/*

 * Copyright (C) 2009 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "PropertyDescriptor.h"

#include "GetterSetter.h"

#include "JSObject.h"

#include "Operations.h"

namespace JSC {

unsigned PropertyDescriptor::defaultAttributes = (DontDelete << 1) - 1;

bool PropertyDescriptor::writable() const

{

    ASSERT(!isAccessorDescriptor());

    return !(m_attributes & ReadOnly);

}

bool PropertyDescriptor::enumerable() const

{

    return !(m_attributes & DontEnum);

}

bool PropertyDescriptor::configurable() const

{

    return !(m_attributes & DontDelete);

}

bool PropertyDescriptor::isDataDescriptor() const

{

    return m_value || (m_seenAttributes & WritablePresent);

}

bool PropertyDescriptor::isGenericDescriptor() const

{

    return !isAccessorDescriptor() && !isDataDescriptor();

}

bool PropertyDescriptor::isAccessorDescriptor() const

{

    return m_getter || m_setter;

}

void PropertyDescriptor::setUndefined()

{

    m_value = jsUndefined();

    m_attributes = ReadOnly | DontDelete | DontEnum;

}

JSValue PropertyDescriptor::getter() const

{

    ASSERT(isAccessorDescriptor());

    return m_getter;

}

JSValue PropertyDescriptor::setter() const

{

    ASSERT(isAccessorDescriptor());

    return m_setter;

}

void PropertyDescriptor::setDescriptor(JSValue value, unsigned attributes)

{

    ASSERT(value);

    m_attributes = attributes;

    if (attributes & (Getter | Setter)) {

        GetterSetter* accessor = asGetterSetter(value);

        m_getter = accessor->getter();

        m_setter = accessor->setter();

        ASSERT(m_getter || m_setter);

        m_seenAttributes = EnumerablePresent | ConfigurablePresent;

        m_attributes &= ~ReadOnly;

    } else {

        m_value = value;

        m_seenAttributes = EnumerablePresent | ConfigurablePresent | WritablePresent;

    }

}

void PropertyDescriptor::setAccessorDescriptor(JSValue getter, JSValue setter, unsigned attributes)

{

    ASSERT(attributes & (Getter | Setter));

    ASSERT(getter || setter);

    m_attributes = attributes;

    m_getter = getter;

    m_setter = setter;

    m_attributes &= ~ReadOnly;

    m_seenAttributes = EnumerablePresent | ConfigurablePresent;

}

void PropertyDescriptor::setWritable(bool writable)

{

    if (writable)

        m_attributes &= ~ReadOnly;

    else

        m_attributes |= ReadOnly;

    m_seenAttributes |= WritablePresent;

}

void PropertyDescriptor::setEnumerable(bool enumerable)

{

    if (enumerable)

        m_attributes &= ~DontEnum;

    else

        m_attributes |= DontEnum;

    m_seenAttributes |= EnumerablePresent;

}

void PropertyDescriptor::setConfigurable(bool configurable)

{

    if (configurable)

        m_attributes &= ~DontDelete;

    else

        m_attributes |= DontDelete;

    m_seenAttributes |= ConfigurablePresent;

}

void PropertyDescriptor::setSetter(JSValue setter)

{

    m_setter = setter;

    m_attributes |= Setter;

    m_attributes &= ~ReadOnly;

}

void PropertyDescriptor::setGetter(JSValue getter)

{

    m_getter = getter;

    m_attributes |= Getter;

    m_attributes &= ~ReadOnly;

}

bool PropertyDescriptor::equalTo(ExecState* exec, const PropertyDescriptor& other) const

{

    if (!other.m_value == m_value ||

        !other.m_getter == m_getter ||

        !other.m_setter == m_setter)

        return false;

    return (!m_value || JSValue::strictEqual(exec, other.m_value, m_value)) && 

           (!m_getter || JSValue::strictEqual(exec, other.m_getter, m_getter)) && 

           (!m_setter || JSValue::strictEqual(exec, other.m_setter, m_setter)) &&

           attributesEqual(other);

}

bool PropertyDescriptor::attributesEqual(const PropertyDescriptor& other) const

{

    unsigned mismatch = other.m_attributes ^ m_attributes;

    unsigned sharedSeen = other.m_seenAttributes & m_seenAttributes;

    if (sharedSeen & WritablePresent && mismatch & ReadOnly)

        return false;

    if (sharedSeen & ConfigurablePresent && mismatch & DontDelete)

        return false;

    if (sharedSeen & EnumerablePresent && mismatch & DontEnum)

        return false;

    return true;

}

unsigned PropertyDescriptor::attributesWithOverride(const PropertyDescriptor& other) const

{

    unsigned mismatch = other.m_attributes ^ m_attributes;

    unsigned sharedSeen = other.m_seenAttributes & m_seenAttributes;

    unsigned newAttributes = m_attributes & defaultAttributes;

    if (sharedSeen & WritablePresent && mismatch & ReadOnly)

        newAttributes ^= ReadOnly;

    if (sharedSeen & ConfigurablePresent && mismatch & DontDelete)

        newAttributes ^= DontDelete;

    if (sharedSeen & EnumerablePresent && mismatch & DontEnum)

        newAttributes ^= DontEnum;

    return newAttributes;

}

}