diff --git a/src/plugins/coreplugin/actionmanager/actioncontainer.h b/src/plugins/coreplugin/actionmanager/actioncontainer.h
index 03d69c4841f..a20962430bd 100644
--- a/src/plugins/coreplugin/actionmanager/actioncontainer.h
+++ b/src/plugins/coreplugin/actionmanager/actioncontainer.h
@@ -66,7 +66,7 @@ public:
     virtual void addMenu(ActionContainer *menu, Id group = Id()) = 0;
     virtual void addMenu(ActionContainer *before, ActionContainer *menu, Id group = Id()) = 0;
     Command *addSeparator(Id group = Id());
-    virtual Command *addSeparator(const Context &context, Id group = Id(), QAction **outSeparator = 0) = 0;
+    virtual Command *addSeparator(const Context &context, Id group = Id(), QAction **outSeparator = nullptr) = 0;
 
     // This clears this menu and submenus from all actions and submenus.
     // It does not destroy the submenus and commands, just removes them from their parents.
diff --git a/src/plugins/coreplugin/actionmanager/actioncontainer_p.h b/src/plugins/coreplugin/actionmanager/actioncontainer_p.h
index da64a97fb8c..27fed6a705a 100644
--- a/src/plugins/coreplugin/actionmanager/actioncontainer_p.h
+++ b/src/plugins/coreplugin/actionmanager/actioncontainer_p.h
@@ -57,7 +57,7 @@ public:
     void addAction(Command *action, Id group = Id()) override;
     void addMenu(ActionContainer *menu, Id group = Id()) override;
     void addMenu(ActionContainer *before, ActionContainer *menu, Id group = Id()) override;
-    Command *addSeparator(const Context &context, Id group = Id(), QAction **outSeparator = 0) override;
+    Command *addSeparator(const Context &context, Id group = Id(), QAction **outSeparator = nullptr) override;
     void clear() override;
 
     Id id() const override;
diff --git a/src/plugins/coreplugin/actionmanager/actionmanager.h b/src/plugins/coreplugin/actionmanager/actionmanager.h
index 59adc46779b..7d6dfb2862a 100644
--- a/src/plugins/coreplugin/actionmanager/actionmanager.h
+++ b/src/plugins/coreplugin/actionmanager/actionmanager.h
@@ -79,7 +79,7 @@ signals:
     void commandAdded(Core::Id id);
 
 private:
-    ActionManager(QObject *parent = 0);
+    ActionManager(QObject *parent = nullptr);
     ~ActionManager() override;
     static void saveSettings();
     static void setContext(const Context &context);
diff --git a/src/plugins/coreplugin/actionmanager/commandbutton.h b/src/plugins/coreplugin/actionmanager/commandbutton.h
index deb7c1ed0c7..c34cbd61fe8 100644
--- a/src/plugins/coreplugin/actionmanager/commandbutton.h
+++ b/src/plugins/coreplugin/actionmanager/commandbutton.h
@@ -41,8 +41,8 @@ class CORE_EXPORT CommandButton : public QToolButton
     Q_OBJECT
     Q_PROPERTY(QString toolTipBase READ toolTipBase WRITE setToolTipBase)
 public:
-    explicit CommandButton(QWidget *parent = 0);
-    explicit CommandButton(Id id, QWidget *parent = 0);
+    explicit CommandButton(QWidget *parent = nullptr);
+    explicit CommandButton(Id id, QWidget *parent = nullptr);
     void setCommandId(Id id);
     QString toolTipBase() const;
     void setToolTipBase(const QString &toolTipBase);
diff --git a/src/plugins/coreplugin/actionmanager/commandmappings.h b/src/plugins/coreplugin/actionmanager/commandmappings.h
index 5b0aece9a0d..b6e9af206ac 100644
--- a/src/plugins/coreplugin/actionmanager/commandmappings.h
+++ b/src/plugins/coreplugin/actionmanager/commandmappings.h
@@ -45,7 +45,7 @@ class CORE_EXPORT CommandMappings : public QWidget
     Q_OBJECT
 
 public:
-    CommandMappings(QWidget *parent = 0);
+    CommandMappings(QWidget *parent = nullptr);
     ~CommandMappings() override;
 
 signals:
diff --git a/src/plugins/coreplugin/basefilewizard.h b/src/plugins/coreplugin/basefilewizard.h
index 43f7dd53c47..2ab7ed5d8fa 100644
--- a/src/plugins/coreplugin/basefilewizard.h
+++ b/src/plugins/coreplugin/basefilewizard.h
@@ -43,7 +43,7 @@ class CORE_EXPORT BaseFileWizard : public Utils::Wizard
 
 public:
     explicit BaseFileWizard(const BaseFileWizardFactory *factory, const QVariantMap &extraValues,
-                            QWidget *parent = 0);
+                            QWidget *parent = nullptr);
 
     void initializePage(int id) override;
 
@@ -58,7 +58,7 @@ private:
     QVariantMap m_extraValues;
     const BaseFileWizardFactory *m_factory;
     QList<QWizardPage *> m_extensionPages;
-    QWizardPage *m_firstExtensionPage = 0;
+    QWizardPage *m_firstExtensionPage = nullptr;
     GeneratedFiles m_files;
 };
 
diff --git a/src/plugins/coreplugin/basefilewizardfactory.h b/src/plugins/coreplugin/basefilewizardfactory.h
index 8e68fb07221..586e350cdc0 100644
--- a/src/plugins/coreplugin/basefilewizardfactory.h
+++ b/src/plugins/coreplugin/basefilewizardfactory.h
@@ -111,7 +111,7 @@ protected:
     enum OverwriteResult { OverwriteOk,  OverwriteError,  OverwriteCanceled };
     OverwriteResult promptOverwrite(GeneratedFiles *files,
                                     QString *errorMessage) const;
-    static bool postGenerateOpenEditors(const GeneratedFiles &l, QString *errorMessage = 0);
+    static bool postGenerateOpenEditors(const GeneratedFiles &l, QString *errorMessage = nullptr);
 
 private:
     // IWizard
diff --git a/src/plugins/coreplugin/coreplugin.h b/src/plugins/coreplugin/coreplugin.h
index 1341a749c0f..7e1ae1664c0 100644
--- a/src/plugins/coreplugin/coreplugin.h
+++ b/src/plugins/coreplugin/coreplugin.h
@@ -53,7 +53,7 @@ public:
     CorePlugin();
     ~CorePlugin() override;
 
-    bool initialize(const QStringList &arguments, QString *errorMessage = 0) override;
+    bool initialize(const QStringList &arguments, QString *errorMessage = nullptr) override;
     void extensionsInitialized() override;
     bool delayedInitialize() override;
     ShutdownFlag aboutToShutdown() override;
diff --git a/src/plugins/coreplugin/dialogs/promptoverwritedialog.h b/src/plugins/coreplugin/dialogs/promptoverwritedialog.h
index 38d93c6a8aa..76196e476bf 100644
--- a/src/plugins/coreplugin/dialogs/promptoverwritedialog.h
+++ b/src/plugins/coreplugin/dialogs/promptoverwritedialog.h
@@ -43,7 +43,7 @@ class CORE_EXPORT PromptOverwriteDialog : public QDialog
 {
     Q_OBJECT
 public:
-    explicit PromptOverwriteDialog(QWidget *parent = 0);
+    explicit PromptOverwriteDialog(QWidget *parent = nullptr);
 
     void setFiles(const QStringList &);
 
diff --git a/src/plugins/coreplugin/dialogs/readonlyfilesdialog.h b/src/plugins/coreplugin/dialogs/readonlyfilesdialog.h
index 74699baab33..6bb9afa7f5f 100644
--- a/src/plugins/coreplugin/dialogs/readonlyfilesdialog.h
+++ b/src/plugins/coreplugin/dialogs/readonlyfilesdialog.h
@@ -58,14 +58,14 @@ public:
     };
 
     explicit ReadOnlyFilesDialog(const QList<QString> &fileNames,
-                                 QWidget *parent = 0);
+                                 QWidget *parent = nullptr);
     explicit ReadOnlyFilesDialog(const QString &fileName,
-                                 QWidget * parent = 0);
+                                 QWidget * parent = nullptr);
     explicit ReadOnlyFilesDialog(IDocument *document,
-                                 QWidget * parent = 0,
+                                 QWidget * parent = nullptr,
                                  bool displaySaveAs = false);
     explicit ReadOnlyFilesDialog(const QList<IDocument *> &documents,
-                                 QWidget * parent = 0);
+                                 QWidget * parent = nullptr);
 
     ~ReadOnlyFilesDialog() override;
 
diff --git a/src/plugins/coreplugin/dialogs/shortcutsettings.h b/src/plugins/coreplugin/dialogs/shortcutsettings.h
index 578c6bc7b1e..f54206cd3eb 100644
--- a/src/plugins/coreplugin/dialogs/shortcutsettings.h
+++ b/src/plugins/coreplugin/dialogs/shortcutsettings.h
@@ -58,7 +58,7 @@ class ShortcutButton : public QPushButton
 {
     Q_OBJECT
 public:
-    ShortcutButton(QWidget *parent = 0);
+    ShortcutButton(QWidget *parent = nullptr);
 
     QSize sizeHint() const override;
 
@@ -84,7 +84,7 @@ class ShortcutSettingsWidget : public CommandMappings
     Q_OBJECT
 
 public:
-    ShortcutSettingsWidget(QWidget *parent = 0);
+    ShortcutSettingsWidget(QWidget *parent = nullptr);
     ~ShortcutSettingsWidget() override;
 
     void apply();
@@ -116,7 +116,7 @@ class ShortcutSettings : public IOptionsPage
     Q_OBJECT
 
 public:
-    ShortcutSettings(QObject *parent = 0);
+    ShortcutSettings(QObject *parent = nullptr);
 
     QWidget *widget() override;
     void apply() override;
diff --git a/src/plugins/coreplugin/editormanager/editormanager_p.h b/src/plugins/coreplugin/editormanager/editormanager_p.h
index ac798222ead..9b29d9d3ca2 100644
--- a/src/plugins/coreplugin/editormanager/editormanager_p.h
+++ b/src/plugins/coreplugin/editormanager/editormanager_p.h
@@ -79,20 +79,20 @@ public:
                                const QString &fileName,
                                Id editorId = Id(),
                                EditorManager::OpenEditorFlags flags = EditorManager::NoFlags,
-                               bool *newEditor = 0);
+                               bool *newEditor = nullptr);
     static IEditor *openEditorAt(EditorView *view,
                                  const QString &fileName,
                                  int line,
                                  int column = 0,
                                  Id editorId = Id(),
                                  EditorManager::OpenEditorFlags flags = EditorManager::NoFlags,
-                                 bool *newEditor = 0);
+                                 bool *newEditor = nullptr);
     static IEditor *openEditorWith(const QString &fileName, Core::Id editorId);
     static IEditor *duplicateEditor(IEditor *editor);
     static IEditor *activateEditor(EditorView *view, IEditor *editor,
                                    EditorManager::OpenEditorFlags flags = EditorManager::NoFlags);
     static IEditor *activateEditorForDocument(EditorView *view, IDocument *document,
-                                              EditorManager::OpenEditorFlags flags = 0);
+                                              EditorManager::OpenEditorFlags flags = nullptr);
     static bool activateEditorForEntry(EditorView *view, DocumentModel::Entry *entry,
                                        EditorManager::OpenEditorFlags flags = EditorManager::NoFlags);
     /* closes the document if there is no other editor on the document visible */
@@ -106,7 +106,7 @@ public:
     static MakeWritableResult makeFileWritable(IDocument *document);
     static void doEscapeKeyFocusMoveMagic();
 
-    static Id getOpenWithEditorId(const QString &fileName, bool *isExternalEditor = 0);
+    static Id getOpenWithEditorId(const QString &fileName, bool *isExternalEditor = nullptr);
 
     static void saveSettings();
     static void readSettings();
@@ -191,8 +191,8 @@ private:
     static IEditor *placeEditor(EditorView *view, IEditor *editor);
     static void restoreEditorState(IEditor *editor);
     static int visibleDocumentsCount();
-    static EditorArea *findEditorArea(const EditorView *view, int *areaIndex = 0);
-    static IEditor *pickUnusedEditor(Internal::EditorView **foundView = 0);
+    static EditorArea *findEditorArea(const EditorView *view, int *areaIndex = nullptr);
+    static IEditor *pickUnusedEditor(Internal::EditorView **foundView = nullptr);
     static void addDocumentToRecentFiles(IDocument *document);
     static void updateAutoSave();
     static void updateMakeWritableWarning();
diff --git a/src/plugins/coreplugin/editormanager/ieditor.h b/src/plugins/coreplugin/editormanager/ieditor.h
index fccf6197790..5f6e64bb7ef 100644
--- a/src/plugins/coreplugin/editormanager/ieditor.h
+++ b/src/plugins/coreplugin/editormanager/ieditor.h
@@ -39,14 +39,14 @@ class CORE_EXPORT IEditor : public IContext
     Q_OBJECT
 
 public:
-    IEditor(QObject *parent = 0);
+    IEditor(QObject *parent = nullptr);
 
     bool duplicateSupported() const;
     void setDuplicateSupported(bool duplicateSupported);
 
     virtual IDocument *document() = 0;
 
-    virtual IEditor *duplicate() { return 0; }
+    virtual IEditor *duplicate() { return nullptr; }
 
     virtual QByteArray saveState() const { return QByteArray(); }
     virtual bool restoreState(const QByteArray &/*state*/) { return true; }
diff --git a/src/plugins/coreplugin/editortoolbar.h b/src/plugins/coreplugin/editortoolbar.h
index b3c9fe30da1..1d0c49ffdf8 100644
--- a/src/plugins/coreplugin/editortoolbar.h
+++ b/src/plugins/coreplugin/editortoolbar.h
@@ -50,7 +50,7 @@ class CORE_EXPORT EditorToolBar : public Utils::StyledBar
     Q_OBJECT
 
 public:
-    explicit EditorToolBar(QWidget *parent = 0);
+    explicit EditorToolBar(QWidget *parent = nullptr);
     ~EditorToolBar() override;
 
     typedef std::function<void(QMenu*)> MenuProvider;
diff --git a/src/plugins/coreplugin/externaltool.h b/src/plugins/coreplugin/externaltool.h
index 319d8fa335f..e284de3e914 100644
--- a/src/plugins/coreplugin/externaltool.h
+++ b/src/plugins/coreplugin/externaltool.h
@@ -75,11 +75,11 @@ public:
     // all tools that are preset (changed or unchanged) have the original value here:
     QSharedPointer<ExternalTool> preset() const;
 
-    static ExternalTool *createFromXml(const QByteArray &xml, QString *errorMessage = 0, const QString &locale = QString());
-    static ExternalTool *createFromFile(const QString &fileName, QString *errorMessage = 0,
+    static ExternalTool *createFromXml(const QByteArray &xml, QString *errorMessage = nullptr, const QString &locale = QString());
+    static ExternalTool *createFromFile(const QString &fileName, QString *errorMessage = nullptr,
                                         const QString &locale = QString());
 
-    bool save(QString *errorMessage = 0) const;
+    bool save(QString *errorMessage = nullptr) const;
 
     bool operator==(const ExternalTool &other) const;
     bool operator!=(const ExternalTool &other) const { return !((*this) == other); }
diff --git a/src/plugins/coreplugin/find/findplugin.h b/src/plugins/coreplugin/find/findplugin.h
index f75d9c15caa..f79ed666e79 100644
--- a/src/plugins/coreplugin/find/findplugin.h
+++ b/src/plugins/coreplugin/find/findplugin.h
@@ -54,7 +54,7 @@ public:
 
     static FindFlags findFlags();
     static bool hasFindFlag(FindFlag flag);
-    static void updateFindCompletion(const QString &text, FindFlags flags = 0);
+    static void updateFindCompletion(const QString &text, FindFlags flags = nullptr);
     static void updateReplaceCompletion(const QString &text);
     static QAbstractListModel *findCompletionModel();
     static QStringListModel *replaceCompletionModel();
diff --git a/src/plugins/coreplugin/find/ifindfilter.h b/src/plugins/coreplugin/find/ifindfilter.h
index 26c6adfbb32..9aa8747bb08 100644
--- a/src/plugins/coreplugin/find/ifindfilter.h
+++ b/src/plugins/coreplugin/find/ifindfilter.h
@@ -60,7 +60,7 @@ public:
     virtual void replaceAll(const QString &txt, FindFlags findFlags)
     { Q_UNUSED(txt) Q_UNUSED(findFlags) }
 
-    virtual QWidget *createConfigWidget() { return 0; }
+    virtual QWidget *createConfigWidget() { return nullptr; }
     virtual void writeSettings(QSettings *settings) { Q_UNUSED(settings) }
     virtual void readSettings(QSettings *settings) { Q_UNUSED(settings) }
 
diff --git a/src/plugins/coreplugin/find/ifindsupport.h b/src/plugins/coreplugin/find/ifindsupport.h
index eff2f777af5..384caddf276 100644
--- a/src/plugins/coreplugin/find/ifindsupport.h
+++ b/src/plugins/coreplugin/find/ifindsupport.h
@@ -39,7 +39,7 @@ class CORE_EXPORT IFindSupport : public QObject
 public:
     enum Result { Found, NotFound, NotYetFound };
 
-    IFindSupport() : QObject(0) {}
+    IFindSupport() : QObject(nullptr) {}
     ~IFindSupport() override {}
 
     virtual bool supportsReplace() const = 0;
diff --git a/src/plugins/coreplugin/findplaceholder.h b/src/plugins/coreplugin/findplaceholder.h
index 78585656712..685fae6fb0b 100644
--- a/src/plugins/coreplugin/findplaceholder.h
+++ b/src/plugins/coreplugin/findplaceholder.h
@@ -37,7 +37,7 @@ class CORE_EXPORT FindToolBarPlaceHolder : public QWidget
 {
     Q_OBJECT
 public:
-    explicit FindToolBarPlaceHolder(QWidget *owner, QWidget *parent = 0);
+    explicit FindToolBarPlaceHolder(QWidget *owner, QWidget *parent = nullptr);
     ~FindToolBarPlaceHolder() override;
 
     static const QList<FindToolBarPlaceHolder *> allFindToolbarPlaceHolders();
diff --git a/src/plugins/coreplugin/icontext.h b/src/plugins/coreplugin/icontext.h
index 486223c664a..01daa739b54 100644
--- a/src/plugins/coreplugin/icontext.h
+++ b/src/plugins/coreplugin/icontext.h
@@ -69,7 +69,7 @@ class CORE_EXPORT IContext : public QObject
 {
     Q_OBJECT
 public:
-    IContext(QObject *parent = 0) : QObject(parent) {}
+    IContext(QObject *parent = nullptr) : QObject(parent) {}
 
     virtual Context context() const { return m_context; }
     virtual QWidget *widget() const { return m_widget; }
diff --git a/src/plugins/coreplugin/icore.h b/src/plugins/coreplugin/icore.h
index ca7f4f96c9b..4d53fedf917 100644
--- a/src/plugins/coreplugin/icore.h
+++ b/src/plugins/coreplugin/icore.h
@@ -78,14 +78,14 @@ public:
                                   const QString &defaultLocation = QString(),
                                   const QVariantMap &extraVariables = QVariantMap());
 
-    static bool showOptionsDialog(Id page, QWidget *parent = 0);
+    static bool showOptionsDialog(Id page, QWidget *parent = nullptr);
     static QString msgShowOptionsDialog();
     static QString msgShowOptionsDialogToolTip();
 
     static bool showWarningWithOptions(const QString &title, const QString &text,
                                        const QString &details = QString(),
                                        Id settingsId = Id(),
-                                       QWidget *parent = 0);
+                                       QWidget *parent = nullptr);
 
     static QSettings *settings(QSettings::Scope scope = QSettings::UserScope);
     static SettingsDatabase *settingsDatabase();
diff --git a/src/plugins/coreplugin/idocument.h b/src/plugins/coreplugin/idocument.h
index acb1feb58b8..4af747dc972 100644
--- a/src/plugins/coreplugin/idocument.h
+++ b/src/plugins/coreplugin/idocument.h
@@ -79,7 +79,7 @@ public:
         FlagIgnore
     };
 
-    IDocument(QObject *parent = 0);
+    IDocument(QObject *parent = nullptr);
     ~IDocument() override;
 
     void setId(Id id);
diff --git a/src/plugins/coreplugin/imode.h b/src/plugins/coreplugin/imode.h
index 63901ba7685..80a819ae40b 100644
--- a/src/plugins/coreplugin/imode.h
+++ b/src/plugins/coreplugin/imode.h
@@ -39,7 +39,7 @@ class CORE_EXPORT IMode : public IContext
     Q_PROPERTY(bool enabled READ isEnabled WRITE setEnabled)
 
 public:
-    IMode(QObject *parent = 0);
+    IMode(QObject *parent = nullptr);
     ~IMode() override;
 
     QString displayName() const { return m_displayName; }
diff --git a/src/plugins/coreplugin/inavigationwidgetfactory.h b/src/plugins/coreplugin/inavigationwidgetfactory.h
index 12608a80bcf..b39786cfa67 100644
--- a/src/plugins/coreplugin/inavigationwidgetfactory.h
+++ b/src/plugins/coreplugin/inavigationwidgetfactory.h
@@ -41,7 +41,7 @@ namespace Core {
 
 struct NavigationView
 {
-    NavigationView(QWidget *w = 0) : widget(w) {}
+    NavigationView(QWidget *w = nullptr) : widget(w) {}
 
     QWidget *widget;
     QList<QToolButton *> dockToolBarWidgets;
diff --git a/src/plugins/coreplugin/infobar.h b/src/plugins/coreplugin/infobar.h
index 6a58b9a3312..f3fbea6a024 100644
--- a/src/plugins/coreplugin/infobar.h
+++ b/src/plugins/coreplugin/infobar.h
@@ -121,7 +121,7 @@ class CORE_EXPORT InfoBarDisplay : public QObject
     Q_OBJECT
 
 public:
-    InfoBarDisplay(QObject *parent = 0);
+    InfoBarDisplay(QObject *parent = nullptr);
     void setTarget(QBoxLayout *layout, int index);
     void setInfoBar(InfoBar *infoBar);
 
diff --git a/src/plugins/coreplugin/iversioncontrol.h b/src/plugins/coreplugin/iversioncontrol.h
index 8e256c3fff1..6386487e70f 100644
--- a/src/plugins/coreplugin/iversioncontrol.h
+++ b/src/plugins/coreplugin/iversioncontrol.h
@@ -86,7 +86,7 @@ public:
 
     };
 
-    explicit IVersionControl(TopicCache *topicCache = 0) : m_topicCache(topicCache) {}
+    explicit IVersionControl(TopicCache *topicCache = nullptr) : m_topicCache(topicCache) {}
     ~IVersionControl() override;
 
     virtual QString displayName() const = 0;
@@ -113,7 +113,7 @@ public:
      * that all files in the returned directory are managed by the same IVersionControl.
      */
 
-    virtual bool managesDirectory(const QString &filename, QString *topLevel = 0) const = 0;
+    virtual bool managesDirectory(const QString &filename, QString *topLevel = nullptr) const = 0;
 
     /*!
      * Returns whether \a fileName is managed by this version control.
@@ -151,7 +151,7 @@ public:
      * Returns settings.
      */
 
-    virtual SettingsFlags settingsFlags() const { return 0; }
+    virtual SettingsFlags settingsFlags() const { return nullptr; }
 
     /*!
      * Called after a file has been added to a project If the version control
diff --git a/src/plugins/coreplugin/iwizardfactory.h b/src/plugins/coreplugin/iwizardfactory.h
index d1f218c1334..4ab761d792f 100644
--- a/src/plugins/coreplugin/iwizardfactory.h
+++ b/src/plugins/coreplugin/iwizardfactory.h
@@ -123,7 +123,7 @@ private:
 
     static void clearWizardFactories();
 
-    QAction *m_action = 0;
+    QAction *m_action = nullptr;
     QIcon m_icon;
     QString m_iconText;
     QString m_description;
@@ -133,7 +133,7 @@ private:
     QString m_descriptionImage;
     QSet<Id> m_requiredFeatures;
     QSet<Id> m_supportedProjectTypes;
-    WizardFlags m_flags = 0;
+    WizardFlags m_flags = nullptr;
     Id m_id;
 
     friend class Internal::CorePlugin;
diff --git a/src/plugins/coreplugin/jsexpander.h b/src/plugins/coreplugin/jsexpander.h
index dbffc8c1591..087f494ac0b 100644
--- a/src/plugins/coreplugin/jsexpander.h
+++ b/src/plugins/coreplugin/jsexpander.h
@@ -41,7 +41,7 @@ class CORE_EXPORT JsExpander
 public:
     static void registerQObjectForJs(const QString &name, QObject *obj);
 
-    static QString evaluate(const QString &expression, QString *errorMessage = 0);
+    static QString evaluate(const QString &expression, QString *errorMessage = nullptr);
 
 private:
     JsExpander();
diff --git a/src/plugins/coreplugin/manhattanstyle.h b/src/plugins/coreplugin/manhattanstyle.h
index 70c83dcfe90..fc136ee0447 100644
--- a/src/plugins/coreplugin/manhattanstyle.h
+++ b/src/plugins/coreplugin/manhattanstyle.h
@@ -40,22 +40,22 @@ public:
 
     ~ManhattanStyle() override;
 
-    void drawPrimitive(PrimitiveElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget = 0) const override;
-    void drawControl(ControlElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget = 0) const override;
-    void drawComplexControl(ComplexControl control, const QStyleOptionComplex *option, QPainter *painter, const QWidget *widget = 0) const override;
+    void drawPrimitive(PrimitiveElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget = nullptr) const override;
+    void drawControl(ControlElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget = nullptr) const override;
+    void drawComplexControl(ComplexControl control, const QStyleOptionComplex *option, QPainter *painter, const QWidget *widget = nullptr) const override;
 
     QSize sizeFromContents(ContentsType type, const QStyleOption *option, const QSize &size, const QWidget *widget) const override;
     QRect subElementRect(SubElement element, const QStyleOption *option, const QWidget *widget) const override;
     QRect subControlRect(ComplexControl cc, const QStyleOptionComplex *opt, SubControl sc, const QWidget *widget) const override;
 
-    SubControl hitTestComplexControl(ComplexControl control, const QStyleOptionComplex *option, const QPoint &pos, const QWidget *widget = 0) const override;
-    QPixmap standardPixmap(StandardPixmap standardPixmap, const QStyleOption *opt, const QWidget *widget = 0) const override;
-    QIcon standardIcon(StandardPixmap standardIcon, const QStyleOption *option = 0, const QWidget *widget = 0) const override;
-    int styleHint(StyleHint hint, const QStyleOption *option = 0, const QWidget *widget = 0, QStyleHintReturn *returnData = 0) const override;
+    SubControl hitTestComplexControl(ComplexControl control, const QStyleOptionComplex *option, const QPoint &pos, const QWidget *widget = nullptr) const override;
+    QPixmap standardPixmap(StandardPixmap standardPixmap, const QStyleOption *opt, const QWidget *widget = nullptr) const override;
+    QIcon standardIcon(StandardPixmap standardIcon, const QStyleOption *option = nullptr, const QWidget *widget = nullptr) const override;
+    int styleHint(StyleHint hint, const QStyleOption *option = nullptr, const QWidget *widget = nullptr, QStyleHintReturn *returnData = nullptr) const override;
     QRect itemRect(QPainter *p, const QRect &r, int flags, bool enabled, const QPixmap *pixmap, const QString &text, int len = -1) const;
     QPixmap generatedIconPixmap(QIcon::Mode iconMode, const QPixmap &pixmap, const QStyleOption *opt) const override;
 
-    int pixelMetric(PixelMetric metric, const QStyleOption *option = 0, const QWidget *widget = 0) const override;
+    int pixelMetric(PixelMetric metric, const QStyleOption *option = nullptr, const QWidget *widget = nullptr) const override;
 
     QPalette standardPalette() const override;
 
diff --git a/src/plugins/coreplugin/minisplitter.h b/src/plugins/coreplugin/minisplitter.h
index 7329b1a109b..712f8f366f4 100644
--- a/src/plugins/coreplugin/minisplitter.h
+++ b/src/plugins/coreplugin/minisplitter.h
@@ -41,7 +41,7 @@ class CORE_EXPORT MiniSplitter : public QSplitter
 public:
     enum SplitterStyle {Dark, Light};
 
-    MiniSplitter(QWidget *parent = 0, SplitterStyle style = Dark);
+    MiniSplitter(QWidget *parent = nullptr, SplitterStyle style = Dark);
     MiniSplitter(Qt::Orientation orientation, SplitterStyle style = Dark);
 
 protected:
diff --git a/src/plugins/coreplugin/navigationwidget.h b/src/plugins/coreplugin/navigationwidget.h
index 37d5cffc646..69b16a96e35 100644
--- a/src/plugins/coreplugin/navigationwidget.h
+++ b/src/plugins/coreplugin/navigationwidget.h
@@ -53,7 +53,7 @@ class CORE_EXPORT NavigationWidgetPlaceHolder : public QWidget
     friend class Core::NavigationWidget;
 
 public:
-    explicit NavigationWidgetPlaceHolder(Id mode, Side side, QWidget *parent = 0);
+    explicit NavigationWidgetPlaceHolder(Id mode, Side side, QWidget *parent = nullptr);
     ~NavigationWidgetPlaceHolder() override;
     static NavigationWidgetPlaceHolder *current(Side side);
     static void setCurrent(Side side, NavigationWidgetPlaceHolder *navWidget);
diff --git a/src/plugins/coreplugin/opendocumentstreeview.h b/src/plugins/coreplugin/opendocumentstreeview.h
index 0390058f0cb..8e3830e4187 100644
--- a/src/plugins/coreplugin/opendocumentstreeview.h
+++ b/src/plugins/coreplugin/opendocumentstreeview.h
@@ -36,7 +36,7 @@ class CORE_EXPORT OpenDocumentsTreeView : public Utils::TreeView
 {
     Q_OBJECT
 public:
-    explicit OpenDocumentsTreeView(QWidget *parent = 0);
+    explicit OpenDocumentsTreeView(QWidget *parent = nullptr);
 
     void setModel(QAbstractItemModel *model) override;
     void setCloseButtonVisible(bool visible);
diff --git a/src/plugins/coreplugin/outputpane.h b/src/plugins/coreplugin/outputpane.h
index a9dbafc01a2..db67c0e6595 100644
--- a/src/plugins/coreplugin/outputpane.h
+++ b/src/plugins/coreplugin/outputpane.h
@@ -42,7 +42,7 @@ class CORE_EXPORT OutputPanePlaceHolder : public QWidget
     Q_OBJECT
 
 public:
-    explicit OutputPanePlaceHolder(Id mode, QSplitter *parent = 0);
+    explicit OutputPanePlaceHolder(Id mode, QSplitter *parent = nullptr);
     ~OutputPanePlaceHolder() override;
 
     static OutputPanePlaceHolder *getCurrent();
diff --git a/src/plugins/coreplugin/outputpanemanager.h b/src/plugins/coreplugin/outputpanemanager.h
index 1520a650430..5570ceeaa8a 100644
--- a/src/plugins/coreplugin/outputpanemanager.h
+++ b/src/plugins/coreplugin/outputpanemanager.h
@@ -75,7 +75,7 @@ private:
     static void create();
     static void destroy();
 
-    explicit OutputPaneManager(QWidget *parent = 0);
+    explicit OutputPaneManager(QWidget *parent = nullptr);
     ~OutputPaneManager() override;
 
     void shortcutTriggered(int idx);
@@ -136,7 +136,7 @@ class OutputPaneToggleButton : public QToolButton
     Q_OBJECT
 public:
     OutputPaneToggleButton(int number, const QString &text, QAction *action,
-                           QWidget *parent = 0);
+                           QWidget *parent = nullptr);
     QSize sizeHint() const override;
     void paintEvent(QPaintEvent*) override;
     void flash(int count = 3);
diff --git a/src/plugins/coreplugin/outputwindow.h b/src/plugins/coreplugin/outputwindow.h
index 82c56b5553f..4e893f03178 100644
--- a/src/plugins/coreplugin/outputwindow.h
+++ b/src/plugins/coreplugin/outputwindow.h
@@ -45,7 +45,7 @@ class CORE_EXPORT OutputWindow : public QPlainTextEdit
     Q_OBJECT
 
 public:
-    OutputWindow(Context context, QWidget *parent = 0);
+    OutputWindow(Context context, QWidget *parent = nullptr);
     ~OutputWindow() override;
 
     Utils::OutputFormatter *formatter() const;
diff --git a/src/plugins/coreplugin/progressmanager/futureprogress.h b/src/plugins/coreplugin/progressmanager/futureprogress.h
index a3a186c2e3f..3f591b2b940 100644
--- a/src/plugins/coreplugin/progressmanager/futureprogress.h
+++ b/src/plugins/coreplugin/progressmanager/futureprogress.h
@@ -45,7 +45,7 @@ public:
         KeepOnFinishTillUserInteraction = 1,
         KeepOnFinish = 2
     };
-    explicit FutureProgress(QWidget *parent = 0);
+    explicit FutureProgress(QWidget *parent = nullptr);
     ~FutureProgress() override;
 
     bool eventFilter(QObject *object, QEvent *) override;
diff --git a/src/plugins/coreplugin/progressmanager/progressmanager.h b/src/plugins/coreplugin/progressmanager/progressmanager.h
index 5f827d7e435..efc2d57705a 100644
--- a/src/plugins/coreplugin/progressmanager/progressmanager.h
+++ b/src/plugins/coreplugin/progressmanager/progressmanager.h
@@ -52,9 +52,9 @@ public:
     static ProgressManager *instance();
 
     static FutureProgress *addTask(const QFuture<void> &future, const QString &title,
-                                   Id type, ProgressFlags flags = 0);
+                                   Id type, ProgressFlags flags = nullptr);
     static FutureProgress *addTimedTask(const QFutureInterface<void> &fi, const QString &title,
-                                   Id type, int expectedSeconds, ProgressFlags flags = 0);
+                                   Id type, int expectedSeconds, ProgressFlags flags = nullptr);
     static void setApplicationLabel(const QString &text);
 
 public slots:
@@ -75,7 +75,7 @@ class CORE_EXPORT ProgressTimer : public QObject
 {
 public:
     ProgressTimer(const QFutureInterfaceBase &futureInterface, int expectedSeconds,
-                  QObject *parent = 0);
+                  QObject *parent = nullptr);
 
 private:
     void handleTimeout();
diff --git a/src/plugins/coreplugin/progressmanager/progressview.h b/src/plugins/coreplugin/progressmanager/progressview.h
index 2748ed5ff56..4d619998a5d 100644
--- a/src/plugins/coreplugin/progressmanager/progressview.h
+++ b/src/plugins/coreplugin/progressmanager/progressview.h
@@ -43,7 +43,7 @@ class ProgressView : public QWidget
     Q_OBJECT
 
 public:
-    ProgressView(QWidget *parent = 0);
+    ProgressView(QWidget *parent = nullptr);
     ~ProgressView() override;
 
     void addProgressWidget(QWidget *widget);
diff --git a/src/plugins/coreplugin/rightpane.h b/src/plugins/coreplugin/rightpane.h
index a50f7ddce80..905d37d4d45 100644
--- a/src/plugins/coreplugin/rightpane.h
+++ b/src/plugins/coreplugin/rightpane.h
@@ -44,7 +44,7 @@ class CORE_EXPORT RightPanePlaceHolder : public QWidget
     Q_OBJECT
 
 public:
-    explicit RightPanePlaceHolder(Id mode, QWidget *parent = 0);
+    explicit RightPanePlaceHolder(Id mode, QWidget *parent = nullptr);
     ~RightPanePlaceHolder() override;
     static RightPanePlaceHolder *current();
 
diff --git a/src/plugins/coreplugin/settingsdatabase.h b/src/plugins/coreplugin/settingsdatabase.h
index 95b745dc8ae..5879de22455 100644
--- a/src/plugins/coreplugin/settingsdatabase.h
+++ b/src/plugins/coreplugin/settingsdatabase.h
@@ -39,7 +39,7 @@ namespace Internal { class SettingsDatabasePrivate; }
 class CORE_EXPORT SettingsDatabase : public QObject
 {
 public:
-    SettingsDatabase(const QString &path, const QString &application, QObject *parent = 0);
+    SettingsDatabase(const QString &path, const QString &application, QObject *parent = nullptr);
     ~SettingsDatabase() override;
 
     void setValue(const QString &key, const QVariant &value);
diff --git a/src/plugins/coreplugin/textdocument.h b/src/plugins/coreplugin/textdocument.h
index 1ff2af7bee2..cc695c1c1f9 100644
--- a/src/plugins/coreplugin/textdocument.h
+++ b/src/plugins/coreplugin/textdocument.h
@@ -40,7 +40,7 @@ class CORE_EXPORT BaseTextDocument : public IDocument
 public:
     typedef Utils::TextFileFormat::ReadResult ReadResult;
 
-    explicit BaseTextDocument(QObject *parent = 0);
+    explicit BaseTextDocument(QObject *parent = nullptr);
     ~BaseTextDocument() override;
 
     Utils::TextFileFormat format() const;
diff --git a/src/plugins/coreplugin/themechooser.h b/src/plugins/coreplugin/themechooser.h
index f823ad00e07..3af09d0055a 100644
--- a/src/plugins/coreplugin/themechooser.h
+++ b/src/plugins/coreplugin/themechooser.h
@@ -62,7 +62,7 @@ class ThemeChooser : public QWidget
     Q_OBJECT
 
 public:
-    ThemeChooser(QWidget *parent = 0);
+    ThemeChooser(QWidget *parent = nullptr);
     ~ThemeChooser() override;
 
     void apply();
diff --git a/src/plugins/coreplugin/variablechooser.h b/src/plugins/coreplugin/variablechooser.h
index 5d2f413f47b..4144f3ea18c 100644
--- a/src/plugins/coreplugin/variablechooser.h
+++ b/src/plugins/coreplugin/variablechooser.h
@@ -41,7 +41,7 @@ class CORE_EXPORT VariableChooser : public QWidget
     Q_OBJECT
 
 public:
-    explicit VariableChooser(QWidget *parent = 0);
+    explicit VariableChooser(QWidget *parent = nullptr);
     ~VariableChooser() override;
 
     void addMacroExpanderProvider(const Utils::MacroExpanderProvider &provider);
diff --git a/src/plugins/coreplugin/vcsmanager.h b/src/plugins/coreplugin/vcsmanager.h
index c648a584717..2015fc0f488 100644
--- a/src/plugins/coreplugin/vcsmanager.h
+++ b/src/plugins/coreplugin/vcsmanager.h
@@ -71,7 +71,7 @@ public:
 
     static void resetVersionControlForDirectory(const QString &inputDirectory);
     static IVersionControl *findVersionControlForDirectory(const QString &directory,
-                                                           QString *topLevelDirectory = 0);
+                                                           QString *topLevelDirectory = nullptr);
     static QString findTopLevelForDirectory(const QString &directory);
 
     static QStringList repositories(const IVersionControl *);
@@ -107,7 +107,7 @@ signals:
     void configurationChanged(const IVersionControl *vcs);
 
 private:
-    explicit VcsManager(QObject *parent = 0);
+    explicit VcsManager(QObject *parent = nullptr);
     ~VcsManager() override;
 
     static void addVersionControl(IVersionControl *vc);