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/*
* Copyright (C) 2005, 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 PropertySlot_h
#define PropertySlot_h
#include "Identifier.h"
#include "JSValue.h"
#include "Register.h"
#include <wtf/Assertions.h>
#include <wtf/NotFound.h>
namespace JSC {
class ExecState;
class JSObject;
#define JSC_VALUE_SLOT_MARKER 0
#define JSC_REGISTER_SLOT_MARKER reinterpret_cast<GetValueFunc>(1)
class PropertySlot {
public:
PropertySlot()
{
clearBase();
clearOffset();
clearValue();
}
explicit PropertySlot(const JSValue base)
: m_slotBase(base)
{
clearOffset();
clearValue();
}
typedef JSValue (*GetValueFunc)(ExecState*, const Identifier&, const PropertySlot&);
JSValue getValue(ExecState* exec, const Identifier& propertyName) const
{
if (m_getValue == JSC_VALUE_SLOT_MARKER)
return *m_data.valueSlot;
if (m_getValue == JSC_REGISTER_SLOT_MARKER)
return (*m_data.registerSlot).jsValue();
return m_getValue(exec, propertyName, *this);
}
JSValue getValue(ExecState* exec, unsigned propertyName) const
{
if (m_getValue == JSC_VALUE_SLOT_MARKER)
return *m_data.valueSlot;
if (m_getValue == JSC_REGISTER_SLOT_MARKER)
return (*m_data.registerSlot).jsValue();
return m_getValue(exec, Identifier::from(exec, propertyName), *this);
}
bool isCacheable() const { return m_offset != WTF::notFound; }
size_t cachedOffset() const
{
ASSERT(isCacheable());
return m_offset;
}
void setValueSlot(JSValue* valueSlot)
{
ASSERT(valueSlot);
clearBase();
clearOffset();
m_getValue = JSC_VALUE_SLOT_MARKER;
m_data.valueSlot = valueSlot;
}
void setValueSlot(JSValue slotBase, JSValue* valueSlot)
{
ASSERT(valueSlot);
m_getValue = JSC_VALUE_SLOT_MARKER;
m_slotBase = slotBase;
m_data.valueSlot = valueSlot;
}
void setValueSlot(JSValue slotBase, JSValue* valueSlot, size_t offset)
{
ASSERT(valueSlot);
m_getValue = JSC_VALUE_SLOT_MARKER;
m_slotBase = slotBase;
m_data.valueSlot = valueSlot;
m_offset = offset;
}
void setValue(JSValue value)
{
ASSERT(value);
clearBase();
clearOffset();
m_getValue = JSC_VALUE_SLOT_MARKER;
m_value = value;
m_data.valueSlot = &m_value;
}
void setRegisterSlot(Register* registerSlot)
{
ASSERT(registerSlot);
clearBase();
clearOffset();
m_getValue = JSC_REGISTER_SLOT_MARKER;
m_data.registerSlot = registerSlot;
}
void setCustom(JSValue slotBase, GetValueFunc getValue)
{
ASSERT(slotBase);
ASSERT(getValue);
m_getValue = getValue;
m_slotBase = slotBase;
}
void setCustomIndex(JSValue slotBase, unsigned index, GetValueFunc getValue)
{
ASSERT(slotBase);
ASSERT(getValue);
m_getValue = getValue;
m_slotBase = slotBase;
m_data.index = index;
}
void setGetterSlot(JSObject* getterFunc)
{
ASSERT(getterFunc);
m_getValue = functionGetter;
m_data.getterFunc = getterFunc;
}
void setUndefined()
{
setValue(jsUndefined());
}
JSValue slotBase() const
{
return m_slotBase;
}
void setBase(JSValue base)
{
ASSERT(m_slotBase);
ASSERT(base);
m_slotBase = base;
}
void clearBase()
{
#ifndef NDEBUG
m_slotBase = JSValue();
#endif
}
void clearValue()
{
#ifndef NDEBUG
m_value = JSValue();
#endif
}
void clearOffset()
{
// Clear offset even in release builds, in case this PropertySlot has been used before.
// (For other data members, we don't need to clear anything because reuse would meaningfully overwrite them.)
m_offset = WTF::notFound;
}
unsigned index() const { return m_data.index; }
private:
static JSValue functionGetter(ExecState*, const Identifier&, const PropertySlot&);
GetValueFunc m_getValue;
JSValue m_slotBase;
union {
JSObject* getterFunc;
JSValue* valueSlot;
Register* registerSlot;
unsigned index;
} m_data;
JSValue m_value;
size_t m_offset;
};
} // namespace JSC
#endif // PropertySlot_h