diff --git a/src/plugins/diffeditor/descriptionwidgetwatcher.cpp b/src/plugins/diffeditor/descriptionwidgetwatcher.cpp
index 5b266ebe74a..0279fdcdb9c 100644
--- a/src/plugins/diffeditor/descriptionwidgetwatcher.cpp
+++ b/src/plugins/diffeditor/descriptionwidgetwatcher.cpp
@@ -68,7 +68,7 @@ QList<TextEditor::TextEditorWidget *> DescriptionWidgetWatcher::descriptionWidge
 
 TextEditor::TextEditorWidget *DescriptionWidgetWatcher::descriptionWidget(Core::IEditor *editor) const
 {
-    if (Internal::DiffEditor *diffEditor = qobject_cast<Internal::DiffEditor *>(editor)) {
+    if (auto diffEditor = qobject_cast<const Internal::DiffEditor *>(editor)) {
         if (diffEditor->document() == m_document)
             return diffEditor->descriptionWidget();
     }
diff --git a/src/plugins/diffeditor/diffeditor.cpp b/src/plugins/diffeditor/diffeditor.cpp
index ca860beb375..3e86febfab6 100644
--- a/src/plugins/diffeditor/diffeditor.cpp
+++ b/src/plugins/diffeditor/diffeditor.cpp
@@ -258,7 +258,7 @@ DiffEditor::~DiffEditor()
 
 Core::IEditor *DiffEditor::duplicate()
 {
-    DiffEditor *editor = new DiffEditor();
+    auto editor = new DiffEditor();
     Utils::GuardLocker guard(editor->m_ignoreChanges);
 
     editor->setDocument(m_document);
diff --git a/src/plugins/diffeditor/diffeditorfactory.h b/src/plugins/diffeditor/diffeditorfactory.h
index bea963632ee..2f89ac6ba31 100644
--- a/src/plugins/diffeditor/diffeditorfactory.h
+++ b/src/plugins/diffeditor/diffeditorfactory.h
@@ -40,7 +40,7 @@ class DiffEditorFactory : public Core::IEditorFactory
 public:
     explicit DiffEditorFactory(QObject *parent);
 
-    Core::IEditor *createEditor();
+    Core::IEditor *createEditor() override;
 };
 
 } // namespace Internal
diff --git a/src/plugins/diffeditor/diffeditorplugin.cpp b/src/plugins/diffeditor/diffeditorplugin.cpp
index 6d3ba8858d8..0c52b55a9e1 100644
--- a/src/plugins/diffeditor/diffeditorplugin.cpp
+++ b/src/plugins/diffeditor/diffeditorplugin.cpp
@@ -129,7 +129,7 @@ class DiffFilesController : public DiffEditorController
     Q_OBJECT
 public:
     DiffFilesController(IDocument *document);
-    ~DiffFilesController();
+    ~DiffFilesController() override;
 
 protected:
     void reload() final;
@@ -203,7 +203,7 @@ QList<ReloadInput> DiffCurrentFileController::reloadInputList() const
 {
     QList<ReloadInput> result;
 
-    TextEditor::TextDocument *textDocument = qobject_cast<TextEditor::TextDocument *>(
+    auto textDocument = qobject_cast<TextEditor::TextDocument *>(
                 DocumentModel::documentForFilePath(m_fileName));
 
     if (textDocument && textDocument->isModified()) {
@@ -259,7 +259,7 @@ QList<ReloadInput> DiffOpenFilesController::reloadInputList() const
     const QList<IDocument *> openedDocuments = DocumentModel::openedDocuments();
 
     for (IDocument *doc : openedDocuments) {
-        TextEditor::TextDocument *textDocument = qobject_cast<TextEditor::TextDocument *>(doc);
+        auto textDocument = qobject_cast<TextEditor::TextDocument *>(doc);
 
         if (textDocument && textDocument->isModified()) {
             QString errorString;
@@ -317,7 +317,7 @@ QList<ReloadInput> DiffModifiedFilesController::reloadInputList() const
     QList<ReloadInput> result;
 
     for (const QString &fileName : m_fileNames) {
-        TextEditor::TextDocument *textDocument = qobject_cast<TextEditor::TextDocument *>(
+        auto textDocument = qobject_cast<TextEditor::TextDocument *>(
                     DocumentModel::documentForFilePath(fileName));
 
         if (textDocument && textDocument->isModified()) {
diff --git a/src/plugins/diffeditor/diffeditorplugin.h b/src/plugins/diffeditor/diffeditorplugin.h
index 28654210150..84d642b9f37 100644
--- a/src/plugins/diffeditor/diffeditorplugin.h
+++ b/src/plugins/diffeditor/diffeditorplugin.h
@@ -54,8 +54,8 @@ class DiffEditorPlugin : public ExtensionSystem::IPlugin
     Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QtCreatorPlugin" FILE "DiffEditor.json")
 
 public:
-    bool initialize(const QStringList &arguments, QString *errorMessage = nullptr);
-    void extensionsInitialized();
+    bool initialize(const QStringList &arguments, QString *errorMessage = nullptr) override;
+    void extensionsInitialized() override;
 
 private:
     void updateDiffCurrentFileAction();
diff --git a/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp b/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp
index 834c320a526..e1c656d5c74 100644
--- a/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp
+++ b/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp
@@ -168,7 +168,7 @@ void DiffEditorWidgetController::patch(bool revert, int fileIndex, int chunkInde
                                 workingDirectory, strip, revert))
             m_document->reload();
     } else { // PatchEditor
-        TextEditor::TextDocument *textDocument = qobject_cast<TextEditor::TextDocument *>(
+        auto textDocument = qobject_cast<TextEditor::TextDocument *>(
                     DocumentModel::documentForFilePath(absFileName));
         if (!textDocument)
             return;
diff --git a/src/plugins/diffeditor/diffutils.h b/src/plugins/diffeditor/diffutils.h
index 31956e62968..605266a0efe 100644
--- a/src/plugins/diffeditor/diffutils.h
+++ b/src/plugins/diffeditor/diffutils.h
@@ -47,7 +47,7 @@ public:
         PatchEditor
     };
 
-    DiffFileInfo() {}
+    DiffFileInfo() = default;
     DiffFileInfo(const QString &file) : fileName(file) {}
     DiffFileInfo(const QString &file, const QString &type)
         : fileName(file), typeInfo(type) {}
diff --git a/src/plugins/diffeditor/diffview.h b/src/plugins/diffeditor/diffview.h
index 93405a04230..1f760d82c4a 100644
--- a/src/plugins/diffeditor/diffview.h
+++ b/src/plugins/diffeditor/diffview.h
@@ -93,17 +93,17 @@ class UnifiedView : public IDiffView
 public:
     UnifiedView();
 
-    QWidget *widget();
+    QWidget *widget() override;
     TextEditor::TextEditorWidget *textEditorWidget();
 
-    void setDocument(DiffEditorDocument *document);
+    void setDocument(DiffEditorDocument *document) override;
 
-    void beginOperation();
-    void setCurrentDiffFileIndex(int index);
-    void setDiff(const QList<FileData> &diffFileList, const QString &workingDirectory);
-    void endOperation(bool success);
+    void beginOperation() override;
+    void setCurrentDiffFileIndex(int index) override;
+    void setDiff(const QList<FileData> &diffFileList, const QString &workingDirectory) override;
+    void endOperation(bool success) override;
 
-    void setSync(bool sync);
+    void setSync(bool sync) override;
 
 private:
     UnifiedDiffEditorWidget *m_widget = nullptr;
@@ -116,18 +116,18 @@ class SideBySideView : public IDiffView
 public:
     SideBySideView();
 
-    QWidget *widget();
+    QWidget *widget() override;
     TextEditor::TextEditorWidget *leftEditorWidget();
     TextEditor::TextEditorWidget *rightEditorWidget();
 
-    void setDocument(DiffEditorDocument *document);
+    void setDocument(DiffEditorDocument *document) override;
 
-    void beginOperation();
-    void setCurrentDiffFileIndex(int index);
-    void setDiff(const QList<FileData> &diffFileList, const QString &workingDirectory);
-    void endOperation(bool success);
+    void beginOperation() override;
+    void setCurrentDiffFileIndex(int index) override;
+    void setDiff(const QList<FileData> &diffFileList, const QString &workingDirectory) override;
+    void endOperation(bool success) override;
 
-    void setSync(bool sync);
+    void setSync(bool sync) override;
 
 private:
     SideBySideDiffEditorWidget *m_widget;
diff --git a/src/plugins/diffeditor/selectabletexteditorwidget.cpp b/src/plugins/diffeditor/selectabletexteditorwidget.cpp
index 68158fdf449..5d35b06e567 100644
--- a/src/plugins/diffeditor/selectabletexteditorwidget.cpp
+++ b/src/plugins/diffeditor/selectabletexteditorwidget.cpp
@@ -40,9 +40,7 @@ SelectableTextEditorWidget::SelectableTextEditorWidget(Core::Id id, QWidget *par
     setupFallBackEditor(id);
 }
 
-SelectableTextEditorWidget::~SelectableTextEditorWidget()
-{
-}
+SelectableTextEditorWidget::~SelectableTextEditorWidget() = default;
 
 static QList<DiffSelection> subtractSelection(
         const DiffSelection &minuendSelection,
diff --git a/src/plugins/diffeditor/selectabletexteditorwidget.h b/src/plugins/diffeditor/selectabletexteditorwidget.h
index e8df6fed7bf..7059177f648 100644
--- a/src/plugins/diffeditor/selectabletexteditorwidget.h
+++ b/src/plugins/diffeditor/selectabletexteditorwidget.h
@@ -33,7 +33,7 @@ namespace Internal {
 class DiffSelection
 {
 public:
-    DiffSelection() {}
+    DiffSelection() = default;
     DiffSelection(QTextCharFormat *f) : format(f) {}
     DiffSelection(int s, int e, QTextCharFormat *f) : start(s), end(e), format(f) {}
 
diff --git a/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp b/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
index f1e893cd1f3..3e9a72050b3 100644
--- a/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
+++ b/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
@@ -174,7 +174,7 @@ SideDiffEditorWidget::SideDiffEditorWidget(QWidget *parent)
             ToolTip::hide();
     });
 
-    TextDocumentLayout *documentLayout = qobject_cast<TextDocumentLayout*>(document()->documentLayout());
+    auto documentLayout = qobject_cast<TextDocumentLayout*>(document()->documentLayout());
     if (documentLayout)
         connect(documentLayout, &TextDocumentLayout::foldChanged,
                 this, &SideDiffEditorWidget::foldChanged);
@@ -210,7 +210,7 @@ void SideDiffEditorWidget::setFolded(int blockNumber, bool folded)
 
     TextDocumentLayout::doFoldOrUnfold(block, !folded);
 
-    TextDocumentLayout *documentLayout = qobject_cast<TextDocumentLayout*>(document()->documentLayout());
+    auto documentLayout = qobject_cast<TextDocumentLayout*>(document()->documentLayout());
     documentLayout->requestUpdate();
     documentLayout->emitDocumentSizeChanged();
 }
diff --git a/src/plugins/diffeditor/sidebysidediffeditorwidget.h b/src/plugins/diffeditor/sidebysidediffeditorwidget.h
index ee6f5f0eb72..1750a13ba8e 100644
--- a/src/plugins/diffeditor/sidebysidediffeditorwidget.h
+++ b/src/plugins/diffeditor/sidebysidediffeditorwidget.h
@@ -57,7 +57,7 @@ class SideBySideDiffEditorWidget : public QWidget
     Q_OBJECT
 public:
     explicit SideBySideDiffEditorWidget(QWidget *parent = nullptr);
-    ~SideBySideDiffEditorWidget();
+    ~SideBySideDiffEditorWidget() override;
 
     TextEditor::TextEditorWidget *leftEditorWidget() const;
     TextEditor::TextEditorWidget *rightEditorWidget() const;