diff --git a/src/completion/expandingtree/expandingwidgetmodel.cpp b/src/completion/expandingtree/expandingwidgetmodel.cpp
--- a/src/completion/expandingtree/expandingwidgetmodel.cpp
+++ b/src/completion/expandingtree/expandingwidgetmodel.cpp
@@ -50,7 +50,7 @@
     clearExpanding();
 }
 
-static QColor doAlternate(QColor color)
+static QColor doAlternate(const QColor &color)
 {
     QColor background = QApplication::palette().window().color();
     return KColorUtils::mix(color, background, 0.15);
diff --git a/src/completion/katecompletionmodel.h b/src/completion/katecompletionmodel.h
--- a/src/completion/katecompletionmodel.h
+++ b/src/completion/katecompletionmodel.h
@@ -274,7 +274,7 @@
     public:
         explicit Group(const QString &title, int attribute, KateCompletionModel *model);
 
-        void addItem(Item i, bool notifyModel = false);
+        void addItem(const Item &i, bool notifyModel = false);
         /// Removes the item specified by \a row.  Returns true if a change was made to rows.
         bool removeItem(const ModelRow &row);
         void resort();
diff --git a/src/completion/katecompletionmodel.cpp b/src/completion/katecompletionmodel.cpp
--- a/src/completion/katecompletionmodel.cpp
+++ b/src/completion/katecompletionmodel.cpp
@@ -1603,7 +1603,7 @@
     return ret < 0;
 }
 
-void KateCompletionModel::Group::addItem(Item i, bool notifyModel)
+void KateCompletionModel::Group::addItem(const Item &i, bool notifyModel)
 {
     if (isEmpty) {
         notifyModel = false;
diff --git a/src/completion/katecompletionwidget.cpp b/src/completion/katecompletionwidget.cpp
--- a/src/completion/katecompletionwidget.cpp
+++ b/src/completion/katecompletionwidget.cpp
@@ -89,9 +89,9 @@
     CALLCI(return, , return, model, aborted(view));
 }
 
-static bool _shouldStartCompletion(KTextEditor::CodeCompletionModel *model, KTextEditor::View *view, QString m_automaticInvocationLine, bool m_lastInsertionByUser, const KTextEditor::Cursor &cursor)
+static bool _shouldStartCompletion(KTextEditor::CodeCompletionModel *model, KTextEditor::View *view, const QString &automaticInvocationLine, bool m_lastInsertionByUser, const KTextEditor::Cursor &cursor)
 {
-    CALLCI(return, , return, model, shouldStartCompletion(view, m_automaticInvocationLine, m_lastInsertionByUser, cursor));
+    CALLCI(return, , return, model, shouldStartCompletion(view, automaticInvocationLine, m_lastInsertionByUser, cursor));
 }
 
 KateCompletionWidget::KateCompletionWidget(KTextEditor::ViewPrivate *parent)
diff --git a/src/document/editorconfig.cpp b/src/document/editorconfig.cpp
--- a/src/document/editorconfig.cpp
+++ b/src/document/editorconfig.cpp
@@ -45,7 +45,7 @@
  * @return whether a string value could be converted to a integer value. The
  * value is put in *result.
  */
-static bool checkIntValue(QString val, int *result)
+static bool checkIntValue(const QString &val, int *result)
 {
     bool ret(false);
     *result = val.toInt(&ret);
diff --git a/src/document/katedocument.h b/src/document/katedocument.h
--- a/src/document/katedocument.h
+++ b/src/document/katedocument.h
@@ -1179,11 +1179,11 @@
       Reads and applies the variables in a single line
       TODO registered variables gets saved in a [map]
     */
-    void readVariableLine(QString t, bool onlyViewAndRenderer = false);
+    void readVariableLine(const QString &t, bool onlyViewAndRenderer = false);
     /**
       Sets a view variable in all the views.
     */
-    void setViewVariable(QString var, QString val);
+    void setViewVariable(const QString &var, const QString &val);
     /**
       @return weather a string value could be converted
       to a bool value as supported.
@@ -1195,12 +1195,12 @@
       to a integer value.
       The value is put in *result.
     */
-    static bool checkIntValue(QString value, int *result);
+    static bool checkIntValue(const QString &value, int *result);
     /**
       Feeds value into @p col using QColor::setNamedColor() and returns
       whether the color is valid
     */
-    static bool checkColorValue(QString value, QColor &col);
+    static bool checkColorValue(const QString &value, QColor &col);
 
     bool m_fileChangedDialogsActivated = false;
 
diff --git a/src/document/katedocument.cpp b/src/document/katedocument.cpp
--- a/src/document/katedocument.cpp
+++ b/src/document/katedocument.cpp
@@ -4628,7 +4628,7 @@
     }
 }
 
-void KTextEditor::DocumentPrivate::readVariableLine(QString t, bool onlyViewAndRenderer)
+void KTextEditor::DocumentPrivate::readVariableLine(const QString &t, bool onlyViewAndRenderer)
 {
     static const QRegularExpression kvLine(QStringLiteral("kate:(.*)"));
     static const QRegularExpression kvLineWildcard(QStringLiteral("kate-wildcard\\((.*)\\):(.*)"));
@@ -4843,7 +4843,7 @@
     }
 }
 
-void KTextEditor::DocumentPrivate::setViewVariable(QString var, QString val)
+void KTextEditor::DocumentPrivate::setViewVariable(const QString &var, const QString &val)
 {
     bool state;
     int n;
@@ -4911,14 +4911,14 @@
     return false;
 }
 
-bool KTextEditor::DocumentPrivate::checkIntValue(QString val, int *result)
+bool KTextEditor::DocumentPrivate::checkIntValue(const QString &val, int *result)
 {
     bool ret(false);
     *result = val.toInt(&ret);
     return ret;
 }
 
-bool KTextEditor::DocumentPrivate::checkColorValue(QString val, QColor &c)
+bool KTextEditor::DocumentPrivate::checkColorValue(const QString &val, QColor &c)
 {
     c.setNamedColor(val);
     return c.isValid();
diff --git a/src/render/katerenderrange.cpp b/src/render/katerenderrange.cpp
--- a/src/render/katerenderrange.cpp
+++ b/src/render/katerenderrange.cpp
@@ -82,7 +82,7 @@
 
 void NormalRenderRange::addRange(const KTextEditor::Range &range, KTextEditor::Attribute::Ptr attribute)
 {
-    m_ranges.push_back(std::make_pair(range, attribute));
+    m_ranges.emplace_back(range, std::move(attribute));
 }
 
 KTextEditor::Cursor NormalRenderRange::nextBoundary() const
diff --git a/src/render/katetextlayout.cpp b/src/render/katetextlayout.cpp
--- a/src/render/katetextlayout.cpp
+++ b/src/render/katetextlayout.cpp
@@ -23,7 +23,7 @@
 #include "katepartdebug.h"
 
 KateTextLayout::KateTextLayout(KateLineLayoutPtr line, int viewLine)
-    : m_lineLayout(line)
+    : m_lineLayout(std::move(line))
     , m_viewLine(viewLine)
     , m_startX(m_viewLine ? -1 : 0)
 {
diff --git a/src/schema/katestyletreewidget.cpp b/src/schema/katestyletreewidget.cpp
--- a/src/schema/katestyletreewidget.cpp
+++ b/src/schema/katestyletreewidget.cpp
@@ -325,12 +325,12 @@
 
 void KateStyleTreeWidget::addItem(const QString &styleName, KTextEditor::Attribute::Ptr defaultstyle, KTextEditor::Attribute::Ptr data)
 {
-    new KateStyleTreeWidgetItem(this, styleName, defaultstyle, data);
+    new KateStyleTreeWidgetItem(this, styleName, std::move(defaultstyle), std::move(data));
 }
 
 void KateStyleTreeWidget::addItem(QTreeWidgetItem *parent, const QString &styleName, KTextEditor::Attribute::Ptr defaultstyle, KTextEditor::Attribute::Ptr data)
 {
-    new KateStyleTreeWidgetItem(parent, styleName, defaultstyle, data);
+    new KateStyleTreeWidgetItem(parent, styleName, std::move(defaultstyle), std::move(data));
     updateGroupHeadings();
 }
 // END
@@ -405,18 +405,18 @@
 KateStyleTreeWidgetItem::KateStyleTreeWidgetItem(QTreeWidgetItem *parent, const QString &stylename, KTextEditor::Attribute::Ptr defaultAttribute, KTextEditor::Attribute::Ptr actualAttribute)
     : QTreeWidgetItem(parent)
     , currentStyle(nullptr)
-    , defaultStyle(defaultAttribute)
-    , actualStyle(actualAttribute)
+    , defaultStyle(std::move(defaultAttribute))
+    , actualStyle(std::move(actualAttribute))
 {
     initStyle();
     setText(0, stylename);
 }
 
 KateStyleTreeWidgetItem::KateStyleTreeWidgetItem(QTreeWidget *parent, const QString &stylename, KTextEditor::Attribute::Ptr defaultAttribute, KTextEditor::Attribute::Ptr actualAttribute)
     : QTreeWidgetItem(parent)
     , currentStyle(nullptr)
-    , defaultStyle(defaultAttribute)
-    , actualStyle(actualAttribute)
+    , defaultStyle(std::move(defaultAttribute))
+    , actualStyle(std::move(actualAttribute))
 {
     initStyle();
     setText(0, stylename);
diff --git a/src/script/katecommandlinescript.h b/src/script/katecommandlinescript.h
--- a/src/script/katecommandlinescript.h
+++ b/src/script/katecommandlinescript.h
@@ -69,7 +69,7 @@
 
     const KateCommandLineScriptHeader &commandHeader();
 
-    bool callFunction(const QString &cmd, const QStringList args, QString &errorMessage);
+    bool callFunction(const QString &cmd, const QStringList &args, QString &errorMessage);
 
     //
     // KTextEditor::Command interface
diff --git a/src/script/katecommandlinescript.cpp b/src/script/katecommandlinescript.cpp
--- a/src/script/katecommandlinescript.cpp
+++ b/src/script/katecommandlinescript.cpp
@@ -47,7 +47,7 @@
     return m_commandHeader;
 }
 
-bool KateCommandLineScript::callFunction(const QString &cmd, const QStringList args, QString &errorMessage)
+bool KateCommandLineScript::callFunction(const QString &cmd, const QStringList &args, QString &errorMessage)
 {
     clearExceptions();
     QJSValue command = function(cmd);
diff --git a/src/search/katesearchbar.cpp b/src/search/katesearchbar.cpp
--- a/src/search/katesearchbar.cpp
+++ b/src/search/katesearchbar.cpp
@@ -98,7 +98,7 @@
         m_menu->setEnabled(enabled);
     }
 
-    void addEntry(const QString &before, const QString after, const QString description, const QString &realBefore = QString(), const QString &realAfter = QString())
+    void addEntry(const QString &before, const QString &after, const QString &description, const QString &realBefore = QString(), const QString &realAfter = QString())
     {
         if (m_menu == nullptr) {
             return;
diff --git a/src/utils/attribute.cpp b/src/utils/attribute.cpp
--- a/src/utils/attribute.cpp
+++ b/src/utils/attribute.cpp
@@ -90,7 +90,7 @@
         return;
     }
 
-    d->dynamicAttributes[type] = attribute;
+    d->dynamicAttributes[type] = std::move(attribute);
 }
 
 QString Attribute::name() const
diff --git a/src/utils/katecmd.cpp b/src/utils/katecmd.cpp
--- a/src/utils/katecmd.cpp
+++ b/src/utils/katecmd.cpp
@@ -38,7 +38,7 @@
 
 bool KateCmd::registerCommand(KTextEditor::Command *cmd)
 {
-    const QStringList l = cmd->cmds();
+    const QStringList &l = cmd->cmds();
 
     for (int z = 0; z < l.count(); z++)
         if (m_dict.contains(l[z])) {
diff --git a/src/utils/kateglobal.cpp b/src/utils/kateglobal.cpp
--- a/src/utils/kateglobal.cpp
+++ b/src/utils/kateglobal.cpp
@@ -550,7 +550,7 @@
     auto applicationConfig = KSharedConfig::openConfig();
     if (!KConfigGroup(applicationConfig, QStringLiteral("KTextEditor Editor")).exists()) {
         auto globalConfig = KSharedConfig::openConfig(QStringLiteral("katepartrc"));
-        for (auto group : {QStringLiteral("Editor"), QStringLiteral("Document"), QStringLiteral("View"), QStringLiteral("Renderer")}) {
+        for (const auto &group : {QStringLiteral("Editor"), QStringLiteral("Document"), QStringLiteral("View"), QStringLiteral("Renderer")}) {
             KConfigGroup origin(globalConfig, group);
             KConfigGroup destination(applicationConfig, QStringLiteral("KTextEditor ") + group);
             origin.copyTo(&destination);
diff --git a/src/utils/variable.cpp b/src/utils/variable.cpp
--- a/src/utils/variable.cpp
+++ b/src/utils/variable.cpp
@@ -23,7 +23,7 @@
 Variable::Variable(const QString &name, const QString &description, Variable::ExpandFunction func, bool isPrefixMatch)
     : m_name(name)
     , m_description(description)
-    , m_function(func)
+    , m_function(std::move(func))
     , m_isPrefixMatch(isPrefixMatch)
 {
 }
diff --git a/src/view/katemessagewidget.cpp b/src/view/katemessagewidget.cpp
--- a/src/view/katemessagewidget.cpp
+++ b/src/view/katemessagewidget.cpp
@@ -184,7 +184,7 @@
 void KateMessageWidget::postMessage(KTextEditor::Message *message, QList<QSharedPointer<QAction>> actions)
 {
     Q_ASSERT(!m_messageHash.contains(message));
-    m_messageHash[message] = actions;
+    m_messageHash[message] = std::move(actions);
 
     // insert message sorted after priority
     int i = 0;
diff --git a/src/view/katestatusbar.cpp b/src/view/katestatusbar.cpp
--- a/src/view/katestatusbar.cpp
+++ b/src/view/katestatusbar.cpp
@@ -325,7 +325,7 @@
     // Check if at the current cursor position is a special dictionary in use
     KTextEditor::Cursor position(m_view->cursorPositionVirtual());
     const QList<QPair<KTextEditor::MovingRange *, QString>> dictRanges = m_view->doc()->dictionaryRanges();
-    for (auto rangeDictPair : dictRanges) {
+    for (const auto &rangeDictPair : dictRanges) {
         const KTextEditor::MovingRange *range = rangeDictPair.first;
         if (range->contains(position) || range->end() == position) {
             newDict = rangeDictPair.second;
diff --git a/src/view/katetextanimation.cpp b/src/view/katetextanimation.cpp
--- a/src/view/katetextanimation.cpp
+++ b/src/view/katetextanimation.cpp
@@ -33,7 +33,7 @@
 KateTextAnimation::KateTextAnimation(const KTextEditor::Range &range, KTextEditor::Attribute::Ptr attribute, KateViewInternal *view)
     : QObject(view)
     , m_range(range)
-    , m_attribute(attribute)
+    , m_attribute(std::move(attribute))
     , m_doc(view->view()->doc())
     , m_view(view)
     , m_timeLine(new QTimeLine(250, this))
diff --git a/src/view/kateview.cpp b/src/view/kateview.cpp
--- a/src/view/kateview.cpp
+++ b/src/view/kateview.cpp
@@ -3693,7 +3693,7 @@
         connect(this, SIGNAL(displayRangeChanged(KTextEditor::ViewPrivate *)), messageWidget, SLOT(startAutoHideTimer()));
         connect(this, SIGNAL(cursorPositionChanged(KTextEditor::View *, KTextEditor::Cursor)), messageWidget, SLOT(startAutoHideTimer()));
     }
-    messageWidget->postMessage(message, actions);
+    messageWidget->postMessage(message, std::move(actions));
 }
 
 KateMessageWidget *KTextEditor::ViewPrivate::messageWidget()
diff --git a/src/view/kateviewinternal.cpp b/src/view/kateviewinternal.cpp
--- a/src/view/kateviewinternal.cpp
+++ b/src/view/kateviewinternal.cpp
@@ -3773,7 +3773,7 @@
         m_imPreeditRangeChildren.clear();
 
         int decorationColumn = 0;
-        const auto attributes = e->attributes();
+        const auto &attributes = e->attributes();
         for (auto &a : attributes) {
             if (a.type == QInputMethodEvent::Cursor) {
                 newCursor = m_imPreeditRange->start() + KTextEditor::Cursor(0, a.start);
@@ -3824,7 +3824,7 @@
     if (m_textAnimation) {
         m_textAnimation->deleteLater();
     }
-    m_textAnimation = new KateTextAnimation(range, attribute, this);
+    m_textAnimation = new KateTextAnimation(range, std::move(attribute), this);
 }
 
 void KateViewInternal::documentTextInserted(KTextEditor::Document *document, const KTextEditor::Range &range)
diff --git a/src/vimode/command.h b/src/vimode/command.h
--- a/src/vimode/command.h
+++ b/src/vimode/command.h
@@ -43,7 +43,7 @@
 class Command
 {
 public:
-    Command(NormalViMode *parent, QString pattern, bool (NormalViMode::*pt2Func)(), unsigned int flags = 0);
+    Command(NormalViMode *parent, const QString &pattern, bool (NormalViMode::*pt2Func)(), unsigned int flags = 0);
     ~Command();
 
     bool matches(const QString &pattern) const;
diff --git a/src/vimode/command.cpp b/src/vimode/command.cpp
--- a/src/vimode/command.cpp
+++ b/src/vimode/command.cpp
@@ -25,7 +25,7 @@
 
 using namespace KateVi;
 
-Command::Command(NormalViMode *parent, QString pattern, bool (NormalViMode::*commandMethod)(), unsigned int flags)
+Command::Command(NormalViMode *parent, const QString &pattern, bool (NormalViMode::*commandMethod)(), unsigned int flags)
 {
     m_parent = parent;
     m_pattern = KeyParser::self()->encodeKeySequence(pattern);
diff --git a/src/vimode/modes/modebase.h b/src/vimode/modes/modebase.h
--- a/src/vimode/modes/modebase.h
+++ b/src/vimode/modes/modebase.h
@@ -84,7 +84,7 @@
 
 protected:
     // helper methods
-    void yankToClipBoard(QChar chosen_register, QString text);
+    void yankToClipBoard(QChar chosen_register, const QString &text);
     bool deleteRange(Range &r, OperationMode mode = LineWise, bool addToRegister = true);
     const QString getRange(Range &r, OperationMode mode = LineWise) const;
     const QString getLine(int line = -1) const;
diff --git a/src/vimode/modes/modebase.cpp b/src/vimode/modes/modebase.cpp
--- a/src/vimode/modes/modebase.cpp
+++ b/src/vimode/modes/modebase.cpp
@@ -57,7 +57,7 @@
 // HELPER METHODS
 ////////////////////////////////////////////////////////////////////////////////
 
-void ModeBase::yankToClipBoard(QChar chosen_register, QString text)
+void ModeBase::yankToClipBoard(QChar chosen_register, const QString &text)
 {
     // only yank to the clipboard if no register was specified,
     // textlength > 1 and there is something else then whitespace
@@ -328,17 +328,15 @@
 {
     QString line = getLine(fromLine);
 
-    QRegExp endOfWORDPattern(QLatin1String("\\S\\s|\\S$|^$"));
-
-    QRegExp endOfWORD(endOfWORDPattern);
+    const QRegExp endOfWORDPattern(QLatin1String("\\S\\s|\\S$|^$"));
 
     int l = fromLine;
     int c = fromColumn;
 
     bool found = false;
 
     while (!found) {
-        int c1 = endOfWORD.lastIndexIn(line, c - 1);
+        int c1 = endOfWORDPattern.lastIndexIn(line, c - 1);
 
         if (c1 != -1 && c - 1 != -1) {
             found = true;