Source/JavaScriptCore/runtime/ObjectToStringAdaptiveStructureWatchpoint.cpp

/*
 * Copyright (C) 2019 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``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 ITS CONTRIBUTORS
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#include "config.h"
#include "ObjectToStringAdaptiveStructureWatchpoint.h"

#include "JSCellInlines.h"
#include "StructureRareData.h"

namespace JSC {

ObjectToStringAdaptiveStructureWatchpoint::ObjectToStringAdaptiveStructureWatchpoint(const ObjectPropertyCondition& key, StructureRareData* structureRareData)
    : Watchpoint(Watchpoint::Type::ObjectToStringAdaptiveStructure)
    , m_structureRareData(structureRareData)
    , m_key(key)
{
    RELEASE_ASSERT(key.watchingRequiresStructureTransitionWatchpoint());
    RELEASE_ASSERT(!key.watchingRequiresReplacementWatchpoint());
}

void ObjectToStringAdaptiveStructureWatchpoint::install(VM& vm)
{
    RELEASE_ASSERT(m_key.isWatchable());

    m_key.object()->structure(vm)->addTransitionWatchpoint(this);
}

void ObjectToStringAdaptiveStructureWatchpoint::fireInternal(VM& vm, const FireDetail&)
{
    if (!m_structureRareData->isLive())
        return;

    if (m_key.isWatchable(PropertyCondition::EnsureWatchability)) {
        install(vm);
        return;
    }

    m_structureRareData->clearObjectToStringValue();
}

} // namespace JSC