C++ Ptr::contextItemType方法代码示例

StaticContext::Ptr CurrentItemStore::newStaticContext(const StaticContext::Ptr &context)
{
    /* It might be we are generated despite there is no focus. In that case
     * an error will reported in case current() is used, but in any case we cannot
     * crash, so use item() in case we have no focus.
     *
     * Such a case is when we're inside a named template, and it's invoked
     * without focus. */
    const ItemType::Ptr t(context->contextItemType());
    return StaticContext::Ptr(new StaticCurrentContext(t ? t : BuiltinTypes::item, context));
}

Expression::Ptr TypeChecker::verifyType(const Expression::Ptr &operand,
                                        const SequenceType::Ptr &reqSeqType,
                                        const StaticContext::Ptr &context,
                                        const ReportContext::ErrorCode code,
                                        const Options options)
{
    const ItemType::Ptr reqType(reqSeqType->itemType());
    const Expression::Properties props(operand->properties());

    /* If operand requires a focus, do the necessary type checking for that. */
    if(props.testFlag(Expression::RequiresFocus) && options.testFlag(CheckFocus))
    {
        const ItemType::Ptr contextType(context->contextItemType());
        if(contextType)
        {
            if(props.testFlag(Expression::RequiresContextItem))
            {
                Q_ASSERT_X(operand->expectedContextItemType(), Q_FUNC_INFO,
                           "When the Expression sets the RequiresContextItem property, it must "
                           "return a type in expectedContextItemType()");
                const ItemType::Ptr expectedContextType(operand->expectedContextItemType());

                /* Allow the empty sequence. We don't want to trigger XPTY0020 on ()/... . */
                if(!expectedContextType->xdtTypeMatches(contextType) && contextType != CommonSequenceTypes::Empty)
                {
                    context->error(wrongType(context->namePool(), operand->expectedContextItemType(), contextType),
                                   ReportContext::XPTY0020, operand.data());
                    return operand;
                }
            }
        }
        else
        {
            context->error(QtXmlPatterns::tr("The focus is undefined."), ReportContext::XPDY0002, operand.data());
            return operand;
        }
    }

    SequenceType::Ptr operandSeqType(operand->staticType());
    ItemType::Ptr operandType(operandSeqType->itemType());

    /* This returns the operand if the types are identical or if operandType
     * is a subtype of reqType. */
    if(reqType->xdtTypeMatches(operandType) || *operandType == *CommonSequenceTypes::Empty)
        return operand;

    /* Since we haven't exited yet, it means that the operandType is a super type
     * of reqType, and that there hence is a path down to it through the
     * type hierachy -- but that doesn't necessarily mean that a up-cast(down the
     * hierarchy) would succeed. */

    Expression::Ptr result(operand);

    if(reqType->isAtomicType())
    {
        const Expression::ID opID = operand->id();
        if((opID == Expression::IDArgumentReference ||
                (opID == Expression::IDCardinalityVerifier && operand->operands().first()->is(Expression::IDArgumentReference)))
                && *BuiltinTypes::item == *operandType)
            return Expression::Ptr(new ArgumentConverter(result, reqType));

        if(!operandType->isAtomicType())
        {
            result = Expression::Ptr(new Atomizer(result));
            /* The atomizer might know more about the type. */
            operandType = result->staticType()->itemType();
        }

        if(reqType->xdtTypeMatches(operandType))
        {
            /* Atomization was sufficient. Either the expected type is xs:anyAtomicType
             * or the type the Atomizer knows it returns, matches the required type. */
            return result;
        }

        const bool compatModeEnabled = context->compatModeEnabled();

        if((options.testFlag(AutomaticallyConvert) && BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(operandType)) ||
                (compatModeEnabled && BuiltinTypes::xsString->xdtTypeMatches(reqType)))
        {
            if(*reqType == *BuiltinTypes::numeric)
            {
                result = typeCheck(new UntypedAtomicConverter(result, BuiltinTypes::xsDouble, code),
                                   context, reqSeqType);
            }
            else
                result = typeCheck(new UntypedAtomicConverter(result, reqType, code), context, reqSeqType);

            /* The UntypedAtomicConverter might know more about the type, so reload. */
            operandType = result->staticType()->itemType();
        }
        else if(compatModeEnabled && *reqType == *BuiltinTypes::xsDouble)
        {
            const FunctionFactory::Ptr functions(context->functionSignatures());
            Expression::List numberArgs;
            numberArgs.append(operand);

            result = functions->createFunctionCall(QXmlName(StandardNamespaces::fn, StandardLocalNames::number),
                                                   numberArgs,
                                                   context,
//.........这里部分代码省略.........

Expression::Ptr ContextItem::typeCheck(const StaticContext::Ptr &context,
                                       const SequenceType::Ptr &reqType)
{
    m_itemType = context->contextItemType();
    return EmptyContainer::typeCheck(context, reqType);
}

Expression::Ptr ExpressionFactory::createExpression(const Tokenizer::Ptr &tokenizer,
                                                    const StaticContext::Ptr &context,
                                                    const QXmlQuery::QueryLanguage lang,
                                                    const SequenceType::Ptr &requiredType,
                                                    const QUrl &queryURI,
                                                    const QXmlName &initialTemplateName)
{
    Q_ASSERT(context);
    Q_ASSERT(requiredType);
    Q_ASSERT(queryURI.isValid());

    Tokenizer::Ptr effectiveTokenizer(tokenizer);
#ifdef Patternist_DEBUG
    effectiveTokenizer = Tokenizer::Ptr(new TokenRevealer(queryURI, tokenizer));
#endif

    OptimizationPasses::Coordinator::init();

    const ParserContext::Ptr info(new ParserContext(context, lang, effectiveTokenizer.data()));
    info->initialTemplateName = initialTemplateName;

    effectiveTokenizer->setParserContext(info);

    const int bisonRetval = QPatternist::XPathparse(info.data());

    Q_ASSERT_X(bisonRetval == 0, Q_FUNC_INFO,
               "We shouldn't be able to get an error, because we throw exceptions.");
    Q_UNUSED(bisonRetval); /* Needed when not compiled in debug mode, since bisonRetval won't
                            * be used in the Q_ASSERT_X above. */

    Expression::Ptr result(info->queryBody);

    if(!result)
    {
        context->error(QtXmlPatterns::tr("A library module cannot be evaluated "
                                         "directly. It must be imported from a "
                                         "main module."),
                       ReportContext::XPST0003,
                       QSourceLocation(queryURI, 1, 1));
    }

    /* Optimization: I think many things are done in the wrong order below. We
     * probably want everything typechecked before compressing, since we can
     * have references all over the place(variable references, template
     * invocations, function callsites). This could even be a source to bugs.
     */

    /* Here, we type check user declared functions and global variables. This
     * means that variables and functions that are not used are type
     * checked(which they otherwise wouldn't have been), and those which are
     * used, are type-checked twice, unfortunately. */

    const bool hasExternalFocus = context->contextItemType();

    if(lang == QXmlQuery::XSLT20)
    {
        /* Bind xsl:call-template instructions to their template bodies.
         *
         * We do this before type checking and compressing them, because a
         * CallTemplate obviously needs its template before being compressed.
         *
         * Also, we do this before type checking and compressing user
         * functions, since they can contain template call sites.
         */
        for(int i = 0; i < info->templateCalls.count(); ++i)
        {
            CallTemplate *const site = info->templateCalls.at(i)->as<CallTemplate>();
            const QXmlName targetName(site->name());
            const Template::Ptr t(info->namedTemplates.value(targetName));

            if(t)
                site->setTemplate(t);
            else
            {
                context->error(QtXmlPatterns::tr("No template by name %1 exists.").arg(formatKeyword(context->namePool(), targetName)),
                               ReportContext::XTSE0650,
                               site);
            }
        }
    }

    /* Type check and compress user functions. */
    {
        const UserFunction::List::const_iterator end(info->userFunctions.constEnd());
        UserFunction::List::const_iterator it(info->userFunctions.constBegin());

        /* If the query has a focus(which is common, in the case of a
         * stylesheet), we must ensure that the focus isn't visible in the
         * function body. */
        StaticContext::Ptr effectiveContext;

        if(hasExternalFocus)
        {
            effectiveContext = StaticContext::Ptr(new StaticFocusContext(ItemType::Ptr(),
                                                                         context));
        }
        else
            effectiveContext = context;

        for(; it != end; ++it)
//.........这里部分代码省略.........

Expression::Ptr ContextItem::compress(const StaticContext::Ptr &context)
{
    m_itemType = context->contextItemType();
    return EmptyContainer::compress(context);
}