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/*
* Copyright (C) 2016-2019 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.
*/
#pragma once
#include <optional>
#include <wtf/TriState.h>
namespace JSC {
class DefinePropertyAttributes {
public:
static_assert(!static_cast<uint8_t>(TriState::False), "TriState::False is 0.");
static_assert(static_cast<uint8_t>(TriState::True) == 1, "TriState::True is 1.");
static_assert(static_cast<uint8_t>(TriState::Indeterminate) == 2, "TriState::Indeterminate is 2.");
static constexpr unsigned ConfigurableShift = 0;
static constexpr unsigned EnumerableShift = 2;
static constexpr unsigned WritableShift = 4;
static constexpr unsigned ValueShift = 6;
static constexpr unsigned GetShift = 7;
static constexpr unsigned SetShift = 8;
DefinePropertyAttributes()
: m_attributes(
(static_cast<uint8_t>(TriState::Indeterminate) << ConfigurableShift)
| (static_cast<uint8_t>(TriState::Indeterminate) << EnumerableShift)
| (static_cast<uint8_t>(TriState::Indeterminate) << WritableShift)
| (static_cast<uint8_t>(TriState::False) << ValueShift)
| (static_cast<uint8_t>(TriState::False) << GetShift)
| (static_cast<uint8_t>(TriState::False) << SetShift))
{
}
explicit DefinePropertyAttributes(unsigned attributes)
: m_attributes(attributes)
{
}
unsigned rawRepresentation() const
{
return m_attributes;
}
bool hasValue() const
{
return m_attributes & (0b1 << ValueShift);
}
void setValue()
{
m_attributes = m_attributes | (0b1 << ValueShift);
}
bool hasGet() const
{
return m_attributes & (0b1 << GetShift);
}
void setGet()
{
m_attributes = m_attributes | (0b1 << GetShift);
}
bool hasSet() const
{
return m_attributes & (0b1 << SetShift);
}
void setSet()
{
m_attributes = m_attributes | (0b1 << SetShift);
}
bool hasWritable() const
{
return extractTriState(WritableShift) != TriState::Indeterminate;
}
std::optional<bool> writable() const
{
if (!hasWritable())
return std::nullopt;
return extractTriState(WritableShift) == TriState::True;
}
bool hasConfigurable() const
{
return extractTriState(ConfigurableShift) != TriState::Indeterminate;
}
std::optional<bool> configurable() const
{
if (!hasConfigurable())
return std::nullopt;
return extractTriState(ConfigurableShift) == TriState::True;
}
bool hasEnumerable() const
{
return extractTriState(EnumerableShift) != TriState::Indeterminate;
}
std::optional<bool> enumerable() const
{
if (!hasEnumerable())
return std::nullopt;
return extractTriState(EnumerableShift) == TriState::True;
}
void setWritable(bool value)
{
fillWithTriState(value ? TriState::True : TriState::False, WritableShift);
}
void setConfigurable(bool value)
{
fillWithTriState(value ? TriState::True : TriState::False, ConfigurableShift);
}
void setEnumerable(bool value)
{
fillWithTriState(value ? TriState::True : TriState::False, EnumerableShift);
}
private:
void fillWithTriState(TriState state, unsigned shift)
{
unsigned mask = 0b11 << shift;
m_attributes = (m_attributes & ~mask) | (static_cast<uint8_t>(state) << shift);
}
TriState extractTriState(unsigned shift) const
{
return static_cast<TriState>((m_attributes >> shift) & 0b11);
}
unsigned m_attributes;
};
} // namespace JSC
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