diff --git a/src/plugins/qmldesigner/components/componentcore/findimplementation.cpp b/src/plugins/qmldesigner/components/componentcore/findimplementation.cpp
index 6ddd66f7274..fa13ef68110 100644
--- a/src/plugins/qmldesigner/components/componentcore/findimplementation.cpp
+++ b/src/plugins/qmldesigner/components/componentcore/findimplementation.cpp
@@ -44,7 +44,7 @@ class FindImplementationVisitor: protected AST::Visitor
 public:
     using Results = QList<AST::SourceLocation>;
 
-    FindImplementationVisitor(Document::Ptr doc, const ContextPtr &context)
+    FindImplementationVisitor(const Document::Ptr &doc, const ContextPtr &context)
         : m_document(doc)
         , m_context(context)
         , m_scopeChain(doc, context)
diff --git a/src/plugins/qmldesigner/components/componentcore/modelnodeoperations.cpp b/src/plugins/qmldesigner/components/componentcore/modelnodeoperations.cpp
index c40de1ea563..f5b701e44d2 100644
--- a/src/plugins/qmldesigner/components/componentcore/modelnodeoperations.cpp
+++ b/src/plugins/qmldesigner/components/componentcore/modelnodeoperations.cpp
@@ -379,7 +379,7 @@ void resetZ(const SelectionContext &selectionState)
     }
 }
 
-static inline void backupPropertyAndRemove(ModelNode node, const PropertyName &propertyName)
+static inline void backupPropertyAndRemove(const ModelNode &node, const PropertyName &propertyName)
 {
     if (node.hasVariantProperty(propertyName)) {
         node.setAuxiliaryData(auxDataString + propertyName, node.variantProperty(propertyName).value());
@@ -480,7 +480,7 @@ bool compareByGrid(const ModelNode &node1, const ModelNode &node2)
 
 
 static void layoutHelperFunction(const SelectionContext &selectionContext,
-                                 TypeName layoutType,
+                                 const TypeName &layoutType,
                                  LessThan lessThan)
 {
     if (!selectionContext.view()
@@ -578,7 +578,7 @@ static PropertyNameList sortedPropertyNameList(const PropertyNameList &nameList)
     return sortedPropertyNameList;
 }
 
-static QString toUpper(const QString signal)
+static QString toUpper(const QString &signal)
 {
     QString ret = signal;
     ret[0] = signal.at(0).toUpper();
diff --git a/src/plugins/qmldesigner/components/integration/designdocumentview.cpp b/src/plugins/qmldesigner/components/integration/designdocumentview.cpp
index 1e3ce5c795b..4b7c5772d82 100644
--- a/src/plugins/qmldesigner/components/integration/designdocumentview.cpp
+++ b/src/plugins/qmldesigner/components/integration/designdocumentview.cpp
@@ -135,7 +135,7 @@ QString DesignDocumentView::toText() const
     //get the text of the root item without imports
 }
 
-void DesignDocumentView::fromText(QString text)
+void DesignDocumentView::fromText(const QString &text)
 {
     QScopedPointer<Model> inputModel(Model::create("QtQuick.Rectangle", 1, 0, model()));
     inputModel->setFileUrl(model()->fileUrl());
diff --git a/src/plugins/qmldesigner/components/integration/designdocumentview.h b/src/plugins/qmldesigner/components/integration/designdocumentview.h
index 9e841c743ac..7c008e222c0 100644
--- a/src/plugins/qmldesigner/components/integration/designdocumentview.h
+++ b/src/plugins/qmldesigner/components/integration/designdocumentview.h
@@ -47,7 +47,7 @@ public:
     void fromClipboard();
 
     QString toText() const;
-    void fromText(QString text);
+    void fromText(const QString &text);
 
     static Model *pasteToModel();
     static void copyModelNodes(const QList<ModelNode> &nodesToCopy);
diff --git a/src/plugins/qmldesigner/components/itemlibrary/customfilesystemmodel.cpp b/src/plugins/qmldesigner/components/itemlibrary/customfilesystemmodel.cpp
index 5c5081fd7cf..4a9147ae4e0 100644
--- a/src/plugins/qmldesigner/components/itemlibrary/customfilesystemmodel.cpp
+++ b/src/plugins/qmldesigner/components/itemlibrary/customfilesystemmodel.cpp
@@ -88,7 +88,7 @@ void CustomFileSystemModel::setFilter(QDir::Filters)
 
 }
 
-QString filterMetaIcons(const QString fileName)
+QString filterMetaIcons(const QString &fileName)
 {
 
     QFileInfo info(fileName);
diff --git a/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.cpp b/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.cpp
index 872bc845181..86b3ac91659 100644
--- a/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.cpp
+++ b/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.cpp
@@ -401,8 +401,8 @@ QString PropertyEditorQmlBackend::propertyEditorResourcesPath() {
     return Core::ICore::resourcePath() + QStringLiteral("/qmldesigner/propertyEditorQmlSources");
 }
 
-QString PropertyEditorQmlBackend::templateGeneration(NodeMetaInfo type,
-                                                     NodeMetaInfo superType,
+QString PropertyEditorQmlBackend::templateGeneration(const NodeMetaInfo &type,
+                                                     const NodeMetaInfo &superType,
                                                      const QmlObjectNode &objectNode)
 {
     if (!templateConfiguration() || !templateConfiguration()->isValid())
diff --git a/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.h b/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.h
index a272b35aef0..a0012a1cc17 100644
--- a/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.h
+++ b/src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.h
@@ -68,7 +68,7 @@ public:
     PropertyEditorValue *propertyValueForName(const QString &propertyName);
 
     static QString propertyEditorResourcesPath();
-    static QString templateGeneration(NodeMetaInfo type, NodeMetaInfo superType,
+    static QString templateGeneration(const NodeMetaInfo &type, const NodeMetaInfo &superType,
                                       const QmlObjectNode &objectNode);
 
     static QUrl getQmlFileUrl(const TypeName &relativeTypeName, const NodeMetaInfo &info = NodeMetaInfo());
diff --git a/src/plugins/qmldesigner/components/propertyeditor/qmlanchorbindingproxy.cpp b/src/plugins/qmldesigner/components/propertyeditor/qmlanchorbindingproxy.cpp
index ca1f307b930..afc7c497152 100644
--- a/src/plugins/qmldesigner/components/propertyeditor/qmlanchorbindingproxy.cpp
+++ b/src/plugins/qmldesigner/components/propertyeditor/qmlanchorbindingproxy.cpp
@@ -39,7 +39,7 @@ class NodeState;
 
 const PropertyName auxDataString("anchors_");
 
-static inline void backupPropertyAndRemove(ModelNode node, const PropertyName &propertyName)
+static inline void backupPropertyAndRemove(const ModelNode &node, const PropertyName &propertyName)
 {
     if (node.hasVariantProperty(propertyName)) {
         node.setAuxiliaryData(auxDataString + propertyName, node.variantProperty(propertyName).value());
diff --git a/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp b/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp
index 117fdb9adca..8bf98d79c97 100644
--- a/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp
+++ b/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp
@@ -199,7 +199,7 @@ bool TextEditorWidget::eventFilter( QObject *, QEvent *event)
                 | Qt::MetaModifier;
 
         QKeySequence keySqeuence(keyEvent->key() | (keyEvent->modifiers() & relevantModifiers));
-        for (QKeySequence overrideSequence : overrideSequences)
+        for (const QKeySequence &overrideSequence : overrideSequences)
             if (keySqeuence.matches(overrideSequence)) {
                 keyEvent->accept();
                 return true;
diff --git a/src/plugins/qmldesigner/designercore/include/nodemetainfo.h b/src/plugins/qmldesigner/designercore/include/nodemetainfo.h
index 89b62939a3d..5d2d171ae72 100644
--- a/src/plugins/qmldesigner/designercore/include/nodemetainfo.h
+++ b/src/plugins/qmldesigner/designercore/include/nodemetainfo.h
@@ -54,7 +54,7 @@ class QMLDESIGNERCORE_EXPORT NodeMetaInfo
 {
 public:
     NodeMetaInfo();
-    NodeMetaInfo(Model *model, TypeName type, int maj, int min);
+    NodeMetaInfo(Model *model, const TypeName &type, int maj, int min);
 
     ~NodeMetaInfo();
 
diff --git a/src/plugins/qmldesigner/designercore/metainfo/nodemetainfo.cpp b/src/plugins/qmldesigner/designercore/metainfo/nodemetainfo.cpp
index a7f151d6e94..f92358efc9f 100644
--- a/src/plugins/qmldesigner/designercore/metainfo/nodemetainfo.cpp
+++ b/src/plugins/qmldesigner/designercore/metainfo/nodemetainfo.cpp
@@ -50,8 +50,8 @@ namespace Internal {
 struct TypeDescription
 {
     QString className;
-    int minorVersion;
-    int majorVersion;
+    int minorVersion{};
+    int majorVersion{};
 };
 
 } //Internal
@@ -736,7 +736,7 @@ const CppComponentValue *NodeMetaInfoPrivate::getCppComponentValue() const
     // get the qml object value that's available in the document
     const QmlJS::Imports *importsPtr = context()->imports(document());
     if (importsPtr) {
-        const QList<QmlJS::Import> imports = importsPtr->all();
+        const QList<QmlJS::Import> &imports = importsPtr->all();
         foreach (const QmlJS::Import &import, imports) {
             if (import.info.path() != QString::fromUtf8(module))
                 continue;
@@ -1317,7 +1317,7 @@ NodeMetaInfo::NodeMetaInfo() : m_privateData(new Internal::NodeMetaInfoPrivate()
 
 }
 
-NodeMetaInfo::NodeMetaInfo(Model *model, TypeName type, int maj, int min) : m_privateData(Internal::NodeMetaInfoPrivate::create(model, type, maj, min))
+NodeMetaInfo::NodeMetaInfo(Model *model, const TypeName &type, int maj, int min) : m_privateData(Internal::NodeMetaInfoPrivate::create(model, type, maj, min))
 {
 
 }
diff --git a/src/plugins/qmldesigner/designercore/model/basetexteditmodifier.cpp b/src/plugins/qmldesigner/designercore/model/basetexteditmodifier.cpp
index 17babff6757..612f3003e51 100644
--- a/src/plugins/qmldesigner/designercore/model/basetexteditmodifier.cpp
+++ b/src/plugins/qmldesigner/designercore/model/basetexteditmodifier.cpp
@@ -105,7 +105,7 @@ bool BaseTextEditModifier::renameId(const QString &oldId, const QString &newId)
     return false;
 }
 
-static QmlJS::AST::UiObjectDefinition *getObjectDefinition(QList<QmlJS::AST::Node *> path, QmlJS::AST::UiQualifiedId *qualifiedId)
+static QmlJS::AST::UiObjectDefinition *getObjectDefinition(const QList<QmlJS::AST::Node *> &path, QmlJS::AST::UiQualifiedId *qualifiedId)
 {
     QmlJS::AST::UiObjectDefinition *object = nullptr;
     for (int i = path.size() - 1; i >= 0; --i) {
diff --git a/src/plugins/qmldesigner/designercore/model/qmltimelinekeyframegroup.cpp b/src/plugins/qmldesigner/designercore/model/qmltimelinekeyframegroup.cpp
index 9e0b7558075..e457e5cdaab 100644
--- a/src/plugins/qmldesigner/designercore/model/qmltimelinekeyframegroup.cpp
+++ b/src/plugins/qmldesigner/designercore/model/qmltimelinekeyframegroup.cpp
@@ -90,7 +90,7 @@ int QmlTimelineKeyframeGroup::getSupposedTargetIndex(qreal newFrame) const
 {
     const NodeListProperty nodeListProperty = modelNode().defaultNodeListProperty();
     int i = 0;
-    for (auto node : nodeListProperty.toModelNodeList()) {
+    for (const auto &node : nodeListProperty.toModelNodeList()) {
         if (node.hasVariantProperty("frame")) {
             const qreal currentFrame = node.variantProperty("frame").value().toReal();
             if (!qFuzzyCompare(currentFrame, newFrame)) { //Ignore the frame itself
diff --git a/src/plugins/qmldesigner/designercore/model/rewriterview.cpp b/src/plugins/qmldesigner/designercore/model/rewriterview.cpp
index 4ccc6a4ef11..f42a125555f 100644
--- a/src/plugins/qmldesigner/designercore/model/rewriterview.cpp
+++ b/src/plugins/qmldesigner/designercore/model/rewriterview.cpp
@@ -468,7 +468,7 @@ QString RewriterView::auxiliaryDataAsQML() const
     QString str = "Designer {\n    ";
 
     int columnCount = 0;
-    for (const auto node : allModelNodes()) {
+    for (const auto &node : allModelNodes()) {
         QHash<PropertyName, QVariant> data = node.auxiliaryData();
         if (!data.isEmpty()) {
             hasAuxData = true;
@@ -918,13 +918,11 @@ QString RewriterView::getRawAuxiliaryData() const
 
     const QString oldText = m_textModifier->text();
 
-    QString newText = oldText;
-
-    int startIndex = newText.indexOf(annotationsStart());
-    int endIndex = newText.indexOf(annotationsEnd());
+    int startIndex = oldText.indexOf(annotationsStart());
+    int endIndex = oldText.indexOf(annotationsEnd());
 
     if (startIndex > 0 && endIndex > 0)
-        return newText.mid(startIndex, endIndex - startIndex + annotationsEnd().length());
+        return oldText.mid(startIndex, endIndex - startIndex + annotationsEnd().length());
 
     return {};
 }
@@ -957,14 +955,14 @@ void RewriterView::writeAuxiliaryData()
     changeSet.apply(&tc);
 }
 
-static void checkNode(QmlJS::SimpleReaderNode::Ptr node, RewriterView *view);
+static void checkNode(const QmlJS::SimpleReaderNode::Ptr &node, RewriterView *view);
 
-static void checkChildNodes(QmlJS::SimpleReaderNode::Ptr node, RewriterView *view)
+static void checkChildNodes(const QmlJS::SimpleReaderNode::Ptr &node, RewriterView *view)
 {
     if (!node)
         return;
 
-    for (auto child : node->children())
+    for (const auto &child : node->children())
         checkNode(child, view);
 }
 
@@ -975,7 +973,7 @@ static QString fixUpIllegalChars(const QString &str)
     return ret;
 }
 
-static void checkNode(QmlJS::SimpleReaderNode::Ptr node, RewriterView *view)
+static void checkNode(const QmlJS::SimpleReaderNode::Ptr &node, RewriterView *view)
 {
     if (!node)
         return;
diff --git a/src/plugins/qmldesigner/designercore/model/viewmanager.cpp b/src/plugins/qmldesigner/designercore/model/viewmanager.cpp
index 800c807dc60..3c35c36f846 100644
--- a/src/plugins/qmldesigner/designercore/model/viewmanager.cpp
+++ b/src/plugins/qmldesigner/designercore/model/viewmanager.cpp
@@ -374,13 +374,13 @@ QWidget *ViewManager::widget(const QString &uniqueId) const
 
 void ViewManager::disableWidgets()
 {
-    for (auto view : views())
+    for (const auto &view : views())
         view->disableWidget();
 }
 
 void ViewManager::enableWidgets()
 {
-    for (auto view : views())
+    for (const auto &view : views())
         view->enableWidget();
 }
 
diff --git a/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.cpp b/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.cpp
index c289c900fea..2c6e14d094c 100644
--- a/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.cpp
+++ b/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.cpp
@@ -66,7 +66,7 @@ static ModelNode pathModelNode(FormEditorItem *formEditorItem)
 
 using PropertyPair = QPair<PropertyName, QVariant>;
 
-void PathItem::writeLinePath(ModelNode pathNode, const CubicSegment &cubicSegment)
+void PathItem::writeLinePath(const ModelNode &pathNode, const CubicSegment &cubicSegment)
 {
     QList<PropertyPair> propertyList;
     propertyList.append(PropertyPair("x", cubicSegment.fourthControlX()));
@@ -76,7 +76,7 @@ void PathItem::writeLinePath(ModelNode pathNode, const CubicSegment &cubicSegmen
     pathNode.nodeListProperty("pathElements").reparentHere(lineNode);
 }
 
-void PathItem::writeQuadPath(ModelNode pathNode, const CubicSegment &cubicSegment)
+void PathItem::writeQuadPath(const ModelNode &pathNode, const CubicSegment &cubicSegment)
 {
     QList<QPair<PropertyName, QVariant> > propertyList;
     propertyList.append(PropertyPair("controlX", cubicSegment.quadraticControlX()));
@@ -88,7 +88,7 @@ void PathItem::writeQuadPath(ModelNode pathNode, const CubicSegment &cubicSegmen
     pathNode.nodeListProperty("pathElements").reparentHere(lineNode);
 }
 
-void PathItem::writeCubicPath(ModelNode pathNode, const CubicSegment &cubicSegment)
+void PathItem::writeCubicPath(const ModelNode &pathNode, const CubicSegment &cubicSegment)
 {
     QList<QPair<PropertyName, QVariant> > propertyList;
     propertyList.append(PropertyPair("control1X", cubicSegment.secondControlX()));
@@ -102,7 +102,7 @@ void PathItem::writeCubicPath(ModelNode pathNode, const CubicSegment &cubicSegme
     pathNode.nodeListProperty("pathElements").reparentHere(lineNode);
 }
 
-void PathItem::writePathAttributes(ModelNode pathNode, const QMap<QString, QVariant> &attributes)
+void PathItem::writePathAttributes(const ModelNode &pathNode, const QMap<QString, QVariant> &attributes)
 {
     QMapIterator<QString, QVariant> attributesIterator(attributes);
     while (attributesIterator.hasNext()) {
@@ -116,7 +116,7 @@ void PathItem::writePathAttributes(ModelNode pathNode, const QMap<QString, QVari
     }
 }
 
-void PathItem::writePathPercent(ModelNode pathNode, double percent)
+void PathItem::writePathPercent(const ModelNode& pathNode, double percent)
 {
     if (percent >= 0.0) {
         QList<QPair<PropertyName, QVariant> > propertyList;
@@ -943,8 +943,8 @@ void PathItem::removeEditPoint(const ControlPoint &controlPoint)
         m_cubicSegments.removeOne(cubicSegments.constFirst());
     } else if (cubicSegments.count()  == 2){
         CubicSegment mergedCubicSegment = CubicSegment::create();
-        CubicSegment firstCubicSegment = cubicSegments.at(0);
-        CubicSegment secondCubicSegment = cubicSegments.at(1);
+        const CubicSegment &firstCubicSegment = cubicSegments.at(0);
+        const CubicSegment &secondCubicSegment = cubicSegments.at(1);
         mergedCubicSegment.setFirstControlPoint(firstCubicSegment.firstControlPoint());
         mergedCubicSegment.setSecondControlPoint(firstCubicSegment.secondControlPoint());
         mergedCubicSegment.setThirdControlPoint(secondCubicSegment.thirdControlPoint());
diff --git a/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.h b/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.h
index 93680c2355f..17981283a67 100644
--- a/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.h
+++ b/src/plugins/qmldesigner/qmldesignerextension/pathtool/pathitem.h
@@ -99,11 +99,11 @@ public:
 protected:
     void updateBoundingRect();
     QRectF instanceBoundingRect() const;
-    void writeLinePath(ModelNode pathNode, const CubicSegment &cubicSegment);
-    void writeQuadPath(ModelNode pathNode, const CubicSegment &cubicSegment);
-    void writeCubicPath(ModelNode pathNode, const CubicSegment &cubicSegment);
-    void writePathAttributes(ModelNode pathNode, const QMap<QString, QVariant> &attributes);
-    void writePathPercent(ModelNode pathNode, double percent);
+    void writeLinePath(const ModelNode &pathNode, const CubicSegment &cubicSegment);
+    void writeQuadPath(const ModelNode &pathNode, const CubicSegment &cubicSegment);
+    void writeCubicPath(const ModelNode &pathNode, const CubicSegment &cubicSegment);
+    void writePathAttributes(const ModelNode &pathNode, const QMap<QString, QVariant> &attributes);
+    void writePathPercent(const ModelNode &pathNode, double percent);
     void readControlPoints();
     void splitCubicSegment(CubicSegment &cubicSegment, double t);
     void closePath();