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// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef INCLUDE_V8_OBJECT_H_
#define INCLUDE_V8_OBJECT_H_
#include "v8-local-handle.h" // NOLINT(build/include_directory)
#include "v8-maybe.h" // NOLINT(build/include_directory)
#include "v8-persistent-handle.h" // NOLINT(build/include_directory)
#include "v8-primitive.h" // NOLINT(build/include_directory)
#include "v8-traced-handle.h" // NOLINT(build/include_directory)
#include "v8-value.h" // NOLINT(build/include_directory)
#include "v8config.h" // NOLINT(build/include_directory)
namespace v8 {
class Array;
class Function;
class FunctionTemplate;
template <typename T>
class PropertyCallbackInfo;
class Module;
class UnboundScript;
/**
* 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);
};
/**
* 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_;
};
/**
* PropertyAttribute.
*/
enum PropertyAttribute {
/** None. **/
None = 0,
/** ReadOnly, i.e., not writable. **/
ReadOnly = 1 << 0,
/** DontEnum, i.e., not enumerable. **/
DontEnum = 1 << 1,
/** DontDelete, i.e., not configurable. **/
DontDelete = 1 << 2
};
/**
* Accessor[Getter|Setter] are used as callback functions when
* setting|getting a particular property. See Object and ObjectTemplate's
* method SetAccessor.
*/
using AccessorGetterCallback =
void (*)(Local<String> property, const PropertyCallbackInfo<Value>& info);
using AccessorNameGetterCallback =
void (*)(Local<Name> property, const PropertyCallbackInfo<Value>& info);
using AccessorSetterCallback = void (*)(Local<String> property,
Local<Value> value,
const PropertyCallbackInfo<void>& info);
using AccessorNameSetterCallback =
void (*)(Local<Name> property, Local<Value> value,
const PropertyCallbackInfo<void>& info);
/**
* Access control specifications.
*
* Some accessors should be accessible across contexts. These
* accessors have an explicit access control parameter which specifies
* the kind of cross-context access that should be allowed.
*
* TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.
*/
enum AccessControl {
DEFAULT = 0,
ALL_CAN_READ = 1,
ALL_CAN_WRITE = 1 << 1,
PROHIBITS_OVERWRITING = 1 << 2
};
/**
* Property filter bits. They can be or'ed to build a composite filter.
*/
enum PropertyFilter {
ALL_PROPERTIES = 0,
ONLY_WRITABLE = 1,
ONLY_ENUMERABLE = 2,
ONLY_CONFIGURABLE = 4,
SKIP_STRINGS = 8,
SKIP_SYMBOLS = 16
};
/**
* Options for marking whether callbacks may trigger JS-observable side effects.
* Side-effect-free callbacks are allowlisted during debug evaluation with
* throwOnSideEffect. It applies when calling a Function, FunctionTemplate,
* or an Accessor callback. For Interceptors, please see
* PropertyHandlerFlags's kHasNoSideEffect.
* Callbacks that only cause side effects to the receiver are allowlisted if
* invoked on receiver objects that are created within the same debug-evaluate
* call, as these objects are temporary and the side effect does not escape.
*/
enum class SideEffectType {
kHasSideEffect,
kHasNoSideEffect,
kHasSideEffectToReceiver
};
/**
* Keys/Properties filter enums:
*
* KeyCollectionMode limits the range of collected properties. kOwnOnly limits
* the collected properties to the given Object only. kIncludesPrototypes will
* include all keys of the objects's prototype chain as well.
*/
enum class KeyCollectionMode { kOwnOnly, kIncludePrototypes };
/**
* kIncludesIndices allows for integer indices to be collected, while
* kSkipIndices will exclude integer indices from being collected.
*/
enum class IndexFilter { kIncludeIndices, kSkipIndices };
/**
* kConvertToString will convert integer indices to strings.
* kKeepNumbers will return numbers for integer indices.
*/
enum class KeyConversionMode { kConvertToString, kKeepNumbers, kNoNumbers };
/**
* Integrity level for objects.
*/
enum class IntegrityLevel { kFrozen, kSealed };
/**
* A JavaScript object (ECMA-262, 4.3.3)
*/
class V8_EXPORT Object : public Value {
public:
/**
* Set only return Just(true) or Empty(), so if it should never fail, use
* result.Check().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context,
Local<Value> key, Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index,
Local<Value> value);
// Implements CreateDataProperty (ECMA-262, 7.3.4).
//
// Defines a configurable, writable, enumerable property with the given value
// on the object unless the property already exists and is not configurable
// or the object is not extensible.
//
// Returns true on success.
V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
Local<Name> key,
Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
uint32_t index,
Local<Value> value);
// Implements DefineOwnProperty.
//
// In general, CreateDataProperty will be faster, however, does not allow
// for specifying attributes.
//
// Returns true on success.
V8_WARN_UNUSED_RESULT Maybe<bool> DefineOwnProperty(
Local<Context> context, Local<Name> key, Local<Value> value,
PropertyAttribute attributes = None);
// Implements Object.DefineProperty(O, P, Attributes), see Ecma-262 19.1.2.4.
//
// The defineProperty function is used to add an own property or
// update the attributes of an existing own property of an object.
//
// Both data and accessor descriptors can be used.
//
// In general, CreateDataProperty is faster, however, does not allow
// for specifying attributes or an accessor descriptor.
//
// The PropertyDescriptor can change when redefining a property.
//
// Returns true on success.
V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
uint32_t index);
/**
* Gets the property attributes of a property which can be None or
* any combination of ReadOnly, DontEnum and DontDelete. Returns
* None when the property doesn't exist.
*/
V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetPropertyAttributes(
Local<Context> context, Local<Value> key);
/**
* Returns Object.getOwnPropertyDescriptor as per ES2016 section 19.1.2.6.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetOwnPropertyDescriptor(
Local<Context> context, Local<Name> key);
/**
* Object::Has() calls the abstract operation HasProperty(O, P) described
* in ECMA-262, 7.3.10. Has() returns
* true, if the object has the property, either own or on the prototype chain.
* Interceptors, i.e., PropertyQueryCallbacks, are called if present.
*
* Has() has the same side effects as JavaScript's `variable in object`.
* For example, calling Has() on a revoked proxy will throw an exception.
*
* \note Has() converts the key to a name, which possibly calls back into
* JavaScript.
*
* See also v8::Object::HasOwnProperty() and
* v8::Object::HasRealNamedProperty().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
Local<Value> key);
V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context, uint32_t index);
V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
uint32_t index);
/**
* Note: SideEffectType affects the getter only, not the setter.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetAccessor(
Local<Context> context, Local<Name> name,
AccessorNameGetterCallback getter,
AccessorNameSetterCallback setter = nullptr,
MaybeLocal<Value> data = MaybeLocal<Value>(),
AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
void SetAccessorProperty(Local<Name> name, Local<Function> getter,
Local<Function> setter = Local<Function>(),
PropertyAttribute attribute = None,
AccessControl settings = DEFAULT);
/**
* Sets a native data property like Template::SetNativeDataProperty, but
* this method sets on this object directly.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetNativeDataProperty(
Local<Context> context, Local<Name> name,
AccessorNameGetterCallback getter,
AccessorNameSetterCallback setter = nullptr,
Local<Value> data = Local<Value>(), PropertyAttribute attributes = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* Attempts to create a property with the given name which behaves like a data
* property, except that the provided getter is invoked (and provided with the
* data value) to supply its value the first time it is read. After the
* property is accessed once, it is replaced with an ordinary data property.
*
* Analogous to Template::SetLazyDataProperty.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetLazyDataProperty(
Local<Context> context, Local<Name> name,
AccessorNameGetterCallback getter, Local<Value> data = Local<Value>(),
PropertyAttribute attributes = None,
SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect,
SideEffectType setter_side_effect_type = SideEffectType::kHasSideEffect);
/**
* Functionality for private properties.
* This is an experimental feature, use at your own risk.
* Note: Private properties are not inherited. Do not rely on this, since it
* may change.
*/
Maybe<bool> HasPrivate(Local<Context> context, Local<Private> key);
Maybe<bool> SetPrivate(Local<Context> context, Local<Private> key,
Local<Value> value);
Maybe<bool> DeletePrivate(Local<Context> context, Local<Private> key);
MaybeLocal<Value> GetPrivate(Local<Context> context, Local<Private> key);
/**
* Returns an array containing the names of the enumerable properties
* of this object, including properties from prototype objects. The
* array returned by this method contains the same values as would
* be enumerated by a for-in statement over this object.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
Local<Context> context);
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
Local<Context> context, KeyCollectionMode mode,
PropertyFilter property_filter, IndexFilter index_filter,
KeyConversionMode key_conversion = KeyConversionMode::kKeepNumbers);
/**
* This function has the same functionality as GetPropertyNames but
* the returned array doesn't contain the names of properties from
* prototype objects.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
Local<Context> context);
/**
* Returns an array containing the names of the filtered properties
* of this object, including properties from prototype objects. The
* array returned by this method contains the same values as would
* be enumerated by a for-in statement over this object.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
Local<Context> context, PropertyFilter filter,
KeyConversionMode key_conversion = KeyConversionMode::kKeepNumbers);
/**
* Get the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
Local<Value> GetPrototype();
/**
* Set the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> SetPrototype(Local<Context> context,
Local<Value> prototype);
/**
* Finds an instance of the given function template in the prototype
* chain.
*/
Local<Object> FindInstanceInPrototypeChain(Local<FunctionTemplate> tmpl);
/**
* Call builtin Object.prototype.toString on this object.
* This is different from Value::ToString() that may call
* user-defined toString function. This one does not.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<String> ObjectProtoToString(
Local<Context> context);
/**
* Returns the name of the function invoked as a constructor for this object.
*/
Local<String> GetConstructorName();
/**
* Sets the integrity level of the object.
*/
Maybe<bool> SetIntegrityLevel(Local<Context> context, IntegrityLevel level);
/** Gets the number of internal fields for this Object. */
int InternalFieldCount() const;
/** Same as above, but works for PersistentBase. */
V8_INLINE static int InternalFieldCount(
const PersistentBase<Object>& object) {
return object.val_->InternalFieldCount();
}
/** Same as above, but works for BasicTracedReference. */
V8_INLINE static int InternalFieldCount(
const BasicTracedReference<Object>& object) {
return object->InternalFieldCount();
}
/** Gets the value from an internal field. */
V8_INLINE Local<Value> GetInternalField(int index);
/** Sets the value in an internal field. */
void SetInternalField(int index, Local<Value> value);
/**
* Warning: These are Node.js-specific extentions used to avoid breaking
* changes in Node.js v20.x. They do not exist in V8 upstream and will
* not exist in Node.js v21.x. Node.js embedders and addon authors should
* not use them from v20.x.
*/
#ifndef NODE_WANT_INTERNALS
V8_DEPRECATED("This extention should only be used by Node.js core")
#endif
void SetInternalFieldForNodeCore(int index, Local<Module> value);
#ifndef NODE_WANT_INTERNALS
V8_DEPRECATED("This extention should only be used by Node.js core")
#endif
void SetInternalFieldForNodeCore(int index, Local<UnboundScript> 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 TracedReference. */
V8_INLINE static void* GetAlignedPointerFromInternalField(
const BasicTracedReference<Object>& object, int index) {
return object->GetAlignedPointerFromInternalField(index);
}
/**
* Sets a 2-byte-aligned native pointer in an internal field. To retrieve such
* a field, GetAlignedPointerFromInternalField must be used, everything else
* leads to undefined behavior.
*/
void SetAlignedPointerInInternalField(int index, void* value);
void SetAlignedPointerInInternalFields(int argc, int indices[],
void* values[]);
/**
* HasOwnProperty() is like JavaScript's Object.prototype.hasOwnProperty().
*
* See also v8::Object::Has() and v8::Object::HasRealNamedProperty().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
Local<Name> key);
V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
uint32_t index);
/**
* Use HasRealNamedProperty() if you want to check if an object has an own
* property without causing side effects, i.e., without calling interceptors.
*
* This function is similar to v8::Object::HasOwnProperty(), but it does not
* call interceptors.
*
* \note Consider using non-masking interceptors, i.e., the interceptors are
* not called if the receiver has the real named property. See
* `v8::PropertyHandlerFlags::kNonMasking`.
*
* See also v8::Object::Has().
*/
V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedProperty(Local<Context> context,
Local<Name> key);
V8_WARN_UNUSED_RESULT Maybe<bool> HasRealIndexedProperty(
Local<Context> context, uint32_t index);
V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedCallbackProperty(
Local<Context> context, Local<Name> key);
/**
* If result.IsEmpty() no real property was located in the prototype chain.
* This means interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedPropertyInPrototypeChain(
Local<Context> context, Local<Name> key);
/**
* Gets the property attributes of a real property in the prototype chain,
* which can be None or any combination of ReadOnly, DontEnum and DontDelete.
* Interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute>
GetRealNamedPropertyAttributesInPrototypeChain(Local<Context> context,
Local<Name> key);
/**
* If result.IsEmpty() no real property was located on the object or
* in the prototype chain.
* This means interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedProperty(
Local<Context> context, Local<Name> key);
/**
* Gets the property attributes of a real property which can be
* None or any combination of ReadOnly, DontEnum and DontDelete.
* Interceptors in the prototype chain are not called.
*/
V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
Local<Context> context, Local<Name> key);
/** Tests for a named lookup interceptor.*/
bool HasNamedLookupInterceptor() const;
/** Tests for an index lookup interceptor.*/
bool HasIndexedLookupInterceptor() const;
/**
* 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.
*/
MaybeLocal<Context> GetCreationContext();
/**
* Shortcut for GetCreationContext().ToLocalChecked().
**/
Local<Context> GetCreationContextChecked();
/** Same as above, but works for Persistents */
V8_INLINE static MaybeLocal<Context> GetCreationContext(
const PersistentBase<Object>& object) {
return object.val_->GetCreationContext();
}
/**
* Gets the context in which the object was created (see GetCreationContext())
* and if it's available reads respective embedder field value.
* If the context can't be obtained nullptr is returned.
* Basically it's a shortcut for
* obj->GetCreationContext().GetAlignedPointerFromEmbedderData(index)
* which doesn't create a handle for Context object on the way and doesn't
* try to expand the embedder data attached to the context.
* In case the Local<Context> is already available because of other reasons,
* it's fine to keep using Context::GetAlignedPointerFromEmbedderData().
*/
void* GetAlignedPointerFromEmbedderDataInCreationContext(int index);
/**
* Checks whether a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
* When an Object is callable this method returns true.
*/
bool IsCallable() const;
/**
* True if this object is a constructor.
*/
bool IsConstructor() const;
/**
* True if this object can carry information relevant to the embedder in its
* embedder fields, false otherwise. This is generally true for objects
* constructed through function templates but also holds for other types where
* V8 automatically adds internal fields at compile time, such as e.g.
* v8::ArrayBuffer.
*/
bool IsApiWrapper() const;
/**
* True if this object was created from an object template which was marked
* as undetectable. See v8::ObjectTemplate::MarkAsUndetectable for more
* information.
*/
bool IsUndetectable() const;
/**
* Call an Object as a function if a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsFunction(Local<Context> context,
Local<Value> recv,
int argc,
Local<Value> argv[]);
/**
* Call an Object as a constructor if a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
* Note: This method behaves like the Function::NewInstance method.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsConstructor(
Local<Context> context, int argc, Local<Value> argv[]);
/**
* Return the isolate to which the Object belongs to.
*/
Isolate* GetIsolate();
/**
* If this object is a Set, Map, WeakSet or WeakMap, this returns a
* representation of the elements of this object as an array.
* If this object is a SetIterator or MapIterator, this returns all
* elements of the underlying collection, starting at the iterator's current
* position.
* For other types, this will return an empty MaybeLocal<Array> (without
* scheduling an exception).
*/
MaybeLocal<Array> PreviewEntries(bool* is_key_value);
static Local<Object> New(Isolate* isolate);
/**
* Creates a JavaScript object with the given properties, and
* a the given prototype_or_null (which can be any JavaScript
* value, and if it's null, the newly created object won't have
* a prototype at all). This is similar to Object.create().
* All properties will be created as enumerable, configurable
* and writable properties.
*/
static Local<Object> New(Isolate* isolate, Local<Value> prototype_or_null,
Local<Name>* names, Local<Value>* values,
size_t length);
V8_INLINE static Object* Cast(Value* obj);
/**
* Support for TC39 "dynamic code brand checks" proposal.
*
* This API allows to query whether an object was constructed from a
* "code like" ObjectTemplate.
*
* See also: v8::ObjectTemplate::SetCodeLike
*/
bool IsCodeLike(Isolate* isolate) const;
private:
Object();
static void CheckCast(Value* obj);
Local<Value> SlowGetInternalField(int index);
void* SlowGetAlignedPointerFromInternalField(int index);
};
// --- Implementation ---
Local<Value> Object::GetInternalField(int index) {
#ifndef V8_ENABLE_CHECKS
using A = internal::Address;
using I = internal::Internals;
A obj = internal::ValueHelper::ValueAsAddress(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.
int instance_type = I::GetInstanceType(obj);
if (I::CanHaveInternalField(instance_type)) {
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::DecompressTaggedField(obj, static_cast<uint32_t>(value));
#endif
#ifdef V8_ENABLE_CONSERVATIVE_STACK_SCANNING
return Local<Value>(reinterpret_cast<Value*>(value));
#else
internal::Isolate* isolate =
internal::IsolateFromNeverReadOnlySpaceObject(obj);
A* result = HandleScope::CreateHandle(isolate, value);
return Local<Value>(reinterpret_cast<Value*>(result));
#endif
}
#endif
return SlowGetInternalField(index);
}
void* Object::GetAlignedPointerFromInternalField(int index) {
#if !defined(V8_ENABLE_CHECKS)
using A = internal::Address;
using I = internal::Internals;
A obj = internal::ValueHelper::ValueAsAddress(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 (I::CanHaveInternalField(instance_type)) {
int offset = I::kJSObjectHeaderSize + (I::kEmbedderDataSlotSize * index) +
I::kEmbedderDataSlotExternalPointerOffset;
Isolate* isolate = I::GetIsolateForSandbox(obj);
A value =
I::ReadExternalPointerField<internal::kEmbedderDataSlotPayloadTag>(
isolate, obj, offset);
return reinterpret_cast<void*>(value);
}
#endif
return SlowGetAlignedPointerFromInternalField(index);
}
Private* Private::Cast(Data* data) {
#ifdef V8_ENABLE_CHECKS
CheckCast(data);
#endif
return reinterpret_cast<Private*>(data);
}
Object* Object::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Object*>(value);
}
} // namespace v8
#endif // INCLUDE_V8_OBJECT_H_
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