weex_core/Source/include/JavaScriptCore/domjit/DOMJITEffect.h

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

#pragma once

#include "DOMJITHeapRange.h"
#include <wtf/Optional.h>

namespace JSC { namespace DOMJIT {

class Effect {
public:
    HeapRange reads { HeapRange::top() };
    HeapRange writes { HeapRange::top() };
    HeapRange def { HeapRange::top() };

    constexpr Effect() = default;
    constexpr Effect(HeapRange reads, HeapRange writes)
        : reads(reads)
        , writes(writes)
    {
    }

    constexpr Effect(HeapRange reads, HeapRange writes, HeapRange def)
        : reads(reads)
        , writes(writes)
        , def(def)
    {
    }

    constexpr static Effect forWrite(HeapRange writeRange)
    {
        return Effect(HeapRange::none(), writeRange);
    }

    constexpr static Effect forRead(HeapRange readRange)
    {
        return Effect(readRange, HeapRange::none());
    }

    constexpr static Effect forReadWrite(HeapRange readRange, HeapRange writeRange)
    {
        return Effect(readRange, writeRange);
    }

    constexpr static Effect forPure()
    {
        return Effect(HeapRange::none(), HeapRange::none(), HeapRange::none());
    }

    constexpr static Effect forDef(HeapRange def)
    {
        return Effect(def, HeapRange::none(), def);
    }

    constexpr static Effect forDef(HeapRange def, HeapRange readRange, HeapRange writeRange)
    {
        return Effect(readRange, writeRange, def);
    }

    constexpr bool mustGenerate() const
    {
        return !!writes;
    }
};

} }