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/*
* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef JSCell_h
#define JSCell_h
#include "CallData.h"
#include "ConstructData.h"
#include "Heap.h"
#include "JSLock.h"
#include "SlotVisitor.h"
#include "TypedArrayDescriptor.h"
#include "WriteBarrier.h"
#include <wtf/Noncopyable.h>
#include <wtf/TypeTraits.h>
namespace JSC {
class CopyVisitor;
class ExecState;
class JSDestructibleObject;
class JSGlobalObject;
class LLIntOffsetsExtractor;
class PropertyDescriptor;
class PropertyNameArray;
class Structure;
enum EnumerationMode {
ExcludeDontEnumProperties,
IncludeDontEnumProperties
};
template<typename T> void* allocateCell(Heap&);
template<typename T> void* allocateCell(Heap&, size_t);
class JSCell {
friend class JSValue;
friend class MarkedBlock;
template<typename T> friend void* allocateCell(Heap&);
template<typename T> friend void* allocateCell(Heap&, size_t);
public:
static const unsigned StructureFlags = 0;
static const bool needsDestruction = false;
static const bool hasImmortalStructure = false;
enum CreatingEarlyCellTag { CreatingEarlyCell };
JSCell(CreatingEarlyCellTag);
protected:
JSCell(VM&, Structure*);
JS_EXPORT_PRIVATE static void destroy(JSCell*);
public:
// Querying the type.
bool isString() const;
bool isObject() const;
bool isGetterSetter() const;
bool isProxy() const;
bool inherits(const ClassInfo*) const;
bool isAPIValueWrapper() const;
Structure* structure() const;
void setStructure(VM&, Structure*);
void clearStructure() { m_structure.clear(); }
const char* className();
// Extracting the value.
JS_EXPORT_PRIVATE bool getString(ExecState*, String&) const;
JS_EXPORT_PRIVATE String getString(ExecState*) const; // null string if not a string
JS_EXPORT_PRIVATE JSObject* getObject(); // NULL if not an object
const JSObject* getObject() const; // NULL if not an object
JS_EXPORT_PRIVATE static CallType getCallData(JSCell*, CallData&);
JS_EXPORT_PRIVATE static ConstructType getConstructData(JSCell*, ConstructData&);
// Basic conversions.
JS_EXPORT_PRIVATE JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
bool toBoolean(ExecState*) const;
TriState pureToBoolean() const;
JS_EXPORT_PRIVATE double toNumber(ExecState*) const;
JS_EXPORT_PRIVATE JSObject* toObject(ExecState*, JSGlobalObject*) const;
static void visitChildren(JSCell*, SlotVisitor&);
JS_EXPORT_PRIVATE static void copyBackingStore(JSCell*, CopyVisitor&);
// Object operations, with the toObject operation included.
const ClassInfo* classInfo() const;
const MethodTable* methodTable() const;
const MethodTable* methodTableForDestruction() const;
static void put(JSCell*, ExecState*, PropertyName, JSValue, PutPropertySlot&);
static void putByIndex(JSCell*, ExecState*, unsigned propertyName, JSValue, bool shouldThrow);
static bool deleteProperty(JSCell*, ExecState*, PropertyName);
static bool deletePropertyByIndex(JSCell*, ExecState*, unsigned propertyName);
static JSObject* toThisObject(JSCell*, ExecState*);
void zap() { *reinterpret_cast<uintptr_t**>(this) = 0; }
bool isZapped() const { return !*reinterpret_cast<uintptr_t* const*>(this); }
// FIXME: Rename getOwnPropertySlot to virtualGetOwnPropertySlot, and
// fastGetOwnPropertySlot to getOwnPropertySlot. Callers should always
// call this function, not its slower virtual counterpart. (For integer
// property names, we want a similar interface with appropriate optimizations.)
bool fastGetOwnPropertySlot(ExecState*, PropertyName, PropertySlot&);
JSValue fastGetOwnProperty(ExecState*, const String&);
static ptrdiff_t structureOffset()
{
return OBJECT_OFFSETOF(JSCell, m_structure);
}
void* structureAddress()
{
return &m_structure;
}
#if ENABLE(GC_VALIDATION)
Structure* unvalidatedStructure() { return m_structure.unvalidatedGet(); }
#endif
static const TypedArrayType TypedArrayStorageType = TypedArrayNone;
protected:
void finishCreation(VM&);
void finishCreation(VM&, Structure*, CreatingEarlyCellTag);
// Base implementation; for non-object classes implements getPropertySlot.
static bool getOwnPropertySlot(JSCell*, ExecState*, PropertyName, PropertySlot&);
static bool getOwnPropertySlotByIndex(JSCell*, ExecState*, unsigned propertyName, PropertySlot&);
// Dummy implementations of override-able static functions for classes to put in their MethodTable
static JSValue defaultValue(const JSObject*, ExecState*, PreferredPrimitiveType);
static NO_RETURN_DUE_TO_CRASH void getOwnPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
static NO_RETURN_DUE_TO_CRASH void getOwnNonIndexPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
static NO_RETURN_DUE_TO_CRASH void getPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
static String className(const JSObject*);
JS_EXPORT_PRIVATE static bool customHasInstance(JSObject*, ExecState*, JSValue);
static NO_RETURN_DUE_TO_CRASH void putDirectVirtual(JSObject*, ExecState*, PropertyName, JSValue, unsigned attributes);
static bool defineOwnProperty(JSObject*, ExecState*, PropertyName, PropertyDescriptor&, bool shouldThrow);
static bool getOwnPropertyDescriptor(JSObject*, ExecState*, PropertyName, PropertyDescriptor&);
private:
friend class LLIntOffsetsExtractor;
WriteBarrier<Structure> m_structure;
};
template<typename To, typename From>
inline To jsCast(From* from)
{
ASSERT(!from || from->JSCell::inherits(&WTF::RemovePointer<To>::Type::s_info));
return static_cast<To>(from);
}
template<typename To>
inline To jsCast(JSValue from)
{
ASSERT(from.isCell() && from.asCell()->JSCell::inherits(&WTF::RemovePointer<To>::Type::s_info));
return static_cast<To>(from.asCell());
}
template<typename To, typename From>
inline To jsDynamicCast(From* from)
{
return from->inherits(&WTF::RemovePointer<To>::Type::s_info) ? static_cast<To>(from) : 0;
}
template<typename To>
inline To jsDynamicCast(JSValue from)
{
return from.isCell() && from.asCell()->inherits(&WTF::RemovePointer<To>::Type::s_info) ? static_cast<To>(from.asCell()) : 0;
}
} // namespace JSC
#endif // JSCell_h
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