Port the QXmlStream API from QStringRef to QStringView

This gives some source incompatibilities, most of them can be
handled by using auto instead of QStringRef explicitly.

[ChangeLog][Important API changes] QXmlStream now uses QStringView
insteead of QStringRef in it's API. Using auto forvariables returning
a QStringRef in Qt 5 should lead to code that can be used against both
Qt versions.

Fixes: QTBUG-84317
Change-Id: I6df3a9507276f5d16d044a6bdbe0e4810cf99440
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>

13 files changed, 138 insertions, 150 deletions

diff --git a/examples/corelib/serialization/convert/xmlconverter.cpp b/examples/corelib/serialization/convert/xmlconverter.cpp
index 42cb10100a..87ba9b5156 100644
--- a/examples/corelib/serialization/convert/xmlconverter.cpp
+++ b/examples/corelib/serialization/convert/xmlconverter.cpp
@@ -195,7 +195,7 @@ static QVariant mapFromXml(QXmlStreamReader &xml, Converter::Options options)
 
 static QVariant variantFromXml(QXmlStreamReader &xml, Converter::Options options)
 {
-    QStringRef name = xml.name();
+    QStringView name = xml.name();
     if (name == QLatin1String("list"))
         return listFromXml(xml, options);
     if (name == QLatin1String("map"))
@@ -207,7 +207,7 @@ static QVariant variantFromXml(QXmlStreamReader &xml, Converter::Options options
     }
 
     QXmlStreamAttributes attrs = xml.attributes();
-    QStringRef type = attrs.value(QLatin1String("type"));
+    QStringView type = attrs.value(QLatin1String("type"));
 
     forever {
         xml.readNext();
@@ -222,7 +222,7 @@ static QVariant variantFromXml(QXmlStreamReader &xml, Converter::Options options
         exit(EXIT_FAILURE);
     }
 
-    QStringRef text = xml.text();
+    QStringView text = xml.text();
     if (!xml.isCDATA())
         text = text.trimmed();
 
@@ -247,7 +247,7 @@ static QVariant variantFromXml(QXmlStreamReader &xml, Converter::Options options
         }
     } else if (type == QLatin1String("bytes")) {
         QByteArray data = text.toLatin1();
-        QStringRef encoding = attrs.value("encoding");
+        QStringView encoding = attrs.value("encoding");
         if (encoding == QLatin1String("base64url")) {
             result = QByteArray::fromBase64(data, QByteArray::Base64UrlEncoding);
         } else if (encoding == QLatin1String("hex")) {
diff --git a/examples/embedded/flightinfo/flightinfo.cpp b/examples/embedded/flightinfo/flightinfo.cpp
index f7df368dd7..0f8dfb5b6a 100644
--- a/examples/embedded/flightinfo/flightinfo.cpp
+++ b/examples/embedded/flightinfo/flightinfo.cpp
@@ -265,20 +265,20 @@ private:
             xml.readNext();
 
             if (xml.tokenType() == QXmlStreamReader::StartElement) {
-                QStringRef className = xml.attributes().value("class");
-                inFlightName |= xml.name() == "h1";
-                inFlightStatus |= className == "FlightDetailHeaderStatus";
-                inFlightMap |= className == "flightMap";
-                if (xml.name() == "td" && !className.isEmpty()) {
-                    if (className.contains("fieldTitle")) {
+                auto className = xml.attributes().value("class");
+                inFlightName |= xml.name() == u"h1";
+                inFlightStatus |= className == u"FlightDetailHeaderStatus";
+                inFlightMap |= className == u"flightMap";
+                if (xml.name() == u"td" && !className.isEmpty()) {
+                    if (className.contains(u"fieldTitle")) {
                         inFieldName = true;
                         fieldNames += QString();
                         fieldValues += QString();
                     }
-                    if (className.contains("fieldValue"))
+                    if (className.contains(u"fieldValue"))
                         inFieldValue = true;
                 }
-                if (xml.name() == "img" && inFlightMap) {
+                if (xml.name() == u"img" && inFlightMap) {
                     const QByteArray encoded
                         = ("http://mobile.flightview.com/" % xml.attributes().value("src")).toLatin1();
                     QUrl url = QUrl::fromPercentEncoding(encoded);
@@ -287,11 +287,11 @@ private:
             }
 
             if (xml.tokenType() == QXmlStreamReader::EndElement) {
-                inFlightName &= xml.name() != "h1";
-                inFlightStatus &= xml.name() != "div";
-                inFlightMap &= xml.name() != "div";
-                inFieldName &= xml.name() != "td";
-                inFieldValue &= xml.name() != "td";
+                inFlightName &= xml.name() != u"h1";
+                inFlightStatus &= xml.name() != u"div";
+                inFlightMap &= xml.name() != u"div";
+                inFieldName &= xml.name() != u"td";
+                inFieldValue &= xml.name() != u"td";
             }
 
             if (xml.tokenType() == QXmlStreamReader::Characters) {
diff --git a/examples/network/googlesuggest/googlesuggest.cpp b/examples/network/googlesuggest/googlesuggest.cpp
index 04a60103b2..b7b6d3ab62 100644
--- a/examples/network/googlesuggest/googlesuggest.cpp
+++ b/examples/network/googlesuggest/googlesuggest.cpp
@@ -217,8 +217,8 @@ void GSuggestCompletion::handleNetworkData(QNetworkReply *networkReply)
         while (!xml.atEnd()) {
             xml.readNext();
             if (xml.tokenType() == QXmlStreamReader::StartElement)
-                if (xml.name() == "suggestion") {
-                    QStringRef str = xml.attributes().value("data");
+                if (xml.name() == u"suggestion") {
+                    auto str = xml.attributes().value("data");
                     choices << str.toString();
                 }
         }
diff --git a/examples/widgets/animation/sub-attaq/graphicsscene.cpp b/examples/widgets/animation/sub-attaq/graphicsscene.cpp
index c7e2d269c8..5248ed9f92 100644
--- a/examples/widgets/animation/sub-attaq/graphicsscene.cpp
+++ b/examples/widgets/animation/sub-attaq/graphicsscene.cpp
@@ -103,21 +103,21 @@ GraphicsScene::GraphicsScene(int x, int y, int width, int height, Mode mode, QOb
     while (!reader.atEnd()) {
          reader.readNext();
          if (reader.tokenType() == QXmlStreamReader::StartElement) {
-             if (reader.name() == "submarine") {
+             if (reader.name() == u"submarine") {
                  SubmarineDescription desc;
                  desc.name = reader.attributes().value("name").toString();
                  desc.points = reader.attributes().value("points").toInt();
                  desc.type = reader.attributes().value("type").toInt();
                  submarinesData.append(desc);
-             } else if (reader.name() == "level") {
+             } else if (reader.name() == u"level") {
                  currentLevel.id = reader.attributes().value("id").toInt();
                  currentLevel.name = reader.attributes().value("name").toString();
-             } else if (reader.name() == "subinstance") {
+             } else if (reader.name() == u"subinstance") {
                  currentLevel.submarines.append(qMakePair(reader.attributes().value("type").toInt(),
                                                           reader.attributes().value("nb").toInt()));
              }
          } else if (reader.tokenType() == QXmlStreamReader::EndElement) {
-            if (reader.name() == "level") {
+            if (reader.name() == u"level") {
                 levelsData.insert(currentLevel.id, currentLevel);
                 currentLevel.submarines.clear();
             }
diff --git a/examples/xml/rsslisting/rsslisting.cpp b/examples/xml/rsslisting/rsslisting.cpp
index 143ad6dcba..0d68d1792a 100644
--- a/examples/xml/rsslisting/rsslisting.cpp
+++ b/examples/xml/rsslisting/rsslisting.cpp
@@ -214,11 +214,11 @@ void RSSListing::parseXml()
     while (!xml.atEnd()) {
         xml.readNext();
         if (xml.isStartElement()) {
-            if (xml.name() == "item")
+            if (xml.name() == u"item")
                 linkString = xml.attributes().value("rss:about").toString();
             currentTag = xml.name().toString();
         } else if (xml.isEndElement()) {
-            if (xml.name() == "item") {
+            if (xml.name() == u"item") {
 
                 QTreeWidgetItem *item = new QTreeWidgetItem;
                 item->setText(0, titleString);
diff --git a/src/corelib/mimetypes/qmimeprovider.cpp b/src/corelib/mimetypes/qmimeprovider.cpp
index 47b5e42167..6766a1bbec 100644
--- a/src/corelib/mimetypes/qmimeprovider.cpp
+++ b/src/corelib/mimetypes/qmimeprovider.cpp
@@ -517,14 +517,14 @@ void QMimeBinaryProvider::loadMimeTypePrivate(QMimeTypePrivate &data)
             if (xml.name() != QLatin1String("mime-type")) {
                 continue;
             }
-            const QStringRef name = xml.attributes().value(QLatin1String("type"));
+            const auto name = xml.attributes().value(QLatin1String("type"));
             if (name.isEmpty())
                 continue;
             if (name.compare(data.name, Qt::CaseInsensitive))
                 qWarning() << "Got name" << name << "in file" << file << "expected" << data.name;
 
             while (xml.readNextStartElement()) {
-                const QStringRef tag = xml.name();
+                const auto tag = xml.name();
                 if (tag == QLatin1String("comment")) {
                     QString lang = xml.attributes().value(QLatin1String("xml:lang")).toString();
                     const QString text = xml.readElementText();
diff --git a/src/corelib/mimetypes/qmimetypeparser.cpp b/src/corelib/mimetypes/qmimetypeparser.cpp
index dc1c444c56..aa5427b16a 100644
--- a/src/corelib/mimetypes/qmimetypeparser.cpp
+++ b/src/corelib/mimetypes/qmimetypeparser.cpp
@@ -107,7 +107,7 @@ static const char matchMaskAttributeC[] = "mask";
     Overwrite to process the sequence of parsed data
 */
 
-QMimeTypeParserBase::ParseState QMimeTypeParserBase::nextState(ParseState currentState, const QStringRef &startElement)
+QMimeTypeParserBase::ParseState QMimeTypeParserBase::nextState(ParseState currentState, QStringView startElement)
 {
     switch (currentState) {
     case ParseBeginning:
@@ -174,7 +174,7 @@ struct CreateMagicMatchRuleResult {
     QString errorMessage; // must be first
     QMimeMagicRule rule;
 
-    CreateMagicMatchRuleResult(const QStringRef &type, const QStringRef &value, const QStringRef &offsets, const QStringRef &mask)
+    CreateMagicMatchRuleResult(QStringView type, QStringView value, QStringView offsets, QStringView mask)
         : errorMessage(), rule(type.toString(), value.toUtf8(), offsets.toString(), mask.toLatin1(), &errorMessage)
     {
 
@@ -183,10 +183,10 @@ struct CreateMagicMatchRuleResult {
 
 static CreateMagicMatchRuleResult createMagicMatchRule(const QXmlStreamAttributes &atts)
 {
-    const QStringRef type = atts.value(QLatin1String(matchTypeAttributeC));
-    const QStringRef value = atts.value(QLatin1String(matchValueAttributeC));
-    const QStringRef offsets = atts.value(QLatin1String(matchOffsetAttributeC));
-    const QStringRef mask = atts.value(QLatin1String(matchMaskAttributeC));
+    const auto type = atts.value(QLatin1String(matchTypeAttributeC));
+    const auto value = atts.value(QLatin1String(matchValueAttributeC));
+    const auto offsets = atts.value(QLatin1String(matchOffsetAttributeC));
+    const auto mask = atts.value(QLatin1String(matchMaskAttributeC));
     return CreateMagicMatchRuleResult(type, value, offsets, mask);
 }
 #endif
@@ -265,7 +265,7 @@ bool QMimeTypeParserBase::parse(QIODevice *dev, const QString &fileName, QString
                 break;
             case ParseMagic: {
                 priority = 50;
-                const QStringRef priorityS = atts.value(QLatin1String(priorityAttributeC));
+                const auto priorityS = atts.value(QLatin1String(priorityAttributeC));
                 if (!priorityS.isEmpty()) {
                     if (!parseNumber(priorityS, &priority, errorMessage))
                         return false;
@@ -301,7 +301,7 @@ bool QMimeTypeParserBase::parse(QIODevice *dev, const QString &fileName, QString
         // continue switch QXmlStreamReader::Token...
         case QXmlStreamReader::EndElement: // Finished element
         {
-            const QStringRef elementName = reader.name();
+            const auto elementName = reader.name();
             if (elementName == QLatin1String(mimeTypeTagC)) {
                 if (!process(QMimeType(data), errorMessage))
                     return false;
diff --git a/src/corelib/mimetypes/qmimetypeparser_p.h b/src/corelib/mimetypes/qmimetypeparser_p.h
index dbd3415d77..6f1869e399 100644
--- a/src/corelib/mimetypes/qmimetypeparser_p.h
+++ b/src/corelib/mimetypes/qmimetypeparser_p.h
@@ -98,7 +98,7 @@ private:
         ParseError
     };
 
-    static ParseState nextState(ParseState currentState, const QStringRef &startElement);
+    static ParseState nextState(ParseState currentState, QStringView startElement);
 };
 
 
diff --git a/src/corelib/serialization/qxmlstream.cpp b/src/corelib/serialization/qxmlstream.cpp
index ba6e3059df..9963fa60ec 100644
--- a/src/corelib/serialization/qxmlstream.cpp
+++ b/src/corelib/serialization/qxmlstream.cpp
@@ -384,13 +384,9 @@ QXmlStreamEntityResolver *QXmlStreamReader::entityResolver() const
   token at the time it is reported. In addition, QXmlStreamReader
   avoids the many small string allocations that it normally takes to
   map an XML document to a convenient and Qt-ish API. It does this by
-  reporting all string data as QStringRef rather than real QString
-  objects. QStringRef is a thin wrapper around QString substrings that
-  provides a subset of the QString API without the memory allocation
-  and reference-counting overhead. Calling
-  \l{QStringRef::toString()}{toString()} on any of those objects
-  returns an equivalent real QString object.
-
+  reporting all string data as QStringView rather than real QString
+  objects. Calling \l{QStringView::toString()}{toString()} on any of
+  those objects returns an equivalent real QString object.
 */
 
 
@@ -1928,7 +1924,7 @@ qint64 QXmlStreamReader::characterOffset() const
 /*!  Returns the text of \l Characters, \l Comment, \l DTD, or
   EntityReference.
  */
-QStringRef QXmlStreamReader::text() const
+QStringView QXmlStreamReader::text() const
 {
     Q_D(const QXmlStreamReader);
     return d->text;
@@ -1971,12 +1967,12 @@ QXmlStreamEntityDeclarations QXmlStreamReader::entityDeclarations() const
   name. Otherwise an empty string is returned.
 
  */
-QStringRef QXmlStreamReader::dtdName() const
+QStringView QXmlStreamReader::dtdName() const
 {
    Q_D(const QXmlStreamReader);
    if (d->type == QXmlStreamReader::DTD)
        return d->dtdName;
-   return QStringRef();
+   return QStringView();
 }
 
 /*!
@@ -1986,12 +1982,12 @@ QStringRef QXmlStreamReader::dtdName() const
   public identifier. Otherwise an empty string is returned.
 
  */
-QStringRef QXmlStreamReader::dtdPublicId() const
+QStringView QXmlStreamReader::dtdPublicId() const
 {
    Q_D(const QXmlStreamReader);
    if (d->type == QXmlStreamReader::DTD)
        return d->dtdPublicId;
-   return QStringRef();
+   return QStringView();
 }
 
 /*!
@@ -2001,12 +1997,12 @@ QStringRef QXmlStreamReader::dtdPublicId() const
   system identifier. Otherwise an empty string is returned.
 
  */
-QStringRef QXmlStreamReader::dtdSystemId() const
+QStringView QXmlStreamReader::dtdSystemId() const
 {
    Q_D(const QXmlStreamReader);
    if (d->type == QXmlStreamReader::DTD)
        return d->dtdSystemId;
-   return QStringRef();
+   return QStringView();
 }
 
 /*!
@@ -2187,7 +2183,7 @@ QXmlStreamReader::Error QXmlStreamReader::error() const
 /*!
   Returns the target of a ProcessingInstruction.
  */
-QStringRef QXmlStreamReader::processingInstructionTarget() const
+QStringView QXmlStreamReader::processingInstructionTarget() const
 {
     Q_D(const QXmlStreamReader);
     return d->processingInstructionTarget;
@@ -2196,7 +2192,7 @@ QStringRef QXmlStreamReader::processingInstructionTarget() const
 /*!
   Returns the data of a ProcessingInstruction.
  */
-QStringRef QXmlStreamReader::processingInstructionData() const
+QStringView QXmlStreamReader::processingInstructionData() const
 {
     Q_D(const QXmlStreamReader);
     return d->processingInstructionData;
@@ -2209,7 +2205,7 @@ QStringRef QXmlStreamReader::processingInstructionData() const
 
   \sa namespaceUri(), qualifiedName()
  */
-QStringRef QXmlStreamReader::name() const
+QStringView QXmlStreamReader::name() const
 {
     Q_D(const QXmlStreamReader);
     return d->name;
@@ -2220,7 +2216,7 @@ QStringRef QXmlStreamReader::name() const
 
   \sa name(), qualifiedName()
  */
-QStringRef QXmlStreamReader::namespaceUri() const
+QStringView QXmlStreamReader::namespaceUri() const
 {
     Q_D(const QXmlStreamReader);
     return d->namespaceUri;
@@ -2238,7 +2234,7 @@ QStringRef QXmlStreamReader::namespaceUri() const
 
    \sa name(), prefix(), namespaceUri()
  */
-QStringRef QXmlStreamReader::qualifiedName() const
+QStringView QXmlStreamReader::qualifiedName() const
 {
     Q_D(const QXmlStreamReader);
     return d->qualifiedName;
@@ -2253,7 +2249,7 @@ QStringRef QXmlStreamReader::qualifiedName() const
 
   \sa name(), qualifiedName()
 */
-QStringRef QXmlStreamReader::prefix() const
+QStringView QXmlStreamReader::prefix() const
 {
     Q_D(const QXmlStreamReader);
     return d->prefix;
@@ -2317,15 +2313,15 @@ QXmlStreamAttribute::QXmlStreamAttribute(const QString &qualifiedName, const QSt
     m_value = QXmlStreamStringRef(QStringRef(&value));
 }
 
-/*! \fn QStringRef QXmlStreamAttribute::namespaceUri() const
+/*! \fn QStringView QXmlStreamAttribute::namespaceUri() const
 
    Returns the attribute's resolved namespaceUri, or an empty string
    reference if the attribute does not have a defined namespace.
  */
-/*! \fn QStringRef QXmlStreamAttribute::name() const
+/*! \fn QStringView QXmlStreamAttribute::name() const
    Returns the attribute's local name.
  */
-/*! \fn QStringRef QXmlStreamAttribute::qualifiedName() const
+/*! \fn QStringView QXmlStreamAttribute::qualifiedName() const
    Returns the attribute's qualified name.
 
    A qualified name is the raw name of an attribute in the XML
@@ -2337,7 +2333,7 @@ QXmlStreamAttribute::QXmlStreamAttribute(const QString &qualifiedName, const QSt
    the attribute's local name().
  */
 /*!
-   \fn QStringRef QXmlStreamAttribute::prefix() const
+   \fn QStringView QXmlStreamAttribute::prefix() const
    \since 4.4
    Returns the attribute's namespace prefix.
 
@@ -2345,7 +2341,7 @@ QXmlStreamAttribute::QXmlStreamAttribute(const QString &qualifiedName, const QSt
 
 */
 
-/*! \fn QStringRef QXmlStreamAttribute::value() const
+/*! \fn QStringView QXmlStreamAttribute::value() const
    Returns the attribute's value.
  */
 
@@ -2421,15 +2417,15 @@ QXmlStreamNotationDeclaration::QXmlStreamNotationDeclaration()
 {
 }
 
-/*! \fn QStringRef QXmlStreamNotationDeclaration::name() const
+/*! \fn QStringView QXmlStreamNotationDeclaration::name() const
 
 Returns the notation name.
 */
-/*! \fn QStringRef QXmlStreamNotationDeclaration::systemId() const
+/*! \fn QStringView QXmlStreamNotationDeclaration::systemId() const
 
 Returns the system identifier.
 */
-/*! \fn QStringRef QXmlStreamNotationDeclaration::publicId() const
+/*! \fn QStringView QXmlStreamNotationDeclaration::publicId() const
 
 Returns the public identifier.
 */
@@ -2492,11 +2488,11 @@ QXmlStreamNamespaceDeclaration::QXmlStreamNamespaceDeclaration(const QString &pr
     m_namespaceUri = namespaceUri;
 }
 
-/*! \fn QStringRef QXmlStreamNamespaceDeclaration::prefix() const
+/*! \fn QStringView QXmlStreamNamespaceDeclaration::prefix() const
 
 Returns the prefix.
 */
-/*! \fn QStringRef QXmlStreamNamespaceDeclaration::namespaceUri() const
+/*! \fn QStringView QXmlStreamNamespaceDeclaration::namespaceUri() const
 
 Returns the namespaceUri.
 */
@@ -2545,23 +2541,23 @@ QXmlStreamEntityDeclaration::QXmlStreamEntityDeclaration()
     This function is very fast and never fails.
 */
 
-/*! \fn QStringRef QXmlStreamEntityDeclaration::name() const
+/*! \fn QStringView QXmlStreamEntityDeclaration::name() const
 
 Returns the entity name.
 */
-/*! \fn QStringRef QXmlStreamEntityDeclaration::notationName() const
+/*! \fn QStringView QXmlStreamEntityDeclaration::notationName() const
 
 Returns the notation name.
 */
-/*! \fn QStringRef QXmlStreamEntityDeclaration::systemId() const
+/*! \fn QStringView QXmlStreamEntityDeclaration::systemId() const
 
 Returns the system identifier.
 */
-/*! \fn QStringRef QXmlStreamEntityDeclaration::publicId() const
+/*! \fn QStringView QXmlStreamEntityDeclaration::publicId() const
 
 Returns the public identifier.
 */
-/*! \fn QStringRef QXmlStreamEntityDeclaration::value() const
+/*! \fn QStringView QXmlStreamEntityDeclaration::value() const
 
 Returns the entity's value.
 */
@@ -2581,13 +2577,13 @@ Returns the entity's value.
   described with \a namespaceUri, or an empty string reference if the
   attribute is not defined. The \a namespaceUri can be empty.
  */
-QStringRef QXmlStreamAttributes::value(const QString &namespaceUri, const QString &name) const
+QStringView QXmlStreamAttributes::value(const QString &namespaceUri, const QString &name) const
 {
     for (const QXmlStreamAttribute &attribute : *this) {
         if (attribute.name() == name && attribute.namespaceUri() == namespaceUri)
             return attribute.value();
     }
-    return QStringRef();
+    return QStringView();
 }
 
 /*!\overload
@@ -2595,13 +2591,13 @@ QStringRef QXmlStreamAttributes::value(const QString &namespaceUri, const QStrin
   described with \a namespaceUri, or an empty string reference if the
   attribute is not defined. The \a namespaceUri can be empty.
  */
-QStringRef QXmlStreamAttributes::value(const QString &namespaceUri, QLatin1String name) const
+QStringView QXmlStreamAttributes::value(const QString &namespaceUri, QLatin1String name) const
 {
     for (const QXmlStreamAttribute &attribute : *this) {
         if (attribute.name() == name && attribute.namespaceUri() == namespaceUri)
             return attribute.value();
     }
-    return QStringRef();
+    return QStringView();
 }
 
 /*!\overload
@@ -2609,13 +2605,13 @@ QStringRef QXmlStreamAttributes::value(const QString &namespaceUri, QLatin1Strin
   described with \a namespaceUri, or an empty string reference if the
   attribute is not defined. The \a namespaceUri can be empty.
  */
-QStringRef QXmlStreamAttributes::value(QLatin1String namespaceUri, QLatin1String name) const
+QStringView QXmlStreamAttributes::value(QLatin1String namespaceUri, QLatin1String name) const
 {
     for (const QXmlStreamAttribute &attribute : *this) {
         if (attribute.name() == name && attribute.namespaceUri() == namespaceUri)
             return attribute.value();
     }
-    return QStringRef();
+    return QStringView();
 }
 
 /*!\overload
@@ -2630,13 +2626,13 @@ QStringRef QXmlStreamAttributes::value(QLatin1String namespaceUri, QLatin1String
   use qualified names, but a resolved namespaceUri and the attribute's
   local name.
  */
-QStringRef QXmlStreamAttributes::value(const QString &qualifiedName) const
+QStringView QXmlStreamAttributes::value(const QString &qualifiedName) const
 {
     for (const QXmlStreamAttribute &attribute : *this) {
         if (attribute.qualifiedName() == qualifiedName)
             return attribute.value();
     }
-    return QStringRef();
+    return QStringView();
 }
 
 /*!\overload
@@ -2651,13 +2647,13 @@ QStringRef QXmlStreamAttributes::value(const QString &qualifiedName) const
   use qualified names, but a resolved namespaceUri and the attribute's
   local name.
  */
-QStringRef QXmlStreamAttributes::value(QLatin1String qualifiedName) const
+QStringView QXmlStreamAttributes::value(QLatin1String qualifiedName) const
 {
     for (const QXmlStreamAttribute &attribute : *this) {
         if (attribute.qualifiedName() == qualifiedName)
             return attribute.value();
     }
-    return QStringRef();
+    return QStringView();
 }
 
 /*!Appends a new attribute with \a name in the namespace
@@ -2754,12 +2750,12 @@ bool QXmlStreamReader::isStandaloneDocument() const
      version string as specified in the XML declaration.
      Otherwise an empty string is returned.
  */
-QStringRef QXmlStreamReader::documentVersion() const
+QStringView QXmlStreamReader::documentVersion() const
 {
    Q_D(const QXmlStreamReader);
    if (d->type == QXmlStreamReader::StartDocument)
        return d->documentVersion;
-   return QStringRef();
+   return QStringView();
 }
 
 /*!
@@ -2769,12 +2765,12 @@ QStringRef QXmlStreamReader::documentVersion() const
      encoding string as specified in the XML declaration.
      Otherwise an empty string is returned.
  */
-QStringRef QXmlStreamReader::documentEncoding() const
+QStringView QXmlStreamReader::documentEncoding() const
 {
    Q_D(const QXmlStreamReader);
    if (d->type == QXmlStreamReader::StartDocument)
        return d->documentEncoding;
-   return QStringRef();
+   return QStringView();
 }
 
 #endif // QT_NO_XMLSTREAMREADER
diff --git a/src/corelib/serialization/qxmlstream.h b/src/corelib/serialization/qxmlstream.h
index 31c605c981..ba495b64f0 100644
--- a/src/corelib/serialization/qxmlstream.h
+++ b/src/corelib/serialization/qxmlstream.h
@@ -70,9 +70,11 @@ public:
 
     inline void clear() { m_string.clear(); m_position = m_size = 0; }
     inline operator QStringRef() const { return QStringRef(&m_string, m_position, m_size); }
+    inline operator QStringView() const { return QStringView(m_string.constData() + m_position, m_size); }
     inline const QString *string() const { return &m_string; }
     inline int position() const { return m_position; }
     inline int size() const { return m_size; }
+    inline QString toString() const { return QString(m_string.constData() + m_position, m_size); }
 };
 Q_DECLARE_SHARED(QXmlStreamStringRef)
 
@@ -89,15 +91,14 @@ public:
     QXmlStreamAttribute(const QString &qualifiedName, const QString &value);
     QXmlStreamAttribute(const QString &namespaceUri, const QString &name, const QString &value);
 
-    inline QStringRef namespaceUri() const { return m_namespaceUri; }
-    inline QStringRef name() const { return m_name; }
-    inline QStringRef qualifiedName() const { return m_qualifiedName; }
-    inline QStringRef prefix() const {
-        return QStringRef(m_qualifiedName.string(),
-                          m_qualifiedName.position(),
+    inline QStringView namespaceUri() const { return m_namespaceUri; }
+    inline QStringView name() const { return m_name; }
+    inline QStringView qualifiedName() const { return m_qualifiedName; }
+    inline QStringView prefix() const {
+        return QStringView(m_qualifiedName.string()->constData() + m_qualifiedName.position(),
                           qMax(0, m_qualifiedName.size() - m_name.size() - 1));
     }
-    inline QStringRef value() const { return m_value; }
+    inline QStringView value() const { return m_value; }
     inline bool isDefault() const { return m_isDefault; }
     inline bool operator==(const QXmlStreamAttribute &other) const {
         return (value() == other.value()
@@ -116,11 +117,11 @@ class QXmlStreamAttributes : public QList<QXmlStreamAttribute>
 {
 public:
     inline QXmlStreamAttributes() {}
-    Q_CORE_EXPORT QStringRef value(const QString &namespaceUri, const QString &name) const;
-    Q_CORE_EXPORT QStringRef value(const QString &namespaceUri, QLatin1String name) const;
-    Q_CORE_EXPORT QStringRef value(QLatin1String namespaceUri, QLatin1String name) const;
-    Q_CORE_EXPORT QStringRef value(const QString &qualifiedName) const;
-    Q_CORE_EXPORT QStringRef value(QLatin1String qualifiedName) const;
+    Q_CORE_EXPORT QStringView value(const QString &namespaceUri, const QString &name) const;
+    Q_CORE_EXPORT QStringView value(const QString &namespaceUri, QLatin1String name) const;
+    Q_CORE_EXPORT QStringView value(QLatin1String namespaceUri, QLatin1String name) const;
+    Q_CORE_EXPORT QStringView value(const QString &qualifiedName) const;
+    Q_CORE_EXPORT QStringView value(QLatin1String qualifiedName) const;
     Q_CORE_EXPORT void append(const QString &namespaceUri, const QString &name, const QString &value);
     Q_CORE_EXPORT void append(const QString &qualifiedName, const QString &value);
 
@@ -150,8 +151,8 @@ public:
     QXmlStreamNamespaceDeclaration();
     QXmlStreamNamespaceDeclaration(const QString &prefix, const QString &namespaceUri);
 
-    inline QStringRef prefix() const { return m_prefix; }
-    inline QStringRef namespaceUri() const { return m_namespaceUri; }
+    inline QStringView prefix() const { return m_prefix; }
+    inline QStringView namespaceUri() const { return m_namespaceUri; }
     inline bool operator==(const QXmlStreamNamespaceDeclaration &other) const {
         return (prefix() == other.prefix() && namespaceUri() == other.namespaceUri());
     }
@@ -169,9 +170,9 @@ class Q_CORE_EXPORT QXmlStreamNotationDeclaration {
 public:
     QXmlStreamNotationDeclaration();
 
-    inline QStringRef name() const { return m_name; }
-    inline QStringRef systemId() const { return m_systemId; }
-    inline QStringRef publicId() const { return m_publicId; }
+    inline QStringView name() const { return m_name; }
+    inline QStringView systemId() const { return m_systemId; }
+    inline QStringView publicId() const { return m_publicId; }
     inline bool operator==(const QXmlStreamNotationDeclaration &other) const {
         return (name() == other.name() && systemId() == other.systemId()
                 && publicId() == other.publicId());
@@ -190,11 +191,11 @@ class Q_CORE_EXPORT QXmlStreamEntityDeclaration {
 public:
     QXmlStreamEntityDeclaration();
 
-    inline QStringRef name() const { return m_name; }
-    inline QStringRef notationName() const { return m_notationName; }
-    inline QStringRef systemId() const { return m_systemId; }
-    inline QStringRef publicId() const { return m_publicId; }
-    inline QStringRef value() const { return m_value; }
+    inline QStringView name() const { return m_name; }
+    inline QStringView notationName() const { return m_notationName; }
+    inline QStringView systemId() const { return m_systemId; }
+    inline QStringView publicId() const { return m_publicId; }
+    inline QStringView value() const { return m_value; }
     inline bool operator==(const QXmlStreamEntityDeclaration &other) const {
         return (name() == other.name()
                 && notationName() == other.notationName()
@@ -276,8 +277,8 @@ public:
     inline bool isProcessingInstruction() const { return tokenType() == ProcessingInstruction; }
 
     bool isStandaloneDocument() const;
-    QStringRef documentVersion() const;
-    QStringRef documentEncoding() const;
+    QStringView documentVersion() const;
+    QStringView documentEncoding() const;
 
     qint64 lineNumber() const;
     qint64 columnNumber() const;
@@ -292,24 +293,24 @@ public:
     };
     QString readElementText(ReadElementTextBehaviour behaviour = ErrorOnUnexpectedElement);
 
-    QStringRef name() const;
-    QStringRef namespaceUri() const;
-    QStringRef qualifiedName() const;
-    QStringRef prefix() const;
+    QStringView name() const;
+    QStringView namespaceUri() const;
+    QStringView qualifiedName() const;
+    QStringView prefix() const;
 
-    QStringRef processingInstructionTarget() const;
-    QStringRef processingInstructionData() const;
+    QStringView processingInstructionTarget() const;
+    QStringView processingInstructionData() const;
 
-    QStringRef text() const;
+    QStringView text() const;
 
     QXmlStreamNamespaceDeclarations namespaceDeclarations() const;
     void addExtraNamespaceDeclaration(const QXmlStreamNamespaceDeclaration &extraNamespaceDeclaraction);
     void addExtraNamespaceDeclarations(const QXmlStreamNamespaceDeclarations &extraNamespaceDeclaractions);
     QXmlStreamNotationDeclarations notationDeclarations() const;
     QXmlStreamEntityDeclarations entityDeclarations() const;
-    QStringRef dtdName() const;
-    QStringRef dtdPublicId() const;
-    QStringRef dtdSystemId() const;
+    QStringView dtdName() const;
+    QStringView dtdPublicId() const;
+    QStringView dtdSystemId() const;
 
     int entityExpansionLimit() const;
     void setEntityExpansionLimit(int limit);
diff --git a/src/tools/qvkgen/qvkgen.cpp b/src/tools/qvkgen/qvkgen.cpp
index efbe54e0a5..0664f6f5db 100644
--- a/src/tools/qvkgen/qvkgen.cpp
+++ b/src/tools/qvkgen/qvkgen.cpp
@@ -104,7 +104,7 @@ void VkSpecParser::parseCommands()
         m_reader.readNext();
         if (m_reader.isEndElement() && m_reader.name() == QStringLiteral("commands"))
             return;
-        if (m_reader.isStartElement() && m_reader.name() == "command")
+        if (m_reader.isStartElement() && m_reader.name() == u"command")
             m_commands.append(parseCommand());
     }
 }
@@ -162,7 +162,7 @@ VkSpecParser::TypedName VkSpecParser::parseParamOrProto(const QString &tag)
                 skip();
             }
         } else {
-            QStringRef text = m_reader.text().trimmed();
+            auto text = m_reader.text().trimmed();
             if (!text.isEmpty()) {
                 if (text.startsWith(QLatin1Char('['))) {
                     t.typeSuffix += text;
diff --git a/src/tools/uic/uic.cpp b/src/tools/uic/uic.cpp
index 5b2a602e5f..3601280144 100644
--- a/src/tools/uic/uic.cpp
+++ b/src/tools/uic/uic.cpp
@@ -172,7 +172,7 @@ static double versionFromUiAttribute(QXmlStreamReader &reader)
     const QString versionAttribute = QLatin1String("version");
     if (!attributes.hasAttribute(versionAttribute))
         return 4.0;
-    const QStringRef version = attributes.value(versionAttribute);
+    const QStringView version = attributes.value(versionAttribute);
     return version.toDouble();
 }
 
diff --git a/src/xml/dom/qdomhelpers.cpp b/src/xml/dom/qdomhelpers.cpp
index 7a9ae1a46c..69fb99715d 100644
--- a/src/xml/dom/qdomhelpers.cpp
+++ b/src/xml/dom/qdomhelpers.cpp
@@ -291,15 +291,6 @@ QT_WARNING_POP
 
 #endif // QT_DEPRECATED_SINCE(5, 15)
 
-inline QString stringRefToString(const QStringRef &stringRef)
-{
-    // Calling QStringRef::toString() on a NULL QStringRef in some cases returns
-    // an empty string (i.e. QString("")) instead of a NULL string (i.e. QString()).
-    // QDom implementation differentiates between NULL and empty strings, so
-    // we need this as workaround to keep the current behavior unchanged.
-    return stringRef.isNull() ? QString() : stringRef.toString();
-}
-
 bool QDomBuilder::startElement(const QString &nsURI, const QString &qName,
                                const QXmlStreamAttributes &atts)
 {
@@ -317,12 +308,12 @@ bool QDomBuilder::startElement(const QString &nsURI, const QString &qName,
     for (const auto &attr : atts) {
         auto domElement = static_cast<QDomElementPrivate *>(node);
         if (nsProcessing) {
-            domElement->setAttributeNS(stringRefToString(attr.namespaceUri()),
-                                       stringRefToString(attr.qualifiedName()),
-                                       stringRefToString(attr.value()));
+            domElement->setAttributeNS(attr.namespaceUri().toString(),
+                                       attr.qualifiedName().toString(),
+                                       attr.value().toString());
         } else {
-            domElement->setAttribute(stringRefToString(attr.qualifiedName()),
-                                     stringRefToString(attr.value()));
+            domElement->setAttribute(attr.qualifiedName().toString(),
+                                     attr.value().toString());
         }
     }
 
@@ -513,9 +504,9 @@ bool QDomParser::parseProlog()
             }
             foundDtd = true;
 
-            if (!domBuilder.startDTD(stringRefToString(reader->dtdName()),
-                                     stringRefToString(reader->dtdPublicId()),
-                                     stringRefToString(reader->dtdSystemId()))) {
+            if (!domBuilder.startDTD(reader->dtdName().toString(),
+                                     reader->dtdPublicId().toString(),
+                                     reader->dtdSystemId().toString())) {
                 domBuilder.fatalError(
                         QDomParser::tr("Error occurred while processing document type declaration"));
                 return false;
@@ -550,13 +541,13 @@ bool QDomParser::parseBody()
 {
     Q_ASSERT(reader);
 
-    std::stack<QStringRef> tagStack;
+    std::stack<QString> tagStack;
     while (!reader->atEnd() && !reader->hasError()) {
         switch (reader->tokenType()) {
         case QXmlStreamReader::StartElement:
-            tagStack.push(reader->qualifiedName());
-            if (!domBuilder.startElement(stringRefToString(reader->namespaceUri()),
-                                         stringRefToString(reader->qualifiedName()),
+            tagStack.push(reader->qualifiedName().toString());
+            if (!domBuilder.startElement(reader->namespaceUri().toString(),
+                                         reader->qualifiedName().toString(),
                                          reader->attributes())) {
                 domBuilder.fatalError(
                         QDomParser::tr("Error occurred while processing a start element"));
@@ -641,10 +632,10 @@ bool QDomParser::parseMarkupDecl()
         // parsed result. So we don't need to do anything for the Internal Entities.
         if (!entityDecl.publicId().isEmpty() || !entityDecl.systemId().isEmpty()) {
             // External Entity
-            if (!domBuilder.unparsedEntityDecl(stringRefToString(entityDecl.name()),
-                                               stringRefToString(entityDecl.publicId()),
-                                               stringRefToString(entityDecl.systemId()),
-                                               stringRefToString(entityDecl.notationName()))) {
+            if (!domBuilder.unparsedEntityDecl(entityDecl.name().toString(),
+                                               entityDecl.publicId().toString(),
+                                               entityDecl.systemId().toString(),
+                                               entityDecl.notationName().toString())) {
                 domBuilder.fatalError(
                         QDomParser::tr("Error occurred while processing entity declaration"));
                 return false;
@@ -654,9 +645,9 @@ bool QDomParser::parseMarkupDecl()
 
     const auto notations = reader->notationDeclarations();
     for (const auto &notationDecl : notations) {
-        if (!domBuilder.notationDecl(stringRefToString(notationDecl.name()),
-                                     stringRefToString(notationDecl.publicId()),
-                                     stringRefToString(notationDecl.systemId()))) {
+        if (!domBuilder.notationDecl(notationDecl.name().toString(),
+                                     notationDecl.publicId().toString(),
+                                     notationDecl.systemId().toString())) {
             domBuilder.fatalError(
                     QDomParser::tr("Error occurred while processing notation declaration"));
             return false;