// Copyright 2012 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.
/** \mainpage V8 API Reference Guide
*
* V8 is Google's open source JavaScript engine.
*
* This set of documents provides reference material generated from the
* V8 header file, include/v8.h.
*
* For other documentation see https://v8.dev/.
*/
#ifndef INCLUDE_V8_H_
#define INCLUDE_V8_H_
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <atomic>
#include <memory>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "cppgc/common.h"
#include "v8-internal.h" // NOLINT(build/include_directory)
#include "v8-version.h" // NOLINT(build/include_directory)
#include "v8config.h" // NOLINT(build/include_directory)
// We reserve the V8_* prefix for macros defined in V8 public API and
// assume there are no name conflicts with the embedder's code.
/**
* The v8 JavaScript engine.
*/
namespace v8 {
class AccessorSignature;
class Array;
class ArrayBuffer;
class BigInt;
class BigIntObject;
class Boolean;
class BooleanObject;
class CFunction;
class CallHandlerHelper;
class Context;
class CppHeap;
class CTypeInfo;
class Data;
class Date;
class EscapableHandleScope;
class External;
class Function;
class FunctionTemplate;
class HeapProfiler;
class ImplementationUtilities;
class Int32;
class Integer;
class Isolate;
class Isolate;
class MicrotaskQueue;
class Name;
class Number;
class NumberObject;
class Object;
class ObjectOperationDescriptor;
class ObjectTemplate;
class Platform;
class Primitive;
class PrimitiveArray;
class Private;
class Promise;
class PropertyDescriptor;
class Proxy;
class RawOperationDescriptor;
class Script;
class SharedArrayBuffer;
class Signature;
class StackFrame;
class StackTrace;
class StartupData;
class String;
class StringObject;
class Symbol;
class SymbolObject;
class TracedReferenceBase;
class Uint32;
class Utils;
class Value;
class WasmMemoryObject;
class WasmModuleObject;
template <class K, class V, class T>
class GlobalValueMap;
template <class K, class V, class T>
class PersistentValueMapBase;
template<class T> class NonCopyablePersistentTraits;
template <class T, class M = NonCopyablePersistentTraits<T>>
class Persistent;
template <class T>
class BasicTracedReference;
template <class T>
class Eternal;
template <class T>
class Global;
template <class T>
class Local;
template <class T>
class Maybe;
template <class T>
class MaybeLocal;
template <class T>
class TracedGlobal;
template <class T>
class TracedReference;
template<class K, class V, class T> class PersistentValueMap;
template<class T, class P> class WeakCallbackObject;
template <class T>
class PersistentBase;
template <class V, class T>
class PersistentValueVector;
template<typename T> class FunctionCallbackInfo;
template<typename T> class PropertyCallbackInfo;
template<typename T> class ReturnValue;
namespace internal {
class BasicTracedReferenceExtractor;
class ExternalString;
class FunctionCallbackArguments;
class GlobalHandles;
class Heap;
class HeapObject;
class Isolate;
class LocalEmbedderHeapTracer;
class MicrotaskQueue;
class PropertyCallbackArguments;
class ReadOnlyHeap;
class ScopedExternalStringLock;
class ThreadLocalTop;
struct ScriptStreamingData;
enum class ArgumentsType;
template <ArgumentsType>
class Arguments;
template <typename T>
class CustomArguments;
namespace wasm {
class NativeModule;
class StreamingDecoder;
} // namespace wasm
} // namespace internal
namespace metrics {
class Recorder;
} // namespace metrics
namespace debug {
class ConsoleCallArguments;
} // namespace debug
// --- Handles ---
/**
* An object reference managed by the v8 garbage collector.
*
* All objects returned from v8 have to be tracked by the garbage
* collector so that it knows that the objects are still alive. Also,
* because the garbage collector may move objects, it is unsafe to
* point directly to an object. Instead, all objects are stored in
* handles which are known by the garbage collector and updated
* whenever an object moves. Handles should always be passed by value
* (except in cases like out-parameters) and they should never be
* allocated on the heap.
*
* There are two types of handles: local and persistent handles.
*
* Local handles are light-weight and transient and typically used in
* local operations. They are managed by HandleScopes. That means that a
* HandleScope must exist on the stack when they are created and that they are
* only valid inside of the HandleScope active during their creation.
* For passing a local handle to an outer HandleScope, an EscapableHandleScope
* and its Escape() method must be used.
*
* Persistent handles can be used when storing objects across several
* independent operations and have to be explicitly deallocated when they're no
* longer used.
*
* It is safe to extract the object stored in the handle by
* dereferencing the handle (for instance, to extract the Object* from
* a Local<Object>); the value will still be governed by a handle
* behind the scenes and the same rules apply to these values as to
* their handles.
*/
template <class T>
class Local {
public:
V8_INLINE Local() : val_(nullptr) {}
template <class S>
V8_INLINE Local(Local<S> that)
: val_(reinterpret_cast<T*>(*that)) {
/**
* This check fails when trying to convert between incompatible
* handles. For example, converting from a Local<String> to a
* Local<Number>.
*/
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* Returns true if the handle is empty.
*/
V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
/**
* Sets the handle to be empty. IsEmpty() will then return true.
*/
V8_INLINE void Clear() { val_ = nullptr; }
V8_INLINE T* operator->() const { return val_; }
V8_INLINE T* operator*() const { return val_; }
/**
* Checks whether two handles are the same.
* Returns true if both are empty, or if the objects to which they refer
* are identical.
*
* If both handles refer to JS objects, this is the same as strict equality.
* For primitives, such as numbers or strings, a `false` return value does not
* indicate that the values aren't equal in the JavaScript sense.
* Use `Value::StrictEquals()` to check primitives for equality.
*/
template <class S>
V8_INLINE bool operator==(const Local<S>& that) const {
internal::Address* a = reinterpret_cast<internal::Address*>(this->val_);
internal::Address* b = reinterpret_cast<internal::Address*>(that.val_);
if (a == nullptr) return b == nullptr;
if (b == nullptr) return false;
return *a == *b;
}
template <class S> V8_INLINE bool operator==(
const PersistentBase<S>& that) const {
internal::Address* a = reinterpret_cast<internal::Address*>(this->val_);
internal::Address* b = reinterpret_cast<internal::Address*>(that.val_);
if (a == nullptr) return b == nullptr;
if (b == nullptr) return false;
return *a == *b;
}
/**
* Checks whether two handles are different.
* Returns true if only one of the handles is empty, or if
* the objects to which they refer are different.
*
* If both handles refer to JS objects, this is the same as strict
* non-equality. For primitives, such as numbers or strings, a `true` return
* value does not indicate that the values aren't equal in the JavaScript
* sense. Use `Value::StrictEquals()` to check primitives for equality.
*/
template <class S>
V8_INLINE bool operator!=(const Local<S>& that) const {
return !operator==(that);
}
template <class S> V8_INLINE bool operator!=(
const Persistent<S>& that) const {
return !operator==(that);
}
/**
* Cast a handle to a subclass, e.g. Local<Value> to Local<Object>.
* This is only valid if the handle actually refers to a value of the
* target type.
*/
template <class S> V8_INLINE static Local<T> Cast(Local<S> that) {
#ifdef V8_ENABLE_CHECKS
// If we're going to perform the type check then we have to check
// that the handle isn't empty before doing the checked cast.
if (that.IsEmpty()) return Local<T>();
#endif
return Local<T>(T::Cast(*that));
}
/**
* Calling this is equivalent to Local<S>::Cast().
* In particular, this is only valid if the handle actually refers to a value
* of the target type.
*/
template <class S>
V8_INLINE Local<S> As() const {
return Local<S>::Cast(*this);
}
/**
* Create a local handle for the content of another handle.
* The referee is kept alive by the local handle even when
* the original handle is destroyed/disposed.
*/
V8_INLINE static Local<T> New(Isolate* isolate, Local<T> that);
V8_INLINE static Local<T> New(Isolate* isolate,
const PersistentBase<T>& that);
V8_INLINE static Local<T> New(Isolate* isolate,
const BasicTracedReference<T>& that);
private:
friend class TracedReferenceBase;
friend class Utils;
template<class F> friend class Eternal;
template<class F> friend class PersistentBase;
template<class F, class M> friend class Persistent;
template<class F> friend class Local;
template <class F>
friend class MaybeLocal;
template<class F> friend class FunctionCallbackInfo;
template<class F> friend class PropertyCallbackInfo;
friend class String;
friend class Object;
friend class Context;
friend class Isolate;
friend class Private;
template<class F> friend class internal::CustomArguments;
friend Local<Primitive> Undefined(Isolate* isolate);
friend Local<Primitive> Null(Isolate* isolate);
friend Local<Boolean> True(Isolate* isolate);
friend Local<Boolean> False(Isolate* isolate);
friend class HandleScope;
friend class EscapableHandleScope;
template <class F1, class F2, class F3>
friend class PersistentValueMapBase;
template<class F1, class F2> friend class PersistentValueVector;
template <class F>
friend class ReturnValue;
template <class F>
friend class Traced;
template <class F>
friend class TracedGlobal;
template <class F>
friend class BasicTracedReference;
template <class F>
friend class TracedReference;
explicit V8_INLINE Local(T* that) : val_(that) {}
V8_INLINE static Local<T> New(Isolate* isolate, T* that);
T* val_;
};
#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
// Handle is an alias for Local for historical reasons.
template <class T>
using Handle = Local<T>;
#endif
/**
* A MaybeLocal<> is a wrapper around Local<> that enforces a check whether
* the Local<> is empty before it can be used.
*
* If an API method returns a MaybeLocal<>, the API method can potentially fail
* either because an exception is thrown, or because an exception is pending,
* e.g. because a previous API call threw an exception that hasn't been caught
* yet, or because a TerminateExecution exception was thrown. In that case, an
* empty MaybeLocal is returned.
*/
template <class T>
class MaybeLocal {
public:
V8_INLINE MaybeLocal() : val_(nullptr) {}
template <class S>
V8_INLINE MaybeLocal(Local<S> that)
: val_(reinterpret_cast<T*>(*that)) {
static_assert(std::is_base_of<T, S>::value, "type check");
}
V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
/**
* Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
* |false| is returned and |out| is left untouched.
*/
template <class S>
V8_WARN_UNUSED_RESULT V8_INLINE bool ToLocal(Local<S>* out) const {
out->val_ = IsEmpty() ? nullptr : this->val_;
return !IsEmpty();
}
/**
* Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
* V8 will crash the process.
*/
V8_INLINE Local<T> ToLocalChecked();
/**
* Converts this MaybeLocal<> to a Local<>, using a default value if this
* MaybeLocal<> is empty.
*/
template <class S>
V8_INLINE Local<S> FromMaybe(Local<S> default_value) const {
return IsEmpty() ? default_value : Local<S>(val_);
}
private:
T* val_;
};
/**
* Eternal handles are set-once handles that live for the lifetime of the
* isolate.
*/
template <class T> class Eternal {
public:
V8_INLINE Eternal() : val_(nullptr) {}
template <class S>
V8_INLINE Eternal(Isolate* isolate, Local<S> handle) : val_(nullptr) {
Set(isolate, handle);
}
// Can only be safely called if already set.
V8_INLINE Local<T> Get(Isolate* isolate) const;
V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
template<class S> V8_INLINE void Set(Isolate* isolate, Local<S> handle);
private:
T* val_;
};
static const int kInternalFieldsInWeakCallback = 2;
static const int kEmbedderFieldsInWeakCallback = 2;
template <typename T>
class WeakCallbackInfo {
public:
using Callback = void (*)(const WeakCallbackInfo<T>& data);
WeakCallbackInfo(Isolate* isolate, T* parameter,
void* embedder_fields[kEmbedderFieldsInWeakCallback],
Callback* callback)
: isolate_(isolate), parameter_(parameter), callback_(callback) {
for (int i = 0; i < kEmbedderFieldsInWeakCallback; ++i) {
embedder_fields_[i] = embedder_fields[i];
}
}
V8_INLINE Isolate* GetIsolate() const { return isolate_; }
V8_INLINE T* GetParameter() const { return parameter_; }
V8_INLINE void* GetInternalField(int index) const;
// When first called, the embedder MUST Reset() the Global which triggered the
// callback. The Global itself is unusable for anything else. No v8 other api
// calls may be called in the first callback. Should additional work be
// required, the embedder must set a second pass callback, which will be
// called after all the initial callbacks are processed.
// Calling SetSecondPassCallback on the second pass will immediately crash.
void SetSecondPassCallback(Callback callback) const { *callback_ = callback; }
private:
Isolate* isolate_;
T* parameter_;
Callback* callback_;
void* embedder_fields_[kEmbedderFieldsInWeakCallback];
};
// kParameter will pass a void* parameter back to the callback, kInternalFields
// will pass the first two internal fields back to the callback, kFinalizer
// will pass a void* parameter back, but is invoked before the object is
// actually collected, so it can be resurrected. In the last case, it is not
// possible to request a second pass callback.
enum class WeakCallbackType { kParameter, kInternalFields, kFinalizer };
/**
* An object reference that is independent of any handle scope. Where
* a Local handle only lives as long as the HandleScope in which it was
* allocated, a PersistentBase handle remains valid until it is explicitly
* disposed using Reset().
*
* A persistent handle contains a reference to a storage cell within
* the V8 engine which holds an object value and which is updated by
* the garbage collector whenever the object is moved. A new storage
* cell can be created using the constructor or PersistentBase::Reset and
* existing handles can be disposed using PersistentBase::Reset.
*
*/
template <class T> class PersistentBase {
public:
/**
* If non-empty, destroy the underlying storage cell
* IsEmpty() will return true after this call.
*/
V8_INLINE void Reset();
/**
* If non-empty, destroy the underlying storage cell
* and create a new one with the contents of other if other is non empty
*/
template <class S>
V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
/**
* If non-empty, destroy the underlying storage cell
* and create a new one with the contents of other if other is non empty
*/
template <class S>
V8_INLINE void Reset(Isolate* isolate, const PersistentBase<S>& other);
V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
V8_INLINE void Empty() { val_ = 0; }
V8_INLINE Local<T> Get(Isolate* isolate) const {
return Local<T>::New(isolate, *this);
}
template <class S>
V8_INLINE bool operator==(const PersistentBase<S>& that) const {
internal::Address* a = reinterpret_cast<internal::Address*>(this->val_);
internal::Address* b = reinterpret_cast<internal::Address*>(that.val_);
if (a == nullptr) return b == nullptr;
if (b == nullptr) return false;
return *a == *b;
}
template <class S>
V8_INLINE bool operator==(const Local<S>& that) const {
internal::Address* a = reinterpret_cast<internal::Address*>(this->val_);
internal::Address* b = reinterpret_cast<internal::Address*>(that.val_);
if (a == nullptr) return b == nullptr;
if (b == nullptr) return false;
return *a == *b;
}
template <class S>
V8_INLINE bool operator!=(const PersistentBase<S>& that) const {
return !operator==(that);
}
template <class S>
V8_INLINE bool operator!=(const Local<S>& that) const {
return !operator==(that);
}
/**
* Install a finalization callback on this object.
* NOTE: There is no guarantee as to *when* or even *if* the callback is
* invoked. The invocation is performed solely on a best effort basis.
* As always, GC-based finalization should *not* be relied upon for any
* critical form of resource management!
*
* The callback is supposed to reset the handle. No further V8 API may be
* called in this callback. In case additional work involving V8 needs to be
* done, a second callback can be scheduled using
* WeakCallbackInfo<void>::SetSecondPassCallback.
*/
template <typename P>
V8_INLINE void SetWeak(P* parameter,
typename WeakCallbackInfo<P>::Callback callback,
WeakCallbackType type);
/**
* Turns this handle into a weak phantom handle without finalization callback.
* The handle will be reset automatically when the garbage collector detects
* that the object is no longer reachable.
* A related function Isolate::NumberOfPhantomHandleResetsSinceLastCall
* returns how many phantom handles were reset by the garbage collector.
*/
V8_INLINE void SetWeak();
template<typename P>
V8_INLINE P* ClearWeak();
// TODO(dcarney): remove this.
V8_INLINE void ClearWeak() { ClearWeak<void>(); }
/**
* Annotates the strong handle with the given label, which is then used by the
* heap snapshot generator as a name of the edge from the root to the handle.
* The function does not take ownership of the label and assumes that the
* label is valid as long as the handle is valid.
*/
V8_INLINE void AnnotateStrongRetainer(const char* label);
/** Returns true if the handle's reference is weak. */
V8_INLINE bool IsWeak() const;
/**
* Assigns a wrapper class ID to the handle.
*/
V8_INLINE void SetWrapperClassId(uint16_t class_id);
/**
* Returns the class ID previously assigned to this handle or 0 if no class ID
* was previously assigned.
*/
V8_INLINE uint16_t WrapperClassId() const;
PersistentBase(const PersistentBase& other) = delete;
void operator=(const PersistentBase&) = delete;
private:
friend class Isolate;
friend class Utils;
template<class F> friend class Local;
template<class F1, class F2> friend class Persistent;
template <class F>
friend class Global;
template<class F> friend class PersistentBase;
template<class F> friend class ReturnValue;
template <class F1, class F2, class F3>
friend class PersistentValueMapBase;
template<class F1, class F2> friend class PersistentValueVector;
friend class Object;
explicit V8_INLINE PersistentBase(T* val) : val_(val) {}
V8_INLINE static T* New(Isolate* isolate, T* that);
T* val_;
};
/**
* Default traits for Persistent. This class does not allow
* use of the copy constructor or assignment operator.
* At present kResetInDestructor is not set, but that will change in a future
* version.
*/
template<class T>
class NonCopyablePersistentTraits {
public:
using NonCopyablePersistent = Persistent<T, NonCopyablePersistentTraits<T>>;
static const bool kResetInDestructor = false;
template<class S, class M>
V8_INLINE static void Copy(const Persistent<S, M>& source,
NonCopyablePersistent* dest) {
static_assert(sizeof(S) < 0,
"NonCopyablePersistentTraits::Copy is not instantiable");
}
};
/**
* Helper class traits to allow copying and assignment of Persistent.
* This will clone the contents of storage cell, but not any of the flags, etc.
*/
template<class T>
struct CopyablePersistentTraits {
using CopyablePersistent = Persistent<T, CopyablePersistentTraits<T>>;
static const bool kResetInDestructor = true;
template<class S, class M>
static V8_INLINE void Copy(const Persistent<S, M>& source,
CopyablePersistent* dest) {
// do nothing, just allow copy
}
};
/**
* A PersistentBase which allows copy and assignment.
*
* Copy, assignment and destructor behavior is controlled by the traits
* class M.
*
* Note: Persistent class hierarchy is subject to future changes.
*/
template <class T, class M> class Persistent : public PersistentBase<T> {
public:
/**
* A Persistent with no storage cell.
*/
V8_INLINE Persistent() : PersistentBase<T>(nullptr) {}
/**
* Construct a Persistent from a Local.
* When the Local is non-empty, a new storage cell is created
* pointing to the same object, and no flags are set.
*/
template <class S>
V8_INLINE Persistent(Isolate* isolate, Local<S> that)
: PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* Construct a Persistent from a Persistent.
* When the Persistent is non-empty, a new storage cell is created
* pointing to the same object, and no flags are set.
*/
template <class S, class M2>
V8_INLINE Persistent(Isolate* isolate, const Persistent<S, M2>& that)
: PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* The copy constructors and assignment operator create a Persistent
* exactly as the Persistent constructor, but the Copy function from the
* traits class is called, allowing the setting of flags based on the
* copied Persistent.
*/
V8_INLINE Persistent(const Persistent& that) : PersistentBase<T>(nullptr) {
Copy(that);
}
template <class S, class M2>
V8_INLINE Persistent(const Persistent<S, M2>& that) : PersistentBase<T>(0) {
Copy(that);
}
V8_INLINE Persistent& operator=(const Persistent& that) {
Copy(that);
return *this;
}
template <class S, class M2>
V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) {
Copy(that);
return *this;
}
/**
* The destructor will dispose the Persistent based on the
* kResetInDestructor flags in the traits class. Since not calling dispose
* can result in a memory leak, it is recommended to always set this flag.
*/
V8_INLINE ~Persistent() {
if (M::kResetInDestructor) this->Reset();
}
// TODO(dcarney): this is pretty useless, fix or remove
template <class S>
V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {
#ifdef V8_ENABLE_CHECKS
// If we're going to perform the type check then we have to check
// that the handle isn't empty before doing the checked cast.
if (!that.IsEmpty()) T::Cast(*that);
#endif
return reinterpret_cast<Persistent<T>&>(const_cast<Persistent<S>&>(that));
}
// TODO(dcarney): this is pretty useless, fix or remove
template <class S>
V8_INLINE Persistent<S>& As() const {
return Persistent<S>::Cast(*this);
}
private:
friend class Isolate;
friend class Utils;
template<class F> friend class Local;
template<class F1, class F2> friend class Persistent;
template<class F> friend class ReturnValue;
explicit V8_INLINE Persistent(T* that) : PersistentBase<T>(that) {}
V8_INLINE T* operator*() const { return this->val_; }
template<class S, class M2>
V8_INLINE void Copy(const Persistent<S, M2>& that);
};
/**
* A PersistentBase which has move semantics.
*
* Note: Persistent class hierarchy is subject to future changes.
*/
template <class T>
class Global : public PersistentBase<T> {
public:
/**
* A Global with no storage cell.
*/
V8_INLINE Global() : PersistentBase<T>(nullptr) {}
/**
* Construct a Global from a Local.
* When the Local is non-empty, a new storage cell is created
* pointing to the same object, and no flags are set.
*/
template <class S>
V8_INLINE Global(Isolate* isolate, Local<S> that)
: PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* Construct a Global from a PersistentBase.
* When the Persistent is non-empty, a new storage cell is created
* pointing to the same object, and no flags are set.
*/
template <class S>
V8_INLINE Global(Isolate* isolate, const PersistentBase<S>& that)
: PersistentBase<T>(PersistentBase<T>::New(isolate, that.val_)) {
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* Move constructor.
*/
V8_INLINE Global(Global&& other);
V8_INLINE ~Global() { this->Reset(); }
/**
* Move via assignment.
*/
template <class S>
V8_INLINE Global& operator=(Global<S>&& rhs);
/**
* Pass allows returning uniques from functions, etc.
*/
Global Pass() { return static_cast<Global&&>(*this); }
/*
* For compatibility with Chromium's base::Bind (base::Passed).
*/
using MoveOnlyTypeForCPP03 = void;
Global(const Global&) = delete;
void operator=(const Global&) = delete;
private:
template <class F>
friend class ReturnValue;
V8_INLINE T* operator*() const { return this->val_; }
};
// UniquePersistent is an alias for Global for historical reason.
template <class T>
using UniquePersistent = Global<T>;
/**
* Deprecated. Use |TracedReference<T>| instead.
*/
template <typename T>
struct TracedGlobalTrait {};
class TracedReferenceBase {
public:
/**
* Returns true if the reference is empty, i.e., has not been assigned
* object.
*/
bool IsEmpty() const { return val_ == nullptr; }
/**
* If non-empty, destroy the underlying storage cell. |IsEmpty| will return
* true after this call.
*/
V8_INLINE void Reset();
/**
* Construct a Local<Value> from this handle.
*/
V8_INLINE v8::Local<v8::Value> Get(v8::Isolate* isolate) const;
/**
* Returns true if this TracedReference is empty, i.e., has not been
* assigned an object. This version of IsEmpty is thread-safe.
*/
bool IsEmptyThreadSafe() const {
return this->GetSlotThreadSafe() == nullptr;
}
/**
* Assigns a wrapper class ID to the handle.
*/
V8_INLINE void SetWrapperClassId(uint16_t class_id);
/**
* Returns the class ID previously assigned to this handle or 0 if no class ID
* was previously assigned.
*/
V8_INLINE uint16_t WrapperClassId() const;
protected:
/**
* Update this reference in a thread-safe way.
*/
void SetSlotThreadSafe(void* new_val) {
reinterpret_cast<std::atomic<void*>*>(&val_)->store(
new_val, std::memory_order_relaxed);
}
/**
* Get this reference in a thread-safe way
*/
const void* GetSlotThreadSafe() const {
return reinterpret_cast<std::atomic<const void*> const*>(&val_)->load(
std::memory_order_relaxed);
}
V8_EXPORT void CheckValue() const;
// val_ points to a GlobalHandles node.
internal::Address* val_ = nullptr;
friend class internal::BasicTracedReferenceExtractor;
template <typename F>
friend class Local;
template <typename U>
friend bool operator==(const TracedReferenceBase&, const Local<U>&);
friend bool operator==(const TracedReferenceBase&,
const TracedReferenceBase&);
};
/**
* A traced handle with copy and move semantics. The handle is to be used
* together with |v8::EmbedderHeapTracer| or as part of GarbageCollected objects
* (see v8-cppgc.h) and specifies edges from C++ objects to JavaScript.
*
* The exact semantics are:
* - Tracing garbage collections use |v8::EmbedderHeapTracer| or cppgc.
* - Non-tracing garbage collections refer to
* |v8::EmbedderRootsHandler::IsRoot()| whether the handle should
* be treated as root or not.
*
* Note that the base class cannot be instantiated itself. Choose from
* - TracedGlobal
* - TracedReference
*/
template <typename T>
class BasicTracedReference : public TracedReferenceBase {
public:
/**
* Construct a Local<T> from this handle.
*/
Local<T> Get(Isolate* isolate) const { return Local<T>::New(isolate, *this); }
template <class S>
V8_INLINE BasicTracedReference<S>& As() const {
return reinterpret_cast<BasicTracedReference<S>&>(
const_cast<BasicTracedReference<T>&>(*this));
}
T* operator->() const {
#ifdef V8_ENABLE_CHECKS
CheckValue();
#endif // V8_ENABLE_CHECKS
return reinterpret_cast<T*>(val_);
}
T* operator*() const {
#ifdef V8_ENABLE_CHECKS
CheckValue();
#endif // V8_ENABLE_CHECKS
return reinterpret_cast<T*>(val_);
}
private:
enum DestructionMode { kWithDestructor, kWithoutDestructor };
/**
* An empty BasicTracedReference without storage cell.
*/
BasicTracedReference() = default;
V8_INLINE static internal::Address* New(Isolate* isolate, T* that, void* slot,
DestructionMode destruction_mode);
friend class EmbedderHeapTracer;
template <typename F>
friend class Local;
friend class Object;
template <typename F>
friend class TracedGlobal;
template <typename F>
friend class TracedReference;
template <typename F>
friend class BasicTracedReference;
template <typename F>
friend class ReturnValue;
};
/**
* A traced handle with destructor that clears the handle. For more details see
* BasicTracedReference.
*/
template <typename T>
class TracedGlobal : public BasicTracedReference<T> {
public:
using BasicTracedReference<T>::Reset;
/**
* Destructor resetting the handle.Is
*/
~TracedGlobal() { this->Reset(); }
/**
* An empty TracedGlobal without storage cell.
*/
TracedGlobal() : BasicTracedReference<T>() {}
/**
* Construct a TracedGlobal from a Local.
*
* When the Local is non-empty, a new storage cell is created
* pointing to the same object.
*/
template <class S>
TracedGlobal(Isolate* isolate, Local<S> that) : BasicTracedReference<T>() {
this->val_ = this->New(isolate, that.val_, &this->val_,
BasicTracedReference<T>::kWithDestructor);
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* Move constructor initializing TracedGlobal from an existing one.
*/
V8_INLINE TracedGlobal(TracedGlobal&& other) {
// Forward to operator=.
*this = std::move(other);
}
/**
* Move constructor initializing TracedGlobal from an existing one.
*/
template <typename S>
V8_INLINE TracedGlobal(TracedGlobal<S>&& other) {
// Forward to operator=.
*this = std::move(other);
}
/**
* Copy constructor initializing TracedGlobal from an existing one.
*/
V8_INLINE TracedGlobal(const TracedGlobal& other) {
// Forward to operator=;
*this = other;
}
/**
* Copy constructor initializing TracedGlobal from an existing one.
*/
template <typename S>
V8_INLINE TracedGlobal(const TracedGlobal<S>& other) {
// Forward to operator=;
*this = other;
}
/**
* Move assignment operator initializing TracedGlobal from an existing one.
*/
V8_INLINE TracedGlobal& operator=(TracedGlobal&& rhs);
/**
* Move assignment operator initializing TracedGlobal from an existing one.
*/
template <class S>
V8_INLINE TracedGlobal& operator=(TracedGlobal<S>&& rhs);
/**
* Copy assignment operator initializing TracedGlobal from an existing one.
*
* Note: Prohibited when |other| has a finalization callback set through
* |SetFinalizationCallback|.
*/
V8_INLINE TracedGlobal& operator=(const TracedGlobal& rhs);
/**
* Copy assignment operator initializing TracedGlobal from an existing one.
*
* Note: Prohibited when |other| has a finalization callback set through
* |SetFinalizationCallback|.
*/
template <class S>
V8_INLINE TracedGlobal& operator=(const TracedGlobal<S>& rhs);
/**
* If non-empty, destroy the underlying storage cell and create a new one with
* the contents of other if other is non empty
*/
template <class S>
V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
template <class S>
V8_INLINE TracedGlobal<S>& As() const {
return reinterpret_cast<TracedGlobal<S>&>(
const_cast<TracedGlobal<T>&>(*this));
}
/**
* Adds a finalization callback to the handle. The type of this callback is
* similar to WeakCallbackType::kInternalFields, i.e., it will pass the
* parameter and the first two internal fields of the object.
*
* The callback is then supposed to reset the handle in the callback. No
* further V8 API may be called in this callback. In case additional work
* involving V8 needs to be done, a second callback can be scheduled using
* WeakCallbackInfo<void>::SetSecondPassCallback.
*/
V8_INLINE void SetFinalizationCallback(
void* parameter, WeakCallbackInfo<void>::Callback callback);
};
/**
* A traced handle without destructor that clears the handle. The embedder needs
* to ensure that the handle is not accessed once the V8 object has been
* reclaimed. This can happen when the handle is not passed through the
* EmbedderHeapTracer. For more details see BasicTracedReference.
*
* The reference assumes the embedder has precise knowledge about references at
* all times. In case V8 needs to separately handle on-stack references, the
* embedder is required to set the stack start through
* |EmbedderHeapTracer::SetStackStart|.
*/
template <typename T>
class TracedReference : public BasicTracedReference<T> {
public:
using BasicTracedReference<T>::Reset;
/**
* An empty TracedReference without storage cell.
*/
TracedReference() : BasicTracedReference<T>() {}
/**
* Construct a TracedReference from a Local.
*
* When the Local is non-empty, a new storage cell is created
* pointing to the same object.
*/
template <class S>
TracedReference(Isolate* isolate, Local<S> that) : BasicTracedReference<T>() {
this->val_ = this->New(isolate, that.val_, &this->val_,
BasicTracedReference<T>::kWithoutDestructor);
static_assert(std::is_base_of<T, S>::value, "type check");
}
/**
* Move constructor initializing TracedReference from an
* existing one.
*/
V8_INLINE TracedReference(TracedReference&& other) {
// Forward to operator=.
*this = std::move(other);
}
/**
* Move constructor initializing TracedReference from an
* existing one.
*/
template <typename S>
V8_INLINE TracedReference(TracedReference<S>&& other) {
// Forward to operator=.
*this = std::move(other);
}
/**
* Copy constructor initializing TracedReference from an
* existing one.
*/
V8_INLINE TracedReference(const TracedReference& other) {
// Forward to operator=;
*this = other;
}
/**
* Copy constructor initializing TracedReference from an
* existing one.
*/
template <typename S>
V8_INLINE TracedReference(const TracedReference<S>& other) {
// Forward to operator=;
*this = other;
}
/**
* Move assignment operator initializing TracedGlobal from an existing one.
*/
V8_INLINE TracedReference& operator=(TracedReference&& rhs);
/**
* Move assignment operator initializing TracedGlobal from an existing one.
*/
template <class S>
V8_INLINE TracedReference& operator=(TracedReference<S>&& rhs);
/**
* Copy assignment operator initializing TracedGlobal from an existing one.
*/
V8_INLINE TracedReference& operator=(const TracedReference& rhs);
/**
* Copy assignment operator initializing TracedGlobal from an existing one.
*/
template <class S>
V8_INLINE TracedReference& operator=(const TracedReference<S>& rhs);
/**
* If non-empty, destroy the underlying storage cell and create a new one with
* the contents of other if other is non empty
*/
template <class S>
V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
template <class S>
V8_INLINE TracedReference<S>& As() const {
return reinterpret_cast<TracedReference<S>&>(
const_cast<TracedReference<T>&>(*this));
}
};
/**
* A stack-allocated class that governs a number of local handles.
* After a handle scope has been created, all local handles will be
* allocated within that handle scope until either the handle scope is
* deleted or another handle scope is created. If there is already a
* handle scope and a new one is created, all allocations will take
* place in the new handle scope until it is deleted. After that,
* new handles will again be allocated in the original handle scope.
*
* After the handle scope of a local handle has been deleted the
* garbage collector will no longer track the object stored in the
* handle and may deallocate it. The behavior of accessing a handle
* for which the handle scope has been deleted is undefined.
*/
class V8_EXPORT V8_NODISCARD HandleScope {
public:
explicit HandleScope(Isolate* isolate);
~HandleScope();
/**
* Counts the number of allocated handles.
*/
static int NumberOfHandles(Isolate* isolate);
V8_INLINE Isolate* GetIsolate() const {
return reinterpret_cast<Isolate*>(isolate_);
}
HandleScope(const HandleScope&) = delete;
void operator=(const HandleScope&) = delete;
protected:
V8_INLINE HandleScope() = default;
void Initialize(Isolate* isolate);
static internal::Address* CreateHandle(internal::Isolate* isolate,
internal::Address value);
private:
// Declaring operator new and delete as deleted is not spec compliant.
// Therefore declare them private instead to disable dynamic alloc
void* operator new(size_t size);
void* operator new[](size_t size);
void operator delete(void*, size_t);
void operator delete[](void*, size_t);
internal::Isolate* isolate_;
internal::Address* prev_next_;
internal::Address* prev_limit_;
// Local::New uses CreateHandle with an Isolate* parameter.
template<class F> friend class Local;
// Object::GetInternalField and Context::GetEmbedderData use CreateHandle with
// a HeapObject in their shortcuts.
friend class Object;
friend class Context;
};
/**
* A HandleScope which first allocates a handle in the current scope
* which will be later filled with the escape value.
*/
class V8_EXPORT V8_NODISCARD EscapableHandleScope : public HandleScope {
public:
explicit EscapableHandleScope(Isolate* isolate);
V8_INLINE ~EscapableHandleScope() = default;
/**
* Pushes the value into the previous scope and returns a handle to it.
* Cannot be called twice.
*/
template <class T>
V8_INLINE Local<T> Escape(Local<T> value) {
internal::Address* slot =
Escape(reinterpret_cast<internal::Address*>(*value));
return Local<T>(reinterpret_cast<T*>(slot));
}
template <class T>
V8_INLINE MaybeLocal<T> EscapeMaybe(MaybeLocal<T> value) {
return Escape(value.FromMaybe(Local<T>()));
}
EscapableHandleScope(const EscapableHandleScope&) = delete;
void operator=(const EscapableHandleScope&) = delete;
private:
// Declaring operator new and delete as deleted is not spec compliant.
// Therefore declare them private instead to disable dynamic alloc
void* operator new(size_t size);
void* operator new[](size_t size);
void operator delete(void*, size_t);
void operator delete[](void*, size_t);
internal::Address* Escape(internal::Address* escape_value);
internal::Address* escape_slot_;
};
/**
* A SealHandleScope acts like a handle scope in which no handle allocations
* are allowed. It can be useful for debugging handle leaks.
* Handles can be allocated within inner normal HandleScopes.
*/
class V8_EXPORT V8_NODISCARD SealHandleScope {
public:
explicit SealHandleScope(Isolate* isolate);
~SealHandleScope();
SealHandleScope(const SealHandleScope&) = delete;
void operator=(const SealHandleScope&) = delete;
private:
// Declaring operator new and delete as deleted is not spec compliant.
// Therefore declare them private instead to disable dynamic alloc
void* operator new(size_t size);
void* operator new[](size_t size);
void operator delete(void*, size_t);
void operator delete[](void*, size_t);
internal::Isolate* const isolate_;
internal::Address* prev_limit_;
int prev_sealed_level_;
};
// --- Special objects ---
/**
* The superclass of objects that can reside on V8's heap.
*/
class V8_EXPORT Data {
public:
/**
* Returns true if this data is a |v8::Value|.
*/
bool IsValue() const;
/**
* Returns true if this data is a |v8::Module|.
*/
bool IsModule() const;
/**
* Returns true if this data is a |v8::Private|.
*/
bool IsPrivate() const;
/**
* Returns true if this data is a |v8::ObjectTemplate|.
*/
bool IsObjectTemplate() const;
/**
* Returns true if this data is a |v8::FunctionTemplate|.
*/
bool IsFunctionTemplate() const;
/**
* Returns true if this data is a |v8::Context|.
*/
bool IsContext() const;
private:
Data();
};
/**
* A container type that holds relevant metadata for module loading.
*
* This is passed back to the embedder as part of
* HostImportModuleDynamicallyCallback for module loading.
*/
class V8_EXPORT ScriptOrModule {
public:
/**
* The name that was passed by the embedder as ResourceName to the
* ScriptOrigin. This can be either a v8::String or v8::Undefined.
*/
Local<Value> GetResourceName();
/**
* The options that were passed by the embedder as HostDefinedOptions to
* the ScriptOrigin.
*/
Local<PrimitiveArray> GetHostDefinedOptions();
};
/**
* An array to hold Primitive values. This is used by the embedder to
* pass host defined options to the ScriptOptions during compilation.
*
* This is passed back to the embedder as part of
* HostImportModuleDynamicallyCallback for module loading.
*
*/
class V8_EXPORT PrimitiveArray {
public:
static Local<PrimitiveArray> New(Isolate* isolate, int length);
int Length() const;
void Set(Isolate* isolate, int index, Local<Primitive> item);
Local<Primitive> Get(Isolate* isolate, int index);
};
/**
* The optional attributes of ScriptOrigin.
*/
class ScriptOriginOptions {
public:
V8_INLINE ScriptOriginOptions(bool is_shared_cross_origin = false,
bool is_opaque = false, bool is_wasm = false,
bool is_module = false)
: flags_((is_shared_cross_origin ? kIsSharedCrossOrigin : 0) |
(is_wasm ? kIsWasm : 0) | (is_opaque ? kIsOpaque : 0) |
(is_module ? kIsModule : 0)) {}
V8_INLINE ScriptOriginOptions(int flags)
: flags_(flags &
(kIsSharedCrossOrigin | kIsOpaque | kIsWasm | kIsModule)) {}
bool IsSharedCrossOrigin() const {
return (flags_ & kIsSharedCrossOrigin) != 0;
}
bool IsOpaque() const { return (flags_ & kIsOpaque) != 0; }
bool IsWasm() const { return (flags_ & kIsWasm) != 0; }
bool IsModule() const { return (flags_ & kIsModule) != 0; }
int Flags() const { return flags_; }
private:
enum {
kIsSharedCrossOrigin = 1,
kIsOpaque = 1 << 1,
kIsWasm = 1 << 2,
kIsModule = 1 << 3
};
const int flags_;
};
/**
* The origin, within a file, of a script.
*/
class ScriptOrigin {
public:
#if defined(_MSC_VER) && _MSC_VER >= 1910 /* Disable on VS2015 */
V8_DEPRECATED("Use constructor with primitive C++ types")
#endif
V8_INLINE explicit ScriptOrigin(
Local<Value> resource_name, Local<Integer> resource_line_offset,
Local<Integer> resource_column_offset,
Local<Boolean> resource_is_shared_cross_origin = Local<Boolean>(),
Local<Integer> script_id = Local<Integer>(),
Local<Value> source_map_url = Local<Value>(),
Local<Boolean> resource_is_opaque = Local<Boolean>(),
Local<Boolean> is_wasm = Local<Boolean>(),
Local<Boolean> is_module = Local<Boolean>(),
Local<PrimitiveArray> host_defined_options = Local<PrimitiveArray>());
#if defined(_MSC_VER) && _MSC_VER >= 1910 /* Disable on VS2015 */
V8_DEPRECATED("Use constructor that takes an isolate")
#endif
V8_INLINE explicit ScriptOrigin(
Local<Value> resource_name, int resource_line_offset = 0,
int resource_column_offset = 0,
bool resource_is_shared_cross_origin = false, int script_id = -1,
Local<Value> source_map_url = Local<Value>(),
bool resource_is_opaque = false, bool is_wasm = false,
bool is_module = false,
Local<PrimitiveArray> host_defined_options = Local<PrimitiveArray>());
V8_INLINE explicit ScriptOrigin(
Isolate* isolate, Local<Value> resource_name,
int resource_line_offset = 0, int resource_column_offset = 0,
bool resource_is_shared_cross_origin = false, int script_id = -1,
Local<Value> source_map_url = Local<Value>(),
bool resource_is_opaque = false, bool is_wasm = false,
bool is_module = false,
Local<PrimitiveArray> host_defined_options = Local<PrimitiveArray>());
V8_INLINE Local<Value> ResourceName() const;
V8_DEPRECATED("Use getter with primitvie C++ types.")
V8_INLINE Local<Integer> ResourceLineOffset() const;
V8_DEPRECATED("Use getter with primitvie C++ types.")
V8_INLINE Local<Integer> ResourceColumnOffset() const;
V8_DEPRECATED("Use getter with primitvie C++ types.")
V8_INLINE Local<Integer> ScriptID() const;
V8_INLINE int LineOffset() const;
V8_INLINE int ColumnOffset() const;
V8_INLINE int ScriptId() const;
V8_INLINE Local<Value> SourceMapUrl() const;
V8_INLINE Local<PrimitiveArray> HostDefinedOptions() const;
V8_INLINE ScriptOriginOptions Options() const { return options_; }
private:
Isolate* isolate_;
Local<Value> resource_name_;
int resource_line_offset_;
int resource_column_offset_;
ScriptOriginOptions options_;
int script_id_;
Local<Value> source_map_url_;
Local<PrimitiveArray> host_defined_options_;
};
/**
* A compiled JavaScript script, not yet tied to a Context.
*/
class V8_EXPORT UnboundScript {
public:
/**
* Binds the script to the currently entered context.
*/
Local<Script> BindToCurrentContext();
int GetId();
Local<Value> GetScriptName();
/**
* Data read from magic sourceURL comments.
*/
Local<Value> GetSourceURL();
/**
* Data read from magic sourceMappingURL comments.
*/
Local<Value> GetSourceMappingURL();
/**
* Returns zero based line number of the code_pos location in the script.
* -1 will be returned if no information available.
*/
int GetLineNumber(int code_pos);
static const int kNoScriptId = 0;
};
/**
* A compiled JavaScript module, not yet tied to a Context.
*/
class V8_EXPORT UnboundModuleScript : public Data {
// Only used as a container for code caching.
};
/**
* A location in JavaScript source.
*/
class V8_EXPORT Location {
public:
int GetLineNumber() { return line_number_; }
int GetColumnNumber() { return column_number_; }
Location(int line_number, int column_number)
: line_number_(line_number), column_number_(column_number) {}
private:
int line_number_;
int column_number_;
};
/**
* A fixed-sized array with elements of type Data.
*/
class V8_EXPORT FixedArray : public Data {
public:
int Length() const;
Local<Data> Get(Local<Context> context, int i) const;
};
class V8_EXPORT ModuleRequest : public Data {
public:
/**
* Returns the module specifier for this ModuleRequest.
*/
Local<String> GetSpecifier() const;
/**
* Returns the source code offset of this module request.
* Use Module::SourceOffsetToLocation to convert this to line/column numbers.
*/
int GetSourceOffset() const;
/**
* Contains the import assertions for this request in the form:
* [key1, value1, source_offset1, key2, value2, source_offset2, ...].
* The keys and values are of type v8::String, and the source offsets are of
* type Int32. Use Module::SourceOffsetToLocation to convert the source
* offsets to Locations with line/column numbers.
*
* All assertions present in the module request will be supplied in this
* list, regardless of whether they are supported by the host. Per
* https://tc39.es/proposal-import-assertions/#sec-hostgetsupportedimportassertions,
* hosts are expected to ignore assertions that they do not support (as
* opposed to, for example, triggering an error if an unsupported assertion is
* present).
*/
Local<FixedArray> GetImportAssertions() const;
V8_INLINE static ModuleRequest* Cast(Data* data);
private:
static void CheckCast(Data* obj);
};
/**
* A compiled JavaScript module.
*/
class V8_EXPORT Module : public Data {
public:
/**
* The different states a module can be in.
*
* This corresponds to the states used in ECMAScript except that "evaluated"
* is split into kEvaluated and kErrored, indicating success and failure,
* respectively.
*/
enum Status {
kUninstantiated,
kInstantiating,
kInstantiated,
kEvaluating,
kEvaluated,
kErrored
};
/**
* Returns the module's current status.
*/
Status GetStatus() const;
/**
* For a module in kErrored status, this returns the corresponding exception.
*/
Local<Value> GetException() const;
/**
* Returns the number of modules requested by this module.
*/
V8_DEPRECATED("Use Module::GetModuleRequests() and FixedArray::Length().")
int GetModuleRequestsLength() const;
/**
* Returns the ith module specifier in this module.
* i must be < GetModuleRequestsLength() and >= 0.
*/
V8_DEPRECATED(
"Use Module::GetModuleRequests() and ModuleRequest::GetSpecifier().")
Local<String> GetModuleRequest(int i) const;
/**
* Returns the source location (line number and column number) of the ith
* module specifier's first occurrence in this module.
*/
V8_DEPRECATED(
"Use Module::GetModuleRequests(), ModuleRequest::GetSourceOffset(), and "
"Module::SourceOffsetToLocation().")
Location GetModuleRequestLocation(int i) const;
/**
* Returns the ModuleRequests for this module.
*/
Local<FixedArray> GetModuleRequests() const;
/**
* For the given source text offset in this module, returns the corresponding
* Location with line and column numbers.
*/
Location SourceOffsetToLocation(int offset) const;
/**
* Returns the identity hash for this object.
*/
int GetIdentityHash() const;
using ResolveCallback =
MaybeLocal<Module> (*)(Local<Context> context, Local<String> specifier,
Local<Module> referrer);
using ResolveModuleCallback = MaybeLocal<Module> (*)(
Local<Context> context, Local<String> specifier,
Local<FixedArray> import_assertions, Local<Module> referrer);
/**
* Instantiates the module and its dependencies.
*
* Returns an empty Maybe<bool> if an exception occurred during
* instantiation. (In the case where the callback throws an exception, that
* exception is propagated.)
*/
V8_DEPRECATED(
"Use the version of InstantiateModule that takes a ResolveModuleCallback "
"parameter")
V8_WARN_UNUSED_RESULT Maybe<bool> InstantiateModule(Local<Context> context,
ResolveCallback callback);
V8_WARN_UNUSED_RESULT Maybe<bool> InstantiateModule(
Local<Context> context, ResolveModuleCallback callback);
/**
* Evaluates the module and its dependencies.
*
* If status is kInstantiated, run the module's code and return a Promise
* object. On success, set status to kEvaluated and resolve the Promise with
* the completion value; on failure, set status to kErrored and reject the
* Promise with the error.
*
* If IsGraphAsync() is false, the returned Promise is settled.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Evaluate(Local<Context> context);
/**
* Returns the namespace object of this module.
*
* The module's status must be at least kInstantiated.
*/
Local<Value> GetModuleNamespace();
/**
* Returns the corresponding context-unbound module script.
*
* The module must be unevaluated, i.e. its status must not be kEvaluating,
* kEvaluated or kErrored.
*/
Local<UnboundModuleScript> GetUnboundModuleScript();
/**
* Returns the underlying script's id.
*
* The module must be a SourceTextModule and must not have a kErrored status.
*/
int ScriptId();
/**
* Returns whether this module or any of its requested modules is async,
* i.e. contains top-level await.
*
* The module's status must be at least kInstantiated.
*/
bool IsGraphAsync() const;
/**
* Returns whether the module is a SourceTextModule.
*/
bool IsSourceTextModule() const;
/**
* Returns whether the module is a SyntheticModule.
*/
bool IsSyntheticModule() const;
/*
* Callback defined in the embedder. This is responsible for setting
* the module's exported values with calls to SetSyntheticModuleExport().
* The callback must return a resolved Promise to indicate success (where no
* exception was thrown) and return an empy MaybeLocal to indicate falure
* (where an exception was thrown).
*/
using SyntheticModuleEvaluationSteps =
MaybeLocal<Value> (*)(Local<Context> context, Local<Module> module);
/**
* Creates a new SyntheticModule with the specified export names, where
* evaluation_steps will be executed upon module evaluation.
* export_names must not contain duplicates.
* module_name is used solely for logging/debugging and doesn't affect module
* behavior.
*/
static Local<Module> CreateSyntheticModule(
Isolate* isolate, Local<String> module_name,
const std::vector<Local<String>>& export_names,
SyntheticModuleEvaluationSteps evaluation_steps);
/**
* Set this module's exported value for the name export_name to the specified
* export_value. This method must be called only on Modules created via
* CreateSyntheticModule. An error will be thrown if export_name is not one
* of the export_names that were passed in that CreateSyntheticModule call.
* Returns Just(true) on success, Nothing<bool>() if an error was thrown.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetSyntheticModuleExport(
Isolate* isolate, Local<String> export_name, Local<Value> export_value);
V8_DEPRECATED(
"Use the preceding SetSyntheticModuleExport with an Isolate parameter, "
"instead of the one that follows. The former will throw a runtime "
"error if called for an export that doesn't exist (as per spec); "
"the latter will crash with a failed CHECK().")
void SetSyntheticModuleExport(Local<String> export_name,
Local<Value> export_value);
V8_INLINE static Module* Cast(Data* data);
private:
static void CheckCast(Data* obj);
};
/**
* A compiled JavaScript script, tied to a Context which was active when the
* script was compiled.
*/
class V8_EXPORT Script {
public:
/**
* A shorthand for ScriptCompiler::Compile().
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
Local<Context> context, Local<String> source,
ScriptOrigin* origin = nullptr);
/**
* Runs the script returning the resulting value. It will be run in the
* context in which it was created (ScriptCompiler::CompileBound or
* UnboundScript::BindToCurrentContext()).
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Run(Local<Context> context);
/**
* Returns the corresponding context-unbound script.
*/
Local<UnboundScript> GetUnboundScript();
};
enum class ScriptType { kClassic, kModule };
/**
* For compiling scripts.
*/
class V8_EXPORT ScriptCompiler {
public:
/**
* Compilation data that the embedder can cache and pass back to speed up
* future compilations. The data is produced if the CompilerOptions passed to
* the compilation functions in ScriptCompiler contains produce_data_to_cache
* = true. The data to cache can then can be retrieved from
* UnboundScript.
*/
struct V8_EXPORT CachedData {
enum BufferPolicy {
BufferNotOwned,
BufferOwned
};
CachedData()
: data(nullptr),
length(0),
rejected(false),
buffer_policy(BufferNotOwned) {}
// If buffer_policy is BufferNotOwned, the caller keeps the ownership of
// data and guarantees that it stays alive until the CachedData object is
// destroyed. If the policy is BufferOwned, the given data will be deleted
// (with delete[]) when the CachedData object is destroyed.
CachedData(const uint8_t* data, int length,
BufferPolicy buffer_policy = BufferNotOwned);
~CachedData();
// TODO(marja): Async compilation; add constructors which take a callback
// which will be called when V8 no longer needs the data.
const uint8_t* data;
int length;
bool rejected;
BufferPolicy buffer_policy;
// Prevent copying.
CachedData(const CachedData&) = delete;
CachedData& operator=(const CachedData&) = delete;
};
/**
* Source code which can be then compiled to a UnboundScript or Script.
*/
class Source {
public:
// Source takes ownership of CachedData.
V8_INLINE Source(Local<String> source_string, const ScriptOrigin& origin,
CachedData* cached_data = nullptr);
V8_INLINE explicit Source(Local<String> source_string,
CachedData* cached_data = nullptr);
V8_INLINE ~Source();
// Ownership of the CachedData or its buffers is *not* transferred to the
// caller. The CachedData object is alive as long as the Source object is
// alive.
V8_INLINE const CachedData* GetCachedData() const;
V8_INLINE const ScriptOriginOptions& GetResourceOptions() const;
// Prevent copying.
Source(const Source&) = delete;
Source& operator=(const Source&) = delete;
private:
friend class ScriptCompiler;
Local<String> source_string;
// Origin information
Local<Value> resource_name;
int resource_line_offset;
int resource_column_offset;
ScriptOriginOptions resource_options;
Local<Value> source_map_url;
Local<PrimitiveArray> host_defined_options;
// Cached data from previous compilation (if a kConsume*Cache flag is
// set), or hold newly generated cache data (kProduce*Cache flags) are
// set when calling a compile method.
CachedData* cached_data;
};
/**
* For streaming incomplete script data to V8. The embedder should implement a
* subclass of this class.
*/
class V8_EXPORT ExternalSourceStream {
public:
virtual ~ExternalSourceStream() = default;
/**
* V8 calls this to request the next chunk of data from the embedder. This
* function will be called on a background thread, so it's OK to block and
* wait for the data, if the embedder doesn't have data yet. Returns the
* length of the data returned. When the data ends, GetMoreData should
* return 0. Caller takes ownership of the data.
*
* When streaming UTF-8 data, V8 handles multi-byte characters split between
* two data chunks, but doesn't handle multi-byte characters split between
* more than two data chunks. The embedder can avoid this problem by always
* returning at least 2 bytes of data.
*
* When streaming UTF-16 data, V8 does not handle characters split between
* two data chunks. The embedder has to make sure that chunks have an even
* length.
*
* If the embedder wants to cancel the streaming, they should make the next
* GetMoreData call return 0. V8 will interpret it as end of data (and most
* probably, parsing will fail). The streaming task will return as soon as
* V8 has parsed the data it received so far.
*/
virtual size_t GetMoreData(const uint8_t** src) = 0;
/**
* V8 calls this method to set a 'bookmark' at the current position in
* the source stream, for the purpose of (maybe) later calling
* ResetToBookmark. If ResetToBookmark is called later, then subsequent
* calls to GetMoreData should return the same data as they did when
* SetBookmark was called earlier.
*
* The embedder may return 'false' to indicate it cannot provide this
* functionality.
*/
virtual bool SetBookmark();
/**
* V8 calls this to return to a previously set bookmark.
*/
virtual void ResetToBookmark();
};
/**
* Source code which can be streamed into V8 in pieces. It will be parsed
* while streaming and compiled after parsing has completed. StreamedSource
* must be kept alive while the streaming task is run (see ScriptStreamingTask
* below).
*/
class V8_EXPORT StreamedSource {
public:
enum Encoding { ONE_BYTE, TWO_BYTE, UTF8, WINDOWS_1252 };
#if defined(_MSC_VER) && _MSC_VER >= 1910 /* Disable on VS2015 */
V8_DEPRECATED(
"This class takes ownership of source_stream, so use the constructor "
"taking a unique_ptr to make these semantics clearer")
#endif
StreamedSource(ExternalSourceStream* source_stream, Encoding encoding);
StreamedSource(std::unique_ptr<ExternalSourceStream> source_stream,
Encoding encoding);
~StreamedSource();
internal::ScriptStreamingData* impl() const { return impl_.get(); }
// Prevent copying.
StreamedSource(const StreamedSource&) = delete;
StreamedSource& operator=(const StreamedSource&) = delete;
private:
std::unique_ptr<internal::ScriptStreamingData> impl_;
};
/**
* A streaming task which the embedder must run on a background thread to
* stream scripts into V8. Returned by ScriptCompiler::StartStreaming.
*/
class V8_EXPORT ScriptStreamingTask final {
public:
void Run();
private:
friend class ScriptCompiler;
explicit ScriptStreamingTask(internal::ScriptStreamingData* data)
: data_(data) {}
internal::ScriptStreamingData* data_;
};
enum CompileOptions {
kNoCompileOptions = 0,
kConsumeCodeCache,
kEagerCompile
};
/**
* The reason for which we are not requesting or providing a code cache.
*/
enum NoCacheReason {
kNoCacheNoReason = 0,
kNoCacheBecauseCachingDisabled,
kNoCacheBecauseNoResource,
kNoCacheBecauseInlineScript,
kNoCacheBecauseModule,
kNoCacheBecauseStreamingSource,
kNoCacheBecauseInspector,
kNoCacheBecauseScriptTooSmall,
kNoCacheBecauseCacheTooCold,
kNoCacheBecauseV8Extension,
kNoCacheBecauseExtensionModule,
kNoCacheBecausePacScript,
kNoCacheBecauseInDocumentWrite,
kNoCacheBecauseResourceWithNoCacheHandler,
kNoCacheBecauseDeferredProduceCodeCache
};
/**
* Compiles the specified script (context-independent).
* Cached data as part of the source object can be optionally produced to be
* consumed later to speed up compilation of identical source scripts.
*
* Note that when producing cached data, the source must point to NULL for
* cached data. When consuming cached data, the cached data must have been
* produced by the same version of V8, and the embedder needs to ensure the
* cached data is the correct one for the given script.
*
* \param source Script source code.
* \return Compiled script object (context independent; for running it must be
* bound to a context).
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundScript(
Isolate* isolate, Source* source,
CompileOptions options = kNoCompileOptions,
NoCacheReason no_cache_reason = kNoCacheNoReason);
/**
* Compiles the specified script (bound to current context).
*
* \param source Script source code.
* \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
* using pre_data speeds compilation if it's done multiple times.
* Owned by caller, no references are kept when this function returns.
* \return Compiled script object, bound to the context that was active
* when this function was called. When run it will always use this
* context.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
Local<Context> context, Source* source,
CompileOptions options = kNoCompileOptions,
NoCacheReason no_cache_reason = kNoCacheNoReason);
/**
* Returns a task which streams script data into V8, or NULL if the script
* cannot be streamed. The user is responsible for running the task on a
* background thread and deleting it. When ran, the task starts parsing the
* script, and it will request data from the StreamedSource as needed. When
* ScriptStreamingTask::Run exits, all data has been streamed and the script
* can be compiled (see Compile below).
*
* This API allows to start the streaming with as little data as possible, and
* the remaining data (for example, the ScriptOrigin) is passed to Compile.
*/
V8_DEPRECATED("Use ScriptCompiler::StartStreaming instead.")
static ScriptStreamingTask* StartStreamingScript(
Isolate* isolate, StreamedSource* source,
CompileOptions options = kNoCompileOptions);
static ScriptStreamingTask* StartStreaming(
Isolate* isolate, StreamedSource* source,
ScriptType type = ScriptType::kClassic);
/**
* Compiles a streamed script (bound to current context).
*
* This can only be called after the streaming has finished
* (ScriptStreamingTask has been run). V8 doesn't construct the source string
* during streaming, so the embedder needs to pass the full source here.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
Local<Context> context, StreamedSource* source,
Local<String> full_source_string, const ScriptOrigin& origin);
/**
* Return a version tag for CachedData for the current V8 version & flags.
*
* This value is meant only for determining whether a previously generated
* CachedData instance is still valid; the tag has no other meaing.
*
* Background: The data carried by CachedData may depend on the exact
* V8 version number or current compiler flags. This means that when
* persisting CachedData, the embedder must take care to not pass in
* data from another V8 version, or the same version with different
* features enabled.
*
* The easiest way to do so is to clear the embedder's cache on any
* such change.
*
* Alternatively, this tag can be stored alongside the cached data and
* compared when it is being used.
*/
static uint32_t CachedDataVersionTag();
/**
* Compile an ES module, returning a Module that encapsulates
* the compiled code.
*
* Corresponds to the ParseModule abstract operation in the
* ECMAScript specification.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Module> CompileModule(
Isolate* isolate, Source* source,
CompileOptions options = kNoCompileOptions,
NoCacheReason no_cache_reason = kNoCacheNoReason);
/**
* Compiles a streamed module script.
*
* This can only be called after the streaming has finished
* (ScriptStreamingTask has been run). V8 doesn't construct the source string
* during streaming, so the embedder needs to pass the full source here.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Module> CompileModule(
Local<Context> context, StreamedSource* v8_source,
Local<String> full_source_string, const ScriptOrigin& origin);
/**
* Compile a function for a given context. This is equivalent to running
*
* with (obj) {
* return function(args) { ... }
* }
*
* It is possible to specify multiple context extensions (obj in the above
* example).
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Function> CompileFunctionInContext(
Local<Context> context, Source* source, size_t arguments_count,
Local<String> arguments[], size_t context_extension_count,
Local<Object> context_extensions[],
CompileOptions options = kNoCompileOptions,
NoCacheReason no_cache_reason = kNoCacheNoReason,
Local<ScriptOrModule>* script_or_module_out = nullptr);
/**
* Creates and returns code cache for the specified unbound_script.
* This will return nullptr if the script cannot be serialized. The
* CachedData returned by this function should be owned by the caller.
*/
static CachedData* CreateCodeCache(Local<UnboundScript> unbound_script);
/**
* Creates and returns code cache for the specified unbound_module_script.
* This will return nullptr if the script cannot be serialized. The
* CachedData returned by this function should be owned by the caller.
*/
static CachedData* CreateCodeCache(
Local<UnboundModuleScript> unbound_module_script);
/**
* Creates and returns code cache for the specified function that was
* previously produced by CompileFunctionInContext.
* This will return nullptr if the script cannot be serialized. The
* CachedData returned by this function should be owned by the caller.
*/
static CachedData* CreateCodeCacheForFunction(Local<Function> function);
private:
static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundInternal(
Isolate* isolate, Source* source, CompileOptions options,
NoCacheReason no_cache_reason);
};
/**
* An error message.
*/
class V8_EXPORT Message {
public:
Local<String> Get() const;
/**
* Return the isolate to which the Message belongs.
*/
Isolate* GetIsolate() const;
V8_WARN_UNUSED_RESULT MaybeLocal<String> GetSource(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<String> GetSourceLine(
Local<Context> context) const;
/**
* Returns the origin for the script from where the function causing the
* error originates.
*/
ScriptOrigin GetScriptOrigin() const;
/**
* Returns the resource name for the script from where the function causing
* the error originates.
*/
Local<Value> GetScriptResourceName() const;
/**
* Exception stack trace. By default stack traces are not captured for
* uncaught exceptions. SetCaptureStackTraceForUncaughtExceptions allows
* to change this option.
*/
Local<StackTrace> GetStackTrace() const;
/**
* Returns the number, 1-based, of the line where the error occurred.
*/
V8_WARN_UNUSED_RESULT Maybe<int> GetLineNumber(Local<Context> context) const;
/**
* Returns the index within the script of the first character where
* the error occurred.
*/
int GetStartPosition() const;
/**
* Returns the index within the script of the last character where
* the error occurred.
*/
int GetEndPosition() const;
/**
* Returns the Wasm function index where the error occurred. Returns -1 if
* message is not from a Wasm script.
*/
int GetWasmFunctionIndex() const;
/**
* Returns the error level of the message.
*/
int ErrorLevel() const;
/**
* Returns the index within the line of the first character where
* the error occurred.
*/
int GetStartColumn() const;
V8_WARN_UNUSED_RESULT Maybe<int> GetStartColumn(Local<Context> context) const;
/**
* Returns the index within the line of the last character where
* the error occurred.
*/
int GetEndColumn() const;
V8_WARN_UNUSED_RESULT Maybe<int> GetEndColumn(Local<Context> context) const;
/**
* Passes on the value set by the embedder when it fed the script from which
* this Message was generated to V8.
*/
bool IsSharedCrossOrigin() const;
bool IsOpaque() const;
// TODO(1245381): Print to a string instead of on a FILE.
static void PrintCurrentStackTrace(Isolate* isolate, FILE* out);
static const int kNoLineNumberInfo = 0;
static const int kNoColumnInfo = 0;
static const int kNoScriptIdInfo = 0;
static const int kNoWasmFunctionIndexInfo = -1;
};
/**
* Representation of a JavaScript stack trace. The information collected is a
* snapshot of the execution stack and the information remains valid after
* execution continues.
*/
class V8_EXPORT StackTrace {
public:
/**
* Flags that determine what information is placed captured for each
* StackFrame when grabbing the current stack trace.
* Note: these options are deprecated and we always collect all available
* information (kDetailed).
*/
enum StackTraceOptions {
kLineNumber = 1,
kColumnOffset = 1 << 1 | kLineNumber,
kScriptName = 1 << 2,
kFunctionName = 1 << 3,
kIsEval = 1 << 4,
kIsConstructor = 1 << 5,
kScriptNameOrSourceURL = 1 << 6,
kScriptId = 1 << 7,
kExposeFramesAcrossSecurityOrigins = 1 << 8,
kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
};
/**
* Returns a StackFrame at a particular index.
*/
Local<StackFrame> GetFrame(Isolate* isolate, uint32_t index) const;
/**
* Returns the number of StackFrames.
*/
int GetFrameCount() const;
/**
* Grab a snapshot of the current JavaScript execution stack.
*
* \param frame_limit The maximum number of stack frames we want to capture.
* \param options Enumerates the set of things we will capture for each
* StackFrame.
*/
static Local<StackTrace> CurrentStackTrace(
Isolate* isolate, int frame_limit, StackTraceOptions options = kDetailed);
};
/**
* A single JavaScript stack frame.
*/
class V8_EXPORT StackFrame {
public:
/**
* Returns the number, 1-based, of the line for the associate function call.
* This method will return Message::kNoLineNumberInfo if it is unable to
* retrieve the line number, or if kLineNumber was not passed as an option
* when capturing the StackTrace.
*/
int GetLineNumber() const;
/**
* Returns the 1-based column offset on the line for the associated function
* call.
* This method will return Message::kNoColumnInfo if it is unable to retrieve
* the column number, or if kColumnOffset was not passed as an option when
* capturing the StackTrace.
*/
int GetColumn() const;
/**
* Returns the id of the script for the function for this StackFrame.
* This method will return Message::kNoScriptIdInfo if it is unable to
* retrieve the script id, or if kScriptId was not passed as an option when
* capturing the StackTrace.
*/
int GetScriptId() const;
/**
* Returns the name of the resource that contains the script for the
* function for this StackFrame.
*/
Local<String> GetScriptName() const;
/**
* Returns the name of the resource that contains the script for the
* function for this StackFrame or sourceURL value if the script name
* is undefined and its source ends with //# sourceURL=... string or
* deprecated //@ sourceURL=... string.
*/
Local<String> GetScriptNameOrSourceURL() const;
/**
* Returns the source of the script for the function for this StackFrame.
*/
Local<String> GetScriptSource() const;
/**
* Returns the source mapping URL (if one is present) of the script for
* the function for this StackFrame.
*/
Local<String> GetScriptSourceMappingURL() const;
/**
* Returns the name of the function associated with this stack frame.
*/
Local<String> GetFunctionName() const;
/**
* Returns whether or not the associated function is compiled via a call to
* eval().
*/
bool IsEval() const;
/**
* Returns whether or not the associated function is called as a
* constructor via "new".
*/
bool IsConstructor() const;
/**
* Returns whether or not the associated functions is defined in wasm.
*/
bool IsWasm() const;
/**
* Returns whether or not the associated function is defined by the user.
*/
bool IsUserJavaScript() const;
};
// A StateTag represents a possible state of the VM.
enum StateTag {
JS,
GC,
PARSER,
BYTECODE_COMPILER,
COMPILER,
OTHER,
EXTERNAL,
ATOMICS_WAIT,
IDLE
};
// Holds the callee saved registers needed for the stack unwinder. It is the
// empty struct if no registers are required. Implemented in
// include/v8-unwinder-state.h.
struct CalleeSavedRegisters;
// A RegisterState represents the current state of registers used
// by the sampling profiler API.
struct V8_EXPORT RegisterState {
RegisterState();
~RegisterState();
RegisterState(const RegisterState& other);
RegisterState& operator=(const RegisterState& other);
void* pc; // Instruction pointer.
void* sp; // Stack pointer.
void* fp; // Frame pointer.
void* lr; // Link register (or nullptr on platforms without a link register).
// Callee saved registers (or null if no callee saved registers were stored)
std::unique_ptr<CalleeSavedRegisters> callee_saved;
};
// The output structure filled up by GetStackSample API function.
struct SampleInfo {
size_t frames_count; // Number of frames collected.
StateTag vm_state; // Current VM state.
void* external_callback_entry; // External callback address if VM is
// executing an external callback.
void* top_context; // Incumbent native context address.
};
struct MemoryRange {
const void* start = nullptr;
size_t length_in_bytes = 0;
};
struct JSEntryStub {
MemoryRange code;
};
struct JSEntryStubs {
JSEntryStub js_entry_stub;
JSEntryStub js_construct_entry_stub;
JSEntryStub js_run_microtasks_entry_stub;
};
/**
* A JSON Parser and Stringifier.
*/
class V8_EXPORT JSON {
public:
/**
* Tries to parse the string |json_string| and returns it as value if
* successful.
*
* \param the context in which to parse and create the value.
* \param json_string The string to parse.
* \return The corresponding value if successfully parsed.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Value> Parse(
Local<Context> context, Local<String> json_string);
/**
* Tries to stringify the JSON-serializable object |json_object| and returns
* it as string if successful.
*
* \param json_object The JSON-serializable object to stringify.
* \return The corresponding string if successfully stringified.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<String> Stringify(
Local<Context> context, Local<Value> json_object,
Local<String> gap = Local<String>());
};
/**
* Value serialization compatible with the HTML structured clone algorithm.
* The format is backward-compatible (i.e. safe to store to disk).
*/
class V8_EXPORT ValueSerializer {
public:
class V8_EXPORT Delegate {
public:
virtual ~Delegate() = default;
/**
* Handles the case where a DataCloneError would be thrown in the structured
* clone spec. Other V8 embedders may throw some other appropriate exception
* type.
*/
virtual void ThrowDataCloneError(Local<String> message) = 0;
/**
* The embedder overrides this method to write some kind of host object, if
* possible. If not, a suitable exception should be thrown and
* Nothing<bool>() returned.
*/
virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);
/**
* Called when the ValueSerializer is going to serialize a
* SharedArrayBuffer object. The embedder must return an ID for the
* object, using the same ID if this SharedArrayBuffer has already been
* serialized in this buffer. When deserializing, this ID will be passed to
* ValueDeserializer::GetSharedArrayBufferFromId as |clone_id|.
*
* If the object cannot be serialized, an
* exception should be thrown and Nothing<uint32_t>() returned.
*/
virtual Maybe<uint32_t> GetSharedArrayBufferId(
Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);
virtual Maybe<uint32_t> GetWasmModuleTransferId(
Isolate* isolate, Local<WasmModuleObject> module);
/**
* Allocates memory for the buffer of at least the size provided. The actual
* size (which may be greater or equal) is written to |actual_size|. If no
* buffer has been allocated yet, nullptr will be provided.
*
* If the memory cannot be allocated, nullptr should be returned.
* |actual_size| will be ignored. It is assumed that |old_buffer| is still
* valid in this case and has not been modified.
*
* The default implementation uses the stdlib's `realloc()` function.
*/
virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,
size_t* actual_size);
/**
* Frees a buffer allocated with |ReallocateBufferMemory|.
*
* The default implementation uses the stdlib's `free()` function.
*/
virtual void FreeBufferMemory(void* buffer);
};
explicit ValueSerializer(Isolate* isolate);
ValueSerializer(Isolate* isolate, Delegate* delegate);
~ValueSerializer();
/**
* Writes out a header, which includes the format version.
*/
void WriteHeader();
/**
* Serializes a JavaScript value into the buffer.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> WriteValue(Local<Context> context,
Local<Value> value);
/**
* Returns the stored data (allocated using the delegate's
* ReallocateBufferMemory) and its size. This serializer should not be used
* once the buffer is released. The contents are undefined if a previous write
* has failed. Ownership of the buffer is transferred to the caller.
*/
V8_WARN_UNUSED_RESULT std::pair<uint8_t*, size_t> Release();
/**
* Marks an ArrayBuffer as havings its contents transferred out of band.
* Pass the corresponding ArrayBuffer in the deserializing context to
* ValueDeserializer::TransferArrayBuffer.
*/
void TransferArrayBuffer(uint32_t transfer_id,
Local<ArrayBuffer> array_buffer);
/**
* Indicate whether to treat ArrayBufferView objects as host objects,
* i.e. pass them to Delegate::WriteHostObject. This should not be
* called when no Delegate was passed.
*
* The default is not to treat ArrayBufferViews as host objects.
*/
void SetTreatArrayBufferViewsAsHostObjects(bool mode);
/**
* Write raw data in various common formats to the buffer.
* Note that integer types are written in base-128 varint format, not with a
* binary copy. For use during an override of Delegate::WriteHostObject.
*/
void WriteUint32(uint32_t value);
void WriteUint64(uint64_t value);
void WriteDouble(double value);
void WriteRawBytes(const void* source, size_t length);
ValueSerializer(const ValueSerializer&) = delete;
void operator=(const ValueSerializer&) = delete;
private:
struct PrivateData;
PrivateData* private_;
};
/**
* Deserializes values from data written with ValueSerializer, or a compatible
* implementation.
*/
class V8_EXPORT ValueDeserializer {
public:
class V8_EXPORT Delegate {
public:
virtual ~Delegate() = default;
/**
* The embedder overrides this method to read some kind of host object, if
* possible. If not, a suitable exception should be thrown and
* MaybeLocal<Object>() returned.
*/
virtual MaybeLocal<Object> ReadHostObject(Isolate* isolate);
/**
* Get a WasmModuleObject given a transfer_id previously provided
* by ValueSerializer::GetWasmModuleTransferId
*/
virtual MaybeLocal<WasmModuleObject> GetWasmModuleFromId(
Isolate* isolate, uint32_t transfer_id);
/**
* Get a SharedArrayBuffer given a clone_id previously provided
* by ValueSerializer::GetSharedArrayBufferId
*/
virtual MaybeLocal<SharedArrayBuffer> GetSharedArrayBufferFromId(
Isolate* isolate, uint32_t clone_id);
};
ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size);
ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size,
Delegate* delegate);
~ValueDeserializer();
/**
* Reads and validates a header (including the format version).
* May, for example, reject an invalid or unsupported wire format.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> ReadHeader(Local<Context> context);
/**
* Deserializes a JavaScript value from the buffer.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> ReadValue(Local<Context> context);
/**
* Accepts the array buffer corresponding to the one passed previously to
* ValueSerializer::TransferArrayBuffer.
*/
void TransferArrayBuffer(uint32_t transfer_id,
Local<ArrayBuffer> array_buffer);
/**
* Similar to TransferArrayBuffer, but for SharedArrayBuffer.
* The id is not necessarily in the same namespace as unshared ArrayBuffer
* objects.
*/
void TransferSharedArrayBuffer(uint32_t id,
Local<SharedArrayBuffer> shared_array_buffer);
/**
* Must be called before ReadHeader to enable support for reading the legacy
* wire format (i.e., which predates this being shipped).
*
* Don't use this unless you need to read data written by previous versions of
* blink::ScriptValueSerializer.
*/
void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
/**
* Reads the underlying wire format version. Likely mostly to be useful to
* legacy code reading old wire format versions. Must be called after
* ReadHeader.
*/
uint32_t GetWireFormatVersion() const;
/**
* Reads raw data in various common formats to the buffer.
* Note that integer types are read in base-128 varint format, not with a
* binary copy. For use during an override of Delegate::ReadHostObject.
*/
V8_WARN_UNUSED_RESULT bool ReadUint32(uint32_t* value);
V8_WARN_UNUSED_RESULT bool ReadUint64(uint64_t* value);
V8_WARN_UNUSED_RESULT bool ReadDouble(double* value);
V8_WARN_UNUSED_RESULT bool ReadRawBytes(size_t length, const void** data);
ValueDeserializer(const ValueDeserializer&) = delete;
void operator=(const ValueDeserializer&) = delete;
private:
struct PrivateData;
PrivateData* private_;
};
// --- Value ---
/**
* The superclass of all JavaScript values and objects.
*/
class V8_EXPORT Value : public Data {
public:
/**
* Returns true if this value is the undefined value. See ECMA-262
* 4.3.10.
*
* This is equivalent to `value === undefined` in JS.
*/
V8_INLINE bool IsUndefined() const;
/**
* Returns true if this value is the null value. See ECMA-262
* 4.3.11.
*
* This is equivalent to `value === null` in JS.
*/
V8_INLINE bool IsNull() const;
/**
* Returns true if this value is either the null or the undefined value.
* See ECMA-262
* 4.3.11. and 4.3.12
*
* This is equivalent to `value == null` in JS.
*/
V8_INLINE bool IsNullOrUndefined() const;
/**
* Returns true if this value is true.
*
* This is not the same as `BooleanValue()`. The latter performs a
* conversion to boolean, i.e. the result of `Boolean(value)` in JS, whereas
* this checks `value === true`.
*/
bool IsTrue() const;
/**
* Returns true if this value is false.
*
* This is not the same as `!BooleanValue()`. The latter performs a
* conversion to boolean, i.e. the result of `!Boolean(value)` in JS, whereas
* this checks `value === false`.
*/
bool IsFalse() const;
/**
* Returns true if this value is a symbol or a string.
*
* This is equivalent to
* `typeof value === 'string' || typeof value === 'symbol'` in JS.
*/
bool IsName() const;
/**
* Returns true if this value is an instance of the String type.
* See ECMA-262 8.4.
*
* This is equivalent to `typeof value === 'string'` in JS.
*/
V8_INLINE bool IsString() const;
/**
* Returns true if this value is a symbol.
*
* This is equivalent to `typeof value === 'symbol'` in JS.
*/
bool IsSymbol() const;
/**
* Returns true if this value is a function.
*
* This is equivalent to `typeof value === 'function'` in JS.
*/
bool IsFunction() const;
/**
* Returns true if this value is an array. Note that it will return false for
* an Proxy for an array.
*/
bool IsArray() const;
/**
* Returns true if this value is an object.
*/
bool IsObject() const;
/**
* Returns true if this value is a bigint.
*
* This is equivalent to `typeof value === 'bigint'` in JS.
*/
bool IsBigInt() const;
/**
* Returns true if this value is boolean.
*
* This is equivalent to `typeof value === 'boolean'` in JS.
*/
bool IsBoolean() const;
/**
* Returns true if this value is a number.
*
* This is equivalent to `typeof value === 'number'` in JS.
*/
bool IsNumber() const;
/**
* Returns true if this value is an `External` object.
*/
bool IsExternal() const;
/**
* Returns true if this value is a 32-bit signed integer.
*/
bool IsInt32() const;
/**
* Returns true if this value is a 32-bit unsigned integer.
*/
bool IsUint32() const;
/**
* Returns true if this value is a Date.
*/
bool IsDate() const;
/**
* Returns true if this value is an Arguments object.
*/
bool IsArgumentsObject() const;
/**
* Returns true if this value is a BigInt object.
*/
bool IsBigIntObject() const;
/**
* Returns true if this value is a Boolean object.
*/
bool IsBooleanObject() const;
/**
* Returns true if this value is a Number object.
*/
bool IsNumberObject() const;
/**
* Returns true if this value is a String object.
*/
bool IsStringObject() const;
/**
* Returns true if this value is a Symbol object.
*/
bool IsSymbolObject() const;
/**
* Returns true if this value is a NativeError.
*/
bool IsNativeError() const;
/**
* Returns true if this value is a RegExp.
*/
bool IsRegExp() const;
/**
* Returns true if this value is an async function.
*/
bool IsAsyncFunction() const;
/**
* Returns true if this value is a Generator function.
*/
bool IsGeneratorFunction() const;
/**
* Returns true if this value is a Generator object (iterator).
*/
bool IsGeneratorObject() const;
/**
* Returns true if this value is a Promise.
*/
bool IsPromise() const;
/**
* Returns true if this value is a Map.
*/
bool IsMap() const;
/**
* Returns true if this value is a Set.
*/
bool IsSet() const;
/**
* Returns true if this value is a Map Iterator.
*/
bool IsMapIterator() const;
/**
* Returns true if this value is a Set Iterator.
*/
bool IsSetIterator() const;
/**
* Returns true if this value is a WeakMap.
*/
bool IsWeakMap() const;
/**
* Returns true if this value is a WeakSet.
*/
bool IsWeakSet() const;
/**
* Returns true if this value is an ArrayBuffer.
*/
bool IsArrayBuffer() const;
/**
* Returns true if this value is an ArrayBufferView.
*/
bool IsArrayBufferView() const;
/**
* Returns true if this value is one of TypedArrays.
*/
bool IsTypedArray() const;
/**
* Returns true if this value is an Uint8Array.
*/
bool IsUint8Array() const;
/**
* Returns true if this value is an Uint8ClampedArray.
*/
bool IsUint8ClampedArray() const;
/**
* Returns true if this value is an Int8Array.
*/
bool IsInt8Array() const;
/**
* Returns true if this value is an Uint16Array.
*/
bool IsUint16Array() const;
/**
* Returns true if this value is an Int16Array.
*/
bool IsInt16Array() const;
/**
* Returns true if this value is an Uint32Array.
*/
bool IsUint32Array() const;
/**
* Returns true if this value is an Int32Array.
*/
bool IsInt32Array() const;
/**
* Returns true if this value is a Float32Array.
*/
bool IsFloat32Array() const;
/**
* Returns true if this value is a Float64Array.
*/
bool IsFloat64Array() const;
/**
* Returns true if this value is a BigInt64Array.
*/
bool IsBigInt64Array() const;
/**
* Returns true if this value is a BigUint64Array.
*/
bool IsBigUint64Array() const;
/**
* Returns true if this value is a DataView.
*/
bool IsDataView() const;
/**
* Returns true if this value is a SharedArrayBuffer.
*/
bool IsSharedArrayBuffer() const;
/**
* Returns true if this value is a JavaScript Proxy.
*/
bool IsProxy() const;
/**
* Returns true if this value is a WasmMemoryObject.
*/
bool IsWasmMemoryObject() const;
/**
* Returns true if this value is a WasmModuleObject.
*/
bool IsWasmModuleObject() const;
/**
* Returns true if the value is a Module Namespace Object.
*/
bool IsModuleNamespaceObject() const;
/**
* Perform the equivalent of `BigInt(value)` in JS.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<BigInt> ToBigInt(
Local<Context> context) const;
/**
* Perform the equivalent of `Number(value)` in JS.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
Local<Context> context) const;
/**
* Perform the equivalent of `String(value)` in JS.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
Local<Context> context) const;
/**
* Provide a string representation of this value usable for debugging.
* This operation has no observable side effects and will succeed
* unless e.g. execution is being terminated.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
Local<Context> context) const;
/**
* Perform the equivalent of `Object(value)` in JS.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
Local<Context> context) const;
/**
* Perform the equivalent of `Number(value)` in JS and convert the result
* to an integer. Negative values are rounded up, positive values are rounded
* down. NaN is converted to 0. Infinite values yield undefined results.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
Local<Context> context) const;
/**
* Perform the equivalent of `Number(value)` in JS and convert the result
* to an unsigned 32-bit integer by performing the steps in
* https://tc39.es/ecma262/#sec-touint32.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
Local<Context> context) const;
/**
* Perform the equivalent of `Number(value)` in JS and convert the result
* to a signed 32-bit integer by performing the steps in
* https://tc39.es/ecma262/#sec-toint32.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
/**
* Perform the equivalent of `Boolean(value)` in JS. This can never fail.
*/
Local<Boolean> ToBoolean(Isolate* isolate) const;
/**
* Attempts to convert a string to an array index.
* Returns an empty handle if the conversion fails.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToArrayIndex(
Local<Context> context) const;
/** Returns the equivalent of `ToBoolean()->Value()`. */
bool BooleanValue(Isolate* isolate) const;
/** Returns the equivalent of `ToNumber()->Value()`. */
V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
/** Returns the equivalent of `ToInteger()->Value()`. */
V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
Local<Context> context) const;
/** Returns the equivalent of `ToUint32()->Value()`. */
V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
Local<Context> context) const;
/** Returns the equivalent of `ToInt32()->Value()`. */
V8_WARN_UNUSED_RESULT Maybe<int32_t> Int32Value(Local<Context> context) const;
/** JS == */
V8_WARN_UNUSED_RESULT Maybe<bool> Equals(Local<Context> context,
Local<Value> that) const;
bool StrictEquals(Local<Value> that) const;
bool SameValue(Local<Value> that) const;
template <class T> V8_INLINE static Value* Cast(T* value);
Local<String> TypeOf(Isolate*);
Maybe<bool> InstanceOf(Local<Context> context, Local<Object> object);
private:
V8_INLINE bool QuickIsUndefined() const;
V8_INLINE bool QuickIsNull() const;
V8_INLINE bool QuickIsNullOrUndefined() const;
V8_INLINE bool QuickIsString() const;
bool FullIsUndefined() const;
bool FullIsNull() const;
bool FullIsString() const;
static void CheckCast(Data* that);
};
/**
* The superclass of primitive values. See ECMA-262 4.3.2.
*/
class V8_EXPORT Primitive : public Value { };
/**
* A primitive boolean value (ECMA-262, 4.3.14). Either the true
* or false value.
*/
class V8_EXPORT Boolean : public Primitive {
public:
bool Value() const;
V8_INLINE static Boolean* Cast(v8::Data* data);
V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value);
private:
static void CheckCast(v8::Data* that);
};
/**
* A superclass for symbols and strings.
*/
class V8_EXPORT Name : public Primitive {
public:
/**
* Returns the identity hash for this object. The current implementation
* uses an inline property on the object to store the identity hash.
*
* The return value will never be 0. Also, it is not guaranteed to be
* unique.
*/
int GetIdentityHash();
V8_INLINE static Name* Cast(Data* data);
private:
static void CheckCast(Data* that);
};
/**
* A flag describing different modes of string creation.
*
* Aside from performance implications there are no differences between the two
* creation modes.
*/
enum class NewStringType {
/**
* Create a new string, always allocating new storage memory.
*/
kNormal,
/**
* 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.
*/
kInternalized
};
/**
* A JavaScript string value (ECMA-262, 4.3.17).
*/
class V8_EXPORT String : public Name {
public:
static constexpr int kMaxLength =
internal::kApiSystemPointerSize == 4 ? (1 << 28) - 16 : (1 << 29) - 24;
enum Encoding {
UNKNOWN_ENCODING = 0x1,
TWO_BYTE_ENCODING = 0x0,
ONE_BYTE_ENCODING = 0x8
};
/**
* Returns the number of characters (UTF-16 code units) in this string.
*/
int Length() const;
/**
* Returns the number of bytes in the UTF-8 encoded
* representation of this string.
*/
int Utf8Length(Isolate* isolate) const;
/**
* Returns whether this string is known to contain only one byte data,
* i.e. ISO-8859-1 code points.
* Does not read the string.
* False negatives are possible.
*/
bool IsOneByte() const;
/**
* Returns whether this string contain only one byte data,
* i.e. ISO-8859-1 code points.
* Will read the entire string in some cases.
*/
bool ContainsOnlyOneByte() const;
/**
* Write the contents of the string to an external buffer.
* If no arguments are given, expects the buffer to be large
* enough to hold the entire string and NULL terminator. Copies
* the contents of the string and the NULL terminator into the
* buffer.
*
* WriteUtf8 will not write partial UTF-8 sequences, preferring to stop
* before the end of the buffer.
*
* Copies up to length characters into the output buffer.
* Only null-terminates if there is enough space in the buffer.
*
* \param buffer The buffer into which the string will be copied.
* \param start The starting position within the string at which
* copying begins.
* \param length The number of characters to copy from the string. For
* WriteUtf8 the number of bytes in the buffer.
* \param nchars_ref The number of characters written, can be NULL.
* \param options Various options that might affect performance of this or
* subsequent operations.
* \return The number of characters copied to the buffer excluding the null
* terminator. For WriteUtf8: The number of bytes copied to the buffer
* including the null terminator (if written).
*/
enum WriteOptions {
NO_OPTIONS = 0,
HINT_MANY_WRITES_EXPECTED = 1,
NO_NULL_TERMINATION = 2,
PRESERVE_ONE_BYTE_NULL = 4,
// Used by WriteUtf8 to replace orphan surrogate code units with the
// unicode replacement character. Needs to be set to guarantee valid UTF-8
// output.
REPLACE_INVALID_UTF8 = 8
};
// 16-bit character codes.
int Write(Isolate* isolate, uint16_t* buffer, int start = 0, int length = -1,
int options = NO_OPTIONS) const;
// One byte characters.
int WriteOneByte(Isolate* isolate, uint8_t* buffer, int start = 0,
int length = -1, int options = NO_OPTIONS) const;
// UTF-8 encoded characters.
int WriteUtf8(Isolate* isolate, char* buffer, int length = -1,
int* nchars_ref = nullptr, int options = NO_OPTIONS) const;
/**
* A zero length string.
*/
V8_INLINE static Local<String> Empty(Isolate* isolate);
/**
* Returns true if the string is external.
*/
bool IsExternal() const;
/**
* Returns true if the string is both external and two-byte.
*/
bool IsExternalTwoByte() const;
/**
* Returns true if the string is both external and one-byte.
*/
bool IsExternalOneByte() const;
class V8_EXPORT ExternalStringResourceBase {
public:
virtual ~ExternalStringResourceBase() = default;
/**
* If a string is cacheable, the value returned by
* ExternalStringResource::data() may be cached, otherwise it is not
* expected to be stable beyond the current top-level task.
*/
virtual bool IsCacheable() const { return true; }
// Disallow copying and assigning.
ExternalStringResourceBase(const ExternalStringResourceBase&) = delete;
void operator=(const ExternalStringResourceBase&) = delete;
protected:
ExternalStringResourceBase() = default;
/**
* Internally V8 will call this Dispose method when the external string
* resource is no longer needed. The default implementation will use the
* delete operator. This method can be overridden in subclasses to
* control how allocated external string resources are disposed.
*/
virtual void Dispose() { delete this; }
/**
* For a non-cacheable string, the value returned by
* |ExternalStringResource::data()| has to be stable between |Lock()| and
* |Unlock()|, that is the string must behave as is |IsCacheable()| returned
* true.
*
* These two functions must be thread-safe, and can be called from anywhere.
* They also must handle lock depth, in the sense that each can be called
* several times, from different threads, and unlocking should only happen
* when the balance of Lock() and Unlock() calls is 0.
*/
virtual void Lock() const {}
/**
* Unlocks the string.
*/
virtual void Unlock() const {}
private:
friend class internal::ExternalString;
friend class v8::String;
friend class internal::ScopedExternalStringLock;
};
/**
* An ExternalStringResource is a wrapper around a two-byte string
* buffer that resides outside V8's heap. Implement an
* ExternalStringResource to manage the life cycle of the underlying
* buffer. Note that the string data must be immutable.
*/
class V8_EXPORT ExternalStringResource
: public ExternalStringResourceBase {
public:
/**
* Override the destructor to manage the life cycle of the underlying
* buffer.
*/
~ExternalStringResource() override = default;
/**
* The string data from the underlying buffer. If the resource is cacheable
* then data() must return the same value for all invocations.
*/
virtual const uint16_t* data() const = 0;
/**
* The length of the string. That is, the number of two-byte characters.
*/
virtual size_t length() const = 0;
/**
* Returns the cached data from the underlying buffer. This method can be
* called only for cacheable resources (i.e. IsCacheable() == true) and only
* after UpdateDataCache() was called.
*/
const uint16_t* cached_data() const {
CheckCachedDataInvariants();
return cached_data_;
}
/**
* Update {cached_data_} with the data from the underlying buffer. This can
* be called only for cacheable resources.
*/
void UpdateDataCache();
protected:
ExternalStringResource() = default;
private:
void CheckCachedDataInvariants() const;
const uint16_t* cached_data_ = nullptr;
};
/**
* An ExternalOneByteStringResource is a wrapper around an one-byte
* string buffer that resides outside V8's heap. Implement an
* ExternalOneByteStringResource to manage the life cycle of the
* underlying buffer. Note that the string data must be immutable
* and that the data must be Latin-1 and not UTF-8, which would require
* special treatment internally in the engine and do not allow efficient
* indexing. Use String::New or convert to 16 bit data for non-Latin1.
*/
class V8_EXPORT ExternalOneByteStringResource
: public ExternalStringResourceBase {
public:
/**
* Override the destructor to manage the life cycle of the underlying
* buffer.
*/
~ExternalOneByteStringResource() override = default;
/**
* The string data from the underlying buffer. If the resource is cacheable
* then data() must return the same value for all invocations.
*/
virtual const char* data() const = 0;
/** The number of Latin-1 characters in the string.*/
virtual size_t length() const = 0;
/**
* Returns the cached data from the underlying buffer. If the resource is
* uncacheable or if UpdateDataCache() was not called before, it has
* undefined behaviour.
*/
const char* cached_data() const {
CheckCachedDataInvariants();
return cached_data_;
}
/**
* Update {cached_data_} with the data from the underlying buffer. This can
* be called only for cacheable resources.
*/
void UpdateDataCache();
protected:
ExternalOneByteStringResource() = default;
private:
void CheckCachedDataInvariants() const;
const char* cached_data_ = nullptr;
};
/**
* If the string is an external string, return the ExternalStringResourceBase
* regardless of the encoding, otherwise return NULL. The encoding of the
* string is returned in encoding_out.
*/
V8_INLINE ExternalStringResourceBase* GetExternalStringResourceBase(
Encoding* encoding_out) const;
/**
* Get the ExternalStringResource for an external string. Returns
* NULL if IsExternal() doesn't return true.
*/
V8_INLINE ExternalStringResource* GetExternalStringResource() const;
/**
* Get the ExternalOneByteStringResource for an external one-byte string.
* Returns NULL if IsExternalOneByte() doesn't return true.
*/
const ExternalOneByteStringResource* GetExternalOneByteStringResource() const;
V8_INLINE static String* Cast(v8::Data* data);
/**
* Allocates a new string from a UTF-8 literal. This is equivalent to calling
* String::NewFromUtf(isolate, "...").ToLocalChecked(), but without the check
* overhead.
*
* When called on a string literal containing '\0', the inferred length is the
* length of the input array minus 1 (for the final '\0') and not the value
* returned by strlen.
**/
template <int N>
static V8_WARN_UNUSED_RESULT Local<String> NewFromUtf8Literal(
Isolate* isolate, const char (&literal)[N],
NewStringType type = NewStringType::kNormal) {
static_assert(N <= kMaxLength, "String is too long");
return NewFromUtf8Literal(isolate, literal, type, N - 1);
}
/** Allocates a new string from UTF-8 data. Only returns an empty value when
* length > kMaxLength. **/
static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8(
Isolate* isolate, const char* data,
NewStringType type = NewStringType::kNormal, int length = -1);
/** Allocates a new string from Latin-1 data. Only returns an empty value
* when length > kMaxLength. **/
static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromOneByte(
Isolate* isolate, const uint8_t* data,
NewStringType type = NewStringType::kNormal, int length = -1);
/** Allocates a new string from UTF-16 data. Only returns an empty value when
* length > kMaxLength. **/
static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromTwoByte(
Isolate* isolate, const uint16_t* data,
NewStringType type = NewStringType::kNormal, int length = -1);
/**
* Creates a new string by concatenating the left and the right strings
* passed in as parameters.
*/
static Local<String> Concat(Isolate* isolate, Local<String> left,
Local<String> right);
/**
* Creates a new external string using the data defined in the given
* resource. When the external string is no longer live on V8's heap the
* resource will be disposed by calling its Dispose method. The caller of
* this function should not otherwise delete or modify the resource. Neither
* should the underlying buffer be deallocated or modified except through the
* destructor of the external string resource.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalTwoByte(
Isolate* isolate, ExternalStringResource* resource);
/**
* Associate an external string resource with this string by transforming it
* in place so that existing references to this string in the JavaScript heap
* will use the external string resource. The external string resource's
* character contents need to be equivalent to this string.
* Returns true if the string has been changed to be an external string.
* The string is not modified if the operation fails. See NewExternal for
* information on the lifetime of the resource.
*/
bool MakeExternal(ExternalStringResource* resource);
/**
* Creates a new external string using the one-byte data defined in the given
* resource. When the external string is no longer live on V8's heap the
* resource will be disposed by calling its Dispose method. The caller of
* this function should not otherwise delete or modify the resource. Neither
* should the underlying buffer be deallocated or modified except through the
* destructor of the external string resource.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalOneByte(
Isolate* isolate, ExternalOneByteStringResource* resource);
/**
* Associate an external string resource with this string by transforming it
* in place so that existing references to this string in the JavaScript heap
* will use the external string resource. The external string resource's
* character contents need to be equivalent to this string.
* Returns true if the string has been changed to be an external string.
* The string is not modified if the operation fails. See NewExternal for
* information on the lifetime of the resource.
*/
bool MakeExternal(ExternalOneByteStringResource* resource);
/**
* Returns true if this string can be made external.
*/
bool CanMakeExternal();
/**
* Returns true if the strings values are equal. Same as JS ==/===.
*/
bool StringEquals(Local<String> str);
/**
* Converts an object to a UTF-8-encoded character array. Useful if
* you want to print the object. If conversion to a string fails
* (e.g. due to an exception in the toString() method of the object)
* then the length() method returns 0 and the * operator returns
* NULL.
*/
class V8_EXPORT Utf8Value {
public:
Utf8Value(Isolate* isolate, Local<v8::Value> obj);
~Utf8Value();
char* operator*() { return str_; }
const char* operator*() const { return str_; }
int length() const { return length_; }
// Disallow copying and assigning.
Utf8Value(const Utf8Value&) = delete;
void operator=(const Utf8Value&) = delete;
private:
char* str_;
int length_;
};
/**
* Converts an object to a two-byte (UTF-16-encoded) string.
* If conversion to a string fails (eg. due to an exception in the toString()
* method of the object) then the length() method returns 0 and the * operator
* returns NULL.
*/
class V8_EXPORT Value {
public:
Value(Isolate* isolate, Local<v8::Value> obj);
~Value();
uint16_t* operator*() { return str_; }
const uint16_t* operator*() const { return str_; }
int length() const { return length_; }
// Disallow copying and assigning.
Value(const Value&) = delete;
void operator=(const Value&) = delete;
private:
uint16_t* str_;
int length_;
};
private:
void VerifyExternalStringResourceBase(ExternalStringResourceBase* v,
Encoding encoding) const;
void VerifyExternalStringResource(ExternalStringResource* val) const;
ExternalStringResource* GetExternalStringResourceSlow() const;
ExternalStringResourceBase* GetExternalStringResourceBaseSlow(
String::Encoding* encoding_out) const;
static Local<v8::String> NewFromUtf8Literal(Isolate* isolate,
const char* literal,
NewStringType type, int length);
static void CheckCast(v8::Data* that);
};
// Zero-length string specialization (templated string size includes
// terminator).
template <>
inline V8_WARN_UNUSED_RESULT Local<String> String::NewFromUtf8Literal(
Isolate* isolate, const char (&literal)[1], NewStringType type) {
return String::Empty(isolate);
}
/**
* A JavaScript symbol (ECMA-262 edition 6)
*/
class V8_EXPORT Symbol : public Name {
public:
/**
* Returns the description string of the symbol, or undefined if none.
*/
Local<Value> Description() const;
Local<Value> Description(Isolate* isolate) const;
V8_DEPRECATED("Use Symbol::Description()")
Local<Value> Name() const { return Description(); }
/**
* Create a symbol. If description is not empty, it will be used as the
* description.
*/
static Local<Symbol> New(Isolate* isolate,
Local<String> description = Local<String>());
/**
* Access global symbol registry.
* Note that symbols created this way are never collected, so
* they should only be used for statically fixed properties.
* Also, there is only one global name space for the descriptions used as
* keys.
* To minimize the potential for clashes, use qualified names as keys.
*/
static Local<Symbol> For(Isolate* isolate, Local<String> description);
/**
* Retrieve a global symbol. Similar to |For|, but using a separate
* registry that is not accessible by (and cannot clash with) JavaScript code.
*/
static Local<Symbol> ForApi(Isolate* isolate, Local<String> description);
// Well-known symbols
static Local<Symbol> GetAsyncIterator(Isolate* isolate);
static Local<Symbol> GetHasInstance(Isolate* isolate);
static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate);
static Local<Symbol> GetIterator(Isolate* isolate);
static Local<Symbol> GetMatch(Isolate* isolate);
static Local<Symbol> GetReplace(Isolate* isolate);
static Local<Symbol> GetSearch(Isolate* isolate);
static Local<Symbol> GetSplit(Isolate* isolate);
static Local<Symbol> GetToPrimitive(Isolate* isolate);
static Local<Symbol> GetToStringTag(Isolate* isolate);
static Local<Symbol> GetUnscopables(Isolate* isolate);
V8_INLINE static Symbol* Cast(Data* data);
private:
Symbol();
static void CheckCast(Data* that);
};
/**
* A private symbol
*
* This is an experimental feature. Use at your own risk.
*/
class V8_EXPORT Private : public Data {
public:
/**
* Returns the print name string of the private symbol, or undefined if none.
*/
Local<Value> Name() const;
/**
* Create a private symbol. If name is not empty, it will be the description.
*/
static Local<Private> New(Isolate* isolate,
Local<String> name = Local<String>());
/**
* Retrieve a global private symbol. If a symbol with this name has not
* been retrieved in the same isolate before, it is created.
* Note that private symbols created this way are never collected, so
* they should only be used for statically fixed properties.
* Also, there is only one global name space for the names used as keys.
* To minimize the potential for clashes, use qualified names as keys,
* e.g., "Class#property".
*/
static Local<Private> ForApi(Isolate* isolate, Local<String> name);
V8_INLINE static Private* Cast(Data* data);
private:
Private();
static void CheckCast(Data* that);
};
/**
* A JavaScript number value (ECMA-262, 4.3.20)
*/
class V8_EXPORT Number : public Primitive {
public:
double Value() const;
static Local<Number> New(Isolate* isolate, double value);
V8_INLINE static Number* Cast(v8::Data* data);
private:
Number();
static void CheckCast(v8::Data* that);
};
/**
* A JavaScript value representing a signed integer.
*/
class V8_EXPORT Integer : public Number {
public:
static Local<Integer> New(Isolate* isolate, int32_t value);
static Local<Integer> NewFromUnsigned(Isolate* isolate, uint32_t value);
int64_t Value() const;
V8_INLINE static Integer* Cast(v8::Data* data);
private:
Integer();
static void CheckCast(v8::Data* that);
};
/**
* A JavaScript value representing a 32-bit signed integer.
*/
class V8_EXPORT Int32 : public Integer {
public:
int32_t Value() const;
V8_INLINE static Int32* Cast(v8::Data* data);
private:
Int32();
static void CheckCast(v8::Data* that);
};
/**
* A JavaScript value representing a 32-bit unsigned integer.
*/
class V8_EXPORT Uint32 : public Integer {
public:
uint32_t Value() const;
V8_INLINE static Uint32* Cast(v8::Data* data);
private:
Uint32();
static void CheckCast(v8::Data* that);
};
/**
* A JavaScript BigInt value (https://tc39.github.io/proposal-bigint)
*/
class V8_EXPORT BigInt : public Primitive {
public:
static Local<BigInt> New(Isolate* isolate, int64_t value);
static Local<BigInt> NewFromUnsigned(Isolate* isolate, uint64_t value);
/**
* Creates a new BigInt object using a specified sign bit and a
* specified list of digits/words.
* The resulting number is calculated as:
*
* (-1)^sign_bit * (words[0] * (2^64)^0 + words[1] * (2^64)^1 + ...)
*/
static MaybeLocal<BigInt> NewFromWords(Local<Context> context, int sign_bit,
int word_count, const uint64_t* words);
/**
* Returns the value of this BigInt as an unsigned 64-bit integer.
* If `lossless` is provided, it will reflect whether the return value was
* truncated or wrapped around. In particular, it is set to `false` if this
* BigInt is negative.
*/
uint64_t Uint64Value(bool* lossless = nullptr) const;
/**
* Returns the value of this BigInt as a signed 64-bit integer.
* If `lossless` is provided, it will reflect whether this BigInt was
* truncated or not.
*/
int64_t Int64Value(bool* lossless = nullptr) const;
/**
* Returns the number of 64-bit words needed to store the result of
* ToWordsArray().
*/
int WordCount() const;
/**
* Writes the contents of this BigInt to a specified memory location.
* `sign_bit` must be provided and will be set to 1 if this BigInt is
* negative.
* `*word_count` has to be initialized to the length of the `words` array.
* Upon return, it will be set to the actual number of words that would
* be needed to store this BigInt (i.e. the return value of `WordCount()`).
*/
void ToWordsArray(int* sign_bit, int* word_count, uint64_t* words) const;
V8_INLINE static BigInt* Cast(v8::Data* data);
private:
BigInt();
static void CheckCast(v8::Data* that);
};
/**
* PropertyAttribute.
*/
enum PropertyAttribute {
/** None. **/
None = 0,
/** ReadOnly, i.e., not writable. **/
ReadOnly = 1 << 0,
/** DontEnum, i.e., not enumerable. **/
DontEnum = 1 << 1,
/** DontDelete, i.e., not configurable. **/
DontDelete = 1 << 2
};
/**
* Accessor[Getter|Setter] are used as callback functions when
* setting|getting a particular property. See Object and ObjectTemplate's
* method SetAccessor.
*/
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);
/**
* 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.
*
* TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.
*/
enum AccessControl {
DEFAULT = 0,
ALL_CAN_READ = 1,
ALL_CAN_WRITE = 1 << 1,
PROHIBITS_OVERWRITING = 1 << 2
};
/**
* Property filter bits. They can be or'ed to build a composite filter.
*/
enum PropertyFilter {
ALL_PROPERTIES = 0,
ONLY_WRITABLE = 1,
ONLY_ENUMERABLE = 2,
ONLY_CONFIGURABLE = 4,
SKIP_STRINGS = 8,
SKIP_SYMBOLS = 16
};
/**
* 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.
*/
enum class SideEffectType {
kHasSideEffect,
kHasNoSideEffect,
kHasSideEffectToReceiver
};
/**
* 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.
*/
enum class KeyCollectionMode { kOwnOnly, kIncludePrototypes };
/**
* kIncludesIndices allows for integer indices to be collected, while
* kSkipIndices will exclude integer indices from being collected.
*/
enum class IndexFilter { kIncludeIndices, kSkipIndices };
/**
* kConvertToString will convert integer indices to strings.
* kKeepNumbers will return numbers for integer indices.
*/
enum class KeyConversionMode { kConvertToString, kKeepNumbers, kNoNumbers };
/**
* Integrity level for objects.
*/
enum class IntegrityLevel { kFrozen, kSealed };
/**
* A JavaScript object (ECMA-262, 4.3.3)
*/
class V8_EXPORT Object : public Value {
public:
/**
* Set only return Just(true) or Empty(), so if it should never fail, use
* result.Check().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context,
Local<Value> key, Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index,
Local<Value> value);
// Implements CreateDataProperty (ECMA-262, 7.3.4).
//
// Defines a configurable, writable, enumerable property with the given value
// on the object unless the property already exists and is not configurable
// or the object is not extensible.
//
// Returns true on success.
V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
Local<Name> key,
Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
uint32_t index,
Local<Value> value);
// Implements DefineOwnProperty.
//
// In general, CreateDataProperty will be faster, however, does not allow
// for specifying attributes.
//
// Returns true on success.
V8_WARN_UNUSED_RESULT Maybe<bool> DefineOwnProperty(
Local<Context> context, Local<Name> key, Local<Value> value,
PropertyAttribute attributes = None);
// Implements Object.DefineProperty(O, P, Attributes), see Ecma-262 19.1.2.4.
//
// The defineProperty function is used to add an own property or
// update the attributes of an existing own property of an object.
//
// Both data and accessor descriptors can be used.
//
// In general, CreateDataProperty is faster, however, does not allow
// for specifying attributes or an accessor descriptor.
//
// The PropertyDescriptor can change when redefining a property.
//
// Returns true on success.
V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
uint32_t index);
/**
* Gets the property attributes of a property which can be None or
* any combination of ReadOnly, DontEnum and DontDelete. Returns
* None when the property doesn't exist.
*/
V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetPropertyAttributes(
Local<Context> context, Local<Value> key);
/**
* Returns Object.getOwnPropertyDescriptor as per ES2016 section 19.1.2.6.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetOwnPropertyDescriptor(
Local<Context> context, Local<Name> key);
/**
* Object::Has() calls the abstract operation HasProperty(O, P) described
* in ECMA-262, 7.3.10. Has() returns
* true, if the object has the property, either own or on the prototype chain.
* Interceptors, i.e., PropertyQueryCallbacks, are called if present.
*
* Has() has the same side effects as JavaScript's `variable in object`.
* For example, calling Has() on a revoked proxy will throw an exception.
*
* \note Has() converts the key to a name, which possibly calls back into
* JavaScript.
*
* See also v8::Object::HasOwnProperty() and
* v8::Object::HasRealNamedProperty().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context, uint32_t index);
V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
uint32_t index);
/**
* Note: SideEffectType affects the getter only, not the setter.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetAccessor(
Local<Context> context, Local<Name> name,
AccessorNameGetterCallback getter,
AccessorNameSetterCallback setter = nullptr,
MaybeLocal<Value> data = MaybeLocal<Value>(),
AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
void SetAccessorProperty(Local<Name> name, Local<Function> getter,
Local<Function> setter = Local<Function>(),
PropertyAttribute attribute = None,
AccessControl settings = DEFAULT);
/**
* Sets a native data property like Template::SetNativeDataProperty, but
* this method sets on this object directly.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetNativeDataProperty(
Local<Context> context, Local<Name> name,
AccessorNameGetterCallback getter,
AccessorNameSetterCallback setter = nullptr,
Local<Value> data = Local<Value>(), PropertyAttribute attributes = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* Attempts to create a property with the given name which behaves like a data
* property, except that the provided getter is invoked (and provided with the
* data value) to supply its value the first time it is read. After the
* property is accessed once, it is replaced with an ordinary data property.
*
* Analogous to Template::SetLazyDataProperty.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetLazyDataProperty(
Local<Context> context, Local<Name> name,
AccessorNameGetterCallback getter, Local<Value> data = Local<Value>(),
PropertyAttribute attributes = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* Functionality for private properties.
* This is an experimental feature, use at your own risk.
* Note: Private properties are not inherited. Do not rely on this, since it
* may change.
*/
Maybe<bool> HasPrivate(Local<Context> context, Local<Private> key);
Maybe<bool> SetPrivate(Local<Context> context, Local<Private> key,
Local<Value> value);
Maybe<bool> DeletePrivate(Local<Context> context, Local<Private> key);
MaybeLocal<Value> GetPrivate(Local<Context> context, Local<Private> key);
/**
* Returns an array containing the names of the enumerable properties
* of this object, including properties from prototype objects. The
* array returned by this method contains the same values as would
* be enumerated by a for-in statement over this object.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
Local<Context> context);
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
Local<Context> context, KeyCollectionMode mode,
PropertyFilter property_filter, IndexFilter index_filter,
KeyConversionMode key_conversion = KeyConversionMode::kKeepNumbers);
/**
* This function has the same functionality as GetPropertyNames but
* the returned array doesn't contain the names of properties from
* prototype objects.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
Local<Context> context);
/**
* Returns an array containing the names of the filtered properties
* of this object, including properties from prototype objects. The
* array returned by this method contains the same values as would
* be enumerated by a for-in statement over this object.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
Local<Context> context, PropertyFilter filter,
KeyConversionMode key_conversion = KeyConversionMode::kKeepNumbers);
/**
* Get the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
Local<Value> GetPrototype();
/**
* Set the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetPrototype(Local<Context> context,
Local<Value> prototype);
/**
* Finds an instance of the given function template in the prototype
* chain.
*/
Local<Object> FindInstanceInPrototypeChain(Local<FunctionTemplate> tmpl);
/**
* Call builtin Object.prototype.toString on this object.
* This is different from Value::ToString() that may call
* user-defined toString function. This one does not.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<String> ObjectProtoToString(
Local<Context> context);
/**
* Returns the name of the function invoked as a constructor for this object.
*/
Local<String> GetConstructorName();
/**
* Sets the integrity level of the object.
*/
Maybe<bool> SetIntegrityLevel(Local<Context> context, IntegrityLevel level);
/** Gets the number of internal fields for this Object. */
int InternalFieldCount();
/** Same as above, but works for PersistentBase. */
V8_INLINE static int InternalFieldCount(
const PersistentBase<Object>& object) {
return object.val_->InternalFieldCount();
}
/** Same as above, but works for BasicTracedReference. */
V8_INLINE static int InternalFieldCount(
const BasicTracedReference<Object>& object) {
return object->InternalFieldCount();
}
/** Gets the value from an internal field. */
V8_INLINE Local<Value> GetInternalField(int index);
/** Sets the value in an internal field. */
void SetInternalField(int index, Local<Value> value);
/**
* Gets a 2-byte-aligned native pointer from an internal field. This field
* must have been set by SetAlignedPointerInInternalField, everything else
* leads to undefined behavior.
*/
V8_INLINE void* GetAlignedPointerFromInternalField(int index);
/** Same as above, but works for PersistentBase. */
V8_INLINE static void* GetAlignedPointerFromInternalField(
const PersistentBase<Object>& object, int index) {
return object.val_->GetAlignedPointerFromInternalField(index);
}
/** Same as above, but works for TracedGlobal. */
V8_INLINE static void* GetAlignedPointerFromInternalField(
const BasicTracedReference<Object>& object, int index) {
return object->GetAlignedPointerFromInternalField(index);
}
/**
* Sets a 2-byte-aligned native pointer in an internal field. To retrieve such
* a field, GetAlignedPointerFromInternalField must be used, everything else
* leads to undefined behavior.
*/
void SetAlignedPointerInInternalField(int index, void* value);
void SetAlignedPointerInInternalFields(int argc, int indices[],
void* values[]);
/**
* HasOwnProperty() is like JavaScript's Object.prototype.hasOwnProperty().
*
* See also v8::Object::Has() and v8::Object::HasRealNamedProperty().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
Local<Name> key);
V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
uint32_t index);
/**
* Use HasRealNamedProperty() if you want to check if an object has an own
* property without causing side effects, i.e., without calling interceptors.
*
* This function is similar to v8::Object::HasOwnProperty(), but it does not
* call interceptors.
*
* \note Consider using non-masking interceptors, i.e., the interceptors are
* not called if the receiver has the real named property. See
* `v8::PropertyHandlerFlags::kNonMasking`.
*
* See also v8::Object::Has().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedProperty(Local<Context> context,
Local<Name> key);
V8_WARN_UNUSED_RESULT Maybe<bool> HasRealIndexedProperty(
Local<Context> context, uint32_t index);
V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedCallbackProperty(
Local<Context> context, Local<Name> key);
/**
* If result.IsEmpty() no real property was located in the prototype chain.
* This means interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedPropertyInPrototypeChain(
Local<Context> context, Local<Name> key);
/**
* Gets the property attributes of a real property in the prototype chain,
* which can be None or any combination of ReadOnly, DontEnum and DontDelete.
* Interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute>
GetRealNamedPropertyAttributesInPrototypeChain(Local<Context> context,
Local<Name> key);
/**
* If result.IsEmpty() no real property was located on the object or
* in the prototype chain.
* This means interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedProperty(
Local<Context> context, Local<Name> key);
/**
* Gets the property attributes of a real property which can be
* None or any combination of ReadOnly, DontEnum and DontDelete.
* Interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
Local<Context> context, Local<Name> key);
/** Tests for a named lookup interceptor.*/
bool HasNamedLookupInterceptor();
/** Tests for an index lookup interceptor.*/
bool HasIndexedLookupInterceptor();
/**
* Returns the identity hash for this object. The current implementation
* uses a hidden property on the object to store the identity hash.
*
* The return value will never be 0. Also, it is not guaranteed to be
* unique.
*/
int GetIdentityHash();
/**
* Clone this object with a fast but shallow copy. Values will point
* to the same values as the original object.
*/
// TODO(dcarney): take an isolate and optionally bail out?
Local<Object> Clone();
/**
* Returns the context in which the object was created.
*/
// TODO(chromium:1166077): Mark as deprecate once users are updated.
V8_DEPRECATE_SOON("Use MaybeLocal<Context> GetCreationContext()")
Local<Context> CreationContext();
MaybeLocal<Context> GetCreationContext();
/** Same as above, but works for Persistents */
// TODO(chromium:1166077): Mark as deprecate once users are updated.
V8_DEPRECATE_SOON(
"Use MaybeLocal<Context> GetCreationContext(const "
"PersistentBase<Object>& object)")
static Local<Context> CreationContext(const PersistentBase<Object>& object);
V8_INLINE static MaybeLocal<Context> GetCreationContext(
const PersistentBase<Object>& object) {
return object.val_->GetCreationContext();
}
/**
* Checks whether a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
* When an Object is callable this method returns true.
*/
bool IsCallable();
/**
* True if this object is a constructor.
*/
bool IsConstructor();
/**
* True if this object can carry information relevant to the embedder in its
* embedder fields, false otherwise. This is generally true for objects
* constructed through function templates but also holds for other types where
* V8 automatically adds internal fields at compile time, such as e.g.
* v8::ArrayBuffer.
*/
bool IsApiWrapper();
/**
* True if this object was created from an object template which was marked
* as undetectable. See v8::ObjectTemplate::MarkAsUndetectable for more
* information.
*/
bool IsUndetectable();
/**
* Call an Object as a function if a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsFunction(Local<Context> context,
Local<Value> recv,
int argc,
Local<Value> argv[]);
/**
* Call an Object as a constructor if a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
* Note: This method behaves like the Function::NewInstance method.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsConstructor(
Local<Context> context, int argc, Local<Value> argv[]);
/**
* Return the isolate to which the Object belongs to.
*/
Isolate* GetIsolate();
/**
* If this object is a Set, Map, WeakSet or WeakMap, this returns a
* representation of the elements of this object as an array.
* If this object is a SetIterator or MapIterator, this returns all
* elements of the underlying collection, starting at the iterator's current
* position.
* For other types, this will return an empty MaybeLocal<Array> (without
* scheduling an exception).
*/
MaybeLocal<Array> PreviewEntries(bool* is_key_value);
static Local<Object> New(Isolate* isolate);
/**
* Creates a JavaScript object with the given properties, and
* a the given prototype_or_null (which can be any JavaScript
* value, and if it's null, the newly created object won't have
* a prototype at all). This is similar to Object.create().
* All properties will be created as enumerable, configurable
* and writable properties.
*/
static Local<Object> New(Isolate* isolate, Local<Value> prototype_or_null,
Local<Name>* names, Local<Value>* values,
size_t length);
V8_INLINE static Object* Cast(Value* obj);
/**
* Support for TC39 "dynamic code brand checks" proposal.
*
* This API allows to query whether an object was constructed from a
* "code like" ObjectTemplate.
*
* See also: v8::ObjectTemplate::SetCodeLike
*/
bool IsCodeLike(Isolate* isolate);
private:
Object();
static void CheckCast(Value* obj);
Local<Value> SlowGetInternalField(int index);
void* SlowGetAlignedPointerFromInternalField(int index);
};
/**
* An instance of the built-in array constructor (ECMA-262, 15.4.2).
*/
class V8_EXPORT Array : public Object {
public:
uint32_t Length() const;
/**
* Creates a JavaScript array with the given length. If the length
* is negative the returned array will have length 0.
*/
static Local<Array> New(Isolate* isolate, int length = 0);
/**
* Creates a JavaScript array out of a Local<Value> array in C++
* with a known length.
*/
static Local<Array> New(Isolate* isolate, Local<Value>* elements,
size_t length);
V8_INLINE static Array* Cast(Value* obj);
private:
Array();
static void CheckCast(Value* obj);
};
/**
* An instance of the built-in Map constructor (ECMA-262, 6th Edition, 23.1.1).
*/
class V8_EXPORT Map : public Object {
public:
size_t Size() const;
void Clear();
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT MaybeLocal<Map> Set(Local<Context> context,
Local<Value> key,
Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
Local<Value> key);
/**
* Returns an array of length Size() * 2, where index N is the Nth key and
* index N + 1 is the Nth value.
*/
Local<Array> AsArray() const;
/**
* Creates a new empty Map.
*/
static Local<Map> New(Isolate* isolate);
V8_INLINE static Map* Cast(Value* obj);
private:
Map();
static void CheckCast(Value* obj);
};
/**
* An instance of the built-in Set constructor (ECMA-262, 6th Edition, 23.2.1).
*/
class V8_EXPORT Set : public Object {
public:
size_t Size() const;
void Clear();
V8_WARN_UNUSED_RESULT MaybeLocal<Set> Add(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
Local<Value> key);
/**
* Returns an array of the keys in this Set.
*/
Local<Array> AsArray() const;
/**
* Creates a new empty Set.
*/
static Local<Set> New(Isolate* isolate);
V8_INLINE static Set* Cast(Value* obj);
private:
Set();
static void CheckCast(Value* obj);
};
template<typename T>
class ReturnValue {
public:
template <class S> V8_INLINE ReturnValue(const ReturnValue<S>& that)
: value_(that.value_) {
static_assert(std::is_base_of<T, S>::value, "type check");
}
// Local setters
template <typename S>
V8_INLINE void Set(const Global<S>& handle);
template <typename S>
V8_INLINE void Set(const BasicTracedReference<S>& handle);
template <typename S>
V8_INLINE void Set(const Local<S> handle);
// Fast primitive setters
V8_INLINE void Set(bool value);
V8_INLINE void Set(double i);
V8_INLINE void Set(int32_t i);
V8_INLINE void Set(uint32_t i);
// Fast JS primitive setters
V8_INLINE void SetNull();
V8_INLINE void SetUndefined();
V8_INLINE void SetEmptyString();
// Convenience getter for Isolate
V8_INLINE Isolate* GetIsolate() const;
// Pointer setter: Uncompilable to prevent inadvertent misuse.
template <typename S>
V8_INLINE void Set(S* whatever);
// Getter. Creates a new Local<> so it comes with a certain performance
// hit. If the ReturnValue was not yet set, this will return the undefined
// value.
V8_INLINE Local<Value> Get() const;
private:
template<class F> friend class ReturnValue;
template<class F> friend class FunctionCallbackInfo;
template<class F> friend class PropertyCallbackInfo;
template <class F, class G, class H>
friend class PersistentValueMapBase;
V8_INLINE void SetInternal(internal::Address value) { *value_ = value; }
V8_INLINE internal::Address GetDefaultValue();
V8_INLINE explicit ReturnValue(internal::Address* slot);
internal::Address* value_;
};
/**
* The argument information given to function call callbacks. This
* class provides access to information about the context of the call,
* including the receiver, the number and values of arguments, and
* the holder of the function.
*/
template<typename T>
class FunctionCallbackInfo {
public:
/** The number of available arguments. */
V8_INLINE int Length() const;
/**
* Accessor for the available arguments. Returns `undefined` if the index
* is out of bounds.
*/
V8_INLINE Local<Value> operator[](int i) const;
/** Returns the receiver. This corresponds to the "this" value. */
V8_INLINE Local<Object> This() const;
/**
* If the callback was created without a Signature, this is the same
* value as This(). If there is a signature, and the signature didn't match
* This() but one of its hidden prototypes, this will be the respective
* hidden prototype.
*
* Note that this is not the prototype of This() on which the accessor
* referencing this callback was found (which in V8 internally is often
* referred to as holder [sic]).
*/
V8_INLINE Local<Object> Holder() const;
/** For construct calls, this returns the "new.target" value. */
V8_INLINE Local<Value> NewTarget() const;
/** Indicates whether this is a regular call or a construct call. */
V8_INLINE bool IsConstructCall() const;
/** The data argument specified when creating the callback. */
V8_INLINE Local<Value> Data() const;
/** The current Isolate. */
V8_INLINE Isolate* GetIsolate() const;
/** The ReturnValue for the call. */
V8_INLINE ReturnValue<T> GetReturnValue() const;
// This shouldn't be public, but the arm compiler needs it.
static const int kArgsLength = 6;
protected:
friend class internal::FunctionCallbackArguments;
friend class internal::CustomArguments<FunctionCallbackInfo>;
friend class debug::ConsoleCallArguments;
static const int kHolderIndex = 0;
static const int kIsolateIndex = 1;
static const int kReturnValueDefaultValueIndex = 2;
static const int kReturnValueIndex = 3;
static const int kDataIndex = 4;
static const int kNewTargetIndex = 5;
V8_INLINE FunctionCallbackInfo(internal::Address* implicit_args,
internal::Address* values, int length);
internal::Address* implicit_args_;
internal::Address* values_;
int length_;
};
/**
* The information passed to a property callback about the context
* of the property access.
*/
template<typename T>
class PropertyCallbackInfo {
public:
/**
* \return The isolate of the property access.
*/
V8_INLINE Isolate* GetIsolate() const;
/**
* \return The data set in the configuration, i.e., in
* `NamedPropertyHandlerConfiguration` or
* `IndexedPropertyHandlerConfiguration.`
*/
V8_INLINE Local<Value> Data() const;
/**
* \return The receiver. In many cases, this is the object on which the
* property access was intercepted. When using
* `Reflect.get`, `Function.prototype.call`, or similar functions, it is the
* object passed in as receiver or thisArg.
*
* \code
* void GetterCallback(Local<Name> name,
* const v8::PropertyCallbackInfo<v8::Value>& info) {
* auto context = info.GetIsolate()->GetCurrentContext();
*
* v8::Local<v8::Value> a_this =
* info.This()
* ->GetRealNamedProperty(context, v8_str("a"))
* .ToLocalChecked();
* v8::Local<v8::Value> a_holder =
* info.Holder()
* ->GetRealNamedProperty(context, v8_str("a"))
* .ToLocalChecked();
*
* CHECK(v8_str("r")->Equals(context, a_this).FromJust());
* CHECK(v8_str("obj")->Equals(context, a_holder).FromJust());
*
* info.GetReturnValue().Set(name);
* }
*
* 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();
*
* CompileRun("obj.a = 'obj'; var r = {a: 'r'}; Reflect.get(obj, 'x', r)");
* \endcode
*/
V8_INLINE Local<Object> This() const;
/**
* \return The object in the prototype chain of the receiver that has the
* interceptor. Suppose you have `x` and its prototype is `y`, and `y`
* has an interceptor. Then `info.This()` is `x` and `info.Holder()` is `y`.
* The Holder() could be a hidden object (the global object, rather
* than the global proxy).
*
* \note For security reasons, do not pass the object back into the runtime.
*/
V8_INLINE Local<Object> Holder() const;
/**
* \return The return value of the callback.
* Can be changed by calling Set().
* \code
* info.GetReturnValue().Set(...)
* \endcode
*
*/
V8_INLINE ReturnValue<T> GetReturnValue() const;
/**
* \return True if the intercepted function should throw if an error occurs.
* Usually, `true` corresponds to `'use strict'`.
*
* \note Always `false` when intercepting `Reflect.set()`
* independent of the language mode.
*/
V8_INLINE bool ShouldThrowOnError() const;
// This shouldn't be public, but the arm compiler needs it.
static const int kArgsLength = 7;
protected:
friend class MacroAssembler;
friend class internal::PropertyCallbackArguments;
friend class internal::CustomArguments<PropertyCallbackInfo>;
static const int kShouldThrowOnErrorIndex = 0;
static const int kHolderIndex = 1;
static const int kIsolateIndex = 2;
static const int kReturnValueDefaultValueIndex = 3;
static const int kReturnValueIndex = 4;
static const int kDataIndex = 5;
static const int kThisIndex = 6;
V8_INLINE PropertyCallbackInfo(internal::Address* args) : args_(args) {}
internal::Address* args_;
};
using FunctionCallback = void (*)(const FunctionCallbackInfo<Value>& info);
enum class ConstructorBehavior { kThrow, kAllow };
/**
* A JavaScript function object (ECMA-262, 15.3).
*/
class V8_EXPORT Function : public Object {
public:
/**
* Create a function in the current execution context
* for a given FunctionCallback.
*/
static MaybeLocal<Function> New(
Local<Context> context, FunctionCallback callback,
Local<Value> data = Local<Value>(), int length = 0,
ConstructorBehavior behavior = ConstructorBehavior::kAllow,
SideEffectType side_effect_type = SideEffectType::kHasSideEffect);
V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
Local<Context> context, int argc, Local<Value> argv[]) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
Local<Context> context) const {
return NewInstance(context, 0, nullptr);
}
/**
* When side effect checks are enabled, passing kHasNoSideEffect allows the
* constructor to be invoked without throwing. Calls made within the
* constructor are still checked.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstanceWithSideEffectType(
Local<Context> context, int argc, Local<Value> argv[],
SideEffectType side_effect_type = SideEffectType::kHasSideEffect) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Call(Local<Context> context,
Local<Value> recv, int argc,
Local<Value> argv[]);
void SetName(Local<String> name);
Local<Value> GetName() const;
/**
* Name inferred from variable or property assignment of this function.
* Used to facilitate debugging and profiling of JavaScript code written
* in an OO style, where many functions are anonymous but are assigned
* to object properties.
*/
Local<Value> GetInferredName() const;
/**
* displayName if it is set, otherwise name if it is configured, otherwise
* function name, otherwise inferred name.
*/
Local<Value> GetDebugName() const;
/**
* User-defined name assigned to the "displayName" property of this function.
* Used to facilitate debugging and profiling of JavaScript code.
*/
V8_DEPRECATED(
"Use v8::Object::Get() instead to look up \"displayName\". "
"V8 and DevTools no longer use \"displayName\" in stack "
"traces, but the standard \"name\" property. "
"See http://crbug.com/1177685.")
Local<Value> GetDisplayName() const;
/**
* Returns zero based line number of function body and
* kLineOffsetNotFound if no information available.
*/
int GetScriptLineNumber() const;
/**
* Returns zero based column number of function body and
* kLineOffsetNotFound if no information available.
*/
int GetScriptColumnNumber() const;
/**
* Returns scriptId.
*/
int ScriptId() const;
/**
* Returns the original function if this function is bound, else returns
* v8::Undefined.
*/
Local<Value> GetBoundFunction() const;
/**
* Calls builtin Function.prototype.toString on this function.
* This is different from Value::ToString() that may call a user-defined
* toString() function, and different than Object::ObjectProtoToString() which
* always serializes "[object Function]".
*/
V8_WARN_UNUSED_RESULT MaybeLocal<String> FunctionProtoToString(
Local<Context> context);
ScriptOrigin GetScriptOrigin() const;
V8_INLINE static Function* Cast(Value* obj);
static const int kLineOffsetNotFound;
private:
Function();
static void CheckCast(Value* obj);
};
#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
// The number of required internal fields can be defined by embedder.
#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
#endif
/**
* An instance of the built-in Promise constructor (ES6 draft).
*/
class V8_EXPORT Promise : public Object {
public:
/**
* State of the promise. Each value corresponds to one of the possible values
* of the [[PromiseState]] field.
*/
enum PromiseState { kPending, kFulfilled, kRejected };
class V8_EXPORT Resolver : public Object {
public:
/**
* Create a new resolver, along with an associated promise in pending state.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Resolver> New(
Local<Context> context);
/**
* Extract the associated promise.
*/
Local<Promise> GetPromise();
/**
* Resolve/reject the associated promise with a given value.
* Ignored if the promise is no longer pending.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> Resolve(Local<Context> context,
Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> Reject(Local<Context> context,
Local<Value> value);
V8_INLINE static Resolver* Cast(Value* obj);
private:
Resolver();
static void CheckCast(Value* obj);
};
/**
* Register a resolution/rejection handler with a promise.
* The handler is given the respective resolution/rejection value as
* an argument. If the promise is already resolved/rejected, the handler is
* invoked at the end of turn.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Catch(Local<Context> context,
Local<Function> handler);
V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
Local<Function> handler);
V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
Local<Function> on_fulfilled,
Local<Function> on_rejected);
/**
* Returns true if the promise has at least one derived promise, and
* therefore resolve/reject handlers (including default handler).
*/
bool HasHandler();
/**
* Returns the content of the [[PromiseResult]] field. The Promise must not
* be pending.
*/
Local<Value> Result();
/**
* Returns the value of the [[PromiseState]] field.
*/
PromiseState State();
/**
* Marks this promise as handled to avoid reporting unhandled rejections.
*/
void MarkAsHandled();
/**
* Marks this promise as silent to prevent pausing the debugger when the
* promise is rejected.
*/
void MarkAsSilent();
V8_INLINE static Promise* Cast(Value* obj);
static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
private:
Promise();
static void CheckCast(Value* obj);
};
/**
* An instance of a Property Descriptor, see Ecma-262 6.2.4.
*
* Properties in a descriptor are present or absent. If you do not set
* `enumerable`, `configurable`, and `writable`, they are absent. If `value`,
* `get`, or `set` are absent, but you must specify them in the constructor, use
* empty handles.
*
* Accessors `get` and `set` must be callable or undefined if they are present.
*
* \note Only query properties if they are present, i.e., call `x()` only if
* `has_x()` returns true.
*
* \code
* // var desc = {writable: false}
* v8::PropertyDescriptor d(Local<Value>()), false);
* d.value(); // error, value not set
* if (d.has_writable()) {
* d.writable(); // false
* }
*
* // var desc = {value: undefined}
* v8::PropertyDescriptor d(v8::Undefined(isolate));
*
* // var desc = {get: undefined}
* v8::PropertyDescriptor d(v8::Undefined(isolate), Local<Value>()));
* \endcode
*/
class V8_EXPORT PropertyDescriptor {
public:
// GenericDescriptor
PropertyDescriptor();
// DataDescriptor
explicit PropertyDescriptor(Local<Value> value);
// DataDescriptor with writable property
PropertyDescriptor(Local<Value> value, bool writable);
// AccessorDescriptor
PropertyDescriptor(Local<Value> get, Local<Value> set);
~PropertyDescriptor();
Local<Value> value() const;
bool has_value() const;
Local<Value> get() const;
bool has_get() const;
Local<Value> set() const;
bool has_set() const;
void set_enumerable(bool enumerable);
bool enumerable() const;
bool has_enumerable() const;
void set_configurable(bool configurable);
bool configurable() const;
bool has_configurable() const;
bool writable() const;
bool has_writable() const;
struct PrivateData;
PrivateData* get_private() const { return private_; }
PropertyDescriptor(const PropertyDescriptor&) = delete;
void operator=(const PropertyDescriptor&) = delete;
private:
PrivateData* private_;
};
/**
* An instance of the built-in Proxy constructor (ECMA-262, 6th Edition,
* 26.2.1).
*/
class V8_EXPORT Proxy : public Object {
public:
Local<Value> GetTarget();
Local<Value> GetHandler();
bool IsRevoked();
void Revoke();
/**
* Creates a new Proxy for the target object.
*/
static MaybeLocal<Proxy> New(Local<Context> context,
Local<Object> local_target,
Local<Object> local_handler);
V8_INLINE static Proxy* Cast(Value* obj);
private:
Proxy();
static void CheckCast(Value* obj);
};
/**
* Points to an unowned continous buffer holding a known number of elements.
*
* This is similar to std::span (under consideration for C++20), but does not
* require advanced C++ support. In the (far) future, this may be replaced with
* or aliased to std::span.
*
* To facilitate future migration, this class exposes a subset of the interface
* implemented by std::span.
*/
template <typename T>
class V8_EXPORT MemorySpan {
public:
/** The default constructor creates an empty span. */
constexpr MemorySpan() = default;
constexpr MemorySpan(T* data, size_t size) : data_(data), size_(size) {}
/** Returns a pointer to the beginning of the buffer. */
constexpr T* data() const { return data_; }
/** Returns the number of elements that the buffer holds. */
constexpr size_t size() const { return size_; }
private:
T* data_ = nullptr;
size_t size_ = 0;
};
/**
* An owned byte buffer with associated size.
*/
struct OwnedBuffer {
std::unique_ptr<const uint8_t[]> buffer;
size_t size = 0;
OwnedBuffer(std::unique_ptr<const uint8_t[]> buffer, size_t size)
: buffer(std::move(buffer)), size(size) {}
OwnedBuffer() = default;
};
// Wrapper around a compiled WebAssembly module, which is potentially shared by
// different WasmModuleObjects.
class V8_EXPORT CompiledWasmModule {
public:
/**
* Serialize the compiled module. The serialized data does not include the
* wire bytes.
*/
OwnedBuffer Serialize();
/**
* Get the (wasm-encoded) wire bytes that were used to compile this module.
*/
MemorySpan<const uint8_t> GetWireBytesRef();
const std::string& source_url() const { return source_url_; }
private:
friend class WasmModuleObject;
friend class WasmStreaming;
explicit CompiledWasmModule(std::shared_ptr<internal::wasm::NativeModule>,
const char* source_url, size_t url_length);
const std::shared_ptr<internal::wasm::NativeModule> native_module_;
const std::string source_url_;
};
// An instance of WebAssembly.Memory.
class V8_EXPORT WasmMemoryObject : public Object {
public:
WasmMemoryObject() = delete;
/**
* Returns underlying ArrayBuffer.
*/
Local<ArrayBuffer> Buffer();
V8_INLINE static WasmMemoryObject* Cast(Value* obj);
private:
static void CheckCast(Value* object);
};
// An instance of WebAssembly.Module.
class V8_EXPORT WasmModuleObject : public Object {
public:
WasmModuleObject() = delete;
/**
* Efficiently re-create a WasmModuleObject, without recompiling, from
* a CompiledWasmModule.
*/
static MaybeLocal<WasmModuleObject> FromCompiledModule(
Isolate* isolate, const CompiledWasmModule&);
/**
* Get the compiled module for this module object. The compiled module can be
* shared by several module objects.
*/
CompiledWasmModule GetCompiledModule();
V8_INLINE static WasmModuleObject* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* The V8 interface for WebAssembly streaming compilation. When streaming
* compilation is initiated, V8 passes a {WasmStreaming} object to the embedder
* such that the embedder can pass the input bytes for streaming compilation to
* V8.
*/
class V8_EXPORT WasmStreaming final {
public:
class WasmStreamingImpl;
/**
* Client to receive streaming event notifications.
*/
class Client {
public:
virtual ~Client() = default;
/**
* Passes the fully compiled module to the client. This can be used to
* implement code caching.
*/
virtual void OnModuleCompiled(CompiledWasmModule compiled_module) = 0;
};
explicit WasmStreaming(std::unique_ptr<WasmStreamingImpl> impl);
~WasmStreaming();
/**
* Pass a new chunk of bytes to WebAssembly streaming compilation.
* The buffer passed into {OnBytesReceived} is owned by the caller.
*/
void OnBytesReceived(const uint8_t* bytes, size_t size);
/**
* {Finish} should be called after all received bytes where passed to
* {OnBytesReceived} to tell V8 that there will be no more bytes. {Finish}
* does not have to be called after {Abort} has been called already.
*/
void Finish();
/**
* Abort streaming compilation. If {exception} has a value, then the promise
* associated with streaming compilation is rejected with that value. If
* {exception} does not have value, the promise does not get rejected.
*/
void Abort(MaybeLocal<Value> exception);
/**
* Passes previously compiled module bytes. This must be called before
* {OnBytesReceived}, {Finish}, or {Abort}. Returns true if the module bytes
* can be used, false otherwise. The buffer passed via {bytes} and {size}
* is owned by the caller. If {SetCompiledModuleBytes} returns true, the
* buffer must remain valid until either {Finish} or {Abort} completes.
*/
bool SetCompiledModuleBytes(const uint8_t* bytes, size_t size);
/**
* Sets the client object that will receive streaming event notifications.
* This must be called before {OnBytesReceived}, {Finish}, or {Abort}.
*/
void SetClient(std::shared_ptr<Client> client);
/*
* Sets the UTF-8 encoded source URL for the {Script} object. This must be
* called before {Finish}.
*/
void SetUrl(const char* url, size_t length);
/**
* Unpacks a {WasmStreaming} object wrapped in a {Managed} for the embedder.
* Since the embedder is on the other side of the API, it cannot unpack the
* {Managed} itself.
*/
static std::shared_ptr<WasmStreaming> Unpack(Isolate* isolate,
Local<Value> value);
private:
std::unique_ptr<WasmStreamingImpl> impl_;
};
// TODO(mtrofin): when streaming compilation is done, we can rename this
// to simply WasmModuleObjectBuilder
class V8_EXPORT WasmModuleObjectBuilderStreaming final {
public:
explicit WasmModuleObjectBuilderStreaming(Isolate* isolate);
/**
* The buffer passed into OnBytesReceived is owned by the caller.
*/
void OnBytesReceived(const uint8_t*, size_t size);
void Finish();
/**
* Abort streaming compilation. If {exception} has a value, then the promise
* associated with streaming compilation is rejected with that value. If
* {exception} does not have value, the promise does not get rejected.
*/
void Abort(MaybeLocal<Value> exception);
Local<Promise> GetPromise();
~WasmModuleObjectBuilderStreaming() = default;
private:
WasmModuleObjectBuilderStreaming(const WasmModuleObjectBuilderStreaming&) =
delete;
WasmModuleObjectBuilderStreaming(WasmModuleObjectBuilderStreaming&&) =
default;
WasmModuleObjectBuilderStreaming& operator=(
const WasmModuleObjectBuilderStreaming&) = delete;
WasmModuleObjectBuilderStreaming& operator=(
WasmModuleObjectBuilderStreaming&&) = default;
Isolate* isolate_ = nullptr;
#if V8_CC_MSVC
/**
* We don't need the static Copy API, so the default
* NonCopyablePersistentTraits would be sufficient, however,
* MSVC eagerly instantiates the Copy.
* We ensure we don't use Copy, however, by compiling with the
* defaults everywhere else.
*/
Persistent<Promise, CopyablePersistentTraits<Promise>> promise_;
#else
Persistent<Promise> promise_;
#endif
std::shared_ptr<internal::wasm::StreamingDecoder> streaming_decoder_;
};
#ifndef V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT
// The number of required internal fields can be defined by embedder.
#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
#endif
enum class ArrayBufferCreationMode { kInternalized, kExternalized };
/**
* A wrapper around the backing store (i.e. the raw memory) of an array buffer.
* See a document linked in http://crbug.com/v8/9908 for more information.
*
* The allocation and destruction of backing stores is generally managed by
* V8. Clients should always use standard C++ memory ownership types (i.e.
* std::unique_ptr and std::shared_ptr) to manage lifetimes of backing stores
* properly, since V8 internal objects may alias backing stores.
*
* This object does not keep the underlying |ArrayBuffer::Allocator| alive by
* default. Use Isolate::CreateParams::array_buffer_allocator_shared when
* creating the Isolate to make it hold a reference to the allocator itself.
*/
class V8_EXPORT BackingStore : public v8::internal::BackingStoreBase {
public:
~BackingStore();
/**
* Return a pointer to the beginning of the memory block for this backing
* store. The pointer is only valid as long as this backing store object
* lives.
*/
void* Data() const;
/**
* The length (in bytes) of this backing store.
*/
size_t ByteLength() const;
/**
* Indicates whether the backing store was created for an ArrayBuffer or
* a SharedArrayBuffer.
*/
bool IsShared() const;
/**
* Prevent implicit instantiation of operator delete with size_t argument.
* The size_t argument would be incorrect because ptr points to the
* internal BackingStore object.
*/
void operator delete(void* ptr) { ::operator delete(ptr); }
/**
* Wrapper around ArrayBuffer::Allocator::Reallocate that preserves IsShared.
* Assumes that the backing_store was allocated by the ArrayBuffer allocator
* of the given isolate.
*/
static std::unique_ptr<BackingStore> Reallocate(
v8::Isolate* isolate, std::unique_ptr<BackingStore> backing_store,
size_t byte_length);
/**
* This callback is used only if the memory block for a BackingStore cannot be
* allocated with an ArrayBuffer::Allocator. In such cases the destructor of
* the BackingStore invokes the callback to free the memory block.
*/
using DeleterCallback = void (*)(void* data, size_t length,
void* deleter_data);
/**
* If the memory block of a BackingStore is static or is managed manually,
* then this empty deleter along with nullptr deleter_data can be passed to
* ArrayBuffer::NewBackingStore to indicate that.
*
* The manually managed case should be used with caution and only when it
* is guaranteed that the memory block freeing happens after detaching its
* ArrayBuffer.
*/
static void EmptyDeleter(void* data, size_t length, void* deleter_data);
private:
/**
* See [Shared]ArrayBuffer::GetBackingStore and
* [Shared]ArrayBuffer::NewBackingStore.
*/
BackingStore();
};
#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
// Use v8::BackingStore::DeleterCallback instead.
using BackingStoreDeleterCallback = void (*)(void* data, size_t length,
void* deleter_data);
#endif
/**
* An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
*/
class V8_EXPORT ArrayBuffer : public Object {
public:
/**
* A thread-safe allocator that V8 uses to allocate |ArrayBuffer|'s memory.
* The allocator is a global V8 setting. It has to be set via
* Isolate::CreateParams.
*
* Memory allocated through this allocator by V8 is accounted for as external
* memory by V8. Note that V8 keeps track of the memory for all internalized
* |ArrayBuffer|s. Responsibility for tracking external memory (using
* Isolate::AdjustAmountOfExternalAllocatedMemory) is handed over to the
* embedder upon externalization and taken over upon internalization (creating
* an internalized buffer from an existing buffer).
*
* Note that it is unsafe to call back into V8 from any of the allocator
* functions.
*/
class V8_EXPORT Allocator {
public:
virtual ~Allocator() = default;
/**
* Allocate |length| bytes. Return nullptr if allocation is not successful.
* Memory should be initialized to zeroes.
*/
virtual void* Allocate(size_t length) = 0;
/**
* Allocate |length| bytes. Return nullptr if allocation is not successful.
* Memory does not have to be initialized.
*/
virtual void* AllocateUninitialized(size_t length) = 0;
/**
* Free the memory block of size |length|, pointed to by |data|.
* That memory is guaranteed to be previously allocated by |Allocate|.
*/
virtual void Free(void* data, size_t length) = 0;
/**
* Reallocate the memory block of size |old_length| to a memory block of
* size |new_length| by expanding, contracting, or copying the existing
* memory block. If |new_length| > |old_length|, then the new part of
* the memory must be initialized to zeros. Return nullptr if reallocation
* is not successful.
*
* The caller guarantees that the memory block was previously allocated
* using Allocate or AllocateUninitialized.
*
* The default implementation allocates a new block and copies data.
*/
virtual void* Reallocate(void* data, size_t old_length, size_t new_length);
/**
* ArrayBuffer allocation mode. kNormal is a malloc/free style allocation,
* while kReservation is for larger allocations with the ability to set
* access permissions.
*/
enum class AllocationMode { kNormal, kReservation };
/**
* malloc/free based convenience allocator.
*
* Caller takes ownership, i.e. the returned object needs to be freed using
* |delete allocator| once it is no longer in use.
*/
static Allocator* NewDefaultAllocator();
};
/**
* The contents of an |ArrayBuffer|. Externalization of |ArrayBuffer|
* returns an instance of this class, populated, with a pointer to data
* and byte length.
*
* The Data pointer of ArrayBuffer::Contents must be freed using the provided
* deleter, which will call ArrayBuffer::Allocator::Free if the buffer
* was allocated with ArraryBuffer::Allocator::Allocate.
*/
class V8_EXPORT Contents { // NOLINT
public:
using DeleterCallback = void (*)(void* buffer, size_t length, void* info);
Contents()
: data_(nullptr),
byte_length_(0),
allocation_base_(nullptr),
allocation_length_(0),
allocation_mode_(Allocator::AllocationMode::kNormal),
deleter_(nullptr),
deleter_data_(nullptr) {}
void* AllocationBase() const { return allocation_base_; }
size_t AllocationLength() const { return allocation_length_; }
Allocator::AllocationMode AllocationMode() const {
return allocation_mode_;
}
void* Data() const { return data_; }
size_t ByteLength() const { return byte_length_; }
DeleterCallback Deleter() const { return deleter_; }
void* DeleterData() const { return deleter_data_; }
private:
Contents(void* data, size_t byte_length, void* allocation_base,
size_t allocation_length,
Allocator::AllocationMode allocation_mode, DeleterCallback deleter,
void* deleter_data);
void* data_;
size_t byte_length_;
void* allocation_base_;
size_t allocation_length_;
Allocator::AllocationMode allocation_mode_;
DeleterCallback deleter_;
void* deleter_data_;
friend class ArrayBuffer;
};
/**
* Data length in bytes.
*/
size_t ByteLength() const;
/**
* Create a new ArrayBuffer. Allocate |byte_length| bytes.
* Allocated memory will be owned by a created ArrayBuffer and
* will be deallocated when it is garbage-collected,
* unless the object is externalized.
*/
static Local<ArrayBuffer> New(Isolate* isolate, size_t byte_length);
/**
* Create a new ArrayBuffer over an existing memory block.
* The created array buffer is by default immediately in externalized state.
* In externalized state, the memory block will not be reclaimed when a
* created ArrayBuffer is garbage-collected.
* In internalized state, the memory block will be released using
* |Allocator::Free| once all ArrayBuffers referencing it are collected by
* the garbage collector.
*/
V8_DEPRECATED(
"Use the version that takes a BackingStore. "
"See http://crbug.com/v8/9908.")
static Local<ArrayBuffer> New(
Isolate* isolate, void* data, size_t byte_length,
ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
/**
* Create a new ArrayBuffer with an existing backing store.
* The created array keeps a reference to the backing store until the array
* is garbage collected. Note that the IsExternal bit does not affect this
* reference from the array to the backing store.
*
* In future IsExternal bit will be removed. Until then the bit is set as
* follows. If the backing store does not own the underlying buffer, then
* the array is created in externalized state. Otherwise, the array is created
* in internalized state. In the latter case the array can be transitioned
* to the externalized state using Externalize(backing_store).
*/
static Local<ArrayBuffer> New(Isolate* isolate,
std::shared_ptr<BackingStore> backing_store);
/**
* Returns a new standalone BackingStore that is allocated using the array
* buffer allocator of the isolate. The result can be later passed to
* ArrayBuffer::New.
*
* If the allocator returns nullptr, then the function may cause GCs in the
* given isolate and re-try the allocation. If GCs do not help, then the
* function will crash with an out-of-memory error.
*/
static std::unique_ptr<BackingStore> NewBackingStore(Isolate* isolate,
size_t byte_length);
/**
* Returns a new standalone BackingStore that takes over the ownership of
* the given buffer. The destructor of the BackingStore invokes the given
* deleter callback.
*
* The result can be later passed to ArrayBuffer::New. The raw pointer
* to the buffer must not be passed again to any V8 API function.
*/
static std::unique_ptr<BackingStore> NewBackingStore(
void* data, size_t byte_length, v8::BackingStore::DeleterCallback deleter,
void* deleter_data);
/**
* Returns true if ArrayBuffer is externalized, that is, does not
* own its memory block.
*/
V8_DEPRECATED(
"With v8::BackingStore externalized ArrayBuffers are "
"the same as ordinary ArrayBuffers. See http://crbug.com/v8/9908.")
bool IsExternal() const;
/**
* Returns true if this ArrayBuffer may be detached.
*/
bool IsDetachable() const;
/**
* Detaches this ArrayBuffer and all its views (typed arrays).
* Detaching sets the byte length of the buffer and all typed arrays to zero,
* preventing JavaScript from ever accessing underlying backing store.
* ArrayBuffer should have been externalized and must be detachable.
*/
void Detach();
/**
* Make this ArrayBuffer external. The pointer to underlying memory block
* and byte length are returned as |Contents| structure. After ArrayBuffer
* had been externalized, it does no longer own the memory block. The caller
* should take steps to free memory when it is no longer needed.
*
* The Data pointer of ArrayBuffer::Contents must be freed using the provided
* deleter, which will call ArrayBuffer::Allocator::Free if the buffer
* was allocated with ArrayBuffer::Allocator::Allocate.
*/
V8_DEPRECATED("Use GetBackingStore or Detach. See http://crbug.com/v8/9908.")
Contents Externalize();
/**
* Marks this ArrayBuffer external given a witness that the embedder
* has fetched the backing store using the new GetBackingStore() function.
*
* With the new lifetime management of backing stores there is no need for
* externalizing, so this function exists only to make the transition easier.
*/
V8_DEPRECATED("This will be removed together with IsExternal.")
void Externalize(const std::shared_ptr<BackingStore>& backing_store);
/**
* Get a pointer to the ArrayBuffer's underlying memory block without
* externalizing it. If the ArrayBuffer is not externalized, this pointer
* will become invalid as soon as the ArrayBuffer gets garbage collected.
*
* The embedder should make sure to hold a strong reference to the
* ArrayBuffer while accessing this pointer.
*/
V8_DEPRECATED("Use GetBackingStore. See http://crbug.com/v8/9908.")
Contents GetContents();
/**
* Get a shared pointer to the backing store of this array buffer. This
* pointer coordinates the lifetime management of the internal storage
* with any live ArrayBuffers on the heap, even across isolates. The embedder
* should not attempt to manage lifetime of the storage through other means.
*
* This function replaces both Externalize() and GetContents().
*/
std::shared_ptr<BackingStore> GetBackingStore();
V8_INLINE static ArrayBuffer* Cast(Value* obj);
static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
static const int kEmbedderFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
private:
ArrayBuffer();
static void CheckCast(Value* obj);
Contents GetContents(bool externalize);
};
#ifndef V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT
// The number of required internal fields can be defined by embedder.
#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
#endif
/**
* A base class for an instance of one of "views" over ArrayBuffer,
* including TypedArrays and DataView (ES6 draft 15.13).
*/
class V8_EXPORT ArrayBufferView : public Object {
public:
/**
* Returns underlying ArrayBuffer.
*/
Local<ArrayBuffer> Buffer();
/**
* Byte offset in |Buffer|.
*/
size_t ByteOffset();
/**
* Size of a view in bytes.
*/
size_t ByteLength();
/**
* Copy the contents of the ArrayBufferView's buffer to an embedder defined
* memory without additional overhead that calling ArrayBufferView::Buffer
* might incur.
*
* Will write at most min(|byte_length|, ByteLength) bytes starting at
* ByteOffset of the underlying buffer to the memory starting at |dest|.
* Returns the number of bytes actually written.
*/
size_t CopyContents(void* dest, size_t byte_length);
/**
* Returns true if ArrayBufferView's backing ArrayBuffer has already been
* allocated.
*/
bool HasBuffer() const;
V8_INLINE static ArrayBufferView* Cast(Value* obj);
static const int kInternalFieldCount =
V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
static const int kEmbedderFieldCount =
V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
private:
ArrayBufferView();
static void CheckCast(Value* obj);
};
/**
* A base class for an instance of TypedArray series of constructors
* (ES6 draft 15.13.6).
*/
class V8_EXPORT TypedArray : public ArrayBufferView {
public:
/*
* The largest typed array size that can be constructed using New.
*/
static constexpr size_t kMaxLength =
internal::kApiSystemPointerSize == 4
? internal::kSmiMaxValue
: static_cast<size_t>(uint64_t{1} << 32);
/**
* Number of elements in this typed array
* (e.g. for Int16Array, |ByteLength|/2).
*/
size_t Length();
V8_INLINE static TypedArray* Cast(Value* obj);
private:
TypedArray();
static void CheckCast(Value* obj);
};
/**
* An instance of Uint8Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Uint8Array : public TypedArray {
public:
static Local<Uint8Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Uint8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Uint8Array* Cast(Value* obj);
private:
Uint8Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Uint8ClampedArray : public TypedArray {
public:
static Local<Uint8ClampedArray> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Uint8ClampedArray> New(
Local<SharedArrayBuffer> shared_array_buffer, size_t byte_offset,
size_t length);
V8_INLINE static Uint8ClampedArray* Cast(Value* obj);
private:
Uint8ClampedArray();
static void CheckCast(Value* obj);
};
/**
* An instance of Int8Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Int8Array : public TypedArray {
public:
static Local<Int8Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Int8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Int8Array* Cast(Value* obj);
private:
Int8Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Uint16Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Uint16Array : public TypedArray {
public:
static Local<Uint16Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Uint16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Uint16Array* Cast(Value* obj);
private:
Uint16Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Int16Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Int16Array : public TypedArray {
public:
static Local<Int16Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Int16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Int16Array* Cast(Value* obj);
private:
Int16Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Uint32Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Uint32Array : public TypedArray {
public:
static Local<Uint32Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Uint32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Uint32Array* Cast(Value* obj);
private:
Uint32Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Int32Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Int32Array : public TypedArray {
public:
static Local<Int32Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Int32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Int32Array* Cast(Value* obj);
private:
Int32Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Float32Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Float32Array : public TypedArray {
public:
static Local<Float32Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Float32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Float32Array* Cast(Value* obj);
private:
Float32Array();
static void CheckCast(Value* obj);
};
/**
* An instance of Float64Array constructor (ES6 draft 15.13.6).
*/
class V8_EXPORT Float64Array : public TypedArray {
public:
static Local<Float64Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<Float64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static Float64Array* Cast(Value* obj);
private:
Float64Array();
static void CheckCast(Value* obj);
};
/**
* An instance of BigInt64Array constructor.
*/
class V8_EXPORT BigInt64Array : public TypedArray {
public:
static Local<BigInt64Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<BigInt64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static BigInt64Array* Cast(Value* obj);
private:
BigInt64Array();
static void CheckCast(Value* obj);
};
/**
* An instance of BigUint64Array constructor.
*/
class V8_EXPORT BigUint64Array : public TypedArray {
public:
static Local<BigUint64Array> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<BigUint64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static BigUint64Array* Cast(Value* obj);
private:
BigUint64Array();
static void CheckCast(Value* obj);
};
/**
* An instance of DataView constructor (ES6 draft 15.13.7).
*/
class V8_EXPORT DataView : public ArrayBufferView {
public:
static Local<DataView> New(Local<ArrayBuffer> array_buffer,
size_t byte_offset, size_t length);
static Local<DataView> New(Local<SharedArrayBuffer> shared_array_buffer,
size_t byte_offset, size_t length);
V8_INLINE static DataView* Cast(Value* obj);
private:
DataView();
static void CheckCast(Value* obj);
};
/**
* An instance of the built-in SharedArrayBuffer constructor.
*/
class V8_EXPORT SharedArrayBuffer : public Object {
public:
/**
* The contents of an |SharedArrayBuffer|. Externalization of
* |SharedArrayBuffer| returns an instance of this class, populated, with a
* pointer to data and byte length.
*
* The Data pointer of ArrayBuffer::Contents must be freed using the provided
* deleter, which will call ArrayBuffer::Allocator::Free if the buffer
* was allocated with ArraryBuffer::Allocator::Allocate.
*/
class V8_EXPORT Contents { // NOLINT
public:
using Allocator = v8::ArrayBuffer::Allocator;
using DeleterCallback = void (*)(void* buffer, size_t length, void* info);
Contents()
: data_(nullptr),
byte_length_(0),
allocation_base_(nullptr),
allocation_length_(0),
allocation_mode_(Allocator::AllocationMode::kNormal),
deleter_(nullptr),
deleter_data_(nullptr) {}
void* AllocationBase() const { return allocation_base_; }
size_t AllocationLength() const { return allocation_length_; }
Allocator::AllocationMode AllocationMode() const {
return allocation_mode_;
}
void* Data() const { return data_; }
size_t ByteLength() const { return byte_length_; }
DeleterCallback Deleter() const { return deleter_; }
void* DeleterData() const { return deleter_data_; }
private:
Contents(void* data, size_t byte_length, void* allocation_base,
size_t allocation_length,
Allocator::AllocationMode allocation_mode, DeleterCallback deleter,
void* deleter_data);
void* data_;
size_t byte_length_;
void* allocation_base_;
size_t allocation_length_;
Allocator::AllocationMode allocation_mode_;
DeleterCallback deleter_;
void* deleter_data_;
friend class SharedArrayBuffer;
};
/**
* Data length in bytes.
*/
size_t ByteLength() const;
/**
* Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
* Allocated memory will be owned by a created SharedArrayBuffer and
* will be deallocated when it is garbage-collected,
* unless the object is externalized.
*/
static Local<SharedArrayBuffer> New(Isolate* isolate, size_t byte_length);
/**
* Create a new SharedArrayBuffer over an existing memory block. The created
* array buffer is immediately in externalized state unless otherwise
* specified. The memory block will not be reclaimed when a created
* SharedArrayBuffer is garbage-collected.
*/
V8_DEPRECATED(
"Use the version that takes a BackingStore. "
"See http://crbug.com/v8/9908.")
static Local<SharedArrayBuffer> New(
Isolate* isolate, void* data, size_t byte_length,
ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
/**
* Create a new SharedArrayBuffer with an existing backing store.
* The created array keeps a reference to the backing store until the array
* is garbage collected. Note that the IsExternal bit does not affect this
* reference from the array to the backing store.
*
* In future IsExternal bit will be removed. Until then the bit is set as
* follows. If the backing store does not own the underlying buffer, then
* the array is created in externalized state. Otherwise, the array is created
* in internalized state. In the latter case the array can be transitioned
* to the externalized state using Externalize(backing_store).
*/
static Local<SharedArrayBuffer> New(
Isolate* isolate, std::shared_ptr<BackingStore> backing_store);
/**
* Returns a new standalone BackingStore that is allocated using the array
* buffer allocator of the isolate. The result can be later passed to
* SharedArrayBuffer::New.
*
* If the allocator returns nullptr, then the function may cause GCs in the
* given isolate and re-try the allocation. If GCs do not help, then the
* function will crash with an out-of-memory error.
*/
static std::unique_ptr<BackingStore> NewBackingStore(Isolate* isolate,
size_t byte_length);
/**
* Returns a new standalone BackingStore that takes over the ownership of
* the given buffer. The destructor of the BackingStore invokes the given
* deleter callback.
*
* The result can be later passed to SharedArrayBuffer::New. The raw pointer
* to the buffer must not be passed again to any V8 functions.
*/
static std::unique_ptr<BackingStore> NewBackingStore(
void* data, size_t byte_length, v8::BackingStore::DeleterCallback deleter,
void* deleter_data);
/**
* Create a new SharedArrayBuffer over an existing memory block. Propagate
* flags to indicate whether the underlying buffer can be grown.
*/
V8_DEPRECATED(
"Use the version that takes a BackingStore. "
"See http://crbug.com/v8/9908.")
static Local<SharedArrayBuffer> New(
Isolate* isolate, const SharedArrayBuffer::Contents&,
ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
/**
* Returns true if SharedArrayBuffer is externalized, that is, does not
* own its memory block.
*/
V8_DEPRECATED(
"With v8::BackingStore externalized SharedArrayBuffers are the same "
"as ordinary SharedArrayBuffers. See http://crbug.com/v8/9908.")
bool IsExternal() const;
/**
* Make this SharedArrayBuffer external. The pointer to underlying memory
* block and byte length are returned as |Contents| structure. After
* SharedArrayBuffer had been externalized, it does no longer own the memory
* block. The caller should take steps to free memory when it is no longer
* needed.
*
* The memory block is guaranteed to be allocated with |Allocator::Allocate|
* by the allocator specified in
* v8::Isolate::CreateParams::array_buffer_allocator.
*
*/
V8_DEPRECATED("Use GetBackingStore or Detach. See http://crbug.com/v8/9908.")
Contents Externalize();
/**
* Marks this SharedArrayBuffer external given a witness that the embedder
* has fetched the backing store using the new GetBackingStore() function.
*
* With the new lifetime management of backing stores there is no need for
* externalizing, so this function exists only to make the transition easier.
*/
V8_DEPRECATED("This will be removed together with IsExternal.")
void Externalize(const std::shared_ptr<BackingStore>& backing_store);
/**
* Get a pointer to the ArrayBuffer's underlying memory block without
* externalizing it. If the ArrayBuffer is not externalized, this pointer
* will become invalid as soon as the ArrayBuffer became garbage collected.
*
* The embedder should make sure to hold a strong reference to the
* ArrayBuffer while accessing this pointer.
*
* The memory block is guaranteed to be allocated with |Allocator::Allocate|
* by the allocator specified in
* v8::Isolate::CreateParams::array_buffer_allocator.
*/
V8_DEPRECATED("Use GetBackingStore. See http://crbug.com/v8/9908.")
Contents GetContents();
/**
* Get a shared pointer to the backing store of this array buffer. This
* pointer coordinates the lifetime management of the internal storage
* with any live ArrayBuffers on the heap, even across isolates. The embedder
* should not attempt to manage lifetime of the storage through other means.
*
* This function replaces both Externalize() and GetContents().
*/
std::shared_ptr<BackingStore> GetBackingStore();
V8_INLINE static SharedArrayBuffer* Cast(Value* obj);
static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
private:
SharedArrayBuffer();
static void CheckCast(Value* obj);
Contents GetContents(bool externalize);
};
/**
* An instance of the built-in Date constructor (ECMA-262, 15.9).
*/
class V8_EXPORT Date : public Object {
public:
static V8_WARN_UNUSED_RESULT MaybeLocal<Value> New(Local<Context> context,
double time);
/**
* A specialization of Value::NumberValue that is more efficient
* because we know the structure of this object.
*/
double ValueOf() const;
V8_INLINE static Date* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* A Number object (ECMA-262, 4.3.21).
*/
class V8_EXPORT NumberObject : public Object {
public:
static Local<Value> New(Isolate* isolate, double value);
double ValueOf() const;
V8_INLINE static NumberObject* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* A BigInt object (https://tc39.github.io/proposal-bigint)
*/
class V8_EXPORT BigIntObject : public Object {
public:
static Local<Value> New(Isolate* isolate, int64_t value);
Local<BigInt> ValueOf() const;
V8_INLINE static BigIntObject* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* A Boolean object (ECMA-262, 4.3.15).
*/
class V8_EXPORT BooleanObject : public Object {
public:
static Local<Value> New(Isolate* isolate, bool value);
bool ValueOf() const;
V8_INLINE static BooleanObject* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* A String object (ECMA-262, 4.3.18).
*/
class V8_EXPORT StringObject : public Object {
public:
static Local<Value> New(Isolate* isolate, Local<String> value);
Local<String> ValueOf() const;
V8_INLINE static StringObject* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* A Symbol object (ECMA-262 edition 6).
*/
class V8_EXPORT SymbolObject : public Object {
public:
static Local<Value> New(Isolate* isolate, Local<Symbol> value);
Local<Symbol> ValueOf() const;
V8_INLINE static SymbolObject* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* An instance of the built-in RegExp constructor (ECMA-262, 15.10).
*/
class V8_EXPORT RegExp : public Object {
public:
/**
* Regular expression flag bits. They can be or'ed to enable a set
* of flags.
* The kLinear value ('l') is experimental and can only be used with
* --enable-experimental-regexp-engine. RegExps with kLinear flag are
* guaranteed to be executed in asymptotic linear time wrt. the length of
* the subject string.
*/
enum Flags {
kNone = 0,
kGlobal = 1 << 0,
kIgnoreCase = 1 << 1,
kMultiline = 1 << 2,
kSticky = 1 << 3,
kUnicode = 1 << 4,
kDotAll = 1 << 5,
kLinear = 1 << 6,
kHasIndices = 1 << 7,
};
static constexpr int kFlagCount = 8;
/**
* Creates a regular expression from the given pattern string and
* the flags bit field. May throw a JavaScript exception as
* described in ECMA-262, 15.10.4.1.
*
* For example,
* RegExp::New(v8::String::New("foo"),
* static_cast<RegExp::Flags>(kGlobal | kMultiline))
* is equivalent to evaluating "/foo/gm".
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<RegExp> New(Local<Context> context,
Local<String> pattern,
Flags flags);
/**
* Like New, but additionally specifies a backtrack limit. If the number of
* backtracks done in one Exec call hits the limit, a match failure is
* immediately returned.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<RegExp> NewWithBacktrackLimit(
Local<Context> context, Local<String> pattern, Flags flags,
uint32_t backtrack_limit);
/**
* Executes the current RegExp instance on the given subject string.
* Equivalent to RegExp.prototype.exec as described in
*
* https://tc39.es/ecma262/#sec-regexp.prototype.exec
*
* On success, an Array containing the matched strings is returned. On
* failure, returns Null.
*
* Note: modifies global context state, accessible e.g. through RegExp.input.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Object> Exec(Local<Context> context,
Local<String> subject);
/**
* Returns the value of the source property: a string representing
* the regular expression.
*/
Local<String> GetSource() const;
/**
* Returns the flags bit field.
*/
Flags GetFlags() const;
V8_INLINE static RegExp* Cast(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* A JavaScript value that wraps a C++ void*. This type of value is mainly used
* to associate C++ data structures with JavaScript objects.
*/
class V8_EXPORT External : public Value {
public:
static Local<External> New(Isolate* isolate, void* value);
V8_INLINE static External* Cast(Value* obj);
void* Value() const;
private:
static void CheckCast(v8::Value* obj);
};
#define V8_INTRINSICS_LIST(F) \
F(ArrayProto_entries, array_entries_iterator) \
F(ArrayProto_forEach, array_for_each_iterator) \
F(ArrayProto_keys, array_keys_iterator) \
F(ArrayProto_values, array_values_iterator) \
F(AsyncIteratorPrototype, initial_async_iterator_prototype) \
F(ErrorPrototype, initial_error_prototype) \
F(IteratorPrototype, initial_iterator_prototype) \
F(ObjProto_valueOf, object_value_of_function)
enum Intrinsic {
#define V8_DECL_INTRINSIC(name, iname) k##name,
V8_INTRINSICS_LIST(V8_DECL_INTRINSIC)
#undef V8_DECL_INTRINSIC
};
// --- Templates ---
/**
* The superclass of object and function templates.
*/
class V8_EXPORT Template : public Data {
public:
/**
* Adds a property to each instance created by this template.
*
* The property must be defined either as a primitive value, or a template.
*/
void Set(Local<Name> name, Local<Data> value,
PropertyAttribute attributes = None);
void SetPrivate(Local<Private> name, Local<Data> value,
PropertyAttribute attributes = None);
V8_INLINE void Set(Isolate* isolate, const char* name, Local<Data> value);
void SetAccessorProperty(
Local<Name> name,
Local<FunctionTemplate> getter = Local<FunctionTemplate>(),
Local<FunctionTemplate> setter = Local<FunctionTemplate>(),
PropertyAttribute attribute = None,
AccessControl settings = DEFAULT);
/**
* Whenever the property with the given name is accessed on objects
* created from this Template the getter and setter callbacks
* are called instead of getting and setting the property directly
* on the JavaScript object.
*
* \param name The name of the property for which an accessor is added.
* \param getter The callback to invoke when getting the property.
* \param setter The callback to invoke when setting the property.
* \param data A piece of data that will be passed to the getter and setter
* callbacks whenever they are invoked.
* \param settings Access control settings for the accessor. This is a bit
* field consisting of one of more of
* DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
* The default is to not allow cross-context access.
* ALL_CAN_READ means that all cross-context reads are allowed.
* ALL_CAN_WRITE means that all cross-context writes are allowed.
* The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
* cross-context access.
* \param attribute The attributes of the property for which an accessor
* is added.
* \param signature The signature describes valid receivers for the accessor
* and is used to perform implicit instance checks against them. If the
* receiver is incompatible (i.e. is not an instance of the constructor as
* defined by FunctionTemplate::HasInstance()), an implicit TypeError is
* thrown and no callback is invoked.
*/
void SetNativeDataProperty(
Local<String> name, AccessorGetterCallback getter,
AccessorSetterCallback setter = nullptr,
Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
Local<AccessorSignature> signature = Local<AccessorSignature>(),
AccessControl settings = DEFAULT,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
void SetNativeDataProperty(
Local<Name> name, AccessorNameGetterCallback getter,
AccessorNameSetterCallback setter = nullptr,
Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
Local<AccessorSignature> signature = Local<AccessorSignature>(),
AccessControl settings = DEFAULT,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* Like SetNativeDataProperty, but V8 will replace the native data property
* with a real data property on first access.
*/
void SetLazyDataProperty(
Local<Name> name, AccessorNameGetterCallback getter,
Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* During template instantiation, sets the value with the intrinsic property
* from the correct context.
*/
void SetIntrinsicDataProperty(Local<Name> name, Intrinsic intrinsic,
PropertyAttribute attribute = None);
private:
Template();
friend class ObjectTemplate;
friend class FunctionTemplate;
};
// TODO(dcarney): Replace GenericNamedPropertyFooCallback with just
// NamedPropertyFooCallback.
/**
* Interceptor for get requests on an object.
*
* Use `info.GetReturnValue().Set()` to set the return value of the
* intercepted get request.
*
* \param property The name of the property for which the request was
* intercepted.
* \param info Information about the intercepted request, such as
* isolate, receiver, return value, or whether running in `'use strict`' mode.
* See `PropertyCallbackInfo`.
*
* \code
* void GetterCallback(
* Local<Name> name,
* const v8::PropertyCallbackInfo<v8::Value>& info) {
* info.GetReturnValue().Set(v8_num(42));
* }
*
* 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());
* \endcode
*
* See also `ObjectTemplate::SetHandler`.
*/
using GenericNamedPropertyGetterCallback =
void (*)(Local<Name> property, const PropertyCallbackInfo<Value>& info);
/**
* Interceptor for set requests on an object.
*
* Use `info.GetReturnValue()` to indicate whether the request was intercepted
* or not. If the setter successfully intercepts the request, i.e., if the
* request should not be further executed, call
* `info.GetReturnValue().Set(value)`. If the setter
* did not intercept the request, i.e., if the request should be handled as
* if no interceptor is present, do not not call `Set()`.
*
* \param property The name of the property for which the request was
* intercepted.
* \param value The value which the property will have if the request
* is not intercepted.
* \param info Information about the intercepted request, such as
* isolate, receiver, return value, or whether running in `'use strict'` mode.
* See `PropertyCallbackInfo`.
*
* See also
* `ObjectTemplate::SetHandler.`
*/
using GenericNamedPropertySetterCallback =
void (*)(Local<Name> property, Local<Value> value,
const PropertyCallbackInfo<Value>& info);
/**
* Intercepts all requests that query the attributes of the
* property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and
* defineProperty().
*
* Use `info.GetReturnValue().Set(value)` to set the property attributes. The
* value is an integer encoding a `v8::PropertyAttribute`.
*
* \param property The name of the property for which the request was
* intercepted.
* \param 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.
*
* See also
* `ObjectTemplate::SetHandler.`
*/
using GenericNamedPropertyQueryCallback =
void (*)(Local<Name> property, const PropertyCallbackInfo<Integer>& info);
/**
* Interceptor for delete requests on an object.
*
* Use `info.GetReturnValue()` to indicate whether the request was intercepted
* or not. If the deleter successfully intercepts the request, i.e., if the
* request should not be further executed, call
* `info.GetReturnValue().Set(value)` with a boolean `value`. The `value` is
* used as the return value of `delete`.
*
* \param property The name of the property for which the request was
* intercepted.
* \param 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.
*
* See also `ObjectTemplate::SetHandler.`
*/
using GenericNamedPropertyDeleterCallback =
void (*)(Local<Name> property, const PropertyCallbackInfo<Boolean>& 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.
*/
using GenericNamedPropertyEnumeratorCallback =
void (*)(const PropertyCallbackInfo<Array>& info);
/**
* Interceptor for defineProperty requests on an object.
*
* Use `info.GetReturnValue()` to indicate whether the request was intercepted
* or not. If the definer successfully intercepts the request, i.e., if the
* request should not be further executed, call
* `info.GetReturnValue().Set(value)`. If the definer
* did not intercept the request, i.e., if the request should be handled as
* if no interceptor is present, do not not call `Set()`.
*
* \param property The name of the property for which the request was
* intercepted.
* \param desc The property descriptor which is used to define the
* property if the request is not intercepted.
* \param info Information about the intercepted request, such as
* isolate, receiver, return value, or whether running in `'use strict'` mode.
* See `PropertyCallbackInfo`.
*
* See also `ObjectTemplate::SetHandler`.
*/
using GenericNamedPropertyDefinerCallback =
void (*)(Local<Name> property, const PropertyDescriptor& desc,
const PropertyCallbackInfo<Value>& info);
/**
* Interceptor for getOwnPropertyDescriptor requests on an object.
*
* Use `info.GetReturnValue().Set()` to set the return value of the
* intercepted request. The return value must be an object that
* can be converted to a PropertyDescriptor, e.g., a `v8::value` returned from
* `v8::Object::getOwnPropertyDescriptor`.
*
* \param 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 GetOwnPropertyDescriptor is intercepted, it will
* always return true, i.e., indicate that the property was found.
*
* See also `ObjectTemplate::SetHandler`.
*/
using GenericNamedPropertyDescriptorCallback =
void (*)(Local<Name> property, const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertyGetterCallback`.
*/
using IndexedPropertyGetterCallback =
void (*)(uint32_t index, const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertySetterCallback`.
*/
using IndexedPropertySetterCallback =
void (*)(uint32_t index, Local<Value> value,
const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertyQueryCallback`.
*/
using IndexedPropertyQueryCallback =
void (*)(uint32_t index, const PropertyCallbackInfo<Integer>& info);
/**
* See `v8::GenericNamedPropertyDeleterCallback`.
*/
using IndexedPropertyDeleterCallback =
void (*)(uint32_t index, const PropertyCallbackInfo<Boolean>& 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.
*/
using IndexedPropertyEnumeratorCallback =
void (*)(const PropertyCallbackInfo<Array>& info);
/**
* See `v8::GenericNamedPropertyDefinerCallback`.
*/
using IndexedPropertyDefinerCallback =
void (*)(uint32_t index, const PropertyDescriptor& desc,
const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertyDescriptorCallback`.
*/
using IndexedPropertyDescriptorCallback =
void (*)(uint32_t index, const PropertyCallbackInfo<Value>& info);
/**
* Access type specification.
*/
enum AccessType {
ACCESS_GET,
ACCESS_SET,
ACCESS_HAS,
ACCESS_DELETE,
ACCESS_KEYS
};
/**
* Returns true if the given context should be allowed to access the given
* object.
*/
using AccessCheckCallback = bool (*)(Local<Context> accessing_context,
Local<Object> accessed_object,
Local<Value> data);
/**
* A FunctionTemplate is used to create functions at runtime. There
* can only be one function created from a FunctionTemplate in a
* context. The lifetime of the created function is equal to the
* lifetime of the context. So in case the embedder needs to create
* temporary functions that can be collected using Scripts is
* preferred.
*
* Any modification of a FunctionTemplate after first instantiation will trigger
* a crash.
*
* A FunctionTemplate can have properties, these properties are added to the
* function object when it is created.
*
* A FunctionTemplate has a corresponding instance template which is
* used to create object instances when the function is used as a
* constructor. Properties added to the instance template are added to
* each object instance.
*
* A FunctionTemplate can have a prototype template. The prototype template
* is used to create the prototype object of the function.
*
* The following example shows how to use a FunctionTemplate:
*
* \code
* v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(isolate);
* t->Set(isolate, "func_property", v8::Number::New(isolate, 1));
*
* v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
* proto_t->Set(isolate,
* "proto_method",
* v8::FunctionTemplate::New(isolate, InvokeCallback));
* proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));
*
* v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
* instance_t->SetAccessor(
String::NewFromUtf8Literal(isolate, "instance_accessor"),
* InstanceAccessorCallback);
* instance_t->SetHandler(
* NamedPropertyHandlerConfiguration(PropertyHandlerCallback));
* instance_t->Set(String::NewFromUtf8Literal(isolate, "instance_property"),
* Number::New(isolate, 3));
*
* v8::Local<v8::Function> function = t->GetFunction();
* v8::Local<v8::Object> instance = function->NewInstance();
* \endcode
*
* Let's use "function" as the JS variable name of the function object
* and "instance" for the instance object created above. The function
* and the instance will have the following properties:
*
* \code
* func_property in function == true;
* function.func_property == 1;
*
* function.prototype.proto_method() invokes 'InvokeCallback'
* function.prototype.proto_const == 2;
*
* instance instanceof function == true;
* instance.instance_accessor calls 'InstanceAccessorCallback'
* instance.instance_property == 3;
* \endcode
*
* A FunctionTemplate can inherit from another one by calling the
* FunctionTemplate::Inherit method. The following graph illustrates
* the semantics of inheritance:
*
* \code
* FunctionTemplate Parent -> Parent() . prototype -> { }
* ^ ^
* | Inherit(Parent) | .__proto__
* | |
* FunctionTemplate Child -> Child() . prototype -> { }
* \endcode
*
* A FunctionTemplate 'Child' inherits from 'Parent', the prototype
* object of the Child() function has __proto__ pointing to the
* Parent() function's prototype object. An instance of the Child
* function has all properties on Parent's instance templates.
*
* Let Parent be the FunctionTemplate initialized in the previous
* section and create a Child FunctionTemplate by:
*
* \code
* Local<FunctionTemplate> parent = t;
* Local<FunctionTemplate> child = FunctionTemplate::New();
* child->Inherit(parent);
*
* Local<Function> child_function = child->GetFunction();
* Local<Object> child_instance = child_function->NewInstance();
* \endcode
*
* The Child function and Child instance will have the following
* properties:
*
* \code
* child_func.prototype.__proto__ == function.prototype;
* child_instance.instance_accessor calls 'InstanceAccessorCallback'
* child_instance.instance_property == 3;
* \endcode
*
* The additional 'c_function' parameter refers to a fast API call, which
* must not trigger GC or JavaScript execution, or call into V8 in other
* ways. For more information how to define them, see
* include/v8-fast-api-calls.h. Please note that this feature is still
* experimental.
*/
class V8_EXPORT FunctionTemplate : public Template {
public:
/** Creates a function template.*/
static Local<FunctionTemplate> New(
Isolate* isolate, FunctionCallback callback = nullptr,
Local<Value> data = Local<Value>(),
Local<Signature> signature = Local<Signature>(), int length = 0,
ConstructorBehavior behavior = ConstructorBehavior::kAllow,
SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
const CFunction* c_function = nullptr);
/** Creates a function template for multiple overloaded fast API calls.*/
static Local<FunctionTemplate> NewWithCFunctionOverloads(
Isolate* isolate, FunctionCallback callback = nullptr,
Local<Value> data = Local<Value>(),
Local<Signature> signature = Local<Signature>(), int length = 0,
ConstructorBehavior behavior = ConstructorBehavior::kAllow,
SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
const MemorySpan<const CFunction>& c_function_overloads = {});
/**
* Creates a function template backed/cached by a private property.
*/
static Local<FunctionTemplate> NewWithCache(
Isolate* isolate, FunctionCallback callback,
Local<Private> cache_property, Local<Value> data = Local<Value>(),
Local<Signature> signature = Local<Signature>(), int length = 0,
SideEffectType side_effect_type = SideEffectType::kHasSideEffect);
/** Returns the unique function instance in the current execution context.*/
V8_WARN_UNUSED_RESULT MaybeLocal<Function> GetFunction(
Local<Context> context);
/**
* Similar to Context::NewRemoteContext, this creates an instance that
* isn't backed by an actual object.
*
* The InstanceTemplate of this FunctionTemplate must have access checks with
* handlers installed.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewRemoteInstance();
/**
* Set the call-handler callback for a FunctionTemplate. This
* callback is called whenever the function created from this
* FunctionTemplate is called. The 'c_function' represents a fast
* API call, see the comment above the class declaration.
*/
void SetCallHandler(
FunctionCallback callback, Local<Value> data = Local<Value>(),
SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
const CFunction* c_function = nullptr);
/**
* Set the call-handler callback for a FunctionTemplate. This
* callback is called whenever the function created from this
* FunctionTemplate is called. The 'c_function' represents a fast
* API call, see the comment above the class declaration.
*/
void SetCallHandlerV8_92(
FunctionCallback callback, Local<Value> data = Local<Value>(),
SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
const MemorySpan<const CFunction>& c_function_overloads = {});
/** Set the predefined length property for the FunctionTemplate. */
void SetLength(int length);
/** Get the InstanceTemplate. */
Local<ObjectTemplate> InstanceTemplate();
/**
* Causes the function template to inherit from a parent function template.
* This means the function's prototype.__proto__ is set to the parent
* function's prototype.
**/
void Inherit(Local<FunctionTemplate> parent);
/**
* A PrototypeTemplate is the template used to create the prototype object
* of the function created by this template.
*/
Local<ObjectTemplate> PrototypeTemplate();
/**
* A PrototypeProviderTemplate is another function template whose prototype
* property is used for this template. This is mutually exclusive with setting
* a prototype template indirectly by calling PrototypeTemplate() or using
* Inherit().
**/
void SetPrototypeProviderTemplate(Local<FunctionTemplate> prototype_provider);
/**
* Set the class name of the FunctionTemplate. This is used for
* printing objects created with the function created from the
* FunctionTemplate as its constructor.
*/
void SetClassName(Local<String> name);
/**
* When set to true, no access check will be performed on the receiver of a
* function call. Currently defaults to true, but this is subject to change.
*/
void SetAcceptAnyReceiver(bool value);
/**
* Sets the ReadOnly flag in the attributes of the 'prototype' property
* of functions created from this FunctionTemplate to true.
*/
void ReadOnlyPrototype();
/**
* Removes the prototype property from functions created from this
* FunctionTemplate.
*/
void RemovePrototype();
/**
* Returns true if the given object is an instance of this function
* template.
*/
bool HasInstance(Local<Value> object);
/**
* Returns true if the given value is an API object that was constructed by an
* instance of this function template (without checking for inheriting
* function templates).
*
* This is an experimental feature and may still change significantly.
*/
bool IsLeafTemplateForApiObject(v8::Local<v8::Value> value) const;
V8_INLINE static FunctionTemplate* Cast(Data* data);
private:
FunctionTemplate();
static void CheckCast(Data* that);
friend class Context;
friend class ObjectTemplate;
};
/**
* Configuration flags for v8::NamedPropertyHandlerConfiguration or
* v8::IndexedPropertyHandlerConfiguration.
*/
enum class PropertyHandlerFlags {
/**
* None.
*/
kNone = 0,
/**
* See ALL_CAN_READ above.
*/
kAllCanRead = 1,
/** 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.
*/
kNonMasking = 1 << 1,
/**
* Will not call into interceptor for symbol lookup. Only meaningful for
* named interceptors.
*/
kOnlyInterceptStrings = 1 << 2,
/**
* The getter, query, enumerator callbacks do not produce side effects.
*/
kHasNoSideEffect = 1 << 3,
};
struct NamedPropertyHandlerConfiguration {
NamedPropertyHandlerConfiguration(
GenericNamedPropertyGetterCallback getter,
GenericNamedPropertySetterCallback setter,
GenericNamedPropertyQueryCallback query,
GenericNamedPropertyDeleterCallback deleter,
GenericNamedPropertyEnumeratorCallback enumerator,
GenericNamedPropertyDefinerCallback definer,
GenericNamedPropertyDescriptorCallback descriptor,
Local<Value> data = Local<Value>(),
PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
: getter(getter),
setter(setter),
query(query),
deleter(deleter),
enumerator(enumerator),
definer(definer),
descriptor(descriptor),
data(data),
flags(flags) {}
NamedPropertyHandlerConfiguration(
/** Note: getter is required */
GenericNamedPropertyGetterCallback getter = nullptr,
GenericNamedPropertySetterCallback setter = nullptr,
GenericNamedPropertyQueryCallback query = nullptr,
GenericNamedPropertyDeleterCallback deleter = nullptr,
GenericNamedPropertyEnumeratorCallback enumerator = nullptr,
Local<Value> data = Local<Value>(),
PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
: getter(getter),
setter(setter),
query(query),
deleter(deleter),
enumerator(enumerator),
definer(nullptr),
descriptor(nullptr),
data(data),
flags(flags) {}
NamedPropertyHandlerConfiguration(
GenericNamedPropertyGetterCallback getter,
GenericNamedPropertySetterCallback setter,
GenericNamedPropertyDescriptorCallback descriptor,
GenericNamedPropertyDeleterCallback deleter,
GenericNamedPropertyEnumeratorCallback enumerator,
GenericNamedPropertyDefinerCallback definer,
Local<Value> data = Local<Value>(),
PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
: getter(getter),
setter(setter),
query(nullptr),
deleter(deleter),
enumerator(enumerator),
definer(definer),
descriptor(descriptor),
data(data),
flags(flags) {}
GenericNamedPropertyGetterCallback getter;
GenericNamedPropertySetterCallback setter;
GenericNamedPropertyQueryCallback query;
GenericNamedPropertyDeleterCallback deleter;
GenericNamedPropertyEnumeratorCallback enumerator;
GenericNamedPropertyDefinerCallback definer;
GenericNamedPropertyDescriptorCallback descriptor;
Local<Value> data;
PropertyHandlerFlags flags;
};
struct IndexedPropertyHandlerConfiguration {
IndexedPropertyHandlerConfiguration(
IndexedPropertyGetterCallback getter,
IndexedPropertySetterCallback setter, IndexedPropertyQueryCallback query,
IndexedPropertyDeleterCallback deleter,
IndexedPropertyEnumeratorCallback enumerator,
IndexedPropertyDefinerCallback definer,
IndexedPropertyDescriptorCallback descriptor,
Local<Value> data = Local<Value>(),
PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
: getter(getter),
setter(setter),
query(query),
deleter(deleter),
enumerator(enumerator),
definer(definer),
descriptor(descriptor),
data(data),
flags(flags) {}
IndexedPropertyHandlerConfiguration(
/** Note: getter is required */
IndexedPropertyGetterCallback getter = nullptr,
IndexedPropertySetterCallback setter = nullptr,
IndexedPropertyQueryCallback query = nullptr,
IndexedPropertyDeleterCallback deleter = nullptr,
IndexedPropertyEnumeratorCallback enumerator = nullptr,
Local<Value> data = Local<Value>(),
PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
: getter(getter),
setter(setter),
query(query),
deleter(deleter),
enumerator(enumerator),
definer(nullptr),
descriptor(nullptr),
data(data),
flags(flags) {}
IndexedPropertyHandlerConfiguration(
IndexedPropertyGetterCallback getter,
IndexedPropertySetterCallback setter,
IndexedPropertyDescriptorCallback descriptor,
IndexedPropertyDeleterCallback deleter,
IndexedPropertyEnumeratorCallback enumerator,
IndexedPropertyDefinerCallback definer,
Local<Value> data = Local<Value>(),
PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
: getter(getter),
setter(setter),
query(nullptr),
deleter(deleter),
enumerator(enumerator),
definer(definer),
descriptor(descriptor),
data(data),
flags(flags) {}
IndexedPropertyGetterCallback getter;
IndexedPropertySetterCallback setter;
IndexedPropertyQueryCallback query;
IndexedPropertyDeleterCallback deleter;
IndexedPropertyEnumeratorCallback enumerator;
IndexedPropertyDefinerCallback definer;
IndexedPropertyDescriptorCallback descriptor;
Local<Value> data;
PropertyHandlerFlags flags;
};
/**
* An ObjectTemplate is used to create objects at runtime.
*
* Properties added to an ObjectTemplate are added to each object
* created from the ObjectTemplate.
*/
class V8_EXPORT ObjectTemplate : public Template {
public:
/** Creates an ObjectTemplate. */
static Local<ObjectTemplate> New(
Isolate* isolate,
Local<FunctionTemplate> constructor = Local<FunctionTemplate>());
/** Creates a new instance of this template.*/
V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(Local<Context> context);
/**
* Sets an accessor on the object template.
*
* Whenever the property with the given name is accessed on objects
* created from this ObjectTemplate the getter and setter callbacks
* are called instead of getting and setting the property directly
* on the JavaScript object.
*
* \param name The name of the property for which an accessor is added.
* \param getter The callback to invoke when getting the property.
* \param setter The callback to invoke when setting the property.
* \param data A piece of data that will be passed to the getter and setter
* callbacks whenever they are invoked.
* \param settings Access control settings for the accessor. This is a bit
* field consisting of one of more of
* DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
* The default is to not allow cross-context access.
* ALL_CAN_READ means that all cross-context reads are allowed.
* ALL_CAN_WRITE means that all cross-context writes are allowed.
* The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
* cross-context access.
* \param attribute The attributes of the property for which an accessor
* is added.
* \param signature The signature describes valid receivers for the accessor
* and is used to perform implicit instance checks against them. If the
* receiver is incompatible (i.e. is not an instance of the constructor as
* defined by FunctionTemplate::HasInstance()), an implicit TypeError is
* thrown and no callback is invoked.
*/
void SetAccessor(
Local<String> name, AccessorGetterCallback getter,
AccessorSetterCallback setter = nullptr,
Local<Value> data = Local<Value>(), AccessControl settings = DEFAULT,
PropertyAttribute attribute = None,
Local<AccessorSignature> signature = Local<AccessorSignature>(),
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
void SetAccessor(
Local<Name> name, AccessorNameGetterCallback getter,
AccessorNameSetterCallback setter = nullptr,
Local<Value> data = Local<Value>(), AccessControl settings = DEFAULT,
PropertyAttribute attribute = None,
Local<AccessorSignature> signature = Local<AccessorSignature>(),
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* Sets a named property handler on the object template.
*
* Whenever a property whose name is a string or a symbol is accessed on
* objects created from this object template, the provided callback is
* invoked instead of accessing the property directly on the JavaScript
* object.
*
* @param configuration The NamedPropertyHandlerConfiguration that defines the
* callbacks to invoke when accessing a property.
*/
void SetHandler(const NamedPropertyHandlerConfiguration& configuration);
/**
* Sets an indexed property handler on the object template.
*
* Whenever an indexed property is accessed on objects created from
* this object template, the provided callback is invoked instead of
* accessing the property directly on the JavaScript object.
*
* \param getter The callback to invoke when getting a property.
* \param setter The callback to invoke when setting a property.
* \param query The callback to invoke to check if an object has a property.
* \param deleter The callback to invoke when deleting a property.
* \param enumerator The callback to invoke to enumerate all the indexed
* properties of an object.
* \param data A piece of data that will be passed to the callbacks
* whenever they are invoked.
*/
// TODO(dcarney): deprecate
void SetIndexedPropertyHandler(
IndexedPropertyGetterCallback getter,
IndexedPropertySetterCallback setter = nullptr,
IndexedPropertyQueryCallback query = nullptr,
IndexedPropertyDeleterCallback deleter = nullptr,
IndexedPropertyEnumeratorCallback enumerator = nullptr,
Local<Value> data = Local<Value>()) {
SetHandler(IndexedPropertyHandlerConfiguration(getter, setter, query,
deleter, enumerator, data));
}
/**
* Sets an indexed property handler on the object template.
*
* Whenever an indexed property is accessed on objects created from
* this object template, the provided callback is invoked instead of
* accessing the property directly on the JavaScript object.
*
* @param configuration The IndexedPropertyHandlerConfiguration that defines
* the callbacks to invoke when accessing a property.
*/
void SetHandler(const IndexedPropertyHandlerConfiguration& configuration);
/**
* Sets the callback to be used when calling instances created from
* this template as a function. If no callback is set, instances
* behave like normal JavaScript objects that cannot be called as a
* function.
*/
void SetCallAsFunctionHandler(FunctionCallback callback,
Local<Value> data = Local<Value>());
/**
* Mark object instances of the template as undetectable.
*
* In many ways, undetectable objects behave as though they are not
* there. They behave like 'undefined' in conditionals and when
* printed. However, properties can be accessed and called as on
* normal objects.
*/
void MarkAsUndetectable();
/**
* Sets access check callback on the object template and enables access
* checks.
*
* When accessing properties on instances of this object template,
* the access check callback will be called to determine whether or
* not to allow cross-context access to the properties.
*/
void SetAccessCheckCallback(AccessCheckCallback callback,
Local<Value> data = Local<Value>());
/**
* Like SetAccessCheckCallback but invokes an interceptor on failed access
* checks instead of looking up all-can-read properties. You can only use
* either this method or SetAccessCheckCallback, but not both at the same
* time.
*/
void SetAccessCheckCallbackAndHandler(
AccessCheckCallback callback,
const NamedPropertyHandlerConfiguration& named_handler,
const IndexedPropertyHandlerConfiguration& indexed_handler,
Local<Value> data = Local<Value>());
/**
* Gets the number of internal fields for objects generated from
* this template.
*/
int InternalFieldCount();
/**
* Sets the number of internal fields for objects generated from
* this template.
*/
void SetInternalFieldCount(int value);
/**
* Returns true if the object will be an immutable prototype exotic object.
*/
bool IsImmutableProto();
/**
* Makes the ObjectTemplate for an immutable prototype exotic object, with an
* immutable __proto__.
*/
void SetImmutableProto();
/**
* Support for TC39 "dynamic code brand checks" proposal.
*
* This API allows to mark (& query) objects as "code like", which causes
* them to be treated like Strings in the context of eval and function
* constructor.
*
* Reference: https://github.com/tc39/proposal-dynamic-code-brand-checks
*/
void SetCodeLike();
bool IsCodeLike();
V8_INLINE static ObjectTemplate* Cast(Data* data);
private:
ObjectTemplate();
static Local<ObjectTemplate> New(internal::Isolate* isolate,
Local<FunctionTemplate> constructor);
static void CheckCast(Data* that);
friend class FunctionTemplate;
};
/**
* A Signature specifies which receiver is valid for a function.
*
* A receiver matches a given signature if the receiver (or any of its
* hidden prototypes) was created from the signature's FunctionTemplate, or
* from a FunctionTemplate that inherits directly or indirectly from the
* signature's FunctionTemplate.
*/
class V8_EXPORT Signature : public Data {
public:
static Local<Signature> New(
Isolate* isolate,
Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
V8_INLINE static Signature* Cast(Data* data);
private:
Signature();
static void CheckCast(Data* that);
};
/**
* An AccessorSignature specifies which receivers are valid parameters
* to an accessor callback.
*/
class V8_EXPORT AccessorSignature : public Data {
public:
static Local<AccessorSignature> New(
Isolate* isolate,
Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
V8_INLINE static AccessorSignature* Cast(Data* data);
private:
AccessorSignature();
static void CheckCast(Data* that);
};
// --- Extensions ---
/**
* Ignore
*/
class V8_EXPORT Extension {
public:
// Note that the strings passed into this constructor must live as long
// as the Extension itself.
Extension(const char* name, const char* source = nullptr, int dep_count = 0,
const char** deps = nullptr, int source_length = -1);
virtual ~Extension() { delete source_; }
virtual Local<FunctionTemplate> GetNativeFunctionTemplate(
Isolate* isolate, Local<String> name) {
return Local<FunctionTemplate>();
}
const char* name() const { return name_; }
size_t source_length() const { return source_length_; }
const String::ExternalOneByteStringResource* source() const {
return source_;
}
int dependency_count() const { return dep_count_; }
const char** dependencies() const { return deps_; }
void set_auto_enable(bool value) { auto_enable_ = value; }
bool auto_enable() { return auto_enable_; }
// Disallow copying and assigning.
Extension(const Extension&) = delete;
void operator=(const Extension&) = delete;
private:
const char* name_;
size_t source_length_; // expected to initialize before source_
String::ExternalOneByteStringResource* source_;
int dep_count_;
const char** deps_;
bool auto_enable_;
};
void V8_EXPORT RegisterExtension(std::unique_ptr<Extension>);
// --- Statics ---
V8_INLINE Local<Primitive> Undefined(Isolate* isolate);
V8_INLINE Local<Primitive> Null(Isolate* isolate);
V8_INLINE Local<Boolean> True(Isolate* isolate);
V8_INLINE Local<Boolean> False(Isolate* isolate);
/**
* A set of constraints that specifies the limits of the runtime's memory use.
* You must set the heap size before initializing the VM - the size cannot be
* adjusted after the VM is initialized.
*
* If you are using threads then you should hold the V8::Locker lock while
* setting the stack limit and you must set a non-default stack limit separately
* for each thread.
*
* The arguments for set_max_semi_space_size, set_max_old_space_size,
* set_max_executable_size, set_code_range_size specify limits in MB.
*
* The argument for set_max_semi_space_size_in_kb is in KB.
*/
class V8_EXPORT ResourceConstraints {
public:
/**
* Configures the constraints with reasonable default values based on the
* provided heap size limit. The heap size includes both the young and
* the old generation.
*
* \param initial_heap_size_in_bytes The initial heap size or zero.
* By default V8 starts with a small heap and dynamically grows it to
* match the set of live objects. This may lead to ineffective
* garbage collections at startup if the live set is large.
* Setting the initial heap size avoids such garbage collections.
* Note that this does not affect young generation garbage collections.
*
* \param maximum_heap_size_in_bytes The hard limit for the heap size.
* When the heap size approaches this limit, V8 will perform series of
* garbage collections and invoke the NearHeapLimitCallback. If the garbage
* collections do not help and the callback does not increase the limit,
* then V8 will crash with V8::FatalProcessOutOfMemory.
*/
void ConfigureDefaultsFromHeapSize(size_t initial_heap_size_in_bytes,
size_t maximum_heap_size_in_bytes);
/**
* Configures the constraints with reasonable default values based on the
* capabilities of the current device the VM is running on.
*
* \param physical_memory The total amount of physical memory on the current
* device, in bytes.
* \param virtual_memory_limit The amount of virtual memory on the current
* device, in bytes, or zero, if there is no limit.
*/
void ConfigureDefaults(uint64_t physical_memory,
uint64_t virtual_memory_limit);
/**
* The address beyond which the VM's stack may not grow.
*/
uint32_t* stack_limit() const { return stack_limit_; }
void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
/**
* The amount of virtual memory reserved for generated code. This is relevant
* for 64-bit architectures that rely on code range for calls in code.
*
* When V8_COMPRESS_POINTERS_IN_SHARED_CAGE is defined, there is a shared
* process-wide code range that is lazily initialized. This value is used to
* configure that shared code range when the first Isolate is
* created. Subsequent Isolates ignore this value.
*/
size_t code_range_size_in_bytes() const { return code_range_size_; }
void set_code_range_size_in_bytes(size_t limit) { code_range_size_ = limit; }
/**
* The maximum size of the old generation.
* When the old generation approaches this limit, V8 will perform series of
* garbage collections and invoke the NearHeapLimitCallback.
* If the garbage collections do not help and the callback does not
* increase the limit, then V8 will crash with V8::FatalProcessOutOfMemory.
*/
size_t max_old_generation_size_in_bytes() const {
return max_old_generation_size_;
}
void set_max_old_generation_size_in_bytes(size_t limit) {
max_old_generation_size_ = limit;
}
/**
* The maximum size of the young generation, which consists of two semi-spaces
* and a large object space. This affects frequency of Scavenge garbage
* collections and should be typically much smaller that the old generation.
*/
size_t max_young_generation_size_in_bytes() const {
return max_young_generation_size_;
}
void set_max_young_generation_size_in_bytes(size_t limit) {
max_young_generation_size_ = limit;
}
size_t initial_old_generation_size_in_bytes() const {
return initial_old_generation_size_;
}
void set_initial_old_generation_size_in_bytes(size_t initial_size) {
initial_old_generation_size_ = initial_size;
}
size_t initial_young_generation_size_in_bytes() const {
return initial_young_generation_size_;
}
void set_initial_young_generation_size_in_bytes(size_t initial_size) {
initial_young_generation_size_ = initial_size;
}
private:
static constexpr size_t kMB = 1048576u;
size_t code_range_size_ = 0;
size_t max_old_generation_size_ = 0;
size_t max_young_generation_size_ = 0;
size_t initial_old_generation_size_ = 0;
size_t initial_young_generation_size_ = 0;
uint32_t* stack_limit_ = nullptr;
};
// --- Exceptions ---
using FatalErrorCallback = void (*)(const char* location, const char* message);
using OOMErrorCallback = void (*)(const char* location, bool is_heap_oom);
using DcheckErrorCallback = void (*)(const char* file, int line,
const char* message);
using MessageCallback = void (*)(Local<Message> message, Local<Value> data);
// --- Tracing ---
enum LogEventStatus : int { kStart = 0, kEnd = 1, kStamp = 2 };
using LogEventCallback = void (*)(const char* name,
int /* LogEventStatus */ status);
/**
* Create new error objects by calling the corresponding error object
* constructor with the message.
*/
class V8_EXPORT Exception {
public:
static Local<Value> RangeError(Local<String> message);
static Local<Value> ReferenceError(Local<String> message);
static Local<Value> SyntaxError(Local<String> message);
static Local<Value> TypeError(Local<String> message);
static Local<Value> WasmCompileError(Local<String> message);
static Local<Value> WasmLinkError(Local<String> message);
static Local<Value> WasmRuntimeError(Local<String> message);
static Local<Value> Error(Local<String> message);
/**
* Creates an error message for the given exception.
* Will try to reconstruct the original stack trace from the exception value,
* or capture the current stack trace if not available.
*/
static Local<Message> CreateMessage(Isolate* isolate, Local<Value> exception);
/**
* Returns the original stack trace that was captured at the creation time
* of a given exception, or an empty handle if not available.
*/
static Local<StackTrace> GetStackTrace(Local<Value> exception);
};
// --- Counters Callbacks ---
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);
// --- Crashkeys Callback ---
enum class CrashKeyId {
kIsolateAddress,
kReadonlySpaceFirstPageAddress,
kMapSpaceFirstPageAddress,
kCodeSpaceFirstPageAddress,
kDumpType,
};
using AddCrashKeyCallback = void (*)(CrashKeyId id, const std::string& value);
// --- Enter/Leave Script Callback ---
using BeforeCallEnteredCallback = void (*)(Isolate*);
using CallCompletedCallback = void (*)(Isolate*);
/**
* 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 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.
*/
using HostImportModuleDynamicallyCallback =
MaybeLocal<Promise> (*)(Local<Context> context,
Local<ScriptOrModule> referrer,
Local<String> specifier);
/**
* HostImportModuleDynamicallyWithImportAssertionsCallback 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_assertions are import assertions 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 assertions.
*
* 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.
*/
using HostImportModuleDynamicallyWithImportAssertionsCallback =
MaybeLocal<Promise> (*)(Local<Context> context,
Local<ScriptOrModule> referrer,
Local<String> specifier,
Local<FixedArray> import_assertions);
/**
* 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.
*/
using HostInitializeImportMetaObjectCallback = void (*)(Local<Context> context,
Local<Module> module,
Local<Object> meta);
/**
* 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
*/
using PrepareStackTraceCallback = MaybeLocal<Value> (*)(Local<Context> context,
Local<Value> error,
Local<Array> sites);
/**
* 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.
*/
enum class PromiseHookType { kInit, kResolve, kBefore, kAfter };
using PromiseHook = void (*)(PromiseHookType type, Local<Promise> promise,
Local<Value> parent);
// --- Promise Reject Callback ---
enum PromiseRejectEvent {
kPromiseRejectWithNoHandler = 0,
kPromiseHandlerAddedAfterReject = 1,
kPromiseRejectAfterResolved = 2,
kPromiseResolveAfterResolved = 3,
};
class PromiseRejectMessage {
public:
PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
Local<Value> value)
: promise_(promise), event_(event), value_(value) {}
V8_INLINE Local<Promise> GetPromise() const { return promise_; }
V8_INLINE PromiseRejectEvent GetEvent() const { return event_; }
V8_INLINE Local<Value> GetValue() const { return value_; }
private:
Local<Promise> promise_;
PromiseRejectEvent event_;
Local<Value> value_;
};
using PromiseRejectCallback = void (*)(PromiseRejectMessage message);
// --- Microtasks Callbacks ---
using MicrotasksCompletedCallbackWithData = void (*)(Isolate*, void*);
using MicrotaskCallback = void (*)(void* data);
/**
* 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.
*/
enum class MicrotasksPolicy { kExplicit, kScoped, kAuto };
/**
* Represents the microtask queue, where microtasks are stored and processed.
* https://html.spec.whatwg.org/multipage/webappapis.html#microtask-queue
* https://html.spec.whatwg.org/multipage/webappapis.html#enqueuejob(queuename,-job,-arguments)
* https://html.spec.whatwg.org/multipage/webappapis.html#perform-a-microtask-checkpoint
*
* A MicrotaskQueue instance may be associated to multiple Contexts by passing
* it to Context::New(), and they can be detached by Context::DetachGlobal().
* The embedder must keep the MicrotaskQueue instance alive until all associated
* Contexts are gone or detached.
*
* Use the same instance of MicrotaskQueue for all Contexts that may access each
* other synchronously. E.g. for Web embedding, use the same instance for all
* origins that share the same URL scheme and eTLD+1.
*/
class V8_EXPORT MicrotaskQueue {
public:
/**
* Creates an empty MicrotaskQueue instance.
*/
static std::unique_ptr<MicrotaskQueue> New(
Isolate* isolate, MicrotasksPolicy policy = MicrotasksPolicy::kAuto);
virtual ~MicrotaskQueue() = default;
/**
* Enqueues the callback to the queue.
*/
virtual void EnqueueMicrotask(Isolate* isolate,
Local<Function> microtask) = 0;
/**
* Enqueues the callback to the queue.
*/
virtual void EnqueueMicrotask(v8::Isolate* isolate,
MicrotaskCallback callback,
void* data = nullptr) = 0;
/**
* Adds a callback to notify the embedder after microtasks were run. The
* callback is triggered by explicit RunMicrotasks call or automatic
* microtasks execution (see Isolate::SetMicrotasksPolicy).
*
* Callback will trigger even if microtasks were attempted to run,
* but the microtasks queue was empty and no single microtask was actually
* executed.
*
* Executing scripts inside the callback will not re-trigger microtasks and
* the callback.
*/
virtual void AddMicrotasksCompletedCallback(
MicrotasksCompletedCallbackWithData callback, void* data = nullptr) = 0;
/**
* Removes callback that was installed by AddMicrotasksCompletedCallback.
*/
virtual void RemoveMicrotasksCompletedCallback(
MicrotasksCompletedCallbackWithData callback, void* data = nullptr) = 0;
/**
* Runs microtasks if no microtask is running on this MicrotaskQueue instance.
*/
virtual void PerformCheckpoint(Isolate* isolate) = 0;
/**
* Returns true if a microtask is running on this MicrotaskQueue instance.
*/
virtual bool IsRunningMicrotasks() const = 0;
/**
* Returns the current depth of nested MicrotasksScope that has
* kRunMicrotasks.
*/
virtual int GetMicrotasksScopeDepth() const = 0;
MicrotaskQueue(const MicrotaskQueue&) = delete;
MicrotaskQueue& operator=(const MicrotaskQueue&) = delete;
private:
friend class internal::MicrotaskQueue;
MicrotaskQueue() = default;
};
/**
* This scope is used to control microtasks when MicrotasksPolicy::kScoped
* is used on Isolate. In this mode every non-primitive call to V8 should be
* done inside some MicrotasksScope.
* Microtasks are executed when topmost MicrotasksScope marked as kRunMicrotasks
* exits.
* kDoNotRunMicrotasks should be used to annotate calls not intended to trigger
* microtasks.
*/
class V8_EXPORT V8_NODISCARD MicrotasksScope {
public:
enum Type { kRunMicrotasks, kDoNotRunMicrotasks };
MicrotasksScope(Isolate* isolate, Type type);
MicrotasksScope(Isolate* isolate, MicrotaskQueue* microtask_queue, Type type);
~MicrotasksScope();
/**
* Runs microtasks if no kRunMicrotasks scope is currently active.
*/
static void PerformCheckpoint(Isolate* isolate);
/**
* Returns current depth of nested kRunMicrotasks scopes.
*/
static int GetCurrentDepth(Isolate* isolate);
/**
* Returns true while microtasks are being executed.
*/
static bool IsRunningMicrotasks(Isolate* isolate);
// Prevent copying.
MicrotasksScope(const MicrotasksScope&) = delete;
MicrotasksScope& operator=(const MicrotasksScope&) = delete;
private:
internal::Isolate* const isolate_;
internal::MicrotaskQueue* const microtask_queue_;
bool run_;
};
// --- Failed Access Check Callback ---
using FailedAccessCheckCallback = void (*)(Local<Object> target,
AccessType type, Local<Value> data);
// --- AllowCodeGenerationFromStrings callbacks ---
/**
* Callback to check if code generation from strings is allowed. See
* Context::AllowCodeGenerationFromStrings.
*/
using AllowCodeGenerationFromStringsCallback = bool (*)(Local<Context> context,
Local<String> source);
struct ModifyCodeGenerationFromStringsResult {
// If true, proceed with the codegen algorithm. Otherwise, block it.
bool codegen_allowed = false;
// Overwrite the original source with this string, if present.
// Use the original source if empty.
// This field is considered only if codegen_allowed is true.
MaybeLocal<String> modified_source;
};
/**
* Callback to check if codegen is allowed from a source object, and convert
* the source to string if necessary. See: ModifyCodeGenerationFromStrings.
*/
using ModifyCodeGenerationFromStringsCallback =
ModifyCodeGenerationFromStringsResult (*)(Local<Context> context,
Local<Value> source);
using ModifyCodeGenerationFromStringsCallback2 =
ModifyCodeGenerationFromStringsResult (*)(Local<Context> context,
Local<Value> source,
bool is_code_like);
// --- WebAssembly compilation callbacks ---
using ExtensionCallback = bool (*)(const FunctionCallbackInfo<Value>&);
using AllowWasmCodeGenerationCallback = bool (*)(Local<Context> context,
Local<String> source);
// --- Callback for APIs defined on v8-supported objects, but implemented
// by the embedder. Example: WebAssembly.{compile|instantiate}Streaming ---
using ApiImplementationCallback = void (*)(const FunctionCallbackInfo<Value>&);
// --- Callback for WebAssembly.compileStreaming ---
using WasmStreamingCallback = void (*)(const FunctionCallbackInfo<Value>&);
// --- Callback for loading source map file for Wasm profiling support
using WasmLoadSourceMapCallback = Local<String> (*)(Isolate* isolate,
const char* name);
// --- Callback for checking if WebAssembly Simd is enabled ---
using WasmSimdEnabledCallback = bool (*)(Local<Context> context);
// --- Callback for checking if WebAssembly exceptions are enabled ---
using WasmExceptionsEnabledCallback = bool (*)(Local<Context> context);
// --- Callback for checking if the SharedArrayBuffer constructor is enabled ---
using SharedArrayBufferConstructorEnabledCallback =
bool (*)(Local<Context> context);
// --- Garbage Collection Callbacks ---
/**
* 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.
*/
enum GCType {
kGCTypeScavenge = 1 << 0,
kGCTypeMarkSweepCompact = 1 << 1,
kGCTypeIncrementalMarking = 1 << 2,
kGCTypeProcessWeakCallbacks = 1 << 3,
kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact |
kGCTypeIncrementalMarking | kGCTypeProcessWeakCallbacks
};
/**
* 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.
*/
enum GCCallbackFlags {
kNoGCCallbackFlags = 0,
kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
kGCCallbackFlagForced = 1 << 2,
kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,
kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4,
kGCCallbackFlagCollectAllExternalMemory = 1 << 5,
kGCCallbackScheduleIdleGarbageCollection = 1 << 6,
};
using GCCallback = void (*)(GCType type, GCCallbackFlags flags);
using InterruptCallback = void (*)(Isolate* isolate, void* data);
/**
* 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.
*/
using NearHeapLimitCallback = size_t (*)(void* data, size_t current_heap_limit,
size_t initial_heap_limit);
/**
* Collection of shared per-process V8 memory information.
*
* Instances of this class can be passed to
* v8::V8::GetSharedMemoryStatistics to get shared memory statistics from V8.
*/
class V8_EXPORT SharedMemoryStatistics {
public:
SharedMemoryStatistics();
size_t read_only_space_size() { return read_only_space_size_; }
size_t read_only_space_used_size() { return read_only_space_used_size_; }
size_t read_only_space_physical_size() {
return read_only_space_physical_size_;
}
private:
size_t read_only_space_size_;
size_t read_only_space_used_size_;
size_t read_only_space_physical_size_;
friend class V8;
friend class internal::ReadOnlyHeap;
};
/**
* Collection of V8 heap information.
*
* Instances of this class can be passed to v8::Isolate::GetHeapStatistics to
* get heap statistics from V8.
*/
class V8_EXPORT HeapStatistics {
public:
HeapStatistics();
size_t total_heap_size() { return total_heap_size_; }
size_t total_heap_size_executable() { return total_heap_size_executable_; }
size_t total_physical_size() { return total_physical_size_; }
size_t total_available_size() { return total_available_size_; }
size_t total_global_handles_size() { return total_global_handles_size_; }
size_t used_global_handles_size() { return used_global_handles_size_; }
size_t used_heap_size() { return used_heap_size_; }
size_t heap_size_limit() { return heap_size_limit_; }
size_t malloced_memory() { return malloced_memory_; }
size_t external_memory() { return external_memory_; }
size_t peak_malloced_memory() { return peak_malloced_memory_; }
size_t number_of_native_contexts() { return number_of_native_contexts_; }
size_t number_of_detached_contexts() { return number_of_detached_contexts_; }
/**
* Returns a 0/1 boolean, which signifies whether the V8 overwrite heap
* garbage with a bit pattern.
*/
size_t does_zap_garbage() { return does_zap_garbage_; }
private:
size_t total_heap_size_;
size_t total_heap_size_executable_;
size_t total_physical_size_;
size_t total_available_size_;
size_t used_heap_size_;
size_t heap_size_limit_;
size_t malloced_memory_;
size_t external_memory_;
size_t peak_malloced_memory_;
bool does_zap_garbage_;
size_t number_of_native_contexts_;
size_t number_of_detached_contexts_;
size_t total_global_handles_size_;
size_t used_global_handles_size_;
friend class V8;
friend class Isolate;
};
class V8_EXPORT HeapSpaceStatistics {
public:
HeapSpaceStatistics();
const char* space_name() { return space_name_; }
size_t space_size() { return space_size_; }
size_t space_used_size() { return space_used_size_; }
size_t space_available_size() { return space_available_size_; }
size_t physical_space_size() { return physical_space_size_; }
private:
const char* space_name_;
size_t space_size_;
size_t space_used_size_;
size_t space_available_size_;
size_t physical_space_size_;
friend class Isolate;
};
class V8_EXPORT HeapObjectStatistics {
public:
HeapObjectStatistics();
const char* object_type() { return object_type_; }
const char* object_sub_type() { return object_sub_type_; }
size_t object_count() { return object_count_; }
size_t object_size() { return object_size_; }
private:
const char* object_type_;
const char* object_sub_type_;
size_t object_count_;
size_t object_size_;
friend class Isolate;
};
class V8_EXPORT HeapCodeStatistics {
public:
HeapCodeStatistics();
size_t code_and_metadata_size() { return code_and_metadata_size_; }
size_t bytecode_and_metadata_size() { return bytecode_and_metadata_size_; }
size_t external_script_source_size() { return external_script_source_size_; }
private:
size_t code_and_metadata_size_;
size_t bytecode_and_metadata_size_;
size_t external_script_source_size_;
friend class Isolate;
};
/**
* A JIT code event is issued each time code is added, moved or removed.
*
* \note removal events are not currently issued.
*/
struct JitCodeEvent {
enum EventType {
CODE_ADDED,
CODE_MOVED,
CODE_REMOVED,
CODE_ADD_LINE_POS_INFO,
CODE_START_LINE_INFO_RECORDING,
CODE_END_LINE_INFO_RECORDING
};
// Definition of the code position type. The "POSITION" type means the place
// in the source code which are of interest when making stack traces to
// pin-point the source location of a stack frame as close as possible.
// The "STATEMENT_POSITION" means the place at the beginning of each
// statement, and is used to indicate possible break locations.
enum PositionType { POSITION, STATEMENT_POSITION };
// There are two different kinds of JitCodeEvents, one for JIT code generated
// by the optimizing compiler, and one for byte code generated for the
// interpreter. For JIT_CODE events, the |code_start| member of the event
// points to the beginning of jitted assembly code, while for BYTE_CODE
// events, |code_start| points to the first bytecode of the interpreted
// function.
enum CodeType { BYTE_CODE, JIT_CODE };
// Type of event.
EventType type;
CodeType code_type;
// Start of the instructions.
void* code_start;
// Size of the instructions.
size_t code_len;
// Script info for CODE_ADDED event.
Local<UnboundScript> script;
// User-defined data for *_LINE_INFO_* event. It's used to hold the source
// code line information which is returned from the
// CODE_START_LINE_INFO_RECORDING event. And it's passed to subsequent
// CODE_ADD_LINE_POS_INFO and CODE_END_LINE_INFO_RECORDING events.
void* user_data;
struct name_t {
// Name of the object associated with the code, note that the string is not
// zero-terminated.
const char* str;
// Number of chars in str.
size_t len;
};
struct line_info_t {
// PC offset
size_t offset;
// Code position
size_t pos;
// The position type.
PositionType position_type;
};
struct wasm_source_info_t {
// Source file name.
const char* filename;
// Length of filename.
size_t filename_size;
// Line number table, which maps offsets of JITted code to line numbers of
// source file.
const line_info_t* line_number_table;
// Number of entries in the line number table.
size_t line_number_table_size;
};
wasm_source_info_t* wasm_source_info;
union {
// Only valid for CODE_ADDED.
struct name_t name;
// Only valid for CODE_ADD_LINE_POS_INFO
struct line_info_t line_info;
// New location of instructions. Only valid for CODE_MOVED.
void* new_code_start;
};
Isolate* isolate;
};
/**
* Option flags passed to the SetRAILMode function.
* See documentation https://developers.google.com/web/tools/chrome-devtools/
* profile/evaluate-performance/rail
*/
enum RAILMode : unsigned {
// Response performance mode: In this mode very low virtual machine latency
// is provided. V8 will try to avoid JavaScript execution interruptions.
// Throughput may be throttled.
PERFORMANCE_RESPONSE,
// Animation performance mode: In this mode low virtual machine latency is
// provided. V8 will try to avoid as many JavaScript execution interruptions
// as possible. Throughput may be throttled. This is the default mode.
PERFORMANCE_ANIMATION,
// Idle performance mode: The embedder is idle. V8 can complete deferred work
// in this mode.
PERFORMANCE_IDLE,
// Load performance mode: In this mode high throughput is provided. V8 may
// turn off latency optimizations.
PERFORMANCE_LOAD
};
/**
* Option flags passed to the SetJitCodeEventHandler function.
*/
enum JitCodeEventOptions {
kJitCodeEventDefault = 0,
// Generate callbacks for already existent code.
kJitCodeEventEnumExisting = 1
};
/**
* Callback function passed to SetJitCodeEventHandler.
*
* \param event code add, move or removal event.
*/
using JitCodeEventHandler = void (*)(const JitCodeEvent* event);
/**
* Callback function passed to SetUnhandledExceptionCallback.
*/
#if defined(V8_OS_WIN)
using UnhandledExceptionCallback =
int (*)(_EXCEPTION_POINTERS* exception_pointers);
#endif
/**
* Interface for iterating through all external resources in the heap.
*/
class V8_EXPORT ExternalResourceVisitor {
public:
virtual ~ExternalResourceVisitor() = default;
virtual void VisitExternalString(Local<String> string) {}
};
/**
* Interface for iterating through all the persistent handles in the heap.
*/
class V8_EXPORT PersistentHandleVisitor {
public:
virtual ~PersistentHandleVisitor() = default;
virtual void VisitPersistentHandle(Persistent<Value>* value,
uint16_t class_id) {}
};
/**
* 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.
*/
enum class MemoryPressureLevel { kNone, kModerate, kCritical };
/**
* Handler for embedder roots on non-unified heap garbage collections.
*/
class V8_EXPORT EmbedderRootsHandler {
public:
virtual ~EmbedderRootsHandler() = default;
/**
* Returns true if the TracedGlobal handle should be considered as root for
* the currently running non-tracing garbage collection and false otherwise.
* The default implementation will keep all TracedGlobal references as roots.
*
* If this returns false, then V8 may decide that the object referred to by
* such a handle is reclaimed. In that case:
* - No action is required if handles are used with destructors, i.e., by just
* using |TracedGlobal|.
* - When run without destructors, i.e., by using |TracedReference|, V8 calls
* |ResetRoot|.
*
* Note that the |handle| is different from the handle that the embedder holds
* for retaining the object. The embedder may use |WrapperClassId()| to
* distinguish cases where it wants handles to be treated as roots from not
* being treated as roots.
*/
virtual bool IsRoot(const v8::TracedReference<v8::Value>& handle) = 0;
virtual bool IsRoot(const v8::TracedGlobal<v8::Value>& handle) = 0;
/**
* Used in combination with |IsRoot|. Called by V8 when an
* object that is backed by a handle is reclaimed by a non-tracing garbage
* collection. It is up to the embedder to reset the original handle.
*
* Note that the |handle| is different from the handle that the embedder holds
* for retaining the object. It is up to the embedder to find the original
* handle via the object or class id.
*/
virtual void ResetRoot(const v8::TracedReference<v8::Value>& handle) = 0;
};
/**
* Interface for tracing through the embedder heap. During a V8 garbage
* collection, V8 collects hidden fields of all potential wrappers, and at the
* end of its marking phase iterates the collection and asks the embedder to
* trace through its heap and use reporter to report each JavaScript object
* reachable from any of the given wrappers.
*/
class V8_EXPORT EmbedderHeapTracer {
public:
using EmbedderStackState = cppgc::EmbedderStackState;
enum TraceFlags : uint64_t {
kNoFlags = 0,
kReduceMemory = 1 << 0,
kForced = 1 << 2,
};
/**
* Interface for iterating through TracedGlobal handles.
*/
class V8_EXPORT TracedGlobalHandleVisitor {
public:
virtual ~TracedGlobalHandleVisitor() = default;
virtual void VisitTracedGlobalHandle(const TracedGlobal<Value>& handle) {}
virtual void VisitTracedReference(const TracedReference<Value>& handle) {}
};
/**
* Summary of a garbage collection cycle. See |TraceEpilogue| on how the
* summary is reported.
*/
struct TraceSummary {
/**
* Time spent managing the retained memory in milliseconds. This can e.g.
* include the time tracing through objects in the embedder.
*/
double time = 0.0;
/**
* Memory retained by the embedder through the |EmbedderHeapTracer|
* mechanism in bytes.
*/
size_t allocated_size = 0;
};
virtual ~EmbedderHeapTracer() = default;
/**
* Iterates all TracedGlobal handles created for the v8::Isolate the tracer is
* attached to.
*/
void IterateTracedGlobalHandles(TracedGlobalHandleVisitor* visitor);
/**
* Called by the embedder to set the start of the stack which is e.g. used by
* V8 to determine whether handles are used from stack or heap.
*/
void SetStackStart(void* stack_start);
/**
* Called by the embedder to notify V8 of an empty execution stack.
*/
V8_DEPRECATE_SOON(
"This call only optimized internal caches which V8 is able to figure out "
"on its own now.")
void NotifyEmptyEmbedderStack();
/**
* Called by v8 to register internal fields of found wrappers.
*
* The embedder is expected to store them somewhere and trace reachable
* wrappers from them when called through |AdvanceTracing|.
*/
virtual void RegisterV8References(
const std::vector<std::pair<void*, void*> >& embedder_fields) = 0;
void RegisterEmbedderReference(const BasicTracedReference<v8::Data>& ref);
/**
* Called at the beginning of a GC cycle.
*/
virtual void TracePrologue(TraceFlags flags) {}
/**
* Called to advance tracing in the embedder.
*
* The embedder is expected to trace its heap starting from wrappers reported
* by RegisterV8References method, and report back all reachable wrappers.
* Furthermore, the embedder is expected to stop tracing by the given
* deadline. A deadline of infinity means that tracing should be finished.
*
* Returns |true| if tracing is done, and false otherwise.
*/
virtual bool AdvanceTracing(double deadline_in_ms) = 0;
/*
* Returns true if there no more tracing work to be done (see AdvanceTracing)
* and false otherwise.
*/
virtual bool IsTracingDone() = 0;
/**
* Called at the end of a GC cycle.
*
* Note that allocation is *not* allowed within |TraceEpilogue|. Can be
* overriden to fill a |TraceSummary| that is used by V8 to schedule future
* garbage collections.
*/
virtual void TraceEpilogue(TraceSummary* trace_summary) {}
/**
* Called upon entering the final marking pause. No more incremental marking
* steps will follow this call.
*/
virtual void EnterFinalPause(EmbedderStackState stack_state) = 0;
/*
* Called by the embedder to request immediate finalization of the currently
* running tracing phase that has been started with TracePrologue and not
* yet finished with TraceEpilogue.
*
* Will be a noop when currently not in tracing.
*
* This is an experimental feature.
*/
void FinalizeTracing();
/**
* See documentation on EmbedderRootsHandler.
*/
virtual bool IsRootForNonTracingGC(
const v8::TracedReference<v8::Value>& handle);
virtual bool IsRootForNonTracingGC(const v8::TracedGlobal<v8::Value>& handle);
/**
* See documentation on EmbedderRootsHandler.
*/
virtual void ResetHandleInNonTracingGC(
const v8::TracedReference<v8::Value>& handle);
/*
* Called by the embedder to immediately perform a full garbage collection.
*
* Should only be used in testing code.
*/
void GarbageCollectionForTesting(EmbedderStackState stack_state);
/*
* Called by the embedder to signal newly allocated or freed memory. Not bound
* to tracing phases. Embedders should trade off when increments are reported
* as V8 may consult global heuristics on whether to trigger garbage
* collection on this change.
*/
void IncreaseAllocatedSize(size_t bytes);
void DecreaseAllocatedSize(size_t bytes);
/*
* Returns the v8::Isolate this tracer is attached too and |nullptr| if it
* is not attached to any v8::Isolate.
*/
v8::Isolate* isolate() const { return isolate_; }
protected:
v8::Isolate* isolate_ = nullptr;
friend class internal::LocalEmbedderHeapTracer;
};
/**
* Callback and supporting data used in SnapshotCreator to implement embedder
* logic to serialize internal fields.
* Internal fields that directly reference V8 objects are serialized without
* calling this callback. Internal fields that contain aligned pointers are
* serialized by this callback if it returns non-zero result. Otherwise it is
* serialized verbatim.
*/
struct SerializeInternalFieldsCallback {
using CallbackFunction = StartupData (*)(Local<Object> holder, int index,
void* data);
SerializeInternalFieldsCallback(CallbackFunction function = nullptr,
void* data_arg = nullptr)
: callback(function), data(data_arg) {}
CallbackFunction callback;
void* data;
};
// Note that these fields are called "internal fields" in the API and called
// "embedder fields" within V8.
using SerializeEmbedderFieldsCallback = SerializeInternalFieldsCallback;
/**
* Callback and supporting data used to implement embedder logic to deserialize
* internal fields.
*/
struct DeserializeInternalFieldsCallback {
using CallbackFunction = void (*)(Local<Object> holder, int index,
StartupData payload, void* data);
DeserializeInternalFieldsCallback(CallbackFunction function = nullptr,
void* data_arg = nullptr)
: callback(function), data(data_arg) {}
void (*callback)(Local<Object> holder, int index, StartupData payload,
void* data);
void* data;
};
using DeserializeEmbedderFieldsCallback = DeserializeInternalFieldsCallback;
/**
* 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.
*/
enum class MeasureMemoryMode { kSummary, kDetailed };
/**
* 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.
*/
enum class MeasureMemoryExecution { kDefault, kEager, kLazy };
/**
* The delegate is used in Isolate::MeasureMemory API.
*
* It specifies the contexts that need to be measured and gets called when
* the measurement is completed to report the results.
*/
class V8_EXPORT MeasureMemoryDelegate {
public:
virtual ~MeasureMemoryDelegate() = default;
/**
* Returns true if the size of the given context needs to be measured.
*/
virtual bool ShouldMeasure(Local<Context> context) = 0;
/**
* This function is called when memory measurement finishes.
*
* \param context_sizes_in_bytes a vector of (context, size) pairs that
* includes each context for which ShouldMeasure returned true and that
* was not garbage collected while the memory measurement was in progress.
*
* \param unattributed_size_in_bytes total size of objects that were not
* attributed to any context (i.e. are likely shared objects).
*/
virtual void MeasurementComplete(
const std::vector<std::pair<Local<Context>, size_t>>&
context_sizes_in_bytes,
size_t unattributed_size_in_bytes) = 0;
/**
* Returns a default delegate that resolves the given promise when
* the memory measurement completes.
*
* \param isolate the current isolate
* \param context the current context
* \param promise_resolver the promise resolver that is given the
* result of the memory measurement.
* \param mode the detail level of the result.
*/
static std::unique_ptr<MeasureMemoryDelegate> Default(
Isolate* isolate, Local<Context> context,
Local<Promise::Resolver> promise_resolver, MeasureMemoryMode mode);
};
/**
* Isolate represents an isolated instance of the V8 engine. V8 isolates have
* completely separate states. Objects from one isolate must not be used in
* other isolates. The embedder can create multiple isolates and use them in
* parallel in multiple threads. An isolate can be entered by at most one
* thread at any given time. The Locker/Unlocker API must be used to
* synchronize.
*/
class V8_EXPORT Isolate {
public:
/**
* Initial configuration parameters for a new Isolate.
*/
struct V8_EXPORT CreateParams {
CreateParams();
~CreateParams();
/**
* Allows the host application to provide the address of a function that is
* notified each time code is added, moved or removed.
*/
JitCodeEventHandler code_event_handler = nullptr;
/**
* ResourceConstraints to use for the new Isolate.
*/
ResourceConstraints constraints;
/**
* Explicitly specify a startup snapshot blob. The embedder owns the blob.
*/
StartupData* snapshot_blob = nullptr;
/**
* Enables the host application to provide a mechanism for recording
* statistics counters.
*/
CounterLookupCallback counter_lookup_callback = nullptr;
/**
* Enables the host application to provide a mechanism for recording
* histograms. The CreateHistogram function returns a
* histogram which will later be passed to the AddHistogramSample
* function.
*/
CreateHistogramCallback create_histogram_callback = nullptr;
AddHistogramSampleCallback add_histogram_sample_callback = nullptr;
/**
* The ArrayBuffer::Allocator to use for allocating and freeing the backing
* store of ArrayBuffers.
*
* If the shared_ptr version is used, the Isolate instance and every
* |BackingStore| allocated using this allocator hold a std::shared_ptr
* to the allocator, in order to facilitate lifetime
* management for the allocator instance.
*/
ArrayBuffer::Allocator* array_buffer_allocator = nullptr;
std::shared_ptr<ArrayBuffer::Allocator> array_buffer_allocator_shared;
/**
* Specifies an optional nullptr-terminated array of raw addresses in the
* embedder that V8 can match against during serialization and use for
* deserialization. This array and its content must stay valid for the
* entire lifetime of the isolate.
*/
const intptr_t* external_references = nullptr;
/**
* Whether calling Atomics.wait (a function that may block) is allowed in
* this isolate. This can also be configured via SetAllowAtomicsWait.
*/
bool allow_atomics_wait = true;
/**
* Termination is postponed when there is no active SafeForTerminationScope.
*/
bool only_terminate_in_safe_scope = false;
/**
* The following parameters describe the offsets for addressing type info
* for wrapped API objects and are used by the fast C API
* (for details see v8-fast-api-calls.h).
*/
int embedder_wrapper_type_index = -1;
int embedder_wrapper_object_index = -1;
V8_DEPRECATED(
"Setting this has no effect. Embedders should ignore import assertions "
"that they do not use.")
std::vector<std::string> supported_import_assertions;
};
/**
* Stack-allocated class which sets the isolate for all operations
* executed within a local scope.
*/
class V8_EXPORT V8_NODISCARD Scope {
public:
explicit Scope(Isolate* isolate) : isolate_(isolate) {
isolate->Enter();
}
~Scope() { isolate_->Exit(); }
// Prevent copying of Scope objects.
Scope(const Scope&) = delete;
Scope& operator=(const Scope&) = delete;
private:
Isolate* const isolate_;
};
/**
* Assert that no Javascript code is invoked.
*/
class V8_EXPORT V8_NODISCARD DisallowJavascriptExecutionScope {
public:
enum OnFailure { CRASH_ON_FAILURE, THROW_ON_FAILURE, DUMP_ON_FAILURE };
DisallowJavascriptExecutionScope(Isolate* isolate, OnFailure on_failure);
~DisallowJavascriptExecutionScope();
// Prevent copying of Scope objects.
DisallowJavascriptExecutionScope(const DisallowJavascriptExecutionScope&) =
delete;
DisallowJavascriptExecutionScope& operator=(
const DisallowJavascriptExecutionScope&) = delete;
private:
OnFailure on_failure_;
Isolate* isolate_;
bool was_execution_allowed_assert_;
bool was_execution_allowed_throws_;
bool was_execution_allowed_dump_;
};
/**
* Introduce exception to DisallowJavascriptExecutionScope.
*/
class V8_EXPORT V8_NODISCARD AllowJavascriptExecutionScope {
public:
explicit AllowJavascriptExecutionScope(Isolate* isolate);
~AllowJavascriptExecutionScope();
// Prevent copying of Scope objects.
AllowJavascriptExecutionScope(const AllowJavascriptExecutionScope&) =
delete;
AllowJavascriptExecutionScope& operator=(
const AllowJavascriptExecutionScope&) = delete;
private:
Isolate* isolate_;
bool was_execution_allowed_assert_;
bool was_execution_allowed_throws_;
bool was_execution_allowed_dump_;
};
/**
* Do not run microtasks while this scope is active, even if microtasks are
* automatically executed otherwise.
*/
class V8_EXPORT V8_NODISCARD SuppressMicrotaskExecutionScope {
public:
explicit SuppressMicrotaskExecutionScope(
Isolate* isolate, MicrotaskQueue* microtask_queue = nullptr);
~SuppressMicrotaskExecutionScope();
// Prevent copying of Scope objects.
SuppressMicrotaskExecutionScope(const SuppressMicrotaskExecutionScope&) =
delete;
SuppressMicrotaskExecutionScope& operator=(
const SuppressMicrotaskExecutionScope&) = delete;
private:
internal::Isolate* const isolate_;
internal::MicrotaskQueue* const microtask_queue_;
internal::Address previous_stack_height_;
friend class internal::ThreadLocalTop;
};
/**
* This scope allows terminations inside direct V8 API calls and forbid them
* inside any recursive API calls without explicit SafeForTerminationScope.
*/
class V8_EXPORT V8_NODISCARD SafeForTerminationScope {
public:
explicit SafeForTerminationScope(v8::Isolate* isolate);
~SafeForTerminationScope();
// Prevent copying of Scope objects.
SafeForTerminationScope(const SafeForTerminationScope&) = delete;
SafeForTerminationScope& operator=(const SafeForTerminationScope&) = delete;
private:
internal::Isolate* isolate_;
bool prev_value_;
};
/**
* Types of garbage collections that can be requested via
* RequestGarbageCollectionForTesting.
*/
enum GarbageCollectionType {
kFullGarbageCollection,
kMinorGarbageCollection
};
/**
* Features reported via the SetUseCounterCallback callback. Do not change
* assigned numbers of existing items; add new features to the end of this
* list.
*/
enum UseCounterFeature {
kUseAsm = 0,
kBreakIterator = 1,
kLegacyConst = 2,
kMarkDequeOverflow = 3,
kStoreBufferOverflow = 4,
kSlotsBufferOverflow = 5,
kObjectObserve = 6,
kForcedGC = 7,
kSloppyMode = 8,
kStrictMode = 9,
kStrongMode = 10,
kRegExpPrototypeStickyGetter = 11,
kRegExpPrototypeToString = 12,
kRegExpPrototypeUnicodeGetter = 13,
kIntlV8Parse = 14,
kIntlPattern = 15,
kIntlResolved = 16,
kPromiseChain = 17,
kPromiseAccept = 18,
kPromiseDefer = 19,
kHtmlCommentInExternalScript = 20,
kHtmlComment = 21,
kSloppyModeBlockScopedFunctionRedefinition = 22,
kForInInitializer = 23,
kArrayProtectorDirtied = 24,
kArraySpeciesModified = 25,
kArrayPrototypeConstructorModified = 26,
kArrayInstanceProtoModified = 27,
kArrayInstanceConstructorModified = 28,
kLegacyFunctionDeclaration = 29,
kRegExpPrototypeSourceGetter = 30, // Unused.
kRegExpPrototypeOldFlagGetter = 31, // Unused.
kDecimalWithLeadingZeroInStrictMode = 32,
kLegacyDateParser = 33,
kDefineGetterOrSetterWouldThrow = 34,
kFunctionConstructorReturnedUndefined = 35,
kAssigmentExpressionLHSIsCallInSloppy = 36,
kAssigmentExpressionLHSIsCallInStrict = 37,
kPromiseConstructorReturnedUndefined = 38,
kConstructorNonUndefinedPrimitiveReturn = 39,
kLabeledExpressionStatement = 40,
kLineOrParagraphSeparatorAsLineTerminator = 41,
kIndexAccessor = 42,
kErrorCaptureStackTrace = 43,
kErrorPrepareStackTrace = 44,
kErrorStackTraceLimit = 45,
kWebAssemblyInstantiation = 46,
kDeoptimizerDisableSpeculation = 47,
kArrayPrototypeSortJSArrayModifiedPrototype = 48,
kFunctionTokenOffsetTooLongForToString = 49,
kWasmSharedMemory = 50,
kWasmThreadOpcodes = 51,
kAtomicsNotify = 52, // Unused.
kAtomicsWake = 53, // Unused.
kCollator = 54,
kNumberFormat = 55,
kDateTimeFormat = 56,
kPluralRules = 57,
kRelativeTimeFormat = 58,
kLocale = 59,
kListFormat = 60,
kSegmenter = 61,
kStringLocaleCompare = 62,
kStringToLocaleUpperCase = 63,
kStringToLocaleLowerCase = 64,
kNumberToLocaleString = 65,
kDateToLocaleString = 66,
kDateToLocaleDateString = 67,
kDateToLocaleTimeString = 68,
kAttemptOverrideReadOnlyOnPrototypeSloppy = 69,
kAttemptOverrideReadOnlyOnPrototypeStrict = 70,
kOptimizedFunctionWithOneShotBytecode = 71, // Unused.
kRegExpMatchIsTrueishOnNonJSRegExp = 72,
kRegExpMatchIsFalseishOnJSRegExp = 73,
kDateGetTimezoneOffset = 74, // Unused.
kStringNormalize = 75,
kCallSiteAPIGetFunctionSloppyCall = 76,
kCallSiteAPIGetThisSloppyCall = 77,
kRegExpMatchAllWithNonGlobalRegExp = 78,
kRegExpExecCalledOnSlowRegExp = 79,
kRegExpReplaceCalledOnSlowRegExp = 80,
kDisplayNames = 81,
kSharedArrayBufferConstructed = 82,
kArrayPrototypeHasElements = 83,
kObjectPrototypeHasElements = 84,
kNumberFormatStyleUnit = 85,
kDateTimeFormatRange = 86,
kDateTimeFormatDateTimeStyle = 87,
kBreakIteratorTypeWord = 88,
kBreakIteratorTypeLine = 89,
kInvalidatedArrayBufferDetachingProtector = 90,
kInvalidatedArrayConstructorProtector = 91,
kInvalidatedArrayIteratorLookupChainProtector = 92,
kInvalidatedArraySpeciesLookupChainProtector = 93,
kInvalidatedIsConcatSpreadableLookupChainProtector = 94,
kInvalidatedMapIteratorLookupChainProtector = 95,
kInvalidatedNoElementsProtector = 96,
kInvalidatedPromiseHookProtector = 97,
kInvalidatedPromiseResolveLookupChainProtector = 98,
kInvalidatedPromiseSpeciesLookupChainProtector = 99,
kInvalidatedPromiseThenLookupChainProtector = 100,
kInvalidatedRegExpSpeciesLookupChainProtector = 101,
kInvalidatedSetIteratorLookupChainProtector = 102,
kInvalidatedStringIteratorLookupChainProtector = 103,
kInvalidatedStringLengthOverflowLookupChainProtector = 104,
kInvalidatedTypedArraySpeciesLookupChainProtector = 105,
kWasmSimdOpcodes = 106,
kVarRedeclaredCatchBinding = 107,
kWasmRefTypes = 108,
kWasmBulkMemory = 109, // Unused.
kWasmMultiValue = 110,
kWasmExceptionHandling = 111,
kInvalidatedMegaDOMProtector = 112,
// If you add new values here, you'll also need to update Chromium's:
// web_feature.mojom, use_counter_callback.cc, and enums.xml. V8 changes to
// this list need to be landed first, then changes on the Chromium side.
kUseCounterFeatureCount // This enum value must be last.
};
enum MessageErrorLevel {
kMessageLog = (1 << 0),
kMessageDebug = (1 << 1),
kMessageInfo = (1 << 2),
kMessageError = (1 << 3),
kMessageWarning = (1 << 4),
kMessageAll = kMessageLog | kMessageDebug | kMessageInfo | kMessageError |
kMessageWarning,
};
using UseCounterCallback = void (*)(Isolate* isolate,
UseCounterFeature feature);
/**
* Allocates a new isolate but does not initialize it. Does not change the
* currently entered isolate.
*
* Only Isolate::GetData() and Isolate::SetData(), which access the
* embedder-controlled parts of the isolate, are allowed to be called on the
* uninitialized isolate. To initialize the isolate, call
* Isolate::Initialize().
*
* When an isolate is no longer used its resources should be freed
* by calling Dispose(). Using the delete operator is not allowed.
*
* V8::Initialize() must have run prior to this.
*/
static Isolate* Allocate();
/**
* Initialize an Isolate previously allocated by Isolate::Allocate().
*/
static void Initialize(Isolate* isolate, const CreateParams& params);
/**
* Creates a new isolate. Does not change the currently entered
* isolate.
*
* When an isolate is no longer used its resources should be freed
* by calling Dispose(). Using the delete operator is not allowed.
*
* V8::Initialize() must have run prior to this.
*/
static Isolate* New(const CreateParams& params);
/**
* Returns the entered isolate for the current thread or NULL in
* case there is no current isolate.
*
* This method must not be invoked before V8::Initialize() was invoked.
*/
static Isolate* GetCurrent();
/**
* Returns the entered isolate for the current thread or NULL in
* case there is no current isolate.
*
* No checks are performed by this method.
*/
static Isolate* TryGetCurrent();
/**
* Clears the set of objects held strongly by the heap. This set of
* objects are originally built when a WeakRef is created or
* successfully dereferenced.
*
* This is invoked automatically after microtasks are run. See
* MicrotasksPolicy for when microtasks are run.
*
* This needs to be manually invoked only if the embedder is manually running
* microtasks via a custom MicrotaskQueue class's PerformCheckpoint. In that
* case, it is the embedder's responsibility to make this call at a time which
* does not interrupt synchronous ECMAScript code execution.
*/
void ClearKeptObjects();
/**
* Custom callback used by embedders to help V8 determine if it should abort
* when it throws and no internal handler is predicted to catch the
* exception. If --abort-on-uncaught-exception is used on the command line,
* then V8 will abort if either:
* - no custom callback is set.
* - the custom callback set returns true.
* Otherwise, the custom callback will not be called and V8 will not abort.
*/
using AbortOnUncaughtExceptionCallback = bool (*)(Isolate*);
void SetAbortOnUncaughtExceptionCallback(
AbortOnUncaughtExceptionCallback callback);
/**
* This specifies the callback called by the upcoming dynamic
* import() language feature to load modules.
*/
V8_DEPRECATED(
"Use the version of SetHostImportModuleDynamicallyCallback that takes a "
"HostImportModuleDynamicallyWithImportAssertionsCallback instead")
void SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyCallback callback);
/**
* This specifies the callback called by the upcoming dynamic
* import() language feature to load modules.
*/
void SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyWithImportAssertionsCallback callback);
/**
* This specifies the callback called by the upcoming import.meta
* language feature to retrieve host-defined meta data for a module.
*/
void SetHostInitializeImportMetaObjectCallback(
HostInitializeImportMetaObjectCallback callback);
/**
* This specifies the callback called when the stack property of Error
* is accessed.
*/
void SetPrepareStackTraceCallback(PrepareStackTraceCallback callback);
/**
* Optional notification that the system is running low on memory.
* V8 uses these notifications to guide heuristics.
* It is allowed to call this function from another thread while
* the isolate is executing long running JavaScript code.
*/
void MemoryPressureNotification(MemoryPressureLevel level);
/**
* Drop non-essential caches. Should only be called from testing code.
* The method can potentially block for a long time and does not necessarily
* trigger GC.
*/
void ClearCachesForTesting();
/**
* Methods below this point require holding a lock (using Locker) in
* a multi-threaded environment.
*/
/**
* Sets this isolate as the entered one for the current thread.
* Saves the previously entered one (if any), so that it can be
* restored when exiting. Re-entering an isolate is allowed.
*/
void Enter();
/**
* Exits this isolate by restoring the previously entered one in the
* current thread. The isolate may still stay the same, if it was
* entered more than once.
*
* Requires: this == Isolate::GetCurrent().
*/
void Exit();
/**
* Disposes the isolate. The isolate must not be entered by any
* thread to be disposable.
*/
void Dispose();
/**
* Dumps activated low-level V8 internal stats. This can be used instead
* of performing a full isolate disposal.
*/
void DumpAndResetStats();
/**
* Discards all V8 thread-specific data for the Isolate. Should be used
* if a thread is terminating and it has used an Isolate that will outlive
* the thread -- all thread-specific data for an Isolate is discarded when
* an Isolate is disposed so this call is pointless if an Isolate is about
* to be Disposed.
*/
void DiscardThreadSpecificMetadata();
/**
* Associate embedder-specific data with the isolate. |slot| has to be
* between 0 and GetNumberOfDataSlots() - 1.
*/
V8_INLINE void SetData(uint32_t slot, void* data);
/**
* Retrieve embedder-specific data from the isolate.
* Returns NULL if SetData has never been called for the given |slot|.
*/
V8_INLINE void* GetData(uint32_t slot);
/**
* Returns the maximum number of available embedder data slots. Valid slots
* are in the range of 0 - GetNumberOfDataSlots() - 1.
*/
V8_INLINE static uint32_t GetNumberOfDataSlots();
/**
* Return data that was previously attached to the isolate snapshot via
* SnapshotCreator, and removes the reference to it.
* Repeated call with the same index returns an empty MaybeLocal.
*/
template <class T>
V8_INLINE MaybeLocal<T> GetDataFromSnapshotOnce(size_t index);
/**
* Get statistics about the heap memory usage.
*/
void GetHeapStatistics(HeapStatistics* heap_statistics);
/**
* Returns the number of spaces in the heap.
*/
size_t NumberOfHeapSpaces();
/**
* Get the memory usage of a space in the heap.
*
* \param space_statistics The HeapSpaceStatistics object to fill in
* statistics.
* \param index The index of the space to get statistics from, which ranges
* from 0 to NumberOfHeapSpaces() - 1.
* \returns true on success.
*/
bool GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
size_t index);
/**
* Returns the number of types of objects tracked in the heap at GC.
*/
size_t NumberOfTrackedHeapObjectTypes();
/**
* Get statistics about objects in the heap.
*
* \param object_statistics The HeapObjectStatistics object to fill in
* statistics of objects of given type, which were live in the previous GC.
* \param type_index The index of the type of object to fill details about,
* which ranges from 0 to NumberOfTrackedHeapObjectTypes() - 1.
* \returns true on success.
*/
bool GetHeapObjectStatisticsAtLastGC(HeapObjectStatistics* object_statistics,
size_t type_index);
/**
* Get statistics about code and its metadata in the heap.
*
* \param object_statistics The HeapCodeStatistics object to fill in
* statistics of code, bytecode and their metadata.
* \returns true on success.
*/
bool GetHeapCodeAndMetadataStatistics(HeapCodeStatistics* object_statistics);
/**
* This API is experimental and may change significantly.
*
* Enqueues a memory measurement request and invokes the delegate with the
* results.
*
* \param delegate the delegate that defines which contexts to measure and
* reports the results.
*
* \param execution promptness executing the memory measurement.
* The kEager value is expected to be used only in tests.
*/
bool MeasureMemory(
std::unique_ptr<MeasureMemoryDelegate> delegate,
MeasureMemoryExecution execution = MeasureMemoryExecution::kDefault);
V8_DEPRECATED("Use the version with a delegate")
MaybeLocal<Promise> MeasureMemory(Local<Context> context,
MeasureMemoryMode mode);
/**
* Get a call stack sample from the isolate.
* \param state Execution state.
* \param frames Caller allocated buffer to store stack frames.
* \param frames_limit Maximum number of frames to capture. The buffer must
* be large enough to hold the number of frames.
* \param sample_info The sample info is filled up by the function
* provides number of actual captured stack frames and
* the current VM state.
* \note GetStackSample should only be called when the JS thread is paused or
* interrupted. Otherwise the behavior is undefined.
*/
void GetStackSample(const RegisterState& state, void** frames,
size_t frames_limit, SampleInfo* sample_info);
/**
* Adjusts the amount of registered external memory. Used to give V8 an
* indication of the amount of externally allocated memory that is kept alive
* by JavaScript objects. V8 uses this to decide when to perform global
* garbage collections. Registering externally allocated memory will trigger
* global garbage collections more often than it would otherwise in an attempt
* to garbage collect the JavaScript objects that keep the externally
* allocated memory alive.
*
* \param change_in_bytes the change in externally allocated memory that is
* kept alive by JavaScript objects.
* \returns the adjusted value.
*/
int64_t AdjustAmountOfExternalAllocatedMemory(int64_t change_in_bytes);
/**
* Returns the number of phantom handles without callbacks that were reset
* by the garbage collector since the last call to this function.
*/
size_t NumberOfPhantomHandleResetsSinceLastCall();
/**
* Returns heap profiler for this isolate. Will return NULL until the isolate
* is initialized.
*/
HeapProfiler* GetHeapProfiler();
/**
* Tells the VM whether the embedder is idle or not.
*/
void SetIdle(bool is_idle);
/** Returns the ArrayBuffer::Allocator used in this isolate. */
ArrayBuffer::Allocator* GetArrayBufferAllocator();
/** Returns true if this isolate has a current context. */
bool InContext();
/**
* Returns the context of the currently running JavaScript, or the context
* on the top of the stack if no JavaScript is running.
*/
Local<Context> GetCurrentContext();
/**
* Returns either the last context entered through V8's C++ API, or the
* context of the currently running microtask while processing microtasks.
* If a context is entered while executing a microtask, that context is
* returned.
*/
Local<Context> GetEnteredOrMicrotaskContext();
/**
* Returns the Context that corresponds to the Incumbent realm in HTML spec.
* https://html.spec.whatwg.org/multipage/webappapis.html#incumbent
*/
Local<Context> GetIncumbentContext();
/**
* Schedules a v8::Exception::Error with the given message.
* See ThrowException for more details. Templatized to provide compile-time
* errors in case of too long strings (see v8::String::NewFromUtf8Literal).
*/
template <int N>
Local<Value> ThrowError(const char (&message)[N]) {
return ThrowError(String::NewFromUtf8Literal(this, message));
}
Local<Value> ThrowError(Local<String> message);
/**
* Schedules an exception to be thrown when returning to JavaScript. When an
* exception has been scheduled it is illegal to invoke any JavaScript
* operation; the caller must return immediately and only after the exception
* has been handled does it become legal to invoke JavaScript operations.
*/
Local<Value> ThrowException(Local<Value> exception);
using GCCallback = void (*)(Isolate* isolate, GCType type,
GCCallbackFlags flags);
using GCCallbackWithData = void (*)(Isolate* isolate, GCType type,
GCCallbackFlags flags, void* data);
/**
* Enables the host application to receive a notification before a
* garbage collection. Allocations are allowed in the callback function,
* but the callback is not re-entrant: if the allocation inside it will
* trigger the garbage collection, the callback won't be called again.
* It is possible to specify the GCType filter for your callback. But it is
* not possible to register the same callback function two times with
* different GCType filters.
*/
void AddGCPrologueCallback(GCCallbackWithData callback, void* data = nullptr,
GCType gc_type_filter = kGCTypeAll);
void AddGCPrologueCallback(GCCallback callback,
GCType gc_type_filter = kGCTypeAll);
/**
* This function removes callback which was installed by
* AddGCPrologueCallback function.
*/
void RemoveGCPrologueCallback(GCCallbackWithData, void* data = nullptr);
void RemoveGCPrologueCallback(GCCallback callback);
/**
* Sets the embedder heap tracer for the isolate.
*/
void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
/*
* Gets the currently active heap tracer for the isolate.
*/
EmbedderHeapTracer* GetEmbedderHeapTracer();
/**
* Sets an embedder roots handle that V8 should consider when performing
* non-unified heap garbage collections.
*
* Using only EmbedderHeapTracer automatically sets up a default handler.
* The intended use case is for setting a custom handler after invoking
* `AttachCppHeap()`.
*
* V8 does not take ownership of the handler.
*/
void SetEmbedderRootsHandler(EmbedderRootsHandler* handler);
/**
* Attaches a managed C++ heap as an extension to the JavaScript heap. The
* embedder maintains ownership of the CppHeap. At most one C++ heap can be
* attached to V8.
*
* This is an experimental feature and may still change significantly.
*/
void AttachCppHeap(CppHeap*);
/**
* Detaches a managed C++ heap if one was attached using `AttachCppHeap()`.
*
* This is an experimental feature and may still change significantly.
*/
void DetachCppHeap();
/**
* This is an experimental feature and may still change significantly.
* \returns the C++ heap managed by V8. Only available if such a heap has been
* attached using `AttachCppHeap()`.
*/
CppHeap* GetCppHeap() const;
/**
* Use for |AtomicsWaitCallback| to indicate the type of event it receives.
*/
enum class AtomicsWaitEvent {
/** Indicates that this call is happening before waiting. */
kStartWait,
/** `Atomics.wait()` finished because of an `Atomics.wake()` call. */
kWokenUp,
/** `Atomics.wait()` finished because it timed out. */
kTimedOut,
/** `Atomics.wait()` was interrupted through |TerminateExecution()|. */
kTerminatedExecution,
/** `Atomics.wait()` was stopped through |AtomicsWaitWakeHandle|. */
kAPIStopped,
/** `Atomics.wait()` did not wait, as the initial condition was not met. */
kNotEqual
};
/**
* Passed to |AtomicsWaitCallback| as a means of stopping an ongoing
* `Atomics.wait` call.
*/
class V8_EXPORT AtomicsWaitWakeHandle {
public:
/**
* Stop this `Atomics.wait()` call and call the |AtomicsWaitCallback|
* with |kAPIStopped|.
*
* This function may be called from another thread. The caller has to ensure
* through proper synchronization that it is not called after
* the finishing |AtomicsWaitCallback|.
*
* Note that the ECMAScript specification does not plan for the possibility
* of wakeups that are neither coming from a timeout or an `Atomics.wake()`
* call, so this may invalidate assumptions made by existing code.
* The embedder may accordingly wish to schedule an exception in the
* finishing |AtomicsWaitCallback|.
*/
void Wake();
};
/**
* Embedder callback for `Atomics.wait()` that can be added through
* |SetAtomicsWaitCallback|.
*
* This will be called just before starting to wait with the |event| value
* |kStartWait| and after finishing waiting with one of the other
* values of |AtomicsWaitEvent| inside of an `Atomics.wait()` call.
*
* |array_buffer| will refer to the underlying SharedArrayBuffer,
* |offset_in_bytes| to the location of the waited-on memory address inside
* the SharedArrayBuffer.
*
* |value| and |timeout_in_ms| will be the values passed to
* the `Atomics.wait()` call. If no timeout was used, |timeout_in_ms|
* will be `INFINITY`.
*
* In the |kStartWait| callback, |stop_handle| will be an object that
* is only valid until the corresponding finishing callback and that
* can be used to stop the wait process while it is happening.
*
* This callback may schedule exceptions, *unless* |event| is equal to
* |kTerminatedExecution|.
*/
using AtomicsWaitCallback = void (*)(AtomicsWaitEvent event,
Local<SharedArrayBuffer> array_buffer,
size_t offset_in_bytes, int64_t value,
double timeout_in_ms,
AtomicsWaitWakeHandle* stop_handle,
void* data);
/**
* Set a new |AtomicsWaitCallback|. This overrides an earlier
* |AtomicsWaitCallback|, if there was any. If |callback| is nullptr,
* this unsets the callback. |data| will be passed to the callback
* as its last parameter.
*/
void SetAtomicsWaitCallback(AtomicsWaitCallback callback, void* data);
/**
* Enables the host application to receive a notification after a
* garbage collection. Allocations are allowed in the callback function,
* but the callback is not re-entrant: if the allocation inside it will
* trigger the garbage collection, the callback won't be called again.
* It is possible to specify the GCType filter for your callback. But it is
* not possible to register the same callback function two times with
* different GCType filters.
*/
void AddGCEpilogueCallback(GCCallbackWithData callback, void* data = nullptr,
GCType gc_type_filter = kGCTypeAll);
void AddGCEpilogueCallback(GCCallback callback,
GCType gc_type_filter = kGCTypeAll);
/**
* This function removes callback which was installed by
* AddGCEpilogueCallback function.
*/
void RemoveGCEpilogueCallback(GCCallbackWithData callback,
void* data = nullptr);
void RemoveGCEpilogueCallback(GCCallback callback);
using GetExternallyAllocatedMemoryInBytesCallback = size_t (*)();
/**
* Set the callback that tells V8 how much memory is currently allocated
* externally of the V8 heap. Ideally this memory is somehow connected to V8
* objects and may get freed-up when the corresponding V8 objects get
* collected by a V8 garbage collection.
*/
void SetGetExternallyAllocatedMemoryInBytesCallback(
GetExternallyAllocatedMemoryInBytesCallback callback);
/**
* Forcefully terminate the current thread of JavaScript execution
* in the given isolate.
*
* This method can be used by any thread even if that thread has not
* acquired the V8 lock with a Locker object.
*/
void TerminateExecution();
/**
* Is V8 terminating JavaScript execution.
*
* Returns true if JavaScript execution is currently terminating
* because of a call to TerminateExecution. In that case there are
* still JavaScript frames on the stack and the termination
* exception is still active.
*/
bool IsExecutionTerminating();
/**
* Resume execution capability in the given isolate, whose execution
* was previously forcefully terminated using TerminateExecution().
*
* When execution is forcefully terminated using TerminateExecution(),
* the isolate can not resume execution until all JavaScript frames
* have propagated the uncatchable exception which is generated. This
* method allows the program embedding the engine to handle the
* termination event and resume execution capability, even if
* JavaScript frames remain on the stack.
*
* This method can be used by any thread even if that thread has not
* acquired the V8 lock with a Locker object.
*/
void CancelTerminateExecution();
/**
* Request V8 to interrupt long running JavaScript code and invoke
* the given |callback| passing the given |data| to it. After |callback|
* returns control will be returned to the JavaScript code.
* There may be a number of interrupt requests in flight.
* Can be called from another thread without acquiring a |Locker|.
* Registered |callback| must not reenter interrupted Isolate.
*/
void RequestInterrupt(InterruptCallback callback, void* data);
/**
* Returns true if there is ongoing background work within V8 that will
* eventually post a foreground task, like asynchronous WebAssembly
* compilation.
*/
bool HasPendingBackgroundTasks();
/**
* Request garbage collection in this Isolate. It is only valid to call this
* function if --expose_gc was specified.
*
* This should only be used for testing purposes and not to enforce a garbage
* collection schedule. It has strong negative impact on the garbage
* collection performance. Use IdleNotificationDeadline() or
* LowMemoryNotification() instead to influence the garbage collection
* schedule.
*/
void RequestGarbageCollectionForTesting(GarbageCollectionType type);
/**
* Set the callback to invoke for logging event.
*/
void SetEventLogger(LogEventCallback that);
/**
* Adds a callback to notify the host application right before a script
* is about to run. If a script re-enters the runtime during executing, the
* BeforeCallEnteredCallback is invoked for each re-entrance.
* Executing scripts inside the callback will re-trigger the callback.
*/
void AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
/**
* Removes callback that was installed by AddBeforeCallEnteredCallback.
*/
void RemoveBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
/**
* Adds a callback to notify the host application when a script finished
* running. If a script re-enters the runtime during executing, the
* CallCompletedCallback is only invoked when the outer-most script
* execution ends. Executing scripts inside the callback do not trigger
* further callbacks.
*/
void AddCallCompletedCallback(CallCompletedCallback callback);
/**
* Removes callback that was installed by AddCallCompletedCallback.
*/
void RemoveCallCompletedCallback(CallCompletedCallback callback);
/**
* Set the PromiseHook callback for various promise lifecycle
* events.
*/
void SetPromiseHook(PromiseHook hook);
/**
* Set callback to notify about promise reject with no handler, or
* revocation of such a previous notification once the handler is added.
*/
void SetPromiseRejectCallback(PromiseRejectCallback callback);
/**
* Runs the default MicrotaskQueue until it gets empty and perform other
* microtask checkpoint steps, such as calling ClearKeptObjects. Asserts that
* the MicrotasksPolicy is not kScoped. Any exceptions thrown by microtask
* callbacks are swallowed.
*/
void PerformMicrotaskCheckpoint();
/**
* Enqueues the callback to the default MicrotaskQueue
*/
void EnqueueMicrotask(Local<Function> microtask);
/**
* Enqueues the callback to the default MicrotaskQueue
*/
void EnqueueMicrotask(MicrotaskCallback callback, void* data = nullptr);
/**
* Controls how Microtasks are invoked. See MicrotasksPolicy for details.
*/
void SetMicrotasksPolicy(MicrotasksPolicy policy);
/**
* Returns the policy controlling how Microtasks are invoked.
*/
MicrotasksPolicy GetMicrotasksPolicy() const;
/**
* Adds a callback to notify the host application after
* microtasks were run on the default MicrotaskQueue. The callback is
* triggered by explicit RunMicrotasks call or automatic microtasks execution
* (see SetMicrotaskPolicy).
*
* Callback will trigger even if microtasks were attempted to run,
* but the microtasks queue was empty and no single microtask was actually
* executed.
*
* Executing scripts inside the callback will not re-trigger microtasks and
* the callback.
*/
void AddMicrotasksCompletedCallback(
MicrotasksCompletedCallbackWithData callback, void* data = nullptr);
/**
* Removes callback that was installed by AddMicrotasksCompletedCallback.
*/
void RemoveMicrotasksCompletedCallback(
MicrotasksCompletedCallbackWithData callback, void* data = nullptr);
/**
* Sets a callback for counting the number of times a feature of V8 is used.
*/
void SetUseCounterCallback(UseCounterCallback callback);
/**
* Enables the host application to provide a mechanism for recording
* statistics counters.
*/
void SetCounterFunction(CounterLookupCallback);
/**
* Enables the host application to provide a mechanism for recording
* histograms. The CreateHistogram function returns a
* histogram which will later be passed to the AddHistogramSample
* function.
*/
void SetCreateHistogramFunction(CreateHistogramCallback);
void SetAddHistogramSampleFunction(AddHistogramSampleCallback);
/**
* Enables the host application to provide a mechanism for recording
* event based metrics. In order to use this interface
* include/v8-metrics.h
* needs to be included and the recorder needs to be derived from the
* Recorder base class defined there.
* This method can only be called once per isolate and must happen during
* isolate initialization before background threads are spawned.
*/
void SetMetricsRecorder(
const std::shared_ptr<metrics::Recorder>& metrics_recorder);
/**
* Enables the host application to provide a mechanism for recording a
* predefined set of data as crash keys to be used in postmortem debugging in
* case of a crash.
*/
void SetAddCrashKeyCallback(AddCrashKeyCallback);
/**
* Optional notification that the embedder is idle.
* V8 uses the notification to perform garbage collection.
* This call can be used repeatedly if the embedder remains idle.
* Returns true if the embedder should stop calling IdleNotificationDeadline
* until real work has been done. This indicates that V8 has done
* as much cleanup as it will be able to do.
*
* The deadline_in_seconds argument specifies the deadline V8 has to finish
* garbage collection work. deadline_in_seconds is compared with
* MonotonicallyIncreasingTime() and should be based on the same timebase as
* that function. There is no guarantee that the actual work will be done
* within the time limit.
*/
bool IdleNotificationDeadline(double deadline_in_seconds);
/**
* Optional notification that the system is running low on memory.
* V8 uses these notifications to attempt to free memory.
*/
void LowMemoryNotification();
/**
* Optional notification that a context has been disposed. V8 uses these
* notifications to guide the GC heuristic and cancel FinalizationRegistry
* cleanup tasks. Returns the number of context disposals - including this one
* - since the last time V8 had a chance to clean up.
*
* The optional parameter |dependant_context| specifies whether the disposed
* context was depending on state from other contexts or not.
*/
int ContextDisposedNotification(bool dependant_context = true);
/**
* Optional notification that the isolate switched to the foreground.
* V8 uses these notifications to guide heuristics.
*/
void IsolateInForegroundNotification();
/**
* Optional notification that the isolate switched to the background.
* V8 uses these notifications to guide heuristics.
*/
void IsolateInBackgroundNotification();
/**
* Optional notification which will enable the memory savings mode.
* V8 uses this notification to guide heuristics which may result in a
* smaller memory footprint at the cost of reduced runtime performance.
*/
void EnableMemorySavingsMode();
/**
* Optional notification which will disable the memory savings mode.
*/
void DisableMemorySavingsMode();
/**
* Optional notification to tell V8 the current performance requirements
* of the embedder based on RAIL.
* V8 uses these notifications to guide heuristics.
* This is an unfinished experimental feature. Semantics and implementation
* may change frequently.
*/
void SetRAILMode(RAILMode rail_mode);
/**
* Update load start time of the RAIL mode
*/
void UpdateLoadStartTime();
/**
* Optional notification to tell V8 the current isolate is used for debugging
* and requires higher heap limit.
*/
void IncreaseHeapLimitForDebugging();
/**
* Restores the original heap limit after IncreaseHeapLimitForDebugging().
*/
void RestoreOriginalHeapLimit();
/**
* Returns true if the heap limit was increased for debugging and the
* original heap limit was not restored yet.
*/
bool IsHeapLimitIncreasedForDebugging();
/**
* Allows the host application to provide the address of a function that is
* notified each time code is added, moved or removed.
*
* \param options options for the JIT code event handler.
* \param event_handler the JIT code event handler, which will be invoked
* each time code is added, moved or removed.
* \note \p event_handler won't get notified of existent code.
* \note since code removal notifications are not currently issued, the
* \p event_handler may get notifications of code that overlaps earlier
* code notifications. This happens when code areas are reused, and the
* earlier overlapping code areas should therefore be discarded.
* \note the events passed to \p event_handler and the strings they point to
* are not guaranteed to live past each call. The \p event_handler must
* copy strings and other parameters it needs to keep around.
* \note the set of events declared in JitCodeEvent::EventType is expected to
* grow over time, and the JitCodeEvent structure is expected to accrue
* new members. The \p event_handler function must ignore event codes
* it does not recognize to maintain future compatibility.
* \note Use Isolate::CreateParams to get events for code executed during
* Isolate setup.
*/
void SetJitCodeEventHandler(JitCodeEventOptions options,
JitCodeEventHandler event_handler);
/**
* Modifies the stack limit for this Isolate.
*
* \param stack_limit An address beyond which the Vm's stack may not grow.
*
* \note If you are using threads then you should hold the V8::Locker lock
* while setting the stack limit and you must set a non-default stack
* limit separately for each thread.
*/
void SetStackLimit(uintptr_t stack_limit);
/**
* Returns a memory range that can potentially contain jitted code. Code for
* V8's 'builtins' will not be in this range if embedded builtins is enabled.
*
* On Win64, embedders are advised to install function table callbacks for
* these ranges, as default SEH won't be able to unwind through jitted code.
* The first page of the code range is reserved for the embedder and is
* committed, writable, and executable, to be used to store unwind data, as
* documented in
* https://docs.microsoft.com/en-us/cpp/build/exception-handling-x64.
*
* Might be empty on other platforms.
*
* https://code.google.com/p/v8/issues/detail?id=3598
*/
void GetCodeRange(void** start, size_t* length_in_bytes);
/**
* As GetCodeRange, but for embedded builtins (these live in a distinct
* memory region from other V8 Code objects).
*/
void GetEmbeddedCodeRange(const void** start, size_t* length_in_bytes);
/**
* Returns the JSEntryStubs necessary for use with the Unwinder API.
*/
JSEntryStubs GetJSEntryStubs();
static constexpr size_t kMinCodePagesBufferSize = 32;
/**
* Copies the code heap pages currently in use by V8 into |code_pages_out|.
* |code_pages_out| must have at least kMinCodePagesBufferSize capacity and
* must be empty.
*
* Signal-safe, does not allocate, does not access the V8 heap.
* No code on the stack can rely on pages that might be missing.
*
* Returns the number of pages available to be copied, which might be greater
* than |capacity|. In this case, only |capacity| pages will be copied into
* |code_pages_out|. The caller should provide a bigger buffer on the next
* call in order to get all available code pages, but this is not required.
*/
size_t CopyCodePages(size_t capacity, MemoryRange* code_pages_out);
/** Set the callback to invoke in case of fatal errors. */
void SetFatalErrorHandler(FatalErrorCallback that);
/** Set the callback to invoke in case of OOM errors. */
void SetOOMErrorHandler(OOMErrorCallback that);
/**
* Add a callback to invoke in case the heap size is close to the heap limit.
* If multiple callbacks are added, only the most recently added callback is
* invoked.
*/
void AddNearHeapLimitCallback(NearHeapLimitCallback callback, void* data);
/**
* Remove the given callback and restore the heap limit to the
* given limit. If the given limit is zero, then it is ignored.
* If the current heap size is greater than the given limit,
* then the heap limit is restored to the minimal limit that
* is possible for the current heap size.
*/
void RemoveNearHeapLimitCallback(NearHeapLimitCallback callback,
size_t heap_limit);
/**
* If the heap limit was changed by the NearHeapLimitCallback, then the
* initial heap limit will be restored once the heap size falls below the
* given threshold percentage of the initial heap limit.
* The threshold percentage is a number in (0.0, 1.0) range.
*/
void AutomaticallyRestoreInitialHeapLimit(double threshold_percent = 0.5);
/**
* Set the callback to invoke to check if code generation from
* strings should be allowed.
*/
V8_DEPRECATED(
"Use Isolate::SetModifyCodeGenerationFromStringsCallback with "
"ModifyCodeGenerationFromStringsCallback2 instead. See "
"http://crbug.com/1096017 and TC39 Dynamic Code Brand Checks proposal "
"at https://github.com/tc39/proposal-dynamic-code-brand-checks.")
void SetModifyCodeGenerationFromStringsCallback(
ModifyCodeGenerationFromStringsCallback callback);
void SetModifyCodeGenerationFromStringsCallback(
ModifyCodeGenerationFromStringsCallback2 callback);
/**
* Set the callback to invoke to check if wasm code generation should
* be allowed.
*/
void SetAllowWasmCodeGenerationCallback(
AllowWasmCodeGenerationCallback callback);
/**
* Embedder over{ride|load} injection points for wasm APIs. The expectation
* is that the embedder sets them at most once.
*/
void SetWasmModuleCallback(ExtensionCallback callback);
void SetWasmInstanceCallback(ExtensionCallback callback);
void SetWasmStreamingCallback(WasmStreamingCallback callback);
void SetWasmLoadSourceMapCallback(WasmLoadSourceMapCallback callback);
void SetWasmSimdEnabledCallback(WasmSimdEnabledCallback callback);
void SetWasmExceptionsEnabledCallback(WasmExceptionsEnabledCallback callback);
void SetSharedArrayBufferConstructorEnabledCallback(
SharedArrayBufferConstructorEnabledCallback callback);
/**
* This function can be called by the embedder to signal V8 that the dynamic
* enabling of features has finished. V8 can now set up dynamically added
* features.
*/
void InstallConditionalFeatures(Local<Context> context);
/**
* Check if V8 is dead and therefore unusable. This is the case after
* fatal errors such as out-of-memory situations.
*/
bool IsDead();
/**
* Adds a message listener (errors only).
*
* The same message listener can be added more than once and in that
* case it will be called more than once for each message.
*
* If data is specified, it will be passed to the callback when it is called.
* Otherwise, the exception object will be passed to the callback instead.
*/
bool AddMessageListener(MessageCallback that,
Local<Value> data = Local<Value>());
/**
* Adds a message listener.
*
* The same message listener can be added more than once and in that
* case it will be called more than once for each message.
*
* If data is specified, it will be passed to the callback when it is called.
* Otherwise, the exception object will be passed to the callback instead.
*
* A listener can listen for particular error levels by providing a mask.
*/
bool AddMessageListenerWithErrorLevel(MessageCallback that,
int message_levels,
Local<Value> data = Local<Value>());
/**
* Remove all message listeners from the specified callback function.
*/
void RemoveMessageListeners(MessageCallback that);
/** Callback function for reporting failed access checks.*/
void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback);
/**
* Tells V8 to capture current stack trace when uncaught exception occurs
* and report it to the message listeners. The option is off by default.
*/
void SetCaptureStackTraceForUncaughtExceptions(
bool capture, int frame_limit = 10,
StackTrace::StackTraceOptions options = StackTrace::kOverview);
/**
* Iterates through all external resources referenced from current isolate
* heap. GC is not invoked prior to iterating, therefore there is no
* guarantee that visited objects are still alive.
*/
void VisitExternalResources(ExternalResourceVisitor* visitor);
/**
* Iterates through all the persistent handles in the current isolate's heap
* that have class_ids.
*/
void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor);
/**
* Iterates through all the persistent handles in the current isolate's heap
* that have class_ids and are weak to be marked as inactive if there is no
* pending activity for the handle.
*/
void VisitWeakHandles(PersistentHandleVisitor* visitor);
/**
* Check if this isolate is in use.
* True if at least one thread Enter'ed this isolate.
*/
bool IsInUse();
/**
* Set whether calling Atomics.wait (a function that may block) is allowed in
* this isolate. This can also be configured via
* CreateParams::allow_atomics_wait.
*/
void SetAllowAtomicsWait(bool allow);
/**
* Time zone redetection indicator for
* DateTimeConfigurationChangeNotification.
*
* kSkip indicates V8 that the notification should not trigger redetecting
* host time zone. kRedetect indicates V8 that host time zone should be
* redetected, and used to set the default time zone.
*
* The host time zone detection may require file system access or similar
* operations unlikely to be available inside a sandbox. If v8 is run inside a
* sandbox, the host time zone has to be detected outside the sandbox before
* calling DateTimeConfigurationChangeNotification function.
*/
enum class TimeZoneDetection { kSkip, kRedetect };
/**
* Notification that the embedder has changed the time zone, daylight savings
* time or other date / time configuration parameters. V8 keeps a cache of
* various values used for date / time computation. This notification will
* reset those cached values for the current context so that date / time
* configuration changes would be reflected.
*
* This API should not be called more than needed as it will negatively impact
* the performance of date operations.
*/
void DateTimeConfigurationChangeNotification(
TimeZoneDetection time_zone_detection = TimeZoneDetection::kSkip);
/**
* Notification that the embedder has changed the locale. V8 keeps a cache of
* various values used for locale computation. This notification will reset
* those cached values for the current context so that locale configuration
* changes would be reflected.
*
* This API should not be called more than needed as it will negatively impact
* the performance of locale operations.
*/
void LocaleConfigurationChangeNotification();
Isolate() = delete;
~Isolate() = delete;
Isolate(const Isolate&) = delete;
Isolate& operator=(const Isolate&) = delete;
// Deleting operator new and delete here is allowed as ctor and dtor is also
// deleted.
void* operator new(size_t size) = delete;
void* operator new[](size_t size) = delete;
void operator delete(void*, size_t) = delete;
void operator delete[](void*, size_t) = delete;
private:
template <class K, class V, class Traits>
friend class PersistentValueMapBase;
internal::Address* GetDataFromSnapshotOnce(size_t index);
void ReportExternalAllocationLimitReached();
};
class V8_EXPORT StartupData {
public:
/**
* Whether the data created can be rehashed and and the hash seed can be
* recomputed when deserialized.
* Only valid for StartupData returned by SnapshotCreator::CreateBlob().
*/
bool CanBeRehashed() const;
/**
* Allows embedders to verify whether the data is valid for the current
* V8 instance.
*/
bool IsValid() const;
const char* data;
int raw_size;
};
/**
* EntropySource is used as a callback function when v8 needs a source
* of entropy.
*/
using EntropySource = bool (*)(unsigned char* buffer, size_t length);
/**
* 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.
*
* \param 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.
*/
using ReturnAddressLocationResolver =
uintptr_t (*)(uintptr_t return_addr_location);
/**
* Container class for static utility functions.
*/
class V8_EXPORT V8 {
public:
/**
* Hand startup data to V8, in case the embedder has chosen to build
* V8 with external startup data.
*
* Note:
* - By default the startup data is linked into the V8 library, in which
* case this function is not meaningful.
* - If this needs to be called, it needs to be called before V8
* tries to make use of its built-ins.
* - To avoid unnecessary copies of data, V8 will point directly into the
* given data blob, so pretty please keep it around until V8 exit.
* - Compression of the startup blob might be useful, but needs to
* handled entirely on the embedders' side.
* - The call will abort if the data is invalid.
*/
static void SetSnapshotDataBlob(StartupData* startup_blob);
/** Set the callback to invoke in case of Dcheck failures. */
static void SetDcheckErrorHandler(DcheckErrorCallback that);
/**
* Sets V8 flags from a string.
*/
static void SetFlagsFromString(const char* str);
static void SetFlagsFromString(const char* str, size_t length);
/**
* Sets V8 flags from the command line.
*/
static void SetFlagsFromCommandLine(int* argc,
char** argv,
bool remove_flags);
/** Get the version string. */
static const char* GetVersion();
/**
* Initializes V8. This function needs to be called before the first Isolate
* is created. It always returns true.
*/
V8_INLINE static bool Initialize() {
const int kBuildConfiguration =
(internal::PointerCompressionIsEnabled() ? kPointerCompression : 0) |
(internal::SmiValuesAre31Bits() ? k31BitSmis : 0) |
(internal::HeapSandboxIsEnabled() ? kHeapSandbox : 0);
return Initialize(kBuildConfiguration);
}
/**
* Allows the host application to provide a callback which can be used
* as a source of entropy for random number generators.
*/
static void SetEntropySource(EntropySource source);
/**
* Allows the host application to provide a callback that allows v8 to
* cooperate with a profiler that rewrites return addresses on stack.
*/
static void SetReturnAddressLocationResolver(
ReturnAddressLocationResolver return_address_resolver);
/**
* Releases any resources used by v8 and stops any utility threads
* that may be running. Note that disposing v8 is permanent, it
* cannot be reinitialized.
*
* It should generally not be necessary to dispose v8 before exiting
* a process, this should happen automatically. It is only necessary
* to use if the process needs the resources taken up by v8.
*/
static bool Dispose();
/**
* Initialize the ICU library bundled with V8. The embedder should only
* invoke this method when using the bundled ICU. Returns true on success.
*
* If V8 was compiled with the ICU data in an external file, the location
* of the data file has to be provided.
*/
static bool InitializeICU(const char* icu_data_file = nullptr);
/**
* Initialize the ICU library bundled with V8. The embedder should only
* invoke this method when using the bundled ICU. If V8 was compiled with
* the ICU data in an external file and when the default location of that
* file should be used, a path to the executable must be provided.
* Returns true on success.
*
* The default is a file called icudtl.dat side-by-side with the executable.
*
* Optionally, the location of the data file can be provided to override the
* default.
*/
static bool InitializeICUDefaultLocation(const char* exec_path,
const char* icu_data_file = nullptr);
/**
* Initialize the external startup data. The embedder only needs to
* invoke this method when external startup data was enabled in a build.
*
* If V8 was compiled with the startup data in an external file, then
* V8 needs to be given those external files during startup. There are
* three ways to do this:
* - InitializeExternalStartupData(const char*)
* This will look in the given directory for the file "snapshot_blob.bin".
* - InitializeExternalStartupDataFromFile(const char*)
* As above, but will directly use the given file name.
* - Call SetSnapshotDataBlob.
* This will read the blobs from the given data structure and will
* not perform any file IO.
*/
static void InitializeExternalStartupData(const char* directory_path);
static void InitializeExternalStartupDataFromFile(const char* snapshot_blob);
/**
* Sets the v8::Platform to use. This should be invoked before V8 is
* initialized.
*/
static void InitializePlatform(Platform* platform);
/**
* Clears all references to the v8::Platform. This should be invoked after
* V8 was disposed.
*/
static void ShutdownPlatform();
#if V8_OS_POSIX
/**
* Give the V8 signal handler a chance to handle a fault.
*
* This function determines whether a memory access violation can be recovered
* by V8. If so, it will return true and modify context to return to a code
* fragment that can recover from the fault. Otherwise, TryHandleSignal will
* return false.
*
* The parameters to this function correspond to those passed to a Linux
* signal handler.
*
* \param signal_number The signal number.
*
* \param info A pointer to the siginfo_t structure provided to the signal
* handler.
*
* \param context The third argument passed to the Linux signal handler, which
* points to a ucontext_t structure.
*/
V8_DEPRECATED("Use TryHandleWebAssemblyTrapPosix")
static bool TryHandleSignal(int signal_number, void* info, void* context);
#endif // V8_OS_POSIX
/**
* Activate trap-based bounds checking for WebAssembly.
*
* \param use_v8_signal_handler Whether V8 should install its own signal
* handler or rely on the embedder's.
*/
static bool EnableWebAssemblyTrapHandler(bool use_v8_signal_handler);
#if defined(V8_OS_WIN)
/**
* On Win64, by default V8 does not emit unwinding data for jitted code,
* which means the OS cannot walk the stack frames and the system Structured
* Exception Handling (SEH) cannot unwind through V8-generated code:
* https://code.google.com/p/v8/issues/detail?id=3598.
*
* This function allows embedders to register a custom exception handler for
* exceptions in V8-generated code.
*/
static void SetUnhandledExceptionCallback(
UnhandledExceptionCallback unhandled_exception_callback);
#endif
/**
* Get statistics about the shared memory usage.
*/
static void GetSharedMemoryStatistics(SharedMemoryStatistics* statistics);
/**
* Notifies V8 that the process is cross-origin-isolated, which enables
* defining the SharedArrayBuffer function on the global object of Contexts.
*/
V8_DEPRECATED(
"Use the command line argument --enable-sharedarraybuffer-per-context "
"together with SetSharedArrayBufferConstructorEnabledCallback")
static void SetIsCrossOriginIsolated();
private:
V8();
enum BuildConfigurationFeatures {
kPointerCompression = 1 << 0,
k31BitSmis = 1 << 1,
kHeapSandbox = 1 << 2,
};
/**
* Checks that the embedder build configuration is compatible with
* the V8 binary and if so initializes V8.
*/
static bool Initialize(int build_config);
static internal::Address* GlobalizeReference(internal::Isolate* isolate,
internal::Address* handle);
static internal::Address* GlobalizeTracedReference(internal::Isolate* isolate,
internal::Address* handle,
internal::Address* slot,
bool has_destructor);
static void MoveGlobalReference(internal::Address** from,
internal::Address** to);
static void MoveTracedGlobalReference(internal::Address** from,
internal::Address** to);
static void CopyTracedGlobalReference(const internal::Address* const* from,
internal::Address** to);
static internal::Address* CopyGlobalReference(internal::Address* from);
static void DisposeGlobal(internal::Address* global_handle);
static void DisposeTracedGlobal(internal::Address* global_handle);
static void MakeWeak(internal::Address* location, void* data,
WeakCallbackInfo<void>::Callback weak_callback,
WeakCallbackType type);
static void MakeWeak(internal::Address** location_addr);
static void* ClearWeak(internal::Address* location);
static void SetFinalizationCallbackTraced(
internal::Address* location, void* parameter,
WeakCallbackInfo<void>::Callback callback);
static void AnnotateStrongRetainer(internal::Address* location,
const char* label);
static Value* Eternalize(Isolate* isolate, Value* handle);
template <class K, class V, class T>
friend class PersistentValueMapBase;
static void FromJustIsNothing();
static void ToLocalEmpty();
static void InternalFieldOutOfBounds(int index);
template <class T>
friend class BasicTracedReference;
template <class T>
friend class Global;
template <class T> friend class Local;
template <class T>
friend class MaybeLocal;
template <class T>
friend class Maybe;
template <class T>
friend class TracedGlobal;
friend class TracedReferenceBase;
template <class T>
friend class TracedReference;
template <class T>
friend class WeakCallbackInfo;
template <class T> friend class Eternal;
template <class T> friend class PersistentBase;
template <class T, class M> friend class Persistent;
friend class Context;
};
/**
* Helper class to create a snapshot data blob.
*
* The Isolate used by a SnapshotCreator is owned by it, and will be entered
* and exited by the constructor and destructor, respectively; The destructor
* will also destroy the Isolate. Experimental language features, including
* those available by default, are not available while creating a snapshot.
*/
class V8_EXPORT SnapshotCreator {
public:
enum class FunctionCodeHandling { kClear, kKeep };
/**
* Initialize and enter an isolate, and set it up for serialization.
* The isolate is either created from scratch or from an existing snapshot.
* The caller keeps ownership of the argument snapshot.
* \param existing_blob existing snapshot from which to create this one.
* \param external_references a null-terminated array of external references
* that must be equivalent to CreateParams::external_references.
*/
SnapshotCreator(Isolate* isolate,
const intptr_t* external_references = nullptr,
StartupData* existing_blob = nullptr);
/**
* Create and enter an isolate, and set it up for serialization.
* The isolate is either created from scratch or from an existing snapshot.
* The caller keeps ownership of the argument snapshot.
* \param existing_blob existing snapshot from which to create this one.
* \param external_references a null-terminated array of external references
* that must be equivalent to CreateParams::external_references.
*/
SnapshotCreator(const intptr_t* external_references = nullptr,
StartupData* existing_blob = nullptr);
/**
* Destroy the snapshot creator, and exit and dispose of the Isolate
* associated with it.
*/
~SnapshotCreator();
/**
* \returns the isolate prepared by the snapshot creator.
*/
Isolate* GetIsolate();
/**
* Set the default context to be included in the snapshot blob.
* The snapshot will not contain the global proxy, and we expect one or a
* global object template to create one, to be provided upon deserialization.
*
* \param callback optional callback to serialize internal fields.
*/
void SetDefaultContext(Local<Context> context,
SerializeInternalFieldsCallback callback =
SerializeInternalFieldsCallback());
/**
* Add additional context to be included in the snapshot blob.
* The snapshot will include the global proxy.
*
* \param callback optional callback to serialize internal fields.
*
* \returns the index of the context in the snapshot blob.
*/
size_t AddContext(Local<Context> context,
SerializeInternalFieldsCallback callback =
SerializeInternalFieldsCallback());
/**
* Attach arbitrary V8::Data to the context snapshot, which can be retrieved
* via Context::GetDataFromSnapshot after deserialization. This data does not
* survive when a new snapshot is created from an existing snapshot.
* \returns the index for retrieval.
*/
template <class T>
V8_INLINE size_t AddData(Local<Context> context, Local<T> object);
/**
* Attach arbitrary V8::Data to the isolate snapshot, which can be retrieved
* via Isolate::GetDataFromSnapshot after deserialization. This data does not
* survive when a new snapshot is created from an existing snapshot.
* \returns the index for retrieval.
*/
template <class T>
V8_INLINE size_t AddData(Local<T> object);
/**
* Created a snapshot data blob.
* This must not be called from within a handle scope.
* \param function_code_handling whether to include compiled function code
* in the snapshot.
* \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
* caller acquires ownership of the data array in the return value.
*/
StartupData CreateBlob(FunctionCodeHandling function_code_handling);
// Disallow copying and assigning.
SnapshotCreator(const SnapshotCreator&) = delete;
void operator=(const SnapshotCreator&) = delete;
private:
size_t AddData(Local<Context> context, internal::Address object);
size_t AddData(internal::Address object);
void* data_;
};
/**
* A simple Maybe type, representing an object which may or may not have a
* value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.
*
* If an API method returns a Maybe<>, the API method can potentially fail
* either because an exception is thrown, or because an exception is pending,
* e.g. because a previous API call threw an exception that hasn't been caught
* yet, or because a TerminateExecution exception was thrown. In that case, a
* "Nothing" value is returned.
*/
template <class T>
class Maybe {
public:
V8_INLINE bool IsNothing() const { return !has_value_; }
V8_INLINE bool IsJust() const { return has_value_; }
/**
* An alias for |FromJust|. Will crash if the Maybe<> is nothing.
*/
V8_INLINE T ToChecked() const { return FromJust(); }
/**
* Short-hand for ToChecked(), which doesn't return a value. To be used, where
* the actual value of the Maybe is not needed like Object::Set.
*/
V8_INLINE void Check() const {
if (V8_UNLIKELY(!IsJust())) V8::FromJustIsNothing();
}
/**
* Converts this Maybe<> to a value of type T. If this Maybe<> is
* nothing (empty), |false| is returned and |out| is left untouched.
*/
V8_WARN_UNUSED_RESULT V8_INLINE bool To(T* out) const {
if (V8_LIKELY(IsJust())) *out = value_;
return IsJust();
}
/**
* Converts this Maybe<> to a value of type T. If this Maybe<> is
* nothing (empty), V8 will crash the process.
*/
V8_INLINE T FromJust() const {
if (V8_UNLIKELY(!IsJust())) V8::FromJustIsNothing();
return value_;
}
/**
* Converts this Maybe<> to a value of type T, using a default value if this
* Maybe<> is nothing (empty).
*/
V8_INLINE T FromMaybe(const T& default_value) const {
return has_value_ ? value_ : default_value;
}
V8_INLINE bool operator==(const Maybe& other) const {
return (IsJust() == other.IsJust()) &&
(!IsJust() || FromJust() == other.FromJust());
}
V8_INLINE bool operator!=(const Maybe& other) const {
return !operator==(other);
}
private:
Maybe() : has_value_(false) {}
explicit Maybe(const T& t) : has_value_(true), value_(t) {}
bool has_value_;
T value_;
template <class U>
friend Maybe<U> Nothing();
template <class U>
friend Maybe<U> Just(const U& u);
};
template <class T>
inline Maybe<T> Nothing() {
return Maybe<T>();
}
template <class T>
inline Maybe<T> Just(const T& t) {
return Maybe<T>(t);
}
// A template specialization of Maybe<T> for the case of T = void.
template <>
class Maybe<void> {
public:
V8_INLINE bool IsNothing() const { return !is_valid_; }
V8_INLINE bool IsJust() const { return is_valid_; }
V8_INLINE bool operator==(const Maybe& other) const {
return IsJust() == other.IsJust();
}
V8_INLINE bool operator!=(const Maybe& other) const {
return !operator==(other);
}
private:
struct JustTag {};
Maybe() : is_valid_(false) {}
explicit Maybe(JustTag) : is_valid_(true) {}
bool is_valid_;
template <class U>
friend Maybe<U> Nothing();
friend Maybe<void> JustVoid();
};
inline Maybe<void> JustVoid() { return Maybe<void>(Maybe<void>::JustTag()); }
/**
* An external exception handler.
*/
class V8_EXPORT TryCatch {
public:
/**
* Creates a new try/catch block and registers it with v8. Note that
* all TryCatch blocks should be stack allocated because the memory
* location itself is compared against JavaScript try/catch blocks.
*/
explicit TryCatch(Isolate* isolate);
/**
* Unregisters and deletes this try/catch block.
*/
~TryCatch();
/**
* Returns true if an exception has been caught by this try/catch block.
*/
bool HasCaught() const;
/**
* For certain types of exceptions, it makes no sense to continue execution.
*
* If CanContinue returns false, the correct action is to perform any C++
* cleanup needed and then return. If CanContinue returns false and
* HasTerminated returns true, it is possible to call
* CancelTerminateExecution in order to continue calling into the engine.
*/
bool CanContinue() const;
/**
* Returns true if an exception has been caught due to script execution
* being terminated.
*
* There is no JavaScript representation of an execution termination
* exception. Such exceptions are thrown when the TerminateExecution
* methods are called to terminate a long-running script.
*
* If such an exception has been thrown, HasTerminated will return true,
* indicating that it is possible to call CancelTerminateExecution in order
* to continue calling into the engine.
*/
bool HasTerminated() const;
/**
* Throws the exception caught by this TryCatch in a way that avoids
* it being caught again by this same TryCatch. As with ThrowException
* it is illegal to execute any JavaScript operations after calling
* ReThrow; the caller must return immediately to where the exception
* is caught.
*/
Local<Value> ReThrow();
/**
* Returns the exception caught by this try/catch block. If no exception has
* been caught an empty handle is returned.
*/
Local<Value> Exception() const;
/**
* Returns the .stack property of an object. If no .stack
* property is present an empty handle is returned.
*/
V8_WARN_UNUSED_RESULT static MaybeLocal<Value> StackTrace(
Local<Context> context, Local<Value> exception);
/**
* Returns the .stack property of the thrown object. If no .stack property is
* present or if this try/catch block has not caught an exception, an empty
* handle is returned.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> StackTrace(
Local<Context> context) const;
/**
* Returns the message associated with this exception. If there is
* no message associated an empty handle is returned.
*/
Local<v8::Message> Message() const;
/**
* Clears any exceptions that may have been caught by this try/catch block.
* After this method has been called, HasCaught() will return false. Cancels
* the scheduled exception if it is caught and ReThrow() is not called before.
*
* It is not necessary to clear a try/catch block before using it again; if
* another exception is thrown the previously caught exception will just be
* overwritten. However, it is often a good idea since it makes it easier
* to determine which operation threw a given exception.
*/
void Reset();
/**
* Set verbosity of the external exception handler.
*
* By default, exceptions that are caught by an external exception
* handler are not reported. Call SetVerbose with true on an
* external exception handler to have exceptions caught by the
* handler reported as if they were not caught.
*/
void SetVerbose(bool value);
/**
* Returns true if verbosity is enabled.
*/
bool IsVerbose() const;
/**
* Set whether or not this TryCatch should capture a Message object
* which holds source information about where the exception
* occurred. True by default.
*/
void SetCaptureMessage(bool value);
/**
* There are cases when the raw address of C++ TryCatch object cannot be
* used for comparisons with addresses into the JS stack. The cases are:
* 1) ARM, ARM64 and MIPS simulators which have separate JS stack.
* 2) Address sanitizer allocates local C++ object in the heap when
* UseAfterReturn mode is enabled.
* This method returns address that can be used for comparisons with
* addresses into the JS stack. When neither simulator nor ASAN's
* UseAfterReturn is enabled, then the address returned will be the address
* of the C++ try catch handler itself.
*/
static void* JSStackComparableAddress(TryCatch* handler) {
if (handler == nullptr) return nullptr;
return handler->js_stack_comparable_address_;
}
TryCatch(const TryCatch&) = delete;
void operator=(const TryCatch&) = delete;
private:
// Declaring operator new and delete as deleted is not spec compliant.
// Therefore declare them private instead to disable dynamic alloc
void* operator new(size_t size);
void* operator new[](size_t size);
void operator delete(void*, size_t);
void operator delete[](void*, size_t);
void ResetInternal();
internal::Isolate* isolate_;
TryCatch* next_;
void* exception_;
void* message_obj_;
void* js_stack_comparable_address_;
bool is_verbose_ : 1;
bool can_continue_ : 1;
bool capture_message_ : 1;
bool rethrow_ : 1;
bool has_terminated_ : 1;
friend class internal::Isolate;
};
// --- Context ---
/**
* A container for extension names.
*/
class V8_EXPORT ExtensionConfiguration {
public:
ExtensionConfiguration() : name_count_(0), names_(nullptr) {}
ExtensionConfiguration(int name_count, const char* names[])
: name_count_(name_count), names_(names) { }
const char** begin() const { return &names_[0]; }
const char** end() const { return &names_[name_count_]; }
private:
const int name_count_;
const char** names_;
};
/**
* A sandboxed execution context with its own set of built-in objects
* and functions.
*/
class V8_EXPORT Context : public Data {
public:
/**
* Returns the global proxy object.
*
* Global proxy object is a thin wrapper whose prototype points to actual
* context's global object with the properties like Object, etc. This is done
* that way for security reasons (for more details see
* https://wiki.mozilla.org/Gecko:SplitWindow).
*
* Please note that changes to global proxy object prototype most probably
* would break VM---v8 expects only global object as a prototype of global
* proxy object.
*/
Local<Object> Global();
/**
* Detaches the global object from its context before
* the global object can be reused to create a new context.
*/
void DetachGlobal();
/**
* Creates a new context and returns a handle to the newly allocated
* context.
*
* \param isolate The isolate in which to create the context.
*
* \param extensions An optional extension configuration containing
* the extensions to be installed in the newly created context.
*
* \param global_template An optional object template from which the
* global object for the newly created context will be created.
*
* \param global_object An optional global object to be reused for
* the newly created context. This global object must have been
* created by a previous call to Context::New with the same global
* template. The state of the global object will be completely reset
* and only object identify will remain.
*/
static Local<Context> New(
Isolate* isolate, ExtensionConfiguration* extensions = nullptr,
MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
MaybeLocal<Value> global_object = MaybeLocal<Value>(),
DeserializeInternalFieldsCallback internal_fields_deserializer =
DeserializeInternalFieldsCallback(),
MicrotaskQueue* microtask_queue = nullptr);
/**
* Create a new context from a (non-default) context snapshot. There
* is no way to provide a global object template since we do not create
* a new global object from template, but we can reuse a global object.
*
* \param isolate See v8::Context::New.
*
* \param context_snapshot_index The index of the context snapshot to
* deserialize from. Use v8::Context::New for the default snapshot.
*
* \param embedder_fields_deserializer Optional callback to deserialize
* internal fields. It should match the SerializeInternalFieldCallback used
* to serialize.
*
* \param extensions See v8::Context::New.
*
* \param global_object See v8::Context::New.
*/
static MaybeLocal<Context> FromSnapshot(
Isolate* isolate, size_t context_snapshot_index,
DeserializeInternalFieldsCallback embedder_fields_deserializer =
DeserializeInternalFieldsCallback(),
ExtensionConfiguration* extensions = nullptr,
MaybeLocal<Value> global_object = MaybeLocal<Value>(),
MicrotaskQueue* microtask_queue = nullptr);
/**
* Returns an global object that isn't backed by an actual context.
*
* The global template needs to have access checks with handlers installed.
* If an existing global object is passed in, the global object is detached
* from its context.
*
* Note that this is different from a detached context where all accesses to
* the global proxy will fail. Instead, the access check handlers are invoked.
*
* It is also not possible to detach an object returned by this method.
* Instead, the access check handlers need to return nothing to achieve the
* same effect.
*
* It is possible, however, to create a new context from the global object
* returned by this method.
*/
static MaybeLocal<Object> NewRemoteContext(
Isolate* isolate, Local<ObjectTemplate> global_template,
MaybeLocal<Value> global_object = MaybeLocal<Value>());
/**
* Sets the security token for the context. To access an object in
* another context, the security tokens must match.
*/
void SetSecurityToken(Local<Value> token);
/** Restores the security token to the default value. */
void UseDefaultSecurityToken();
/** Returns the security token of this context.*/
Local<Value> GetSecurityToken();
/**
* Enter this context. After entering a context, all code compiled
* and run is compiled and run in this context. If another context
* is already entered, this old context is saved so it can be
* restored when the new context is exited.
*/
void Enter();
/**
* Exit this context. Exiting the current context restores the
* context that was in place when entering the current context.
*/
void Exit();
/** Returns the isolate associated with a current context. */
Isolate* GetIsolate();
/** Returns the microtask queue associated with a current context. */
MicrotaskQueue* GetMicrotaskQueue();
/**
* The field at kDebugIdIndex used to be reserved for the inspector.
* It now serves no purpose.
*/
enum EmbedderDataFields { kDebugIdIndex = 0 };
/**
* Return the number of fields allocated for embedder data.
*/
uint32_t GetNumberOfEmbedderDataFields();
/**
* Gets the embedder data with the given index, which must have been set by a
* previous call to SetEmbedderData with the same index.
*/
V8_INLINE Local<Value> GetEmbedderData(int index);
/**
* Gets the binding object used by V8 extras. Extra natives get a reference
* to this object and can use it to "export" functionality by adding
* properties. Extra natives can also "import" functionality by accessing
* properties added by the embedder using the V8 API.
*/
Local<Object> GetExtrasBindingObject();
/**
* Sets the embedder data with the given index, growing the data as
* needed. Note that index 0 currently has a special meaning for Chrome's
* debugger.
*/
void SetEmbedderData(int index, Local<Value> value);
/**
* Gets a 2-byte-aligned native pointer from the embedder data with the given
* index, which must have been set by a previous call to
* SetAlignedPointerInEmbedderData with the same index. Note that index 0
* currently has a special meaning for Chrome's debugger.
*/
V8_INLINE void* GetAlignedPointerFromEmbedderData(int index);
/**
* Sets a 2-byte-aligned native pointer in the embedder data with the given
* index, growing the data as needed. Note that index 0 currently has a
* special meaning for Chrome's debugger.
*/
void SetAlignedPointerInEmbedderData(int index, void* value);
/**
* Control whether code generation from strings is allowed. Calling
* this method with false will disable 'eval' and the 'Function'
* constructor for code running in this context. If 'eval' or the
* 'Function' constructor are used an exception will be thrown.
*
* If code generation from strings is not allowed the
* V8::AllowCodeGenerationFromStrings callback will be invoked if
* set before blocking the call to 'eval' or the 'Function'
* constructor. If that callback returns true, the call will be
* allowed, otherwise an exception will be thrown. If no callback is
* set an exception will be thrown.
*/
void AllowCodeGenerationFromStrings(bool allow);
/**
* Returns true if code generation from strings is allowed for the context.
* For more details see AllowCodeGenerationFromStrings(bool) documentation.
*/
bool IsCodeGenerationFromStringsAllowed();
/**
* Sets the error description for the exception that is thrown when
* code generation from strings is not allowed and 'eval' or the 'Function'
* constructor are called.
*/
void SetErrorMessageForCodeGenerationFromStrings(Local<String> message);
/**
* Return data that was previously attached to the context snapshot via
* SnapshotCreator, and removes the reference to it.
* Repeated call with the same index returns an empty MaybeLocal.
*/
template <class T>
V8_INLINE MaybeLocal<T> GetDataFromSnapshotOnce(size_t index);
/**
* If callback is set, abort any attempt to execute JavaScript in this
* context, call the specified callback, and throw an exception.
* To unset abort, pass nullptr as callback.
*/
using AbortScriptExecutionCallback = void (*)(Isolate* isolate,
Local<Context> context);
void SetAbortScriptExecution(AbortScriptExecutionCallback callback);
/**
* Returns the value that was set or restored by
* SetContinuationPreservedEmbedderData(), if any.
*/
Local<Value> GetContinuationPreservedEmbedderData() const;
/**
* Sets a value that will be stored on continuations and reset while the
* continuation runs.
*/
void SetContinuationPreservedEmbedderData(Local<Value> context);
/**
* Set or clear hooks to be invoked for promise lifecycle operations.
* To clear a hook, set it to an empty v8::Function. Each function will
* receive the observed promise as the first argument. If a chaining
* operation is used on a promise, the init will additionally receive
* the parent promise as the second argument.
*/
void SetPromiseHooks(Local<Function> init_hook,
Local<Function> before_hook,
Local<Function> after_hook,
Local<Function> resolve_hook);
/**
* Stack-allocated class which sets the execution context for all
* operations executed within a local scope.
*/
class V8_NODISCARD Scope {
public:
explicit V8_INLINE Scope(Local<Context> context) : context_(context) {
context_->Enter();
}
V8_INLINE ~Scope() { context_->Exit(); }
private:
Local<Context> context_;
};
/**
* Stack-allocated class to support the backup incumbent settings object
* stack.
* https://html.spec.whatwg.org/multipage/webappapis.html#backup-incumbent-settings-object-stack
*/
class V8_EXPORT V8_NODISCARD BackupIncumbentScope final {
public:
/**
* |backup_incumbent_context| is pushed onto the backup incumbent settings
* object stack.
*/
explicit BackupIncumbentScope(Local<Context> backup_incumbent_context);
~BackupIncumbentScope();
/**
* Returns address that is comparable with JS stack address. Note that JS
* stack may be allocated separately from the native stack. See also
* |TryCatch::JSStackComparableAddress| for details.
*/
uintptr_t JSStackComparableAddress() const {
return js_stack_comparable_address_;
}
private:
friend class internal::Isolate;
Local<Context> backup_incumbent_context_;
uintptr_t js_stack_comparable_address_ = 0;
const BackupIncumbentScope* prev_ = nullptr;
};
V8_INLINE static Context* Cast(Data* data);
private:
friend class Value;
friend class Script;
friend class Object;
friend class Function;
static void CheckCast(Data* obj);
internal::Address* GetDataFromSnapshotOnce(size_t index);
Local<Value> SlowGetEmbedderData(int index);
void* SlowGetAlignedPointerFromEmbedderData(int index);
};
/**
* Multiple threads in V8 are allowed, but only one thread at a time is allowed
* to use any given V8 isolate, see the comments in the Isolate class. The
* definition of 'using a V8 isolate' includes accessing handles or holding onto
* object pointers obtained from V8 handles while in the particular V8 isolate.
* It is up to the user of V8 to ensure, perhaps with locking, that this
* constraint is not violated. In addition to any other synchronization
* mechanism that may be used, the v8::Locker and v8::Unlocker classes must be
* used to signal thread switches to V8.
*
* v8::Locker is a scoped lock object. While it's active, i.e. between its
* construction and destruction, the current thread is allowed to use the locked
* isolate. V8 guarantees that an isolate can be locked by at most one thread at
* any time. In other words, the scope of a v8::Locker is a critical section.
*
* Sample usage:
* \code
* ...
* {
* v8::Locker locker(isolate);
* v8::Isolate::Scope isolate_scope(isolate);
* ...
* // Code using V8 and isolate goes here.
* ...
* } // Destructor called here
* \endcode
*
* If you wish to stop using V8 in a thread A you can do this either by
* destroying the v8::Locker object as above or by constructing a v8::Unlocker
* object:
*
* \code
* {
* isolate->Exit();
* v8::Unlocker unlocker(isolate);
* ...
* // Code not using V8 goes here while V8 can run in another thread.
* ...
* } // Destructor called here.
* isolate->Enter();
* \endcode
*
* The Unlocker object is intended for use in a long-running callback from V8,
* where you want to release the V8 lock for other threads to use.
*
* The v8::Locker is a recursive lock, i.e. you can lock more than once in a
* given thread. This can be useful if you have code that can be called either
* from code that holds the lock or from code that does not. The Unlocker is
* not recursive so you can not have several Unlockers on the stack at once, and
* you can not use an Unlocker in a thread that is not inside a Locker's scope.
*
* An unlocker will unlock several lockers if it has to and reinstate the
* correct depth of locking on its destruction, e.g.:
*
* \code
* // V8 not locked.
* {
* v8::Locker locker(isolate);
* Isolate::Scope isolate_scope(isolate);
* // V8 locked.
* {
* v8::Locker another_locker(isolate);
* // V8 still locked (2 levels).
* {
* isolate->Exit();
* v8::Unlocker unlocker(isolate);
* // V8 not locked.
* }
* isolate->Enter();
* // V8 locked again (2 levels).
* }
* // V8 still locked (1 level).
* }
* // V8 Now no longer locked.
* \endcode
*/
class V8_EXPORT Unlocker {
public:
/**
* Initialize Unlocker for a given Isolate.
*/
V8_INLINE explicit Unlocker(Isolate* isolate) { Initialize(isolate); }
~Unlocker();
private:
void Initialize(Isolate* isolate);
internal::Isolate* isolate_;
};
class V8_EXPORT Locker {
public:
/**
* Initialize Locker for a given Isolate.
*/
V8_INLINE explicit Locker(Isolate* isolate) { Initialize(isolate); }
~Locker();
/**
* Returns whether or not the locker for a given isolate, is locked by the
* current thread.
*/
static bool IsLocked(Isolate* isolate);
/**
* Returns whether v8::Locker is being used by this V8 instance.
*/
static bool IsActive();
// Disallow copying and assigning.
Locker(const Locker&) = delete;
void operator=(const Locker&) = delete;
private:
void Initialize(Isolate* isolate);
bool has_lock_;
bool top_level_;
internal::Isolate* isolate_;
};
/**
* Various helpers for skipping over V8 frames in a given stack.
*
* The unwinder API is only supported on the x64, ARM64 and ARM32 architectures.
*/
class V8_EXPORT Unwinder {
public:
/**
* Attempt to unwind the stack to the most recent C++ frame. This function is
* signal-safe and does not access any V8 state and thus doesn't require an
* Isolate.
*
* The unwinder needs to know the location of the JS Entry Stub (a piece of
* code that is run when C++ code calls into generated JS code). This is used
* for edge cases where the current frame is being constructed or torn down
* when the stack sample occurs.
*
* The unwinder also needs the virtual memory range of all possible V8 code
* objects. There are two ranges required - the heap code range and the range
* for code embedded in the binary.
*
* Available on x64, ARM64 and ARM32.
*
* \param code_pages A list of all of the ranges in which V8 has allocated
* executable code. The caller should obtain this list by calling
* Isolate::CopyCodePages() during the same interrupt/thread suspension that
* captures the stack.
* \param register_state The current registers. This is an in-out param that
* will be overwritten with the register values after unwinding, on success.
* \param stack_base The resulting stack pointer and frame pointer values are
* bounds-checked against the stack_base and the original stack pointer value
* to ensure that they are valid locations in the given stack. If these values
* or any intermediate frame pointer values used during unwinding are ever out
* of these bounds, unwinding will fail.
*
* \return True on success.
*/
static bool TryUnwindV8Frames(const JSEntryStubs& entry_stubs,
size_t code_pages_length,
const MemoryRange* code_pages,
RegisterState* register_state,
const void* stack_base);
/**
* Whether the PC is within the V8 code range represented by code_pages.
*
* If this returns false, then calling UnwindV8Frames() with the same PC
* and unwind_state will always fail. If it returns true, then unwinding may
* (but not necessarily) be successful.
*
* Available on x64, ARM64 and ARM32
*/
static bool PCIsInV8(size_t code_pages_length, const MemoryRange* code_pages,
void* pc);
};
// --- Implementation ---
template <class T>
Local<T> Local<T>::New(Isolate* isolate, Local<T> that) {
return New(isolate, that.val_);
}
template <class T>
Local<T> Local<T>::New(Isolate* isolate, const PersistentBase<T>& that) {
return New(isolate, that.val_);
}
template <class T>
Local<T> Local<T>::New(Isolate* isolate, const BasicTracedReference<T>& that) {
return New(isolate, *that);
}
template <class T>
Local<T> Local<T>::New(Isolate* isolate, T* that) {
if (that == nullptr) return Local<T>();
T* that_ptr = that;
internal::Address* p = reinterpret_cast<internal::Address*>(that_ptr);
return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(
reinterpret_cast<internal::Isolate*>(isolate), *p)));
}
template<class T>
template<class S>
void Eternal<T>::Set(Isolate* isolate, Local<S> handle) {
static_assert(std::is_base_of<T, S>::value, "type check");
val_ = reinterpret_cast<T*>(
V8::Eternalize(isolate, reinterpret_cast<Value*>(*handle)));
}
template <class T>
Local<T> Eternal<T>::Get(Isolate* isolate) const {
// The eternal handle will never go away, so as with the roots, we don't even
// need to open a handle.
return Local<T>(val_);
}
template <class T>
Local<T> MaybeLocal<T>::ToLocalChecked() {
if (V8_UNLIKELY(val_ == nullptr)) V8::ToLocalEmpty();
return Local<T>(val_);
}
template <class T>
void* WeakCallbackInfo<T>::GetInternalField(int index) const {
#ifdef V8_ENABLE_CHECKS
if (index < 0 || index >= kEmbedderFieldsInWeakCallback) {
V8::InternalFieldOutOfBounds(index);
}
#endif
return embedder_fields_[index];
}
template <class T>
T* PersistentBase<T>::New(Isolate* isolate, T* that) {
if (that == nullptr) return nullptr;
internal::Address* p = reinterpret_cast<internal::Address*>(that);
return reinterpret_cast<T*>(
V8::GlobalizeReference(reinterpret_cast<internal::Isolate*>(isolate),
p));
}
template <class T, class M>
template <class S, class M2>
void Persistent<T, M>::Copy(const Persistent<S, M2>& that) {
static_assert(std::is_base_of<T, S>::value, "type check");
this->Reset();
if (that.IsEmpty()) return;
internal::Address* p = reinterpret_cast<internal::Address*>(that.val_);
this->val_ = reinterpret_cast<T*>(V8::CopyGlobalReference(p));
M::Copy(that, this);
}
template <class T>
bool PersistentBase<T>::IsWeak() const {
using I = internal::Internals;
if (this->IsEmpty()) return false;
return I::GetNodeState(reinterpret_cast<internal::Address*>(this->val_)) ==
I::kNodeStateIsWeakValue;
}
template <class T>
void PersistentBase<T>::Reset() {
if (this->IsEmpty()) return;
V8::DisposeGlobal(reinterpret_cast<internal::Address*>(this->val_));
val_ = nullptr;
}
template <class T>
template <class S>
void PersistentBase<T>::Reset(Isolate* isolate, const Local<S>& other) {
static_assert(std::is_base_of<T, S>::value, "type check");
Reset();
if (other.IsEmpty()) return;
this->val_ = New(isolate, other.val_);
}
template <class T>
template <class S>
void PersistentBase<T>::Reset(Isolate* isolate,
const PersistentBase<S>& other) {
static_assert(std::is_base_of<T, S>::value, "type check");
Reset();
if (other.IsEmpty()) return;
this->val_ = New(isolate, other.val_);
}
template <class T>
template <typename P>
V8_INLINE void PersistentBase<T>::SetWeak(
P* parameter, typename WeakCallbackInfo<P>::Callback callback,
WeakCallbackType type) {
using Callback = WeakCallbackInfo<void>::Callback;
#if (__GNUC__ >= 8) && !defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-function-type"
#endif
V8::MakeWeak(reinterpret_cast<internal::Address*>(this->val_), parameter,
reinterpret_cast<Callback>(callback), type);
#if (__GNUC__ >= 8) && !defined(__clang__)
#pragma GCC diagnostic pop
#endif
}
template <class T>
void PersistentBase<T>::SetWeak() {
V8::MakeWeak(reinterpret_cast<internal::Address**>(&this->val_));
}
template <class T>
template <typename P>
P* PersistentBase<T>::ClearWeak() {
return reinterpret_cast<P*>(
V8::ClearWeak(reinterpret_cast<internal::Address*>(this->val_)));
}
template <class T>
void PersistentBase<T>::AnnotateStrongRetainer(const char* label) {
V8::AnnotateStrongRetainer(reinterpret_cast<internal::Address*>(this->val_),
label);
}
template <class T>
void PersistentBase<T>::SetWrapperClassId(uint16_t class_id) {
using I = internal::Internals;
if (this->IsEmpty()) return;
internal::Address* obj = reinterpret_cast<internal::Address*>(this->val_);
uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
*reinterpret_cast<uint16_t*>(addr) = class_id;
}
template <class T>
uint16_t PersistentBase<T>::WrapperClassId() const {
using I = internal::Internals;
if (this->IsEmpty()) return 0;
internal::Address* obj = reinterpret_cast<internal::Address*>(this->val_);
uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
return *reinterpret_cast<uint16_t*>(addr);
}
template <class T>
Global<T>::Global(Global&& other) : PersistentBase<T>(other.val_) {
if (other.val_ != nullptr) {
V8::MoveGlobalReference(reinterpret_cast<internal::Address**>(&other.val_),
reinterpret_cast<internal::Address**>(&this->val_));
other.val_ = nullptr;
}
}
template <class T>
template <class S>
Global<T>& Global<T>::operator=(Global<S>&& rhs) {
static_assert(std::is_base_of<T, S>::value, "type check");
if (this != &rhs) {
this->Reset();
if (rhs.val_ != nullptr) {
this->val_ = rhs.val_;
V8::MoveGlobalReference(
reinterpret_cast<internal::Address**>(&rhs.val_),
reinterpret_cast<internal::Address**>(&this->val_));
rhs.val_ = nullptr;
}
}
return *this;
}
template <class T>
internal::Address* BasicTracedReference<T>::New(
Isolate* isolate, T* that, void* slot, DestructionMode destruction_mode) {
if (that == nullptr) return nullptr;
internal::Address* p = reinterpret_cast<internal::Address*>(that);
return V8::GlobalizeTracedReference(
reinterpret_cast<internal::Isolate*>(isolate), p,
reinterpret_cast<internal::Address*>(slot),
destruction_mode == kWithDestructor);
}
void TracedReferenceBase::Reset() {
if (IsEmpty()) return;
V8::DisposeTracedGlobal(reinterpret_cast<internal::Address*>(val_));
SetSlotThreadSafe(nullptr);
}
v8::Local<v8::Value> TracedReferenceBase::Get(v8::Isolate* isolate) const {
if (IsEmpty()) return Local<Value>();
return Local<Value>::New(isolate, reinterpret_cast<Value*>(val_));
}
V8_INLINE bool operator==(const TracedReferenceBase& lhs,
const TracedReferenceBase& rhs) {
v8::internal::Address* a = reinterpret_cast<v8::internal::Address*>(lhs.val_);
v8::internal::Address* b = reinterpret_cast<v8::internal::Address*>(rhs.val_);
if (a == nullptr) return b == nullptr;
if (b == nullptr) return false;
return *a == *b;
}
template <typename U>
V8_INLINE bool operator==(const TracedReferenceBase& lhs,
const v8::Local<U>& rhs) {
v8::internal::Address* a = reinterpret_cast<v8::internal::Address*>(lhs.val_);
v8::internal::Address* b = reinterpret_cast<v8::internal::Address*>(*rhs);
if (a == nullptr) return b == nullptr;
if (b == nullptr) return false;
return *a == *b;
}
template <typename U>
V8_INLINE bool operator==(const v8::Local<U>& lhs,
const TracedReferenceBase& rhs) {
return rhs == lhs;
}
V8_INLINE bool operator!=(const TracedReferenceBase& lhs,
const TracedReferenceBase& rhs) {
return !(lhs == rhs);
}
template <typename U>
V8_INLINE bool operator!=(const TracedReferenceBase& lhs,
const v8::Local<U>& rhs) {
return !(lhs == rhs);
}
template <typename U>
V8_INLINE bool operator!=(const v8::Local<U>& lhs,
const TracedReferenceBase& rhs) {
return !(rhs == lhs);
}
template <class T>
template <class S>
void TracedGlobal<T>::Reset(Isolate* isolate, const Local<S>& other) {
static_assert(std::is_base_of<T, S>::value, "type check");
Reset();
if (other.IsEmpty()) return;
this->val_ = this->New(isolate, other.val_, &this->val_,
BasicTracedReference<T>::kWithDestructor);
}
template <class T>
template <class S>
TracedGlobal<T>& TracedGlobal<T>::operator=(TracedGlobal<S>&& rhs) {
static_assert(std::is_base_of<T, S>::value, "type check");
*this = std::move(rhs.template As<T>());
return *this;
}
template <class T>
template <class S>
TracedGlobal<T>& TracedGlobal<T>::operator=(const TracedGlobal<S>& rhs) {
static_assert(std::is_base_of<T, S>::value, "type check");
*this = rhs.template As<T>();
return *this;
}
template <class T>
TracedGlobal<T>& TracedGlobal<T>::operator=(TracedGlobal&& rhs) {
if (this != &rhs) {
V8::MoveTracedGlobalReference(
reinterpret_cast<internal::Address**>(&rhs.val_),
reinterpret_cast<internal::Address**>(&this->val_));
}
return *this;
}
template <class T>
TracedGlobal<T>& TracedGlobal<T>::operator=(const TracedGlobal& rhs) {
if (this != &rhs) {
this->Reset();
if (rhs.val_ != nullptr) {
V8::CopyTracedGlobalReference(
reinterpret_cast<const internal::Address* const*>(&rhs.val_),
reinterpret_cast<internal::Address**>(&this->val_));
}
}
return *this;
}
template <class T>
template <class S>
void TracedReference<T>::Reset(Isolate* isolate, const Local<S>& other) {
static_assert(std::is_base_of<T, S>::value, "type check");
this->Reset();
if (other.IsEmpty()) return;
this->SetSlotThreadSafe(
this->New(isolate, other.val_, &this->val_,
BasicTracedReference<T>::kWithoutDestructor));
}
template <class T>
template <class S>
TracedReference<T>& TracedReference<T>::operator=(TracedReference<S>&& rhs) {
static_assert(std::is_base_of<T, S>::value, "type check");
*this = std::move(rhs.template As<T>());
return *this;
}
template <class T>
template <class S>
TracedReference<T>& TracedReference<T>::operator=(
const TracedReference<S>& rhs) {
static_assert(std::is_base_of<T, S>::value, "type check");
*this = rhs.template As<T>();
return *this;
}
template <class T>
TracedReference<T>& TracedReference<T>::operator=(TracedReference&& rhs) {
if (this != &rhs) {
V8::MoveTracedGlobalReference(
reinterpret_cast<internal::Address**>(&rhs.val_),
reinterpret_cast<internal::Address**>(&this->val_));
}
return *this;
}
template <class T>
TracedReference<T>& TracedReference<T>::operator=(const TracedReference& rhs) {
if (this != &rhs) {
this->Reset();
if (rhs.val_ != nullptr) {
V8::CopyTracedGlobalReference(
reinterpret_cast<const internal::Address* const*>(&rhs.val_),
reinterpret_cast<internal::Address**>(&this->val_));
}
}
return *this;
}
void TracedReferenceBase::SetWrapperClassId(uint16_t class_id) {
using I = internal::Internals;
if (IsEmpty()) return;
internal::Address* obj = reinterpret_cast<internal::Address*>(val_);
uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
*reinterpret_cast<uint16_t*>(addr) = class_id;
}
uint16_t TracedReferenceBase::WrapperClassId() const {
using I = internal::Internals;
if (IsEmpty()) return 0;
internal::Address* obj = reinterpret_cast<internal::Address*>(val_);
uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
return *reinterpret_cast<uint16_t*>(addr);
}
template <class T>
void TracedGlobal<T>::SetFinalizationCallback(
void* parameter, typename WeakCallbackInfo<void>::Callback callback) {
V8::SetFinalizationCallbackTraced(
reinterpret_cast<internal::Address*>(this->val_), parameter, callback);
}
template <typename T>
ReturnValue<T>::ReturnValue(internal::Address* slot) : value_(slot) {}
template <typename T>
template <typename S>
void ReturnValue<T>::Set(const Global<S>& handle) {
static_assert(std::is_base_of<T, S>::value, "type check");
if (V8_UNLIKELY(handle.IsEmpty())) {
*value_ = GetDefaultValue();
} else {
*value_ = *reinterpret_cast<internal::Address*>(*handle);
}
}
template <typename T>
template <typename S>
void ReturnValue<T>::Set(const BasicTracedReference<S>& handle) {
static_assert(std::is_base_of<T, S>::value, "type check");
if (V8_UNLIKELY(handle.IsEmpty())) {
*value_ = GetDefaultValue();
} else {
*value_ = *reinterpret_cast<internal::Address*>(handle.val_);
}
}
template <typename T>
template <typename S>
void ReturnValue<T>::Set(const Local<S> handle) {
static_assert(std::is_void<T>::value || std::is_base_of<T, S>::value,
"type check");
if (V8_UNLIKELY(handle.IsEmpty())) {
*value_ = GetDefaultValue();
} else {
*value_ = *reinterpret_cast<internal::Address*>(*handle);
}
}
template<typename T>
void ReturnValue<T>::Set(double i) {
static_assert(std::is_base_of<T, Number>::value, "type check");
Set(Number::New(GetIsolate(), i));
}
template<typename T>
void ReturnValue<T>::Set(int32_t i) {
static_assert(std::is_base_of<T, Integer>::value, "type check");
using I = internal::Internals;
if (V8_LIKELY(I::IsValidSmi(i))) {
*value_ = I::IntToSmi(i);
return;
}
Set(Integer::New(GetIsolate(), i));
}
template<typename T>
void ReturnValue<T>::Set(uint32_t i) {
static_assert(std::is_base_of<T, Integer>::value, "type check");
// Can't simply use INT32_MAX here for whatever reason.
bool fits_into_int32_t = (i & (1U << 31)) == 0;
if (V8_LIKELY(fits_into_int32_t)) {
Set(static_cast<int32_t>(i));
return;
}
Set(Integer::NewFromUnsigned(GetIsolate(), i));
}
template<typename T>
void ReturnValue<T>::Set(bool value) {
static_assert(std::is_base_of<T, Boolean>::value, "type check");
using I = internal::Internals;
int root_index;
if (value) {
root_index = I::kTrueValueRootIndex;
} else {
root_index = I::kFalseValueRootIndex;
}
*value_ = *I::GetRoot(GetIsolate(), root_index);
}
template<typename T>
void ReturnValue<T>::SetNull() {
static_assert(std::is_base_of<T, Primitive>::value, "type check");
using I = internal::Internals;
*value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
}
template<typename T>
void ReturnValue<T>::SetUndefined() {
static_assert(std::is_base_of<T, Primitive>::value, "type check");
using I = internal::Internals;
*value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
}
template<typename T>
void ReturnValue<T>::SetEmptyString() {
static_assert(std::is_base_of<T, String>::value, "type check");
using I = internal::Internals;
*value_ = *I::GetRoot(GetIsolate(), I::kEmptyStringRootIndex);
}
template <typename T>
Isolate* ReturnValue<T>::GetIsolate() const {
// Isolate is always the pointer below the default value on the stack.
return *reinterpret_cast<Isolate**>(&value_[-2]);
}
template <typename T>
Local<Value> ReturnValue<T>::Get() const {
using I = internal::Internals;
if (*value_ == *I::GetRoot(GetIsolate(), I::kTheHoleValueRootIndex))
return Local<Value>(*Undefined(GetIsolate()));
return Local<Value>::New(GetIsolate(), reinterpret_cast<Value*>(value_));
}
template <typename T>
template <typename S>
void ReturnValue<T>::Set(S* whatever) {
static_assert(sizeof(S) < 0, "incompilable to prevent inadvertent misuse");
}
template <typename T>
internal::Address ReturnValue<T>::GetDefaultValue() {
// Default value is always the pointer below value_ on the stack.
return value_[-1];
}
template <typename T>
FunctionCallbackInfo<T>::FunctionCallbackInfo(internal::Address* implicit_args,
internal::Address* values,
int length)
: implicit_args_(implicit_args), values_(values), length_(length) {}
template<typename T>
Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
// values_ points to the first argument (not the receiver).
if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
return Local<Value>(reinterpret_cast<Value*>(values_ + i));
}
template<typename T>
Local<Object> FunctionCallbackInfo<T>::This() const {
// values_ points to the first argument (not the receiver).
return Local<Object>(reinterpret_cast<Object*>(values_ - 1));
}
template<typename T>
Local<Object> FunctionCallbackInfo<T>::Holder() const {
return Local<Object>(reinterpret_cast<Object*>(
&implicit_args_[kHolderIndex]));
}
template <typename T>
Local<Value> FunctionCallbackInfo<T>::NewTarget() const {
return Local<Value>(
reinterpret_cast<Value*>(&implicit_args_[kNewTargetIndex]));
}
template <typename T>
Local<Value> FunctionCallbackInfo<T>::Data() const {
return Local<Value>(reinterpret_cast<Value*>(&implicit_args_[kDataIndex]));
}
template<typename T>
Isolate* FunctionCallbackInfo<T>::GetIsolate() const {
return *reinterpret_cast<Isolate**>(&implicit_args_[kIsolateIndex]);
}
template<typename T>
ReturnValue<T> FunctionCallbackInfo<T>::GetReturnValue() const {
return ReturnValue<T>(&implicit_args_[kReturnValueIndex]);
}
template<typename T>
bool FunctionCallbackInfo<T>::IsConstructCall() const {
return !NewTarget()->IsUndefined();
}
template<typename T>
int FunctionCallbackInfo<T>::Length() const {
return length_;
}
ScriptOrigin::ScriptOrigin(
Local<Value> resource_name, Local<Integer> line_offset,
Local<Integer> column_offset, Local<Boolean> is_shared_cross_origin,
Local<Integer> script_id, Local<Value> source_map_url,
Local<Boolean> is_opaque, Local<Boolean> is_wasm, Local<Boolean> is_module,
Local<PrimitiveArray> host_defined_options)
: ScriptOrigin(
Isolate::GetCurrent(), resource_name,
line_offset.IsEmpty() ? 0 : static_cast<int>(line_offset->Value()),
column_offset.IsEmpty() ? 0
: static_cast<int>(column_offset->Value()),
!is_shared_cross_origin.IsEmpty() && is_shared_cross_origin->IsTrue(),
static_cast<int>(script_id.IsEmpty() ? -1 : script_id->Value()),
source_map_url, !is_opaque.IsEmpty() && is_opaque->IsTrue(),
!is_wasm.IsEmpty() && is_wasm->IsTrue(),
!is_module.IsEmpty() && is_module->IsTrue(), host_defined_options) {}
ScriptOrigin::ScriptOrigin(Local<Value> resource_name, int line_offset,
int column_offset, bool is_shared_cross_origin,
int script_id, Local<Value> source_map_url,
bool is_opaque, bool is_wasm, bool is_module,
Local<PrimitiveArray> host_defined_options)
: isolate_(Isolate::GetCurrent()),
resource_name_(resource_name),
resource_line_offset_(line_offset),
resource_column_offset_(column_offset),
options_(is_shared_cross_origin, is_opaque, is_wasm, is_module),
script_id_(script_id),
source_map_url_(source_map_url),
host_defined_options_(host_defined_options) {}
ScriptOrigin::ScriptOrigin(Isolate* isolate, Local<Value> resource_name,
int line_offset, int column_offset,
bool is_shared_cross_origin, int script_id,
Local<Value> source_map_url, bool is_opaque,
bool is_wasm, bool is_module,
Local<PrimitiveArray> host_defined_options)
: isolate_(isolate),
resource_name_(resource_name),
resource_line_offset_(line_offset),
resource_column_offset_(column_offset),
options_(is_shared_cross_origin, is_opaque, is_wasm, is_module),
script_id_(script_id),
source_map_url_(source_map_url),
host_defined_options_(host_defined_options) {}
Local<Value> ScriptOrigin::ResourceName() const { return resource_name_; }
Local<PrimitiveArray> ScriptOrigin::HostDefinedOptions() const {
return host_defined_options_;
}
Local<Integer> ScriptOrigin::ResourceLineOffset() const {
return v8::Integer::New(isolate_, resource_line_offset_);
}
Local<Integer> ScriptOrigin::ResourceColumnOffset() const {
return v8::Integer::New(isolate_, resource_column_offset_);
}
Local<Integer> ScriptOrigin::ScriptID() const {
return v8::Integer::New(isolate_, script_id_);
}
int ScriptOrigin::LineOffset() const { return resource_line_offset_; }
int ScriptOrigin::ColumnOffset() const { return resource_column_offset_; }
int ScriptOrigin::ScriptId() const { return script_id_; }
Local<Value> ScriptOrigin::SourceMapUrl() const { return source_map_url_; }
ScriptCompiler::Source::Source(Local<String> string, const ScriptOrigin& origin,
CachedData* data)
: source_string(string),
resource_name(origin.ResourceName()),
resource_line_offset(origin.LineOffset()),
resource_column_offset(origin.ColumnOffset()),
resource_options(origin.Options()),
source_map_url(origin.SourceMapUrl()),
host_defined_options(origin.HostDefinedOptions()),
cached_data(data) {}
ScriptCompiler::Source::Source(Local<String> string,
CachedData* data)
: source_string(string), cached_data(data) {}
ScriptCompiler::Source::~Source() {
delete cached_data;
}
const ScriptCompiler::CachedData* ScriptCompiler::Source::GetCachedData()
const {
return cached_data;
}
const ScriptOriginOptions& ScriptCompiler::Source::GetResourceOptions() const {
return resource_options;
}
Local<Boolean> Boolean::New(Isolate* isolate, bool value) {
return value ? True(isolate) : False(isolate);
}
void Template::Set(Isolate* isolate, const char* name, Local<Data> value) {
Set(String::NewFromUtf8(isolate, name, NewStringType::kInternalized)
.ToLocalChecked(),
value);
}
FunctionTemplate* FunctionTemplate::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<FunctionTemplate*>(data);
}
ObjectTemplate* ObjectTemplate::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<ObjectTemplate*>(data);
}
Signature* Signature::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<Signature*>(data);
}
AccessorSignature* AccessorSignature::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<AccessorSignature*>(data);
}
Local<Value> Object::GetInternalField(int index) {
#ifndef V8_ENABLE_CHECKS
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<A*>(this);
// Fast path: If the object is a plain JSObject, which is the common case, we
// know where to find the internal fields and can return the value directly.
auto instance_type = I::GetInstanceType(obj);
if (instance_type == I::kJSObjectType ||
instance_type == I::kJSApiObjectType ||
instance_type == I::kJSSpecialApiObjectType) {
int offset = I::kJSObjectHeaderSize + (I::kEmbedderDataSlotSize * index);
A value = I::ReadRawField<A>(obj, offset);
#ifdef V8_COMPRESS_POINTERS
// We read the full pointer value and then decompress it in order to avoid
// dealing with potential endiannes issues.
value = I::DecompressTaggedAnyField(obj, static_cast<uint32_t>(value));
#endif
internal::Isolate* isolate =
internal::IsolateFromNeverReadOnlySpaceObject(obj);
A* result = HandleScope::CreateHandle(isolate, value);
return Local<Value>(reinterpret_cast<Value*>(result));
}
#endif
return SlowGetInternalField(index);
}
void* Object::GetAlignedPointerFromInternalField(int index) {
#ifndef V8_ENABLE_CHECKS
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<A*>(this);
// Fast path: If the object is a plain JSObject, which is the common case, we
// know where to find the internal fields and can return the value directly.
auto instance_type = I::GetInstanceType(obj);
if (V8_LIKELY(instance_type == I::kJSObjectType ||
instance_type == I::kJSApiObjectType ||
instance_type == I::kJSSpecialApiObjectType)) {
int offset = I::kJSObjectHeaderSize + (I::kEmbedderDataSlotSize * index);
#ifdef V8_HEAP_SANDBOX
offset += I::kEmbedderDataSlotRawPayloadOffset;
#endif
internal::Isolate* isolate = I::GetIsolateForHeapSandbox(obj);
A value = I::ReadExternalPointerField(
isolate, obj, offset, internal::kEmbedderDataSlotPayloadTag);
return reinterpret_cast<void*>(value);
}
#endif
return SlowGetAlignedPointerFromInternalField(index);
}
String* String::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<String*>(data);
}
Local<String> String::Empty(Isolate* isolate) {
using S = internal::Address;
using I = internal::Internals;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex);
return Local<String>(reinterpret_cast<String*>(slot));
}
String::ExternalStringResource* String::GetExternalStringResource() const {
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<const A*>(this);
ExternalStringResource* result;
if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
internal::Isolate* isolate = I::GetIsolateForHeapSandbox(obj);
A value =
I::ReadExternalPointerField(isolate, obj, I::kStringResourceOffset,
internal::kExternalStringResourceTag);
result = reinterpret_cast<String::ExternalStringResource*>(value);
} else {
result = GetExternalStringResourceSlow();
}
#ifdef V8_ENABLE_CHECKS
VerifyExternalStringResource(result);
#endif
return result;
}
String::ExternalStringResourceBase* String::GetExternalStringResourceBase(
String::Encoding* encoding_out) const {
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<const A*>(this);
int type = I::GetInstanceType(obj) & I::kFullStringRepresentationMask;
*encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask);
ExternalStringResourceBase* resource;
if (type == I::kExternalOneByteRepresentationTag ||
type == I::kExternalTwoByteRepresentationTag) {
internal::Isolate* isolate = I::GetIsolateForHeapSandbox(obj);
A value =
I::ReadExternalPointerField(isolate, obj, I::kStringResourceOffset,
internal::kExternalStringResourceTag);
resource = reinterpret_cast<ExternalStringResourceBase*>(value);
} else {
resource = GetExternalStringResourceBaseSlow(encoding_out);
}
#ifdef V8_ENABLE_CHECKS
VerifyExternalStringResourceBase(resource, *encoding_out);
#endif
return resource;
}
bool Value::IsUndefined() const {
#ifdef V8_ENABLE_CHECKS
return FullIsUndefined();
#else
return QuickIsUndefined();
#endif
}
bool Value::QuickIsUndefined() const {
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<const A*>(this);
if (!I::HasHeapObjectTag(obj)) return false;
if (I::GetInstanceType(obj) != I::kOddballType) return false;
return (I::GetOddballKind(obj) == I::kUndefinedOddballKind);
}
bool Value::IsNull() const {
#ifdef V8_ENABLE_CHECKS
return FullIsNull();
#else
return QuickIsNull();
#endif
}
bool Value::QuickIsNull() const {
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<const A*>(this);
if (!I::HasHeapObjectTag(obj)) return false;
if (I::GetInstanceType(obj) != I::kOddballType) return false;
return (I::GetOddballKind(obj) == I::kNullOddballKind);
}
bool Value::IsNullOrUndefined() const {
#ifdef V8_ENABLE_CHECKS
return FullIsNull() || FullIsUndefined();
#else
return QuickIsNullOrUndefined();
#endif
}
bool Value::QuickIsNullOrUndefined() const {
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<const A*>(this);
if (!I::HasHeapObjectTag(obj)) return false;
if (I::GetInstanceType(obj) != I::kOddballType) return false;
int kind = I::GetOddballKind(obj);
return kind == I::kNullOddballKind || kind == I::kUndefinedOddballKind;
}
bool Value::IsString() const {
#ifdef V8_ENABLE_CHECKS
return FullIsString();
#else
return QuickIsString();
#endif
}
bool Value::QuickIsString() const {
using A = internal::Address;
using I = internal::Internals;
A obj = *reinterpret_cast<const A*>(this);
if (!I::HasHeapObjectTag(obj)) return false;
return (I::GetInstanceType(obj) < I::kFirstNonstringType);
}
template <class T> Value* Value::Cast(T* value) {
return static_cast<Value*>(value);
}
template <>
V8_INLINE Value* Value::Cast(Data* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Value*>(value);
}
Boolean* Boolean::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Boolean*>(data);
}
Name* Name::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Name*>(data);
}
Symbol* Symbol::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Symbol*>(data);
}
Private* Private::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<Private*>(data);
}
ModuleRequest* ModuleRequest::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<ModuleRequest*>(data);
}
Module* Module::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<Module*>(data);
}
Number* Number::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Number*>(data);
}
Integer* Integer::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Integer*>(data);
}
Int32* Int32::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Int32*>(data);
}
Uint32* Uint32::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Uint32*>(data);
}
BigInt* BigInt::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<BigInt*>(data);
}
Context* Context::Cast(v8::Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return static_cast<Context*>(data);
}
Date* Date::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Date*>(value);
}
StringObject* StringObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<StringObject*>(value);
}
SymbolObject* SymbolObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<SymbolObject*>(value);
}
NumberObject* NumberObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<NumberObject*>(value);
}
BigIntObject* BigIntObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<BigIntObject*>(value);
}
BooleanObject* BooleanObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<BooleanObject*>(value);
}
RegExp* RegExp::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<RegExp*>(value);
}
Object* Object::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Object*>(value);
}
Array* Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Array*>(value);
}
Map* Map::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Map*>(value);
}
Set* Set::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Set*>(value);
}
Promise* Promise::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Promise*>(value);
}
Proxy* Proxy::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Proxy*>(value);
}
WasmMemoryObject* WasmMemoryObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<WasmMemoryObject*>(value);
}
WasmModuleObject* WasmModuleObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<WasmModuleObject*>(value);
}
Promise::Resolver* Promise::Resolver::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Promise::Resolver*>(value);
}
ArrayBuffer* ArrayBuffer::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<ArrayBuffer*>(value);
}
ArrayBufferView* ArrayBufferView::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<ArrayBufferView*>(value);
}
TypedArray* TypedArray::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<TypedArray*>(value);
}
Uint8Array* Uint8Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Uint8Array*>(value);
}
Int8Array* Int8Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Int8Array*>(value);
}
Uint16Array* Uint16Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Uint16Array*>(value);
}
Int16Array* Int16Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Int16Array*>(value);
}
Uint32Array* Uint32Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Uint32Array*>(value);
}
Int32Array* Int32Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Int32Array*>(value);
}
Float32Array* Float32Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Float32Array*>(value);
}
Float64Array* Float64Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Float64Array*>(value);
}
BigInt64Array* BigInt64Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<BigInt64Array*>(value);
}
BigUint64Array* BigUint64Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<BigUint64Array*>(value);
}
Uint8ClampedArray* Uint8ClampedArray::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Uint8ClampedArray*>(value);
}
DataView* DataView::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<DataView*>(value);
}
SharedArrayBuffer* SharedArrayBuffer::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<SharedArrayBuffer*>(value);
}
Function* Function::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Function*>(value);
}
External* External::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<External*>(value);
}
template<typename T>
Isolate* PropertyCallbackInfo<T>::GetIsolate() const {
return *reinterpret_cast<Isolate**>(&args_[kIsolateIndex]);
}
template<typename T>
Local<Value> PropertyCallbackInfo<T>::Data() const {
return Local<Value>(reinterpret_cast<Value*>(&args_[kDataIndex]));
}
template<typename T>
Local<Object> PropertyCallbackInfo<T>::This() const {
return Local<Object>(reinterpret_cast<Object*>(&args_[kThisIndex]));
}
template<typename T>
Local<Object> PropertyCallbackInfo<T>::Holder() const {
return Local<Object>(reinterpret_cast<Object*>(&args_[kHolderIndex]));
}
template<typename T>
ReturnValue<T> PropertyCallbackInfo<T>::GetReturnValue() const {
return ReturnValue<T>(&args_[kReturnValueIndex]);
}
template <typename T>
bool PropertyCallbackInfo<T>::ShouldThrowOnError() const {
using I = internal::Internals;
if (args_[kShouldThrowOnErrorIndex] !=
I::IntToSmi(I::kInferShouldThrowMode)) {
return args_[kShouldThrowOnErrorIndex] != I::IntToSmi(I::kDontThrow);
}
return v8::internal::ShouldThrowOnError(
reinterpret_cast<v8::internal::Isolate*>(GetIsolate()));
}
Local<Primitive> Undefined(Isolate* isolate) {
using S = internal::Address;
using I = internal::Internals;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex);
return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
}
Local<Primitive> Null(Isolate* isolate) {
using S = internal::Address;
using I = internal::Internals;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kNullValueRootIndex);
return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
}
Local<Boolean> True(Isolate* isolate) {
using S = internal::Address;
using I = internal::Internals;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex);
return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
}
Local<Boolean> False(Isolate* isolate) {
using S = internal::Address;
using I = internal::Internals;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kFalseValueRootIndex);
return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
}
void Isolate::SetData(uint32_t slot, void* data) {
using I = internal::Internals;
I::SetEmbedderData(this, slot, data);
}
void* Isolate::GetData(uint32_t slot) {
using I = internal::Internals;
return I::GetEmbedderData(this, slot);
}
uint32_t Isolate::GetNumberOfDataSlots() {
using I = internal::Internals;
return I::kNumIsolateDataSlots;
}
template <class T>
MaybeLocal<T> Isolate::GetDataFromSnapshotOnce(size_t index) {
T* data = reinterpret_cast<T*>(GetDataFromSnapshotOnce(index));
if (data) internal::PerformCastCheck(data);
return Local<T>(data);
}
Local<Value> Context::GetEmbedderData(int index) {
#ifndef V8_ENABLE_CHECKS
using A = internal::Address;
using I = internal::Internals;
A ctx = *reinterpret_cast<const A*>(this);
A embedder_data =
I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
int value_offset =
I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
A value = I::ReadRawField<A>(embedder_data, value_offset);
#ifdef V8_COMPRESS_POINTERS
// We read the full pointer value and then decompress it in order to avoid
// dealing with potential endiannes issues.
value =
I::DecompressTaggedAnyField(embedder_data, static_cast<uint32_t>(value));
#endif
internal::Isolate* isolate = internal::IsolateFromNeverReadOnlySpaceObject(
*reinterpret_cast<A*>(this));
A* result = HandleScope::CreateHandle(isolate, value);
return Local<Value>(reinterpret_cast<Value*>(result));
#else
return SlowGetEmbedderData(index);
#endif
}
void* Context::GetAlignedPointerFromEmbedderData(int index) {
#ifndef V8_ENABLE_CHECKS
using A = internal::Address;
using I = internal::Internals;
A ctx = *reinterpret_cast<const A*>(this);
A embedder_data =
I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
int value_offset =
I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
#ifdef V8_HEAP_SANDBOX
value_offset += I::kEmbedderDataSlotRawPayloadOffset;
#endif
internal::Isolate* isolate = I::GetIsolateForHeapSandbox(ctx);
return reinterpret_cast<void*>(
I::ReadExternalPointerField(isolate, embedder_data, value_offset,
internal::kEmbedderDataSlotPayloadTag));
#else
return SlowGetAlignedPointerFromEmbedderData(index);
#endif
}
template <class T>
MaybeLocal<T> Context::GetDataFromSnapshotOnce(size_t index) {
T* data = reinterpret_cast<T*>(GetDataFromSnapshotOnce(index));
if (data) internal::PerformCastCheck(data);
return Local<T>(data);
}
template <class T>
size_t SnapshotCreator::AddData(Local<Context> context, Local<T> object) {
T* object_ptr = *object;
internal::Address* p = reinterpret_cast<internal::Address*>(object_ptr);
return AddData(context, *p);
}
template <class T>
size_t SnapshotCreator::AddData(Local<T> object) {
T* object_ptr = *object;
internal::Address* p = reinterpret_cast<internal::Address*>(object_ptr);
return AddData(*p);
}
/**
* \example shell.cc
* A simple shell that takes a list of expressions on the
* command-line and executes them.
*/
/**
* \example process.cc
*/
} // namespace v8
#endif // INCLUDE_V8_H_
Mini Shell