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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, 2006, 2007, 2008 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 JSObject_h
#define JSObject_h
#include "ArgList.h"
#include "ClassInfo.h"
#include "CommonIdentifiers.h"
#include "CallFrame.h"
#include "JSNumberCell.h"
#include "PropertySlot.h"
#include "PutPropertySlot.h"
#include "ScopeChain.h"
#include "Structure.h"
#include "JSGlobalData.h"
#include <wtf/StdLibExtras.h>
namespace JSC {
inline JSCell* getJSFunction(JSGlobalData& globalData, JSValue value)
{
if (value.isCell() && (value.asCell()->vptr() == globalData.jsFunctionVPtr))
return value.asCell();
return 0;
}
class InternalFunction;
class PropertyNameArray;
class Structure;
struct HashEntry;
struct HashTable;
// ECMA 262-3 8.6.1
// Property attributes
enum Attribute {
None = 0,
ReadOnly = 1 << 1, // property can be only read, not written
DontEnum = 1 << 2, // property doesn't appear in (for .. in ..)
DontDelete = 1 << 3, // property can't be deleted
Function = 1 << 4, // property is a function - only used by static hashtables
Getter = 1 << 5, // property is a getter
Setter = 1 << 6 // property is a setter
};
typedef EncodedJSValue* PropertyStorage;
typedef const EncodedJSValue* ConstPropertyStorage;
class JSObject : public JSCell {
friend class BatchedTransitionOptimizer;
friend class JIT;
friend class JSCell;
public:
explicit JSObject(PassRefPtr<Structure>);
virtual void mark();
// The inline virtual destructor cannot be the first virtual function declared
// in the class as it results in the vtable being generated as a weak symbol
virtual ~JSObject();
bool inherits(const ClassInfo* classInfo) const { return JSCell::isObject(classInfo); }
JSValue prototype() const;
void setPrototype(JSValue prototype);
void setStructure(PassRefPtr<Structure>);
Structure* inheritorID();
virtual UString className() const;
JSValue get(ExecState*, const Identifier& propertyName) const;
JSValue get(ExecState*, unsigned propertyName) const;
bool getPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
bool getPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
virtual void put(ExecState*, const Identifier& propertyName, JSValue value, PutPropertySlot&);
virtual void put(ExecState*, unsigned propertyName, JSValue value);
virtual void putWithAttributes(ExecState*, const Identifier& propertyName, JSValue value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot);
virtual void putWithAttributes(ExecState*, const Identifier& propertyName, JSValue value, unsigned attributes);
virtual void putWithAttributes(ExecState*, unsigned propertyName, JSValue value, unsigned attributes);
bool propertyIsEnumerable(ExecState*, const Identifier& propertyName) const;
bool hasProperty(ExecState*, const Identifier& propertyName) const;
bool hasProperty(ExecState*, unsigned propertyName) const;
bool hasOwnProperty(ExecState*, const Identifier& propertyName) const;
virtual bool deleteProperty(ExecState*, const Identifier& propertyName);
virtual bool deleteProperty(ExecState*, unsigned propertyName);
virtual JSValue defaultValue(ExecState*, PreferredPrimitiveType) const;
virtual bool hasInstance(ExecState*, JSValue, JSValue prototypeProperty);
virtual void getPropertyNames(ExecState*, PropertyNameArray&);
virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType = NoPreference) const;
virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue& value);
virtual bool toBoolean(ExecState*) const;
virtual double toNumber(ExecState*) const;
virtual UString toString(ExecState*) const;
virtual JSObject* toObject(ExecState*) const;
virtual JSObject* toThisObject(ExecState*) const;
virtual JSObject* unwrappedObject();
virtual bool getPropertyAttributes(ExecState*, const Identifier& propertyName, unsigned& attributes) const;
bool getPropertySpecificValue(ExecState* exec, const Identifier& propertyName, JSCell*& specificFunction) const;
// This get function only looks at the property map.
JSValue getDirect(const Identifier& propertyName) const
{
size_t offset = m_structure->get(propertyName);
return offset != WTF::notFound ? getDirectOffset(offset) : JSValue();
}
JSValue* getDirectLocation(const Identifier& propertyName)
{
size_t offset = m_structure->get(propertyName);
return offset != WTF::notFound ? locationForOffset(offset) : 0;
}
JSValue* getDirectLocation(const Identifier& propertyName, unsigned& attributes)
{
JSCell* specificFunction;
size_t offset = m_structure->get(propertyName, attributes, specificFunction);
return offset != WTF::notFound ? locationForOffset(offset) : 0;
}
size_t offsetForLocation(JSValue* location) const
{
return location - reinterpret_cast<const JSValue*>(propertyStorage());
}
void transitionTo(Structure*);
void removeDirect(const Identifier& propertyName);
bool hasCustomProperties() { return !m_structure->isEmpty(); }
bool hasGetterSetterProperties() { return m_structure->hasGetterSetterProperties(); }
void putDirect(const Identifier& propertyName, JSValue value, unsigned attr, bool checkReadOnly, PutPropertySlot& slot);
void putDirect(const Identifier& propertyName, JSValue value, unsigned attr = 0);
void putDirectFunction(const Identifier& propertyName, JSCell* value, unsigned attr = 0);
void putDirectFunction(const Identifier& propertyName, JSCell* value, unsigned attr, bool checkReadOnly, PutPropertySlot& slot);
void putDirectFunction(ExecState* exec, InternalFunction* function, unsigned attr = 0);
void putDirectWithoutTransition(const Identifier& propertyName, JSValue value, unsigned attr = 0);
void putDirectFunctionWithoutTransition(const Identifier& propertyName, JSCell* value, unsigned attr = 0);
void putDirectFunctionWithoutTransition(ExecState* exec, InternalFunction* function, unsigned attr = 0);
// Fast access to known property offsets.
JSValue getDirectOffset(size_t offset) const { return JSValue::decode(propertyStorage()[offset]); }
void putDirectOffset(size_t offset, JSValue value) { propertyStorage()[offset] = JSValue::encode(value); }
void fillGetterPropertySlot(PropertySlot&, JSValue* location);
virtual void defineGetter(ExecState*, const Identifier& propertyName, JSObject* getterFunction);
virtual void defineSetter(ExecState*, const Identifier& propertyName, JSObject* setterFunction);
virtual JSValue lookupGetter(ExecState*, const Identifier& propertyName);
virtual JSValue lookupSetter(ExecState*, const Identifier& propertyName);
virtual bool isGlobalObject() const { return false; }
virtual bool isVariableObject() const { return false; }
virtual bool isActivationObject() const { return false; }
virtual bool isWatchdogException() const { return false; }
virtual bool isNotAnObjectErrorStub() const { return false; }
void allocatePropertyStorage(size_t oldSize, size_t newSize);
void allocatePropertyStorageInline(size_t oldSize, size_t newSize);
bool isUsingInlineStorage() const { return m_structure->isUsingInlineStorage(); }
static const size_t inlineStorageCapacity = sizeof(EncodedJSValue) == 2 * sizeof(void*) ? 4 : 3;
static const size_t nonInlineBaseStorageCapacity = 16;
static PassRefPtr<Structure> createStructure(JSValue prototype)
{
return Structure::create(prototype, TypeInfo(ObjectType, HasStandardGetOwnPropertySlot));
}
private:
ConstPropertyStorage propertyStorage() const { return (isUsingInlineStorage() ? m_inlineStorage : m_externalStorage); }
PropertyStorage propertyStorage() { return (isUsingInlineStorage() ? m_inlineStorage : m_externalStorage); }
const JSValue* locationForOffset(size_t offset) const
{
return reinterpret_cast<const JSValue*>(&propertyStorage()[offset]);
}
JSValue* locationForOffset(size_t offset)
{
return reinterpret_cast<JSValue*>(&propertyStorage()[offset]);
}
void putDirectInternal(const Identifier& propertyName, JSValue value, unsigned attr, bool checkReadOnly, PutPropertySlot& slot, JSCell*);
void putDirectInternal(JSGlobalData&, const Identifier& propertyName, JSValue value, unsigned attr, bool checkReadOnly, PutPropertySlot& slot);
void putDirectInternal(JSGlobalData&, const Identifier& propertyName, JSValue value, unsigned attr = 0);
bool inlineGetOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
const HashEntry* findPropertyHashEntry(ExecState*, const Identifier& propertyName) const;
Structure* createInheritorID();
union {
PropertyStorage m_externalStorage;
EncodedJSValue m_inlineStorage[inlineStorageCapacity];
};
RefPtr<Structure> m_inheritorID;
};
JSObject* constructEmptyObject(ExecState*);
inline JSObject* asObject(JSValue value)
{
ASSERT(asCell(value)->isObject());
return static_cast<JSObject*>(asCell(value));
}
inline JSObject::JSObject(PassRefPtr<Structure> structure)
: JSCell(structure.releaseRef()) // ~JSObject balances this ref()
{
ASSERT(m_structure);
ASSERT(m_structure->propertyStorageCapacity() == inlineStorageCapacity);
ASSERT(m_structure->isEmpty());
ASSERT(prototype().isNull() || Heap::heap(this) == Heap::heap(prototype()));
#if USE(JSVALUE64) || USE(JSVALUE32_64)
ASSERT(OBJECT_OFFSETOF(JSObject, m_inlineStorage) % sizeof(double) == 0);
#endif
}
inline JSObject::~JSObject()
{
ASSERT(m_structure);
if (!isUsingInlineStorage())
delete [] m_externalStorage;
m_structure->deref();
}
inline JSValue JSObject::prototype() const
{
return m_structure->storedPrototype();
}
inline void JSObject::setPrototype(JSValue prototype)
{
ASSERT(prototype);
RefPtr<Structure> newStructure = Structure::changePrototypeTransition(m_structure, prototype);
setStructure(newStructure.release());
}
inline void JSObject::setStructure(PassRefPtr<Structure> structure)
{
m_structure->deref();
m_structure = structure.releaseRef(); // ~JSObject balances this ref()
}
inline Structure* JSObject::inheritorID()
{
if (m_inheritorID)
return m_inheritorID.get();
return createInheritorID();
}
inline bool Structure::isUsingInlineStorage() const
{
return (propertyStorageCapacity() == JSObject::inlineStorageCapacity);
}
inline bool JSCell::isObject(const ClassInfo* info) const
{
for (const ClassInfo* ci = classInfo(); ci; ci = ci->parentClass) {
if (ci == info)
return true;
}
return false;
}
// this method is here to be after the inline declaration of JSCell::isObject
inline bool JSValue::isObject(const ClassInfo* classInfo) const
{
return isCell() && asCell()->isObject(classInfo);
}
ALWAYS_INLINE bool JSObject::inlineGetOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
if (JSValue* location = getDirectLocation(propertyName)) {
if (m_structure->hasGetterSetterProperties() && location[0].isGetterSetter())
fillGetterPropertySlot(slot, location);
else
slot.setValueSlot(this, location, offsetForLocation(location));
return true;
}
// non-standard Netscape extension
if (propertyName == exec->propertyNames().underscoreProto) {
slot.setValue(prototype());
return true;
}
return false;
}
// It may seem crazy to inline a function this large, especially a virtual function,
// but it makes a big difference to property lookup that derived classes can inline their
// base class call to this.
ALWAYS_INLINE bool JSObject::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
return inlineGetOwnPropertySlot(exec, propertyName, slot);
}
ALWAYS_INLINE bool JSCell::fastGetOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
if (structure()->typeInfo().hasStandardGetOwnPropertySlot())
return asObject(this)->inlineGetOwnPropertySlot(exec, propertyName, slot);
return getOwnPropertySlot(exec, propertyName, slot);
}
// It may seem crazy to inline a function this large but it makes a big difference
// since this is function very hot in variable lookup
inline bool JSObject::getPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
JSObject* object = this;
while (true) {
if (object->fastGetOwnPropertySlot(exec, propertyName, slot))
return true;
JSValue prototype = object->prototype();
if (!prototype.isObject())
return false;
object = asObject(prototype);
}
}
inline bool JSObject::getPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
JSObject* object = this;
while (true) {
if (object->getOwnPropertySlot(exec, propertyName, slot))
return true;
JSValue prototype = object->prototype();
if (!prototype.isObject())
return false;
object = asObject(prototype);
}
}
inline JSValue JSObject::get(ExecState* exec, const Identifier& propertyName) const
{
PropertySlot slot(this);
if (const_cast<JSObject*>(this)->getPropertySlot(exec, propertyName, slot))
return slot.getValue(exec, propertyName);
return jsUndefined();
}
inline JSValue JSObject::get(ExecState* exec, unsigned propertyName) const
{
PropertySlot slot(this);
if (const_cast<JSObject*>(this)->getPropertySlot(exec, propertyName, slot))
return slot.getValue(exec, propertyName);
return jsUndefined();
}
inline void JSObject::putDirectInternal(const Identifier& propertyName, JSValue value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot, JSCell* specificFunction)
{
ASSERT(value);
ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
if (m_structure->isDictionary()) {
unsigned currentAttributes;
JSCell* currentSpecificFunction;
size_t offset = m_structure->get(propertyName, currentAttributes, currentSpecificFunction);
if (offset != WTF::notFound) {
if (currentSpecificFunction && (specificFunction != currentSpecificFunction))
m_structure->despecifyDictionaryFunction(propertyName);
if (checkReadOnly && currentAttributes & ReadOnly)
return;
putDirectOffset(offset, value);
if (!specificFunction && !currentSpecificFunction)
slot.setExistingProperty(this, offset);
return;
}
size_t currentCapacity = m_structure->propertyStorageCapacity();
offset = m_structure->addPropertyWithoutTransition(propertyName, attributes, specificFunction);
if (currentCapacity != m_structure->propertyStorageCapacity())
allocatePropertyStorage(currentCapacity, m_structure->propertyStorageCapacity());
ASSERT(offset < m_structure->propertyStorageCapacity());
putDirectOffset(offset, value);
// See comment on setNewProperty call below.
if (!specificFunction)
slot.setNewProperty(this, offset);
return;
}
size_t offset;
size_t currentCapacity = m_structure->propertyStorageCapacity();
if (RefPtr<Structure> structure = Structure::addPropertyTransitionToExistingStructure(m_structure, propertyName, attributes, specificFunction, offset)) {
if (currentCapacity != structure->propertyStorageCapacity())
allocatePropertyStorage(currentCapacity, structure->propertyStorageCapacity());
ASSERT(offset < structure->propertyStorageCapacity());
setStructure(structure.release());
putDirectOffset(offset, value);
// See comment on setNewProperty call below.
if (!specificFunction)
slot.setNewProperty(this, offset);
return;
}
unsigned currentAttributes;
JSCell* currentSpecificFunction;
offset = m_structure->get(propertyName, currentAttributes, currentSpecificFunction);
if (offset != WTF::notFound) {
if (checkReadOnly && currentAttributes & ReadOnly)
return;
if (currentSpecificFunction && (specificFunction != currentSpecificFunction)) {
setStructure(Structure::despecifyFunctionTransition(m_structure, propertyName));
putDirectOffset(offset, value);
// Function transitions are not currently cachable, so leave the slot in an uncachable state.
return;
}
putDirectOffset(offset, value);
slot.setExistingProperty(this, offset);
return;
}
// If we have a specific function, we may have got to this point if there is
// already a transition with the correct property name and attributes, but
// specialized to a different function. In this case we just want to give up
// and despecialize the transition.
// In this case we clear the value of specificFunction which will result
// in us adding a non-specific transition, and any subsequent lookup in
// Structure::addPropertyTransitionToExistingStructure will just use that.
if (specificFunction && m_structure->hasTransition(propertyName, attributes))
specificFunction = 0;
RefPtr<Structure> structure = Structure::addPropertyTransition(m_structure, propertyName, attributes, specificFunction, offset);
if (currentCapacity != structure->propertyStorageCapacity())
allocatePropertyStorage(currentCapacity, structure->propertyStorageCapacity());
ASSERT(offset < structure->propertyStorageCapacity());
setStructure(structure.release());
putDirectOffset(offset, value);
// Function transitions are not currently cachable, so leave the slot in an uncachable state.
if (!specificFunction)
slot.setNewProperty(this, offset);
}
inline void JSObject::putDirectInternal(JSGlobalData& globalData, const Identifier& propertyName, JSValue value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot)
{
ASSERT(value);
ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
putDirectInternal(propertyName, value, attributes, checkReadOnly, slot, getJSFunction(globalData, value));
}
inline void JSObject::putDirectInternal(JSGlobalData& globalData, const Identifier& propertyName, JSValue value, unsigned attributes)
{
PutPropertySlot slot;
putDirectInternal(propertyName, value, attributes, false, slot, getJSFunction(globalData, value));
}
inline void JSObject::putDirect(const Identifier& propertyName, JSValue value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot)
{
ASSERT(value);
ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
putDirectInternal(propertyName, value, attributes, checkReadOnly, slot, 0);
}
inline void JSObject::putDirect(const Identifier& propertyName, JSValue value, unsigned attributes)
{
PutPropertySlot slot;
putDirectInternal(propertyName, value, attributes, false, slot, 0);
}
inline void JSObject::putDirectFunction(const Identifier& propertyName, JSCell* value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot)
{
putDirectInternal(propertyName, value, attributes, checkReadOnly, slot, value);
}
inline void JSObject::putDirectFunction(const Identifier& propertyName, JSCell* value, unsigned attr)
{
PutPropertySlot slot;
putDirectInternal(propertyName, value, attr, false, slot, value);
}
inline void JSObject::putDirectWithoutTransition(const Identifier& propertyName, JSValue value, unsigned attributes)
{
size_t currentCapacity = m_structure->propertyStorageCapacity();
size_t offset = m_structure->addPropertyWithoutTransition(propertyName, attributes, 0);
if (currentCapacity != m_structure->propertyStorageCapacity())
allocatePropertyStorage(currentCapacity, m_structure->propertyStorageCapacity());
putDirectOffset(offset, value);
}
inline void JSObject::putDirectFunctionWithoutTransition(const Identifier& propertyName, JSCell* value, unsigned attributes)
{
size_t currentCapacity = m_structure->propertyStorageCapacity();
size_t offset = m_structure->addPropertyWithoutTransition(propertyName, attributes, value);
if (currentCapacity != m_structure->propertyStorageCapacity())
allocatePropertyStorage(currentCapacity, m_structure->propertyStorageCapacity());
putDirectOffset(offset, value);
}
inline void JSObject::transitionTo(Structure* newStructure)
{
if (m_structure->propertyStorageCapacity() != newStructure->propertyStorageCapacity())
allocatePropertyStorage(m_structure->propertyStorageCapacity(), newStructure->propertyStorageCapacity());
setStructure(newStructure);
}
inline JSValue JSObject::toPrimitive(ExecState* exec, PreferredPrimitiveType preferredType) const
{
return defaultValue(exec, preferredType);
}
inline JSValue JSValue::get(ExecState* exec, const Identifier& propertyName) const
{
PropertySlot slot(asValue());
return get(exec, propertyName, slot);
}
inline JSValue JSValue::get(ExecState* exec, const Identifier& propertyName, PropertySlot& slot) const
{
if (UNLIKELY(!isCell())) {
JSObject* prototype = synthesizePrototype(exec);
if (propertyName == exec->propertyNames().underscoreProto)
return prototype;
if (!prototype->getPropertySlot(exec, propertyName, slot))
return jsUndefined();
return slot.getValue(exec, propertyName);
}
JSCell* cell = asCell();
while (true) {
if (cell->fastGetOwnPropertySlot(exec, propertyName, slot))
return slot.getValue(exec, propertyName);
ASSERT(cell->isObject());
JSValue prototype = static_cast<JSObject*>(cell)->prototype();
if (!prototype.isObject())
return jsUndefined();
cell = asObject(prototype);
}
}
inline JSValue JSValue::get(ExecState* exec, unsigned propertyName) const
{
PropertySlot slot(asValue());
return get(exec, propertyName, slot);
}
inline JSValue JSValue::get(ExecState* exec, unsigned propertyName, PropertySlot& slot) const
{
if (UNLIKELY(!isCell())) {
JSObject* prototype = synthesizePrototype(exec);
if (!prototype->getPropertySlot(exec, propertyName, slot))
return jsUndefined();
return slot.getValue(exec, propertyName);
}
JSCell* cell = const_cast<JSCell*>(asCell());
while (true) {
if (cell->getOwnPropertySlot(exec, propertyName, slot))
return slot.getValue(exec, propertyName);
ASSERT(cell->isObject());
JSValue prototype = static_cast<JSObject*>(cell)->prototype();
if (!prototype.isObject())
return jsUndefined();
cell = prototype.asCell();
}
}
inline void JSValue::put(ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
{
if (UNLIKELY(!isCell())) {
synthesizeObject(exec)->put(exec, propertyName, value, slot);
return;
}
asCell()->put(exec, propertyName, value, slot);
}
inline void JSValue::put(ExecState* exec, unsigned propertyName, JSValue value)
{
if (UNLIKELY(!isCell())) {
synthesizeObject(exec)->put(exec, propertyName, value);
return;
}
asCell()->put(exec, propertyName, value);
}
ALWAYS_INLINE void JSObject::allocatePropertyStorageInline(size_t oldSize, size_t newSize)
{
ASSERT(newSize > oldSize);
// It's important that this function not rely on m_structure, since
// we might be in the middle of a transition.
bool wasInline = (oldSize == JSObject::inlineStorageCapacity);
PropertyStorage oldPropertyStorage = (wasInline ? m_inlineStorage : m_externalStorage);
PropertyStorage newPropertyStorage = new EncodedJSValue[newSize];
for (unsigned i = 0; i < oldSize; ++i)
newPropertyStorage[i] = oldPropertyStorage[i];
if (!wasInline)
delete [] oldPropertyStorage;
m_externalStorage = newPropertyStorage;
}
} // namespace JSC
#endif // JSObject_h