// Copyright 2018 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_ROOTS_ROOTS_H_ #define V8_ROOTS_ROOTS_H_ #include "src/base/macros.h" #include "src/builtins/accessors.h" #include "src/common/globals.h" #include "src/handles/handles.h" #include "src/init/heap-symbols.h" #include "src/objects/objects-definitions.h" #include "src/objects/objects.h" #include "src/objects/slots.h" namespace v8 { namespace internal { // Forward declarations. enum ElementsKind : uint8_t; template class Handle; class Heap; class Isolate; class Map; class PropertyCell; class ReadOnlyHeap; class RootVisitor; class String; class Symbol; // Defines all the read-only roots in Heap. #define STRONG_READ_ONLY_ROOT_LIST(V) \ /* Cluster the most popular ones in a few cache lines here at the top. */ \ /* The first 32 entries are most often used in the startup snapshot and */ \ /* can use a shorter representation in the serialization format. */ \ V(Map, free_space_map, FreeSpaceMap) \ V(Map, one_pointer_filler_map, OnePointerFillerMap) \ V(Map, two_pointer_filler_map, TwoPointerFillerMap) \ V(Oddball, uninitialized_value, UninitializedValue) \ V(Oddball, undefined_value, UndefinedValue) \ V(Oddball, the_hole_value, TheHoleValue) \ V(Oddball, null_value, NullValue) \ V(Oddball, true_value, TrueValue) \ V(Oddball, false_value, FalseValue) \ V(String, empty_string, empty_string) \ V(Map, meta_map, MetaMap) \ V(Map, byte_array_map, ByteArrayMap) \ V(Map, fixed_array_map, FixedArrayMap) \ V(Map, fixed_cow_array_map, FixedCOWArrayMap) \ V(Map, hash_table_map, HashTableMap) \ V(Map, symbol_map, SymbolMap) \ V(Map, one_byte_string_map, OneByteStringMap) \ V(Map, one_byte_internalized_string_map, OneByteInternalizedStringMap) \ V(Map, scope_info_map, ScopeInfoMap) \ V(Map, shared_function_info_map, SharedFunctionInfoMap) \ V(Map, code_map, CodeMap) \ V(Map, cell_map, CellMap) \ V(Map, global_property_cell_map, GlobalPropertyCellMap) \ V(Map, foreign_map, ForeignMap) \ V(Map, heap_number_map, HeapNumberMap) \ V(Map, transition_array_map, TransitionArrayMap) \ V(Map, thin_one_byte_string_map, ThinOneByteStringMap) \ /* TODO(mythria): Once lazy feedback lands, check if feedback vector map */ \ /* is still a popular map */ \ V(Map, feedback_vector_map, FeedbackVectorMap) \ V(ScopeInfo, empty_scope_info, EmptyScopeInfo) \ V(FixedArray, empty_fixed_array, EmptyFixedArray) \ V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray) \ /* Entries beyond the first 32 */ \ /* Oddballs */ \ V(Oddball, arguments_marker, ArgumentsMarker) \ V(Oddball, exception, Exception) \ V(Oddball, termination_exception, TerminationException) \ V(Oddball, optimized_out, OptimizedOut) \ V(Oddball, stale_register, StaleRegister) \ /* Maps */ \ V(Map, script_context_table_map, ScriptContextTableMap) \ V(Map, closure_feedback_cell_array_map, ClosureFeedbackCellArrayMap) \ V(Map, feedback_metadata_map, FeedbackMetadataArrayMap) \ V(Map, array_list_map, ArrayListMap) \ V(Map, bigint_map, BigIntMap) \ V(Map, object_boilerplate_description_map, ObjectBoilerplateDescriptionMap) \ V(Map, bytecode_array_map, BytecodeArrayMap) \ V(Map, code_data_container_map, CodeDataContainerMap) \ V(Map, coverage_info_map, CoverageInfoMap) \ V(Map, fixed_double_array_map, FixedDoubleArrayMap) \ V(Map, global_dictionary_map, GlobalDictionaryMap) \ V(Map, many_closures_cell_map, ManyClosuresCellMap) \ V(Map, mega_dom_handler_map, MegaDomHandlerMap) \ V(Map, module_info_map, ModuleInfoMap) \ V(Map, name_dictionary_map, NameDictionaryMap) \ V(Map, no_closures_cell_map, NoClosuresCellMap) \ V(Map, number_dictionary_map, NumberDictionaryMap) \ V(Map, one_closure_cell_map, OneClosureCellMap) \ V(Map, ordered_hash_map_map, OrderedHashMapMap) \ V(Map, ordered_hash_set_map, OrderedHashSetMap) \ V(Map, name_to_index_hash_table_map, NameToIndexHashTableMap) \ V(Map, registered_symbol_table_map, RegisteredSymbolTableMap) \ V(Map, ordered_name_dictionary_map, OrderedNameDictionaryMap) \ V(Map, preparse_data_map, PreparseDataMap) \ V(Map, property_array_map, PropertyArrayMap) \ V(Map, side_effect_call_handler_info_map, SideEffectCallHandlerInfoMap) \ V(Map, side_effect_free_call_handler_info_map, \ SideEffectFreeCallHandlerInfoMap) \ V(Map, next_call_side_effect_free_call_handler_info_map, \ NextCallSideEffectFreeCallHandlerInfoMap) \ V(Map, simple_number_dictionary_map, SimpleNumberDictionaryMap) \ V(Map, small_ordered_hash_map_map, SmallOrderedHashMapMap) \ V(Map, small_ordered_hash_set_map, SmallOrderedHashSetMap) \ V(Map, small_ordered_name_dictionary_map, SmallOrderedNameDictionaryMap) \ V(Map, source_text_module_map, SourceTextModuleMap) \ V(Map, swiss_name_dictionary_map, SwissNameDictionaryMap) \ V(Map, synthetic_module_map, SyntheticModuleMap) \ IF_WASM(V, Map, wasm_api_function_ref_map, WasmApiFunctionRefMap) \ IF_WASM(V, Map, wasm_capi_function_data_map, WasmCapiFunctionDataMap) \ IF_WASM(V, Map, wasm_exported_function_data_map, \ WasmExportedFunctionDataMap) \ IF_WASM(V, Map, wasm_internal_function_map, WasmInternalFunctionMap) \ IF_WASM(V, Map, wasm_js_function_data_map, WasmJSFunctionDataMap) \ IF_WASM(V, Map, wasm_onfulfilled_data_map, WasmOnFulfilledDataMap) \ IF_WASM(V, Map, wasm_type_info_map, WasmTypeInfoMap) \ V(Map, weak_fixed_array_map, WeakFixedArrayMap) \ V(Map, weak_array_list_map, WeakArrayListMap) \ V(Map, ephemeron_hash_table_map, EphemeronHashTableMap) \ V(Map, embedder_data_array_map, EmbedderDataArrayMap) \ V(Map, weak_cell_map, WeakCellMap) \ /* String maps */ \ V(Map, string_map, StringMap) \ V(Map, cons_one_byte_string_map, ConsOneByteStringMap) \ V(Map, cons_string_map, ConsStringMap) \ V(Map, thin_string_map, ThinStringMap) \ V(Map, sliced_string_map, SlicedStringMap) \ V(Map, sliced_one_byte_string_map, SlicedOneByteStringMap) \ V(Map, external_string_map, ExternalStringMap) \ V(Map, external_one_byte_string_map, ExternalOneByteStringMap) \ V(Map, uncached_external_string_map, UncachedExternalStringMap) \ V(Map, internalized_string_map, InternalizedStringMap) \ V(Map, external_internalized_string_map, ExternalInternalizedStringMap) \ V(Map, external_one_byte_internalized_string_map, \ ExternalOneByteInternalizedStringMap) \ V(Map, uncached_external_internalized_string_map, \ UncachedExternalInternalizedStringMap) \ V(Map, uncached_external_one_byte_internalized_string_map, \ UncachedExternalOneByteInternalizedStringMap) \ V(Map, uncached_external_one_byte_string_map, \ UncachedExternalOneByteStringMap) \ V(Map, shared_one_byte_string_map, SharedOneByteStringMap) \ V(Map, shared_string_map, SharedStringMap) \ V(Map, shared_thin_one_byte_string_map, SharedThinOneByteStringMap) \ V(Map, shared_thin_string_map, SharedThinStringMap) \ V(Map, seq_string_migration_sentinel_map, \ TwoByteSeqStringMigrationSentinelMap) \ V(Map, one_byte_seq_string_migration_sentinel_map, \ OneByteSeqStringMigrationSentinelMap) \ /* Oddball maps */ \ V(Map, undefined_map, UndefinedMap) \ V(Map, the_hole_map, TheHoleMap) \ V(Map, null_map, NullMap) \ V(Map, boolean_map, BooleanMap) \ V(Map, uninitialized_map, UninitializedMap) \ V(Map, arguments_marker_map, ArgumentsMarkerMap) \ V(Map, exception_map, ExceptionMap) \ V(Map, termination_exception_map, TerminationExceptionMap) \ V(Map, optimized_out_map, OptimizedOutMap) \ V(Map, stale_register_map, StaleRegisterMap) \ V(Map, self_reference_marker_map, SelfReferenceMarkerMap) \ V(Map, basic_block_counters_marker_map, BasicBlockCountersMarkerMap) \ /* Canonical empty values */ \ V(EnumCache, empty_enum_cache, EmptyEnumCache) \ V(PropertyArray, empty_property_array, EmptyPropertyArray) \ V(ByteArray, empty_byte_array, EmptyByteArray) \ V(ObjectBoilerplateDescription, empty_object_boilerplate_description, \ EmptyObjectBoilerplateDescription) \ V(ArrayBoilerplateDescription, empty_array_boilerplate_description, \ EmptyArrayBoilerplateDescription) \ V(ClosureFeedbackCellArray, empty_closure_feedback_cell_array, \ EmptyClosureFeedbackCellArray) \ V(NumberDictionary, empty_slow_element_dictionary, \ EmptySlowElementDictionary) \ V(OrderedHashMap, empty_ordered_hash_map, EmptyOrderedHashMap) \ V(OrderedHashSet, empty_ordered_hash_set, EmptyOrderedHashSet) \ V(FeedbackMetadata, empty_feedback_metadata, EmptyFeedbackMetadata) \ V(NameDictionary, empty_property_dictionary, EmptyPropertyDictionary) \ V(OrderedNameDictionary, empty_ordered_property_dictionary, \ EmptyOrderedPropertyDictionary) \ V(SwissNameDictionary, empty_swiss_property_dictionary, \ EmptySwissPropertyDictionary) \ V(InterceptorInfo, noop_interceptor_info, NoOpInterceptorInfo) \ V(ArrayList, empty_array_list, EmptyArrayList) \ V(WeakFixedArray, empty_weak_fixed_array, EmptyWeakFixedArray) \ V(WeakArrayList, empty_weak_array_list, EmptyWeakArrayList) \ /* Special numbers */ \ V(HeapNumber, nan_value, NanValue) \ V(HeapNumber, hole_nan_value, HoleNanValue) \ V(HeapNumber, infinity_value, InfinityValue) \ V(HeapNumber, minus_zero_value, MinusZeroValue) \ V(HeapNumber, minus_infinity_value, MinusInfinityValue) \ /* Marker for self-references during code-generation */ \ V(HeapObject, self_reference_marker, SelfReferenceMarker) \ /* Marker for basic-block usage counters array during code-generation */ \ V(Oddball, basic_block_counters_marker, BasicBlockCountersMarker) \ /* Canonical off-heap trampoline data */ \ V(ByteArray, off_heap_trampoline_relocation_info, \ OffHeapTrampolineRelocationInfo) \ V(HeapObject, trampoline_trivial_code_data_container, \ TrampolineTrivialCodeDataContainer) \ V(HeapObject, trampoline_promise_rejection_code_data_container, \ TrampolinePromiseRejectionCodeDataContainer) \ /* Canonical scope infos */ \ V(ScopeInfo, global_this_binding_scope_info, GlobalThisBindingScopeInfo) \ V(ScopeInfo, empty_function_scope_info, EmptyFunctionScopeInfo) \ V(ScopeInfo, native_scope_info, NativeScopeInfo) \ /* Hash seed */ \ V(ByteArray, hash_seed, HashSeed) // Mutable roots that are known to be immortal immovable, for which we can // safely skip write barriers. #define STRONG_MUTABLE_IMMOVABLE_ROOT_LIST(V) \ ACCESSOR_INFO_ROOT_LIST(V) \ /* Maps */ \ V(Map, external_map, ExternalMap) \ V(Map, message_object_map, JSMessageObjectMap) \ /* Canonical empty values */ \ V(Script, empty_script, EmptyScript) \ V(FeedbackCell, many_closures_cell, ManyClosuresCell) \ V(Cell, invalid_prototype_validity_cell, InvalidPrototypeValidityCell) \ /* Protectors */ \ V(PropertyCell, array_constructor_protector, ArrayConstructorProtector) \ V(PropertyCell, no_elements_protector, NoElementsProtector) \ V(PropertyCell, mega_dom_protector, MegaDOMProtector) \ V(PropertyCell, is_concat_spreadable_protector, IsConcatSpreadableProtector) \ V(PropertyCell, array_species_protector, ArraySpeciesProtector) \ V(PropertyCell, typed_array_species_protector, TypedArraySpeciesProtector) \ V(PropertyCell, promise_species_protector, PromiseSpeciesProtector) \ V(PropertyCell, regexp_species_protector, RegExpSpeciesProtector) \ V(PropertyCell, string_length_protector, StringLengthProtector) \ V(PropertyCell, array_iterator_protector, ArrayIteratorProtector) \ V(PropertyCell, array_buffer_detaching_protector, \ ArrayBufferDetachingProtector) \ V(PropertyCell, promise_hook_protector, PromiseHookProtector) \ V(PropertyCell, promise_resolve_protector, PromiseResolveProtector) \ V(PropertyCell, map_iterator_protector, MapIteratorProtector) \ V(PropertyCell, promise_then_protector, PromiseThenProtector) \ V(PropertyCell, set_iterator_protector, SetIteratorProtector) \ V(PropertyCell, string_iterator_protector, StringIteratorProtector) \ /* Caches */ \ V(FixedArray, single_character_string_cache, SingleCharacterStringCache) \ V(FixedArray, string_split_cache, StringSplitCache) \ V(FixedArray, regexp_multiple_cache, RegExpMultipleCache) \ /* Indirection lists for isolate-independent builtins */ \ V(FixedArray, builtins_constants_table, BuiltinsConstantsTable) \ /* Internal SharedFunctionInfos */ \ V(SharedFunctionInfo, async_function_await_reject_shared_fun, \ AsyncFunctionAwaitRejectSharedFun) \ V(SharedFunctionInfo, async_function_await_resolve_shared_fun, \ AsyncFunctionAwaitResolveSharedFun) \ V(SharedFunctionInfo, async_generator_await_reject_shared_fun, \ AsyncGeneratorAwaitRejectSharedFun) \ V(SharedFunctionInfo, async_generator_await_resolve_shared_fun, \ AsyncGeneratorAwaitResolveSharedFun) \ V(SharedFunctionInfo, async_generator_yield_resolve_shared_fun, \ AsyncGeneratorYieldResolveSharedFun) \ V(SharedFunctionInfo, async_generator_return_resolve_shared_fun, \ AsyncGeneratorReturnResolveSharedFun) \ V(SharedFunctionInfo, async_generator_return_closed_reject_shared_fun, \ AsyncGeneratorReturnClosedRejectSharedFun) \ V(SharedFunctionInfo, async_generator_return_closed_resolve_shared_fun, \ AsyncGeneratorReturnClosedResolveSharedFun) \ V(SharedFunctionInfo, async_iterator_value_unwrap_shared_fun, \ AsyncIteratorValueUnwrapSharedFun) \ V(SharedFunctionInfo, promise_all_resolve_element_shared_fun, \ PromiseAllResolveElementSharedFun) \ V(SharedFunctionInfo, promise_all_settled_resolve_element_shared_fun, \ PromiseAllSettledResolveElementSharedFun) \ V(SharedFunctionInfo, promise_all_settled_reject_element_shared_fun, \ PromiseAllSettledRejectElementSharedFun) \ V(SharedFunctionInfo, promise_any_reject_element_shared_fun, \ PromiseAnyRejectElementSharedFun) \ V(SharedFunctionInfo, promise_capability_default_reject_shared_fun, \ PromiseCapabilityDefaultRejectSharedFun) \ V(SharedFunctionInfo, promise_capability_default_resolve_shared_fun, \ PromiseCapabilityDefaultResolveSharedFun) \ V(SharedFunctionInfo, promise_catch_finally_shared_fun, \ PromiseCatchFinallySharedFun) \ V(SharedFunctionInfo, promise_get_capabilities_executor_shared_fun, \ PromiseGetCapabilitiesExecutorSharedFun) \ V(SharedFunctionInfo, promise_then_finally_shared_fun, \ PromiseThenFinallySharedFun) \ V(SharedFunctionInfo, promise_thrower_finally_shared_fun, \ PromiseThrowerFinallySharedFun) \ V(SharedFunctionInfo, promise_value_thunk_finally_shared_fun, \ PromiseValueThunkFinallySharedFun) \ V(SharedFunctionInfo, proxy_revoke_shared_fun, ProxyRevokeSharedFun) // These root references can be updated by the mutator. #define STRONG_MUTABLE_MOVABLE_ROOT_LIST(V) \ /* Caches */ \ V(FixedArray, number_string_cache, NumberStringCache) \ /* Lists and dictionaries */ \ V(RegisteredSymbolTable, public_symbol_table, PublicSymbolTable) \ V(RegisteredSymbolTable, api_symbol_table, ApiSymbolTable) \ V(RegisteredSymbolTable, api_private_symbol_table, ApiPrivateSymbolTable) \ V(WeakArrayList, script_list, ScriptList) \ V(FixedArray, materialized_objects, MaterializedObjects) \ V(WeakArrayList, detached_contexts, DetachedContexts) \ V(WeakArrayList, retaining_path_targets, RetainingPathTargets) \ /* Feedback vectors that we need for code coverage or type profile */ \ V(Object, feedback_vectors_for_profiling_tools, \ FeedbackVectorsForProfilingTools) \ V(FixedArray, serialized_objects, SerializedObjects) \ V(FixedArray, serialized_global_proxy_sizes, SerializedGlobalProxySizes) \ V(TemplateList, message_listeners, MessageListeners) \ /* Support for async stack traces */ \ V(HeapObject, current_microtask, CurrentMicrotask) \ /* KeepDuringJob set for JS WeakRefs */ \ V(HeapObject, weak_refs_keep_during_job, WeakRefsKeepDuringJob) \ V(HeapObject, interpreter_entry_trampoline_for_profiling, \ InterpreterEntryTrampolineForProfiling) \ V(Object, pending_optimize_for_test_bytecode, \ PendingOptimizeForTestBytecode) \ V(ArrayList, basic_block_profiling_data, BasicBlockProfilingData) \ V(WeakArrayList, shared_wasm_memories, SharedWasmMemories) \ IF_WASM(V, HeapObject, active_continuation, ActiveContinuation) \ IF_WASM(V, HeapObject, active_suspender, ActiveSuspender) \ IF_WASM(V, WeakArrayList, wasm_canonical_rtts, WasmCanonicalRtts) // Entries in this list are limited to Smis and are not visited during GC. #define SMI_ROOT_LIST(V) \ V(Smi, last_script_id, LastScriptId) \ V(Smi, last_debugging_id, LastDebuggingId) \ /* To distinguish the function templates, so that we can find them in the */ \ /* function cache of the native context. */ \ V(Smi, next_template_serial_number, NextTemplateSerialNumber) \ V(Smi, construct_stub_create_deopt_pc_offset, \ ConstructStubCreateDeoptPCOffset) \ V(Smi, construct_stub_invoke_deopt_pc_offset, \ ConstructStubInvokeDeoptPCOffset) \ V(Smi, interpreter_entry_return_pc_offset, InterpreterEntryReturnPCOffset) // Adapts one INTERNALIZED_STRING_LIST_GENERATOR entry to // the ROOT_LIST-compatible entry #define INTERNALIZED_STRING_LIST_ADAPTER(V, name, ...) V(String, name, name) // Produces (String, name, CamelCase) entries #define INTERNALIZED_STRING_ROOT_LIST(V) \ INTERNALIZED_STRING_LIST_GENERATOR(INTERNALIZED_STRING_LIST_ADAPTER, V) // Adapts one XXX_SYMBOL_LIST_GENERATOR entry to the ROOT_LIST-compatible entry #define SYMBOL_ROOT_LIST_ADAPTER(V, name, ...) V(Symbol, name, name) // Produces (Symbol, name, CamelCase) entries #define PRIVATE_SYMBOL_ROOT_LIST(V) \ PRIVATE_SYMBOL_LIST_GENERATOR(SYMBOL_ROOT_LIST_ADAPTER, V) #define PUBLIC_SYMBOL_ROOT_LIST(V) \ PUBLIC_SYMBOL_LIST_GENERATOR(SYMBOL_ROOT_LIST_ADAPTER, V) #define WELL_KNOWN_SYMBOL_ROOT_LIST(V) \ WELL_KNOWN_SYMBOL_LIST_GENERATOR(SYMBOL_ROOT_LIST_ADAPTER, V) // Adapts one ACCESSOR_INFO_LIST_GENERATOR entry to the ROOT_LIST-compatible // entry #define ACCESSOR_INFO_ROOT_LIST_ADAPTER(V, name, CamelName, ...) \ V(AccessorInfo, name##_accessor, CamelName##Accessor) // Produces (AccessorInfo, name, CamelCase) entries #define ACCESSOR_INFO_ROOT_LIST(V) \ ACCESSOR_INFO_LIST_GENERATOR(ACCESSOR_INFO_ROOT_LIST_ADAPTER, V) #define READ_ONLY_ROOT_LIST(V) \ STRONG_READ_ONLY_ROOT_LIST(V) \ INTERNALIZED_STRING_ROOT_LIST(V) \ PRIVATE_SYMBOL_ROOT_LIST(V) \ PUBLIC_SYMBOL_ROOT_LIST(V) \ WELL_KNOWN_SYMBOL_ROOT_LIST(V) \ STRUCT_MAPS_LIST(V) \ TORQUE_DEFINED_MAP_ROOT_LIST(V) \ ALLOCATION_SITE_MAPS_LIST(V) \ DATA_HANDLER_MAPS_LIST(V) #define MUTABLE_ROOT_LIST(V) \ STRONG_MUTABLE_IMMOVABLE_ROOT_LIST(V) \ STRONG_MUTABLE_MOVABLE_ROOT_LIST(V) \ SMI_ROOT_LIST(V) #define ROOT_LIST(V) \ READ_ONLY_ROOT_LIST(V) \ MUTABLE_ROOT_LIST(V) // Declare all the root indices. This defines the root list order. // clang-format off enum class RootIndex : uint16_t { #define DECL(type, name, CamelName) k##CamelName, ROOT_LIST(DECL) #undef DECL kRootListLength, // Helper aliases for inclusive regions of root indices. kFirstRoot = 0, kLastRoot = kRootListLength - 1, #define ROOT(...) +1 kReadOnlyRootsCount = 0 READ_ONLY_ROOT_LIST(ROOT), kImmortalImmovableRootsCount = kReadOnlyRootsCount STRONG_MUTABLE_IMMOVABLE_ROOT_LIST(ROOT), #undef ROOT kFirstReadOnlyRoot = kFirstRoot, kLastReadOnlyRoot = kFirstReadOnlyRoot + kReadOnlyRootsCount - 1, // The strong roots visited by the garbage collector (not including read-only // roots). #define ROOT(...) +1 kMutableRootsCount = 0 STRONG_MUTABLE_IMMOVABLE_ROOT_LIST(ROOT) STRONG_MUTABLE_MOVABLE_ROOT_LIST(ROOT), #undef ROOT kFirstStrongRoot = kLastReadOnlyRoot + 1, kLastStrongRoot = kFirstStrongRoot + kMutableRootsCount - 1, // All of the strong roots plus the read-only roots. kFirstStrongOrReadOnlyRoot = kFirstRoot, kLastStrongOrReadOnlyRoot = kLastStrongRoot, // All immortal immovable roots including read only ones. kFirstImmortalImmovableRoot = kFirstReadOnlyRoot, kLastImmortalImmovableRoot = kFirstImmortalImmovableRoot + kImmortalImmovableRootsCount - 1, kFirstSmiRoot = kLastStrongRoot + 1, kLastSmiRoot = kLastRoot }; // clang-format on // Represents a storage of V8 heap roots. class RootsTable { public: static constexpr size_t kEntriesCount = static_cast(RootIndex::kRootListLength); RootsTable() : roots_{} {} inline bool IsRootHandleLocation(Address* handle_location, RootIndex* index) const; template bool IsRootHandle(Handle handle, RootIndex* index) const; Address const& operator[](RootIndex root_index) const { size_t index = static_cast(root_index); DCHECK_LT(index, kEntriesCount); return roots_[index]; } FullObjectSlot slot(RootIndex root_index) { size_t index = static_cast(root_index); DCHECK_LT(index, kEntriesCount); return FullObjectSlot(&roots_[index]); } static const char* name(RootIndex root_index) { size_t index = static_cast(root_index); DCHECK_LT(index, kEntriesCount); return root_names_[index]; } static constexpr int offset_of(RootIndex root_index) { return static_cast(root_index) * kSystemPointerSize; } // Immortal immovable root objects are allocated in OLD space and GC never // moves them and the root table entries are guaranteed to not be modified // after initialization. Note, however, that contents of those root objects // that are allocated in writable space can still be modified after // initialization. // Generated code can treat direct references to these roots as constants. static constexpr bool IsImmortalImmovable(RootIndex root_index) { STATIC_ASSERT(static_cast(RootIndex::kFirstImmortalImmovableRoot) == 0); return static_cast(root_index) <= static_cast(RootIndex::kLastImmortalImmovableRoot); } private: FullObjectSlot begin() { return FullObjectSlot(&roots_[static_cast(RootIndex::kFirstRoot)]); } FullObjectSlot end() { return FullObjectSlot( &roots_[static_cast(RootIndex::kLastRoot) + 1]); } // Used for iterating over all of the read-only and mutable strong roots. FullObjectSlot strong_or_read_only_roots_begin() const { STATIC_ASSERT(static_cast(RootIndex::kLastReadOnlyRoot) == static_cast(RootIndex::kFirstStrongRoot) - 1); return FullObjectSlot( &roots_[static_cast(RootIndex::kFirstStrongOrReadOnlyRoot)]); } FullObjectSlot strong_or_read_only_roots_end() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kLastStrongOrReadOnlyRoot) + 1]); } // The read-only, strong and Smi roots as defined by these accessors are all // disjoint. FullObjectSlot read_only_roots_begin() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kFirstReadOnlyRoot)]); } FullObjectSlot read_only_roots_end() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kLastReadOnlyRoot) + 1]); } FullObjectSlot strong_roots_begin() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kFirstStrongRoot)]); } FullObjectSlot strong_roots_end() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kLastStrongRoot) + 1]); } FullObjectSlot smi_roots_begin() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kFirstSmiRoot)]); } FullObjectSlot smi_roots_end() const { return FullObjectSlot( &roots_[static_cast(RootIndex::kLastSmiRoot) + 1]); } Address& operator[](RootIndex root_index) { size_t index = static_cast(root_index); DCHECK_LT(index, kEntriesCount); return roots_[index]; } Address roots_[kEntriesCount]; static const char* root_names_[kEntriesCount]; friend class Isolate; friend class Heap; friend class Factory; friend class PointerCompressedReadOnlyArtifacts; friend class ReadOnlyHeap; friend class ReadOnlyRoots; friend class RootsSerializer; friend class SoleReadOnlyHeap; }; class ReadOnlyRoots { public: static constexpr size_t kEntriesCount = static_cast(RootIndex::kReadOnlyRootsCount); V8_INLINE explicit ReadOnlyRoots(Heap* heap); V8_INLINE explicit ReadOnlyRoots(Isolate* isolate); V8_INLINE explicit ReadOnlyRoots(LocalIsolate* isolate); // For `v8_enable_map_packing=true`, this will return a packed (also untagged) // map-word instead of a tagged heap pointer. MapWord one_pointer_filler_map_word(); #define ROOT_ACCESSOR(Type, name, CamelName) \ V8_INLINE class Type name() const; \ V8_INLINE class Type unchecked_##name() const; \ V8_INLINE Handle name##_handle() const; READ_ONLY_ROOT_LIST(ROOT_ACCESSOR) #undef ROOT_ACCESSOR // Get the address of a given read-only root index, without type checks. V8_INLINE Address at(RootIndex root_index) const; // Iterate over all the read-only roots. This is not necessary for garbage // collection and is usually only performed as part of (de)serialization or // heap verification. void Iterate(RootVisitor* visitor); private: #ifdef DEBUG #define ROOT_TYPE_CHECK(Type, name, CamelName) \ V8_EXPORT_PRIVATE bool CheckType_##name() const; READ_ONLY_ROOT_LIST(ROOT_TYPE_CHECK) #undef ROOT_TYPE_CHECK #endif V8_INLINE explicit ReadOnlyRoots(Address* ro_roots) : read_only_roots_(ro_roots) {} V8_INLINE Address* GetLocation(RootIndex root_index) const; Address* read_only_roots_; friend class ReadOnlyHeap; friend class DeserializerAllocator; }; } // namespace internal } // namespace v8 #endif // V8_ROOTS_ROOTS_H_