Source/JavaScriptCore/runtime/WideningNumberPredictionFuzzerAgent.cpp

/*
 * Copyright (C) 2019 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
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 *
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#include "config.h"
#include "WideningNumberPredictionFuzzerAgent.h"

#include "CodeBlock.h"

namespace JSC {

WideningNumberPredictionFuzzerAgent::WideningNumberPredictionFuzzerAgent(VM& vm)
    : NumberPredictionFuzzerAgent(vm)
{
}

SpeculatedType WideningNumberPredictionFuzzerAgent::getPrediction(CodeBlock* codeBlock, const CodeOrigin& codeOrigin, SpeculatedType original)
{
    auto locker = holdLock(m_lock);

    if (!(original && speculationChecked(original, SpecBytecodeNumber)))
        return original;

    if (original == SpecBytecodeNumber)
        return original;

    Vector<SpeculatedType> numberTypesNotIncludedInSpeculation;
    for (auto numberType : bytecodeNumberTypes()) {
        if (!(numberType & original))
            numberTypesNotIncludedInSpeculation.append(numberType);
    }

    unsigned numberOfTypesToAdd = m_random.getUint32(numberTypesNotIncludedInSpeculation.size() + 1);
    if (!numberOfTypesToAdd)
        return original;

    SpeculatedType generated = original;
    for (unsigned i = 0; i < numberOfTypesToAdd; i++) {
        unsigned indexOfNewType = m_random.getUint32(numberTypesNotIncludedInSpeculation.size());
        mergeSpeculation(generated, numberTypesNotIncludedInSpeculation[indexOfNewType]);
        numberTypesNotIncludedInSpeculation.remove(indexOfNewType);
    }

    if (Options::dumpFuzzerAgentPredictions())
        dataLogLn("WideningNumberPredictionFuzzerAgent::getPrediction name:(", codeBlock->inferredName(), "#", codeBlock->hashAsStringIfPossible(), "),bytecodeIndex:(", codeOrigin.bytecodeIndex(), "),original:(", SpeculationDump(original), "),generated:(", SpeculationDump(generated), ")");

    return generated;
}

} // namespace JSC