qv4debugjob.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant
 
#include "qv4debugjob.h"
 
#include <private/qqmlcontext_p.h>
#include <private/qqmldebugservice_p.h>
#include <private/qv4jscall_p.h>
#include <private/qv4qmlcontext_p.h>
#include <private/qv4qobjectwrapper_p.h>
#include <private/qv4script_p.h>
#include <private/qv4stackframe_p.h>
 
#include <QtQml/qqmlengine.h>
 
#include <QtCore/qpointer.h>
 
QT_BEGIN_NAMESPACE
 
QV4DebugJob::~QV4DebugJob()
{
}
 
JavaScriptJob::JavaScriptJob(QV4::ExecutionEngine *engine, int frameNr, int context,
                             const QString &script) :
    engine(engine), frameNr(frameNr), context(context), script(script),
    resultIsException(false)
{}
 
void JavaScriptJob::run()
{
    QV4::Scope scope(engine);
 
    QV4::ScopedContext ctx(scope, engine->currentStackFrame ? engine->currentContext()
                                                            : engine->scriptContext());
 
    QV4::CppStackFrame *frame = engine->currentStackFrame;
 
    for (int i = 0; frame && i < frameNr; ++i)
        frame = frame->parentFrame();
    if (frameNr > 0 && frame)
        ctx = frame->context();
 
    if (context >= 0) {
        QObject *forId = QQmlDebugService::objectForId(context);
        QQmlContext *extraContext = qmlContext(forId);
        if (extraContext)
            ctx = QV4::QmlContext::create(ctx, QQmlContextData::get(extraContext), forId);
    } else if (frameNr < 0) { // Use QML context if available
        QQmlEngine *qmlEngine = engine->qmlEngine();
        if (qmlEngine) {
            QQmlContext *qmlRootContext = qmlEngine->rootContext();
            QQmlContextPrivate *ctxtPriv = QQmlContextPrivate::get(qmlRootContext);
 
            QV4::ScopedObject withContext(scope, engine->newObject());
            QV4::ScopedString k(scope);
            QV4::ScopedValue v(scope);
            const QList<QPointer<QObject>> instances = ctxtPriv->instances();
            for (const QPointer<QObject> &object : instances) {
                if (QQmlContext *context = qmlContext(object.data())) {
                    if (QQmlRefPointer<QQmlContextData> cdata = QQmlContextData::get(context)) {
                        v = QV4::QObjectWrapper::wrap(engine, object);
                        k = engine->newString(cdata->findObjectId(object));
                        withContext->put(k, v);
                    }
                }
            }
            if (!engine->qmlContext())
                ctx = QV4::QmlContext::create(ctx, QQmlContextData::get(qmlRootContext), nullptr);
        }
    }
 
    QV4::Script script(ctx, QV4::Compiler::ContextType::Eval, this->script);
    if (const QV4::Function *function = frame ? frame->v4Function : engine->globalCode)
        script.setStrictMode(function->isStrict());
 
    // In order for property lookups in QML to work, we need to disable fast v4 lookups. That
    // is a side-effect of inheritContext.
    script.setInheritContext();
    script.parse();
    QV4::ScopedValue result(scope);
    if (!scope.hasException()) {
        if (frame) {
            QV4::ScopedValue thisObject(scope, frame->thisObject());
            result = script.run(thisObject);
        } else {
            result = script.run();
        }
    }
    if (scope.hasException()) {
        result = scope.engine->catchException();
        resultIsException = true;
    }
    handleResult(result);
}
 
bool JavaScriptJob::hasExeption() const
{
    return resultIsException;
}
 
BacktraceJob::BacktraceJob(QV4DataCollector *collector, int fromFrame, int toFrame) :
    CollectJob(collector), fromFrame(fromFrame), toFrame(toFrame)
{
}
 
void BacktraceJob::run()
{
    QJsonArray frameArray;
    QVector<QV4::StackFrame> frames = collector->engine()->stackTrace(toFrame);
    for (int i = fromFrame; i < toFrame && i < frames.size(); ++i)
        frameArray.push_back(collector->buildFrame(frames[i], i));
    if (frameArray.isEmpty()) {
        result.insert(QStringLiteral("totalFrames"), 0);
    } else {
        result.insert(QStringLiteral("fromFrame"), fromFrame);
        result.insert(QStringLiteral("toFrame"), fromFrame + frameArray.size());
        result.insert(QStringLiteral("frames"), frameArray);
    }
}
 
FrameJob::FrameJob(QV4DataCollector *collector, int frameNr) :
    CollectJob(collector), frameNr(frameNr), success(false)
{
}
 
void FrameJob::run()
{
    QVector<QV4::StackFrame> frames = collector->engine()->stackTrace(frameNr + 1);
    if (frameNr >= frames.size()) {
        success = false;
    } else {
        result = collector->buildFrame(frames[frameNr], frameNr);
        success = true;
    }
}
 
bool FrameJob::wasSuccessful() const
{
    return success;
}
 
ScopeJob::ScopeJob(QV4DataCollector *collector, int frameNr, int scopeNr) :
    CollectJob(collector), frameNr(frameNr), scopeNr(scopeNr), success(false)
{
}
 
void ScopeJob::run()
{
    QJsonObject object;
    success = collector->collectScope(&object, frameNr, scopeNr);
 
    if (success) {
        QVector<QV4::Heap::ExecutionContext::ContextType> scopeTypes =
                collector->getScopeTypes(frameNr);
        result[QLatin1String("type")] = QV4DataCollector::encodeScopeType(scopeTypes[scopeNr]);
    } else {
        result[QLatin1String("type")] = -1;
    }
    result[QLatin1String("index")] = scopeNr;
    result[QLatin1String("frameIndex")] = frameNr;
    result[QLatin1String("object")] = object;
}
 
bool ScopeJob::wasSuccessful() const
{
    return success;
}
 
ValueLookupJob::ValueLookupJob(const QJsonArray &handles, QV4DataCollector *collector) :
    CollectJob(collector), handles(handles) {}
 
void ValueLookupJob::run()
{
    // Open a QML context if we don't have one, yet. We might run into QML objects when looking up
    // refs and that will crash without a valid QML context. Mind that engine->qmlContext() is only
    // set if the engine is currently executing QML code.
    QScopedPointer<QObject> scopeObject;
    QV4::ExecutionEngine *engine = collector->engine();
    QV4::Scope scope(engine);
    QV4::Heap::ExecutionContext *qmlContext = engine->qmlContext();
    if (engine->qmlEngine() && !qmlContext) {
        scopeObject.reset(new QObject);
        qmlContext = QV4::QmlContext::create(engine->currentContext(),
                                QQmlContextData::get(engine->qmlEngine()->rootContext()),
                                scopeObject.data());
    }
    QV4::Scoped<QV4::ExecutionContext> scopedContext(scope, qmlContext);
    QV4::ScopedStackFrame frame(scope, scopedContext);
    for (const QJsonValue handle : handles) {
        QV4DataCollector::Ref ref = handle.toInt();
        if (!collector->isValidRef(ref)) {
            exception = QString::fromLatin1("Invalid Ref: %1").arg(ref);
            break;
        }
        result[QString::number(ref)] = collector->lookupRef(ref);
    }
}
 
const QString &ValueLookupJob::exceptionMessage() const
{
    return exception;
}
 
ExpressionEvalJob::ExpressionEvalJob(QV4::ExecutionEngine *engine, int frameNr,
                                     int context, const QString &expression,
                                     QV4DataCollector *collector) :
    JavaScriptJob(engine, frameNr, context, expression), collector(collector)
{
}
 
void ExpressionEvalJob::handleResult(QV4::ScopedValue &value)
{
    if (hasExeption())
        exception = value->toQStringNoThrow();
    result = collector->lookupRef(collector->addValueRef(value));
}
 
const QString &ExpressionEvalJob::exceptionMessage() const
{
    return exception;
}
 
const QJsonObject &ExpressionEvalJob::returnValue() const
{
    return result;
}
 
GatherSourcesJob::GatherSourcesJob(QV4::ExecutionEngine *engine)
    : engine(engine)
{}
 
void GatherSourcesJob::run()
{
    const auto compilationUnits = engine->compilationUnits();
    for (const auto &unit : compilationUnits) {
        QString fileName = unit->fileName();
        if (!fileName.isEmpty())
            sources.append(fileName);
    }
}
 
const QStringList &GatherSourcesJob::result() const
{
    return sources;
}
 
EvalJob::EvalJob(QV4::ExecutionEngine *engine, const QString &script) :
    JavaScriptJob(engine, /*frameNr*/-1, /*context*/ -1, script), result(false)
{}
 
void EvalJob::handleResult(QV4::ScopedValue &result)
{
    this->result = result->toBoolean();
}
 
bool EvalJob::resultAsBoolean() const
{
    return result;
}
 
QT_END_NAMESPACE