Namespaces
namespace	api_internal

namespace	base

namespace	debug

namespace	detail

namespace	internal

namespace	metrics

namespace	platform

Classes
class	ActivityControl

class	AllocationProfile

union	AnyCType

class	Array

class	ArrayBuffer

class	ArrayBufferView

class	BackingStore

class	BasicTracedReference

class	BigInt

class	BigInt64Array

class	BigIntObject

class	BigUint64Array

class	Boolean

class	BooleanObject

class	CFunction

class	CFunctionInfo

class	CodeEvent

class	CodeEventHandler

class	CompiledWasmModule

class	Context

class	ConvertableToTraceFormat

class	CppHeap

struct	CppHeapCreateParams

class	CpuProfile

struct	CpuProfileDeoptFrame

struct	CpuProfileDeoptInfo

class	CpuProfileNode

class	CpuProfiler

class	CpuProfilingOptions

struct	CpuProfilingResult

class	CTypeInfo

class	CTypeInfoBuilder

class	CustomSpaceStatisticsReceiver

class	Data

class	DataView

class	Date

class	DefaultGlobalMapTraits

class	DefaultPersistentValueMapTraits

class	DefaultPersistentValueVectorTraits

struct	DeserializeAPIWrapperCallback

struct	DeserializeContextDataCallback

struct	DeserializeInternalFieldsCallback

class	DictionaryTemplate

class	DiscardedSamplesDelegate

class	EmbedderGraph

class	EmbedderRootsHandler

class	EmbedderStateScope

class	EscapableHandleScope

class	EscapableHandleScopeBase

class	Eternal

class	Exception

class	Extension

class	ExtensionConfiguration

class	External

class	ExternalResourceVisitor

struct	FastApiArrayBuffer

struct	FastApiArrayBufferView

struct	FastApiCallbackOptions

struct	FastApiTypedArray

struct	FastApiTypedArrayBase

struct	FastOneByteString

class	FixedArray

class	Float16Array

class	Float32Array

class	Float64Array

class	Function

class	FunctionCallbackInfo

class	FunctionTemplate

class	Global

class	GlobalValueMap

class	HandleScope

class	HeapCodeStatistics

class	HeapGraphEdge

class	HeapGraphNode

class	HeapObjectStatistics

class	HeapProfiler

class	HeapSnapshot

class	HeapSpaceStatistics

class	HeapStatistics

struct	HeapStatsUpdate

class	HighAllocationThroughputObserver

class	IdleTask

struct	IndexedPropertyHandlerConfiguration

class	Int16Array

class	Int32

class	Int32Array

class	Int8Array

class	Integer

class	Isolate

struct	JitCodeEvent

class	JobDelegate

class	JobHandle

class	JobTask

struct	JSEntryStub

struct	JSEntryStubs

class	JSON

class	JSVisitor

class	Local

class	LocalBase

class	LocalVector

class	Location

class	Locker

class	Map

class	Maybe

class	Maybe< void >

class	MaybeLocal

class	MeasureMemoryDelegate

struct	MemoryRange

class	MemorySpan

class	Message

class	MicrotaskQueue

class	MicrotasksScope

struct	ModifyCodeGenerationFromStringsResult

class	Module

class	ModuleRequest

class	Name

struct	NamedPropertyHandlerConfiguration

class	NonCopyablePersistentTraits

class	Number

class	NumberObject

class	Numeric

class	Object

class	ObjectTemplate

struct	OOMDetails

class	OutputStream

struct	OwnedBuffer

class	PageAllocator

class	Persistent

class	PersistentBase

class	PersistentHandleVisitor

class	PersistentValueMap

class	PersistentValueMapBase

class	PersistentValueVector

class	Platform

class	Primitive

class	PrimitiveArray

class	Private

class	Promise

class	PromiseRejectMessage

class	PropertyCallbackInfo

class	PropertyDescriptor

class	Proxy

class	QueryObjectPredicate

class	RegExp

struct	RegisterState

class	ResourceConstraints

class	ReturnValue

struct	SampleInfo

class	ScopedBlockingCall

class	Script

class	ScriptCompiler

class	ScriptOrigin

class	ScriptOriginOptions

class	ScriptOrModule

class	SealHandleScope

struct	SerializeAPIWrapperCallback

struct	SerializeContextDataCallback

struct	SerializeInternalFieldsCallback

class	Set

class	SharedArrayBuffer

class	SharedMemoryStatistics

class	SharedValueConveyor

class	Signature

class	SnapshotCreator

class	SourceLocation

class	StackFrame

class	StackTrace

class	StartupData

class	StdGlobalValueMap

class	StdMapTraits

class	StdPersistentValueMap

class	String

class	StringObject

class	Symbol

class	SymbolObject

class	Task

class	TaskRunner

class	Template

class	ThreadIsolatedAllocator

class	Traced

class	TracedReference

class	TracedReferenceBase

class	TracingController

class	TryCatch

class	TypecheckWitness

class	TypedArray

class	Uint16Array

class	Uint32

class	Uint32Array

class	Uint8Array

class	Uint8ClampedArray

class	UnboundModuleScript

class	UnboundScript

class	Unlocker

class	Unwinder

class	V8

class	Value

class	ValueDeserializer

class	ValueSerializer

class	VirtualAddressSpace

class	WasmMemoryObject

class	WasmModuleObject

class	WasmStreaming

class	WeakCallbackInfo

struct	WrapperDescriptor

class	ZoneBackingAllocator

Typedefs
using	BackingStoreDeleterCallback = void()(void data, size_t length, void *deleter_data)

using	JitCodeEventHandler = void()(const JitCodeEvent event)

using	GCCallback = void(*)(GCType type, GCCallbackFlags flags)

using	InterruptCallback = void()(Isolate isolate, void *data)

using	NearHeapLimitCallback = size_t()(void data, size_t current_heap_limit, size_t initial_heap_limit)

using	CounterLookupCallback = int ()(const char *name)

using	CreateHistogramCallback = void ()(const char *name, int min, int max, size_t buckets)

using	AddHistogramSampleCallback = void()(void histogram, int sample)

using	FatalErrorCallback = void()(const char location, const char *message)

using	OOMErrorCallback = void()(const char location, const OOMDetails &details)

using	MessageCallback = void(*)(Local< Message > message, Local< Value > data)

using	LogEventCallback = void()(const char name, int status)

using	AddCrashKeyCallback = void(*)(CrashKeyId id, const std::string &value)

using	BeforeCallEnteredCallback = void()(Isolate )

using	CallCompletedCallback = void()(Isolate )

using	AllowCodeGenerationFromStringsCallback = bool(*)(Local< Context > context, Local< String > source)

using	FailedAccessCheckCallback = void(*)(Local< Object > target, AccessType type, Local< Value > data)

using	ModifyCodeGenerationFromStringsCallback = ModifyCodeGenerationFromStringsResult(*)(Local< Context > context, Local< Value > source)

using	ModifyCodeGenerationFromStringsCallback2 = ModifyCodeGenerationFromStringsResult(*)(Local< Context > context, Local< Value > source, bool is_code_like)

using	ExtensionCallback = bool(*)(const FunctionCallbackInfo< Value > &)

using	AllowWasmCodeGenerationCallback = bool(*)(Local< Context > context, Local< String > source)

using	ApiImplementationCallback = void(*)(const FunctionCallbackInfo< Value > &)

using	WasmStreamingCallback = void(*)(const FunctionCallbackInfo< Value > &)

using	WasmAsyncResolvePromiseCallback = void()(Isolate isolate, Local< Context > context, Local< Promise::Resolver > resolver, Local< Value > result, WasmAsyncSuccess success)

using	WasmLoadSourceMapCallback = Local< String >()(Isolate isolate, const char *name)

using	WasmImportedStringsEnabledCallback = bool(*)(Local< Context > context)

using	SharedArrayBufferConstructorEnabledCallback = bool(*)(Local< Context > context)

using	JavaScriptCompileHintsMagicEnabledCallback = bool(*)(Local< Context > context)

using	WasmJSPIEnabledCallback = bool(*)(Local< Context > context)

using	HostImportModuleDynamicallyCallback = MaybeLocal< Promise >(*)(Local< Context > context, Local< Data > host_defined_options, Local< Value > resource_name, Local< String > specifier, Local< FixedArray > import_attributes)

using	CompileHintCallback = bool()(int, void )

using	HostInitializeImportMetaObjectCallback = void(*)(Local< Context > context, Local< Module > module, Local< Object > meta)

using	HostCreateShadowRealmContextCallback = MaybeLocal< Context >(*)(Local< Context > initiator_context)

using	PrepareStackTraceCallback = MaybeLocal< Value >(*)(Local< Context > context, Local< Value > error, Local< Array > sites)

using	CFunctionBuilder = internal::CFunctionBuilder

using	FunctionCallback = void(*)(const FunctionCallbackInfo< Value > &info)

using	EntropySource = bool()(unsigned char buffer, size_t length)

using	ReturnAddressLocationResolver = uintptr_t(*)(uintptr_t return_addr_location)

using	DcheckErrorCallback = void()(const char file, int line, const char *message)

using	StackState = cppgc::EmbedderStackState

template<class T >
using	Handle = Local< T >

using	MicrotasksCompletedCallbackWithData = void()(Isolate , void *)

using	MicrotaskCallback = void()(void data)

using	AccessorGetterCallback = void(*)(Local< String > property, const PropertyCallbackInfo< Value > &info)

using	AccessorNameGetterCallback = void(*)(Local< Name > property, const PropertyCallbackInfo< Value > &info)

using	AccessorSetterCallback = void(*)(Local< String > property, Local< Value > value, const PropertyCallbackInfo< void > &info)

using	AccessorNameSetterCallback = void(*)(Local< Name > property, Local< Value > value, const PropertyCallbackInfo< void > &info)

template<class T >
using	UniquePersistent = Global< T >

using	PlatformSharedMemoryHandle = intptr_t

using	NativeObject = void *

using	SnapshotObjectId = uint32_t

using	ProfilerId = uint32_t

using	PromiseHook = void(*)(PromiseHookType type, Local< Promise > promise, Local< Value > parent)

using	PromiseRejectCallback = void(*)(PromiseRejectMessage message)

using	NamedPropertyGetterCallback = Intercepted(*)(Local< Name > property, const PropertyCallbackInfo< Value > &info)

using	GenericNamedPropertyGetterCallback = void(*)(Local< Name > property, const PropertyCallbackInfo< Value > &info)

using	NamedPropertySetterCallback = Intercepted(*)(Local< Name > property, Local< Value > value, const PropertyCallbackInfo< void > &info)

using	GenericNamedPropertySetterCallback = void(*)(Local< Name > property, Local< Value > value, const PropertyCallbackInfo< Value > &info)

using	NamedPropertyQueryCallback = Intercepted(*)(Local< Name > property, const PropertyCallbackInfo< Integer > &info)

using	GenericNamedPropertyQueryCallback = void(*)(Local< Name > property, const PropertyCallbackInfo< Integer > &info)

using	NamedPropertyDeleterCallback = Intercepted(*)(Local< Name > property, const PropertyCallbackInfo< Boolean > &info)

using	GenericNamedPropertyDeleterCallback = void(*)(Local< Name > property, const PropertyCallbackInfo< Boolean > &info)

using	NamedPropertyEnumeratorCallback = void(*)(const PropertyCallbackInfo< Array > &info)

using	GenericNamedPropertyEnumeratorCallback = NamedPropertyEnumeratorCallback

using	NamedPropertyDefinerCallback = Intercepted(*)(Local< Name > property, const PropertyDescriptor &desc, const PropertyCallbackInfo< void > &info)

using	GenericNamedPropertyDefinerCallback = void(*)(Local< Name > property, const PropertyDescriptor &desc, const PropertyCallbackInfo< Value > &info)

using	NamedPropertyDescriptorCallback = Intercepted(*)(Local< Name > property, const PropertyCallbackInfo< Value > &info)

using	GenericNamedPropertyDescriptorCallback = void(*)(Local< Name > property, const PropertyCallbackInfo< Value > &info)

using	IndexedPropertyGetterCallbackV2 = Intercepted(*)(uint32_t index, const PropertyCallbackInfo< Value > &info)

using	IndexedPropertyGetterCallback = void(*)(uint32_t index, const PropertyCallbackInfo< Value > &info)

using	IndexedPropertySetterCallbackV2 = Intercepted(*)(uint32_t index, Local< Value > value, const PropertyCallbackInfo< void > &info)

using	IndexedPropertySetterCallback = void(*)(uint32_t index, Local< Value > value, const PropertyCallbackInfo< Value > &info)

using	IndexedPropertyQueryCallbackV2 = Intercepted(*)(uint32_t index, const PropertyCallbackInfo< Integer > &info)

using	IndexedPropertyQueryCallback = void(*)(uint32_t index, const PropertyCallbackInfo< Integer > &info)

using	IndexedPropertyDeleterCallbackV2 = Intercepted(*)(uint32_t index, const PropertyCallbackInfo< Boolean > &info)

using	IndexedPropertyDeleterCallback = void(*)(uint32_t index, const PropertyCallbackInfo< Boolean > &info)

using	IndexedPropertyEnumeratorCallback = void(*)(const PropertyCallbackInfo< Array > &info)

using	IndexedPropertyDefinerCallbackV2 = Intercepted(*)(uint32_t index, const PropertyDescriptor &desc, const PropertyCallbackInfo< void > &info)

using	IndexedPropertyDefinerCallback = void(*)(uint32_t index, const PropertyDescriptor &desc, const PropertyCallbackInfo< Value > &info)

using	IndexedPropertyDescriptorCallbackV2 = Intercepted(*)(uint32_t index, const PropertyCallbackInfo< Value > &info)

using	IndexedPropertyDescriptorCallback = void(*)(uint32_t index, const PropertyCallbackInfo< Value > &info)

using	AccessCheckCallback = bool(*)(Local< Context > accessing_context, Local< Object > accessed_object, Local< Value > data)

typedef uintptr_t	PersistentContainerValue

Enumerations
enum class	ArrayBufferCreationMode { kInternalized , kExternalized }

enum	JitCodeEventOptions { kJitCodeEventDefault = 0 , kJitCodeEventEnumExisting = 1 }

enum	GCType { kGCTypeScavenge = 1 << 0 , kGCTypeMinorMarkSweep = 1 << 1 , kGCTypeMinorMarkCompact , kGCTypeMarkSweepCompact = 1 << 2 , kGCTypeIncrementalMarking = 1 << 3 , kGCTypeProcessWeakCallbacks = 1 << 4 , kGCTypeAll }

enum	GCCallbackFlags { kNoGCCallbackFlags = 0 , kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1 , kGCCallbackFlagForced = 1 << 2 , kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3 , kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4 , kGCCallbackFlagCollectAllExternalMemory = 1 << 5 , kGCCallbackScheduleIdleGarbageCollection = 1 << 6 }

enum	LogEventStatus : int { kStart = 0 , kEnd = 1 , kStamp = 2 }

enum class	CrashKeyId { kIsolateAddress , kReadonlySpaceFirstPageAddress , kMapSpaceFirstPageAddress , kOldSpaceFirstPageAddress , kCodeRangeBaseAddress , kCodeSpaceFirstPageAddress , kDumpType , kSnapshotChecksumCalculated , kSnapshotChecksumExpected }

enum	AccessType { ACCESS_GET , ACCESS_SET , ACCESS_HAS , ACCESS_DELETE , ACCESS_KEYS }

enum class	WasmAsyncSuccess { kSuccess , kFail }

enum class	EmbedderStateTag : uint8_t { EMPTY = 0 , OTHER = 1 }

enum	RAILMode : unsigned { PERFORMANCE_RESPONSE , PERFORMANCE_ANIMATION , PERFORMANCE_IDLE , PERFORMANCE_LOAD }

enum class	MemoryPressureLevel { kNone , kModerate , kCritical }

enum class	MicrotasksPolicy { kExplicit , kScoped , kAuto }

enum	PropertyAttribute { None = 0 , ReadOnly = 1 << 0 , DontEnum = 1 << 1 , DontDelete = 1 << 2 }

enum	AccessControl { DEFAULT = 0 }

enum	PropertyFilter { ALL_PROPERTIES = 0 , ONLY_WRITABLE = 1 , ONLY_ENUMERABLE = 2 , ONLY_CONFIGURABLE = 4 , SKIP_STRINGS = 8 , SKIP_SYMBOLS = 16 }

enum class	SideEffectType { kHasSideEffect , kHasNoSideEffect , kHasSideEffectToReceiver }

enum class	KeyCollectionMode { kOwnOnly , kIncludePrototypes }

enum class	IndexFilter { kIncludeIndices , kSkipIndices }

enum class	KeyConversionMode { kConvertToString , kKeepNumbers , kNoNumbers }

enum class	IntegrityLevel { kFrozen , kSealed }

enum class	TaskPriority : uint8_t { kBestEffort , kUserVisible , kUserBlocking , kMaxPriority = kUserBlocking }

enum class	BlockingType { kMayBlock , kWillBlock }

enum class	PagePermissions { kNoAccess , kRead , kReadWrite , kReadWriteExecute , kReadExecute }

enum class	NewStringType { kNormal , kInternalized }

enum	CpuProfilingMode { kLeafNodeLineNumbers , kCallerLineNumbers }

enum	CpuProfilingNamingMode { kStandardNaming , kDebugNaming }

enum	CpuProfilingLoggingMode { kLazyLogging , kEagerLogging }

enum class	CpuProfilingStatus { kStarted , kAlreadyStarted , kErrorTooManyProfilers }

enum	CodeEventType { kUnknownType , kBuiltinType , kCallbackType , kEvalType , kFunctionType , kInterpretedFunctionType , kHandlerType , kBytecodeHandlerType , kLazyCompileType , kRegExpType , kScriptType , kStubType , kRelocationType }

enum class	PromiseHookType { kInit , kResolve , kBefore , kAfter }

enum	PromiseRejectEvent { kPromiseRejectWithNoHandler = 0 , kPromiseHandlerAddedAfterReject = 1 , kPromiseRejectAfterResolved = 2 , kPromiseResolveAfterResolved = 3 }

enum class	CppHeapPointerTag : uint64_t { kDefaultTag = internal::ExternalPointerTag::kExternalObjectValueTag }

enum class	ScriptType { kClassic , kModule }

enum class	MeasureMemoryMode { kSummary , kDetailed }

enum class	MeasureMemoryExecution { kDefault , kEager , kLazy }

enum	Intrinsic { kArrayProto_entries , kArrayProto_forEach , kArrayProto_keys , kArrayProto_values , kArrayPrototype , kAsyncIteratorPrototype , kErrorPrototype , kIteratorPrototype , kMapIteratorPrototype , kObjProto_valueOf , kSetIteratorPrototype }

enum class	Intercepted : uint8_t { kNo = 0 , kYes = 1 }

enum class	ConstructorBehavior { kThrow , kAllow }

enum class	PropertyHandlerFlags { kNone = 0 , kNonMasking = 1 , kOnlyInterceptStrings = 1 << 1 , kHasNoSideEffect = 1 << 2 , kInternalNewCallbacksSignatures = 1 << 10 }

enum	StateTag : uint16_t { JS , GC , PARSER , BYTECODE_COMPILER , COMPILER , OTHER , EXTERNAL , ATOMICS_WAIT , IDLE , LOGGING }

enum	PersistentContainerCallbackType { kNotWeak , kWeakWithParameter , kWeakWithInternalFields }

enum class	WeakCallbackType { kParameter , kInternalFields }

Functions
void	RegisterExtension (std::unique_ptr< Extension >)

template<CTypeInfo::Identifier type_info_id, typename T >
bool	TryToCopyAndConvertArrayToCppBuffer (Local< Array > src, T *dst, uint32_t max_length)

template<class T >
Maybe< T >	Nothing ()

template<class T >
Maybe< T >	Just (const T &t)

template<class T , std::enable_if_t<!std::is_lvalue_reference_v< T > > * = nullptr>
Maybe< T >	Just (T &&t)

Maybe< void >	JustVoid ()

template<class T , std::size_t N>
constexpr std::array< std::remove_cv_t< T >, N >	to_array (T(&a)[N])

template<class T , std::size_t N>
constexpr std::array< std::remove_cv_t< T >, N >	to_array (T(&&a)[N])

PlatformSharedMemoryHandle	SharedMemoryHandleFromFileDescriptor (int fd)

int	FileDescriptorFromSharedMemoryHandle (PlatformSharedMemoryHandle handle)

Local< Primitive >	Undefined (Isolate *isolate)

Local< Primitive >	Null (Isolate *isolate)

Local< Boolean >	True (Isolate *isolate)

Local< Boolean >	False (Isolate *isolate)

bool	operator== (const TracedReferenceBase &lhs, const TracedReferenceBase &rhs)

template<typename U >
bool	operator== (const TracedReferenceBase &lhs, const v8::Local< U > &rhs)

template<typename U >
bool	operator== (const v8::Local< U > &lhs, const TracedReferenceBase &rhs)

bool	operator!= (const TracedReferenceBase &lhs, const TracedReferenceBase &rhs)

template<typename U >
bool	operator!= (const TracedReferenceBase &lhs, const v8::Local< U > &rhs)

template<typename U >
bool	operator!= (const v8::Local< U > &lhs, const TracedReferenceBase &rhs)

constexpr uint32_t	CurrentValueSerializerFormatVersion ()

bool	TryHandleWebAssemblyTrapPosix (int sig_code, siginfo_t info, void context)

bool	TryHandleWebAssemblyTrapWindows (EXCEPTION_POINTERS *exception)

Detailed Description

This file provides additional API on top of the default one for making API calls, which come from embedder C++ functions. The functions are being called directly from optimized code, doing all the necessary typechecks in the compiler itself, instead of on the embedder side. Hence the "fast" in the name. Example usage might look like:

void FastMethod(int param, bool another_param);
 
v8::FunctionTemplate::New(isolate, SlowCallback, data,
                          signature, length, constructor_behavior
                          side_effect_type,
                          &v8::CFunction::Make(FastMethod));

By design, fast calls are limited by the following requirements, which the embedder should enforce themselves:

they should not allocate on the JS heap;
they should not trigger JS execution. To enforce them, the embedder could use the existing v8::Isolate::DisallowJavascriptExecutionScope and a utility similar to Blink's NoAllocationScope: https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/renderer/platform/heap/thread_state_scopes.h;l=16

Due to these limitations, it's not directly possible to report errors by throwing a JS exception or to otherwise do an allocation. There is an alternative way of creating fast calls that supports falling back to the slow call and then performing the necessary allocation. When one creates the fast method by using CFunction::MakeWithFallbackSupport instead of CFunction::Make, the fast callback gets as last parameter an output variable, through which it can request falling back to the slow call. So one might declare their method like:

void FastMethodWithFallback(int param, FastApiCallbackOptions& options);

v8::FastApiCallbackOptions

Definition: v8-fast-api-calls.h:574

If the callback wants to signal an error condition or to perform an allocation, it must set options.fallback to true and do an early return from the fast method. Then V8 checks the value of options.fallback and if it's true, falls back to executing the SlowCallback, which is capable of reporting the error (either by throwing a JS exception or logging to the console) or doing the allocation. It's the embedder's responsibility to ensure that the fast callback is idempotent up to the point where error and fallback conditions are checked, because otherwise executing the slow callback might produce visible side-effects twice.

An example for custom embedder type support might employ a way to wrap/ unwrap various C++ types in JSObject instances, e.g:

// Helper method with a check for field count.
template <typename T, int offset>
inline T* GetInternalField(v8::Local<v8::Object> wrapper) {
  assert(offset < wrapper->InternalFieldCount());
  return reinterpret_cast<T*>(
      wrapper->GetAlignedPointerFromInternalField(offset));
}
 
class CustomEmbedderType {
 public:
  // Returns the raw C object from a wrapper JS object.
  static CustomEmbedderType* Unwrap(v8::Local<v8::Object> wrapper) {
    return GetInternalField<CustomEmbedderType,
                            kV8EmbedderWrapperObjectIndex>(wrapper);
  }
  static void FastMethod(v8::Local<v8::Object> receiver_obj, int param) {
    CustomEmbedderType* receiver = static_cast<CustomEmbedderType*>(
      receiver_obj->GetAlignedPointerFromInternalField(
        kV8EmbedderWrapperObjectIndex));
 
    // Type checks are already done by the optimized code.
    // Then call some performance-critical method like:
    // receiver->Method(param);
  }
 
  static void SlowMethod(
      const v8::FunctionCallbackInfo<v8::Value>& info) {
    v8::Local<v8::Object> instance =
      v8::Local<v8::Object>::Cast(info.Holder());
    CustomEmbedderType* receiver = Unwrap(instance);
    // TODO: Do type checks and extract {param}.
    receiver->Method(param);
  }
};
 
// TODO(mslekova): Clean-up these constants
// The constants kV8EmbedderWrapperTypeIndex and
// kV8EmbedderWrapperObjectIndex describe the offsets for the type info
// struct and the native object, when expressed as internal field indices
// within a JSObject. The existance of this helper function assumes that
// all embedder objects have their JSObject-side type info at the same
// offset, but this is not a limitation of the API itself. For a detailed
// use case, see the third example.
static constexpr int kV8EmbedderWrapperTypeIndex = 0;
static constexpr int kV8EmbedderWrapperObjectIndex = 1;
 
// The following setup function can be templatized based on
// the {embedder_object} argument.
void SetupCustomEmbedderObject(v8::Isolate* isolate,
                               v8::Local<v8::Context> context,
                               CustomEmbedderType* embedder_object) {
  isolate->set_embedder_wrapper_type_index(
    kV8EmbedderWrapperTypeIndex);
  isolate->set_embedder_wrapper_object_index(
    kV8EmbedderWrapperObjectIndex);
 
  v8::CFunction c_func =
    MakeV8CFunction(CustomEmbedderType::FastMethod);
 
  Local<v8::FunctionTemplate> method_template =
    v8::FunctionTemplate::New(
      isolate, CustomEmbedderType::SlowMethod, v8::Local<v8::Value>(),
      v8::Local<v8::Signature>(), 1, v8::ConstructorBehavior::kAllow,
      v8::SideEffectType::kHasSideEffect, &c_func);
 
  v8::Local<v8::ObjectTemplate> object_template =
    v8::ObjectTemplate::New(isolate);
  object_template->SetInternalFieldCount(
    kV8EmbedderWrapperObjectIndex + 1);
  object_template->Set(isolate, "method", method_template);
 
  // Instantiate the wrapper JS object.
  v8::Local<v8::Object> object =
      object_template->NewInstance(context).ToLocalChecked();
  object->SetAlignedPointerInInternalField(
    kV8EmbedderWrapperObjectIndex,
    reinterpret_cast<void*>(embedder_object));
 
  // TODO: Expose {object} where it's necessary.
}

For instance if {object} is exposed via a global "obj" variable, one could write in JS: function hot_func() { obj.method(42); } and once {hot_func} gets optimized, CustomEmbedderType::FastMethod will be called instead of the slow version, with the following arguments: receiver := the {embedder_object} from above param := 42

Currently supported return types:

void
bool
int32_t
uint32_t
float32_t
float64_t Currently supported argument types:

pointer to an embedder type

JavaScript array of primitive types
bool
int32_t
uint32_t
int64_t
uint64_t
float32_t
float64_t

The 64-bit integer types currently have the IDL (unsigned) long long semantics: https://heycam.github.io/webidl/#abstract-opdef-converttoint In the future we'll extend the API to also provide conversions from/to BigInt to preserve full precision. The floating point types currently have the IDL (unrestricted) semantics, which is the only one used by WebGL. We plan to add support also for restricted floats/doubles, similarly to the BigInt conversion policies. We also differ from the specific NaN bit pattern that WebIDL prescribes (https://heycam.github.io/webidl/#es-unrestricted-float) in that Blink passes NaN values as-is, i.e. doesn't normalize them.

To be supported types:

TypedArrays and ArrayBuffers
arrays of embedder types

The API offers a limited support for function overloads:

void FastMethod_2Args(int param, bool another_param);
void FastMethod_3Args(int param, bool another_param, int third_param);
 
v8::CFunction fast_method_2args_c_func =
     MakeV8CFunction(FastMethod_2Args);
v8::CFunction fast_method_3args_c_func =
     MakeV8CFunction(FastMethod_3Args);
const v8::CFunction fast_method_overloads[] = {fast_method_2args_c_func,
                                               fast_method_3args_c_func};
Local<v8::FunctionTemplate> method_template =
    v8::FunctionTemplate::NewWithCFunctionOverloads(
        isolate, SlowCallback, data, signature, length,
        constructor_behavior, side_effect_type,
        {fast_method_overloads, 2});

In this example a single FunctionTemplate is associated to multiple C++ functions. The overload resolution is currently only based on the number of arguments passed in a call. For example, if this method_template is registered with a wrapper JS object as described above, a call with two arguments: obj.method(42, true); will result in a fast call to FastMethod_2Args, while a call with three or more arguments: obj.method(42, true, 11); will result in a fast call to FastMethod_3Args. Instead a call with less than two arguments, like: obj.method(42); would not result in a fast call but would fall back to executing the associated SlowCallback.

The v8 JavaScript engine.

Profiler support for the V8 JavaScript engine.

Support for Persistent containers.

C++11 embedders can use STL containers with Global values, but pre-C++11 does not support the required move semantic and hence may want these container classes.

Compile-time constants.

This header provides access to information about the value serializer at compile time, without declaring or defining any symbols that require linking to V8.

Typedef Documentation

◆ AccessCheckCallback

using v8::AccessCheckCallback = typedef bool (*)(Local<Context> accessing_context, Local<Object> accessed_object, Local<Value> data)

Returns true if the given context should be allowed to access the given object.

◆ AccessorGetterCallback

using v8::AccessorGetterCallback = typedef void (*)(Local<String> property, const PropertyCallbackInfo<Value>& info)

Accessor[Getter|Setter] are used as callback functions when setting|getting a particular data property. See Object::SetNativeDataProperty and ObjectTemplate::SetNativeDataProperty methods.

◆ AccessorNameGetterCallback

using v8::AccessorNameGetterCallback = typedef void (*)(Local<Name> property, const PropertyCallbackInfo<Value>& info)

◆ AccessorNameSetterCallback

using v8::AccessorNameSetterCallback = typedef void (*)(Local<Name> property, Local<Value> value, const PropertyCallbackInfo<void>& info)

◆ AccessorSetterCallback

using v8::AccessorSetterCallback = typedef void (*)(Local<String> property, Local<Value> value, const PropertyCallbackInfo<void>& info)

◆ AddCrashKeyCallback

using v8::AddCrashKeyCallback = typedef void (*)(CrashKeyId id, const std::string& value)

◆ AddHistogramSampleCallback

using v8::AddHistogramSampleCallback = typedef void (*)(void* histogram, int sample)

◆ AllowCodeGenerationFromStringsCallback

using v8::AllowCodeGenerationFromStringsCallback = typedef bool (*)(Local<Context> context, Local<String> source)

Callback to check if code generation from strings is allowed. See Context::AllowCodeGenerationFromStrings.

◆ AllowWasmCodeGenerationCallback

using v8::AllowWasmCodeGenerationCallback = typedef bool (*)(Local<Context> context, Local<String> source)

◆ ApiImplementationCallback

using v8::ApiImplementationCallback = typedef void (*)(const FunctionCallbackInfo<Value>&)

◆ BackingStoreDeleterCallback

using v8::BackingStoreDeleterCallback = typedef void (*)(void* data, size_t length, void* deleter_data)

◆ BeforeCallEnteredCallback

using v8::BeforeCallEnteredCallback = typedef void (*)(Isolate*)

◆ CallCompletedCallback

using v8::CallCompletedCallback = typedef void (*)(Isolate*)

◆ CFunctionBuilder

using v8::CFunctionBuilder = typedef internal::CFunctionBuilder

◆ CompileHintCallback

using v8::CompileHintCallback = typedef bool (*)(int, void*)

Callback for requesting a compile hint for a function from the embedder. The first parameter is the position of the function in source code and the second parameter is embedder data to be passed back.

◆ CounterLookupCallback

using v8::CounterLookupCallback = typedef int* (*)(const char* name)

Callback function passed to SetUnhandledExceptionCallback.

◆ CreateHistogramCallback

using v8::CreateHistogramCallback = typedef void* (*)(const char* name, int min, int max, size_t buckets)

◆ DcheckErrorCallback

using v8::DcheckErrorCallback = typedef void (*)(const char* file, int line, const char* message)

◆ EntropySource

using v8::EntropySource = typedef bool (*)(unsigned char* buffer, size_t length)

EntropySource is used as a callback function when v8 needs a source of entropy.

◆ ExtensionCallback

using v8::ExtensionCallback = typedef bool (*)(const FunctionCallbackInfo<Value>&)

◆ FailedAccessCheckCallback

using v8::FailedAccessCheckCallback = typedef void (*)(Local<Object> target, AccessType type, Local<Value> data)

◆ FatalErrorCallback

using v8::FatalErrorCallback = typedef void (*)(const char* location, const char* message)

◆ FunctionCallback

using v8::FunctionCallback = typedef void (*)(const FunctionCallbackInfo<Value>& info)

◆ GCCallback

using v8::GCCallback = typedef void (*)(GCType type, GCCallbackFlags flags)

◆ GenericNamedPropertyDefinerCallback

using v8::GenericNamedPropertyDefinerCallback = typedef void (*)(Local<Name> property, const PropertyDescriptor& desc, const PropertyCallbackInfo<Value>& info)

◆ GenericNamedPropertyDeleterCallback

using v8::GenericNamedPropertyDeleterCallback = typedef void (*)(Local<Name> property, const PropertyCallbackInfo<Boolean>& info)

◆ GenericNamedPropertyDescriptorCallback

using v8::GenericNamedPropertyDescriptorCallback = typedef void (*)(Local<Name> property, const PropertyCallbackInfo<Value>& info)

◆ GenericNamedPropertyEnumeratorCallback

using v8::GenericNamedPropertyEnumeratorCallback = typedef NamedPropertyEnumeratorCallback

◆ GenericNamedPropertyGetterCallback

using v8::GenericNamedPropertyGetterCallback = typedef void (*)(Local<Name> property, const PropertyCallbackInfo<Value>& info)

◆ GenericNamedPropertyQueryCallback

using v8::GenericNamedPropertyQueryCallback = typedef void (*)(Local<Name> property, const PropertyCallbackInfo<Integer>& info)

◆ GenericNamedPropertySetterCallback

using v8::GenericNamedPropertySetterCallback = typedef void (*)(Local<Name> property, Local<Value> value, const PropertyCallbackInfo<Value>& info)

◆ Handle

template<class T >

using v8::Handle = typedef Local<T>

◆ HostCreateShadowRealmContextCallback

using v8::HostCreateShadowRealmContextCallback = typedef MaybeLocal<Context> (*)(Local<Context> initiator_context)

HostCreateShadowRealmContextCallback is called each time a ShadowRealm is being constructed in the initiator_context.

The method combines Context creation and implementation defined abstract operation HostInitializeShadowRealm into one.

The embedder should use v8::Context::New or v8::Context:NewFromSnapshot to create a new context. If the creation fails, the embedder must propagate that exception by returning an empty MaybeLocal.

◆ HostImportModuleDynamicallyCallback

using v8::HostImportModuleDynamicallyCallback = typedef MaybeLocal<Promise> (*)( Local<Context> context, Local<Data> host_defined_options, Local<Value> resource_name, Local<String> specifier, Local<FixedArray> import_attributes)

HostImportModuleDynamicallyCallback is called when we require the embedder to load a module. This is used as part of the dynamic import syntax.

The referrer contains metadata about the script/module that calls import.

The specifier is the name of the module that should be imported.

The import_attributes are import attributes for this request in the form: [key1, value1, key2, value2, ...] where the keys and values are of type v8::String. Note, unlike the FixedArray passed to ResolveModuleCallback and returned from ModuleRequest::GetImportAssertions(), this array does not contain the source Locations of the attributes.

The embedder must compile, instantiate, evaluate the Module, and obtain its namespace object.

The Promise returned from this function is forwarded to userland JavaScript. The embedder must resolve this promise with the module namespace object. In case of an exception, the embedder must reject this promise with the exception. If the promise creation itself fails (e.g. due to stack overflow), the embedder must propagate that exception by returning an empty MaybeLocal.

◆ HostInitializeImportMetaObjectCallback

using v8::HostInitializeImportMetaObjectCallback = typedef void (*)(Local<Context> context, Local<Module> module, Local<Object> meta)

HostInitializeImportMetaObjectCallback is called the first time import.meta is accessed for a module. Subsequent access will reuse the same value.

The method combines two implementation-defined abstract operations into one: HostGetImportMetaProperties and HostFinalizeImportMeta.

The embedder should use v8::Object::CreateDataProperty to add properties on the meta object.

◆ IndexedPropertyDefinerCallback

using v8::IndexedPropertyDefinerCallback = typedef void (*)(uint32_t index, const PropertyDescriptor& desc, const PropertyCallbackInfo<Value>& info)

◆ IndexedPropertyDefinerCallbackV2

using v8::IndexedPropertyDefinerCallbackV2 = typedef Intercepted (*)(uint32_t index, const PropertyDescriptor& desc, const PropertyCallbackInfo<void>& info)

See v8::NamedPropertyDefinerCallback.

◆ IndexedPropertyDeleterCallback

using v8::IndexedPropertyDeleterCallback = typedef void (*)(uint32_t index, const PropertyCallbackInfo<Boolean>& info)

◆ IndexedPropertyDeleterCallbackV2

using v8::IndexedPropertyDeleterCallbackV2 = typedef Intercepted (*)(uint32_t index, const PropertyCallbackInfo<Boolean>& info)

See v8::NamedPropertyDeleterCallback.

◆ IndexedPropertyDescriptorCallback

using v8::IndexedPropertyDescriptorCallback = typedef void (*)(uint32_t index, const PropertyCallbackInfo<Value>& info)

◆ IndexedPropertyDescriptorCallbackV2

using v8::IndexedPropertyDescriptorCallbackV2 = typedef Intercepted (*)(uint32_t index, const PropertyCallbackInfo<Value>& info)

See v8::NamedPropertyDescriptorCallback.

◆ IndexedPropertyEnumeratorCallback

using v8::IndexedPropertyEnumeratorCallback = typedef void (*)(const PropertyCallbackInfo<Array>& info)

Returns an array containing the indices of the properties the indexed property getter intercepts.

Note: The values in the array must be uint32_t.

◆ IndexedPropertyGetterCallback

using v8::IndexedPropertyGetterCallback = typedef void (*)(uint32_t index, const PropertyCallbackInfo<Value>& info)

◆ IndexedPropertyGetterCallbackV2

using v8::IndexedPropertyGetterCallbackV2 = typedef Intercepted (*)(uint32_t index, const PropertyCallbackInfo<Value>& info)

See v8::NamedPropertyGetterCallback.

◆ IndexedPropertyQueryCallback

using v8::IndexedPropertyQueryCallback = typedef void (*)(uint32_t index, const PropertyCallbackInfo<Integer>& info)

◆ IndexedPropertyQueryCallbackV2

using v8::IndexedPropertyQueryCallbackV2 = typedef Intercepted (*)(uint32_t index, const PropertyCallbackInfo<Integer>& info)

See v8::NamedPropertyQueryCallback.

◆ IndexedPropertySetterCallback

using v8::IndexedPropertySetterCallback = typedef void (*)(uint32_t index, Local<Value> value, const PropertyCallbackInfo<Value>& info)

◆ IndexedPropertySetterCallbackV2

using v8::IndexedPropertySetterCallbackV2 = typedef Intercepted (*)( uint32_t index, Local<Value> value, const PropertyCallbackInfo<void>& info)

See v8::NamedPropertySetterCallback.

◆ InterruptCallback

using v8::InterruptCallback = typedef void (*)(Isolate* isolate, void* data)

◆ JavaScriptCompileHintsMagicEnabledCallback

using v8::JavaScriptCompileHintsMagicEnabledCallback = typedef bool (*)(Local<Context> context)

◆ JitCodeEventHandler

using v8::JitCodeEventHandler = typedef void (*)(const JitCodeEvent* event)

Callback function passed to SetJitCodeEventHandler.

Parameters

event code add, move or removal event.

◆ LogEventCallback

using v8::LogEventCallback = typedef void (*)(const char* name, int status)

◆ MessageCallback

using v8::MessageCallback = typedef void (*)(Local<Message> message, Local<Value> data)

◆ MicrotaskCallback

using v8::MicrotaskCallback = typedef void (*)(void* data)

◆ MicrotasksCompletedCallbackWithData

using v8::MicrotasksCompletedCallbackWithData = typedef void (*)(Isolate*, void*)

◆ ModifyCodeGenerationFromStringsCallback

using v8::ModifyCodeGenerationFromStringsCallback = typedef ModifyCodeGenerationFromStringsResult (*)(Local<Context> context, Local<Value> source)

Callback to check if codegen is allowed from a source object, and convert the source to string if necessary. See: ModifyCodeGenerationFromStrings.

◆ ModifyCodeGenerationFromStringsCallback2

using v8::ModifyCodeGenerationFromStringsCallback2 = typedef ModifyCodeGenerationFromStringsResult (*)(Local<Context> context, Local<Value> source, bool is_code_like)

◆ NamedPropertyDefinerCallback

using v8::NamedPropertyDefinerCallback = typedef Intercepted (*)(Local<Name> property, const PropertyDescriptor& desc, const PropertyCallbackInfo<void>& info)

Interceptor for defineProperty requests on an object.

If the interceptor handles the request (i.e. the property should not be looked up beyond the interceptor or in case an exception was thrown) it should return Intercepted::kYes. If the interceptor does not handle the request it must return Intercepted::kNo and it must not produce side effects.

Parameters

property	The name of the property for which the request was intercepted.
desc	The property descriptor which is used to define the property if the request is not intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’`mode. See`PropertyCallbackInfo`.

◆ NamedPropertyDeleterCallback

using v8::NamedPropertyDeleterCallback = typedef Intercepted (*)( Local<Name> property, const PropertyCallbackInfo<Boolean>& info)

Interceptor for delete requests on an object.

If the interceptor handles the request (i.e. the property should not be looked up beyond the interceptor or in case an exception was thrown) it should

(optionally) use info.GetReturnValue().Set() to set to a Boolean value indicating whether the property deletion was successful or not,
return Intercepted::kYes. If the interceptor does not handle the request it must return Intercepted::kNo and it must not produce side effects.

Parameters

property	The name of the property for which the request was intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’`mode. See`PropertyCallbackInfo`.

Note: If you need to mimic the behavior of delete, i.e., throw in strict mode instead of returning false, use info.ShouldThrowOnError() to determine if you are in strict mode.

◆ NamedPropertyDescriptorCallback

using v8::NamedPropertyDescriptorCallback = typedef Intercepted (*)( Local<Name> property, const PropertyCallbackInfo<Value>& info)

Interceptor for getOwnPropertyDescriptor requests on an object.

If the interceptor handles the request (i.e. the property should not be looked up beyond the interceptor or in case an exception was thrown) it should

(optionally) use info.GetReturnValue().Set() to set the return value which must be object that can be converted to a PropertyDescriptor (for example, a value returned by v8::Object::getOwnPropertyDescriptor),
return Intercepted::kYes. If the interceptor does not handle the request it must return Intercepted::kNo and it must not produce side effects.

Parameters

property The name of the property for which the request was intercepted. \info Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’mode. SeePropertyCallbackInfo`.

Note: If GetOwnPropertyDescriptor is intercepted, it will always return true, i.e., indicate that the property was found.

◆ NamedPropertyEnumeratorCallback

using v8::NamedPropertyEnumeratorCallback = typedef void (*)(const PropertyCallbackInfo<Array>& info)

Returns an array containing the names of the properties the named property getter intercepts.

Note: The values in the array must be of type v8::Name.

◆ NamedPropertyGetterCallback

using v8::NamedPropertyGetterCallback = typedef Intercepted (*)( Local<Name> property, const PropertyCallbackInfo<Value>& info)

Interceptor for get requests on an object.

If the interceptor handles the request (i.e. the property should not be looked up beyond the interceptor or in case an exception was thrown) it should

(optionally) use info.GetReturnValue().Set()` to set the return value (by default the result is set to v8::Undefined),
return Intercepted::kYes. If the interceptor does not handle the request it must return Intercepted::kNo and it must not produce side effects.

Parameters

property	The name of the property for which the request was intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’`mode. See`PropertyCallbackInfo`.

Intercepted GetterCallback(
    Local<Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
  if (!IsKnownProperty(info.GetIsolate(), name)) return Intercepted::kNo;
  info.GetReturnValue().Set(v8_num(42));
  return Intercepted::kYes;
}
 
v8::Local<v8::FunctionTemplate> templ =
    v8::FunctionTemplate::New(isolate);
templ->InstanceTemplate()->SetHandler(
    v8::NamedPropertyHandlerConfiguration(GetterCallback));
LocalContext env;
env->Global()
    ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
                                           .ToLocalChecked()
                                           ->NewInstance(env.local())
                                           .ToLocalChecked())
    .FromJust();
v8::Local<v8::Value> result = CompileRun("obj.a = 17; obj.a");
CHECK(v8_num(42)->Equals(env.local(), result).FromJust());

◆ NamedPropertyQueryCallback

using v8::NamedPropertyQueryCallback = typedef Intercepted (*)( Local<Name> property, const PropertyCallbackInfo<Integer>& info)

Intercepts all requests that query the attributes of the property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and defineProperty().

If the interceptor handles the request (i.e. the property should not be looked up beyond the interceptor or in case an exception was thrown) it should

(optionally) use info.GetReturnValue().Set() to set to an Integer value encoding a v8::PropertyAttribute bits,
return Intercepted::kYes. If the interceptor does not handle the request it must return Intercepted::kNo and it must not produce side effects.

Parameters

property	The name of the property for which the request was intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’`mode. See`PropertyCallbackInfo`.

Note: Some functions query the property attributes internally, even though they do not return the attributes. For example, hasOwnProperty() can trigger this interceptor depending on the state of the object.

◆ NamedPropertySetterCallback

using v8::NamedPropertySetterCallback = typedef Intercepted (*)(Local<Name> property, Local<Value> value, const PropertyCallbackInfo<void>& info)

Interceptor for set requests on an object.

If the interceptor handles the request (i.e. the property should not be looked up beyond the interceptor or in case an exception was thrown) it should return Intercepted::kYes. If the interceptor does not handle the request it must return Intercepted::kNo and it must not produce side effects.

Parameters

property	The name of the property for which the request was intercepted.
value	The value which the property will have if the request is not intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’`mode. See`PropertyCallbackInfo`.

◆ NativeObject

using v8::NativeObject = typedef void*

◆ NearHeapLimitCallback

using v8::NearHeapLimitCallback = typedef size_t (*)(void* data, size_t current_heap_limit, size_t initial_heap_limit)

This callback is invoked when the heap size is close to the heap limit and V8 is likely to abort with out-of-memory error. The callback can extend the heap limit by returning a value that is greater than the current_heap_limit. The initial heap limit is the limit that was set after heap setup.

◆ OOMErrorCallback

using v8::OOMErrorCallback = typedef void (*)(const char* location, const OOMDetails& details)

◆ PersistentContainerValue

typedef uintptr_t v8::PersistentContainerValue

◆ PlatformSharedMemoryHandle

using v8::PlatformSharedMemoryHandle = typedef intptr_t

◆ PrepareStackTraceCallback

using v8::PrepareStackTraceCallback = typedef MaybeLocal<Value> (*)(Local<Context> context, Local<Value> error, Local<Array> sites)

PrepareStackTraceCallback is called when the stack property of an error is first accessed. The return value will be used as the stack value. If this callback is registed, the |Error.prepareStackTrace| API will be disabled. |sites| is an array of call sites, specified in https://v8.dev/docs/stack-trace-api

◆ ProfilerId

using v8::ProfilerId = typedef uint32_t

◆ PromiseHook

using v8::PromiseHook = typedef void (*)(PromiseHookType type, Local<Promise> promise, Local<Value> parent)

◆ PromiseRejectCallback

using v8::PromiseRejectCallback = typedef void (*)(PromiseRejectMessage message)

◆ ReturnAddressLocationResolver

using v8::ReturnAddressLocationResolver = typedef uintptr_t (*)(uintptr_t return_addr_location)

ReturnAddressLocationResolver is used as a callback function when v8 is resolving the location of a return address on the stack. Profilers that change the return address on the stack can use this to resolve the stack location to wherever the profiler stashed the original return address.

Parameters

return_addr_location A location on stack where a machine return address resides.

Returns: Either return_addr_location, or else a pointer to the profiler's copy of the original return address.

Note: The resolver function must not cause garbage collection.

◆ SharedArrayBufferConstructorEnabledCallback

using v8::SharedArrayBufferConstructorEnabledCallback = typedef bool (*)(Local<Context> context)

◆ SnapshotObjectId

using v8::SnapshotObjectId = typedef uint32_t

◆ StackState

using v8::StackState = typedef cppgc::EmbedderStackState

Indicator for the stack state.

◆ UniquePersistent

template<class T >

using v8::UniquePersistent = typedef Global<T>

◆ WasmAsyncResolvePromiseCallback

using v8::WasmAsyncResolvePromiseCallback = typedef void (*)( Isolate* isolate, Local<Context> context, Local<Promise::Resolver> resolver, Local<Value> result, WasmAsyncSuccess success)

◆ WasmImportedStringsEnabledCallback

using v8::WasmImportedStringsEnabledCallback = typedef bool (*)(Local<Context> context)

◆ WasmJSPIEnabledCallback

using v8::WasmJSPIEnabledCallback = typedef bool (*)(Local<Context> context)

◆ WasmLoadSourceMapCallback

using v8::WasmLoadSourceMapCallback = typedef Local<String> (*)(Isolate* isolate, const char* name)

◆ WasmStreamingCallback

using v8::WasmStreamingCallback = typedef void (*)(const FunctionCallbackInfo<Value>&)

Enumeration Type Documentation

◆ AccessControl

enum v8::AccessControl

Access control specifications.

Some accessors should be accessible across contexts. These accessors have an explicit access control parameter which specifies the kind of cross-context access that should be allowed.

Enumerator
DEFAULT

◆ AccessType

enum v8::AccessType

Access type specification.

Enumerator
ACCESS_GET
ACCESS_SET
ACCESS_HAS
ACCESS_DELETE
ACCESS_KEYS

◆ ArrayBufferCreationMode

enum class v8::ArrayBufferCreationMode

strong

Enumerator
kInternalized
kExternalized

◆ BlockingType

enum class v8::BlockingType

strong

A "blocking call" refers to any call that causes the calling thread to wait off-CPU. It includes but is not limited to calls that wait on synchronous file I/O operations: read or write a file from disk, interact with a pipe or a socket, rename or delete a file, enumerate files in a directory, etc. Acquiring a low contention lock is not considered a blocking call. BlockingType indicates the likelihood that a blocking call will actually block.

Enumerator
kMayBlock
kWillBlock

◆ CodeEventType

enum v8::CodeEventType

Note that this enum may be extended in the future. Please include a default case if this enum is used in a switch statement.

Enumerator
kUnknownType
kBuiltinType
kCallbackType
kEvalType
kFunctionType
kInterpretedFunctionType
kHandlerType
kBytecodeHandlerType
kLazyCompileType
kRegExpType
kScriptType
kStubType
kRelocationType

◆ ConstructorBehavior

enum class v8::ConstructorBehavior

strong

Enumerator
kThrow
kAllow

◆ CppHeapPointerTag

enum class v8::CppHeapPointerTag : uint64_t

strong

A pointer tag used for wrapping and unwrapping CppHeap pointers as used with JS API wrapper objects that rely on v8::Object::Wrap() and v8::Object::Unwrap().

Enumerator
kDefaultTag

◆ CpuProfilingLoggingMode

enum v8::CpuProfilingLoggingMode

Enumerator
kLazyLogging
kEagerLogging

◆ CpuProfilingMode

enum v8::CpuProfilingMode

Enumerator
kLeafNodeLineNumbers
kCallerLineNumbers

◆ CpuProfilingNamingMode

enum v8::CpuProfilingNamingMode

Enumerator
kStandardNaming
kDebugNaming

◆ CpuProfilingStatus

enum class v8::CpuProfilingStatus

strong

Enumerator
kStarted
kAlreadyStarted
kErrorTooManyProfilers

◆ CrashKeyId

enum class v8::CrashKeyId

strong

Enumerator
kIsolateAddress
kReadonlySpaceFirstPageAddress
kMapSpaceFirstPageAddress
kOldSpaceFirstPageAddress
kCodeRangeBaseAddress
kCodeSpaceFirstPageAddress
kDumpType
kSnapshotChecksumCalculated
kSnapshotChecksumExpected

◆ EmbedderStateTag

enum class v8::EmbedderStateTag : uint8_t

strong

Enumerator
EMPTY
OTHER

◆ GCCallbackFlags

enum v8::GCCallbackFlags

GCCallbackFlags is used to notify additional information about the GC callback.

kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for constructing retained object infos.
kGCCallbackFlagForced: The GC callback is for a forced GC for testing.
kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback is called synchronously without getting posted to an idle task.
kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called in a phase where V8 is trying to collect all available garbage (e.g., handling a low memory notification).
kGCCallbackScheduleIdleGarbageCollection: The GC callback is called to trigger an idle garbage collection.

Enumerator
kNoGCCallbackFlags
kGCCallbackFlagConstructRetainedObjectInfos
kGCCallbackFlagForced
kGCCallbackFlagSynchronousPhantomCallbackProcessing
kGCCallbackFlagCollectAllAvailableGarbage
kGCCallbackFlagCollectAllExternalMemory
kGCCallbackScheduleIdleGarbageCollection

◆ GCType

enum v8::GCType

Applications can register callback functions which will be called before and after certain garbage collection operations. Allocations are not allowed in the callback functions, you therefore cannot manipulate objects (set or delete properties for example) since it is possible such operations will result in the allocation of objects. TODO(v8:12612): Deprecate kGCTypeMinorMarkSweep after updating blink.

Enumerator
kGCTypeScavenge
kGCTypeMinorMarkSweep
kGCTypeMinorMarkCompact
kGCTypeMarkSweepCompact
kGCTypeIncrementalMarking
kGCTypeProcessWeakCallbacks
kGCTypeAll

◆ IndexFilter

enum class v8::IndexFilter

strong

kIncludesIndices allows for integer indices to be collected, while kSkipIndices will exclude integer indices from being collected.

Enumerator
kIncludeIndices
kSkipIndices

◆ IntegrityLevel

enum class v8::IntegrityLevel

strong

Integrity level for objects.

Enumerator
kFrozen
kSealed

◆ Intercepted

enum class v8::Intercepted : uint8_t

strong

Interceptor callbacks use this value to indicate whether the request was intercepted or not.

Enumerator
kNo
kYes

◆ Intrinsic

enum v8::Intrinsic

Enumerator
kArrayProto_entries
kArrayProto_forEach
kArrayProto_keys
kArrayProto_values
kArrayPrototype
kAsyncIteratorPrototype
kErrorPrototype
kIteratorPrototype
kMapIteratorPrototype
kObjProto_valueOf
kSetIteratorPrototype

◆ JitCodeEventOptions

enum v8::JitCodeEventOptions

Option flags passed to the SetJitCodeEventHandler function.

Enumerator
kJitCodeEventDefault
kJitCodeEventEnumExisting

◆ KeyCollectionMode

enum class v8::KeyCollectionMode

strong

Keys/Properties filter enums:

KeyCollectionMode limits the range of collected properties. kOwnOnly limits the collected properties to the given Object only. kIncludesPrototypes will include all keys of the objects's prototype chain as well.

Enumerator
kOwnOnly
kIncludePrototypes

◆ KeyConversionMode

enum class v8::KeyConversionMode

strong

kConvertToString will convert integer indices to strings. kKeepNumbers will return numbers for integer indices.

Enumerator
kConvertToString
kKeepNumbers
kNoNumbers

◆ LogEventStatus

enum v8::LogEventStatus : int

Enumerator
kStart
kEnd
kStamp

◆ MeasureMemoryExecution

enum class v8::MeasureMemoryExecution

strong

Controls how promptly a memory measurement request is executed. By default the measurement is folded with the next scheduled GC which may happen after a while and is forced after some timeout. The kEager mode starts incremental GC right away and is useful for testing. The kLazy mode does not force GC.

Enumerator
kDefault
kEager
kLazy

◆ MeasureMemoryMode

enum class v8::MeasureMemoryMode

strong

Controls how the default MeasureMemoryDelegate reports the result of the memory measurement to JS. With kSummary only the total size is reported. With kDetailed the result includes the size of each native context.

Enumerator
kSummary
kDetailed

◆ MemoryPressureLevel

enum class v8::MemoryPressureLevel

strong

Memory pressure level for the MemoryPressureNotification. kNone hints V8 that there is no memory pressure. kModerate hints V8 to speed up incremental garbage collection at the cost of of higher latency due to garbage collection pauses. kCritical hints V8 to free memory as soon as possible. Garbage collection pauses at this level will be large.

Enumerator
kNone
kModerate
kCritical

◆ MicrotasksPolicy

enum class v8::MicrotasksPolicy

strong

Policy for running microtasks:

explicit: microtasks are invoked with the Isolate::PerformMicrotaskCheckpoint() method;
scoped: microtasks invocation is controlled by MicrotasksScope objects;
auto: microtasks are invoked when the script call depth decrements to zero.

Enumerator
kExplicit
kScoped
kAuto

◆ NewStringType

enum class v8::NewStringType

strong

A flag describing different modes of string creation.

Aside from performance implications there are no differences between the two creation modes.

Enumerator
kNormal	Create a new string, always allocating new storage memory.
kInternalized	Acts as a hint that the string should be created in the old generation heap space and be deduplicated if an identical string already exists.

◆ PagePermissions

enum class v8::PagePermissions

strong

Possible permissions for memory pages.

Enumerator
kNoAccess
kRead
kReadWrite
kReadWriteExecute
kReadExecute

◆ PersistentContainerCallbackType

enum v8::PersistentContainerCallbackType

Enumerator
kNotWeak
kWeakWithParameter
kWeakWithInternalFields

◆ PromiseHookType

enum class v8::PromiseHookType

strong

PromiseHook with type kInit is called when a new promise is created. When a new promise is created as part of the chain in the case of Promise.then or in the intermediate promises created by Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise otherwise we pass undefined.

PromiseHook with type kResolve is called at the beginning of resolve or reject function defined by CreateResolvingFunctions.

PromiseHook with type kBefore is called at the beginning of the PromiseReactionJob.

PromiseHook with type kAfter is called right at the end of the PromiseReactionJob.

Enumerator
kInit
kResolve
kBefore
kAfter

◆ PromiseRejectEvent

enum v8::PromiseRejectEvent

Enumerator
kPromiseRejectWithNoHandler
kPromiseHandlerAddedAfterReject
kPromiseRejectAfterResolved
kPromiseResolveAfterResolved

◆ PropertyAttribute

enum v8::PropertyAttribute

PropertyAttribute.

Enumerator
None	None.
ReadOnly	ReadOnly, i.e., not writable.
DontEnum	DontEnum, i.e., not enumerable.
DontDelete	DontDelete, i.e., not configurable.

◆ PropertyFilter

enum v8::PropertyFilter

Property filter bits. They can be or'ed to build a composite filter.

Enumerator
ALL_PROPERTIES
ONLY_WRITABLE
ONLY_ENUMERABLE
ONLY_CONFIGURABLE
SKIP_STRINGS
SKIP_SYMBOLS

◆ PropertyHandlerFlags

enum class v8::PropertyHandlerFlags

strong

Configuration flags for v8::NamedPropertyHandlerConfiguration or v8::IndexedPropertyHandlerConfiguration.

Enumerator
kNone	None.
kNonMasking	Will not call into interceptor for properties on the receiver or prototype chain, i.e., only call into interceptor for properties that do not exist. Currently only valid for named interceptors.
kOnlyInterceptStrings	Will not call into interceptor for symbol lookup. Only meaningful for named interceptors.
kHasNoSideEffect	The getter, query, enumerator callbacks do not produce side effects.
kInternalNewCallbacksSignatures	This flag is used to distinguish which callbacks were provided - GenericNamedPropertyXXXCallback (old signature) or NamedPropertyXXXCallback (new signature). DO NOT use this flag, it'll be removed once embedders migrate to new callbacks signatures.

◆ RAILMode

enum v8::RAILMode : unsigned

Option flags passed to the SetRAILMode function. See documentation https://developers.google.com/web/tools/chrome-devtools/ profile/evaluate-performance/rail

Enumerator
PERFORMANCE_RESPONSE
PERFORMANCE_ANIMATION
PERFORMANCE_IDLE
PERFORMANCE_LOAD

◆ ScriptType

enum class v8::ScriptType

strong

Enumerator
kClassic
kModule

◆ SideEffectType

enum class v8::SideEffectType

strong

Options for marking whether callbacks may trigger JS-observable side effects. Side-effect-free callbacks are allowlisted during debug evaluation with throwOnSideEffect. It applies when calling a Function, FunctionTemplate, or an Accessor callback. For Interceptors, please see PropertyHandlerFlags's kHasNoSideEffect. Callbacks that only cause side effects to the receiver are allowlisted if invoked on receiver objects that are created within the same debug-evaluate call, as these objects are temporary and the side effect does not escape.

Enumerator
kHasSideEffect
kHasNoSideEffect
kHasSideEffectToReceiver

◆ StateTag

enum v8::StateTag : uint16_t

Enumerator
JS
GC
PARSER
BYTECODE_COMPILER
COMPILER
OTHER
EXTERNAL
ATOMICS_WAIT
IDLE
LOGGING

◆ TaskPriority

enum class v8::TaskPriority : uint8_t

strong

Enumerator
kBestEffort	Best effort tasks are not critical for performance of the application. The platform implementation should preempt such tasks if higher priority tasks arrive.
kUserVisible	User visible tasks are long running background tasks that will improve performance and memory usage of the application upon completion. Example: background compilation and garbage collection.
kUserBlocking	User blocking tasks are highest priority tasks that block the execution thread (e.g. major garbage collection). They must be finished as soon as possible.
kMaxPriority

◆ WasmAsyncSuccess

enum class v8::WasmAsyncSuccess

strong

Enumerator
kSuccess
kFail

◆ WeakCallbackType

enum class v8::WeakCallbackType

strong

Weakness type for weak handles.

Enumerator
kParameter	Passes a user-defined void* parameter back to the callback.
kInternalFields	Passes the first two internal fields of the object back to the callback.

Function Documentation

◆ CurrentValueSerializerFormatVersion()

constexpr uint32_t v8::CurrentValueSerializerFormatVersion ( )

constexpr

◆ False()

Local< Boolean > v8::False ( Isolate * isolate )

inline

Here is the caller graph for this function:

◆ FileDescriptorFromSharedMemoryHandle()

int v8::FileDescriptorFromSharedMemoryHandle ( PlatformSharedMemoryHandle handle )

inline

◆ Just() [1/2]

template<class T >

Maybe< T > v8::Just ( const T & t )

inline

◆ Just() [2/2]

template<class T , std::enable_if_t<!std::is_lvalue_reference_v< T > > * = nullptr>

Maybe< T > v8::Just ( T && t )

inline

◆ JustVoid()

Maybe< void > v8::JustVoid ( )

inline

◆ Nothing()

template<class T >

Maybe< T > v8::Nothing ( )

inline

◆ Null()

Local< Primitive > v8::Null ( Isolate * isolate )

inline

◆ operator!=() [1/3]

bool v8::operator!=	(	const TracedReferenceBase &	lhs,
		const TracedReferenceBase &	rhs
	)

inline

◆ operator!=() [2/3]

template<typename U >

bool v8::operator!=	(	const TracedReferenceBase &	lhs,
		const v8::Local< U > &	rhs
	)

inline

◆ operator!=() [3/3]

template<typename U >

bool v8::operator!=	(	const v8::Local< U > &	lhs,
		const TracedReferenceBase &	rhs
	)

inline

◆ operator==() [1/3]

bool v8::operator==	(	const TracedReferenceBase &	lhs,
		const TracedReferenceBase &	rhs
	)

inline

◆ operator==() [2/3]

template<typename U >

bool v8::operator==	(	const TracedReferenceBase &	lhs,
		const v8::Local< U > &	rhs
	)

inline

◆ operator==() [3/3]

template<typename U >

bool v8::operator==	(	const v8::Local< U > &	lhs,
		const TracedReferenceBase &	rhs
	)

inline

◆ RegisterExtension()

void v8::RegisterExtension ( std::unique_ptr< Extension > )

◆ SharedMemoryHandleFromFileDescriptor()

PlatformSharedMemoryHandle v8::SharedMemoryHandleFromFileDescriptor ( int fd )

inline

◆ to_array() [1/2]

template<class T , std::size_t N>

constexpr std::array< std::remove_cv_t< T >, N > v8::to_array ( T(&&) a[N] )

constexpr

Here is the call graph for this function:

◆ to_array() [2/2]

template<class T , std::size_t N>

constexpr std::array< std::remove_cv_t< T >, N > v8::to_array ( T(&) a[N] )

constexpr

Here is the call graph for this function:

◆ True()

Local< Boolean > v8::True ( Isolate * isolate )

inline

Here is the caller graph for this function:

◆ TryHandleWebAssemblyTrapPosix()

bool v8::TryHandleWebAssemblyTrapPosix	(	int	sig_code,
		siginfo_t *	info,
		void *	context
	)

This function determines whether a memory access violation has been an out-of-bounds memory access in WebAssembly. If so, it will modify the context parameter and add a return address where the execution can continue after the signal handling, and return true. Otherwise, false will be returned.

The parameters to this function correspond to those passed to a Posix signal handler. Use this function only on Linux and Mac.

Parameters

sig_code	The signal code, e.g. SIGSEGV.
info	A pointer to the siginfo_t struct provided to the signal handler.
context	A pointer to a ucontext_t struct provided to the signal handler.

◆ TryHandleWebAssemblyTrapWindows()

bool v8::TryHandleWebAssemblyTrapWindows ( EXCEPTION_POINTERS * exception )

This function determines whether a memory access violation has been an out-of-bounds memory access in WebAssembly. If so, it will modify the exception parameter and add a return address where the execution can continue after the exception handling, and return true. Otherwise the return value will be false.

The parameter to this function corresponds to the one passed to a Windows vectored exception handler. Use this function only on Windows.

Parameters

exception An EXCEPTION_POINTERS* as provided to the exception handler.

◆ TryToCopyAndConvertArrayToCppBuffer()

template<CTypeInfo::Identifier type_info_id, typename T >

bool v8::TryToCopyAndConvertArrayToCppBuffer	(	Local< Array >	src,
		T *	dst,
		uint32_t	max_length
	)

Copies the contents of this JavaScript array to a C++ buffer with a given max_length. A CTypeInfo is passed as an argument, instructing different rules for conversion (e.g. restricted float/double). The element type T of the destination array must match the C type corresponding to the CTypeInfo (specified by CTypeInfoTraits). If the array length is larger than max_length or the array is of unsupported type, the operation will fail, returning false. Generally, an array which contains objects, undefined, null or anything not convertible to the requested destination type, is considered unsupported. The operation returns true on success. type_info will be used for conversions.

◆ Undefined()

Local< Primitive > v8::Undefined ( Isolate * isolate )

inline

Here is the caller graph for this function:

Namespaces

Classes

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ AccessCheckCallback

◆ AccessorGetterCallback

◆ AccessorNameGetterCallback

◆ AccessorNameSetterCallback

◆ AccessorSetterCallback

◆ AddCrashKeyCallback

◆ AddHistogramSampleCallback

◆ AllowCodeGenerationFromStringsCallback

◆ AllowWasmCodeGenerationCallback

◆ ApiImplementationCallback

◆ BackingStoreDeleterCallback

◆ BeforeCallEnteredCallback

◆ CallCompletedCallback

◆ CFunctionBuilder

◆ CompileHintCallback

◆ CounterLookupCallback

◆ CreateHistogramCallback

◆ DcheckErrorCallback

◆ EntropySource

◆ ExtensionCallback

◆ FailedAccessCheckCallback

◆ FatalErrorCallback

◆ FunctionCallback

◆ GCCallback

◆ GenericNamedPropertyDefinerCallback

◆ GenericNamedPropertyDeleterCallback

◆ GenericNamedPropertyDescriptorCallback

◆ GenericNamedPropertyEnumeratorCallback

◆ GenericNamedPropertyGetterCallback

◆ GenericNamedPropertyQueryCallback

◆ GenericNamedPropertySetterCallback

◆ Handle

◆ HostCreateShadowRealmContextCallback

◆ HostImportModuleDynamicallyCallback

◆ HostInitializeImportMetaObjectCallback

◆ IndexedPropertyDefinerCallback

◆ IndexedPropertyDefinerCallbackV2

◆ IndexedPropertyDeleterCallback

◆ IndexedPropertyDeleterCallbackV2

◆ IndexedPropertyDescriptorCallback

◆ IndexedPropertyDescriptorCallbackV2

◆ IndexedPropertyEnumeratorCallback

◆ IndexedPropertyGetterCallback

◆ IndexedPropertyGetterCallbackV2

◆ IndexedPropertyQueryCallback

◆ IndexedPropertyQueryCallbackV2

◆ IndexedPropertySetterCallback

◆ IndexedPropertySetterCallbackV2

◆ InterruptCallback

◆ JavaScriptCompileHintsMagicEnabledCallback

◆ JitCodeEventHandler

◆ LogEventCallback

◆ MessageCallback

◆ MicrotaskCallback

◆ MicrotasksCompletedCallbackWithData

◆ ModifyCodeGenerationFromStringsCallback

◆ ModifyCodeGenerationFromStringsCallback2

◆ NamedPropertyDefinerCallback

◆ NamedPropertyDeleterCallback

◆ NamedPropertyDescriptorCallback

◆ NamedPropertyEnumeratorCallback

◆ NamedPropertyGetterCallback

◆ NamedPropertyQueryCallback

◆ NamedPropertySetterCallback

◆ NativeObject

◆ NearHeapLimitCallback

◆ OOMErrorCallback

◆ PersistentContainerValue

◆ PlatformSharedMemoryHandle

◆ PrepareStackTraceCallback

◆ ProfilerId

◆ PromiseHook

◆ PromiseRejectCallback