiver includes types on which properties can be defined, i.e.,
// JSObject and JSProxy.
class JSReceiver: public HeapObject {
public:
// [properties]: Backing storage for properties.
// properties is a FixedArray in the fast case and a Dictionary in the
// slow case.
DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties.
inline void initialize_properties();
inline bool HasFastProperties();
// Gets slow properties for non-global objects.
inline NameDictionary* property_dictionary();
// Deletes an existing named property in a normalized object.
static void DeleteNormalizedProperty(Handle<JSReceiver> object,
Handle<Name> name, int entry);
DECLARE_CAST(JSReceiver)
// ES6 section 7.1.1 ToPrimitive
MUST_USE_RESULT static MaybeHandle<Object> ToPrimitive(
Handle<JSReceiver> receiver,
ToPrimitiveHint hint = ToPrimitiveHint::kDefault);
MUST_USE_RESULT static MaybeHandle<Object> OrdinaryToPrimitive(
Handle<JSReceiver> receiver, OrdinaryToPrimitiveHint hint);
static MaybeHandle<Context> GetFunctionRealm(Handle<JSReceiver> receiver);
// Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
MUST_USE_RESULT static Maybe<bool> HasProperty(LookupIterator* it);
MUST_USE_RESULT static inline Maybe<bool> HasProperty(
Handle<JSReceiver> object, Handle<Name> name);
MUST_USE_RESULT static inline Maybe<bool> HasElement(
Handle<JSReceiver> object, uint32_t index);
MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty(
Handle<JSReceiver> object, Handle<Name> name);
// Implementation of ES6 [[Delete]]
MUST_USE_RESULT static Maybe<bool> DeletePropertyOrElement(
Handle<JSReceiver> object, Handle<Name> name,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static Maybe<bool> DeleteProperty(
Handle<JSReceiver> object, Handle<Name> name,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static Maybe<bool> DeleteProperty(LookupIterator* it,
LanguageMode language_mode);
MUST_USE_RESULT static Maybe<bool> DeleteElement(
Handle<JSReceiver> object, uint32_t index,
LanguageMode language_mode = SLOPPY);
MUST_USE_RESULT static Object* DefineProperty(Isolate* isolate,
Handle<Object> object,
Handle<Object> name,
Handle<Object> attributes);
MUST_USE_RESULT static MaybeHandle<Object> DefineProperties(
Isolate* isolate, Handle<Object> object, Handle<Object> properties);
// "virtual" dispatcher to the correct [[DefineOwnProperty]] implementation.
MUST_USE_RESULT static Maybe<bool> DefineOwnProperty(
Isolate* isolate, Handle<JSReceiver> object, Handle<Object> key,
PropertyDescriptor* desc, ShouldThrow should_throw);
// ES6 7.3.4 (when passed DONT_THROW)
MUST_USE_RESULT static Maybe<bool> CreateDataProperty(
LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
// ES6 9.1.6.1
MUST_USE_RESULT static Maybe<bool> OrdinaryDefineOwnProperty(
Isolate* isolate, Handle<JSObject> object, Handle<Object> key,
PropertyDescriptor* desc, ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> OrdinaryDefineOwnProperty(
LookupIterator* it, PropertyDescriptor* desc, ShouldThrow should_throw);
// ES6 9.1.6.2
MUST_USE_RESULT static Maybe<bool> IsCompatiblePropertyDescriptor(
Isolate* isolate, bool extensible, PropertyDescriptor* desc,
PropertyDescriptor* current, Handle<Name> property_name,
ShouldThrow should_throw);
// ES6 9.1.6.3
// |it| can be NULL in cases where the ES spec passes |undefined| as the
// receiver. Exactly one of |it| and |property_name| must be provided.
MUST_USE_RESULT static Maybe<bool> ValidateAndApplyPropertyDescriptor(
Isolate* isolate, LookupIterator* it, bool extensible,
PropertyDescriptor* desc, PropertyDescriptor* current,
ShouldThrow should_throw, Handle<Name> property_name = Handle<Name>());
MUST_USE_RESULT static Maybe<bool> GetOwnPropertyDescriptor(
Isolate* isolate, Handle<JSReceiver> object, Handle<Object> key,
PropertyDescriptor* desc);
MUST_USE_RESULT static Maybe<bool> GetOwnPropertyDescriptor(
LookupIterator* it, PropertyDescriptor* desc);
typedef PropertyAttributes IntegrityLevel;
// ES6 7.3.14 (when passed DONT_THROW)
// 'level' must be SEALED or FROZEN.
MUST_USE_RESULT static Maybe<bool> SetIntegrityLevel(
Handle<JSReceiver> object, IntegrityLevel lvl, ShouldThrow should_throw);
// ES6 7.3.15
// 'level' must be SEALED or FROZEN.
MUST_USE_RESULT static Maybe<bool> TestIntegrityLevel(
Handle<JSReceiver> object, IntegrityLevel lvl);
// ES6 [[PreventExtensions]] (when passed DONT_THROW)
MUST_USE_RESULT static Maybe<bool> PreventExtensions(
Handle<JSReceiver> object, ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSReceiver> object);
// Tests for the fast common case for property enumeration.
bool IsSimpleEnum();
// Returns the class name ([[Class]] property in the specification).
String* class_name();
// Returns the builtin string tag used in Object.prototype.toString.
MUST_USE_RESULT static MaybeHandle<String> BuiltinStringTag(
Handle<JSReceiver> object);
// Returns the constructor name (the name (possibly, inferred name) of the
// function that was used to instantiate the object).
static Handle<String> GetConstructorName(Handle<JSReceiver> receiver);
Context* GetCreationContext();
MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes(
Handle<JSReceiver> object, Handle<Name> name);
MUST_USE_RESULT static inline Maybe<PropertyAttributes>
GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetElementAttributes(
Handle<JSReceiver> object, uint32_t index);
MUST_USE_RESULT static inline Maybe<PropertyAttributes>
GetOwnElementAttributes(Handle<JSReceiver> object, uint32_t index);
MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
LookupIterator* it);
// Set the object's prototype (only JSReceiver and null are allowed values).
MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSReceiver> object,
Handle<Object> value,
bool from_javascript,
ShouldThrow should_throw);
static Handle<Object> GetDataProperty(Handle<JSReceiver> object,
Handle<Name> name);
static Handle<Object> GetDataProperty(LookupIterator* it);
// Retrieves a permanent object identity hash code. The undefined value might
// be returned in case no hash was created yet.
inline Object* GetIdentityHash();
// Retrieves a permanent object identity hash code. May create and store a
// hash code if needed and none exists.
inline static Handle<Smi> GetOrCreateIdentityHash(
Handle<JSReceiver> object);
enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS };
// ES6 [[OwnPropertyKeys]] (modulo return type)
MUST_USE_RESULT static MaybeHandle<FixedArray> OwnPropertyKeys(
Handle<JSReceiver> object) {
return GetKeys(object, JSReceiver::OWN_ONLY, ALL_PROPERTIES,
CONVERT_TO_STRING);
}
// Computes the enumerable keys for a JSObject. Used for implementing
// "for (n in object) { }".
MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys(
Handle<JSReceiver> object, KeyCollectionType type, PropertyFilter filter,
GetKeysConversion keys_conversion = KEEP_NUMBERS);
// Layout description.
static const int kPropertiesOffset = HeapObject::kHeaderSize;
static const int kHeaderSize = HeapObject::kHeaderSize + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
};
// The JSObject describes real heap allocated JavaScript objects with
// properties.
// Note that the map of JSObject changes during execution to enable inline
// caching.
class JSObject: public JSReceiver {
public:
static MUST_USE_RESULT MaybeHandle<JSObject> New(
Handle<JSFunction> constructor, Handle<JSReceiver> new_target,
Handle<AllocationSite> site = Handle<AllocationSite>::null());
// Gets global object properties.
inline GlobalDictionary* global_dictionary();
static MaybeHandle<Context> GetFunctionRealm(Handle<JSObject> object);
// [elements]: The elements (properties with names that are integers).
//
// Elements can be in two general modes: fast and slow. Each mode
// corrensponds to a set of object representations of elements that
// have something in common.
//
// In the fast mode elements is a FixedArray and so each element can
// be quickly accessed. This fact is used in the generated code. The
// elements array can have one of three maps in this mode:
// fixed_array_map, sloppy_arguments_elements_map or
// fixed_cow_array_map (for copy-on-write arrays). In the latter case
// the elements array may be shared by a few objects and so before
// writing to any element the array must be copied. Use
// EnsureWritableFastElements in this case.
//
// In the slow mode the elements is either a NumberDictionary, a
// FixedArray parameter map for a (sloppy) arguments object.
DECL_ACCESSORS(elements, FixedArrayBase)
inline void initialize_elements();
static void ResetElements(Handle<JSObject> object);
static inline void SetMapAndElements(Handle<JSObject> object,
Handle<Map> map,
Handle<FixedArrayBase> elements);
inline ElementsKind GetElementsKind();
ElementsAccessor* GetElementsAccessor();
// Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
inline bool HasFastSmiElements();
// Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
inline bool HasFastObjectElements();
// Returns true if an object has elements of FAST_ELEMENTS or
// FAST_SMI_ONLY_ELEMENTS.
inline bool HasFastSmiOrObjectElements();
// Returns true if an object has any of the fast elements kinds.
inline bool HasFastElements();
// Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
// ElementsKind.
inline bool HasFastDoubleElements();
// Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
// ElementsKind.
inline bool HasFastHoleyElements();
inline bool HasSloppyArgumentsElements();
inline bool HasDictionaryElements();
inline bool HasFixedTypedArrayElements();
inline bool HasFixedUint8ClampedElements();
inline bool HasFixedArrayElements();
inline bool HasFixedInt8Elements();
inline bool HasFixedUint8Elements();
inline bool HasFixedInt16Elements();
inline bool HasFixedUint16Elements();
inline bool HasFixedInt32Elements();
inline bool HasFixedUint32Elements();
inline bool HasFixedFloat32Elements();
inline bool HasFixedFloat64Elements();
inline bool HasFastArgumentsElements();
inline bool HasSlowArgumentsElements();
inline SeededNumberDictionary* element_dictionary(); // Gets slow elements.
// Requires: HasFastElements().
static Handle<FixedArray> EnsureWritableFastElements(
Handle<JSObject> object);
// Collects elements starting at index 0.
// Undefined values are placed after non-undefined values.
// Returns the number of non-undefined values.
static Handle<Object> PrepareElementsForSort(Handle<JSObject> object,
uint32_t limit);
// As PrepareElementsForSort, but only on objects where elements is
// a dictionary, and it will stay a dictionary. Collates undefined and
// unexisting elements below limit from position zero of the elements.
static Handle<Object> PrepareSlowElementsForSort(Handle<JSObject> object,
uint32_t limit);
MUST_USE_RESULT static Maybe<bool> SetPropertyWithInterceptor(
LookupIterator* it, Handle<Object> value);
// SetLocalPropertyIgnoreAttributes converts callbacks to fields. We need to
// grant an exemption to ExecutableAccessor callbacks in some cases.
enum ExecutableAccessorInfoHandling { DEFAULT_HANDLING, DONT_FORCE_FIELD };
MUST_USE_RESULT static MaybeHandle<Object> DefineOwnPropertyIgnoreAttributes(
LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
MUST_USE_RESULT static Maybe<bool> DefineOwnPropertyIgnoreAttributes(
LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
ShouldThrow should_throw,
ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes(
Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
PropertyAttributes attributes,
ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
MUST_USE_RESULT static MaybeHandle<Object> SetOwnElementIgnoreAttributes(
Handle<JSObject> object, uint32_t index, Handle<Object> value,
PropertyAttributes attributes,
ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
// Equivalent to one of the above depending on whether |name| can be converted
// to an array index.
MUST_USE_RESULT static MaybeHandle<Object>
DefinePropertyOrElementIgnoreAttributes(
Handle<JSObject> object, Handle<Name> name, Handle<Object> value,
PropertyAttributes attributes = NONE,
ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
// Adds or reconfigures a property to attributes NONE. It will fail when it
// cannot.
MUST_USE_RESULT static Maybe<bool> CreateDataProperty(LookupIterator* it,
Handle<Object> value);
static void AddProperty(Handle<JSObject> object, Handle<Name> name,
Handle<Object> value, PropertyAttributes attributes);
MUST_USE_RESULT static Maybe<bool> AddDataElement(
Handle<JSObject> receiver, uint32_t index, Handle<Object> value,
PropertyAttributes attributes, ShouldThrow should_throw);
MUST_USE_RESULT static MaybeHandle<Object> AddDataElement(
Handle<JSObject> receiver, uint32_t index, Handle<Object> value,
PropertyAttributes attributes);
// Extend the receiver with a single fast property appeared first in the
// passed map. This also extends the property backing store if necessary.
static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
// Migrates the given object to a map whose field representations are the
// lowest upper bound of all known representations for that field.
static void MigrateInstance(Handle<JSObject> instance);
// Migrates the given object only if the target map is already available,
// or returns false if such a map is not yet available.
static bool TryMigrateInstance(Handle<JSObject> instance);
// Sets the property value in a normalized object given (key, value, details).
// Handles the special representation of JS global objects.
static void SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name,
Handle<Object> value,
PropertyDetails details);
static void SetDictionaryElement(Handle<JSObject> object, uint32_t index,
Handle<Object> value,
PropertyAttributes attributes);
static void SetDictionaryArgumentsElement(Handle<JSObject> object,
uint32_t index,
Handle<Object> value,
PropertyAttributes attributes);
static void OptimizeAsPrototype(Handle<JSObject> object,
PrototypeOptimizationMode mode);
static void ReoptimizeIfPrototype(Handle<JSObject> object);
static void LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate);
static void UpdatePrototypeUserRegistration(Handle<Map> old_map,
Handle<Map> new_map,
Isolate* isolate);
static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate);
static void InvalidatePrototypeChains(Map* map);
// Alternative implementation of WeakFixedArray::NullCallback.
class PrototypeRegistryCompactionCallback {
public:
static void Callback(Object* value, int old_index, int new_index);
};
// Retrieve interceptors.
InterceptorInfo* GetNamedInterceptor();
inline InterceptorInfo* GetIndexedInterceptor();
// Used from JSReceiver.
MUST_USE_RESULT static Maybe<PropertyAttributes>
GetPropertyAttributesWithInterceptor(LookupIterator* it);
MUST_USE_RESULT static Maybe<PropertyAttributes>
GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
// Retrieves an AccessorPair property from the given object. Might return
// undefined if the property doesn't exist or is of a different kind.
MUST_USE_RESULT static MaybeHandle<Object> GetAccessor(
Handle<JSObject> object,
Handle<Name> name,
AccessorComponent component);
// Defines an AccessorPair property on the given object.
// TODO(mstarzinger): Rename to SetAccessor().
static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
Handle<Name> name,
Handle<Object> getter,
Handle<Object> setter,
PropertyAttributes attributes);
static MaybeHandle<Object> DefineAccessor(LookupIterator* it,
Handle<Object> getter,
Handle<Object> setter,
PropertyAttributes attributes);
// Defines an AccessorInfo property on the given object.
MUST_USE_RESULT static MaybeHandle<Object> SetAccessor(
Handle<JSObject> object,
Handle<AccessorInfo> info);
// The result must be checked first for exceptions. If there's no exception,
// the output parameter |done| indicates whether the interceptor has a result
// or not.
MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
LookupIterator* it, bool* done);
// Accessors for hidden properties object.
//
// Hidden properties are not own properties of the object itself.
// Instead they are stored in an auxiliary structure kept as an own
// property with a special name Heap::hidden_string(). But if the
// receiver is a JSGlobalProxy then the auxiliary object is a property
// of its prototype, and if it's a detached proxy, then you can't have
// hidden properties.
// Sets a hidden property on this object. Returns this object if successful,
// undefined if called on a detached proxy.
static Handle<Object> SetHiddenProperty(Handle<JSObject> object,
Handle<Name> key,
Handle<Object> value);
// Gets the value of a hidden property with the given key. Returns the hole
// if the property doesn't exist (or if called on a detached proxy),
// otherwise returns the value set for the key.
Object* GetHiddenProperty(Handle<Name> key);
// Deletes a hidden property. Deleting a non-existing property is
// considered successful.
static void DeleteHiddenProperty(Handle<JSObject> object,
Handle<Name> key);
// Returns true if the object has a property with the hidden string as name.
static bool HasHiddenProperties(Handle<JSObject> object);
static void SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash);
static void ValidateElements(Handle<JSObject> object);
// Makes sure that this object can contain HeapObject as elements.
static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
// Makes sure that this object can contain the specified elements.
static inline void EnsureCanContainElements(
Handle<JSObject> object,
Object** elements,
uint32_t count,
EnsureElementsMode mode);
static inline void EnsureCanContainElements(
Handle<JSObject> object,
Handle<FixedArrayBase> elements,
uint32_t length,
EnsureElementsMode mode);
static void EnsureCanContainElements(
Handle<JSObject> object,
Arguments* arguments,
uint32_t first_arg,
uint32_t arg_count,
EnsureElementsMode mode);
// Would we convert a fast elements array to dictionary mode given
// an access at key?
bool WouldConvertToSlowElements(uint32_t index);
// Computes the new capacity when expanding the elements of a JSObject.
static uint32_t NewElementsCapacity(uint32_t old_capacity) {
// (old_capacity + 50%) + 16
return old_capacity + (old_capacity >> 1) + 16;
}
// These methods do not perform access checks!
static void UpdateAllocationSite(Handle<JSObject> object,
ElementsKind to_kind);
// Lookup interceptors are used for handling properties controlled by host
// objects.
inline bool HasNamedInterceptor();
inline bool HasIndexedInterceptor();
// Support functions for v8 api (needed for correct interceptor behavior).
MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
Handle<JSObject> object, Handle<Name> name);
MUST_USE_RESULT static Maybe<bool> HasRealElementProperty(
Handle<JSObject> object, uint32_t index);
MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
Handle<JSObject> object, Handle<Name> name);
// Get the header size for a JSObject. Used to compute the index of
// internal fields as well as the number of internal fields.
static inline int GetHeaderSize(InstanceType instance_type);
inline int GetHeaderSize();
static inline int GetInternalFieldCount(Map* map);
inline int GetInternalFieldCount();
inline int GetInternalFieldOffset(int index);
inline Object* GetInternalField(int index);
inline void SetInternalField(int index, Object* value);
inline void SetInternalField(int index, Smi* value);
void CollectOwnPropertyNames(KeyAccumulator* keys,
PropertyFilter filter = ALL_PROPERTIES);
// Returns the number of properties on this object filtering out properties
// with the specified attributes (ignoring interceptors).
// TODO(jkummerow): Deprecated, only used by Object.observe.
int NumberOfOwnElements(PropertyFilter filter);
// Returns the number of elements on this object filtering out elements
// with the specified attributes (ignoring interceptors).
// TODO(jkummerow): Deprecated, only used by Object.observe.
int GetOwnElementKeys(FixedArray* storage, PropertyFilter filter);
static void CollectOwnElementKeys(Handle<JSObject> object,
KeyAccumulator* keys,
PropertyFilter filter);
static Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object,
bool cache_result);
// Returns a new map with all transitions dropped from the object's current
// map and the ElementsKind set.
static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
ElementsKind to_kind);
static void TransitionElementsKind(Handle<JSObject> object,
ElementsKind to_kind);
// Always use this to migrate an object to a new map.
// |expected_additional_properties| is only used for fast-to-slow transitions
// and ignored otherwise.
static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map,
int expected_additional_properties = 0);
// Convert the object to use the canonical dictionary
// representation. If the object is expected to have additional properties
// added this number can be indicated to have the backing store allocated to
// an initial capacity for holding these properties.
static void NormalizeProperties(Handle<JSObject> object,
PropertyNormalizationMode mode,
int expected_additional_properties,
const char* reason);
// Convert and update the elements backing store to be a
// SeededNumberDictionary dictionary. Returns the backing after conversion.
static Handle<SeededNumberDictionary> NormalizeElements(
Handle<JSObject> object);
void RequireSlowElements(SeededNumberDictionary* dictionary);
// Transform slow named properties to fast variants.
static void MigrateSlowToFast(Handle<JSObject> object,
int unused_property_fields, const char* reason);
inline bool IsUnboxedDoubleField(FieldIndex index);
// Access fast-case object properties at index.
static Handle<Object> FastPropertyAt(Handle<JSObject> object,
Representation representation,
FieldIndex index);
inline Object* RawFastPropertyAt(FieldIndex index);
inline double RawFastDoublePropertyAt(FieldIndex index);
inline void FastPropertyAtPut(FieldIndex index, Object* value);
inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
inline void RawFastDoublePropertyAtPut(FieldIndex index, double value);
inline void WriteToField(int descriptor, Object* value);
// Access to in object properties.
inline int GetInObjectPropertyOffset(int index);
inline Object* InObjectPropertyAt(int index);
inline Object* InObjectPropertyAtPut(int index,
Object* value,
WriteBarrierMode mode
= UPDATE_WRITE_BARRIER);
// Set the object's prototype (only JSReceiver and null are allowed values).
MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSObject> object,
Handle<Object> value,
bool from_javascript,
ShouldThrow should_throw);
// Initializes the body starting at |start_offset|. It is responsibility of
// the caller to initialize object header. Fill the pre-allocated fields with
// pre_allocated_value and the rest with filler_value.
// Note: this call does not update write barrier, the caller is responsible
// to ensure that |filler_value| can be collected without WB here.
inline void InitializeBody(Map* map, int start_offset,
Object* pre_allocated_value, Object* filler_value);
// Check whether this object references another object
bool ReferencesObject(Object* obj);
MUST_USE_RESULT static Maybe<bool> PreventExtensions(
Handle<JSObject> object, ShouldThrow should_throw);
static bool IsExtensible(Handle<JSObject> object);
// Called the first time an object is observed with ES7 Object.observe.
static void SetObserved(Handle<JSObject> object);
// Copy object.
enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 };
MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy(
Handle<JSObject> object,
AllocationSiteUsageContext* site_context,
DeepCopyHints hints = kNoHints);
MUST_USE_RESULT static MaybeHandle<JSObject> DeepWalk(
Handle<JSObject> object,
AllocationSiteCreationContext* site_context);
DECLARE_CAST(JSObject)
// Dispatched behavior.
void JSObjectShortPrint(StringStream* accumulator);
DECLARE_PRINTER(JSObject)
DECLARE_VERIFIER(JSObject)
#ifdef OBJECT_PRINT
void PrintProperties(std::ostream& os); // NOLINT
void PrintElements(std::ostream& os); // NOLINT
#endif
#if defined(DEBUG) || defined(OBJECT_PRINT)
void PrintTransitions(std::ostream& os); // NOLINT
#endif
static void PrintElementsTransition(
FILE* file, Handle<JSObject> object,
ElementsKind from_kind, Handle<FixedArrayBase> from_elements,
ElementsKind to_kind, Handle<FixedArrayBase> to_elements);
void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
#ifdef DEBUG
// Structure for collecting spill information about JSObjects.
class SpillInformation {
public:
void Clear();
void Print();
int number_of_objects_;
int number_of_objects_with_fast_properties_;
int number_of_objects_with_fast_elements_;
int number_of_fast_used_fields_;
int number_of_fast_unused_fields_;
int number_of_slow_used_properties_;
int number_of_slow_unused_properties_;
int number_of_fast_used_elements_;
int number_of_fast_unused_elements_;
int number_of_slow_used_elements_;
int number_of_slow_unused_elements_;
};
void IncrementSpillStatistics(SpillInformation* info);
#endif
#ifdef VERIFY_HEAP
// If a GC was caused while constructing this object, the elements pointer
// may point to a one pointer filler map. The object won't be rooted, but
// our heap verification code could stumble across it.
bool ElementsAreSafeToExamine();
#endif
Object* SlowReverseLookup(Object* value);
// Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
// Also maximal value of JSArray's length property.
static const uint32_t kMaxElementCount = 0xffffffffu;
// Constants for heuristics controlling conversion of fast elements
// to slow elements.
// Maximal gap that can be introduced by adding an element beyond
// the current elements length.
static const uint32_t kMaxGap = 1024;
// Maximal length of fast elements array that won't be checked for
// being dense enough on expansion.
static const int kMaxUncheckedFastElementsLength = 5000;
// Same as above but for old arrays. This limit is more strict. We
// don't want to be wasteful with long lived objects.
static const int kMaxUncheckedOldFastElementsLength = 500;
// This constant applies only to the initial map of "global.Object" and
// not to arbitrary other JSObject maps.
static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
static const int kMaxInstanceSize = 255 * kPointerSize;
// When extending the backing storage for property values, we increase
// its size by more than the 1 entry necessary, so sequentially adding fields
// to the same object requires fewer allocations and copies.
static const int kFieldsAdded = 3;
// Layout description.
static const int kElementsOffset = JSReceiver::kHeaderSize;
static const int kHeaderSize = kElementsOffset + kPointerSize;
STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
typedef FlexibleBodyDescriptor<JSReceiver::kPropertiesOffset> BodyDescriptor;
// Enqueue change record for Object.observe. May cause GC.
MUST_USE_RESULT static MaybeHandle<Object> EnqueueChangeRecord(
Handle<JSObject> object, const char* type, Handle<Name> name,
Handle<Object> old_value);
// Gets the number of currently used elements.
int GetFastElementsUsage();
static bool AllCanRead(LookupIterator* it);
static bool AllCanWrite(LookupIterator* it);
private:
friend class JSReceiver;
friend class Object;
static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map);
static void MigrateFastToSlow(Handle<JSObject> object,
Handle<Map> new_map,
int expected_additional_properties);
// Used from Object::GetProperty().
MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
LookupIterator* it);
MUST_USE_RESULT static Maybe<bool> SetPropertyWithFailedAccessCheck(
LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
// Add a property to a slow-case object.
static void AddSlowProperty(Handle<JSObject> object,
Handle<Name> name,
Handle<Object> value,
PropertyAttributes attributes);
MUST_USE_RESULT static Maybe<bool> DeletePropertyWithInterceptor(
LookupIterator* it);
bool ReferencesObjectFromElements(FixedArray* elements,
ElementsKind kind,
Object* object);
// Return the hash table backing store or the inline stored identity hash,
// whatever is found.
MUST_USE_RESULT Object* GetHiddenPropertiesHashTable();
// Return the hash table backing store for hidden properties. If there is no
// backing store, allocate one.
static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable(
Handle<JSObject> object);
// Set the hidden property backing store to either a hash table or
// the inline-stored identity hash.
static Handle<Object> SetHiddenPropertiesHashTable(
Handle<JSObject> object,
Handle<Object> value);
MUST_USE_RESULT Object* GetIdentityHash();
static Handle<Smi> GetOrCreateIdentityHash(Handle<JSObject> object);
static Handle<SeededNumberDictionary> GetNormalizedElementDictionary(
Handle<JSObject> object, Handle<FixedArrayBase> elements);
// Helper for fast versions of preventExtensions, seal, and freeze.
// attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
template <PropertyAttributes attrs>
MUST_USE_RESULT static Maybe<bool> PreventExtensionsWithTransition(
Handle<JSObject> object, ShouldThrow should_throw);
MUST_USE_RESULT static Maybe<bool> SetPrototypeUnobserved(
Handle<JSObject> object, Handle<Object> value, bool from_javascript,
ShouldThrow should_throw);
DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
};
// Common superclass for FixedArrays that allow implementations to share
// common accessors and some code paths.
class FixedArrayBase: public HeapObject {
public:
// [length]: length of the array.
inline int length() const;
inline void set_length(int value);
// Get and set the length using acquire loads and release stores.
inline int synchronized_length() const;
inline void synchronized_set_length(int value);
DECLARE_CAST(FixedArrayBase)
// Layout description.
// Length is smi tagged when it is stored.
static const int kLengthOffset = HeapObject::kHeaderSize;
static const int kHeaderSize = kLengthOffset + kPointerSize;
};
class FixedDoubleArray;
class IncrementalMarking;
// FixedArray describes fixed-sized arrays with element type Object*.
class FixedArray: public FixedArrayBase {
public:
// Setter and getter for elements.
inline Object* get(int index) const;
static inline Handle<Object> get(Handle<FixedArray> array, int index);
// Setter that uses write barrier.
inline void set(int index, Object* value);
inline bool is_the_hole(int index);
// Setter that doesn't need write barrier.
inline void set(int index, Smi* value);
// Setter with explicit barrier mode.
inline void set(int index, Object* value, WriteBarrierMode mode);
// Setters for frequently used oddballs located in old space.
inline void set_undefined(int index);
inline void set_null(int index);
inline void set_the_hole(int index);
inline Object** GetFirstElementAddress();
inline bool ContainsOnlySmisOrHoles();
// Gives access to raw memory which stores the array's data.
inline Object** data_start();
inline void FillWithHoles(int from, int to);
// Shrink length and insert filler objects.
void Shrink(int length);
// Copy a sub array from the receiver to dest.
void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
// Garbage collection support.
static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
// Code Generation support.
static int OffsetOfElementAt(int index) { return SizeFor(index); }
// Garbage collection support.
inline Object** RawFieldOfElementAt(int index);
DECLARE_CAST(FixedArray)
// Maximal allowed size, in bytes, of a single FixedArray.
// Prevents overflowing size computations, as well as extreme memory
// consumption.
static const int kMaxSize = 128 * MB * kPointerSize;
// Maximally allowed length of a FixedArray.
static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
// Dispatched behavior.
DECLARE_PRINTER(FixedArray)
DECLARE_VERIFIER(FixedArray)
#ifdef DEBUG
// Checks if two FixedArrays have identical contents.
bool IsEqualTo(FixedArray* other);
#endif
// Swap two elements in a pair of arrays. If this array and the
// numbers array are the same object, the elements are only swapped
// once.
void SwapPairs(FixedArray* numbers, int i, int j);
// Sort prefix of this array and the numbers array as pairs wrt. the
// numbers. If the numbers array and the this array are the same
// object, the prefix of this array is sorted.
void SortPairs(FixedArray* numbers, uint32_t len);
typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor;
protected:
// Set operation on FixedArray without using write barriers. Can
// only be used for storing old space objects or smis.
static inline void NoWriteBarrierSet(FixedArray* array,
int index,
Object* value);
private:
STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize);
DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray);
};
// FixedDoubleArray describes fixed-sized arrays with element type double.
class FixedDoubleArray: public FixedArrayBase {
public:
// Setter and getter for elements.
inline double get_scalar(int index);
inline uint64_t get_representation(int index);
static inline Handle<Object> get(Handle<FixedDoubleArray> array, int index);
inline void set(int index, double value);
inline void set_the_hole(int index);
// Checking for the hole.
inline bool is_the_hole(int index);
// Garbage collection support.
inline static int SizeFor(int length) {
return kHeaderSize + length * kDoubleSize;
}
// Gives access to raw memory which stores the array's data.
inline double* data_start();
inline void FillWithHoles(int from, int to);
// Code Generation support.
static int OffsetOfElementAt(int index) { return SizeFor(index); }
DECLARE_CAST(FixedDoubleArray)
// Maximal allowed size, in bytes, of a single FixedDoubleArray.
// Prevents overflowing size computations, as well as extreme memory
// consumption.
static const int kMaxSize = 512 * MB;
// Maximally allowed length of a FixedArray.
static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize;
// Dispatched behavior.
DECLARE_PRINTER(FixedDoubleArray)
DECLARE_VERIFIER(FixedDoubleArray)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
};
class WeakFixedArray : public FixedArray {
public:
// If |maybe_array| is not a WeakFixedArray, a fresh one will be allocated.
// This function does not check if the value exists already, callers must
// ensure this themselves if necessary.
static Handle<WeakFixedArray> Add(Handle<Object> maybe_array,
Handle<HeapObject> value,
int* assigned_index = NULL);
// Returns true if an entry was found and removed.
bool Remove(Handle<HeapObject> value);
class NullCallback {
public:
static void Callback(Object* value, int old_index, int new_index) {}
};
template <class CompactionCallback>
void Compact();
inline Object* Get(int index) const;
inline void Clear(int index);
inline int Length() const;
inline bool IsEmptySlot(int index) const;
static Object* Empty() { return Smi::FromInt(0); }
class Iterator {
public:
explicit Iterator(Object* maybe_array) : list_(NULL) { Reset(maybe_array); }
void Reset(Object* maybe_array);
template <class T>
inline T* Next();
private:
int index_;
WeakFixedArray* list_;
#ifdef DEBUG
int last_used_index_;
DisallowHeapAllocation no_gc_;
#endif // DEBUG
DISALLOW_COPY_AND_ASSIGN(Iterator);
};
DECLARE_CAST(WeakFixedArray)
private:
static const int kLastUsedIndexIndex = 0;
static const int kFirstIndex = 1;
static Handle<WeakFixedArray> Allocate(
Isolate* isolate, int size, Handle<WeakFixedArray> initialize_from);
static void Set(Handle<WeakFixedArray> array, int index,
Handle<HeapObject> value);
inline void clear(int index);
inline int last_used_index() const;
inline void set_last_used_index(int index);
// Disallow inherited setters.
void set(int index, Smi* value);
void set(int index, Object* value);
void set(int index, Object* value, WriteBarrierMode mode);
DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray);
};
// Generic array grows dynamically with O(1) amortized insertion.
class ArrayList : public FixedArray {
public:
enum AddMode {
kNone,
// Use this if GC can delete elements from the array.
kReloadLengthAfterAllocation,
};
static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj,
AddMode mode = kNone);
static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj1,
Handle<Object> obj2, AddMode = kNone);
inline int Length();
inline void SetLength(int length);
inline Object* Get(int index);
inline Object** Slot(int index);
inline void Set(int index, Object* obj);
inline void Clear(int index, Object* undefined);
bool IsFull();
DECLARE_CAST(ArrayList)
private:
static Handle<ArrayList> EnsureSpace(Handle<ArrayList> array, int length);
static const int kLengthIndex = 0;
static const int kFirstIndex = 1;
DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
};
// DescriptorArrays are fixed arrays used to hold instance descriptors.
// The format of the these objects is:
// [0]: Number of descriptors
// [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array:
// [0]: pointer to fixed array with enum cache
// [1]: either Smi(0) or pointer to fixed array with indices
// [2]: first key
// [2 + number of descriptors * kDescriptorSize]: start of slack
class DescriptorArray: public FixedArray {
public:
// Returns true for both shared empty_descriptor_array and for smis, which the
// map uses to encode additional bit fields when the descriptor array is not
// yet used.
inline bool IsEmpty();
// Returns the number of descriptors in the array.
inline int number_of_descriptors();
inline int number_of_descriptors_storage();
inline int NumberOfSlackDescriptors();
inline void SetNumberOfDescriptors(int number_of_descriptors);
inline int number_of_entries();
inline bool HasEnumCache();
inline void CopyEnumCacheFrom(DescriptorArray* array);
inline FixedArray* GetEnumCache();
inline bool HasEnumIndicesCache();
inline FixedArray* GetEnumIndicesCache();
inline Object** GetEnumCacheSlot();
void ClearEnumCache();
// Initialize or change the enum cache,
// using the supplied storage for the small "bridge".
static void SetEnumCache(Handle<DescriptorArray> descriptors,
Isolate* isolate, Handle<FixedArray> new_cache,
Handle<FixedArray> new_index_cache);
bool CanHoldValue(int descriptor, Object* value);
// Accessors for fetching instance descriptor at descriptor number.
inline Name* GetKey(int descriptor_number);
inline Object** GetKeySlot(int descriptor_number);
inline Object* GetValue(int descriptor_number);
inline void SetValue(int descriptor_number, Object* value);
inline Object** GetValueSlot(int descriptor_number);
static inline int GetValueOffset(int descriptor_number);
inline Object** GetDescriptorStartSlot(int descriptor_number);
inline Object** GetDescriptorEndSlot(int descriptor_number);
inline PropertyDetails GetDetails(int descriptor_number);
inline PropertyType GetType(int descriptor_number);
inline int GetFieldIndex(int descriptor_number);
inline HeapType* GetFieldType(int descriptor_number);
inline Object* GetConstant(int descriptor_number);
inline Object* GetCallbacksObject(int descriptor_number);
inline AccessorDescriptor* GetCallbacks(int descriptor_number);
inline Name* GetSortedKey(int descriptor_number);
inline int GetSortedKeyIndex(int descriptor_number);
inline void SetSortedKey(int pointer, int descriptor_number);
inline void SetRepresentation(int descriptor_number,
Representation representation);
// Accessor for complete descriptor.
inline void Get(int descriptor_number, Descriptor* desc);
inline void Set(int descriptor_number, Descriptor* desc);
void Replace(int descriptor_number, Descriptor* descriptor);
// Append automatically sets the enumeration index. This should only be used
// to add descriptors in bulk at the end, followed by sorting the descriptor
// array.
inline void Append(Descriptor* desc);
static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc,
int enumeration_index,
int slack = 0);
static Handle<DescriptorArray> CopyUpToAddAttributes(
Handle<DescriptorArray> desc,
int enumeration_index,
PropertyAttributes attributes,
int slack = 0);
// Sort the instance descriptors by the hash codes of their keys.
void Sort();
// Search the instance descriptors for given name.
INLINE(int Search(Name* name, int number_of_own_descriptors));
// As the above, but uses DescriptorLookupCache and updates it when
// necessary.
INLINE(int SearchWithCache(Name* name, Map* map));
bool IsEqualUpTo(DescriptorArray* desc, int nof_descriptors);
// Allocates a DescriptorArray, but returns the singleton
// empty descriptor array object if number_of_descriptors is 0.
static Handle<DescriptorArray> Allocate(Isolate* isolate,
int number_of_descriptors,
int slack = 0);
DECLARE_CAST(DescriptorArray)
// Constant for denoting key was not found.
static const int kNotFound = -1;
static const int kDescriptorLengthIndex = 0;
static const int kEnumCacheIndex = 1;
static const int kFirstIndex = 2;
// The length of the "bridge" to the enum cache.
static const int kEnumCacheBridgeLength = 2;
static const int kEnumCacheBridgeCacheIndex = 0;
static const int kEnumCacheBridgeIndicesCacheIndex = 1;
// Layout description.
static const int kDescriptorLengthOffset = FixedArray::kHeaderSize;
static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize;
static const int kFirstOffset = kEnumCacheOffset + kPointerSize;
// Layout description for the bridge array.
static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize;
// Layout of descriptor.
static const int kDescriptorKey = 0;
static const int kDescriptorDetails = 1;
static const int kDescriptorValue = 2;
static const int kDescriptorSize = 3;
#if defined(DEBUG) || defined(OBJECT_PRINT)
// For our gdb macros, we should perhaps change these in the future.
void Print();
// Print all the descriptors.
void PrintDescriptors(std::ostream& os); // NOLINT
#endif
#ifdef DEBUG
// Is the descriptor array sorted and without duplicates?
bool IsSortedNoDuplicates(int valid_descriptors = -1);
// Is the descriptor array consistent with the back pointers in targets?
bool IsConsistentWithBackPointers(Map* current_map);
// Are two DescriptorArrays equal?
bool IsEqualTo(DescriptorArray* other);
#endif
// Returns the fixed array length required to hold number_of_descriptors
// descriptors.
static int LengthFor(int number_of_descriptors) {
return ToKeyIndex(number_of_descriptors);
}
private:
// An entry in a DescriptorArray, represented as an (array, index) pair.
class Entry {
public:
inline explicit Entry(DescriptorArray* descs, int index) :
descs_(descs), index_(index) { }
inline PropertyType type();
inline Object* GetCallbackObject();
private:
DescriptorArray* descs_;
int index_;
};
// Conversion from descriptor number to array indices.
static int ToKeyIndex(int descriptor_number) {
return kFirstIndex +
(descriptor_number * kDescriptorSize) +
kDescriptorKey;
}
static int ToDetailsIndex(int descriptor_number) {
return kFirstIndex +
(descriptor_number * kDescriptorSize) +
kDescriptorDetails;
}
static int ToValueIndex(int descriptor_number) {
return kFirstIndex +
(descriptor_number * kDescriptorSize) +
kDescriptorValue;
}
// Transfer a complete descriptor from the src descriptor array to this
// descriptor array.
void CopyFrom(int index, DescriptorArray* src);
inline void SetDescriptor(int descriptor_number, Descriptor* desc);
// Swap first and second descriptor.
inline void SwapSortedKeys(int first, int second);
DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
};
enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
template <SearchMode search_mode, typename T>
inline int Search(T* array, Name* name, int valid_entries = 0,
int* out_insertion_index = NULL);
// HashTable is a subclass of FixedArray that implements a hash table
// that uses open addressing and quadratic probing.
//
// In order for the quadratic probing to work, elements that have not
// yet been used and elements that have been deleted are
// distinguished. Probing continues when deleted elements are
// encountered and stops when unused elements are encountered.
//
// - Elements with key == undefined have not been used yet.
// - Elements with key == the_hole have been deleted.
//
// The hash table class is parameterized with a Shape and a Key.
// Shape must be a class with the following interface:
// class ExampleShape {
// public:
// // Tells whether key matches other.
// static bool IsMatch(Key key, Object* other);
// // Returns the hash value for key.
// static uint32_t Hash(Key key);
// // Returns the hash value for object.
// static uint32_t HashForObject(Key key, Object* object);
// // Convert key to an object.
// static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
// // The prefix size indicates number of elements in the beginning
// // of the backing storage.
// static const int kPrefixSize = ..;
// // The Element size indicates number of elements per entry.
// static const int kEntrySize = ..;
// };
// The prefix size indicates an amount of memory in the
// beginning of the backing storage that can be used for non-element
// information by subclasses.
template<typename Key>
class BaseShape {
public:
static const bool UsesSeed = false;
static uint32_t Hash(Key key) { return 0; }
static uint32_t SeededHash(Key key, uint32_t seed) {
DCHECK(UsesSeed);
return Hash(key);
}
static uint32_t HashForObject(Key key, Object* object) { return 0; }
static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) {
DCHECK(UsesSeed);
return HashForObject(key, object);
}
};
class HashTableBase : public FixedArray {
public:
// Returns the number of elements in the hash table.
inline int NumberOfElements();
// Returns the number of deleted elements in the hash table.
inline int NumberOfDeletedElements();
// Returns the capacity of the hash table.
inline int Capacity();
// ElementAdded should be called whenever an element is added to a
// hash table.
inline void ElementAdded();
// ElementRemoved should be called whenever an element is removed from
// a hash table.
inline void ElementRemoved();
inline void ElementsRemoved(int n);
// Computes the required capacity for a table holding the given
// number of elements. May be more than HashTable::kMaxCapacity.
static inline int ComputeCapacity(int at_least_space_for);
// Tells whether k is a real key. The hole and undefined are not allowed
// as keys and can be used to indicate missing or deleted elements.
inline bool IsKey(Object* k);
// Compute the probe offset (quadratic probing).
INLINE(static uint32_t GetProbeOffset(uint32_t n)) {
return (n + n * n) >> 1;
}
static const int kNumberOfElementsIndex = 0;
static const int kNumberOfDeletedElementsIndex = 1;
static const int kCapacityIndex = 2;
static const int kPrefixStartIndex = 3;
// Constant used for denoting a absent entry.
static const int kNotFound = -1;
protected:
// Update the number of elements in the hash table.
inline void SetNumberOfElements(int nof);
// Update the number of deleted elements in the hash table.
inline void SetNumberOfDeletedElements(int nod);
// Returns probe entry.
static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) {
DCHECK(base::bits::IsPowerOfTwo32(size));
return (hash + GetProbeOffset(number)) & (size - 1);
}
inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) {
return hash & (size - 1);
}
inline static uint32_t NextProbe(
uint32_t last, uint32_t number, uint32_t size) {
return (last + number) & (size - 1);
}
};
template <typename Derived, typename Shape, typename Key>
class HashTable : public HashTableBase {
public:
// Wrapper methods
inline uint32_t Hash(Key key) {
if (Shape::UsesSeed) {
return Shape::SeededHash(key, GetHeap()->HashSeed());
} else {
return Shape::Hash(key);
}
}
inline uint32_t HashForObject(Key key, Object* object) {
if (Shape::UsesSeed) {
return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object);
} else {
return Shape::HashForObject(key, object);
}
}
// Returns a new HashTable object.
MUST_USE_RESULT static Handle<Derived> New(
Isolate* isolate, int at_least_space_for,
MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
PretenureFlag pretenure = NOT_TENURED);
DECLARE_CAST(HashTable)
// Garbage collection support.
void IteratePrefix(ObjectVisitor* visitor);
void IterateElements(ObjectVisitor* visitor);
// Find entry for key otherwise return kNotFound.
inline int FindEntry(Key key);
inline int FindEntry(Isolate* isolate, Key key, int32_t hash);
int FindEntry(Isolate* isolate, Key key);
// Rehashes the table in-place.
void Rehash(Key key);
// Returns the key at entry.
Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize;
static const int kEntrySize = Shape::kEntrySize;
static const int kElementsStartOffset =
kHeaderSize + kElementsStartIndex * kPointerSize;
static const int kCapacityOffset =
kHeaderSize + kCapacityIndex * kPointerSize;
// Returns the index for an entry (of the key)
static inline int EntryToIndex(int entry) {
return (entry * kEntrySize) + kElementsStartIndex;
}
protected:
friend class ObjectHashTable;
// Find the entry at which to insert element with the given key that
// has the given hash value.
uint32_t FindInsertionEntry(uint32_t hash);
// Attempt to shrink hash table after removal of key.
MUST_USE_RESULT static Handle<Derived> Shrink(Handle<Derived> table, Key key);
// Ensure enough space for n additional elements.
MUST_USE_RESULT static Handle<Derived> EnsureCapacity(
Handle<Derived> table,
int n,
Key key,
PretenureFlag pretenure = NOT_TENURED);
// Returns true if this table has sufficient capacity for adding n elements.
bool HasSufficientCapacity(int n);
// Sets the capacity of the hash table.
void SetCapacity(int capacity) {
// To scale a computed hash code to fit within the hash table, we
// use bit-wise AND with a mask, so the capacity must be positive
// and non-zero.
DCHECK(capacity > 0);
DCHECK(capacity <= kMaxCapacity);
set(kCapacityIndex, Smi::FromInt(capacity));
}
// Maximal capacity of HashTable. Based on maximal length of underlying
// FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex
// cannot overflow.
static const int kMaxCapacity =
(FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize;
private:
// Returns _expected_ if one of entries given by the first _probe_ probes is
// equal to _expected_. Otherwise, returns the entry given by the probe
// number _probe_.
uint32_t EntryForProbe(Key key, Object* k, int probe, uint32_t expected);
void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode);
// Rehashes this hash-table into the new table.
void Rehash(Handle<Derived> new_table, Key key);
};
// HashTableKey is an abstract superclass for virtual key behavior.
class HashTableKey {
public:
// Returns whether the other object matches this key.
virtual bool IsMatch(Object* other) = 0;
// Returns the hash value for this key.
virtual uint32_t Hash() = 0;
// Returns the hash value for object.
virtual uint32_t HashForObject(Object* key) = 0;
// Returns the key object for storing into the hash table.
MUST_USE_RESULT virtual Handle<Object> AsHandle(Isolate* isolate) = 0;
// Required.
virtual ~HashTableKey() {}
};
class StringTableShape : public BaseShape<HashTableKey*> {
public:
static inline bool IsMatch(HashTableKey* key, Object* value) {
return key->IsMatch(value);
}
static inline uint32_t Hash(HashTableKey* key) {
return key->Hash();
}
static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
return key->HashForObject(object);
}
static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
static const int kPrefixSize = 0;
static const int kEntrySize = 1;
};
class SeqOneByteString;
// StringTable.
//
// No special elements in the prefix and the element size is 1
// because only the string itself (the key) needs to be stored.
class StringTable: public HashTable<StringTable,
StringTableShape,
HashTableKey*> {
public:
// Find string in the string table. If it is not there yet, it is
// added. The return value is the string found.
static Handle<String> LookupString(Isolate* isolate, Handle<String> key);
static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key);
static String* LookupKeyIfExists(Isolate* isolate, HashTableKey* key);
// Tries to internalize given string and returns string handle on success
// or an empty handle otherwise.
MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists(
Isolate* isolate,
Handle<String> string);
// Looks up a string that is equal to the given string and returns
// string handle if it is found, or an empty handle otherwise.
MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists(
Isolate* isolate,
Handle<String> str);
MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists(
Isolate* isolate,
uint16_t c1,
uint16_t c2);
static void EnsureCapacityForDeserialization(Isolate* isolate, int expected);
DECLARE_CAST(StringTable)
private:
template <bool seq_one_byte>
friend class JsonParser;
DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable);
};
template <typename Derived, typename Shape, typename Key>
class Dictionary: public HashTable<Derived, Shape, Key> {
typedef HashTable<Derived, Shape, Key> DerivedHashTable;
public:
// Returns the value at entry.
Object* ValueAt(int entry) {
return this->get(Derived::EntryToIndex(entry) + 1);
}
// Set the value for entry.
void ValueAtPut(int entry, Object* value) {
this->set(Derived::EntryToIndex(entry) + 1, value);
}
// Returns the property details for the property at entry.
PropertyDetails DetailsAt(int entry) {
return Shape::DetailsAt(static_cast<Derived*>(this), entry);
}
// Set the details for entry.
void DetailsAtPut(int entry, PropertyDetails value) {
Shape::DetailsAtPut(static_cast<Derived*>(this), entry, value);
}
// Returns true if property at given entry is deleted.
bool IsDeleted(int entry) {
return Shape::IsDeleted(static_cast<Derived*>(this), entry);
}
// Delete a property from the dictionary.
static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry);
// Attempt to shrink the dictionary after deletion of key.
MUST_USE_RESULT static inline Handle<Derived> Shrink(
Handle<Derived> dictionary,
Key key) {
return DerivedHashTable::Shrink(dictionary, key);
}
// Sorting support
// TODO(dcarney): templatize or move to SeededNumberDictionary
void CopyValuesTo(FixedArray* elements);
// Returns the number of elements in the dictionary filtering out properties
// with the specified attributes.
// TODO(jkummerow): Deprecated, only used by Object.observe.
int NumberOfElementsFilterAttributes(PropertyFilter filter);
// Returns the number of enumerable elements in the dictionary.
// TODO(jkummerow): Deprecated, only used by Object.observe.
int NumberOfEnumElements() {
return NumberOfElementsFilterAttributes(ENUMERABLE_STRINGS);
}
// Returns true if the dictionary contains any elements that are non-writable,
// non-configurable, non-enumerable, or have getters/setters.
bool HasComplexElements();
enum SortMode { UNSORTED, SORTED };
// Fill in details for properties into storage.
// Returns the number of properties added.
// TODO(jkummerow): Deprecated, only used by Object.observe.
int CopyKeysTo(FixedArray* storage, int index, PropertyFilter filter,
SortMode sort_mode);
// Collect the keys into the given KeyAccumulator, in ascending chronological
// order of property creation.
static void CollectKeysTo(Handle<Dictionary<Derived, Shape, Key> > dictionary,
KeyAccumulator* keys, PropertyFilter filter);
// Copies enumerable keys to preallocated fixed array.
void CopyEnumKeysTo(FixedArray* storage);
// Accessors for next enumeration index.
void SetNextEnumerationIndex(int index) {
DCHECK(index != 0);
this->set(kNextEnumerationIndexIndex, Smi::FromInt(index));
}
int NextEnumerationIndex() {
return Smi::cast(this->get(kNextEnumerationIndexIndex))->value();
}
// Creates a new dictionary.
MUST_USE_RESULT static Handle<Derived> New(
Isolate* isolate,
int at_least_space_for,
PretenureFlag pretenure = NOT_TENURED);
// Ensures that a new dictionary is created when the capacity is checked.
void SetRequiresCopyOnCapacityChange();
// Ensure enough space for n additional elements.
static Handle<Derived> EnsureCapacity(Handle<Derived> obj, int n, Key key);
#ifdef OBJECT_PRINT
void Print(std::ostream& os); // NOLINT
#endif
// Returns the key (slow).
Object* SlowReverseLookup(Object* value);
// Sets the entry to (key, value) pair.
inline void SetEntry(int entry,
Handle<Object> key,
Handle<Object> value);
inline void SetEntry(int entry,
Handle<Object> key,
Handle<Object> value,
PropertyDetails details);
MUST_USE_RESULT static Handle<Derived> Add(
Handle<Derived> dictionary,
Key key,
Handle<Object> value,
PropertyDetails details);
// Returns iteration indices array for the |dictionary|.
// Values are direct indices in the |HashTable| array.
static Handle<FixedArray> BuildIterationIndicesArray(
Handle<Derived> dictionary);
protected:
// Generic at put operation.
MUST_USE_RESULT static Handle<Derived> AtPut(
Handle<Derived> dictionary,
Key key,
Handle<Object> value);
// Add entry to dictionary.
static void AddEntry(
Handle<Derived> dictionary,
Key key,
Handle<Object> value,
PropertyDetails details,
uint32_t hash);
// Generate new enumeration indices to avoid enumeration index overflow.
// Returns iteration indices array for the |dictionary|.
static Handle<FixedArray> GenerateNewEnumerationIndices(
Handle<Derived> dictionary);
static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex;
static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
};
template <typename Derived, typename Shape>
class NameDictionaryBase : public Dictionary<Derived, Shape, Handle<Name> > {
typedef Dictionary<Derived, Shape, Handle<Name> > DerivedDictionary;
public:
// Find entry for key, otherwise return kNotFound. Optimized version of
// HashTable::FindEntry.
int FindEntry(Handle<Name> key);
};
template <typename Key>
class BaseDictionaryShape : public BaseShape<Key> {
public:
template <typename Dictionary>
static inline PropertyDetails DetailsAt(Dictionary* dict, int entry) {
STATIC_ASSERT(Dictionary::kEntrySize == 3);
DCHECK(entry >= 0); // Not found is -1, which is not caught by get().
return PropertyDetails(
Smi::cast(dict->get(Dictionary::EntryToIndex(entry) + 2)));
}
template <typename Dictionary>
static inline void DetailsAtPut(Dictionary* dict, int entry,
PropertyDetails value) {
STATIC_ASSERT(Dictionary::kEntrySize == 3);
dict->set(Dictionary::EntryToIndex(entry) + 2, value.AsSmi());
}
template <typename Dictionary>
static bool IsDeleted(Dictionary* dict, int entry) {
return false;
}
template <typename Dictionary>
static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key,
Handle<Object> value, PropertyDetails details);
};
class NameDictionaryShape : public BaseDictionaryShape<Handle<Name> > {
public:
static inline bool IsMatch(Handle<Name> key, Object* other);
static inline uint32_t Hash(Handle<Name> key);
static inline uint32_t HashForObject(Handle<Name> key, Object* object);
static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
static const int kPrefixSize = 2;
static const int kEntrySize = 3;
static const bool kIsEnumerable = true;
};
class NameDictionary
: public NameDictionaryBase<NameDictionary, NameDictionaryShape> {
typedef NameDictionaryBase<NameDictionary, NameDictionaryShape>
DerivedDictionary;
public:
DECLARE_CAST(NameDictionary)
inline static Handle<FixedArray> DoGenerateNewEnumerationIndices(
Handle<NameDictionary> dictionary);
};
class GlobalDictionaryShape : public NameDictionaryShape {
public:
static const int kEntrySize = 2; // Overrides NameDictionaryShape::kEntrySize
template <typename Dictionary>
static inline PropertyDetails DetailsAt(Dictionary* dict, int entry);
template <typename Dictionary>
static inline void DetailsAtPut(Dictionary* dict, int entry,
PropertyDetails value);
template <typename Dictionary>
static bool IsDeleted(Dictionary* dict, int entry);
template <typename Dictionary>
static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key,
Handle<Object> value, PropertyDetails details);
};
class GlobalDictionary
: public NameDictionaryBase<GlobalDictionary, GlobalDictionaryShape> {
public:
DECLARE_CAST(GlobalDictionary)
};
class NumberDictionaryShape : public BaseDictionaryShape<uint32_t> {
public:
static inline bool IsMatch(uint32_t key, Object* other);
static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key);
static const int kEntrySize = 3;
static const bool kIsEnumerable = false;
};
class SeededNumberDictionaryShape : public NumberDictionaryShape {
public:
static const bool UsesSeed = true;
static const int kPrefixSize = 2;
static inline uint32_t SeededHash(uint32_t key, uint32_t seed);
static inline uint32_t SeededHashForObject(uint32_t key,
uint32_t seed,
Object* object);
};
class UnseededNumberDictionaryShape : public NumberDictionaryShape {
public:
static const int kPrefixSize = 0;
static inline uint32_t Hash(uint32_t key);
static inline uint32_t HashForObject(uint32_t key, Object* object);
};
class SeededNumberDictionary
: public Dictionary<SeededNumberDictionary,
SeededNumberDictionaryShape,
uint32_t> {
public:
DECLARE_CAST(SeededNumberDictionary)
// Type specific at put (default NONE attributes is used when adding).
MUST_USE_RESULT static Handle<SeededNumberDictionary> AtNumberPut(
Handle<SeededNumberDictionary> dictionary, uint32_t key,
Handle<Object> value, bool used_as_prototype);
MUST_USE_RESULT static Handle<SeededNumberDictionary> AddNumberEntry(
Handle<SeededNumberDictionary> dictionary, uint32_t key,
Handle<Object> value, PropertyDetails details, bool used_as_prototype);
// Set an existing entry or add a new one if needed.
// Return the updated dictionary.
MUST_USE_RESULT static Handle<SeededNumberDictionary> Set(
Handle<SeededNumberDictionary> dictionary, uint32_t key,
Handle<Object> value, PropertyDetails details, bool used_as_prototype);
void UpdateMaxNumberKey(uint32_t key, bool used_as_prototype);
// If slow elements are required we will never go back to fast-case
// for the elements kept in this dictionary. We require slow
// elements if an element has been added at an index larger than
// kRequiresSlowElementsLimit or set_requires_slow_elements() has been called
// when defining a getter or setter with a number key.
inline bool requires_slow_elements();
inline void set_requires_slow_elements();
// Get the value of the max number key that has been added to this
// dictionary. max_number_key can only be called if
// requires_slow_elements returns false.
inline uint32_t max_number_key();
// Bit masks.
static const int kRequiresSlowElementsMask = 1;
static const int kRequiresSlowElementsTagSize = 1;
static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1;
};
class UnseededNumberDictionary
: public Dictionary<UnseededNumberDictionary,
UnseededNumberDictionaryShape,
uint32_t> {
public:
DECLARE_CAST(UnseededNumberDictionary)
// Type specific at put (default NONE attributes is used when adding).
MUST_USE_RESULT static Handle<UnseededNumberDictionary> AtNumberPut(
Handle<UnseededNumberDictionary> dictionary,
uint32_t key,
Handle<Object> value);
MUST_USE_RESULT static Handle<UnseededNumberDictionary> AddNumberEntry(
Handle<UnseededNumberDictionary> dictionary,
uint32_t key,
Handle<Object> value);
// Set an existing entry or add a new one if needed.
// Return the updated dictionary.
MUST_USE_RESULT static Handle<UnseededNumberDictionary> Set(
Handle<UnseededNumberDictionary> dictionary,
uint32_t key,
Handle<Object> value);
};
class ObjectHashTableShape : public BaseShape<Handle<Object> > {
public:
static inline bool IsMatch(Handle<Object> key, Object* other);
static inline uint32_t Hash(Handle<Object> key);
static inline uint32_t HashForObject(Handle<Object> key, Object* object);
static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
static const int kPrefixSize = 0;
static const int kEntrySize = 2;
};
// ObjectHashTable maps keys that are arbitrary objects to object values by
// using the identity hash of the key for hashing purposes.
class ObjectHashTable: public HashTable<ObjectHashTable,
ObjectHashTableShape,
Handle<Object> > {
typedef HashTable<
ObjectHashTable, ObjectHashTableShape, Handle<Object> > DerivedHashTable;
public:
DECLARE_CAST(ObjectHashTable)
// Attempt to shrink hash table after removal of key.
MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink(
Handle<ObjectHashTable> table,
Handle<Object> key);
// Looks up the value associated with the given key. The hole value is
// returned in case the key is not present.
Object* Lookup(Handle<Object> key);
Object* Lookup(Handle<Object> key, int32_t hash);
Object* Lookup(Isolate* isolate, Handle<Object> key, int32_t hash);
// Adds (or overwrites) the value associated with the given key.
static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
Handle<Object> key,
Handle<Object> value);
static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
Handle<Object> key, Handle<Object> value,
int32_t hash);
// Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
Handle<Object> key,
bool* was_present);
static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
Handle<Object> key, bool* was_present,
int32_t hash);
protected:
friend class MarkCompactCollector;
void AddEntry(int entry, Object* key, Object* value);
void RemoveEntry(int entry);
// Returns the index to the value of an entry.
static inline int EntryToValueIndex(int entry) {
return EntryToIndex(entry) + 1;
}
};
// OrderedHashTable is a HashTable with Object keys that preserves
// insertion order. There are Map and Set interfaces (OrderedHashMap
// and OrderedHashTable, below). It is meant to be used by JSMap/JSSet.
//
// Only Object* keys are supported, with Object::SameValueZero() used as the
// equality operator and Object::GetHash() for the hash function.
//
// Based on the "Deterministic Hash Table" as described by Jason Orendorff at
// https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables
// Originally attributed to Tyler Close.
//
// Memory layout:
// [0]: bucket count
// [1]: element count
// [2]: deleted element count
// [3..(3 + NumberOfBuckets() - 1)]: "hash table", where each item is an
// offset into the data table (see below) where the
// first item in this bucket is stored.
// [3 + NumberOfBuckets()..length]: "data table", an array of length
// Capacity() * kEntrySize, where the first entrysize
// items are handled by the derived class and the
// item at kChainOffset is another entry into the
// data table indicating the next entry in this hash
// bucket.
//
// When we transition the table to a new version we obsolete it and reuse parts
// of the memory to store information how to transition an iterator to the new
// table:
//
// Memory layout for obsolete table:
// [0]: bucket count
// [1]: Next newer table
// [2]: Number of removed holes or -1 when the table was cleared.
// [3..(3 + NumberOfRemovedHoles() - 1)]: The indexes of the removed holes.
// [3 + NumberOfRemovedHoles()..length]: Not used
//
template<class Derived, class Iterator, int entrysize>
class OrderedHashTable: public FixedArray {
public:
// Returns an OrderedHashTable with a capacity of at least |capacity|.
static Handle<Derived> Allocate(
Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED);
// Returns an OrderedHashTable (possibly |table|) with enough space
// to add at least one new element.
static Handle<Derived> EnsureGrowable(Handle<Derived> table);
// Returns an OrderedHashTable (possibly |table|) that's shrunken
// if possible.
static Handle<Derived> Shrink(Handle<Derived> table);
// Returns a new empty OrderedHashTable and records the clearing so that
// exisiting iterators can be updated.
static Handle<Derived> Clear(Handle<Derived> table);
// Returns a true if the OrderedHashTable contains the key
static bool HasKey(Handle<Derived> table, Handle<Object> key);
int NumberOfElements() {
return Smi::cast(get(kNumberOfElementsIndex))->value();
}
int NumberOfDeletedElements() {
return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
}
int UsedCapacity() { return NumberOfElements() + NumberOfDeletedElements(); }
int NumberOfBuckets() {
return Smi::cast(get(kNumberOfBucketsIndex))->value();
}
// Returns an index into |this| for the given entry.
int EntryToIndex(int entry) {
return kHashTableStartIndex + NumberOfBuckets() + (entry * kEntrySize);
}
int HashToBucket(int hash) { return hash & (NumberOfBuckets() - 1); }
int HashToEntry(int hash) {
int bucket = HashToBucket(hash);
Object* entry = this->get(kHashTableStartIndex + bucket);
return Smi::cast(entry)->value();
}
int KeyToFirstEntry(Object* key) {
Object* hash = key->GetHash();
// If the object does not have an identity hash, it was never used as a key
if (hash->IsUndefined()) return kNotFound;
return HashToEntry(Smi::cast(hash)->value());
}
int NextChainEntry(int entry) {
Object* next_entry = get(EntryToIndex(entry) + kChainOffset);
return Smi::cast(next_entry)->value();
}
Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
bool IsObsolete() {
return !get(kNextTableIndex)->IsSmi();
}
// The next newer table. This is only valid if the table is obsolete.
Derived* NextTable() {
return Derived::cast(get(kNextTableIndex));
}
// When the table is obsolete we store the indexes of the removed holes.
int RemovedIndexAt(int index) {
return Smi::cast(get(kRemovedHolesIndex + index))->value();
}
static const int kNotFound = -1;
static const int kMinCapacity = 4;
static const int kNumberOfBucketsIndex = 0;
static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1;
static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1;
static const int kNextTableIndex = kNumberOfElementsIndex;
static const int kNumberOfBucketsOffset =
kHeaderSize + kNumberOfBucketsIndex * kPointerSize;
static const int kNumberOfElementsOffset =
kHeaderSize + kNumberOfElementsIndex * kPointerSize;
static const int kNumberOfDeletedElementsOffset =
kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize;
static const int kHashTableStartOffset =
kHeaderSize + kHashTableStartIndex * kPointerSize;
static const int kNextTableOffset =
kHeaderSize + kNextTableIndex * kPointerSize;
static const int kEntrySize = entrysize + 1;
static const int kChainOffset = entrysize;
static const int kLoadFactor = 2;
// NumberOfDeletedElements is set to kClearedTableSentinel when
// the table is cleared, which allows iterator transitions to
// optimize that case.
static const int kClearedTableSentinel = -1;
protected:
static Handle<Derived> Rehash(Handle<Derived> table, int new_capacity);
void SetNumberOfBuckets(int num) {
set(kNumberOfBucketsIndex, Smi::FromInt(num));
}
void SetNumberOfElements(int num) {
set(kNumberOfElementsIndex, Smi::FromInt(num));
}
void SetNumberOfDeletedElements(int num) {
set(kNumberOfDeletedElementsIndex, Smi::FromInt(num));
}
int Capacity() {
return NumberOfBuckets() * kLoadFactor;
}
void SetNextTable(Derived* next_table) {
set(kNextTableIndex, next_table);
}
void SetRemovedIndexAt(int index, int removed_index) {
return set(kRemovedHolesIndex + index, Smi::FromInt(removed_index));
}
static const int kRemovedHolesIndex = kHashTableStartIndex;
static const int kMaxCapacity =
(FixedArray::kMaxLength - kHashTableStartIndex)
/ (1 + (kEntrySize * kLoadFactor));
};
class JSSetIterator;
class OrderedHashSet: public OrderedHashTable<
OrderedHashSet, JSSetIterator, 1> {
public:
DECLARE_CAST(OrderedHashSet)
static Handle<OrderedHashSet> Add(Handle<OrderedHashSet> table,
Handle<Object> value);
};
class JSMapIterator;
class OrderedHashMap
: public OrderedHashTable<OrderedHashMap, JSMapIterator, 2> {
public:
DECLARE_CAST(OrderedHashMap)
inline Object* ValueAt(int entry);
static const int kValueOffset = 1;
};
template <int entrysize>
class WeakHashTableShape : public BaseShape<Handle<Object> > {
public:
static inline bool IsMatch(Handle<Object> key, Object* other);
static inline uint32_t Hash(Handle<Object> key);
static inline uint32_t HashForObject(Handle<Object> key, Object* object);
static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key);
static const int kPrefixSize = 0;
static const int kEntrySize = entrysize;
};
// WeakHashTable maps keys that are arbitrary heap objects to heap object
// values. The table wraps the keys in weak cells and store values directly.
// Thus it references keys weakly and values strongly.
class WeakHashTable: public HashTable<WeakHashTable,
WeakHashTableShape<2>,
Handle<Object> > {
typedef HashTable<
WeakHashTable, WeakHashTableShape<2>, Handle<Object> > DerivedHashTable;
public:
DECLARE_CAST(WeakHashTable)
// Looks up the value associated with the given key. The hole value is
// returned in case the key is not present.
Object* Lookup(Handle<HeapObject> key);
// Adds (or overwrites) the value associated with the given key. Mapping a
// key to the hole value causes removal of the whole entry.
MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table,
Handle<HeapObject> key,
Handle<HeapObject> value);
static Handle<FixedArray> GetValues(Handle<WeakHashTable> table);
private:
friend class MarkCompactCollector;
void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value);
// Returns the index to the value of an entry.
static inline int EntryToValueIndex(int entry) {
return EntryToIndex(entry) + 1;
}
};
// ScopeInfo represents information about different scopes of a source
// program and the allocation of the scope's variables. Scope information
// is stored in a compressed form in ScopeInfo objects and is used
// at runtime (stack dumps, deoptimization, etc.).
// This object provides quick access to scope info details for runtime
// routines.
class ScopeInfo : public FixedArray {
public:
DECLARE_CAST(ScopeInfo)
// Return the type of this scope.
ScopeType scope_type();
// Does this scope call eval?
bool CallsEval();
// Return the language mode of this scope.
LanguageMode language_mode();
// True if this scope is a (var) declaration scope.
bool is_declaration_scope();
// Does this scope make a sloppy eval call?
bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); }
// Return the total number of locals allocated on the stack and in the
// context. This includes the parameters that are allocated in the context.
int LocalCount();
// Return the number of stack slots for code. This number consists of two
// parts:
// 1. One stack slot per stack allocated local.
// 2. One stack slot for the function name if it is stack allocated.
int StackSlotCount();
// Return the number of context slots for code if a context is allocated. This
// number consists of three parts:
// 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS
// 2. One context slot per context allocated local.
// 3. One context slot for the function name if it is context allocated.
// Parameters allocated in the context count as context allocated locals. If
// no contexts are allocated for this scope ContextLength returns 0.
int ContextLength();
// Does this scope declare a "this" binding?
bool HasReceiver();
// Does this scope declare a "this" binding, and the "this" binding is stack-
// or context-allocated?
bool HasAllocatedReceiver();
// Does this scope declare a "new.target" binding?
bool HasNewTarget();
// Is this scope the scope of a named function expression?
bool HasFunctionName();
// Return if this has context allocated locals.
bool HasHeapAllocatedLocals();
// Return if contexts are allocated for this scope.
bool HasContext();
// Return if this is a function scope with "use asm".
inline bool IsAsmModule();
// Return if this is a nested function within an asm module scope.
inline bool IsAsmFunction();
inline bool HasSimpleParameters();
// Return the function_name if present.
String* FunctionName();
// Return the name of the given parameter.
String* ParameterName(int var);
// Return the name of the given local.
String* LocalName(int var);
// Return the name of the given stack local.
String* StackLocalName(int var);
// Return the name of the given stack local.
int StackLocalIndex(int var);
// Return the name of the given context local.
String* ContextLocalName(int var);
// Return the mode of the given context local.
VariableMode ContextLocalMode(int var);
// Return the initialization flag of the given context local.
InitializationFlag ContextLocalInitFlag(int var);
// Return the initialization flag of the given context local.
MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var);
// Return true if this local was introduced by the compiler, and should not be
// exposed to the user in a debugger.
bool LocalIsSynthetic(int var);
String* StrongModeFreeVariableName(int var);
int StrongModeFreeVariableStartPosition(int var);
int StrongModeFreeVariableEndPosition(int var);
// Lookup support for serialized scope info. Returns the
// the stack slot index for a given slot name if the slot is
// present; otherwise returns a value < 0. The name must be an internalized
// string.
int StackSlotIndex(String* name);
// Lookup support for serialized scope info. Returns the local context slot
// index for a given slot name if the slot is present; otherwise
// returns a value < 0. The name must be an internalized string.
// If the slot is present and mode != NULL, sets *mode to the corresponding
// mode for that variable.
static int ContextSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name,
VariableMode* mode, InitializationFlag* init_flag,
MaybeAssignedFlag* maybe_assigned_flag);
// Similar to ContextSlotIndex() but this method searches only among
// global slots of the serialized scope info. Returns the context slot index
// for a given slot name if the slot is present; otherwise returns a
// value < 0. The name must be an internalized string. If the slot is present
// and mode != NULL, sets *mode to the corresponding mode for that variable.
static int ContextGlobalSlotIndex(Handle<ScopeInfo> scope_info,
Handle<String> name, VariableMode* mode,
InitializationFlag* init_flag,
MaybeAssignedFlag* maybe_assigned_flag);
// Lookup the name of a certain context slot by its index.
String* ContextSlotName(int slot_index);
// Lookup support for serialized scope info. Returns the
// parameter index for a given parameter name if the parameter is present;
// otherwise returns a value < 0. The name must be an internalized string.
int ParameterIndex(String* name);
// Lookup support for serialized scope info. Returns the function context
// slot index if the function name is present and context-allocated (named
// function expressions, only), otherwise returns a value < 0. The name
// must be an internalized string.
int FunctionContextSlotIndex(String* name, VariableMode* mode);
// Lookup support for serialized scope info. Returns the receiver context
// slot index if scope has a "this" binding, and the binding is
// context-allocated. Otherwise returns a value < 0.
int ReceiverContextSlotIndex();
FunctionKind function_kind();
static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope);
static Handle<ScopeInfo> CreateGlobalThisBinding(Isolate* isolate);
// Serializes empty scope info.
static ScopeInfo* Empty(Isolate* isolate);
#ifdef DEBUG
void Print();
#endif
// The layout of the static part of a ScopeInfo is as follows. Each entry is
// numeric and occupies one array slot.
// 1. A set of properties of the scope
// 2. The number of parameters. This only applies to function scopes. For
// non-function scopes this is 0.
// 3. The number of non-parameter variables allocated on the stack.
// 4. The number of non-parameter and parameter variables allocated in the
// context.
#define FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(V) \
V(Flags) \
V(ParameterCount) \
V(StackLocalCount) \
V(ContextLocalCount) \
V(ContextGlobalCount) \
V(StrongModeFreeVariableCount)
#define FIELD_ACCESSORS(name) \
inline void Set##name(int value); \
inline int name();
FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(FIELD_ACCESSORS)
#undef FIELD_ACCESSORS
enum {
#define DECL_INDEX(name) k##name,
FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(DECL_INDEX)
#undef DECL_INDEX
kVariablePartIndex
};
private:
// The layout of the variable part of a ScopeInfo is as follows:
// 1. ParameterEntries:
// This part stores the names of the parameters for function scopes. One
// slot is used per parameter, so in total this part occupies
// ParameterCount() slots in the array. For other scopes than function
// scopes ParameterCount() is 0.
// 2. StackLocalFirstSlot:
// Index of a first stack slot for stack local. Stack locals belonging to
// this scope are located on a stack at slots starting from this index.
// 3. StackLocalEntries:
// Contains the names of local variables that are allocated on the stack,
// in increasing order of the stack slot index. First local variable has
// a stack slot index defined in StackLocalFirstSlot (point 2 above).
// One slot is used per stack local, so in total this part occupies
// StackLocalCount() slots in the array.
// 4. ContextLocalNameEntries:
// Contains the names of local variables and parameters that are allocated
// in the context. They are stored in increasing order of the context slot
// index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
// context local, so in total this part occupies ContextLocalCount() slots
// in the array.
// 5. ContextLocalInfoEntries:
// Contains the variable modes and initialization flags corresponding to
// the context locals in ContextLocalNameEntries. One slot is used per
// context local, so in total this part occupies ContextLocalCount()
// slots in the array.
// 6. StrongModeFreeVariableNameEntries:
// Stores the names of strong mode free variables.
// 7. StrongModeFreeVariablePositionEntries:
// Stores the locations (start and end position) of strong mode free
// variables.
// 8. RecieverEntryIndex:
// If the scope binds a "this" value, one slot is reserved to hold the
// context or stack slot index for the variable.
// 9. FunctionNameEntryIndex:
// If the scope belongs to a named function expression this part contains
// information about the function variable. It always occupies two array
// slots: a. The name of the function variable.
// b. The context or stack slot index for the variable.
int ParameterEntriesIndex();
int StackLocalFirstSlotIndex();
int StackLocalEntriesIndex();
int ContextLocalNameEntriesIndex();
int ContextGlobalNameEntriesIndex();
int ContextLocalInfoEntriesIndex();
int ContextGlobalInfoEntriesIndex();
int StrongModeFreeVariableNameEntriesIndex();
int StrongModeFreeVariablePositionEntriesIndex();
int ReceiverEntryIndex();
int FunctionNameEntryIndex();
int Lookup(Handle<String> name, int start, int end, VariableMode* mode,
VariableLocation* location, InitializationFlag* init_flag,
MaybeAssignedFlag* maybe_assigned_flag);
// Used for the function name variable for named function expressions, and for
// the receiver.
enum VariableAllocationInfo { NONE, STACK, CONTEXT, UNUSED };
// Properties of scopes.
class ScopeTypeField : public BitField<ScopeType, 0, 4> {};
class CallsEvalField : public BitField<bool, ScopeTypeField::kNext, 1> {};
STATIC_ASSERT(LANGUAGE_END == 3);
class LanguageModeField
: public BitField<LanguageMode, CallsEvalField::kNext, 2> {};
class DeclarationScopeField
: public BitField<bool, LanguageModeField::kNext, 1> {};
class ReceiverVariableField
: public BitField<VariableAllocationInfo, DeclarationScopeField::kNext,
2> {};
class HasNewTargetField
: public BitField<bool, ReceiverVariableField::kNext, 1> {};
class FunctionVariableField
: public BitField<VariableAllocationInfo, HasNewTargetField::kNext, 2> {};
class FunctionVariableMode
: public BitField<VariableMode, FunctionVariableField::kNext, 3> {};
class AsmModuleField : public BitField<bool, FunctionVariableMode::kNext, 1> {
};
class AsmFunctionField : public BitField<bool, AsmModuleField::kNext, 1> {};
class HasSimpleParametersField
: public BitField<bool, AsmFunctionField::kNext, 1> {};
class FunctionKindField
: public BitField<FunctionKind, HasSimpleParametersField::kNext, 8> {};
// BitFields representing the encoded information for context locals in the
// ContextLocalInfoEntries part.
class ContextLocalMode: public BitField<VariableMode, 0, 3> {};
class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {};
class ContextLocalMaybeAssignedFlag
: public BitField<MaybeAssignedFlag, 4, 1> {};
friend class ScopeIterator;
};
// The cache for maps used by normalized (dictionary mode) objects.
// Such maps do not have property descriptors, so a typical program
// needs very limited number of distinct normalized maps.
class NormalizedMapCache: public FixedArray {
public:
static Handle<NormalizedMapCache> New(Isolate* isolate);
MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
PropertyNormalizationMode mode);
void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
void Clear();
DECLARE_CAST(NormalizedMapCache)
static inline bool IsNormalizedMapCache(const Object* obj);
DECLARE_VERIFIER(NormalizedMapCache)
private:
static const int kEntries = 64;
static inline int GetIndex(Handle<Map> map);
// The following declarations hide base class methods.
Object* get(int index);
void set(int index, Object* value);
};
// ByteArray represents fixed sized byte arrays. Used for the relocation info
// that is attached to code objects.
class ByteArray: public FixedArrayBase {
public:
inline int Size();
// Setter and getter.
inline byte get(int index);
inline void set(int index, byte value);
// Treat contents as an int array.
inline int get_int(int index);
static int SizeFor(int length) {
return OBJECT_POINTER_ALIGN(kHeaderSize + length);
}
// We use byte arrays for free blocks in the heap. Given a desired size in
// bytes that is a multiple of the word size and big enough to hold a byte
// array, this function returns the number of elements a byte array should
// have.
static int LengthFor(int size_in_bytes) {
DCHECK(IsAligned(size_in_bytes, kPointerSize));
DCHECK(size_in_bytes >= kHeaderSize);
return size_in_bytes - kHeaderSize;
}
// Returns data start address.
inline Address GetDataStartAddress();
// Returns a pointer to the ByteArray object for a given data start address.
static inline ByteArray* FromDataStartAddress(Address address);
DECLARE_CAST(ByteArray)
// Dispatched behavior.
inline int ByteArraySize();
DECLARE_PRINTER(ByteArray)
DECLARE_VERIFIER(ByteArray)
// Layout description.
static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
// Maximal memory consumption for a single ByteArray.
static const int kMaxSize = 512 * MB;
// Maximal length of a single ByteArray.
static const int kMaxLength = kMaxSize - kHeaderSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
};
// BytecodeArray represents a sequence of interpreter bytecodes.
class BytecodeArray : public FixedArrayBase {
public:
static int SizeFor(int length) {
return OBJECT_POINTER_ALIGN(kHeaderSize + length);
}
// Setter and getter
inline byte get(int index);
inline void set(int index, byte value);
// Returns data start address.
inline Address GetFirstBytecodeAddress();
// Accessors for frame size.
inline int frame_size() const;
inline void set_frame_size(int frame_size);
// Accessor for register count (derived from frame_size).
inline int register_count() const;
// Accessors for parameter count (including implicit 'this' receiver).
inline int parameter_count() const;
inline void set_parameter_count(int number_of_parameters);
// Accessors for the constant pool.
DECL_ACCESSORS(constant_pool, FixedArray)
DECLARE_CAST(BytecodeArray)
// Dispatched behavior.
inline int BytecodeArraySize();
DECLARE_PRINTER(BytecodeArray)
DECLARE_VERIFIER(BytecodeArray)
void Disassemble(std::ostream& os);
// Layout description.
static const int kFrameSizeOffset = FixedArrayBase::kHeaderSize;
static const int kParameterSizeOffset = kFrameSizeOffset + kIntSize;
static const int kConstantPoolOffset = kParameterSizeOffset + kIntSize;
static const int kHeaderSize = kConstantPoolOffset + kPointerSize;
static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
// Maximal memory consumption for a single BytecodeArray.
static const int kMaxSize = 512 * MB;
// Maximal length of a single BytecodeArray.
static const int kMaxLength = kMaxSize - kHeaderSize;
class BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArray);
};
// 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 nobarrier_size() const;
inline void nobarrier_set_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.
DECLARE_PRINTER(FreeSpace)
DECLARE_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);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
};
// V has parameters (Type, type, TYPE, C type, element_size)
#define TYPED_ARRAYS(V) \
V(Uint8, uint8, UINT8, uint8_t, 1) \
V(Int8, int8, INT8, int8_t, 1) \
V(Uint16, uint16, UINT16, uint16_t, 2) \
V(Int16, int16, INT16, int16_t, 2) \
V(Uint32, uint32, UINT32, uint32_t, 4) \
V(Int32, int32, INT32, int32_t, 4) \
V(Float32, float32, FLOAT32, float, 4) \
V(Float64, float64, FLOAT64, double, 8) \
V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1)
class FixedTypedArrayBase: public FixedArrayBase {
public:
// [base_pointer]: Either points to the FixedTypedArrayBase itself or nullptr.
DECL_ACCESSORS(base_pointer, Object)
// [external_pointer]: Contains the offset between base_pointer and the start
// of the data. If the base_pointer is a nullptr, the external_pointer
// therefore points to the actual backing store.
DECL_ACCESSORS(external_pointer, void)
// Dispatched behavior.
DECLARE_CAST(FixedTypedArrayBase)
static const int kBasePointerOffset = FixedArrayBase::kHeaderSize;
static const int kExternalPointerOffset = kBasePointerOffset + kPointerSize;
static const int kHeaderSize =
DOUBLE_POINTER_ALIGN(kExternalPointerOffset + kPointerSize);
static const int kDataOffset = kHeaderSize;
class BodyDescriptor;
inline int size();
static inline int TypedArraySize(InstanceType type, int length);
inline int TypedArraySize(InstanceType type);
// Use with care: returns raw pointer into heap.
inline void* DataPtr();
inline int DataSize();
private:
static inline int ElementSize(InstanceType type);
inline int DataSize(InstanceType type);
DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase);
};
template <class Traits>
class FixedTypedArray: public FixedTypedArrayBase {
public:
typedef typename Traits::ElementType ElementType;
static const InstanceType kInstanceType = Traits::kInstanceType;
DECLARE_CAST(FixedTypedArray<Traits>)
inline ElementType get_scalar(int index);
static inline Handle<Object> get(Handle<FixedTypedArray> array, int index);
inline void set(int index, ElementType value);
static inline ElementType from_int(int value);
static inline ElementType from_double(double value);
// This accessor applies the correct conversion from Smi, HeapNumber
// and undefined.
inline void SetValue(uint32_t index, Object* value);
DECLARE_PRINTER(FixedTypedArray)
DECLARE_VERIFIER(FixedTypedArray)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray);
};
#define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType, size) \
class Type##ArrayTraits { \
public: /* NOLINT */ \
typedef elementType ElementType; \
static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE; \
static const char* Designator() { return #type " array"; } \
static inline Handle<Object> ToHandle(Isolate* isolate, \
elementType scalar); \
static inline elementType defaultValue(); \
}; \
\
typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array;
TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS)
#undef FIXED_TYPED_ARRAY_TRAITS
// DeoptimizationInputData is a fixed array used to hold the deoptimization
// data for code generated by the Hydrogen/Lithium compiler. It also
// contains information about functions that were inlined. If N different
// functions were inlined then first N elements of the literal array will
// contain these functions.
//
// It can be empty.
class DeoptimizationInputData: public FixedArray {
public:
// Layout description. Indices in the array.
static const int kTranslationByteArrayIndex = 0;
static const int kInlinedFunctionCountIndex = 1;
static const int kLiteralArrayIndex = 2;
static const int kOsrAstIdIndex = 3;
static const int kOsrPcOffsetIndex = 4;
static const int kOptimizationIdIndex = 5;
static const int kSharedFunctionInfoIndex = 6;
static const int kWeakCellCacheIndex = 7;
static const int kFirstDeoptEntryIndex = 8;
// Offsets of deopt entry elements relative to the start of the entry.
static const int kAstIdRawOffset = 0;
static const int kTranslationIndexOffset = 1;
static const int kArgumentsStackHeightOffset = 2;
static const int kPcOffset = 3;
static const int kDeoptEntrySize = 4;
// Simple element accessors.
#define DECLARE_ELEMENT_ACCESSORS(name, type) \
inline type* name(); \
inline void Set##name(type* value);
DECLARE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray)
DECLARE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi)
DECLARE_ELEMENT_ACCESSORS(LiteralArray, FixedArray)
DECLARE_ELEMENT_ACCESSORS(OsrAstId, Smi)
DECLARE_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
DECLARE_ELEMENT_ACCESSORS(OptimizationId, Smi)
DECLARE_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
DECLARE_ELEMENT_ACCESSORS(WeakCellCache, Object)
#undef DECLARE_ELEMENT_ACCESSORS
// Accessors for elements of the ith deoptimization entry.
#define DECLARE_ENTRY_ACCESSORS(name, type) \
inline type* name(int i); \
inline void Set##name(int i, type* value);
DECLARE_ENTRY_ACCESSORS(AstIdRaw, Smi)
DECLARE_ENTRY_ACCESSORS(TranslationIndex, Smi)
DECLARE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi)
DECLARE_ENTRY_ACCESSORS(Pc, Smi)
#undef DECLARE_ENTRY_ACCESSORS
inline BailoutId AstId(int i);
inline void SetAstId(int i, BailoutId value);
inline int DeoptCount();
// Allocates a DeoptimizationInputData.
static Handle<DeoptimizationInputData> New(Isolate* isolate,
int deopt_entry_count,
PretenureFlag pretenure);
DECLARE_CAST(DeoptimizationInputData)
#ifdef ENABLE_DISASSEMBLER
void DeoptimizationInputDataPrint(std::ostream& os); // NOLINT
#endif
private:
static int IndexForEntry(int i) {
return kFirstDeoptEntryIndex + (i * kDeoptEntrySize);
}
static int LengthFor(int entry_count) { return IndexForEntry(entry_count); }
};
// DeoptimizationOutputData is a fixed array used to hold the deoptimization
// data for code generated by the full compiler.
// The format of the these objects is
// [i * 2]: Ast ID for ith deoptimization.
// [i * 2 + 1]: PC and state of ith deoptimization
class DeoptimizationOutputData: public FixedArray {
public:
inline int DeoptPoints();
inline BailoutId AstId(int index);
inline void SetAstId(int index, BailoutId id);
inline Smi* PcAndState(int index);
inline void SetPcAndState(int index, Smi* offset);
static int LengthOfFixedArray(int deopt_points) {
return deopt_points * 2;
}
// Allocates a DeoptimizationOutputData.
static Handle<DeoptimizationOutputData> New(Isolate* isolate,
int number_of_deopt_points,
PretenureFlag pretenure);
DECLARE_CAST(DeoptimizationOutputData)
#if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT
#endif
};
// A literals array contains the literals for a JSFunction. It also holds
// the type feedback vector.
class LiteralsArray : public FixedArray {
public:
static const int kVectorIndex = 0;
static const int kFirstLiteralIndex = 1;
static const int kOffsetToFirstLiteral =
FixedArray::kHeaderSize + kPointerSize;
static int OffsetOfLiteralAt(int index) {
return SizeFor(index + kFirstLiteralIndex);
}
inline TypeFeedbackVector* feedback_vector() const;
inline void set_feedback_vector(TypeFeedbackVector* vector);
inline Object* literal(int literal_index) const;
inline void set_literal(int literal_index, Object* literal);
inline int literals_count() const;
static Handle<LiteralsArray> New(Isolate* isolate,
Handle<TypeFeedbackVector> vector,
int number_of_literals,
PretenureFlag pretenure);
DECLARE_CAST(LiteralsArray)
private:
inline Object* get(int index) const;
inline void set(int index, Object* value);
inline void set(int index, Smi* value);
inline void set(int index, Object* value, WriteBarrierMode mode);
};
// HandlerTable is a fixed array containing entries for exception handlers in
// the code object it is associated with. The tables comes in two flavors:
// 1) Based on ranges: Used for unoptimized code. Contains one entry per
// exception handler and a range representing the try-block covered by that
// handler. Layout looks as follows:
// [ range-start , range-end , handler-offset , stack-depth ]
// 2) Based on return addresses: Used for turbofanned code. Contains one entry
// per call-site that could throw an exception. Layout looks as follows:
// [ return-address-offset , handler-offset ]
class HandlerTable : public FixedArray {
public:
// Conservative prediction whether a given handler will locally catch an
// exception or cause a re-throw to outside the code boundary. Since this is
// undecidable it is merely an approximation (e.g. useful for debugger).
enum CatchPrediction { UNCAUGHT, CAUGHT };
// Accessors for handler table based on ranges.
inline void SetRangeStart(int index, int value);
inline void SetRangeEnd(int index, int value);
inline void SetRangeHandler(int index, int offset, CatchPrediction pred);
inline void SetRangeDepth(int index, int value);
// Accessors for handler table based on return addresses.
inline void SetReturnOffset(int index, int value);
inline void SetReturnHandler(int index, int offset, CatchPrediction pred);
// Lookup handler in a table based on ranges.
int LookupRange(int pc_offset, int* stack_depth, CatchPrediction* prediction);
// Lookup handler in a table based on return addresses.
int LookupReturn(int pc_offset, CatchPrediction* prediction);
// Returns the required length of the underlying fixed array.
static int LengthForRange(int entries) { return entries * kRangeEntrySize; }
static int LengthForReturn(int entries) { return entries * kReturnEntrySize; }
DECLARE_CAST(HandlerTable)
#if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
void HandlerTableRangePrint(std::ostream& os); // NOLINT
void HandlerTableReturnPrint(std::ostream& os); // NOLINT
#endif
private:
// Layout description for handler table based on ranges.
static const int kRangeStartIndex = 0;
static const int kRangeEndIndex = 1;
static const int kRangeHandlerIndex = 2;
static const int kRangeDepthIndex = 3;
static const int kRangeEntrySize = 4;
// Layout description for handler table based on return addresses.
static const int kReturnOffsetIndex = 0;
static const int kReturnHandlerIndex = 1;
static const int kReturnEntrySize = 2;
// Encoding of the {handler} field.
class HandlerPredictionField : public BitField<CatchPrediction, 0, 1> {};
class HandlerOffsetField : public BitField<int, 1, 30> {};
};
// Code describes objects with on-the-fly generated machine code.
class Code: public HeapObject {
public:
// Opaque data type for encapsulating code flags like kind, inline
// cache state, and arguments count.
typedef uint32_t Flags;
#define NON_IC_KIND_LIST(V) \
V(FUNCTION) \
V(OPTIMIZED_FUNCTION) \
V(STUB) \
V(HANDLER) \
V(BUILTIN) \
V(REGEXP) \
V(WASM_FUNCTION)
#define IC_KIND_LIST(V) \
V(LOAD_IC) \
V(KEYED_LOAD_IC) \
V(CALL_IC) \
V(STORE_IC) \
V(KEYED_STORE_IC) \
V(BINARY_OP_IC) \
V(COMPARE_IC) \
V(COMPARE_NIL_IC) \
V(TO_BOOLEAN_IC)
#define CODE_KIND_LIST(V) \
NON_IC_KIND_LIST(V) \
IC_KIND_LIST(V)
enum Kind {
#define DEFINE_CODE_KIND_ENUM(name) name,
CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM)
#undef DEFINE_CODE_KIND_ENUM
NUMBER_OF_KINDS
};
// No more than 32 kinds. The value is currently encoded in five bits in
// Flags.
STATIC_ASSERT(NUMBER_OF_KINDS <= 32);
static const char* Kind2String(Kind kind);
// Types of stubs.
enum StubType {
NORMAL,
FAST
};
static const int kPrologueOffsetNotSet = -1;
#ifdef ENABLE_DISASSEMBLER
// Printing
static const char* ICState2String(InlineCacheState state);
static const char* StubType2String(StubType type);
static void PrintExtraICState(std::ostream& os, // NOLINT
Kind kind, ExtraICState extra);
void Disassemble(const char* name, std::ostream& os); // NOLINT
#endif // ENABLE_DISASSEMBLER
// [instruction_size]: Size of the native instructions
inline int instruction_size() const;
inline void set_instruction_size(int value);
// [relocation_info]: Code relocation information
DECL_ACCESSORS(relocation_info, ByteArray)
void InvalidateRelocation();
void InvalidateEmbeddedObjects();
// [handler_table]: Fixed array containing offsets of exception handlers.
DECL_ACCESSORS(handler_table, FixedArray)
// [deoptimization_data]: Array containing data for deopt.
DECL_ACCESSORS(deoptimization_data, FixedArray)
// [raw_type_feedback_info]: This field stores various things, depending on
// the kind of the code object.
// FUNCTION => type feedback information.
// STUB and ICs => major/minor key as Smi.
DECL_ACCESSORS(raw_type_feedback_info, Object)
inline Object* type_feedback_info();
inline void set_type_feedback_info(
Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
inline uint32_t stub_key();
inline void set_stub_key(uint32_t key);
// [next_code_link]: Link for lists of optimized or deoptimized code.
// Note that storage for this field is overlapped with typefeedback_info.
DECL_ACCESSORS(next_code_link, Object)
// [gc_metadata]: Field used to hold GC related metadata. The contents of this
// field does not have to be traced during garbage collection since
// it is only used by the garbage collector itself.
DECL_ACCESSORS(gc_metadata, Object)
// [ic_age]: Inline caching age: the value of the Heap::global_ic_age
// at the moment when this object was created.
inline void set_ic_age(int count);
inline int ic_age() const;
// [prologue_offset]: Offset of the function prologue, used for aging
// FUNCTIONs and OPTIMIZED_FUNCTIONs.
inline int prologue_offset() const;
inline void set_prologue_offset(int offset);
// [constant_pool offset]: Offset of the constant pool.
// Valid for FLAG_enable_embedded_constant_pool only
inline int constant_pool_offset() const;
inline void set_constant_pool_offset(int offset);
// Unchecked accessors to be used during GC.
inline ByteArray* unchecked_relocation_info();
inline int relocation_size();
// [flags]: Various code flags.
inline Flags flags();
inline void set_flags(Flags flags);
// [flags]: Access to specific code flags.
inline Kind kind();
inline InlineCacheState ic_state(); // Only valid for IC stubs.
inline ExtraICState extra_ic_state(); // Only valid for IC stubs.
inline StubType type(); // Only valid for monomorphic IC stubs.
// Testers for IC stub kinds.
inline bool is_inline_cache_stub();
inline bool is_debug_stub();
inline bool is_handler();
inline bool is_load_stub();
inline bool is_keyed_load_stub();
inline bool is_store_stub();
inline bool is_keyed_store_stub();
inline bool is_call_stub();
inline bool is_binary_op_stub();
inline bool is_compare_ic_stub();
inline bool is_compare_nil_ic_stub();
inline bool is_to_boolean_ic_stub();
inline bool is_keyed_stub();
inline bool is_optimized_code();
inline bool is_interpreter_entry_trampoline();
inline bool embeds_maps_weakly();
inline bool IsCodeStubOrIC();
inline bool IsJavaScriptCode();
inline void set_raw_kind_specific_flags1(int value);
inline void set_raw_kind_specific_flags2(int value);
// [is_crankshafted]: For kind STUB or ICs, tells whether or not a code
// object was generated by either the hydrogen or the TurboFan optimizing
// compiler (but it may not be an optimized function).
inline bool is_crankshafted();
inline bool is_hydrogen_stub(); // Crankshafted, but not a function.
inline void set_is_crankshafted(bool value);
// [is_turbofanned]: For kind STUB or OPTIMIZED_FUNCTION, tells whether the
// code object was generated by the TurboFan optimizing compiler.
inline bool is_turbofanned();
inline void set_is_turbofanned(bool value);
// [can_have_weak_objects]: For kind OPTIMIZED_FUNCTION, tells whether the
// embedded objects in code should be treated weakly.
inline bool can_have_weak_objects();
inline void set_can_have_weak_objects(bool value);
// [has_deoptimization_support]: For FUNCTION kind, tells if it has
// deoptimization support.
inline bool has_deoptimization_support();
inline void set_has_deoptimization_support(bool value);
// [has_debug_break_slots]: For FUNCTION kind, tells if it has
// been compiled with debug break slots.
inline bool has_debug_break_slots();
inline void set_has_debug_break_slots(bool value);
// [has_reloc_info_for_serialization]: For FUNCTION kind, tells if its
// reloc info includes runtime and external references to support
// serialization/deserialization.
inline bool has_reloc_info_for_serialization();
inline void set_has_reloc_info_for_serialization(bool value);
// [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for
// how long the function has been marked for OSR and therefore which
// level of loop nesting we are willing to do on-stack replacement
// for.
inline void set_allow_osr_at_loop_nesting_level(int level);
inline int allow_osr_at_loop_nesting_level();
// [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks
// the code object was seen on the stack with no IC patching going on.
inline int profiler_ticks();
inline void set_profiler_ticks(int ticks);
// [builtin_index]: For BUILTIN kind, tells which builtin index it has.
// For builtins, tells which builtin index it has.
// Note that builtins can have a code kind other than BUILTIN, which means
// that for arbitrary code objects, this index value may be random garbage.
// To verify in that case, compare the code object to the indexed builtin.
inline int builtin_index();
inline void set_builtin_index(int id);
// [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots
// reserved in the code prologue.
inline unsigned stack_slots();
inline void set_stack_slots(unsigned slots);
// [safepoint_table_start]: For kind OPTIMIZED_FUNCTION, the offset in
// the instruction stream where the safepoint table starts.
inline unsigned safepoint_table_offset();
inline void set_safepoint_table_offset(unsigned offset);
// [back_edge_table_start]: For kind FUNCTION, the offset in the
// instruction stream where the back edge table starts.
inline unsigned back_edge_table_offset();
inline void set_back_edge_table_offset(unsigned offset);
inline bool back_edges_patched_for_osr();
// [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in.
inline uint16_t to_boolean_state();
// [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether
// the code is going to be deoptimized because of dead embedded maps.
inline bool marked_for_deoptimization();
inline void set_marked_for_deoptimization(bool flag);
// [constant_pool]: The constant pool for this function.
inline Address constant_pool();
// Get the safepoint entry for the given pc.
SafepointEntry GetSafepointEntry(Address pc);
// Find an object in a stub with a specified map
Object* FindNthObject(int n, Map* match_map);
// Find the first allocation site in an IC stub.
AllocationSite* FindFirstAllocationSite();
// Find the first map in an IC stub.
Map* FindFirstMap();
void FindAllMaps(MapHandleList* maps);
// Find the first handler in an IC stub.
Code* FindFirstHandler();
// Find |length| handlers and put them into |code_list|. Returns false if not
// enough handlers can be found.
bool FindHandlers(CodeHandleList* code_list, int length = -1);
// Find the handler for |map|.
MaybeHandle<Code> FindHandlerForMap(Map* map);
// Find the first name in an IC stub.
Name* FindFirstName();
class FindAndReplacePattern;
// For each (map-to-find, object-to-replace) pair in the pattern, this
// function replaces the corresponding placeholder in the code with the
// object-to-replace. The function assumes that pairs in the pattern come in
// the same order as the placeholders in the code.
// If the placeholder is a weak cell, then the value of weak cell is matched
// against the map-to-find.
void FindAndReplace(const FindAndReplacePattern& pattern);
// The entire code object including its header is copied verbatim to the
// snapshot so that it can be written in one, fast, memcpy during
// deserialization. The deserializer will overwrite some pointers, rather
// like a runtime linker, but the random allocation addresses used in the
// mksnapshot process would still be present in the unlinked snapshot data,
// which would make snapshot production non-reproducible. This method wipes
// out the to-be-overwritten header data for reproducible snapshots.
inline void WipeOutHeader();
// Flags operations.
static inline Flags ComputeFlags(
Kind kind, InlineCacheState ic_state = UNINITIALIZED,
ExtraICState extra_ic_state = kNoExtraICState, StubType type = NORMAL,
CacheHolderFlag holder = kCacheOnReceiver);
static inline Flags ComputeMonomorphicFlags(
Kind kind, ExtraICState extra_ic_state = kNoExtraICState,
CacheHolderFlag holder = kCacheOnReceiver, StubType type = NORMAL);
static inline Flags ComputeHandlerFlags(
Kind handler_kind, StubType type = NORMAL,
CacheHolderFlag holder = kCacheOnReceiver);
static inline InlineCacheState ExtractICStateFromFlags(Flags flags);
static inline StubType ExtractTypeFromFlags(Flags flags);
static inline CacheHolderFlag ExtractCacheHolderFromFlags(Flags flags);
static inline Kind ExtractKindFromFlags(Flags flags);
static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags);
static inline Flags RemoveTypeFromFlags(Flags flags);
static inline Flags RemoveTypeAndHolderFromFlags(Flags flags);
// Convert a target address into a code object.
static inline Code* GetCodeFromTargetAddress(Address address);
// Convert an entry address into an object.
static inline Object* GetObjectFromEntryAddress(Address location_of_address);
// Returns the address of the first instruction.
inline byte* instruction_start();
// Returns the address right after the last instruction.
inline byte* instruction_end();
// Returns the size of the instructions, padding, and relocation information.
inline int body_size();
// Returns the address of the first relocation info (read backwards!).
inline byte* relocation_start();
// Code entry point.
inline byte* entry();
// Returns true if pc is inside this object's instructions.
inline bool contains(byte* pc);
// Relocate the code by delta bytes. Called to signal that this code
// object has been moved by delta bytes.
void Relocate(intptr_t delta);
// Migrate code described by desc.
void CopyFrom(const CodeDesc& desc);
// Returns the object size for a given body (used for allocation).
static int SizeFor(int body_size) {
DCHECK_SIZE_TAG_ALIGNED(body_size);
return RoundUp(kHeaderSize + body_size, kCodeAlignment);
}
// Calculate the size of the code object to report for log events. This takes
// the layout of the code object into account.
inline int ExecutableSize();
// Locating source position.
int SourcePosition(Address pc);
int SourceStatementPosition(Address pc);
DECLARE_CAST(Code)
// Dispatched behavior.
inline int CodeSize();
DECLARE_PRINTER(Code)
DECLARE_VERIFIER(Code)
void ClearInlineCaches();
void ClearInlineCaches(Kind kind);
BailoutId TranslatePcOffsetToAstId(uint32_t pc_offset);
uint32_t TranslateAstIdToPcOffset(BailoutId ast_id);
#define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
enum Age {
kToBeExecutedOnceCodeAge = -3,
kNotExecutedCodeAge = -2,
kExecutedOnceCodeAge = -1,
kNoAgeCodeAge = 0,
CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
kAfterLastCodeAge,
kFirstCodeAge = kToBeExecutedOnceCodeAge,
kLastCodeAge = kAfterLastCodeAge - 1,
kCodeAgeCount = kAfterLastCodeAge - kFirstCodeAge - 1,
kIsOldCodeAge = kSexagenarianCodeAge,
kPreAgedCodeAge = kIsOldCodeAge - 1
};
#undef DECLARE_CODE_AGE_ENUM
// Code aging. Indicates how many full GCs this code has survived without
// being entered through the prologue. Used to determine when it is
// relatively safe to flush this code object and replace it with the lazy
// compilation stub.
static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate);
static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate);
void MakeYoung(Isolate* isolate);
void MarkToBeExecutedOnce(Isolate* isolate);
void MakeOlder(MarkingParity);
static bool IsYoungSequence(Isolate* isolate, byte* sequence);
bool IsOld();
Age GetAge();
static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) {
return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY);
}
void PrintDeoptLocation(FILE* out, Address pc);
bool CanDeoptAt(Address pc);
#ifdef VERIFY_HEAP
void VerifyEmbeddedObjectsDependency();
#endif
#ifdef DEBUG
enum VerifyMode { kNoContextSpecificPointers, kNoContextRetainingPointers };
void VerifyEmbeddedObjects(VerifyMode mode = kNoContextRetainingPointers);
static void VerifyRecompiledCode(Code* old_code, Code* new_code);
#endif // DEBUG
inline bool CanContainWeakObjects();
inline bool IsWeakObject(Object* object);
static inline bool IsWeakObjectInOptimizedCode(Object* object);
static Handle<WeakCell> WeakCellFor(Handle<Code> code);
WeakCell* CachedWeakCell();
// Max loop nesting marker used to postpose OSR. We don't take loop
// nesting that is deeper than 5 levels into account.
static const int kMaxLoopNestingMarker = 6;
static const int kConstantPoolSize =
FLAG_enable_embedded_constant_pool ? kIntSize : 0;
// Layout description.
static const int kRelocationInfoOffset = HeapObject::kHeaderSize;
static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
static const int kDeoptimizationDataOffset =
kHandlerTableOffset + kPointerSize;
// For FUNCTION kind, we store the type feedback info here.
static const int kTypeFeedbackInfoOffset =
kDeoptimizationDataOffset + kPointerSize;
static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
static const int kGCMetadataOffset = kNextCodeLinkOffset + kPointerSize;
static const int kInstructionSizeOffset = kGCMetadataOffset + kPointerSize;
static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
static const int kFlagsOffset = kICAgeOffset + kIntSize;
static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
static const int kKindSpecificFlags2Offset =
kKindSpecificFlags1Offset + kIntSize;
// Note: We might be able to squeeze this into the flags above.
static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
static const int kHeaderPaddingStart =
kConstantPoolOffset + kConstantPoolSize;
// Add padding to align the instruction start following right after
// the Code object header.
static const int kHeaderSize =
(kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
class BodyDescriptor;
// Byte offsets within kKindSpecificFlags1Offset.
static const int kFullCodeFlags = kKindSpecificFlags1Offset;
class FullCodeFlagsHasDeoptimizationSupportField:
public BitField<bool, 0, 1> {}; // NOLINT
class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {};
class FullCodeFlagsHasRelocInfoForSerialization
: public BitField<bool, 2, 1> {};
// Bit 3 in this bitfield is unused.
class ProfilerTicksField : public BitField<int, 4, 28> {};
// Flags layout. BitField<type, shift, size>.
class ICStateField : public BitField<InlineCacheState, 0, 3> {};
class TypeField : public BitField<StubType, 3, 1> {};
class CacheHolderField : public BitField<CacheHolderFlag, 4, 2> {};
class KindField : public BitField<Kind, 6, 5> {};
class ExtraICStateField: public BitField<ExtraICState, 11,
PlatformSmiTagging::kSmiValueSize - 11 + 1> {}; // NOLINT
// KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
static const int kStackSlotsFirstBit = 0;
static const int kStackSlotsBitCount = 24;
static const int kMarkedForDeoptimizationBit =
kStackSlotsFirstBit + kStackSlotsBitCount;
static const int kIsTurbofannedBit = kMarkedForDeoptimizationBit + 1;
static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1;
STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32);
STATIC_ASSERT(kCanHaveWeakObjects + 1 <= 32);
class StackSlotsField: public BitField<int,
kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT
class MarkedForDeoptimizationField
: public BitField<bool, kMarkedForDeoptimizationBit, 1> {}; // NOLINT
class IsTurbofannedField : public BitField<bool, kIsTurbofannedBit, 1> {
}; // NOLINT
class CanHaveWeakObjectsField
: public BitField<bool, kCanHaveWeakObjects, 1> {}; // NOLINT
// KindSpecificFlags2 layout (ALL)
static const int kIsCrankshaftedBit = 0;
class IsCrankshaftedField: public BitField<bool,
kIsCrankshaftedBit, 1> {}; // NOLINT
// KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1;
static const int kSafepointTableOffsetBitCount = 30;
STATIC_ASSERT(kSafepointTableOffsetFirstBit +
kSafepointTableOffsetBitCount <= 32);
STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32);
class SafepointTableOffsetField: public BitField<int,
kSafepointTableOffsetFirstBit,
kSafepointTableOffsetBitCount> {}; // NOLINT
// KindSpecificFlags2 layout (FUNCTION)
class BackEdgeTableOffsetField: public BitField<int,
kIsCrankshaftedBit + 1, 27> {}; // NOLINT
class AllowOSRAtLoopNestingLevelField: public BitField<int,
kIsCrankshaftedBit + 1 + 27, 4> {}; // NOLINT
STATIC_ASSERT(AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker);
static const int kArgumentsBits = 16;
static const int kMaxArguments = (1 << kArgumentsBits) - 1;
// This constant should be encodable in an ARM instruction.
static const int kFlagsNotUsedInLookup =
TypeField::kMask | CacheHolderField::kMask;
private:
friend class RelocIterator;
friend class Deoptimizer; // For FindCodeAgeSequence.
void ClearInlineCaches(Kind* kind);
// Code aging
byte* FindCodeAgeSequence();
static void GetCodeAgeAndParity(Code* code, Age* age,
MarkingParity* parity);
static void GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
MarkingParity* parity);
static Code* GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity);
// Code aging -- platform-specific
static void PatchPlatformCodeAge(Isolate* isolate,
byte* sequence, Age age,
MarkingParity parity);
DISALLOW_IMPLICIT_CONSTRUCTORS(Code);
};
// Dependent code is a singly linked list of fixed arrays. Each array contains
// code objects in weak cells for one dependent group. The suffix of the array
// can be filled with the undefined value if the number of codes is less than
// the length of the array.
//
// +------+-----------------+--------+--------+-----+--------+-----------+-----+
// | next | count & group 1 | code 1 | code 2 | ... | code n | undefined | ... |
// +------+-----------------+--------+--------+-----+--------+-----------+-----+
// |
// V
// +------+-----------------+--------+--------+-----+--------+-----------+-----+
// | next | count & group 2 | code 1 | code 2 | ... | code m | undefined | ... |
// +------+-----------------+--------+--------+-----+--------+-----------+-----+
// |
// V
// empty_fixed_array()
//
// The list of fixed arrays is ordered by dependency groups.
class DependentCode: public FixedArray {
public:
enum DependencyGroup {
// Group of code that weakly embed this map and depend on being
// deoptimized when the map is garbage collected.
kWeakCodeGroup,
// Group of code that embed a transition to this map, and depend on being
// deoptimized when the transition is replaced by a new version.
kTransitionGroup,
// Group of code that omit run-time prototype checks for prototypes
// described by this map. The group is deoptimized whenever an object
// described by this map changes shape (and transitions to a new map),
// possibly invalidating the assumptions embedded in the code.
kPrototypeCheckGroup,
// Group of code that depends on global property values in property cells
// not being changed.
kPropertyCellChangedGroup,
// Group of code that omit run-time type checks for the field(s) introduced
// by this map.
kFieldTypeGroup,
// Group of code that omit run-time type checks for initial maps of
// constructors.
kInitialMapChangedGroup,
// Group of code that depends on tenuring information in AllocationSites
// not being changed.
kAllocationSiteTenuringChangedGroup,
// Group of code that depends on element transition information in
// AllocationSites not being changed.
kAllocationSiteTransitionChangedGroup
};
static const int kGroupCount = kAllocationSiteTransitionChangedGroup + 1;
bool Contains(DependencyGroup group, WeakCell* code_cell);
bool IsEmpty(DependencyGroup group);
static Handle<DependentCode> InsertCompilationDependencies(
Handle<DependentCode> entries, DependencyGroup group,
Handle<Foreign> info);
static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries,
DependencyGroup group,
Handle<WeakCell> code_cell);
void UpdateToFinishedCode(DependencyGroup group, Foreign* info,
WeakCell* code_cell);
void RemoveCompilationDependencies(DependentCode::DependencyGroup group,
Foreign* info);
void DeoptimizeDependentCodeGroup(Isolate* isolate,
DependentCode::DependencyGroup group);
bool MarkCodeForDeoptimization(Isolate* isolate,
DependentCode::DependencyGroup group);
// The following low-level accessors should only be used by this class
// and the mark compact collector.
inline DependentCode* next_link();
inline void set_next_link(DependentCode* next);
inline int count();
inline void set_count(int value);
inline DependencyGroup group();
inline void set_group(DependencyGroup group);
inline Object* object_at(int i);
inline void set_object_at(int i, Object* object);
inline void clear_at(int i);
inline void copy(int from, int to);
DECLARE_CAST(DependentCode)
static const char* DependencyGroupName(DependencyGroup group);
static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
private:
static Handle<DependentCode> Insert(Handle<DependentCode> entries,
DependencyGroup group,
Handle<Object> object);
static Handle<DependentCode> New(DependencyGroup group, Handle<Object> object,
Handle<DependentCode> next);
static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries);
// Compact by removing cleared weak cells and return true if there was
// any cleared weak cell.
bool Compact();
static int Grow(int number_of_entries) {
if (number_of_entries < 5) return number_of_entries + 1;
return number_of_entries * 5 / 4;
}
inline int flags();
inline void set_flags(int flags);
class GroupField : public BitField<int, 0, 3> {};
class CountField : public BitField<int, 3, 27> {};
STATIC_ASSERT(kGroupCount <= GroupField::kMax + 1);
static const int kNextLinkIndex = 0;
static const int kFlagsIndex = 1;
static const int kCodesStartIndex = 2;
};
class PrototypeInfo;
// All heap objects have a Map that describes their structure.
// A Map contains information about:
// - Size information about the object
// - How to iterate over an object (for garbage collection)
class Map: public HeapObject {
public:
// Instance size.
// Size in bytes or kVariableSizeSentinel if instances do not have
// a fixed size.
inline int instance_size();
inline void set_instance_size(int value);
// Only to clear an unused byte, remove once byte is used.
inline void clear_unused();
// [inobject_properties_or_constructor_function_index]: Provides access
// to the inobject properties in case of JSObject maps, or the constructor
// function index in case of primitive maps.
inline int inobject_properties_or_constructor_function_index();
inline void set_inobject_properties_or_constructor_function_index(int value);
// Count of properties allocated in the object (JSObject only).
inline int GetInObjectProperties();
inline void SetInObjectProperties(int value);
// Index of the constructor function in the native context (primitives only),
// or the special sentinel value to indicate that there is no object wrapper
// for the primitive (i.e. in case of null or undefined).
static const int kNoConstructorFunctionIndex = 0;
inline int GetConstructorFunctionIndex();
inline void SetConstructorFunctionIndex(int value);
static MaybeHandle<JSFunction> GetConstructorFunction(
Handle<Map> map, Handle<Context> native_context);
// Instance type.
inline InstanceType instance_type();
inline void set_instance_type(InstanceType value);
// Tells how many unused property fields are available in the
// instance (only used for JSObject in fast mode).
inline int unused_property_fields();
inline void set_unused_property_fields(int value);
// Bit field.
inline byte bit_field() const;
inline void set_bit_field(byte value);
// Bit field 2.
inline byte bit_field2() const;
inline void set_bit_field2(byte value);
// Bit field 3.
inline uint32_t bit_field3() const;
inline void set_bit_field3(uint32_t bits);
class EnumLengthBits: public BitField<int,
0, kDescriptorIndexBitCount> {}; // NOLINT
class NumberOfOwnDescriptorsBits: public BitField<int,
kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT
STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
class DictionaryMap : public BitField<bool, 20, 1> {};
class OwnsDescriptors : public BitField<bool, 21, 1> {};
class IsHiddenPrototype : public BitField<bool, 22, 1> {};
class Deprecated : public BitField<bool, 23, 1> {};
class IsUnstable : public BitField<bool, 24, 1> {};
class IsMigrationTarget : public BitField<bool, 25, 1> {};
class IsStrong : public BitField<bool, 26, 1> {};
class NewTargetIsBase : public BitField<bool, 27, 1> {};
// Bit 28 is free.
// Keep this bit field at the very end for better code in
// Builtins::kJSConstructStubGeneric stub.
// This counter is used for in-object slack tracking.
// The in-object slack tracking is considered enabled when the counter is
// non zero.
class ConstructionCounter : public BitField<int, 29, 3> {};
static const int kSlackTrackingCounterStart = 7;
static const int kSlackTrackingCounterEnd = 1;
static const int kNoSlackTracking = 0;
STATIC_ASSERT(kSlackTrackingCounterStart <= ConstructionCounter::kMax);
// Inobject slack tracking is the way to reclaim unused inobject space.
//
// The instance size is initially determined by adding some slack to
// expected_nof_properties (to allow for a few extra properties added
// after the constructor). There is no guarantee that the extra space
// will not be wasted.
//
// Here is the algorithm to reclaim the unused inobject space:
// - Detect the first constructor call for this JSFunction.
// When it happens enter the "in progress" state: initialize construction
// counter in the initial_map.
// - While the tracking is in progress initialize unused properties of a new
// object with one_pointer_filler_map instead of undefined_value (the "used"
// part is initialized with undefined_value as usual). This way they can
// be resized quickly and safely.
// - Once enough objects have been created compute the 'slack'
// (traverse the map transition tree starting from the
// initial_map and find the lowest value of unused_property_fields).
// - Traverse the transition tree again and decrease the instance size
// of every map. Existing objects will resize automatically (they are
// filled with one_pointer_filler_map). All further allocations will
// use the adjusted instance size.
// - SharedFunctionInfo's expected_nof_properties left unmodified since
// allocations made using different closures could actually create different
// kind of objects (see prototype inheritance pattern).
//
// Important: inobject slack tracking is not attempted during the snapshot
// creation.
static const int kGenerousAllocationCount =
kSlackTrackingCounterStart - kSlackTrackingCounterEnd + 1;
// Starts the tracking by initializing object constructions countdown counter.
void StartInobjectSlackTracking();
// True if the object constructions countdown counter is a range
// [kSlackTrackingCounterEnd, kSlackTrackingCounterStart].
inline bool IsInobjectSlackTrackingInProgress();
// Does the tracking step.
inline void InobjectSlackTrackingStep();
// Completes inobject slack tracking for the transition tree starting at this
// initial map.
void CompleteInobjectSlackTracking();
// Tells whether the object in the prototype property will be used
// for instances created from this function. If the prototype
// property is set to a value that is not a JSObject, the prototype
// property will not be used to create instances of the function.
// See ECMA-262, 13.2.2.
inline void set_non_instance_prototype(bool value);
inline bool has_non_instance_prototype();
// Tells whether the instance has a [[Construct]] internal method.
// This property is implemented according to ES6, section 7.2.4.
inline void set_is_constructor();
inline bool is_constructor() const;
// Tells whether the instance with this map should be ignored by the
// Object.getPrototypeOf() function and the __proto__ accessor.
inline void set_is_hidden_prototype();
inline bool is_hidden_prototype() const;
// Records and queries whether the instance has a named interceptor.
inline void set_has_named_interceptor();
inline bool has_named_interceptor();
// Records and queries whether the instance has an indexed interceptor.
inline void set_has_indexed_interceptor();
inline bool has_indexed_interceptor();
// Tells whether the instance is undetectable.
// An undetectable object is a special class of JSObject: 'typeof' operator
// returns undefined, ToBoolean returns false. Otherwise it behaves like
// a normal JS object. It is useful for implementing undetectable
// document.all in Firefox & Safari.
// See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
inline void set_is_undetectable();
inline bool is_undetectable();
// Tells whether the instance has a call-as-function handler.
inline void set_is_observed();
inline bool is_observed();
// Tells whether the instance has a [[Call]] internal method.
// This property is implemented according to ES6, section 7.2.3.
inline void set_is_callable();
inline bool is_callable() const;
inline void set_is_strong();
inline bool is_strong();
inline void set_new_target_is_base(bool value);
inline bool new_target_is_base();
inline void set_is_extensible(bool value);
inline bool is_extensible();
inline void set_is_prototype_map(bool value);
inline bool is_prototype_map() const;
inline void set_elements_kind(ElementsKind elements_kind);
inline ElementsKind elements_kind();
// Tells whether the instance has fast elements that are only Smis.
inline bool has_fast_smi_elements();
// Tells whether the instance has fast elements.
inline bool has_fast_object_elements();
inline bool has_fast_smi_or_object_elements();
inline bool has_fast_double_elements();
inline bool has_fast_elements();
inline bool has_sloppy_arguments_elements();
inline bool has_fixed_typed_array_elements();
inline bool has_dictionary_elements();
static bool IsValidElementsTransition(ElementsKind from_kind,
ElementsKind to_kind);
// Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
// map with DICTIONARY_ELEMENTS was found in the prototype chain.
bool DictionaryElementsInPrototypeChainOnly();
inline Map* ElementsTransitionMap();
inline FixedArrayBase* GetInitialElements();
// [raw_transitions]: Provides access to the transitions storage field.
// Don't call set_raw_transitions() directly to overwrite transitions, use
// the TransitionArray::ReplaceTransitions() wrapper instead!
DECL_ACCESSORS(raw_transitions, Object)
// [prototype_info]: Per-prototype metadata. Aliased with transitions
// (which prototype maps don't have).
DECL_ACCESSORS(prototype_info, Object)
// PrototypeInfo is created lazily using this helper (which installs it on
// the given prototype's map).
static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
Handle<JSObject> prototype, Isolate* isolate);
static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
Handle<Map> prototype_map, Isolate* isolate);
// [prototype chain validity cell]: Associated with a prototype object,
// stored in that object's map's PrototypeInfo, indicates that prototype
// chains through this object are currently valid. The cell will be
// invalidated and replaced when the prototype chain changes.
static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map,
Isolate* isolate);
static const int kPrototypeChainValid = 0;
static const int kPrototypeChainInvalid = 1;
Map* FindRootMap();
Map* FindFieldOwner(int descriptor);
inline int GetInObjectPropertyOffset(int index);
int NumberOfFields();
// TODO(ishell): candidate with JSObject::MigrateToMap().
bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
int target_inobject, int target_unused,
int* old_number_of_fields);
// TODO(ishell): moveit!
static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map);
MUST_USE_RESULT static Handle<HeapType> GeneralizeFieldType(
Representation rep1, Handle<HeapType> type1, Representation rep2,
Handle<HeapType> type2, Isolate* isolate);
static void GeneralizeFieldType(Handle<Map> map, int modify_index,
Representation new_representation,
Handle<HeapType> new_field_type);
static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
PropertyKind new_kind,
PropertyAttributes new_attributes,
Representation new_representation,
Handle<HeapType> new_field_type,
StoreMode store_mode);
static Handle<Map> CopyGeneralizeAllRepresentations(
Handle<Map> map, int modify_index, StoreMode store_mode,
PropertyKind kind, PropertyAttributes attributes, const char* reason);
static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
int descriptor_number,
Handle<Object> value);
static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
const char* reason);
// Tells whether the map is used for JSObjects in dictionary mode (ie
// normalized objects, ie objects for which HasFastProperties returns false).
// A map can never be used for both dictionary mode and fast mode JSObjects.
// False by default and for HeapObjects that are not JSObjects.
inline void set_dictionary_map(bool value);
inline bool is_dictionary_map();
// Tells whether the instance needs security checks when accessing its
// properties.
inline void set_is_access_check_needed(bool access_check_needed);
inline bool is_access_check_needed();
// Returns true if map has a non-empty stub code cache.
inline bool has_code_cache();
// [prototype]: implicit prototype object.
DECL_ACCESSORS(prototype, Object)
// TODO(jkummerow): make set_prototype private.
static void SetPrototype(
Handle<Map> map, Handle<Object> prototype,
PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
// [constructor]: points back to the function responsible for this map.
// The field overlaps with the back pointer. All maps in a transition tree
// have the same constructor, so maps with back pointers can walk the
// back pointer chain until they find the map holding their constructor.
DECL_ACCESSORS(constructor_or_backpointer, Object)
inline Object* GetConstructor() const;
inline void SetConstructor(Object* constructor,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// [back pointer]: points back to the parent map from which a transition
// leads to this map. The field overlaps with the constructor (see above).
inline Object* GetBackPointer();
inline void SetBackPointer(Object* value,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// [instance descriptors]: describes the object.
DECL_ACCESSORS(instance_descriptors, DescriptorArray)
// [layout descriptor]: describes the object layout.
DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
// |layout descriptor| accessor which can be used from GC.
inline LayoutDescriptor* layout_descriptor_gc_safe();
inline bool HasFastPointerLayout() const;
// |layout descriptor| accessor that is safe to call even when
// FLAG_unbox_double_fields is disabled (in this case Map does not contain
// |layout_descriptor| field at all).
inline LayoutDescriptor* GetLayoutDescriptor();
inline void UpdateDescriptors(DescriptorArray* descriptors,
LayoutDescriptor* layout_descriptor);
inline void InitializeDescriptors(DescriptorArray* descriptors,
LayoutDescriptor* layout_descriptor);
// [stub cache]: contains stubs compiled for this map.
DECL_ACCESSORS(code_cache, Object)
// [dependent code]: list of optimized codes that weakly embed this map.
DECL_ACCESSORS(dependent_code, DependentCode)
// [weak cell cache]: cache that stores a weak cell pointing to this map.
DECL_ACCESSORS(weak_cell_cache, Object)
inline PropertyDetails GetLastDescriptorDetails();
inline int LastAdded();
inline int NumberOfOwnDescriptors();
inline void SetNumberOfOwnDescriptors(int number);
inline Cell* RetrieveDescriptorsPointer();
inline int EnumLength();
inline void SetEnumLength(int length);
inline bool owns_descriptors();
inline void set_owns_descriptors(bool owns_descriptors);
inline void mark_unstable();
inline bool is_stable();
inline void set_migration_target(bool value);
inline bool is_migration_target();
inline void set_construction_counter(int value);
inline int construction_counter();
inline void deprecate();
inline bool is_deprecated();
inline bool CanBeDeprecated();
// Returns a non-deprecated version of the input. If the input was not
// deprecated, it is directly returned. Otherwise, the non-deprecated version
// is found by re-transitioning from the root of the transition tree using the
// descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
// is found.
static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
// Returns a non-deprecated version of the input. This method may deprecate
// existing maps along the way if encodings conflict. Not for use while
// gathering type feedback. Use TryUpdate in those cases instead.
static Handle<Map> Update(Handle<Map> map);
static inline Handle<Map> CopyInitialMap(Handle<Map> map);
static Handle<Map> CopyInitialMap(Handle<Map> map, int instance_size,
int in_object_properties,
int unused_property_fields);
static Handle<Map> CopyDropDescriptors(Handle<Map> map);
static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
Descriptor* descriptor,
TransitionFlag flag);
MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
Handle<Map> map,
Handle<Name> name,
Handle<HeapType> type,
PropertyAttributes attributes,
Representation representation,
TransitionFlag flag);
MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
Handle<Map> map,
Handle<Name> name,
Handle<Object> constant,
PropertyAttributes attributes,
TransitionFlag flag);
// Returns a new map with all transitions dropped from the given map and
// the ElementsKind set.
static Handle<Map> TransitionElementsTo(Handle<Map> map,
ElementsKind to_kind);
static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
static Handle<Map> CopyAsElementsKind(Handle<Map> map,
ElementsKind kind,
TransitionFlag flag);
static Handle<Map> AsLanguageMode(Handle<Map> initial_map,
LanguageMode language_mode,
FunctionKind kind);
static Handle<Map> CopyForObserved(Handle<Map> map);
static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
PropertyAttributes attrs_to_add,
Handle<Symbol> transition_marker,
const char* reason);
static Handle<Map> FixProxy(Handle<Map> map, InstanceType type, int size);
// Maximal number of fast properties. Used to restrict the number of map
// transitions to avoid an explosion in the number of maps for objects used as
// dictionaries.
inline bool TooManyFastProperties(StoreFromKeyed store_mode);
static Handle<Map> TransitionToDataProperty(Handle<Map> map,
Handle<Name> name,
Handle<Object> value,
PropertyAttributes attributes,
StoreFromKeyed store_mode);
static Handle<Map> TransitionToAccessorProperty(
Handle<Map> map, Handle<Name> name, AccessorComponent component,
Handle<Object> accessor, PropertyAttributes attributes);
static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
int descriptor,
PropertyKind kind,
PropertyAttributes attributes);
inline void AppendDescriptor(Descriptor* desc);
// Returns a copy of the map, prepared for inserting into the transition
// tree (if the |map| owns descriptors then the new one will share
// descriptors with |map|).
static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
// Returns a copy of the map, with all transitions dropped from the
// instance descriptors.
static Handle<Map> Copy(Handle<Map> map, const char* reason);
static Handle<Map> Create(Isolate* isolate, int inobject_properties);
// Returns the next free property index (only valid for FAST MODE).
int NextFreePropertyIndex();
// Returns the number of properties described in instance_descriptors
// filtering out properties with the specified attributes.
int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
PropertyFilter filter = ALL_PROPERTIES);
DECLARE_CAST(Map)
// Code cache operations.
// Clears the code cache.
inline void ClearCodeCache(Heap* heap);
// Update code cache.
static void UpdateCodeCache(Handle<Map> map,
Handle<Name> name,
Handle<Code> code);
// Extend the descriptor array of the map with the list of descriptors.
// In case of duplicates, the latest descriptor is used.
static void AppendCallbackDescriptors(Handle<Map> map,
Handle<Object> descriptors);
static inline int SlackForArraySize(int old_size, int size_limit);
static void EnsureDescriptorSlack(Handle<Map> map, int slack);
// Returns the found code or undefined if absent.
Object* FindInCodeCache(Name* name, Code::Flags flags);
// Returns the non-negative index of the code object if it is in the
// cache and -1 otherwise.
int IndexInCodeCache(Object* name, Code* code);
// Removes a code object from the code cache at the given index.
void RemoveFromCodeCache(Name* name, Code* code, int index);
// Computes a hash value for this map, to be used in HashTables and such.
int Hash();
// Returns the map that this map transitions to if its elements_kind
// is changed to |elements_kind|, or NULL if no such map is cached yet.
// |safe_to_add_transitions| is set to false if adding transitions is not
// allowed.
Map* LookupElementsTransitionMap(ElementsKind elements_kind);
// Returns the transitioned map for this map with the most generic
// elements_kind that's found in |candidates|, or null handle if no match is
// found at all.
static Handle<Map> FindTransitionedMap(Handle<Map> map,
MapHandleList* candidates);
inline bool CanTransition();
inline bool IsBooleanMap();
inline bool IsPrimitiveMap();
inline bool IsJSReceiverMap();
inline bool IsJSObjectMap();
inline bool IsJSArrayMap();
inline bool IsJSFunctionMap();
inline bool IsStringMap();
inline bool IsJSProxyMap();
inline bool IsJSGlobalProxyMap();
inline bool IsJSGlobalObjectMap();
inline bool IsJSTypedArrayMap();
inline bool IsJSDataViewMap();
inline bool CanOmitMapChecks();
static void AddDependentCode(Handle<Map> map,
DependentCode::DependencyGroup group,
Handle<Code> code);
bool IsMapInArrayPrototypeChain();
static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
// Dispatched behavior.
DECLARE_PRINTER(Map)
DECLARE_VERIFIER(Map)
#ifdef VERIFY_HEAP
void DictionaryMapVerify();
void VerifyOmittedMapChecks();
#endif
inline int visitor_id();
inline void set_visitor_id(int visitor_id);
static Handle<Map> TransitionToPrototype(Handle<Map> map,
Handle<Object> prototype,
PrototypeOptimizationMode mode);
static const int kMaxPreAllocatedPropertyFields = 255;
// Layout description.
static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
static const int kConstructorOrBackPointerOffset =
kPrototypeOffset + kPointerSize;
// When there is only one transition, it is stored directly in this field;
// otherwise a transition array is used.
// For prototype maps, this slot is used to store this map's PrototypeInfo
// struct.
static const int kTransitionsOrPrototypeInfoOffset =
kConstructorOrBackPointerOffset + kPointerSize;
static const int kDescriptorsOffset =
kTransitionsOrPrototypeInfoOffset + kPointerSize;
#if V8_DOUBLE_FIELDS_UNBOXING
static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize;
static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize;
#else
static const int kLayoutDecriptorOffset = 1; // Must not be ever accessed.
static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
#endif
static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
static const int kSize = kWeakCellCacheOffset + kPointerSize;
// Layout of pointer fields. Heap iteration code relies on them
// being continuously allocated.
static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
static const int kPointerFieldsEndOffset = kSize;
// Byte offsets within kInstanceSizesOffset.
static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
static const int kInObjectPropertiesOrConstructorFunctionIndexByte = 1;
static const int kInObjectPropertiesOrConstructorFunctionIndexOffset =
kInstanceSizesOffset + kInObjectPropertiesOrConstructorFunctionIndexByte;
// Note there is one byte available for use here.
static const int kUnusedByte = 2;
static const int kUnusedOffset = kInstanceSizesOffset + kUnusedByte;
static const int kVisitorIdByte = 3;
static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
// Byte offsets within kInstanceAttributesOffset attributes.
#if V8_TARGET_LITTLE_ENDIAN
// Order instance type and bit field together such that they can be loaded
// together as a 16-bit word with instance type in the lower 8 bits regardless
// of endianess. Also provide endian-independent offset to that 16-bit word.
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
#else
static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
#endif
static const int kInstanceTypeAndBitFieldOffset =
kInstanceAttributesOffset + 0;
static const int kBitField2Offset = kInstanceAttributesOffset + 2;
static const int kUnusedPropertyFieldsByte = 3;
static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
Internals::kMapInstanceTypeAndBitFieldOffset);
// Bit positions for bit field.
static const int kHasNonInstancePrototype = 0;
static const int kIsCallable = 1;
static const int kHasNamedInterceptor = 2;
static const int kHasIndexedInterceptor = 3;
static const int kIsUndetectable = 4;
static const int kIsObserved = 5;
static const int kIsAccessCheckNeeded = 6;
static const int kIsConstructor = 7;
// Bit positions for bit field 2
static const int kIsExtensible = 0;
// Bit 1 is free.
class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
class ElementsKindBits: public BitField<ElementsKind, 3, 5> {};
// Derived values from bit field 2
static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
(FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1;
static const int8_t kMaximumBitField2FastSmiElementValue =
static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
Map::ElementsKindBits::kShift) - 1;
static const int8_t kMaximumBitField2FastHoleyElementValue =
static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
Map::ElementsKindBits::kShift) - 1;
static const int8_t kMaximumBitField2FastHoleySmiElementValue =
static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
Map::ElementsKindBits::kShift) - 1;
typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
kPointerFieldsEndOffset,
kSize> BodyDescriptor;
// Compares this map to another to see if they describe equivalent objects.
// If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
// it had exactly zero inobject properties.
// The "shared" flags of both this map and |other| are ignored.
bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
// Returns true if given field is unboxed double.
inline bool IsUnboxedDoubleField(FieldIndex index);
#if TRACE_MAPS
static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
static void TraceAllTransitions(Map* map);
#endif
static inline Handle<Map> AddMissingTransitionsForTesting(
Handle<Map> split_map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
private:
static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
Handle<Name> name, SimpleTransitionFlag flag);
bool EquivalentToForTransition(Map* other);
static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
static Handle<Map> ShareDescriptor(Handle<Map> map,
Handle<DescriptorArray> descriptors,
Descriptor* descriptor);
static Handle<Map> AddMissingTransitions(
Handle<Map> map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
static void InstallDescriptors(
Handle<Map> parent_map, Handle<Map> child_map, int new_descriptor,
Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
static Handle<Map> CopyAddDescriptor(Handle<Map> map,
Descriptor* descriptor,
TransitionFlag flag);
static Handle<Map> CopyReplaceDescriptors(
Handle<Map> map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
MaybeHandle<Name> maybe_name, const char* reason,
SimpleTransitionFlag simple_flag);
static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
Handle<DescriptorArray> descriptors,
Descriptor* descriptor,
int index,
TransitionFlag flag);
static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
Handle<Map> map, int descriptor, PropertyKind kind,
PropertyAttributes attributes, const char** reason);
static Handle<Map> CopyNormalized(Handle<Map> map,
PropertyNormalizationMode mode);
// Fires when the layout of an object with a leaf map changes.
// This includes adding transitions to the leaf map or changing
// the descriptor array.
inline void NotifyLeafMapLayoutChange();
void DeprecateTransitionTree();
void ReplaceDescriptors(DescriptorArray* new_descriptors,
LayoutDescriptor* new_layout_descriptor);
Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
// Update field type of the given descriptor to new representation and new
// type. The type must be prepared for storing in descriptor array:
// it must be either a simple type or a map wrapped in a weak cell.
void UpdateFieldType(int descriptor_number, Handle<Name> name,
Representation new_representation,
Handle<Object> new_wrapped_type);
void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
PropertyAttributes attributes);
void PrintGeneralization(FILE* file,
const char* reason,
int modify_index,
int split,
int descriptors,
bool constant_to_field,
Representation old_representation,
Representation new_representation,
HeapType* old_field_type,
HeapType* new_field_type);
static const int kFastPropertiesSoftLimit = 12;
static const int kMaxFastProperties = 128;
DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
};
// 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);
DECLARE_CAST(Struct)
};
// A simple one-element struct, useful where smis need to be boxed.
class Box : public Struct {
public:
// [value]: the boxed contents.
DECL_ACCESSORS(value, Object)
DECLARE_CAST(Box)
// Dispatched behavior.
DECLARE_PRINTER(Box)
DECLARE_VERIFIER(Box)
static const int kValueOffset = HeapObject::kHeaderSize;
static const int kSize = kValueOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Box);
};
// Container for metadata stored on each prototype map.
class PrototypeInfo : public Struct {
public:
static const int UNREGISTERED = -1;
// [prototype_users]: WeakFixedArray containing maps using this prototype,
// or Smi(0) if uninitialized.
DECL_ACCESSORS(prototype_users, Object)
// [registry_slot]: Slot in prototype's user registry where this user
// is stored. Returns UNREGISTERED if this prototype has not been registered.
inline int registry_slot() const;
inline void set_registry_slot(int slot);
// [validity_cell]: Cell containing the validity bit for prototype chains
// going through this object, or Smi(0) if uninitialized.
// When a prototype object changes its map, then both its own validity cell
// and those of all "downstream" prototypes are invalidated; handlers for a
// given receiver embed the currently valid cell for that receiver's prototype
// during their compilation and check it on execution.
DECL_ACCESSORS(validity_cell, Object)
DECLARE_CAST(PrototypeInfo)
// Dispatched behavior.
DECLARE_PRINTER(PrototypeInfo)
DECLARE_VERIFIER(PrototypeInfo)
static const int kPrototypeUsersOffset = HeapObject::kHeaderSize;
static const int kRegistrySlotOffset = kPrototypeUsersOffset + kPointerSize;
static const int kValidityCellOffset = kRegistrySlotOffset + kPointerSize;
static const int kConstructorNameOffset = kValidityCellOffset + kPointerSize;
static const int kSize = kConstructorNameOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeInfo);
};
// Pair used to store both a ScopeInfo and an extension object in the extension
// slot of a block context. Needed in the rare case where a declaration block
// scope (a "varblock" as used to desugar parameter destructuring) also contains
// a sloppy direct eval. (In no other case both are needed at the same time.)
class SloppyBlockWithEvalContextExtension : public Struct {
public:
// [scope_info]: Scope info.
DECL_ACCESSORS(scope_info, ScopeInfo)
// [extension]: Extension object.
DECL_ACCESSORS(extension, JSObject)
DECLARE_CAST(SloppyBlockWithEvalContextExtension)
// Dispatched behavior.
DECLARE_PRINTER(SloppyBlockWithEvalContextExtension)
DECLARE_VERIFIER(SloppyBlockWithEvalContextExtension)
static const int kScopeInfoOffset = HeapObject::kHeaderSize;
static const int kExtensionOffset = kScopeInfoOffset + kPointerSize;
static const int kSize = kExtensionOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SloppyBlockWithEvalContextExtension);
};
// Script describes a script which has been added to the VM.
class Script: public Struct {
public:
// Script types.
enum Type {
TYPE_NATIVE = 0,
TYPE_EXTENSION = 1,
TYPE_NORMAL = 2
};
// Script compilation types.
enum CompilationType {
COMPILATION_TYPE_HOST = 0,
COMPILATION_TYPE_EVAL = 1
};
// Script compilation state.
enum CompilationState {
COMPILATION_STATE_INITIAL = 0,
COMPILATION_STATE_COMPILED = 1
};
// [source]: the script source.
DECL_ACCESSORS(source, Object)
// [name]: the script name.
DECL_ACCESSORS(name, Object)
// [id]: the script id.
DECL_INT_ACCESSORS(id)
// [line_offset]: script line offset in resource from where it was extracted.
DECL_INT_ACCESSORS(line_offset)
// [column_offset]: script column offset in resource from where it was
// extracted.
DECL_INT_ACCESSORS(column_offset)
// [context_data]: context data for the context this script was compiled in.
DECL_ACCESSORS(context_data, Object)
// [wrapper]: the wrapper cache. This is either undefined or a WeakCell.
DECL_ACCESSORS(wrapper, HeapObject)
// [type]: the script type.
DECL_INT_ACCESSORS(type)
// [line_ends]: FixedArray of line ends positions.
DECL_ACCESSORS(line_ends, Object)
// [eval_from_shared]: for eval scripts the shared funcion info for the
// function from which eval was called.
DECL_ACCESSORS(eval_from_shared, Object)
// [eval_from_instructions_offset]: the instruction offset in the code for the
// function from which eval was called where eval was called.
DECL_INT_ACCESSORS(eval_from_instructions_offset)
// [shared_function_infos]: weak fixed array containing all shared
// function infos created from this script.
DECL_ACCESSORS(shared_function_infos, Object)
// [flags]: Holds an exciting bitfield.
DECL_INT_ACCESSORS(flags)
// [source_url]: sourceURL from magic comment
DECL_ACCESSORS(source_url, Object)
// [source_url]: sourceMappingURL magic comment
DECL_ACCESSORS(source_mapping_url, Object)
// [compilation_type]: how the the script was compiled. Encoded in the
// 'flags' field.
inline CompilationType compilation_type();
inline void set_compilation_type(CompilationType type);
// [compilation_state]: determines whether the script has already been
// compiled. Encoded in the 'flags' field.
inline CompilationState compilation_state();
inline void set_compilation_state(CompilationState state);
// [hide_source]: determines whether the script source can be exposed as
// function source. Encoded in the 'flags' field.
inline bool hide_source();
inline void set_hide_source(bool value);
// [origin_options]: optional attributes set by the embedder via ScriptOrigin,
// and used by the embedder to make decisions about the script. V8 just passes
// this through. Encoded in the 'flags' field.
inline v8::ScriptOriginOptions origin_options();
inline void set_origin_options(ScriptOriginOptions origin_options);
DECLARE_CAST(Script)
// If script source is an external string, check that the underlying
// resource is accessible. Otherwise, always return true.
inline bool HasValidSource();
// Convert code position into column number.
static int GetColumnNumber(Handle<Script> script, int code_pos);
// Convert code position into (zero-based) line number.
// The non-handlified version does not allocate, but may be much slower.
static int GetLineNumber(Handle<Script> script, int code_pos);
int GetLineNumber(int code_pos);
static Handle<Object> GetNameOrSourceURL(Handle<Script> script);
// Init line_ends array with code positions of line ends inside script source.
static void InitLineEnds(Handle<Script> script);
// Get the JS object wrapping the given script; create it if none exists.
static Handle<JSObject> GetWrapper(Handle<Script> script);
// Look through the list of existing shared function infos to find one
// that matches the function literal. Return empty handle if not found.
MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(FunctionLiteral* fun);
// Iterate over all script objects on the heap.
class Iterator {
public:
explicit Iterator(Isolate* isolate);
Script* Next();
private:
WeakFixedArray::Iterator iterator_;
DISALLOW_COPY_AND_ASSIGN(Iterator);
};
// Dispatched behavior.
DECLARE_PRINTER(Script)
DECLARE_VERIFIER(Script)
static const int kSourceOffset = HeapObject::kHeaderSize;
static const int kNameOffset = kSourceOffset + kPointerSize;
static const int kLineOffsetOffset = kNameOffset + kPointerSize;
static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
static const int kContextOffset = kColumnOffsetOffset + kPointerSize;
static const int kWrapperOffset = kContextOffset + kPointerSize;
static const int kTypeOffset = kWrapperOffset + kPointerSize;
static const int kLineEndsOffset = kTypeOffset + kPointerSize;
static const int kIdOffset = kLineEndsOffset + kPointerSize;
static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
static const int kEvalFrominstructionsOffsetOffset =
kEvalFromSharedOffset + kPointerSize;
static const int kSharedFunctionInfosOffset =
kEvalFrominstructionsOffsetOffset + kPointerSize;
static const int kFlagsOffset = kSharedFunctionInfosOffset + kPointerSize;
static const int kSourceUrlOffset = kFlagsOffset + kPointerSize;
static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
static const int kSize = kSourceMappingUrlOffset + kPointerSize;
private:
int GetLineNumberWithArray(int code_pos);
// Bit positions in the flags field.
static const int kCompilationTypeBit = 0;
static const int kCompilationStateBit = 1;
static const int kHideSourceBit = 2;
static const int kOriginOptionsShift = 3;
static const int kOriginOptionsSize = 3;
static const int kOriginOptionsMask = ((1 << kOriginOptionsSize) - 1)
<< kOriginOptionsShift;
DISALLOW_IMPLICIT_CONSTRUCTORS(Script);
};
// List of builtin functions we want to identify to improve code
// generation.
//
// Each entry has a name of a global object property holding an object
// optionally followed by ".prototype", a name of a builtin function
// on the object (the one the id is set for), and a label.
//
// Installation of ids for the selected builtin functions is handled
// by the bootstrapper.
#define FUNCTIONS_WITH_ID_LIST(V) \
V(Array.prototype, indexOf, ArrayIndexOf) \
V(Array.prototype, lastIndexOf, ArrayLastIndexOf) \
V(Array.prototype, push, ArrayPush) \
V(Array.prototype, pop, ArrayPop) \
V(Array.prototype, shift, ArrayShift) \
V(Function.prototype, apply, FunctionApply) \
V(Function.prototype, call, FunctionCall) \
V(String.prototype, charCodeAt, StringCharCodeAt) \
V(String.prototype, charAt, StringCharAt) \
V(String, fromCharCode, StringFromCharCode) \
V(Math, random, MathRandom) \
V(Math, floor, MathFloor) \
V(Math, round, MathRound) \
V(Math, ceil, MathCeil) \
V(Math, abs, MathAbs) \
V(Math, log, MathLog) \
V(Math, exp, MathExp) \
V(Math, sqrt, MathSqrt) \
V(Math, pow, MathPow) \
V(Math, max, MathMax) \
V(Math, min, MathMin) \
V(Math, cos, MathCos) \
V(Math, sin, MathSin) \
V(Math, tan, MathTan) \
V(Math, acos, MathAcos) \
V(Math, asin, MathAsin) \
V(Math, atan, MathAtan) \
V(Math, atan2, MathAtan2) \
V(Math, imul, MathImul) \
V(Math, clz32, MathClz32) \
V(Math, fround, MathFround)
#define ATOMIC_FUNCTIONS_WITH_ID_LIST(V) \
V(Atomics, load, AtomicsLoad) \
V(Atomics, store, AtomicsStore)
enum BuiltinFunctionId {
kArrayCode,
#define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \
k##name,
FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
ATOMIC_FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID)
#undef DECLARE_FUNCTION_ID
// Fake id for a special case of Math.pow. Note, it continues the
// list of math functions.
kMathPowHalf
};
// Result of searching in an optimized code map of a SharedFunctionInfo. Note
// that both {code} and {literals} can be NULL to pass search result status.
struct CodeAndLiterals {
Code* code; // Cached optimized code.
LiteralsArray* literals; // Cached literals array.
};
// SharedFunctionInfo describes the JSFunction information that can be
// shared by multiple instances of the function.
class SharedFunctionInfo: public HeapObject {
public:
// [name]: Function name.
DECL_ACCESSORS(name, Object)
// [code]: Function code.
DECL_ACCESSORS(code, Code)
inline void ReplaceCode(Code* code);
// [optimized_code_map]: Map from native context to optimized code
// and a shared literals array.
DECL_ACCESSORS(optimized_code_map, FixedArray)
// Returns entry from optimized code map for specified context and OSR entry.
// Note that {code == nullptr, literals == nullptr} indicates no matching
// entry has been found, whereas {code, literals == nullptr} indicates that
// code is context-independent.
CodeAndLiterals SearchOptimizedCodeMap(Context* native_context,
BailoutId osr_ast_id);
// Clear optimized code map.
void ClearOptimizedCodeMap();
// We have a special root FixedArray with the right shape and values
// to represent the cleared optimized code map. This predicate checks
// if that root is installed.
inline bool OptimizedCodeMapIsCleared() const;
// Removes a specific optimized code object from the optimized code map.
// In case of non-OSR the code reference is cleared from the cache entry but
// the entry itself is left in the map in order to proceed sharing literals.
void EvictFromOptimizedCodeMap(Code* optimized_code, const char* reason);
// Trims the optimized code map after entries have been removed.
void TrimOptimizedCodeMap(int shrink_by);
// Add a new entry to the optimized code map for context-independent code.
static void AddSharedCodeToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
Handle<Code> code);
// Add a new entry to the optimized code map for context-dependent code.
inline static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
Handle<Context> native_context,
Handle<Code> code,
Handle<LiteralsArray> literals,
BailoutId osr_ast_id);
// We may already have cached the code, but want to store literals in the
// cache.
inline static void AddLiteralsToOptimizedCodeMap(
Handle<SharedFunctionInfo> shared, Handle<Context> native_context,
Handle<LiteralsArray> literals);
// Set up the link between shared function info and the script. The shared
// function info is added to the list on the script.
static void SetScript(Handle<SharedFunctionInfo> shared,
Handle<Object> script_object);
// Layout description of the optimized code map.
static const int kSharedCodeIndex = 0;
static const int kEntriesStart = 1;
static const int kContextOffset = 0;
static const int kCachedCodeOffset = 1;
static const int kLiteralsOffset = 2;
static const int kOsrAstIdOffset = 3;
static const int kEntryLength = 4;
static const int kInitialLength = kEntriesStart + kEntryLength;
static const int kNotFound = -1;
// [scope_info]: Scope info.
DECL_ACCESSORS(scope_info, ScopeInfo)
// [construct stub]: Code stub for constructing instances of this function.
DECL_ACCESSORS(construct_stub, Code)
// Returns if this function has been compiled to native code yet.
inline bool is_compiled();
// [length]: The function length - usually the number of declared parameters.
// Use up to 2^30 parameters.
inline int length() const;
inline void set_length(int value);
// [internal formal parameter count]: The declared number of parameters.
// For subclass constructors, also includes new.target.
// The size of function's frame is internal_formal_parameter_count + 1.
inline int internal_formal_parameter_count() const;
inline void set_internal_formal_parameter_count(int value);
// Set the formal parameter count so the function code will be
// called without using argument adaptor frames.
inline void DontAdaptArguments();
// [expected_nof_properties]: Expected number of properties for the function.
inline int expected_nof_properties() const;
inline void set_expected_nof_properties(int value);
// [feedback_vector] - accumulates ast node feedback from full-codegen and
// (increasingly) from crankshafted code where sufficient feedback isn't
// available.
DECL_ACCESSORS(feedback_vector, TypeFeedbackVector)
// Unconditionally clear the type feedback vector (including vector ICs).
void ClearTypeFeedbackInfo();
// Clear the type feedback vector with a more subtle policy at GC time.
void ClearTypeFeedbackInfoAtGCTime();
#if TRACE_MAPS
// [unique_id] - For --trace-maps purposes, an identifier that's persistent
// even if the GC moves this SharedFunctionInfo.
inline int unique_id() const;
inline void set_unique_id(int value);
#endif
// [instance class name]: class name for instances.
DECL_ACCESSORS(instance_class_name, Object)
// [function data]: This field holds some additional data for function.
// Currently it has one of:
// - a FunctionTemplateInfo to make benefit the API [IsApiFunction()].
// - a Smi identifying a builtin function [HasBuiltinFunctionId()].
// - a BytecodeArray for the interpreter [HasBytecodeArray()].
// In the long run we don't want all functions to have this field but
// we can fix that when we have a better model for storing hidden data
// on objects.
DECL_ACCESSORS(function_data, Object)
inline bool IsApiFunction();
inline FunctionTemplateInfo* get_api_func_data();
inline bool HasBuiltinFunctionId();
inline BuiltinFunctionId builtin_function_id();
inline bool HasBytecodeArray();
inline BytecodeArray* bytecode_array();
// [script info]: Script from which the function originates.
DECL_ACCESSORS(script, Object)
// [num_literals]: Number of literals used by this function.
inline int num_literals() const;
inline void set_num_literals(int value);
// [start_position_and_type]: Field used to store both the source code
// position, whether or not the function is a function expression,
// and whether or not the function is a toplevel function. The two
// least significants bit indicates whether the function is an
// expression and the rest contains the source code position.
inline int start_position_and_type() const;
inline void set_start_position_and_type(int value);
// The function is subject to debugging if a debug info is attached.
inline bool HasDebugInfo();
inline DebugInfo* GetDebugInfo();
// A function has debug code if the compiled code has debug break slots.
inline bool HasDebugCode();
// [debug info]: Debug information.
DECL_ACCESSORS(debug_info, Object)
// [inferred name]: Name inferred from variable or property
// assignment of this function. Used to facilitate debugging and
// profiling of JavaScript code written in OO style, where almost
// all functions are anonymous but are assigned to object
// properties.
DECL_ACCESSORS(inferred_name, String)
// The function's name if it is non-empty, otherwise the inferred name.
String* DebugName();
// Position of the 'function' token in the script source.
inline int function_token_position() const;
inline void set_function_token_position(int function_token_position);
// Position of this function in the script source.
inline int start_position() const;
inline void set_start_position(int start_position);
// End position of this function in the script source.
inline int end_position() const;
inline void set_end_position(int end_position);
// Is this function a function expression in the source code.
DECL_BOOLEAN_ACCESSORS(is_expression)
// Is this function a top-level function (scripts, evals).
DECL_BOOLEAN_ACCESSORS(is_toplevel)
// Bit field containing various information collected by the compiler to
// drive optimization.
inline int compiler_hints() const;
inline void set_compiler_hints(int value);
inline int ast_node_count() const;
inline void set_ast_node_count(int count);
inline int profiler_ticks() const;
inline void set_profiler_ticks(int ticks);
// Inline cache age is used to infer whether the function survived a context
// disposal or not. In the former case we reset the opt_count.
inline int ic_age();
inline void set_ic_age(int age);
// Indicates if this function can be lazy compiled.
// This is used to determine if we can safely flush code from a function
// when doing GC if we expect that the function will no longer be used.
DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation)
// Indicates if this function can be lazy compiled without a context.
// This is used to determine if we can force compilation without reaching
// the function through program execution but through other means (e.g. heap
// iteration by the debugger).
DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context)
// Indicates whether optimizations have been disabled for this
// shared function info. If a function is repeatedly optimized or if
// we cannot optimize the function we disable optimization to avoid
// spending time attempting to optimize it again.
DECL_BOOLEAN_ACCESSORS(optimization_disabled)
// Indicates the language mode.
inline LanguageMode language_mode();
inline void set_language_mode(LanguageMode language_mode);
// False if the function definitely does not allocate an arguments object.
DECL_BOOLEAN_ACCESSORS(uses_arguments)
// Indicates that this function uses a super property (or an eval that may
// use a super property).
// This is needed to set up the [[HomeObject]] on the function instance.
DECL_BOOLEAN_ACCESSORS(needs_home_object)
// True if the function has any duplicated parameter names.
DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
// Indicates whether the function is a native function.
// These needs special treatment in .call and .apply since
// null passed as the receiver should not be translated to the
// global object.
DECL_BOOLEAN_ACCESSORS(native)
// Indicate that this function should always be inlined in optimized code.
DECL_BOOLEAN_ACCESSORS(force_inline)
// Indicates that the function was created by the Function function.
// Though it's anonymous, toString should treat it as if it had the name
// "anonymous". We don't set the name itself so that the system does not
// see a binding for it.
DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous)
// Indicates that the function is anonymous (the name field can be set
// through the API, which does not change this flag).
DECL_BOOLEAN_ACCESSORS(is_anonymous)
// Is this a function or top-level/eval code.
DECL_BOOLEAN_ACCESSORS(is_function)
// Indicates that code for this function cannot be compiled with Crankshaft.
DECL_BOOLEAN_ACCESSORS(dont_crankshaft)
// Indicates that code for this function cannot be flushed.
DECL_BOOLEAN_ACCESSORS(dont_flush)
// Indicates that this function is a generator.
DECL_BOOLEAN_ACCESSORS(is_generator)
// Indicates that this function is an arrow function.
DECL_BOOLEAN_ACCESSORS(is_arrow)
// Indicates that this function is a concise method.
DECL_BOOLEAN_ACCESSORS(is_concise_method)
// Indicates that this function is an accessor (getter or setter).
DECL_BOOLEAN_ACCESSORS(is_accessor_function)
// Indicates that this function is a default constructor.
DECL_BOOLEAN_ACCESSORS(is_default_constructor)
// Indicates that this function is an asm function.
DECL_BOOLEAN_ACCESSORS(asm_function)
// Indicates that the the shared function info is deserialized from cache.
DECL_BOOLEAN_ACCESSORS(deserialized)
// Indicates that the the shared function info has never been compiled before.
DECL_BOOLEAN_ACCESSORS(never_compiled)
inline FunctionKind kind();
inline void set_kind(FunctionKind kind);
// Indicates whether or not the code in the shared function support
// deoptimization.
inline bool has_deoptimization_support();
// Enable deoptimization support through recompiled code.
void EnableDeoptimizationSupport(Code* recompiled);
// Disable (further) attempted optimization of all functions sharing this
// shared function info.
void DisableOptimization(BailoutReason reason);
inline BailoutReason disable_optimization_reason();
// Lookup the bailout ID and DCHECK that it exists in the non-optimized
// code, returns whether it asserted (i.e., always true if assertions are
// disabled).
bool VerifyBailoutId(BailoutId id);
// [source code]: Source code for the function.
bool HasSourceCode() const;
Handle<Object> GetSourceCode();
// Number of times the function was optimized.
inline int opt_count();
inline void set_opt_count(int opt_count);
// Number of times the function was deoptimized.
inline void set_deopt_count(int value);
inline int deopt_count();
inline void increment_deopt_count();
// Number of time we tried to re-enable optimization after it
// was disabled due to high number of deoptimizations.
inline void set_opt_reenable_tries(int value);
inline int opt_reenable_tries();
inline void TryReenableOptimization();
// Stores deopt_count, opt_reenable_tries and ic_age as bit-fields.
inline void set_counters(int value);
inline int counters() const;
// Stores opt_count and bailout_reason as bit-fields.
inline void set_opt_count_and_bailout_reason(int value);
inline int opt_count_and_bailout_reason() const;
inline void set_disable_optimization_reason(BailoutReason reason);
// Tells whether this function should be subject to debugging.
inline bool IsSubjectToDebugging();
// Whether this function is defined in native code or extensions.
inline bool IsBuiltin();
// Check whether or not this function is inlineable.
bool IsInlineable();
// Source size of this function.
int SourceSize();
// Returns `false` if formal parameters include rest parameters, optional
// parameters, or destructuring parameters.
// TODO(caitp): make this a flag set during parsing
inline bool has_simple_parameters();
// Initialize a SharedFunctionInfo from a parsed function literal.
static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info,
FunctionLiteral* lit);
// Dispatched behavior.
DECLARE_PRINTER(SharedFunctionInfo)
DECLARE_VERIFIER(SharedFunctionInfo)
void ResetForNewContext(int new_ic_age);
// Iterate over all shared function infos.
class Iterator {
public:
explicit Iterator(Isolate* isolate);
SharedFunctionInfo* Next();
private:
bool NextScript();
Script::Iterator script_iterator_;
WeakFixedArray::Iterator sfi_iterator_;
DisallowHeapAllocation no_gc_;
DISALLOW_COPY_AND_ASSIGN(Iterator);
};
DECLARE_CAST(SharedFunctionInfo)
// Constants.
static const int kDontAdaptArgumentsSentinel = -1;
// Layout description.
// Pointer fields.
static const int kNameOffset = HeapObject::kHeaderSize;
static const int kCodeOffset = kNameOffset + kPointerSize;
static const int kOptimizedCodeMapOffset = kCodeOffset + kPointerSize;
static const int kScopeInfoOffset = kOptimizedCodeMapOffset + kPointerSize;
static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize;
static const int kInstanceClassNameOffset =
kConstructStubOffset + kPointerSize;
static const int kFunctionDataOffset =
kInstanceClassNameOffset + kPointerSize;
static const int kScriptOffset = kFunctionDataOffset + kPointerSize;
static const int kDebugInfoOffset = kScriptOffset + kPointerSize;
static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize;
static const int kFeedbackVectorOffset =
kInferredNameOffset + kPointerSize;
#if TRACE_MAPS
static const int kUniqueIdOffset = kFeedbackVectorOffset + kPointerSize;
static const int kLastPointerFieldOffset = kUniqueIdOffset;
#else
// Just to not break the postmortrem support with conditional offsets
static const int kUniqueIdOffset = kFeedbackVectorOffset;
static const int kLastPointerFieldOffset = kFeedbackVectorOffset;
#endif
#if V8_HOST_ARCH_32_BIT
// Smi fields.
static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize;
static const int kExpectedNofPropertiesOffset =
kFormalParameterCountOffset + kPointerSize;
static const int kNumLiteralsOffset =
kExpectedNofPropertiesOffset + kPointerSize;
static const int kStartPositionAndTypeOffset =
kNumLiteralsOffset + kPointerSize;
static const int kEndPositionOffset =
kStartPositionAndTypeOffset + kPointerSize;
static const int kFunctionTokenPositionOffset =
kEndPositionOffset + kPointerSize;
static const int kCompilerHintsOffset =
kFunctionTokenPositionOffset + kPointerSize;
static const int kOptCountAndBailoutReasonOffset =
kCompilerHintsOffset + kPointerSize;
static const int kCountersOffset =
kOptCountAndBailoutReasonOffset + kPointerSize;
static const int kAstNodeCountOffset =
kCountersOffset + kPointerSize;
static const int kProfilerTicksOffset =
kAstNodeCountOffset + kPointerSize;
// Total size.
static const int kSize = kProfilerTicksOffset + kPointerSize;
#else
// The only reason to use smi fields instead of int fields is to allow
// iteration without maps decoding during garbage collections.
// To avoid wasting space on 64-bit architectures we use the following trick:
// we group integer fields into pairs
// The least significant integer in each pair is shifted left by 1. By doing
// this we guarantee that LSB of each kPointerSize aligned word is not set and
// thus this word cannot be treated as pointer to HeapObject during old space
// traversal.
#if V8_TARGET_LITTLE_ENDIAN
static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize;
static const int kFormalParameterCountOffset =
kLengthOffset + kIntSize;
static const int kExpectedNofPropertiesOffset =
kFormalParameterCountOffset + kIntSize;
static const int kNumLiteralsOffset =
kExpectedNofPropertiesOffset + kIntSize;
static const int kEndPositionOffset =
kNumLiteralsOffset + kIntSize;
static const int kStartPositionAndTypeOffset =
kEndPositionOffset + kIntSize;
static const int kFunctionTokenPositionOffset =
kStartPositionAndTypeOffset + kIntSize;
static const int kCompilerHintsOffset =
kFunctionTokenPositionOffset + kIntSize;
static const int kOptCountAndBailoutReasonOffset =
kCompilerHintsOffset + kIntSize;
static const int kCountersOffset =
kOptCountAndBailoutReasonOffset + kIntSize;
static const int kAstNodeCountOffset =
kCountersOffset + kIntSize;
static const int kProfilerTicksOffset =
kAstNodeCountOffset + kIntSize;
// Total size.
static const int kSize = kProfilerTicksOffset + kIntSize;
#elif V8_TARGET_BIG_ENDIAN
static const int kFormalParameterCountOffset =
kLastPointerFieldOffset + kPointerSize;
static const int kLengthOffset = kFormalParameterCountOffset + kIntSize;
static const int kNumLiteralsOffset = kLengthOffset + kIntSize;
static const int kExpectedNofPropertiesOffset = kNumLiteralsOffset + kIntSize;
static const int kStartPositionAndTypeOffset =
kExpectedNofPropertiesOffset + kIntSize;
static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize;
static const int kCompilerHintsOffset = kEndPositionOffset + kIntSize;
static const int kFunctionTokenPositionOffset =
kCompilerHintsOffset + kIntSize;
static const int kCountersOffset = kFunctionTokenPositionOffset + kIntSize;
static const int kOptCountAndBailoutReasonOffset = kCountersOffset + kIntSize;
static const int kProfilerTicksOffset =
kOptCountAndBailoutReasonOffset + kIntSize;
static const int kAstNodeCountOffset = kProfilerTicksOffset + kIntSize;
// Total size.
static const int kSize = kAstNodeCountOffset + kIntSize;
#else
#error Unknown byte ordering
#endif // Big endian
#endif // 64-bit
static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
typedef FixedBodyDescriptor<kNameOffset,
kLastPointerFieldOffset + kPointerSize,
kSize> BodyDescriptor;
// Bit positions in start_position_and_type.
// The source code start position is in the 30 most significant bits of
// the start_position_and_type field.
static const int kIsExpressionBit = 0;
static const int kIsTopLevelBit = 1;
static const int kStartPositionShift = 2;
static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1);
// Bit positions in compiler_hints.
enum CompilerHints {
// byte 0
kAllowLazyCompilation,
kAllowLazyCompilationWithoutContext,
kOptimizationDisabled,
kNative,
kStrictModeFunction,
kStrongModeFunction,
kUsesArguments,
kNeedsHomeObject,
// byte 1
kHasDuplicateParameters,
kForceInline,
kIsAsmFunction,
kIsAnonymous,
kNameShouldPrintAsAnonymous,
kIsFunction,
kDontCrankshaft,
kDontFlush,
// byte 2
kFunctionKind,
kIsArrow = kFunctionKind,
kIsGenerator,
kIsConciseMethod,
kIsAccessorFunction,
kIsDefaultConstructor,
kIsSubclassConstructor,
kIsBaseConstructor,
kIsInObjectLiteral,
// byte 3
kDeserialized,
kNeverCompiled,
kCompilerHintsCount, // Pseudo entry
};
// Add hints for other modes when they're added.
STATIC_ASSERT(LANGUAGE_END == 3);
// kFunctionKind has to be byte-aligned
STATIC_ASSERT((kFunctionKind % kBitsPerByte) == 0);
// Make sure that FunctionKind and byte 2 are in sync:
#define ASSERT_FUNCTION_KIND_ORDER(functionKind, compilerFunctionKind) \
STATIC_ASSERT(FunctionKind::functionKind == \
1 << (compilerFunctionKind - kFunctionKind))
ASSERT_FUNCTION_KIND_ORDER(kArrowFunction, kIsArrow);
ASSERT_FUNCTION_KIND_ORDER(kGeneratorFunction, kIsGenerator);
ASSERT_FUNCTION_KIND_ORDER(kConciseMethod, kIsConciseMethod);
ASSERT_FUNCTION_KIND_ORDER(kAccessorFunction, kIsAccessorFunction);
ASSERT_FUNCTION_KIND_ORDER(kDefaultConstructor, kIsDefaultConstructor);
ASSERT_FUNCTION_KIND_ORDER(kSubclassConstructor, kIsSubclassConstructor);
ASSERT_FUNCTION_KIND_ORDER(kBaseConstructor, kIsBaseConstructor);
ASSERT_FUNCTION_KIND_ORDER(kInObjectLiteral, kIsInObjectLiteral);
#undef ASSERT_FUNCTION_KIND_ORDER
class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 8> {};
class DeoptCountBits : public BitField<int, 0, 4> {};
class OptReenableTriesBits : public BitField<int, 4, 18> {};
class ICAgeBits : public BitField<int, 22, 8> {};
class OptCountBits : public BitField<int, 0, 22> {};
class DisabledOptimizationReasonBits : public BitField<int, 22, 8> {};
private:
#if V8_HOST_ARCH_32_BIT
// On 32 bit platforms, compiler hints is a smi.
static const int kCompilerHintsSmiTagSize = kSmiTagSize;
static const int kCompilerHintsSize = kPointerSize;
#else
// On 64 bit platforms, compiler hints is not a smi, see comment above.
static const int kCompilerHintsSmiTagSize = 0;
static const int kCompilerHintsSize = kIntSize;
#endif
STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <=
SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte);
public:
// Constants for optimizing codegen for strict mode function and
// native tests when using integer-width instructions.
static const int kStrictModeBit =
kStrictModeFunction + kCompilerHintsSmiTagSize;
static const int kStrongModeBit =
kStrongModeFunction + kCompilerHintsSmiTagSize;
static const int kNativeBit = kNative + kCompilerHintsSmiTagSize;
static const int kClassConstructorBits =
FunctionKind::kClassConstructor
<< (kFunctionKind + kCompilerHintsSmiTagSize);
// Constants for optimizing codegen for strict mode function and
// native tests.
// Allows to use byte-width instructions.
static const int kStrictModeBitWithinByte = kStrictModeBit % kBitsPerByte;
static const int kStrongModeBitWithinByte = kStrongModeBit % kBitsPerByte;
static const int kNativeBitWithinByte = kNativeBit % kBitsPerByte;
static const int kClassConstructorBitsWithinByte =
FunctionKind::kClassConstructor << kCompilerHintsSmiTagSize;
STATIC_ASSERT(kClassConstructorBitsWithinByte < (1 << kBitsPerByte));
#if defined(V8_TARGET_LITTLE_ENDIAN)
#define BYTE_OFFSET(compiler_hint) \
kCompilerHintsOffset + \
(compiler_hint + kCompilerHintsSmiTagSize) / kBitsPerByte
#elif defined(V8_TARGET_BIG_ENDIAN)
#define BYTE_OFFSET(compiler_hint) \
kCompilerHintsOffset + (kCompilerHintsSize - 1) - \
((compiler_hint + kCompilerHintsSmiTagSize) / kBitsPerByte)
#else
#error Unknown byte ordering
#endif
static const int kStrictModeByteOffset = BYTE_OFFSET(kStrictModeFunction);
static const int kStrongModeByteOffset = BYTE_OFFSET(kStrongModeFunction);
static const int kNativeByteOffset = BYTE_OFFSET(kNative);
static const int kFunctionKindByteOffset = BYTE_OFFSET(kFunctionKind);
#undef BYTE_OFFSET
private:
// Returns entry from optimized code map for specified context and OSR entry.
// The result is either kNotFound, kSharedCodeIndex for context-independent
// entry or a start index of the context-dependent entry.
int SearchOptimizedCodeMapEntry(Context* native_context,
BailoutId osr_ast_id);
// If code is undefined, then existing code won't be overwritten.
static void AddToOptimizedCodeMapInternal(Handle<SharedFunctionInfo> shared,
Handle<Context> native_context,
Handle<HeapObject> code,
Handle<LiteralsArray> literals,
BailoutId osr_ast_id);
DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo);
};
// Printing support.
struct SourceCodeOf {
explicit SourceCodeOf(SharedFunctionInfo* v, int max = -1)
: value(v), max_length(max) {}
const SharedFunctionInfo* value;
int max_length;
};
std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v);
class JSGeneratorObject: public JSObject {
public:
// [function]: The function corresponding to this generator object.
DECL_ACCESSORS(function, JSFunction)
// [context]: The context of the suspended computation.
DECL_ACCESSORS(context, Context)
// [receiver]: The receiver of the suspended computation.
DECL_ACCESSORS(receiver, Object)
// [continuation]: Offset into code of continuation.
//
// A positive offset indicates a suspended generator. The special
// kGeneratorExecuting and kGeneratorClosed values indicate that a generator
// cannot be resumed.
inline int continuation() const;
inline void set_continuation(int continuation);
inline bool is_closed();
inline bool is_executing();
inline bool is_suspended();
// [operand_stack]: Saved operand stack.
DECL_ACCESSORS(operand_stack, FixedArray)
DECLARE_CAST(JSGeneratorObject)
// Dispatched behavior.
DECLARE_PRINTER(JSGeneratorObject)
DECLARE_VERIFIER(JSGeneratorObject)
// Magic sentinel values for the continuation.
static const int kGeneratorExecuting = -1;
static const int kGeneratorClosed = 0;
// Layout description.
static const int kFunctionOffset = JSObject::kHeaderSize;
static const int kContextOffset = kFunctionOffset + kPointerSize;
static const int kReceiverOffset = kContextOffset + kPointerSize;
static const int kContinuationOffset = kReceiverOffset + kPointerSize;
static const int kOperandStackOffset = kContinuationOffset + kPointerSize;
static const int kSize = kOperandStackOffset + kPointerSize;
// Resume mode, for use by runtime functions.
enum ResumeMode { NEXT, THROW };
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
};
// Representation for module instance objects.
class JSModule: public JSObject {
public:
// [context]: the context holding the module's locals, or undefined if none.
DECL_ACCESSORS(context, Object)
// [scope_info]: Scope info.
DECL_ACCESSORS(scope_info, ScopeInfo)
DECLARE_CAST(JSModule)
// Dispatched behavior.
DECLARE_PRINTER(JSModule)
DECLARE_VERIFIER(JSModule)
// Layout description.
static const int kContextOffset = JSObject::kHeaderSize;
static const int kScopeInfoOffset = kContextOffset + kPointerSize;
static const int kSize = kScopeInfoOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule);
};
// JSBoundFunction describes a bound function exotic object.
class JSBoundFunction : public JSObject {
public:
// [length]: The bound function "length" property.
DECL_ACCESSORS(length, Object)
// [name]: The bound function "name" property.
DECL_ACCESSORS(name, Object)
// [bound_target_function]: The wrapped function object.
DECL_ACCESSORS(bound_target_function, JSReceiver)
// [bound_this]: The value that is always passed as the this value when
// calling the wrapped function.
DECL_ACCESSORS(bound_this, Object)
// [bound_arguments]: A list of values whose elements are used as the first
// arguments to any call to the wrapped function.
DECL_ACCESSORS(bound_arguments, FixedArray)
// [creation_context]: The native context in which the function was bound.
// TODO(bmeurer, verwaest): Can we (mis)use (unused) constructor field in
// the Map instead of putting this into the object? Only required for
// JSReceiver::GetCreationContext() anyway.
DECL_ACCESSORS(creation_context, Context)
static MaybeHandle<Context> GetFunctionRealm(
Handle<JSBoundFunction> function);
DECLARE_CAST(JSBoundFunction)
// Dispatched behavior.
DECLARE_PRINTER(JSBoundFunction)
DECLARE_VERIFIER(JSBoundFunction)
// The bound function's string representation implemented according
// to ES6 section 19.2.3.5 Function.prototype.toString ( ).
static Handle<String> ToString(Handle<JSBoundFunction> function);
// Layout description.
static const int kBoundTargetFunctionOffset = JSObject::kHeaderSize;
static const int kBoundThisOffset = kBoundTargetFunctionOffset + kPointerSize;
static const int kBoundArgumentsOffset = kBoundThisOffset + kPointerSize;
static const int kCreationContextOffset =
kBoundArgumentsOffset + kPointerSize;
static const int kLengthOffset = kCreationContextOffset + kPointerSize;
static const int kNameOffset = kLengthOffset + kPointerSize;
static const int kSize = kNameOffset + kPointerSize;
// Indices of in-object properties.
static const int kLengthIndex = 0;
static const int kNameIndex = 1;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSBoundFunction);
};
// JSFunction describes JavaScript functions.
class JSFunction: public JSObject {
public:
// [prototype_or_initial_map]:
DECL_ACCESSORS(prototype_or_initial_map, Object)
// [shared]: The information about the function that
// can be shared by instances.
DECL_ACCESSORS(shared, SharedFunctionInfo)
// [context]: The context for this function.
inline Context* context();
inline void set_context(Object* context);
inline JSObject* global_proxy();
inline Context* native_context();
static Handle<Context> GetFunctionRealm(Handle<JSFunction> function);
// [code]: The generated code object for this function. Executed
// when the function is invoked, e.g. foo() or new foo(). See
// [[Call]] and [[Construct]] description in ECMA-262, section
// 8.6.2, page 27.
inline Code* code();
inline void set_code(Code* code);
inline void set_code_no_write_barrier(Code* code);
inline void ReplaceCode(Code* code);
// Tells whether this function inlines the given shared function info.
bool Inlines(SharedFunctionInfo* candidate);
// Tells whether or not this function has been optimized.
inline bool IsOptimized();
// Mark this function for lazy recompilation. The function will be
// recompiled the next time it is executed.
void MarkForOptimization();
void AttemptConcurrentOptimization();
// Tells whether or not the function is already marked for lazy
// recompilation.
inline bool IsMarkedForOptimization();
inline bool IsMarkedForConcurrentOptimization();
// Tells whether or not the function is on the concurrent recompilation queue.
inline bool IsInOptimizationQueue();
// Completes inobject slack tracking on initial map if it is active.
inline void CompleteInobjectSlackTrackingIfActive();
// [literals]: Fixed array holding the materialized literals.
//
// If the function contains object, regexp or array literals, the
// literals array prefix contains the object, regexp, and array
// function to be used when creating these literals. This is
// necessary so that we do not dynamically lookup the object, regexp
// or array functions. Performing a dynamic lookup, we might end up
// using the functions from a new context that we should not have
// access to.
DECL_ACCESSORS(literals, LiteralsArray)
// The initial map for an object created by this constructor.
inline Map* initial_map();
static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
Handle<Object> prototype);
inline bool has_initial_map();
static void EnsureHasInitialMap(Handle<JSFunction> function);
// Creates a map that matches the constructor's initial map, but with
// [[prototype]] being new.target.prototype. Because new.target can be a
// JSProxy, this can call back into JavaScript.
static MUST_USE_RESULT MaybeHandle<Map> GetDerivedMap(
Isolate* isolate, Handle<JSFunction> constructor,
Handle<JSReceiver> new_target);
// Get and set the prototype property on a JSFunction. If the
// function has an initial map the prototype is set on the initial
// map. Otherwise, the prototype is put in the initial map field
// until an initial map is needed.
inline bool has_prototype();
inline bool has_instance_prototype();
inline Object* prototype();
inline Object* instance_prototype();
static void SetPrototype(Handle<JSFunction> function,
Handle<Object> value);
static void SetInstancePrototype(Handle<JSFunction> function,
Handle<Object> value);
// After prototype is removed, it will not be created when accessed, and
// [[Construct]] from this function will not be allowed.
bool RemovePrototype();
// Returns if this function has been compiled to native code yet.
inline bool is_compiled();
// [next_function_link]: Links functions into various lists, e.g. the list
// of optimized functions hanging off the native_context. The CodeFlusher
// uses this link to chain together flushing candidates. Treated weakly
// by the garbage collector.
DECL_ACCESSORS(next_function_link, Object)
// Prints the name of the function using PrintF.
void PrintName(FILE* out = stdout);
DECLARE_CAST(JSFunction)
// Calculate the instance size and in-object properties count.
void CalculateInstanceSize(InstanceType instance_type,
int requested_internal_fields, int* instance_size,
int* in_object_properties);
void CalculateInstanceSizeForDerivedClass(InstanceType instance_type,
int requested_internal_fields,
int* instance_size,
int* in_object_properties);
// Visiting policy flags define whether the code entry or next function
// should be visited or not.
enum BodyVisitingPolicy {
kVisitCodeEntry = 1 << 0,
kVisitNextFunction = 1 << 1,
kSkipCodeEntryAndNextFunction = 0,
kVisitCodeEntryAndNextFunction = kVisitCodeEntry | kVisitNextFunction
};
// Iterates the function object according to the visiting policy.
template <BodyVisitingPolicy>
class BodyDescriptorImpl;
// Visit the whole object.
typedef BodyDescriptorImpl<kVisitCodeEntryAndNextFunction> BodyDescriptor;
// Don't visit next function.
typedef BodyDescriptorImpl<kVisitCodeEntry> BodyDescriptorStrongCode;
typedef BodyDescriptorImpl<kSkipCodeEntryAndNextFunction>
BodyDescriptorWeakCode;
// Dispatched behavior.
DECLARE_PRINTER(JSFunction)
DECLARE_VERIFIER(JSFunction)
// Returns the number of allocated literals.
inline int NumberOfLiterals();
// Used for flags such as --hydrogen-filter.
bool PassesFilter(const char* raw_filter);
// The function's name if it is configured, otherwise shared function info
// debug name.
static Handle<String> GetName(Handle<JSFunction> function);
// The function's displayName if it is set, otherwise name if it is
// configured, otherwise shared function info
// debug name.
static Handle<String> GetDebugName(Handle<JSFunction> function);
// The function's string representation implemented according to
// ES6 section 19.2.3.5 Function.prototype.toString ( ).
static Handle<String> ToString(Handle<JSFunction> function);
// Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
// kSize) is weak and has special handling during garbage collection.
static const int kPrototypeOrInitialMapOffset = JSObject::kHeaderSize;
static const int kSharedFunctionInfoOffset =
kPrototypeOrInitialMapOffset + kPointerSize;
static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize;
static const int kLiteralsOffset = kContextOffset + kPointerSize;
static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize;
static const int kCodeEntryOffset = kNonWeakFieldsEndOffset;
static const int kNextFunctionLinkOffset = kCodeEntryOffset + kPointerSize;
static const int kSize = kNextFunctionLinkOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
};
// JSGlobalProxy's prototype must be a JSGlobalObject or null,
// and the prototype is hidden. JSGlobalProxy always delegates
// property accesses to its prototype if the prototype is not null.
//
// A JSGlobalProxy can be reinitialized which will preserve its identity.
//
// Accessing a JSGlobalProxy requires security check.
class JSGlobalProxy : public JSObject {
public:
// [native_context]: the owner native context of this global proxy object.
// It is null value if this object is not used by any context.
DECL_ACCESSORS(native_context, Object)
// [hash]: The hash code property (undefined if not initialized yet).
DECL_ACCESSORS(hash, Object)
DECLARE_CAST(JSGlobalProxy)
inline bool IsDetachedFrom(JSGlobalObject* global) const;
// Dispatched behavior.
DECLARE_PRINTER(JSGlobalProxy)
DECLARE_VERIFIER(JSGlobalProxy)
// Layout description.
static const int kNativeContextOffset = JSObject::kHeaderSize;
static const int kHashOffset = kNativeContextOffset + kPointerSize;
static const int kSize = kHashOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
};
// JavaScript global object.
class JSGlobalObject : public JSObject {
public:
// [native context]: the natives corresponding to this global object.
DECL_ACCESSORS(native_context, Context)
// [global proxy]: the global proxy object of the context
DECL_ACCESSORS(global_proxy, JSObject)
static void InvalidatePropertyCell(Handle<JSGlobalObject> object,
Handle<Name> name);
// Ensure that the global object has a cell for the given property name.
static Handle<PropertyCell> EnsurePropertyCell(Handle<JSGlobalObject> global,
Handle<Name> name);
DECLARE_CAST(JSGlobalObject)
inline bool IsDetached();
// Dispatched behavior.
DECLARE_PRINTER(JSGlobalObject)
DECLARE_VERIFIER(JSGlobalObject)
// Layout description.
static const int kNativeContextOffset = JSObject::kHeaderSize;
static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
static const int kSize = kHeaderSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
};
// Representation for JS Wrapper objects, String, Number, Boolean, etc.
class JSValue: public JSObject {
public:
// [value]: the object being wrapped.
DECL_ACCESSORS(value, Object)
DECLARE_CAST(JSValue)
// Dispatched behavior.
DECLARE_PRINTER(JSValue)
DECLARE_VERIFIER(JSValue)
// Layout description.
static const int kValueOffset = JSObject::kHeaderSize;
static const int kSize = kValueOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
};
class DateCache;
// Representation for JS date objects.
class JSDate: public JSObject {
public:
static MUST_USE_RESULT MaybeHandle<JSDate> New(Handle<JSFunction> constructor,
Handle<JSReceiver> new_target,
double tv);
// If one component is NaN, all of them are, indicating a NaN time value.
// [value]: the time value.
DECL_ACCESSORS(value, Object)
// [year]: caches year. Either undefined, smi, or NaN.
DECL_ACCESSORS(year, Object)
// [month]: caches month. Either undefined, smi, or NaN.
DECL_ACCESSORS(month, Object)
// [day]: caches day. Either undefined, smi, or NaN.
DECL_ACCESSORS(day, Object)
// [weekday]: caches day of week. Either undefined, smi, or NaN.
DECL_ACCESSORS(weekday, Object)
// [hour]: caches hours. Either undefined, smi, or NaN.
DECL_ACCESSORS(hour, Object)
// [min]: caches minutes. Either undefined, smi, or NaN.
DECL_ACCESSORS(min, Object)
// [sec]: caches seconds. Either undefined, smi, or NaN.
DECL_ACCESSORS(sec, Object)
// [cache stamp]: sample of the date cache stamp at the
// moment when chached fields were cached.
DECL_ACCESSORS(cache_stamp, Object)
DECLARE_CAST(JSDate)
// Returns the time value (UTC) identifying the current time.
static double CurrentTimeValue(Isolate* isolate);
// Returns the date field with the specified index.
// See FieldIndex for the list of date fields.
static Object* GetField(Object* date, Smi* index);
static Handle<Object> SetValue(Handle<JSDate> date, double v);
void SetValue(Object* value, bool is_value_nan);
// ES6 section 20.3.4.45 Date.prototype [ @@toPrimitive ]
static MUST_USE_RESULT MaybeHandle<Object> ToPrimitive(
Handle<JSReceiver> receiver, Handle<Object> hint);
// Dispatched behavior.
DECLARE_PRINTER(JSDate)
DECLARE_VERIFIER(JSDate)
// The order is important. It must be kept in sync with date macros
// in macros.py.
enum FieldIndex {
kDateValue,
kYear,
kMonth,
kDay,
kWeekday,
kHour,
kMinute,
kSecond,
kFirstUncachedField,
kMillisecond = kFirstUncachedField,
kDays,
kTimeInDay,
kFirstUTCField,
kYearUTC = kFirstUTCField,
kMonthUTC,
kDayUTC,
kWeekdayUTC,
kHourUTC,
kMinuteUTC,
kSecondUTC,
kMillisecondUTC,
kDaysUTC,
kTimeInDayUTC,
kTimezoneOffset
};
// Layout description.
static const int kValueOffset = JSObject::kHeaderSize;
static const int kYearOffset = kValueOffset + kPointerSize;
static const int kMonthOffset = kYearOffset + kPointerSize;
static const int kDayOffset = kMonthOffset + kPointerSize;
static const int kWeekdayOffset = kDayOffset + kPointerSize;
static const int kHourOffset = kWeekdayOffset + kPointerSize;
static const int kMinOffset = kHourOffset + kPointerSize;
static const int kSecOffset = kMinOffset + kPointerSize;
static const int kCacheStampOffset = kSecOffset + kPointerSize;
static const int kSize = kCacheStampOffset + kPointerSize;
private:
inline Object* DoGetField(FieldIndex index);
Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
// Computes and caches the cacheable fields of the date.
inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
};
// Representation of message objects used for error reporting through
// the API. The messages are formatted in JavaScript so this object is
// a real JavaScript object. The information used for formatting the
// error messages are not directly accessible from JavaScript to
// prevent leaking information to user code called during error
// formatting.
class JSMessageObject: public JSObject {
public:
// [type]: the type of error message.
inline int type() const;
inline void set_type(int value);
// [arguments]: the arguments for formatting the error message.
DECL_ACCESSORS(argument, Object)
// [script]: the script from which the error message originated.
DECL_ACCESSORS(script, Object)
// [stack_frames]: an array of stack frames for this error object.
DECL_ACCESSORS(stack_frames, Object)
// [start_position]: the start position in the script for the error message.
inline int start_position() const;
inline void set_start_position(int value);
// [end_position]: the end position in the script for the error message.
inline int end_position() const;
inline void set_end_position(int value);
DECLARE_CAST(JSMessageObject)
// Dispatched behavior.
DECLARE_PRINTER(JSMessageObject)
DECLARE_VERIFIER(JSMessageObject)
// Layout description.
static const int kTypeOffset = JSObject::kHeaderSize;
static const int kArgumentsOffset = kTypeOffset + kPointerSize;
static const int kScriptOffset = kArgumentsOffset + kPointerSize;
static const int kStackFramesOffset = kScriptOffset + kPointerSize;
static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
static const int kSize = kEndPositionOffset + kPointerSize;
typedef FixedBodyDescriptor<HeapObject::kMapOffset,
kStackFramesOffset + kPointerSize,
kSize> BodyDescriptor;
};
// Regular expressions
// The regular expression holds a single reference to a FixedArray in
// the kDataOffset field.
// The FixedArray contains the following data:
// - tag : type of regexp implementation (not compiled yet, atom or irregexp)
// - reference to the original source string
// - reference to the original flag string
// If it is an atom regexp
// - a reference to a literal string to search for
// If it is an irregexp regexp:
// - a reference to code for Latin1 inputs (bytecode or compiled), or a smi
// used for tracking the last usage (used for code flushing).
// - a reference to code for UC16 inputs (bytecode or compiled), or a smi
// used for tracking the last usage (used for code flushing)..
// - max number of registers used by irregexp implementations.
// - number of capture registers (output values) of the regexp.
class JSRegExp: public JSObject {
public:
// Meaning of Type:
// NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet.
// ATOM: A simple string to match against using an indexOf operation.
// IRREGEXP: Compiled with Irregexp.
// IRREGEXP_NATIVE: Compiled to native code with Irregexp.
enum Type { NOT_COMPILED, ATOM, IRREGEXP };
enum Flag {
kNone = 0,
kGlobal = 1 << 0,
kIgnoreCase = 1 << 1,
kMultiline = 1 << 2,
kSticky = 1 << 3,
kUnicode = 1 << 4,
};
typedef base::Flags<Flag> Flags;
DECL_ACCESSORS(data, Object)
DECL_ACCESSORS(flags, Object)
DECL_ACCESSORS(source, Object)
static MaybeHandle<JSRegExp> New(Handle<String> source, Flags flags);
static MaybeHandle<JSRegExp> New(Handle<String> source, Handle<String> flags);
static Handle<JSRegExp> Copy(Handle<JSRegExp> regexp);
static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp,
Handle<String> source, Flags flags);
static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp,
Handle<String> source,
Handle<String> flags_string);
inline Type TypeTag();
inline int CaptureCount();
inline Flags GetFlags();
inline String* Pattern();
inline Object* DataAt(int index);
// Set implementation data after the object has been prepared.
inline void SetDataAt(int index, Object* value);
static int code_index(bool is_latin1) {
if (is_latin1) {
return kIrregexpLatin1CodeIndex;
} else {
return kIrregexpUC16CodeIndex;
}
}
static int saved_code_index(bool is_latin1) {
if (is_latin1) {
return kIrregexpLatin1CodeSavedIndex;
} else {
return kIrregexpUC16CodeSavedIndex;
}
}
DECLARE_CAST(JSRegExp)
// Dispatched behavior.
DECLARE_PRINTER(JSRegExp)
DECLARE_VERIFIER(JSRegExp)
static const int kDataOffset = JSObject::kHeaderSize;
static const int kSourceOffset = kDataOffset + kPointerSize;
static const int kFlagsOffset = kSourceOffset + kPointerSize;
static const int kSize = kFlagsOffset + kPointerSize;
// Indices in the data array.
static const int kTagIndex = 0;
static const int kSourceIndex = kTagIndex + 1;
static const int kFlagsIndex = kSourceIndex + 1;
static const int kDataIndex = kFlagsIndex + 1;
// The data fields are used in different ways depending on the
// value of the tag.
// Atom regexps (literal strings).
static const int kAtomPatternIndex = kDataIndex;
static const int kAtomDataSize = kAtomPatternIndex + 1;
// Irregexp compiled code or bytecode for Latin1. If compilation
// fails, this fields hold an exception object that should be
// thrown if the regexp is used again.
static const int kIrregexpLatin1CodeIndex = kDataIndex;
// Irregexp compiled code or bytecode for UC16. If compilation
// fails, this fields hold an exception object that should be
// thrown if the regexp is used again.
static const int kIrregexpUC16CodeIndex = kDataIndex + 1;
// Saved instance of Irregexp compiled code or bytecode for Latin1 that
// is a potential candidate for flushing.
static const int kIrregexpLatin1CodeSavedIndex = kDataIndex + 2;
// Saved instance of Irregexp compiled code or bytecode for UC16 that is
// a potential candidate for flushing.
static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3;
// Maximal number of registers used by either Latin1 or UC16.
// Only used to check that there is enough stack space
static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4;
// Number of captures in the compiled regexp.
static const int kIrregexpCaptureCountIndex = kDataIndex + 5;
static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1;
// Offsets directly into the data fixed array.
static const int kDataTagOffset =
FixedArray::kHeaderSize + kTagIndex * kPointerSize;
static const int kDataOneByteCodeOffset =
FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize;
static const int kDataUC16CodeOffset =
FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize;
static const int kIrregexpCaptureCountOffset =
FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize;
// In-object fields.
static const int kLastIndexFieldIndex = 0;
static const int kInObjectFieldCount = 1;
// The uninitialized value for a regexp code object.
static const int kUninitializedValue = -1;
// The compilation error value for the regexp code object. The real error
// object is in the saved code field.
static const int kCompilationErrorValue = -2;
// When we store the sweep generation at which we moved the code from the
// code index to the saved code index we mask it of to be in the [0:255]
// range.
static const int kCodeAgeMask = 0xff;
};
DEFINE_OPERATORS_FOR_FLAGS(JSRegExp::Flags)
class CompilationCacheShape : public BaseShape<HashTableKey*> {
public:
static inline bool IsMatch(HashTableKey* key, Object* value) {
return key->IsMatch(value);
}
static inline uint32_t Hash(HashTableKey* key) {
return key->Hash();
}
static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
return key->HashForObject(object);
}
static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
static const int kPrefixSize = 0;
static const int kEntrySize = 2;
};
// This cache is used in two different variants. For regexp caching, it simply
// maps identifying info of the regexp to the cached regexp object. Scripts and
// eval code only gets cached after a second probe for the code object. To do
// so, on first "put" only a hash identifying the source is entered into the
// cache, mapping it to a lifetime count of the hash. On each call to Age all
// such lifetimes get reduced, and removed once they reach zero. If a second put
// is called while such a hash is live in the cache, the hash gets replaced by
// an actual cache entry. Age also removes stale live entries from the cache.
// Such entries are identified by SharedFunctionInfos pointing to either the
// recompilation stub, or to "old" code. This avoids memory leaks due to
// premature caching of scripts and eval strings that are never needed later.
class CompilationCacheTable: public HashTable<CompilationCacheTable,
CompilationCacheShape,
HashTableKey*> {
public:
// Find cached value for a string key, otherwise return null.
Handle<Object> Lookup(
Handle<String> src, Handle<Context> context, LanguageMode language_mode);
Handle<Object> LookupEval(
Handle<String> src, Handle<SharedFunctionInfo> shared,
LanguageMode language_mode, int scope_position);
Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags);
static Handle<CompilationCacheTable> Put(
Handle<CompilationCacheTable> cache, Handle<String> src,
Handle<Context> context, LanguageMode language_mode,
Handle<Object> value);
static Handle<CompilationCacheTable> PutEval(
Handle<CompilationCacheTable> cache, Handle<String> src,
Handle<SharedFunctionInfo> context, Handle<SharedFunctionInfo> value,
int scope_position);
static Handle<CompilationCacheTable> PutRegExp(
Handle<CompilationCacheTable> cache, Handle<String> src,
JSRegExp::Flags flags, Handle<FixedArray> value);
void Remove(Object* value);
void Age();
static const int kHashGenerations = 10;
DECLARE_CAST(CompilationCacheTable)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable);
};
class CodeCache: public Struct {
public:
DECL_ACCESSORS(default_cache, FixedArray)
DECL_ACCESSORS(normal_type_cache, Object)
// Add the code object to the cache.
static void Update(
Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code);
// Lookup code object in the cache. Returns code object if found and undefined
// if not.
Object* Lookup(Name* name, Code::Flags flags);
// Get the internal index of a code object in the cache. Returns -1 if the
// code object is not in that cache. This index can be used to later call
// RemoveByIndex. The cache cannot be modified between a call to GetIndex and
// RemoveByIndex.
int GetIndex(Object* name, Code* code);
// Remove an object from the cache with the provided internal index.
void RemoveByIndex(Object* name, Code* code, int index);
DECLARE_CAST(CodeCache)
// Dispatched behavior.
DECLARE_PRINTER(CodeCache)
DECLARE_VERIFIER(CodeCache)
static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
static const int kNormalTypeCacheOffset =
kDefaultCacheOffset + kPointerSize;
static const int kSize = kNormalTypeCacheOffset + kPointerSize;
private:
static void UpdateDefaultCache(
Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
static void UpdateNormalTypeCache(
Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
Object* LookupDefaultCache(Name* name, Code::Flags flags);
Object* LookupNormalTypeCache(Name* name, Code::Flags flags);
// Code cache layout of the default cache. Elements are alternating name and
// code objects for non normal load/store/call IC's.
static const int kCodeCacheEntrySize = 2;
static const int kCodeCacheEntryNameOffset = 0;
static const int kCodeCacheEntryCodeOffset = 1;
DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
};
class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
public:
static inline bool IsMatch(HashTableKey* key, Object* value) {
return key->IsMatch(value);
}
static inline uint32_t Hash(HashTableKey* key) {
return key->Hash();
}
static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
return key->HashForObject(object);
}
static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key);
static const int kPrefixSize = 0;
static const int kEntrySize = 2;
};
class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
CodeCacheHashTableShape,
HashTableKey*> {
public:
Object* Lookup(Name* name, Code::Flags flags);
static Handle<CodeCacheHashTable> Put(
Handle<CodeCacheHashTable> table,
Handle<Name> name,
Handle<Code> code);
int GetIndex(Name* name, Code::Flags flags);
void RemoveByIndex(int index);
DECLARE_CAST(CodeCacheHashTable)
// Initial size of the fixed array backing the hash table.
static const int kInitialSize = 64;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
};
class PolymorphicCodeCache: public Struct {
public:
DECL_ACCESSORS(cache, Object)
static void Update(Handle<PolymorphicCodeCache> cache,
MapHandleList* maps,
Code::Flags flags,
Handle<Code> code);
// Returns an undefined value if the entry is not found.
Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags);
DECLARE_CAST(PolymorphicCodeCache)
// Dispatched behavior.
DECLARE_PRINTER(PolymorphicCodeCache)
DECLARE_VERIFIER(PolymorphicCodeCache)
static const int kCacheOffset = HeapObject::kHeaderSize;
static const int kSize = kCacheOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache);
};
class PolymorphicCodeCacheHashTable
: public HashTable<PolymorphicCodeCacheHashTable,
CodeCacheHashTableShape,
HashTableKey*> {
public:
Object* Lookup(MapHandleList* maps, int code_kind);
static Handle<PolymorphicCodeCacheHashTable> Put(
Handle<PolymorphicCodeCacheHashTable> hash_table,
MapHandleList* maps,
int code_kind,
Handle<Code> code);
DECLARE_CAST(PolymorphicCodeCacheHashTable)
static const int kInitialSize = 64;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable);
};
class TypeFeedbackInfo: public Struct {
public:
inline int ic_total_count();
inline void set_ic_total_count(int count);
inline int ic_with_type_info_count();
inline void change_ic_with_type_info_count(int delta);
inline int ic_generic_count();
inline void change_ic_generic_count(int delta);
inline void initialize_storage();
inline void change_own_type_change_checksum();
inline int own_type_change_checksum();
inline void set_inlined_type_change_checksum(int checksum);
inline bool matches_inlined_type_change_checksum(int checksum);
DECLARE_CAST(TypeFeedbackInfo)
// Dispatched behavior.
DECLARE_PRINTER(TypeFeedbackInfo)
DECLARE_VERIFIER(TypeFeedbackInfo)
static const int kStorage1Offset = HeapObject::kHeaderSize;
static const int kStorage2Offset = kStorage1Offset + kPointerSize;
static const int kStorage3Offset = kStorage2Offset + kPointerSize;
static const int kSize = kStorage3Offset + kPointerSize;
private:
static const int kTypeChangeChecksumBits = 7;
class ICTotalCountField: public BitField<int, 0,
kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
class OwnTypeChangeChecksum: public BitField<int,
kSmiValueSize - kTypeChangeChecksumBits,
kTypeChangeChecksumBits> {}; // NOLINT
class ICsWithTypeInfoCountField: public BitField<int, 0,
kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
class InlinedTypeChangeChecksum: public BitField<int,
kSmiValueSize - kTypeChangeChecksumBits,
kTypeChangeChecksumBits> {}; // NOLINT
DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo);
};
enum AllocationSiteMode {
DONT_TRACK_ALLOCATION_SITE,
TRACK_ALLOCATION_SITE,
LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE
};
class AllocationSite: public Struct {
public:
static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
static const double kPretenureRatio;
static const int kPretenureMinimumCreated = 100;
// Values for pretenure decision field.
enum PretenureDecision {
kUndecided = 0,
kDontTenure = 1,
kMaybeTenure = 2,
kTenure = 3,
kZombie = 4,
kLastPretenureDecisionValue = kZombie
};
const char* PretenureDecisionName(PretenureDecision decision);
DECL_ACCESSORS(transition_info, Object)
// nested_site threads a list of sites that represent nested literals
// walked in a particular order. So [[1, 2], 1, 2] will have one
// nested_site, but [[1, 2], 3, [4]] will have a list of two.
DECL_ACCESSORS(nested_site, Object)
DECL_INT_ACCESSORS(pretenure_data)
DECL_INT_ACCESSORS(pretenure_create_count)
DECL_ACCESSORS(dependent_code, DependentCode)
DECL_ACCESSORS(weak_next, Object)
inline void Initialize();
// This method is expensive, it should only be called for reporting.
bool IsNestedSite();
// transition_info bitfields, for constructed array transition info.
class ElementsKindBits: public BitField<ElementsKind, 0, 15> {};
class UnusedBits: public BitField<int, 15, 14> {};
class DoNotInlineBit: public BitField<bool, 29, 1> {};
// Bitfields for pretenure_data
class MementoFoundCountBits: public BitField<int, 0, 26> {};
class PretenureDecisionBits: public BitField<PretenureDecision, 26, 3> {};
class DeoptDependentCodeBit: public BitField<bool, 29, 1> {};
STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
// Increments the mementos found counter and returns true when the first
// memento was found for a given allocation site.
inline bool IncrementMementoFoundCount(int increment = 1);
inline void IncrementMementoCreateCount();
PretenureFlag GetPretenureMode();
void ResetPretenureDecision();
inline PretenureDecision pretenure_decision();
inline void set_pretenure_decision(PretenureDecision decision);
inline bool deopt_dependent_code();
inline void set_deopt_dependent_code(bool deopt);
inline int memento_found_count();
inline void set_memento_found_count(int count);
inline int memento_create_count();
inline void set_memento_create_count(int count);
// The pretenuring decision is made during gc, and the zombie state allows
// us to recognize when an allocation site is just being kept alive because
// a later traversal of new space may discover AllocationMementos that point
// to this AllocationSite.
inline bool IsZombie();
inline bool IsMaybeTenure();
inline void MarkZombie();
inline bool MakePretenureDecision(PretenureDecision current_decision,
double ratio,
bool maximum_size_scavenge);
inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
inline ElementsKind GetElementsKind();
inline void SetElementsKind(ElementsKind kind);
inline bool CanInlineCall();
inline void SetDoNotInlineCall();
inline bool SitePointsToLiteral();
static void DigestTransitionFeedback(Handle<AllocationSite> site,
ElementsKind to_kind);
DECLARE_PRINTER(AllocationSite)
DECLARE_VERIFIER(AllocationSite)
DECLARE_CAST(AllocationSite)
static inline AllocationSiteMode GetMode(
ElementsKind boilerplate_elements_kind);
static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to);
static inline bool CanTrack(InstanceType type);
static const int kTransitionInfoOffset = HeapObject::kHeaderSize;
static const int kNestedSiteOffset = kTransitionInfoOffset + kPointerSize;
static const int kPretenureDataOffset = kNestedSiteOffset + kPointerSize;
static const int kPretenureCreateCountOffset =
kPretenureDataOffset + kPointerSize;
static const int kDependentCodeOffset =
kPretenureCreateCountOffset + kPointerSize;
static const int kWeakNextOffset = kDependentCodeOffset + kPointerSize;
static const int kSize = kWeakNextOffset + kPointerSize;
// During mark compact we need to take special care for the dependent code
// field.
static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
static const int kPointerFieldsEndOffset = kWeakNextOffset;
// For other visitors, use the fixed body descriptor below.
typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
kDependentCodeOffset + kPointerSize,
kSize> BodyDescriptor;
private:
inline bool PretenuringDecisionMade();
DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
};
class AllocationMemento: public Struct {
public:
static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
static const int kSize = kAllocationSiteOffset + kPointerSize;
DECL_ACCESSORS(allocation_site, Object)
inline bool IsValid();
inline AllocationSite* GetAllocationSite();
DECLARE_PRINTER(AllocationMemento)
DECLARE_VERIFIER(AllocationMemento)
DECLARE_CAST(AllocationMemento)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
};
// Representation of a slow alias as part of a sloppy arguments objects.
// For fast aliases (if HasSloppyArgumentsElements()):
// - the parameter map contains an index into the context
// - all attributes of the element have default values
// For slow aliases (if HasDictionaryArgumentsElements()):
// - the parameter map contains no fast alias mapping (i.e. the hole)
// - this struct (in the slow backing store) contains an index into the context
// - all attributes are available as part if the property details
class AliasedArgumentsEntry: public Struct {
public:
inline int aliased_context_slot() const;
inline void set_aliased_context_slot(int count);
DECLARE_CAST(AliasedArgumentsEntry)
// Dispatched behavior.
DECLARE_PRINTER(AliasedArgumentsEntry)
DECLARE_VERIFIER(AliasedArgumentsEntry)
static const int kAliasedContextSlot = HeapObject::kHeaderSize;
static const int kSize = kAliasedContextSlot + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry);
};
enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};
class StringHasher {
public:
explicit inline StringHasher(int length, uint32_t seed);
template <typename schar>
static inline uint32_t HashSequentialString(const schar* chars,
int length,
uint32_t seed);
// Reads all the data, even for long strings and computes the utf16 length.
static uint32_t ComputeUtf8Hash(Vector<const char> chars,
uint32_t seed,
int* utf16_length_out);
// Calculated hash value for a string consisting of 1 to
// String::kMaxArrayIndexSize digits with no leading zeros (except "0").
// value is represented decimal value.
static uint32_t MakeArrayIndexHash(uint32_t value, int length);
// No string is allowed to have a hash of zero. That value is reserved
// for internal properties. If the hash calculation yields zero then we
// use 27 instead.
static const int kZeroHash = 27;
// Reusable parts of the hashing algorithm.
INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
INLINE(static uint32_t GetHashCore(uint32_t running_hash));
INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
const uc16* chars, int length));
INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
const char* chars,
int length));
protected:
// Returns the value to store in the hash field of a string with
// the given length and contents.
uint32_t GetHashField();
// Returns true if the hash of this string can be computed without
// looking at the contents.
inline bool has_trivial_hash();
// Adds a block of characters to the hash.
template<typename Char>
inline void AddCharacters(const Char* chars, int len);
private:
// Add a character to the hash.
inline void AddCharacter(uint16_t c);
// Update index. Returns true if string is still an index.
inline bool UpdateIndex(uint16_t c);
int length_;
uint32_t raw_running_hash_;
uint32_t array_index_;
bool is_array_index_;
bool is_first_char_;
DISALLOW_COPY_AND_ASSIGN(StringHasher);
};
class IteratingStringHasher : public StringHasher {
public:
static inline uint32_t Hash(String* string, uint32_t seed);
inline void VisitOneByteString(const uint8_t* chars, int length);
inline void VisitTwoByteString(const uint16_t* chars, int length);
private:
inline IteratingStringHasher(int len, uint32_t seed);
void VisitConsString(ConsString* cons_string);
DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
};
// The characteristics of a string are stored in its map. Retrieving these
// few bits of information is moderately expensive, involving two memory
// loads where the second is dependent on the first. To improve efficiency
// the shape of the string is given its own class so that it can be retrieved
// once and used for several string operations. A StringShape is small enough
// to be passed by value and is immutable, but be aware that flattening a
// string can potentially alter its shape. Also be aware that a GC caused by
// something else can alter the shape of a string due to ConsString
// shortcutting. Keeping these restrictions in mind has proven to be error-
// prone and so we no longer put StringShapes in variables unless there is a
// concrete performance benefit at that particular point in the code.
class StringShape BASE_EMBEDDED {
public:
inline explicit StringShape(const String* s);
inline explicit StringShape(Map* s);
inline explicit StringShape(InstanceType t);
inline bool IsSequential();
inline bool IsExternal();
inline bool IsCons();
inline bool IsSliced();
inline bool IsIndirect();
inline bool IsExternalOneByte();
inline bool IsExternalTwoByte();
inline bool IsSequentialOneByte();
inline bool IsSequentialTwoByte();
inline bool IsInternalized();
inline StringRepresentationTag representation_tag();
inline uint32_t encoding_tag();
inline uint32_t full_representation_tag();
inline uint32_t size_tag();
#ifdef DEBUG
inline uint32_t type() { return type_; }
inline void invalidate() { valid_ = false; }
inline bool valid() { return valid_; }
#else
inline void invalidate() { }
#endif
private:
uint32_t type_;
#ifdef DEBUG
inline void set_valid() { valid_ = true; }
bool valid_;
#else
inline void set_valid() { }
#endif
};
// The Name abstract class captures anything that can be used as a property
// name, i.e., strings and symbols. All names store a hash value.
class Name: public HeapObject {
public:
// Get and set the hash field of the name.
inline uint32_t hash_field();
inline void set_hash_field(uint32_t value);
// Tells whether the hash code has been computed.
inline bool HasHashCode();
// Returns a hash value used for the property table
inline uint32_t Hash();
// Equality operations.
inline bool Equals(Name* other);
inline static bool Equals(Handle<Name> one, Handle<Name> two);
// Conversion.
inline bool AsArrayIndex(uint32_t* index);
// If the name is private, it can only name own properties.
inline bool IsPrivate();
// If the name is a non-flat string, this method returns a flat version of the
// string. Otherwise it'll just return the input.
static inline Handle<Name> Flatten(Handle<Name> name,
PretenureFlag pretenure = NOT_TENURED);
// Return a string version of this name that is converted according to the
// rules described in ES6 section 9.2.11.
MUST_USE_RESULT static MaybeHandle<String> ToFunctionName(Handle<Name> name);
DECLARE_CAST(Name)
DECLARE_PRINTER(Name)
#if TRACE_MAPS
void NameShortPrint();
int NameShortPrint(Vector<char> str);
#endif
// Layout description.
static const int kHashFieldSlot = HeapObject::kHeaderSize;
#if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
static const int kHashFieldOffset = kHashFieldSlot;
#else
static const int kHashFieldOffset = kHashFieldSlot + kIntSize;
#endif
static const int kSize = kHashFieldSlot + kPointerSize;
// Mask constant for checking if a name has a computed hash code
// and if it is a string that is an array index. The least significant bit
// indicates whether a hash code has been computed. If the hash code has
// been computed the 2nd bit tells whether the string can be used as an
// array index.
static const int kHashNotComputedMask = 1;
static const int kIsNotArrayIndexMask = 1 << 1;
static const int kNofHashBitFields = 2;
// Shift constant retrieving hash code from hash field.
static const int kHashShift = kNofHashBitFields;
// Only these bits are relevant in the hash, since the top two are shifted
// out.
static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift;
// Array index strings this short can keep their index in the hash field.
static const int kMaxCachedArrayIndexLength = 7;
// For strings which are array indexes the hash value has the string length
// mixed into the hash, mainly to avoid a hash value of zero which would be
// the case for the string '0'. 24 bits are used for the array index value.
static const int kArrayIndexValueBits = 24;
static const int kArrayIndexLengthBits =
kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
STATIC_ASSERT((kArrayIndexLengthBits > 0));
class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
kArrayIndexValueBits> {}; // NOLINT
class ArrayIndexLengthBits : public BitField<unsigned int,
kNofHashBitFields + kArrayIndexValueBits,
kArrayIndexLengthBits> {}; // NOLINT
// Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
// could use a mask to test if the length of string is less than or equal to
// kMaxCachedArrayIndexLength.
STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
static const unsigned int kContainsCachedArrayIndexMask =
(~static_cast<unsigned>(kMaxCachedArrayIndexLength)
<< ArrayIndexLengthBits::kShift) |
kIsNotArrayIndexMask;
// Value of empty hash field indicating that the hash is not computed.
static const int kEmptyHashField =
kIsNotArrayIndexMask | kHashNotComputedMask;
protected:
static inline bool IsHashFieldComputed(uint32_t field);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Name);
};
// ES6 symbols.
class Symbol: public Name {
public:
// [name]: The print name of a symbol, or undefined if none.
DECL_ACCESSORS(name, Object)
DECL_INT_ACCESSORS(flags)
// [is_private]: Whether this is a private symbol. Private symbols can only
// be used to designate own properties of objects.
DECL_BOOLEAN_ACCESSORS(is_private)
// [is_well_known_symbol]: Whether this is a spec-defined well-known symbol,
// or not. Well-known symbols do not throw when an access check fails during
// a load.
DECL_BOOLEAN_ACCESSORS(is_well_known_symbol)
DECLARE_CAST(Symbol)
// Dispatched behavior.
DECLARE_PRINTER(Symbol)
DECLARE_VERIFIER(Symbol)
// Layout description.
static const int kNameOffset = Name::kSize;
static const int kFlagsOffset = kNameOffset + kPointerSize;
static const int kSize = kFlagsOffset + kPointerSize;
typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
void SymbolShortPrint(std::ostream& os);
private:
static const int kPrivateBit = 0;
static const int kWellKnownSymbolBit = 1;
const char* PrivateSymbolToName() const;
#if TRACE_MAPS
friend class Name; // For PrivateSymbolToName.
#endif
DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol);
};
class ConsString;
// The String abstract class captures JavaScript string values:
//
// Ecma-262:
// 4.3.16 String Value
// A string value is a member of the type String and is a finite
// ordered sequence of zero or more 16-bit unsigned integer values.
//
// All string values have a length field.
class String: public Name {
public:
enum Encoding { ONE_BYTE_ENCODING, TWO_BYTE_ENCODING };
// Array index strings this short can keep their index in the hash field.
static const int kMaxCachedArrayIndexLength = 7;
// For strings which are array indexes the hash value has the string length
// mixed into the hash, mainly to avoid a hash value of zero which would be
// the case for the string '0'. 24 bits are used for the array index value.
static const int kArrayIndexValueBits = 24;
static const int kArrayIndexLengthBits =
kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
STATIC_ASSERT((kArrayIndexLengthBits > 0));
class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields,
kArrayIndexValueBits> {}; // NOLINT
class ArrayIndexLengthBits : public BitField<unsigned int,
kNofHashBitFields + kArrayIndexValueBits,
kArrayIndexLengthBits> {}; // NOLINT
// Check that kMaxCachedArrayIndexLength + 1 is a power of two so we
// could use a mask to test if the length of string is less than or equal to
// kMaxCachedArrayIndexLength.
STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1));
static const unsigned int kContainsCachedArrayIndexMask =
(~static_cast<unsigned>(kMaxCachedArrayIndexLength)
<< ArrayIndexLengthBits::kShift) |
kIsNotArrayIndexMask;
class SubStringRange {
public:
explicit inline SubStringRange(String* string, int first = 0,
int length = -1);
class iterator;
inline iterator begin();
inline iterator end();
private:
String* string_;
int first_;
int length_;
};
// Representation of the flat content of a String.
// A non-flat string doesn't have flat content.
// A flat string has content that's encoded as a sequence of either
// one-byte chars or two-byte UC16.
// Returned by String::GetFlatContent().
class FlatContent {
public:
// Returns true if the string is flat and this structure contains content.
bool IsFlat() { return state_ != NON_FLAT; }
// Returns true if the structure contains one-byte content.
bool IsOneByte() { return state_ == ONE_BYTE; }
// Returns true if the structure contains two-byte content.
bool IsTwoByte() { return state_ == TWO_BYTE; }
// Return the one byte content of the string. Only use if IsOneByte()
// returns true.
Vector<const uint8_t> ToOneByteVector() {
DCHECK_EQ(ONE_BYTE, state_);
return Vector<const uint8_t>(onebyte_start, length_);
}
// Return the two-byte content of the string. Only use if IsTwoByte()
// returns true.
Vector<const uc16> ToUC16Vector() {
DCHECK_EQ(TWO_BYTE, state_);
return Vector<const uc16>(twobyte_start, length_);
}
uc16 Get(int i) {
DCHECK(i < length_);
DCHECK(state_ != NON_FLAT);
if (state_ == ONE_BYTE) return onebyte_start[i];
return twobyte_start[i];
}
bool UsesSameString(const FlatContent& other) const {
return onebyte_start == other.onebyte_start;
}
private:
enum State { NON_FLAT, ONE_BYTE, TWO_BYTE };
// Constructors only used by String::GetFlatContent().
explicit FlatContent(const uint8_t* start, int length)
: onebyte_start(start), length_(length), state_(ONE_BYTE) {}
explicit FlatContent(const uc16* start, int length)
: twobyte_start(start), length_(length), state_(TWO_BYTE) { }
FlatContent() : onebyte_start(NULL), length_(0), state_(NON_FLAT) { }
union {
const uint8_t* onebyte_start;
const uc16* twobyte_start;
};
int length_;
State state_;
friend class String;
friend class IterableSubString;
};
template <typename Char>
INLINE(Vector<const Char> GetCharVector());
// Get and set the length of the string.
inline int length() const;
inline void set_length(int value);
// Get and set the length of the string using acquire loads and release
// stores.
inline int synchronized_length() const;
inline void synchronized_set_length(int value);
// Returns whether this string has only one-byte chars, i.e. all of them can
// be one-byte encoded. This might be the case even if the string is
// two-byte. Such strings may appear when the embedder prefers
// two-byte external representations even for one-byte data.
inline bool IsOneByteRepresentation() const;
inline bool IsTwoByteRepresentation() const;
// Cons and slices have an encoding flag that may not represent the actual
// encoding of the underlying string. This is taken into account here.
// Requires: this->IsFlat()
inline bool IsOneByteRepresentationUnderneath();
inline bool IsTwoByteRepresentationUnderneath();
// NOTE: this should be considered only a hint. False negatives are
// possible.
inline bool HasOnlyOneByteChars();
// Get and set individual two byte chars in the string.
inline void Set(int index, uint16_t value);
// Get individual two byte char in the string. Repeated calls
// to this method are not efficient unless the string is flat.
INLINE(uint16_t Get(int index));
// ES6 section 7.1.3.1 ToNumber Applied to the String Type
static Handle<Object> ToNumber(Handle<String> subject);
// Flattens the string. Checks first inline to see if it is
// necessary. Does nothing if the string is not a cons string.
// Flattening allocates a sequential string with the same data as
// the given string and mutates the cons string to a degenerate
// form, where the first component is the new sequential string and
// the second component is the empty string. If allocation fails,
// this function returns a failure. If flattening succeeds, this
// function returns the sequential string that is now the first
// component of the cons string.
//
// Degenerate cons strings are handled specially by the garbage
// collector (see IsShortcutCandidate).
static inline Handle<String> Flatten(Handle<String> string,
PretenureFlag pretenure = NOT_TENURED);
// Tries to return the content of a flat string as a structure holding either
// a flat vector of char or of uc16.
// If the string isn't flat, and therefore doesn't have flat content, the
// returned structure will report so, and can't provide a vector of either
// kind.
FlatContent GetFlatContent();
// Returns the parent of a sliced string or first part of a flat cons string.
// Requires: StringShape(this).IsIndirect() && this->IsFlat()
inline String* GetUnderlying();
// String relational comparison, implemented according to ES6 section 7.2.11
// Abstract Relational Comparison (step 5): The comparison of Strings uses a
// simple lexicographic ordering on sequences of code unit values. There is no
// attempt to use the more complex, semantically oriented definitions of
// character or string equality and collating order defined in the Unicode
// specification. Therefore String values that are canonically equal according
// to the Unicode standard could test as unequal. In effect this algorithm
// assumes that both Strings are already in normalized form. Also, note that
// for strings containing supplementary characters, lexicographic ordering on
// sequences of UTF-16 code unit values differs from that on sequences of code
// point values.
MUST_USE_RESULT static ComparisonResult Compare(Handle<String> x,
Handle<String> y);
// String equality operations.
inline bool Equals(String* other);
inline static bool Equals(Handle<String> one, Handle<String> two);
bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
bool IsOneByteEqualTo(Vector<const uint8_t> str);
bool IsTwoByteEqualTo(Vector<const uc16> str);
// Return a UTF8 representation of the string. The string is null
// terminated but may optionally contain nulls. Length is returned
// in length_output if length_output is not a null pointer The string
// should be nearly flat, otherwise the performance of this method may
// be very slow (quadratic in the length). Setting robustness_flag to
// ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
// handles unexpected data without causing assert failures and it does not
// do any heap allocations. This is useful when printing stack traces.
base::SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls,
RobustnessFlag robustness_flag,
int offset, int length,
int* length_output = 0);
base::SmartArrayPointer<char> ToCString(
AllowNullsFlag allow_nulls = DISALLOW_NULLS,
RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL,
int* length_output = 0);
// Return a 16 bit Unicode representation of the string.
// The string should be nearly flat, otherwise the performance of
// of this method may be very bad. Setting robustness_flag to
// ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it
// handles unexpected data without causing assert failures and it does not
// do any heap allocations. This is useful when printing stack traces.
base::SmartArrayPointer<uc16> ToWideCString(
RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL);
bool ComputeArrayIndex(uint32_t* index);
// Externalization.
bool MakeExternal(v8::String::ExternalStringResource* resource);
bool MakeExternal(v8::String::ExternalOneByteStringResource* resource);
// Conversion.
inline bool AsArrayIndex(uint32_t* index);
DECLARE_CAST(String)
void PrintOn(FILE* out);
// For use during stack traces. Performs rudimentary sanity check.
bool LooksValid();
// Dispatched behavior.
void StringShortPrint(StringStream* accumulator);
void PrintUC16(std::ostream& os, int start = 0, int end = -1); // NOLINT
#if defined(DEBUG) || defined(OBJECT_PRINT)
char* ToAsciiArray();
#endif
DECLARE_PRINTER(String)
DECLARE_VERIFIER(String)
inline bool IsFlat();
// Layout description.
static const int kLengthOffset = Name::kSize;
static const int kSize = kLengthOffset + kPointerSize;
// Maximum number of characters to consider when trying to convert a string
// value into an array index.
static const int kMaxArrayIndexSize = 10;
STATIC_ASSERT(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits));
// Max char codes.
static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar;
static const uint32_t kMaxOneByteCharCodeU = unibrow::Latin1::kMaxChar;
static const int kMaxUtf16CodeUnit = 0xffff;
static const uint32_t kMaxUtf16CodeUnitU = kMaxUtf16CodeUnit;
// Value of hash field containing computed hash equal to zero.
static const int kEmptyStringHash = kIsNotArrayIndexMask;
// Maximal string length.
static const int kMaxLength = (1 << 28) - 16;
// Max length for computing hash. For strings longer than this limit the
// string length is used as the hash value.
static const int kMaxHashCalcLength = 16383;
// Limit for truncation in short printing.
static const int kMaxShortPrintLength = 1024;
// Support for regular expressions.
const uc16* GetTwoByteData(unsigned start);
// Helper function for flattening strings.
template <typename sinkchar>
static void WriteToFlat(String* source,
sinkchar* sink,
int from,
int to);
// The return value may point to the first aligned word containing the first
// non-one-byte character, rather than directly to the non-one-byte character.
// If the return value is >= the passed length, the entire string was
// one-byte.
static inline int NonAsciiStart(const char* chars, int length) {
const char* start = chars;
const char* limit = chars + length;
if (length >= kIntptrSize) {
// Check unaligned bytes.
while (!IsAligned(reinterpret_cast<intptr_t>(chars), sizeof(uintptr_t))) {
if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
return static_cast<int>(chars - start);
}
++chars;
}
// Check aligned words.
DCHECK(unibrow::Utf8::kMaxOneByteChar == 0x7F);
const uintptr_t non_one_byte_mask = kUintptrAllBitsSet / 0xFF * 0x80;
while (chars + sizeof(uintptr_t) <= limit) {
if (*reinterpret_cast<const uintptr_t*>(chars) & non_one_byte_mask) {
return static_cast<int>(chars - start);
}
chars += sizeof(uintptr_t);
}
}
// Check remaining unaligned bytes.
while (chars < limit) {
if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) {
return static_cast<int>(chars - start);
}
++chars;
}
return static_cast<int>(chars - start);
}
static inline bool IsAscii(const char* chars, int length) {
return NonAsciiStart(chars, length) >= length;
}
static inline bool IsAscii(const uint8_t* chars, int length) {
return
NonAsciiStart(reinterpret_cast<const char*>(chars), length) >= length;
}
static inline int NonOneByteStart(const uc16* chars, int length) {
const uc16* limit = chars + length;
const uc16* start = chars;
while (chars < limit) {
if (*chars > kMaxOneByteCharCodeU) return static_cast<int>(chars - start);
++chars;
}
return static_cast<int>(chars - start);
}
static inline bool IsOneByte(const uc16* chars, int length) {
return NonOneByteStart(chars, length) >= length;
}
template<class Visitor>
static inline ConsString* VisitFlat(Visitor* visitor,
String* string,
int offset = 0);
static Handle<FixedArray> CalculateLineEnds(Handle<String> string,
bool include_ending_line);
// Use the hash field to forward to the canonical internalized string
// when deserializing an internalized string.
inline void SetForwardedInternalizedString(String* string);
inline String* GetForwardedInternalizedString();
private:
friend class Name;
friend class StringTableInsertionKey;
static Handle<String> SlowFlatten(Handle<ConsString> cons,
PretenureFlag tenure);
// Slow case of String::Equals. This implementation works on any strings
// but it is most efficient on strings that are almost flat.
bool SlowEquals(String* other);
static bool SlowEquals(Handle<String> one, Handle<String> two);
// Slow case of AsArrayIndex.
bool SlowAsArrayIndex(uint32_t* index);
// Compute and set the hash code.
uint32_t ComputeAndSetHash();
DISALLOW_IMPLICIT_CONSTRUCTORS(String);
};
// The SeqString abstract class captures sequential string values.
class SeqString: public String {
public:
DECLARE_CAST(SeqString)
// Layout description.
static const int kHeaderSize = String::kSize;
// Truncate the string in-place if possible and return the result.
// In case of new_length == 0, the empty string is returned without
// truncating the original string.
MUST_USE_RESULT static Handle<String> Truncate(Handle<SeqString> string,
int new_length);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString);
};
// The OneByteString class captures sequential one-byte string objects.
// Each character in the OneByteString is an one-byte character.
class SeqOneByteString: public SeqString {
public:
static const bool kHasOneByteEncoding = true;
// Dispatched behavior.
inline uint16_t SeqOneByteStringGet(int index);
inline void SeqOneByteStringSet(int index, uint16_t value);
// Get the address of the characters in this string.
inline Address GetCharsAddress();
inline uint8_t* GetChars();
DECLARE_CAST(SeqOneByteString)
// Garbage collection support. This method is called by the
// garbage collector to compute the actual size of an OneByteString
// instance.
inline int SeqOneByteStringSize(InstanceType instance_type);
// Computes the size for an OneByteString instance of a given length.
static int SizeFor(int length) {
return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize);
}
// Maximal memory usage for a single sequential one-byte string.
static const int kMaxSize = 512 * MB - 1;
STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
};
// The TwoByteString class captures sequential unicode string objects.
// Each character in the TwoByteString is a two-byte uint16_t.
class SeqTwoByteString: public SeqString {
public:
static const bool kHasOneByteEncoding = false;
// Dispatched behavior.
inline uint16_t SeqTwoByteStringGet(int index);
inline void SeqTwoByteStringSet(int index, uint16_t value);
// Get the address of the characters in this string.
inline Address GetCharsAddress();
inline uc16* GetChars();
// For regexp code.
const uint16_t* SeqTwoByteStringGetData(unsigned start);
DECLARE_CAST(SeqTwoByteString)
// Garbage collection support. This method is called by the
// garbage collector to compute the actual size of a TwoByteString
// instance.
inline int SeqTwoByteStringSize(InstanceType instance_type);
// Computes the size for a TwoByteString instance of a given length.
static int SizeFor(int length) {
return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize);
}
// Maximal memory usage for a single sequential two-byte string.
static const int kMaxSize = 512 * MB - 1;
STATIC_ASSERT(static_cast<int>((kMaxSize - kHeaderSize)/sizeof(uint16_t)) >=
String::kMaxLength);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString);
};
// The ConsString class describes string values built by using the
// addition operator on strings. A ConsString is a pair where the
// first and second components are pointers to other string values.
// One or both components of a ConsString can be pointers to other
// ConsStrings, creating a binary tree of ConsStrings where the leaves
// are non-ConsString string values. The string value represented by
// a ConsString can be obtained by concatenating the leaf string
// values in a left-to-right depth-first traversal of the tree.
class ConsString: public String {
public:
// First string of the cons cell.
inline String* first();
// Doesn't check that the result is a string, even in debug mode. This is
// useful during GC where the mark bits confuse the checks.
inline Object* unchecked_first();
inline void set_first(String* first,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// Second string of the cons cell.
inline String* second();
// Doesn't check that the result is a string, even in debug mode. This is
// useful during GC where the mark bits confuse the checks.
inline Object* unchecked_second();
inline void set_second(String* second,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// Dispatched behavior.
uint16_t ConsStringGet(int index);
DECLARE_CAST(ConsString)
// Layout description.
static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize);
static const int kSecondOffset = kFirstOffset + kPointerSize;
static const int kSize = kSecondOffset + kPointerSize;
// Minimum length for a cons string.
static const int kMinLength = 13;
typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize>
BodyDescriptor;
DECLARE_VERIFIER(ConsString)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString);
};
// The Sliced String class describes strings that are substrings of another
// sequential string. The motivation is to save time and memory when creating
// a substring. A Sliced String is described as a pointer to the parent,
// the offset from the start of the parent string and the length. Using
// a Sliced String therefore requires unpacking of the parent string and
// adding the offset to the start address. A substring of a Sliced String
// are not nested since the double indirection is simplified when creating
// such a substring.
// Currently missing features are:
// - handling externalized parent strings
// - external strings as parent
// - truncating sliced string to enable otherwise unneeded parent to be GC'ed.
class SlicedString: public String {
public:
inline String* parent();
inline void set_parent(String* parent,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
inline int offset() const;
inline void set_offset(int offset);
// Dispatched behavior.
uint16_t SlicedStringGet(int index);
DECLARE_CAST(SlicedString)
// Layout description.
static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize);
static const int kOffsetOffset = kParentOffset + kPointerSize;
static const int kSize = kOffsetOffset + kPointerSize;
// Minimum length for a sliced string.
static const int kMinLength = 13;
typedef FixedBodyDescriptor<kParentOffset,
kOffsetOffset + kPointerSize, kSize>
BodyDescriptor;
DECLARE_VERIFIER(SlicedString)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString);
};
// The ExternalString class describes string values that are backed by
// a string resource that lies outside the V8 heap. ExternalStrings
// consist of the length field common to all strings, a pointer to the
// external resource. It is important to ensure (externally) that the
// resource is not deallocated while the ExternalString is live in the
// V8 heap.
//
// The API expects that all ExternalStrings are created through the
// API. Therefore, ExternalStrings should not be used internally.
class ExternalString: public String {
public:
DECLARE_CAST(ExternalString)
// Layout description.
static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
static const int kShortSize = kResourceOffset + kPointerSize;
static const int kResourceDataOffset = kResourceOffset + kPointerSize;
static const int kSize = kResourceDataOffset + kPointerSize;
static const int kMaxShortLength =
(kShortSize - SeqString::kHeaderSize) / kCharSize;
// Return whether external string is short (data pointer is not cached).
inline bool is_short();
STATIC_ASSERT(kResourceOffset == Internals::kStringResourceOffset);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString);
};
// The ExternalOneByteString class is an external string backed by an
// one-byte string.
class ExternalOneByteString : public ExternalString {
public:
static const bool kHasOneByteEncoding = true;
typedef v8::String::ExternalOneByteStringResource Resource;
// The underlying resource.
inline const Resource* resource();
inline void set_resource(const Resource* buffer);
// Update the pointer cache to the external character array.
// The cached pointer is always valid, as the external character array does =
// not move during lifetime. Deserialization is the only exception, after
// which the pointer cache has to be refreshed.
inline void update_data_cache();
inline const uint8_t* GetChars();
// Dispatched behavior.
inline uint16_t ExternalOneByteStringGet(int index);
DECLARE_CAST(ExternalOneByteString)
class BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString);
};
// The ExternalTwoByteString class is an external string backed by a UTF-16
// encoded string.
class ExternalTwoByteString: public ExternalString {
public:
static const bool kHasOneByteEncoding = false;
typedef v8::String::ExternalStringResource Resource;
// The underlying string resource.
inline const Resource* resource();
inline void set_resource(const Resource* buffer);
// Update the pointer cache to the external character array.
// The cached pointer is always valid, as the external character array does =
// not move during lifetime. Deserialization is the only exception, after
// which the pointer cache has to be refreshed.
inline void update_data_cache();
inline const uint16_t* GetChars();
// Dispatched behavior.
inline uint16_t ExternalTwoByteStringGet(int index);
// For regexp code.
inline const uint16_t* ExternalTwoByteStringGetData(unsigned start);
DECLARE_CAST(ExternalTwoByteString)
class BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString);
};
// 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 BASE_EMBEDDED {
public:
explicit inline Relocatable(Isolate* isolate);
inline virtual ~Relocatable();
virtual void IterateInstance(ObjectVisitor* 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, ObjectVisitor* v);
static void Iterate(ObjectVisitor* v, Relocatable* top);
static char* Iterate(ObjectVisitor* v, char* t);
private:
Isolate* isolate_;
Relocatable* prev_;
};
// A flat string reader provides random access to the contents of a
// string independent of the character width of the string. The handle
// must be valid as long as the reader is being used.
class FlatStringReader : public Relocatable {
public:
FlatStringReader(Isolate* isolate, Handle<String> str);
FlatStringReader(Isolate* isolate, Vector<const char> input);
void PostGarbageCollection();
inline uc32 Get(int index);
template <typename Char>
inline Char Get(int index);
int length() { return length_; }
private:
String** str_;
bool is_one_byte_;
int length_;
const void* start_;
};
// This maintains an off-stack representation of the stack frames required
// to traverse a ConsString, allowing an entirely iterative and restartable
// traversal of the entire string
class ConsStringIterator {
public:
inline ConsStringIterator() {}
inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) {
Reset(cons_string, offset);
}
inline void Reset(ConsString* cons_string, int offset = 0) {
depth_ = 0;
// Next will always return NULL.
if (cons_string == NULL) return;
Initialize(cons_string, offset);
}
// Returns NULL when complete.
inline String* Next(int* offset_out) {
*offset_out = 0;
if (depth_ == 0) return NULL;
return Continue(offset_out);
}
private:
static const int kStackSize = 32;
// Use a mask instead of doing modulo operations for stack wrapping.
static const int kDepthMask = kStackSize-1;
STATIC_ASSERT(IS_POWER_OF_TWO(kStackSize));
static inline int OffsetForDepth(int depth);
inline void PushLeft(ConsString* string);
inline void PushRight(ConsString* string);
inline void AdjustMaximumDepth();
inline void Pop();
inline bool StackBlown() { return maximum_depth_ - depth_ == kStackSize; }
void Initialize(ConsString* cons_string, int offset);
String* Continue(int* offset_out);
String* NextLeaf(bool* blew_stack);
String* Search(int* offset_out);
// Stack must always contain only frames for which right traversal
// has not yet been performed.
ConsString* frames_[kStackSize];
ConsString* root_;
int depth_;
int maximum_depth_;
int consumed_;
DISALLOW_COPY_AND_ASSIGN(ConsStringIterator);
};
class StringCharacterStream {
public:
inline StringCharacterStream(String* string,
int offset = 0);
inline uint16_t GetNext();
inline bool HasMore();
inline void Reset(String* string, int offset = 0);
inline void VisitOneByteString(const uint8_t* chars, int length);
inline void VisitTwoByteString(const uint16_t* chars, int length);
private:
ConsStringIterator iter_;
bool is_one_byte_;
union {
const uint8_t* buffer8_;
const uint16_t* buffer16_;
};
const uint8_t* end_;
DISALLOW_COPY_AND_ASSIGN(StringCharacterStream);
};
template <typename T>
class VectorIterator {
public:
VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { }
explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { }
T GetNext() { return data_[index_++]; }
bool has_more() { return index_ < data_.length(); }
private:
Vector<const T> data_;
int index_;
};
// The Oddball describes objects null, undefined, true, and false.
class Oddball: public HeapObject {
public:
// [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.
MUST_USE_RESULT static inline Handle<Object> ToNumber(Handle<Oddball> input);
DECLARE_CAST(Oddball)
// Dispatched behavior.
DECLARE_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 kToStringOffset = HeapObject::kHeaderSize;
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 = ~1;
static const byte kTheHole = 2;
static const byte kNull = 3;
static const byte kArgumentMarker = 4;
static const byte kUndefined = 5;
static const byte kUninitialized = 6;
static const byte kOther = 7;
static const byte kException = 8;
typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize,
kSize> BodyDescriptor;
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)
DECLARE_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.
DECLARE_PRINTER(Cell)
DECLARE_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);
};
class PropertyCell : public HeapObject {
public:
// [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();
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(Handle<PropertyCell> cell,
Handle<Object> value,
PropertyDetails details);
static void UpdateCell(Handle<GlobalDictionary> dictionary, int entry,
Handle<Object> value, PropertyDetails details);
static Handle<PropertyCell> InvalidateEntry(
Handle<GlobalDictionary> dictionary, int entry);
static void SetValueWithInvalidation(Handle<PropertyCell> cell,
Handle<Object> new_value);
DECLARE_CAST(PropertyCell)
// Dispatched behavior.
DECLARE_PRINTER(PropertyCell)
DECLARE_VERIFIER(PropertyCell)
// Layout description.
static const int kDetailsOffset = HeapObject::kHeaderSize;
static const int kValueOffset = kDetailsOffset + kPointerSize;
static const int kDependentCodeOffset = kValueOffset + kPointerSize;
static const int kSize = kDependentCodeOffset + kPointerSize;
static const int kPointerFieldsBeginOffset = kValueOffset;
static const int kPointerFieldsEndOffset = kSize;
typedef FixedBodyDescriptor<kValueOffset,
kSize,
kSize> BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
};
class WeakCell : public HeapObject {
public:
inline Object* value() const;
// This should not be called by anyone except GC.
inline void clear();
// This should not be called by anyone except allocator.
inline void initialize(HeapObject* value);
inline bool cleared() const;
DECL_ACCESSORS(next, Object)
inline void clear_next(Object* the_hole_value);
inline bool next_cleared();
DECLARE_CAST(WeakCell)
DECLARE_PRINTER(WeakCell)
DECLARE_VERIFIER(WeakCell)
// Layout description.
static const int kValueOffset = HeapObject::kHeaderSize;
static const int kNextOffset = kValueOffset + kPointerSize;
static const int kSize = kNextOffset + kPointerSize;
typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCell);
};
// The JSProxy describes EcmaScript Harmony proxies
class JSProxy: public JSReceiver {
public:
MUST_USE_RESULT static MaybeHandle<JSProxy> New(Isolate* isolate,
Handle<Object>,
Handle<Object>);
// [handler]: The handler property.
DECL_ACCESSORS(handler, Object)
// [target]: The target property.
DECL_ACCESSORS(target, JSReceiver)
// [hash]: The hash code property (undefined if not initialized yet).
DECL_ACCESSORS(hash, Object)
static MaybeHandle<Context> GetFunctionRealm(Handle<JSProxy> proxy);
DECLARE_CAST(JSProxy)
INLINE(bool IsRevoked() const);
static void Revoke(Handle<JSProxy> proxy);
// ES6 9.5.1
static MaybeHandle<Object> GetPrototype(Handle<JSProxy> receiver);
// ES6 9.5.2
MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSProxy> proxy,
Handle<Object> value,
bool from_javascript,
ShouldThrow should_throw);
// ES6 9.5.3
MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSProxy> proxy);
// ES6 9.5.4 (when passed DONT_THROW)
MUST_USE_RESULT static Maybe<bool> PreventExtensions(
Handle<JSProxy> proxy, ShouldThrow should_throw);
// ES6 9.5.5
MUST_USE_RESULT static Maybe<bool> GetOwnPropertyDescriptor(
Isolate* isolate, Handle<JSProxy> proxy, Handle<Name> name,
PropertyDescriptor* desc);
// ES6 9.5.6
MUST_USE_RESULT static Maybe<bool> DefineOwnProperty(
Isolate* isolate, Handle<JSProxy> object, Handle<Object> key,
PropertyDescriptor* desc, ShouldThrow should_throw);
// ES6 9.5.7
MUST_USE_RESULT static Maybe<bool> HasProperty(Isolate* isolate,
Handle<JSProxy> proxy,
Handle<Name> name);
// ES6 9.5.8
MUST_USE_RESULT static MaybeHandle<Object> GetProperty(
Isolate* isolate, Handle<JSProxy> proxy, Handle<Name> name,
Handle<Object> receiver, LanguageMode language_mode);
// ES6 9.5.9
MUST_USE_RESULT static Maybe<bool> SetProperty(Handle<JSProxy> proxy,
Handle<Name> name,
Handle<Object> value,
Handle<Object> receiver,
LanguageMode language_mode);
// ES6 9.5.10 (when passed SLOPPY)
MUST_USE_RESULT static Maybe<bool> DeletePropertyOrElement(
Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode);
// ES6 9.5.11
MUST_USE_RESULT static Maybe<bool> Enumerate(Isolate* isolate,
Handle<JSReceiver> receiver,
Handle<JSProxy> proxy,
KeyAccumulator* accumulator);
// ES6 9.5.12
MUST_USE_RESULT static Maybe<bool> OwnPropertyKeys(
Isolate* isolate, Handle<JSReceiver> receiver, Handle<JSProxy> proxy,
PropertyFilter filter, KeyAccumulator* accumulator);
MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
LookupIterator* it);
// Dispatched behavior.
DECLARE_PRINTER(JSProxy)
DECLARE_VERIFIER(JSProxy)
// Layout description.
static const int kTargetOffset = JSReceiver::kHeaderSize;
static const int kHandlerOffset = kTargetOffset + kPointerSize;
static const int kHashOffset = kHandlerOffset + kPointerSize;
static const int kSize = kHashOffset + kPointerSize;
typedef FixedBodyDescriptor<JSReceiver::kPropertiesOffset, kSize, kSize>
BodyDescriptor;
MUST_USE_RESULT Object* GetIdentityHash();
static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy);
private:
static Maybe<bool> AddPrivateProperty(Isolate* isolate, Handle<JSProxy> proxy,
Handle<Symbol> private_name,
PropertyDescriptor* desc,
ShouldThrow should_throw);
DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy);
};
class JSCollection : public JSObject {
public:
// [table]: the backing hash table
DECL_ACCESSORS(table, Object)
static const int kTableOffset = JSObject::kHeaderSize;
static const int kSize = kTableOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollection);
};
// The JSSet describes EcmaScript Harmony sets
class JSSet : public JSCollection {
public:
DECLARE_CAST(JSSet)
static void Initialize(Handle<JSSet> set, Isolate* isolate);
static void Clear(Handle<JSSet> set);
// Dispatched behavior.
DECLARE_PRINTER(JSSet)
DECLARE_VERIFIER(JSSet)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet);
};
// The JSMap describes EcmaScript Harmony maps
class JSMap : public JSCollection {
public:
DECLARE_CAST(JSMap)
static void Initialize(Handle<JSMap> map, Isolate* isolate);
static void Clear(Handle<JSMap> map);
// Dispatched behavior.
DECLARE_PRINTER(JSMap)
DECLARE_VERIFIER(JSMap)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
};
// OrderedHashTableIterator is an iterator that iterates over the keys and
// values of an OrderedHashTable.
//
// The iterator has a reference to the underlying OrderedHashTable data,
// [table], as well as the current [index] the iterator is at.
//
// When the OrderedHashTable is rehashed it adds a reference from the old table
// to the new table as well as storing enough data about the changes so that the
// iterator [index] can be adjusted accordingly.
//
// When the [Next] result from the iterator is requested, the iterator checks if
// there is a newer table that it needs to transition to.
template<class Derived, class TableType>
class OrderedHashTableIterator: public JSObject {
public:
// [table]: the backing hash table mapping keys to values.
DECL_ACCESSORS(table, Object)
// [index]: The index into the data table.
DECL_ACCESSORS(index, Object)
// [kind]: The kind of iteration this is. One of the [Kind] enum values.
DECL_ACCESSORS(kind, Object)
#ifdef OBJECT_PRINT
void OrderedHashTableIteratorPrint(std::ostream& os); // NOLINT
#endif
static const int kTableOffset = JSObject::kHeaderSize;
static const int kIndexOffset = kTableOffset + kPointerSize;
static const int kKindOffset = kIndexOffset + kPointerSize;
static const int kSize = kKindOffset + kPointerSize;
enum Kind {
kKindKeys = 1,
kKindValues = 2,
kKindEntries = 3
};
// Whether the iterator has more elements. This needs to be called before
// calling |CurrentKey| and/or |CurrentValue|.
bool HasMore();
// Move the index forward one.
void MoveNext() {
set_index(Smi::FromInt(Smi::cast(index())->value() + 1));
}
// Populates the array with the next key and value and then moves the iterator
// forward.
// This returns the |kind| or 0 if the iterator is already at the end.
Smi* Next(JSArray* value_array);
// Returns the current key of the iterator. This should only be called when
// |HasMore| returns true.
inline Object* CurrentKey();
private:
// Transitions the iterator to the non obsolete backing store. This is a NOP
// if the [table] is not obsolete.
void Transition();
DISALLOW_IMPLICIT_CONSTRUCTORS(OrderedHashTableIterator);
};
class JSSetIterator: public OrderedHashTableIterator<JSSetIterator,
OrderedHashSet> {
public:
// Dispatched behavior.
DECLARE_PRINTER(JSSetIterator)
DECLARE_VERIFIER(JSSetIterator)
DECLARE_CAST(JSSetIterator)
// Called by |Next| to populate the array. This allows the subclasses to
// populate the array differently.
inline void PopulateValueArray(FixedArray* array);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSSetIterator);
};
class JSMapIterator: public OrderedHashTableIterator<JSMapIterator,
OrderedHashMap> {
public:
// Dispatched behavior.
DECLARE_PRINTER(JSMapIterator)
DECLARE_VERIFIER(JSMapIterator)
DECLARE_CAST(JSMapIterator)
// Called by |Next| to populate the array. This allows the subclasses to
// populate the array differently.
inline void PopulateValueArray(FixedArray* array);
private:
// Returns the current value of the iterator. This should only be called when
// |HasMore| returns true.
inline Object* CurrentValue();
DISALLOW_IMPLICIT_CONSTRUCTORS(JSMapIterator);
};
// ES6 section 25.1.1.3 The IteratorResult Interface
class JSIteratorResult final : public JSObject {
public:
// [done]: This is the result status of an iterator next method call. If the
// end of the iterator was reached done is true. If the end was not reached
// done is false and a [value] is available.
DECL_ACCESSORS(done, Object)
// [value]: If [done] is false, this is the current iteration element value.
// If [done] is true, this is the return value of the iterator, if it supplied
// one. If the iterator does not have a return value, value is undefined.
// In that case, the value property may be absent from the conforming object
// if it does not inherit an explicit value property.
DECL_ACCESSORS(value, Object)
// Dispatched behavior.
DECLARE_PRINTER(JSIteratorResult)
DECLARE_VERIFIER(JSIteratorResult)
DECLARE_CAST(JSIteratorResult)
static const int kValueOffset = JSObject::kHeaderSize;
static const int kDoneOffset = kValueOffset + kPointerSize;
static const int kSize = kDoneOffset + kPointerSize;
// Indices of in-object properties.
static const int kValueIndex = 0;
static const int kDoneIndex = 1;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSIteratorResult);
};
// Base class for both JSWeakMap and JSWeakSet
class JSWeakCollection: public JSObject {
public:
// [table]: the backing hash table mapping keys to values.
DECL_ACCESSORS(table, Object)
// [next]: linked list of encountered weak maps during GC.
DECL_ACCESSORS(next, Object)
static void Initialize(Handle<JSWeakCollection> collection, Isolate* isolate);
static void Set(Handle<JSWeakCollection> collection, Handle<Object> key,
Handle<Object> value, int32_t hash);
static bool Delete(Handle<JSWeakCollection> collection, Handle<Object> key,
int32_t hash);
static const int kTableOffset = JSObject::kHeaderSize;
static const int kNextOffset = kTableOffset + kPointerSize;
static const int kSize = kNextOffset + kPointerSize;
// Visiting policy defines whether the table and next collection fields
// should be visited or not.
enum BodyVisitingPolicy { kVisitStrong, kVisitWeak };
// Iterates the function object according to the visiting policy.
template <BodyVisitingPolicy>
class BodyDescriptorImpl;
// Visit the whole object.
typedef BodyDescriptorImpl<kVisitStrong> BodyDescriptor;
// Don't visit table and next collection fields.
typedef BodyDescriptorImpl<kVisitWeak> BodyDescriptorWeak;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection);
};
// The JSWeakMap describes EcmaScript Harmony weak maps
class JSWeakMap: public JSWeakCollection {
public:
DECLARE_CAST(JSWeakMap)
// Dispatched behavior.
DECLARE_PRINTER(JSWeakMap)
DECLARE_VERIFIER(JSWeakMap)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
};
// The JSWeakSet describes EcmaScript Harmony weak sets
class JSWeakSet: public JSWeakCollection {
public:
DECLARE_CAST(JSWeakSet)
// Dispatched behavior.
DECLARE_PRINTER(JSWeakSet)
DECLARE_VERIFIER(JSWeakSet)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet);
};
// Whether a JSArrayBuffer is a SharedArrayBuffer or not.
enum class SharedFlag { kNotShared, kShared };
class JSArrayBuffer: public JSObject {
public:
// [backing_store]: backing memory for this array
DECL_ACCESSORS(backing_store, void)
// [byte_length]: length in bytes
DECL_ACCESSORS(byte_length, Object)
inline uint32_t bit_field() const;
inline void set_bit_field(uint32_t bits);
inline bool is_external();
inline void set_is_external(bool value);
inline bool is_neuterable();
inline void set_is_neuterable(bool value);
inline bool was_neutered();
inline void set_was_neutered(bool value);
inline bool is_shared();
inline void set_is_shared(bool value);
DECLARE_CAST(JSArrayBuffer)
void Neuter();
static void Setup(Handle<JSArrayBuffer> array_buffer, Isolate* isolate,
bool is_external, void* data, size_t allocated_length,
SharedFlag shared = SharedFlag::kNotShared);
static bool SetupAllocatingData(Handle<JSArrayBuffer> array_buffer,
Isolate* isolate, size_t allocated_length,
bool initialize = true,
SharedFlag shared = SharedFlag::kNotShared);
// Dispatched behavior.
DECLARE_PRINTER(JSArrayBuffer)
DECLARE_VERIFIER(JSArrayBuffer)
static const int kByteLengthOffset = JSObject::kHeaderSize;
static const int kBackingStoreOffset = kByteLengthOffset + kPointerSize;
static const int kBitFieldSlot = kBackingStoreOffset + kPointerSize;
#if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
static const int kBitFieldOffset = kBitFieldSlot;
#else
static const int kBitFieldOffset = kBitFieldSlot + kIntSize;
#endif
static const int kSize = kBitFieldSlot + kPointerSize;
static const int kSizeWithInternalFields =
kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
// Iterates all fields in the object including internal ones except
// kBackingStoreOffset and kBitFieldSlot.
class BodyDescriptor;
class IsExternal : public BitField<bool, 1, 1> {};
class IsNeuterable : public BitField<bool, 2, 1> {};
class WasNeutered : public BitField<bool, 3, 1> {};
class IsShared : public BitField<bool, 4, 1> {};
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
};
class JSArrayBufferView: public JSObject {
public:
// [buffer]: ArrayBuffer that this typed array views.
DECL_ACCESSORS(buffer, Object)
// [byte_offset]: offset of typed array in bytes.
DECL_ACCESSORS(byte_offset, Object)
// [byte_length]: length of typed array in bytes.
DECL_ACCESSORS(byte_length, Object)
DECLARE_CAST(JSArrayBufferView)
DECLARE_VERIFIER(JSArrayBufferView)
inline bool WasNeutered() const;
static const int kBufferOffset = JSObject::kHeaderSize;
static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
static const int kViewSize = kByteLengthOffset + kPointerSize;
private:
#ifdef VERIFY_HEAP
DECL_ACCESSORS(raw_byte_offset, Object)
DECL_ACCESSORS(raw_byte_length, Object)
#endif
DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
};
class JSTypedArray: public JSArrayBufferView {
public:
// [length]: length of typed array in elements.
DECL_ACCESSORS(length, Object)
inline uint32_t length_value() const;
DECLARE_CAST(JSTypedArray)
ExternalArrayType type();
size_t element_size();
Handle<JSArrayBuffer> GetBuffer();
// Dispatched behavior.
DECLARE_PRINTER(JSTypedArray)
DECLARE_VERIFIER(JSTypedArray)
static const int kLengthOffset = kViewSize + kPointerSize;
static const int kSize = kLengthOffset + kPointerSize;
static const int kSizeWithInternalFields =
kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
private:
static Handle<JSArrayBuffer> MaterializeArrayBuffer(
Handle<JSTypedArray> typed_array);
#ifdef VERIFY_HEAP
DECL_ACCESSORS(raw_length, Object)
#endif
DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray);
};
class JSDataView: public JSArrayBufferView {
public:
DECLARE_CAST(JSDataView)
// Dispatched behavior.
DECLARE_PRINTER(JSDataView)
DECLARE_VERIFIER(JSDataView)
static const int kSize = kViewSize;
static const int kSizeWithInternalFields =
kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView);
};
// Foreign describes objects pointing from JavaScript to C structures.
class Foreign: public HeapObject {
public:
// [address]: field containing the address.
inline Address foreign_address();
inline void set_foreign_address(Address value);
DECLARE_CAST(Foreign)
// Dispatched behavior.
DECLARE_PRINTER(Foreign)
DECLARE_VERIFIER(Foreign)
// Layout description.
static const int kForeignAddressOffset = HeapObject::kHeaderSize;
static const int kSize = kForeignAddressOffset + kPointerSize;
STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
class BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
};
// The JSArray describes JavaScript Arrays
// Such an array can be in one of two modes:
// - fast, backing storage is a FixedArray and length <= elements.length();
// Please note: push and pop can be used to grow and shrink the array.
// - slow, backing storage is a HashTable with numbers as keys.
class JSArray: public JSObject {
public:
// [length]: The length property.
DECL_ACCESSORS(length, Object)
// Overload the length setter to skip write barrier when the length
// is set to a smi. This matches the set function on FixedArray.
inline void set_length(Smi* length);
static bool HasReadOnlyLength(Handle<JSArray> array);
static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index);
// Initialize the array with the given capacity. The function may
// fail due to out-of-memory situations, but only if the requested
// capacity is non-zero.
static void Initialize(Handle<JSArray> array, int capacity, int length = 0);
// If the JSArray has fast elements, and new_length would result in
// normalization, returns true.
bool SetLengthWouldNormalize(uint32_t new_length);
static inline bool SetLengthWouldNormalize(Heap* heap, uint32_t new_length);
// Initializes the array to a certain length.
inline bool AllowsSetLength();
static void SetLength(Handle<JSArray> array, uint32_t length);
// Same as above but will also queue splice records if |array| is observed.
static MaybeHandle<Object> ObservableSetLength(Handle<JSArray> array,
uint32_t length);
// Set the content of the array to the content of storage.
static inline void SetContent(Handle<JSArray> array,
Handle<FixedArrayBase> storage);
// ES6 9.4.2.1
MUST_USE_RESULT static Maybe<bool> DefineOwnProperty(
Isolate* isolate, Handle<JSArray> o, Handle<Object> name,
PropertyDescriptor* desc, ShouldThrow should_throw);
static bool AnythingToArrayLength(Isolate* isolate,
Handle<Object> length_object,
uint32_t* output);
MUST_USE_RESULT static Maybe<bool> ArraySetLength(Isolate* isolate,
Handle<JSArray> a,
PropertyDescriptor* desc,
ShouldThrow should_throw);
DECLARE_CAST(JSArray)
// Dispatched behavior.
DECLARE_PRINTER(JSArray)
DECLARE_VERIFIER(JSArray)
// Number of element slots to pre-allocate for an empty array.
static const int kPreallocatedArrayElements = 4;
// Layout description.
static const int kLengthOffset = JSObject::kHeaderSize;
static const int kSize = kLengthOffset + kPointerSize;
// 600 * KB is the Page::kMaxRegularHeapObjectSize defined in spaces.h which
// we do not want to include in objects.h
// Note that Page::kMaxRegularHeapObjectSize has to be in sync with
// kInitialMaxFastElementArray which is checked in a DCHECK in heap.cc.
static const int kInitialMaxFastElementArray =
(600 * KB - FixedArray::kHeaderSize - kSize - AllocationMemento::kSize) /
kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray);
};
Handle<Object> CacheInitialJSArrayMaps(Handle<Context> native_context,
Handle<Map> initial_map);
// JSRegExpResult is just a JSArray with a specific initial map.
// This initial map adds in-object properties for "index" and "input"
// properties, as assigned by RegExp.prototype.exec, which allows
// faster creation of RegExp exec results.
// This class just holds constants used when creating the result.
// After creation the result must be treated as a JSArray in all regards.
class JSRegExpResult: public JSArray {
public:
// Offsets of object fields.
static const int kIndexOffset = JSArray::kSize;
static const int kInputOffset = kIndexOffset + kPointerSize;
static const int kSize = kInputOffset + kPointerSize;
// Indices of in-object properties.
static const int kIndexIndex = 0;
static const int kInputIndex = 1;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
};
class AccessorInfo: public Struct {
public:
DECL_ACCESSORS(name, Object)
DECL_INT_ACCESSORS(flag)
DECL_ACCESSORS(expected_receiver_type, Object)
inline bool all_can_read();
inline void set_all_can_read(bool value);
inline bool all_can_write();
inline void set_all_can_write(bool value);
inline bool is_special_data_property();
inline void set_is_special_data_property(bool value);
inline PropertyAttributes property_attributes();
inline void set_property_attributes(PropertyAttributes attributes);
// Checks whether the given receiver is compatible with this accessor.
static bool IsCompatibleReceiverMap(Isolate* isolate,
Handle<AccessorInfo> info,
Handle<Map> map);
inline bool IsCompatibleReceiver(Object* receiver);
DECLARE_CAST(AccessorInfo)
// Dispatched behavior.
DECLARE_VERIFIER(AccessorInfo)
// Append all descriptors to the array that are not already there.
// Return number added.
static int AppendUnique(Handle<Object> descriptors,
Handle<FixedArray> array,
int valid_descriptors);
static const int kNameOffset = HeapObject::kHeaderSize;
static const int kFlagOffset = kNameOffset + kPointerSize;
static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
static const int kSize = kExpectedReceiverTypeOffset + kPointerSize;
private:
inline bool HasExpectedReceiverType();
// Bit positions in flag.
static const int kAllCanReadBit = 0;
static const int kAllCanWriteBit = 1;
static const int kSpecialDataProperty = 2;
class AttributesField : public BitField<PropertyAttributes, 3, 3> {};
DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo);
};
// An accessor must have a getter, but can have no setter.
//
// When setting a property, V8 searches accessors in prototypes.
// If an accessor was found and it does not have a setter,
// the request is ignored.
//
// If the accessor in the prototype has the READ_ONLY property attribute, then
// a new value is added to the derived object when the property is set.
// This shadows the accessor in the prototype.
class ExecutableAccessorInfo: public AccessorInfo {
public:
DECL_ACCESSORS(getter, Object)
DECL_ACCESSORS(setter, Object)
DECL_ACCESSORS(data, Object)
DECLARE_CAST(ExecutableAccessorInfo)
// Dispatched behavior.
DECLARE_PRINTER(ExecutableAccessorInfo)
DECLARE_VERIFIER(ExecutableAccessorInfo)
static const int kGetterOffset = AccessorInfo::kSize;
static const int kSetterOffset = kGetterOffset + kPointerSize;
static const int kDataOffset = kSetterOffset + kPointerSize;
static const int kSize = kDataOffset + kPointerSize;
static void ClearSetter(Handle<ExecutableAccessorInfo> info);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutableAccessorInfo);
};
// Support for JavaScript accessors: A pair of a getter and a setter. Each
// accessor can either be
// * a pointer to a JavaScript function or proxy: a real accessor
// * undefined: considered an accessor by the spec, too, strangely enough
// * the hole: an accessor which has not been set
// * a pointer to a map: a transition used to ensure map sharing
class AccessorPair: public Struct {
public:
DECL_ACCESSORS(getter, Object)
DECL_ACCESSORS(setter, Object)
DECLARE_CAST(AccessorPair)
static Handle<AccessorPair> Copy(Handle<AccessorPair> pair);
inline Object* get(AccessorComponent component);
inline void set(AccessorComponent component, Object* value);
// Note: Returns undefined instead in case of a hole.
Object* GetComponent(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.
DECLARE_PRINTER(AccessorPair)
DECLARE_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);
};
class AccessCheckInfo: public Struct {
public:
DECL_ACCESSORS(named_callback, Object)
DECL_ACCESSORS(indexed_callback, Object)
DECL_ACCESSORS(callback, Object)
DECL_ACCESSORS(data, Object)
DECLARE_CAST(AccessCheckInfo)
// Dispatched behavior.
DECLARE_PRINTER(AccessCheckInfo)
DECLARE_VERIFIER(AccessCheckInfo)
static const int kNamedCallbackOffset = HeapObject::kHeaderSize;
static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize;
static const int kCallbackOffset = kIndexedCallbackOffset + kPointerSize;
static const int kDataOffset = kCallbackOffset + kPointerSize;
static const int kSize = kDataOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo);
};
class InterceptorInfo: public Struct {
public:
DECL_ACCESSORS(getter, Object)
DECL_ACCESSORS(setter, Object)
DECL_ACCESSORS(query, Object)
DECL_ACCESSORS(deleter, Object)
DECL_ACCESSORS(enumerator, Object)
DECL_ACCESSORS(data, Object)
DECL_BOOLEAN_ACCESSORS(can_intercept_symbols)
DECL_BOOLEAN_ACCESSORS(all_can_read)
DECL_BOOLEAN_ACCESSORS(non_masking)
inline int flags() const;
inline void set_flags(int flags);
DECLARE_CAST(InterceptorInfo)
// Dispatched behavior.
DECLARE_PRINTER(InterceptorInfo)
DECLARE_VERIFIER(InterceptorInfo)
static const int kGetterOffset = HeapObject::kHeaderSize;
static const int kSetterOffset = kGetterOffset + kPointerSize;
static const int kQueryOffset = kSetterOffset + kPointerSize;
static const int kDeleterOffset = kQueryOffset + kPointerSize;
static const int kEnumeratorOffset = kDeleterOffset + kPointerSize;
static const int kDataOffset = kEnumeratorOffset + kPointerSize;
static const int kFlagsOffset = kDataOffset + kPointerSize;
static const int kSize = kFlagsOffset + kPointerSize;
static const int kCanInterceptSymbolsBit = 0;
static const int kAllCanReadBit = 1;
static const int kNonMasking = 2;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo);
};
class CallHandlerInfo: public Struct {
public:
DECL_ACCESSORS(callback, Object)
DECL_ACCESSORS(data, Object)
DECL_ACCESSORS(fast_handler, Object)
DECLARE_CAST(CallHandlerInfo)
// Dispatched behavior.
DECLARE_PRINTER(CallHandlerInfo)
DECLARE_VERIFIER(CallHandlerInfo)
static const int kCallbackOffset = HeapObject::kHeaderSize;
static const int kDataOffset = kCallbackOffset + kPointerSize;
static const int kFastHandlerOffset = kDataOffset + kPointerSize;
static const int kSize = kFastHandlerOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo);
};
class TemplateInfo: public Struct {
public:
DECL_ACCESSORS(tag, Object)
inline int number_of_properties() const;
inline void set_number_of_properties(int value);
DECL_ACCESSORS(property_list, Object)
DECL_ACCESSORS(property_accessors, Object)
DECLARE_VERIFIER(TemplateInfo)
static const int kTagOffset = HeapObject::kHeaderSize;
static const int kNumberOfProperties = kTagOffset + kPointerSize;
static const int kPropertyListOffset = kNumberOfProperties + kPointerSize;
static const int kPropertyAccessorsOffset =
kPropertyListOffset + kPointerSize;
static const int kPropertyIntrinsicsOffset =
kPropertyAccessorsOffset + kPointerSize;
static const int kHeaderSize = kPropertyIntrinsicsOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo);
};
class FunctionTemplateInfo: public TemplateInfo {
public:
DECL_ACCESSORS(serial_number, Object)
DECL_ACCESSORS(call_code, Object)
DECL_ACCESSORS(prototype_template, Object)
DECL_ACCESSORS(parent_template, Object)
DECL_ACCESSORS(named_property_handler, Object)
DECL_ACCESSORS(indexed_property_handler, Object)
DECL_ACCESSORS(instance_template, Object)
DECL_ACCESSORS(class_name, Object)
DECL_ACCESSORS(signature, Object)
DECL_ACCESSORS(instance_call_handler, Object)
DECL_ACCESSORS(access_check_info, Object)
DECL_INT_ACCESSORS(flag)
inline int length() const;
inline void set_length(int value);
// Following properties use flag bits.
DECL_BOOLEAN_ACCESSORS(hidden_prototype)
DECL_BOOLEAN_ACCESSORS(undetectable)
// If the bit is set, object instances created by this function
// requires access check.
DECL_BOOLEAN_ACCESSORS(needs_access_check)
DECL_BOOLEAN_ACCESSORS(read_only_prototype)
DECL_BOOLEAN_ACCESSORS(remove_prototype)
DECL_BOOLEAN_ACCESSORS(do_not_cache)
DECL_BOOLEAN_ACCESSORS(instantiated)
DECL_BOOLEAN_ACCESSORS(accept_any_receiver)
DECLARE_CAST(FunctionTemplateInfo)
// Dispatched behavior.
DECLARE_PRINTER(FunctionTemplateInfo)
DECLARE_VERIFIER(FunctionTemplateInfo)
static const int kSerialNumberOffset = TemplateInfo::kHeaderSize;
static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize;
static const int kPrototypeTemplateOffset =
kCallCodeOffset + kPointerSize;
static const int kParentTemplateOffset =
kPrototypeTemplateOffset + kPointerSize;
static const int kNamedPropertyHandlerOffset =
kParentTemplateOffset + kPointerSize;
static const int kIndexedPropertyHandlerOffset =
kNamedPropertyHandlerOffset + kPointerSize;
static const int kInstanceTemplateOffset =
kIndexedPropertyHandlerOffset + kPointerSize;
static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize;
static const int kSignatureOffset = kClassNameOffset + kPointerSize;
static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize;
static const int kAccessCheckInfoOffset =
kInstanceCallHandlerOffset + kPointerSize;
static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize;
static const int kLengthOffset = kFlagOffset + kPointerSize;
static const int kSize = kLengthOffset + kPointerSize;
// Returns true if |object| is an instance of this function template.
bool IsTemplateFor(Object* object);
bool IsTemplateFor(Map* map);
// Returns the holder JSObject if the function can legally be called with this
// receiver. Returns Heap::null_value() if the call is illegal.
Object* GetCompatibleReceiver(Isolate* isolate, Object* receiver);
private:
// Bit position in the flag, from least significant bit position.
static const int kHiddenPrototypeBit = 0;
static const int kUndetectableBit = 1;
static const int kNeedsAccessCheckBit = 2;
static const int kReadOnlyPrototypeBit = 3;
static const int kRemovePrototypeBit = 4;
static const int kDoNotCacheBit = 5;
static const int kInstantiatedBit = 6;
static const int kAcceptAnyReceiver = 7;
DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo);
};
class ObjectTemplateInfo: public TemplateInfo {
public:
DECL_ACCESSORS(constructor, Object)
DECL_ACCESSORS(internal_field_count, Object)
DECLARE_CAST(ObjectTemplateInfo)
// Dispatched behavior.
DECLARE_PRINTER(ObjectTemplateInfo)
DECLARE_VERIFIER(ObjectTemplateInfo)
static const int kConstructorOffset = TemplateInfo::kHeaderSize;
static const int kInternalFieldCountOffset =
kConstructorOffset + kPointerSize;
static const int kSize = kInternalFieldCountOffset + kPointerSize;
};
// The DebugInfo class holds additional information for a function being
// debugged.
class DebugInfo: public Struct {
public:
// The shared function info for the source being debugged.
DECL_ACCESSORS(shared, SharedFunctionInfo)
// Code object for the patched code. This code object is the code object
// currently active for the function.
DECL_ACCESSORS(code, Code)
// Fixed array holding status information for each active break point.
DECL_ACCESSORS(break_points, FixedArray)
// Check if there is a break point at a code position.
bool HasBreakPoint(int code_position);
// Get the break point info object for a code position.
Object* GetBreakPointInfo(int code_position);
// Clear a break point.
static void ClearBreakPoint(Handle<DebugInfo> debug_info,
int code_position,
Handle<Object> break_point_object);
// Set a break point.
static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position,
int source_position, int statement_position,
Handle<Object> break_point_object);
// Get the break point objects for a code position.
Handle<Object> GetBreakPointObjects(int code_position);
// Find the break point info holding this break point object.
static Handle<Object> FindBreakPointInfo(Handle<DebugInfo> debug_info,
Handle<Object> break_point_object);
// Get the number of break points for this function.
int GetBreakPointCount();
DECLARE_CAST(DebugInfo)
// Dispatched behavior.
DECLARE_PRINTER(DebugInfo)
DECLARE_VERIFIER(DebugInfo)
static const int kSharedFunctionInfoIndex = Struct::kHeaderSize;
static const int kCodeIndex = kSharedFunctionInfoIndex + kPointerSize;
static const int kBreakPointsStateIndex = kCodeIndex + kPointerSize;
static const int kSize = kBreakPointsStateIndex + kPointerSize;
static const int kEstimatedNofBreakPointsInFunction = 16;
private:
static const int kNoBreakPointInfo = -1;
// Lookup the index in the break_points array for a code position.
int GetBreakPointInfoIndex(int code_position);
DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo);
};
// The BreakPointInfo class holds information for break points set in a
// function. The DebugInfo object holds a BreakPointInfo object for each code
// position with one or more break points.
class BreakPointInfo: public Struct {
public:
// The position in the code for the break point.
DECL_INT_ACCESSORS(code_position)
// The position in the source for the break position.
DECL_INT_ACCESSORS(source_position)
// The position in the source for the last statement before this break
// position.
DECL_INT_ACCESSORS(statement_position)
// List of related JavaScript break points.
DECL_ACCESSORS(break_point_objects, Object)
// Removes a break point.
static void ClearBreakPoint(Handle<BreakPointInfo> info,
Handle<Object> break_point_object);
// Set a break point.
static void SetBreakPoint(Handle<BreakPointInfo> info,
Handle<Object> break_point_object);
// Check if break point info has this break point object.
static bool HasBreakPointObject(Handle<BreakPointInfo> info,
Handle<Object> break_point_object);
// Get the number of break points for this code position.
int GetBreakPointCount();
DECLARE_CAST(BreakPointInfo)
// Dispatched behavior.
DECLARE_PRINTER(BreakPointInfo)
DECLARE_VERIFIER(BreakPointInfo)
static const int kCodePositionIndex = Struct::kHeaderSize;
static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize;
static const int kStatementPositionIndex =
kSourcePositionIndex + kPointerSize;
static const int kBreakPointObjectsIndex =
kStatementPositionIndex + kPointerSize;
static const int kSize = kBreakPointObjectsIndex + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo);
};
#undef DECL_BOOLEAN_ACCESSORS
#undef DECL_ACCESSORS
#undef DECLARE_CAST
#undef DECLARE_VERIFIER
#define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \
V(kStringTable, "string_table", "(Internalized strings)") \
V(kExternalStringsTable, "external_strings_table", "(External strings)") \
V(kStrongRootList, "strong_root_list", "(Strong roots)") \
V(kSmiRootList, "smi_root_list", "(Smi roots)") \
V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \
V(kTop, "top", "(Isolate)") \
V(kRelocatable, "relocatable", "(Relocatable)") \
V(kDebug, "debug", "(Debugger)") \
V(kCompilationCache, "compilationcache", "(Compilation cache)") \
V(kHandleScope, "handlescope", "(Handle scope)") \
V(kBuiltins, "builtins", "(Builtins)") \
V(kGlobalHandles, "globalhandles", "(Global handles)") \
V(kEternalHandles, "eternalhandles", "(Eternal handles)") \
V(kThreadManager, "threadmanager", "(Thread manager)") \
V(kStrongRoots, "strong roots", "(Strong roots)") \
V(kExtensions, "Extensions", "(Extensions)")
class VisitorSynchronization : public AllStatic {
public:
#define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item,
enum SyncTag {
VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM)
kNumberOfSyncTags
};
#undef DECLARE_ENUM
static const char* const kTags[kNumberOfSyncTags];
static const char* const kTagNames[kNumberOfSyncTags];
};
// Abstract base class for visiting, and optionally modifying, the
// pointers contained in Objects. Used in GC and serialization/deserialization.
class ObjectVisitor BASE_EMBEDDED {
public:
virtual ~ObjectVisitor() {}
// Visits a contiguous arrays of pointers in the half-open range
// [start, end). Any or all of the values may be modified on return.
virtual void VisitPointers(Object** start, Object** end) = 0;
// Handy shorthand for visiting a single pointer.
virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
// Visit weak next_code_link in Code object.
virtual void VisitNextCodeLink(Object** p) { VisitPointers(p, p + 1); }
// To allow lazy clearing of inline caches the visitor has
// a rich interface for iterating over Code objects..
// Visits a code target in the instruction stream.
virtual void VisitCodeTarget(RelocInfo* rinfo);
// Visits a code entry in a JS function.
virtual void VisitCodeEntry(Address entry_address);
// Visits a global property cell reference in the instruction stream.
virtual void VisitCell(RelocInfo* rinfo);
// Visits a runtime entry in the instruction stream.
virtual void VisitRuntimeEntry(RelocInfo* rinfo) {}
// Visits the resource of an one-byte or two-byte string.
virtual void VisitExternalOneByteString(
v8::String::ExternalOneByteStringResource** resource) {}
virtual void VisitExternalTwoByteString(
v8::String::ExternalStringResource** resource) {}
// Visits a debug call target in the instruction stream.
virtual void VisitDebugTarget(RelocInfo* rinfo);
// Visits the byte sequence in a function's prologue that contains information
// about the code's age.
virtual void VisitCodeAgeSequence(RelocInfo* rinfo);
// Visit pointer embedded into a code object.
virtual void VisitEmbeddedPointer(RelocInfo* rinfo);
// Visits an external reference embedded into a code object.
virtual void VisitExternalReference(RelocInfo* rinfo);
// Visits an external reference.
virtual void VisitExternalReference(Address* p) {}
// Visits an (encoded) internal reference.
virtual void VisitInternalReference(RelocInfo* rinfo) {}
// Visits a handle that has an embedder-assigned class ID.
virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {}
// Intended for serialization/deserialization checking: insert, or
// check for the presence of, a tag at this position in the stream.
// Also used for marking up GC roots in heap snapshots.
virtual void Synchronize(VisitorSynchronization::SyncTag tag) {}
};
// 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.
#endif // V8_OBJECTS_H_