// 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 #include #include "src/assert-scope.h" #include "src/bailout-reason.h" #include "src/base/bits.h" #include "src/base/flags.h" #include "src/builtins/builtins-definitions.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/messages.h" #include "src/property-details.h" #include "src/unicode-decoder.h" #include "src/unicode.h" #include "src/zone/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 #elif V8_TARGET_ARCH_S390 #include "src/s390/constants-s390.h" // NOLINT #endif // Has to be the last include (doesn't have include guards): #include "src/objects/object-macros.h" // // Most object types in the V8 JavaScript are described in this file. // // Inheritance hierarchy: // - Object // - Smi (immediate small integer) // - HeapObject (superclass for everything allocated in the heap) // - JSReceiver (suitable for property access) // - JSObject // - JSArray // - JSArrayBuffer // - JSArrayBufferView // - JSTypedArray // - JSDataView // - JSBoundFunction // - JSCollection // - JSSet // - JSMap // - JSStringIterator // - JSSetIterator // - JSMapIterator // - JSWeakCollection // - JSWeakMap // - JSWeakSet // - JSRegExp // - JSFunction // - JSGeneratorObject // - JSGlobalObject // - JSGlobalProxy // - JSValue // - JSDate // - JSMessageObject // - JSModuleNamespace // - JSProxy // - FixedArrayBase // - ByteArray // - BytecodeArray // - FixedArray // - DescriptorArray // - FrameArray // - HashTable // - Dictionary // - StringTable // - StringSet // - CompilationCacheTable // - CodeCacheHashTable // - MapCache // - OrderedHashTable // - OrderedHashSet // - OrderedHashMap // - Context // - FeedbackMetadata // - FeedbackVector // - TemplateList // - TransitionArray // - ScopeInfo // - ModuleInfo // - ScriptContextTable // - WeakFixedArray // - FixedDoubleArray // - Name // - String // - SeqString // - SeqOneByteString // - SeqTwoByteString // - SlicedString // - ConsString // - ThinString // - ExternalString // - ExternalOneByteString // - ExternalTwoByteString // - InternalizedString // - SeqInternalizedString // - SeqOneByteInternalizedString // - SeqTwoByteInternalizedString // - ConsInternalizedString // - ExternalInternalizedString // - ExternalOneByteInternalizedString // - ExternalTwoByteInternalizedString // - Symbol // - HeapNumber // - Cell // - PropertyCell // - Code // - AbstractCode, a wrapper around Code or BytecodeArray // - Map // - Oddball // - Foreign // - SharedFunctionInfo // - Struct // - AccessorInfo // - PromiseResolveThenableJobInfo // - PromiseReactionJobInfo // - AccessorPair // - AccessCheckInfo // - InterceptorInfo // - CallHandlerInfo // - TemplateInfo // - FunctionTemplateInfo // - ObjectTemplateInfo // - Script // - DebugInfo // - BreakPointInfo // - StackFrameInfo // - CodeCache // - PrototypeInfo // - Module // - ModuleInfoEntry // - WeakCell // // Formats of Object*: // Smi: [31 bit signed int] 0 // HeapObject: [32 bit direct pointer] (4 byte aligned) | 01 namespace v8 { namespace internal { struct InliningPosition; 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 }; enum MutableMode { MUTABLE, IMMUTABLE }; 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 }; // 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 }; // 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 = 8; 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(INTERNALIZED_STRING_TYPE) \ V(EXTERNAL_INTERNALIZED_STRING_TYPE) \ V(ONE_BYTE_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(STRING_TYPE) \ V(CONS_STRING_TYPE) \ V(EXTERNAL_STRING_TYPE) \ V(SLICED_STRING_TYPE) \ V(THIN_STRING_TYPE) \ V(ONE_BYTE_STRING_TYPE) \ V(CONS_ONE_BYTE_STRING_TYPE) \ V(EXTERNAL_ONE_BYTE_STRING_TYPE) \ V(SLICED_ONE_BYTE_STRING_TYPE) \ V(THIN_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(SYMBOL_TYPE) \ V(HEAP_NUMBER_TYPE) \ V(ODDBALL_TYPE) \ \ V(MAP_TYPE) \ V(CODE_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(FIXED_DOUBLE_ARRAY_TYPE) \ V(FILLER_TYPE) \ \ V(ACCESSOR_INFO_TYPE) \ V(ACCESSOR_PAIR_TYPE) \ V(ACCESS_CHECK_INFO_TYPE) \ V(INTERCEPTOR_INFO_TYPE) \ V(FUNCTION_TEMPLATE_INFO_TYPE) \ V(OBJECT_TEMPLATE_INFO_TYPE) \ V(ALLOCATION_SITE_TYPE) \ V(ALLOCATION_MEMENTO_TYPE) \ V(SCRIPT_TYPE) \ V(ALIASED_ARGUMENTS_ENTRY_TYPE) \ V(PROMISE_RESOLVE_THENABLE_JOB_INFO_TYPE) \ V(PROMISE_REACTION_JOB_INFO_TYPE) \ V(DEBUG_INFO_TYPE) \ V(STACK_FRAME_INFO_TYPE) \ V(PROTOTYPE_INFO_TYPE) \ V(TUPLE2_TYPE) \ V(TUPLE3_TYPE) \ V(CONTEXT_EXTENSION_TYPE) \ V(MODULE_TYPE) \ V(MODULE_INFO_ENTRY_TYPE) \ V(ASYNC_GENERATOR_REQUEST_TYPE) \ V(FIXED_ARRAY_TYPE) \ V(TRANSITION_ARRAY_TYPE) \ V(SHARED_FUNCTION_INFO_TYPE) \ V(CELL_TYPE) \ V(WEAK_CELL_TYPE) \ V(PROPERTY_CELL_TYPE) \ /* TODO(yangguo): these padding types are for ABI stability. Remove after*/ \ /* version 6.0 branch, or replace them when there is demand for new types.*/ \ V(PADDING_TYPE_1) \ V(PADDING_TYPE_2) \ V(PADDING_TYPE_3) \ V(PADDING_TYPE_4) \ \ V(JS_PROXY_TYPE) \ V(JS_GLOBAL_OBJECT_TYPE) \ V(JS_GLOBAL_PROXY_TYPE) \ V(JS_SPECIAL_API_OBJECT_TYPE) \ V(JS_VALUE_TYPE) \ V(JS_MESSAGE_OBJECT_TYPE) \ V(JS_DATE_TYPE) \ V(JS_API_OBJECT_TYPE) \ V(JS_OBJECT_TYPE) \ V(JS_ARGUMENTS_TYPE) \ V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \ V(JS_GENERATOR_OBJECT_TYPE) \ V(JS_ASYNC_GENERATOR_OBJECT_TYPE) \ V(JS_MODULE_NAMESPACE_TYPE) \ V(JS_ARRAY_TYPE) \ V(JS_ARRAY_BUFFER_TYPE) \ V(JS_TYPED_ARRAY_TYPE) \ V(JS_DATA_VIEW_TYPE) \ V(JS_SET_TYPE) \ V(JS_MAP_TYPE) \ V(JS_SET_ITERATOR_TYPE) \ V(JS_MAP_ITERATOR_TYPE) \ V(JS_WEAK_MAP_TYPE) \ V(JS_WEAK_SET_TYPE) \ V(JS_PROMISE_CAPABILITY_TYPE) \ V(JS_PROMISE_TYPE) \ V(JS_REGEXP_TYPE) \ V(JS_ERROR_TYPE) \ V(JS_ASYNC_FROM_SYNC_ITERATOR_TYPE) \ V(JS_STRING_ITERATOR_TYPE) \ \ V(JS_TYPED_ARRAY_KEY_ITERATOR_TYPE) \ V(JS_FAST_ARRAY_KEY_ITERATOR_TYPE) \ V(JS_GENERIC_ARRAY_KEY_ITERATOR_TYPE) \ \ V(JS_UINT8_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_INT8_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_UINT16_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_INT16_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_UINT32_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_INT32_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FLOAT32_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FLOAT64_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_UINT8_CLAMPED_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ \ V(JS_FAST_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_HOLEY_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_HOLEY_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_HOLEY_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ V(JS_GENERIC_ARRAY_KEY_VALUE_ITERATOR_TYPE) \ \ V(JS_UINT8_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_INT8_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_UINT16_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_INT16_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_UINT32_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_INT32_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FLOAT32_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FLOAT64_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_UINT8_CLAMPED_ARRAY_VALUE_ITERATOR_TYPE) \ \ V(JS_FAST_SMI_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_HOLEY_SMI_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_HOLEY_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_FAST_HOLEY_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE) \ V(JS_GENERIC_ARRAY_VALUE_ITERATOR_TYPE) \ \ V(JS_BOUND_FUNCTION_TYPE) \ V(JS_FUNCTION_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) \ V(THIN_STRING_TYPE, ThinString::kSize, thin_string, ThinString) \ V(THIN_ONE_BYTE_STRING_TYPE, ThinString::kSize, thin_one_byte_string, \ ThinOneByteString) // 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(ACCESSOR_INFO, AccessorInfo, accessor_info) \ V(ACCESSOR_PAIR, AccessorPair, accessor_pair) \ V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \ V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \ V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \ V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \ V(ALLOCATION_SITE, AllocationSite, allocation_site) \ V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento) \ V(SCRIPT, Script, script) \ V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \ V(PROMISE_RESOLVE_THENABLE_JOB_INFO, PromiseResolveThenableJobInfo, \ promise_resolve_thenable_job_info) \ V(PROMISE_REACTION_JOB_INFO, PromiseReactionJobInfo, \ promise_reaction_job_info) \ V(DEBUG_INFO, DebugInfo, debug_info) \ V(STACK_FRAME_INFO, StackFrameInfo, stack_frame_info) \ V(PROTOTYPE_INFO, PrototypeInfo, prototype_info) \ V(TUPLE2, Tuple2, tuple2) \ V(TUPLE3, Tuple3, tuple3) \ V(CONTEXT_EXTENSION, ContextExtension, context_extension) \ V(MODULE, Module, module) \ V(MODULE_INFO_ENTRY, ModuleInfoEntry, module_info_entry) \ V(ASYNC_GENERATOR_REQUEST, AsyncGeneratorRequest, async_generator_request) // 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 3 indicates whether the string consists of // two-byte characters or one-byte characters. const uint32_t kStringEncodingMask = 0x8; const uint32_t kTwoByteStringTag = 0x0; const uint32_t kOneByteStringTag = 0x8; // If bit 7 is clear, the low-order 3 bits indicate the representation // of the string. const uint32_t kStringRepresentationMask = 0x07; enum StringRepresentationTag { kSeqStringTag = 0x0, kConsStringTag = 0x1, kExternalStringTag = 0x2, kSlicedStringTag = 0x3, kThinStringTag = 0x5 }; const uint32_t kIsIndirectStringMask = 0x1; const uint32_t kIsIndirectStringTag = 0x1; STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); // NOLINT STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); // NOLINT STATIC_ASSERT((kConsStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT STATIC_ASSERT((kSlicedStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT STATIC_ASSERT((kThinStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); // If bit 7 is clear, then bit 4 indicates whether this two-byte // string actually contains one byte data. const uint32_t kOneByteDataHintMask = 0x10; const uint32_t kOneByteDataHintTag = 0x10; // If bit 7 is clear and string representation indicates an external string, // then bit 5 indicates whether the data pointer is cached. const uint32_t kShortExternalStringMask = 0x20; const uint32_t kShortExternalStringTag = 0x20; // A ConsString with an empty string as the right side is a candidate // for being shortcut by the garbage collector. We don't allocate any // non-flat internalized strings, so we do not shortcut them thereby // avoiding turning internalized strings into strings. The bit-masks // below contain the internalized bit as additional safety. // See heap.cc, mark-compact.cc and objects-visiting.cc. const uint32_t kShortcutTypeMask = kIsNotStringMask | kIsNotInternalizedMask | kStringRepresentationMask; const uint32_t kShortcutTypeTag = kConsStringTag | kNotInternalizedTag; static inline bool IsShortcutCandidate(int type) { return ((type & kShortcutTypeMask) == kShortcutTypeTag); } enum InstanceType { // 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, THIN_STRING_TYPE = kTwoByteStringTag | kThinStringTag | kNotInternalizedTag, THIN_ONE_BYTE_STRING_TYPE = kOneByteStringTag | kThinStringTag | 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, 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. ACCESSOR_INFO_TYPE, ACCESSOR_PAIR_TYPE, ACCESS_CHECK_INFO_TYPE, INTERCEPTOR_INFO_TYPE, FUNCTION_TEMPLATE_INFO_TYPE, OBJECT_TEMPLATE_INFO_TYPE, ALLOCATION_SITE_TYPE, ALLOCATION_MEMENTO_TYPE, SCRIPT_TYPE, ALIASED_ARGUMENTS_ENTRY_TYPE, PROMISE_RESOLVE_THENABLE_JOB_INFO_TYPE, PROMISE_REACTION_JOB_INFO_TYPE, DEBUG_INFO_TYPE, STACK_FRAME_INFO_TYPE, PROTOTYPE_INFO_TYPE, TUPLE2_TYPE, TUPLE3_TYPE, CONTEXT_EXTENSION_TYPE, MODULE_TYPE, MODULE_INFO_ENTRY_TYPE, ASYNC_GENERATOR_REQUEST_TYPE, FIXED_ARRAY_TYPE, TRANSITION_ARRAY_TYPE, SHARED_FUNCTION_INFO_TYPE, CELL_TYPE, WEAK_CELL_TYPE, PROPERTY_CELL_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 PADDING_TYPE_1, PADDING_TYPE_2, PADDING_TYPE_3, PADDING_TYPE_4, // 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_GLOBAL_OBJECT_TYPE, // FIRST_JS_OBJECT_TYPE JS_GLOBAL_PROXY_TYPE, // Like JS_API_OBJECT_TYPE, but requires access checks and/or has // interceptors. JS_SPECIAL_API_OBJECT_TYPE, // LAST_SPECIAL_RECEIVER_TYPE JS_VALUE_TYPE, // LAST_CUSTOM_ELEMENTS_RECEIVER JS_MESSAGE_OBJECT_TYPE, JS_DATE_TYPE, // Like JS_OBJECT_TYPE, but created from API function. JS_API_OBJECT_TYPE, JS_OBJECT_TYPE, JS_ARGUMENTS_TYPE, JS_CONTEXT_EXTENSION_OBJECT_TYPE, JS_GENERATOR_OBJECT_TYPE, JS_ASYNC_GENERATOR_OBJECT_TYPE, JS_MODULE_NAMESPACE_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_WEAK_MAP_TYPE, JS_WEAK_SET_TYPE, JS_PROMISE_CAPABILITY_TYPE, JS_PROMISE_TYPE, JS_REGEXP_TYPE, JS_ERROR_TYPE, JS_ASYNC_FROM_SYNC_ITERATOR_TYPE, JS_STRING_ITERATOR_TYPE, JS_TYPED_ARRAY_KEY_ITERATOR_TYPE, JS_FAST_ARRAY_KEY_ITERATOR_TYPE, JS_GENERIC_ARRAY_KEY_ITERATOR_TYPE, JS_UINT8_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_INT8_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_UINT16_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_INT16_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_UINT32_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_INT32_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FLOAT32_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FLOAT64_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_UINT8_CLAMPED_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FAST_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FAST_HOLEY_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FAST_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FAST_HOLEY_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FAST_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_FAST_HOLEY_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_GENERIC_ARRAY_KEY_VALUE_ITERATOR_TYPE, JS_UINT8_ARRAY_VALUE_ITERATOR_TYPE, JS_INT8_ARRAY_VALUE_ITERATOR_TYPE, JS_UINT16_ARRAY_VALUE_ITERATOR_TYPE, JS_INT16_ARRAY_VALUE_ITERATOR_TYPE, JS_UINT32_ARRAY_VALUE_ITERATOR_TYPE, JS_INT32_ARRAY_VALUE_ITERATOR_TYPE, JS_FLOAT32_ARRAY_VALUE_ITERATOR_TYPE, JS_FLOAT64_ARRAY_VALUE_ITERATOR_TYPE, JS_UINT8_CLAMPED_ARRAY_VALUE_ITERATOR_TYPE, JS_FAST_SMI_ARRAY_VALUE_ITERATOR_TYPE, JS_FAST_HOLEY_SMI_ARRAY_VALUE_ITERATOR_TYPE, JS_FAST_ARRAY_VALUE_ITERATOR_TYPE, JS_FAST_HOLEY_ARRAY_VALUE_ITERATOR_TYPE, JS_FAST_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE, JS_FAST_HOLEY_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE, JS_GENERIC_ARRAY_VALUE_ITERATOR_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_GLOBAL_OBJECT_TYPE, LAST_JS_OBJECT_TYPE = LAST_TYPE, // Boundary for testing JSReceivers that need special property lookup handling LAST_SPECIAL_RECEIVER_TYPE = JS_SPECIAL_API_OBJECT_TYPE, // Boundary case for testing JSReceivers that may have elements while having // an empty fixed array as elements backing store. This is true for string // wrappers. LAST_CUSTOM_ELEMENTS_RECEIVER = JS_VALUE_TYPE, FIRST_ARRAY_KEY_ITERATOR_TYPE = JS_TYPED_ARRAY_KEY_ITERATOR_TYPE, LAST_ARRAY_KEY_ITERATOR_TYPE = JS_GENERIC_ARRAY_KEY_ITERATOR_TYPE, FIRST_ARRAY_KEY_VALUE_ITERATOR_TYPE = JS_UINT8_ARRAY_KEY_VALUE_ITERATOR_TYPE, LAST_ARRAY_KEY_VALUE_ITERATOR_TYPE = JS_GENERIC_ARRAY_KEY_VALUE_ITERATOR_TYPE, FIRST_ARRAY_VALUE_ITERATOR_TYPE = JS_UINT8_ARRAY_VALUE_ITERATOR_TYPE, LAST_ARRAY_VALUE_ITERATOR_TYPE = JS_GENERIC_ARRAY_VALUE_ITERATOR_TYPE, FIRST_ARRAY_ITERATOR_TYPE = FIRST_ARRAY_KEY_ITERATOR_TYPE, LAST_ARRAY_ITERATOR_TYPE = LAST_ARRAY_VALUE_ITERATOR_TYPE, }; STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType); STATIC_ASSERT(JS_API_OBJECT_TYPE == Internals::kJSApiObjectType); STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType); STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType); STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType); V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, InstanceType instance_type); #define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \ V(BYTECODE_ARRAY_CONSTANT_POOL_SUB_TYPE) \ V(BYTECODE_ARRAY_HANDLER_TABLE_SUB_TYPE) \ V(CODE_STUBS_TABLE_SUB_TYPE) \ V(COMPILATION_CACHE_TABLE_SUB_TYPE) \ V(CONTEXT_SUB_TYPE) \ V(COPY_ON_WRITE_SUB_TYPE) \ V(DEOPTIMIZATION_DATA_SUB_TYPE) \ V(DESCRIPTOR_ARRAY_SUB_TYPE) \ V(EMBEDDED_OBJECT_SUB_TYPE) \ V(ENUM_CACHE_SUB_TYPE) \ V(ENUM_INDICES_CACHE_SUB_TYPE) \ V(DEPENDENT_CODE_SUB_TYPE) \ V(DICTIONARY_ELEMENTS_SUB_TYPE) \ V(DICTIONARY_PROPERTIES_SUB_TYPE) \ V(EMPTY_PROPERTIES_DICTIONARY_SUB_TYPE) \ V(FAST_ELEMENTS_SUB_TYPE) \ V(FAST_PROPERTIES_SUB_TYPE) \ V(FAST_TEMPLATE_INSTANTIATIONS_CACHE_SUB_TYPE) \ V(HANDLER_TABLE_SUB_TYPE) \ V(JS_COLLECTION_SUB_TYPE) \ V(JS_WEAK_COLLECTION_SUB_TYPE) \ V(MAP_CODE_CACHE_SUB_TYPE) \ V(NOSCRIPT_SHARED_FUNCTION_INFOS_SUB_TYPE) \ V(NUMBER_STRING_CACHE_SUB_TYPE) \ V(OBJECT_TO_CODE_SUB_TYPE) \ V(OPTIMIZED_CODE_LITERALS_SUB_TYPE) \ V(OPTIMIZED_CODE_MAP_SUB_TYPE) \ V(PROTOTYPE_USERS_SUB_TYPE) \ V(REGEXP_MULTIPLE_CACHE_SUB_TYPE) \ V(RETAINED_MAPS_SUB_TYPE) \ V(SCOPE_INFO_SUB_TYPE) \ V(SCRIPT_LIST_SUB_TYPE) \ V(SERIALIZED_TEMPLATES_SUB_TYPE) \ V(SHARED_FUNCTION_INFOS_SUB_TYPE) \ V(SINGLE_CHARACTER_STRING_CACHE_SUB_TYPE) \ V(SLOW_TEMPLATE_INSTANTIATIONS_CACHE_SUB_TYPE) \ V(STRING_SPLIT_CACHE_SUB_TYPE) \ V(STRING_TABLE_SUB_TYPE) \ V(TEMPLATE_INFO_SUB_TYPE) \ V(FEEDBACK_VECTOR_SUB_TYPE) \ V(FEEDBACK_METADATA_SUB_TYPE) \ V(WEAK_NEW_SPACE_OBJECT_TO_CODE_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 = WEAK_NEW_SPACE_OBJECT_TO_CODE_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 }; class AbstractCode; class AccessorPair; class AllocationSite; class AllocationSiteCreationContext; class AllocationSiteUsageContext; class Cell; class ConsString; class ElementsAccessor; class FindAndReplacePattern; class FixedArrayBase; class FunctionLiteral; class JSGlobalObject; class KeyAccumulator; class LayoutDescriptor; class LookupIterator; class FieldType; class Module; class ModuleDescriptor; class ModuleInfoEntry; class ModuleInfo; class ObjectHashTable; class ObjectVisitor; class PropertyCell; class PropertyDescriptor; class RootVisitor; class SafepointEntry; class SharedFunctionInfo; class StringStream; class TypeFeedbackInfo; class FeedbackMetadata; class FeedbackVector; class WeakCell; class TransitionArray; class TemplateList; // A template-ized version of the IsXXX functions. template inline bool Is(Object* obj); #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(LayoutDescriptor) \ V(HeapObject) \ V(Primitive) \ V(Number) #define HEAP_OBJECT_TYPE_LIST(V) \ V(AbstractCode) \ V(AccessCheckNeeded) \ V(ArrayList) \ V(BoilerplateDescription) \ V(Boolean) \ V(BreakPointInfo) \ V(ByteArray) \ V(BytecodeArray) \ V(Callable) \ V(CallHandlerInfo) \ V(Cell) \ V(Code) \ V(CodeCacheHashTable) \ V(CompilationCacheTable) \ V(ConsString) \ V(ConstantElementsPair) \ V(Constructor) \ V(Context) \ V(DeoptimizationInputData) \ V(DeoptimizationOutputData) \ V(DependentCode) \ V(DescriptorArray) \ V(Dictionary) \ V(External) \ V(ExternalOneByteString) \ V(ExternalString) \ V(ExternalTwoByteString) \ V(FeedbackMetadata) \ V(FeedbackVector) \ V(Filler) \ V(FixedArray) \ V(FixedArrayBase) \ V(FixedDoubleArray) \ V(FixedFloat32Array) \ V(FixedFloat64Array) \ V(FixedInt16Array) \ V(FixedInt32Array) \ V(FixedInt8Array) \ V(FixedTypedArrayBase) \ V(FixedUint16Array) \ V(FixedUint32Array) \ V(FixedUint8Array) \ V(FixedUint8ClampedArray) \ V(Foreign) \ V(FrameArray) \ V(FreeSpace) \ V(Function) \ V(HandlerTable) \ V(HashTable) \ V(HeapNumber) \ V(InternalizedString) \ V(JSArgumentsObject) \ V(JSArray) \ V(JSArrayBuffer) \ V(JSArrayBufferView) \ V(JSArrayIterator) \ V(JSAsyncFromSyncIterator) \ V(JSAsyncGeneratorObject) \ V(JSBoundFunction) \ V(JSCollection) \ V(JSContextExtensionObject) \ V(JSDataView) \ V(JSDate) \ V(JSError) \ V(JSFunction) \ V(JSGeneratorObject) \ V(JSGlobalObject) \ V(JSGlobalProxy) \ V(JSMap) \ V(JSMapIterator) \ V(JSMessageObject) \ V(JSModuleNamespace) \ V(JSObject) \ V(JSPromise) \ V(JSPromiseCapability) \ V(JSProxy) \ V(JSReceiver) \ V(JSRegExp) \ V(JSSet) \ V(JSSetIterator) \ V(JSSloppyArgumentsObject) \ V(JSStringIterator) \ V(JSTypedArray) \ V(JSValue) \ V(JSWeakCollection) \ V(JSWeakMap) \ V(JSWeakSet) \ V(Map) \ V(MapCache) \ V(ModuleInfo) \ V(MutableHeapNumber) \ V(Name) \ V(NativeContext) \ V(NormalizedMapCache) \ V(ObjectHashSet) \ V(ObjectHashTable) \ V(Oddball) \ V(OrderedHashTable) \ V(PropertyCell) \ V(RegExpMatchInfo) \ V(ScopeInfo) \ V(ScriptContextTable) \ V(SeqOneByteString) \ V(SeqString) \ V(SeqTwoByteString) \ V(SharedFunctionInfo) \ V(SlicedString) \ V(SloppyArgumentsElements) \ V(SourcePositionTableWithFrameCache) \ V(String) \ V(StringSet) \ V(StringTable) \ V(StringWrapper) \ V(Struct) \ V(Symbol) \ V(TemplateInfo) \ V(TemplateList) \ V(ThinString) \ V(TransitionArray) \ V(TypeFeedbackInfo) \ V(Undetectable) \ V(UniqueName) \ V(UnseededNumberDictionary) \ V(WeakCell) \ V(WeakFixedArray) \ V(WeakHashTable) #define ODDBALL_LIST(V) \ V(Undefined, undefined_value) \ V(Null, null_value) \ V(TheHole, the_hole_value) \ V(Exception, exception) \ V(Uninitialized, uninitialized_value) \ V(True, true_value) \ V(False, false_value) \ V(ArgumentsMarker, arguments_marker) \ V(OptimizedOut, optimized_out) \ V(StaleRegister, stale_register) // 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 #define IS_TYPE_FUNCTION_DECL(Type, Value) \ INLINE(bool Is##Type(Isolate* isolate) const); ODDBALL_LIST(IS_TYPE_FUNCTION_DECL) #undef IS_TYPE_FUNCTION_DECL INLINE(bool IsNullOrUndefined(Isolate* isolate) const); // 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(); \ } \ } while (false) #define MAYBE_RETURN(call, value) \ do { \ if ((call).IsNothing()) return value; \ } while (false) #define MAYBE_RETURN_NULL(call) MAYBE_RETURN(call, MaybeHandle()) #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 IsArray(Handle object); INLINE(bool IsNameDictionary() const); INLINE(bool IsGlobalDictionary() const); INLINE(bool IsSeededNumberDictionary() const); INLINE(bool IsOrderedHashSet() const); INLINE(bool IsOrderedHashMap() const); // Extract the number. inline double Number() const; INLINE(bool IsNaN() const); INLINE(bool IsMinusZero() const); V8_EXPORT_PRIVATE bool ToInt32(int32_t* value); inline 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 OptimalType(Isolate* isolate, Representation representation); inline static Handle NewStorageFor(Isolate* isolate, Handle object, Representation representation); inline static Handle WrapForRead(Isolate* isolate, Handle 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 Compare(Handle x, Handle y); // ES6 section 7.2.12 Abstract Equality Comparison MUST_USE_RESULT static Maybe Equals(Handle x, Handle y); // ES6 section 7.2.13 Strict Equality Comparison bool StrictEquals(Object* that); // ES6 section 7.1.13 ToObject // Convert to a JSObject if needed. // native_context is used when creating wrapper object. // // Passing a non-null method_name allows us to give a more informative // error message for those cases where ToObject is being called on // the receiver of a built-in method. MUST_USE_RESULT static inline MaybeHandle ToObject( Isolate* isolate, Handle object, const char* method_name = nullptr); MUST_USE_RESULT static MaybeHandle ToObject( Isolate* isolate, Handle object, Handle native_context, const char* method_name = nullptr); // ES6 section 9.2.1.2, OrdinaryCallBindThis for sloppy callee. MUST_USE_RESULT static MaybeHandle ConvertReceiver( Isolate* isolate, Handle object); // ES6 section 7.1.14 ToPropertyKey MUST_USE_RESULT static inline MaybeHandle ToName(Isolate* isolate, Handle input); // ES6 section 7.1.1 ToPrimitive MUST_USE_RESULT static inline MaybeHandle ToPrimitive( Handle input, ToPrimitiveHint hint = ToPrimitiveHint::kDefault); // ES6 section 7.1.3 ToNumber MUST_USE_RESULT static inline MaybeHandle ToNumber( Handle input); // ES6 section 7.1.4 ToInteger MUST_USE_RESULT static inline MaybeHandle ToInteger( Isolate* isolate, Handle input); // ES6 section 7.1.5 ToInt32 MUST_USE_RESULT static inline MaybeHandle ToInt32( Isolate* isolate, Handle input); // ES6 section 7.1.6 ToUint32 MUST_USE_RESULT inline static MaybeHandle ToUint32( Isolate* isolate, Handle input); // ES6 section 7.1.12 ToString MUST_USE_RESULT static inline MaybeHandle ToString( Isolate* isolate, Handle input); static Handle NoSideEffectsToString(Isolate* isolate, Handle input); // ES6 section 7.1.14 ToPropertyKey MUST_USE_RESULT static inline MaybeHandle ToPropertyKey( Isolate* isolate, Handle value); // ES6 section 7.1.15 ToLength MUST_USE_RESULT static inline MaybeHandle ToLength( Isolate* isolate, Handle input); // ES6 section 7.1.17 ToIndex MUST_USE_RESULT static inline MaybeHandle ToIndex( Isolate* isolate, Handle input, MessageTemplate::Template error_index); // ES6 section 7.3.9 GetMethod MUST_USE_RESULT static MaybeHandle GetMethod( Handle receiver, Handle name); // ES6 section 7.3.17 CreateListFromArrayLike MUST_USE_RESULT static MaybeHandle CreateListFromArrayLike( Isolate* isolate, Handle object, ElementTypes element_types); // Get length property and apply ToLength. MUST_USE_RESULT static MaybeHandle GetLengthFromArrayLike( Isolate* isolate, Handle object); // ES6 section 12.5.6 The typeof Operator static Handle TypeOf(Isolate* isolate, Handle object); // ES6 section 12.6 Multiplicative Operators MUST_USE_RESULT static MaybeHandle Multiply(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle Divide(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle Modulus(Isolate* isolate, Handle lhs, Handle rhs); // ES6 section 12.7 Additive Operators MUST_USE_RESULT static MaybeHandle Add(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle Subtract(Isolate* isolate, Handle lhs, Handle rhs); // ES6 section 12.8 Bitwise Shift Operators MUST_USE_RESULT static MaybeHandle ShiftLeft(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle ShiftRight(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle ShiftRightLogical( Isolate* isolate, Handle lhs, Handle rhs); // ES6 section 12.9 Relational Operators MUST_USE_RESULT static inline Maybe GreaterThan(Handle x, Handle y); MUST_USE_RESULT static inline Maybe GreaterThanOrEqual( Handle x, Handle y); MUST_USE_RESULT static inline Maybe LessThan(Handle x, Handle y); MUST_USE_RESULT static inline Maybe LessThanOrEqual(Handle x, Handle y); // ES6 section 12.11 Binary Bitwise Operators MUST_USE_RESULT static MaybeHandle BitwiseAnd(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle BitwiseOr(Isolate* isolate, Handle lhs, Handle rhs); MUST_USE_RESULT static MaybeHandle BitwiseXor(Isolate* isolate, Handle lhs, Handle rhs); // ES6 section 7.3.19 OrdinaryHasInstance (C, O). MUST_USE_RESULT static MaybeHandle OrdinaryHasInstance( Isolate* isolate, Handle callable, Handle object); // ES6 section 12.10.4 Runtime Semantics: InstanceofOperator(O, C) MUST_USE_RESULT static MaybeHandle InstanceOf( Isolate* isolate, Handle object, Handle callable); V8_EXPORT_PRIVATE MUST_USE_RESULT static MaybeHandle GetProperty( LookupIterator* it); // 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 SetProperty(LookupIterator* it, Handle value, LanguageMode language_mode, StoreFromKeyed store_mode); MUST_USE_RESULT static MaybeHandle SetProperty( Handle object, Handle name, Handle value, LanguageMode language_mode, StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED); MUST_USE_RESULT static inline MaybeHandle SetPropertyOrElement( Handle object, Handle name, Handle value, LanguageMode language_mode, StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED); MUST_USE_RESULT static Maybe SetSuperProperty( LookupIterator* it, Handle value, LanguageMode language_mode, StoreFromKeyed store_mode); MUST_USE_RESULT static Maybe CannotCreateProperty( Isolate* isolate, Handle receiver, Handle name, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe WriteToReadOnlyProperty( LookupIterator* it, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe WriteToReadOnlyProperty( Isolate* isolate, Handle receiver, Handle name, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe RedefineIncompatibleProperty( Isolate* isolate, Handle name, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe SetDataProperty(LookupIterator* it, Handle value); MUST_USE_RESULT static Maybe AddDataProperty( LookupIterator* it, Handle value, PropertyAttributes attributes, ShouldThrow should_throw, StoreFromKeyed store_mode); MUST_USE_RESULT static inline MaybeHandle GetPropertyOrElement( Handle object, Handle name); MUST_USE_RESULT static inline MaybeHandle GetPropertyOrElement( Handle receiver, Handle name, Handle holder); MUST_USE_RESULT static inline MaybeHandle GetProperty( Handle object, Handle name); MUST_USE_RESULT static MaybeHandle GetPropertyWithAccessor( LookupIterator* it); MUST_USE_RESULT static Maybe SetPropertyWithAccessor( LookupIterator* it, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static MaybeHandle GetPropertyWithDefinedGetter( Handle receiver, Handle getter); MUST_USE_RESULT static Maybe SetPropertyWithDefinedSetter( Handle receiver, Handle setter, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static inline MaybeHandle GetElement( Isolate* isolate, Handle object, uint32_t index); MUST_USE_RESULT static inline MaybeHandle SetElement( Isolate* isolate, Handle object, uint32_t index, Handle value, LanguageMode language_mode); // Returns the permanent hash code associated with this object. May return // undefined if not yet created. Object* GetHash(); // Returns the permanent hash code associated with this object depending on // the actual object type. May create and store a hash code if needed and none // exists. static Smi* GetOrCreateHash(Isolate* isolate, Handle 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. V8_EXPORT_PRIVATE bool SameValue(Object* other); // Checks whether this object has the same value as the given one. // +0 and -0 are treated equal. Everything else is the same as SameValue. // This function is implemented according to ES6, section 7.2.4 and is used // by ES6 Map and Set. bool SameValueZero(Object* other); // ES6 section 9.4.2.3 ArraySpeciesCreate (part of it) MUST_USE_RESULT static MaybeHandle ArraySpeciesConstructor( Isolate* isolate, Handle original_array); // ES6 section 7.3.20 SpeciesConstructor ( O, defaultConstructor ) MUST_USE_RESULT static MaybeHandle SpeciesConstructor( Isolate* isolate, Handle recv, Handle default_ctor); // Tries to convert an object to an array length. Returns true and sets the // output parameter if it succeeds. inline bool ToArrayLength(uint32_t* index); // 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 the result of iterating over the object is the same // (including observable effects) as simply accessing the properties between 0 // and length. bool IterationHasObservableEffects(); DECLARE_VERIFIER(Object) #ifdef VERIFY_HEAP // Verify a pointer is a valid object pointer. static void VerifyPointer(Object* p); #endif inline void VerifyApiCallResultType(); // Prints this object without details. void ShortPrint(FILE* out = stdout); // Prints this object without details to a message accumulator. void ShortPrint(StringStream* accumulator); void ShortPrint(std::ostream& os); // NOLINT 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 StringStream; // Return the map of the root of object's prototype chain. Map* GetPrototypeChainRootMap(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 SetPropertyInternal( LookupIterator* it, Handle value, LanguageMode language_mode, StoreFromKeyed store_mode, bool* found); MUST_USE_RESULT static MaybeHandle ConvertToName(Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToPropertyKey( Isolate* isolate, Handle value); MUST_USE_RESULT static MaybeHandle ConvertToString( Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToNumber( Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToInteger( Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToInt32( Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToUint32( Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToLength( Isolate* isolate, Handle input); MUST_USE_RESULT static MaybeHandle ConvertToIndex( Isolate* isolate, Handle input, MessageTemplate::Template error_index); DISALLOW_IMPLICIT_CONSTRUCTORS(Object); }; // In objects.h to be usable without objects-inl.h inclusion. bool Object::IsSmi() const { return HAS_SMI_TAG(this); } bool Object::IsHeapObject() const { DCHECK_EQ(!IsSmi(), Internals::HasHeapObjectTag(this)); return !IsSmi(); } struct Brief { explicit Brief(const Object* const v) : value(v) {} const Object* value; }; V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, const Brief& v); // Smi represents integer Numbers that can be stored in 31 bits. // Smis are immediate which means they are NOT allocated in the heap. // The this pointer has the following format: [31 bit signed int] 0 // For long smis it has the following format: // [32 bit signed int] [31 bits zero padding] 0 // Smi stands for small integer. class Smi: public Object { public: // Returns the integer value. inline int value() const { return Internals::SmiValue(this); } inline Smi* ToUint32Smi() { if (value() <= 0) return Smi::kZero; return Smi::FromInt(static_cast(value())); } // Convert a value to a Smi object. static inline Smi* FromInt(int value) { DCHECK(Smi::IsValid(value)); return reinterpret_cast(Internals::IntToSmi(value)); } static inline Smi* FromIntptr(intptr_t value) { DCHECK(Smi::IsValid(value)); int smi_shift_bits = kSmiTagSize + kSmiShiftSize; return reinterpret_cast((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. V8_EXPORT_PRIVATE void SmiPrint(std::ostream& os) const; // NOLINT DECLARE_VERIFIER(Smi) static constexpr Smi* const kZero = nullptr; static const int kMinValue = (static_cast(-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() const; // Create a map word from a forwarding address. static inline MapWord FromForwardingAddress(HeapObject* object); // View this map word as a forwarding address. inline HeapObject* ToForwardingAddress(); static inline MapWord FromRawValue(uintptr_t value) { return MapWord(value); } inline uintptr_t ToRawValue() { return value_; } private: // HeapObject calls the private constructor and directly reads the value. friend class HeapObject; explicit MapWord(uintptr_t value) : value_(value) {} uintptr_t value_; }; // HeapObject is the superclass for all classes describing heap allocated // objects. class HeapObject: public Object { public: // [map]: Contains a map which contains the object's reflective // information. inline Map* map() const; inline void set_map(Map* value); // 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; #define IS_TYPE_FUNCTION_DECL(Type) INLINE(bool Is##Type() const); HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) #undef IS_TYPE_FUNCTION_DECL #define IS_TYPE_FUNCTION_DECL(Type, Value) \ INLINE(bool Is##Type(Isolate* isolate) const); ODDBALL_LIST(IS_TYPE_FUNCTION_DECL) #undef IS_TYPE_FUNCTION_DECL INLINE(bool IsNullOrUndefined(Isolate* isolate) const); #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \ INLINE(bool Is##Name() const); STRUCT_LIST(DECLARE_STRUCT_PREDICATE) #undef DECLARE_STRUCT_PREDICATE // Converts an address to a HeapObject pointer. static inline HeapObject* FromAddress(Address address) { DCHECK_TAG_ALIGNED(address); return reinterpret_cast(address + kHeapObjectTag); } // Returns the address of this HeapObject. inline Address address() { return reinterpret_cast
(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 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 inline void IterateBodyFast(ObjectVisitor* v); template 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 object, Handle name, Handle 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 class FixedBodyDescriptor; template 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); inline uint64_t value_as_bits() const; inline void set_value_as_bits(uint64_t bits); DECLARE_CAST(HeapNumber) // Dispatched behavior. bool HeapNumberBooleanValue(); V8_EXPORT_PRIVATE 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); }; enum EnsureElementsMode { DONT_ALLOW_DOUBLE_ELEMENTS, ALLOW_COPIED_DOUBLE_ELEMENTS, ALLOW_CONVERTED_DOUBLE_ELEMENTS }; // Indicator for one component of an AccessorPair. enum AccessorComponent { ACCESSOR_GETTER, ACCESSOR_SETTER }; enum class GetKeysConversion { kKeepNumbers, kConvertToString }; enum class KeyCollectionMode { kOwnOnly = static_cast(v8::KeyCollectionMode::kOwnOnly), kIncludePrototypes = static_cast(v8::KeyCollectionMode::kIncludePrototypes) }; enum class AllocationSiteUpdateMode { kUpdate, kCheckOnly }; // 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 object, Handle name, int entry); DECLARE_CAST(JSReceiver) // ES6 section 7.1.1 ToPrimitive MUST_USE_RESULT static MaybeHandle ToPrimitive( Handle receiver, ToPrimitiveHint hint = ToPrimitiveHint::kDefault); // ES6 section 7.1.1.1 OrdinaryToPrimitive MUST_USE_RESULT static MaybeHandle OrdinaryToPrimitive( Handle receiver, OrdinaryToPrimitiveHint hint); static MaybeHandle GetFunctionRealm(Handle receiver); // Get the first non-hidden prototype. static inline MaybeHandle GetPrototype(Isolate* isolate, Handle receiver); MUST_USE_RESULT static Maybe HasInPrototypeChain( Isolate* isolate, Handle object, Handle proto); // Reads all enumerable own properties of source and adds them to // target, using either Set or CreateDataProperty depending on the // use_set argument. This only copies values not present in the // maybe_excluded_properties list. MUST_USE_RESULT static Maybe SetOrCopyDataProperties( Isolate* isolate, Handle target, Handle source, const ScopedVector>* excluded_properties = nullptr, bool use_set = true); // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6. MUST_USE_RESULT static Maybe HasProperty(LookupIterator* it); MUST_USE_RESULT static inline Maybe HasProperty( Handle object, Handle name); MUST_USE_RESULT static inline Maybe HasElement( Handle object, uint32_t index); MUST_USE_RESULT static inline Maybe HasOwnProperty( Handle object, Handle name); MUST_USE_RESULT static inline Maybe HasOwnProperty( Handle object, uint32_t index); MUST_USE_RESULT static inline MaybeHandle GetProperty( Isolate* isolate, Handle receiver, const char* key); MUST_USE_RESULT static inline MaybeHandle GetProperty( Handle receiver, Handle name); MUST_USE_RESULT static inline MaybeHandle GetElement( Isolate* isolate, Handle receiver, uint32_t index); // Implementation of ES6 [[Delete]] MUST_USE_RESULT static Maybe DeletePropertyOrElement( Handle object, Handle name, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static Maybe DeleteProperty( Handle object, Handle name, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static Maybe DeleteProperty(LookupIterator* it, LanguageMode language_mode); MUST_USE_RESULT static Maybe DeleteElement( Handle object, uint32_t index, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static Object* DefineProperty(Isolate* isolate, Handle object, Handle name, Handle attributes); MUST_USE_RESULT static MaybeHandle DefineProperties( Isolate* isolate, Handle object, Handle properties); // "virtual" dispatcher to the correct [[DefineOwnProperty]] implementation. MUST_USE_RESULT static Maybe DefineOwnProperty( Isolate* isolate, Handle object, Handle key, PropertyDescriptor* desc, ShouldThrow should_throw); // ES6 7.3.4 (when passed DONT_THROW) MUST_USE_RESULT static Maybe CreateDataProperty( LookupIterator* it, Handle value, ShouldThrow should_throw); // ES6 9.1.6.1 MUST_USE_RESULT static Maybe OrdinaryDefineOwnProperty( Isolate* isolate, Handle object, Handle key, PropertyDescriptor* desc, ShouldThrow should_throw); MUST_USE_RESULT static Maybe OrdinaryDefineOwnProperty( LookupIterator* it, PropertyDescriptor* desc, ShouldThrow should_throw); // ES6 9.1.6.2 MUST_USE_RESULT static Maybe IsCompatiblePropertyDescriptor( Isolate* isolate, bool extensible, PropertyDescriptor* desc, PropertyDescriptor* current, Handle 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 ValidateAndApplyPropertyDescriptor( Isolate* isolate, LookupIterator* it, bool extensible, PropertyDescriptor* desc, PropertyDescriptor* current, ShouldThrow should_throw, Handle property_name = Handle()); V8_EXPORT_PRIVATE MUST_USE_RESULT static Maybe GetOwnPropertyDescriptor( Isolate* isolate, Handle object, Handle key, PropertyDescriptor* desc); MUST_USE_RESULT static Maybe 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 SetIntegrityLevel( Handle object, IntegrityLevel lvl, ShouldThrow should_throw); // ES6 7.3.15 // 'level' must be SEALED or FROZEN. MUST_USE_RESULT static Maybe TestIntegrityLevel( Handle object, IntegrityLevel lvl); // ES6 [[PreventExtensions]] (when passed DONT_THROW) MUST_USE_RESULT static Maybe PreventExtensions( Handle object, ShouldThrow should_throw); MUST_USE_RESULT static Maybe IsExtensible(Handle object); // Returns the class name ([[Class]] property in the specification). V8_EXPORT_PRIVATE String* class_name(); // Returns the constructor name (the name (possibly, inferred name) of the // function that was used to instantiate the object). static Handle GetConstructorName(Handle receiver); Handle GetCreationContext(); MUST_USE_RESULT static inline Maybe GetPropertyAttributes( Handle object, Handle name); MUST_USE_RESULT static inline Maybe GetOwnPropertyAttributes(Handle object, Handle name); MUST_USE_RESULT static inline Maybe GetOwnPropertyAttributes(Handle object, uint32_t index); MUST_USE_RESULT static inline Maybe GetElementAttributes( Handle object, uint32_t index); MUST_USE_RESULT static inline Maybe GetOwnElementAttributes(Handle object, uint32_t index); MUST_USE_RESULT static Maybe GetPropertyAttributes( LookupIterator* it); // Set the object's prototype (only JSReceiver and null are allowed values). MUST_USE_RESULT static Maybe SetPrototype(Handle object, Handle value, bool from_javascript, ShouldThrow should_throw); inline static Handle GetDataProperty(Handle object, Handle name); static Handle GetDataProperty(LookupIterator* it); // Retrieves a permanent object identity hash code. The undefined value might // be returned in case no hash was created yet. static inline Object* GetIdentityHash(Isolate* isolate, Handle object); // Retrieves a permanent object identity hash code. May create and store a // hash code if needed and none exists. inline static Smi* GetOrCreateIdentityHash(Isolate* isolate, Handle object); // ES6 [[OwnPropertyKeys]] (modulo return type) MUST_USE_RESULT static inline MaybeHandle OwnPropertyKeys( Handle object); MUST_USE_RESULT static MaybeHandle GetOwnValues( Handle object, PropertyFilter filter); MUST_USE_RESULT static MaybeHandle GetOwnEntries( Handle object, PropertyFilter filter); // Layout description. static const int kPropertiesOffset = HeapObject::kHeaderSize; static const int kHeaderSize = HeapObject::kHeaderSize + kPointerSize; bool HasProxyInPrototype(Isolate* isolate); 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 New( Handle constructor, Handle new_target, Handle site = Handle::null()); // Gets global object properties. inline GlobalDictionary* global_dictionary(); static MaybeHandle GetFunctionRealm(Handle object); // [elements]: The elements (properties with names that are integers). // // Elements can be in two general modes: fast and slow. Each mode // corresponds 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 object); static inline void SetMapAndElements(Handle object, Handle map, Handle 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 HasStringWrapperElements(); 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 bool HasFastStringWrapperElements(); inline bool HasSlowStringWrapperElements(); bool HasEnumerableElements(); inline SeededNumberDictionary* element_dictionary(); // Gets slow elements. // Requires: HasFastElements(). static void EnsureWritableFastElements(Handle object); // Collects elements starting at index 0. // Undefined values are placed after non-undefined values. // Returns the number of non-undefined values. static Handle PrepareElementsForSort(Handle 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 PrepareSlowElementsForSort(Handle object, uint32_t limit); MUST_USE_RESULT static Maybe SetPropertyWithInterceptor( LookupIterator* it, ShouldThrow should_throw, Handle value); // The API currently still wants DefineOwnPropertyIgnoreAttributes to convert // AccessorInfo objects to data fields. We allow FORCE_FIELD as an exception // to the default behavior that calls the setter. enum AccessorInfoHandling { FORCE_FIELD, DONT_FORCE_FIELD }; MUST_USE_RESULT static MaybeHandle DefineOwnPropertyIgnoreAttributes( LookupIterator* it, Handle value, PropertyAttributes attributes, AccessorInfoHandling handling = DONT_FORCE_FIELD); MUST_USE_RESULT static Maybe DefineOwnPropertyIgnoreAttributes( LookupIterator* it, Handle value, PropertyAttributes attributes, ShouldThrow should_throw, AccessorInfoHandling handling = DONT_FORCE_FIELD); MUST_USE_RESULT static MaybeHandle SetOwnPropertyIgnoreAttributes( Handle object, Handle name, Handle value, PropertyAttributes attributes); MUST_USE_RESULT static MaybeHandle SetOwnElementIgnoreAttributes( Handle object, uint32_t index, Handle value, PropertyAttributes attributes); // Equivalent to one of the above depending on whether |name| can be converted // to an array index. MUST_USE_RESULT static MaybeHandle DefinePropertyOrElementIgnoreAttributes(Handle object, Handle name, Handle value, PropertyAttributes attributes = NONE); // Adds or reconfigures a property to attributes NONE. It will fail when it // cannot. MUST_USE_RESULT static Maybe CreateDataProperty( LookupIterator* it, Handle value, ShouldThrow should_throw = DONT_THROW); static void AddProperty(Handle object, Handle name, Handle value, PropertyAttributes attributes); MUST_USE_RESULT static Maybe AddDataElement( Handle receiver, uint32_t index, Handle value, PropertyAttributes attributes, ShouldThrow should_throw); MUST_USE_RESULT static MaybeHandle AddDataElement( Handle receiver, uint32_t index, Handle 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 object, Handle 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 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 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 object, Handle name, Handle value, PropertyDetails details); static void SetDictionaryElement(Handle object, uint32_t index, Handle value, PropertyAttributes attributes); static void SetDictionaryArgumentsElement(Handle object, uint32_t index, Handle value, PropertyAttributes attributes); static void OptimizeAsPrototype(Handle object, PrototypeOptimizationMode mode); static void ReoptimizeIfPrototype(Handle object); static void MakePrototypesFast(Handle receiver, WhereToStart where_to_start, Isolate* isolate); static void LazyRegisterPrototypeUser(Handle user, Isolate* isolate); static void UpdatePrototypeUserRegistration(Handle old_map, Handle new_map, Isolate* isolate); static bool UnregisterPrototypeUser(Handle user, Isolate* isolate); static void InvalidatePrototypeChains(Map* map); // Updates prototype chain tracking information when an object changes its // map from |old_map| to |new_map|. static void NotifyMapChange(Handle old_map, Handle new_map, Isolate* isolate); // Utility used by many Array builtins and runtime functions static inline bool PrototypeHasNoElements(Isolate* isolate, JSObject* object); // Alternative implementation of WeakFixedArray::NullCallback. class PrototypeRegistryCompactionCallback { public: static void Callback(Object* value, int old_index, int new_index); }; // Retrieve interceptors. inline InterceptorInfo* GetNamedInterceptor(); inline InterceptorInfo* GetIndexedInterceptor(); // Used from JSReceiver. MUST_USE_RESULT static Maybe GetPropertyAttributesWithInterceptor(LookupIterator* it); MUST_USE_RESULT static Maybe GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it); // Defines an AccessorPair property on the given object. // TODO(mstarzinger): Rename to SetAccessor(). static MaybeHandle DefineAccessor(Handle object, Handle name, Handle getter, Handle setter, PropertyAttributes attributes); static MaybeHandle DefineAccessor(LookupIterator* it, Handle getter, Handle setter, PropertyAttributes attributes); // Defines an AccessorInfo property on the given object. MUST_USE_RESULT static MaybeHandle SetAccessor( Handle object, Handle 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 GetPropertyWithInterceptor( LookupIterator* it, bool* done); static void ValidateElements(Handle object); // Makes sure that this object can contain HeapObject as elements. static inline void EnsureCanContainHeapObjectElements(Handle obj); // Makes sure that this object can contain the specified elements. static inline void EnsureCanContainElements( Handle object, Object** elements, uint32_t count, EnsureElementsMode mode); static inline void EnsureCanContainElements( Handle object, Handle elements, uint32_t length, EnsureElementsMode mode); static void EnsureCanContainElements( Handle 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! template static bool UpdateAllocationSite(Handle 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 HasRealNamedProperty( Handle object, Handle name); MUST_USE_RESULT static Maybe HasRealElementProperty( Handle object, uint32_t index); MUST_USE_RESULT static Maybe HasRealNamedCallbackProperty( Handle object, Handle name); // Get the header size for a JSObject. Used to compute the index of // embedder fields as well as the number of embedder fields. static inline int GetHeaderSize(InstanceType instance_type); inline int GetHeaderSize(); static inline int GetEmbedderFieldCount(Map* map); inline int GetEmbedderFieldCount(); inline int GetEmbedderFieldOffset(int index); inline Object* GetEmbedderField(int index); inline void SetEmbedderField(int index, Object* value); inline void SetEmbedderField(int index, Smi* value); bool WasConstructedFromApiFunction(); // Returns a new map with all transitions dropped from the object's current // map and the ElementsKind set. static Handle GetElementsTransitionMap(Handle object, ElementsKind to_kind); static void TransitionElementsKind(Handle 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 object, Handle new_map, int expected_additional_properties = 0); // Forces a prototype without any of the checks that the regular SetPrototype // would do. static void ForceSetPrototype(Handle object, Handle proto); // 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 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 NormalizeElements( Handle object); void RequireSlowElements(SeededNumberDictionary* dictionary); // Transform slow named properties to fast variants. static void MigrateSlowToFast(Handle object, int unused_property_fields, const char* reason); inline bool IsUnboxedDoubleField(FieldIndex index); // Access fast-case object properties at index. static Handle FastPropertyAt(Handle object, Representation representation, FieldIndex index); inline Object* RawFastPropertyAt(FieldIndex index); inline double RawFastDoublePropertyAt(FieldIndex index); inline uint64_t RawFastDoublePropertyAsBitsAt(FieldIndex index); inline void FastPropertyAtPut(FieldIndex index, Object* value); inline void RawFastPropertyAtPut(FieldIndex index, Object* value); inline void RawFastDoublePropertyAsBitsAtPut(FieldIndex index, uint64_t bits); inline void WriteToField(int descriptor, PropertyDetails details, 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 SetPrototype(Handle object, Handle value, bool from_javascript, ShouldThrow should_throw); // Makes the object prototype immutable // Never called from JavaScript static void SetImmutableProto(Handle object); // 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 PreventExtensions( Handle object, ShouldThrow should_throw); static bool IsExtensible(Handle object); // Copy object. enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 }; MUST_USE_RESULT static MaybeHandle DeepCopy( Handle object, AllocationSiteUsageContext* site_context, DeepCopyHints hints = kNoHints); MUST_USE_RESULT static MaybeHandle DeepWalk( Handle object, AllocationSiteCreationContext* site_context); DECLARE_CAST(JSObject) // Dispatched behavior. void JSObjectShortPrint(StringStream* accumulator); DECLARE_PRINTER(JSObject) DECLARE_VERIFIER(JSObject) #ifdef OBJECT_PRINT bool 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 object, ElementsKind from_kind, Handle from_elements, ElementsKind to_kind, Handle 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); class BodyDescriptor; class FastBodyDescriptor; // 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; // Used from Object::GetProperty(). MUST_USE_RESULT static MaybeHandle GetPropertyWithFailedAccessCheck( LookupIterator* it); MUST_USE_RESULT static Maybe SetPropertyWithFailedAccessCheck( LookupIterator* it, Handle value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe DeletePropertyWithInterceptor( LookupIterator* it, ShouldThrow should_throw); bool ReferencesObjectFromElements(FixedArray* elements, ElementsKind kind, Object* object); static Object* GetIdentityHash(Isolate* isolate, Handle object); static Smi* GetOrCreateIdentityHash(Isolate* isolate, Handle object); // Helper for fast versions of preventExtensions, seal, and freeze. // attrs is one of NONE, SEALED, or FROZEN (depending on the operation). template MUST_USE_RESULT static Maybe PreventExtensionsWithTransition( Handle object, ShouldThrow should_throw); DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject); }; // JSAccessorPropertyDescriptor is just a JSObject with a specific initial // map. This initial map adds in-object properties for "get", "set", // "enumerable" and "configurable" properties, as assigned by the // FromPropertyDescriptor function for regular accessor properties. class JSAccessorPropertyDescriptor: public JSObject { public: // Offsets of object fields. static const int kGetOffset = JSObject::kHeaderSize; static const int kSetOffset = kGetOffset + kPointerSize; static const int kEnumerableOffset = kSetOffset + kPointerSize; static const int kConfigurableOffset = kEnumerableOffset + kPointerSize; static const int kSize = kConfigurableOffset + kPointerSize; // Indices of in-object properties. static const int kGetIndex = 0; static const int kSetIndex = 1; static const int kEnumerableIndex = 2; static const int kConfigurableIndex = 3; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSAccessorPropertyDescriptor); }; // JSDataPropertyDescriptor is just a JSObject with a specific initial map. // This initial map adds in-object properties for "value", "writable", // "enumerable" and "configurable" properties, as assigned by the // FromPropertyDescriptor function for regular data properties. class JSDataPropertyDescriptor: public JSObject { public: // Offsets of object fields. static const int kValueOffset = JSObject::kHeaderSize; static const int kWritableOffset = kValueOffset + kPointerSize; static const int kEnumerableOffset = kWritableOffset + kPointerSize; static const int kConfigurableOffset = kEnumerableOffset + kPointerSize; static const int kSize = kConfigurableOffset + kPointerSize; // Indices of in-object properties. static const int kValueIndex = 0; static const int kWritableIndex = 1; static const int kEnumerableIndex = 2; static const int kConfigurableIndex = 3; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataPropertyDescriptor); }; // JSIteratorResult is just a JSObject with a specific initial map. // This initial map adds in-object properties for "done" and "value", // as specified by ES6 section 25.1.1.3 The IteratorResult Interface class JSIteratorResult: public JSObject { public: DECL_ACCESSORS(value, Object) DECL_ACCESSORS(done, Object) // Offsets of object fields. 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); }; // Common superclass for JSSloppyArgumentsObject and JSStrictArgumentsObject. class JSArgumentsObject: public JSObject { public: // Offsets of object fields. static const int kLengthOffset = JSObject::kHeaderSize; static const int kHeaderSize = kLengthOffset + kPointerSize; // Indices of in-object properties. static const int kLengthIndex = 0; DECL_ACCESSORS(length, Object) DECLARE_VERIFIER(JSArgumentsObject) DECLARE_CAST(JSArgumentsObject) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSArgumentsObject); }; // JSSloppyArgumentsObject is just a JSObject with specific initial map. // This initial map adds in-object properties for "length" and "callee". class JSSloppyArgumentsObject: public JSArgumentsObject { public: // Offsets of object fields. static const int kCalleeOffset = JSArgumentsObject::kHeaderSize; static const int kSize = kCalleeOffset + kPointerSize; // Indices of in-object properties. static const int kCalleeIndex = 1; DECL_ACCESSORS(callee, Object) DECLARE_VERIFIER(JSSloppyArgumentsObject) DECLARE_CAST(JSSloppyArgumentsObject) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSSloppyArgumentsObject); }; // JSStrictArgumentsObject is just a JSObject with specific initial map. // This initial map adds an in-object property for "length". class JSStrictArgumentsObject: public JSArgumentsObject { public: // Offsets of object fields. static const int kSize = JSArgumentsObject::kHeaderSize; DECLARE_CAST(JSStrictArgumentsObject) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSStrictArgumentsObject); }; // 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) static int GetMaxLengthForNewSpaceAllocation(ElementsKind kind); // 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 get(FixedArray* array, int index, Isolate* isolate); template MaybeHandle GetValue(Isolate* isolate, int index) const; template Handle GetValueChecked(Isolate* isolate, int index) const; // Return a grown copy if the index is bigger than the array's length. static Handle SetAndGrow(Handle array, int index, Handle value); // Setter that uses write barrier. inline void set(int index, Object* value); inline bool is_the_hole(Isolate* isolate, 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_undefined(Isolate* isolate, int index); inline void set_null(int index); inline void set_null(Isolate* isolate, int index); inline void set_the_hole(int index); inline void set_the_hole(Isolate* isolate, 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) const; // Garbage collection support. static constexpr int SizeFor(int length) { return kHeaderSize + length * kPointerSize; } // Code Generation support. static constexpr 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; // Maximally allowed length for regular (non large object space) object. STATIC_ASSERT(kMaxRegularHeapObjectSize < kMaxSize); static const int kMaxRegularLength = (kMaxRegularHeapObjectSize - kHeaderSize) / kPointerSize; // Dispatched behavior. DECLARE_PRINTER(FixedArray) DECLARE_VERIFIER(FixedArray) #ifdef DEBUG // Checks if two FixedArrays have identical contents. bool IsEqualTo(FixedArray* other); #endif typedef FlexibleBodyDescriptor 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 get(FixedDoubleArray* array, int index, Isolate* isolate); inline void set(int index, double value); inline void set_the_hole(Isolate* isolate, int index); inline void set_the_hole(int index); // Checking for the hole. inline bool is_the_hole(Isolate* isolate, int index); 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) class BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray); }; // Helper class to access FAST_ and SLOW_SLOPPY_ARGUMENTS_ELEMENTS // // +---+-----------------------+ // | 0 | Context* context | // +---------------------------+ // | 1 | FixedArray* arguments +----+ FAST_HOLEY_ELEMENTS // +---------------------------+ v-----+-----------+ // | 2 | Object* param_1_map | | 0 | the_hole | // |...| ... | | ... | ... | // |n+1| Object* param_n_map | | n-1 | the_hole | // +---------------------------+ | n | element_1 | // | ... | ... | // |n+m-1| element_m | // +-----------------+ // // Parameter maps give the index into the provided context. If a map entry is // the_hole it means that the given entry has been deleted from the arguments // object. // The arguments backing store kind depends on the ElementsKind of the outer // JSArgumentsObject: // - FAST_SLOPPY_ARGUMENTS_ELEMENTS: FAST_HOLEY_ELEMENTS // - SLOW_SLOPPY_ARGUMENTS_ELEMENTS: DICTIONARY_ELEMENTS // - SLOW_SLOPPY_ARGUMENTS_ELEMENTS: DICTIONARY_ELEMENTS class SloppyArgumentsElements : public FixedArray { public: static const int kContextIndex = 0; static const int kArgumentsIndex = 1; static const uint32_t kParameterMapStart = 2; inline Context* context(); inline FixedArray* arguments(); inline void set_arguments(FixedArray* arguments); inline uint32_t parameter_map_length(); inline Object* get_mapped_entry(uint32_t entry); inline void set_mapped_entry(uint32_t entry, Object* object); DECLARE_CAST(SloppyArgumentsElements) #ifdef VERIFY_HEAP void SloppyArgumentsElementsVerify(JSSloppyArgumentsObject* holder); #endif private: DISALLOW_IMPLICIT_CONSTRUCTORS(SloppyArgumentsElements); }; 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 Add(Handle maybe_array, Handle value, int* assigned_index = NULL); // Returns true if an entry was found and removed. bool Remove(Handle value); class NullCallback { public: static void Callback(Object* value, int old_index, int new_index) {} }; template 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::kZero; } class Iterator { public: explicit Iterator(Object* maybe_array) : list_(NULL) { Reset(maybe_array); } void Reset(Object* maybe_array); template 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 Allocate( Isolate* isolate, int size, Handle initialize_from); static void Set(Handle array, int index, Handle 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. // // ArrayList is a FixedArray with static convenience methods for adding more // elements. The Length() method returns the number of elements in the list, not // the allocated size. The number of elements is stored at kLengthIndex and is // updated with every insertion. The elements of the ArrayList are stored in the // underlying FixedArray starting at kFirstIndex. class ArrayList : public FixedArray { public: enum AddMode { kNone, // Use this if GC can delete elements from the array. kReloadLengthAfterAllocation, }; static Handle Add(Handle array, Handle obj, AddMode mode = kNone); static Handle Add(Handle array, Handle obj1, Handle obj2, AddMode = kNone); static Handle New(Isolate* isolate, int size); // Returns the number of elements in the list, not the allocated size, which // is length(). Lower and upper case length() return different results! inline int Length() const; // Sets the Length() as used by Elements(). Does not change the underlying // storage capacity, i.e., length(). inline void SetLength(int length); inline Object* Get(int index) const; inline Object** Slot(int index); // Set the element at index to obj. The underlying array must be large enough. // If you need to grow the ArrayList, use the static Add() methods instead. inline void Set(int index, Object* obj, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Set the element at index to undefined. This does not change the Length(). inline void Clear(int index, Object* undefined); // Return a copy of the list of size Length() without the first entry. The // number returned by Length() is stored in the first entry. Handle Elements() const; bool IsFull(); DECLARE_CAST(ArrayList) private: static Handle EnsureSpace(Handle array, int length); static const int kLengthIndex = 0; static const int kFirstIndex = 1; DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList); }; enum SearchMode { ALL_ENTRIES, VALID_ENTRIES }; template inline int Search(T* array, Name* name, int valid_entries = 0, int* out_insertion_index = NULL); // 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 New(Isolate* isolate); MUST_USE_RESULT MaybeHandle Get(Handle fast_map, PropertyNormalizationMode mode); void Set(Handle fast_map, Handle normalized_map); void Clear(); DECLARE_CAST(NormalizedMapCache) static inline bool IsNormalizedMapCache(const HeapObject* obj); DECLARE_VERIFIER(NormalizedMapCache) private: static const int kEntries = 64; static inline int GetIndex(Handle map); // The following declarations hide base class methods. Object* get(int index); void set(int index, Object* value); }; // 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 , handler-data ] // 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, // The handler will (likely) rethrow the exception. CAUGHT, // The exception will be caught by the handler. PROMISE, // The exception will be caught and cause a promise rejection. DESUGARING, // The exception will be caught, but both the exception and the // catching are part of a desugaring and should therefore not // be visible to the user (we won't notify the debugger of such // exceptions). ASYNC_AWAIT, // The exception will be caught and cause a promise rejection // in the desugaring of an async function, so special // async/await handling in the debugger can take place. }; // Getters for handler table based on ranges. inline int GetRangeStart(int index) const; inline int GetRangeEnd(int index) const; inline int GetRangeHandler(int index) const; inline int GetRangeData(int index) const; // Setters 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 SetRangeData(int index, int value); // Setters for handler table based on return addresses. inline void SetReturnOffset(int index, int value); inline void SetReturnHandler(int index, int offset); // Lookup handler in a table based on ranges. The {pc_offset} is an offset to // the start of the potentially throwing instruction (using return addresses // for this value would be invalid). int LookupRange(int pc_offset, int* data, CatchPrediction* prediction); // Lookup handler in a table based on return addresses. int LookupReturn(int pc_offset); // Returns the number of entries in the table. inline int NumberOfRangeEntries() const; // 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) #ifdef 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 kRangeDataIndex = 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 {}; class HandlerOffsetField : public BitField {}; }; // 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); // Copy in / copy out whole byte slices. inline void copy_out(int index, byte* buffer, int length); inline void copy_in(int index, const byte* buffer, int length); // Treat contents as an int array. inline int get_int(int index); inline void set_int(int index, int value); 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; class BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray); }; // Wrapper class for ByteArray which can store arbitrary C++ classes, as long // as they can be copied with memcpy. template class PodArray : public ByteArray { public: static Handle> New(Isolate* isolate, int length, PretenureFlag pretenure = NOT_TENURED); void copy_out(int index, T* result) { ByteArray::copy_out(index * sizeof(T), reinterpret_cast(result), sizeof(T)); } T get(int index) { T result; copy_out(index, &result); return result; } void set(int index, const T& value) { copy_in(index * sizeof(T), reinterpret_cast(&value), sizeof(T)); } int length() { return ByteArray::length() / sizeof(T); } DECLARE_CAST(PodArray) private: DISALLOW_IMPLICIT_CONSTRUCTORS(PodArray); }; // BytecodeArray represents a sequence of interpreter bytecodes. class BytecodeArray : public FixedArrayBase { public: #define DECLARE_BYTECODE_AGE_ENUM(X) k##X##BytecodeAge, enum Age { kNoAgeBytecodeAge = 0, CODE_AGE_LIST(DECLARE_BYTECODE_AGE_ENUM) kAfterLastBytecodeAge, kFirstBytecodeAge = kNoAgeBytecodeAge, kLastBytecodeAge = kAfterLastBytecodeAge - 1, kBytecodeAgeCount = kAfterLastBytecodeAge - kFirstBytecodeAge - 1, kIsOldBytecodeAge = kSexagenarianBytecodeAge }; #undef DECLARE_BYTECODE_AGE_ENUM 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 profiling count. inline int interrupt_budget() const; inline void set_interrupt_budget(int interrupt_budget); // Accessors for OSR loop nesting level. inline int osr_loop_nesting_level() const; inline void set_osr_loop_nesting_level(int depth); // Accessors for bytecode's code age. inline Age bytecode_age() const; inline void set_bytecode_age(Age age); // Accessors for the constant pool. DECL_ACCESSORS(constant_pool, FixedArray) // Accessors for handler table containing offsets of exception handlers. DECL_ACCESSORS(handler_table, FixedArray) // Accessors for source position table containing mappings between byte code // offset and source position. DECL_ACCESSORS(source_position_table, Object) inline ByteArray* SourcePositionTable(); DECLARE_CAST(BytecodeArray) // Dispatched behavior. inline int BytecodeArraySize(); inline int instruction_size(); // Returns the size of bytecode and its metadata. This includes the size of // bytecode, constant pool, source position table, and handler table. inline int SizeIncludingMetadata(); int SourcePosition(int offset); int SourceStatementPosition(int offset); DECLARE_PRINTER(BytecodeArray) DECLARE_VERIFIER(BytecodeArray) void Disassemble(std::ostream& os); void CopyBytecodesTo(BytecodeArray* to); // Bytecode aging bool IsOld() const; void MakeOlder(); // Layout description. static const int kConstantPoolOffset = FixedArrayBase::kHeaderSize; static const int kHandlerTableOffset = kConstantPoolOffset + kPointerSize; static const int kSourcePositionTableOffset = kHandlerTableOffset + kPointerSize; static const int kFrameSizeOffset = kSourcePositionTableOffset + kPointerSize; static const int kParameterSizeOffset = kFrameSizeOffset + kIntSize; static const int kInterruptBudgetOffset = kParameterSizeOffset + kIntSize; static const int kOSRNestingLevelOffset = kInterruptBudgetOffset + kIntSize; static const int kBytecodeAgeOffset = kOSRNestingLevelOffset + kCharSize; static const int kHeaderSize = kBytecodeAgeOffset + kCharSize; // 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; static const int kPointerFieldsBeginOffset = kConstantPoolOffset; static const int kPointerFieldsEndOffset = kFrameSizeOffset; typedef FixedBodyDescriptor MarkingBodyDescriptor; 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); static const int kSize = kNextOffset + 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; static const int kMaxElementSize = 8; #ifdef V8_HOST_ARCH_32_BIT static const size_t kMaxByteLength = std::numeric_limits::max(); #else static const size_t kMaxByteLength = static_cast(Smi::kMaxValue) * kMaxElementSize; #endif // V8_HOST_ARCH_32_BIT static const size_t kMaxLength = Smi::kMaxValue; class BodyDescriptor; inline int size(); static inline int TypedArraySize(InstanceType type, int length); inline int TypedArraySize(InstanceType type); static inline int ElementSize(InstanceType type); // Use with care: returns raw pointer into heap. inline void* DataPtr(); inline int DataSize(); private: inline int DataSize(InstanceType type); DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase); }; template class FixedTypedArray: public FixedTypedArrayBase { public: typedef typename Traits::ElementType ElementType; static const InstanceType kInstanceType = Traits::kInstanceType; DECLARE_CAST(FixedTypedArray) inline ElementType get_scalar(int index); static inline Handle get(FixedTypedArray* array, int index); inline void set(int index, ElementType value); static inline ElementType from(int value); static inline ElementType from(uint32_t value); static inline ElementType from(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) \ STATIC_ASSERT(size <= FixedTypedArrayBase::kMaxElementSize); \ 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 ToHandle(Isolate* isolate, \ elementType scalar); \ static inline elementType defaultValue(); \ }; \ \ typedef FixedTypedArray 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 optimized code. 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 kInliningPositionsIndex = 8; static const int kFirstDeoptEntryIndex = 9; // 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) DECLARE_ELEMENT_ACCESSORS(InliningPositions, PodArray) #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(); static const int kNotInlinedIndex = -1; // Returns the inlined function at the given position in LiteralArray, or the // outer function if index == kNotInlinedIndex. class SharedFunctionInfo* GetInlinedFunction(int index); // Allocates a DeoptimizationInputData. static Handle 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 New(Isolate* isolate, int number_of_deopt_points, PretenureFlag pretenure); DECLARE_CAST(DeoptimizationOutputData) #ifdef ENABLE_DISASSEMBLER void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT #endif }; class TemplateList : public FixedArray { public: static Handle New(Isolate* isolate, int size); inline int length() const; inline Object* get(int index) const; inline void set(int index, Object* value); static Handle Add(Isolate* isolate, Handle list, Handle value); DECLARE_CAST(TemplateList) private: static const int kLengthIndex = 0; static const int kFirstElementIndex = kLengthIndex + 1; DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateList); }; // 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(BYTECODE_HANDLER) \ V(STUB) \ V(HANDLER) \ V(BUILTIN) \ V(REGEXP) \ V(WASM_FUNCTION) \ V(WASM_TO_JS_FUNCTION) \ V(JS_TO_WASM_FUNCTION) \ V(WASM_INTERPRETER_ENTRY) #define IC_KIND_LIST(V) \ V(LOAD_IC) \ V(LOAD_GLOBAL_IC) \ V(KEYED_LOAD_IC) \ V(STORE_IC) \ V(STORE_GLOBAL_IC) \ V(KEYED_STORE_IC) \ V(BINARY_OP_IC) \ V(COMPARE_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 }; static const char* Kind2String(Kind kind); static const int kPrologueOffsetNotSet = -1; #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER) // Printing static const char* ICState2String(InlineCacheState state); static void PrintExtraICState(std::ostream& os, // NOLINT Kind kind, ExtraICState extra); #endif // defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER) #ifdef ENABLE_DISASSEMBLER 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) // [source_position_table]: ByteArray for the source positions table. // SourcePositionTableWithFrameCache. DECL_ACCESSORS(source_position_table, Object) inline ByteArray* SourcePositionTable(); // [trap_handler_index]: An index into the trap handler's master list of code // objects. DECL_ACCESSORS(trap_handler_index, Smi) // [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 ExtraICState extra_ic_state(); // Only valid for 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_stub(); inline bool is_binary_op_stub(); inline bool is_compare_ic_stub(); inline bool is_to_boolean_ic_stub(); inline bool is_optimized_code(); inline bool is_wasm_code(); inline bool IsCodeStubOrIC(); inline void set_raw_kind_specific_flags1(int value); inline void set_raw_kind_specific_flags2(int value); // Testers for interpreter builtins. inline bool is_interpreter_trampoline_builtin(); // [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); // [has_tagged_params]: For compiled code or builtins: Tells whether the // outgoing parameters of this code are tagged pointers. True for other kinds. inline bool has_tagged_params(); inline void set_has_tagged_params(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); // [is_construct_stub]: For kind BUILTIN, tells whether the code object // represents a hand-written construct stub // (e.g., NumberConstructor_ConstructStub). inline bool is_construct_stub(); inline void set_is_construct_stub(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 builtins, tells which builtin index the code object // has. Note that builtins can have a code kind other than BUILTIN. The // builtin index is a non-negative integer for builtins, and -1 otherwise. 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); // [is_promise_rejection]: For kind BUILTIN tells whether the exception // thrown by the code will lead to promise rejection. inline bool deopt_already_counted(); inline void set_deopt_already_counted(bool flag); // [is_promise_rejection]: For kind BUILTIN tells whether the exception // thrown by the code will lead to promise rejection. inline bool is_promise_rejection(); inline void set_is_promise_rejection(bool flag); // [is_exception_caught]: For kind BUILTIN tells whether the exception // thrown by the code will be caught internally. inline bool is_exception_caught(); inline void set_is_exception_caught(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(); // 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, ExtraICState extra_ic_state = kNoExtraICState); static inline Flags ComputeHandlerFlags(Kind handler_kind); static inline Kind ExtractKindFromFlags(Flags flags); static inline ExtraICState ExtractExtraICStateFromFlags(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, relocation and unwinding // information. inline int body_size(); // Returns the size of code and its metadata. This includes the size of code // relocation information, deoptimization data and handler table. inline int SizeIncludingMetadata(); // Returns the address of the first relocation info (read backwards!). inline byte* relocation_start(); // [has_unwinding_info]: Whether this code object has unwinding information. // If it doesn't, unwinding_information_start() will point to invalid data. // // The body of all code objects has the following layout. // // +--------------------------+ <-- instruction_start() // | instructions | // | ... | // +--------------------------+ // | relocation info | // | ... | // +--------------------------+ <-- instruction_end() // // If has_unwinding_info() is false, instruction_end() points to the first // memory location after the end of the code object. Otherwise, the body // continues as follows: // // +--------------------------+ // | padding to the next | // | 8-byte aligned address | // +--------------------------+ <-- instruction_end() // | [unwinding_info_size] | // | as uint64_t | // +--------------------------+ <-- unwinding_info_start() // | unwinding info | // | ... | // +--------------------------+ <-- unwinding_info_end() // // and unwinding_info_end() points to the first memory location after the end // of the code object. // DECL_BOOLEAN_ACCESSORS(has_unwinding_info) // [unwinding_info_size]: Size of the unwinding information. inline int unwinding_info_size() const; inline void set_unwinding_info_size(int value); // Returns the address of the unwinding information, if any. inline byte* unwinding_info_start(); // Returns the address right after the end of the unwinding information. inline byte* unwinding_info_end(); // 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(); DECLARE_CAST(Code) // Dispatched behavior. inline int CodeSize(); DECLARE_PRINTER(Code) DECLARE_VERIFIER(Code) void ClearInlineCaches(); 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 PreAge(Isolate* isolate); void MarkToBeExecutedOnce(Isolate* isolate); void MakeOlder(); static bool IsYoungSequence(Isolate* isolate, byte* sequence); bool IsOld(); Age GetAge(); static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) { return GetCodeAgeStub(isolate, kNotExecutedCodeAge); } 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 WeakCellFor(Handle code); WeakCell* CachedWeakCell(); 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; static const int kSourcePositionTableOffset = kDeoptimizationDataOffset + kPointerSize; // For FUNCTION kind, we store the type feedback info here. static const int kTypeFeedbackInfoOffset = kSourcePositionTableOffset + 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 kBuiltinIndexOffset = kConstantPoolOffset + kConstantPoolSize; static const int kTrapHandlerIndex = kBuiltinIndexOffset + kIntSize; static const int kHeaderPaddingStart = kTrapHandlerIndex + kPointerSize; enum TrapFields { kTrapCodeOffset, kTrapLandingOffset, kTrapDataSize }; // Add padding to align the instruction start following right after // the Code object header. static const int kHeaderSize = (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask; inline int GetUnwindingInfoSizeOffset() const; class BodyDescriptor; // Byte offsets within kKindSpecificFlags1Offset. static const int kFullCodeFlags = kKindSpecificFlags1Offset; class FullCodeFlagsHasDeoptimizationSupportField: public BitField {}; // NOLINT class FullCodeFlagsHasDebugBreakSlotsField: public BitField {}; class FullCodeFlagsHasRelocInfoForSerialization : public BitField {}; // Bit 3 in this bitfield is unused. class ProfilerTicksField : public BitField {}; // Flags layout. BitField. class HasUnwindingInfoField : public BitField {}; class KindField : public BitField {}; STATIC_ASSERT(NUMBER_OF_KINDS <= KindField::kMax); class ExtraICStateField : public BitField { }; // KindSpecificFlags1 layout (STUB, BUILTIN and OPTIMIZED_FUNCTION) static const int kStackSlotsFirstBit = 0; static const int kStackSlotsBitCount = 24; static const int kMarkedForDeoptimizationBit = kStackSlotsFirstBit + kStackSlotsBitCount; static const int kDeoptAlreadyCountedBit = kMarkedForDeoptimizationBit + 1; static const int kIsTurbofannedBit = kDeoptAlreadyCountedBit + 1; static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1; // Could be moved to overlap previous bits when we need more space. static const int kIsConstructStub = kCanHaveWeakObjects + 1; static const int kIsPromiseRejection = kIsConstructStub + 1; static const int kIsExceptionCaught = kIsPromiseRejection + 1; STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32); STATIC_ASSERT(kIsExceptionCaught + 1 <= 32); class StackSlotsField: public BitField {}; // NOLINT class MarkedForDeoptimizationField : public BitField {}; // NOLINT class DeoptAlreadyCountedField : public BitField {}; // NOLINT class IsTurbofannedField : public BitField { }; // NOLINT class CanHaveWeakObjectsField : public BitField {}; // NOLINT class IsConstructStubField : public BitField { }; // NOLINT class IsPromiseRejectionField : public BitField {}; // NOLINT class IsExceptionCaughtField : public BitField { }; // NOLINT // KindSpecificFlags2 layout (ALL) static const int kIsCrankshaftedBit = 0; class IsCrankshaftedField : public BitField {}; static const int kHasTaggedStackBit = kIsCrankshaftedBit + 1; class HasTaggedStackField : public BitField {}; // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION) static const int kSafepointTableOffsetFirstBit = kHasTaggedStackBit + 1; static const int kSafepointTableOffsetBitCount = 30; STATIC_ASSERT(kSafepointTableOffsetFirstBit + kSafepointTableOffsetBitCount <= 32); STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32); class SafepointTableOffsetField: public BitField {}; // NOLINT // KindSpecificFlags2 layout (FUNCTION) class BackEdgeTableOffsetField: public BitField {}; // NOLINT class AllowOSRAtLoopNestingLevelField: public BitField {}; // NOLINT static const int kArgumentsBits = 16; static const int kMaxArguments = (1 << kArgumentsBits) - 1; private: friend class RelocIterator; friend class Deoptimizer; // For FindCodeAgeSequence. // Code aging byte* FindCodeAgeSequence(); static Age GetCodeAge(Isolate* isolate, byte* sequence); static Age GetAgeOfCodeAgeStub(Code* code); static Code* GetCodeAgeStub(Isolate* isolate, Age age); // Code aging -- platform-specific static void PatchPlatformCodeAge(Isolate* isolate, byte* sequence, Age age); DISALLOW_IMPLICIT_CONSTRUCTORS(Code); }; class AbstractCode : public HeapObject { public: // All code kinds and INTERPRETED_FUNCTION. enum Kind { #define DEFINE_CODE_KIND_ENUM(name) name, CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM) #undef DEFINE_CODE_KIND_ENUM INTERPRETED_FUNCTION, NUMBER_OF_KINDS }; static const char* Kind2String(Kind kind); int SourcePosition(int offset); int SourceStatementPosition(int offset); // Returns the address of the first instruction. inline Address instruction_start(); // Returns the address right after the last instruction. inline Address instruction_end(); // Returns the size of the code instructions. inline int instruction_size(); // Return the source position table. inline ByteArray* source_position_table(); // Set the source position table. inline void set_source_position_table(ByteArray* source_position_table); inline Object* stack_frame_cache(); static void SetStackFrameCache(Handle abstract_code, Handle cache); void DropStackFrameCache(); // Returns the size of instructions and the metadata. inline int SizeIncludingMetadata(); // Returns true if pc is inside this object's instructions. inline bool contains(byte* pc); // Returns the AbstractCode::Kind of the code. inline Kind kind(); // 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(); DECLARE_CAST(AbstractCode) inline Code* GetCode(); inline BytecodeArray* GetBytecodeArray(); // 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_ASSERT(Code::AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker); }; // 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 checks for field(s) introduced by // this map, i.e. for the field type. kFieldOwnerGroup, // 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; static const int kNextLinkIndex = 0; static const int kFlagsIndex = 1; static const int kCodesStartIndex = 2; bool Contains(DependencyGroup group, WeakCell* code_cell); bool IsEmpty(DependencyGroup group); static Handle InsertCompilationDependencies( Handle entries, DependencyGroup group, Handle info); static Handle InsertWeakCode(Handle entries, DependencyGroup group, Handle 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 Insert(Handle entries, DependencyGroup group, Handle object); static Handle New(DependencyGroup group, Handle object, Handle next); static Handle EnsureSpace(Handle 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 {}; class CountField : public BitField {}; STATIC_ASSERT(kGroupCount <= GroupField::kMax + 1); }; 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 GetConstructorFunction( Handle map, Handle native_context); // Retrieve interceptors. inline InterceptorInfo* GetNamedInterceptor(); inline InterceptorInfo* GetIndexedInterceptor(); // 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 {}; // NOLINT class NumberOfOwnDescriptorsBits: public BitField {}; // NOLINT STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20); class DictionaryMap : public BitField {}; class OwnsDescriptors : public BitField {}; class HasHiddenPrototype : public BitField {}; class Deprecated : public BitField {}; class IsUnstable : public BitField {}; class IsMigrationTarget : public BitField {}; class ImmutablePrototype : public BitField {}; class NewTargetIsBase : public BitField {}; // 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. The counter only has a valid count for initial maps. For // transitioned maps only kNoSlackTracking has a meaning, namely that inobject // slack tracking already finished for the transition tree. Any other value // indicates that either inobject slack tracking is still in progress, or that // the map isn't part of the transition tree anymore. class ConstructionCounter : public BitField {}; 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(bool value); inline bool is_constructor() const; // Tells whether the instance with this map has a hidden prototype. inline void set_has_hidden_prototype(bool value); inline bool has_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]] 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_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_fast_sloppy_arguments_elements(); inline bool has_fast_string_wrapper_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 GetOrCreatePrototypeInfo( Handle prototype, Isolate* isolate); static Handle GetOrCreatePrototypeInfo( Handle prototype_map, Isolate* isolate); inline bool should_be_fast_prototype_map() const; static void SetShouldBeFastPrototypeMap(Handle map, bool value, 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 GetOrCreatePrototypeChainValidityCell(Handle map, Isolate* isolate); static const int kPrototypeChainValid = 0; static const int kPrototypeChainInvalid = 1; // Return the map of the root of object's prototype chain. Map* GetPrototypeChainRootMap(Isolate* isolate); // Returns a WeakCell object containing given prototype. The cell is cached // in PrototypeInfo which is created lazily. static Handle GetOrCreatePrototypeWeakCell( Handle prototype, Isolate* isolate); Map* FindRootMap(); Map* FindFieldOwner(int descriptor); inline int GetInObjectPropertyOffset(int index); int NumberOfFields(); // Returns true if transition to the given map requires special // synchronization with the concurrent marker. bool TransitionRequiresSynchronizationWithGC(Map* target); // Returns true if transition to the given map removes a tagged in-object // field. bool TransitionRemovesTaggedField(Map* target); // Returns true if transition to the given map replaces a tagged in-object // field with an untagged in-object field. bool TransitionChangesTaggedFieldToUntaggedField(Map* target); // TODO(ishell): candidate with JSObject::MigrateToMap(). bool InstancesNeedRewriting(Map* target); 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 GeneralizeAllFields(Handle map); MUST_USE_RESULT static Handle GeneralizeFieldType( Representation rep1, Handle type1, Representation rep2, Handle type2, Isolate* isolate); static void GeneralizeField(Handle map, int modify_index, PropertyConstness new_constness, Representation new_representation, Handle new_field_type); static Handle ReconfigureProperty(Handle map, int modify_index, PropertyKind new_kind, PropertyAttributes new_attributes, Representation new_representation, Handle new_field_type); static Handle ReconfigureElementsKind(Handle map, ElementsKind new_elements_kind); static Handle PrepareForDataProperty(Handle old_map, int descriptor_number, PropertyConstness constness, Handle value); static Handle Normalize(Handle 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, Handle prototype, PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE); // [constructor]: points back to the function or FunctionTemplateInfo // 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. // Returns null_value if there's neither a constructor function nor a // FunctionTemplateInfo available. DECL_ACCESSORS(constructor_or_backpointer, Object) inline Object* GetConstructor() const; inline FunctionTemplateInfo* GetFunctionTemplateInfo() 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, FixedArray) // [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(); // Checks whether all properties are stored either in the map or on the object // (inobject, properties, or elements backing store), requiring no special // checks. bool OnlyHasSimpleProperties(); 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_immutable_proto(bool value); inline bool is_immutable_proto(); 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() if no updated map // is found. static MaybeHandle TryUpdate(Handle 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 Update(Handle map); static inline Handle CopyInitialMap(Handle map); static Handle CopyInitialMap(Handle map, int instance_size, int in_object_properties, int unused_property_fields); static Handle CopyInitialMapNormalized( Handle map, PropertyNormalizationMode mode = CLEAR_INOBJECT_PROPERTIES); static Handle CopyDropDescriptors(Handle map); static Handle CopyInsertDescriptor(Handle map, Descriptor* descriptor, TransitionFlag flag); static Handle WrapFieldType(Handle type); static FieldType* UnwrapFieldType(Object* wrapped_type); MUST_USE_RESULT static MaybeHandle CopyWithField( Handle map, Handle name, Handle type, PropertyAttributes attributes, PropertyConstness constness, Representation representation, TransitionFlag flag); MUST_USE_RESULT static MaybeHandle CopyWithConstant( Handle map, Handle name, Handle constant, PropertyAttributes attributes, TransitionFlag flag); // Returns a new map with all transitions dropped from the given map and // the ElementsKind set. static Handle TransitionElementsTo(Handle map, ElementsKind to_kind); static Handle AsElementsKind(Handle map, ElementsKind kind); static Handle CopyAsElementsKind(Handle map, ElementsKind kind, TransitionFlag flag); static Handle AsLanguageMode(Handle initial_map, LanguageMode language_mode, FunctionKind kind); static Handle CopyForPreventExtensions(Handle map, PropertyAttributes attrs_to_add, Handle transition_marker, const char* reason); static Handle FixProxy(Handle 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 TransitionToDataProperty(Handle map, Handle name, Handle value, PropertyAttributes attributes, PropertyConstness constness, StoreFromKeyed store_mode); static Handle TransitionToAccessorProperty( Isolate* isolate, Handle map, Handle name, int descriptor, Handle getter, Handle setter, PropertyAttributes attributes); static Handle ReconfigureExistingProperty(Handle 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 CopyForTransition(Handle map, const char* reason); // Returns a copy of the map, with all transitions dropped from the // instance descriptors. static Handle Copy(Handle map, const char* reason); static Handle 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, Handle name, Handle 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, Handle descriptors); static inline int SlackForArraySize(int old_size, int size_limit); static void EnsureDescriptorSlack(Handle map, int slack); Code* LookupInCodeCache(Name* name, Code::Flags code); static Handle GetObjectCreateMap(Handle prototype); // Computes a hash value for this map, to be used in HashTables and such. int Hash(); // Returns the transitioned map for this map with the most generic // elements_kind that's found in |candidates|, or |nullptr| if no match is // found at all. Map* FindElementsKindTransitionedMap(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 IsModuleMap(); inline bool IsJSGlobalProxyMap(); inline bool IsJSGlobalObjectMap(); inline bool IsJSTypedArrayMap(); inline bool IsJSDataViewMap(); inline bool IsSpecialReceiverMap(); inline bool CanOmitMapChecks(); static void AddDependentCode(Handle map, DependentCode::DependencyGroup group, Handle code); bool IsMapInArrayPrototypeChain(); static Handle WeakCellForMap(Handle 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 TransitionToPrototype(Handle map, Handle prototype, PrototypeOptimizationMode mode); static Handle TransitionToImmutableProto(Handle map); 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 kLayoutDescriptorOffset = kDescriptorsOffset + kPointerSize; static const int kCodeCacheOffset = kLayoutDescriptorOffset + kPointerSize; #else static const int kLayoutDescriptorOffset = 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 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 kIsAccessCheckNeeded = 5; static const int kIsConstructor = 6; // Bit 7 is free. // Bit positions for bit field 2 static const int kIsExtensible = 0; // Bit 1 is free. class IsPrototypeMapBits : public BitField {}; class ElementsKindBits: public BitField {}; // Derived values from bit field 2 static const int8_t kMaximumBitField2FastElementValue = static_cast( (FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; static const int8_t kMaximumBitField2FastSmiElementValue = static_cast((FAST_SMI_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; static const int8_t kMaximumBitField2FastHoleyElementValue = static_cast((FAST_HOLEY_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; static const int8_t kMaximumBitField2FastHoleySmiElementValue = static_cast((FAST_HOLEY_SMI_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; typedef FixedBodyDescriptor 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 AddMissingTransitionsForTesting( Handle split_map, Handle descriptors, Handle full_layout_descriptor); // 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(); private: // Returns the map that this (root) map transitions to if its elements_kind // is changed to |elements_kind|, or |nullptr| if no such map is cached yet. Map* LookupElementsTransitionMap(ElementsKind elements_kind); // Tries to replay property transitions starting from this (root) map using // the descriptor array of the |map|. The |root_map| is expected to have // proper elements kind and therefore elements kinds transitions are not // taken by this function. Returns |nullptr| if matching transition map is // not found. Map* TryReplayPropertyTransitions(Map* map); static void ConnectTransition(Handle parent, Handle child, Handle name, SimpleTransitionFlag flag); bool EquivalentToForTransition(Map* other); static Handle RawCopy(Handle map, int instance_size); static Handle ShareDescriptor(Handle map, Handle descriptors, Descriptor* descriptor); static Handle AddMissingTransitions( Handle map, Handle descriptors, Handle full_layout_descriptor); static void InstallDescriptors( Handle parent_map, Handle child_map, int new_descriptor, Handle descriptors, Handle full_layout_descriptor); static Handle CopyAddDescriptor(Handle map, Descriptor* descriptor, TransitionFlag flag); static Handle CopyReplaceDescriptors( Handle map, Handle descriptors, Handle layout_descriptor, TransitionFlag flag, MaybeHandle maybe_name, const char* reason, SimpleTransitionFlag simple_flag); static Handle CopyReplaceDescriptor(Handle map, Handle descriptors, Descriptor* descriptor, int index, TransitionFlag flag); static MUST_USE_RESULT MaybeHandle TryReconfigureExistingProperty( Handle map, int descriptor, PropertyKind kind, PropertyAttributes attributes, const char** reason); static Handle CopyNormalized(Handle map, PropertyNormalizationMode mode); // TODO(ishell): Move to MapUpdater. static Handle CopyGeneralizeAllFields( Handle map, ElementsKind elements_kind, int modify_index, PropertyKind kind, PropertyAttributes attributes, const char* reason); void DeprecateTransitionTree(); void ReplaceDescriptors(DescriptorArray* new_descriptors, LayoutDescriptor* new_layout_descriptor); // 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, PropertyConstness new_constness, Representation new_representation, Handle new_wrapped_type); // TODO(ishell): Move to MapUpdater. void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind, PropertyAttributes attributes); // TODO(ishell): Move to MapUpdater. void PrintGeneralization(FILE* file, const char* reason, int modify_index, int split, int descriptors, bool constant_to_field, Representation old_representation, Representation new_representation, MaybeHandle old_field_type, MaybeHandle old_value, MaybeHandle new_field_type, MaybeHandle new_value); static const int kFastPropertiesSoftLimit = 12; static const int kMaxFastProperties = 128; friend class MapUpdater; 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 container struct to hold state required for PromiseResolveThenableJob. class PromiseResolveThenableJobInfo : public Struct { public: DECL_ACCESSORS(thenable, JSReceiver) DECL_ACCESSORS(then, JSReceiver) DECL_ACCESSORS(resolve, JSFunction) DECL_ACCESSORS(reject, JSFunction) DECL_ACCESSORS(context, Context) static const int kThenableOffset = Struct::kHeaderSize; static const int kThenOffset = kThenableOffset + kPointerSize; static const int kResolveOffset = kThenOffset + kPointerSize; static const int kRejectOffset = kResolveOffset + kPointerSize; static const int kContextOffset = kRejectOffset + kPointerSize; static const int kSize = kContextOffset + kPointerSize; DECLARE_CAST(PromiseResolveThenableJobInfo) DECLARE_PRINTER(PromiseResolveThenableJobInfo) DECLARE_VERIFIER(PromiseResolveThenableJobInfo) private: DISALLOW_IMPLICIT_CONSTRUCTORS(PromiseResolveThenableJobInfo); }; class JSPromise; // Struct to hold state required for PromiseReactionJob. class PromiseReactionJobInfo : public Struct { public: DECL_ACCESSORS(value, Object) DECL_ACCESSORS(tasks, Object) // Check comment in JSPromise for information on what state these // deferred fields could be in. DECL_ACCESSORS(deferred_promise, Object) DECL_ACCESSORS(deferred_on_resolve, Object) DECL_ACCESSORS(deferred_on_reject, Object) DECL_INT_ACCESSORS(debug_id) DECL_ACCESSORS(context, Context) static const int kValueOffset = Struct::kHeaderSize; static const int kTasksOffset = kValueOffset + kPointerSize; static const int kDeferredPromiseOffset = kTasksOffset + kPointerSize; static const int kDeferredOnResolveOffset = kDeferredPromiseOffset + kPointerSize; static const int kDeferredOnRejectOffset = kDeferredOnResolveOffset + kPointerSize; static const int kContextOffset = kDeferredOnRejectOffset + kPointerSize; static const int kSize = kContextOffset + kPointerSize; DECLARE_CAST(PromiseReactionJobInfo) DECLARE_PRINTER(PromiseReactionJobInfo) DECLARE_VERIFIER(PromiseReactionJobInfo) private: DISALLOW_IMPLICIT_CONSTRUCTORS(PromiseReactionJobInfo); }; class AsyncGeneratorRequest : public Struct { public: // Holds an AsyncGeneratorRequest, or Undefined. DECL_ACCESSORS(next, Object) DECL_INT_ACCESSORS(resume_mode) DECL_ACCESSORS(value, Object) DECL_ACCESSORS(promise, Object) static const int kNextOffset = Struct::kHeaderSize; static const int kResumeModeOffset = kNextOffset + kPointerSize; static const int kValueOffset = kResumeModeOffset + kPointerSize; static const int kPromiseOffset = kValueOffset + kPointerSize; static const int kSize = kPromiseOffset + kPointerSize; DECLARE_CAST(AsyncGeneratorRequest) DECLARE_PRINTER(AsyncGeneratorRequest) DECLARE_VERIFIER(AsyncGeneratorRequest) private: DISALLOW_IMPLICIT_CONSTRUCTORS(AsyncGeneratorRequest); }; // Container for metadata stored on each prototype map. class PrototypeInfo : public Struct { public: static const int UNREGISTERED = -1; // [weak_cell]: A WeakCell containing this prototype. ICs cache the cell here. DECL_ACCESSORS(weak_cell, Object) // [prototype_users]: WeakFixedArray containing maps using this prototype, // or Smi(0) if uninitialized. DECL_ACCESSORS(prototype_users, Object) // [object_create_map]: A field caching the map for Object.create(prototype). static inline void SetObjectCreateMap(Handle info, Handle map); inline Map* ObjectCreateMap(); inline bool HasObjectCreateMap(); // [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) // [bit_field] inline int bit_field() const; inline void set_bit_field(int bit_field); DECL_BOOLEAN_ACCESSORS(should_be_fast_map) DECLARE_CAST(PrototypeInfo) // Dispatched behavior. DECLARE_PRINTER(PrototypeInfo) DECLARE_VERIFIER(PrototypeInfo) static const int kWeakCellOffset = HeapObject::kHeaderSize; static const int kPrototypeUsersOffset = kWeakCellOffset + kPointerSize; static const int kRegistrySlotOffset = kPrototypeUsersOffset + kPointerSize; static const int kValidityCellOffset = kRegistrySlotOffset + kPointerSize; static const int kObjectCreateMap = kValidityCellOffset + kPointerSize; static const int kBitFieldOffset = kObjectCreateMap + kPointerSize; static const int kSize = kBitFieldOffset + kPointerSize; // Bit field usage. static const int kShouldBeFastBit = 0; private: DECL_ACCESSORS(object_create_map, Object) DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeInfo); }; class Tuple2 : public Struct { public: DECL_ACCESSORS(value1, Object) DECL_ACCESSORS(value2, Object) DECLARE_CAST(Tuple2) // Dispatched behavior. DECLARE_PRINTER(Tuple2) DECLARE_VERIFIER(Tuple2) static const int kValue1Offset = HeapObject::kHeaderSize; static const int kValue2Offset = kValue1Offset + kPointerSize; static const int kSize = kValue2Offset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple2); }; class Tuple3 : public Tuple2 { public: DECL_ACCESSORS(value3, Object) DECLARE_CAST(Tuple3) // Dispatched behavior. DECLARE_PRINTER(Tuple3) DECLARE_VERIFIER(Tuple3) static const int kValue3Offset = Tuple2::kSize; static const int kSize = kValue3Offset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple3); }; // Pair used to store both a ScopeInfo and an extension object in the extension // slot of a block, catch, or with 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, or for with and catch // scopes. (In no other case both are needed at the same time.) class ContextExtension : public Struct { public: // [scope_info]: Scope info. DECL_ACCESSORS(scope_info, ScopeInfo) // [extension]: Extension object. DECL_ACCESSORS(extension, Object) DECLARE_CAST(ContextExtension) // Dispatched behavior. DECLARE_PRINTER(ContextExtension) DECLARE_VERIFIER(ContextExtension) static const int kScopeInfoOffset = HeapObject::kHeaderSize; static const int kExtensionOffset = kScopeInfoOffset + kPointerSize; static const int kSize = kExtensionOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ContextExtension); }; // 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, TYPE_WASM = 3, TYPE_INSPECTOR = 4 }; // 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 function info for the // function from which eval was called. DECL_ACCESSORS(eval_from_shared, Object) // [eval_from_position]: the source position in the code for the function // from which eval was called, as positive integer. Or the code offset in the // code from which eval was called, as negative integer. DECL_INT_ACCESSORS(eval_from_position) // [shared_function_infos]: weak fixed array containing all shared // function infos created from this script. DECL_ACCESSORS(shared_function_infos, FixedArray) // [flags]: Holds an exciting bitfield. DECL_INT_ACCESSORS(flags) // [source_url]: sourceURL from magic comment DECL_ACCESSORS(source_url, Object) // [source_mapping_url]: sourceMappingURL magic comment DECL_ACCESSORS(source_mapping_url, Object) // [wasm_compiled_module]: the compiled wasm module this script belongs to. // This must only be called if the type of this script is TYPE_WASM. DECL_ACCESSORS(wasm_compiled_module, Object) DECL_ACCESSORS(preparsed_scope_data, PodArray) // [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); // [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(); Object* GetNameOrSourceURL(); // Set eval origin for stack trace formatting. static void SetEvalOrigin(Handle