// Copyright 2015 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_OBJECTS_H_ #define V8_OBJECTS_H_ #include <iosfwd> #include "src/allocation.h" #include "src/assert-scope.h" #include "src/bailout-reason.h" #include "src/base/bits.h" #include "src/base/flags.h" #include "src/base/smart-pointers.h" #include "src/builtins.h" #include "src/checks.h" #include "src/elements-kind.h" #include "src/field-index.h" #include "src/flags.h" #include "src/list.h" #include "src/property-details.h" #include "src/unicode.h" #include "src/unicode-decoder.h" #include "src/zone.h" #if V8_TARGET_ARCH_ARM #include "src/arm/constants-arm.h" // NOLINT #elif V8_TARGET_ARCH_ARM64 #include "src/arm64/constants-arm64.h" // NOLINT #elif V8_TARGET_ARCH_MIPS #include "src/mips/constants-mips.h" // NOLINT #elif V8_TARGET_ARCH_MIPS64 #include "src/mips64/constants-mips64.h" // NOLINT #elif V8_TARGET_ARCH_PPC #include "src/ppc/constants-ppc.h" // NOLINT #endif // // Most object types in the V8 JavaScript are described in this file. // // Inheritance hierarchy: // - Object // - Smi (immediate small integer) // - HeapObject (superclass for everything allocated in the heap) // - JSReceiver (suitable for property access) // - JSObject // - JSArray // - JSArrayBuffer // - JSArrayBufferView // - JSTypedArray // - JSDataView // - JSBoundFunction // - JSCollection // - JSSet // - JSMap // - JSSetIterator // - JSMapIterator // - JSWeakCollection // - JSWeakMap // - JSWeakSet // - JSRegExp // - JSFunction // - JSGeneratorObject // - JSModule // - JSGlobalObject // - JSGlobalProxy // - JSValue // - JSDate // - JSMessageObject // - JSProxy // - FixedArrayBase // - ByteArray // - BytecodeArray // - FixedArray // - DescriptorArray // - LiteralsArray // - HashTable // - Dictionary // - StringTable // - CompilationCacheTable // - CodeCacheHashTable // - MapCache // - OrderedHashTable // - OrderedHashSet // - OrderedHashMap // - Context // - TypeFeedbackMetadata // - TypeFeedbackVector // - ScopeInfo // - TransitionArray // - ScriptContextTable // - WeakFixedArray // - FixedDoubleArray // - Name // - String // - SeqString // - SeqOneByteString // - SeqTwoByteString // - SlicedString // - ConsString // - ExternalString // - ExternalOneByteString // - ExternalTwoByteString // - InternalizedString // - SeqInternalizedString // - SeqOneByteInternalizedString // - SeqTwoByteInternalizedString // - ConsInternalizedString // - ExternalInternalizedString // - ExternalOneByteInternalizedString // - ExternalTwoByteInternalizedString // - Symbol // - HeapNumber // - Simd128Value // - Float32x4 // - Int32x4 // - Uint32x4 // - Bool32x4 // - Int16x8 // - Uint16x8 // - Bool16x8 // - Int8x16 // - Uint8x16 // - Bool8x16 // - Cell // - PropertyCell // - Code // - AbstractCode, a wrapper around Code or BytecodeArray // - Map // - Oddball // - Foreign // - SharedFunctionInfo // - Struct // - Box // - AccessorInfo // - AccessorPair // - AccessCheckInfo // - InterceptorInfo // - CallHandlerInfo // - TemplateInfo // - FunctionTemplateInfo // - ObjectTemplateInfo // - Script // - DebugInfo // - BreakPointInfo // - CodeCache // - PrototypeInfo // - WeakCell // // Formats of Object*: // Smi: [31 bit signed int] 0 // HeapObject: [32 bit direct pointer] (4 byte aligned) | 01 namespace v8 { namespace internal { enum KeyedAccessStoreMode { STANDARD_STORE, STORE_TRANSITION_TO_OBJECT, STORE_TRANSITION_TO_DOUBLE, STORE_AND_GROW_NO_TRANSITION, STORE_AND_GROW_TRANSITION_TO_OBJECT, STORE_AND_GROW_TRANSITION_TO_DOUBLE, STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS, STORE_NO_TRANSITION_HANDLE_COW }; // Valid hints for the abstract operation ToPrimitive, // implemented according to ES6, section 7.1.1. enum class ToPrimitiveHint { kDefault, kNumber, kString }; // Valid hints for the abstract operation OrdinaryToPrimitive, // implemented according to ES6, section 7.1.1. enum class OrdinaryToPrimitiveHint { kNumber, kString }; enum TypeofMode : int { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF }; enum MutableMode { MUTABLE, IMMUTABLE }; enum ExternalArrayType { kExternalInt8Array = 1, kExternalUint8Array, kExternalInt16Array, kExternalUint16Array, kExternalInt32Array, kExternalUint32Array, kExternalFloat32Array, kExternalFloat64Array, kExternalUint8ClampedArray, }; static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) { return store_mode == STORE_TRANSITION_TO_OBJECT || store_mode == STORE_TRANSITION_TO_DOUBLE || store_mode == STORE_AND_GROW_TRANSITION_TO_OBJECT || store_mode == STORE_AND_GROW_TRANSITION_TO_DOUBLE; } static inline KeyedAccessStoreMode GetNonTransitioningStoreMode( KeyedAccessStoreMode store_mode) { if (store_mode >= STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) { return store_mode; } if (store_mode >= STORE_AND_GROW_NO_TRANSITION) { return STORE_AND_GROW_NO_TRANSITION; } return STANDARD_STORE; } static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) { return store_mode >= STORE_AND_GROW_NO_TRANSITION && store_mode <= STORE_AND_GROW_TRANSITION_TO_DOUBLE; } enum IcCheckType { ELEMENT, PROPERTY }; // SKIP_WRITE_BARRIER skips the write barrier. // UPDATE_WEAK_WRITE_BARRIER skips the marking part of the write barrier and // only performs the generational part. // UPDATE_WRITE_BARRIER is doing the full barrier, marking and generational. enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WEAK_WRITE_BARRIER, UPDATE_WRITE_BARRIER }; // Indicates whether a value can be loaded as a constant. enum StoreMode { ALLOW_IN_DESCRIPTOR, FORCE_FIELD }; // PropertyNormalizationMode is used to specify whether to keep // inobject properties when normalizing properties of a JSObject. enum PropertyNormalizationMode { CLEAR_INOBJECT_PROPERTIES, KEEP_INOBJECT_PROPERTIES }; // Indicates how aggressively the prototype should be optimized. FAST_PROTOTYPE // will give the fastest result by tailoring the map to the prototype, but that // will cause polymorphism with other objects. REGULAR_PROTOTYPE is to be used // (at least for now) when dynamically modifying the prototype chain of an // object using __proto__ or Object.setPrototypeOf. enum PrototypeOptimizationMode { REGULAR_PROTOTYPE, FAST_PROTOTYPE }; // Indicates whether transitions can be added to a source map or not. enum TransitionFlag { INSERT_TRANSITION, OMIT_TRANSITION }; // Indicates whether the transition is simple: the target map of the transition // either extends the current map with a new property, or it modifies the // property that was added last to the current map. enum SimpleTransitionFlag { SIMPLE_PROPERTY_TRANSITION, PROPERTY_TRANSITION, SPECIAL_TRANSITION }; // Indicates whether we are only interested in the descriptors of a particular // map, or in all descriptors in the descriptor array. enum DescriptorFlag { ALL_DESCRIPTORS, OWN_DESCRIPTORS }; // The GC maintains a bit of information, the MarkingParity, which toggles // from odd to even and back every time marking is completed. Incremental // marking can visit an object twice during a marking phase, so algorithms that // that piggy-back on marking can use the parity to ensure that they only // perform an operation on an object once per marking phase: they record the // MarkingParity when they visit an object, and only re-visit the object when it // is marked again and the MarkingParity changes. enum MarkingParity { NO_MARKING_PARITY, ODD_MARKING_PARITY, EVEN_MARKING_PARITY }; // ICs store extra state in a Code object. The default extra state is // kNoExtraICState. typedef int ExtraICState; static const ExtraICState kNoExtraICState = 0; // Instance size sentinel for objects of variable size. const int kVariableSizeSentinel = 0; // We may store the unsigned bit field as signed Smi value and do not // use the sign bit. const int kStubMajorKeyBits = 7; const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1; // All Maps have a field instance_type containing a InstanceType. // It describes the type of the instances. // // As an example, a JavaScript object is a heap object and its map // instance_type is JS_OBJECT_TYPE. // // The names of the string instance types are intended to systematically // mirror their encoding in the instance_type field of the map. The default // encoding is considered TWO_BYTE. It is not mentioned in the name. ONE_BYTE // encoding is mentioned explicitly in the name. Likewise, the default // representation is considered sequential. It is not mentioned in the // name. The other representations (e.g. CONS, EXTERNAL) are explicitly // mentioned. Finally, the string is either a STRING_TYPE (if it is a normal // string) or a INTERNALIZED_STRING_TYPE (if it is a internalized string). // // NOTE: The following things are some that depend on the string types having // instance_types that are less than those of all other types: // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and // Object::IsString. // // NOTE: Everything following JS_VALUE_TYPE is considered a // JSObject for GC purposes. The first four entries here have typeof // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'. #define INSTANCE_TYPE_LIST(V) \ V(STRING_TYPE) \ V(ONE_BYTE_STRING_TYPE) \ V(CONS_STRING_TYPE) \ V(CONS_ONE_BYTE_STRING_TYPE) \ V(SLICED_STRING_TYPE) \ V(SLICED_ONE_BYTE_STRING_TYPE) \ V(EXTERNAL_STRING_TYPE) \ V(EXTERNAL_ONE_BYTE_STRING_TYPE) \ V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \ V(SHORT_EXTERNAL_STRING_TYPE) \ V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE) \ V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE) \ \ V(INTERNALIZED_STRING_TYPE) \ V(ONE_BYTE_INTERNALIZED_STRING_TYPE) \ V(EXTERNAL_INTERNALIZED_STRING_TYPE) \ V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \ V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \ V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE) \ V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE) \ V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \ \ V(SYMBOL_TYPE) \ V(SIMD128_VALUE_TYPE) \ \ V(MAP_TYPE) \ V(CODE_TYPE) \ V(ODDBALL_TYPE) \ V(CELL_TYPE) \ V(PROPERTY_CELL_TYPE) \ \ V(HEAP_NUMBER_TYPE) \ V(MUTABLE_HEAP_NUMBER_TYPE) \ V(FOREIGN_TYPE) \ V(BYTE_ARRAY_TYPE) \ V(BYTECODE_ARRAY_TYPE) \ V(FREE_SPACE_TYPE) \ \ V(FIXED_INT8_ARRAY_TYPE) \ V(FIXED_UINT8_ARRAY_TYPE) \ V(FIXED_INT16_ARRAY_TYPE) \ V(FIXED_UINT16_ARRAY_TYPE) \ V(FIXED_INT32_ARRAY_TYPE) \ V(FIXED_UINT32_ARRAY_TYPE) \ V(FIXED_FLOAT32_ARRAY_TYPE) \ V(FIXED_FLOAT64_ARRAY_TYPE) \ V(FIXED_UINT8_CLAMPED_ARRAY_TYPE) \ \ V(FILLER_TYPE) \ \ V(ACCESSOR_INFO_TYPE) \ V(ACCESSOR_PAIR_TYPE) \ V(ACCESS_CHECK_INFO_TYPE) \ V(INTERCEPTOR_INFO_TYPE) \ V(CALL_HANDLER_INFO_TYPE) \ V(FUNCTION_TEMPLATE_INFO_TYPE) \ V(OBJECT_TEMPLATE_INFO_TYPE) \ V(SIGNATURE_INFO_TYPE) \ V(TYPE_SWITCH_INFO_TYPE) \ V(ALLOCATION_MEMENTO_TYPE) \ V(ALLOCATION_SITE_TYPE) \ V(SCRIPT_TYPE) \ V(CODE_CACHE_TYPE) \ V(POLYMORPHIC_CODE_CACHE_TYPE) \ V(TYPE_FEEDBACK_INFO_TYPE) \ V(ALIASED_ARGUMENTS_ENTRY_TYPE) \ V(BOX_TYPE) \ V(PROTOTYPE_INFO_TYPE) \ V(SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION_TYPE) \ \ V(FIXED_ARRAY_TYPE) \ V(FIXED_DOUBLE_ARRAY_TYPE) \ V(SHARED_FUNCTION_INFO_TYPE) \ V(WEAK_CELL_TYPE) \ V(TRANSITION_ARRAY_TYPE) \ \ V(JS_MESSAGE_OBJECT_TYPE) \ \ V(JS_VALUE_TYPE) \ V(JS_DATE_TYPE) \ V(JS_OBJECT_TYPE) \ V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \ V(JS_GENERATOR_OBJECT_TYPE) \ V(JS_MODULE_TYPE) \ V(JS_GLOBAL_OBJECT_TYPE) \ V(JS_GLOBAL_PROXY_TYPE) \ V(JS_ARRAY_TYPE) \ V(JS_ARRAY_BUFFER_TYPE) \ V(JS_TYPED_ARRAY_TYPE) \ V(JS_DATA_VIEW_TYPE) \ V(JS_PROXY_TYPE) \ V(JS_SET_TYPE) \ V(JS_MAP_TYPE) \ V(JS_SET_ITERATOR_TYPE) \ V(JS_MAP_ITERATOR_TYPE) \ V(JS_WEAK_MAP_TYPE) \ V(JS_WEAK_SET_TYPE) \ V(JS_PROMISE_TYPE) \ V(JS_REGEXP_TYPE) \ \ V(JS_BOUND_FUNCTION_TYPE) \ V(JS_FUNCTION_TYPE) \ V(DEBUG_INFO_TYPE) \ V(BREAK_POINT_INFO_TYPE) // Since string types are not consecutive, this macro is used to // iterate over them. #define STRING_TYPE_LIST(V) \ V(STRING_TYPE, kVariableSizeSentinel, string, String) \ V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string, \ OneByteString) \ V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString) \ V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string, \ ConsOneByteString) \ V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString) \ V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string, \ SlicedOneByteString) \ V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string, \ ExternalString) \ V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize, \ external_one_byte_string, ExternalOneByteString) \ V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize, \ external_string_with_one_byte_data, ExternalStringWithOneByteData) \ V(SHORT_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kShortSize, \ short_external_string, ShortExternalString) \ V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kShortSize, \ short_external_one_byte_string, ShortExternalOneByteString) \ V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, \ ExternalTwoByteString::kShortSize, \ short_external_string_with_one_byte_data, \ ShortExternalStringWithOneByteData) \ \ V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string, \ InternalizedString) \ V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, \ one_byte_internalized_string, OneByteInternalizedString) \ V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize, \ external_internalized_string, ExternalInternalizedString) \ V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize, \ external_one_byte_internalized_string, ExternalOneByteInternalizedString) \ V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \ ExternalTwoByteString::kSize, \ external_internalized_string_with_one_byte_data, \ ExternalInternalizedStringWithOneByteData) \ V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE, \ ExternalTwoByteString::kShortSize, short_external_internalized_string, \ ShortExternalInternalizedString) \ V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, \ ExternalOneByteString::kShortSize, \ short_external_one_byte_internalized_string, \ ShortExternalOneByteInternalizedString) \ V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE, \ ExternalTwoByteString::kShortSize, \ short_external_internalized_string_with_one_byte_data, \ ShortExternalInternalizedStringWithOneByteData) // A struct is a simple object a set of object-valued fields. Including an // object type in this causes the compiler to generate most of the boilerplate // code for the class including allocation and garbage collection routines, // casts and predicates. All you need to define is the class, methods and // object verification routines. Easy, no? // // Note that for subtle reasons related to the ordering or numerical values of // type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST // manually. #define STRUCT_LIST(V) \ V(BOX, Box, box) \ V(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(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \ V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \ V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \ V(SCRIPT, Script, script) \ V(ALLOCATION_SITE, AllocationSite, allocation_site) \ V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento) \ V(CODE_CACHE, CodeCache, code_cache) \ V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) \ V(TYPE_FEEDBACK_INFO, TypeFeedbackInfo, type_feedback_info) \ V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \ V(DEBUG_INFO, DebugInfo, debug_info) \ V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) \ V(PROTOTYPE_INFO, PrototypeInfo, prototype_info) \ V(SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION, \ SloppyBlockWithEvalContextExtension, \ sloppy_block_with_eval_context_extension) // We use the full 8 bits of the instance_type field to encode heap object // instance types. The high-order bit (bit 7) is set if the object is not a // string, and cleared if it is a string. const uint32_t kIsNotStringMask = 0x80; const uint32_t kStringTag = 0x0; const uint32_t kNotStringTag = 0x80; // Bit 6 indicates that the object is an internalized string (if set) or not. // Bit 7 has to be clear as well. const uint32_t kIsNotInternalizedMask = 0x40; const uint32_t kNotInternalizedTag = 0x40; const uint32_t kInternalizedTag = 0x0; // If bit 7 is clear then bit 2 indicates whether the string consists of // two-byte characters or one-byte characters. const uint32_t kStringEncodingMask = 0x4; const uint32_t kTwoByteStringTag = 0x0; const uint32_t kOneByteStringTag = 0x4; // If bit 7 is clear, the low-order 2 bits indicate the representation // of the string. const uint32_t kStringRepresentationMask = 0x03; enum StringRepresentationTag { kSeqStringTag = 0x0, kConsStringTag = 0x1, kExternalStringTag = 0x2, kSlicedStringTag = 0x3 }; const uint32_t kIsIndirectStringMask = 0x1; const uint32_t kIsIndirectStringTag = 0x1; STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); // NOLINT STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); // NOLINT STATIC_ASSERT((kConsStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT STATIC_ASSERT((kSlicedStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); // NOLINT // Use this mask to distinguish between cons and slice only after making // sure that the string is one of the two (an indirect string). const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag; STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask)); // If bit 7 is clear, then bit 3 indicates whether this two-byte // string actually contains one byte data. const uint32_t kOneByteDataHintMask = 0x08; const uint32_t kOneByteDataHintTag = 0x08; // If bit 7 is clear and string representation indicates an external string, // then bit 4 indicates whether the data pointer is cached. const uint32_t kShortExternalStringMask = 0x10; const uint32_t kShortExternalStringTag = 0x10; // A ConsString with an empty string as the right side is a candidate // for being shortcut by the garbage collector. We don't allocate any // non-flat internalized strings, so we do not shortcut them thereby // avoiding turning internalized strings into strings. The bit-masks // below contain the internalized bit as additional safety. // See heap.cc, mark-compact.cc and objects-visiting.cc. const uint32_t kShortcutTypeMask = kIsNotStringMask | kIsNotInternalizedMask | kStringRepresentationMask; const uint32_t kShortcutTypeTag = kConsStringTag | kNotInternalizedTag; static inline bool IsShortcutCandidate(int type) { return ((type & kShortcutTypeMask) == kShortcutTypeTag); } enum InstanceType { // String types. INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kSeqStringTag | kInternalizedTag, // FIRST_PRIMITIVE_TYPE ONE_BYTE_INTERNALIZED_STRING_TYPE = kOneByteStringTag | kSeqStringTag | kInternalizedTag, EXTERNAL_INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kExternalStringTag | kInternalizedTag, EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE = kOneByteStringTag | kExternalStringTag | kInternalizedTag, EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE | kOneByteDataHintTag | kInternalizedTag, SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE | kShortExternalStringTag | kInternalizedTag, SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE = EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kShortExternalStringTag | kInternalizedTag, SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE = EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE | kShortExternalStringTag | kInternalizedTag, STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag, ONE_BYTE_STRING_TYPE = ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag, CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag | kNotInternalizedTag, CONS_ONE_BYTE_STRING_TYPE = kOneByteStringTag | kConsStringTag | kNotInternalizedTag, SLICED_STRING_TYPE = kTwoByteStringTag | kSlicedStringTag | kNotInternalizedTag, SLICED_ONE_BYTE_STRING_TYPE = kOneByteStringTag | kSlicedStringTag | kNotInternalizedTag, EXTERNAL_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag, EXTERNAL_ONE_BYTE_STRING_TYPE = EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag, EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE = EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE | kNotInternalizedTag, SHORT_EXTERNAL_STRING_TYPE = SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag, SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE = SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag, SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE = SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE | kNotInternalizedTag, // Non-string names SYMBOL_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE // Other primitives (cannot contain non-map-word pointers to heap objects). HEAP_NUMBER_TYPE, SIMD128_VALUE_TYPE, ODDBALL_TYPE, // LAST_PRIMITIVE_TYPE // Objects allocated in their own spaces (never in new space). MAP_TYPE, CODE_TYPE, // "Data", objects that cannot contain non-map-word pointers to heap // objects. MUTABLE_HEAP_NUMBER_TYPE, FOREIGN_TYPE, BYTE_ARRAY_TYPE, BYTECODE_ARRAY_TYPE, FREE_SPACE_TYPE, FIXED_INT8_ARRAY_TYPE, // FIRST_FIXED_TYPED_ARRAY_TYPE FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE, FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE, FIXED_FLOAT32_ARRAY_TYPE, FIXED_FLOAT64_ARRAY_TYPE, FIXED_UINT8_CLAMPED_ARRAY_TYPE, // LAST_FIXED_TYPED_ARRAY_TYPE FIXED_DOUBLE_ARRAY_TYPE, FILLER_TYPE, // LAST_DATA_TYPE // Structs. ACCESSOR_INFO_TYPE, ACCESSOR_PAIR_TYPE, ACCESS_CHECK_INFO_TYPE, INTERCEPTOR_INFO_TYPE, CALL_HANDLER_INFO_TYPE, FUNCTION_TEMPLATE_INFO_TYPE, OBJECT_TEMPLATE_INFO_TYPE, SIGNATURE_INFO_TYPE, TYPE_SWITCH_INFO_TYPE, ALLOCATION_SITE_TYPE, ALLOCATION_MEMENTO_TYPE, SCRIPT_TYPE, CODE_CACHE_TYPE, POLYMORPHIC_CODE_CACHE_TYPE, TYPE_FEEDBACK_INFO_TYPE, ALIASED_ARGUMENTS_ENTRY_TYPE, BOX_TYPE, DEBUG_INFO_TYPE, BREAK_POINT_INFO_TYPE, FIXED_ARRAY_TYPE, SHARED_FUNCTION_INFO_TYPE, CELL_TYPE, WEAK_CELL_TYPE, TRANSITION_ARRAY_TYPE, PROPERTY_CELL_TYPE, PROTOTYPE_INFO_TYPE, SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION_TYPE, // All the following types are subtypes of JSReceiver, which corresponds to // objects in the JS sense. The first and the last type in this range are // the two forms of function. This organization enables using the same // compares for checking the JS_RECEIVER and the NONCALLABLE_JS_OBJECT range. JS_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE JS_MESSAGE_OBJECT_TYPE, JS_DATE_TYPE, JS_OBJECT_TYPE, JS_CONTEXT_EXTENSION_OBJECT_TYPE, JS_GENERATOR_OBJECT_TYPE, JS_MODULE_TYPE, JS_GLOBAL_OBJECT_TYPE, JS_GLOBAL_PROXY_TYPE, JS_ARRAY_TYPE, JS_ARRAY_BUFFER_TYPE, JS_TYPED_ARRAY_TYPE, JS_DATA_VIEW_TYPE, JS_SET_TYPE, JS_MAP_TYPE, JS_SET_ITERATOR_TYPE, JS_MAP_ITERATOR_TYPE, JS_WEAK_MAP_TYPE, JS_WEAK_SET_TYPE, JS_PROMISE_TYPE, JS_REGEXP_TYPE, JS_BOUND_FUNCTION_TYPE, JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE // Pseudo-types FIRST_TYPE = 0x0, LAST_TYPE = JS_FUNCTION_TYPE, FIRST_NAME_TYPE = FIRST_TYPE, LAST_NAME_TYPE = SYMBOL_TYPE, FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE, LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE, FIRST_NONSTRING_TYPE = SYMBOL_TYPE, FIRST_PRIMITIVE_TYPE = FIRST_NAME_TYPE, LAST_PRIMITIVE_TYPE = ODDBALL_TYPE, FIRST_FUNCTION_TYPE = JS_BOUND_FUNCTION_TYPE, LAST_FUNCTION_TYPE = JS_FUNCTION_TYPE, // Boundaries for testing for a fixed typed array. FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE, LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_UINT8_CLAMPED_ARRAY_TYPE, // Boundary for promotion to old space. LAST_DATA_TYPE = FILLER_TYPE, // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy). // Note that there is no range for JSObject or JSProxy, since their subtypes // are not continuous in this enum! The enum ranges instead reflect the // external class names, where proxies are treated as either ordinary objects, // or functions. FIRST_JS_RECEIVER_TYPE = JS_PROXY_TYPE, LAST_JS_RECEIVER_TYPE = LAST_TYPE, // Boundaries for testing the types represented as JSObject FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE, LAST_JS_OBJECT_TYPE = LAST_TYPE, }; STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType); STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType); STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType); STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType); std::ostream& operator<<(std::ostream& os, InstanceType instance_type); #define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \ V(FAST_ELEMENTS_SUB_TYPE) \ V(DICTIONARY_ELEMENTS_SUB_TYPE) \ V(FAST_PROPERTIES_SUB_TYPE) \ V(DICTIONARY_PROPERTIES_SUB_TYPE) \ V(MAP_CODE_CACHE_SUB_TYPE) \ V(SCOPE_INFO_SUB_TYPE) \ V(STRING_TABLE_SUB_TYPE) \ V(DESCRIPTOR_ARRAY_SUB_TYPE) enum FixedArraySubInstanceType { #define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name, FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE) #undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE LAST_FIXED_ARRAY_SUB_TYPE = DESCRIPTOR_ARRAY_SUB_TYPE }; // TODO(bmeurer): Remove this in favor of the ComparisonResult below. enum CompareResult { LESS = -1, EQUAL = 0, GREATER = 1, NOT_EQUAL = GREATER }; // Result of an abstract relational comparison of x and y, implemented according // to ES6 section 7.2.11 Abstract Relational Comparison. enum class ComparisonResult { kLessThan, // x < y kEqual, // x = y kGreaterThan, // x > y kUndefined // at least one of x or y was undefined or NaN }; #define DECL_BOOLEAN_ACCESSORS(name) \ inline bool name() const; \ inline void set_##name(bool value); #define DECL_INT_ACCESSORS(name) \ inline int name() const; \ inline void set_##name(int value); #define DECL_ACCESSORS(name, type) \ inline type* name() const; \ inline void set_##name(type* value, \ WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \ #define DECLARE_CAST(type) \ INLINE(static type* cast(Object* object)); \ INLINE(static const type* cast(const Object* object)); class AccessorPair; class AllocationSite; class AllocationSiteCreationContext; class AllocationSiteUsageContext; class Cell; class ConsString; class ElementsAccessor; class FixedArrayBase; class FunctionLiteral; class JSGlobalObject; class KeyAccumulator; class LayoutDescriptor; class LiteralsArray; class LookupIterator; class FieldType; class ObjectHashTable; class ObjectVisitor; class PropertyCell; class PropertyDescriptor; class SafepointEntry; class SharedFunctionInfo; class StringStream; class TypeFeedbackInfo; class TypeFeedbackVector; class WeakCell; class TransitionArray; // A template-ized version of the IsXXX functions. template <class C> inline bool Is(Object* obj); #ifdef VERIFY_HEAP #define DECLARE_VERIFIER(Name) void Name##Verify(); #else #define DECLARE_VERIFIER(Name) #endif #ifdef OBJECT_PRINT #define DECLARE_PRINTER(Name) void Name##Print(std::ostream& os); // NOLINT #else #define DECLARE_PRINTER(Name) #endif #define OBJECT_TYPE_LIST(V) \ V(Smi) \ V(HeapObject) \ V(Number) #define HEAP_OBJECT_TYPE_LIST(V) \ V(HeapNumber) \ V(MutableHeapNumber) \ V(Simd128Value) \ V(Float32x4) \ V(Int32x4) \ V(Uint32x4) \ V(Bool32x4) \ V(Int16x8) \ V(Uint16x8) \ V(Bool16x8) \ V(Int8x16) \ V(Uint8x16) \ V(Bool8x16) \ V(Name) \ V(UniqueName) \ V(String) \ V(SeqString) \ V(ExternalString) \ V(ConsString) \ V(SlicedString) \ V(ExternalTwoByteString) \ V(ExternalOneByteString) \ V(SeqTwoByteString) \ V(SeqOneByteString) \ V(InternalizedString) \ V(Symbol) \ \ V(FixedTypedArrayBase) \ V(FixedUint8Array) \ V(FixedInt8Array) \ V(FixedUint16Array) \ V(FixedInt16Array) \ V(FixedUint32Array) \ V(FixedInt32Array) \ V(FixedFloat32Array) \ V(FixedFloat64Array) \ V(FixedUint8ClampedArray) \ V(ByteArray) \ V(BytecodeArray) \ V(FreeSpace) \ V(JSReceiver) \ V(JSObject) \ V(JSContextExtensionObject) \ V(JSGeneratorObject) \ V(JSModule) \ V(LayoutDescriptor) \ V(Map) \ V(DescriptorArray) \ V(TransitionArray) \ V(LiteralsArray) \ V(TypeFeedbackMetadata) \ V(TypeFeedbackVector) \ V(DeoptimizationInputData) \ V(DeoptimizationOutputData) \ V(DependentCode) \ V(HandlerTable) \ V(FixedArray) \ V(FixedDoubleArray) \ V(WeakFixedArray) \ V(ArrayList) \ V(Context) \ V(ScriptContextTable) \ V(NativeContext) \ V(ScopeInfo) \ V(JSBoundFunction) \ V(JSFunction) \ V(Code) \ V(AbstractCode) \ V(Oddball) \ V(SharedFunctionInfo) \ V(JSValue) \ V(JSDate) \ V(JSMessageObject) \ V(StringWrapper) \ V(Foreign) \ V(Boolean) \ V(JSArray) \ V(JSArrayBuffer) \ V(JSArrayBufferView) \ V(JSTypedArray) \ V(JSDataView) \ V(JSProxy) \ V(JSSet) \ V(JSMap) \ V(JSSetIterator) \ V(JSMapIterator) \ V(JSWeakCollection) \ V(JSWeakMap) \ V(JSWeakSet) \ V(JSRegExp) \ V(HashTable) \ V(Dictionary) \ V(StringTable) \ V(NormalizedMapCache) \ V(CompilationCacheTable) \ V(CodeCacheHashTable) \ V(PolymorphicCodeCacheHashTable) \ V(MapCache) \ V(Primitive) \ V(JSGlobalObject) \ V(JSGlobalProxy) \ V(UndetectableObject) \ V(AccessCheckNeeded) \ V(Cell) \ V(PropertyCell) \ V(WeakCell) \ V(ObjectHashTable) \ V(WeakHashTable) \ V(OrderedHashTable) // The element types selection for CreateListFromArrayLike. enum class ElementTypes { kAll, kStringAndSymbol }; // Object is the abstract superclass for all classes in the // object hierarchy. // Object does not use any virtual functions to avoid the // allocation of the C++ vtable. // Since both Smi and HeapObject are subclasses of Object no // data members can be present in Object. class Object { public: // Type testing. bool IsObject() const { return true; } #define IS_TYPE_FUNCTION_DECL(type_) INLINE(bool Is##type_() const); OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) #undef IS_TYPE_FUNCTION_DECL // A non-keyed store is of the form a.x = foo or a["x"] = foo whereas // a keyed store is of the form a[expression] = foo. enum StoreFromKeyed { MAY_BE_STORE_FROM_KEYED, CERTAINLY_NOT_STORE_FROM_KEYED }; enum ShouldThrow { THROW_ON_ERROR, DONT_THROW }; #define RETURN_FAILURE(isolate, should_throw, call) \ do { \ if ((should_throw) == DONT_THROW) { \ return Just(false); \ } else { \ isolate->Throw(*isolate->factory()->call); \ return Nothing<bool>(); \ } \ } while (false) #define MAYBE_RETURN(call, value) \ do { \ if ((call).IsNothing()) return value; \ } while (false) #define MAYBE_RETURN_NULL(call) MAYBE_RETURN(call, MaybeHandle<Object>()) INLINE(bool IsFixedArrayBase() const); INLINE(bool IsExternal() const); INLINE(bool IsStruct() const); #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \ INLINE(bool Is##Name() const); STRUCT_LIST(DECLARE_STRUCT_PREDICATE) #undef DECLARE_STRUCT_PREDICATE // ES6, section 7.2.2 IsArray. NOT to be confused with %_IsArray. MUST_USE_RESULT static Maybe<bool> IsArray(Handle<Object> object); // Test for JSBoundFunction or JSFunction. INLINE(bool IsFunction() const); // ES6, section 7.2.3 IsCallable. INLINE(bool IsCallable() const); // ES6, section 7.2.4 IsConstructor. INLINE(bool IsConstructor() const); INLINE(bool IsTemplateInfo()) const; INLINE(bool IsNameDictionary() const); INLINE(bool IsGlobalDictionary() const); INLINE(bool IsSeededNumberDictionary() const); INLINE(bool IsUnseededNumberDictionary() const); INLINE(bool IsOrderedHashSet() const); INLINE(bool IsOrderedHashMap() const); static bool IsPromise(Handle<Object> object); // Oddball testing. INLINE(bool IsUndefined() const); INLINE(bool IsNull() const); INLINE(bool IsTheHole() const); INLINE(bool IsException() const); INLINE(bool IsUninitialized() const); INLINE(bool IsTrue() const); INLINE(bool IsFalse() const); INLINE(bool IsArgumentsMarker() const); // Filler objects (fillers and free space objects). INLINE(bool IsFiller() const); // Extract the number. inline double Number() const; INLINE(bool IsNaN() const); INLINE(bool IsMinusZero() const); bool ToInt32(int32_t* value); bool ToUint32(uint32_t* value); inline Representation OptimalRepresentation(); inline ElementsKind OptimalElementsKind(); inline bool FitsRepresentation(Representation representation); // Checks whether two valid primitive encodings of a property name resolve to // the same logical property. E.g., the smi 1, the string "1" and the double // 1 all refer to the same property, so this helper will return true. inline bool KeyEquals(Object* other); inline bool FilterKey(PropertyFilter filter); Handle<FieldType> OptimalType(Isolate* isolate, Representation representation); inline static Handle<Object> NewStorageFor(Isolate* isolate, Handle<Object> object, Representation representation); inline static Handle<Object> WrapForRead(Isolate* isolate, Handle<Object> object, Representation representation); // Returns true if the object is of the correct type to be used as a // implementation of a JSObject's elements. inline bool HasValidElements(); inline bool HasSpecificClassOf(String* name); bool BooleanValue(); // ECMA-262 9.2. // ES6 section 7.2.11 Abstract Relational Comparison MUST_USE_RESULT static Maybe<ComparisonResult> Compare( Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK); // ES6 section 7.2.12 Abstract Equality Comparison MUST_USE_RESULT static Maybe<bool> Equals(Handle<Object> x, Handle<Object> y); // ES6 section 7.2.13 Strict Equality Comparison bool StrictEquals(Object* that); // Convert to a JSObject if needed. // native_context is used when creating wrapper object. MUST_USE_RESULT static inline MaybeHandle<JSReceiver> ToObject( Isolate* isolate, Handle<Object> object); MUST_USE_RESULT static MaybeHandle<JSReceiver> ToObject( Isolate* isolate, Handle<Object> object, Handle<Context> context); // ES6 section 7.1.14 ToPropertyKey MUST_USE_RESULT static MaybeHandle<Name> ToName(Isolate* isolate, Handle<Object> input); // ES6 section 7.1.1 ToPrimitive MUST_USE_RESULT static inline MaybeHandle<Object> ToPrimitive( Handle<Object> input, ToPrimitiveHint hint = ToPrimitiveHint::kDefault); // ES6 section 7.1.3 ToNumber MUST_USE_RESULT static MaybeHandle<Object> ToNumber(Handle<Object> input); // ES6 section 7.1.4 ToInteger MUST_USE_RESULT static MaybeHandle<Object> ToInteger(Isolate* isolate, Handle<Object> input); // ES6 section 7.1.5 ToInt32 MUST_USE_RESULT static MaybeHandle<Object> ToInt32(Isolate* isolate, Handle<Object> input); // ES6 section 7.1.6 ToUint32 MUST_USE_RESULT static MaybeHandle<Object> ToUint32(Isolate* isolate, Handle<Object> input); // ES6 section 7.1.12 ToString MUST_USE_RESULT static MaybeHandle<String> ToString(Isolate* isolate, Handle<Object> input); // ES6 section 7.1.15 ToLength MUST_USE_RESULT static MaybeHandle<Object> ToLength(Isolate* isolate, Handle<Object> input); // ES6 section 7.3.9 GetMethod MUST_USE_RESULT static MaybeHandle<Object> GetMethod( Handle<JSReceiver> receiver, Handle<Name> name); // ES6 section 7.3.17 CreateListFromArrayLike MUST_USE_RESULT static MaybeHandle<FixedArray> CreateListFromArrayLike( Isolate* isolate, Handle<Object> object, ElementTypes element_types); // Check whether |object| is an instance of Error or NativeError. static bool IsErrorObject(Isolate* isolate, Handle<Object> object); // ES6 section 12.5.6 The typeof Operator static Handle<String> TypeOf(Isolate* isolate, Handle<Object> object); // ES6 section 12.6 Multiplicative Operators MUST_USE_RESULT static MaybeHandle<Object> Multiply( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> Divide( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> Modulus( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); // ES6 section 12.7 Additive Operators MUST_USE_RESULT static MaybeHandle<Object> Add( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> Subtract( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); // ES6 section 12.8 Bitwise Shift Operators MUST_USE_RESULT static MaybeHandle<Object> ShiftLeft( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> ShiftRight( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> ShiftRightLogical( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); // ES6 section 12.9 Relational Operators MUST_USE_RESULT static inline Maybe<bool> GreaterThan( Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK); MUST_USE_RESULT static inline Maybe<bool> GreaterThanOrEqual( Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK); MUST_USE_RESULT static inline Maybe<bool> LessThan( Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK); MUST_USE_RESULT static inline Maybe<bool> LessThanOrEqual( Handle<Object> x, Handle<Object> y, Strength strength = Strength::WEAK); // ES6 section 12.11 Binary Bitwise Operators MUST_USE_RESULT static MaybeHandle<Object> BitwiseAnd( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> BitwiseOr( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> BitwiseXor( Isolate* isolate, Handle<Object> lhs, Handle<Object> rhs, Strength strength = Strength::WEAK); MUST_USE_RESULT static MaybeHandle<Object> GetProperty( LookupIterator* it, LanguageMode language_mode = SLOPPY); // ES6 [[Set]] (when passed DONT_THROW) // Invariants for this and related functions (unless stated otherwise): // 1) When the result is Nothing, an exception is pending. // 2) When passed THROW_ON_ERROR, the result is never Just(false). // In some cases, an exception is thrown regardless of the ShouldThrow // argument. These cases are either in accordance with the spec or not // covered by it (eg., concerning API callbacks). MUST_USE_RESULT static Maybe<bool> SetProperty(LookupIterator* it, Handle<Object> value, LanguageMode language_mode, StoreFromKeyed store_mode); MUST_USE_RESULT static MaybeHandle<Object> SetProperty( Handle<Object> object, Handle<Name> name, Handle<Object> value, LanguageMode language_mode, StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED); MUST_USE_RESULT static Maybe<bool> SetSuperProperty( LookupIterator* it, Handle<Object> value, LanguageMode language_mode, StoreFromKeyed store_mode); MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty( LookupIterator* it, LanguageMode language_mode); MUST_USE_RESULT static MaybeHandle<Object> ReadAbsentProperty( Isolate* isolate, Handle<Object> receiver, Handle<Object> name, LanguageMode language_mode); MUST_USE_RESULT static Maybe<bool> CannotCreateProperty( Isolate* isolate, Handle<Object> receiver, Handle<Object> name, Handle<Object> value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> WriteToReadOnlyProperty( LookupIterator* it, Handle<Object> value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> WriteToReadOnlyProperty( Isolate* isolate, Handle<Object> receiver, Handle<Object> name, Handle<Object> value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> RedefineIncompatibleProperty( Isolate* isolate, Handle<Object> name, Handle<Object> value, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> SetDataProperty(LookupIterator* it, Handle<Object> value); MUST_USE_RESULT static Maybe<bool> AddDataProperty( LookupIterator* it, Handle<Object> value, PropertyAttributes attributes, ShouldThrow should_throw, StoreFromKeyed store_mode); MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement( Handle<Object> object, Handle<Name> name, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static inline MaybeHandle<Object> GetPropertyOrElement( Handle<Object> receiver, Handle<Name> name, Handle<JSReceiver> holder, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty( Isolate* isolate, Handle<Object> object, const char* key, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static inline MaybeHandle<Object> GetProperty( Handle<Object> object, Handle<Name> name, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithAccessor( LookupIterator* it, LanguageMode language_mode); MUST_USE_RESULT static Maybe<bool> SetPropertyWithAccessor( LookupIterator* it, Handle<Object> value, ShouldThrow should_throw); MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithDefinedGetter( Handle<Object> receiver, Handle<JSReceiver> getter); MUST_USE_RESULT static Maybe<bool> SetPropertyWithDefinedSetter( Handle<Object> receiver, Handle<JSReceiver> setter, Handle<Object> value, ShouldThrow should_throw); MUST_USE_RESULT static inline MaybeHandle<Object> GetElement( Isolate* isolate, Handle<Object> object, uint32_t index, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static inline MaybeHandle<Object> SetElement( Isolate* isolate, Handle<Object> object, uint32_t index, Handle<Object> value, LanguageMode language_mode); // Returns the permanent hash code associated with this object. May return // undefined if not yet created. Object* GetHash(); // Returns undefined for JSObjects, but returns the hash code for simple // objects. This avoids a double lookup in the cases where we know we will // add the hash to the JSObject if it does not already exist. Object* GetSimpleHash(); // Returns the permanent hash code associated with this object depending on // the actual object type. May create and store a hash code if needed and none // exists. static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object); // Checks whether this object has the same value as the given one. This // function is implemented according to ES5, section 9.12 and can be used // to implement the Harmony "egal" function. bool SameValue(Object* other); // Checks whether this object has the same value as the given one. // +0 and -0 are treated equal. Everything else is the same as SameValue. // This function is implemented according to ES6, section 7.2.4 and is used // by ES6 Map and Set. bool SameValueZero(Object* other); // ES6 section 9.4.2.3 ArraySpeciesCreate (part of it) MUST_USE_RESULT static MaybeHandle<Object> ArraySpeciesConstructor( Isolate* isolate, Handle<Object> original_array); // Tries to convert an object to an array length. Returns true and sets the // output parameter if it succeeds. inline bool ToArrayLength(uint32_t* index); // Tries to convert an object to an array index. Returns true and sets the // output parameter if it succeeds. Equivalent to ToArrayLength, but does not // allow kMaxUInt32. inline bool ToArrayIndex(uint32_t* index); DECLARE_VERIFIER(Object) #ifdef VERIFY_HEAP // Verify a pointer is a valid object pointer. static void VerifyPointer(Object* p); #endif inline void VerifyApiCallResultType(); // ES6 19.1.3.6 Object.prototype.toString MUST_USE_RESULT static MaybeHandle<String> ObjectProtoToString( Isolate* isolate, Handle<Object> object); // Prints this object without details. void ShortPrint(FILE* out = stdout); // Prints this object without details to a message accumulator. void ShortPrint(StringStream* accumulator); void ShortPrint(std::ostream& os); // NOLINT DECLARE_CAST(Object) // Layout description. static const int kHeaderSize = 0; // Object does not take up any space. #ifdef OBJECT_PRINT // For our gdb macros, we should perhaps change these in the future. void Print(); // Prints this object with details. void Print(std::ostream& os); // NOLINT #else void Print() { ShortPrint(); } void Print(std::ostream& os) { ShortPrint(os); } // NOLINT #endif private: friend class LookupIterator; friend class StringStream; // Return the map of the root of object's prototype chain. Map* GetRootMap(Isolate* isolate); // Helper for SetProperty and SetSuperProperty. // Return value is only meaningful if [found] is set to true on return. MUST_USE_RESULT static Maybe<bool> SetPropertyInternal( LookupIterator* it, Handle<Object> value, LanguageMode language_mode, StoreFromKeyed store_mode, bool* found); DISALLOW_IMPLICIT_CONSTRUCTORS(Object); }; // In objects.h to be usable without objects-inl.h inclusion. bool Object::IsSmi() const { return HAS_SMI_TAG(this); } bool Object::IsHeapObject() const { return Internals::HasHeapObjectTag(this); } struct Brief { explicit Brief(const Object* const v) : value(v) {} const Object* value; }; std::ostream& operator<<(std::ostream& os, const Brief& v); // Smi represents integer Numbers that can be stored in 31 bits. // Smis are immediate which means they are NOT allocated in the heap. // The this pointer has the following format: [31 bit signed int] 0 // For long smis it has the following format: // [32 bit signed int] [31 bits zero padding] 0 // Smi stands for small integer. class Smi: public Object { public: // Returns the integer value. inline int value() const { return Internals::SmiValue(this); } // Convert a value to a Smi object. static inline Smi* FromInt(int value) { DCHECK(Smi::IsValid(value)); return reinterpret_cast<Smi*>(Internals::IntToSmi(value)); } static inline Smi* FromIntptr(intptr_t value) { DCHECK(Smi::IsValid(value)); int smi_shift_bits = kSmiTagSize + kSmiShiftSize; return reinterpret_cast<Smi*>((value << smi_shift_bits) | kSmiTag); } // Returns whether value can be represented in a Smi. static inline bool IsValid(intptr_t value) { bool result = Internals::IsValidSmi(value); DCHECK_EQ(result, value >= kMinValue && value <= kMaxValue); return result; } DECLARE_CAST(Smi) // Dispatched behavior. void SmiPrint(std::ostream& os) const; // NOLINT DECLARE_VERIFIER(Smi) static const int kMinValue = (static_cast<unsigned int>(-1)) << (kSmiValueSize - 1); static const int kMaxValue = -(kMinValue + 1); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Smi); }; // Heap objects typically have a map pointer in their first word. However, // during GC other data (e.g. mark bits, forwarding addresses) is sometimes // encoded in the first word. The class MapWord is an abstraction of the // value in a heap object's first word. class MapWord BASE_EMBEDDED { public: // Normal state: the map word contains a map pointer. // Create a map word from a map pointer. static inline MapWord FromMap(const Map* map); // View this map word as a map pointer. inline Map* ToMap(); // Scavenge collection: the map word of live objects in the from space // contains a forwarding address (a heap object pointer in the to space). // True if this map word is a forwarding address for a scavenge // collection. Only valid during a scavenge collection (specifically, // when all map words are heap object pointers, i.e. not during a full GC). inline bool IsForwardingAddress(); // Create a map word from a forwarding address. static inline MapWord FromForwardingAddress(HeapObject* object); // View this map word as a forwarding address. inline HeapObject* ToForwardingAddress(); static inline MapWord FromRawValue(uintptr_t value) { return MapWord(value); } inline uintptr_t ToRawValue() { return value_; } private: // HeapObject calls the private constructor and directly reads the value. friend class HeapObject; explicit MapWord(uintptr_t value) : value_(value) {} uintptr_t value_; }; // HeapObject is the superclass for all classes describing heap allocated // objects. class HeapObject: public Object { public: // [map]: Contains a map which contains the object's reflective // information. inline Map* map() const; inline void set_map(Map* value); // The no-write-barrier version. This is OK if the object is white and in // new space, or if the value is an immortal immutable object, like the maps // of primitive (non-JS) objects like strings, heap numbers etc. inline void set_map_no_write_barrier(Map* value); // Get the map using acquire load. inline Map* synchronized_map(); inline MapWord synchronized_map_word() const; // Set the map using release store inline void synchronized_set_map(Map* value); inline void synchronized_set_map_no_write_barrier(Map* value); inline void synchronized_set_map_word(MapWord map_word); // During garbage collection, the map word of a heap object does not // necessarily contain a map pointer. inline MapWord map_word() const; inline void set_map_word(MapWord map_word); // The Heap the object was allocated in. Used also to access Isolate. inline Heap* GetHeap() const; // Convenience method to get current isolate. inline Isolate* GetIsolate() const; // Converts an address to a HeapObject pointer. static inline HeapObject* FromAddress(Address address) { DCHECK_TAG_ALIGNED(address); return reinterpret_cast<HeapObject*>(address + kHeapObjectTag); } // Returns the address of this HeapObject. inline Address address() { return reinterpret_cast<Address>(this) - kHeapObjectTag; } // Iterates over pointers contained in the object (including the Map). // If it's not performance critical iteration use the non-templatized // version. void Iterate(ObjectVisitor* v); template <typename ObjectVisitor> inline void IterateFast(ObjectVisitor* v); // Iterates over all pointers contained in the object except the // first map pointer. The object type is given in the first // parameter. This function does not access the map pointer in the // object, and so is safe to call while the map pointer is modified. // If it's not performance critical iteration use the non-templatized // version. void IterateBody(ObjectVisitor* v); void IterateBody(InstanceType type, int object_size, ObjectVisitor* v); template <typename ObjectVisitor> inline void IterateBodyFast(ObjectVisitor* v); template <typename ObjectVisitor> inline void IterateBodyFast(InstanceType type, int object_size, ObjectVisitor* v); // Returns true if the object contains a tagged value at given offset. // It is used for invalid slots filtering. If the offset points outside // of the object or to the map word, the result is UNDEFINED (!!!). bool IsValidSlot(int offset); // Returns the heap object's size in bytes inline int Size(); // Given a heap object's map pointer, returns the heap size in bytes // Useful when the map pointer field is used for other purposes. // GC internal. inline int SizeFromMap(Map* map); // Returns the field at offset in obj, as a read/write Object* reference. // Does no checking, and is safe to use during GC, while maps are invalid. // Does not invoke write barrier, so should only be assigned to // during marking GC. static inline Object** RawField(HeapObject* obj, int offset); // Adds the |code| object related to |name| to the code cache of this map. If // this map is a dictionary map that is shared, the map copied and installed // onto the object. static void UpdateMapCodeCache(Handle<HeapObject> object, Handle<Name> name, Handle<Code> code); DECLARE_CAST(HeapObject) // Return the write barrier mode for this. Callers of this function // must be able to present a reference to an DisallowHeapAllocation // object as a sign that they are not going to use this function // from code that allocates and thus invalidates the returned write // barrier mode. inline WriteBarrierMode GetWriteBarrierMode( const DisallowHeapAllocation& promise); // Dispatched behavior. void HeapObjectShortPrint(std::ostream& os); // NOLINT #ifdef OBJECT_PRINT void PrintHeader(std::ostream& os, const char* id); // NOLINT #endif DECLARE_PRINTER(HeapObject) DECLARE_VERIFIER(HeapObject) #ifdef VERIFY_HEAP inline void VerifyObjectField(int offset); inline void VerifySmiField(int offset); // Verify a pointer is a valid HeapObject pointer that points to object // areas in the heap. static void VerifyHeapPointer(Object* p); #endif inline AllocationAlignment RequiredAlignment(); // Layout description. // First field in a heap object is map. static const int kMapOffset = Object::kHeaderSize; static const int kHeaderSize = kMapOffset + kPointerSize; STATIC_ASSERT(kMapOffset == Internals::kHeapObjectMapOffset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject); }; template <int start_offset, int end_offset, int size> class FixedBodyDescriptor; template <int start_offset> class FlexibleBodyDescriptor; // The HeapNumber class describes heap allocated numbers that cannot be // represented in a Smi (small integer) class HeapNumber: public HeapObject { public: // [value]: number value. inline double value() const; inline void set_value(double value); DECLARE_CAST(HeapNumber) // Dispatched behavior. bool HeapNumberBooleanValue(); void HeapNumberPrint(std::ostream& os); // NOLINT DECLARE_VERIFIER(HeapNumber) inline int get_exponent(); inline int get_sign(); // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; // IEEE doubles are two 32 bit words. The first is just mantissa, the second // is a mixture of sign, exponent and mantissa. The offsets of two 32 bit // words within double numbers are endian dependent and they are set // accordingly. #if defined(V8_TARGET_LITTLE_ENDIAN) static const int kMantissaOffset = kValueOffset; static const int kExponentOffset = kValueOffset + 4; #elif defined(V8_TARGET_BIG_ENDIAN) static const int kMantissaOffset = kValueOffset + 4; static const int kExponentOffset = kValueOffset; #else #error Unknown byte ordering #endif static const int kSize = kValueOffset + kDoubleSize; static const uint32_t kSignMask = 0x80000000u; static const uint32_t kExponentMask = 0x7ff00000u; static const uint32_t kMantissaMask = 0xfffffu; static const int kMantissaBits = 52; static const int kExponentBits = 11; static const int kExponentBias = 1023; static const int kExponentShift = 20; static const int kInfinityOrNanExponent = (kExponentMask >> kExponentShift) - kExponentBias; static const int kMantissaBitsInTopWord = 20; static const int kNonMantissaBitsInTopWord = 12; private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber); }; // The Simd128Value class describes heap allocated 128 bit SIMD values. class Simd128Value : public HeapObject { public: DECLARE_CAST(Simd128Value) DECLARE_PRINTER(Simd128Value) DECLARE_VERIFIER(Simd128Value) static Handle<String> ToString(Handle<Simd128Value> input); // Equality operations. inline bool Equals(Simd128Value* that); static inline bool Equals(Handle<Simd128Value> one, Handle<Simd128Value> two); // Checks that another instance is bit-wise equal. bool BitwiseEquals(const Simd128Value* other) const; // Computes a hash from the 128 bit value, viewed as 4 32-bit integers. uint32_t Hash() const; // Copies the 16 bytes of SIMD data to the destination address. void CopyBits(void* destination) const; // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; static const int kSize = kValueOffset + kSimd128Size; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Simd128Value); }; // V has parameters (TYPE, Type, type, lane count, lane type) #define SIMD128_TYPES(V) \ V(FLOAT32X4, Float32x4, float32x4, 4, float) \ V(INT32X4, Int32x4, int32x4, 4, int32_t) \ V(UINT32X4, Uint32x4, uint32x4, 4, uint32_t) \ V(BOOL32X4, Bool32x4, bool32x4, 4, bool) \ V(INT16X8, Int16x8, int16x8, 8, int16_t) \ V(UINT16X8, Uint16x8, uint16x8, 8, uint16_t) \ V(BOOL16X8, Bool16x8, bool16x8, 8, bool) \ V(INT8X16, Int8x16, int8x16, 16, int8_t) \ V(UINT8X16, Uint8x16, uint8x16, 16, uint8_t) \ V(BOOL8X16, Bool8x16, bool8x16, 16, bool) #define SIMD128_VALUE_CLASS(TYPE, Type, type, lane_count, lane_type) \ class Type final : public Simd128Value { \ public: \ inline lane_type get_lane(int lane) const; \ inline void set_lane(int lane, lane_type value); \ \ DECLARE_CAST(Type) \ \ DECLARE_PRINTER(Type) \ \ static Handle<String> ToString(Handle<Type> input); \ \ inline bool Equals(Type* that); \ \ private: \ DISALLOW_IMPLICIT_CONSTRUCTORS(Type); \ }; SIMD128_TYPES(SIMD128_VALUE_CLASS) #undef SIMD128_VALUE_CLASS enum EnsureElementsMode { DONT_ALLOW_DOUBLE_ELEMENTS, ALLOW_COPIED_DOUBLE_ELEMENTS, ALLOW_CONVERTED_DOUBLE_ELEMENTS }; // Indicator for one component of an AccessorPair. enum AccessorComponent { ACCESSOR_GETTER, ACCESSOR_SETTER }; enum GetKeysConversion { KEEP_NUMBERS, CONVERT_TO_STRING }; enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS }; // JSReceiver includes types on which properties can be defined, i.e., // JSObject and JSProxy. class JSReceiver: public HeapObject { public: // [properties]: Backing storage for properties. // properties is a FixedArray in the fast case and a Dictionary in the // slow case. DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties. inline void initialize_properties(); inline bool HasFastProperties(); // Gets slow properties for non-global objects. inline NameDictionary* property_dictionary(); // Deletes an existing named property in a normalized object. static void DeleteNormalizedProperty(Handle<JSReceiver> object, Handle<Name> name, int entry); DECLARE_CAST(JSReceiver) // ES6 section 7.1.1 ToPrimitive MUST_USE_RESULT static MaybeHandle<Object> ToPrimitive( Handle<JSReceiver> receiver, ToPrimitiveHint hint = ToPrimitiveHint::kDefault); MUST_USE_RESULT static MaybeHandle<Object> OrdinaryToPrimitive( Handle<JSReceiver> receiver, OrdinaryToPrimitiveHint hint); static MaybeHandle<Context> GetFunctionRealm(Handle<JSReceiver> receiver); // Get the first non-hidden prototype. static inline MaybeHandle<Object> GetPrototype(Isolate* isolate, Handle<JSReceiver> receiver); MUST_USE_RESULT static Maybe<bool> HasInPrototypeChain( Isolate* isolate, Handle<JSReceiver> object, Handle<Object> proto); // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6. MUST_USE_RESULT static Maybe<bool> HasProperty(LookupIterator* it); MUST_USE_RESULT static inline Maybe<bool> HasProperty( Handle<JSReceiver> object, Handle<Name> name); MUST_USE_RESULT static inline Maybe<bool> HasElement( Handle<JSReceiver> object, uint32_t index); MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty( Handle<JSReceiver> object, Handle<Name> name); // Implementation of ES6 [[Delete]] MUST_USE_RESULT static Maybe<bool> DeletePropertyOrElement( Handle<JSReceiver> object, Handle<Name> name, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static Maybe<bool> DeleteProperty( Handle<JSReceiver> object, Handle<Name> name, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static Maybe<bool> DeleteProperty(LookupIterator* it, LanguageMode language_mode); MUST_USE_RESULT static Maybe<bool> DeleteElement( Handle<JSReceiver> object, uint32_t index, LanguageMode language_mode = SLOPPY); MUST_USE_RESULT static Object* DefineProperty(Isolate* isolate, Handle<Object> object, Handle<Object> name, Handle<Object> attributes); MUST_USE_RESULT static MaybeHandle<Object> DefineProperties( Isolate* isolate, Handle<Object> object, Handle<Object> properties); // "virtual" dispatcher to the correct [[DefineOwnProperty]] implementation. MUST_USE_RESULT static Maybe<bool> DefineOwnProperty( Isolate* isolate, Handle<JSReceiver> object, Handle<Object> key, PropertyDescriptor* desc, ShouldThrow should_throw); // ES6 7.3.4 (when passed DONT_THROW) MUST_USE_RESULT static Maybe<bool> CreateDataProperty( LookupIterator* it, Handle<Object> value, ShouldThrow should_throw); // ES6 9.1.6.1 MUST_USE_RESULT static Maybe<bool> OrdinaryDefineOwnProperty( Isolate* isolate, Handle<JSObject> object, Handle<Object> key, PropertyDescriptor* desc, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> OrdinaryDefineOwnProperty( LookupIterator* it, PropertyDescriptor* desc, ShouldThrow should_throw); // ES6 9.1.6.2 MUST_USE_RESULT static Maybe<bool> IsCompatiblePropertyDescriptor( Isolate* isolate, bool extensible, PropertyDescriptor* desc, PropertyDescriptor* current, Handle<Name> property_name, ShouldThrow should_throw); // ES6 9.1.6.3 // |it| can be NULL in cases where the ES spec passes |undefined| as the // receiver. Exactly one of |it| and |property_name| must be provided. MUST_USE_RESULT static Maybe<bool> ValidateAndApplyPropertyDescriptor( Isolate* isolate, LookupIterator* it, bool extensible, PropertyDescriptor* desc, PropertyDescriptor* current, ShouldThrow should_throw, Handle<Name> property_name = Handle<Name>()); MUST_USE_RESULT static Maybe<bool> GetOwnPropertyDescriptor( Isolate* isolate, Handle<JSReceiver> object, Handle<Object> key, PropertyDescriptor* desc); MUST_USE_RESULT static Maybe<bool> GetOwnPropertyDescriptor( LookupIterator* it, PropertyDescriptor* desc); typedef PropertyAttributes IntegrityLevel; // ES6 7.3.14 (when passed DONT_THROW) // 'level' must be SEALED or FROZEN. MUST_USE_RESULT static Maybe<bool> SetIntegrityLevel( Handle<JSReceiver> object, IntegrityLevel lvl, ShouldThrow should_throw); // ES6 7.3.15 // 'level' must be SEALED or FROZEN. MUST_USE_RESULT static Maybe<bool> TestIntegrityLevel( Handle<JSReceiver> object, IntegrityLevel lvl); // ES6 [[PreventExtensions]] (when passed DONT_THROW) MUST_USE_RESULT static Maybe<bool> PreventExtensions( Handle<JSReceiver> object, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSReceiver> object); // Tests for the fast common case for property enumeration. bool IsSimpleEnum(); // Returns the class name ([[Class]] property in the specification). String* class_name(); // Returns the builtin string tag used in Object.prototype.toString. MUST_USE_RESULT static MaybeHandle<String> BuiltinStringTag( Handle<JSReceiver> object); // Returns the constructor name (the name (possibly, inferred name) of the // function that was used to instantiate the object). static Handle<String> GetConstructorName(Handle<JSReceiver> receiver); Context* GetCreationContext(); MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes( Handle<JSReceiver> object, Handle<Name> name); MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name); MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetElementAttributes( Handle<JSReceiver> object, uint32_t index); MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetOwnElementAttributes(Handle<JSReceiver> object, uint32_t index); MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes( LookupIterator* it); // Set the object's prototype (only JSReceiver and null are allowed values). MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSReceiver> object, Handle<Object> value, bool from_javascript, ShouldThrow should_throw); static Handle<Object> GetDataProperty(Handle<JSReceiver> object, Handle<Name> name); static Handle<Object> GetDataProperty(LookupIterator* it); // Retrieves a permanent object identity hash code. The undefined value might // be returned in case no hash was created yet. inline Object* GetIdentityHash(); // Retrieves a permanent object identity hash code. May create and store a // hash code if needed and none exists. inline static Handle<Smi> GetOrCreateIdentityHash( Handle<JSReceiver> object); // ES6 [[OwnPropertyKeys]] (modulo return type) MUST_USE_RESULT static MaybeHandle<FixedArray> OwnPropertyKeys( Handle<JSReceiver> object) { return GetKeys(object, OWN_ONLY, ALL_PROPERTIES, CONVERT_TO_STRING); } // Computes the enumerable keys for a JSObject. Used for implementing // "for (n in object) { }". MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys( Handle<JSReceiver> object, KeyCollectionType type, PropertyFilter filter, GetKeysConversion keys_conversion = KEEP_NUMBERS); MUST_USE_RESULT static MaybeHandle<FixedArray> GetOwnValues( Handle<JSReceiver> object, PropertyFilter filter); MUST_USE_RESULT static MaybeHandle<FixedArray> GetOwnEntries( Handle<JSReceiver> object, PropertyFilter filter); // Layout description. static const int kPropertiesOffset = HeapObject::kHeaderSize; static const int kHeaderSize = HeapObject::kHeaderSize + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver); }; // The JSObject describes real heap allocated JavaScript objects with // properties. // Note that the map of JSObject changes during execution to enable inline // caching. class JSObject: public JSReceiver { public: static MUST_USE_RESULT MaybeHandle<JSObject> New( Handle<JSFunction> constructor, Handle<JSReceiver> new_target, Handle<AllocationSite> site = Handle<AllocationSite>::null()); // Gets global object properties. inline GlobalDictionary* global_dictionary(); static MaybeHandle<Context> GetFunctionRealm(Handle<JSObject> object); // [elements]: The elements (properties with names that are integers). // // Elements can be in two general modes: fast and slow. Each mode // corrensponds to a set of object representations of elements that // have something in common. // // In the fast mode elements is a FixedArray and so each element can // be quickly accessed. This fact is used in the generated code. The // elements array can have one of three maps in this mode: // fixed_array_map, sloppy_arguments_elements_map or // fixed_cow_array_map (for copy-on-write arrays). In the latter case // the elements array may be shared by a few objects and so before // writing to any element the array must be copied. Use // EnsureWritableFastElements in this case. // // In the slow mode the elements is either a NumberDictionary, a // FixedArray parameter map for a (sloppy) arguments object. DECL_ACCESSORS(elements, FixedArrayBase) inline void initialize_elements(); static void ResetElements(Handle<JSObject> object); static inline void SetMapAndElements(Handle<JSObject> object, Handle<Map> map, Handle<FixedArrayBase> elements); inline ElementsKind GetElementsKind(); ElementsAccessor* GetElementsAccessor(); // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind. inline bool HasFastSmiElements(); // Returns true if an object has elements of FAST_ELEMENTS ElementsKind. inline bool HasFastObjectElements(); // Returns true if an object has elements of FAST_ELEMENTS or // FAST_SMI_ONLY_ELEMENTS. inline bool HasFastSmiOrObjectElements(); // Returns true if an object has any of the fast elements kinds. inline bool HasFastElements(); // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS // ElementsKind. inline bool HasFastDoubleElements(); // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS // ElementsKind. inline bool HasFastHoleyElements(); inline bool HasSloppyArgumentsElements(); inline bool 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(); inline SeededNumberDictionary* element_dictionary(); // Gets slow elements. // Requires: HasFastElements(). static Handle<FixedArray> EnsureWritableFastElements( Handle<JSObject> object); // Collects elements starting at index 0. // Undefined values are placed after non-undefined values. // Returns the number of non-undefined values. static Handle<Object> PrepareElementsForSort(Handle<JSObject> object, uint32_t limit); // As PrepareElementsForSort, but only on objects where elements is // a dictionary, and it will stay a dictionary. Collates undefined and // unexisting elements below limit from position zero of the elements. static Handle<Object> PrepareSlowElementsForSort(Handle<JSObject> object, uint32_t limit); MUST_USE_RESULT static Maybe<bool> SetPropertyWithInterceptor( LookupIterator* it, ShouldThrow should_throw, Handle<Object> 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<Object> DefineOwnPropertyIgnoreAttributes( LookupIterator* it, Handle<Object> value, PropertyAttributes attributes, AccessorInfoHandling handling = DONT_FORCE_FIELD); MUST_USE_RESULT static Maybe<bool> DefineOwnPropertyIgnoreAttributes( LookupIterator* it, Handle<Object> value, PropertyAttributes attributes, ShouldThrow should_throw, AccessorInfoHandling handling = DONT_FORCE_FIELD); MUST_USE_RESULT static MaybeHandle<Object> SetOwnPropertyIgnoreAttributes( Handle<JSObject> object, Handle<Name> name, Handle<Object> value, PropertyAttributes attributes); MUST_USE_RESULT static MaybeHandle<Object> SetOwnElementIgnoreAttributes( Handle<JSObject> object, uint32_t index, Handle<Object> 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<Object> DefinePropertyOrElementIgnoreAttributes(Handle<JSObject> object, Handle<Name> name, Handle<Object> value, PropertyAttributes attributes = NONE); // Adds or reconfigures a property to attributes NONE. It will fail when it // cannot. MUST_USE_RESULT static Maybe<bool> CreateDataProperty(LookupIterator* it, Handle<Object> value); static void AddProperty(Handle<JSObject> object, Handle<Name> name, Handle<Object> value, PropertyAttributes attributes); MUST_USE_RESULT static Maybe<bool> AddDataElement( Handle<JSObject> receiver, uint32_t index, Handle<Object> value, PropertyAttributes attributes, ShouldThrow should_throw); MUST_USE_RESULT static MaybeHandle<Object> AddDataElement( Handle<JSObject> receiver, uint32_t index, Handle<Object> value, PropertyAttributes attributes); // Extend the receiver with a single fast property appeared first in the // passed map. This also extends the property backing store if necessary. static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map); // Migrates the given object to a map whose field representations are the // lowest upper bound of all known representations for that field. static void MigrateInstance(Handle<JSObject> instance); // Migrates the given object only if the target map is already available, // or returns false if such a map is not yet available. static bool TryMigrateInstance(Handle<JSObject> instance); // Sets the property value in a normalized object given (key, value, details). // Handles the special representation of JS global objects. static void SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name, Handle<Object> value, PropertyDetails details); static void SetDictionaryElement(Handle<JSObject> object, uint32_t index, Handle<Object> value, PropertyAttributes attributes); static void SetDictionaryArgumentsElement(Handle<JSObject> object, uint32_t index, Handle<Object> value, PropertyAttributes attributes); static void OptimizeAsPrototype(Handle<JSObject> object, PrototypeOptimizationMode mode); static void ReoptimizeIfPrototype(Handle<JSObject> object); static void LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate); static void UpdatePrototypeUserRegistration(Handle<Map> old_map, Handle<Map> new_map, Isolate* isolate); static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate); static void InvalidatePrototypeChains(Map* map); // Alternative implementation of WeakFixedArray::NullCallback. class PrototypeRegistryCompactionCallback { public: static void Callback(Object* value, int old_index, int new_index); }; // Retrieve interceptors. InterceptorInfo* GetNamedInterceptor(); inline InterceptorInfo* GetIndexedInterceptor(); // Used from JSReceiver. MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributesWithInterceptor(LookupIterator* it); MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it); // Retrieves an AccessorPair property from the given object. Might return // undefined if the property doesn't exist or is of a different kind. MUST_USE_RESULT static MaybeHandle<Object> GetAccessor( Handle<JSObject> object, Handle<Name> name, AccessorComponent component); // Defines an AccessorPair property on the given object. // TODO(mstarzinger): Rename to SetAccessor(). static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object, Handle<Name> name, Handle<Object> getter, Handle<Object> setter, PropertyAttributes attributes); static MaybeHandle<Object> DefineAccessor(LookupIterator* it, Handle<Object> getter, Handle<Object> setter, PropertyAttributes attributes); // Defines an AccessorInfo property on the given object. MUST_USE_RESULT static MaybeHandle<Object> SetAccessor( Handle<JSObject> object, Handle<AccessorInfo> info); // The result must be checked first for exceptions. If there's no exception, // the output parameter |done| indicates whether the interceptor has a result // or not. MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor( LookupIterator* it, bool* done); // Accessors for hidden properties object. // // Hidden properties are not own properties of the object itself. // Instead they are stored in an auxiliary structure kept as an own // property with a special name Heap::hidden_string(). But if the // receiver is a JSGlobalProxy then the auxiliary object is a property // of its prototype, and if it's a detached proxy, then you can't have // hidden properties. // Sets a hidden property on this object. Returns this object if successful, // undefined if called on a detached proxy. static Handle<Object> SetHiddenProperty(Handle<JSObject> object, Handle<Name> key, Handle<Object> value); // Gets the value of a hidden property with the given key. Returns the hole // if the property doesn't exist (or if called on a detached proxy), // otherwise returns the value set for the key. Object* GetHiddenProperty(Handle<Name> key); // Deletes a hidden property. Deleting a non-existing property is // considered successful. static void DeleteHiddenProperty(Handle<JSObject> object, Handle<Name> key); // Returns true if the object has a property with the hidden string as name. static bool HasHiddenProperties(Handle<JSObject> object); static void SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash); static void ValidateElements(Handle<JSObject> object); // Makes sure that this object can contain HeapObject as elements. static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj); // Makes sure that this object can contain the specified elements. static inline void EnsureCanContainElements( Handle<JSObject> object, Object** elements, uint32_t count, EnsureElementsMode mode); static inline void EnsureCanContainElements( Handle<JSObject> object, Handle<FixedArrayBase> elements, uint32_t length, EnsureElementsMode mode); static void EnsureCanContainElements( Handle<JSObject> object, Arguments* arguments, uint32_t first_arg, uint32_t arg_count, EnsureElementsMode mode); // Would we convert a fast elements array to dictionary mode given // an access at key? bool WouldConvertToSlowElements(uint32_t index); // Computes the new capacity when expanding the elements of a JSObject. static uint32_t NewElementsCapacity(uint32_t old_capacity) { // (old_capacity + 50%) + 16 return old_capacity + (old_capacity >> 1) + 16; } // These methods do not perform access checks! static void UpdateAllocationSite(Handle<JSObject> object, ElementsKind to_kind); // Lookup interceptors are used for handling properties controlled by host // objects. inline bool HasNamedInterceptor(); inline bool HasIndexedInterceptor(); // Support functions for v8 api (needed for correct interceptor behavior). MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty( Handle<JSObject> object, Handle<Name> name); MUST_USE_RESULT static Maybe<bool> HasRealElementProperty( Handle<JSObject> object, uint32_t index); MUST_USE_RESULT static Maybe<bool> HasRealNamedCallbackProperty( Handle<JSObject> object, Handle<Name> name); // Get the header size for a JSObject. Used to compute the index of // internal fields as well as the number of internal fields. static inline int GetHeaderSize(InstanceType instance_type); inline int GetHeaderSize(); static inline int GetInternalFieldCount(Map* map); inline int GetInternalFieldCount(); inline int GetInternalFieldOffset(int index); inline Object* GetInternalField(int index); inline void SetInternalField(int index, Object* value); inline void SetInternalField(int index, Smi* value); void CollectOwnPropertyNames(KeyAccumulator* keys, PropertyFilter filter = ALL_PROPERTIES); // Returns the number of properties on this object filtering out properties // with the specified attributes (ignoring interceptors). // TODO(jkummerow): Deprecated, only used by Object.observe. int NumberOfOwnElements(PropertyFilter filter); // Returns the number of elements on this object filtering out elements // with the specified attributes (ignoring interceptors). // TODO(jkummerow): Deprecated, only used by Object.observe. int GetOwnElementKeys(FixedArray* storage, PropertyFilter filter); static void CollectOwnElementKeys(Handle<JSObject> object, KeyAccumulator* keys, PropertyFilter filter); static Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object, bool cache_result); // Returns a new map with all transitions dropped from the object's current // map and the ElementsKind set. static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object, ElementsKind to_kind); static void TransitionElementsKind(Handle<JSObject> object, ElementsKind to_kind); // Always use this to migrate an object to a new map. // |expected_additional_properties| is only used for fast-to-slow transitions // and ignored otherwise. static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map, int expected_additional_properties = 0); // Convert the object to use the canonical dictionary // representation. If the object is expected to have additional properties // added this number can be indicated to have the backing store allocated to // an initial capacity for holding these properties. static void NormalizeProperties(Handle<JSObject> object, PropertyNormalizationMode mode, int expected_additional_properties, const char* reason); // Convert and update the elements backing store to be a // SeededNumberDictionary dictionary. Returns the backing after conversion. static Handle<SeededNumberDictionary> NormalizeElements( Handle<JSObject> object); void RequireSlowElements(SeededNumberDictionary* dictionary); // Transform slow named properties to fast variants. static void MigrateSlowToFast(Handle<JSObject> object, int unused_property_fields, const char* reason); inline bool IsUnboxedDoubleField(FieldIndex index); // Access fast-case object properties at index. static Handle<Object> FastPropertyAt(Handle<JSObject> object, Representation representation, FieldIndex index); inline Object* RawFastPropertyAt(FieldIndex index); inline double RawFastDoublePropertyAt(FieldIndex index); inline void FastPropertyAtPut(FieldIndex index, Object* value); inline void RawFastPropertyAtPut(FieldIndex index, Object* value); inline void RawFastDoublePropertyAtPut(FieldIndex index, double value); inline void WriteToField(int descriptor, Object* value); // Access to in object properties. inline int GetInObjectPropertyOffset(int index); inline Object* InObjectPropertyAt(int index); inline Object* InObjectPropertyAtPut(int index, Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Set the object's prototype (only JSReceiver and null are allowed values). MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSObject> object, Handle<Object> value, bool from_javascript, ShouldThrow should_throw); // Initializes the body starting at |start_offset|. It is responsibility of // the caller to initialize object header. Fill the pre-allocated fields with // pre_allocated_value and the rest with filler_value. // Note: this call does not update write barrier, the caller is responsible // to ensure that |filler_value| can be collected without WB here. inline void InitializeBody(Map* map, int start_offset, Object* pre_allocated_value, Object* filler_value); // Check whether this object references another object bool ReferencesObject(Object* obj); MUST_USE_RESULT static Maybe<bool> PreventExtensions( Handle<JSObject> object, ShouldThrow should_throw); static bool IsExtensible(Handle<JSObject> object); // Called the first time an object is observed with ES7 Object.observe. static void SetObserved(Handle<JSObject> object); // Copy object. enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 }; MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy( Handle<JSObject> object, AllocationSiteUsageContext* site_context, DeepCopyHints hints = kNoHints); // Deep copies given object with special handling for JSFunctions which // 1) must be Api functions and 2) are not copied but left as is. MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopyApiBoilerplate( Handle<JSObject> object); MUST_USE_RESULT static MaybeHandle<JSObject> DeepWalk( Handle<JSObject> object, AllocationSiteCreationContext* site_context); DECLARE_CAST(JSObject) // Dispatched behavior. void JSObjectShortPrint(StringStream* accumulator); DECLARE_PRINTER(JSObject) DECLARE_VERIFIER(JSObject) #ifdef OBJECT_PRINT void PrintProperties(std::ostream& os); // NOLINT void PrintElements(std::ostream& os); // NOLINT #endif #if defined(DEBUG) || defined(OBJECT_PRINT) void PrintTransitions(std::ostream& os); // NOLINT #endif static void PrintElementsTransition( FILE* file, Handle<JSObject> object, ElementsKind from_kind, Handle<FixedArrayBase> from_elements, ElementsKind to_kind, Handle<FixedArrayBase> to_elements); void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map); #ifdef DEBUG // Structure for collecting spill information about JSObjects. class SpillInformation { public: void Clear(); void Print(); int number_of_objects_; int number_of_objects_with_fast_properties_; int number_of_objects_with_fast_elements_; int number_of_fast_used_fields_; int number_of_fast_unused_fields_; int number_of_slow_used_properties_; int number_of_slow_unused_properties_; int number_of_fast_used_elements_; int number_of_fast_unused_elements_; int number_of_slow_used_elements_; int number_of_slow_unused_elements_; }; void IncrementSpillStatistics(SpillInformation* info); #endif #ifdef VERIFY_HEAP // If a GC was caused while constructing this object, the elements pointer // may point to a one pointer filler map. The object won't be rooted, but // our heap verification code could stumble across it. bool ElementsAreSafeToExamine(); #endif Object* SlowReverseLookup(Object* value); // Maximal number of elements (numbered 0 .. kMaxElementCount - 1). // Also maximal value of JSArray's length property. static const uint32_t kMaxElementCount = 0xffffffffu; // Constants for heuristics controlling conversion of fast elements // to slow elements. // Maximal gap that can be introduced by adding an element beyond // the current elements length. static const uint32_t kMaxGap = 1024; // Maximal length of fast elements array that won't be checked for // being dense enough on expansion. static const int kMaxUncheckedFastElementsLength = 5000; // Same as above but for old arrays. This limit is more strict. We // don't want to be wasteful with long lived objects. static const int kMaxUncheckedOldFastElementsLength = 500; // This constant applies only to the initial map of "global.Object" and // not to arbitrary other JSObject maps. static const int kInitialGlobalObjectUnusedPropertiesCount = 4; static const int kMaxInstanceSize = 255 * kPointerSize; // When extending the backing storage for property values, we increase // its size by more than the 1 entry necessary, so sequentially adding fields // to the same object requires fewer allocations and copies. static const int kFieldsAdded = 3; // Layout description. static const int kElementsOffset = JSReceiver::kHeaderSize; static const int kHeaderSize = kElementsOffset + kPointerSize; STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize); typedef FlexibleBodyDescriptor<JSReceiver::kPropertiesOffset> BodyDescriptor; // Enqueue change record for Object.observe. May cause GC. MUST_USE_RESULT static MaybeHandle<Object> EnqueueChangeRecord( Handle<JSObject> object, const char* type, Handle<Name> name, Handle<Object> old_value); // Gets the number of currently used elements. int GetFastElementsUsage(); static bool AllCanRead(LookupIterator* it); static bool AllCanWrite(LookupIterator* it); private: friend class JSReceiver; friend class Object; static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map); static void MigrateFastToSlow(Handle<JSObject> object, Handle<Map> new_map, int expected_additional_properties); // Used from Object::GetProperty(). MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck( LookupIterator* it); MUST_USE_RESULT static Maybe<bool> SetPropertyWithFailedAccessCheck( LookupIterator* it, Handle<Object> value, ShouldThrow should_throw); // Add a property to a slow-case object. static void AddSlowProperty(Handle<JSObject> object, Handle<Name> name, Handle<Object> value, PropertyAttributes attributes); MUST_USE_RESULT static Maybe<bool> DeletePropertyWithInterceptor( LookupIterator* it, ShouldThrow should_throw); bool ReferencesObjectFromElements(FixedArray* elements, ElementsKind kind, Object* object); // Return the hash table backing store or the inline stored identity hash, // whatever is found. MUST_USE_RESULT Object* GetHiddenPropertiesHashTable(); // Return the hash table backing store for hidden properties. If there is no // backing store, allocate one. static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable( Handle<JSObject> object); // Set the hidden property backing store to either a hash table or // the inline-stored identity hash. static Handle<Object> SetHiddenPropertiesHashTable( Handle<JSObject> object, Handle<Object> value); MUST_USE_RESULT Object* GetIdentityHash(); static Handle<Smi> GetOrCreateIdentityHash(Handle<JSObject> object); static Handle<SeededNumberDictionary> GetNormalizedElementDictionary( Handle<JSObject> object, Handle<FixedArrayBase> elements); // Helper for fast versions of preventExtensions, seal, and freeze. // attrs is one of NONE, SEALED, or FROZEN (depending on the operation). template <PropertyAttributes attrs> MUST_USE_RESULT static Maybe<bool> PreventExtensionsWithTransition( Handle<JSObject> object, ShouldThrow should_throw); MUST_USE_RESULT static Maybe<bool> SetPrototypeUnobserved( Handle<JSObject> object, Handle<Object> value, bool from_javascript, ShouldThrow should_throw); DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject); }; // 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: // 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 FixedArrays that allow implementations to share // common accessors and some code paths. class FixedArrayBase: public HeapObject { public: // [length]: length of the array. inline int length() const; inline void set_length(int value); // Get and set the length using acquire loads and release stores. inline int synchronized_length() const; inline void synchronized_set_length(int value); DECLARE_CAST(FixedArrayBase) // Layout description. // Length is smi tagged when it is stored. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHeaderSize = kLengthOffset + kPointerSize; }; class FixedDoubleArray; class IncrementalMarking; // FixedArray describes fixed-sized arrays with element type Object*. class FixedArray: public FixedArrayBase { public: // Setter and getter for elements. inline Object* get(int index) const; static inline Handle<Object> get(FixedArray* array, int index, Isolate* isolate); // Setter that uses write barrier. inline void set(int index, Object* value); inline bool is_the_hole(int index); // Setter that doesn't need write barrier. inline void set(int index, Smi* value); // Setter with explicit barrier mode. inline void set(int index, Object* value, WriteBarrierMode mode); // Setters for frequently used oddballs located in old space. inline void set_undefined(int index); inline void set_null(int index); inline void set_the_hole(int index); inline Object** GetFirstElementAddress(); inline bool ContainsOnlySmisOrHoles(); // Gives access to raw memory which stores the array's data. inline Object** data_start(); inline void FillWithHoles(int from, int to); // Shrink length and insert filler objects. void Shrink(int length); // Copy a sub array from the receiver to dest. void CopyTo(int pos, FixedArray* dest, int dest_pos, int len); // Garbage collection support. static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; } // Code Generation support. static int OffsetOfElementAt(int index) { return SizeFor(index); } // Garbage collection support. inline Object** RawFieldOfElementAt(int index); DECLARE_CAST(FixedArray) // Maximal allowed size, in bytes, of a single FixedArray. // Prevents overflowing size computations, as well as extreme memory // consumption. static const int kMaxSize = 128 * MB * kPointerSize; // Maximally allowed length of a FixedArray. static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize; // Dispatched behavior. DECLARE_PRINTER(FixedArray) DECLARE_VERIFIER(FixedArray) #ifdef DEBUG // Checks if two FixedArrays have identical contents. bool IsEqualTo(FixedArray* other); #endif // Swap two elements in a pair of arrays. If this array and the // numbers array are the same object, the elements are only swapped // once. void SwapPairs(FixedArray* numbers, int i, int j); // Sort prefix of this array and the numbers array as pairs wrt. the // numbers. If the numbers array and the this array are the same // object, the prefix of this array is sorted. void SortPairs(FixedArray* numbers, uint32_t len); typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor; protected: // Set operation on FixedArray without using write barriers. Can // only be used for storing old space objects or smis. static inline void NoWriteBarrierSet(FixedArray* array, int index, Object* value); private: STATIC_ASSERT(kHeaderSize == Internals::kFixedArrayHeaderSize); DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray); }; // FixedDoubleArray describes fixed-sized arrays with element type double. class FixedDoubleArray: public FixedArrayBase { public: // Setter and getter for elements. inline double get_scalar(int index); inline uint64_t get_representation(int index); static inline Handle<Object> get(FixedDoubleArray* array, int index, Isolate* isolate); inline void set(int index, double value); inline void set_the_hole(int index); // Checking for the hole. inline bool is_the_hole(int index); // Garbage collection support. inline static int SizeFor(int length) { return kHeaderSize + length * kDoubleSize; } // Gives access to raw memory which stores the array's data. inline double* data_start(); inline void FillWithHoles(int from, int to); // Code Generation support. static int OffsetOfElementAt(int index) { return SizeFor(index); } DECLARE_CAST(FixedDoubleArray) // Maximal allowed size, in bytes, of a single FixedDoubleArray. // Prevents overflowing size computations, as well as extreme memory // consumption. static const int kMaxSize = 512 * MB; // Maximally allowed length of a FixedArray. static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize; // Dispatched behavior. DECLARE_PRINTER(FixedDoubleArray) DECLARE_VERIFIER(FixedDoubleArray) private: DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray); }; class WeakFixedArray : public FixedArray { public: // If |maybe_array| is not a WeakFixedArray, a fresh one will be allocated. // This function does not check if the value exists already, callers must // ensure this themselves if necessary. static Handle<WeakFixedArray> Add(Handle<Object> maybe_array, Handle<HeapObject> value, int* assigned_index = NULL); // Returns true if an entry was found and removed. bool Remove(Handle<HeapObject> value); class NullCallback { public: static void Callback(Object* value, int old_index, int new_index) {} }; template <class CompactionCallback> void Compact(); inline Object* Get(int index) const; inline void Clear(int index); inline int Length() const; inline bool IsEmptySlot(int index) const; static Object* Empty() { return Smi::FromInt(0); } class Iterator { public: explicit Iterator(Object* maybe_array) : list_(NULL) { Reset(maybe_array); } void Reset(Object* maybe_array); template <class T> inline T* Next(); private: int index_; WeakFixedArray* list_; #ifdef DEBUG int last_used_index_; DisallowHeapAllocation no_gc_; #endif // DEBUG DISALLOW_COPY_AND_ASSIGN(Iterator); }; DECLARE_CAST(WeakFixedArray) private: static const int kLastUsedIndexIndex = 0; static const int kFirstIndex = 1; static Handle<WeakFixedArray> Allocate( Isolate* isolate, int size, Handle<WeakFixedArray> initialize_from); static void Set(Handle<WeakFixedArray> array, int index, Handle<HeapObject> value); inline void clear(int index); inline int last_used_index() const; inline void set_last_used_index(int index); // Disallow inherited setters. void set(int index, Smi* value); void set(int index, Object* value); void set(int index, Object* value, WriteBarrierMode mode); DISALLOW_IMPLICIT_CONSTRUCTORS(WeakFixedArray); }; // Generic array grows dynamically with O(1) amortized insertion. class ArrayList : public FixedArray { public: enum AddMode { kNone, // Use this if GC can delete elements from the array. kReloadLengthAfterAllocation, }; static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj, AddMode mode = kNone); static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj1, Handle<Object> obj2, AddMode = kNone); inline int Length(); inline void SetLength(int length); inline Object* Get(int index); inline Object** Slot(int index); inline void Set(int index, Object* obj); inline void Clear(int index, Object* undefined); bool IsFull(); DECLARE_CAST(ArrayList) private: static Handle<ArrayList> EnsureSpace(Handle<ArrayList> array, int length); static const int kLengthIndex = 0; static const int kFirstIndex = 1; DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList); }; // DescriptorArrays are fixed arrays used to hold instance descriptors. // The format of the these objects is: // [0]: Number of descriptors // [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array: // [0]: pointer to fixed array with enum cache // [1]: either Smi(0) or pointer to fixed array with indices // [2]: first key // [2 + number of descriptors * kDescriptorSize]: start of slack class DescriptorArray: public FixedArray { public: // Returns true for both shared empty_descriptor_array and for smis, which the // map uses to encode additional bit fields when the descriptor array is not // yet used. inline bool IsEmpty(); // Returns the number of descriptors in the array. inline int number_of_descriptors(); inline int number_of_descriptors_storage(); inline int NumberOfSlackDescriptors(); inline void SetNumberOfDescriptors(int number_of_descriptors); inline int number_of_entries(); inline bool HasEnumCache(); inline void CopyEnumCacheFrom(DescriptorArray* array); inline FixedArray* GetEnumCache(); inline bool HasEnumIndicesCache(); inline FixedArray* GetEnumIndicesCache(); inline Object** GetEnumCacheSlot(); void ClearEnumCache(); // Initialize or change the enum cache, // using the supplied storage for the small "bridge". static void SetEnumCache(Handle<DescriptorArray> descriptors, Isolate* isolate, Handle<FixedArray> new_cache, Handle<FixedArray> new_index_cache); bool CanHoldValue(int descriptor, Object* value); // Accessors for fetching instance descriptor at descriptor number. inline Name* GetKey(int descriptor_number); inline Object** GetKeySlot(int descriptor_number); inline Object* GetValue(int descriptor_number); inline void SetValue(int descriptor_number, Object* value); inline Object** GetValueSlot(int descriptor_number); static inline int GetValueOffset(int descriptor_number); inline Object** GetDescriptorStartSlot(int descriptor_number); inline Object** GetDescriptorEndSlot(int descriptor_number); inline PropertyDetails GetDetails(int descriptor_number); inline PropertyType GetType(int descriptor_number); inline int GetFieldIndex(int descriptor_number); inline FieldType* GetFieldType(int descriptor_number); inline Object* GetConstant(int descriptor_number); inline Object* GetCallbacksObject(int descriptor_number); inline AccessorDescriptor* GetCallbacks(int descriptor_number); inline Name* GetSortedKey(int descriptor_number); inline int GetSortedKeyIndex(int descriptor_number); inline void SetSortedKey(int pointer, int descriptor_number); inline void SetRepresentation(int descriptor_number, Representation representation); // Accessor for complete descriptor. inline void Get(int descriptor_number, Descriptor* desc); inline void Set(int descriptor_number, Descriptor* desc); void Replace(int descriptor_number, Descriptor* descriptor); // Append automatically sets the enumeration index. This should only be used // to add descriptors in bulk at the end, followed by sorting the descriptor // array. inline void Append(Descriptor* desc); static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc, int enumeration_index, int slack = 0); static Handle<DescriptorArray> CopyUpToAddAttributes( Handle<DescriptorArray> desc, int enumeration_index, PropertyAttributes attributes, int slack = 0); // Sort the instance descriptors by the hash codes of their keys. void Sort(); // Search the instance descriptors for given name. INLINE(int Search(Name* name, int number_of_own_descriptors)); // As the above, but uses DescriptorLookupCache and updates it when // necessary. INLINE(int SearchWithCache(Name* name, Map* map)); bool IsEqualUpTo(DescriptorArray* desc, int nof_descriptors); // Allocates a DescriptorArray, but returns the singleton // empty descriptor array object if number_of_descriptors is 0. static Handle<DescriptorArray> Allocate( Isolate* isolate, int number_of_descriptors, int slack, PretenureFlag pretenure = NOT_TENURED); DECLARE_CAST(DescriptorArray) // Constant for denoting key was not found. static const int kNotFound = -1; static const int kDescriptorLengthIndex = 0; static const int kEnumCacheIndex = 1; static const int kFirstIndex = 2; // The length of the "bridge" to the enum cache. static const int kEnumCacheBridgeLength = 2; static const int kEnumCacheBridgeCacheIndex = 0; static const int kEnumCacheBridgeIndicesCacheIndex = 1; // Layout description. static const int kDescriptorLengthOffset = FixedArray::kHeaderSize; static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize; static const int kFirstOffset = kEnumCacheOffset + kPointerSize; // Layout description for the bridge array. static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize; // Layout of descriptor. static const int kDescriptorKey = 0; static const int kDescriptorDetails = 1; static const int kDescriptorValue = 2; static const int kDescriptorSize = 3; #if defined(DEBUG) || defined(OBJECT_PRINT) // For our gdb macros, we should perhaps change these in the future. void Print(); // Print all the descriptors. void PrintDescriptors(std::ostream& os); // NOLINT #endif #ifdef DEBUG // Is the descriptor array sorted and without duplicates? bool IsSortedNoDuplicates(int valid_descriptors = -1); // Is the descriptor array consistent with the back pointers in targets? bool IsConsistentWithBackPointers(Map* current_map); // Are two DescriptorArrays equal? bool IsEqualTo(DescriptorArray* other); #endif // Returns the fixed array length required to hold number_of_descriptors // descriptors. static int LengthFor(int number_of_descriptors) { return ToKeyIndex(number_of_descriptors); } private: // An entry in a DescriptorArray, represented as an (array, index) pair. class Entry { public: inline explicit Entry(DescriptorArray* descs, int index) : descs_(descs), index_(index) { } inline PropertyType type(); inline Object* GetCallbackObject(); private: DescriptorArray* descs_; int index_; }; // Conversion from descriptor number to array indices. static int ToKeyIndex(int descriptor_number) { return kFirstIndex + (descriptor_number * kDescriptorSize) + kDescriptorKey; } static int ToDetailsIndex(int descriptor_number) { return kFirstIndex + (descriptor_number * kDescriptorSize) + kDescriptorDetails; } static int ToValueIndex(int descriptor_number) { return kFirstIndex + (descriptor_number * kDescriptorSize) + kDescriptorValue; } // Transfer a complete descriptor from the src descriptor array to this // descriptor array. void CopyFrom(int index, DescriptorArray* src); inline void SetDescriptor(int descriptor_number, Descriptor* desc); // Swap first and second descriptor. inline void SwapSortedKeys(int first, int second); DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray); }; enum SearchMode { ALL_ENTRIES, VALID_ENTRIES }; template <SearchMode search_mode, typename T> inline int Search(T* array, Name* name, int valid_entries = 0, int* out_insertion_index = NULL); // HashTable is a subclass of FixedArray that implements a hash table // that uses open addressing and quadratic probing. // // In order for the quadratic probing to work, elements that have not // yet been used and elements that have been deleted are // distinguished. Probing continues when deleted elements are // encountered and stops when unused elements are encountered. // // - Elements with key == undefined have not been used yet. // - Elements with key == the_hole have been deleted. // // The hash table class is parameterized with a Shape and a Key. // Shape must be a class with the following interface: // class ExampleShape { // public: // // Tells whether key matches other. // static bool IsMatch(Key key, Object* other); // // Returns the hash value for key. // static uint32_t Hash(Key key); // // Returns the hash value for object. // static uint32_t HashForObject(Key key, Object* object); // // Convert key to an object. // static inline Handle<Object> AsHandle(Isolate* isolate, Key key); // // The prefix size indicates number of elements in the beginning // // of the backing storage. // static const int kPrefixSize = ..; // // The Element size indicates number of elements per entry. // static const int kEntrySize = ..; // }; // The prefix size indicates an amount of memory in the // beginning of the backing storage that can be used for non-element // information by subclasses. template<typename Key> class BaseShape { public: static const bool UsesSeed = false; static uint32_t Hash(Key key) { return 0; } static uint32_t SeededHash(Key key, uint32_t seed) { DCHECK(UsesSeed); return Hash(key); } static uint32_t HashForObject(Key key, Object* object) { return 0; } static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) { DCHECK(UsesSeed); return HashForObject(key, object); } }; class HashTableBase : public FixedArray { public: // Returns the number of elements in the hash table. inline int NumberOfElements(); // Returns the number of deleted elements in the hash table. inline int NumberOfDeletedElements(); // Returns the capacity of the hash table. inline int Capacity(); // ElementAdded should be called whenever an element is added to a // hash table. inline void ElementAdded(); // ElementRemoved should be called whenever an element is removed from // a hash table. inline void ElementRemoved(); inline void ElementsRemoved(int n); // Computes the required capacity for a table holding the given // number of elements. May be more than HashTable::kMaxCapacity. static inline int ComputeCapacity(int at_least_space_for); // Tells whether k is a real key. The hole and undefined are not allowed // as keys and can be used to indicate missing or deleted elements. inline bool IsKey(Object* k); // Compute the probe offset (quadratic probing). INLINE(static uint32_t GetProbeOffset(uint32_t n)) { return (n + n * n) >> 1; } static const int kNumberOfElementsIndex = 0; static const int kNumberOfDeletedElementsIndex = 1; static const int kCapacityIndex = 2; static const int kPrefixStartIndex = 3; // Constant used for denoting a absent entry. static const int kNotFound = -1; protected: // Update the number of elements in the hash table. inline void SetNumberOfElements(int nof); // Update the number of deleted elements in the hash table. inline void SetNumberOfDeletedElements(int nod); // Returns probe entry. static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) { DCHECK(base::bits::IsPowerOfTwo32(size)); return (hash + GetProbeOffset(number)) & (size - 1); } inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) { return hash & (size - 1); } inline static uint32_t NextProbe( uint32_t last, uint32_t number, uint32_t size) { return (last + number) & (size - 1); } }; template <typename Derived, typename Shape, typename Key> class HashTable : public HashTableBase { public: // Wrapper methods inline uint32_t Hash(Key key) { if (Shape::UsesSeed) { return Shape::SeededHash(key, GetHeap()->HashSeed()); } else { return Shape::Hash(key); } } inline uint32_t HashForObject(Key key, Object* object) { if (Shape::UsesSeed) { return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object); } else { return Shape::HashForObject(key, object); } } // Returns a new HashTable object. MUST_USE_RESULT static Handle<Derived> New( Isolate* isolate, int at_least_space_for, MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY, PretenureFlag pretenure = NOT_TENURED); DECLARE_CAST(HashTable) // Garbage collection support. void IteratePrefix(ObjectVisitor* visitor); void IterateElements(ObjectVisitor* visitor); // Find entry for key otherwise return kNotFound. inline int FindEntry(Key key); inline int FindEntry(Isolate* isolate, Key key, int32_t hash); int FindEntry(Isolate* isolate, Key key); // Rehashes the table in-place. void Rehash(Key key); // Returns the key at entry. Object* KeyAt(int entry) { return get(EntryToIndex(entry)); } static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize; static const int kEntrySize = Shape::kEntrySize; static const int kElementsStartOffset = kHeaderSize + kElementsStartIndex * kPointerSize; static const int kCapacityOffset = kHeaderSize + kCapacityIndex * kPointerSize; // Returns the index for an entry (of the key) static inline int EntryToIndex(int entry) { return (entry * kEntrySize) + kElementsStartIndex; } protected: friend class ObjectHashTable; // Find the entry at which to insert element with the given key that // has the given hash value. uint32_t FindInsertionEntry(uint32_t hash); // Attempt to shrink hash table after removal of key. MUST_USE_RESULT static Handle<Derived> Shrink(Handle<Derived> table, Key key); // Ensure enough space for n additional elements. MUST_USE_RESULT static Handle<Derived> EnsureCapacity( Handle<Derived> table, int n, Key key, PretenureFlag pretenure = NOT_TENURED); // Returns true if this table has sufficient capacity for adding n elements. bool HasSufficientCapacity(int n); // Sets the capacity of the hash table. void SetCapacity(int capacity) { // To scale a computed hash code to fit within the hash table, we // use bit-wise AND with a mask, so the capacity must be positive // and non-zero. DCHECK(capacity > 0); DCHECK(capacity <= kMaxCapacity); set(kCapacityIndex, Smi::FromInt(capacity)); } // Maximal capacity of HashTable. Based on maximal length of underlying // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex // cannot overflow. static const int kMaxCapacity = (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize; private: // Returns _expected_ if one of entries given by the first _probe_ probes is // equal to _expected_. Otherwise, returns the entry given by the probe // number _probe_. uint32_t EntryForProbe(Key key, Object* k, int probe, uint32_t expected); void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode); // Rehashes this hash-table into the new table. void Rehash(Handle<Derived> new_table, Key key); }; // HashTableKey is an abstract superclass for virtual key behavior. class HashTableKey { public: // Returns whether the other object matches this key. virtual bool IsMatch(Object* other) = 0; // Returns the hash value for this key. virtual uint32_t Hash() = 0; // Returns the hash value for object. virtual uint32_t HashForObject(Object* key) = 0; // Returns the key object for storing into the hash table. MUST_USE_RESULT virtual Handle<Object> AsHandle(Isolate* isolate) = 0; // Required. virtual ~HashTableKey() {} }; class StringTableShape : public BaseShape<HashTableKey*> { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key); static const int kPrefixSize = 0; static const int kEntrySize = 1; }; class SeqOneByteString; // StringTable. // // No special elements in the prefix and the element size is 1 // because only the string itself (the key) needs to be stored. class StringTable: public HashTable<StringTable, StringTableShape, HashTableKey*> { public: // Find string in the string table. If it is not there yet, it is // added. The return value is the string found. static Handle<String> LookupString(Isolate* isolate, Handle<String> key); static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key); static String* LookupKeyIfExists(Isolate* isolate, HashTableKey* key); // Tries to internalize given string and returns string handle on success // or an empty handle otherwise. MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists( Isolate* isolate, Handle<String> string); // Looks up a string that is equal to the given string and returns // string handle if it is found, or an empty handle otherwise. MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists( Isolate* isolate, Handle<String> str); MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists( Isolate* isolate, uint16_t c1, uint16_t c2); static void EnsureCapacityForDeserialization(Isolate* isolate, int expected); DECLARE_CAST(StringTable) private: template <bool seq_one_byte> friend class JsonParser; DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable); }; template <typename Derived, typename Shape, typename Key> class Dictionary: public HashTable<Derived, Shape, Key> { typedef HashTable<Derived, Shape, Key> DerivedHashTable; public: // Returns the value at entry. Object* ValueAt(int entry) { return this->get(Derived::EntryToIndex(entry) + 1); } // Set the value for entry. void ValueAtPut(int entry, Object* value) { this->set(Derived::EntryToIndex(entry) + 1, value); } // Returns the property details for the property at entry. PropertyDetails DetailsAt(int entry) { return Shape::DetailsAt(static_cast<Derived*>(this), entry); } // Set the details for entry. void DetailsAtPut(int entry, PropertyDetails value) { Shape::DetailsAtPut(static_cast<Derived*>(this), entry, value); } // Returns true if property at given entry is deleted. bool IsDeleted(int entry) { return Shape::IsDeleted(static_cast<Derived*>(this), entry); } // Delete a property from the dictionary. static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry); // Attempt to shrink the dictionary after deletion of key. MUST_USE_RESULT static inline Handle<Derived> Shrink( Handle<Derived> dictionary, Key key) { return DerivedHashTable::Shrink(dictionary, key); } // Sorting support // TODO(dcarney): templatize or move to SeededNumberDictionary void CopyValuesTo(FixedArray* elements); // Returns the number of elements in the dictionary filtering out properties // with the specified attributes. // TODO(jkummerow): Deprecated, only used by Object.observe. int NumberOfElementsFilterAttributes(PropertyFilter filter); // Returns the number of enumerable elements in the dictionary. // TODO(jkummerow): Deprecated, only used by Object.observe. int NumberOfEnumElements() { return NumberOfElementsFilterAttributes(ENUMERABLE_STRINGS); } // Returns true if the dictionary contains any elements that are non-writable, // non-configurable, non-enumerable, or have getters/setters. bool HasComplexElements(); enum SortMode { UNSORTED, SORTED }; // Fill in details for properties into storage. // Returns the number of properties added. // TODO(jkummerow): Deprecated, only used by Object.observe. int CopyKeysTo(FixedArray* storage, int index, PropertyFilter filter, SortMode sort_mode); // Collect the keys into the given KeyAccumulator, in ascending chronological // order of property creation. static void CollectKeysTo(Handle<Dictionary<Derived, Shape, Key> > dictionary, KeyAccumulator* keys, PropertyFilter filter); // Copies enumerable keys to preallocated fixed array. void CopyEnumKeysTo(FixedArray* storage); // Accessors for next enumeration index. void SetNextEnumerationIndex(int index) { DCHECK(index != 0); this->set(kNextEnumerationIndexIndex, Smi::FromInt(index)); } int NextEnumerationIndex() { return Smi::cast(this->get(kNextEnumerationIndexIndex))->value(); } // Creates a new dictionary. MUST_USE_RESULT static Handle<Derived> New( Isolate* isolate, int at_least_space_for, PretenureFlag pretenure = NOT_TENURED); // Ensures that a new dictionary is created when the capacity is checked. void SetRequiresCopyOnCapacityChange(); // Ensure enough space for n additional elements. static Handle<Derived> EnsureCapacity(Handle<Derived> obj, int n, Key key); #ifdef OBJECT_PRINT void Print(std::ostream& os); // NOLINT #endif // Returns the key (slow). Object* SlowReverseLookup(Object* value); // Sets the entry to (key, value) pair. inline void SetEntry(int entry, Handle<Object> key, Handle<Object> value); inline void SetEntry(int entry, Handle<Object> key, Handle<Object> value, PropertyDetails details); MUST_USE_RESULT static Handle<Derived> Add( Handle<Derived> dictionary, Key key, Handle<Object> value, PropertyDetails details); // Returns iteration indices array for the |dictionary|. // Values are direct indices in the |HashTable| array. static Handle<FixedArray> BuildIterationIndicesArray( Handle<Derived> dictionary); protected: // Generic at put operation. MUST_USE_RESULT static Handle<Derived> AtPut( Handle<Derived> dictionary, Key key, Handle<Object> value); // Add entry to dictionary. static void AddEntry( Handle<Derived> dictionary, Key key, Handle<Object> value, PropertyDetails details, uint32_t hash); // Generate new enumeration indices to avoid enumeration index overflow. // Returns iteration indices array for the |dictionary|. static Handle<FixedArray> GenerateNewEnumerationIndices( Handle<Derived> dictionary); static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex; static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1; }; template <typename Derived, typename Shape> class NameDictionaryBase : public Dictionary<Derived, Shape, Handle<Name> > { typedef Dictionary<Derived, Shape, Handle<Name> > DerivedDictionary; public: // Find entry for key, otherwise return kNotFound. Optimized version of // HashTable::FindEntry. int FindEntry(Handle<Name> key); }; template <typename Key> class BaseDictionaryShape : public BaseShape<Key> { public: template <typename Dictionary> static inline PropertyDetails DetailsAt(Dictionary* dict, int entry) { STATIC_ASSERT(Dictionary::kEntrySize == 3); DCHECK(entry >= 0); // Not found is -1, which is not caught by get(). return PropertyDetails( Smi::cast(dict->get(Dictionary::EntryToIndex(entry) + 2))); } template <typename Dictionary> static inline void DetailsAtPut(Dictionary* dict, int entry, PropertyDetails value) { STATIC_ASSERT(Dictionary::kEntrySize == 3); dict->set(Dictionary::EntryToIndex(entry) + 2, value.AsSmi()); } template <typename Dictionary> static bool IsDeleted(Dictionary* dict, int entry) { return false; } template <typename Dictionary> static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key, Handle<Object> value, PropertyDetails details); }; class NameDictionaryShape : public BaseDictionaryShape<Handle<Name> > { public: static inline bool IsMatch(Handle<Name> key, Object* other); static inline uint32_t Hash(Handle<Name> key); static inline uint32_t HashForObject(Handle<Name> key, Object* object); static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key); static const int kPrefixSize = 2; static const int kEntrySize = 3; static const bool kIsEnumerable = true; }; class NameDictionary : public NameDictionaryBase<NameDictionary, NameDictionaryShape> { typedef NameDictionaryBase<NameDictionary, NameDictionaryShape> DerivedDictionary; public: DECLARE_CAST(NameDictionary) inline static Handle<FixedArray> DoGenerateNewEnumerationIndices( Handle<NameDictionary> dictionary); }; class GlobalDictionaryShape : public NameDictionaryShape { public: static const int kEntrySize = 2; // Overrides NameDictionaryShape::kEntrySize template <typename Dictionary> static inline PropertyDetails DetailsAt(Dictionary* dict, int entry); template <typename Dictionary> static inline void DetailsAtPut(Dictionary* dict, int entry, PropertyDetails value); template <typename Dictionary> static bool IsDeleted(Dictionary* dict, int entry); template <typename Dictionary> static inline void SetEntry(Dictionary* dict, int entry, Handle<Object> key, Handle<Object> value, PropertyDetails details); }; class GlobalDictionary : public NameDictionaryBase<GlobalDictionary, GlobalDictionaryShape> { public: DECLARE_CAST(GlobalDictionary) }; class NumberDictionaryShape : public BaseDictionaryShape<uint32_t> { public: static inline bool IsMatch(uint32_t key, Object* other); static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key); static const int kEntrySize = 3; static const bool kIsEnumerable = false; }; class SeededNumberDictionaryShape : public NumberDictionaryShape { public: static const bool UsesSeed = true; static const int kPrefixSize = 2; static inline uint32_t SeededHash(uint32_t key, uint32_t seed); static inline uint32_t SeededHashForObject(uint32_t key, uint32_t seed, Object* object); }; class UnseededNumberDictionaryShape : public NumberDictionaryShape { public: static const int kPrefixSize = 0; static inline uint32_t Hash(uint32_t key); static inline uint32_t HashForObject(uint32_t key, Object* object); }; class SeededNumberDictionary : public Dictionary<SeededNumberDictionary, SeededNumberDictionaryShape, uint32_t> { public: DECLARE_CAST(SeededNumberDictionary) // Type specific at put (default NONE attributes is used when adding). MUST_USE_RESULT static Handle<SeededNumberDictionary> AtNumberPut( Handle<SeededNumberDictionary> dictionary, uint32_t key, Handle<Object> value, bool used_as_prototype); MUST_USE_RESULT static Handle<SeededNumberDictionary> AddNumberEntry( Handle<SeededNumberDictionary> dictionary, uint32_t key, Handle<Object> value, PropertyDetails details, bool used_as_prototype); // Set an existing entry or add a new one if needed. // Return the updated dictionary. MUST_USE_RESULT static Handle<SeededNumberDictionary> Set( Handle<SeededNumberDictionary> dictionary, uint32_t key, Handle<Object> value, PropertyDetails details, bool used_as_prototype); void UpdateMaxNumberKey(uint32_t key, bool used_as_prototype); // If slow elements are required we will never go back to fast-case // for the elements kept in this dictionary. We require slow // elements if an element has been added at an index larger than // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called // when defining a getter or setter with a number key. inline bool requires_slow_elements(); inline void set_requires_slow_elements(); // Get the value of the max number key that has been added to this // dictionary. max_number_key can only be called if // requires_slow_elements returns false. inline uint32_t max_number_key(); // Bit masks. static const int kRequiresSlowElementsMask = 1; static const int kRequiresSlowElementsTagSize = 1; static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1; }; class UnseededNumberDictionary : public Dictionary<UnseededNumberDictionary, UnseededNumberDictionaryShape, uint32_t> { public: DECLARE_CAST(UnseededNumberDictionary) // Type specific at put (default NONE attributes is used when adding). MUST_USE_RESULT static Handle<UnseededNumberDictionary> AtNumberPut( Handle<UnseededNumberDictionary> dictionary, uint32_t key, Handle<Object> value); MUST_USE_RESULT static Handle<UnseededNumberDictionary> AddNumberEntry( Handle<UnseededNumberDictionary> dictionary, uint32_t key, Handle<Object> value); // Set an existing entry or add a new one if needed. // Return the updated dictionary. MUST_USE_RESULT static Handle<UnseededNumberDictionary> Set( Handle<UnseededNumberDictionary> dictionary, uint32_t key, Handle<Object> value); }; class ObjectHashTableShape : public BaseShape<Handle<Object> > { public: static inline bool IsMatch(Handle<Object> key, Object* other); static inline uint32_t Hash(Handle<Object> key); static inline uint32_t HashForObject(Handle<Object> key, Object* object); static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key); static const int kPrefixSize = 0; static const int kEntrySize = 2; }; // ObjectHashTable maps keys that are arbitrary objects to object values by // using the identity hash of the key for hashing purposes. class ObjectHashTable: public HashTable<ObjectHashTable, ObjectHashTableShape, Handle<Object> > { typedef HashTable< ObjectHashTable, ObjectHashTableShape, Handle<Object> > DerivedHashTable; public: DECLARE_CAST(ObjectHashTable) // Attempt to shrink hash table after removal of key. MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink( Handle<ObjectHashTable> table, Handle<Object> key); // Looks up the value associated with the given key. The hole value is // returned in case the key is not present. Object* Lookup(Handle<Object> key); Object* Lookup(Handle<Object> key, int32_t hash); Object* Lookup(Isolate* isolate, Handle<Object> key, int32_t hash); // Adds (or overwrites) the value associated with the given key. static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table, Handle<Object> key, Handle<Object> value); static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table, Handle<Object> key, Handle<Object> value, int32_t hash); // Returns an ObjectHashTable (possibly |table|) where |key| has been removed. static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table, Handle<Object> key, bool* was_present); static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table, Handle<Object> key, bool* was_present, int32_t hash); protected: friend class MarkCompactCollector; void AddEntry(int entry, Object* key, Object* value); void RemoveEntry(int entry); // Returns the index to the value of an entry. static inline int EntryToValueIndex(int entry) { return EntryToIndex(entry) + 1; } }; // OrderedHashTable is a HashTable with Object keys that preserves // insertion order. There are Map and Set interfaces (OrderedHashMap // and OrderedHashTable, below). It is meant to be used by JSMap/JSSet. // // Only Object* keys are supported, with Object::SameValueZero() used as the // equality operator and Object::GetHash() for the hash function. // // Based on the "Deterministic Hash Table" as described by Jason Orendorff at // https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables // Originally attributed to Tyler Close. // // Memory layout: // [0]: bucket count // [1]: element count // [2]: deleted element count // [3..(3 + NumberOfBuckets() - 1)]: "hash table", where each item is an // offset into the data table (see below) where the // first item in this bucket is stored. // [3 + NumberOfBuckets()..length]: "data table", an array of length // Capacity() * kEntrySize, where the first entrysize // items are handled by the derived class and the // item at kChainOffset is another entry into the // data table indicating the next entry in this hash // bucket. // // When we transition the table to a new version we obsolete it and reuse parts // of the memory to store information how to transition an iterator to the new // table: // // Memory layout for obsolete table: // [0]: bucket count // [1]: Next newer table // [2]: Number of removed holes or -1 when the table was cleared. // [3..(3 + NumberOfRemovedHoles() - 1)]: The indexes of the removed holes. // [3 + NumberOfRemovedHoles()..length]: Not used // template<class Derived, class Iterator, int entrysize> class OrderedHashTable: public FixedArray { public: // Returns an OrderedHashTable with a capacity of at least |capacity|. static Handle<Derived> Allocate( Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED); // Returns an OrderedHashTable (possibly |table|) with enough space // to add at least one new element. static Handle<Derived> EnsureGrowable(Handle<Derived> table); // Returns an OrderedHashTable (possibly |table|) that's shrunken // if possible. static Handle<Derived> Shrink(Handle<Derived> table); // Returns a new empty OrderedHashTable and records the clearing so that // exisiting iterators can be updated. static Handle<Derived> Clear(Handle<Derived> table); // Returns a true if the OrderedHashTable contains the key static bool HasKey(Handle<Derived> table, Handle<Object> key); int NumberOfElements() { return Smi::cast(get(kNumberOfElementsIndex))->value(); } int NumberOfDeletedElements() { return Smi::cast(get(kNumberOfDeletedElementsIndex))->value(); } int UsedCapacity() { return NumberOfElements() + NumberOfDeletedElements(); } int NumberOfBuckets() { return Smi::cast(get(kNumberOfBucketsIndex))->value(); } // Returns an index into |this| for the given entry. int EntryToIndex(int entry) { return kHashTableStartIndex + NumberOfBuckets() + (entry * kEntrySize); } int HashToBucket(int hash) { return hash & (NumberOfBuckets() - 1); } int HashToEntry(int hash) { int bucket = HashToBucket(hash); Object* entry = this->get(kHashTableStartIndex + bucket); return Smi::cast(entry)->value(); } int KeyToFirstEntry(Object* key) { Object* hash = key->GetHash(); // If the object does not have an identity hash, it was never used as a key if (hash->IsUndefined()) return kNotFound; return HashToEntry(Smi::cast(hash)->value()); } int NextChainEntry(int entry) { Object* next_entry = get(EntryToIndex(entry) + kChainOffset); return Smi::cast(next_entry)->value(); } Object* KeyAt(int entry) { return get(EntryToIndex(entry)); } bool IsObsolete() { return !get(kNextTableIndex)->IsSmi(); } // The next newer table. This is only valid if the table is obsolete. Derived* NextTable() { return Derived::cast(get(kNextTableIndex)); } // When the table is obsolete we store the indexes of the removed holes. int RemovedIndexAt(int index) { return Smi::cast(get(kRemovedHolesIndex + index))->value(); } static const int kNotFound = -1; static const int kMinCapacity = 4; static const int kNumberOfBucketsIndex = 0; static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1; static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1; static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1; static const int kNextTableIndex = kNumberOfElementsIndex; static const int kNumberOfBucketsOffset = kHeaderSize + kNumberOfBucketsIndex * kPointerSize; static const int kNumberOfElementsOffset = kHeaderSize + kNumberOfElementsIndex * kPointerSize; static const int kNumberOfDeletedElementsOffset = kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize; static const int kHashTableStartOffset = kHeaderSize + kHashTableStartIndex * kPointerSize; static const int kNextTableOffset = kHeaderSize + kNextTableIndex * kPointerSize; static const int kEntrySize = entrysize + 1; static const int kChainOffset = entrysize; static const int kLoadFactor = 2; // NumberOfDeletedElements is set to kClearedTableSentinel when // the table is cleared, which allows iterator transitions to // optimize that case. static const int kClearedTableSentinel = -1; protected: static Handle<Derived> Rehash(Handle<Derived> table, int new_capacity); void SetNumberOfBuckets(int num) { set(kNumberOfBucketsIndex, Smi::FromInt(num)); } void SetNumberOfElements(int num) { set(kNumberOfElementsIndex, Smi::FromInt(num)); } void SetNumberOfDeletedElements(int num) { set(kNumberOfDeletedElementsIndex, Smi::FromInt(num)); } int Capacity() { return NumberOfBuckets() * kLoadFactor; } void SetNextTable(Derived* next_table) { set(kNextTableIndex, next_table); } void SetRemovedIndexAt(int index, int removed_index) { return set(kRemovedHolesIndex + index, Smi::FromInt(removed_index)); } static const int kRemovedHolesIndex = kHashTableStartIndex; static const int kMaxCapacity = (FixedArray::kMaxLength - kHashTableStartIndex) / (1 + (kEntrySize * kLoadFactor)); }; class JSSetIterator; class OrderedHashSet: public OrderedHashTable< OrderedHashSet, JSSetIterator, 1> { public: DECLARE_CAST(OrderedHashSet) static Handle<OrderedHashSet> Add(Handle<OrderedHashSet> table, Handle<Object> value); }; class JSMapIterator; class OrderedHashMap : public OrderedHashTable<OrderedHashMap, JSMapIterator, 2> { public: DECLARE_CAST(OrderedHashMap) inline Object* ValueAt(int entry); static const int kValueOffset = 1; }; template <int entrysize> class WeakHashTableShape : public BaseShape<Handle<Object> > { public: static inline bool IsMatch(Handle<Object> key, Object* other); static inline uint32_t Hash(Handle<Object> key); static inline uint32_t HashForObject(Handle<Object> key, Object* object); static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Object> key); static const int kPrefixSize = 0; static const int kEntrySize = entrysize; }; // WeakHashTable maps keys that are arbitrary heap objects to heap object // values. The table wraps the keys in weak cells and store values directly. // Thus it references keys weakly and values strongly. class WeakHashTable: public HashTable<WeakHashTable, WeakHashTableShape<2>, Handle<Object> > { typedef HashTable< WeakHashTable, WeakHashTableShape<2>, Handle<Object> > DerivedHashTable; public: DECLARE_CAST(WeakHashTable) // Looks up the value associated with the given key. The hole value is // returned in case the key is not present. Object* Lookup(Handle<HeapObject> key); // Adds (or overwrites) the value associated with the given key. Mapping a // key to the hole value causes removal of the whole entry. MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table, Handle<HeapObject> key, Handle<HeapObject> value); static Handle<FixedArray> GetValues(Handle<WeakHashTable> table); private: friend class MarkCompactCollector; void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value); // Returns the index to the value of an entry. static inline int EntryToValueIndex(int entry) { return EntryToIndex(entry) + 1; } }; // ScopeInfo represents information about different scopes of a source // program and the allocation of the scope's variables. Scope information // is stored in a compressed form in ScopeInfo objects and is used // at runtime (stack dumps, deoptimization, etc.). // This object provides quick access to scope info details for runtime // routines. class ScopeInfo : public FixedArray { public: DECLARE_CAST(ScopeInfo) // Return the type of this scope. ScopeType scope_type(); // Does this scope call eval? bool CallsEval(); // Return the language mode of this scope. LanguageMode language_mode(); // True if this scope is a (var) declaration scope. bool is_declaration_scope(); // Does this scope make a sloppy eval call? bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); } // Return the total number of locals allocated on the stack and in the // context. This includes the parameters that are allocated in the context. int LocalCount(); // Return the number of stack slots for code. This number consists of two // parts: // 1. One stack slot per stack allocated local. // 2. One stack slot for the function name if it is stack allocated. int StackSlotCount(); // Return the number of context slots for code if a context is allocated. This // number consists of three parts: // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS // 2. One context slot per context allocated local. // 3. One context slot for the function name if it is context allocated. // Parameters allocated in the context count as context allocated locals. If // no contexts are allocated for this scope ContextLength returns 0. int ContextLength(); // Does this scope declare a "this" binding? bool HasReceiver(); // Does this scope declare a "this" binding, and the "this" binding is stack- // or context-allocated? bool HasAllocatedReceiver(); // Does this scope declare a "new.target" binding? bool HasNewTarget(); // Is this scope the scope of a named function expression? bool HasFunctionName(); // Return if this has context allocated locals. bool HasHeapAllocatedLocals(); // Return if contexts are allocated for this scope. bool HasContext(); // Return if this is a function scope with "use asm". inline bool IsAsmModule(); // Return if this is a nested function within an asm module scope. inline bool IsAsmFunction(); inline bool HasSimpleParameters(); // Return the function_name if present. String* FunctionName(); // Return the name of the given parameter. String* ParameterName(int var); // Return the name of the given local. String* LocalName(int var); // Return the name of the given stack local. String* StackLocalName(int var); // Return the name of the given stack local. int StackLocalIndex(int var); // Return the name of the given context local. String* ContextLocalName(int var); // Return the mode of the given context local. VariableMode ContextLocalMode(int var); // Return the initialization flag of the given context local. InitializationFlag ContextLocalInitFlag(int var); // Return the initialization flag of the given context local. MaybeAssignedFlag ContextLocalMaybeAssignedFlag(int var); // Return true if this local was introduced by the compiler, and should not be // exposed to the user in a debugger. bool LocalIsSynthetic(int var); String* StrongModeFreeVariableName(int var); int StrongModeFreeVariableStartPosition(int var); int StrongModeFreeVariableEndPosition(int var); // Lookup support for serialized scope info. Returns the // the stack slot index for a given slot name if the slot is // present; otherwise returns a value < 0. The name must be an internalized // string. int StackSlotIndex(String* name); // Lookup support for serialized scope info. Returns the local context slot // index for a given slot name if the slot is present; otherwise // returns a value < 0. The name must be an internalized string. // If the slot is present and mode != NULL, sets *mode to the corresponding // mode for that variable. static int ContextSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name, VariableMode* mode, InitializationFlag* init_flag, MaybeAssignedFlag* maybe_assigned_flag); // Similar to ContextSlotIndex() but this method searches only among // global slots of the serialized scope info. Returns the context slot index // for a given slot name if the slot is present; otherwise returns a // value < 0. The name must be an internalized string. If the slot is present // and mode != NULL, sets *mode to the corresponding mode for that variable. static int ContextGlobalSlotIndex(Handle<ScopeInfo> scope_info, Handle<String> name, VariableMode* mode, InitializationFlag* init_flag, MaybeAssignedFlag* maybe_assigned_flag); // Lookup the name of a certain context slot by its index. String* ContextSlotName(int slot_index); // Lookup support for serialized scope info. Returns the // parameter index for a given parameter name if the parameter is present; // otherwise returns a value < 0. The name must be an internalized string. int ParameterIndex(String* name); // Lookup support for serialized scope info. Returns the function context // slot index if the function name is present and context-allocated (named // function expressions, only), otherwise returns a value < 0. The name // must be an internalized string. int FunctionContextSlotIndex(String* name, VariableMode* mode); // Lookup support for serialized scope info. Returns the receiver context // slot index if scope has a "this" binding, and the binding is // context-allocated. Otherwise returns a value < 0. int ReceiverContextSlotIndex(); FunctionKind function_kind(); static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope); static Handle<ScopeInfo> CreateGlobalThisBinding(Isolate* isolate); // Serializes empty scope info. static ScopeInfo* Empty(Isolate* isolate); #ifdef DEBUG void Print(); #endif // The layout of the static part of a ScopeInfo is as follows. Each entry is // numeric and occupies one array slot. // 1. A set of properties of the scope // 2. The number of parameters. This only applies to function scopes. For // non-function scopes this is 0. // 3. The number of non-parameter variables allocated on the stack. // 4. The number of non-parameter and parameter variables allocated in the // context. #define FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(V) \ V(Flags) \ V(ParameterCount) \ V(StackLocalCount) \ V(ContextLocalCount) \ V(ContextGlobalCount) \ V(StrongModeFreeVariableCount) #define FIELD_ACCESSORS(name) \ inline void Set##name(int value); \ inline int name(); FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(FIELD_ACCESSORS) #undef FIELD_ACCESSORS enum { #define DECL_INDEX(name) k##name, FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(DECL_INDEX) #undef DECL_INDEX kVariablePartIndex }; private: // The layout of the variable part of a ScopeInfo is as follows: // 1. ParameterEntries: // This part stores the names of the parameters for function scopes. One // slot is used per parameter, so in total this part occupies // ParameterCount() slots in the array. For other scopes than function // scopes ParameterCount() is 0. // 2. StackLocalFirstSlot: // Index of a first stack slot for stack local. Stack locals belonging to // this scope are located on a stack at slots starting from this index. // 3. StackLocalEntries: // Contains the names of local variables that are allocated on the stack, // in increasing order of the stack slot index. First local variable has // a stack slot index defined in StackLocalFirstSlot (point 2 above). // One slot is used per stack local, so in total this part occupies // StackLocalCount() slots in the array. // 4. ContextLocalNameEntries: // Contains the names of local variables and parameters that are allocated // in the context. They are stored in increasing order of the context slot // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per // context local, so in total this part occupies ContextLocalCount() slots // in the array. // 5. ContextLocalInfoEntries: // Contains the variable modes and initialization flags corresponding to // the context locals in ContextLocalNameEntries. One slot is used per // context local, so in total this part occupies ContextLocalCount() // slots in the array. // 6. StrongModeFreeVariableNameEntries: // Stores the names of strong mode free variables. // 7. StrongModeFreeVariablePositionEntries: // Stores the locations (start and end position) of strong mode free // variables. // 8. RecieverEntryIndex: // If the scope binds a "this" value, one slot is reserved to hold the // context or stack slot index for the variable. // 9. FunctionNameEntryIndex: // If the scope belongs to a named function expression this part contains // information about the function variable. It always occupies two array // slots: a. The name of the function variable. // b. The context or stack slot index for the variable. int ParameterEntriesIndex(); int StackLocalFirstSlotIndex(); int StackLocalEntriesIndex(); int ContextLocalNameEntriesIndex(); int ContextGlobalNameEntriesIndex(); int ContextLocalInfoEntriesIndex(); int ContextGlobalInfoEntriesIndex(); int StrongModeFreeVariableNameEntriesIndex(); int StrongModeFreeVariablePositionEntriesIndex(); int ReceiverEntryIndex(); int FunctionNameEntryIndex(); int Lookup(Handle<String> name, int start, int end, VariableMode* mode, VariableLocation* location, InitializationFlag* init_flag, MaybeAssignedFlag* maybe_assigned_flag); // Used for the function name variable for named function expressions, and for // the receiver. enum VariableAllocationInfo { NONE, STACK, CONTEXT, UNUSED }; // Properties of scopes. class ScopeTypeField : public BitField<ScopeType, 0, 4> {}; class CallsEvalField : public BitField<bool, ScopeTypeField::kNext, 1> {}; STATIC_ASSERT(LANGUAGE_END == 3); class LanguageModeField : public BitField<LanguageMode, CallsEvalField::kNext, 2> {}; class DeclarationScopeField : public BitField<bool, LanguageModeField::kNext, 1> {}; class ReceiverVariableField : public BitField<VariableAllocationInfo, DeclarationScopeField::kNext, 2> {}; class HasNewTargetField : public BitField<bool, ReceiverVariableField::kNext, 1> {}; class FunctionVariableField : public BitField<VariableAllocationInfo, HasNewTargetField::kNext, 2> {}; class FunctionVariableMode : public BitField<VariableMode, FunctionVariableField::kNext, 3> {}; class AsmModuleField : public BitField<bool, FunctionVariableMode::kNext, 1> { }; class AsmFunctionField : public BitField<bool, AsmModuleField::kNext, 1> {}; class HasSimpleParametersField : public BitField<bool, AsmFunctionField::kNext, 1> {}; class FunctionKindField : public BitField<FunctionKind, HasSimpleParametersField::kNext, 8> {}; // BitFields representing the encoded information for context locals in the // ContextLocalInfoEntries part. class ContextLocalMode: public BitField<VariableMode, 0, 3> {}; class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {}; class ContextLocalMaybeAssignedFlag : public BitField<MaybeAssignedFlag, 4, 1> {}; friend class ScopeIterator; }; // The cache for maps used by normalized (dictionary mode) objects. // Such maps do not have property descriptors, so a typical program // needs very limited number of distinct normalized maps. class NormalizedMapCache: public FixedArray { public: static Handle<NormalizedMapCache> New(Isolate* isolate); MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map, PropertyNormalizationMode mode); void Set(Handle<Map> fast_map, Handle<Map> normalized_map); void Clear(); DECLARE_CAST(NormalizedMapCache) static inline bool IsNormalizedMapCache(const Object* obj); DECLARE_VERIFIER(NormalizedMapCache) private: static const int kEntries = 64; static inline int GetIndex(Handle<Map> map); // The following declarations hide base class methods. Object* get(int index); void set(int index, Object* value); }; // ByteArray represents fixed sized byte arrays. Used for the relocation info // that is attached to code objects. class ByteArray: public FixedArrayBase { public: inline int Size(); // Setter and getter. inline byte get(int index); inline void set(int index, byte value); // Treat contents as an int array. inline int get_int(int index); static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length); } // We use byte arrays for free blocks in the heap. Given a desired size in // bytes that is a multiple of the word size and big enough to hold a byte // array, this function returns the number of elements a byte array should // have. static int LengthFor(int size_in_bytes) { DCHECK(IsAligned(size_in_bytes, kPointerSize)); DCHECK(size_in_bytes >= kHeaderSize); return size_in_bytes - kHeaderSize; } // Returns data start address. inline Address GetDataStartAddress(); // Returns a pointer to the ByteArray object for a given data start address. static inline ByteArray* FromDataStartAddress(Address address); DECLARE_CAST(ByteArray) // Dispatched behavior. inline int ByteArraySize(); DECLARE_PRINTER(ByteArray) DECLARE_VERIFIER(ByteArray) // Layout description. static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); // Maximal memory consumption for a single ByteArray. static const int kMaxSize = 512 * MB; // Maximal length of a single ByteArray. static const int kMaxLength = kMaxSize - kHeaderSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray); }; // BytecodeArray represents a sequence of interpreter bytecodes. class BytecodeArray : public FixedArrayBase { public: static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length); } // Setter and getter inline byte get(int index); inline void set(int index, byte value); // Returns data start address. inline Address GetFirstBytecodeAddress(); // Accessors for frame size. inline int frame_size() const; inline void set_frame_size(int frame_size); // Accessor for register count (derived from frame_size). inline int register_count() const; // Accessors for parameter count (including implicit 'this' receiver). inline int parameter_count() const; inline void set_parameter_count(int number_of_parameters); // Accessors for the constant pool. DECL_ACCESSORS(constant_pool, FixedArray) // 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, FixedArray) DECLARE_CAST(BytecodeArray) // Dispatched behavior. inline int BytecodeArraySize(); inline int instruction_size(); int SourcePosition(int offset); DECLARE_PRINTER(BytecodeArray) DECLARE_VERIFIER(BytecodeArray) void Disassemble(std::ostream& os); // Layout description. static const int kFrameSizeOffset = FixedArrayBase::kHeaderSize; static const int kParameterSizeOffset = kFrameSizeOffset + kIntSize; static const int kConstantPoolOffset = kParameterSizeOffset + kIntSize; static const int kHandlerTableOffset = kConstantPoolOffset + kPointerSize; static const int kSourcePositionTableOffset = kHandlerTableOffset + kPointerSize; static const int kHeaderSize = kSourcePositionTableOffset + kPointerSize; // Maximal memory consumption for a single BytecodeArray. static const int kMaxSize = 512 * MB; // Maximal length of a single BytecodeArray. static const int kMaxLength = kMaxSize - kHeaderSize; class BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArray); }; // FreeSpace are fixed-size free memory blocks used by the heap and GC. // They look like heap objects (are heap object tagged and have a map) so that // the heap remains iterable. They have a size and a next pointer. // The next pointer is the raw address of the next FreeSpace object (or NULL) // in the free list. class FreeSpace: public HeapObject { public: // [size]: size of the free space including the header. inline int size() const; inline void set_size(int value); inline int nobarrier_size() const; inline void nobarrier_set_size(int value); inline int Size(); // Accessors for the next field. inline FreeSpace* next(); inline void set_next(FreeSpace* next); inline static FreeSpace* cast(HeapObject* obj); // Dispatched behavior. DECLARE_PRINTER(FreeSpace) DECLARE_VERIFIER(FreeSpace) // Layout description. // Size is smi tagged when it is stored. static const int kSizeOffset = HeapObject::kHeaderSize; static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize); private: DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace); }; // V has parameters (Type, type, TYPE, C type, element_size) #define TYPED_ARRAYS(V) \ V(Uint8, uint8, UINT8, uint8_t, 1) \ V(Int8, int8, INT8, int8_t, 1) \ V(Uint16, uint16, UINT16, uint16_t, 2) \ V(Int16, int16, INT16, int16_t, 2) \ V(Uint32, uint32, UINT32, uint32_t, 4) \ V(Int32, int32, INT32, int32_t, 4) \ V(Float32, float32, FLOAT32, float, 4) \ V(Float64, float64, FLOAT64, double, 8) \ V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1) class FixedTypedArrayBase: public FixedArrayBase { public: // [base_pointer]: Either points to the FixedTypedArrayBase itself or nullptr. DECL_ACCESSORS(base_pointer, Object) // [external_pointer]: Contains the offset between base_pointer and the start // of the data. If the base_pointer is a nullptr, the external_pointer // therefore points to the actual backing store. DECL_ACCESSORS(external_pointer, void) // Dispatched behavior. DECLARE_CAST(FixedTypedArrayBase) static const int kBasePointerOffset = FixedArrayBase::kHeaderSize; static const int kExternalPointerOffset = kBasePointerOffset + kPointerSize; static const int kHeaderSize = DOUBLE_POINTER_ALIGN(kExternalPointerOffset + kPointerSize); static const int kDataOffset = kHeaderSize; class BodyDescriptor; inline int size(); static inline int TypedArraySize(InstanceType type, int length); inline int TypedArraySize(InstanceType type); // Use with care: returns raw pointer into heap. inline void* DataPtr(); inline int DataSize(); private: static inline int ElementSize(InstanceType type); inline int DataSize(InstanceType type); DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArrayBase); }; template <class Traits> class FixedTypedArray: public FixedTypedArrayBase { public: typedef typename Traits::ElementType ElementType; static const InstanceType kInstanceType = Traits::kInstanceType; DECLARE_CAST(FixedTypedArray<Traits>) inline ElementType get_scalar(int index); static inline Handle<Object> get(FixedTypedArray* array, int index); inline void set(int index, ElementType value); static inline ElementType from_int(int value); static inline ElementType from_double(double value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. inline void SetValue(uint32_t index, Object* value); DECLARE_PRINTER(FixedTypedArray) DECLARE_VERIFIER(FixedTypedArray) private: DISALLOW_IMPLICIT_CONSTRUCTORS(FixedTypedArray); }; #define FIXED_TYPED_ARRAY_TRAITS(Type, type, TYPE, elementType, size) \ class Type##ArrayTraits { \ public: /* NOLINT */ \ typedef elementType ElementType; \ static const InstanceType kInstanceType = FIXED_##TYPE##_ARRAY_TYPE; \ static const char* Designator() { return #type " array"; } \ static inline Handle<Object> ToHandle(Isolate* isolate, \ elementType scalar); \ static inline elementType defaultValue(); \ }; \ \ typedef FixedTypedArray<Type##ArrayTraits> Fixed##Type##Array; TYPED_ARRAYS(FIXED_TYPED_ARRAY_TRAITS) #undef FIXED_TYPED_ARRAY_TRAITS // DeoptimizationInputData is a fixed array used to hold the deoptimization // data for code generated by the Hydrogen/Lithium compiler. It also // contains information about functions that were inlined. If N different // functions were inlined then first N elements of the literal array will // contain these functions. // // It can be empty. class DeoptimizationInputData: public FixedArray { public: // Layout description. Indices in the array. static const int kTranslationByteArrayIndex = 0; static const int kInlinedFunctionCountIndex = 1; static const int kLiteralArrayIndex = 2; static const int kOsrAstIdIndex = 3; static const int kOsrPcOffsetIndex = 4; static const int kOptimizationIdIndex = 5; static const int kSharedFunctionInfoIndex = 6; static const int kWeakCellCacheIndex = 7; static const int kFirstDeoptEntryIndex = 8; // Offsets of deopt entry elements relative to the start of the entry. static const int kAstIdRawOffset = 0; static const int kTranslationIndexOffset = 1; static const int kArgumentsStackHeightOffset = 2; static const int kPcOffset = 3; static const int kDeoptEntrySize = 4; // Simple element accessors. #define DECLARE_ELEMENT_ACCESSORS(name, type) \ inline type* name(); \ inline void Set##name(type* value); DECLARE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray) DECLARE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi) DECLARE_ELEMENT_ACCESSORS(LiteralArray, FixedArray) DECLARE_ELEMENT_ACCESSORS(OsrAstId, Smi) DECLARE_ELEMENT_ACCESSORS(OsrPcOffset, Smi) DECLARE_ELEMENT_ACCESSORS(OptimizationId, Smi) DECLARE_ELEMENT_ACCESSORS(SharedFunctionInfo, Object) DECLARE_ELEMENT_ACCESSORS(WeakCellCache, Object) #undef DECLARE_ELEMENT_ACCESSORS // Accessors for elements of the ith deoptimization entry. #define DECLARE_ENTRY_ACCESSORS(name, type) \ inline type* name(int i); \ inline void Set##name(int i, type* value); DECLARE_ENTRY_ACCESSORS(AstIdRaw, Smi) DECLARE_ENTRY_ACCESSORS(TranslationIndex, Smi) DECLARE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi) DECLARE_ENTRY_ACCESSORS(Pc, Smi) #undef DECLARE_ENTRY_ACCESSORS inline BailoutId AstId(int i); inline void SetAstId(int i, BailoutId value); inline int DeoptCount(); // Allocates a DeoptimizationInputData. static Handle<DeoptimizationInputData> New(Isolate* isolate, int deopt_entry_count, PretenureFlag pretenure); DECLARE_CAST(DeoptimizationInputData) #ifdef ENABLE_DISASSEMBLER void DeoptimizationInputDataPrint(std::ostream& os); // NOLINT #endif private: static int IndexForEntry(int i) { return kFirstDeoptEntryIndex + (i * kDeoptEntrySize); } static int LengthFor(int entry_count) { return IndexForEntry(entry_count); } }; // DeoptimizationOutputData is a fixed array used to hold the deoptimization // data for code generated by the full compiler. // The format of the these objects is // [i * 2]: Ast ID for ith deoptimization. // [i * 2 + 1]: PC and state of ith deoptimization class DeoptimizationOutputData: public FixedArray { public: inline int DeoptPoints(); inline BailoutId AstId(int index); inline void SetAstId(int index, BailoutId id); inline Smi* PcAndState(int index); inline void SetPcAndState(int index, Smi* offset); static int LengthOfFixedArray(int deopt_points) { return deopt_points * 2; } // Allocates a DeoptimizationOutputData. static Handle<DeoptimizationOutputData> New(Isolate* isolate, int number_of_deopt_points, PretenureFlag pretenure); DECLARE_CAST(DeoptimizationOutputData) #ifdef ENABLE_DISASSEMBLER void DeoptimizationOutputDataPrint(std::ostream& os); // NOLINT #endif }; // A literals array contains the literals for a JSFunction. It also holds // the type feedback vector. class LiteralsArray : public FixedArray { public: static const int kVectorIndex = 0; static const int kFirstLiteralIndex = 1; static const int kOffsetToFirstLiteral = FixedArray::kHeaderSize + kPointerSize; static int OffsetOfLiteralAt(int index) { return SizeFor(index + kFirstLiteralIndex); } inline TypeFeedbackVector* feedback_vector() const; inline void set_feedback_vector(TypeFeedbackVector* vector); inline Object* literal(int literal_index) const; inline void set_literal(int literal_index, Object* literal); inline int literals_count() const; static Handle<LiteralsArray> New(Isolate* isolate, Handle<TypeFeedbackVector> vector, int number_of_literals, PretenureFlag pretenure); DECLARE_CAST(LiteralsArray) private: inline Object* get(int index) const; inline void set(int index, Object* value); inline void set(int index, Smi* value); inline void set(int index, Object* value, WriteBarrierMode mode); }; // HandlerTable is a fixed array containing entries for exception handlers in // the code object it is associated with. The tables comes in two flavors: // 1) Based on ranges: Used for unoptimized code. Contains one entry per // exception handler and a range representing the try-block covered by that // handler. Layout looks as follows: // [ range-start , range-end , handler-offset , 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, CAUGHT }; // 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, CatchPrediction pred); // Lookup handler in a table based on ranges. int LookupRange(int pc_offset, int* data, CatchPrediction* prediction); // Lookup handler in a table based on return addresses. int LookupReturn(int pc_offset, CatchPrediction* prediction); // 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<CatchPrediction, 0, 1> {}; class HandlerOffsetField : public BitField<int, 1, 30> {}; }; // Code describes objects with on-the-fly generated machine code. class Code: public HeapObject { public: // Opaque data type for encapsulating code flags like kind, inline // cache state, and arguments count. typedef uint32_t Flags; #define NON_IC_KIND_LIST(V) \ V(FUNCTION) \ V(OPTIMIZED_FUNCTION) \ V(STUB) \ V(HANDLER) \ V(BUILTIN) \ V(REGEXP) \ V(WASM_FUNCTION) #define IC_KIND_LIST(V) \ V(LOAD_IC) \ V(KEYED_LOAD_IC) \ V(CALL_IC) \ V(STORE_IC) \ V(KEYED_STORE_IC) \ V(BINARY_OP_IC) \ V(COMPARE_IC) \ V(COMPARE_NIL_IC) \ V(TO_BOOLEAN_IC) #define CODE_KIND_LIST(V) \ NON_IC_KIND_LIST(V) \ IC_KIND_LIST(V) enum Kind { #define DEFINE_CODE_KIND_ENUM(name) name, CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM) #undef DEFINE_CODE_KIND_ENUM NUMBER_OF_KINDS }; // No more than 32 kinds. The value is currently encoded in five bits in // Flags. STATIC_ASSERT(NUMBER_OF_KINDS <= 32); static const char* Kind2String(Kind kind); // Types of stubs. enum StubType { NORMAL, FAST }; static const int kPrologueOffsetNotSet = -1; #ifdef ENABLE_DISASSEMBLER // Printing static const char* ICState2String(InlineCacheState state); static const char* StubType2String(StubType type); static void PrintExtraICState(std::ostream& os, // NOLINT Kind kind, ExtraICState extra); void Disassemble(const char* name, std::ostream& os); // NOLINT #endif // ENABLE_DISASSEMBLER // [instruction_size]: Size of the native instructions inline int instruction_size() const; inline void set_instruction_size(int value); // [relocation_info]: Code relocation information DECL_ACCESSORS(relocation_info, ByteArray) void InvalidateRelocation(); void InvalidateEmbeddedObjects(); // [handler_table]: Fixed array containing offsets of exception handlers. DECL_ACCESSORS(handler_table, FixedArray) // [deoptimization_data]: Array containing data for deopt. DECL_ACCESSORS(deoptimization_data, FixedArray) // [raw_type_feedback_info]: This field stores various things, depending on // the kind of the code object. // FUNCTION => type feedback information. // STUB and ICs => major/minor key as Smi. DECL_ACCESSORS(raw_type_feedback_info, Object) inline Object* type_feedback_info(); inline void set_type_feedback_info( Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); inline uint32_t stub_key(); inline void set_stub_key(uint32_t key); // [next_code_link]: Link for lists of optimized or deoptimized code. // Note that storage for this field is overlapped with typefeedback_info. DECL_ACCESSORS(next_code_link, Object) // [gc_metadata]: Field used to hold GC related metadata. The contents of this // field does not have to be traced during garbage collection since // it is only used by the garbage collector itself. DECL_ACCESSORS(gc_metadata, Object) // [ic_age]: Inline caching age: the value of the Heap::global_ic_age // at the moment when this object was created. inline void set_ic_age(int count); inline int ic_age() const; // [prologue_offset]: Offset of the function prologue, used for aging // FUNCTIONs and OPTIMIZED_FUNCTIONs. inline int prologue_offset() const; inline void set_prologue_offset(int offset); // [constant_pool offset]: Offset of the constant pool. // Valid for FLAG_enable_embedded_constant_pool only inline int constant_pool_offset() const; inline void set_constant_pool_offset(int offset); // Unchecked accessors to be used during GC. inline ByteArray* unchecked_relocation_info(); inline int relocation_size(); // [flags]: Various code flags. inline Flags flags(); inline void set_flags(Flags flags); // [flags]: Access to specific code flags. inline Kind kind(); inline InlineCacheState ic_state(); // Only valid for IC stubs. inline ExtraICState extra_ic_state(); // Only valid for IC stubs. inline StubType type(); // Only valid for monomorphic IC stubs. // Testers for IC stub kinds. inline bool is_inline_cache_stub(); inline bool is_debug_stub(); inline bool is_handler(); inline bool is_load_stub(); inline bool is_keyed_load_stub(); inline bool is_store_stub(); inline bool is_keyed_store_stub(); inline bool is_call_stub(); inline bool is_binary_op_stub(); inline bool is_compare_ic_stub(); inline bool is_compare_nil_ic_stub(); inline bool is_to_boolean_ic_stub(); inline bool is_keyed_stub(); inline bool is_optimized_code(); inline bool embeds_maps_weakly(); inline bool IsCodeStubOrIC(); inline bool IsJavaScriptCode(); inline void set_raw_kind_specific_flags1(int value); inline void set_raw_kind_specific_flags2(int value); // Testers for interpreter builtins. inline bool is_interpreter_entry_trampoline(); inline bool is_interpreter_enter_bytecode_dispatch(); // [is_crankshafted]: For kind STUB or ICs, tells whether or not a code // object was generated by either the hydrogen or the TurboFan optimizing // compiler (but it may not be an optimized function). inline bool is_crankshafted(); inline bool is_hydrogen_stub(); // Crankshafted, but not a function. inline void set_is_crankshafted(bool value); // [is_turbofanned]: For kind STUB or OPTIMIZED_FUNCTION, tells whether the // code object was generated by the TurboFan optimizing compiler. inline bool is_turbofanned(); inline void set_is_turbofanned(bool value); // [can_have_weak_objects]: For kind OPTIMIZED_FUNCTION, tells whether the // embedded objects in code should be treated weakly. inline bool can_have_weak_objects(); inline void set_can_have_weak_objects(bool value); // [has_deoptimization_support]: For FUNCTION kind, tells if it has // deoptimization support. inline bool has_deoptimization_support(); inline void set_has_deoptimization_support(bool value); // [has_debug_break_slots]: For FUNCTION kind, tells if it has // been compiled with debug break slots. inline bool has_debug_break_slots(); inline void set_has_debug_break_slots(bool value); // [has_reloc_info_for_serialization]: For FUNCTION kind, tells if its // reloc info includes runtime and external references to support // serialization/deserialization. inline bool has_reloc_info_for_serialization(); inline void set_has_reloc_info_for_serialization(bool value); // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for // how long the function has been marked for OSR and therefore which // level of loop nesting we are willing to do on-stack replacement // for. inline void set_allow_osr_at_loop_nesting_level(int level); inline int allow_osr_at_loop_nesting_level(); // [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks // the code object was seen on the stack with no IC patching going on. inline int profiler_ticks(); inline void set_profiler_ticks(int ticks); // [builtin_index]: For BUILTIN kind, tells which builtin index it has. // For builtins, tells which builtin index it has. // Note that builtins can have a code kind other than BUILTIN, which means // that for arbitrary code objects, this index value may be random garbage. // To verify in that case, compare the code object to the indexed builtin. inline int builtin_index(); inline void set_builtin_index(int id); // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots // reserved in the code prologue. inline unsigned stack_slots(); inline void set_stack_slots(unsigned slots); // [safepoint_table_start]: For kind OPTIMIZED_FUNCTION, the offset in // the instruction stream where the safepoint table starts. inline unsigned safepoint_table_offset(); inline void set_safepoint_table_offset(unsigned offset); // [back_edge_table_start]: For kind FUNCTION, the offset in the // instruction stream where the back edge table starts. inline unsigned back_edge_table_offset(); inline void set_back_edge_table_offset(unsigned offset); inline bool back_edges_patched_for_osr(); // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in. inline uint16_t to_boolean_state(); // [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether // the code is going to be deoptimized because of dead embedded maps. inline bool marked_for_deoptimization(); inline void set_marked_for_deoptimization(bool flag); // [constant_pool]: The constant pool for this function. inline Address constant_pool(); // Get the safepoint entry for the given pc. SafepointEntry GetSafepointEntry(Address pc); // Find an object in a stub with a specified map Object* FindNthObject(int n, Map* match_map); // Find the first allocation site in an IC stub. AllocationSite* FindFirstAllocationSite(); // Find the first map in an IC stub. Map* FindFirstMap(); void FindAllMaps(MapHandleList* maps); // Find the first handler in an IC stub. Code* FindFirstHandler(); // Find |length| handlers and put them into |code_list|. Returns false if not // enough handlers can be found. bool FindHandlers(CodeHandleList* code_list, int length = -1); // Find the handler for |map|. MaybeHandle<Code> FindHandlerForMap(Map* map); // Find the first name in an IC stub. Name* FindFirstName(); class FindAndReplacePattern; // For each (map-to-find, object-to-replace) pair in the pattern, this // function replaces the corresponding placeholder in the code with the // object-to-replace. The function assumes that pairs in the pattern come in // the same order as the placeholders in the code. // If the placeholder is a weak cell, then the value of weak cell is matched // against the map-to-find. void FindAndReplace(const FindAndReplacePattern& pattern); // The entire code object including its header is copied verbatim to the // snapshot so that it can be written in one, fast, memcpy during // deserialization. The deserializer will overwrite some pointers, rather // like a runtime linker, but the random allocation addresses used in the // mksnapshot process would still be present in the unlinked snapshot data, // which would make snapshot production non-reproducible. This method wipes // out the to-be-overwritten header data for reproducible snapshots. inline void WipeOutHeader(); // Flags operations. static inline Flags ComputeFlags( Kind kind, InlineCacheState ic_state = UNINITIALIZED, ExtraICState extra_ic_state = kNoExtraICState, StubType type = NORMAL, CacheHolderFlag holder = kCacheOnReceiver); static inline Flags ComputeMonomorphicFlags( Kind kind, ExtraICState extra_ic_state = kNoExtraICState, CacheHolderFlag holder = kCacheOnReceiver, StubType type = NORMAL); static inline Flags ComputeHandlerFlags( Kind handler_kind, StubType type = NORMAL, CacheHolderFlag holder = kCacheOnReceiver); static inline InlineCacheState ExtractICStateFromFlags(Flags flags); static inline StubType ExtractTypeFromFlags(Flags flags); static inline CacheHolderFlag ExtractCacheHolderFromFlags(Flags flags); static inline Kind ExtractKindFromFlags(Flags flags); static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags); static inline Flags RemoveTypeFromFlags(Flags flags); static inline Flags RemoveTypeAndHolderFromFlags(Flags flags); // Convert a target address into a code object. static inline Code* GetCodeFromTargetAddress(Address address); // Convert an entry address into an object. static inline Object* GetObjectFromEntryAddress(Address location_of_address); // Returns the address of the first instruction. inline byte* instruction_start(); // Returns the address right after the last instruction. inline byte* instruction_end(); // Returns the size of the instructions, padding, and relocation information. inline int body_size(); // Returns the address of the first relocation info (read backwards!). inline byte* relocation_start(); // Code entry point. inline byte* entry(); // Returns true if pc is inside this object's instructions. inline bool contains(byte* pc); // Relocate the code by delta bytes. Called to signal that this code // object has been moved by delta bytes. void Relocate(intptr_t delta); // Migrate code described by desc. void CopyFrom(const CodeDesc& desc); // Returns the object size for a given body (used for allocation). static int SizeFor(int body_size) { DCHECK_SIZE_TAG_ALIGNED(body_size); return RoundUp(kHeaderSize + body_size, kCodeAlignment); } // Calculate the size of the code object to report for log events. This takes // the layout of the code object into account. inline int ExecutableSize(); // Locating source position. int SourcePosition(int code_offset); int SourceStatementPosition(int code_offset); DECLARE_CAST(Code) // Dispatched behavior. inline int CodeSize(); DECLARE_PRINTER(Code) DECLARE_VERIFIER(Code) void ClearInlineCaches(); void ClearInlineCaches(Kind kind); BailoutId TranslatePcOffsetToAstId(uint32_t pc_offset); uint32_t TranslateAstIdToPcOffset(BailoutId ast_id); #define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge, enum Age { kToBeExecutedOnceCodeAge = -3, kNotExecutedCodeAge = -2, kExecutedOnceCodeAge = -1, kNoAgeCodeAge = 0, CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM) kAfterLastCodeAge, kFirstCodeAge = kToBeExecutedOnceCodeAge, kLastCodeAge = kAfterLastCodeAge - 1, kCodeAgeCount = kAfterLastCodeAge - kFirstCodeAge - 1, kIsOldCodeAge = kSexagenarianCodeAge, kPreAgedCodeAge = kIsOldCodeAge - 1 }; #undef DECLARE_CODE_AGE_ENUM // Code aging. Indicates how many full GCs this code has survived without // being entered through the prologue. Used to determine when it is // relatively safe to flush this code object and replace it with the lazy // compilation stub. static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate); static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate); void MakeYoung(Isolate* isolate); void MarkToBeExecutedOnce(Isolate* isolate); void MakeOlder(MarkingParity); static bool IsYoungSequence(Isolate* isolate, byte* sequence); bool IsOld(); Age GetAge(); static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) { return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY); } void PrintDeoptLocation(FILE* out, Address pc); bool CanDeoptAt(Address pc); #ifdef VERIFY_HEAP void VerifyEmbeddedObjectsDependency(); #endif #ifdef DEBUG enum VerifyMode { kNoContextSpecificPointers, kNoContextRetainingPointers }; void VerifyEmbeddedObjects(VerifyMode mode = kNoContextRetainingPointers); static void VerifyRecompiledCode(Code* old_code, Code* new_code); #endif // DEBUG inline bool CanContainWeakObjects(); inline bool IsWeakObject(Object* object); static inline bool IsWeakObjectInOptimizedCode(Object* object); static Handle<WeakCell> WeakCellFor(Handle<Code> code); WeakCell* CachedWeakCell(); // Max loop nesting marker used to postpose OSR. We don't take loop // nesting that is deeper than 5 levels into account. static const int kMaxLoopNestingMarker = 6; static const int kConstantPoolSize = FLAG_enable_embedded_constant_pool ? kIntSize : 0; // Layout description. static const int kRelocationInfoOffset = HeapObject::kHeaderSize; static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize; static const int kDeoptimizationDataOffset = kHandlerTableOffset + kPointerSize; // For FUNCTION kind, we store the type feedback info here. static const int kTypeFeedbackInfoOffset = kDeoptimizationDataOffset + kPointerSize; static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize; static const int kGCMetadataOffset = kNextCodeLinkOffset + kPointerSize; static const int kInstructionSizeOffset = kGCMetadataOffset + kPointerSize; static const int kICAgeOffset = kInstructionSizeOffset + kIntSize; static const int kFlagsOffset = kICAgeOffset + kIntSize; static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize; static const int kKindSpecificFlags2Offset = kKindSpecificFlags1Offset + kIntSize; // Note: We might be able to squeeze this into the flags above. static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize; static const int kConstantPoolOffset = kPrologueOffset + kIntSize; static const int kHeaderPaddingStart = kConstantPoolOffset + kConstantPoolSize; // Add padding to align the instruction start following right after // the Code object header. static const int kHeaderSize = (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask; class BodyDescriptor; // Byte offsets within kKindSpecificFlags1Offset. static const int kFullCodeFlags = kKindSpecificFlags1Offset; class FullCodeFlagsHasDeoptimizationSupportField: public BitField<bool, 0, 1> {}; // NOLINT class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {}; class FullCodeFlagsHasRelocInfoForSerialization : public BitField<bool, 2, 1> {}; // Bit 3 in this bitfield is unused. class ProfilerTicksField : public BitField<int, 4, 28> {}; // Flags layout. BitField<type, shift, size>. class ICStateField : public BitField<InlineCacheState, 0, 3> {}; class TypeField : public BitField<StubType, 3, 1> {}; class CacheHolderField : public BitField<CacheHolderFlag, 4, 2> {}; class KindField : public BitField<Kind, 6, 5> {}; class ExtraICStateField: public BitField<ExtraICState, 11, PlatformSmiTagging::kSmiValueSize - 11 + 1> {}; // NOLINT // KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION) static const int kStackSlotsFirstBit = 0; static const int kStackSlotsBitCount = 24; static const int kMarkedForDeoptimizationBit = kStackSlotsFirstBit + kStackSlotsBitCount; static const int kIsTurbofannedBit = kMarkedForDeoptimizationBit + 1; static const int kCanHaveWeakObjects = kIsTurbofannedBit + 1; STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32); STATIC_ASSERT(kCanHaveWeakObjects + 1 <= 32); class StackSlotsField: public BitField<int, kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT class MarkedForDeoptimizationField : public BitField<bool, kMarkedForDeoptimizationBit, 1> {}; // NOLINT class IsTurbofannedField : public BitField<bool, kIsTurbofannedBit, 1> { }; // NOLINT class CanHaveWeakObjectsField : public BitField<bool, kCanHaveWeakObjects, 1> {}; // NOLINT // KindSpecificFlags2 layout (ALL) static const int kIsCrankshaftedBit = 0; class IsCrankshaftedField: public BitField<bool, kIsCrankshaftedBit, 1> {}; // NOLINT // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION) static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1; static const int kSafepointTableOffsetBitCount = 30; STATIC_ASSERT(kSafepointTableOffsetFirstBit + kSafepointTableOffsetBitCount <= 32); STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32); class SafepointTableOffsetField: public BitField<int, kSafepointTableOffsetFirstBit, kSafepointTableOffsetBitCount> {}; // NOLINT // KindSpecificFlags2 layout (FUNCTION) class BackEdgeTableOffsetField: public BitField<int, kIsCrankshaftedBit + 1, 27> {}; // NOLINT class AllowOSRAtLoopNestingLevelField: public BitField<int, kIsCrankshaftedBit + 1 + 27, 4> {}; // NOLINT STATIC_ASSERT(AllowOSRAtLoopNestingLevelField::kMax >= kMaxLoopNestingMarker); static const int kArgumentsBits = 16; static const int kMaxArguments = (1 << kArgumentsBits) - 1; // This constant should be encodable in an ARM instruction. static const int kFlagsNotUsedInLookup = TypeField::kMask | CacheHolderField::kMask; private: friend class RelocIterator; friend class Deoptimizer; // For FindCodeAgeSequence. void ClearInlineCaches(Kind* kind); // Code aging byte* FindCodeAgeSequence(); static void GetCodeAgeAndParity(Code* code, Age* age, MarkingParity* parity); static void GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age, MarkingParity* parity); static Code* GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity); // Code aging -- platform-specific static void PatchPlatformCodeAge(Isolate* isolate, byte* sequence, Age age, MarkingParity parity); DISALLOW_IMPLICIT_CONSTRUCTORS(Code); }; class AbstractCode : public HeapObject { public: int SourcePosition(int offset); DECLARE_CAST(AbstractCode) inline Code* GetCode(); inline BytecodeArray* GetBytecodeArray(); }; // Dependent code is a singly linked list of fixed arrays. Each array contains // code objects in weak cells for one dependent group. The suffix of the array // can be filled with the undefined value if the number of codes is less than // the length of the array. // // +------+-----------------+--------+--------+-----+--------+-----------+-----+ // | next | count & group 1 | code 1 | code 2 | ... | code n | undefined | ... | // +------+-----------------+--------+--------+-----+--------+-----------+-----+ // | // V // +------+-----------------+--------+--------+-----+--------+-----------+-----+ // | next | count & group 2 | code 1 | code 2 | ... | code m | undefined | ... | // +------+-----------------+--------+--------+-----+--------+-----------+-----+ // | // V // empty_fixed_array() // // The list of fixed arrays is ordered by dependency groups. class DependentCode: public FixedArray { public: enum DependencyGroup { // Group of code that weakly embed this map and depend on being // deoptimized when the map is garbage collected. kWeakCodeGroup, // Group of code that embed a transition to this map, and depend on being // deoptimized when the transition is replaced by a new version. kTransitionGroup, // Group of code that omit run-time prototype checks for prototypes // described by this map. The group is deoptimized whenever an object // described by this map changes shape (and transitions to a new map), // possibly invalidating the assumptions embedded in the code. kPrototypeCheckGroup, // Group of code that depends on global property values in property cells // not being changed. kPropertyCellChangedGroup, // Group of code that omit run-time type checks for the field(s) introduced // by this map. kFieldTypeGroup, // Group of code that omit run-time type checks for initial maps of // constructors. kInitialMapChangedGroup, // Group of code that depends on tenuring information in AllocationSites // not being changed. kAllocationSiteTenuringChangedGroup, // Group of code that depends on element transition information in // AllocationSites not being changed. kAllocationSiteTransitionChangedGroup }; static const int kGroupCount = kAllocationSiteTransitionChangedGroup + 1; bool Contains(DependencyGroup group, WeakCell* code_cell); bool IsEmpty(DependencyGroup group); static Handle<DependentCode> InsertCompilationDependencies( Handle<DependentCode> entries, DependencyGroup group, Handle<Foreign> info); static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries, DependencyGroup group, Handle<WeakCell> code_cell); void UpdateToFinishedCode(DependencyGroup group, Foreign* info, WeakCell* code_cell); void RemoveCompilationDependencies(DependentCode::DependencyGroup group, Foreign* info); void DeoptimizeDependentCodeGroup(Isolate* isolate, DependentCode::DependencyGroup group); bool MarkCodeForDeoptimization(Isolate* isolate, DependentCode::DependencyGroup group); // The following low-level accessors should only be used by this class // and the mark compact collector. inline DependentCode* next_link(); inline void set_next_link(DependentCode* next); inline int count(); inline void set_count(int value); inline DependencyGroup group(); inline void set_group(DependencyGroup group); inline Object* object_at(int i); inline void set_object_at(int i, Object* object); inline void clear_at(int i); inline void copy(int from, int to); DECLARE_CAST(DependentCode) static const char* DependencyGroupName(DependencyGroup group); static void SetMarkedForDeoptimization(Code* code, DependencyGroup group); private: static Handle<DependentCode> Insert(Handle<DependentCode> entries, DependencyGroup group, Handle<Object> object); static Handle<DependentCode> New(DependencyGroup group, Handle<Object> object, Handle<DependentCode> next); static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries); // Compact by removing cleared weak cells and return true if there was // any cleared weak cell. bool Compact(); static int Grow(int number_of_entries) { if (number_of_entries < 5) return number_of_entries + 1; return number_of_entries * 5 / 4; } inline int flags(); inline void set_flags(int flags); class GroupField : public BitField<int, 0, 3> {}; class CountField : public BitField<int, 3, 27> {}; STATIC_ASSERT(kGroupCount <= GroupField::kMax + 1); static const int kNextLinkIndex = 0; static const int kFlagsIndex = 1; static const int kCodesStartIndex = 2; }; class PrototypeInfo; // All heap objects have a Map that describes their structure. // A Map contains information about: // - Size information about the object // - How to iterate over an object (for garbage collection) class Map: public HeapObject { public: // Instance size. // Size in bytes or kVariableSizeSentinel if instances do not have // a fixed size. inline int instance_size(); inline void set_instance_size(int value); // Only to clear an unused byte, remove once byte is used. inline void clear_unused(); // [inobject_properties_or_constructor_function_index]: Provides access // to the inobject properties in case of JSObject maps, or the constructor // function index in case of primitive maps. inline int inobject_properties_or_constructor_function_index(); inline void set_inobject_properties_or_constructor_function_index(int value); // Count of properties allocated in the object (JSObject only). inline int GetInObjectProperties(); inline void SetInObjectProperties(int value); // Index of the constructor function in the native context (primitives only), // or the special sentinel value to indicate that there is no object wrapper // for the primitive (i.e. in case of null or undefined). static const int kNoConstructorFunctionIndex = 0; inline int GetConstructorFunctionIndex(); inline void SetConstructorFunctionIndex(int value); static MaybeHandle<JSFunction> GetConstructorFunction( Handle<Map> map, Handle<Context> native_context); // Instance type. inline InstanceType instance_type(); inline void set_instance_type(InstanceType value); // Tells how many unused property fields are available in the // instance (only used for JSObject in fast mode). inline int unused_property_fields(); inline void set_unused_property_fields(int value); // Bit field. inline byte bit_field() const; inline void set_bit_field(byte value); // Bit field 2. inline byte bit_field2() const; inline void set_bit_field2(byte value); // Bit field 3. inline uint32_t bit_field3() const; inline void set_bit_field3(uint32_t bits); class EnumLengthBits: public BitField<int, 0, kDescriptorIndexBitCount> {}; // NOLINT class NumberOfOwnDescriptorsBits: public BitField<int, kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20); class DictionaryMap : public BitField<bool, 20, 1> {}; class OwnsDescriptors : public BitField<bool, 21, 1> {}; class HasHiddenPrototype : public BitField<bool, 22, 1> {}; class Deprecated : public BitField<bool, 23, 1> {}; class IsUnstable : public BitField<bool, 24, 1> {}; class IsMigrationTarget : public BitField<bool, 25, 1> {}; class IsStrong : public BitField<bool, 26, 1> {}; class NewTargetIsBase : public BitField<bool, 27, 1> {}; // Bit 28 is free. // Keep this bit field at the very end for better code in // Builtins::kJSConstructStubGeneric stub. // This counter is used for in-object slack tracking. // The in-object slack tracking is considered enabled when the counter is // non zero. class ConstructionCounter : public BitField<int, 29, 3> {}; static const int kSlackTrackingCounterStart = 7; static const int kSlackTrackingCounterEnd = 1; static const int kNoSlackTracking = 0; STATIC_ASSERT(kSlackTrackingCounterStart <= ConstructionCounter::kMax); // Inobject slack tracking is the way to reclaim unused inobject space. // // The instance size is initially determined by adding some slack to // expected_nof_properties (to allow for a few extra properties added // after the constructor). There is no guarantee that the extra space // will not be wasted. // // Here is the algorithm to reclaim the unused inobject space: // - Detect the first constructor call for this JSFunction. // When it happens enter the "in progress" state: initialize construction // counter in the initial_map. // - While the tracking is in progress initialize unused properties of a new // object with one_pointer_filler_map instead of undefined_value (the "used" // part is initialized with undefined_value as usual). This way they can // be resized quickly and safely. // - Once enough objects have been created compute the 'slack' // (traverse the map transition tree starting from the // initial_map and find the lowest value of unused_property_fields). // - Traverse the transition tree again and decrease the instance size // of every map. Existing objects will resize automatically (they are // filled with one_pointer_filler_map). All further allocations will // use the adjusted instance size. // - SharedFunctionInfo's expected_nof_properties left unmodified since // allocations made using different closures could actually create different // kind of objects (see prototype inheritance pattern). // // Important: inobject slack tracking is not attempted during the snapshot // creation. static const int kGenerousAllocationCount = kSlackTrackingCounterStart - kSlackTrackingCounterEnd + 1; // Starts the tracking by initializing object constructions countdown counter. void StartInobjectSlackTracking(); // True if the object constructions countdown counter is a range // [kSlackTrackingCounterEnd, kSlackTrackingCounterStart]. inline bool IsInobjectSlackTrackingInProgress(); // Does the tracking step. inline void InobjectSlackTrackingStep(); // Completes inobject slack tracking for the transition tree starting at this // initial map. void CompleteInobjectSlackTracking(); // Tells whether the object in the prototype property will be used // for instances created from this function. If the prototype // property is set to a value that is not a JSObject, the prototype // property will not be used to create instances of the function. // See ECMA-262, 13.2.2. inline void set_non_instance_prototype(bool value); inline bool has_non_instance_prototype(); // Tells whether the instance has a [[Construct]] internal method. // This property is implemented according to ES6, section 7.2.4. inline void set_is_constructor(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-as-function handler. inline void set_is_observed(); inline bool is_observed(); // Tells whether the instance has a [[Call]] internal method. // This property is implemented according to ES6, section 7.2.3. inline void set_is_callable(); inline bool is_callable() const; inline void set_is_strong(); inline bool is_strong(); inline void set_new_target_is_base(bool value); inline bool new_target_is_base(); inline void set_is_extensible(bool value); inline bool is_extensible(); inline void set_is_prototype_map(bool value); inline bool is_prototype_map() const; inline void set_elements_kind(ElementsKind elements_kind); inline ElementsKind elements_kind(); // Tells whether the instance has fast elements that are only Smis. inline bool has_fast_smi_elements(); // Tells whether the instance has fast elements. inline bool has_fast_object_elements(); inline bool has_fast_smi_or_object_elements(); inline bool has_fast_double_elements(); inline bool has_fast_elements(); inline bool has_sloppy_arguments_elements(); inline bool has_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<PrototypeInfo> GetOrCreatePrototypeInfo( Handle<JSObject> prototype, Isolate* isolate); static Handle<PrototypeInfo> GetOrCreatePrototypeInfo( Handle<Map> prototype_map, Isolate* isolate); // [prototype chain validity cell]: Associated with a prototype object, // stored in that object's map's PrototypeInfo, indicates that prototype // chains through this object are currently valid. The cell will be // invalidated and replaced when the prototype chain changes. static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map, Isolate* isolate); static const int kPrototypeChainValid = 0; static const int kPrototypeChainInvalid = 1; Map* FindRootMap(); Map* FindFieldOwner(int descriptor); inline int GetInObjectPropertyOffset(int index); int NumberOfFields(); // TODO(ishell): candidate with JSObject::MigrateToMap(). bool InstancesNeedRewriting(Map* target, int target_number_of_fields, int target_inobject, int target_unused, int* old_number_of_fields); // TODO(ishell): moveit! static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map); MUST_USE_RESULT static Handle<FieldType> GeneralizeFieldType( Representation rep1, Handle<FieldType> type1, Representation rep2, Handle<FieldType> type2, Isolate* isolate); static void GeneralizeFieldType(Handle<Map> map, int modify_index, Representation new_representation, Handle<FieldType> new_field_type); static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index, PropertyKind new_kind, PropertyAttributes new_attributes, Representation new_representation, Handle<FieldType> new_field_type, StoreMode store_mode); static Handle<Map> CopyGeneralizeAllRepresentations( Handle<Map> map, int modify_index, StoreMode store_mode, PropertyKind kind, PropertyAttributes attributes, const char* reason); static Handle<Map> PrepareForDataProperty(Handle<Map> old_map, int descriptor_number, Handle<Object> value); static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode, const char* reason); // Tells whether the map is used for JSObjects in dictionary mode (ie // normalized objects, ie objects for which HasFastProperties returns false). // A map can never be used for both dictionary mode and fast mode JSObjects. // False by default and for HeapObjects that are not JSObjects. inline void set_dictionary_map(bool value); inline bool is_dictionary_map(); // Tells whether the instance needs security checks when accessing its // properties. inline void set_is_access_check_needed(bool access_check_needed); inline bool is_access_check_needed(); // Returns true if map has a non-empty stub code cache. inline bool has_code_cache(); // [prototype]: implicit prototype object. DECL_ACCESSORS(prototype, Object) // TODO(jkummerow): make set_prototype private. static void SetPrototype( Handle<Map> map, Handle<Object> prototype, PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE); // [constructor]: points back to the function responsible for this map. // The field overlaps with the back pointer. All maps in a transition tree // have the same constructor, so maps with back pointers can walk the // back pointer chain until they find the map holding their constructor. DECL_ACCESSORS(constructor_or_backpointer, Object) inline Object* GetConstructor() const; inline void SetConstructor(Object* constructor, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // [back pointer]: points back to the parent map from which a transition // leads to this map. The field overlaps with the constructor (see above). inline Object* GetBackPointer(); inline void SetBackPointer(Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // [instance descriptors]: describes the object. DECL_ACCESSORS(instance_descriptors, DescriptorArray) // [layout descriptor]: describes the object layout. DECL_ACCESSORS(layout_descriptor, LayoutDescriptor) // |layout descriptor| accessor which can be used from GC. inline LayoutDescriptor* layout_descriptor_gc_safe(); inline bool HasFastPointerLayout() const; // |layout descriptor| accessor that is safe to call even when // FLAG_unbox_double_fields is disabled (in this case Map does not contain // |layout_descriptor| field at all). inline LayoutDescriptor* GetLayoutDescriptor(); inline void UpdateDescriptors(DescriptorArray* descriptors, LayoutDescriptor* layout_descriptor); inline void InitializeDescriptors(DescriptorArray* descriptors, LayoutDescriptor* layout_descriptor); // [stub cache]: contains stubs compiled for this map. DECL_ACCESSORS(code_cache, Object) // [dependent code]: list of optimized codes that weakly embed this map. DECL_ACCESSORS(dependent_code, DependentCode) // [weak cell cache]: cache that stores a weak cell pointing to this map. DECL_ACCESSORS(weak_cell_cache, Object) inline PropertyDetails GetLastDescriptorDetails(); inline int LastAdded(); inline int NumberOfOwnDescriptors(); inline void SetNumberOfOwnDescriptors(int number); inline Cell* RetrieveDescriptorsPointer(); inline int EnumLength(); inline void SetEnumLength(int length); inline bool owns_descriptors(); inline void set_owns_descriptors(bool owns_descriptors); inline void mark_unstable(); inline bool is_stable(); inline void set_migration_target(bool value); inline bool is_migration_target(); inline void set_construction_counter(int value); inline int construction_counter(); inline void deprecate(); inline bool is_deprecated(); inline bool CanBeDeprecated(); // Returns a non-deprecated version of the input. If the input was not // deprecated, it is directly returned. Otherwise, the non-deprecated version // is found by re-transitioning from the root of the transition tree using the // descriptor array of the map. Returns MaybeHandle<Map>() if no updated map // is found. static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT; // Returns a non-deprecated version of the input. This method may deprecate // existing maps along the way if encodings conflict. Not for use while // gathering type feedback. Use TryUpdate in those cases instead. static Handle<Map> Update(Handle<Map> map); static inline Handle<Map> CopyInitialMap(Handle<Map> map); static Handle<Map> CopyInitialMap(Handle<Map> map, int instance_size, int in_object_properties, int unused_property_fields); static Handle<Map> CopyDropDescriptors(Handle<Map> map); static Handle<Map> CopyInsertDescriptor(Handle<Map> map, Descriptor* descriptor, TransitionFlag flag); MUST_USE_RESULT static MaybeHandle<Map> CopyWithField( Handle<Map> map, Handle<Name> name, Handle<FieldType> type, PropertyAttributes attributes, Representation representation, TransitionFlag flag); MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant( Handle<Map> map, Handle<Name> name, Handle<Object> constant, PropertyAttributes attributes, TransitionFlag flag); // Returns a new map with all transitions dropped from the given map and // the ElementsKind set. static Handle<Map> TransitionElementsTo(Handle<Map> map, ElementsKind to_kind); static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind); static Handle<Map> CopyAsElementsKind(Handle<Map> map, ElementsKind kind, TransitionFlag flag); static Handle<Map> AsLanguageMode(Handle<Map> initial_map, LanguageMode language_mode, FunctionKind kind); static Handle<Map> CopyForObserved(Handle<Map> map); static Handle<Map> CopyForPreventExtensions(Handle<Map> map, PropertyAttributes attrs_to_add, Handle<Symbol> transition_marker, const char* reason); static Handle<Map> FixProxy(Handle<Map> map, InstanceType type, int size); // Maximal number of fast properties. Used to restrict the number of map // transitions to avoid an explosion in the number of maps for objects used as // dictionaries. inline bool TooManyFastProperties(StoreFromKeyed store_mode); static Handle<Map> TransitionToDataProperty(Handle<Map> map, Handle<Name> name, Handle<Object> value, PropertyAttributes attributes, StoreFromKeyed store_mode); static Handle<Map> TransitionToAccessorProperty( Handle<Map> map, Handle<Name> name, AccessorComponent component, Handle<Object> accessor, PropertyAttributes attributes); static Handle<Map> ReconfigureExistingProperty(Handle<Map> map, int descriptor, PropertyKind kind, PropertyAttributes attributes); inline void AppendDescriptor(Descriptor* desc); // Returns a copy of the map, prepared for inserting into the transition // tree (if the |map| owns descriptors then the new one will share // descriptors with |map|). static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason); // Returns a copy of the map, with all transitions dropped from the // instance descriptors. static Handle<Map> Copy(Handle<Map> map, const char* reason); static Handle<Map> Create(Isolate* isolate, int inobject_properties); // Returns the next free property index (only valid for FAST MODE). int NextFreePropertyIndex(); // Returns the number of properties described in instance_descriptors // filtering out properties with the specified attributes. int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS, PropertyFilter filter = ALL_PROPERTIES); DECLARE_CAST(Map) // Code cache operations. // Clears the code cache. inline void ClearCodeCache(Heap* heap); // Update code cache. static void UpdateCodeCache(Handle<Map> map, Handle<Name> name, Handle<Code> code); // Extend the descriptor array of the map with the list of descriptors. // In case of duplicates, the latest descriptor is used. static void AppendCallbackDescriptors(Handle<Map> map, Handle<Object> descriptors); static inline int SlackForArraySize(int old_size, int size_limit); static void EnsureDescriptorSlack(Handle<Map> map, int slack); // Returns the found code or undefined if absent. Object* FindInCodeCache(Name* name, Code::Flags flags); // Returns the non-negative index of the code object if it is in the // cache and -1 otherwise. int IndexInCodeCache(Object* name, Code* code); // Removes a code object from the code cache at the given index. void RemoveFromCodeCache(Name* name, Code* code, int index); // Computes a hash value for this map, to be used in HashTables and such. int Hash(); // Returns the map that this map transitions to if its elements_kind // is changed to |elements_kind|, or NULL if no such map is cached yet. // |safe_to_add_transitions| is set to false if adding transitions is not // allowed. Map* LookupElementsTransitionMap(ElementsKind elements_kind); // Returns the transitioned map for this map with the most generic // elements_kind that's found in |candidates|, or null handle if no match is // found at all. static Handle<Map> FindTransitionedMap(Handle<Map> map, MapHandleList* candidates); inline bool CanTransition(); inline bool IsBooleanMap(); inline bool IsPrimitiveMap(); inline bool IsJSReceiverMap(); inline bool IsJSObjectMap(); inline bool IsJSArrayMap(); inline bool IsJSFunctionMap(); inline bool IsStringMap(); inline bool IsJSProxyMap(); inline bool IsJSGlobalProxyMap(); inline bool IsJSGlobalObjectMap(); inline bool IsJSTypedArrayMap(); inline bool IsJSDataViewMap(); inline bool CanOmitMapChecks(); static void AddDependentCode(Handle<Map> map, DependentCode::DependencyGroup group, Handle<Code> code); bool IsMapInArrayPrototypeChain(); static Handle<WeakCell> WeakCellForMap(Handle<Map> map); // Dispatched behavior. DECLARE_PRINTER(Map) DECLARE_VERIFIER(Map) #ifdef VERIFY_HEAP void DictionaryMapVerify(); void VerifyOmittedMapChecks(); #endif inline int visitor_id(); inline void set_visitor_id(int visitor_id); static Handle<Map> TransitionToPrototype(Handle<Map> map, Handle<Object> prototype, PrototypeOptimizationMode mode); static const int kMaxPreAllocatedPropertyFields = 255; // Layout description. static const int kInstanceSizesOffset = HeapObject::kHeaderSize; static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize; static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize; static const int kPrototypeOffset = kBitField3Offset + kPointerSize; static const int kConstructorOrBackPointerOffset = kPrototypeOffset + kPointerSize; // When there is only one transition, it is stored directly in this field; // otherwise a transition array is used. // For prototype maps, this slot is used to store this map's PrototypeInfo // struct. static const int kTransitionsOrPrototypeInfoOffset = kConstructorOrBackPointerOffset + kPointerSize; static const int kDescriptorsOffset = kTransitionsOrPrototypeInfoOffset + kPointerSize; #if V8_DOUBLE_FIELDS_UNBOXING static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize; static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize; #else static const int kLayoutDecriptorOffset = 1; // Must not be ever accessed. static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize; #endif static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize; static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize; static const int kSize = kWeakCellCacheOffset + kPointerSize; // Layout of pointer fields. Heap iteration code relies on them // being continuously allocated. static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset; static const int kPointerFieldsEndOffset = kSize; // Byte offsets within kInstanceSizesOffset. static const int kInstanceSizeOffset = kInstanceSizesOffset + 0; static const int kInObjectPropertiesOrConstructorFunctionIndexByte = 1; static const int kInObjectPropertiesOrConstructorFunctionIndexOffset = kInstanceSizesOffset + kInObjectPropertiesOrConstructorFunctionIndexByte; // Note there is one byte available for use here. static const int kUnusedByte = 2; static const int kUnusedOffset = kInstanceSizesOffset + kUnusedByte; static const int kVisitorIdByte = 3; static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte; // Byte offsets within kInstanceAttributesOffset attributes. #if V8_TARGET_LITTLE_ENDIAN // Order instance type and bit field together such that they can be loaded // together as a 16-bit word with instance type in the lower 8 bits regardless // of endianess. Also provide endian-independent offset to that 16-bit word. static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0; static const int kBitFieldOffset = kInstanceAttributesOffset + 1; #else static const int kBitFieldOffset = kInstanceAttributesOffset + 0; static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1; #endif static const int kInstanceTypeAndBitFieldOffset = kInstanceAttributesOffset + 0; static const int kBitField2Offset = kInstanceAttributesOffset + 2; static const int kUnusedPropertyFieldsByte = 3; static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3; STATIC_ASSERT(kInstanceTypeAndBitFieldOffset == Internals::kMapInstanceTypeAndBitFieldOffset); // Bit positions for bit field. static const int kHasNonInstancePrototype = 0; static const int kIsCallable = 1; static const int kHasNamedInterceptor = 2; static const int kHasIndexedInterceptor = 3; static const int kIsUndetectable = 4; static const int kIsObserved = 5; static const int kIsAccessCheckNeeded = 6; static const int kIsConstructor = 7; // Bit positions for bit field 2 static const int kIsExtensible = 0; // Bit 1 is free. class IsPrototypeMapBits : public BitField<bool, 2, 1> {}; class ElementsKindBits: public BitField<ElementsKind, 3, 5> {}; // Derived values from bit field 2 static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>( (FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; static const int8_t kMaximumBitField2FastSmiElementValue = static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; static const int8_t kMaximumBitField2FastHoleyElementValue = static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; static const int8_t kMaximumBitField2FastHoleySmiElementValue = static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1; typedef FixedBodyDescriptor<kPointerFieldsBeginOffset, kPointerFieldsEndOffset, kSize> BodyDescriptor; // Compares this map to another to see if they describe equivalent objects. // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if // it had exactly zero inobject properties. // The "shared" flags of both this map and |other| are ignored. bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode); // Returns true if given field is unboxed double. inline bool IsUnboxedDoubleField(FieldIndex index); #if TRACE_MAPS static void TraceTransition(const char* what, Map* from, Map* to, Name* name); static void TraceAllTransitions(Map* map); #endif static inline Handle<Map> AddMissingTransitionsForTesting( Handle<Map> split_map, Handle<DescriptorArray> descriptors, Handle<LayoutDescriptor> full_layout_descriptor); private: static void ConnectTransition(Handle<Map> parent, Handle<Map> child, Handle<Name> name, SimpleTransitionFlag flag); bool EquivalentToForTransition(Map* other); static Handle<Map> RawCopy(Handle<Map> map, int instance_size); static Handle<Map> ShareDescriptor(Handle<Map> map, Handle<DescriptorArray> descriptors, Descriptor* descriptor); static Handle<Map> AddMissingTransitions( Handle<Map> map, Handle<DescriptorArray> descriptors, Handle<LayoutDescriptor> full_layout_descriptor); static void InstallDescriptors( Handle<Map> parent_map, Handle<Map> child_map, int new_descriptor, Handle<DescriptorArray> descriptors, Handle<LayoutDescriptor> full_layout_descriptor); static Handle<Map> CopyAddDescriptor(Handle<Map> map, Descriptor* descriptor, TransitionFlag flag); static Handle<Map> CopyReplaceDescriptors( Handle<Map> map, Handle<DescriptorArray> descriptors, Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag, MaybeHandle<Name> maybe_name, const char* reason, SimpleTransitionFlag simple_flag); static Handle<Map> CopyReplaceDescriptor(Handle<Map> map, Handle<DescriptorArray> descriptors, Descriptor* descriptor, int index, TransitionFlag flag); static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty( Handle<Map> map, int descriptor, PropertyKind kind, PropertyAttributes attributes, const char** reason); static Handle<Map> CopyNormalized(Handle<Map> map, PropertyNormalizationMode mode); // Fires when the layout of an object with a leaf map changes. // This includes adding transitions to the leaf map or changing // the descriptor array. inline void NotifyLeafMapLayoutChange(); void DeprecateTransitionTree(); void ReplaceDescriptors(DescriptorArray* new_descriptors, LayoutDescriptor* new_layout_descriptor); Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors); // Update field type of the given descriptor to new representation and new // type. The type must be prepared for storing in descriptor array: // it must be either a simple type or a map wrapped in a weak cell. void UpdateFieldType(int descriptor_number, Handle<Name> name, Representation new_representation, Handle<Object> new_wrapped_type); void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind, PropertyAttributes attributes); void PrintGeneralization(FILE* file, const char* reason, int modify_index, int split, int descriptors, bool constant_to_field, Representation old_representation, Representation new_representation, MaybeHandle<FieldType> old_field_type, MaybeHandle<Object> old_value, MaybeHandle<FieldType> new_field_type, MaybeHandle<Object> new_value); static const int kFastPropertiesSoftLimit = 12; static const int kMaxFastProperties = 128; DISALLOW_IMPLICIT_CONSTRUCTORS(Map); }; // An abstract superclass, a marker class really, for simple structure classes. // It doesn't carry much functionality but allows struct classes to be // identified in the type system. class Struct: public HeapObject { public: inline void InitializeBody(int object_size); DECLARE_CAST(Struct) }; // A simple one-element struct, useful where smis need to be boxed. class Box : public Struct { public: // [value]: the boxed contents. DECL_ACCESSORS(value, Object) DECLARE_CAST(Box) // Dispatched behavior. DECLARE_PRINTER(Box) DECLARE_VERIFIER(Box) static const int kValueOffset = HeapObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Box); }; // Container for metadata stored on each prototype map. class PrototypeInfo : public Struct { public: static const int UNREGISTERED = -1; // [prototype_users]: WeakFixedArray containing maps using this prototype, // or Smi(0) if uninitialized. DECL_ACCESSORS(prototype_users, Object) // [registry_slot]: Slot in prototype's user registry where this user // is stored. Returns UNREGISTERED if this prototype has not been registered. inline int registry_slot() const; inline void set_registry_slot(int slot); // [validity_cell]: Cell containing the validity bit for prototype chains // going through this object, or Smi(0) if uninitialized. // When a prototype object changes its map, then both its own validity cell // and those of all "downstream" prototypes are invalidated; handlers for a // given receiver embed the currently valid cell for that receiver's prototype // during their compilation and check it on execution. DECL_ACCESSORS(validity_cell, Object) DECLARE_CAST(PrototypeInfo) // Dispatched behavior. DECLARE_PRINTER(PrototypeInfo) DECLARE_VERIFIER(PrototypeInfo) static const int kPrototypeUsersOffset = HeapObject::kHeaderSize; static const int kRegistrySlotOffset = kPrototypeUsersOffset + kPointerSize; static const int kValidityCellOffset = kRegistrySlotOffset + kPointerSize; static const int kConstructorNameOffset = kValidityCellOffset + kPointerSize; static const int kSize = kConstructorNameOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeInfo); }; // Pair used to store both a ScopeInfo and an extension object in the extension // slot of a block context. Needed in the rare case where a declaration block // scope (a "varblock" as used to desugar parameter destructuring) also contains // a sloppy direct eval. (In no other case both are needed at the same time.) class SloppyBlockWithEvalContextExtension : public Struct { public: // [scope_info]: Scope info. DECL_ACCESSORS(scope_info, ScopeInfo) // [extension]: Extension object. DECL_ACCESSORS(extension, JSObject) DECLARE_CAST(SloppyBlockWithEvalContextExtension) // Dispatched behavior. DECLARE_PRINTER(SloppyBlockWithEvalContextExtension) DECLARE_VERIFIER(SloppyBlockWithEvalContextExtension) static const int kScopeInfoOffset = HeapObject::kHeaderSize; static const int kExtensionOffset = kScopeInfoOffset + kPointerSize; static const int kSize = kExtensionOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(SloppyBlockWithEvalContextExtension); }; // Script describes a script which has been added to the VM. class Script: public Struct { public: // Script types. enum Type { TYPE_NATIVE = 0, TYPE_EXTENSION = 1, TYPE_NORMAL = 2 }; // Script compilation types. enum CompilationType { COMPILATION_TYPE_HOST = 0, COMPILATION_TYPE_EVAL = 1 }; // Script compilation state. enum CompilationState { COMPILATION_STATE_INITIAL = 0, COMPILATION_STATE_COMPILED = 1 }; // [source]: the script source. DECL_ACCESSORS(source, Object) // [name]: the script name. DECL_ACCESSORS(name, Object) // [id]: the script id. DECL_INT_ACCESSORS(id) // [line_offset]: script line offset in resource from where it was extracted. DECL_INT_ACCESSORS(line_offset) // [column_offset]: script column offset in resource from where it was // extracted. DECL_INT_ACCESSORS(column_offset) // [context_data]: context data for the context this script was compiled in. DECL_ACCESSORS(context_data, Object) // [wrapper]: the wrapper cache. This is either undefined or a WeakCell. DECL_ACCESSORS(wrapper, HeapObject) // [type]: the script type. DECL_INT_ACCESSORS(type) // [line_ends]: FixedArray of line ends positions. DECL_ACCESSORS(line_ends, Object) // [eval_from_shared]: for eval scripts the shared funcion info for the // function from which eval was called. DECL_ACCESSORS(eval_from_shared, Object) // [eval_from_instructions_offset]: the instruction offset in the code for the // function from which eval was called where eval was called. DECL_INT_ACCESSORS(eval_from_instructions_offset) // [shared_function_infos]: weak fixed array containing all shared // function infos created from this script. DECL_ACCESSORS(shared_function_infos, Object) // [flags]: Holds an exciting bitfield. DECL_INT_ACCESSORS(flags) // [source_url]: sourceURL from magic comment DECL_ACCESSORS(source_url, Object) // [source_url]: sourceMappingURL magic comment DECL_ACCESSORS(source_mapping_url, Object) // [compilation_type]: how the the script was compiled. Encoded in the // 'flags' field. inline CompilationType compilation_type(); inline void set_compilation_type(CompilationType type); // [compilation_state]: determines whether the script has already been // compiled. Encoded in the 'flags' field. inline CompilationState compilation_state(); inline void set_compilation_state(CompilationState state); // [hide_source]: determines whether the script source can be exposed as // function source. Encoded in the 'flags' field. inline bool hide_source(); inline void set_hide_source(bool value); // [origin_options]: optional attributes set by the embedder via ScriptOrigin, // and used by the embedder to make decisions about the script. V8 just passes // this through. Encoded in the 'flags' field. inline v8::ScriptOriginOptions origin_options(); inline void set_origin_options(ScriptOriginOptions origin_options); DECLARE_CAST(Script) // If script source is an external string, check that the underlying // resource is accessible. Otherwise, always return true. inline bool HasValidSource(); // Convert code offset into column number. static int GetColumnNumber(Handle<Script> script, int code_offset); // Convert code offset into (zero-based) line number. // The non-handlified version does not allocate, but may be much slower. static int GetLineNumber(Handle<Script> script, int code_offset); int GetLineNumber(int code_pos); static Handle<Object> GetNameOrSourceURL(Handle<Script> script); // Init line_ends array with source code positions of line ends. static void InitLineEnds(Handle<Script> script); // Get the JS object wrapping the given script; create it if none exists. static Handle<JSObject> GetWrapper(Handle<Script> script); // Look through the list of existing shared function infos to find one // that matches the function literal. Return empty handle if not found. MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(FunctionLiteral* fun); // Iterate over all script objects on the heap. class Iterator { public: explicit Iterator(Isolate* isolate); Script* Next(); private: WeakFixedArray::Iterator iterator_; DISALLOW_COPY_AND_ASSIGN(Iterator); }; // Dispatched behavior. DECLARE_PRINTER(Script) DECLARE_VERIFIER(Script) static const int kSourceOffset = HeapObject::kHeaderSize; static const int kNameOffset = kSourceOffset + kPointerSize; static const int kLineOffsetOffset = kNameOffset + kPointerSize; static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize; static const int kContextOffset = kColumnOffsetOffset + kPointerSize; static const int kWrapperOffset = kContextOffset + kPointerSize; static const int kTypeOffset = kWrapperOffset + kPointerSize; static const int kLineEndsOffset = kTypeOffset + kPointerSize; static const int kIdOffset = kLineEndsOffset + kPointerSize; static const int kEvalFromSharedOffset = kIdOffset + kPointerSize; static const int kEvalFrominstructionsOffsetOffset = kEvalFromSharedOffset + kPointerSize; static const int kSharedFunctionInfosOffset = kEvalFrominstructionsOffsetOffset + kPointerSize; static const int kFlagsOffset = kSharedFunctionInfosOffset + kPointerSize; static const int kSourceUrlOffset = kFlagsOffset + kPointerSize; static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize; static const int kSize = kSourceMappingUrlOffset + kPointerSize; private: int GetLineNumberWithArray(int code_pos); // Bit positions in the flags field. static const int kCompilationTypeBit = 0; static const int kCompilationStateBit = 1; static const int kHideSourceBit = 2; static const int kOriginOptionsShift = 3; static const int kOriginOptionsSize = 3; static const int kOriginOptionsMask = ((1 << kOriginOptionsSize) - 1) << kOriginOptionsShift; DISALLOW_IMPLICIT_CONSTRUCTORS(Script); }; // List of builtin functions we want to identify to improve code // generation. // // Each entry has a name of a global object property holding an object // optionally followed by ".prototype", a name of a builtin function // on the object (the one the id is set for), and a label. // // Installation of ids for the selected builtin functions is handled // by the bootstrapper. #define FUNCTIONS_WITH_ID_LIST(V) \ V(Array.prototype, indexOf, ArrayIndexOf) \ V(Array.prototype, lastIndexOf, ArrayLastIndexOf) \ V(Array.prototype, push, ArrayPush) \ V(Array.prototype, pop, ArrayPop) \ V(Array.prototype, shift, ArrayShift) \ V(Function.prototype, apply, FunctionApply) \ V(Function.prototype, call, FunctionCall) \ V(String.prototype, charCodeAt, StringCharCodeAt) \ V(String.prototype, charAt, StringCharAt) \ V(String, fromCharCode, StringFromCharCode) \ V(Math, random, MathRandom) \ V(Math, floor, MathFloor) \ V(Math, round, MathRound) \ V(Math, ceil, MathCeil) \ V(Math, abs, MathAbs) \ V(Math, log, MathLog) \ V(Math, exp, MathExp) \ V(Math, sqrt, MathSqrt) \ V(Math, pow, MathPow) \ V(Math, max, MathMax) \ V(Math, min, MathMin) \ V(Math, cos, MathCos) \ V(Math, sin, MathSin) \ V(Math, tan, MathTan) \ V(Math, acos, MathAcos) \ V(Math, asin, MathAsin) \ V(Math, atan, MathAtan) \ V(Math, atan2, MathAtan2) \ V(Math, imul, MathImul) \ V(Math, clz32, MathClz32) \ V(Math, fround, MathFround) #define ATOMIC_FUNCTIONS_WITH_ID_LIST(V) \ V(Atomics, load, AtomicsLoad) \ V(Atomics, store, AtomicsStore) enum BuiltinFunctionId { kArrayCode, #define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \ k##name, FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID) ATOMIC_FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID) #undef DECLARE_FUNCTION_ID // Fake id for a special case of Math.pow. Note, it continues the // list of math functions. kMathPowHalf }; // Result of searching in an optimized code map of a SharedFunctionInfo. Note // that both {code} and {literals} can be NULL to pass search result status. struct CodeAndLiterals { Code* code; // Cached optimized code. LiteralsArray* literals; // Cached literals array. }; // SharedFunctionInfo describes the JSFunction information that can be // shared by multiple instances of the function. class SharedFunctionInfo: public HeapObject { public: // [name]: Function name. DECL_ACCESSORS(name, Object) // [code]: Function code. DECL_ACCESSORS(code, Code) inline void ReplaceCode(Code* code); // [optimized_code_map]: Map from native context to optimized code // and a shared literals array. DECL_ACCESSORS(optimized_code_map, FixedArray) // Returns entry from optimized code map for specified context and OSR entry. // Note that {code == nullptr, literals == nullptr} indicates no matching // entry has been found, whereas {code, literals == nullptr} indicates that // code is context-independent. CodeAndLiterals SearchOptimizedCodeMap(Context* native_context, BailoutId osr_ast_id); // Clear optimized code map. void ClearOptimizedCodeMap(); // We have a special root FixedArray with the right shape and values // to represent the cleared optimized code map. This predicate checks // if that root is installed. inline bool OptimizedCodeMapIsCleared() const; // Removes a specific optimized code object from the optimized code map. // In case of non-OSR the code reference is cleared from the cache entry but // the entry itself is left in the map in order to proceed sharing literals. void EvictFromOptimizedCodeMap(Code* optimized_code, const char* reason); // Trims the optimized code map after entries have been removed. void TrimOptimizedCodeMap(int shrink_by); // Add a new entry to the optimized code map for context-independent code. static void AddSharedCodeToOptimizedCodeMap(Handle<SharedFunctionInfo> shared, Handle<Code> code); // Add a new entry to the optimized code map for context-dependent code. inline static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared, Handle<Context> native_context, Handle<Code> code, Handle<LiteralsArray> literals, BailoutId osr_ast_id); // We may already have cached the code, but want to store literals in the // cache. inline static void AddLiteralsToOptimizedCodeMap( Handle<SharedFunctionInfo> shared, Handle<Context> native_context, Handle<LiteralsArray> literals); // Set up the link between shared function info and the script. The shared // function info is added to the list on the script. static void SetScript(Handle<SharedFunctionInfo> shared, Handle<Object> script_object); // Layout description of the optimized code map. static const int kSharedCodeIndex = 0; static const int kEntriesStart = 1; static const int kContextOffset = 0; static const int kCachedCodeOffset = 1; static const int kLiteralsOffset = 2; static const int kOsrAstIdOffset = 3; static const int kEntryLength = 4; static const int kInitialLength = kEntriesStart + kEntryLength; static const int kNotFound = -1; // [scope_info]: Scope info. DECL_ACCESSORS(scope_info, ScopeInfo) // [construct stub]: Code stub for constructing instances of this function. DECL_ACCESSORS(construct_stub, Code) // Returns if this function has been compiled to native code yet. inline bool is_compiled(); // [length]: The function length - usually the number of declared parameters. // Use up to 2^30 parameters. inline int length() const; inline void set_length(int value); // [internal formal parameter count]: The declared number of parameters. // For subclass constructors, also includes new.target. // The size of function's frame is internal_formal_parameter_count + 1. inline int internal_formal_parameter_count() const; inline void set_internal_formal_parameter_count(int value); // Set the formal parameter count so the function code will be // called without using argument adaptor frames. inline void DontAdaptArguments(); // [expected_nof_properties]: Expected number of properties for the function. inline int expected_nof_properties() const; inline void set_expected_nof_properties(int value); // [feedback_vector] - accumulates ast node feedback from full-codegen and // (increasingly) from crankshafted code where sufficient feedback isn't // available. DECL_ACCESSORS(feedback_vector, TypeFeedbackVector) // Unconditionally clear the type feedback vector (including vector ICs). void ClearTypeFeedbackInfo(); // Clear the type feedback vector with a more subtle policy at GC time. void ClearTypeFeedbackInfoAtGCTime(); #if TRACE_MAPS // [unique_id] - For --trace-maps purposes, an identifier that's persistent // even if the GC moves this SharedFunctionInfo. inline int unique_id() const; inline void set_unique_id(int value); #endif // [instance class name]: class name for instances. DECL_ACCESSORS(instance_class_name, Object) // [function data]: This field holds some additional data for function. // Currently it has one of: // - a FunctionTemplateInfo to make benefit the API [IsApiFunction()]. // - a Smi identifying a builtin function [HasBuiltinFunctionId()]. // - a BytecodeArray for the interpreter [HasBytecodeArray()]. // In the long run we don't want all functions to have this field but // we can fix that when we have a better model for storing hidden data // on objects. DECL_ACCESSORS(function_data, Object) inline bool IsApiFunction(); inline FunctionTemplateInfo* get_api_func_data(); inline bool HasBuiltinFunctionId(); inline BuiltinFunctionId builtin_function_id(); inline bool HasBytecodeArray(); inline BytecodeArray* bytecode_array(); // [script info]: Script from which the function originates. DECL_ACCESSORS(script, Object) // [num_literals]: Number of literals used by this function. inline int num_literals() const; inline void set_num_literals(int value); // [start_position_and_type]: Field used to store both the source code // position, whether or not the function is a function expression, // and whether or not the function is a toplevel function. The two // least significants bit indicates whether the function is an // expression and the rest contains the source code position. inline int start_position_and_type() const; inline void set_start_position_and_type(int value); // The function is subject to debugging if a debug info is attached. inline bool HasDebugInfo(); inline DebugInfo* GetDebugInfo(); // A function has debug code if the compiled code has debug break slots. inline bool HasDebugCode(); // [debug info]: Debug information. DECL_ACCESSORS(debug_info, Object) // [inferred name]: Name inferred from variable or property // assignment of this function. Used to facilitate debugging and // profiling of JavaScript code written in OO style, where almost // all functions are anonymous but are assigned to object // properties. DECL_ACCESSORS(inferred_name, String) // The function's name if it is non-empty, otherwise the inferred name. String* DebugName(); // Position of the 'function' token in the script source. inline int function_token_position() const; inline void set_function_token_position(int function_token_position); // Position of this function in the script source. inline int start_position() const; inline void set_start_position(int start_position); // End position of this function in the script source. inline int end_position() const; inline void set_end_position(int end_position); // Is this function a function expression in the source code. DECL_BOOLEAN_ACCESSORS(is_expression) // Is this function a top-level function (scripts, evals). DECL_BOOLEAN_ACCESSORS(is_toplevel) // Bit field containing various information collected by the compiler to // drive optimization. inline int compiler_hints() const; inline void set_compiler_hints(int value); inline int ast_node_count() const; inline void set_ast_node_count(int count); inline int profiler_ticks() const; inline void set_profiler_ticks(int ticks); // Inline cache age is used to infer whether the function survived a context // disposal or not. In the former case we reset the opt_count. inline int ic_age(); inline void set_ic_age(int age); // Indicates if this function can be lazy compiled. // This is used to determine if we can safely flush code from a function // when doing GC if we expect that the function will no longer be used. DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation) // Indicates if this function can be lazy compiled without a context. // This is used to determine if we can force compilation without reaching // the function through program execution but through other means (e.g. heap // iteration by the debugger). DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context) // Indicates whether optimizations have been disabled for this // shared function info. If a function is repeatedly optimized or if // we cannot optimize the function we disable optimization to avoid // spending time attempting to optimize it again. DECL_BOOLEAN_ACCESSORS(optimization_disabled) // Indicates the language mode. inline LanguageMode language_mode(); inline void set_language_mode(LanguageMode language_mode); // False if the function definitely does not allocate an arguments object. DECL_BOOLEAN_ACCESSORS(uses_arguments) // Indicates that this function uses a super property (or an eval that may // use a super property). // This is needed to set up the [[HomeObject]] on the function instance. DECL_BOOLEAN_ACCESSORS(needs_home_object) // True if the function has any duplicated parameter names. DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters) // Indicates whether the function is a native function. // These needs special treatment in .call and .apply since // null passed as the receiver should not be translated to the // global object. DECL_BOOLEAN_ACCESSORS(native) // Indicate that this function should always be inlined in optimized code. DECL_BOOLEAN_ACCESSORS(force_inline) // Indicates that the function was created by the Function function. // Though it's anonymous, toString should treat it as if it had the name // "anonymous". We don't set the name itself so that the system does not // see a binding for it. DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous) // Indicates that the function is anonymous (the name field can be set // through the API, which does not change this flag). DECL_BOOLEAN_ACCESSORS(is_anonymous) // Is this a function or top-level/eval code. DECL_BOOLEAN_ACCESSORS(is_function) // Indicates that code for this function cannot be compiled with Crankshaft. DECL_BOOLEAN_ACCESSORS(dont_crankshaft) // Indicates that code for this function cannot be flushed. DECL_BOOLEAN_ACCESSORS(dont_flush) // Indicates that this function is a generator. DECL_BOOLEAN_ACCESSORS(is_generator) // Indicates that this function is an arrow function. DECL_BOOLEAN_ACCESSORS(is_arrow) // Indicates that this function is a concise method. DECL_BOOLEAN_ACCESSORS(is_concise_method) // Indicates that this function is an accessor (getter or setter). DECL_BOOLEAN_ACCESSORS(is_accessor_function) // Indicates that this function is a default constructor. DECL_BOOLEAN_ACCESSORS(is_default_constructor) // Indicates that this function is an asm function. DECL_BOOLEAN_ACCESSORS(asm_function) // Indicates that the the shared function info is deserialized from cache. DECL_BOOLEAN_ACCESSORS(deserialized) // Indicates that the the shared function info has never been compiled before. DECL_BOOLEAN_ACCESSORS(never_compiled) inline FunctionKind kind(); inline void set_kind(FunctionKind kind); // Indicates whether or not the code in the shared function support // deoptimization. inline bool has_deoptimization_support(); // Enable deoptimization support through recompiled code. void EnableDeoptimizationSupport(Code* recompiled); // Disable (further) attempted optimization of all functions sharing this // shared function info. void DisableOptimization(BailoutReason reason); inline BailoutReason disable_optimization_reason(); // Lookup the bailout ID and DCHECK that it exists in the non-optimized // code, returns whether it asserted (i.e., always true if assertions are // disabled). bool VerifyBailoutId(BailoutId id); // [source code]: Source code for the function. bool HasSourceCode() const; Handle<Object> GetSourceCode(); // Number of times the function was optimized. inline int opt_count(); inline void set_opt_count(int opt_count); // Number of times the function was deoptimized. inline void set_deopt_count(int value); inline int deopt_count(); inline void increment_deopt_count(); // Number of time we tried to re-enable optimization after it // was disabled due to high number of deoptimizations. inline void set_opt_reenable_tries(int value); inline int opt_reenable_tries(); inline void TryReenableOptimization(); // Stores deopt_count, opt_reenable_tries and ic_age as bit-fields. inline void set_counters(int value); inline int counters() const; // Stores opt_count and bailout_reason as bit-fields. inline void set_opt_count_and_bailout_reason(int value); inline int opt_count_and_bailout_reason() const; inline void set_disable_optimization_reason(BailoutReason reason); // Tells whether this function should be subject to debugging. inline bool IsSubjectToDebugging(); // Whether this function is defined in native code or extensions. inline bool IsBuiltin(); // Check whether or not this function is inlineable. bool IsInlineable(); // Source size of this function. int SourceSize(); // Returns `false` if formal parameters include rest parameters, optional // parameters, or destructuring parameters. // TODO(caitp): make this a flag set during parsing inline bool has_simple_parameters(); // Initialize a SharedFunctionInfo from a parsed function literal. static void InitFromFunctionLiteral(Handle<SharedFunctionInfo> shared_info, FunctionLiteral* lit); // Dispatched behavior. DECLARE_PRINTER(SharedFunctionInfo) DECLARE_VERIFIER(SharedFunctionInfo) void ResetForNewContext(int new_ic_age); // Iterate over all shared function infos. class Iterator { public: explicit Iterator(Isolate* isolate); SharedFunctionInfo* Next(); private: bool NextScript(); Script::Iterator script_iterator_; WeakFixedArray::Iterator sfi_iterator_; DisallowHeapAllocation no_gc_; DISALLOW_COPY_AND_ASSIGN(Iterator); }; DECLARE_CAST(SharedFunctionInfo) // Constants. static const int kDontAdaptArgumentsSentinel = -1; // Layout description. // Pointer fields. static const int kNameOffset = HeapObject::kHeaderSize; static const int kCodeOffset = kNameOffset + kPointerSize; static const int kOptimizedCodeMapOffset = kCodeOffset + kPointerSize; static const int kScopeInfoOffset = kOptimizedCodeMapOffset + kPointerSize; static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize; static const int kInstanceClassNameOffset = kConstructStubOffset + kPointerSize; static const int kFunctionDataOffset = kInstanceClassNameOffset + kPointerSize; static const int kScriptOffset = kFunctionDataOffset + kPointerSize; static const int kDebugInfoOffset = kScriptOffset + kPointerSize; static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize; static const int kFeedbackVectorOffset = kInferredNameOffset + kPointerSize; #if TRACE_MAPS static const int kUniqueIdOffset = kFeedbackVectorOffset + kPointerSize; static const int kLastPointerFieldOffset = kUniqueIdOffset; #else // Just to not break the postmortrem support with conditional offsets static const int kUniqueIdOffset = kFeedbackVectorOffset; static const int kLastPointerFieldOffset = kFeedbackVectorOffset; #endif #if V8_HOST_ARCH_32_BIT // Smi fields. static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kPointerSize; static const int kNumLiteralsOffset = kExpectedNofPropertiesOffset + kPointerSize; static const int kStartPositionAndTypeOffset = kNumLiteralsOffset + kPointerSize; static const int kEndPositionOffset = kStartPositionAndTypeOffset + kPointerSize; static const int kFunctionTokenPositionOffset = kEndPositionOffset + kPointerSize; static const int kCompilerHintsOffset = kFunctionTokenPositionOffset + kPointerSize; static const int kOptCountAndBailoutReasonOffset = kCompilerHintsOffset + kPointerSize; static const int kCountersOffset = kOptCountAndBailoutReasonOffset + kPointerSize; static const int kAstNodeCountOffset = kCountersOffset + kPointerSize; static const int kProfilerTicksOffset = kAstNodeCountOffset + kPointerSize; // Total size. static const int kSize = kProfilerTicksOffset + kPointerSize; #else // The only reason to use smi fields instead of int fields is to allow // iteration without maps decoding during garbage collections. // To avoid wasting space on 64-bit architectures we use the following trick: // we group integer fields into pairs // The least significant integer in each pair is shifted left by 1. By doing // this we guarantee that LSB of each kPointerSize aligned word is not set and // thus this word cannot be treated as pointer to HeapObject during old space // traversal. #if V8_TARGET_LITTLE_ENDIAN static const int kLengthOffset = kLastPointerFieldOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kIntSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kIntSize; static const int kNumLiteralsOffset = kExpectedNofPropertiesOffset + kIntSize; static const int kEndPositionOffset = kNumLiteralsOffset + kIntSize; static const int kStartPositionAndTypeOffset = kEndPositionOffset + kIntSize; static const int kFunctionTokenPositionOffset = kStartPositionAndTypeOffset + kIntSize; static const int kCompilerHintsOffset = kFunctionTokenPositionOffset + kIntSize; static const int kOptCountAndBailoutReasonOffset = kCompilerHintsOffset + kIntSize; static const int kCountersOffset = kOptCountAndBailoutReasonOffset + kIntSize; static const int kAstNodeCountOffset = kCountersOffset + kIntSize; static const int kProfilerTicksOffset = kAstNodeCountOffset + kIntSize; // Total size. static const int kSize = kProfilerTicksOffset + kIntSize; #elif V8_TARGET_BIG_ENDIAN static const int kFormalParameterCountOffset = kLastPointerFieldOffset + kPointerSize; static const int kLengthOffset = kFormalParameterCountOffset + kIntSize; static const int kNumLiteralsOffset = kLengthOffset + kIntSize; static const int kExpectedNofPropertiesOffset = kNumLiteralsOffset + kIntSize; static const int kStartPositionAndTypeOffset = kExpectedNofPropertiesOffset + kIntSize; static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize; static const int kCompilerHintsOffset = kEndPositionOffset + kIntSize; static const int kFunctionTokenPositionOffset = kCompilerHintsOffset + kIntSize; static const int kCountersOffset = kFunctionTokenPositionOffset + kIntSize; static const int kOptCountAndBailoutReasonOffset = kCountersOffset + kIntSize; static const int kProfilerTicksOffset = kOptCountAndBailoutReasonOffset + kIntSize; static const int kAstNodeCountOffset = kProfilerTicksOffset + kIntSize; // Total size. static const int kSize = kAstNodeCountOffset + kIntSize; #else #error Unknown byte ordering #endif // Big endian #endif // 64-bit static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize); typedef FixedBodyDescriptor<kNameOffset, kLastPointerFieldOffset + kPointerSize, kSize> BodyDescriptor; // Bit positions in start_position_and_type. // The source code start position is in the 30 most significant bits of // the start_position_and_type field. static const int kIsExpressionBit = 0; static const int kIsTopLevelBit = 1; static const int kStartPositionShift = 2; static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1); // Bit positions in compiler_hints. enum CompilerHints { // byte 0 kAllowLazyCompilation, kAllowLazyCompilationWithoutContext, kOptimizationDisabled, kNative, kStrictModeFunction, kStrongModeFunction, kUsesArguments, kNeedsHomeObject, // byte 1 kHasDuplicateParameters, kForceInline, kIsAsmFunction, kIsAnonymous, kNameShouldPrintAsAnonymous, kIsFunction, kDontCrankshaft, kDontFlush, // byte 2 kFunctionKind, kIsArrow = kFunctionKind, kIsGenerator, kIsConciseMethod, kIsAccessorFunction, kIsDefaultConstructor, kIsSubclassConstructor, kIsBaseConstructor, kIsInObjectLiteral, // byte 3 kDeserialized, kNeverCompiled, kCompilerHintsCount, // Pseudo entry }; // Add hints for other modes when they're added. STATIC_ASSERT(LANGUAGE_END == 3); // kFunctionKind has to be byte-aligned STATIC_ASSERT((kFunctionKind % kBitsPerByte) == 0); // Make sure that FunctionKind and byte 2 are in sync: #define ASSERT_FUNCTION_KIND_ORDER(functionKind, compilerFunctionKind) \ STATIC_ASSERT(FunctionKind::functionKind == \ 1 << (compilerFunctionKind - kFunctionKind)) ASSERT_FUNCTION_KIND_ORDER(kArrowFunction, kIsArrow); ASSERT_FUNCTION_KIND_ORDER(kGeneratorFunction, kIsGenerator); ASSERT_FUNCTION_KIND_ORDER(kConciseMethod, kIsConciseMethod); ASSERT_FUNCTION_KIND_ORDER(kAccessorFunction, kIsAccessorFunction); ASSERT_FUNCTION_KIND_ORDER(kDefaultConstructor, kIsDefaultConstructor); ASSERT_FUNCTION_KIND_ORDER(kSubclassConstructor, kIsSubclassConstructor); ASSERT_FUNCTION_KIND_ORDER(kBaseConstructor, kIsBaseConstructor); ASSERT_FUNCTION_KIND_ORDER(kInObjectLiteral, kIsInObjectLiteral); #undef ASSERT_FUNCTION_KIND_ORDER class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 8> {}; class DeoptCountBits : public BitField<int, 0, 4> {}; class OptReenableTriesBits : public BitField<int, 4, 18> {}; class ICAgeBits : public BitField<int, 22, 8> {}; class OptCountBits : public BitField<int, 0, 22> {}; class DisabledOptimizationReasonBits : public BitField<int, 22, 8> {}; private: #if V8_HOST_ARCH_32_BIT // On 32 bit platforms, compiler hints is a smi. static const int kCompilerHintsSmiTagSize = kSmiTagSize; static const int kCompilerHintsSize = kPointerSize; #else // On 64 bit platforms, compiler hints is not a smi, see comment above. static const int kCompilerHintsSmiTagSize = 0; static const int kCompilerHintsSize = kIntSize; #endif STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <= SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte); public: // Constants for optimizing codegen for strict mode function and // native tests when using integer-width instructions. static const int kStrictModeBit = kStrictModeFunction + kCompilerHintsSmiTagSize; static const int kStrongModeBit = kStrongModeFunction + kCompilerHintsSmiTagSize; static const int kNativeBit = kNative + kCompilerHintsSmiTagSize; static const int kClassConstructorBits = FunctionKind::kClassConstructor << (kFunctionKind + kCompilerHintsSmiTagSize); // Constants for optimizing codegen for strict mode function and // native tests. // Allows to use byte-width instructions. static const int kStrictModeBitWithinByte = kStrictModeBit % kBitsPerByte; static const int kStrongModeBitWithinByte = kStrongModeBit % kBitsPerByte; static const int kNativeBitWithinByte = kNativeBit % kBitsPerByte; static const int kClassConstructorBitsWithinByte = FunctionKind::kClassConstructor << kCompilerHintsSmiTagSize; STATIC_ASSERT(kClassConstructorBitsWithinByte < (1 << kBitsPerByte)); #if defined(V8_TARGET_LITTLE_ENDIAN) #define BYTE_OFFSET(compiler_hint) \ kCompilerHintsOffset + \ (compiler_hint + kCompilerHintsSmiTagSize) / kBitsPerByte #elif defined(V8_TARGET_BIG_ENDIAN) #define BYTE_OFFSET(compiler_hint) \ kCompilerHintsOffset + (kCompilerHintsSize - 1) - \ ((compiler_hint + kCompilerHintsSmiTagSize) / kBitsPerByte) #else #error Unknown byte ordering #endif static const int kStrictModeByteOffset = BYTE_OFFSET(kStrictModeFunction); static const int kStrongModeByteOffset = BYTE_OFFSET(kStrongModeFunction); static const int kNativeByteOffset = BYTE_OFFSET(kNative); static const int kFunctionKindByteOffset = BYTE_OFFSET(kFunctionKind); #undef BYTE_OFFSET private: // Returns entry from optimized code map for specified context and OSR entry. // The result is either kNotFound, kSharedCodeIndex for context-independent // entry or a start index of the context-dependent entry. int SearchOptimizedCodeMapEntry(Context* native_context, BailoutId osr_ast_id); // If code is undefined, then existing code won't be overwritten. static void AddToOptimizedCodeMapInternal(Handle<SharedFunctionInfo> shared, Handle<Context> native_context, Handle<HeapObject> code, Handle<LiteralsArray> literals, BailoutId osr_ast_id); DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo); }; // Printing support. struct SourceCodeOf { explicit SourceCodeOf(SharedFunctionInfo* v, int max = -1) : value(v), max_length(max) {} const SharedFunctionInfo* value; int max_length; }; std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v); class JSGeneratorObject: public JSObject { public: // [function]: The function corresponding to this generator object. DECL_ACCESSORS(function, JSFunction) // [context]: The context of the suspended computation. DECL_ACCESSORS(context, Context) // [receiver]: The receiver of the suspended computation. DECL_ACCESSORS(receiver, Object) // [input]: The most recent input value. DECL_ACCESSORS(input, Object) // [continuation]: Offset into code of continuation. // // A positive offset indicates a suspended generator. The special // kGeneratorExecuting and kGeneratorClosed values indicate that a generator // cannot be resumed. inline int continuation() const; inline void set_continuation(int continuation); inline bool is_closed(); inline bool is_executing(); inline bool is_suspended(); // [operand_stack]: Saved operand stack. DECL_ACCESSORS(operand_stack, FixedArray) DECLARE_CAST(JSGeneratorObject) // Dispatched behavior. DECLARE_PRINTER(JSGeneratorObject) DECLARE_VERIFIER(JSGeneratorObject) // Magic sentinel values for the continuation. static const int kGeneratorExecuting = -1; static const int kGeneratorClosed = 0; // Layout description. static const int kFunctionOffset = JSObject::kHeaderSize; static const int kContextOffset = kFunctionOffset + kPointerSize; static const int kReceiverOffset = kContextOffset + kPointerSize; static const int kInputOffset = kReceiverOffset + kPointerSize; static const int kContinuationOffset = kInputOffset + kPointerSize; static const int kOperandStackOffset = kContinuationOffset + kPointerSize; static const int kSize = kOperandStackOffset + kPointerSize; // Resume mode, for use by runtime functions. enum ResumeMode { NEXT, RETURN, THROW }; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject); }; // Representation for module instance objects. class JSModule: public JSObject { public: // [context]: the context holding the module's locals, or undefined if none. DECL_ACCESSORS(context, Object) // [scope_info]: Scope info. DECL_ACCESSORS(scope_info, ScopeInfo) DECLARE_CAST(JSModule) // Dispatched behavior. DECLARE_PRINTER(JSModule) DECLARE_VERIFIER(JSModule) // Layout description. static const int kContextOffset = JSObject::kHeaderSize; static const int kScopeInfoOffset = kContextOffset + kPointerSize; static const int kSize = kScopeInfoOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule); }; // JSBoundFunction describes a bound function exotic object. class JSBoundFunction : public JSObject { public: // [length]: The bound function "length" property. DECL_ACCESSORS(length, Object) // [name]: The bound function "name" property. DECL_ACCESSORS(name, Object) // [bound_target_function]: The wrapped function object. DECL_ACCESSORS(bound_target_function, JSReceiver) // [bound_this]: The value that is always passed as the this value when // calling the wrapped function. DECL_ACCESSORS(bound_this, Object) // [bound_arguments]: A list of values whose elements are used as the first // arguments to any call to the wrapped function. DECL_ACCESSORS(bound_arguments, FixedArray) static MaybeHandle<Context> GetFunctionRealm( Handle<JSBoundFunction> function); DECLARE_CAST(JSBoundFunction) // Dispatched behavior. DECLARE_PRINTER(JSBoundFunction) DECLARE_VERIFIER(JSBoundFunction) // The bound function's string representation implemented according // to ES6 section 19.2.3.5 Function.prototype.toString ( ). static Handle<String> ToString(Handle<JSBoundFunction> function); // Layout description. static const int kBoundTargetFunctionOffset = JSObject::kHeaderSize; static const int kBoundThisOffset = kBoundTargetFunctionOffset + kPointerSize; static const int kBoundArgumentsOffset = kBoundThisOffset + kPointerSize; static const int kLengthOffset = kBoundArgumentsOffset + kPointerSize; static const int kNameOffset = kLengthOffset + kPointerSize; static const int kSize = kNameOffset + kPointerSize; // Indices of in-object properties. static const int kLengthIndex = 0; static const int kNameIndex = 1; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSBoundFunction); }; // JSFunction describes JavaScript functions. class JSFunction: public JSObject { public: // [prototype_or_initial_map]: DECL_ACCESSORS(prototype_or_initial_map, Object) // [shared]: The information about the function that // can be shared by instances. DECL_ACCESSORS(shared, SharedFunctionInfo) // [context]: The context for this function. inline Context* context(); inline void set_context(Object* context); inline JSObject* global_proxy(); inline Context* native_context(); static Handle<Context> GetFunctionRealm(Handle<JSFunction> function); // [code]: The generated code object for this function. Executed // when the function is invoked, e.g. foo() or new foo(). See // [[Call]] and [[Construct]] description in ECMA-262, section // 8.6.2, page 27. inline Code* code(); inline void set_code(Code* code); inline void set_code_no_write_barrier(Code* code); inline void ReplaceCode(Code* code); // Tells whether this function inlines the given shared function info. bool Inlines(SharedFunctionInfo* candidate); // Tells whether or not this function has been optimized. inline bool IsOptimized(); // Mark this function for lazy recompilation. The function will be // recompiled the next time it is executed. void MarkForOptimization(); void AttemptConcurrentOptimization(); // Tells whether or not the function is already marked for lazy // recompilation. inline bool IsMarkedForOptimization(); inline bool IsMarkedForConcurrentOptimization(); // Tells whether or not the function is on the concurrent recompilation queue. inline bool IsInOptimizationQueue(); // Completes inobject slack tracking on initial map if it is active. inline void CompleteInobjectSlackTrackingIfActive(); // [literals]: Fixed array holding the materialized literals. // // If the function contains object, regexp or array literals, the // literals array prefix contains the object, regexp, and array // function to be used when creating these literals. This is // necessary so that we do not dynamically lookup the object, regexp // or array functions. Performing a dynamic lookup, we might end up // using the functions from a new context that we should not have // access to. DECL_ACCESSORS(literals, LiteralsArray) // The initial map for an object created by this constructor. inline Map* initial_map(); static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map, Handle<Object> prototype); inline bool has_initial_map(); static void EnsureHasInitialMap(Handle<JSFunction> function); // Creates a map that matches the constructor's initial map, but with // [[prototype]] being new.target.prototype. Because new.target can be a // JSProxy, this can call back into JavaScript. static MUST_USE_RESULT MaybeHandle<Map> GetDerivedMap( Isolate* isolate, Handle<JSFunction> constructor, Handle<JSReceiver> new_target); // Get and set the prototype property on a JSFunction. If the // function has an initial map the prototype is set on the initial // map. Otherwise, the prototype is put in the initial map field // until an initial map is needed. inline bool has_prototype(); inline bool has_instance_prototype(); inline Object* prototype(); inline Object* instance_prototype(); static void SetPrototype(Handle<JSFunction> function, Handle<Object> value); static void SetInstancePrototype(Handle<JSFunction> function, Handle<Object> value); // After prototype is removed, it will not be created when accessed, and // [[Construct]] from this function will not be allowed. bool RemovePrototype(); // Returns if this function has been compiled to native code yet. inline bool is_compiled(); // [next_function_link]: Links functions into various lists, e.g. the list // of optimized functions hanging off the native_context. The CodeFlusher // uses this link to chain together flushing candidates. Treated weakly // by the garbage collector. DECL_ACCESSORS(next_function_link, Object) // Prints the name of the function using PrintF. void PrintName(FILE* out = stdout); DECLARE_CAST(JSFunction) // Calculate the instance size and in-object properties count. void CalculateInstanceSize(InstanceType instance_type, int requested_internal_fields, int* instance_size, int* in_object_properties); void CalculateInstanceSizeForDerivedClass(InstanceType instance_type, int requested_internal_fields, int* instance_size, int* in_object_properties); // Visiting policy flags define whether the code entry or next function // should be visited or not. enum BodyVisitingPolicy { kVisitCodeEntry = 1 << 0, kVisitNextFunction = 1 << 1, kSkipCodeEntryAndNextFunction = 0, kVisitCodeEntryAndNextFunction = kVisitCodeEntry | kVisitNextFunction }; // Iterates the function object according to the visiting policy. template <BodyVisitingPolicy> class BodyDescriptorImpl; // Visit the whole object. typedef BodyDescriptorImpl<kVisitCodeEntryAndNextFunction> BodyDescriptor; // Don't visit next function. typedef BodyDescriptorImpl<kVisitCodeEntry> BodyDescriptorStrongCode; typedef BodyDescriptorImpl<kSkipCodeEntryAndNextFunction> BodyDescriptorWeakCode; // Dispatched behavior. DECLARE_PRINTER(JSFunction) DECLARE_VERIFIER(JSFunction) // Returns the number of allocated literals. inline int NumberOfLiterals(); // Used for flags such as --hydrogen-filter. bool PassesFilter(const char* raw_filter); // The function's name if it is configured, otherwise shared function info // debug name. static Handle<String> GetName(Handle<JSFunction> function); // ES6 section 9.2.11 SetFunctionName // Because of the way this abstract operation is used in the spec, // it should never fail. static void SetName(Handle<JSFunction> function, Handle<Name> name, Handle<String> prefix); // The function's displayName if it is set, otherwise name if it is // configured, otherwise shared function info // debug name. static Handle<String> GetDebugName(Handle<JSFunction> function); // The function's string representation implemented according to // ES6 section 19.2.3.5 Function.prototype.toString ( ). static Handle<String> ToString(Handle<JSFunction> function); // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to // kSize) is weak and has special handling during garbage collection. static const int kPrototypeOrInitialMapOffset = JSObject::kHeaderSize; static const int kSharedFunctionInfoOffset = kPrototypeOrInitialMapOffset + kPointerSize; static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize; static const int kLiteralsOffset = kContextOffset + kPointerSize; static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize; static const int kCodeEntryOffset = kNonWeakFieldsEndOffset; static const int kNextFunctionLinkOffset = kCodeEntryOffset + kPointerSize; static const int kSize = kNextFunctionLinkOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction); }; // JSGlobalProxy's prototype must be a JSGlobalObject or null, // and the prototype is hidden. JSGlobalProxy always delegates // property accesses to its prototype if the prototype is not null. // // A JSGlobalProxy can be reinitialized which will preserve its identity. // // Accessing a JSGlobalProxy requires security check. class JSGlobalProxy : public JSObject { public: // [native_context]: the owner native context of this global proxy object. // It is null value if this object is not used by any context. DECL_ACCESSORS(native_context, Object) // [hash]: The hash code property (undefined if not initialized yet). DECL_ACCESSORS(hash, Object) DECLARE_CAST(JSGlobalProxy) inline bool IsDetachedFrom(JSGlobalObject* global) const; // Dispatched behavior. DECLARE_PRINTER(JSGlobalProxy) DECLARE_VERIFIER(JSGlobalProxy) // Layout description. static const int kNativeContextOffset = JSObject::kHeaderSize; static const int kHashOffset = kNativeContextOffset + kPointerSize; static const int kSize = kHashOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy); }; // JavaScript global object. class JSGlobalObject : public JSObject { public: // [native context]: the natives corresponding to this global object. DECL_ACCESSORS(native_context, Context) // [global proxy]: the global proxy object of the context DECL_ACCESSORS(global_proxy, JSObject) static void InvalidatePropertyCell(Handle<JSGlobalObject> object, Handle<Name> name); // Ensure that the global object has a cell for the given property name. static Handle<PropertyCell> EnsurePropertyCell(Handle<JSGlobalObject> global, Handle<Name> name); DECLARE_CAST(JSGlobalObject) inline bool IsDetached(); // Dispatched behavior. DECLARE_PRINTER(JSGlobalObject) DECLARE_VERIFIER(JSGlobalObject) // Layout description. static const int kNativeContextOffset = JSObject::kHeaderSize; static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize; static const int kHeaderSize = kGlobalProxyOffset + kPointerSize; static const int kSize = kHeaderSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject); }; // Representation for JS Wrapper objects, String, Number, Boolean, etc. class JSValue: public JSObject { public: // [value]: the object being wrapped. DECL_ACCESSORS(value, Object) DECLARE_CAST(JSValue) // Dispatched behavior. DECLARE_PRINTER(JSValue) DECLARE_VERIFIER(JSValue) // Layout description. static const int kValueOffset = JSObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue); }; class DateCache; // Representation for JS date objects. class JSDate: public JSObject { public: static MUST_USE_RESULT MaybeHandle<JSDate> New(Handle<JSFunction> constructor, Handle<JSReceiver> new_target, double tv); // If one component is NaN, all of them are, indicating a NaN time value. // [value]: the time value. DECL_ACCESSORS(value, Object) // [year]: caches year. Either undefined, smi, or NaN. DECL_ACCESSORS(year, Object) // [month]: caches month. Either undefined, smi, or NaN. DECL_ACCESSORS(month, Object) // [day]: caches day. Either undefined, smi, or NaN. DECL_ACCESSORS(day, Object) // [weekday]: caches day of week. Either undefined, smi, or NaN. DECL_ACCESSORS(weekday, Object) // [hour]: caches hours. Either undefined, smi, or NaN. DECL_ACCESSORS(hour, Object) // [min]: caches minutes. Either undefined, smi, or NaN. DECL_ACCESSORS(min, Object) // [sec]: caches seconds. Either undefined, smi, or NaN. DECL_ACCESSORS(sec, Object) // [cache stamp]: sample of the date cache stamp at the // moment when chached fields were cached. DECL_ACCESSORS(cache_stamp, Object) DECLARE_CAST(JSDate) // Returns the time value (UTC) identifying the current time. static double CurrentTimeValue(Isolate* isolate); // Returns the date field with the specified index. // See FieldIndex for the list of date fields. static Object* GetField(Object* date, Smi* index); static Handle<Object> SetValue(Handle<JSDate> date, double v); void SetValue(Object* value, bool is_value_nan); // ES6 section 20.3.4.45 Date.prototype [ @@toPrimitive ] static MUST_USE_RESULT MaybeHandle<Object> ToPrimitive( Handle<JSReceiver> receiver, Handle<Object> hint); // Dispatched behavior. DECLARE_PRINTER(JSDate) DECLARE_VERIFIER(JSDate) // The order is important. It must be kept in sync with date macros // in macros.py. enum FieldIndex { kDateValue, kYear, kMonth, kDay, kWeekday, kHour, kMinute, kSecond, kFirstUncachedField, kMillisecond = kFirstUncachedField, kDays, kTimeInDay, kFirstUTCField, kYearUTC = kFirstUTCField, kMonthUTC, kDayUTC, kWeekdayUTC, kHourUTC, kMinuteUTC, kSecondUTC, kMillisecondUTC, kDaysUTC, kTimeInDayUTC, kTimezoneOffset }; // Layout description. static const int kValueOffset = JSObject::kHeaderSize; static const int kYearOffset = kValueOffset + kPointerSize; static const int kMonthOffset = kYearOffset + kPointerSize; static const int kDayOffset = kMonthOffset + kPointerSize; static const int kWeekdayOffset = kDayOffset + kPointerSize; static const int kHourOffset = kWeekdayOffset + kPointerSize; static const int kMinOffset = kHourOffset + kPointerSize; static const int kSecOffset = kMinOffset + kPointerSize; static const int kCacheStampOffset = kSecOffset + kPointerSize; static const int kSize = kCacheStampOffset + kPointerSize; private: inline Object* DoGetField(FieldIndex index); Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache); // Computes and caches the cacheable fields of the date. inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache); DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate); }; // Representation of message objects used for error reporting through // the API. The messages are formatted in JavaScript so this object is // a real JavaScript object. The information used for formatting the // error messages are not directly accessible from JavaScript to // prevent leaking information to user code called during error // formatting. class JSMessageObject: public JSObject { public: // [type]: the type of error message. inline int type() const; inline void set_type(int value); // [arguments]: the arguments for formatting the error message. DECL_ACCESSORS(argument, Object) // [script]: the script from which the error message originated. DECL_ACCESSORS(script, Object) // [stack_frames]: an array of stack frames for this error object. DECL_ACCESSORS(stack_frames, Object) // [start_position]: the start position in the script for the error message. inline int start_position() const; inline void set_start_position(int value); // [end_position]: the end position in the script for the error message. inline int end_position() const; inline void set_end_position(int value); DECLARE_CAST(JSMessageObject) // Dispatched behavior. DECLARE_PRINTER(JSMessageObject) DECLARE_VERIFIER(JSMessageObject) // Layout description. static const int kTypeOffset = JSObject::kHeaderSize; static const int kArgumentsOffset = kTypeOffset + kPointerSize; static const int kScriptOffset = kArgumentsOffset + kPointerSize; static const int kStackFramesOffset = kScriptOffset + kPointerSize; static const int kStartPositionOffset = kStackFramesOffset + kPointerSize; static const int kEndPositionOffset = kStartPositionOffset + kPointerSize; static const int kSize = kEndPositionOffset + kPointerSize; typedef FixedBodyDescriptor<HeapObject::kMapOffset, kStackFramesOffset + kPointerSize, kSize> BodyDescriptor; }; // Regular expressions // The regular expression holds a single reference to a FixedArray in // the kDataOffset field. // The FixedArray contains the following data: // - tag : type of regexp implementation (not compiled yet, atom or irregexp) // - reference to the original source string // - reference to the original flag string // If it is an atom regexp // - a reference to a literal string to search for // If it is an irregexp regexp: // - a reference to code for Latin1 inputs (bytecode or compiled), or a smi // used for tracking the last usage (used for code flushing). // - a reference to code for UC16 inputs (bytecode or compiled), or a smi // used for tracking the last usage (used for code flushing).. // - max number of registers used by irregexp implementations. // - number of capture registers (output values) of the regexp. class JSRegExp: public JSObject { public: // Meaning of Type: // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet. // ATOM: A simple string to match against using an indexOf operation. // IRREGEXP: Compiled with Irregexp. // IRREGEXP_NATIVE: Compiled to native code with Irregexp. enum Type { NOT_COMPILED, ATOM, IRREGEXP }; enum Flag { kNone = 0, kGlobal = 1 << 0, kIgnoreCase = 1 << 1, kMultiline = 1 << 2, kSticky = 1 << 3, kUnicode = 1 << 4, }; typedef base::Flags<Flag> Flags; DECL_ACCESSORS(data, Object) DECL_ACCESSORS(flags, Object) DECL_ACCESSORS(source, Object) static MaybeHandle<JSRegExp> New(Handle<String> source, Flags flags); static MaybeHandle<JSRegExp> New(Handle<String> source, Handle<String> flags); static Handle<JSRegExp> Copy(Handle<JSRegExp> regexp); static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp, Handle<String> source, Flags flags); static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp, Handle<String> source, Handle<String> flags_string); inline Type TypeTag(); inline int CaptureCount(); inline Flags GetFlags(); inline String* Pattern(); inline Object* DataAt(int index); // Set implementation data after the object has been prepared. inline void SetDataAt(int index, Object* value); static int code_index(bool is_latin1) { if (is_latin1) { return kIrregexpLatin1CodeIndex; } else { return kIrregexpUC16CodeIndex; } } static int saved_code_index(bool is_latin1) { if (is_latin1) { return kIrregexpLatin1CodeSavedIndex; } else { return kIrregexpUC16CodeSavedIndex; } } DECLARE_CAST(JSRegExp) // Dispatched behavior. DECLARE_PRINTER(JSRegExp) DECLARE_VERIFIER(JSRegExp) static const int kDataOffset = JSObject::kHeaderSize; static const int kSourceOffset = kDataOffset + kPointerSize; static const int kFlagsOffset = kSourceOffset + kPointerSize; static const int kSize = kFlagsOffset + kPointerSize; // Indices in the data array. static const int kTagIndex = 0; static const int kSourceIndex = kTagIndex + 1; static const int kFlagsIndex = kSourceIndex + 1; static const int kDataIndex = kFlagsIndex + 1; // The data fields are used in different ways depending on the // value of the tag. // Atom regexps (literal strings). static const int kAtomPatternIndex = kDataIndex; static const int kAtomDataSize = kAtomPatternIndex + 1; // Irregexp compiled code or bytecode for Latin1. If compilation // fails, this fields hold an exception object that should be // thrown if the regexp is used again. static const int kIrregexpLatin1CodeIndex = kDataIndex; // Irregexp compiled code or bytecode for UC16. If compilation // fails, this fields hold an exception object that should be // thrown if the regexp is used again. static const int kIrregexpUC16CodeIndex = kDataIndex + 1; // Saved instance of Irregexp compiled code or bytecode for Latin1 that // is a potential candidate for flushing. static const int kIrregexpLatin1CodeSavedIndex = kDataIndex + 2; // Saved instance of Irregexp compiled code or bytecode for UC16 that is // a potential candidate for flushing. static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3; // Maximal number of registers used by either Latin1 or UC16. // Only used to check that there is enough stack space static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4; // Number of captures in the compiled regexp. static const int kIrregexpCaptureCountIndex = kDataIndex + 5; static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1; // Offsets directly into the data fixed array. static const int kDataTagOffset = FixedArray::kHeaderSize + kTagIndex * kPointerSize; static const int kDataOneByteCodeOffset = FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize; static const int kDataUC16CodeOffset = FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize; static const int kIrregexpCaptureCountOffset = FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize; // In-object fields. static const int kLastIndexFieldIndex = 0; static const int kInObjectFieldCount = 1; // The uninitialized value for a regexp code object. static const int kUninitializedValue = -1; // The compilation error value for the regexp code object. The real error // object is in the saved code field. static const int kCompilationErrorValue = -2; // When we store the sweep generation at which we moved the code from the // code index to the saved code index we mask it of to be in the [0:255] // range. static const int kCodeAgeMask = 0xff; }; DEFINE_OPERATORS_FOR_FLAGS(JSRegExp::Flags) class CompilationCacheShape : public BaseShape<HashTableKey*> { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key); static const int kPrefixSize = 0; static const int kEntrySize = 2; }; // This cache is used in two different variants. For regexp caching, it simply // maps identifying info of the regexp to the cached regexp object. Scripts and // eval code only gets cached after a second probe for the code object. To do // so, on first "put" only a hash identifying the source is entered into the // cache, mapping it to a lifetime count of the hash. On each call to Age all // such lifetimes get reduced, and removed once they reach zero. If a second put // is called while such a hash is live in the cache, the hash gets replaced by // an actual cache entry. Age also removes stale live entries from the cache. // Such entries are identified by SharedFunctionInfos pointing to either the // recompilation stub, or to "old" code. This avoids memory leaks due to // premature caching of scripts and eval strings that are never needed later. class CompilationCacheTable: public HashTable<CompilationCacheTable, CompilationCacheShape, HashTableKey*> { public: // Find cached value for a string key, otherwise return null. Handle<Object> Lookup( Handle<String> src, Handle<Context> context, LanguageMode language_mode); Handle<Object> LookupEval( Handle<String> src, Handle<SharedFunctionInfo> shared, LanguageMode language_mode, int scope_position); Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags); static Handle<CompilationCacheTable> Put( Handle<CompilationCacheTable> cache, Handle<String> src, Handle<Context> context, LanguageMode language_mode, Handle<Object> value); static Handle<CompilationCacheTable> PutEval( Handle<CompilationCacheTable> cache, Handle<String> src, Handle<SharedFunctionInfo> context, Handle<SharedFunctionInfo> value, int scope_position); static Handle<CompilationCacheTable> PutRegExp( Handle<CompilationCacheTable> cache, Handle<String> src, JSRegExp::Flags flags, Handle<FixedArray> value); void Remove(Object* value); void Age(); static const int kHashGenerations = 10; DECLARE_CAST(CompilationCacheTable) private: DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable); }; class CodeCache: public Struct { public: DECL_ACCESSORS(default_cache, FixedArray) DECL_ACCESSORS(normal_type_cache, Object) // Add the code object to the cache. static void Update( Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code); // Lookup code object in the cache. Returns code object if found and undefined // if not. Object* Lookup(Name* name, Code::Flags flags); // Get the internal index of a code object in the cache. Returns -1 if the // code object is not in that cache. This index can be used to later call // RemoveByIndex. The cache cannot be modified between a call to GetIndex and // RemoveByIndex. int GetIndex(Object* name, Code* code); // Remove an object from the cache with the provided internal index. void RemoveByIndex(Object* name, Code* code, int index); DECLARE_CAST(CodeCache) // Dispatched behavior. DECLARE_PRINTER(CodeCache) DECLARE_VERIFIER(CodeCache) static const int kDefaultCacheOffset = HeapObject::kHeaderSize; static const int kNormalTypeCacheOffset = kDefaultCacheOffset + kPointerSize; static const int kSize = kNormalTypeCacheOffset + kPointerSize; private: static void UpdateDefaultCache( Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code); static void UpdateNormalTypeCache( Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code); Object* LookupDefaultCache(Name* name, Code::Flags flags); Object* LookupNormalTypeCache(Name* name, Code::Flags flags); // Code cache layout of the default cache. Elements are alternating name and // code objects for non normal load/store/call IC's. static const int kCodeCacheEntrySize = 2; static const int kCodeCacheEntryNameOffset = 0; static const int kCodeCacheEntryCodeOffset = 1; DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache); }; class CodeCacheHashTableShape : public BaseShape<HashTableKey*> { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } static inline Handle<Object> AsHandle(Isolate* isolate, HashTableKey* key); static const int kPrefixSize = 0; static const int kEntrySize = 2; }; class CodeCacheHashTable: public HashTable<CodeCacheHashTable, CodeCacheHashTableShape, HashTableKey*> { public: Object* Lookup(Name* name, Code::Flags flags); static Handle<CodeCacheHashTable> Put( Handle<CodeCacheHashTable> table, Handle<Name> name, Handle<Code> code); int GetIndex(Name* name, Code::Flags flags); void RemoveByIndex(int index); DECLARE_CAST(CodeCacheHashTable) // Initial size of the fixed array backing the hash table. static const int kInitialSize = 64; private: DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable); }; class PolymorphicCodeCache: public Struct { public: DECL_ACCESSORS(cache, Object) static void Update(Handle<PolymorphicCodeCache> cache, MapHandleList* maps, Code::Flags flags, Handle<Code> code); // Returns an undefined value if the entry is not found. Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags); DECLARE_CAST(PolymorphicCodeCache) // Dispatched behavior. DECLARE_PRINTER(PolymorphicCodeCache) DECLARE_VERIFIER(PolymorphicCodeCache) static const int kCacheOffset = HeapObject::kHeaderSize; static const int kSize = kCacheOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache); }; class PolymorphicCodeCacheHashTable : public HashTable<PolymorphicCodeCacheHashTable, CodeCacheHashTableShape, HashTableKey*> { public: Object* Lookup(MapHandleList* maps, int code_kind); static Handle<PolymorphicCodeCacheHashTable> Put( Handle<PolymorphicCodeCacheHashTable> hash_table, MapHandleList* maps, int code_kind, Handle<Code> code); DECLARE_CAST(PolymorphicCodeCacheHashTable) static const int kInitialSize = 64; private: DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable); }; class TypeFeedbackInfo: public Struct { public: inline int ic_total_count(); inline void set_ic_total_count(int count); inline int ic_with_type_info_count(); inline void change_ic_with_type_info_count(int delta); inline int ic_generic_count(); inline void change_ic_generic_count(int delta); inline void initialize_storage(); inline void change_own_type_change_checksum(); inline int own_type_change_checksum(); inline void set_inlined_type_change_checksum(int checksum); inline bool matches_inlined_type_change_checksum(int checksum); DECLARE_CAST(TypeFeedbackInfo) // Dispatched behavior. DECLARE_PRINTER(TypeFeedbackInfo) DECLARE_VERIFIER(TypeFeedbackInfo) static const int kStorage1Offset = HeapObject::kHeaderSize; static const int kStorage2Offset = kStorage1Offset + kPointerSize; static const int kStorage3Offset = kStorage2Offset + kPointerSize; static const int kSize = kStorage3Offset + kPointerSize; private: static const int kTypeChangeChecksumBits = 7; class ICTotalCountField: public BitField<int, 0, kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT class OwnTypeChangeChecksum: public BitField<int, kSmiValueSize - kTypeChangeChecksumBits, kTypeChangeChecksumBits> {}; // NOLINT class ICsWithTypeInfoCountField: public BitField<int, 0, kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT class InlinedTypeChangeChecksum: public BitField<int, kSmiValueSize - kTypeChangeChecksumBits, kTypeChangeChecksumBits> {}; // NOLINT DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo); }; enum AllocationSiteMode { DONT_TRACK_ALLOCATION_SITE, TRACK_ALLOCATION_SITE, LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE }; class AllocationSite: public Struct { public: static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024; static const double kPretenureRatio; static const int kPretenureMinimumCreated = 100; // Values for pretenure decision field. enum PretenureDecision { kUndecided = 0, kDontTenure = 1, kMaybeTenure = 2, kTenure = 3, kZombie = 4, kLastPretenureDecisionValue = kZombie }; const char* PretenureDecisionName(PretenureDecision decision); DECL_ACCESSORS(transition_info, Object) // nested_site threads a list of sites that represent nested literals // walked in a particular order. So [[1, 2], 1, 2] will have one // nested_site, but [[1, 2], 3, [4]] will have a list of two. DECL_ACCESSORS(nested_site, Object) DECL_INT_ACCESSORS(pretenure_data) DECL_INT_ACCESSORS(pretenure_create_count) DECL_ACCESSORS(dependent_code, DependentCode) DECL_ACCESSORS(weak_next, Object) inline void Initialize(); // This method is expensive, it should only be called for reporting. bool IsNestedSite(); // transition_info bitfields, for constructed array transition info. class ElementsKindBits: public BitField<ElementsKind, 0, 15> {}; class UnusedBits: public BitField<int, 15, 14> {}; class DoNotInlineBit: public BitField<bool, 29, 1> {}; // Bitfields for pretenure_data class MementoFoundCountBits: public BitField<int, 0, 26> {}; class PretenureDecisionBits: public BitField<PretenureDecision, 26, 3> {}; class DeoptDependentCodeBit: public BitField<bool, 29, 1> {}; STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue); // Increments the mementos found counter and returns true when the first // memento was found for a given allocation site. inline bool IncrementMementoFoundCount(int increment = 1); inline void IncrementMementoCreateCount(); PretenureFlag GetPretenureMode(); void ResetPretenureDecision(); inline PretenureDecision pretenure_decision(); inline void set_pretenure_decision(PretenureDecision decision); inline bool deopt_dependent_code(); inline void set_deopt_dependent_code(bool deopt); inline int memento_found_count(); inline void set_memento_found_count(int count); inline int memento_create_count(); inline void set_memento_create_count(int count); // The pretenuring decision is made during gc, and the zombie state allows // us to recognize when an allocation site is just being kept alive because // a later traversal of new space may discover AllocationMementos that point // to this AllocationSite. inline bool IsZombie(); inline bool IsMaybeTenure(); inline void MarkZombie(); inline bool MakePretenureDecision(PretenureDecision current_decision, double ratio, bool maximum_size_scavenge); inline bool DigestPretenuringFeedback(bool maximum_size_scavenge); inline ElementsKind GetElementsKind(); inline void SetElementsKind(ElementsKind kind); inline bool CanInlineCall(); inline void SetDoNotInlineCall(); inline bool SitePointsToLiteral(); static void DigestTransitionFeedback(Handle<AllocationSite> site, ElementsKind to_kind); DECLARE_PRINTER(AllocationSite) DECLARE_VERIFIER(AllocationSite) DECLARE_CAST(AllocationSite) static inline AllocationSiteMode GetMode( ElementsKind boilerplate_elements_kind); static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to); static inline bool CanTrack(InstanceType type); static const int kTransitionInfoOffset = HeapObject::kHeaderSize; static const int kNestedSiteOffset = kTransitionInfoOffset + kPointerSize; static const int kPretenureDataOffset = kNestedSiteOffset + kPointerSize; static const int kPretenureCreateCountOffset = kPretenureDataOffset + kPointerSize; static const int kDependentCodeOffset = kPretenureCreateCountOffset + kPointerSize; static const int kWeakNextOffset = kDependentCodeOffset + kPointerSize; static const int kSize = kWeakNextOffset + kPointerSize; // During mark compact we need to take special care for the dependent code // field. static const int kPointerFieldsBeginOffset = kTransitionInfoOffset; static const int kPointerFieldsEndOffset = kWeakNextOffset; // For other visitors, use the fixed body descriptor below. typedef FixedBodyDescriptor<HeapObject::kHeaderSize, kDependentCodeOffset + kPointerSize, kSize> BodyDescriptor; private: inline bool PretenuringDecisionMade(); DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite); }; class AllocationMemento: public Struct { public: static const int kAllocationSiteOffset = HeapObject::kHeaderSize; static const int kSize = kAllocationSiteOffset + kPointerSize; DECL_ACCESSORS(allocation_site, Object) inline bool IsValid(); inline AllocationSite* GetAllocationSite(); inline Address GetAllocationSiteUnchecked(); DECLARE_PRINTER(AllocationMemento) DECLARE_VERIFIER(AllocationMemento) DECLARE_CAST(AllocationMemento) private: DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento); }; // Representation of a slow alias as part of a sloppy arguments objects. // For fast aliases (if HasSloppyArgumentsElements()): // - the parameter map contains an index into the context // - all attributes of the element have default values // For slow aliases (if HasDictionaryArgumentsElements()): // - the parameter map contains no fast alias mapping (i.e. the hole) // - this struct (in the slow backing store) contains an index into the context // - all attributes are available as part if the property details class AliasedArgumentsEntry: public Struct { public: inline int aliased_context_slot() const; inline void set_aliased_context_slot(int count); DECLARE_CAST(AliasedArgumentsEntry) // Dispatched behavior. DECLARE_PRINTER(AliasedArgumentsEntry) DECLARE_VERIFIER(AliasedArgumentsEntry) static const int kAliasedContextSlot = HeapObject::kHeaderSize; static const int kSize = kAliasedContextSlot + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry); }; enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS}; enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL}; class StringHasher { public: explicit inline StringHasher(int length, uint32_t seed); template <typename schar> static inline uint32_t HashSequentialString(const schar* chars, int length, uint32_t seed); // Reads all the data, even for long strings and computes the utf16 length. static uint32_t ComputeUtf8Hash(Vector<const char> chars, uint32_t seed, int* utf16_length_out); // Calculated hash value for a string consisting of 1 to // String::kMaxArrayIndexSize digits with no leading zeros (except "0"). // value is represented decimal value. static uint32_t MakeArrayIndexHash(uint32_t value, int length); // No string is allowed to have a hash of zero. That value is reserved // for internal properties. If the hash calculation yields zero then we // use 27 instead. static const int kZeroHash = 27; // Reusable parts of the hashing algorithm. INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c)); INLINE(static uint32_t GetHashCore(uint32_t running_hash)); INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash, const uc16* chars, int length)); INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash, const char* chars, int length)); protected: // Returns the value to store in the hash field of a string with // the given length and contents. uint32_t GetHashField(); // Returns true if the hash of this string can be computed without // looking at the contents. inline bool has_trivial_hash(); // Adds a block of characters to the hash. template<typename Char> inline void AddCharacters(const Char* chars, int len); private: // Add a character to the hash. inline void AddCharacter(uint16_t c); // Update index. Returns true if string is still an index. inline bool UpdateIndex(uint16_t c); int length_; uint32_t raw_running_hash_; uint32_t array_index_; bool is_array_index_; bool is_first_char_; DISALLOW_COPY_AND_ASSIGN(StringHasher); }; class IteratingStringHasher : public StringHasher { public: static inline uint32_t Hash(String* string, uint32_t seed); inline void VisitOneByteString(const uint8_t* chars, int length); inline void VisitTwoByteString(const uint16_t* chars, int length); private: inline IteratingStringHasher(int len, uint32_t seed); void VisitConsString(ConsString* cons_string); DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher); }; // The characteristics of a string are stored in its map. Retrieving these // few bits of information is moderately expensive, involving two memory // loads where the second is dependent on the first. To improve efficiency // the shape of the string is given its own class so that it can be retrieved // once and used for several string operations. A StringShape is small enough // to be passed by value and is immutable, but be aware that flattening a // string can potentially alter its shape. Also be aware that a GC caused by // something else can alter the shape of a string due to ConsString // shortcutting. Keeping these restrictions in mind has proven to be error- // prone and so we no longer put StringShapes in variables unless there is a // concrete performance benefit at that particular point in the code. class StringShape BASE_EMBEDDED { public: inline explicit StringShape(const String* s); inline explicit StringShape(Map* s); inline explicit StringShape(InstanceType t); inline bool IsSequential(); inline bool IsExternal(); inline bool IsCons(); inline bool IsSliced(); inline bool IsIndirect(); inline bool IsExternalOneByte(); inline bool IsExternalTwoByte(); inline bool IsSequentialOneByte(); inline bool IsSequentialTwoByte(); inline bool IsInternalized(); inline StringRepresentationTag representation_tag(); inline uint32_t encoding_tag(); inline uint32_t full_representation_tag(); inline uint32_t size_tag(); #ifdef DEBUG inline uint32_t type() { return type_; } inline void invalidate() { valid_ = false; } inline bool valid() { return valid_; } #else inline void invalidate() { } #endif private: uint32_t type_; #ifdef DEBUG inline void set_valid() { valid_ = true; } bool valid_; #else inline void set_valid() { } #endif }; // The Name abstract class captures anything that can be used as a property // name, i.e., strings and symbols. All names store a hash value. class Name: public HeapObject { public: // Get and set the hash field of the name. inline uint32_t hash_field(); inline void set_hash_field(uint32_t value); // Tells whether the hash code has been computed. inline bool HasHashCode(); // Returns a hash value used for the property table inline uint32_t Hash(); // Equality operations. inline bool Equals(Name* other); inline static bool Equals(Handle<Name> one, Handle<Name> two); // Conversion. inline bool AsArrayIndex(uint32_t* index); // If the name is private, it can only name own properties. inline bool IsPrivate(); // If the name is a non-flat string, this method returns a flat version of the // string. Otherwise it'll just return the input. static inline Handle<Name> Flatten(Handle<Name> name, PretenureFlag pretenure = NOT_TENURED); // Return a string version of this name that is converted according to the // rules described in ES6 section 9.2.11. MUST_USE_RESULT static MaybeHandle<String> ToFunctionName(Handle<Name> name); DECLARE_CAST(Name) DECLARE_PRINTER(Name) #if TRACE_MAPS void NameShortPrint(); int NameShortPrint(Vector<char> str); #endif // Layout description. static const int kHashFieldSlot = HeapObject::kHeaderSize; #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT static const int kHashFieldOffset = kHashFieldSlot; #else static const int kHashFieldOffset = kHashFieldSlot + kIntSize; #endif static const int kSize = kHashFieldSlot + kPointerSize; // Mask constant for checking if a name has a computed hash code // and if it is a string that is an array index. The least significant bit // indicates whether a hash code has been computed. If the hash code has // been computed the 2nd bit tells whether the string can be used as an // array index. static const int kHashNotComputedMask = 1; static const int kIsNotArrayIndexMask = 1 << 1; static const int kNofHashBitFields = 2; // Shift constant retrieving hash code from hash field. static const int kHashShift = kNofHashBitFields; // Only these bits are relevant in the hash, since the top two are shifted // out. static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift; // Array index strings this short can keep their index in the hash field. static const int kMaxCachedArrayIndexLength = 7; // For strings which are array indexes the hash value has the string length // mixed into the hash, mainly to avoid a hash value of zero which would be // the case for the string '0'. 24 bits are used for the array index value. static const int kArrayIndexValueBits = 24; static const int kArrayIndexLengthBits = kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields; STATIC_ASSERT((kArrayIndexLengthBits > 0)); class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields, kArrayIndexValueBits> {}; // NOLINT class ArrayIndexLengthBits : public BitField<unsigned int, kNofHashBitFields + kArrayIndexValueBits, kArrayIndexLengthBits> {}; // NOLINT // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we // could use a mask to test if the length of string is less than or equal to // kMaxCachedArrayIndexLength. STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1)); static const unsigned int kContainsCachedArrayIndexMask = (~static_cast<unsigned>(kMaxCachedArrayIndexLength) << ArrayIndexLengthBits::kShift) | kIsNotArrayIndexMask; // Value of empty hash field indicating that the hash is not computed. static const int kEmptyHashField = kIsNotArrayIndexMask | kHashNotComputedMask; protected: static inline bool IsHashFieldComputed(uint32_t field); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Name); }; // ES6 symbols. class Symbol: public Name { public: // [name]: The print name of a symbol, or undefined if none. DECL_ACCESSORS(name, Object) DECL_INT_ACCESSORS(flags) // [is_private]: Whether this is a private symbol. Private symbols can only // be used to designate own properties of objects. DECL_BOOLEAN_ACCESSORS(is_private) // [is_well_known_symbol]: Whether this is a spec-defined well-known symbol, // or not. Well-known symbols do not throw when an access check fails during // a load. DECL_BOOLEAN_ACCESSORS(is_well_known_symbol) DECLARE_CAST(Symbol) // Dispatched behavior. DECLARE_PRINTER(Symbol) DECLARE_VERIFIER(Symbol) // Layout description. static const int kNameOffset = Name::kSize; static const int kFlagsOffset = kNameOffset + kPointerSize; static const int kSize = kFlagsOffset + kPointerSize; typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor; void SymbolShortPrint(std::ostream& os); private: static const int kPrivateBit = 0; static const int kWellKnownSymbolBit = 1; const char* PrivateSymbolToName() const; #if TRACE_MAPS friend class Name; // For PrivateSymbolToName. #endif DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol); }; class ConsString; // The String abstract class captures JavaScript string values: // // Ecma-262: // 4.3.16 String Value // A string value is a member of the type String and is a finite // ordered sequence of zero or more 16-bit unsigned integer values. // // All string values have a length field. class String: public Name { public: enum Encoding { ONE_BYTE_ENCODING, TWO_BYTE_ENCODING }; // Array index strings this short can keep their index in the hash field. static const int kMaxCachedArrayIndexLength = 7; // For strings which are array indexes the hash value has the string length // mixed into the hash, mainly to avoid a hash value of zero which would be // the case for the string '0'. 24 bits are used for the array index value. static const int kArrayIndexValueBits = 24; static const int kArrayIndexLengthBits = kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields; STATIC_ASSERT((kArrayIndexLengthBits > 0)); class ArrayIndexValueBits : public BitField<unsigned int, kNofHashBitFields, kArrayIndexValueBits> {}; // NOLINT class ArrayIndexLengthBits : public BitField<unsigned int, kNofHashBitFields + kArrayIndexValueBits, kArrayIndexLengthBits> {}; // NOLINT // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we // could use a mask to test if the length of string is less than or equal to // kMaxCachedArrayIndexLength. STATIC_ASSERT(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1)); static const unsigned int kContainsCachedArrayIndexMask = (~static_cast<unsigned>(kMaxCachedArrayIndexLength) << ArrayIndexLengthBits::kShift) | kIsNotArrayIndexMask; class SubStringRange { public: explicit inline SubStringRange(String* string, int first = 0, int length = -1); class iterator; inline iterator begin(); inline iterator end(); private: String* string_; int first_; int length_; }; // Representation of the flat content of a String. // A non-flat string doesn't have flat content. // A flat string has content that's encoded as a sequence of either // one-byte chars or two-byte UC16. // Returned by String::GetFlatContent(). class FlatContent { public: // Returns true if the string is flat and this structure contains content. bool IsFlat() { return state_ != NON_FLAT; } // Returns true if the structure contains one-byte content. bool IsOneByte() { return state_ == ONE_BYTE; } // Returns true if the structure contains two-byte content. bool IsTwoByte() { return state_ == TWO_BYTE; } // Return the one byte content of the string. Only use if IsOneByte() // returns true. Vector<const uint8_t> ToOneByteVector() { DCHECK_EQ(ONE_BYTE, state_); return Vector<const uint8_t>(onebyte_start, length_); } // Return the two-byte content of the string. Only use if IsTwoByte() // returns true. Vector<const uc16> ToUC16Vector() { DCHECK_EQ(TWO_BYTE, state_); return Vector<const uc16>(twobyte_start, length_); } uc16 Get(int i) { DCHECK(i < length_); DCHECK(state_ != NON_FLAT); if (state_ == ONE_BYTE) return onebyte_start[i]; return twobyte_start[i]; } bool UsesSameString(const FlatContent& other) const { return onebyte_start == other.onebyte_start; } private: enum State { NON_FLAT, ONE_BYTE, TWO_BYTE }; // Constructors only used by String::GetFlatContent(). explicit FlatContent(const uint8_t* start, int length) : onebyte_start(start), length_(length), state_(ONE_BYTE) {} explicit FlatContent(const uc16* start, int length) : twobyte_start(start), length_(length), state_(TWO_BYTE) { } FlatContent() : onebyte_start(NULL), length_(0), state_(NON_FLAT) { } union { const uint8_t* onebyte_start; const uc16* twobyte_start; }; int length_; State state_; friend class String; friend class IterableSubString; }; template <typename Char> INLINE(Vector<const Char> GetCharVector()); // Get and set the length of the string. inline int length() const; inline void set_length(int value); // Get and set the length of the string using acquire loads and release // stores. inline int synchronized_length() const; inline void synchronized_set_length(int value); // Returns whether this string has only one-byte chars, i.e. all of them can // be one-byte encoded. This might be the case even if the string is // two-byte. Such strings may appear when the embedder prefers // two-byte external representations even for one-byte data. inline bool IsOneByteRepresentation() const; inline bool IsTwoByteRepresentation() const; // Cons and slices have an encoding flag that may not represent the actual // encoding of the underlying string. This is taken into account here. // Requires: this->IsFlat() inline bool IsOneByteRepresentationUnderneath(); inline bool IsTwoByteRepresentationUnderneath(); // NOTE: this should be considered only a hint. False negatives are // possible. inline bool HasOnlyOneByteChars(); // Get and set individual two byte chars in the string. inline void Set(int index, uint16_t value); // Get individual two byte char in the string. Repeated calls // to this method are not efficient unless the string is flat. INLINE(uint16_t Get(int index)); // ES6 section 7.1.3.1 ToNumber Applied to the String Type static Handle<Object> ToNumber(Handle<String> subject); // Flattens the string. Checks first inline to see if it is // necessary. Does nothing if the string is not a cons string. // Flattening allocates a sequential string with the same data as // the given string and mutates the cons string to a degenerate // form, where the first component is the new sequential string and // the second component is the empty string. If allocation fails, // this function returns a failure. If flattening succeeds, this // function returns the sequential string that is now the first // component of the cons string. // // Degenerate cons strings are handled specially by the garbage // collector (see IsShortcutCandidate). static inline Handle<String> Flatten(Handle<String> string, PretenureFlag pretenure = NOT_TENURED); // Tries to return the content of a flat string as a structure holding either // a flat vector of char or of uc16. // If the string isn't flat, and therefore doesn't have flat content, the // returned structure will report so, and can't provide a vector of either // kind. FlatContent GetFlatContent(); // Returns the parent of a sliced string or first part of a flat cons string. // Requires: StringShape(this).IsIndirect() && this->IsFlat() inline String* GetUnderlying(); // String relational comparison, implemented according to ES6 section 7.2.11 // Abstract Relational Comparison (step 5): The comparison of Strings uses a // simple lexicographic ordering on sequences of code unit values. There is no // attempt to use the more complex, semantically oriented definitions of // character or string equality and collating order defined in the Unicode // specification. Therefore String values that are canonically equal according // to the Unicode standard could test as unequal. In effect this algorithm // assumes that both Strings are already in normalized form. Also, note that // for strings containing supplementary characters, lexicographic ordering on // sequences of UTF-16 code unit values differs from that on sequences of code // point values. MUST_USE_RESULT static ComparisonResult Compare(Handle<String> x, Handle<String> y); // String equality operations. inline bool Equals(String* other); inline static bool Equals(Handle<String> one, Handle<String> two); bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false); bool IsOneByteEqualTo(Vector<const uint8_t> str); bool IsTwoByteEqualTo(Vector<const uc16> str); // Return a UTF8 representation of the string. The string is null // terminated but may optionally contain nulls. Length is returned // in length_output if length_output is not a null pointer The string // should be nearly flat, otherwise the performance of this method may // be very slow (quadratic in the length). Setting robustness_flag to // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it // handles unexpected data without causing assert failures and it does not // do any heap allocations. This is useful when printing stack traces. base::SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls, RobustnessFlag robustness_flag, int offset, int length, int* length_output = 0); base::SmartArrayPointer<char> ToCString( AllowNullsFlag allow_nulls = DISALLOW_NULLS, RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL, int* length_output = 0); // Return a 16 bit Unicode representation of the string. // The string should be nearly flat, otherwise the performance of // of this method may be very bad. Setting robustness_flag to // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it // handles unexpected data without causing assert failures and it does not // do any heap allocations. This is useful when printing stack traces. base::SmartArrayPointer<uc16> ToWideCString( RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL); bool ComputeArrayIndex(uint32_t* index); // Externalization. bool MakeExternal(v8::String::ExternalStringResource* resource); bool MakeExternal(v8::String::ExternalOneByteStringResource* resource); // Conversion. inline bool AsArrayIndex(uint32_t* index); DECLARE_CAST(String) void PrintOn(FILE* out); // For use during stack traces. Performs rudimentary sanity check. bool LooksValid(); // Dispatched behavior. void StringShortPrint(StringStream* accumulator); void PrintUC16(std::ostream& os, int start = 0, int end = -1); // NOLINT #if defined(DEBUG) || defined(OBJECT_PRINT) char* ToAsciiArray(); #endif DECLARE_PRINTER(String) DECLARE_VERIFIER(String) inline bool IsFlat(); // Layout description. static const int kLengthOffset = Name::kSize; static const int kSize = kLengthOffset + kPointerSize; // Maximum number of characters to consider when trying to convert a string // value into an array index. static const int kMaxArrayIndexSize = 10; STATIC_ASSERT(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits)); // Max char codes. static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar; static const uint32_t kMaxOneByteCharCodeU = unibrow::Latin1::kMaxChar; static const int kMaxUtf16CodeUnit = 0xffff; static const uint32_t kMaxUtf16CodeUnitU = kMaxUtf16CodeUnit; static const uc32 kMaxCodePoint = 0x10ffff; // Value of hash field containing computed hash equal to zero. static const int kEmptyStringHash = kIsNotArrayIndexMask; // Maximal string length. static const int kMaxLength = (1 << 28) - 16; // Max length for computing hash. For strings longer than this limit the // string length is used as the hash value. static const int kMaxHashCalcLength = 16383; // Limit for truncation in short printing. static const int kMaxShortPrintLength = 1024; // Support for regular expressions. const uc16* GetTwoByteData(unsigned start); // Helper function for flattening strings. template <typename sinkchar> static void WriteToFlat(String* source, sinkchar* sink, int from, int to); // The return value may point to the first aligned word containing the first // non-one-byte character, rather than directly to the non-one-byte character. // If the return value is >= the passed length, the entire string was // one-byte. static inline int NonAsciiStart(const char* chars, int length) { const char* start = chars; const char* limit = chars + length; if (length >= kIntptrSize) { // Check unaligned bytes. while (!IsAligned(reinterpret_cast<intptr_t>(chars), sizeof(uintptr_t))) { if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) { return static_cast<int>(chars - start); } ++chars; } // Check aligned words. DCHECK(unibrow::Utf8::kMaxOneByteChar == 0x7F); const uintptr_t non_one_byte_mask = kUintptrAllBitsSet / 0xFF * 0x80; while (chars + sizeof(uintptr_t) <= limit) { if (*reinterpret_cast<const uintptr_t*>(chars) & non_one_byte_mask) { return static_cast<int>(chars - start); } chars += sizeof(uintptr_t); } } // Check remaining unaligned bytes. while (chars < limit) { if (static_cast<uint8_t>(*chars) > unibrow::Utf8::kMaxOneByteChar) { return static_cast<int>(chars - start); } ++chars; } return static_cast<int>(chars - start); } static inline bool IsAscii(const char* chars, int length) { return NonAsciiStart(chars, length) >= length; } static inline bool IsAscii(const uint8_t* chars, int length) { return NonAsciiStart(reinterpret_cast<const char*>(chars), length) >= length; } static inline int NonOneByteStart(const uc16* chars, int length) { const uc16* limit = chars + length; const uc16* start = chars; while (chars < limit) { if (*chars > kMaxOneByteCharCodeU) return static_cast<int>(chars - start); ++chars; } return static_cast<int>(chars - start); } static inline bool IsOneByte(const uc16* chars, int length) { return NonOneByteStart(chars, length) >= length; } template<class Visitor> static inline ConsString* VisitFlat(Visitor* visitor, String* string, int offset = 0); static Handle<FixedArray> CalculateLineEnds(Handle<String> string, bool include_ending_line); // Use the hash field to forward to the canonical internalized string // when deserializing an internalized string. inline void SetForwardedInternalizedString(String* string); inline String* GetForwardedInternalizedString(); private: friend class Name; friend class StringTableInsertionKey; static Handle<String> SlowFlatten(Handle<ConsString> cons, PretenureFlag tenure); // Slow case of String::Equals. This implementation works on any strings // but it is most efficient on strings that are almost flat. bool SlowEquals(String* other); static bool SlowEquals(Handle<String> one, Handle<String> two); // Slow case of AsArrayIndex. bool SlowAsArrayIndex(uint32_t* index); // Compute and set the hash code. uint32_t ComputeAndSetHash(); DISALLOW_IMPLICIT_CONSTRUCTORS(String); }; // The SeqString abstract class captures sequential string values. class SeqString: public String { public: DECLARE_CAST(SeqString) // Layout description. static const int kHeaderSize = String::kSize; // Truncate the string in-place if possible and return the result. // In case of new_length == 0, the empty string is returned without // truncating the original string. MUST_USE_RESULT static Handle<String> Truncate(Handle<SeqString> string, int new_length); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString); }; // The OneByteString class captures sequential one-byte string objects. // Each character in the OneByteString is an one-byte character. class SeqOneByteString: public SeqString { public: static const bool kHasOneByteEncoding = true; // Dispatched behavior. inline uint16_t SeqOneByteStringGet(int index); inline void SeqOneByteStringSet(int index, uint16_t value); // Get the address of the characters in this string. inline Address GetCharsAddress(); inline uint8_t* GetChars(); DECLARE_CAST(SeqOneByteString) // Garbage collection support. This method is called by the // garbage collector to compute the actual size of an OneByteString // instance. inline int SeqOneByteStringSize(InstanceType instance_type); // Computes the size for an OneByteString instance of a given length. static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize); } // Maximal memory usage for a single sequential one-byte string. static const int kMaxSize = 512 * MB - 1; STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString); }; // The TwoByteString class captures sequential unicode string objects. // Each character in the TwoByteString is a two-byte uint16_t. class SeqTwoByteString: public SeqString { public: static const bool kHasOneByteEncoding = false; // Dispatched behavior. inline uint16_t SeqTwoByteStringGet(int index); inline void SeqTwoByteStringSet(int index, uint16_t value); // Get the address of the characters in this string. inline Address GetCharsAddress(); inline uc16* GetChars(); // For regexp code. const uint16_t* SeqTwoByteStringGetData(unsigned start); DECLARE_CAST(SeqTwoByteString) // Garbage collection support. This method is called by the // garbage collector to compute the actual size of a TwoByteString // instance. inline int SeqTwoByteStringSize(InstanceType instance_type); // Computes the size for a TwoByteString instance of a given length. static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize); } // Maximal memory usage for a single sequential two-byte string. static const int kMaxSize = 512 * MB - 1; STATIC_ASSERT(static_cast<int>((kMaxSize - kHeaderSize)/sizeof(uint16_t)) >= String::kMaxLength); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString); }; // The ConsString class describes string values built by using the // addition operator on strings. A ConsString is a pair where the // first and second components are pointers to other string values. // One or both components of a ConsString can be pointers to other // ConsStrings, creating a binary tree of ConsStrings where the leaves // are non-ConsString string values. The string value represented by // a ConsString can be obtained by concatenating the leaf string // values in a left-to-right depth-first traversal of the tree. class ConsString: public String { public: // First string of the cons cell. inline String* first(); // Doesn't check that the result is a string, even in debug mode. This is // useful during GC where the mark bits confuse the checks. inline Object* unchecked_first(); inline void set_first(String* first, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Second string of the cons cell. inline String* second(); // Doesn't check that the result is a string, even in debug mode. This is // useful during GC where the mark bits confuse the checks. inline Object* unchecked_second(); inline void set_second(String* second, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Dispatched behavior. uint16_t ConsStringGet(int index); DECLARE_CAST(ConsString) // Layout description. static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kSecondOffset = kFirstOffset + kPointerSize; static const int kSize = kSecondOffset + kPointerSize; // Minimum length for a cons string. static const int kMinLength = 13; typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize> BodyDescriptor; DECLARE_VERIFIER(ConsString) private: DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString); }; // The Sliced String class describes strings that are substrings of another // sequential string. The motivation is to save time and memory when creating // a substring. A Sliced String is described as a pointer to the parent, // the offset from the start of the parent string and the length. Using // a Sliced String therefore requires unpacking of the parent string and // adding the offset to the start address. A substring of a Sliced String // are not nested since the double indirection is simplified when creating // such a substring. // Currently missing features are: // - handling externalized parent strings // - external strings as parent // - truncating sliced string to enable otherwise unneeded parent to be GC'ed. class SlicedString: public String { public: inline String* parent(); inline void set_parent(String* parent, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); inline int offset() const; inline void set_offset(int offset); // Dispatched behavior. uint16_t SlicedStringGet(int index); DECLARE_CAST(SlicedString) // Layout description. static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kOffsetOffset = kParentOffset + kPointerSize; static const int kSize = kOffsetOffset + kPointerSize; // Minimum length for a sliced string. static const int kMinLength = 13; typedef FixedBodyDescriptor<kParentOffset, kOffsetOffset + kPointerSize, kSize> BodyDescriptor; DECLARE_VERIFIER(SlicedString) private: DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString); }; // The ExternalString class describes string values that are backed by // a string resource that lies outside the V8 heap. ExternalStrings // consist of the length field common to all strings, a pointer to the // external resource. It is important to ensure (externally) that the // resource is not deallocated while the ExternalString is live in the // V8 heap. // // The API expects that all ExternalStrings are created through the // API. Therefore, ExternalStrings should not be used internally. class ExternalString: public String { public: DECLARE_CAST(ExternalString) // Layout description. static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kShortSize = kResourceOffset + kPointerSize; static const int kResourceDataOffset = kResourceOffset + kPointerSize; static const int kSize = kResourceDataOffset + kPointerSize; static const int kMaxShortLength = (kShortSize - SeqString::kHeaderSize) / kCharSize; // Return whether external string is short (data pointer is not cached). inline bool is_short(); STATIC_ASSERT(kResourceOffset == Internals::kStringResourceOffset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString); }; // The ExternalOneByteString class is an external string backed by an // one-byte string. class ExternalOneByteString : public ExternalString { public: static const bool kHasOneByteEncoding = true; typedef v8::String::ExternalOneByteStringResource Resource; // The underlying resource. inline const Resource* resource(); inline void set_resource(const Resource* buffer); // Update the pointer cache to the external character array. // The cached pointer is always valid, as the external character array does = // not move during lifetime. Deserialization is the only exception, after // which the pointer cache has to be refreshed. inline void update_data_cache(); inline const uint8_t* GetChars(); // Dispatched behavior. inline uint16_t ExternalOneByteStringGet(int index); DECLARE_CAST(ExternalOneByteString) class BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString); }; // The ExternalTwoByteString class is an external string backed by a UTF-16 // encoded string. class ExternalTwoByteString: public ExternalString { public: static const bool kHasOneByteEncoding = false; typedef v8::String::ExternalStringResource Resource; // The underlying string resource. inline const Resource* resource(); inline void set_resource(const Resource* buffer); // Update the pointer cache to the external character array. // The cached pointer is always valid, as the external character array does = // not move during lifetime. Deserialization is the only exception, after // which the pointer cache has to be refreshed. inline void update_data_cache(); inline const uint16_t* GetChars(); // Dispatched behavior. inline uint16_t ExternalTwoByteStringGet(int index); // For regexp code. inline const uint16_t* ExternalTwoByteStringGetData(unsigned start); DECLARE_CAST(ExternalTwoByteString) class BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString); }; // Utility superclass for stack-allocated objects that must be updated // on gc. It provides two ways for the gc to update instances, either // iterating or updating after gc. class Relocatable BASE_EMBEDDED { public: explicit inline Relocatable(Isolate* isolate); inline virtual ~Relocatable(); virtual void IterateInstance(ObjectVisitor* v) { } virtual void PostGarbageCollection() { } static void PostGarbageCollectionProcessing(Isolate* isolate); static int ArchiveSpacePerThread(); static char* ArchiveState(Isolate* isolate, char* to); static char* RestoreState(Isolate* isolate, char* from); static void Iterate(Isolate* isolate, ObjectVisitor* v); static void Iterate(ObjectVisitor* v, Relocatable* top); static char* Iterate(ObjectVisitor* v, char* t); private: Isolate* isolate_; Relocatable* prev_; }; // A flat string reader provides random access to the contents of a // string independent of the character width of the string. The handle // must be valid as long as the reader is being used. class FlatStringReader : public Relocatable { public: FlatStringReader(Isolate* isolate, Handle<String> str); FlatStringReader(Isolate* isolate, Vector<const char> input); void PostGarbageCollection(); inline uc32 Get(int index); template <typename Char> inline Char Get(int index); int length() { return length_; } private: String** str_; bool is_one_byte_; int length_; const void* start_; }; // This maintains an off-stack representation of the stack frames required // to traverse a ConsString, allowing an entirely iterative and restartable // traversal of the entire string class ConsStringIterator { public: inline ConsStringIterator() {} inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) { Reset(cons_string, offset); } inline void Reset(ConsString* cons_string, int offset = 0) { depth_ = 0; // Next will always return NULL. if (cons_string == NULL) return; Initialize(cons_string, offset); } // Returns NULL when complete. inline String* Next(int* offset_out) { *offset_out = 0; if (depth_ == 0) return NULL; return Continue(offset_out); } private: static const int kStackSize = 32; // Use a mask instead of doing modulo operations for stack wrapping. static const int kDepthMask = kStackSize-1; STATIC_ASSERT(IS_POWER_OF_TWO(kStackSize)); static inline int OffsetForDepth(int depth); inline void PushLeft(ConsString* string); inline void PushRight(ConsString* string); inline void AdjustMaximumDepth(); inline void Pop(); inline bool StackBlown() { return maximum_depth_ - depth_ == kStackSize; } void Initialize(ConsString* cons_string, int offset); String* Continue(int* offset_out); String* NextLeaf(bool* blew_stack); String* Search(int* offset_out); // Stack must always contain only frames for which right traversal // has not yet been performed. ConsString* frames_[kStackSize]; ConsString* root_; int depth_; int maximum_depth_; int consumed_; DISALLOW_COPY_AND_ASSIGN(ConsStringIterator); }; class StringCharacterStream { public: inline StringCharacterStream(String* string, int offset = 0); inline uint16_t GetNext(); inline bool HasMore(); inline void Reset(String* string, int offset = 0); inline void VisitOneByteString(const uint8_t* chars, int length); inline void VisitTwoByteString(const uint16_t* chars, int length); private: ConsStringIterator iter_; bool is_one_byte_; union { const uint8_t* buffer8_; const uint16_t* buffer16_; }; const uint8_t* end_; DISALLOW_COPY_AND_ASSIGN(StringCharacterStream); }; template <typename T> class VectorIterator { public: VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { } explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { } T GetNext() { return data_[index_++]; } bool has_more() { return index_ < data_.length(); } private: Vector<const T> data_; int index_; }; // The Oddball describes objects null, undefined, true, and false. class Oddball: public HeapObject { public: // [to_string]: Cached to_string computed at startup. DECL_ACCESSORS(to_string, String) // [to_number]: Cached to_number computed at startup. DECL_ACCESSORS(to_number, Object) // [typeof]: Cached type_of computed at startup. DECL_ACCESSORS(type_of, String) inline byte kind() const; inline void set_kind(byte kind); // ES6 section 7.1.3 ToNumber for Boolean, Null, Undefined. MUST_USE_RESULT static inline Handle<Object> ToNumber(Handle<Oddball> input); DECLARE_CAST(Oddball) // Dispatched behavior. DECLARE_VERIFIER(Oddball) // Initialize the fields. static void Initialize(Isolate* isolate, Handle<Oddball> oddball, const char* to_string, Handle<Object> to_number, const char* type_of, byte kind); // Layout description. static const int kToStringOffset = HeapObject::kHeaderSize; static const int kToNumberOffset = kToStringOffset + kPointerSize; static const int kTypeOfOffset = kToNumberOffset + kPointerSize; static const int kKindOffset = kTypeOfOffset + kPointerSize; static const int kSize = kKindOffset + kPointerSize; static const byte kFalse = 0; static const byte kTrue = 1; static const byte kNotBooleanMask = ~1; static const byte kTheHole = 2; static const byte kNull = 3; static const byte kArgumentMarker = 4; static const byte kUndefined = 5; static const byte kUninitialized = 6; static const byte kOther = 7; static const byte kException = 8; typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize, kSize> BodyDescriptor; STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset); STATIC_ASSERT(kNull == Internals::kNullOddballKind); STATIC_ASSERT(kUndefined == Internals::kUndefinedOddballKind); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball); }; class Cell: public HeapObject { public: // [value]: value of the cell. DECL_ACCESSORS(value, Object) DECLARE_CAST(Cell) static inline Cell* FromValueAddress(Address value) { Object* result = FromAddress(value - kValueOffset); return static_cast<Cell*>(result); } inline Address ValueAddress() { return address() + kValueOffset; } // Dispatched behavior. DECLARE_PRINTER(Cell) DECLARE_VERIFIER(Cell) // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; typedef FixedBodyDescriptor<kValueOffset, kValueOffset + kPointerSize, kSize> BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Cell); }; class PropertyCell : public HeapObject { public: // [property_details]: details of the global property. DECL_ACCESSORS(property_details_raw, Object) // [value]: value of the global property. DECL_ACCESSORS(value, Object) // [dependent_code]: dependent code that depends on the type of the global // property. DECL_ACCESSORS(dependent_code, DependentCode) inline PropertyDetails property_details(); inline void set_property_details(PropertyDetails details); PropertyCellConstantType GetConstantType(); // Computes the new type of the cell's contents for the given value, but // without actually modifying the details. static PropertyCellType UpdatedType(Handle<PropertyCell> cell, Handle<Object> value, PropertyDetails details); static void UpdateCell(Handle<GlobalDictionary> dictionary, int entry, Handle<Object> value, PropertyDetails details); static Handle<PropertyCell> InvalidateEntry( Handle<GlobalDictionary> dictionary, int entry); static void SetValueWithInvalidation(Handle<PropertyCell> cell, Handle<Object> new_value); DECLARE_CAST(PropertyCell) // Dispatched behavior. DECLARE_PRINTER(PropertyCell) DECLARE_VERIFIER(PropertyCell) // Layout description. static const int kDetailsOffset = HeapObject::kHeaderSize; static const int kValueOffset = kDetailsOffset + kPointerSize; static const int kDependentCodeOffset = kValueOffset + kPointerSize; static const int kSize = kDependentCodeOffset + kPointerSize; static const int kPointerFieldsBeginOffset = kValueOffset; static const int kPointerFieldsEndOffset = kSize; typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell); }; class WeakCell : public HeapObject { public: inline Object* value() const; // This should not be called by anyone except GC. inline void clear(); // This should not be called by anyone except allocator. inline void initialize(HeapObject* value); inline bool cleared() const; DECL_ACCESSORS(next, Object) inline void clear_next(Object* the_hole_value); inline bool next_cleared(); DECLARE_CAST(WeakCell) DECLARE_PRINTER(WeakCell) DECLARE_VERIFIER(WeakCell) // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; static const int kNextOffset = kValueOffset + kPointerSize; static const int kSize = kNextOffset + kPointerSize; typedef FixedBodyDescriptor<kValueOffset, kSize, kSize> BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCell); }; // The JSProxy describes EcmaScript Harmony proxies class JSProxy: public JSReceiver { public: MUST_USE_RESULT static MaybeHandle<JSProxy> New(Isolate* isolate, Handle<Object>, Handle<Object>); // [handler]: The handler property. DECL_ACCESSORS(handler, Object) // [target]: The target property. DECL_ACCESSORS(target, JSReceiver) // [hash]: The hash code property (undefined if not initialized yet). DECL_ACCESSORS(hash, Object) static MaybeHandle<Context> GetFunctionRealm(Handle<JSProxy> proxy); DECLARE_CAST(JSProxy) INLINE(bool IsRevoked() const); static void Revoke(Handle<JSProxy> proxy); // ES6 9.5.1 static MaybeHandle<Object> GetPrototype(Handle<JSProxy> receiver); // ES6 9.5.2 MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSProxy> proxy, Handle<Object> value, bool from_javascript, ShouldThrow should_throw); // ES6 9.5.3 MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSProxy> proxy); // ES6 9.5.4 (when passed DONT_THROW) MUST_USE_RESULT static Maybe<bool> PreventExtensions( Handle<JSProxy> proxy, ShouldThrow should_throw); // ES6 9.5.5 MUST_USE_RESULT static Maybe<bool> GetOwnPropertyDescriptor( Isolate* isolate, Handle<JSProxy> proxy, Handle<Name> name, PropertyDescriptor* desc); // ES6 9.5.6 MUST_USE_RESULT static Maybe<bool> DefineOwnProperty( Isolate* isolate, Handle<JSProxy> object, Handle<Object> key, PropertyDescriptor* desc, ShouldThrow should_throw); // ES6 9.5.7 MUST_USE_RESULT static Maybe<bool> HasProperty(Isolate* isolate, Handle<JSProxy> proxy, Handle<Name> name); // ES6 9.5.8 MUST_USE_RESULT static MaybeHandle<Object> GetProperty( Isolate* isolate, Handle<JSProxy> proxy, Handle<Name> name, Handle<Object> receiver, LanguageMode language_mode); // ES6 9.5.9 MUST_USE_RESULT static Maybe<bool> SetProperty(Handle<JSProxy> proxy, Handle<Name> name, Handle<Object> value, Handle<Object> receiver, LanguageMode language_mode); // ES6 9.5.10 (when passed SLOPPY) MUST_USE_RESULT static Maybe<bool> DeletePropertyOrElement( Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode); // ES6 9.5.11 MUST_USE_RESULT static Maybe<bool> Enumerate(Isolate* isolate, Handle<JSReceiver> receiver, Handle<JSProxy> proxy, KeyAccumulator* accumulator); // ES6 9.5.12 MUST_USE_RESULT static Maybe<bool> OwnPropertyKeys( Isolate* isolate, Handle<JSReceiver> receiver, Handle<JSProxy> proxy, PropertyFilter filter, KeyAccumulator* accumulator); MUST_USE_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes( LookupIterator* it); // Dispatched behavior. DECLARE_PRINTER(JSProxy) DECLARE_VERIFIER(JSProxy) // Layout description. static const int kTargetOffset = JSReceiver::kHeaderSize; static const int kHandlerOffset = kTargetOffset + kPointerSize; static const int kHashOffset = kHandlerOffset + kPointerSize; static const int kSize = kHashOffset + kPointerSize; typedef FixedBodyDescriptor<JSReceiver::kPropertiesOffset, kSize, kSize> BodyDescriptor; MUST_USE_RESULT Object* GetIdentityHash(); static Handle<Smi> GetOrCreateIdentityHash(Handle<JSProxy> proxy); private: static Maybe<bool> AddPrivateProperty(Isolate* isolate, Handle<JSProxy> proxy, Handle<Symbol> private_name, PropertyDescriptor* desc, ShouldThrow should_throw); DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy); }; class JSCollection : public JSObject { public: // [table]: the backing hash table DECL_ACCESSORS(table, Object) static const int kTableOffset = JSObject::kHeaderSize; static const int kSize = kTableOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollection); }; // The JSSet describes EcmaScript Harmony sets class JSSet : public JSCollection { public: DECLARE_CAST(JSSet) static void Initialize(Handle<JSSet> set, Isolate* isolate); static void Clear(Handle<JSSet> set); // Dispatched behavior. DECLARE_PRINTER(JSSet) DECLARE_VERIFIER(JSSet) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet); }; // The JSMap describes EcmaScript Harmony maps class JSMap : public JSCollection { public: DECLARE_CAST(JSMap) static void Initialize(Handle<JSMap> map, Isolate* isolate); static void Clear(Handle<JSMap> map); // Dispatched behavior. DECLARE_PRINTER(JSMap) DECLARE_VERIFIER(JSMap) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap); }; // OrderedHashTableIterator is an iterator that iterates over the keys and // values of an OrderedHashTable. // // The iterator has a reference to the underlying OrderedHashTable data, // [table], as well as the current [index] the iterator is at. // // When the OrderedHashTable is rehashed it adds a reference from the old table // to the new table as well as storing enough data about the changes so that the // iterator [index] can be adjusted accordingly. // // When the [Next] result from the iterator is requested, the iterator checks if // there is a newer table that it needs to transition to. template<class Derived, class TableType> class OrderedHashTableIterator: public JSObject { public: // [table]: the backing hash table mapping keys to values. DECL_ACCESSORS(table, Object) // [index]: The index into the data table. DECL_ACCESSORS(index, Object) // [kind]: The kind of iteration this is. One of the [Kind] enum values. DECL_ACCESSORS(kind, Object) #ifdef OBJECT_PRINT void OrderedHashTableIteratorPrint(std::ostream& os); // NOLINT #endif static const int kTableOffset = JSObject::kHeaderSize; static const int kIndexOffset = kTableOffset + kPointerSize; static const int kKindOffset = kIndexOffset + kPointerSize; static const int kSize = kKindOffset + kPointerSize; enum Kind { kKindKeys = 1, kKindValues = 2, kKindEntries = 3 }; // Whether the iterator has more elements. This needs to be called before // calling |CurrentKey| and/or |CurrentValue|. bool HasMore(); // Move the index forward one. void MoveNext() { set_index(Smi::FromInt(Smi::cast(index())->value() + 1)); } // Populates the array with the next key and value and then moves the iterator // forward. // This returns the |kind| or 0 if the iterator is already at the end. Smi* Next(JSArray* value_array); // Returns the current key of the iterator. This should only be called when // |HasMore| returns true. inline Object* CurrentKey(); private: // Transitions the iterator to the non obsolete backing store. This is a NOP // if the [table] is not obsolete. void Transition(); DISALLOW_IMPLICIT_CONSTRUCTORS(OrderedHashTableIterator); }; class JSSetIterator: public OrderedHashTableIterator<JSSetIterator, OrderedHashSet> { public: // Dispatched behavior. DECLARE_PRINTER(JSSetIterator) DECLARE_VERIFIER(JSSetIterator) DECLARE_CAST(JSSetIterator) // Called by |Next| to populate the array. This allows the subclasses to // populate the array differently. inline void PopulateValueArray(FixedArray* array); private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSSetIterator); }; class JSMapIterator: public OrderedHashTableIterator<JSMapIterator, OrderedHashMap> { public: // Dispatched behavior. DECLARE_PRINTER(JSMapIterator) DECLARE_VERIFIER(JSMapIterator) DECLARE_CAST(JSMapIterator) // Called by |Next| to populate the array. This allows the subclasses to // populate the array differently. inline void PopulateValueArray(FixedArray* array); private: // Returns the current value of the iterator. This should only be called when // |HasMore| returns true. inline Object* CurrentValue(); DISALLOW_IMPLICIT_CONSTRUCTORS(JSMapIterator); }; // Base class for both JSWeakMap and JSWeakSet class JSWeakCollection: public JSObject { public: // [table]: the backing hash table mapping keys to values. DECL_ACCESSORS(table, Object) // [next]: linked list of encountered weak maps during GC. DECL_ACCESSORS(next, Object) static void Initialize(Handle<JSWeakCollection> collection, Isolate* isolate); static void Set(Handle<JSWeakCollection> collection, Handle<Object> key, Handle<Object> value, int32_t hash); static bool Delete(Handle<JSWeakCollection> collection, Handle<Object> key, int32_t hash); static const int kTableOffset = JSObject::kHeaderSize; static const int kNextOffset = kTableOffset + kPointerSize; static const int kSize = kNextOffset + kPointerSize; // Visiting policy defines whether the table and next collection fields // should be visited or not. enum BodyVisitingPolicy { kVisitStrong, kVisitWeak }; // Iterates the function object according to the visiting policy. template <BodyVisitingPolicy> class BodyDescriptorImpl; // Visit the whole object. typedef BodyDescriptorImpl<kVisitStrong> BodyDescriptor; // Don't visit table and next collection fields. typedef BodyDescriptorImpl<kVisitWeak> BodyDescriptorWeak; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection); }; // The JSWeakMap describes EcmaScript Harmony weak maps class JSWeakMap: public JSWeakCollection { public: DECLARE_CAST(JSWeakMap) // Dispatched behavior. DECLARE_PRINTER(JSWeakMap) DECLARE_VERIFIER(JSWeakMap) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap); }; // The JSWeakSet describes EcmaScript Harmony weak sets class JSWeakSet: public JSWeakCollection { public: DECLARE_CAST(JSWeakSet) // Dispatched behavior. DECLARE_PRINTER(JSWeakSet) DECLARE_VERIFIER(JSWeakSet) private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet); }; // Whether a JSArrayBuffer is a SharedArrayBuffer or not. enum class SharedFlag { kNotShared, kShared }; class JSArrayBuffer: public JSObject { public: // [backing_store]: backing memory for this array DECL_ACCESSORS(backing_store, void) // [byte_length]: length in bytes DECL_ACCESSORS(byte_length, Object) inline uint32_t bit_field() const; inline void set_bit_field(uint32_t bits); inline bool is_external(); inline void set_is_external(bool value); inline bool is_neuterable(); inline void set_is_neuterable(bool value); inline bool was_neutered(); inline void set_was_neutered(bool value); inline bool is_shared(); inline void set_is_shared(bool value); DECLARE_CAST(JSArrayBuffer) void Neuter(); static void Setup(Handle<JSArrayBuffer> array_buffer, Isolate* isolate, bool is_external, void* data, size_t allocated_length, SharedFlag shared = SharedFlag::kNotShared); static bool SetupAllocatingData(Handle<JSArrayBuffer> array_buffer, Isolate* isolate, size_t allocated_length, bool initialize = true, SharedFlag shared = SharedFlag::kNotShared); // Dispatched behavior. DECLARE_PRINTER(JSArrayBuffer) DECLARE_VERIFIER(JSArrayBuffer) static const int kByteLengthOffset = JSObject::kHeaderSize; static const int kBackingStoreOffset = kByteLengthOffset + kPointerSize; static const int kBitFieldSlot = kBackingStoreOffset + kPointerSize; #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT static const int kBitFieldOffset = kBitFieldSlot; #else static const int kBitFieldOffset = kBitFieldSlot + kIntSize; #endif static const int kSize = kBitFieldSlot + kPointerSize; static const int kSizeWithInternalFields = kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize; // Iterates all fields in the object including internal ones except // kBackingStoreOffset and kBitFieldSlot. class BodyDescriptor; class IsExternal : public BitField<bool, 1, 1> {}; class IsNeuterable : public BitField<bool, 2, 1> {}; class WasNeutered : public BitField<bool, 3, 1> {}; class IsShared : public BitField<bool, 4, 1> {}; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer); }; class JSArrayBufferView: public JSObject { public: // [buffer]: ArrayBuffer that this typed array views. DECL_ACCESSORS(buffer, Object) // [byte_offset]: offset of typed array in bytes. DECL_ACCESSORS(byte_offset, Object) // [byte_length]: length of typed array in bytes. DECL_ACCESSORS(byte_length, Object) DECLARE_CAST(JSArrayBufferView) DECLARE_VERIFIER(JSArrayBufferView) inline bool WasNeutered() const; static const int kBufferOffset = JSObject::kHeaderSize; static const int kByteOffsetOffset = kBufferOffset + kPointerSize; static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize; static const int kViewSize = kByteLengthOffset + kPointerSize; private: #ifdef VERIFY_HEAP DECL_ACCESSORS(raw_byte_offset, Object) DECL_ACCESSORS(raw_byte_length, Object) #endif DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView); }; class JSTypedArray: public JSArrayBufferView { public: // [length]: length of typed array in elements. DECL_ACCESSORS(length, Object) inline uint32_t length_value() const; DECLARE_CAST(JSTypedArray) ExternalArrayType type(); size_t element_size(); Handle<JSArrayBuffer> GetBuffer(); // Dispatched behavior. DECLARE_PRINTER(JSTypedArray) DECLARE_VERIFIER(JSTypedArray) static const int kLengthOffset = kViewSize + kPointerSize; static const int kSize = kLengthOffset + kPointerSize; static const int kSizeWithInternalFields = kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize; private: static Handle<JSArrayBuffer> MaterializeArrayBuffer( Handle<JSTypedArray> typed_array); #ifdef VERIFY_HEAP DECL_ACCESSORS(raw_length, Object) #endif DISALLOW_IMPLICIT_CONSTRUCTORS(JSTypedArray); }; class JSDataView: public JSArrayBufferView { public: DECLARE_CAST(JSDataView) // Dispatched behavior. DECLARE_PRINTER(JSDataView) DECLARE_VERIFIER(JSDataView) static const int kSize = kViewSize; static const int kSizeWithInternalFields = kSize + v8::ArrayBufferView::kInternalFieldCount * kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataView); }; // Foreign describes objects pointing from JavaScript to C structures. class Foreign: public HeapObject { public: // [address]: field containing the address. inline Address foreign_address(); inline void set_foreign_address(Address value); DECLARE_CAST(Foreign) // Dispatched behavior. DECLARE_PRINTER(Foreign) DECLARE_VERIFIER(Foreign) // Layout description. static const int kForeignAddressOffset = HeapObject::kHeaderSize; static const int kSize = kForeignAddressOffset + kPointerSize; STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset); class BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign); }; // The JSArray describes JavaScript Arrays // Such an array can be in one of two modes: // - fast, backing storage is a FixedArray and length <= elements.length(); // Please note: push and pop can be used to grow and shrink the array. // - slow, backing storage is a HashTable with numbers as keys. class JSArray: public JSObject { public: // [length]: The length property. DECL_ACCESSORS(length, Object) // Overload the length setter to skip write barrier when the length // is set to a smi. This matches the set function on FixedArray. inline void set_length(Smi* length); static bool HasReadOnlyLength(Handle<JSArray> array); static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index); // Initialize the array with the given capacity. The function may // fail due to out-of-memory situations, but only if the requested // capacity is non-zero. static void Initialize(Handle<JSArray> array, int capacity, int length = 0); // If the JSArray has fast elements, and new_length would result in // normalization, returns true. bool SetLengthWouldNormalize(uint32_t new_length); static inline bool SetLengthWouldNormalize(Heap* heap, uint32_t new_length); // Initializes the array to a certain length. inline bool AllowsSetLength(); static void SetLength(Handle<JSArray> array, uint32_t length); // Same as above but will also queue splice records if |array| is observed. static MaybeHandle<Object> ObservableSetLength(Handle<JSArray> array, uint32_t length); // Set the content of the array to the content of storage. static inline void SetContent(Handle<JSArray> array, Handle<FixedArrayBase> storage); // ES6 9.4.2.1 MUST_USE_RESULT static Maybe<bool> DefineOwnProperty( Isolate* isolate, Handle<JSArray> o, Handle<Object> name, PropertyDescriptor* desc, ShouldThrow should_throw); static bool AnythingToArrayLength(Isolate* isolate, Handle<Object> length_object, uint32_t* output); MUST_USE_RESULT static Maybe<bool> ArraySetLength(Isolate* isolate, Handle<JSArray> a, PropertyDescriptor* desc, ShouldThrow should_throw); DECLARE_CAST(JSArray) // Dispatched behavior. DECLARE_PRINTER(JSArray) DECLARE_VERIFIER(JSArray) // Number of element slots to pre-allocate for an empty array. static const int kPreallocatedArrayElements = 4; // Layout description. static const int kLengthOffset = JSObject::kHeaderSize; static const int kSize = kLengthOffset + kPointerSize; // 600 * KB is the Page::kMaxRegularHeapObjectSize defined in spaces.h which // we do not want to include in objects.h // Note that Page::kMaxRegularHeapObjectSize has to be in sync with // kInitialMaxFastElementArray which is checked in a DCHECK in heap.cc. static const int kInitialMaxFastElementArray = (600 * KB - FixedArray::kHeaderSize - kSize - AllocationMemento::kSize) / kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray); }; Handle<Object> CacheInitialJSArrayMaps(Handle<Context> native_context, Handle<Map> initial_map); // JSRegExpResult is just a JSArray with a specific initial map. // This initial map adds in-object properties for "index" and "input" // properties, as assigned by RegExp.prototype.exec, which allows // faster creation of RegExp exec results. // This class just holds constants used when creating the result. // After creation the result must be treated as a JSArray in all regards. class JSRegExpResult: public JSArray { public: // Offsets of object fields. static const int kIndexOffset = JSArray::kSize; static const int kInputOffset = kIndexOffset + kPointerSize; static const int kSize = kInputOffset + kPointerSize; // Indices of in-object properties. static const int kIndexIndex = 0; static const int kInputIndex = 1; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult); }; // An accessor must have a getter, but can have no setter. // // When setting a property, V8 searches accessors in prototypes. // If an accessor was found and it does not have a setter, // the request is ignored. // // If the accessor in the prototype has the READ_ONLY property attribute, then // a new value is added to the derived object when the property is set. // This shadows the accessor in the prototype. class AccessorInfo: public Struct { public: DECL_ACCESSORS(name, Object) DECL_INT_ACCESSORS(flag) DECL_ACCESSORS(expected_receiver_type, Object) DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) DECL_ACCESSORS(data, Object) // Dispatched behavior. DECLARE_PRINTER(AccessorInfo) inline bool all_can_read(); inline void set_all_can_read(bool value); inline bool all_can_write(); inline void set_all_can_write(bool value); inline bool is_special_data_property(); inline void set_is_special_data_property(bool value); inline PropertyAttributes property_attributes(); inline void set_property_attributes(PropertyAttributes attributes); // Checks whether the given receiver is compatible with this accessor. static bool IsCompatibleReceiverMap(Isolate* isolate, Handle<AccessorInfo> info, Handle<Map> map); inline bool IsCompatibleReceiver(Object* receiver); DECLARE_CAST(AccessorInfo) // Dispatched behavior. DECLARE_VERIFIER(AccessorInfo) // Append all descriptors to the array that are not already there. // Return number added. static int AppendUnique(Handle<Object> descriptors, Handle<FixedArray> array, int valid_descriptors); static const int kNameOffset = HeapObject::kHeaderSize; static const int kFlagOffset = kNameOffset + kPointerSize; static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize; static const int kGetterOffset = kExpectedReceiverTypeOffset + kPointerSize; static const int kSetterOffset = kGetterOffset + kPointerSize; static const int kDataOffset = kSetterOffset + kPointerSize; static const int kSize = kDataOffset + kPointerSize; private: inline bool HasExpectedReceiverType(); // Bit positions in flag. static const int kAllCanReadBit = 0; static const int kAllCanWriteBit = 1; static const int kSpecialDataProperty = 2; class AttributesField : public BitField<PropertyAttributes, 3, 3> {}; DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo); }; // Support for JavaScript accessors: A pair of a getter and a setter. Each // accessor can either be // * a pointer to a JavaScript function or proxy: a real accessor // * undefined: considered an accessor by the spec, too, strangely enough // * the hole: an accessor which has not been set // * a pointer to a map: a transition used to ensure map sharing class AccessorPair: public Struct { public: DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) DECLARE_CAST(AccessorPair) static Handle<AccessorPair> Copy(Handle<AccessorPair> pair); inline Object* get(AccessorComponent component); inline void set(AccessorComponent component, Object* value); // Note: Returns undefined instead in case of a hole. Object* GetComponent(AccessorComponent component); // Set both components, skipping arguments which are a JavaScript null. inline void SetComponents(Object* getter, Object* setter); inline bool Equals(AccessorPair* pair); inline bool Equals(Object* getter_value, Object* setter_value); inline bool ContainsAccessor(); // Dispatched behavior. DECLARE_PRINTER(AccessorPair) DECLARE_VERIFIER(AccessorPair) static const int kGetterOffset = HeapObject::kHeaderSize; static const int kSetterOffset = kGetterOffset + kPointerSize; static const int kSize = kSetterOffset + kPointerSize; private: // Strangely enough, in addition to functions and harmony proxies, the spec // requires us to consider undefined as a kind of accessor, too: // var obj = {}; // Object.defineProperty(obj, "foo", {get: undefined}); // assertTrue("foo" in obj); inline bool IsJSAccessor(Object* obj); DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair); }; class AccessCheckInfo: public Struct { public: DECL_ACCESSORS(named_callback, Object) DECL_ACCESSORS(indexed_callback, Object) DECL_ACCESSORS(callback, Object) DECL_ACCESSORS(data, Object) DECLARE_CAST(AccessCheckInfo) // Dispatched behavior. DECLARE_PRINTER(AccessCheckInfo) DECLARE_VERIFIER(AccessCheckInfo) static const int kNamedCallbackOffset = HeapObject::kHeaderSize; static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize; static const int kCallbackOffset = kIndexedCallbackOffset + kPointerSize; static const int kDataOffset = kCallbackOffset + kPointerSize; static const int kSize = kDataOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo); }; class InterceptorInfo: public Struct { public: DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) DECL_ACCESSORS(query, Object) DECL_ACCESSORS(deleter, Object) DECL_ACCESSORS(enumerator, Object) DECL_ACCESSORS(data, Object) DECL_BOOLEAN_ACCESSORS(can_intercept_symbols) DECL_BOOLEAN_ACCESSORS(all_can_read) DECL_BOOLEAN_ACCESSORS(non_masking) inline int flags() const; inline void set_flags(int flags); DECLARE_CAST(InterceptorInfo) // Dispatched behavior. DECLARE_PRINTER(InterceptorInfo) DECLARE_VERIFIER(InterceptorInfo) static const int kGetterOffset = HeapObject::kHeaderSize; static const int kSetterOffset = kGetterOffset + kPointerSize; static const int kQueryOffset = kSetterOffset + kPointerSize; static const int kDeleterOffset = kQueryOffset + kPointerSize; static const int kEnumeratorOffset = kDeleterOffset + kPointerSize; static const int kDataOffset = kEnumeratorOffset + kPointerSize; static const int kFlagsOffset = kDataOffset + kPointerSize; static const int kSize = kFlagsOffset + kPointerSize; static const int kCanInterceptSymbolsBit = 0; static const int kAllCanReadBit = 1; static const int kNonMasking = 2; private: DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo); }; class CallHandlerInfo: public Struct { public: DECL_ACCESSORS(callback, Object) DECL_ACCESSORS(data, Object) DECL_ACCESSORS(fast_handler, Object) DECLARE_CAST(CallHandlerInfo) // Dispatched behavior. DECLARE_PRINTER(CallHandlerInfo) DECLARE_VERIFIER(CallHandlerInfo) static const int kCallbackOffset = HeapObject::kHeaderSize; static const int kDataOffset = kCallbackOffset + kPointerSize; static const int kFastHandlerOffset = kDataOffset + kPointerSize; static const int kSize = kFastHandlerOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo); }; class TemplateInfo: public Struct { public: DECL_ACCESSORS(tag, Object) DECL_ACCESSORS(serial_number, Object) DECL_INT_ACCESSORS(number_of_properties) DECL_ACCESSORS(property_list, Object) DECL_ACCESSORS(property_accessors, Object) DECLARE_VERIFIER(TemplateInfo) static const int kTagOffset = HeapObject::kHeaderSize; static const int kSerialNumberOffset = kTagOffset + kPointerSize; static const int kNumberOfProperties = kSerialNumberOffset + kPointerSize; static const int kPropertyListOffset = kNumberOfProperties + kPointerSize; static const int kPropertyAccessorsOffset = kPropertyListOffset + kPointerSize; static const int kPropertyIntrinsicsOffset = kPropertyAccessorsOffset + kPointerSize; static const int kHeaderSize = kPropertyIntrinsicsOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo); }; class FunctionTemplateInfo: public TemplateInfo { public: DECL_ACCESSORS(call_code, Object) DECL_ACCESSORS(prototype_template, Object) DECL_ACCESSORS(parent_template, Object) DECL_ACCESSORS(named_property_handler, Object) DECL_ACCESSORS(indexed_property_handler, Object) DECL_ACCESSORS(instance_template, Object) DECL_ACCESSORS(class_name, Object) DECL_ACCESSORS(signature, Object) DECL_ACCESSORS(instance_call_handler, Object) DECL_ACCESSORS(access_check_info, Object) DECL_INT_ACCESSORS(flag) inline int length() const; inline void set_length(int value); // Following properties use flag bits. DECL_BOOLEAN_ACCESSORS(hidden_prototype) DECL_BOOLEAN_ACCESSORS(undetectable) // If the bit is set, object instances created by this function // requires access check. DECL_BOOLEAN_ACCESSORS(needs_access_check) DECL_BOOLEAN_ACCESSORS(read_only_prototype) DECL_BOOLEAN_ACCESSORS(remove_prototype) DECL_BOOLEAN_ACCESSORS(do_not_cache) DECL_BOOLEAN_ACCESSORS(instantiated) DECL_BOOLEAN_ACCESSORS(accept_any_receiver) DECLARE_CAST(FunctionTemplateInfo) // Dispatched behavior. DECLARE_PRINTER(FunctionTemplateInfo) DECLARE_VERIFIER(FunctionTemplateInfo) static const int kCallCodeOffset = TemplateInfo::kHeaderSize; static const int kPrototypeTemplateOffset = kCallCodeOffset + kPointerSize; static const int kParentTemplateOffset = kPrototypeTemplateOffset + kPointerSize; static const int kNamedPropertyHandlerOffset = kParentTemplateOffset + kPointerSize; static const int kIndexedPropertyHandlerOffset = kNamedPropertyHandlerOffset + kPointerSize; static const int kInstanceTemplateOffset = kIndexedPropertyHandlerOffset + kPointerSize; static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize; static const int kSignatureOffset = kClassNameOffset + kPointerSize; static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize; static const int kAccessCheckInfoOffset = kInstanceCallHandlerOffset + kPointerSize; static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize; static const int kLengthOffset = kFlagOffset + kPointerSize; static const int kSize = kLengthOffset + kPointerSize; // Returns true if |object| is an instance of this function template. bool IsTemplateFor(Object* object); bool IsTemplateFor(Map* map); // Returns the holder JSObject if the function can legally be called with this // receiver. Returns Heap::null_value() if the call is illegal. Object* GetCompatibleReceiver(Isolate* isolate, Object* receiver); private: // Bit position in the flag, from least significant bit position. static const int kHiddenPrototypeBit = 0; static const int kUndetectableBit = 1; static const int kNeedsAccessCheckBit = 2; static const int kReadOnlyPrototypeBit = 3; static const int kRemovePrototypeBit = 4; static const int kDoNotCacheBit = 5; static const int kInstantiatedBit = 6; static const int kAcceptAnyReceiver = 7; DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo); }; class ObjectTemplateInfo: public TemplateInfo { public: DECL_ACCESSORS(constructor, Object) DECL_ACCESSORS(internal_field_count, Object) DECLARE_CAST(ObjectTemplateInfo) // Dispatched behavior. DECLARE_PRINTER(ObjectTemplateInfo) DECLARE_VERIFIER(ObjectTemplateInfo) static const int kConstructorOffset = TemplateInfo::kHeaderSize; static const int kInternalFieldCountOffset = kConstructorOffset + kPointerSize; static const int kSize = kInternalFieldCountOffset + kPointerSize; }; // The DebugInfo class holds additional information for a function being // debugged. class DebugInfo: public Struct { public: // The shared function info for the source being debugged. DECL_ACCESSORS(shared, SharedFunctionInfo) // Code object for the patched code. This code object is the code object // currently active for the function. DECL_ACCESSORS(code, Code) // Fixed array holding status information for each active break point. DECL_ACCESSORS(break_points, FixedArray) // Check if there is a break point at a code offset. bool HasBreakPoint(int code_offset); // Get the break point info object for a code offset. Object* GetBreakPointInfo(int code_offset); // Clear a break point. static void ClearBreakPoint(Handle<DebugInfo> debug_info, int code_offset, Handle<Object> break_point_object); // Set a break point. static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_offset, int source_position, int statement_position, Handle<Object> break_point_object); // Get the break point objects for a code offset. Handle<Object> GetBreakPointObjects(int code_offset); // Find the break point info holding this break point object. static Handle<Object> FindBreakPointInfo(Handle<DebugInfo> debug_info, Handle<Object> break_point_object); // Get the number of break points for this function. int GetBreakPointCount(); DECLARE_CAST(DebugInfo) // Dispatched behavior. DECLARE_PRINTER(DebugInfo) DECLARE_VERIFIER(DebugInfo) static const int kSharedFunctionInfoIndex = Struct::kHeaderSize; static const int kCodeIndex = kSharedFunctionInfoIndex + kPointerSize; static const int kBreakPointsStateIndex = kCodeIndex + kPointerSize; static const int kSize = kBreakPointsStateIndex + kPointerSize; static const int kEstimatedNofBreakPointsInFunction = 16; private: static const int kNoBreakPointInfo = -1; // Lookup the index in the break_points array for a code offset. int GetBreakPointInfoIndex(int code_offset); DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo); }; // The BreakPointInfo class holds information for break points set in a // function. The DebugInfo object holds a BreakPointInfo object for each code // position with one or more break points. class BreakPointInfo: public Struct { public: // The code offset for the break point. DECL_INT_ACCESSORS(code_offset) // The position in the source for the break position. DECL_INT_ACCESSORS(source_position) // The position in the source for the last statement before this break // position. DECL_INT_ACCESSORS(statement_position) // List of related JavaScript break points. DECL_ACCESSORS(break_point_objects, Object) // Removes a break point. static void ClearBreakPoint(Handle<BreakPointInfo> info, Handle<Object> break_point_object); // Set a break point. static void SetBreakPoint(Handle<BreakPointInfo> info, Handle<Object> break_point_object); // Check if break point info has this break point object. static bool HasBreakPointObject(Handle<BreakPointInfo> info, Handle<Object> break_point_object); // Get the number of break points for this code offset. int GetBreakPointCount(); DECLARE_CAST(BreakPointInfo) // Dispatched behavior. DECLARE_PRINTER(BreakPointInfo) DECLARE_VERIFIER(BreakPointInfo) static const int kCodeOffsetIndex = Struct::kHeaderSize; static const int kSourcePositionIndex = kCodeOffsetIndex + kPointerSize; static const int kStatementPositionIndex = kSourcePositionIndex + kPointerSize; static const int kBreakPointObjectsIndex = kStatementPositionIndex + kPointerSize; static const int kSize = kBreakPointObjectsIndex + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo); }; #undef DECL_BOOLEAN_ACCESSORS #undef DECL_ACCESSORS #undef DECLARE_CAST #undef DECLARE_VERIFIER #define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \ V(kStringTable, "string_table", "(Internalized strings)") \ V(kExternalStringsTable, "external_strings_table", "(External strings)") \ V(kStrongRootList, "strong_root_list", "(Strong roots)") \ V(kSmiRootList, "smi_root_list", "(Smi roots)") \ V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \ V(kTop, "top", "(Isolate)") \ V(kRelocatable, "relocatable", "(Relocatable)") \ V(kDebug, "debug", "(Debugger)") \ V(kCompilationCache, "compilationcache", "(Compilation cache)") \ V(kHandleScope, "handlescope", "(Handle scope)") \ V(kDispatchTable, "dispatchtable", "(Dispatch table)") \ V(kBuiltins, "builtins", "(Builtins)") \ V(kGlobalHandles, "globalhandles", "(Global handles)") \ V(kEternalHandles, "eternalhandles", "(Eternal handles)") \ V(kThreadManager, "threadmanager", "(Thread manager)") \ V(kStrongRoots, "strong roots", "(Strong roots)") \ V(kExtensions, "Extensions", "(Extensions)") class VisitorSynchronization : public AllStatic { public: #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item, enum SyncTag { VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM) kNumberOfSyncTags }; #undef DECLARE_ENUM static const char* const kTags[kNumberOfSyncTags]; static const char* const kTagNames[kNumberOfSyncTags]; }; // Abstract base class for visiting, and optionally modifying, the // pointers contained in Objects. Used in GC and serialization/deserialization. class ObjectVisitor BASE_EMBEDDED { public: virtual ~ObjectVisitor() {} // Visits a contiguous arrays of pointers in the half-open range // [start, end). Any or all of the values may be modified on return. virtual void VisitPointers(Object** start, Object** end) = 0; // Handy shorthand for visiting a single pointer. virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); } // Visit weak next_code_link in Code object. virtual void VisitNextCodeLink(Object** p) { VisitPointers(p, p + 1); } // To allow lazy clearing of inline caches the visitor has // a rich interface for iterating over Code objects.. // Visits a code target in the instruction stream. virtual void VisitCodeTarget(RelocInfo* rinfo); // Visits a code entry in a JS function. virtual void VisitCodeEntry(Address entry_address); // Visits a global property cell reference in the instruction stream. virtual void VisitCell(RelocInfo* rinfo); // Visits a runtime entry in the instruction stream. virtual void VisitRuntimeEntry(RelocInfo* rinfo) {} // Visits the resource of an one-byte or two-byte string. virtual void VisitExternalOneByteString( v8::String::ExternalOneByteStringResource** resource) {} virtual void VisitExternalTwoByteString( v8::String::ExternalStringResource** resource) {} // Visits a debug call target in the instruction stream. virtual void VisitDebugTarget(RelocInfo* rinfo); // Visits the byte sequence in a function's prologue that contains information // about the code's age. virtual void VisitCodeAgeSequence(RelocInfo* rinfo); // Visit pointer embedded into a code object. virtual void VisitEmbeddedPointer(RelocInfo* rinfo); // Visits an external reference embedded into a code object. virtual void VisitExternalReference(RelocInfo* rinfo); // Visits an external reference. virtual void VisitExternalReference(Address* p) {} // Visits an (encoded) internal reference. virtual void VisitInternalReference(RelocInfo* rinfo) {} // Visits a handle that has an embedder-assigned class ID. virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {} // Intended for serialization/deserialization checking: insert, or // check for the presence of, a tag at this position in the stream. // Also used for marking up GC roots in heap snapshots. virtual void Synchronize(VisitorSynchronization::SyncTag tag) {} }; // BooleanBit is a helper class for setting and getting a bit in an integer. class BooleanBit : public AllStatic { public: static inline bool get(int value, int bit_position) { return (value & (1 << bit_position)) != 0; } static inline int set(int value, int bit_position, bool v) { if (v) { value |= (1 << bit_position); } else { value &= ~(1 << bit_position); } return value; } }; } // NOLINT, false-positive due to second-order macros. } // NOLINT, false-positive due to second-order macros. #endif // V8_OBJECTS_H_