webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

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diff --git a/Source/JavaScriptCore/runtime/DefinePropertyAttributes.h b/Source/JavaScriptCore/runtime/DefinePropertyAttributes.h
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+++ b/Source/JavaScriptCore/runtime/DefinePropertyAttributes.h
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+/*
+ * Copyright (C) 2016 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 <wtf/Optional.h>
+#include <wtf/TriState.h>
+
+namespace JSC {
+
+class DefinePropertyAttributes {
+public:
+    static_assert(FalseTriState == 0, "FalseTriState is 0.");
+    static_assert(TrueTriState == 1, "TrueTriState is 1.");
+    static_assert(MixedTriState == 2, "MixedTriState is 2.");
+
+    static const unsigned ConfigurableShift = 0;
+    static const unsigned EnumerableShift = 2;
+    static const unsigned WritableShift = 4;
+    static const unsigned ValueShift = 6;
+    static const unsigned GetShift = 7;
+    static const unsigned SetShift = 8;
+
+    DefinePropertyAttributes()
+        : m_attributes(
+            (MixedTriState << ConfigurableShift)
+            | (MixedTriState << EnumerableShift)
+            | (MixedTriState << WritableShift)
+            | (0 << ValueShift)
+            | (0 << GetShift)
+            | (0 << 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) != MixedTriState;
+    }
+
+    std::optional<bool> writable() const
+    {
+        if (!hasWritable())
+            return std::nullopt;
+        return extractTriState(WritableShift) == TrueTriState;
+    }
+
+    bool hasConfigurable() const
+    {
+        return extractTriState(ConfigurableShift) != MixedTriState;
+    }
+
+    std::optional<bool> configurable() const
+    {
+        if (!hasConfigurable())
+            return std::nullopt;
+        return extractTriState(ConfigurableShift) == TrueTriState;
+    }
+
+    bool hasEnumerable() const
+    {
+        return extractTriState(EnumerableShift) != MixedTriState;
+    }
+
+    std::optional<bool> enumerable() const
+    {
+        if (!hasEnumerable())
+            return std::nullopt;
+        return extractTriState(EnumerableShift) == TrueTriState;
+    }
+
+    void setWritable(bool value)
+    {
+        fillWithTriState(value ? TrueTriState : FalseTriState, WritableShift);
+    }
+
+    void setConfigurable(bool value)
+    {
+        fillWithTriState(value ? TrueTriState : FalseTriState, ConfigurableShift);
+    }
+
+    void setEnumerable(bool value)
+    {
+        fillWithTriState(value ? TrueTriState : FalseTriState, EnumerableShift);
+    }
+
+private:
+    void fillWithTriState(TriState state, unsigned shift)
+    {
+        unsigned mask = 0b11 << shift;
+        m_attributes = (m_attributes & ~mask) | (state << shift);
+    }
+
+    TriState extractTriState(unsigned shift) const
+    {
+        return static_cast<TriState>((m_attributes >> shift) & 0b11);
+    }
+
+    unsigned m_attributes;
+};
+
+
+} // namespace JSC