Source/JavaScriptCore/dfg/DFGVariableEventStream.h

/*
 * Copyright (C) 2012-2017 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

#if ENABLE(DFG_JIT)

#include "DFGMinifiedGraph.h"
#include "DFGVariableEvent.h"
#include "Operands.h"
#include "ValueRecovery.h"
#include <wtf/Vector.h>

namespace JSC { namespace DFG {

struct UndefinedOperandSpan {
    unsigned firstIndex;
    int minOffset;
    unsigned numberOfRegisters;
};

class VariableEventStream {
public:
    VariableEventStream() = default;
    VariableEventStream(Vector<VariableEvent>&& stream)
        : m_stream(WTFMove(stream))
    {
    }

    unsigned reconstruct(CodeBlock*, CodeOrigin, MinifiedGraph&, unsigned index, Operands<ValueRecovery>&) const;
    unsigned reconstruct(CodeBlock*, CodeOrigin, MinifiedGraph&, unsigned index, Operands<ValueRecovery>&, Vector<UndefinedOperandSpan>*) const;

private:
    enum class ReconstructionStyle {
        Combined,
        Separated
    };
    template<ReconstructionStyle style>
    unsigned reconstruct(
        CodeBlock*, CodeOrigin, MinifiedGraph&,
        unsigned index, Operands<ValueRecovery>&, Vector<UndefinedOperandSpan>*) const;

    FixedVector<VariableEvent> m_stream;
};

class VariableEventStreamBuilder {
    WTF_MAKE_NONCOPYABLE(VariableEventStreamBuilder);
public:
    static constexpr bool verbose = false;

    VariableEventStreamBuilder() = default;

    void appendAndLog(const VariableEvent& event)
    {
        if (verbose)
            logEvent(event);
        m_stream.append(event);
    }

    unsigned size() const { return m_stream.size(); }

    Vector<VariableEvent> finalize() { return WTFMove(m_stream); }

private:
    void logEvent(const VariableEvent&);

    Vector<VariableEvent> m_stream;
};

} } // namespace JSC::DFG

#endif // ENABLE(DFG_JIT)