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v8/include/v8.h
Ulan Degenbaev f391faf1d1 [heap] Add a flag for setting the initial heap size 
When the --initial-heap-size flag is set V8's heap will grow to that
value without full GCs. Additionally, full GCs will be skipped
if the heap size drops below that value.

This patch also adds a comment for the initial_heap_size_in_bytes
parameter of ResourceConstraints:ConfigureDefaultsFromHeapSize

Change-Id: I85fda14bc6422af7bf2193d530efbc9b0bd0553d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1728622
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63054}
2019-08-02 16:14:39 +00:00

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// 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 http://code.google.com/apis/v8/
*/
#ifndef INCLUDE_V8_H_
#define INCLUDE_V8_H_
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <memory>
#include <utility>
#include <vector>
#include "v8-internal.h" // NOLINT(build/include)
#include "v8-version.h" // NOLINT(build/include)
#include "v8config.h" // NOLINT(build/include)
// 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 Context;
class Data;
class Date;
class External;
class Function;
class FunctionTemplate;
class HeapProfiler;
class ImplementationUtilities;
class Int32;
class Integer;
class Isolate;
template <class T>
class Maybe;
class MicrotaskQueue;
class Name;
class Number;
class NumberObject;
class Object;
class ObjectOperationDescriptor;
class ObjectTemplate;
class Platform;
class Primitive;
class Promise;
class PropertyDescriptor;
class Proxy;
class RawOperationDescriptor;
class Script;
class SharedArrayBuffer;
class Signature;
class StartupData;
class StackFrame;
class StackTrace;
class String;
class StringObject;
class Symbol;
class SymbolObject;
class PrimitiveArray;
class Private;
class Uint32;
class Utils;
class Value;
class WasmModuleObject;
template <class T> class Local;
template <class T>
class MaybeLocal;
template <class T> class Eternal;
template<class T> class NonCopyablePersistentTraits;
template<class T> class PersistentBase;
template <class T, class M = NonCopyablePersistentTraits<T> >
class Persistent;
template <class T>
class Global;
template <class T>
class TracedGlobal;
template<class K, class V, class T> class PersistentValueMap;
template <class K, class V, class T>
class PersistentValueMapBase;
template <class K, class V, class T>
class GlobalValueMap;
template<class V, class T> class PersistentValueVector;
template<class T, class P> class WeakCallbackObject;
class FunctionTemplate;
class ObjectTemplate;
template<typename T> class FunctionCallbackInfo;
template<typename T> class PropertyCallbackInfo;
class StackTrace;
class StackFrame;
class Isolate;
class CallHandlerHelper;
class EscapableHandleScope;
template<typename T> class ReturnValue;
namespace internal {
class Arguments;
class DeferredHandles;
class Heap;
class HeapObject;
class ExternalString;
class Isolate;
class LocalEmbedderHeapTracer;
class MicrotaskQueue;
struct ScriptStreamingData;
template<typename T> class CustomArguments;
class PropertyCallbackArguments;
class FunctionCallbackArguments;
class GlobalHandles;
class ScopedExternalStringLock;
namespace wasm {
class NativeModule;
class StreamingDecoder;
} // namespace wasm
} // namespace internal
namespace debug {
class ConsoleCallArguments;
} // namespace debug
// --- Handles ---
#define TYPE_CHECK(T, S) \
while (false) { \
*(static_cast<T* volatile*>(0)) = static_cast<S*>(0); \
}
/**
* 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>.
*/
TYPE_CHECK(T, S);
}
/**
* 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.
* The handles' references are not checked.
*/
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.
* The handles' references are not checked.
*/
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 TracedGlobal<T>& that);
private:
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 TracedGlobal;
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)) {
TYPE_CHECK(T, S);
}
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:
typedef void (*Callback)(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!
*/
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; // NOLINT
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:
typedef Persistent<T, NonCopyablePersistentTraits<T> > NonCopyablePersistent;
static const bool kResetInDestructor = false;
template<class S, class M>
V8_INLINE static void Copy(const Persistent<S, M>& source,
NonCopyablePersistent* dest) {
Uncompilable<Object>();
}
// TODO(dcarney): come up with a good compile error here.
template<class O> V8_INLINE static void Uncompilable() {
TYPE_CHECK(O, Primitive);
}
};
/**
* 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 {
typedef Persistent<T, CopyablePersistentTraits<T> > CopyablePersistent;
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)) {
TYPE_CHECK(T, S);
}
/**
* 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)) {
TYPE_CHECK(T, S);
}
/**
* 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) { // NOLINT
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) { // NOLINT
#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 { // NOLINT
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)) {
TYPE_CHECK(T, S);
}
/**
* 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_)) {
TYPE_CHECK(T, S);
}
/**
* 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); } // NOLINT
/*
* For compatibility with Chromium's base::Bind (base::Passed).
*/
typedef void MoveOnlyTypeForCPP03;
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>;
/**
* A traced handle with move semantics, similar to std::unique_ptr. The handle
* is to be used together with |v8::EmbedderHeapTracer| and specifies edges from
* the embedder into V8's heap.
*
* The exact semantics are:
* - Tracing garbage collections use |v8::EmbedderHeapTracer|.
* - Non-tracing garbage collections refer to
* |v8::EmbedderHeapTracer::IsRootForNonTracingGC()| whether the handle should
* be treated as root or not.
*/
template <typename T>
class V8_EXPORT TracedGlobal {
public:
/**
* An empty TracedGlobal without storage cell.
*/
TracedGlobal() = default;
~TracedGlobal() { Reset(); }
/**
* 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)
: val_(New(isolate, *that, &val_)) {
TYPE_CHECK(T, S);
}
/**
* Move constructor initializing TracedGlobal from an existing one.
*/
V8_INLINE TracedGlobal(TracedGlobal&& other);
/**
* Move assignment operator initializing TracedGlobal from an existing one.
*/
template <class S>
V8_INLINE TracedGlobal& operator=(TracedGlobal<S>&& rhs);
/**
* TracedGlobal only supports move semantics and forbids copying.
*/
TracedGlobal(const TracedGlobal&) = delete;
void operator=(const TracedGlobal&) = delete;
/**
* Returns true if this TracedGlobal is empty, i.e., has not been assigned an
* 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();
/**
* 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);
/**
* Construct a Local<T> from this handle.
*/
Local<T> Get(Isolate* isolate) const { return Local<T>::New(isolate, *this); }
template <class S>
V8_INLINE TracedGlobal<S>& As() const {
return reinterpret_cast<TracedGlobal<S>&>(
const_cast<TracedGlobal<T>&>(*this));
}
template <class S>
V8_INLINE bool operator==(const TracedGlobal<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 TracedGlobal<S>& that) const {
return !operator==(that);
}
template <class S>
V8_INLINE bool operator!=(const Local<S>& that) const {
return !operator==(that);
}
/**
* 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;
/**
* 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);
private:
V8_INLINE static T* New(Isolate* isolate, T* that, T** slot);
T* operator*() const { return this->val_; }
T* val_ = nullptr;
friend class EmbedderHeapTracer;
template <typename F>
friend class Local;
friend class Object;
template <typename F>
friend class ReturnValue;
};
/**
* 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 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 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 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 values and API object templates.
*/
class V8_EXPORT Data {
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:
V8_INLINE ScriptOrigin(
Local<Value> resource_name,
Local<Integer> resource_line_offset = Local<Integer>(),
Local<Integer> resource_column_offset = Local<Integer>(),
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>());
V8_INLINE Local<Value> ResourceName() const;
V8_INLINE Local<Integer> ResourceLineOffset() const;
V8_INLINE Local<Integer> ResourceColumnOffset() const;
V8_INLINE Local<Integer> ScriptID() const;
V8_INLINE Local<Value> SourceMapUrl() const;
V8_INLINE Local<PrimitiveArray> HostDefinedOptions() const;
V8_INLINE ScriptOriginOptions Options() const { return options_; }
private:
Local<Value> resource_name_;
Local<Integer> resource_line_offset_;
Local<Integer> resource_column_offset_;
ScriptOriginOptions options_;
Local<Integer> 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 {
// 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 compiled JavaScript module.
*/
class V8_EXPORT Module {
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.
*/
int GetModuleRequestsLength() const;
/**
* Returns the ith module specifier in this module.
* i must be < GetModuleRequestsLength() and >= 0.
*/
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.
*/
Location GetModuleRequestLocation(int i) const;
/**
* Returns the identity hash for this object.
*/
int GetIdentityHash() const;
typedef MaybeLocal<Module> (*ResolveCallback)(Local<Context> context,
Local<String> specifier,
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_WARN_UNUSED_RESULT Maybe<bool> InstantiateModule(Local<Context> context,
ResolveCallback callback);
/**
* Evaluates the module and its dependencies.
*
* If status is kInstantiated, run the module's code. On success, set status
* to kEvaluated and return the completion value; on failure, set status to
* kErrored and propagate the thrown exception (which is then also available
* via |GetException|).
*/
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();
/*
* Callback defined in the embedder. This is responsible for setting
* the module's exported values with calls to SetSyntheticModuleExport().
* The callback must return a Value to indicate success (where no
* exception was thrown) and return an empy MaybeLocal to indicate falure
* (where an exception was thrown).
*/
typedef MaybeLocal<Value> (*SyntheticModuleEvaluationSteps)(
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. export_name must be one of the export_names that
* were passed in that CreateSyntheticModule call.
*/
void SetSyntheticModuleExport(Local<String> export_name,
Local<Value> export_value);
};
/**
* 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();
};
/**
* 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 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;
Local<Integer> resource_line_offset;
Local<Integer> 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 };
V8_DEPRECATE_SOON(
"This class takes ownership of source_stream, so use the constructor "
"taking a unique_ptr to make these semantics clearer",
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::StartStreamingScript.
*/
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.
*
* \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.
*/
static ScriptStreamingTask* StartStreamingScript(
Isolate* isolate, StreamedSource* source,
CompileOptions options = kNoCompileOptions);
/**
* 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);
/**
* 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> 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 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;
};
/**
* 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 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,
IDLE
};
// A RegisterState represents the current state of registers used
// by the sampling profiler API.
struct RegisterState {
RegisterState() : pc(nullptr), sp(nullptr), fp(nullptr), lr(nullptr) {}
void* pc; // Instruction pointer.
void* sp; // Stack pointer.
void* fp; // Frame pointer.
void* lr; // Link register (or nullptr on platforms without a link register).
};
// 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.
};
struct MemoryRange {
const void* start = nullptr;
size_t length_in_bytes = 0;
};
struct JSEntryStub {
MemoryRange code;
};
struct UnwindState {
MemoryRange code_range;
MemoryRange embedded_code_range;
JSEntryStub js_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);
/**
* Expect inline wasm in the data stream (rather than in-memory transfer)
*/
void SetExpectInlineWasm(bool allow_inline_wasm);
/**
* 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.
*/
V8_INLINE bool IsUndefined() const;
/**
* Returns true if this value is the null value. See ECMA-262
* 4.3.11.
*/
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
*/
V8_INLINE bool IsNullOrUndefined() const;
/**
* Returns true if this value is true.
*/
bool IsTrue() const;
/**
* Returns true if this value is false.
*/
bool IsFalse() const;
/**
* Returns true if this value is a symbol or a string.
*/
bool IsName() const;
/**
* Returns true if this value is an instance of the String type.
* See ECMA-262 8.4.
*/
V8_INLINE bool IsString() const;
/**
* Returns true if this value is a symbol.
*/
bool IsSymbol() const;
/**
* Returns true if this value is a function.
*/
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.
*/
bool IsBigInt() const;
/**
* Returns true if this value is boolean.
*/
bool IsBoolean() const;
/**
* Returns true if this value is a number.
*/
bool IsNumber() const;
/**
* Returns true if this value is external.
*/
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.
* This is an experimental feature.
*/
bool IsSharedArrayBuffer() const;
/**
* Returns true if this value is a JavaScript Proxy.
*/
bool IsProxy() const;
bool IsWebAssemblyCompiledModule() const;
/**
* Returns true if the value is a Module Namespace Object.
*/
bool IsModuleNamespaceObject() const;
V8_WARN_UNUSED_RESULT MaybeLocal<BigInt> ToBigInt(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
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;
bool BooleanValue(Isolate* isolate) const;
V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
Local<Context> context) const;
V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
Local<Context> context) const;
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;
};
/**
* 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::Value* obj);
V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value);
private:
static void CheckCast(v8::Value* obj);
};
/**
* 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(Value* obj);
private:
static void CheckCast(Value* obj);
};
/**
* 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::kApiTaggedSize == 4
? (1 << 28) - 16
: internal::kSmiMaxValue / 2 - 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 one-byte.
*/
bool IsExternalOneByte() const;
class V8_EXPORT ExternalStringResourceBase { // NOLINT
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.
*/
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;
protected:
ExternalStringResource() = default;
};
/**
* 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.*/
virtual const char* data() const = 0;
/** The number of Latin-1 characters in the string.*/
virtual size_t length() const = 0;
protected:
ExternalOneByteStringResource() = default;
};
/**
* 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::Value* obj);
/** 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 void CheckCast(v8::Value* obj);
};
/**
* A JavaScript symbol (ECMA-262 edition 6)
*/
class V8_EXPORT Symbol : public Name {
public:
/**
* Returns the print name string of the symbol, or undefined if none.
*/
Local<Value> Name() const;
/**
* Create a symbol. If name is not empty, it will be used as the description.
*/
static Local<Symbol> New(Isolate* isolate,
Local<String> name = 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 names used as keys.
* To minimize the potential for clashes, use qualified names as keys.
*/
static Local<Symbol> For(Isolate *isolate, Local<String> name);
/**
* 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> name);
// 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(Value* obj);
private:
Symbol();
static void CheckCast(Value* obj);
};
/**
* 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::Value* obj);
private:
Number();
static void CheckCast(v8::Value* obj);
};
/**
* 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::Value* obj);
private:
Integer();
static void CheckCast(v8::Value* obj);
};
/**
* 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::Value* obj);
private:
Int32();
static void CheckCast(v8::Value* obj);
};
/**
* 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::Value* obj);
private:
Uint32();
static void CheckCast(v8::Value* obj);
};
/**
* 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::Value* obj);
private:
BigInt();
static void CheckCast(v8::Value* obj);
};
/**
* 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.
*/
typedef void (*AccessorGetterCallback)(
Local<String> property,
const PropertyCallbackInfo<Value>& info);
typedef void (*AccessorNameGetterCallback)(
Local<Name> property,
const PropertyCallbackInfo<Value>& info);
typedef void (*AccessorSetterCallback)(
Local<String> property,
Local<Value> value,
const PropertyCallbackInfo<void>& info);
typedef void (*AccessorNameSetterCallback)(
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 whitelisted 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 whitelisted 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 };
/**
* 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); // NOLINT(runtime/references)
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 TracedGlobal. */
V8_INLINE static int InternalFieldCount(const TracedGlobal<Object>& object) {
return object.val_->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 TracedGlobal<Object>& object, int index) {
return object.val_->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.
*/
Local<Context> CreationContext();
/** Same as above, but works for Persistents */
V8_INLINE static Local<Context> CreationContext(
const PersistentBase<Object>& object) {
return object.val_->CreationContext();
}
/**
* 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();
/**
* 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);
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_) {
TYPE_CHECK(T, S);
}
// Local setters
template <typename S>
V8_INLINE void Set(const Global<S>& handle);
template <typename S>
V8_INLINE void Set(const TracedGlobal<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. */
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_;
};
typedef void (*FunctionCallback)(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.
*/
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;
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();
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();
private:
explicit CompiledWasmModule(std::shared_ptr<internal::wasm::NativeModule>);
friend class Utils;
const std::shared_ptr<internal::wasm::NativeModule> native_module_;
};
// An instance of WebAssembly.Module.
class V8_EXPORT WasmModuleObject : public Object {
public:
/**
* An opaque, native heap object for transferring wasm modules. It
* supports move semantics, and does not support copy semantics.
* TODO(wasm): Merge this with CompiledWasmModule once code sharing is always
* enabled.
*/
class TransferrableModule final {
public:
TransferrableModule(TransferrableModule&& src) = default;
TransferrableModule(const TransferrableModule& src) = delete;
TransferrableModule& operator=(TransferrableModule&& src) = default;
TransferrableModule& operator=(const TransferrableModule& src) = delete;
private:
typedef std::shared_ptr<internal::wasm::NativeModule> SharedModule;
friend class WasmModuleObject;
explicit TransferrableModule(SharedModule shared_module)
: shared_module_(std::move(shared_module)) {}
TransferrableModule(OwnedBuffer serialized, OwnedBuffer bytes)
: serialized_(std::move(serialized)), wire_bytes_(std::move(bytes)) {}
SharedModule shared_module_;
OwnedBuffer serialized_ = {nullptr, 0};
OwnedBuffer wire_bytes_ = {nullptr, 0};
};
/**
* Get an in-memory, non-persistable, and context-independent (meaning,
* suitable for transfer to another Isolate and Context) representation
* of this wasm compiled module.
*/
TransferrableModule GetTransferrableModule();
/**
* Efficiently re-create a WasmModuleObject, without recompiling, from
* a TransferrableModule.
*/
static MaybeLocal<WasmModuleObject> FromTransferrableModule(
Isolate* isolate, const TransferrableModule&);
/**
* Get the compiled module for this module object. The compiled module can be
* shared by several module objects.
*/
CompiledWasmModule GetCompiledModule();
/**
* If possible, deserialize the module, otherwise compile it from the provided
* uncompiled bytes.
*/
static MaybeLocal<WasmModuleObject> DeserializeOrCompile(
Isolate* isolate, MemorySpan<const uint8_t> serialized_module,
MemorySpan<const uint8_t> wire_bytes);
V8_INLINE static WasmModuleObject* Cast(Value* obj);
private:
static MaybeLocal<WasmModuleObject> Deserialize(
Isolate* isolate, MemorySpan<const uint8_t> serialized_module,
MemorySpan<const uint8_t> wire_bytes);
static MaybeLocal<WasmModuleObject> Compile(Isolate* isolate,
const uint8_t* start,
size_t length);
static MemorySpan<const uint8_t> AsReference(const OwnedBuffer& buff) {
return {buff.buffer.get(), buff.size};
}
WasmModuleObject();
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);
/**
* 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 };
/**
* 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 { // NOLINT
public:
virtual ~Allocator() = default;
/**
* Allocate |length| bytes. Return NULL if allocation is not successful.
* Memory should be initialized to zeroes.
*/
virtual void* Allocate(size_t length) = 0;
/**
* Allocate |length| bytes. Return NULL 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;
/**
* 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.
*/
static Local<ArrayBuffer> New(
Isolate* isolate, void* data, size_t byte_length,
ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
/**
* Returns true if ArrayBuffer is externalized, that is, does not
* own its memory block.
*/
bool IsExternal() const;
/**
* Returns true if this ArrayBuffer may be detached.
*/
bool IsDetachable() const;
// TODO(913887): fix the use of 'neuter' in the API.
V8_DEPRECATE_SOON("Use IsDetachable() instead.",
inline bool IsNeuterable() const) {
return IsDetachable();
}
/**
* 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();
// TODO(913887): fix the use of 'neuter' in the API.
V8_DEPRECATE_SOON("Use Detach() instead.", inline void Neuter()) { 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.
*/
Contents Externalize();
/**
* 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.
*/
Contents GetContents();
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::kSmiMaxValue;
/**
* 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.
* This API is experimental and may change significantly.
*/
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.
*
* This API is experimental and may change significantly.
*/
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.
*/
static Local<SharedArrayBuffer> New(
Isolate* isolate, void* data, size_t byte_length,
ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
/**
* Create a new SharedArrayBuffer over an existing memory block. Propagate
* flags to indicate whether the underlying buffer can be grown.
*/
V8_DEPRECATED("Use New method with data, and byte_length instead.",
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.
*/
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.
*
*/
Contents Externalize();
/**
* 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.
*/
Contents GetContents();
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.
*/
enum Flags {
kNone = 0,
kGlobal = 1 << 0,
kIgnoreCase = 1 << 1,
kMultiline = 1 << 2,
kSticky = 1 << 3,
kUnicode = 1 << 4,
kDotAll = 1 << 5,
};
static constexpr int kFlagCount = 6;
/**
* 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);
/**
* 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);
};
/**
* An instance of the built-in FinalizationGroup constructor.
*
* This API is experimental and may change significantly.
*/
class V8_EXPORT FinalizationGroup : public Object {
public:
/**
* Runs the cleanup callback of the given FinalizationGroup.
*
* V8 will inform the embedder that there are finalizer callbacks be
* called through HostCleanupFinalizationGroupCallback.
*
* HostCleanupFinalizationGroupCallback should schedule a task to
* call FinalizationGroup::Cleanup() at some point in the
* future. It's the embedders responsiblity to make this call at a
* time which does not interrupt synchronous ECMAScript code
* execution.
*
* If the result is Nothing<bool> then an exception has
* occurred. Otherwise the result is |true| if the cleanup callback
* was called successfully. The result is never |false|.
*/
static V8_WARN_UNUSED_RESULT Maybe<bool> Cleanup(
Local<FinalizationGroup> finalization_group);
};
/**
* 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(ErrorPrototype, initial_error_prototype) \
F(IteratorPrototype, initial_iterator_prototype)
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,
// TODO(dcarney): gcc can't handle Local below
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,
// TODO(dcarney): gcc can't handle Local below
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`.
*/
typedef void (*GenericNamedPropertyGetterCallback)(
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.`
*/
typedef void (*GenericNamedPropertySetterCallback)(
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.`
*/
typedef void (*GenericNamedPropertyQueryCallback)(
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.`
*/
typedef void (*GenericNamedPropertyDeleterCallback)(
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.
*/
typedef void (*GenericNamedPropertyEnumeratorCallback)(
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`.
*/
typedef void (*GenericNamedPropertyDefinerCallback)(
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`.
*/
typedef void (*GenericNamedPropertyDescriptorCallback)(
Local<Name> property, const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertyGetterCallback`.
*/
typedef void (*IndexedPropertyGetterCallback)(
uint32_t index,
const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertySetterCallback`.
*/
typedef void (*IndexedPropertySetterCallback)(
uint32_t index,
Local<Value> value,
const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertyQueryCallback`.
*/
typedef void (*IndexedPropertyQueryCallback)(
uint32_t index,
const PropertyCallbackInfo<Integer>& info);
/**
* See `v8::GenericNamedPropertyDeleterCallback`.
*/
typedef void (*IndexedPropertyDeleterCallback)(
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.
*/
typedef void (*IndexedPropertyEnumeratorCallback)(
const PropertyCallbackInfo<Array>& info);
/**
* See `v8::GenericNamedPropertyDefinerCallback`.
*/
typedef void (*IndexedPropertyDefinerCallback)(
uint32_t index, const PropertyDescriptor& desc,
const PropertyCallbackInfo<Value>& info);
/**
* See `v8::GenericNamedPropertyDescriptorCallback`.
*/
typedef void (*IndexedPropertyDescriptorCallback)(
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.
*/
typedef bool (*AccessCheckCallback)(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::NewFromUtf8(isolate, "instance_accessor"),
* InstanceAccessorCallback);
* instance_t->SetHandler(
* NamedPropertyHandlerConfiguration(PropertyHandlerCallback));
* instance_t->Set(String::NewFromUtf8(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
*/
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);
/** Get a template included in the snapshot by index. */
static MaybeLocal<FunctionTemplate> FromSnapshot(Isolate* isolate,
size_t index);
/**
* 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.
*/
void SetCallHandler(
FunctionCallback callback, Local<Value> data = Local<Value>(),
SideEffectType side_effect_type = SideEffectType::kHasSideEffect);
/** 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);
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>());
/** Get a template included in the snapshot by index. */
static MaybeLocal<ObjectTemplate> FromSnapshot(Isolate* isolate,
size_t index);
/** 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();
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 { // NOLINT
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.
*/
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;
}
/**
* Deprecated functions. Do not use in new code.
*/
V8_DEPRECATE_SOON("Use code_range_size_in_bytes.",
size_t code_range_size() const) {
return code_range_size_ / kMB;
}
V8_DEPRECATE_SOON("Use set_code_range_size_in_bytes.",
void set_code_range_size(size_t limit_in_mb)) {
code_range_size_ = limit_in_mb * kMB;
}
V8_DEPRECATE_SOON("Use max_young_generation_size_in_bytes.",
size_t max_semi_space_size_in_kb() const);
V8_DEPRECATE_SOON("Use set_max_young_generation_size_in_bytes.",
void set_max_semi_space_size_in_kb(size_t limit_in_kb));
V8_DEPRECATE_SOON("Use max_old_generation_size_in_bytes.",
size_t max_old_space_size() const) {
return max_old_generation_size_ / kMB;
}
V8_DEPRECATE_SOON("Use set_max_old_generation_size_in_bytes.",
void set_max_old_space_size(size_t limit_in_mb)) {
max_old_generation_size_ = limit_in_mb * kMB;
}
V8_DEPRECATE_SOON("Zone does not pool memory any more.",
size_t max_zone_pool_size() const) {
return max_zone_pool_size_;
}
V8_DEPRECATE_SOON("Zone does not pool memory any more.",
void set_max_zone_pool_size(size_t bytes)) {
max_zone_pool_size_ = bytes;
}
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 max_zone_pool_size_ = 0;
size_t initial_old_generation_size_ = 0;
size_t initial_young_generation_size_ = 0;
uint32_t* stack_limit_ = nullptr;
};
// --- Exceptions ---
typedef void (*FatalErrorCallback)(const char* location, const char* message);
typedef void (*OOMErrorCallback)(const char* location, bool is_heap_oom);
typedef void (*DcheckErrorCallback)(const char* file, int line,
const char* message);
typedef void (*MessageCallback)(Local<Message> message, Local<Value> data);
// --- Tracing ---
typedef void (*LogEventCallback)(const char* name, int event);
/**
* 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> 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 ---
typedef int* (*CounterLookupCallback)(const char* name);
typedef void* (*CreateHistogramCallback)(const char* name,
int min,
int max,
size_t buckets);
typedef void (*AddHistogramSampleCallback)(void* histogram, int sample);
// --- Enter/Leave Script Callback ---
typedef void (*BeforeCallEnteredCallback)(Isolate*);
typedef void (*CallCompletedCallback)(Isolate*);
/**
* HostCleanupFinalizationGroupCallback is called when we require the
* embedder to enqueue a task that would call
* FinalizationGroup::Cleanup().
*
* The FinalizationGroup is the one for which the embedder needs to
* call FinalizationGroup::Cleanup() on.
*
* The context provided is the one in which the FinalizationGroup was
* created in.
*/
typedef void (*HostCleanupFinalizationGroupCallback)(
Local<Context> context, Local<FinalizationGroup> fg);
/**
* 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 it's 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.
*/
typedef MaybeLocal<Promise> (*HostImportModuleDynamicallyCallback)(
Local<Context> context, Local<ScriptOrModule> referrer,
Local<String> specifier);
/**
* 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.
*/
typedef void (*HostInitializeImportMetaObjectCallback)(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
*/
typedef MaybeLocal<Value> (*PrepareStackTraceCallback)(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 };
typedef void (*PromiseHook)(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_;
};
typedef void (*PromiseRejectCallback)(PromiseRejectMessage message);
// --- Microtasks Callbacks ---
V8_DEPRECATE_SOON("Use *WithData version.",
typedef void (*MicrotasksCompletedCallback)(Isolate*));
typedef void (*MicrotasksCompletedCallbackWithData)(Isolate*, void*);
typedef void (*MicrotaskCallback)(void* data);
/**
* Policy for running microtasks:
* - explicit: microtasks are invoked with Isolate::RunMicrotasks() 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 kScopeMicrotasksInvocation
* 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 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 ---
typedef void (*FailedAccessCheckCallback)(Local<Object> target,
AccessType type,
Local<Value> data);
// --- AllowCodeGenerationFromStrings callbacks ---
/**
* Callback to check if code generation from strings is allowed. See
* Context::AllowCodeGenerationFromStrings.
*/
typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context,
Local<String> source);
typedef MaybeLocal<String> (*ModifyCodeGenerationFromStringsCallback)(
Local<Context> context, Local<Value> source);
// --- WebAssembly compilation callbacks ---
typedef bool (*ExtensionCallback)(const FunctionCallbackInfo<Value>&);
typedef bool (*AllowWasmCodeGenerationCallback)(Local<Context> context,
Local<String> source);
// --- Callback for APIs defined on v8-supported objects, but implemented
// by the embedder. Example: WebAssembly.{compile|instantiate}Streaming ---
typedef void (*ApiImplementationCallback)(const FunctionCallbackInfo<Value>&);
// --- Callback for WebAssembly.compileStreaming ---
typedef void (*WasmStreamingCallback)(const FunctionCallbackInfo<Value>&);
// --- Callback for checking if WebAssembly threads are enabled ---
typedef bool (*WasmThreadsEnabledCallback)(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,
};
typedef void (*GCCallback)(GCType type, GCCallbackFlags flags);
typedef void (*InterruptCallback)(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.
*/
typedef size_t (*NearHeapLimitCallback)(void* data, size_t current_heap_limit,
size_t initial_heap_limit);
/**
* Collection of V8 heap information.
*
* Instances of this class can be passed to v8::V8::HeapStatistics 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 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_;
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;
};
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.
*/
typedef void (*JitCodeEventHandler)(const JitCodeEvent* event);
/**
* Callback function passed to SetUnhandledExceptionCallback.
*/
#if defined(V8_OS_WIN)
typedef int (*UnhandledExceptionCallback)(
_EXCEPTION_POINTERS* exception_pointers);
#endif
/**
* Interface for iterating through all external resources in the heap.
*/
class V8_EXPORT ExternalResourceVisitor { // NOLINT
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 { // NOLINT
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 };
/**
* 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:
enum TraceFlags : uint64_t {
kNoFlags = 0,
kReduceMemory = 1 << 0,
};
// Indicator for the stack state of the embedder.
enum EmbedderStackState {
kUnknown,
kNonEmpty,
kEmpty,
};
/**
* Interface for iterating through TracedGlobal handles.
*/
class V8_EXPORT TracedGlobalHandleVisitor {
public:
virtual ~TracedGlobalHandleVisitor() = default;
virtual void VisitTracedGlobalHandle(const TracedGlobal<Value>& value) = 0;
};
/**
* 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 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 TracedGlobal<v8::Value>& ref);
/**
* Called at the beginning of a GC cycle.
*/
V8_DEPRECATE_SOON("Use version with flags.", virtual void TracePrologue()) {}
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() {}
virtual void TraceEpilogue(TraceSummary* trace_summary) { TraceEpilogue(); }
/**
* 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();
/**
* Returns true if the TracedGlobal handle should be considered as root for
* the currently running non-tracing garbage collection and false otherwise.
*
* Default implementation will keep all TracedGlobal references as roots.
*/
virtual bool IsRootForNonTracingGC(
const v8::TracedGlobal<v8::Value>& handle) {
return true;
}
/*
* 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 {
typedef StartupData (*CallbackFunction)(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.
typedef SerializeInternalFieldsCallback SerializeEmbedderFieldsCallback;
/**
* Callback and supporting data used to implement embedder logic to deserialize
* internal fields.
*/
struct DeserializeInternalFieldsCallback {
typedef void (*CallbackFunction)(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;
};
typedef DeserializeInternalFieldsCallback DeserializeEmbedderFieldsCallback;
/**
* 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 CreateParams {
CreateParams()
: code_event_handler(nullptr),
snapshot_blob(nullptr),
counter_lookup_callback(nullptr),
create_histogram_callback(nullptr),
add_histogram_sample_callback(nullptr),
array_buffer_allocator(nullptr),
external_references(nullptr),
allow_atomics_wait(true),
only_terminate_in_safe_scope(false) {}
/**
* 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;
/**
* ResourceConstraints to use for the new Isolate.
*/
ResourceConstraints constraints;
/**
* Explicitly specify a startup snapshot blob. The embedder owns the blob.
*/
StartupData* snapshot_blob;
/**
* Enables the host application to provide a mechanism for recording
* statistics counters.
*/
CounterLookupCallback counter_lookup_callback;
/**
* 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;
AddHistogramSampleCallback add_histogram_sample_callback;
/**
* The ArrayBuffer::Allocator to use for allocating and freeing the backing
* store of ArrayBuffers.
*/
ArrayBuffer::Allocator* array_buffer_allocator;
/**
* 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;
/**
* 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;
/**
* Termination is postponed when there is no active SafeForTerminationScope.
*/
bool only_terminate_in_safe_scope;
};
/**
* Stack-allocated class which sets the isolate for all operations
* executed within a local scope.
*/
class V8_EXPORT 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 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_;
void* internal_;
};
/**
* Introduce exception to DisallowJavascriptExecutionScope.
*/
class V8_EXPORT AllowJavascriptExecutionScope {
public:
explicit AllowJavascriptExecutionScope(Isolate* isolate);
~AllowJavascriptExecutionScope();
// Prevent copying of Scope objects.
AllowJavascriptExecutionScope(const AllowJavascriptExecutionScope&) =
delete;
AllowJavascriptExecutionScope& operator=(
const AllowJavascriptExecutionScope&) = delete;
private:
void* internal_throws_;
void* internal_assert_;
void* internal_dump_;
};
/**
* Do not run microtasks while this scope is active, even if microtasks are
* automatically executed otherwise.
*/
class V8_EXPORT SuppressMicrotaskExecutionScope {
public:
explicit SuppressMicrotaskExecutionScope(Isolate* isolate);
explicit SuppressMicrotaskExecutionScope(MicrotaskQueue* microtask_queue);
~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_;
};
/**
* This scope allows terminations inside direct V8 API calls and forbid them
* inside any recursice API calls without explicit SafeForTerminationScope.
*/
class V8_EXPORT 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,
kRegExpPrototypeOldFlagGetter = 31,
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,
kAtomicsWake = 53,
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,
kRegExpMatchIsTrueishOnNonJSRegExp = 72,
kRegExpMatchIsFalseishOnJSRegExp = 73,
kDateGetTimezoneOffset = 74,
kStringNormalize = 75,
kCallSiteAPIGetFunctionSloppyCall = 76,
kCallSiteAPIGetThisSloppyCall = 77,
kRegExpMatchAllWithNonGlobalRegExp = 78,
// 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,
};
typedef void (*UseCounterCallback)(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();
/**
* 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.
*
* The embedder is expected to call this when a synchronous sequence
* of ECMAScript execution completes. It's the embedders
* responsiblity 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.
*/
typedef bool (*AbortOnUncaughtExceptionCallback)(Isolate*);
void SetAbortOnUncaughtExceptionCallback(
AbortOnUncaughtExceptionCallback callback);
/**
* This specifies the callback to be called when finalization groups
* are ready to be cleaned up and require FinalizationGroup::Cleanup()
* to be called in a future task.
*/
void SetHostCleanupFinalizationGroupCallback(
HostCleanupFinalizationGroupCallback callback);
/**
* This specifies the callback called by the upcoming dynamic
* import() language feature to load modules.
*/
void SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyCallback callback);
/**
* This specifies the callback called by the upcoming importa.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);
/**
* 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);
/**
* 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.
*/
V8_INLINE 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 the last context entered through V8's C++ API. */
V8_DEPRECATED("Use GetEnteredOrMicrotaskContext().",
Local<Context> GetEnteredContext());
/**
* 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 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);
typedef void (*GCCallback)(Isolate* isolate, GCType type,
GCCallbackFlags flags);
typedef void (*GCCallbackWithData)(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();
/**
* 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|.
*/
typedef void (*AtomicsWaitCallback)(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);
typedef size_t (*GetExternallyAllocatedMemoryInBytesCallback)();
/**
* 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);
/**
* 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.
* Any exceptions thrown by microtask callbacks are swallowed.
*/
void RunMicrotasks();
/**
* 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.
*/
V8_DEPRECATE_SOON("Use *WithData version.",
void AddMicrotasksCompletedCallback(
MicrotasksCompletedCallback callback));
void AddMicrotasksCompletedCallback(
MicrotasksCompletedCallbackWithData callback, void* data = nullptr);
/**
* Removes callback that was installed by AddMicrotasksCompletedCallback.
*/
V8_DEPRECATE_SOON("Use *WithData version.",
void RemoveMicrotasksCompletedCallback(
MicrotasksCompletedCallback callback));
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);
/**
* 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. 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);
/**
* 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);
/**
* Returns the UnwindState necessary for use with the Unwinder API.
*/
UnwindState GetUnwindState();
/** 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.
*/
void SetAllowCodeGenerationFromStringsCallback(
AllowCodeGenerationFromStringsCallback callback);
void SetModifyCodeGenerationFromStringsCallback(
ModifyCodeGenerationFromStringsCallback 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 SetWasmThreadsEnabledCallback(WasmThreadsEnabledCallback callback);
/**
* 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();
void CheckMemoryPressure();
};
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;
const char* data;
int raw_size;
};
/**
* EntropySource is used as a callback function when v8 needs a source
* of entropy.
*/
typedef bool (*EntropySource)(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.
*/
typedef uintptr_t (*ReturnAddressLocationResolver)(
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 SetNativesDataBlob(StartupData* startup_blob);
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);
V8_DEPRECATED("use size_t version",
static void SetFlagsFromString(const char* str, int 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.
*/
static bool Initialize();
/**
* 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 files "natives_blob.bin"
* and "snapshot_blob.bin" - which is what the default build calls them.
* - InitializeExternalStartupData(const char*, const char*)
* As above, but will directly use the two given file names.
* - Call SetNativesDataBlob, SetNativesDataBlob.
* This will read the blobs from the given data structures and will
* not perform any file IO.
*/
static void InitializeExternalStartupData(const char* directory_path);
static void InitializeExternalStartupData(const char* natives_blob,
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_DEPRECATE_SOON("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
private:
V8();
static internal::Address* GlobalizeReference(internal::Isolate* isolate,
internal::Address* handle);
static internal::Address* GlobalizeTracedReference(internal::Isolate* isolate,
internal::Address* handle,
internal::Address* slot);
static void MoveGlobalReference(internal::Address** from,
internal::Address** to);
static void MoveTracedGlobalReference(internal::Address** 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 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;
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.
*/
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);
~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());
/**
* Add a template to be included in the snapshot blob.
* \returns the index of the template in the snapshot blob.
*/
size_t AddTemplate(Local<Template> template_obj);
/**
* 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.
*
* The returned handle is valid until this TryCatch block has been destroyed.
*/
Local<Value> Exception() const;
/**
* Returns the .stack property of the thrown object. If no .stack
* property is present 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.
*
* The returned handle is valid until this TryCatch block has been
* destroyed.
*/
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:
/**
* 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 an isolate associated with a current context. */
Isolate* GetIsolate();
/**
* 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.
*/
typedef void (*AbortScriptExecutionCallback)(Isolate* isolate,
Local<Context> context);
void SetAbortScriptExecution(AbortScriptExecutionCallback callback);
/**
* Stack-allocated class which sets the execution context for all
* operations executed within a local scope.
*/
class 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 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;
};
private:
friend class Value;
friend class Script;
friend class Object;
friend class Function;
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 architecture.
*/
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. The V8 API provides all required inputs
* via an UnwindState object through the Isolate::GetUnwindState() API. These
* values will not change after Isolate initialization, so the same
* |unwind_state| can be used for multiple calls.
*
* \param unwind_state Input state for the Isolate that the stack comes from.
* \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 UnwindState& unwind_state,
RegisterState* register_state,
const void* stack_base);
/**
* Whether the PC is within the V8 code range represented by code_range or
* embedded_code_range in |unwind_state|.
*
* 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.
*/
static bool PCIsInV8(const UnwindState& unwind_state, 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 TracedGlobal<T>& that) {
return New(isolate, that.val_);
}
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) {
TYPE_CHECK(T, S);
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) {
TYPE_CHECK(T, S);
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 {
typedef internal::Internals I;
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) {
TYPE_CHECK(T, S);
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) {
TYPE_CHECK(T, S);
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) {
typedef typename WeakCallbackInfo<void>::Callback Callback;
V8::MakeWeak(reinterpret_cast<internal::Address*>(this->val_), parameter,
reinterpret_cast<Callback>(callback), type);
}
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) {
typedef internal::Internals I;
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 {
typedef internal::Internals I;
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) {
TYPE_CHECK(T, S);
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>
T* TracedGlobal<T>::New(Isolate* isolate, T* that, T** slot) {
if (that == nullptr) return nullptr;
internal::Address* p = reinterpret_cast<internal::Address*>(that);
return reinterpret_cast<T*>(V8::GlobalizeTracedReference(
reinterpret_cast<internal::Isolate*>(isolate), p,
reinterpret_cast<internal::Address*>(slot)));
}
template <class T>
void TracedGlobal<T>::Reset() {
if (IsEmpty()) return;
V8::DisposeTracedGlobal(reinterpret_cast<internal::Address*>(val_));
val_ = nullptr;
}
template <class T>
template <class S>
void TracedGlobal<T>::Reset(Isolate* isolate, const Local<S>& other) {
TYPE_CHECK(T, S);
Reset();
if (other.IsEmpty()) return;
this->val_ = New(isolate, other.val_, &val_);
}
template <class T>
TracedGlobal<T>::TracedGlobal(TracedGlobal&& other) : val_(other.val_) {
if (other.val_ != nullptr) {
V8::MoveTracedGlobalReference(
reinterpret_cast<internal::Address**>(&other.val_),
reinterpret_cast<internal::Address**>(&this->val_));
other.val_ = nullptr;
}
}
template <class T>
template <class S>
TracedGlobal<T>& TracedGlobal<T>::operator=(TracedGlobal<S>&& rhs) {
TYPE_CHECK(T, S);
if (this != &rhs) {
this->Reset();
if (rhs.val_ != nullptr) {
this->val_ = rhs.val_;
V8::MoveTracedGlobalReference(
reinterpret_cast<internal::Address**>(&rhs.val_),
reinterpret_cast<internal::Address**>(&this->val_));
rhs.val_ = nullptr;
}
}
return *this;
}
template <class T>
void TracedGlobal<T>::SetWrapperClassId(uint16_t class_id) {
typedef internal::Internals I;
if (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 TracedGlobal<T>::WrapperClassId() const {
typedef internal::Internals I;
if (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>
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) {
TYPE_CHECK(T, S);
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 TracedGlobal<S>& handle) {
TYPE_CHECK(T, S);
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 Local<S> handle) {
TYPE_CHECK(T, S);
if (V8_UNLIKELY(handle.IsEmpty())) {
*value_ = GetDefaultValue();
} else {
*value_ = *reinterpret_cast<internal::Address*>(*handle);
}
}
template<typename T>
void ReturnValue<T>::Set(double i) {
TYPE_CHECK(T, Number);
Set(Number::New(GetIsolate(), i));
}
template<typename T>
void ReturnValue<T>::Set(int32_t i) {
TYPE_CHECK(T, Integer);
typedef internal::Internals I;
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) {
TYPE_CHECK(T, Integer);
// 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) {
TYPE_CHECK(T, Boolean);
typedef internal::Internals I;
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() {
TYPE_CHECK(T, Primitive);
typedef internal::Internals I;
*value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
}
template<typename T>
void ReturnValue<T>::SetUndefined() {
TYPE_CHECK(T, Primitive);
typedef internal::Internals I;
*value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
}
template<typename T>
void ReturnValue<T>::SetEmptyString() {
TYPE_CHECK(T, String);
typedef internal::Internals I;
*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 {
typedef internal::Internals I;
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) {
// Uncompilable to prevent inadvertent misuse.
TYPE_CHECK(S*, Primitive);
}
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 {
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 {
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> resource_line_offset,
Local<Integer> resource_column_offset,
Local<Boolean> resource_is_shared_cross_origin,
Local<Integer> script_id,
Local<Value> source_map_url,
Local<Boolean> resource_is_opaque,
Local<Boolean> is_wasm, Local<Boolean> is_module,
Local<PrimitiveArray> host_defined_options)
: resource_name_(resource_name),
resource_line_offset_(resource_line_offset),
resource_column_offset_(resource_column_offset),
options_(!resource_is_shared_cross_origin.IsEmpty() &&
resource_is_shared_cross_origin->IsTrue(),
!resource_is_opaque.IsEmpty() && resource_is_opaque->IsTrue(),
!is_wasm.IsEmpty() && is_wasm->IsTrue(),
!is_module.IsEmpty() && is_module->IsTrue()),
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 resource_line_offset_;
}
Local<Integer> ScriptOrigin::ResourceColumnOffset() const {
return resource_column_offset_;
}
Local<Integer> 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.ResourceLineOffset()),
resource_column_offset(origin.ResourceColumnOffset()),
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
typedef internal::Address A;
typedef internal::Internals I;
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<int32_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
typedef internal::Address A;
typedef internal::Internals I;
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);
return I::ReadRawField<void*>(obj, offset);
}
#endif
return SlowGetAlignedPointerFromInternalField(index);
}
String* String::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<String*>(value);
}
Local<String> String::Empty(Isolate* isolate) {
typedef internal::Address S;
typedef internal::Internals I;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex);
return Local<String>(reinterpret_cast<String*>(slot));
}
String::ExternalStringResource* String::GetExternalStringResource() const {
typedef internal::Address A;
typedef internal::Internals I;
A obj = *reinterpret_cast<const A*>(this);
ExternalStringResource* result;
if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
void* value = I::ReadRawField<void*>(obj, I::kStringResourceOffset);
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 {
typedef internal::Address A;
typedef internal::Internals I;
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) {
void* value = I::ReadRawField<void*>(obj, I::kStringResourceOffset);
resource = static_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 {
typedef internal::Address A;
typedef internal::Internals I;
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 {
typedef internal::Address A;
typedef internal::Internals I;
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 {
typedef internal::Address A;
typedef internal::Internals I;
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 {
typedef internal::Address A;
typedef internal::Internals I;
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);
}
Boolean* Boolean::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Boolean*>(value);
}
Name* Name::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Name*>(value);
}
Symbol* Symbol::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Symbol*>(value);
}
Private* Private::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<Private*>(data);
}
Number* Number::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Number*>(value);
}
Integer* Integer::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Integer*>(value);
}
Int32* Int32::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Int32*>(value);
}
Uint32* Uint32::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Uint32*>(value);
}
BigInt* BigInt::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<BigInt*>(value);
}
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);
}
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 {
typedef internal::Internals I;
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) {
typedef internal::Address S;
typedef internal::Internals I;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex);
return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
}
Local<Primitive> Null(Isolate* isolate) {
typedef internal::Address S;
typedef internal::Internals I;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kNullValueRootIndex);
return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
}
Local<Boolean> True(Isolate* isolate) {
typedef internal::Address S;
typedef internal::Internals I;
I::CheckInitialized(isolate);
S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex);
return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
}
Local<Boolean> False(Isolate* isolate) {
typedef internal::Address S;
typedef internal::Internals I;
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) {
typedef internal::Internals I;
I::SetEmbedderData(this, slot, data);
}
void* Isolate::GetData(uint32_t slot) {
typedef internal::Internals I;
return I::GetEmbedderData(this, slot);
}
uint32_t Isolate::GetNumberOfDataSlots() {
typedef internal::Internals I;
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);
}
int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
int64_t change_in_bytes) {
typedef internal::Internals I;
constexpr int64_t kMemoryReducerActivationLimit = 32 * 1024 * 1024;
int64_t* external_memory = reinterpret_cast<int64_t*>(
reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryOffset);
int64_t* external_memory_limit = reinterpret_cast<int64_t*>(
reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryLimitOffset);
int64_t* external_memory_at_last_mc =
reinterpret_cast<int64_t*>(reinterpret_cast<uint8_t*>(this) +
I::kExternalMemoryAtLastMarkCompactOffset);
// Embedders are weird: we see both over- and underflows here. Perform the
// addition with unsigned types to avoid undefined behavior.
const int64_t amount =
static_cast<int64_t>(static_cast<uint64_t>(change_in_bytes) +
static_cast<uint64_t>(*external_memory));
*external_memory = amount;
int64_t allocation_diff_since_last_mc =
static_cast<int64_t>(static_cast<uint64_t>(*external_memory) -
static_cast<uint64_t>(*external_memory_at_last_mc));
// Only check memory pressure and potentially trigger GC if the amount of
// external memory increased.
if (allocation_diff_since_last_mc > kMemoryReducerActivationLimit) {
CheckMemoryPressure();
}
if (change_in_bytes < 0) {
const int64_t lower_limit = *external_memory_limit + change_in_bytes;
if (lower_limit > I::kExternalAllocationSoftLimit)
*external_memory_limit = lower_limit;
} else if (change_in_bytes > 0 && amount > *external_memory_limit) {
ReportExternalAllocationLimitReached();
}
return *external_memory;
}
Local<Value> Context::GetEmbedderData(int index) {
#ifndef V8_ENABLE_CHECKS
typedef internal::Address A;
typedef internal::Internals I;
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<int32_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
typedef internal::Address A;
typedef internal::Internals I;
A ctx = *reinterpret_cast<const A*>(this);
A embedder_data =
I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
int value_offset =
I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
return I::ReadRawField<void*>(embedder_data, value_offset);
#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
#undef TYPE_CHECK
#endif // INCLUDE_V8_H_
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