C++ QScriptEngine::clearExceptions方法代码示例

bool HttpHandlerQtScript::handleRequest(Pillow::HttpRequest *request)
{
    if (!_scriptFunction.isFunction()) return false;

    QScriptEngine* engine = _scriptFunction.engine();
    QScriptValue requestObject = engine->newObject();
    requestObject.setProperty("nativeRequest", _scriptFunction.engine()->newQObject(request));
    requestObject.setProperty("requestMethod", QUrl::fromPercentEncoding(request->requestMethod()));
    requestObject.setProperty("requestUri", QUrl::fromPercentEncoding(request->requestUri()));
    requestObject.setProperty("requestFragment", QUrl::fromPercentEncoding(request->requestFragment()));
    requestObject.setProperty("requestPath", QUrl::fromPercentEncoding(request->requestPath()));
    requestObject.setProperty("requestQueryString", QUrl::fromPercentEncoding(request->requestQueryString()));
    requestObject.setProperty("requestHeaders", qScriptValueFromValue(engine, request->requestHeaders()));

    QList<QPair<QString, QString> > queryParams = QUrl(request->requestUri()).queryItems();
    QScriptValue queryParamsObject = engine->newObject();
    for (int i = 0, iE = queryParams.size(); i < iE; ++i)
        queryParamsObject.setProperty(queryParams.at(i).first, queryParams.at(i).second);
    requestObject.setProperty("requestQueryParams", queryParamsObject);

    QScriptValue result = _scriptFunction.call(_scriptFunction, QScriptValueList() << requestObject);

    if (result.isError())
    {
        if (request->state() == HttpRequest::SendingHeaders)
        {
            // Nothing was sent yet... We have a chance to let the client know we had an error.
            request->writeResponseString(500, HttpHeaderCollection(), objectToString(result));
        }
        engine->clearExceptions();
        return true;
    }

    return result.toBool();
}

 void handleException() {
     Q_ASSERT( m_engine );
     Q_ASSERT( m_engine->hasUncaughtException() );
     const QString err = m_engine->uncaughtException().toString();
     const int linenr = m_engine->uncaughtExceptionLineNumber();
     const QString trace = m_engine->uncaughtExceptionBacktrace().join("\n");
     qrossdebug( QString("%1, line:%2, backtrace:\n%3").arg(err).arg(linenr).arg(trace) );
     m_script->action()->setError(err, trace, linenr);
     m_engine->clearExceptions();
 }

QScriptValue QDeclarativeQtScriptExpression::eval(QObject *secondaryScope, bool *isUndefined)
{
    Q_ASSERT(context() && context()->engine);

    DeleteWatcher watcher(this);

    QDeclarativeEngine *engine = context()->engine;
    QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine);

    QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine);

    QDeclarativeContextData *oldSharedContext = 0;
    QObject *oldSharedScope = 0;
    QObject *oldOverride = 0;
    bool isShared = (expressionFunctionMode == SharedContext);

    if (isShared) {
        oldSharedContext = ep->sharedContext;
        oldSharedScope = ep->sharedScope;
        ep->sharedContext = context();
        ep->sharedScope = scopeObject;
    } else {
        oldOverride = ep->contextClass->setOverrideObject(expressionContext, secondaryScope);
    }

    QScriptValue thisObject;
    if (evalFlags & RequiresThisObject)
        thisObject = ep->objectClass->newQObject(scopeObject);
    QScriptValue svalue = expressionFunction.call(thisObject); // This could cause this c++ object to be deleted

    if (isShared) {
        ep->sharedContext = oldSharedContext;
        ep->sharedScope = oldSharedScope;
    } else if (!watcher.wasDeleted()) {
        ep->contextClass->setOverrideObject(expressionContext, oldOverride);
    }

    if (isUndefined)
        *isUndefined = svalue.isUndefined() || scriptEngine->hasUncaughtException();

    // Handle exception
    if (scriptEngine->hasUncaughtException()) {
        if (!watcher.wasDeleted()) 
           QDeclarativeExpressionPrivate::exceptionToError(scriptEngine, error);

       scriptEngine->clearExceptions();
       return QScriptValue();
    } else {
        if (!watcher.wasDeleted())
            error = QDeclarativeError();

        return svalue;
    }
}

static bool hadUncaughtExceptions(QScriptEngine& engine, const QString& fileName) {
    if (engine.hasUncaughtException()) {
        const auto backtrace = engine.uncaughtExceptionBacktrace();
        const auto exception = engine.uncaughtException().toString();
        const auto line = QString::number(engine.uncaughtExceptionLineNumber());
        engine.clearExceptions();

        auto message = QString("[UncaughtException] %1 in %2:%3").arg(exception, fileName, line);
        if (!backtrace.empty()) {
            static const auto lineSeparator = "\n    ";
            message += QString("\n[Backtrace]%1%2").arg(lineSeparator, backtrace.join(lineSeparator));
        }
        qWarning() << qPrintable(message);
        return true;
    }
    return false;
}

QVariant QDeclarativeExpressionPrivate::evalQtScript(QObject *secondaryScope, bool *isUndefined)
{
    QDeclarativeExpressionData *data = this->data;
    QDeclarativeEngine *engine = data->context()->engine;
    QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine);

    QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine);

    if (!data->expressionFunctionValid) {

        QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine);
        data->expressionContext = ep->contextClass->newContext(data->context(), data->me);
        scriptContext->pushScope(data->expressionContext);
        scriptContext->pushScope(ep->globalClass->globalObject());

        if (data->expressionRewritten) {
            data->expressionFunction = scriptEngine->evaluate(data->expression, 
                                                              data->url, data->line);
        } else {
            QDeclarativeRewrite::RewriteBinding rewriteBinding;

            bool ok = true;
            const QString code = rewriteBinding(data->expression, &ok);
            if (!ok) {
                scriptEngine->popContext();
                return QVariant();
            }
            data->expressionFunction = scriptEngine->evaluate(code, data->url, data->line);
        }

        scriptEngine->popContext();
        data->expressionFunctionValid = true;
    }

    QDeclarativeContextData *oldSharedContext = 0;
    QObject *oldSharedScope = 0;
    QObject *oldOverride = 0;
    if (data->isShared) {
        oldSharedContext = ep->sharedContext;
        oldSharedScope = ep->sharedScope;
        ep->sharedContext = data->context();
        ep->sharedScope = data->me;
    } else {
        oldOverride = ep->contextClass->setOverrideObject(data->expressionContext, secondaryScope);
    }

    QScriptValue svalue = data->expressionFunction.call();

    if (data->isShared) {
        ep->sharedContext = oldSharedContext;
        ep->sharedScope = oldSharedScope;
    } else {
        ep->contextClass->setOverrideObject(data->expressionContext, oldOverride);
    }

    if (isUndefined)
        *isUndefined = svalue.isUndefined() || scriptEngine->hasUncaughtException();

    // Handle exception
    if (scriptEngine->hasUncaughtException()) {
       exceptionToError(scriptEngine, data->error);
       scriptEngine->clearExceptions();
       return QVariant();
    } else {
        data->error = QDeclarativeError();
    }

    QVariant rv;

    if (svalue.isArray()) {
        int length = svalue.property(QLatin1String("length")).toInt32();
        if (length && svalue.property(0).isObject()) {
            QList<QObject *> list;
            for (int ii = 0; ii < length; ++ii) {
                QScriptValue arrayItem = svalue.property(ii);
                QObject *d = arrayItem.toQObject();
                list << d;
            }
            rv = QVariant::fromValue(list);
        }
    } else if (svalue.isObject() &&
               ep->objectClass->scriptClass(svalue) == ep->objectClass) {
        QObject *o = svalue.toQObject();
        int type = QMetaType::QObjectStar;
        // If the object is null, we extract the predicted type.  While this isn't
        // 100% reliable, in many cases it gives us better error messages if we
        // assign this null-object to an incompatible property
        if (!o) type = ep->objectClass->objectType(svalue);

        return QVariant(type, &o);
    }

    if (rv.isNull())
        rv = svalue.toVariant();

    return rv;
}

//.........这里部分代码省略.........
        response.setResult(QVariant::fromValue(backend->contextsCheckpoint()));
    }   break;

    case QScriptDebuggerCommand::GetPropertyExpressionValue: {
        QScriptContext *ctx = backend->context(command.contextIndex());
        int lineNumber = command.lineNumber();
        QVariant attr = command.attribute(QScriptDebuggerCommand::UserAttribute);
        QStringList path = attr.toStringList();
        if (!ctx || path.isEmpty())
            break;
        QScriptContextInfo ctxInfo(ctx);
        if (ctx->callee().isValid()
            && ((lineNumber < ctxInfo.functionStartLineNumber())
                || (lineNumber > ctxInfo.functionEndLineNumber()))) {
            break;
        }
        QScriptValueList objects;
        int pathIndex = 0;
        if (path.at(0) == QLatin1String("this")) {
            objects.append(ctx->thisObject());
            ++pathIndex;
        } else {
            objects << ctx->scopeChain();
        }
        for (int i = 0; i < objects.size(); ++i) {
            QScriptValue val = objects.at(i);
            for (int j = pathIndex; val.isValid() && (j < path.size()); ++j) {
                val = val.property(path.at(j));
            }
            if (val.isValid()) {
                bool hadException = (ctx->state() == QScriptContext::ExceptionState);
                QString str = val.toString();
                if (!hadException && backend->engine()->hasUncaughtException())
                    backend->engine()->clearExceptions();
                response.setResult(str);
                break;
            }
        }
    }   break;

    case QScriptDebuggerCommand::GetCompletions: {
        QScriptContext *ctx = backend->context(command.contextIndex());
        QVariant attr = command.attribute(QScriptDebuggerCommand::UserAttribute);
        QStringList path = attr.toStringList();
        if (!ctx || path.isEmpty())
            break;
        QScriptValueList objects;
        QString prefix = path.last();
        QSet<QString> matches;
        if (path.size() > 1) {
            const QString &topLevelIdent = path.at(0);
            QScriptValue obj;
            if (topLevelIdent == QLatin1String("this")) {
                obj = ctx->thisObject();
            } else {
                QScriptValueList scopeChain;
                scopeChain = ctx->scopeChain();
                for (int i = 0; i < scopeChain.size(); ++i) {
                    QScriptValue oo = scopeChain.at(i).property(topLevelIdent);
                    if (oo.isObject()) {
                        obj = oo;
                        break;
                    }
                }
            }
            for (int i = 1; obj.isObject() && (i < path.size()-1); ++i)

void tst_QScriptContext::pushAndPopScope()
{
    QScriptEngine eng;
    QScriptContext *ctx = eng.currentContext();
    QCOMPARE(ctx->scopeChain().size(), 1);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(eng.globalObject()));

    QVERIFY(ctx->popScope().strictlyEquals(eng.globalObject()));
    ctx->pushScope(eng.globalObject());
    QCOMPARE(ctx->scopeChain().size(), 1);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(eng.globalObject()));

    QScriptValue obj = eng.newObject();
    ctx->pushScope(obj);
    QCOMPARE(ctx->scopeChain().size(), 2);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(obj));
    QVERIFY(ctx->scopeChain().at(1).strictlyEquals(eng.globalObject()));

    QVERIFY(ctx->popScope().strictlyEquals(obj));
    QCOMPARE(ctx->scopeChain().size(), 1);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(eng.globalObject()));

    {
        QScriptValue ret = eng.evaluate("x");
        QVERIFY(ret.isError());
        eng.clearExceptions();
    }
    QCOMPARE(ctx->scopeChain().size(), 1);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(eng.globalObject()));

    // task 236685
    QScriptValue qobj = eng.newQObject(this, QScriptEngine::QtOwnership, QScriptEngine::AutoCreateDynamicProperties);
    ctx->pushScope(qobj);
    QCOMPARE(ctx->scopeChain().size(), 2);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(qobj));
    QVERIFY(ctx->scopeChain().at(1).strictlyEquals(eng.globalObject()));
    {
        QScriptValue ret = eng.evaluate("print");
        QVERIFY(ret.isFunction());
    }
    ctx->popScope();

    ctx->pushScope(obj);
    QCOMPARE(ctx->scopeChain().size(), 2);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(obj));
    obj.setProperty("x", 123);
    {
        QScriptValue ret = eng.evaluate("x");
        QVERIFY(ret.isNumber());
        QCOMPARE(ret.toInt32(), 123);
    }
    QVERIFY(ctx->popScope().strictlyEquals(obj));
    QCOMPARE(ctx->scopeChain().size(), 1);
    QVERIFY(ctx->scopeChain().at(0).strictlyEquals(eng.globalObject()));

    ctx->pushScope(QScriptValue());
    QCOMPARE(ctx->scopeChain().size(), 1);

    QVERIFY(ctx->popScope().strictlyEquals(eng.globalObject()));
    QVERIFY(ctx->scopeChain().isEmpty());

    // Used to work with old back-end, doesn't with new one because JSC requires that the last object in
    // a scope chain is the Global Object.
    QTest::ignoreMessage(QtWarningMsg, "QScriptContext::pushScope() failed: initial object in scope chain has to be the Global Object");
    ctx->pushScope(obj);
    QCOMPARE(ctx->scopeChain().size(), 0);

    QScriptEngine eng2;
    QScriptValue obj2 = eng2.newObject();
    QTest::ignoreMessage(QtWarningMsg, "QScriptContext::pushScope() failed: cannot push an object created in a different engine");
    ctx->pushScope(obj2);
    QVERIFY(ctx->scopeChain().isEmpty());

    QVERIFY(!ctx->popScope().isValid());
}