Replace Q_NULLPTR with nullptr where possible

Remaining uses of Q_NULLPTR are in:
src/corelib/global/qcompilerdetection.h
  (definition and documentation of Q_NULLPTR)
tests/manual/qcursor/qcursorhighdpi/main.cpp
  (a test executable compilable both under Qt4 and Qt5)

Change-Id: If6b074d91486e9b784138f4514f5c6d072acda9a
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

550 files changed, 1565 insertions, 1565 deletions

diff --git a/examples/network/fortuneclient/client.cpp b/examples/network/fortuneclient/client.cpp
index c0043e246f..3156a9d62c 100644
--- a/examples/network/fortuneclient/client.cpp
+++ b/examples/network/fortuneclient/client.cpp
@@ -60,7 +60,7 @@ Client::Client(QWidget *parent)
     , portLineEdit(new QLineEdit)
     , getFortuneButton(new QPushButton(tr("Get Fortune")))
     , tcpSocket(new QTcpSocket(this))
-    , networkSession(Q_NULLPTR)
+    , networkSession(nullptr)
 {
     setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
 //! [0]
@@ -127,7 +127,7 @@ Client::Client(QWidget *parent)
             this, &Client::displayError);
 //! [4]
 
-    QGridLayout *mainLayout = Q_NULLPTR;
+    QGridLayout *mainLayout = nullptr;
     if (QGuiApplication::styleHints()->showIsFullScreen() || QGuiApplication::styleHints()->showIsMaximized()) {
         QVBoxLayout *outerVerticalLayout = new QVBoxLayout(this);
         outerVerticalLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::Ignored, QSizePolicy::MinimumExpanding));
diff --git a/examples/network/fortuneclient/client.h b/examples/network/fortuneclient/client.h
index 8037e9b047..3ba15173a4 100644
--- a/examples/network/fortuneclient/client.h
+++ b/examples/network/fortuneclient/client.h
@@ -70,7 +70,7 @@ class Client : public QDialog
     Q_OBJECT
 
 public:
-    explicit Client(QWidget *parent = Q_NULLPTR);
+    explicit Client(QWidget *parent = nullptr);
 
 private slots:
     void requestNewFortune();
diff --git a/examples/network/fortuneserver/server.cpp b/examples/network/fortuneserver/server.cpp
index f027d68dd9..aac95ad820 100644
--- a/examples/network/fortuneserver/server.cpp
+++ b/examples/network/fortuneserver/server.cpp
@@ -58,7 +58,7 @@
 Server::Server(QWidget *parent)
     : QDialog(parent)
     , statusLabel(new QLabel)
-    , tcpServer(Q_NULLPTR)
+    , tcpServer(nullptr)
     , networkSession(0)
 {
     setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
@@ -109,7 +109,7 @@ Server::Server(QWidget *parent)
         buttonLayout->addWidget(quitButton);
         buttonLayout->addStretch(1);
 
-        QVBoxLayout *mainLayout = Q_NULLPTR;
+        QVBoxLayout *mainLayout = nullptr;
         if (QGuiApplication::styleHints()->showIsFullScreen() || QGuiApplication::styleHints()->showIsMaximized()) {
             QVBoxLayout *outerVerticalLayout = new QVBoxLayout(this);
             outerVerticalLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::Ignored, QSizePolicy::MinimumExpanding));
diff --git a/examples/network/fortuneserver/server.h b/examples/network/fortuneserver/server.h
index ea5ed78292..87cdea9c8c 100644
--- a/examples/network/fortuneserver/server.h
+++ b/examples/network/fortuneserver/server.h
@@ -66,7 +66,7 @@ class Server : public QDialog
     Q_OBJECT
 
 public:
-    explicit Server(QWidget *parent = Q_NULLPTR);
+    explicit Server(QWidget *parent = nullptr);
 
 private slots:
     void sessionOpened();
diff --git a/examples/network/http/httpwindow.cpp b/examples/network/http/httpwindow.cpp
index fddd2c809a..9640907673 100644
--- a/examples/network/http/httpwindow.cpp
+++ b/examples/network/http/httpwindow.cpp
@@ -87,8 +87,8 @@ HttpWindow::HttpWindow(QWidget *parent)
     , launchCheckBox(new QCheckBox("Launch file"))
     , defaultFileLineEdit(new QLineEdit(defaultFileName))
     , downloadDirectoryLineEdit(new QLineEdit)
-    , reply(Q_NULLPTR)
-    , file(Q_NULLPTR)
+    , reply(nullptr)
+    , file(nullptr)
     , httpRequestAborted(false)
 {
     setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
@@ -204,7 +204,7 @@ QFile *HttpWindow::openFileForWrite(const QString &fileName)
                                  tr("Unable to save the file %1: %2.")
                                  .arg(QDir::toNativeSeparators(fileName),
                                       file->errorString()));
-        return Q_NULLPTR;
+        return nullptr;
     }
     return file.take();
 }
@@ -224,12 +224,12 @@ void HttpWindow::httpFinished()
         fi.setFile(file->fileName());
         file->close();
         delete file;
-        file = Q_NULLPTR;
+        file = nullptr;
     }
 
     if (httpRequestAborted) {
         reply->deleteLater();
-        reply = Q_NULLPTR;
+        reply = nullptr;
         return;
     }
 
@@ -238,14 +238,14 @@ void HttpWindow::httpFinished()
         statusLabel->setText(tr("Download failed:\n%1.").arg(reply->errorString()));
         downloadButton->setEnabled(true);
         reply->deleteLater();
-        reply = Q_NULLPTR;
+        reply = nullptr;
         return;
     }
 
     const QVariant redirectionTarget = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
 
     reply->deleteLater();
-    reply = Q_NULLPTR;
+    reply = nullptr;
 
     if (!redirectionTarget.isNull()) {
         const QUrl redirectedUrl = url.resolved(redirectionTarget.toUrl());
diff --git a/examples/network/http/httpwindow.h b/examples/network/http/httpwindow.h
index 3bb43dbf89..f942c33952 100644
--- a/examples/network/http/httpwindow.h
+++ b/examples/network/http/httpwindow.h
@@ -71,7 +71,7 @@ class ProgressDialog : public QProgressDialog {
     Q_OBJECT
 
 public:
-    explicit ProgressDialog(const QUrl &url, QWidget *parent = Q_NULLPTR);
+    explicit ProgressDialog(const QUrl &url, QWidget *parent = nullptr);
 
 public slots:
    void networkReplyProgress(qint64 bytesRead, qint64 totalBytes);
@@ -82,7 +82,7 @@ class HttpWindow : public QDialog
     Q_OBJECT
 
 public:
-    explicit HttpWindow(QWidget *parent = Q_NULLPTR);
+    explicit HttpWindow(QWidget *parent = nullptr);
 
     void startRequest(const QUrl &requestedUrl);
 
diff --git a/examples/opengl/qopenglwindow/background_renderer.cpp b/examples/opengl/qopenglwindow/background_renderer.cpp
index d57198444e..cba4ae1f2f 100644
--- a/examples/opengl/qopenglwindow/background_renderer.cpp
+++ b/examples/opengl/qopenglwindow/background_renderer.cpp
@@ -146,7 +146,7 @@ void FragmentToy::draw(const QSize &windowSize)
             m_fragment_shader.reset(new QOpenGLShader(QOpenGLShader::Fragment));
             if (!m_fragment_shader->compileSourceCode(data)) {
                 qWarning() << "Failed to compile fragment shader:" << m_fragment_shader->log();
-                m_fragment_shader.reset(Q_NULLPTR);
+                m_fragment_shader.reset(nullptr);
             }
         } else {
             qWarning() << "Unknown error, no fragment shader";
@@ -198,14 +198,14 @@ void FragmentToy::fileChanged(const QString &path)
             m_recompile_shaders = true;
             if (m_program) {
                 m_program->removeShader(m_fragment_shader.data());
-                m_fragment_shader.reset(Q_NULLPTR);
+                m_fragment_shader.reset(nullptr);
             }
         }
     } else {
         m_recompile_shaders = true;
         if (m_program) {
             m_program->removeShader(m_fragment_shader.data());
-            m_fragment_shader.reset(Q_NULLPTR);
+            m_fragment_shader.reset(nullptr);
         }
     }
 }
diff --git a/examples/widgets/mainwindows/mainwindow/colorswatch.cpp b/examples/widgets/mainwindows/mainwindow/colorswatch.cpp
index c47b80275f..720f9a2085 100644
--- a/examples/widgets/mainwindows/mainwindow/colorswatch.cpp
+++ b/examples/widgets/mainwindows/mainwindow/colorswatch.cpp
@@ -468,7 +468,7 @@ static ColorSwatch *findByName(const QMainWindow *mainWindow, const QString &nam
         if (name == dock->objectName())
             return dock;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void ColorSwatch::splitInto(QAction *action)
diff --git a/examples/widgets/mainwindows/mainwindow/colorswatch.h b/examples/widgets/mainwindows/mainwindow/colorswatch.h
index ec9d9e7372..7f73e46f31 100644
--- a/examples/widgets/mainwindows/mainwindow/colorswatch.h
+++ b/examples/widgets/mainwindows/mainwindow/colorswatch.h
@@ -62,7 +62,7 @@ class ColorSwatch : public QDockWidget
     Q_OBJECT
 
 public:
-    explicit ColorSwatch(const QString &colorName, QMainWindow *parent = Q_NULLPTR, Qt::WindowFlags flags = 0);
+    explicit ColorSwatch(const QString &colorName, QMainWindow *parent = nullptr, Qt::WindowFlags flags = 0);
 
     void setCustomSizeHint(const QSize &size);
     QMenu *colorSwatchMenu() const { return menu; }
@@ -128,7 +128,7 @@ class BlueTitleBar : public QWidget
 {
     Q_OBJECT
 public:
-    explicit BlueTitleBar(QWidget *parent = Q_NULLPTR);
+    explicit BlueTitleBar(QWidget *parent = nullptr);
 
     QSize sizeHint() const override { return minimumSizeHint(); }
     QSize minimumSizeHint() const override;
diff --git a/examples/widgets/mainwindows/mainwindow/mainwindow.cpp b/examples/widgets/mainwindows/mainwindow/mainwindow.cpp
index afceddfca1..b2c5ccc473 100644
--- a/examples/widgets/mainwindows/mainwindow/mainwindow.cpp
+++ b/examples/widgets/mainwindows/mainwindow/mainwindow.cpp
@@ -382,7 +382,7 @@ void MainWindow::switchLayoutDirection()
 class CreateDockWidgetDialog : public QDialog
 {
 public:
-    explicit CreateDockWidgetDialog(QWidget *parent = Q_NULLPTR);
+    explicit CreateDockWidgetDialog(QWidget *parent = nullptr);
 
     QString enteredObjectName() const { return m_objectName->text(); }
     Qt::DockWidgetArea location() const;
diff --git a/examples/widgets/mainwindows/mainwindow/mainwindow.h b/examples/widgets/mainwindows/mainwindow/mainwindow.h
index af4f1f5745..9b1af6df80 100644
--- a/examples/widgets/mainwindows/mainwindow/mainwindow.h
+++ b/examples/widgets/mainwindows/mainwindow/mainwindow.h
@@ -64,7 +64,7 @@ public:
     typedef QMap<QString, QSize> CustomSizeHintMap;
 
     explicit MainWindow(const CustomSizeHintMap &customSizeHints,
-                        QWidget *parent = Q_NULLPTR,
+                        QWidget *parent = nullptr,
                         Qt::WindowFlags flags = 0);
 
 public slots:
diff --git a/examples/widgets/mainwindows/mainwindow/toolbar.cpp b/examples/widgets/mainwindows/mainwindow/toolbar.cpp
index 97152a64a3..bb30b63b02 100644
--- a/examples/widgets/mainwindows/mainwindow/toolbar.cpp
+++ b/examples/widgets/mainwindows/mainwindow/toolbar.cpp
@@ -81,8 +81,8 @@ static QPixmap genIcon(const QSize &iconSize, int number, const QColor &color)
 
 ToolBar::ToolBar(const QString &title, QWidget *parent)
     : QToolBar(parent)
-    , spinbox(Q_NULLPTR)
-    , spinboxAction(Q_NULLPTR)
+    , spinbox(nullptr)
+    , spinboxAction(nullptr)
 {
     setWindowTitle(title);
     setObjectName(title);
diff --git a/examples/widgets/mainwindows/sdi/main.cpp b/examples/widgets/mainwindows/sdi/main.cpp
index bed990d34d..6e29fafd6f 100644
--- a/examples/widgets/mainwindows/sdi/main.cpp
+++ b/examples/widgets/mainwindows/sdi/main.cpp
@@ -67,7 +67,7 @@ int main(int argc, char *argv[])
     parser.addPositionalArgument("file", "The file(s) to open.");
     parser.process(app);
 
-    MainWindow *mainWin = Q_NULLPTR;
+    MainWindow *mainWin = nullptr;
     foreach (const QString &file, parser.positionalArguments()) {
         MainWindow *newWin = new MainWindow(file);
         newWin->tile(mainWin);
diff --git a/examples/widgets/tools/codecs/previewform.h b/examples/widgets/tools/codecs/previewform.h
index 1846b976de..6335b6539f 100644
--- a/examples/widgets/tools/codecs/previewform.h
+++ b/examples/widgets/tools/codecs/previewform.h
@@ -69,7 +69,7 @@ class PreviewForm : public QDialog
     Q_OBJECT
 
 public:
-    explicit PreviewForm(QWidget *parent = Q_NULLPTR);
+    explicit PreviewForm(QWidget *parent = nullptr);
 
     void setCodecList(const QList<QTextCodec *> &list);
     void setEncodedData(const QByteArray &data);
diff --git a/examples/widgets/tools/settingseditor/mainwindow.cpp b/examples/widgets/tools/settingseditor/mainwindow.cpp
index ab9837c513..a7a1e9b415 100644
--- a/examples/widgets/tools/settingseditor/mainwindow.cpp
+++ b/examples/widgets/tools/settingseditor/mainwindow.cpp
@@ -56,7 +56,7 @@
 
 MainWindow::MainWindow()
     : settingsTree(new SettingsTree)
-    , locationDialog(Q_NULLPTR)
+    , locationDialog(nullptr)
 {
     setCentralWidget(settingsTree);
 
diff --git a/examples/widgets/widgets/charactermap/mainwindow.cpp b/examples/widgets/widgets/charactermap/mainwindow.cpp
index 5f17128a2f..d3ac55483c 100644
--- a/examples/widgets/widgets/charactermap/mainwindow.cpp
+++ b/examples/widgets/widgets/charactermap/mainwindow.cpp
@@ -244,7 +244,7 @@ void MainWindow::updateClipboard()
 class FontInfoDialog : public QDialog
 {
 public:
-    explicit FontInfoDialog(QWidget *parent = Q_NULLPTR);
+    explicit FontInfoDialog(QWidget *parent = nullptr);
 
 private:
     QString text() const;
diff --git a/examples/widgets/widgets/icons/iconpreviewarea.cpp b/examples/widgets/widgets/icons/iconpreviewarea.cpp
index 35379610c5..9cb54c47f6 100644
--- a/examples/widgets/widgets/icons/iconpreviewarea.cpp
+++ b/examples/widgets/widgets/icons/iconpreviewarea.cpp
@@ -190,7 +190,7 @@ QLabel *IconPreviewArea::createPixmapLabel()
 //! [5]
 void IconPreviewArea::updatePixmapLabels()
 {
-    QWindow *window = Q_NULLPTR;
+    QWindow *window = nullptr;
     if (const QWidget *nativeParent = nativeParentWidget())
         window = nativeParent->windowHandle();
     for (int column = 0; column < NumModes; ++column) {
diff --git a/examples/widgets/widgets/icons/iconpreviewarea.h b/examples/widgets/widgets/icons/iconpreviewarea.h
index 3ebb9ed3ce..6ea35a5230 100644
--- a/examples/widgets/widgets/icons/iconpreviewarea.h
+++ b/examples/widgets/widgets/icons/iconpreviewarea.h
@@ -66,7 +66,7 @@ class IconPreviewArea : public QWidget
     Q_OBJECT
 
 public:
-    explicit IconPreviewArea(QWidget *parent = Q_NULLPTR);
+    explicit IconPreviewArea(QWidget *parent = nullptr);
 
     void setIcon(const QIcon &icon);
     void setSize(const QSize &size);
diff --git a/examples/widgets/widgets/icons/iconsizespinbox.h b/examples/widgets/widgets/icons/iconsizespinbox.h
index 96a56e75c9..87415ac5d6 100644
--- a/examples/widgets/widgets/icons/iconsizespinbox.h
+++ b/examples/widgets/widgets/icons/iconsizespinbox.h
@@ -59,7 +59,7 @@ class IconSizeSpinBox : public QSpinBox
     Q_OBJECT
 
 public:
-    explicit IconSizeSpinBox(QWidget *parent = Q_NULLPTR);
+    explicit IconSizeSpinBox(QWidget *parent = nullptr);
 
     int valueFromText(const QString &text) const override;
     QString textFromValue(int value) const override;
diff --git a/examples/widgets/widgets/icons/imagedelegate.h b/examples/widgets/widgets/icons/imagedelegate.h
index 928085d85b..3b76b78339 100644
--- a/examples/widgets/widgets/icons/imagedelegate.h
+++ b/examples/widgets/widgets/icons/imagedelegate.h
@@ -59,7 +59,7 @@ class ImageDelegate : public QItemDelegate
     Q_OBJECT
 
 public:
-    explicit ImageDelegate(QObject *parent = Q_NULLPTR);
+    explicit ImageDelegate(QObject *parent = nullptr);
 //! [0]
 
 //! [1]
diff --git a/examples/widgets/widgets/tablet/mainwindow.cpp b/examples/widgets/widgets/tablet/mainwindow.cpp
index 0d63ac316b..c02e02f0a4 100644
--- a/examples/widgets/widgets/tablet/mainwindow.cpp
+++ b/examples/widgets/widgets/tablet/mainwindow.cpp
@@ -55,7 +55,7 @@
 
 //! [0]
 MainWindow::MainWindow(TabletCanvas *canvas)
-  : m_canvas(canvas), m_colorDialog(Q_NULLPTR)
+  : m_canvas(canvas), m_colorDialog(nullptr)
 {
     createMenus();
     setWindowTitle(tr("Tablet Example"));
diff --git a/examples/widgets/widgets/tablet/tabletcanvas.cpp b/examples/widgets/widgets/tablet/tabletcanvas.cpp
index d74c21f072..73678ab754 100644
--- a/examples/widgets/widgets/tablet/tabletcanvas.cpp
+++ b/examples/widgets/widgets/tablet/tabletcanvas.cpp
@@ -55,7 +55,7 @@
 
 //! [0]
 TabletCanvas::TabletCanvas()
-  : QWidget(Q_NULLPTR)
+  : QWidget(nullptr)
   , m_alphaChannelValuator(TangentialPressureValuator)
   , m_colorSaturationValuator(NoValuator)
   , m_lineWidthValuator(PressureValuator)
diff --git a/src/concurrent/qtconcurrentiteratekernel.h b/src/concurrent/qtconcurrentiteratekernel.h
index dbd000e8ba..082fa9e838 100644
--- a/src/concurrent/qtconcurrentiteratekernel.h
+++ b/src/concurrent/qtconcurrentiteratekernel.h
@@ -159,7 +159,7 @@ public:
     inline ResultReporter(ThreadEngine<void> *) { }
     inline void reserveSpace(int) { }
     inline void reportResults(int) { }
-    inline void * getPointer() { return Q_NULLPTR; }
+    inline void * getPointer() { return nullptr; }
 };
 
 inline bool selectIteration(std::bidirectional_iterator_tag)
diff --git a/src/concurrent/qtconcurrentthreadengine.h b/src/concurrent/qtconcurrentthreadengine.h
index 44e714044e..450e7b8d50 100644
--- a/src/concurrent/qtconcurrentthreadengine.h
+++ b/src/concurrent/qtconcurrentthreadengine.h
@@ -132,7 +132,7 @@ class ThreadEngine : public virtual ThreadEngineBase
 public:
     typedef T ResultType;
 
-    virtual T *result() { return Q_NULLPTR; }
+    virtual T *result() { return nullptr; }
 
     QFutureInterface<T> *futureInterfaceTyped()
     {
diff --git a/src/corelib/animation/qabstractanimation.h b/src/corelib/animation/qabstractanimation.h
index 4b6eb9e14e..0ff6bc5176 100644
--- a/src/corelib/animation/qabstractanimation.h
+++ b/src/corelib/animation/qabstractanimation.h
@@ -82,7 +82,7 @@ public:
         DeleteWhenStopped
     };
 
-    QAbstractAnimation(QObject *parent = Q_NULLPTR);
+    QAbstractAnimation(QObject *parent = nullptr);
     virtual ~QAbstractAnimation();
 
     State state() const;
@@ -117,7 +117,7 @@ public Q_SLOTS:
     void setCurrentTime(int msecs);
 
 protected:
-    QAbstractAnimation(QAbstractAnimationPrivate &dd, QObject *parent = Q_NULLPTR);
+    QAbstractAnimation(QAbstractAnimationPrivate &dd, QObject *parent = nullptr);
     bool event(QEvent *event) override;
 
     virtual void updateCurrentTime(int currentTime) = 0;
@@ -136,7 +136,7 @@ class Q_CORE_EXPORT QAnimationDriver : public QObject
     Q_DECLARE_PRIVATE(QAnimationDriver)
 
 public:
-    QAnimationDriver(QObject *parent = Q_NULLPTR);
+    QAnimationDriver(QObject *parent = nullptr);
     ~QAnimationDriver();
 
     virtual void advance();
@@ -162,7 +162,7 @@ protected:
     virtual void start();
     virtual void stop();
 
-    QAnimationDriver(QAnimationDriverPrivate &dd, QObject *parent = Q_NULLPTR);
+    QAnimationDriver(QAnimationDriverPrivate &dd, QObject *parent = nullptr);
 
 private:
     friend class QUnifiedTimer;
diff --git a/src/corelib/animation/qanimationgroup.h b/src/corelib/animation/qanimationgroup.h
index 574a828ee1..136ad3ca9f 100644
--- a/src/corelib/animation/qanimationgroup.h
+++ b/src/corelib/animation/qanimationgroup.h
@@ -53,7 +53,7 @@ class Q_CORE_EXPORT QAnimationGroup : public QAbstractAnimation
     Q_OBJECT
 
 public:
-    QAnimationGroup(QObject *parent = Q_NULLPTR);
+    QAnimationGroup(QObject *parent = nullptr);
     ~QAnimationGroup();
 
     QAbstractAnimation *animationAt(int index) const;
diff --git a/src/corelib/animation/qparallelanimationgroup.h b/src/corelib/animation/qparallelanimationgroup.h
index 19a7f2fd83..09a439ef24 100644
--- a/src/corelib/animation/qparallelanimationgroup.h
+++ b/src/corelib/animation/qparallelanimationgroup.h
@@ -53,7 +53,7 @@ class Q_CORE_EXPORT QParallelAnimationGroup : public QAnimationGroup
     Q_OBJECT
 
 public:
-    QParallelAnimationGroup(QObject *parent = Q_NULLPTR);
+    QParallelAnimationGroup(QObject *parent = nullptr);
     ~QParallelAnimationGroup();
 
     int duration() const override;
diff --git a/src/corelib/animation/qpauseanimation.h b/src/corelib/animation/qpauseanimation.h
index 541186fa48..e2095a39d6 100644
--- a/src/corelib/animation/qpauseanimation.h
+++ b/src/corelib/animation/qpauseanimation.h
@@ -54,8 +54,8 @@ class Q_CORE_EXPORT QPauseAnimation : public QAbstractAnimation
     Q_OBJECT
     Q_PROPERTY(int duration READ duration WRITE setDuration)
 public:
-    QPauseAnimation(QObject *parent = Q_NULLPTR);
-    QPauseAnimation(int msecs, QObject *parent = Q_NULLPTR);
+    QPauseAnimation(QObject *parent = nullptr);
+    QPauseAnimation(int msecs, QObject *parent = nullptr);
     ~QPauseAnimation();
 
     int duration() const override;
diff --git a/src/corelib/animation/qpropertyanimation.h b/src/corelib/animation/qpropertyanimation.h
index 419fd1e51c..3270591d1d 100644
--- a/src/corelib/animation/qpropertyanimation.h
+++ b/src/corelib/animation/qpropertyanimation.h
@@ -55,8 +55,8 @@ class Q_CORE_EXPORT QPropertyAnimation : public QVariantAnimation
     Q_PROPERTY(QObject* targetObject READ targetObject WRITE setTargetObject)
 
 public:
-    QPropertyAnimation(QObject *parent = Q_NULLPTR);
-    QPropertyAnimation(QObject *target, const QByteArray &propertyName, QObject *parent = Q_NULLPTR);
+    QPropertyAnimation(QObject *parent = nullptr);
+    QPropertyAnimation(QObject *target, const QByteArray &propertyName, QObject *parent = nullptr);
     ~QPropertyAnimation();
 
     QObject *targetObject() const;
diff --git a/src/corelib/animation/qsequentialanimationgroup.h b/src/corelib/animation/qsequentialanimationgroup.h
index 636e39a075..1c8e67d256 100644
--- a/src/corelib/animation/qsequentialanimationgroup.h
+++ b/src/corelib/animation/qsequentialanimationgroup.h
@@ -56,7 +56,7 @@ class Q_CORE_EXPORT QSequentialAnimationGroup : public QAnimationGroup
     Q_PROPERTY(QAbstractAnimation* currentAnimation READ currentAnimation NOTIFY currentAnimationChanged)
 
 public:
-    QSequentialAnimationGroup(QObject *parent = Q_NULLPTR);
+    QSequentialAnimationGroup(QObject *parent = nullptr);
     ~QSequentialAnimationGroup();
 
     QPauseAnimation *addPause(int msecs);
diff --git a/src/corelib/animation/qvariantanimation.h b/src/corelib/animation/qvariantanimation.h
index 74d804dacd..ed38979ad0 100644
--- a/src/corelib/animation/qvariantanimation.h
+++ b/src/corelib/animation/qvariantanimation.h
@@ -65,7 +65,7 @@ public:
     typedef QPair<qreal, QVariant> KeyValue;
     typedef QVector<KeyValue> KeyValues;
 
-    QVariantAnimation(QObject *parent = Q_NULLPTR);
+    QVariantAnimation(QObject *parent = nullptr);
     ~QVariantAnimation();
 
     QVariant startValue() const;
@@ -94,7 +94,7 @@ Q_SIGNALS:
     void valueChanged(const QVariant &value);
 
 protected:
-    QVariantAnimation(QVariantAnimationPrivate &dd, QObject *parent = Q_NULLPTR);
+    QVariantAnimation(QVariantAnimationPrivate &dd, QObject *parent = nullptr);
     bool event(QEvent *event) override;
 
     void updateCurrentTime(int) override;
diff --git a/src/corelib/arch/qatomic_cxx11.h b/src/corelib/arch/qatomic_cxx11.h
index 1404849382..2fc0bf5419 100644
--- a/src/corelib/arch/qatomic_cxx11.h
+++ b/src/corelib/arch/qatomic_cxx11.h
@@ -276,7 +276,7 @@ template <typename X> struct QAtomicOps
     static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return false; }
 
     template <typename T>
-    static bool testAndSetRelaxed(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = Q_NULLPTR) Q_DECL_NOTHROW
+    static bool testAndSetRelaxed(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_relaxed, std::memory_order_relaxed);
         if (currentValue)
@@ -285,7 +285,7 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static bool testAndSetAcquire(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = Q_NULLPTR) Q_DECL_NOTHROW
+    static bool testAndSetAcquire(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_acquire, std::memory_order_acquire);
         if (currentValue)
@@ -294,7 +294,7 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static bool testAndSetRelease(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = Q_NULLPTR) Q_DECL_NOTHROW
+    static bool testAndSetRelease(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_release, std::memory_order_relaxed);
         if (currentValue)
@@ -303,7 +303,7 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static bool testAndSetOrdered(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = Q_NULLPTR) Q_DECL_NOTHROW
+    static bool testAndSetOrdered(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_acq_rel, std::memory_order_acquire);
         if (currentValue)
diff --git a/src/corelib/codecs/qtextcodec.h b/src/corelib/codecs/qtextcodec.h
index 5163d37238..8153bebac8 100644
--- a/src/corelib/codecs/qtextcodec.h
+++ b/src/corelib/codecs/qtextcodec.h
@@ -100,7 +100,7 @@ public:
 
     struct Q_CORE_EXPORT ConverterState {
         ConverterState(ConversionFlags f = DefaultConversion)
-            : flags(f), remainingChars(0), invalidChars(0), d(Q_NULLPTR) { state_data[0] = state_data[1] = state_data[2] = 0; }
+            : flags(f), remainingChars(0), invalidChars(0), d(nullptr) { state_data[0] = state_data[1] = state_data[2] = 0; }
         ~ConverterState();
         ConversionFlags flags;
         int remainingChars;
@@ -111,9 +111,9 @@ public:
         Q_DISABLE_COPY(ConverterState)
     };
 
-    QString toUnicode(const char *in, int length, ConverterState *state = Q_NULLPTR) const
+    QString toUnicode(const char *in, int length, ConverterState *state = nullptr) const
         { return convertToUnicode(in, length, state); }
-    QByteArray fromUnicode(const QChar *in, int length, ConverterState *state = Q_NULLPTR) const
+    QByteArray fromUnicode(const QChar *in, int length, ConverterState *state = nullptr) const
         { return convertFromUnicode(in, length, state); }
 
     QTextDecoder* makeDecoder(ConversionFlags flags = DefaultConversion) const;
diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index feeb488acd..4806f6cd74 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -118,7 +118,7 @@ public:
     Q_DECL_CONSTEXPR inline QFlags &operator=(const QFlags &other);
 #endif
     Q_DECL_CONSTEXPR inline QFlags(Enum f) Q_DECL_NOTHROW : i(Int(f)) {}
-    Q_DECL_CONSTEXPR inline QFlags(Zero = Q_NULLPTR) Q_DECL_NOTHROW : i(0) {}
+    Q_DECL_CONSTEXPR inline QFlags(Zero = nullptr) Q_DECL_NOTHROW : i(0) {}
     Q_DECL_CONSTEXPR inline QFlags(QFlag f) Q_DECL_NOTHROW : i(f) {}
 
 #ifdef Q_COMPILER_INITIALIZER_LISTS
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h
index ff388770f5..c9ec46c67f 100644
--- a/src/corelib/global/qglobal.h
+++ b/src/corelib/global/qglobal.h
@@ -1138,7 +1138,7 @@ Q_CORE_EXPORT bool qunsetenv(const char *varName);
 
 Q_CORE_EXPORT bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT;
 Q_CORE_EXPORT bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT;
-Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=Q_NULLPTR) Q_DECL_NOEXCEPT;
+Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=nullptr) Q_DECL_NOEXCEPT;
 
 inline int qIntCast(double f) { return int(f); }
 inline int qIntCast(float f) { return int(f); }
diff --git a/src/corelib/global/qlogging.h b/src/corelib/global/qlogging.h
index ec21198784..0c8d7dab38 100644
--- a/src/corelib/global/qlogging.h
+++ b/src/corelib/global/qlogging.h
@@ -64,7 +64,7 @@ class QMessageLogContext
     Q_DISABLE_COPY(QMessageLogContext)
 public:
     Q_DECL_CONSTEXPR QMessageLogContext()
-        : version(2), line(0), file(Q_NULLPTR), function(Q_NULLPTR), category(Q_NULLPTR) {}
+        : version(2), line(0), file(nullptr), function(nullptr), category(nullptr) {}
     Q_DECL_CONSTEXPR QMessageLogContext(const char *fileName, int lineNumber, const char *functionName, const char *categoryName)
         : version(2), line(lineNumber), file(fileName), function(functionName), category(categoryName) {}
 
@@ -150,9 +150,9 @@ private:
   #define QT_MESSAGELOG_LINE __LINE__
   #define QT_MESSAGELOG_FUNC Q_FUNC_INFO
 #else
-  #define QT_MESSAGELOG_FILE Q_NULLPTR
+  #define QT_MESSAGELOG_FILE nullptr
   #define QT_MESSAGELOG_LINE 0
-  #define QT_MESSAGELOG_FUNC Q_NULLPTR
+  #define QT_MESSAGELOG_FUNC nullptr
 #endif
 
 #define qDebug QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).debug
diff --git a/src/corelib/io/qbuffer.h b/src/corelib/io/qbuffer.h
index 1c5b16ee50..39e1e7b39d 100644
--- a/src/corelib/io/qbuffer.h
+++ b/src/corelib/io/qbuffer.h
@@ -57,8 +57,8 @@ class Q_CORE_EXPORT QBuffer : public QIODevice
 
 public:
 #ifndef QT_NO_QOBJECT
-     explicit QBuffer(QObject *parent = Q_NULLPTR);
-     QBuffer(QByteArray *buf, QObject *parent = Q_NULLPTR);
+     explicit QBuffer(QObject *parent = nullptr);
+     QBuffer(QByteArray *buf, QObject *parent = nullptr);
 #else
      QBuffer();
      explicit QBuffer(QByteArray *buf);
diff --git a/src/corelib/io/qfile.h b/src/corelib/io/qfile.h
index 02d644446d..e6f3d942fe 100644
--- a/src/corelib/io/qfile.h
+++ b/src/corelib/io/qfile.h
@@ -142,7 +142,7 @@ protected:
 #ifdef QT_NO_QOBJECT
     QFile(QFilePrivate &dd);
 #else
-    QFile(QFilePrivate &dd, QObject *parent = Q_NULLPTR);
+    QFile(QFilePrivate &dd, QObject *parent = nullptr);
 #endif
 
 private:
diff --git a/src/corelib/io/qfiledevice.h b/src/corelib/io/qfiledevice.h
index 020c90afaf..af41bec2f6 100644
--- a/src/corelib/io/qfiledevice.h
+++ b/src/corelib/io/qfiledevice.h
@@ -136,7 +136,7 @@ protected:
     QFileDevice(QFileDevicePrivate &dd);
 #else
     explicit QFileDevice(QObject *parent);
-    QFileDevice(QFileDevicePrivate &dd, QObject *parent = Q_NULLPTR);
+    QFileDevice(QFileDevicePrivate &dd, QObject *parent = nullptr);
 #endif
 
     qint64 readData(char *data, qint64 maxlen) override;
diff --git a/src/corelib/io/qfileselector.h b/src/corelib/io/qfileselector.h
index fafb7f7609..c9c2f564f6 100644
--- a/src/corelib/io/qfileselector.h
+++ b/src/corelib/io/qfileselector.h
@@ -50,7 +50,7 @@ class Q_CORE_EXPORT QFileSelector : public QObject
 {
     Q_OBJECT
 public:
-    explicit QFileSelector(QObject *parent = Q_NULLPTR);
+    explicit QFileSelector(QObject *parent = nullptr);
     ~QFileSelector();
 
     QString select(const QString &filePath) const;
diff --git a/src/corelib/io/qfilesystemwatcher.h b/src/corelib/io/qfilesystemwatcher.h
index 09d4e8e65e..057a20672c 100644
--- a/src/corelib/io/qfilesystemwatcher.h
+++ b/src/corelib/io/qfilesystemwatcher.h
@@ -55,8 +55,8 @@ class Q_CORE_EXPORT QFileSystemWatcher : public QObject
     Q_DECLARE_PRIVATE(QFileSystemWatcher)
 
 public:
-    QFileSystemWatcher(QObject *parent = Q_NULLPTR);
-    QFileSystemWatcher(const QStringList &paths, QObject *parent = Q_NULLPTR);
+    QFileSystemWatcher(QObject *parent = nullptr);
+    QFileSystemWatcher(const QStringList &paths, QObject *parent = nullptr);
     ~QFileSystemWatcher();
 
     bool addPath(const QString &file);
diff --git a/src/corelib/io/qfilesystemwatcher_fsevents.mm b/src/corelib/io/qfilesystemwatcher_fsevents.mm
index b4517cbac7..792ea387ac 100644
--- a/src/corelib/io/qfilesystemwatcher_fsevents.mm
+++ b/src/corelib/io/qfilesystemwatcher_fsevents.mm
@@ -336,7 +336,7 @@ QStringList QFseventsFileSystemWatcherEngine::addPaths(const QStringList &paths,
 
     QMutexLocker locker(&lock);
 
-    bool wasRunning = stream != Q_NULLPTR;
+    bool wasRunning = stream != nullptr;
     bool needsRestart = false;
 
     WatchingState oldState = watchingState;
diff --git a/src/corelib/io/qiodevice.h b/src/corelib/io/qiodevice.h
index e64a4d0bb1..af37b3fd53 100644
--- a/src/corelib/io/qiodevice.h
+++ b/src/corelib/io/qiodevice.h
@@ -161,7 +161,7 @@ protected:
 #ifdef QT_NO_QOBJECT
     QIODevice(QIODevicePrivate &dd);
 #else
-    QIODevice(QIODevicePrivate &dd, QObject *parent = Q_NULLPTR);
+    QIODevice(QIODevicePrivate &dd, QObject *parent = nullptr);
 #endif
     virtual qint64 readData(char *data, qint64 maxlen) = 0;
     virtual qint64 readLineData(char *data, qint64 maxlen);
diff --git a/src/corelib/io/qiodevice_p.h b/src/corelib/io/qiodevice_p.h
index de2aa1597e..15a53a67dc 100644
--- a/src/corelib/io/qiodevice_p.h
+++ b/src/corelib/io/qiodevice_p.h
@@ -88,14 +88,14 @@ public:
 
     class QRingBufferRef {
         QRingBuffer *m_buf;
-        inline QRingBufferRef() : m_buf(Q_NULLPTR) { }
+        inline QRingBufferRef() : m_buf(nullptr) { }
         friend class QIODevicePrivate;
     public:
         // wrap functions from QRingBuffer
         inline void setChunkSize(int size) { Q_ASSERT(m_buf); m_buf->setChunkSize(size); }
         inline int chunkSize() const { Q_ASSERT(m_buf); return m_buf->chunkSize(); }
         inline qint64 nextDataBlockSize() const { return (m_buf ? m_buf->nextDataBlockSize() : Q_INT64_C(0)); }
-        inline const char *readPointer() const { return (m_buf ? m_buf->readPointer() : Q_NULLPTR); }
+        inline const char *readPointer() const { return (m_buf ? m_buf->readPointer() : nullptr); }
         inline const char *readPointerAtPosition(qint64 pos, qint64 &length) const { Q_ASSERT(m_buf); return m_buf->readPointerAtPosition(pos, length); }
         inline void free(qint64 bytes) { Q_ASSERT(m_buf); m_buf->free(bytes); }
         inline char *reserve(qint64 bytes) { Q_ASSERT(m_buf); return m_buf->reserve(bytes); }
diff --git a/src/corelib/io/qprocess.h b/src/corelib/io/qprocess.h
index 7ce94d5ecd..474fc87de8 100644
--- a/src/corelib/io/qprocess.h
+++ b/src/corelib/io/qprocess.h
@@ -155,7 +155,7 @@ public:
     };
     Q_ENUM(ExitStatus)
 
-    explicit QProcess(QObject *parent = Q_NULLPTR);
+    explicit QProcess(QObject *parent = nullptr);
     virtual ~QProcess();
 
     void start(const QString &program, const QStringList &arguments, OpenMode mode = ReadWrite);
@@ -253,7 +253,7 @@ public:
 #if defined(Q_QDOC)
                               = QString()
 #endif
-                              , qint64 *pid = Q_NULLPTR);
+                              , qint64 *pid = nullptr);
 #if !defined(Q_QDOC)
     static bool startDetached(const QString &program, const QStringList &arguments); // ### Qt6: merge overloads
 #endif
diff --git a/src/corelib/io/qprocess_p.h b/src/corelib/io/qprocess_p.h
index deb29dca0a..aa7ecbe91d 100644
--- a/src/corelib/io/qprocess_p.h
+++ b/src/corelib/io/qprocess_p.h
@@ -352,7 +352,7 @@ public:
 #if defined(Q_OS_UNIX)
     void execChild(const char *workingDirectory, char **argv, char **envp);
 #endif
-    bool processStarted(QString *errorMessage = Q_NULLPTR);
+    bool processStarted(QString *errorMessage = nullptr);
     void terminateProcess();
     void killProcess();
     void findExitCode();
diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 15752f84b2..68b7a8bf9b 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -885,7 +885,7 @@ bool QProcessPrivate::waitForDeadChild()
     // read the process information from our fd
     forkfd_info info;
     int ret;
-    EINTR_LOOP(ret, forkfd_wait(forkfd, &info, Q_NULLPTR));
+    EINTR_LOOP(ret, forkfd_wait(forkfd, &info, nullptr));
 
     exitCode = info.status;
     crashed = info.code != CLD_EXITED;
diff --git a/src/corelib/io/qsavefile.h b/src/corelib/io/qsavefile.h
index 8bfd14eb63..200068d30d 100644
--- a/src/corelib/io/qsavefile.h
+++ b/src/corelib/io/qsavefile.h
@@ -67,7 +67,7 @@ public:
 
     explicit QSaveFile(const QString &name);
 #ifndef QT_NO_QOBJECT
-    explicit QSaveFile(QObject *parent = Q_NULLPTR);
+    explicit QSaveFile(QObject *parent = nullptr);
     explicit QSaveFile(const QString &name, QObject *parent);
 #endif
     ~QSaveFile();
diff --git a/src/corelib/io/qsettings.h b/src/corelib/io/qsettings.h
index d68d4d65f9..f34e6bea1b 100644
--- a/src/corelib/io/qsettings.h
+++ b/src/corelib/io/qsettings.h
@@ -125,13 +125,13 @@ public:
 
 #ifndef QT_NO_QOBJECT
     explicit QSettings(const QString &organization,
-                       const QString &application = QString(), QObject *parent = Q_NULLPTR);
+                       const QString &application = QString(), QObject *parent = nullptr);
     QSettings(Scope scope, const QString &organization,
-              const QString &application = QString(), QObject *parent = Q_NULLPTR);
+              const QString &application = QString(), QObject *parent = nullptr);
     QSettings(Format format, Scope scope, const QString &organization,
-              const QString &application = QString(), QObject *parent = Q_NULLPTR);
-    QSettings(const QString &fileName, Format format, QObject *parent = Q_NULLPTR);
-    explicit QSettings(QObject *parent = Q_NULLPTR);
+              const QString &application = QString(), QObject *parent = nullptr);
+    QSettings(const QString &fileName, Format format, QObject *parent = nullptr);
+    explicit QSettings(QObject *parent = nullptr);
 #else
     explicit QSettings(const QString &organization,
                        const QString &application = QString());
diff --git a/src/corelib/io/qsettings_mac.cpp b/src/corelib/io/qsettings_mac.cpp
index 2a08ee2e64..aa14d8435a 100644
--- a/src/corelib/io/qsettings_mac.cpp
+++ b/src/corelib/io/qsettings_mac.cpp
@@ -616,7 +616,7 @@ bool QConfFileSettingsPrivate::readPlistFile(const QByteArray &data, ParsedSetti
 {
     QCFType<CFDataRef> cfData = data.toRawCFData();
     QCFType<CFPropertyListRef> propertyList =
-            CFPropertyListCreateWithData(kCFAllocatorDefault, cfData, kCFPropertyListImmutable, Q_NULLPTR, Q_NULLPTR);
+            CFPropertyListCreateWithData(kCFAllocatorDefault, cfData, kCFPropertyListImmutable, nullptr, nullptr);
 
     if (!propertyList)
         return true;
diff --git a/src/corelib/io/qstorageinfo_mac.cpp b/src/corelib/io/qstorageinfo_mac.cpp
index 0f271f2bc6..8b06543d71 100644
--- a/src/corelib/io/qstorageinfo_mac.cpp
+++ b/src/corelib/io/qstorageinfo_mac.cpp
@@ -112,7 +112,7 @@ void QStorageInfoPrivate::retrieveUrlProperties(bool initRootPath)
     QCFType<CFArrayRef> keys = CFArrayCreate(kCFAllocatorDefault,
                                              initRootPath ? rootPathKeys : propertyKeys,
                                              size,
-                                             Q_NULLPTR);
+                                             nullptr);
 
     if (!keys)
         return;
@@ -178,9 +178,9 @@ QList<QStorageInfo> QStorageInfoPrivate::mountedVolumes()
     QList<QStorageInfo> volumes;
 
     QCFType<CFURLEnumeratorRef> enumerator;
-    enumerator = CFURLEnumeratorCreateForMountedVolumes(Q_NULLPTR,
+    enumerator = CFURLEnumeratorCreateForMountedVolumes(nullptr,
                                                         kCFURLEnumeratorSkipInvisibles,
-                                                        Q_NULLPTR);
+                                                        nullptr);
 
     CFURLEnumeratorResult result = kCFURLEnumeratorSuccess;
     do {
diff --git a/src/corelib/io/qstorageinfo_unix.cpp b/src/corelib/io/qstorageinfo_unix.cpp
index 9072b34f54..0911083bac 100644
--- a/src/corelib/io/qstorageinfo_unix.cpp
+++ b/src/corelib/io/qstorageinfo_unix.cpp
@@ -257,7 +257,7 @@ inline QStorageIterator::~QStorageIterator()
 
 inline bool QStorageIterator::isValid() const
 {
-    return fp != Q_NULLPTR;
+    return fp != nullptr;
 }
 
 inline bool QStorageIterator::next()
@@ -357,12 +357,12 @@ inline QStorageIterator::~QStorageIterator()
 
 inline bool QStorageIterator::isValid() const
 {
-    return fp != Q_NULLPTR;
+    return fp != nullptr;
 }
 
 inline bool QStorageIterator::next()
 {
-    return ::getmntent_r(fp, &mnt, buffer.data(), buffer.size()) != Q_NULLPTR;
+    return ::getmntent_r(fp, &mnt, buffer.data(), buffer.size()) != nullptr;
 }
 
 inline QString QStorageIterator::rootPath() const
diff --git a/src/corelib/io/qstorageinfo_win.cpp b/src/corelib/io/qstorageinfo_win.cpp
index 3830c5480c..8a3db90f87 100644
--- a/src/corelib/io/qstorageinfo_win.cpp
+++ b/src/corelib/io/qstorageinfo_win.cpp
@@ -147,8 +147,8 @@ void QStorageInfoPrivate::retrieveVolumeInfo()
     const bool result = ::GetVolumeInformation(reinterpret_cast<const wchar_t *>(path.utf16()),
                                                nameBuffer,
                                                defaultBufferSize,
-                                               Q_NULLPTR,
-                                               Q_NULLPTR,
+                                               nullptr,
+                                               nullptr,
                                                &fileSystemFlags,
                                                fileSystemTypeBuffer,
                                                defaultBufferSize);
diff --git a/src/corelib/io/qtextstream.h b/src/corelib/io/qtextstream.h
index e72b7942fd..ee0b09419d 100644
--- a/src/corelib/io/qtextstream.h
+++ b/src/corelib/io/qtextstream.h
@@ -212,8 +212,8 @@ typedef void (QTextStream::*QTSMFC)(QChar); // manipulator w/QChar argument
 class Q_CORE_EXPORT QTextStreamManipulator
 {
 public:
-    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFI m, int a) Q_DECL_NOTHROW : mf(m), mc(Q_NULLPTR), arg(a), ch() {}
-    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFC m, QChar c) Q_DECL_NOTHROW : mf(Q_NULLPTR), mc(m), arg(-1), ch(c) {}
+    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFI m, int a) Q_DECL_NOTHROW : mf(m), mc(nullptr), arg(a), ch() {}
+    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFC m, QChar c) Q_DECL_NOTHROW : mf(nullptr), mc(m), arg(-1), ch(c) {}
     void exec(QTextStream &s) { if (mf) { (s.*mf)(arg); } else { (s.*mc)(ch); } }
 
 private:
diff --git a/src/corelib/io/qurl.h b/src/corelib/io/qurl.h
index 0bb8707ff9..5062ef7905 100644
--- a/src/corelib/io/qurl.h
+++ b/src/corelib/io/qurl.h
@@ -184,7 +184,7 @@ public:
 #endif
 #ifdef Q_COMPILER_RVALUE_REFS
     QUrl(QUrl &&other) Q_DECL_NOTHROW : d(other.d)
-    { other.d = Q_NULLPTR; }
+    { other.d = nullptr; }
     inline QUrl &operator=(QUrl &&other) Q_DECL_NOTHROW
     { qSwap(d, other.d); return *this; }
 #endif
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index 48e0791cb5..d012be6c61 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -55,7 +55,7 @@ class Q_CORE_EXPORT QModelIndex
 {
     friend class QAbstractItemModel;
 public:
-    Q_DECL_CONSTEXPR inline QModelIndex() Q_DECL_NOTHROW : r(-1), c(-1), i(0), m(Q_NULLPTR) {}
+    Q_DECL_CONSTEXPR inline QModelIndex() Q_DECL_NOTHROW : r(-1), c(-1), i(0), m(nullptr) {}
     // compiler-generated copy/move ctors/assignment operators are fine!
     Q_DECL_CONSTEXPR inline int row() const Q_DECL_NOTHROW { return r; }
     Q_DECL_CONSTEXPR inline int column() const Q_DECL_NOTHROW { return c; }
@@ -69,7 +69,7 @@ public:
     inline QVariant data(int role = Qt::DisplayRole) const;
     inline Qt::ItemFlags flags() const;
     Q_DECL_CONSTEXPR inline const QAbstractItemModel *model() const Q_DECL_NOTHROW { return m; }
-    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW { return (r >= 0) && (c >= 0) && (m != Q_NULLPTR); }
+    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW { return (r >= 0) && (c >= 0) && (m != nullptr); }
     Q_DECL_CONSTEXPR inline bool operator==(const QModelIndex &other) const Q_DECL_NOTHROW
         { return (other.r == r) && (other.i == i) && (other.c == c) && (other.m == m); }
     Q_DECL_CONSTEXPR inline bool operator!=(const QModelIndex &other) const Q_DECL_NOTHROW
@@ -115,7 +115,7 @@ public:
     QPersistentModelIndex &operator=(const QPersistentModelIndex &other);
 #ifdef Q_COMPILER_RVALUE_REFS
     inline QPersistentModelIndex(QPersistentModelIndex &&other) Q_DECL_NOTHROW
-        : d(other.d) { other.d = Q_NULLPTR; }
+        : d(other.d) { other.d = nullptr; }
     inline QPersistentModelIndex &operator=(QPersistentModelIndex &&other) Q_DECL_NOTHROW
     { qSwap(d, other.d); return *this; }
 #endif
@@ -171,7 +171,7 @@ class Q_CORE_EXPORT QAbstractItemModel : public QObject
     friend class QIdentityProxyModel;
 public:
 
-    explicit QAbstractItemModel(QObject *parent = Q_NULLPTR);
+    explicit QAbstractItemModel(QObject *parent = nullptr);
     virtual ~QAbstractItemModel();
 
     Q_INVOKABLE bool hasIndex(int row, int column, const QModelIndex &parent = QModelIndex()) const;
@@ -286,9 +286,9 @@ protected Q_SLOTS:
     void resetInternalData();
 
 protected:
-    QAbstractItemModel(QAbstractItemModelPrivate &dd, QObject *parent = Q_NULLPTR);
+    QAbstractItemModel(QAbstractItemModelPrivate &dd, QObject *parent = nullptr);
 
-    inline QModelIndex createIndex(int row, int column, void *data = Q_NULLPTR) const;
+    inline QModelIndex createIndex(int row, int column, void *data = nullptr) const;
     inline QModelIndex createIndex(int row, int column, quintptr id) const;
 
     void encodeData(const QModelIndexList &indexes, QDataStream &stream) const;
@@ -367,7 +367,7 @@ class Q_CORE_EXPORT QAbstractTableModel : public QAbstractItemModel
     Q_OBJECT
 
 public:
-    explicit QAbstractTableModel(QObject *parent = Q_NULLPTR);
+    explicit QAbstractTableModel(QObject *parent = nullptr);
     ~QAbstractTableModel();
 
     QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
@@ -393,7 +393,7 @@ class Q_CORE_EXPORT QAbstractListModel : public QAbstractItemModel
     Q_OBJECT
 
 public:
-    explicit QAbstractListModel(QObject *parent = Q_NULLPTR);
+    explicit QAbstractListModel(QObject *parent = nullptr);
     ~QAbstractListModel();
 
     QModelIndex index(int row, int column = 0, const QModelIndex &parent = QModelIndex()) const override;
diff --git a/src/corelib/itemmodels/qabstractproxymodel.h b/src/corelib/itemmodels/qabstractproxymodel.h
index ed7bc91b79..6aa82b21ee 100644
--- a/src/corelib/itemmodels/qabstractproxymodel.h
+++ b/src/corelib/itemmodels/qabstractproxymodel.h
@@ -56,7 +56,7 @@ class Q_CORE_EXPORT QAbstractProxyModel : public QAbstractItemModel
     Q_PROPERTY(QAbstractItemModel* sourceModel READ sourceModel WRITE setSourceModel NOTIFY sourceModelChanged)
 
 public:
-    explicit QAbstractProxyModel(QObject *parent = Q_NULLPTR);
+    explicit QAbstractProxyModel(QObject *parent = nullptr);
     ~QAbstractProxyModel();
 
     virtual void setSourceModel(QAbstractItemModel *sourceModel);
diff --git a/src/corelib/itemmodels/qidentityproxymodel.h b/src/corelib/itemmodels/qidentityproxymodel.h
index 4c5f08f7d3..d2b1ed9498 100644
--- a/src/corelib/itemmodels/qidentityproxymodel.h
+++ b/src/corelib/itemmodels/qidentityproxymodel.h
@@ -54,7 +54,7 @@ class Q_CORE_EXPORT QIdentityProxyModel : public QAbstractProxyModel
 {
     Q_OBJECT
 public:
-    explicit QIdentityProxyModel(QObject* parent = Q_NULLPTR);
+    explicit QIdentityProxyModel(QObject* parent = nullptr);
     ~QIdentityProxyModel();
 
     int columnCount(const QModelIndex& parent = QModelIndex()) const override;
diff --git a/src/corelib/itemmodels/qitemselectionmodel.h b/src/corelib/itemmodels/qitemselectionmodel.h
index 9d33303ddc..091c5a21a5 100644
--- a/src/corelib/itemmodels/qitemselectionmodel.h
+++ b/src/corelib/itemmodels/qitemselectionmodel.h
@@ -164,7 +164,7 @@ public:
     Q_DECLARE_FLAGS(SelectionFlags, SelectionFlag)
     Q_FLAG(SelectionFlags)
 
-    explicit QItemSelectionModel(QAbstractItemModel *model = Q_NULLPTR);
+    explicit QItemSelectionModel(QAbstractItemModel *model = nullptr);
     explicit QItemSelectionModel(QAbstractItemModel *model, QObject *parent);
     virtual ~QItemSelectionModel();
 
diff --git a/src/corelib/itemmodels/qsortfilterproxymodel.h b/src/corelib/itemmodels/qsortfilterproxymodel.h
index 3c840406e0..2f93836544 100644
--- a/src/corelib/itemmodels/qsortfilterproxymodel.h
+++ b/src/corelib/itemmodels/qsortfilterproxymodel.h
@@ -70,7 +70,7 @@ class Q_CORE_EXPORT QSortFilterProxyModel : public QAbstractProxyModel
     Q_PROPERTY(bool recursiveFiltering READ recursiveFiltering WRITE setRecursiveFiltering)
 
 public:
-    explicit QSortFilterProxyModel(QObject *parent = Q_NULLPTR);
+    explicit QSortFilterProxyModel(QObject *parent = nullptr);
     ~QSortFilterProxyModel();
 
     void setSourceModel(QAbstractItemModel *sourceModel) override;
diff --git a/src/corelib/itemmodels/qstringlistmodel.h b/src/corelib/itemmodels/qstringlistmodel.h
index bd601e4f4e..38da1022ea 100644
--- a/src/corelib/itemmodels/qstringlistmodel.h
+++ b/src/corelib/itemmodels/qstringlistmodel.h
@@ -52,8 +52,8 @@ class Q_CORE_EXPORT QStringListModel : public QAbstractListModel
 {
     Q_OBJECT
 public:
-    explicit QStringListModel(QObject *parent = Q_NULLPTR);
-    explicit QStringListModel(const QStringList &strings, QObject *parent = Q_NULLPTR);
+    explicit QStringListModel(QObject *parent = nullptr);
+    explicit QStringListModel(const QStringList &strings, QObject *parent = nullptr);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     QModelIndex sibling(int row, int column, const QModelIndex &idx) const override;
diff --git a/src/corelib/json/qjsonarray.h b/src/corelib/json/qjsonarray.h
index ddba2ca78e..8d41138c97 100644
--- a/src/corelib/json/qjsonarray.h
+++ b/src/corelib/json/qjsonarray.h
@@ -133,7 +133,7 @@ public:
         typedef QJsonValueRef reference;
         typedef QJsonValueRefPtr pointer;
 
-        inline iterator() : a(Q_NULLPTR), i(0) { }
+        inline iterator() : a(nullptr), i(0) { }
         explicit inline iterator(QJsonArray *array, int index) : a(array), i(index) { }
 
         inline QJsonValueRef operator*() const { return QJsonValueRef(a, i); }
@@ -178,7 +178,7 @@ public:
         typedef QJsonValue reference;
         typedef QJsonValuePtr pointer;
 
-        inline const_iterator() : a(Q_NULLPTR), i(0) { }
+        inline const_iterator() : a(nullptr), i(0) { }
         explicit inline const_iterator(const QJsonArray *array, int index) : a(array), i(index) { }
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
         inline const_iterator(const const_iterator &o) : a(o.a), i(o.i) {} // ### Qt 6: Removed so class can be trivially-copyable
diff --git a/src/corelib/json/qjsondocument.h b/src/corelib/json/qjsondocument.h
index 4e76af21e2..e1730cf374 100644
--- a/src/corelib/json/qjsondocument.h
+++ b/src/corelib/json/qjsondocument.h
@@ -129,7 +129,7 @@ public:
         Compact
     };
 
-    static QJsonDocument fromJson(const QByteArray &json, QJsonParseError *error = Q_NULLPTR);
+    static QJsonDocument fromJson(const QByteArray &json, QJsonParseError *error = nullptr);
 
 #ifdef Q_QDOC
     QByteArray toJson(JsonFormat format = Indented) const;
diff --git a/src/corelib/json/qjsonobject.h b/src/corelib/json/qjsonobject.h
index c77e2164a8..610bce694c 100644
--- a/src/corelib/json/qjsonobject.h
+++ b/src/corelib/json/qjsonobject.h
@@ -135,7 +135,7 @@ public:
         typedef QJsonValueRef reference;
         typedef QJsonValuePtr pointer;
 
-        Q_DECL_CONSTEXPR inline iterator() : o(Q_NULLPTR), i(0) {}
+        Q_DECL_CONSTEXPR inline iterator() : o(nullptr), i(0) {}
         Q_DECL_CONSTEXPR inline iterator(QJsonObject *obj, int index) : o(obj), i(index) {}
 
         inline QString key() const { return o->keyAt(i); }
@@ -178,7 +178,7 @@ public:
         typedef QJsonValue reference;
         typedef QJsonValuePtr pointer;
 
-        Q_DECL_CONSTEXPR inline const_iterator() : o(Q_NULLPTR), i(0) {}
+        Q_DECL_CONSTEXPR inline const_iterator() : o(nullptr), i(0) {}
         Q_DECL_CONSTEXPR inline const_iterator(const QJsonObject *obj, int index)
             : o(obj), i(index) {}
         inline const_iterator(const iterator &other)
diff --git a/src/corelib/json/qjsonvalue.h b/src/corelib/json/qjsonvalue.h
index 5d5ec72605..96538ebbf9 100644
--- a/src/corelib/json/qjsonvalue.h
+++ b/src/corelib/json/qjsonvalue.h
@@ -82,7 +82,7 @@ public:
     QJsonValue(QLatin1String s);
 #ifndef QT_NO_CAST_FROM_ASCII
     inline QT_ASCII_CAST_WARN QJsonValue(const char *s)
-        : d(Q_NULLPTR), t(String) { stringDataFromQStringHelper(QString::fromUtf8(s)); }
+        : d(nullptr), t(String) { stringDataFromQStringHelper(QString::fromUtf8(s)); }
 #endif
     QJsonValue(const QJsonArray &a);
     QJsonValue(const QJsonObject &o);
diff --git a/src/corelib/kernel/qabstracteventdispatcher.h b/src/corelib/kernel/qabstracteventdispatcher.h
index 3a530cf1de..b84e047f3f 100644
--- a/src/corelib/kernel/qabstracteventdispatcher.h
+++ b/src/corelib/kernel/qabstracteventdispatcher.h
@@ -70,10 +70,10 @@ public:
         { }
     };
 
-    explicit QAbstractEventDispatcher(QObject *parent = Q_NULLPTR);
+    explicit QAbstractEventDispatcher(QObject *parent = nullptr);
     ~QAbstractEventDispatcher();
 
-    static QAbstractEventDispatcher *instance(QThread *thread = Q_NULLPTR);
+    static QAbstractEventDispatcher *instance(QThread *thread = nullptr);
 
     virtual bool processEvents(QEventLoop::ProcessEventsFlags flags) = 0;
     virtual bool hasPendingEvents() = 0; // ### Qt6: remove, mark final or make protected
@@ -112,7 +112,7 @@ public:
     bool filterNativeEvent(const QByteArray &eventType, void *message, long *result);
 #if QT_DEPRECATED_SINCE(5, 0)
     QT_DEPRECATED bool filterEvent(void *message)
-    { return filterNativeEvent("", message, Q_NULLPTR); }
+    { return filterNativeEvent("", message, nullptr); }
 #endif
 
 Q_SIGNALS:
diff --git a/src/corelib/kernel/qcore_unix.cpp b/src/corelib/kernel/qcore_unix.cpp
index 3b0da136ca..eb98cbef8f 100644
--- a/src/corelib/kernel/qcore_unix.cpp
+++ b/src/corelib/kernel/qcore_unix.cpp
@@ -130,7 +130,7 @@ int qt_safe_poll(struct pollfd *fds, nfds_t nfds, const struct timespec *timeout
     if (!timeout_ts) {
         // no timeout -> block forever
         int ret;
-        EINTR_LOOP(ret, qt_ppoll(fds, nfds, Q_NULLPTR));
+        EINTR_LOOP(ret, qt_ppoll(fds, nfds, nullptr));
         return ret;
     }
 
diff --git a/src/corelib/kernel/qcore_unix_p.h b/src/corelib/kernel/qcore_unix_p.h
index f78d2b9f24..e538a7e22b 100644
--- a/src/corelib/kernel/qcore_unix_p.h
+++ b/src/corelib/kernel/qcore_unix_p.h
@@ -362,7 +362,7 @@ Q_CORE_EXPORT int qt_safe_poll(struct pollfd *fds, nfds_t nfds, const struct tim
 
 static inline int qt_poll_msecs(struct pollfd *fds, nfds_t nfds, int timeout)
 {
-    timespec ts, *pts = Q_NULLPTR;
+    timespec ts, *pts = nullptr;
 
     if (timeout >= 0) {
         ts.tv_sec = timeout / 1000;
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 6b6009d757..19db06b015 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -426,7 +426,7 @@ QCoreApplicationPrivate::QCoreApplicationPrivate(int &aargc, char **aargv, uint
     , argv(aargv)
 #if defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
     , origArgc(0)
-    , origArgv(Q_NULLPTR)
+    , origArgv(nullptr)
 #endif
     , application_type(QCoreApplicationPrivate::Tty)
 #ifndef QT_NO_QOBJECT
diff --git a/src/corelib/kernel/qcoreapplication.h b/src/corelib/kernel/qcoreapplication.h
index f36c62845a..b4d83414ae 100644
--- a/src/corelib/kernel/qcoreapplication.h
+++ b/src/corelib/kernel/qcoreapplication.h
@@ -123,7 +123,7 @@ public:
 
     static bool sendEvent(QObject *receiver, QEvent *event);
     static void postEvent(QObject *receiver, QEvent *event, int priority = Qt::NormalEventPriority);
-    static void sendPostedEvents(QObject *receiver = Q_NULLPTR, int event_type = 0);
+    static void sendPostedEvents(QObject *receiver = nullptr, int event_type = 0);
     static void removePostedEvents(QObject *receiver, int eventType = 0);
 #if QT_DEPRECATED_SINCE(5, 3)
     QT_DEPRECATED static bool hasPendingEvents();
@@ -155,7 +155,7 @@ public:
 
     static QString translate(const char * context,
                              const char * key,
-                             const char * disambiguation = Q_NULLPTR,
+                             const char * disambiguation = nullptr,
                              int n = -1);
 #if QT_DEPRECATED_SINCE(5, 0)
     enum Encoding { UnicodeUTF8, Latin1, DefaultCodec = UnicodeUTF8, CodecForTr = UnicodeUTF8 };
@@ -241,13 +241,13 @@ inline bool QCoreApplication::sendSpontaneousEvent(QObject *receiver, QEvent *ev
 #  define QT_DECLARE_DEPRECATED_TR_FUNCTIONS(context)
 #else
 #  define QT_DECLARE_DEPRECATED_TR_FUNCTIONS(context) \
-    QT_DEPRECATED static inline QString trUtf8(const char *sourceText, const char *disambiguation = Q_NULLPTR, int n = -1) \
+    QT_DEPRECATED static inline QString trUtf8(const char *sourceText, const char *disambiguation = nullptr, int n = -1) \
         { return QCoreApplication::translate(#context, sourceText, disambiguation, n); }
 #endif
 
 #define Q_DECLARE_TR_FUNCTIONS(context) \
 public: \
-    static inline QString tr(const char *sourceText, const char *disambiguation = Q_NULLPTR, int n = -1) \
+    static inline QString tr(const char *sourceText, const char *disambiguation = nullptr, int n = -1) \
         { return QCoreApplication::translate(#context, sourceText, disambiguation, n); } \
     QT_DECLARE_DEPRECATED_TR_FUNCTIONS(context) \
 private:
diff --git a/src/corelib/kernel/qeventloop.h b/src/corelib/kernel/qeventloop.h
index 0cb431d7ce..eb1348220b 100644
--- a/src/corelib/kernel/qeventloop.h
+++ b/src/corelib/kernel/qeventloop.h
@@ -53,7 +53,7 @@ class Q_CORE_EXPORT QEventLoop : public QObject
     Q_DECLARE_PRIVATE(QEventLoop)
 
 public:
-    explicit QEventLoop(QObject *parent = Q_NULLPTR);
+    explicit QEventLoop(QObject *parent = nullptr);
     ~QEventLoop();
 
     enum ProcessEventsFlag {
diff --git a/src/corelib/kernel/qjni.cpp b/src/corelib/kernel/qjni.cpp
index 60154328c2..75a2436d9d 100644
--- a/src/corelib/kernel/qjni.cpp
+++ b/src/corelib/kernel/qjni.cpp
@@ -260,7 +260,7 @@ QJNIEnvironmentPrivate::QJNIEnvironmentPrivate()
         return;
 
     if (ret == JNI_EDETACHED) { // We need to (re-)attach
-        JavaVMAttachArgs args = { JNI_VERSION_1_6, qJniThreadName, Q_NULLPTR };
+        JavaVMAttachArgs args = { JNI_VERSION_1_6, qJniThreadName, nullptr };
         if (vm->AttachCurrentThread(&jniEnv, &args) != JNI_OK)
             return;
 
diff --git a/src/corelib/kernel/qjnihelpers.cpp b/src/corelib/kernel/qjnihelpers.cpp
index 02c58858ff..c7109a6506 100644
--- a/src/corelib/kernel/qjnihelpers.cpp
+++ b/src/corelib/kernel/qjnihelpers.cpp
@@ -64,14 +64,14 @@ namespace QtAndroidPrivate {
     KeyEventListener::~KeyEventListener() {}
 }
 
-static JavaVM *g_javaVM = Q_NULLPTR;
-static jobject g_jActivity = Q_NULLPTR;
-static jobject g_jService = Q_NULLPTR;
-static jobject g_jClassLoader = Q_NULLPTR;
+static JavaVM *g_javaVM = nullptr;
+static jobject g_jActivity = nullptr;
+static jobject g_jService = nullptr;
+static jobject g_jClassLoader = nullptr;
 static jint g_androidSdkVersion = 0;
-static jclass g_jNativeClass = Q_NULLPTR;
-static jmethodID g_runPendingCppRunnablesMethodID = Q_NULLPTR;
-static jmethodID g_hideSplashScreenMethodID = Q_NULLPTR;
+static jclass g_jNativeClass = nullptr;
+static jmethodID g_runPendingCppRunnablesMethodID = nullptr;
+static jmethodID g_hideSplashScreenMethodID = nullptr;
 Q_GLOBAL_STATIC(std::deque<QtAndroidPrivate::Runnable>, g_pendingRunnables);
 static QBasicMutex g_pendingRunnablesMutex;
 
diff --git a/src/corelib/kernel/qjnionload.cpp b/src/corelib/kernel/qjnionload.cpp
index 8f60800dba..0550b86553 100644
--- a/src/corelib/kernel/qjnionload.cpp
+++ b/src/corelib/kernel/qjnionload.cpp
@@ -61,7 +61,7 @@ Q_CORE_EXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved)
     __android_log_print(ANDROID_LOG_INFO, logTag, "Start");
 
     _JNIEnv uenv;
-    uenv.venv = Q_NULLPTR;
+    uenv.venv = nullptr;
 
     if (vm->GetEnv(&uenv.venv, JNI_VERSION_1_6) != JNI_OK)
     {
diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index f07b463482..f24a511295 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -1589,7 +1589,7 @@ bool QMetaObject::invokeMethodImpl(QObject *object, QtPrivate::QSlotObjectBase *
 */
 
 /*!
-    \fn bool QMetaObject::invokeMethod(QObject *receiver, PointerToMemberFunction function, Qt::ConnectionType type = Qt::AutoConnection, MemberFunctionReturnType *ret = Q_NULLPTR)
+    \fn bool QMetaObject::invokeMethod(QObject *receiver, PointerToMemberFunction function, Qt::ConnectionType type = Qt::AutoConnection, MemberFunctionReturnType *ret = nullptr)
 
     \since 5.10
 
@@ -1607,7 +1607,7 @@ bool QMetaObject::invokeMethodImpl(QObject *object, QtPrivate::QSlotObjectBase *
 */
 
 /*!
-    \fn bool QMetaObject::invokeMethod(QObject *context, Functor function, Qt::ConnectionType type = Qt::AutoConnection, FunctorReturnType *ret = Q_NULLPTR)
+    \fn bool QMetaObject::invokeMethod(QObject *context, Functor function, Qt::ConnectionType type = Qt::AutoConnection, FunctorReturnType *ret = nullptr)
 
     \since 5.10
 
@@ -1617,7 +1617,7 @@ bool QMetaObject::invokeMethodImpl(QObject *object, QtPrivate::QSlotObjectBase *
 */
 
 /*!
-    \fn bool QMetaObject::invokeMethod(QObject *context, Functor function, FunctorReturnType *ret = Q_NULLPTR)
+    \fn bool QMetaObject::invokeMethod(QObject *context, Functor function, FunctorReturnType *ret = nullptr)
 
     \since 5.10
 
diff --git a/src/corelib/kernel/qmetaobject.h b/src/corelib/kernel/qmetaobject.h
index 40b2aa6402..51df8faad3 100644
--- a/src/corelib/kernel/qmetaobject.h
+++ b/src/corelib/kernel/qmetaobject.h
@@ -54,7 +54,7 @@ template <typename T> class QList;
 class Q_CORE_EXPORT QMetaMethod
 {
 public:
-    Q_DECL_CONSTEXPR inline QMetaMethod() : mobj(Q_NULLPTR), handle(0) {}
+    Q_DECL_CONSTEXPR inline QMetaMethod() : mobj(nullptr), handle(0) {}
 
     QByteArray methodSignature() const;
     QByteArray name() const;
@@ -80,7 +80,7 @@ public:
     bool invoke(QObject *object,
                 Qt::ConnectionType connectionType,
                 QGenericReturnArgument returnValue,
-                QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                QGenericArgument val0 = QGenericArgument(nullptr),
                 QGenericArgument val1 = QGenericArgument(),
                 QGenericArgument val2 = QGenericArgument(),
                 QGenericArgument val3 = QGenericArgument(),
@@ -92,7 +92,7 @@ public:
                 QGenericArgument val9 = QGenericArgument()) const;
     inline bool invoke(QObject *object,
                        QGenericReturnArgument returnValue,
-                       QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                       QGenericArgument val0 = QGenericArgument(nullptr),
                        QGenericArgument val1 = QGenericArgument(),
                        QGenericArgument val2 = QGenericArgument(),
                        QGenericArgument val3 = QGenericArgument(),
@@ -108,7 +108,7 @@ public:
     }
     inline bool invoke(QObject *object,
                        Qt::ConnectionType connectionType,
-                       QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                       QGenericArgument val0 = QGenericArgument(nullptr),
                        QGenericArgument val1 = QGenericArgument(),
                        QGenericArgument val2 = QGenericArgument(),
                        QGenericArgument val3 = QGenericArgument(),
@@ -123,7 +123,7 @@ public:
                       val0, val1, val2, val3, val4, val5, val6, val7, val8, val9);
     }
     inline bool invoke(QObject *object,
-                       QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                       QGenericArgument val0 = QGenericArgument(nullptr),
                        QGenericArgument val1 = QGenericArgument(),
                        QGenericArgument val2 = QGenericArgument(),
                        QGenericArgument val3 = QGenericArgument(),
@@ -140,7 +140,7 @@ public:
 
     bool invokeOnGadget(void *gadget,
                 QGenericReturnArgument returnValue,
-                QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                QGenericArgument val0 = QGenericArgument(nullptr),
                 QGenericArgument val1 = QGenericArgument(),
                 QGenericArgument val2 = QGenericArgument(),
                 QGenericArgument val3 = QGenericArgument(),
@@ -151,7 +151,7 @@ public:
                 QGenericArgument val8 = QGenericArgument(),
                 QGenericArgument val9 = QGenericArgument()) const;
     inline bool invokeOnGadget(void *gadget,
-                       QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                       QGenericArgument val0 = QGenericArgument(nullptr),
                        QGenericArgument val1 = QGenericArgument(),
                        QGenericArgument val2 = QGenericArgument(),
                        QGenericArgument val3 = QGenericArgument(),
@@ -166,7 +166,7 @@ public:
                       val0, val1, val2, val3, val4, val5, val6, val7, val8, val9);
     }
 
-    inline bool isValid() const { return mobj != Q_NULLPTR; }
+    inline bool isValid() const { return mobj != nullptr; }
 
     template <typename PointerToMemberFunction>
     static inline QMetaMethod fromSignal(PointerToMemberFunction signal)
@@ -183,7 +183,7 @@ private:
     // signature() has been renamed to methodSignature() in Qt 5.
     // Warning, that function returns a QByteArray; check the life time if
     // you convert to char*.
-    char *signature(struct renamedInQt5_warning_checkTheLifeTime * = Q_NULLPTR) Q_DECL_EQ_DELETE;
+    char *signature(struct renamedInQt5_warning_checkTheLifeTime * = nullptr) Q_DECL_EQ_DELETE;
 #endif
     static QMetaMethod fromSignalImpl(const QMetaObject *, void **);
 
@@ -206,7 +206,7 @@ inline bool operator!=(const QMetaMethod &m1, const QMetaMethod &m2)
 class Q_CORE_EXPORT QMetaEnum
 {
 public:
-    Q_DECL_CONSTEXPR inline QMetaEnum() : mobj(Q_NULLPTR), handle(0) {}
+    Q_DECL_CONSTEXPR inline QMetaEnum() : mobj(nullptr), handle(0) {}
 
     const char *name() const;
     bool isFlag() const;
@@ -218,14 +218,14 @@ public:
 
     const char *scope() const;
 
-    int keyToValue(const char *key, bool *ok = Q_NULLPTR) const;
+    int keyToValue(const char *key, bool *ok = nullptr) const;
     const char* valueToKey(int value) const;
-    int keysToValue(const char * keys, bool *ok = Q_NULLPTR) const;
+    int keysToValue(const char * keys, bool *ok = nullptr) const;
     QByteArray valueToKeys(int value) const;
 
     inline const QMetaObject *enclosingMetaObject() const { return mobj; }
 
-    inline bool isValid() const { return name() != Q_NULLPTR; }
+    inline bool isValid() const { return name() != nullptr; }
 
     template<typename T> static QMetaEnum fromType() {
         Q_STATIC_ASSERT_X(QtPrivate::IsQEnumHelper<T>::Value,
@@ -256,11 +256,11 @@ public:
     bool isReadable() const;
     bool isWritable() const;
     bool isResettable() const;
-    bool isDesignable(const QObject *obj = Q_NULLPTR) const;
-    bool isScriptable(const QObject *obj = Q_NULLPTR) const;
-    bool isStored(const QObject *obj = Q_NULLPTR) const;
-    bool isEditable(const QObject *obj = Q_NULLPTR) const;
-    bool isUser(const QObject *obj = Q_NULLPTR) const;
+    bool isDesignable(const QObject *obj = nullptr) const;
+    bool isScriptable(const QObject *obj = nullptr) const;
+    bool isStored(const QObject *obj = nullptr) const;
+    bool isEditable(const QObject *obj = nullptr) const;
+    bool isUser(const QObject *obj = nullptr) const;
     bool isConstant() const;
     bool isFinal() const;
 
@@ -300,7 +300,7 @@ private:
 class Q_CORE_EXPORT QMetaClassInfo
 {
 public:
-    Q_DECL_CONSTEXPR inline QMetaClassInfo() : mobj(Q_NULLPTR), handle(0) {}
+    Q_DECL_CONSTEXPR inline QMetaClassInfo() : mobj(nullptr), handle(0) {}
     const char *name() const;
     const char *value() const;
     inline const QMetaObject *enclosingMetaObject() const { return mobj; }
diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index f704c5b21a..47c3a1c6f6 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -234,7 +234,7 @@ struct AbstractDebugStreamFunction
 {
     typedef void (*Stream)(const AbstractDebugStreamFunction *, QDebug&, const void *);
     typedef void (*Destroy)(AbstractDebugStreamFunction *);
-    explicit AbstractDebugStreamFunction(Stream s = Q_NULLPTR, Destroy d = Q_NULLPTR)
+    explicit AbstractDebugStreamFunction(Stream s = nullptr, Destroy d = nullptr)
         : stream(s), destroy(d) {}
     Q_DISABLE_COPY(AbstractDebugStreamFunction)
     Stream stream;
@@ -264,7 +264,7 @@ struct AbstractComparatorFunction
     typedef bool (*LessThan)(const AbstractComparatorFunction *, const void *, const void *);
     typedef bool (*Equals)(const AbstractComparatorFunction *, const void *, const void *);
     typedef void (*Destroy)(AbstractComparatorFunction *);
-    explicit AbstractComparatorFunction(LessThan lt = Q_NULLPTR, Equals e = Q_NULLPTR, Destroy d = Q_NULLPTR)
+    explicit AbstractComparatorFunction(LessThan lt = nullptr, Equals e = nullptr, Destroy d = nullptr)
         : lessThan(lt), equals(e), destroy(d) {}
     Q_DISABLE_COPY(AbstractComparatorFunction)
     LessThan lessThan;
@@ -301,7 +301,7 @@ template<typename T>
 struct BuiltInEqualsComparatorFunction : public AbstractComparatorFunction
 {
     BuiltInEqualsComparatorFunction()
-        : AbstractComparatorFunction(Q_NULLPTR, equals, destroy) {}
+        : AbstractComparatorFunction(nullptr, equals, destroy) {}
     static bool equals(const AbstractComparatorFunction *, const void *l, const void *r)
     {
         const T *lhs = static_cast<const T *>(l);
@@ -318,7 +318,7 @@ struct BuiltInEqualsComparatorFunction : public AbstractComparatorFunction
 struct AbstractConverterFunction
 {
     typedef bool (*Converter)(const AbstractConverterFunction *, const void *, void*);
-    explicit AbstractConverterFunction(Converter c = Q_NULLPTR)
+    explicit AbstractConverterFunction(Converter c = nullptr)
         : convert(c) {}
     Q_DISABLE_COPY(AbstractConverterFunction)
     Converter convert;
@@ -513,9 +513,9 @@ public:
     static TypeFlags typeFlags(int type);
     static const QMetaObject *metaObjectForType(int type);
     static bool isRegistered(int type);
-    static void *create(int type, const void *copy = Q_NULLPTR);
+    static void *create(int type, const void *copy = nullptr);
 #if QT_DEPRECATED_SINCE(5, 0)
-    QT_DEPRECATED static void *construct(int type, const void *copy = Q_NULLPTR)
+    QT_DEPRECATED static void *construct(int type, const void *copy = nullptr)
     { return create(type, copy); }
 #endif
     static void destroy(int type, void *data);
@@ -536,9 +536,9 @@ public:
     inline TypeFlags flags() const;
     inline const QMetaObject *metaObject() const;
 
-    inline void *create(const void *copy = Q_NULLPTR) const;
+    inline void *create(const void *copy = nullptr) const;
     inline void destroy(void *data) const;
-    inline void *construct(void *where, const void *copy = Q_NULLPTR) const;
+    inline void *construct(void *where, const void *copy = nullptr) const;
     inline void destruct(void *data) const;
 
 public:
@@ -617,7 +617,7 @@ public:
         return registerConverterFunction(&f, fromTypeId, toTypeId);
     }
 
-    // member function as in "double QString::toDouble(bool *ok = Q_NULLPTR) const"
+    // member function as in "double QString::toDouble(bool *ok = nullptr) const"
     template<typename From, typename To>
     static bool registerConverter(To(From::*function)(bool*) const)
     {
@@ -680,9 +680,9 @@ private:
     uint sizeExtended() const;
     QMetaType::TypeFlags flagsExtended() const;
     const QMetaObject *metaObjectExtended() const;
-    void *createExtended(const void *copy = Q_NULLPTR) const;
+    void *createExtended(const void *copy = nullptr) const;
     void destroyExtended(void *data) const;
-    void *constructExtended(void *where, const void *copy = Q_NULLPTR) const;
+    void *constructExtended(void *where, const void *copy = nullptr) const;
     void destructExtended(void *data) const;
 
     static bool registerComparatorFunction(const QtPrivate::AbstractComparatorFunction *f, int type);
@@ -782,7 +782,7 @@ struct QMetaTypeFunctionHelper {
 template <typename T>
 struct QMetaTypeFunctionHelper<T, /* Accepted */ false> {
     static void Destruct(void *) {}
-    static void *Construct(void *, const void *) { return Q_NULLPTR; }
+    static void *Construct(void *, const void *) { return nullptr; }
 #ifndef QT_NO_DATASTREAM
     static void Save(QDataStream &, const void *) {}
     static void Load(QDataStream &, void *) {}
@@ -1020,7 +1020,7 @@ public:
 public:
     template<class T> QSequentialIterableImpl(const T*p)
       : _iterable(p)
-      , _iterator(Q_NULLPTR)
+      , _iterator(nullptr)
       , _metaType_id(qMetaTypeId<typename T::value_type>())
       , _metaType_flags(QTypeInfo<typename T::value_type>::isPointer)
       , _iteratorCapabilities(ContainerAPI<T>::IteratorCapabilities)
@@ -1037,20 +1037,20 @@ public:
     }
 
     QSequentialIterableImpl()
-      : _iterable(Q_NULLPTR)
-      , _iterator(Q_NULLPTR)
+      : _iterable(nullptr)
+      , _iterator(nullptr)
       , _metaType_id(QMetaType::UnknownType)
       , _metaType_flags(0)
       , _iteratorCapabilities(0)
-      , _size(Q_NULLPTR)
-      , _at(Q_NULLPTR)
-      , _moveToBegin(Q_NULLPTR)
-      , _moveToEnd(Q_NULLPTR)
-      , _advance(Q_NULLPTR)
-      , _get(Q_NULLPTR)
-      , _destroyIter(Q_NULLPTR)
-      , _equalIter(Q_NULLPTR)
-      , _copyIter(Q_NULLPTR)
+      , _size(nullptr)
+      , _at(nullptr)
+      , _moveToBegin(nullptr)
+      , _moveToEnd(nullptr)
+      , _advance(nullptr)
+      , _get(nullptr)
+      , _destroyIter(nullptr)
+      , _equalIter(nullptr)
+      , _copyIter(nullptr)
     {
     }
 
@@ -1189,7 +1189,7 @@ public:
 public:
     template<class T> QAssociativeIterableImpl(const T*p)
       : _iterable(p)
-      , _iterator(Q_NULLPTR)
+      , _iterator(nullptr)
       , _metaType_id_key(qMetaTypeId<typename T::key_type>())
       , _metaType_flags_key(QTypeInfo<typename T::key_type>::isPointer)
       , _metaType_id_value(qMetaTypeId<typename T::mapped_type>())
@@ -1208,22 +1208,22 @@ public:
     }
 
     QAssociativeIterableImpl()
-      : _iterable(Q_NULLPTR)
-      , _iterator(Q_NULLPTR)
+      : _iterable(nullptr)
+      , _iterator(nullptr)
       , _metaType_id_key(QMetaType::UnknownType)
       , _metaType_flags_key(0)
       , _metaType_id_value(QMetaType::UnknownType)
       , _metaType_flags_value(0)
-      , _size(Q_NULLPTR)
-      , _find(Q_NULLPTR)
-      , _begin(Q_NULLPTR)
-      , _end(Q_NULLPTR)
-      , _advance(Q_NULLPTR)
-      , _getKey(Q_NULLPTR)
-      , _getValue(Q_NULLPTR)
-      , _destroyIter(Q_NULLPTR)
-      , _equalIter(Q_NULLPTR)
-      , _copyIter(Q_NULLPTR)
+      , _size(nullptr)
+      , _find(nullptr)
+      , _begin(nullptr)
+      , _end(nullptr)
+      , _advance(nullptr)
+      , _getKey(nullptr)
+      , _getValue(nullptr)
+      , _destroyIter(nullptr)
+      , _equalIter(nullptr)
+      , _copyIter(nullptr)
     {
     }
 
@@ -1292,13 +1292,13 @@ public:
     }
 
     QPairVariantInterfaceImpl()
-      : _pair(Q_NULLPTR)
+      : _pair(nullptr)
       , _metaType_id_first(QMetaType::UnknownType)
       , _metaType_flags_first(0)
       , _metaType_id_second(QMetaType::UnknownType)
       , _metaType_flags_second(0)
-      , _getFirst(Q_NULLPTR)
-      , _getSecond(Q_NULLPTR)
+      , _getFirst(nullptr)
+      , _getSecond(nullptr)
     {
     }
 
@@ -1374,7 +1374,7 @@ namespace QtPrivate
 #endif
         static no_type checkType(...);
         Q_STATIC_ASSERT_X(sizeof(T), "Type argument of Q_DECLARE_METATYPE(T*) must be fully defined");
-        enum { Value = sizeof(checkType(static_cast<T*>(Q_NULLPTR))) == sizeof(yes_type) };
+        enum { Value = sizeof(checkType(static_cast<T*>(nullptr))) == sizeof(yes_type) };
     };
 
     template<typename T, typename Enable = void>
@@ -1419,12 +1419,12 @@ namespace QtPrivate
     template<typename T, typename Enable = void>
     struct MetaObjectForType
     {
-        static inline const QMetaObject *value() { return Q_NULLPTR; }
+        static inline const QMetaObject *value() { return nullptr; }
     };
     template<>
     struct MetaObjectForType<void>
     {
-        static inline const QMetaObject *value() { return Q_NULLPTR; }
+        static inline const QMetaObject *value() { return nullptr; }
     };
     template<typename T>
     struct MetaObjectForType<T*, typename std::enable_if<IsPointerToTypeDerivedFromQObject<T*>::Value>::type>
@@ -1720,7 +1720,7 @@ int qRegisterNormalizedMetaType(const QT_PREPEND_NAMESPACE(QByteArray) &normaliz
 template <typename T>
 int qRegisterMetaType(const char *typeName
 #ifndef Q_QDOC
-    , T * dummy = Q_NULLPTR
+    , T * dummy = nullptr
     , typename QtPrivate::MetaTypeDefinedHelper<T, QMetaTypeId2<T>::Defined && !QMetaTypeId2<T>::IsBuiltIn>::DefinedType defined = QtPrivate::MetaTypeDefinedHelper<T, QMetaTypeId2<T>::Defined && !QMetaTypeId2<T>::IsBuiltIn>::Defined
 #endif
 )
@@ -1737,7 +1737,7 @@ int qRegisterMetaType(const char *typeName
 template <typename T>
 void qRegisterMetaTypeStreamOperators(const char *typeName
 #ifndef Q_QDOC
-    , T * /* dummy */ = Q_NULLPTR
+    , T * /* dummy */ = nullptr
 #endif
 )
 {
@@ -2150,7 +2150,7 @@ inline QMetaType::QMetaType(const ExtensionFlag extensionFlags, const QMetaTypeI
     , m_loadOp(loadOp)
     , m_constructor(constructor)
     , m_destructor(destructor)
-    , m_extension(Q_NULLPTR)
+    , m_extension(nullptr)
     , m_size(size)
     , m_typeFlags(theTypeFlags)
     , m_extensionFlags(extensionFlags)
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 3b0f7ead09..aa228af21a 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -998,7 +998,7 @@ QObject::~QObject()
             if (senderLists)
                 senderLists->dirty = true;
 
-            QtPrivate::QSlotObjectBase *slotObj = Q_NULLPTR;
+            QtPrivate::QSlotObjectBase *slotObj = nullptr;
             if (node->isSlotObject) {
                 slotObj = node->slotObj;
                 node->isSlotObject = false;
@@ -1468,14 +1468,14 @@ void QObject::moveToThread(QThread *targetThread)
     }
 
     QThreadData *currentData = QThreadData::current();
-    QThreadData *targetData = targetThread ? QThreadData::get2(targetThread) : Q_NULLPTR;
+    QThreadData *targetData = targetThread ? QThreadData::get2(targetThread) : nullptr;
     if (d->threadData->thread == 0 && currentData == targetData) {
         // one exception to the rule: we allow moving objects with no thread affinity to the current thread
         currentData = d->threadData;
     } else if (d->threadData != currentData) {
         qWarning("QObject::moveToThread: Current thread (%p) is not the object's thread (%p).\n"
                  "Cannot move to target thread (%p)\n",
-                 currentData->thread.load(), d->threadData->thread.load(), targetData ? targetData->thread.load() : Q_NULLPTR);
+                 currentData->thread.load(), d->threadData->thread.load(), targetData ? targetData->thread.load() : nullptr);
 
 #ifdef Q_OS_MAC
         qWarning("You might be loading two sets of Qt binaries into the same process. "
diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h
index 2e66daa914..d297109acb 100644
--- a/src/corelib/kernel/qobject.h
+++ b/src/corelib/kernel/qobject.h
@@ -120,23 +120,23 @@ class Q_CORE_EXPORT QObject
     Q_DECLARE_PRIVATE(QObject)
 
 public:
-    Q_INVOKABLE explicit QObject(QObject *parent=Q_NULLPTR);
+    Q_INVOKABLE explicit QObject(QObject *parent=nullptr);
     virtual ~QObject();
 
     virtual bool event(QEvent *event);
     virtual bool eventFilter(QObject *watched, QEvent *event);
 
 #ifdef Q_QDOC
-    static QString tr(const char *sourceText, const char *comment = Q_NULLPTR, int n = -1);
-    static QString trUtf8(const char *sourceText, const char *comment = Q_NULLPTR, int n = -1);
+    static QString tr(const char *sourceText, const char *comment = nullptr, int n = -1);
+    static QString trUtf8(const char *sourceText, const char *comment = nullptr, int n = -1);
     virtual const QMetaObject *metaObject() const;
     static const QMetaObject staticMetaObject;
 #endif
 #ifdef QT_NO_TRANSLATION
-    static QString tr(const char *sourceText, const char * = Q_NULLPTR, int = -1)
+    static QString tr(const char *sourceText, const char * = nullptr, int = -1)
         { return QString::fromUtf8(sourceText); }
 #if QT_DEPRECATED_SINCE(5, 0)
-    QT_DEPRECATED static QString trUtf8(const char *sourceText, const char * = Q_NULLPTR, int = -1)
+    QT_DEPRECATED static QString trUtf8(const char *sourceText, const char * = nullptr, int = -1)
         { return QString::fromUtf8(sourceText); }
 #endif
 #endif //QT_NO_TRANSLATION
@@ -248,7 +248,7 @@ public:
         Q_STATIC_ASSERT_X((QtPrivate::AreArgumentsCompatible<typename SlotType::ReturnType, typename SignalType::ReturnType>::value),
                           "Return type of the slot is not compatible with the return type of the signal.");
 
-        const int *types = Q_NULLPTR;
+        const int *types = nullptr;
         if (type == Qt::QueuedConnection || type == Qt::BlockingQueuedConnection)
             types = QtPrivate::ConnectionTypes<typename SignalType::Arguments>::types();
 
@@ -288,11 +288,11 @@ public:
         Q_STATIC_ASSERT_X((QtPrivate::AreArgumentsCompatible<typename SlotType::ReturnType, typename SignalType::ReturnType>::value),
                           "Return type of the slot is not compatible with the return type of the signal.");
 
-        const int *types = Q_NULLPTR;
+        const int *types = nullptr;
         if (type == Qt::QueuedConnection || type == Qt::BlockingQueuedConnection)
             types = QtPrivate::ConnectionTypes<typename SignalType::Arguments>::types();
 
-        return connectImpl(sender, reinterpret_cast<void **>(&signal), context, Q_NULLPTR,
+        return connectImpl(sender, reinterpret_cast<void **>(&signal), context, nullptr,
                            new QtPrivate::QStaticSlotObject<Func2,
                                                  typename QtPrivate::List_Left<typename SignalType::Arguments, SlotType::ArgumentCount>::Value,
                                                  typename SignalType::ReturnType>(slot),
@@ -327,11 +327,11 @@ public:
         Q_STATIC_ASSERT_X(QtPrivate::HasQ_OBJECT_Macro<typename SignalType::Object>::Value,
                           "No Q_OBJECT in the class with the signal");
 
-        const int *types = Q_NULLPTR;
+        const int *types = nullptr;
         if (type == Qt::QueuedConnection || type == Qt::BlockingQueuedConnection)
             types = QtPrivate::ConnectionTypes<typename SignalType::Arguments>::types();
 
-        return connectImpl(sender, reinterpret_cast<void **>(&signal), context, Q_NULLPTR,
+        return connectImpl(sender, reinterpret_cast<void **>(&signal), context, nullptr,
                            new QtPrivate::QFunctorSlotObject<Func2, SlotArgumentCount,
                                 typename QtPrivate::List_Left<typename SignalType::Arguments, SlotArgumentCount>::Value,
                                 typename SignalType::ReturnType>(std::move(slot)),
@@ -343,11 +343,11 @@ public:
                            const QObject *receiver, const char *member);
     static bool disconnect(const QObject *sender, const QMetaMethod &signal,
                            const QObject *receiver, const QMetaMethod &member);
-    inline bool disconnect(const char *signal = Q_NULLPTR,
-                           const QObject *receiver = Q_NULLPTR, const char *member = Q_NULLPTR) const
+    inline bool disconnect(const char *signal = nullptr,
+                           const QObject *receiver = nullptr, const char *member = nullptr) const
         { return disconnect(this, signal, receiver, member); }
-    inline bool disconnect(const QObject *receiver, const char *member = Q_NULLPTR) const
-        { return disconnect(this, Q_NULLPTR, receiver, member); }
+    inline bool disconnect(const QObject *receiver, const char *member = nullptr) const
+        { return disconnect(this, nullptr, receiver, member); }
     static bool disconnect(const QMetaObject::Connection &);
 
 #ifdef Q_QDOC
@@ -375,7 +375,7 @@ public:
     static inline bool disconnect(const typename QtPrivate::FunctionPointer<Func1>::Object *sender, Func1 signal,
                                   const QObject *receiver, void **zero)
     {
-        // This is the overload for when one wish to disconnect a signal from any slot. (slot=Q_NULLPTR)
+        // This is the overload for when one wish to disconnect a signal from any slot. (slot=nullptr)
         // Since the function template parameter cannot be deduced from '0', we use a
         // dummy void ** parameter that must be equal to 0
         Q_ASSERT(!zero);
@@ -406,14 +406,14 @@ public:
 #endif // QT_NO_USERDATA
 
 Q_SIGNALS:
-    void destroyed(QObject * = Q_NULLPTR);
+    void destroyed(QObject * = nullptr);
     void objectNameChanged(const QString &objectName, QPrivateSignal);
 
 public:
     inline QObject *parent() const { return d_ptr->parent; }
 
     inline bool inherits(const char *classname) const
-        { return const_cast<QObject *>(this)->qt_metacast(classname) != Q_NULLPTR; }
+        { return const_cast<QObject *>(this)->qt_metacast(classname) != nullptr; }
 
 public Q_SLOTS:
     void deleteLater();
@@ -432,7 +432,7 @@ protected:
     virtual void disconnectNotify(const QMetaMethod &signal);
 
 protected:
-    QObject(QObjectPrivate &dd, QObject *parent = Q_NULLPTR);
+    QObject(QObjectPrivate &dd, QObject *parent = nullptr);
 
 protected:
     QScopedPointer<QObjectData> d_ptr;
@@ -525,16 +525,16 @@ inline T qobject_cast(const QObject *object)
 
 
 template <class T> inline const char * qobject_interface_iid()
-{ return Q_NULLPTR; }
+{ return nullptr; }
 
 #ifndef Q_MOC_RUN
 #  define Q_DECLARE_INTERFACE(IFace, IId) \
     template <> inline const char *qobject_interface_iid<IFace *>() \
     { return IId; } \
     template <> inline IFace *qobject_cast<IFace *>(QObject *object) \
-    { return reinterpret_cast<IFace *>((object ? object->qt_metacast(IId) : Q_NULLPTR)); } \
+    { return reinterpret_cast<IFace *>((object ? object->qt_metacast(IId) : nullptr)); } \
     template <> inline IFace *qobject_cast<IFace *>(const QObject *object) \
-    { return reinterpret_cast<IFace *>((object ? const_cast<QObject *>(object)->qt_metacast(IId) : Q_NULLPTR)); }
+    { return reinterpret_cast<IFace *>((object ? const_cast<QObject *>(object)->qt_metacast(IId) : nullptr)); }
 #endif // Q_MOC_RUN
 
 #ifndef QT_NO_DEBUG_STREAM
@@ -580,7 +580,7 @@ QSignalBlocker::QSignalBlocker(QSignalBlocker &&other) Q_DECL_NOTHROW
       m_blocked(other.m_blocked),
       m_inhibited(other.m_inhibited)
 {
-    other.m_o = Q_NULLPTR;
+    other.m_o = nullptr;
 }
 
 QSignalBlocker &QSignalBlocker::operator=(QSignalBlocker &&other) Q_DECL_NOTHROW
@@ -594,7 +594,7 @@ QSignalBlocker &QSignalBlocker::operator=(QSignalBlocker &&other) Q_DECL_NOTHROW
         m_blocked = other.m_blocked;
         m_inhibited = other.m_inhibited;
         // disable other:
-        other.m_o = Q_NULLPTR;
+        other.m_o = nullptr;
     }
     return *this;
 }
diff --git a/src/corelib/kernel/qobject_impl.h b/src/corelib/kernel/qobject_impl.h
index c775d807b1..1a14b93dcd 100644
--- a/src/corelib/kernel/qobject_impl.h
+++ b/src/corelib/kernel/qobject_impl.h
@@ -68,9 +68,9 @@ namespace QtPrivate {
     { enum { Value = QMetaTypeId2<Arg>::Defined && TypesAreDeclaredMetaType<List<Tail...>>::Value }; };
 
     template <typename ArgList, bool Declared = TypesAreDeclaredMetaType<ArgList>::Value > struct ConnectionTypes
-    { static const int *types() { return Q_NULLPTR; } };
+    { static const int *types() { return nullptr; } };
     template <> struct ConnectionTypes<List<>, true>
-    { static const int *types() { return Q_NULLPTR; } };
+    { static const int *types() { return nullptr; } };
     template <typename... Args> struct ConnectionTypes<List<Args...>, true>
     { static const int *types() { static const int t[sizeof...(Args) + 1] = { (QtPrivate::QMetaTypeIdHelper<Args>::qt_metatype_id())..., 0 }; return t; } };
 
diff --git a/src/corelib/kernel/qobjectdefs.h b/src/corelib/kernel/qobjectdefs.h
index 5fc8937f23..6cd0e82a86 100644
--- a/src/corelib/kernel/qobjectdefs.h
+++ b/src/corelib/kernel/qobjectdefs.h
@@ -137,9 +137,9 @@ class QString;
 #ifndef QT_NO_TRANSLATION
 // full set of tr functions
 #  define QT_TR_FUNCTIONS \
-    static inline QString tr(const char *s, const char *c = Q_NULLPTR, int n = -1) \
+    static inline QString tr(const char *s, const char *c = nullptr, int n = -1) \
         { return staticMetaObject.tr(s, c, n); } \
-    QT_DEPRECATED static inline QString trUtf8(const char *s, const char *c = Q_NULLPTR, int n = -1) \
+    QT_DEPRECATED static inline QString trUtf8(const char *s, const char *c = nullptr, int n = -1) \
         { return staticMetaObject.tr(s, c, n); }
 #else
 // inherit the ones from QObject
@@ -294,7 +294,7 @@ class QMetaClassInfo;
 class Q_CORE_EXPORT QGenericArgument
 {
 public:
-    inline QGenericArgument(const char *aName = Q_NULLPTR, const void *aData = Q_NULLPTR)
+    inline QGenericArgument(const char *aName = nullptr, const void *aData = nullptr)
         : _data(aData), _name(aName) {}
     inline void *data() const { return const_cast<void *>(_data); }
     inline const char *name() const { return _name; }
@@ -307,7 +307,7 @@ private:
 class Q_CORE_EXPORT QGenericReturnArgument: public QGenericArgument
 {
 public:
-    inline QGenericReturnArgument(const char *aName = Q_NULLPTR, void *aData = Q_NULLPTR)
+    inline QGenericReturnArgument(const char *aName = nullptr, void *aData = nullptr)
         : QGenericArgument(aName, aData)
         {}
 };
@@ -388,7 +388,7 @@ struct Q_CORE_EXPORT QMetaObject
     // internal index-based connect
     static Connection connect(const QObject *sender, int signal_index,
                         const QObject *receiver, int method_index,
-                        int type = 0, int *types = Q_NULLPTR);
+                        int type = 0, int *types = nullptr);
     // internal index-based disconnect
     static bool disconnect(const QObject *sender, int signal_index,
                            const QObject *receiver, int method_index);
@@ -405,7 +405,7 @@ struct Q_CORE_EXPORT QMetaObject
     static bool invokeMethod(QObject *obj, const char *member,
                              Qt::ConnectionType,
                              QGenericReturnArgument ret,
-                             QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                             QGenericArgument val0 = QGenericArgument(nullptr),
                              QGenericArgument val1 = QGenericArgument(),
                              QGenericArgument val2 = QGenericArgument(),
                              QGenericArgument val3 = QGenericArgument(),
@@ -418,7 +418,7 @@ struct Q_CORE_EXPORT QMetaObject
 
     static inline bool invokeMethod(QObject *obj, const char *member,
                              QGenericReturnArgument ret,
-                             QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                             QGenericArgument val0 = QGenericArgument(nullptr),
                              QGenericArgument val1 = QGenericArgument(),
                              QGenericArgument val2 = QGenericArgument(),
                              QGenericArgument val3 = QGenericArgument(),
@@ -435,7 +435,7 @@ struct Q_CORE_EXPORT QMetaObject
 
     static inline bool invokeMethod(QObject *obj, const char *member,
                              Qt::ConnectionType type,
-                             QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                             QGenericArgument val0 = QGenericArgument(nullptr),
                              QGenericArgument val1 = QGenericArgument(),
                              QGenericArgument val2 = QGenericArgument(),
                              QGenericArgument val3 = QGenericArgument(),
@@ -451,7 +451,7 @@ struct Q_CORE_EXPORT QMetaObject
     }
 
     static inline bool invokeMethod(QObject *obj, const char *member,
-                             QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+                             QGenericArgument val0 = QGenericArgument(nullptr),
                              QGenericArgument val1 = QGenericArgument(),
                              QGenericArgument val2 = QGenericArgument(),
                              QGenericArgument val3 = QGenericArgument(),
@@ -551,7 +551,7 @@ struct Q_CORE_EXPORT QMetaObject
 
 #endif
 
-    QObject *newInstance(QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
+    QObject *newInstance(QGenericArgument val0 = QGenericArgument(nullptr),
                          QGenericArgument val1 = QGenericArgument(),
                          QGenericArgument val2 = QGenericArgument(),
                          QGenericArgument val3 = QGenericArgument(),
@@ -611,11 +611,11 @@ public:
     operator bool() const;
 #else
     typedef void *Connection::*RestrictedBool;
-    operator RestrictedBool() const { return d_ptr && isConnected_helper() ? &Connection::d_ptr : Q_NULLPTR; }
+    operator RestrictedBool() const { return d_ptr && isConnected_helper() ? &Connection::d_ptr : nullptr; }
 #endif
 
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline Connection(Connection &&o) : d_ptr(o.d_ptr) { o.d_ptr = Q_NULLPTR; }
+    inline Connection(Connection &&o) : d_ptr(o.d_ptr) { o.d_ptr = nullptr; }
     inline Connection &operator=(Connection &&other)
     { qSwap(d_ptr, other.d_ptr); return *this; }
 #endif
diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h
index b9f2e47e32..17872d830e 100644
--- a/src/corelib/kernel/qobjectdefs_impl.h
+++ b/src/corelib/kernel/qobjectdefs_impl.h
@@ -372,10 +372,10 @@ namespace QtPrivate {
 
         inline int ref() Q_DECL_NOTHROW { return m_ref.ref(); }
         inline void destroyIfLastRef() Q_DECL_NOTHROW
-        { if (!m_ref.deref()) m_impl(Destroy, this, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR); }
+        { if (!m_ref.deref()) m_impl(Destroy, this, nullptr, nullptr, nullptr); }
 
-        inline bool compare(void **a) { bool ret = false; m_impl(Compare, this, Q_NULLPTR, a, &ret); return ret; }
-        inline void call(QObject *r, void **a)  { m_impl(Call,    this, r, a, Q_NULLPTR); }
+        inline bool compare(void **a) { bool ret = false; m_impl(Compare, this, nullptr, a, &ret); return ret; }
+        inline void call(QObject *r, void **a)  { m_impl(Call,    this, r, a, nullptr); }
     protected:
         ~QSlotObjectBase() {}
     private:
diff --git a/src/corelib/kernel/qsharedmemory.h b/src/corelib/kernel/qsharedmemory.h
index 0d4edef23d..67cf52ac17 100644
--- a/src/corelib/kernel/qsharedmemory.h
+++ b/src/corelib/kernel/qsharedmemory.h
@@ -74,8 +74,8 @@ public:
         UnknownError
     };
 
-    QSharedMemory(QObject *parent = Q_NULLPTR);
-    QSharedMemory(const QString &key, QObject *parent = Q_NULLPTR);
+    QSharedMemory(QObject *parent = nullptr);
+    QSharedMemory(const QString &key, QObject *parent = nullptr);
     ~QSharedMemory();
 
     void setKey(const QString &key);
diff --git a/src/corelib/kernel/qsocketnotifier.h b/src/corelib/kernel/qsocketnotifier.h
index 360e93a5fb..38e5f27247 100644
--- a/src/corelib/kernel/qsocketnotifier.h
+++ b/src/corelib/kernel/qsocketnotifier.h
@@ -53,7 +53,7 @@ class Q_CORE_EXPORT QSocketNotifier : public QObject
 public:
     enum Type { Read, Write, Exception };
 
-    QSocketNotifier(qintptr socket, Type, QObject *parent = Q_NULLPTR);
+    QSocketNotifier(qintptr socket, Type, QObject *parent = nullptr);
     ~QSocketNotifier();
 
     qintptr socket() const;
diff --git a/src/corelib/kernel/qtimer.h b/src/corelib/kernel/qtimer.h
index 6790841f8e..1a65e6298d 100644
--- a/src/corelib/kernel/qtimer.h
+++ b/src/corelib/kernel/qtimer.h
@@ -63,7 +63,7 @@ class Q_CORE_EXPORT QTimer : public QObject
     Q_PROPERTY(Qt::TimerType timerType READ timerType WRITE setTimerType)
     Q_PROPERTY(bool active READ isActive)
 public:
-    explicit QTimer(QObject *parent = Q_NULLPTR);
+    explicit QTimer(QObject *parent = nullptr);
     ~QTimer();
 
     inline bool isActive() const { return id >= 0; }
diff --git a/src/corelib/kernel/qtranslator.h b/src/corelib/kernel/qtranslator.h
index 97be16bc90..e7c39191e7 100644
--- a/src/corelib/kernel/qtranslator.h
+++ b/src/corelib/kernel/qtranslator.h
@@ -55,11 +55,11 @@ class Q_CORE_EXPORT QTranslator : public QObject
 {
     Q_OBJECT
 public:
-    explicit QTranslator(QObject *parent = Q_NULLPTR);
+    explicit QTranslator(QObject *parent = nullptr);
     ~QTranslator();
 
     virtual QString translate(const char *context, const char *sourceText,
-                              const char *disambiguation = Q_NULLPTR, int n = -1) const;
+                              const char *disambiguation = nullptr, int n = -1) const;
 
     virtual bool isEmpty() const;
 
diff --git a/src/corelib/kernel/qvariant.h b/src/corelib/kernel/qvariant.h
index a2c5711993..6d4c163e76 100644
--- a/src/corelib/kernel/qvariant.h
+++ b/src/corelib/kernel/qvariant.h
@@ -284,14 +284,14 @@ class Q_CORE_EXPORT QVariant
     void detach();
     inline bool isDetached() const;
 
-    int toInt(bool *ok = Q_NULLPTR) const;
-    uint toUInt(bool *ok = Q_NULLPTR) const;
-    qlonglong toLongLong(bool *ok = Q_NULLPTR) const;
-    qulonglong toULongLong(bool *ok = Q_NULLPTR) const;
+    int toInt(bool *ok = nullptr) const;
+    uint toUInt(bool *ok = nullptr) const;
+    qlonglong toLongLong(bool *ok = nullptr) const;
+    qulonglong toULongLong(bool *ok = nullptr) const;
     bool toBool() const;
-    double toDouble(bool *ok = Q_NULLPTR) const;
-    float toFloat(bool *ok = Q_NULLPTR) const;
-    qreal toReal(bool *ok = Q_NULLPTR) const;
+    double toDouble(bool *ok = nullptr) const;
+    float toFloat(bool *ok = nullptr) const;
+    qreal toReal(bool *ok = nullptr) const;
     QByteArray toByteArray() const;
     QBitArray toBitArray() const;
     QString toString() const;
@@ -370,7 +370,7 @@ class Q_CORE_EXPORT QVariant
     struct Private
     {
         inline Private() Q_DECL_NOTHROW : type(Invalid), is_shared(false), is_null(true)
-        { data.ptr = Q_NULLPTR; }
+        { data.ptr = nullptr; }
 
         // Internal constructor for initialized variants.
         explicit inline Private(uint variantType) Q_DECL_NOTHROW
diff --git a/src/corelib/kernel/qwineventnotifier.h b/src/corelib/kernel/qwineventnotifier.h
index f29f325d13..624e77e638 100644
--- a/src/corelib/kernel/qwineventnotifier.h
+++ b/src/corelib/kernel/qwineventnotifier.h
@@ -54,8 +54,8 @@ class Q_CORE_EXPORT QWinEventNotifier : public QObject
     typedef Qt::HANDLE HANDLE;
 
 public:
-    explicit QWinEventNotifier(QObject *parent = Q_NULLPTR);
-    explicit QWinEventNotifier(HANDLE hEvent, QObject *parent = Q_NULLPTR);
+    explicit QWinEventNotifier(QObject *parent = nullptr);
+    explicit QWinEventNotifier(HANDLE hEvent, QObject *parent = nullptr);
     ~QWinEventNotifier();
 
     void setHandle(HANDLE hEvent);
diff --git a/src/corelib/mimetypes/qmimemagicrule_p.h b/src/corelib/mimetypes/qmimemagicrule_p.h
index 0c6c1dbcd7..9b27ef2657 100644
--- a/src/corelib/mimetypes/qmimemagicrule_p.h
+++ b/src/corelib/mimetypes/qmimemagicrule_p.h
@@ -90,7 +90,7 @@ public:
     int endPos() const { return m_endPos; }
     QByteArray mask() const;
 
-    bool isValid() const { return m_matchFunction != Q_NULLPTR; }
+    bool isValid() const { return m_matchFunction != nullptr; }
 
     bool matches(const QByteArray &data) const;
 
diff --git a/src/corelib/plugin/qlibrary.h b/src/corelib/plugin/qlibrary.h
index 89be52aac3..0b37b8b134 100644
--- a/src/corelib/plugin/qlibrary.h
+++ b/src/corelib/plugin/qlibrary.h
@@ -65,10 +65,10 @@ public:
     Q_FLAG(LoadHint)
     Q_FLAG(LoadHints)
 
-    explicit QLibrary(QObject *parent = Q_NULLPTR);
-    explicit QLibrary(const QString& fileName, QObject *parent = Q_NULLPTR);
-    explicit QLibrary(const QString& fileName, int verNum, QObject *parent = Q_NULLPTR);
-    explicit QLibrary(const QString& fileName, const QString &version, QObject *parent = Q_NULLPTR);
+    explicit QLibrary(QObject *parent = nullptr);
+    explicit QLibrary(const QString& fileName, QObject *parent = nullptr);
+    explicit QLibrary(const QString& fileName, int verNum, QObject *parent = nullptr);
+    explicit QLibrary(const QString& fileName, const QString &version, QObject *parent = nullptr);
     ~QLibrary();
 
     QFunctionPointer resolve(const char *symbol);
diff --git a/src/corelib/plugin/qpluginloader.h b/src/corelib/plugin/qpluginloader.h
index 80b10f76bf..5e417249a4 100644
--- a/src/corelib/plugin/qpluginloader.h
+++ b/src/corelib/plugin/qpluginloader.h
@@ -59,8 +59,8 @@ class Q_CORE_EXPORT QPluginLoader : public QObject
     Q_PROPERTY(QString fileName READ fileName WRITE setFileName)
     Q_PROPERTY(QLibrary::LoadHints loadHints READ loadHints WRITE setLoadHints)
 public:
-    explicit QPluginLoader(QObject *parent = Q_NULLPTR);
-    explicit QPluginLoader(const QString &fileName, QObject *parent = Q_NULLPTR);
+    explicit QPluginLoader(QObject *parent = nullptr);
+    explicit QPluginLoader(const QString &fileName, QObject *parent = nullptr);
     ~QPluginLoader();
 
     QObject *instance();
diff --git a/src/corelib/statemachine/qabstractstate.h b/src/corelib/statemachine/qabstractstate.h
index fa735ea33d..ffc2eaae13 100644
--- a/src/corelib/statemachine/qabstractstate.h
+++ b/src/corelib/statemachine/qabstractstate.h
@@ -68,7 +68,7 @@ Q_SIGNALS:
     void activeChanged(bool active);
 
 protected:
-    QAbstractState(QState *parent = Q_NULLPTR);
+    QAbstractState(QState *parent = nullptr);
 
     virtual void onEntry(QEvent *event) = 0;
     virtual void onExit(QEvent *event) = 0;
diff --git a/src/corelib/statemachine/qabstracttransition.cpp b/src/corelib/statemachine/qabstracttransition.cpp
index 53c713d6a8..272e681fb4 100644
--- a/src/corelib/statemachine/qabstracttransition.cpp
+++ b/src/corelib/statemachine/qabstracttransition.cpp
@@ -258,7 +258,7 @@ void QAbstractTransition::setTargetStates(const QList<QAbstractState*> &targets)
 
     // Verify if any of the new target states is a null-pointer:
     for (int i = 0; i < targets.size(); ++i) {
-        if (targets.at(i) == Q_NULLPTR) {
+        if (targets.at(i) == nullptr) {
             qWarning("QAbstractTransition::setTargetStates: target state(s) cannot be null");
             return;
         }
diff --git a/src/corelib/statemachine/qabstracttransition.h b/src/corelib/statemachine/qabstracttransition.h
index ec81b8ec2e..9b35e0cdb6 100644
--- a/src/corelib/statemachine/qabstracttransition.h
+++ b/src/corelib/statemachine/qabstracttransition.h
@@ -72,7 +72,7 @@ public:
     };
     Q_ENUM(TransitionType)
 
-    QAbstractTransition(QState *sourceState = Q_NULLPTR);
+    QAbstractTransition(QState *sourceState = nullptr);
     virtual ~QAbstractTransition();
 
     QState *sourceState() const;
diff --git a/src/corelib/statemachine/qeventtransition.h b/src/corelib/statemachine/qeventtransition.h
index 53f3b4cd36..ff4a991162 100644
--- a/src/corelib/statemachine/qeventtransition.h
+++ b/src/corelib/statemachine/qeventtransition.h
@@ -54,8 +54,8 @@ class Q_CORE_EXPORT QEventTransition : public QAbstractTransition
     Q_PROPERTY(QObject* eventSource READ eventSource WRITE setEventSource)
     Q_PROPERTY(QEvent::Type eventType READ eventType WRITE setEventType)
 public:
-    QEventTransition(QState *sourceState = Q_NULLPTR);
-    QEventTransition(QObject *object, QEvent::Type type, QState *sourceState = Q_NULLPTR);
+    QEventTransition(QState *sourceState = nullptr);
+    QEventTransition(QObject *object, QEvent::Type type, QState *sourceState = nullptr);
     ~QEventTransition();
 
     QObject *eventSource() const;
diff --git a/src/corelib/statemachine/qfinalstate.h b/src/corelib/statemachine/qfinalstate.h
index 3e7a844653..1e52a0411d 100644
--- a/src/corelib/statemachine/qfinalstate.h
+++ b/src/corelib/statemachine/qfinalstate.h
@@ -51,7 +51,7 @@ class Q_CORE_EXPORT QFinalState : public QAbstractState
 {
     Q_OBJECT
 public:
-    QFinalState(QState *parent = Q_NULLPTR);
+    QFinalState(QState *parent = nullptr);
     ~QFinalState();
 
 protected:
diff --git a/src/corelib/statemachine/qhistorystate.cpp b/src/corelib/statemachine/qhistorystate.cpp
index a179d7c75b..d4fb214a31 100644
--- a/src/corelib/statemachine/qhistorystate.cpp
+++ b/src/corelib/statemachine/qhistorystate.cpp
@@ -203,7 +203,7 @@ void QHistoryState::setDefaultTransition(QAbstractTransition *transition)
 QAbstractState *QHistoryState::defaultState() const
 {
     Q_D(const QHistoryState);
-    return d->defaultTransition ? d->defaultTransition->targetState() : Q_NULLPTR;
+    return d->defaultTransition ? d->defaultTransition->targetState() : nullptr;
 }
 
 static inline bool isSoleEntry(const QList<QAbstractState*> &states, const QAbstractState * state)
diff --git a/src/corelib/statemachine/qhistorystate.h b/src/corelib/statemachine/qhistorystate.h
index e531a2d9fb..44f4c5d6d4 100644
--- a/src/corelib/statemachine/qhistorystate.h
+++ b/src/corelib/statemachine/qhistorystate.h
@@ -61,8 +61,8 @@ public:
     };
     Q_ENUM(HistoryType)
 
-    QHistoryState(QState *parent = Q_NULLPTR);
-    QHistoryState(HistoryType type, QState *parent = Q_NULLPTR);
+    QHistoryState(QState *parent = nullptr);
+    QHistoryState(HistoryType type, QState *parent = nullptr);
     ~QHistoryState();
 
     QAbstractTransition *defaultTransition() const;
diff --git a/src/corelib/statemachine/qsignaltransition.h b/src/corelib/statemachine/qsignaltransition.h
index e64d09384a..e785a18c73 100644
--- a/src/corelib/statemachine/qsignaltransition.h
+++ b/src/corelib/statemachine/qsignaltransition.h
@@ -55,17 +55,17 @@ class Q_CORE_EXPORT QSignalTransition : public QAbstractTransition
     Q_PROPERTY(QByteArray signal READ signal WRITE setSignal NOTIFY signalChanged)
 
 public:
-    QSignalTransition(QState *sourceState = Q_NULLPTR);
+    QSignalTransition(QState *sourceState = nullptr);
     QSignalTransition(const QObject *sender, const char *signal,
-                      QState *sourceState = Q_NULLPTR);
+                      QState *sourceState = nullptr);
 #ifdef Q_QDOC
     template<typename PointerToMemberFunction>
     QSignalTransition(const QObject *object, PointerToMemberFunction signal,
-                      QState *sourceState = Q_NULLPTR);
+                      QState *sourceState = nullptr);
 #elif defined(Q_COMPILER_DELEGATING_CONSTRUCTORS)
     template <typename Func>
     QSignalTransition(const typename QtPrivate::FunctionPointer<Func>::Object *obj,
-                      Func sig, QState *srcState = Q_NULLPTR)
+                      Func sig, QState *srcState = nullptr)
     : QSignalTransition(obj, QMetaMethod::fromSignal(sig).methodSignature().constData(), srcState)
     {
     }
diff --git a/src/corelib/statemachine/qstate.cpp b/src/corelib/statemachine/qstate.cpp
index ada20cd6a5..6efa4897d6 100644
--- a/src/corelib/statemachine/qstate.cpp
+++ b/src/corelib/statemachine/qstate.cpp
@@ -524,7 +524,7 @@ void QState::setChildMode(ChildMode mode)
     if (mode == QState::ParallelStates && d->initialState) {
         qWarning("QState::setChildMode: setting the child-mode of state %p to "
                  "parallel removes the initial state", this);
-        d->initialState = Q_NULLPTR;
+        d->initialState = nullptr;
         emit initialStateChanged(QState::QPrivateSignal());
     }
 
diff --git a/src/corelib/statemachine/qstate.h b/src/corelib/statemachine/qstate.h
index 1b39d37f3d..9f1f07dfcc 100644
--- a/src/corelib/statemachine/qstate.h
+++ b/src/corelib/statemachine/qstate.h
@@ -71,8 +71,8 @@ public:
     };
     Q_ENUM(RestorePolicy)
 
-    QState(QState *parent = Q_NULLPTR);
-    QState(ChildMode childMode, QState *parent = Q_NULLPTR);
+    QState(QState *parent = nullptr);
+    QState(ChildMode childMode, QState *parent = nullptr);
     ~QState();
 
     QAbstractState *errorState() const;
diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp
index b6f0420db0..eb425bcd4f 100644
--- a/src/corelib/statemachine/qstatemachine.cpp
+++ b/src/corelib/statemachine/qstatemachine.cpp
@@ -560,7 +560,7 @@ QList<QAbstractTransition*> QStateMachinePrivate::selectTransitions(QEvent *even
     QList<QAbstractTransition*> enabledTransitions;
     const_cast<QStateMachine*>(q)->beginSelectTransitions(event);
     for (QAbstractState *state : qAsConst(configuration_sorted)) {
-        QVector<QState*> lst = getProperAncestors(state, Q_NULLPTR);
+        QVector<QState*> lst = getProperAncestors(state, nullptr);
         if (QState *grp = toStandardState(state))
             lst.prepend(grp);
         bool found = false;
@@ -767,7 +767,7 @@ QSet<QAbstractState*> QStateMachinePrivate::computeExitSet_Unordered(QAbstractTr
 
     QList<QAbstractState *> effectiveTargetStates = getEffectiveTargetStates(t, cache);
     QAbstractState *domain = getTransitionDomain(t, effectiveTargetStates, cache);
-    if (domain == Q_NULLPTR && !t->targetStates().isEmpty()) {
+    if (domain == nullptr && !t->targetStates().isEmpty()) {
         // So we didn't find the least common ancestor for the source and target states of the
         // transition. If there were not target states, that would be fine: then the transition
         // will fire any events or signals, but not exit the state.
@@ -909,7 +909,7 @@ QAbstractState *QStateMachinePrivate::getTransitionDomain(QAbstractTransition *t
     if (effectiveTargetStates.isEmpty())
         return 0;
 
-    QAbstractState *domain = Q_NULLPTR;
+    QAbstractState *domain = nullptr;
     if (cache->transitionDomain(t, &domain))
         return domain;
 
diff --git a/src/corelib/statemachine/qstatemachine.h b/src/corelib/statemachine/qstatemachine.h
index 7268d0f233..fd90b86fd5 100644
--- a/src/corelib/statemachine/qstatemachine.h
+++ b/src/corelib/statemachine/qstatemachine.h
@@ -109,8 +109,8 @@ public:
         NoCommonAncestorForTransitionError
     };
 
-    explicit QStateMachine(QObject *parent = Q_NULLPTR);
-    explicit QStateMachine(QState::ChildMode childMode, QObject *parent = Q_NULLPTR);
+    explicit QStateMachine(QObject *parent = nullptr);
+    explicit QStateMachine(QState::ChildMode childMode, QObject *parent = nullptr);
     ~QStateMachine();
 
     void addState(QAbstractState *state);
diff --git a/src/corelib/thread/qexception.cpp b/src/corelib/thread/qexception.cpp
index 62c2b608d8..e00181e64b 100644
--- a/src/corelib/thread/qexception.cpp
+++ b/src/corelib/thread/qexception.cpp
@@ -171,7 +171,7 @@ public:
 };
 
 ExceptionHolder::ExceptionHolder(QException *exception)
-: base(exception ? new Base(exception) : Q_NULLPTR) {}
+: base(exception ? new Base(exception) : nullptr) {}
 
 ExceptionHolder::ExceptionHolder(const ExceptionHolder &other)
 : base(other.base)
@@ -188,7 +188,7 @@ ExceptionHolder::~ExceptionHolder()
 QException *ExceptionHolder::exception() const
 {
     if (!base)
-        return Q_NULLPTR;
+        return nullptr;
     return base->exception;
 }
 
diff --git a/src/corelib/thread/qexception.h b/src/corelib/thread/qexception.h
index 8bbe597f90..5c43cedffd 100644
--- a/src/corelib/thread/qexception.h
+++ b/src/corelib/thread/qexception.h
@@ -90,7 +90,7 @@ class Base;
 class Q_CORE_EXPORT ExceptionHolder
 {
 public:
-    ExceptionHolder(QException *exception = Q_NULLPTR);
+    ExceptionHolder(QException *exception = nullptr);
     ExceptionHolder(const ExceptionHolder &other);
     void operator=(const ExceptionHolder &other); // ### Qt6: copy-assign operator shouldn't return void. Remove this method and the copy-ctor, they are unneeded.
     ~ExceptionHolder();
diff --git a/src/corelib/thread/qfutureinterface.h b/src/corelib/thread/qfutureinterface.h
index 7b12f51e3e..320c2d7b33 100644
--- a/src/corelib/thread/qfutureinterface.h
+++ b/src/corelib/thread/qfutureinterface.h
@@ -291,7 +291,7 @@ public:
 
     void reportResult(const void *, int) { }
     void reportResults(const QVector<void> &, int) { }
-    void reportFinished(const void * = Q_NULLPTR) { QFutureInterfaceBase::reportFinished(); }
+    void reportFinished(const void * = nullptr) { QFutureInterfaceBase::reportFinished(); }
 };
 
 QT_END_NAMESPACE
diff --git a/src/corelib/thread/qfuturewatcher.h b/src/corelib/thread/qfuturewatcher.h
index 531babb82a..5143db8d2e 100644
--- a/src/corelib/thread/qfuturewatcher.h
+++ b/src/corelib/thread/qfuturewatcher.h
@@ -58,7 +58,7 @@ class Q_CORE_EXPORT QFutureWatcherBase : public QObject
     Q_DECLARE_PRIVATE(QFutureWatcherBase)
 
 public:
-    explicit QFutureWatcherBase(QObject *parent = Q_NULLPTR);
+    explicit QFutureWatcherBase(QObject *parent = nullptr);
     // de-inline dtor
 
     int progressValue() const;
@@ -185,7 +185,7 @@ template <>
 class QFutureWatcher<void> : public QFutureWatcherBase
 {
 public:
-    explicit QFutureWatcher(QObject *_parent = Q_NULLPTR)
+    explicit QFutureWatcher(QObject *_parent = nullptr)
         : QFutureWatcherBase(_parent)
     { }
     ~QFutureWatcher()
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index 12987f16c3..f40dd3c814 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -92,16 +92,16 @@ public:
 
 private:
     inline bool fastTryLock() Q_DECL_NOTHROW {
-        return d_ptr.testAndSetAcquire(Q_NULLPTR, dummyLocked());
+        return d_ptr.testAndSetAcquire(nullptr, dummyLocked());
     }
     inline bool fastTryUnlock() Q_DECL_NOTHROW {
-        return d_ptr.testAndSetRelease(dummyLocked(), Q_NULLPTR);
+        return d_ptr.testAndSetRelease(dummyLocked(), nullptr);
     }
     inline bool fastTryLock(QMutexData *&current) Q_DECL_NOTHROW {
-        return d_ptr.testAndSetAcquire(Q_NULLPTR, dummyLocked(), current);
+        return d_ptr.testAndSetAcquire(nullptr, dummyLocked(), current);
     }
     inline bool fastTryUnlock(QMutexData *&current) Q_DECL_NOTHROW {
-        return d_ptr.testAndSetRelease(dummyLocked(), Q_NULLPTR, current);
+        return d_ptr.testAndSetRelease(dummyLocked(), nullptr, current);
     }
 
     void lockInternal() QT_MUTEX_LOCK_NOEXCEPT;
@@ -287,7 +287,7 @@ public:
 
     inline void unlock() Q_DECL_NOTHROW {}
     void relock() Q_DECL_NOTHROW {}
-    inline QMutex *mutex() const Q_DECL_NOTHROW { return Q_NULLPTR; }
+    inline QMutex *mutex() const Q_DECL_NOTHROW { return nullptr; }
 
 private:
     Q_DISABLE_COPY(QMutexLocker)
diff --git a/src/corelib/thread/qreadwritelock.h b/src/corelib/thread/qreadwritelock.h
index 777efdb3bf..ecdb98f2f5 100644
--- a/src/corelib/thread/qreadwritelock.h
+++ b/src/corelib/thread/qreadwritelock.h
@@ -205,7 +205,7 @@ public:
 
     static inline void unlock() Q_DECL_NOTHROW { }
     static inline void relock() Q_DECL_NOTHROW { }
-    static inline QReadWriteLock *readWriteLock() Q_DECL_NOTHROW { return Q_NULLPTR; }
+    static inline QReadWriteLock *readWriteLock() Q_DECL_NOTHROW { return nullptr; }
 
 private:
     Q_DISABLE_COPY(QReadLocker)
@@ -219,7 +219,7 @@ public:
 
     static inline void unlock() Q_DECL_NOTHROW { }
     static inline void relock() Q_DECL_NOTHROW { }
-    static inline QReadWriteLock *readWriteLock() Q_DECL_NOTHROW { return Q_NULLPTR; }
+    static inline QReadWriteLock *readWriteLock() Q_DECL_NOTHROW { return nullptr; }
 
 private:
     Q_DISABLE_COPY(QWriteLocker)
diff --git a/src/corelib/thread/qresultstore.h b/src/corelib/thread/qresultstore.h
index 6c814ef854..5f0cefa133 100644
--- a/src/corelib/thread/qresultstore.h
+++ b/src/corelib/thread/qresultstore.h
@@ -67,8 +67,8 @@ class ResultItem
 public:
     ResultItem(const void *_result, int _count) : m_count(_count), result(_result) { } // contruct with vector of results
     ResultItem(const void *_result) : m_count(0), result(_result) { } // construct with result
-    ResultItem() : m_count(0), result(Q_NULLPTR) { }
-    bool isValid() const { return result != Q_NULLPTR; }
+    ResultItem() : m_count(0), result(nullptr) { }
+    bool isValid() const { return result != nullptr; }
     bool isVector() const { return m_count != 0; }
     int count() const { return (m_count == 0) ?  1 : m_count; }
     int m_count;          // result is either a pointer to a result or to a vector of results,
diff --git a/src/corelib/thread/qthread.h b/src/corelib/thread/qthread.h
index 21e7cc74f9..b1d02a2b75 100644
--- a/src/corelib/thread/qthread.h
+++ b/src/corelib/thread/qthread.h
@@ -82,7 +82,7 @@ public:
     static int idealThreadCount() Q_DECL_NOTHROW;
     static void yieldCurrentThread();
 
-    explicit QThread(QObject *parent = Q_NULLPTR);
+    explicit QThread(QObject *parent = nullptr);
     ~QThread();
 
     enum Priority {
@@ -153,7 +153,7 @@ protected:
     static void setTerminationEnabled(bool enabled = true);
 
 protected:
-    QThread(QThreadPrivate &dd, QObject *parent = Q_NULLPTR);
+    QThread(QThreadPrivate &dd, QObject *parent = nullptr);
 
 private:
     Q_DECLARE_PRIVATE(QThread)
diff --git a/src/corelib/thread/qthreadpool.h b/src/corelib/thread/qthreadpool.h
index a65eacc996..606e192768 100644
--- a/src/corelib/thread/qthreadpool.h
+++ b/src/corelib/thread/qthreadpool.h
@@ -62,7 +62,7 @@ class Q_CORE_EXPORT QThreadPool : public QObject
     friend class QFutureInterfaceBase;
 
 public:
-    QThreadPool(QObject *parent = Q_NULLPTR);
+    QThreadPool(QObject *parent = nullptr);
     ~QThreadPool();
 
     static QThreadPool *globalInstance();
diff --git a/src/corelib/tools/qarraydata.h b/src/corelib/tools/qarraydata.h
index 88f0cfb0ea..f0cc56e899 100644
--- a/src/corelib/tools/qarraydata.h
+++ b/src/corelib/tools/qarraydata.h
@@ -139,7 +139,7 @@ struct QTypedArrayData
         typedef T *pointer;
         typedef T &reference;
 
-        inline iterator() : i(Q_NULLPTR) {}
+        inline iterator() : i(nullptr) {}
         inline iterator(T *n) : i(n) {}
         inline iterator(const iterator &o): i(o.i){} // #### Qt 6: remove, the implicit version is fine
         inline T &operator*() const { return *i; }
@@ -173,7 +173,7 @@ struct QTypedArrayData
         typedef const T *pointer;
         typedef const T &reference;
 
-        inline const_iterator() : i(Q_NULLPTR) {}
+        inline const_iterator() : i(nullptr) {}
         inline const_iterator(const T *n) : i(n) {}
         inline const_iterator(const const_iterator &o): i(o.i) {} // #### Qt 6: remove, the default version is fine
         inline explicit const_iterator(const iterator &o): i(o.i) {}
diff --git a/src/corelib/tools/qbytearray.h b/src/corelib/tools/qbytearray.h
index 9a600ca366..38c1820685 100644
--- a/src/corelib/tools/qbytearray.h
+++ b/src/corelib/tools/qbytearray.h
@@ -340,16 +340,16 @@ public:
     inline QT_ASCII_CAST_WARN bool operator>=(const QString &s2) const;
 #endif
 
-    short toShort(bool *ok = Q_NULLPTR, int base = 10) const;
-    ushort toUShort(bool *ok = Q_NULLPTR, int base = 10) const;
-    int toInt(bool *ok = Q_NULLPTR, int base = 10) const;
-    uint toUInt(bool *ok = Q_NULLPTR, int base = 10) const;
-    long toLong(bool *ok = Q_NULLPTR, int base = 10) const;
-    ulong toULong(bool *ok = Q_NULLPTR, int base = 10) const;
-    qlonglong toLongLong(bool *ok = Q_NULLPTR, int base = 10) const;
-    qulonglong toULongLong(bool *ok = Q_NULLPTR, int base = 10) const;
-    float toFloat(bool *ok = Q_NULLPTR) const;
-    double toDouble(bool *ok = Q_NULLPTR) const;
+    short toShort(bool *ok = nullptr, int base = 10) const;
+    ushort toUShort(bool *ok = nullptr, int base = 10) const;
+    int toInt(bool *ok = nullptr, int base = 10) const;
+    uint toUInt(bool *ok = nullptr, int base = 10) const;
+    long toLong(bool *ok = nullptr, int base = 10) const;
+    ulong toULong(bool *ok = nullptr, int base = 10) const;
+    qlonglong toLongLong(bool *ok = nullptr, int base = 10) const;
+    qulonglong toULongLong(bool *ok = nullptr, int base = 10) const;
+    float toFloat(bool *ok = nullptr) const;
+    double toDouble(bool *ok = nullptr) const;
     QByteArray toBase64(Base64Options options) const;
     QByteArray toBase64() const; // ### Qt6 merge with previous
     QByteArray toHex() const;
diff --git a/src/corelib/tools/qbytearraylist.h b/src/corelib/tools/qbytearraylist.h
index 501bb2e0d5..ed014dd157 100644
--- a/src/corelib/tools/qbytearraylist.h
+++ b/src/corelib/tools/qbytearraylist.h
@@ -70,7 +70,7 @@ protected:
 #endif
 public:
     inline QByteArray join() const
-    { return QtPrivate::QByteArrayList_join(self(), Q_NULLPTR, 0); }
+    { return QtPrivate::QByteArrayList_join(self(), nullptr, 0); }
     inline QByteArray join(const QByteArray &sep) const
     { return QtPrivate::QByteArrayList_join(self(), sep.constData(), sep.size()); }
     inline QByteArray join(char sep) const
diff --git a/src/corelib/tools/qcollator.h b/src/corelib/tools/qcollator.h
index d81c7c85e3..6fa199cb0f 100644
--- a/src/corelib/tools/qcollator.h
+++ b/src/corelib/tools/qcollator.h
@@ -89,7 +89,7 @@ public:
     QCollator &operator=(const QCollator &);
 #ifdef Q_COMPILER_RVALUE_REFS
     QCollator(QCollator &&other) Q_DECL_NOTHROW
-        : d(other.d) { other.d = Q_NULLPTR; }
+        : d(other.d) { other.d = nullptr; }
     QCollator &operator=(QCollator &&other) Q_DECL_NOTHROW
     { swap(other); return *this; }
 #endif
diff --git a/src/corelib/tools/qdatetime.h b/src/corelib/tools/qdatetime.h
index adab47fc1f..a390bce95f 100644
--- a/src/corelib/tools/qdatetime.h
+++ b/src/corelib/tools/qdatetime.h
@@ -79,7 +79,7 @@ public:
     int dayOfYear() const;
     int daysInMonth() const;
     int daysInYear() const;
-    int weekNumber(int *yearNum = Q_NULLPTR) const;
+    int weekNumber(int *yearNum = nullptr) const;
 
 #if QT_DEPRECATED_SINCE(5, 11) && !defined QT_NO_TEXTDATE
     QT_DEPRECATED_X("Use QLocale::monthName or QLocale::standaloneMonthName")
diff --git a/src/corelib/tools/qeasingcurve.cpp b/src/corelib/tools/qeasingcurve.cpp
index 1098d7e24c..0b8fa4ca74 100644
--- a/src/corelib/tools/qeasingcurve.cpp
+++ b/src/corelib/tools/qeasingcurve.cpp
@@ -1488,7 +1488,7 @@ QDataStream &operator>>(QDataStream &stream, QEasingCurve &easing)
     bool hasConfig;
     stream >> hasConfig;
     delete easing.d_ptr->config;
-    easing.d_ptr->config = Q_NULLPTR;
+    easing.d_ptr->config = nullptr;
     if (hasConfig) {
         QEasingCurveFunction *config = curveToFunctionObject(type);
         stream >> config->_p;
diff --git a/src/corelib/tools/qeasingcurve.h b/src/corelib/tools/qeasingcurve.h
index ba06de8f9e..74bde5825a 100644
--- a/src/corelib/tools/qeasingcurve.h
+++ b/src/corelib/tools/qeasingcurve.h
@@ -81,7 +81,7 @@ public:
     QEasingCurve &operator=(const QEasingCurve &other)
     { if ( this != &other ) { QEasingCurve copy(other); swap(copy); } return *this; }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QEasingCurve(QEasingCurve &&other) Q_DECL_NOTHROW : d_ptr(other.d_ptr) { other.d_ptr = Q_NULLPTR; }
+    QEasingCurve(QEasingCurve &&other) Q_DECL_NOTHROW : d_ptr(other.d_ptr) { other.d_ptr = nullptr; }
     QEasingCurve &operator=(QEasingCurve &&other) Q_DECL_NOTHROW
     { qSwap(d_ptr, other.d_ptr); return *this; }
 #endif
diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index 715acc77ce..e7ce4b658f 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -315,7 +315,7 @@ public:
         typedef T *pointer;
         typedef T &reference;
 
-        inline iterator() : i(Q_NULLPTR) { }
+        inline iterator() : i(nullptr) { }
         explicit inline iterator(void *node) : i(reinterpret_cast<QHashData::Node *>(node)) { }
 
         inline const Key &key() const { return concrete(i)->key; }
@@ -373,7 +373,7 @@ public:
         typedef const T *pointer;
         typedef const T &reference;
 
-        Q_DECL_CONSTEXPR inline const_iterator() : i(Q_NULLPTR) { }
+        Q_DECL_CONSTEXPR inline const_iterator() : i(nullptr) { }
         explicit inline const_iterator(void *node)
             : i(reinterpret_cast<QHashData::Node *>(node)) { }
 #ifdef QT_STRICT_ITERATORS
@@ -502,7 +502,7 @@ public:
 private:
     void detach_helper();
     void freeData(QHashData *d);
-    Node **findNode(const Key &key, uint *hp = Q_NULLPTR) const;
+    Node **findNode(const Key &key, uint *hp = nullptr) const;
     Node **findNode(const Key &key, uint h) const;
     Node *createNode(uint h, const Key &key, const T &value, Node **nextNode);
     void deleteNode(Node *node);
@@ -550,7 +550,7 @@ template <class Key, class T>
 Q_INLINE_TEMPLATE void QHash<Key, T>::duplicateNode(QHashData::Node *node, void *newNode)
 {
     Node *concreteNode = concrete(node);
-    new (newNode) Node(concreteNode->key, concreteNode->value, concreteNode->h, Q_NULLPTR);
+    new (newNode) Node(concreteNode->key, concreteNode->value, concreteNode->h, nullptr);
 }
 
 template <class Key, class T>
diff --git a/src/corelib/tools/qlinkedlist.h b/src/corelib/tools/qlinkedlist.h
index 9f54ba7825..c8f3f4c8c3 100644
--- a/src/corelib/tools/qlinkedlist.h
+++ b/src/corelib/tools/qlinkedlist.h
@@ -134,7 +134,7 @@ public:
         typedef T *pointer;
         typedef T &reference;
         Node *i;
-        inline iterator() : i(Q_NULLPTR) {}
+        inline iterator() : i(nullptr) {}
         inline iterator(Node *n) : i(n) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
         iterator(const iterator &other) Q_DECL_NOTHROW : i(other.i) {}
@@ -171,7 +171,7 @@ public:
         typedef const T *pointer;
         typedef const T &reference;
         Node *i;
-        inline const_iterator() : i(Q_NULLPTR) {}
+        inline const_iterator() : i(nullptr) {}
         inline const_iterator(Node *n) : i(n) {}
         inline const_iterator(iterator ci) : i(ci.i){}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
diff --git a/src/corelib/tools/qlist.h b/src/corelib/tools/qlist.h
index 1042c29460..af7659e995 100644
--- a/src/corelib/tools/qlist.h
+++ b/src/corelib/tools/qlist.h
@@ -231,7 +231,7 @@ public:
         typedef T *pointer;
         typedef T &reference;
 
-        inline iterator() Q_DECL_NOTHROW : i(Q_NULLPTR) {}
+        inline iterator() Q_DECL_NOTHROW : i(nullptr) {}
         inline iterator(Node *n) Q_DECL_NOTHROW : i(n) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
         // can't remove it in Qt 5, since doing so would make the type trivial,
@@ -283,7 +283,7 @@ public:
         typedef const T *pointer;
         typedef const T &reference;
 
-        inline const_iterator() Q_DECL_NOTHROW : i(Q_NULLPTR) {}
+        inline const_iterator() Q_DECL_NOTHROW : i(nullptr) {}
         inline const_iterator(Node *n) Q_DECL_NOTHROW : i(n) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
         // can't remove it in Qt 5, since doing so would make the type trivial,
diff --git a/src/corelib/tools/qlocale.h b/src/corelib/tools/qlocale.h
index 54b1a32946..ef7a26ea79 100644
--- a/src/corelib/tools/qlocale.h
+++ b/src/corelib/tools/qlocale.h
@@ -949,23 +949,23 @@ public:
     QString nativeCountryName() const;
 
 #if QT_STRINGVIEW_LEVEL < 2
-    short toShort(const QString &s, bool *ok = Q_NULLPTR) const;
-    ushort toUShort(const QString &s, bool *ok = Q_NULLPTR) const;
-    int toInt(const QString &s, bool *ok = Q_NULLPTR) const;
-    uint toUInt(const QString &s, bool *ok = Q_NULLPTR) const;
-    qlonglong toLongLong(const QString &s, bool *ok = Q_NULLPTR) const;
-    qulonglong toULongLong(const QString &s, bool *ok = Q_NULLPTR) const;
-    float toFloat(const QString &s, bool *ok = Q_NULLPTR) const;
-    double toDouble(const QString &s, bool *ok = Q_NULLPTR) const;
+    short toShort(const QString &s, bool *ok = nullptr) const;
+    ushort toUShort(const QString &s, bool *ok = nullptr) const;
+    int toInt(const QString &s, bool *ok = nullptr) const;
+    uint toUInt(const QString &s, bool *ok = nullptr) const;
+    qlonglong toLongLong(const QString &s, bool *ok = nullptr) const;
+    qulonglong toULongLong(const QString &s, bool *ok = nullptr) const;
+    float toFloat(const QString &s, bool *ok = nullptr) const;
+    double toDouble(const QString &s, bool *ok = nullptr) const;
 
-    short toShort(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    ushort toUShort(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    int toInt(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    uint toUInt(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    qlonglong toLongLong(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    qulonglong toULongLong(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    float toFloat(const QStringRef &s, bool *ok = Q_NULLPTR) const;
-    double toDouble(const QStringRef &s, bool *ok = Q_NULLPTR) const;
+    short toShort(const QStringRef &s, bool *ok = nullptr) const;
+    ushort toUShort(const QStringRef &s, bool *ok = nullptr) const;
+    int toInt(const QStringRef &s, bool *ok = nullptr) const;
+    uint toUInt(const QStringRef &s, bool *ok = nullptr) const;
+    qlonglong toLongLong(const QStringRef &s, bool *ok = nullptr) const;
+    qulonglong toULongLong(const QStringRef &s, bool *ok = nullptr) const;
+    float toFloat(const QStringRef &s, bool *ok = nullptr) const;
+    double toDouble(const QStringRef &s, bool *ok = nullptr) const;
 #endif
 
     short toShort(QStringView s, bool *ok = nullptr) const;
diff --git a/src/corelib/tools/qmap.h b/src/corelib/tools/qmap.h
index 16442014ff..fc72c6e32c 100644
--- a/src/corelib/tools/qmap.h
+++ b/src/corelib/tools/qmap.h
@@ -150,7 +150,7 @@ template <class Key, class T>
 inline QMapNode<Key, T> *QMapNode<Key, T>::lowerBound(const Key &akey)
 {
     QMapNode<Key, T> *n = this;
-    QMapNode<Key, T> *lastNode = Q_NULLPTR;
+    QMapNode<Key, T> *lastNode = nullptr;
     while (n) {
         if (!qMapLessThanKey(n->key, akey)) {
             lastNode = n;
@@ -166,7 +166,7 @@ template <class Key, class T>
 inline QMapNode<Key, T> *QMapNode<Key, T>::upperBound(const Key &akey)
 {
     QMapNode<Key, T> *n = this;
-    QMapNode<Key, T> *lastNode = Q_NULLPTR;
+    QMapNode<Key, T> *lastNode = nullptr;
     while (n) {
         if (qMapLessThanKey(akey, n->key)) {
             lastNode = n;
@@ -220,7 +220,7 @@ struct QMapData : public QMapDataBase
     Node *findNode(const Key &akey) const;
     void nodeRange(const Key &akey, Node **firstNode, Node **lastNode);
 
-    Node *createNode(const Key &k, const T &v, Node *parent = Q_NULLPTR, bool left = false)
+    Node *createNode(const Key &k, const T &v, Node *parent = nullptr, bool left = false)
     {
         Node *n = static_cast<Node *>(QMapDataBase::createNode(sizeof(Node), Q_ALIGNOF(Node),
                                       parent, left));
@@ -261,13 +261,13 @@ QMapNode<Key, T> *QMapNode<Key, T>::copy(QMapData<Key, T> *d) const
         n->left = leftNode()->copy(d);
         n->left->setParent(n);
     } else {
-        n->left = Q_NULLPTR;
+        n->left = nullptr;
     }
     if (right) {
         n->right = rightNode()->copy(d);
         n->right->setParent(n);
     } else {
-        n->right = Q_NULLPTR;
+        n->right = nullptr;
     }
     return n;
 }
@@ -288,7 +288,7 @@ QMapNode<Key, T> *QMapData<Key, T>::findNode(const Key &akey) const
         if (lb && !qMapLessThanKey(akey, lb->key))
             return lb;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 
@@ -304,10 +304,10 @@ void QMapData<Key, T>::nodeRange(const Key &akey, QMapNode<Key, T> **firstNode,
         } else if (qMapLessThanKey(n->key, akey)) {
             n = n->rightNode();
         } else {
-            *firstNode = n->leftNode() ? n->leftNode()->lowerBound(akey) : Q_NULLPTR;
+            *firstNode = n->leftNode() ? n->leftNode()->lowerBound(akey) : nullptr;
             if (!*firstNode)
                 *firstNode = n;
-            *lastNode = n->rightNode() ? n->rightNode()->upperBound(akey) : Q_NULLPTR;
+            *lastNode = n->rightNode() ? n->rightNode()->upperBound(akey) : nullptr;
             if (!*lastNode)
                 *lastNode = l;
             return;
@@ -416,7 +416,7 @@ public:
         typedef T *pointer;
         typedef T &reference;
 
-        inline iterator() : i(Q_NULLPTR) { }
+        inline iterator() : i(nullptr) { }
         inline iterator(Node *node) : i(node) { }
 
         inline const Key &key() const { return i->key; }
@@ -473,7 +473,7 @@ public:
         typedef const T *pointer;
         typedef const T &reference;
 
-        Q_DECL_CONSTEXPR inline const_iterator() : i(Q_NULLPTR) { }
+        Q_DECL_CONSTEXPR inline const_iterator() : i(nullptr) { }
         inline const_iterator(const Node *node) : i(node) { }
 #ifdef QT_STRICT_ITERATORS
         explicit inline const_iterator(const iterator &o)
@@ -695,7 +695,7 @@ Q_INLINE_TEMPLATE int QMap<Key, T>::count(const Key &akey) const
 template <class Key, class T>
 Q_INLINE_TEMPLATE bool QMap<Key, T>::contains(const Key &akey) const
 {
-    return d->findNode(akey) != Q_NULLPTR;
+    return d->findNode(akey) != nullptr;
 }
 
 template <class Key, class T>
@@ -704,7 +704,7 @@ Q_INLINE_TEMPLATE typename QMap<Key, T>::iterator QMap<Key, T>::insert(const Key
     detach();
     Node *n = d->root();
     Node *y = d->end();
-    Node *lastNode = Q_NULLPTR;
+    Node *lastNode = nullptr;
     bool  left = true;
     while (n) {
         y = n;
@@ -779,15 +779,15 @@ typename QMap<Key, T>::iterator QMap<Key, T>::insert(const_iterator pos, const K
             }
 
             // we need to insert (not overwrite)
-            if (prev->right == Q_NULLPTR) {
+            if (prev->right == nullptr) {
                 Node *z = d->createNode(akey, avalue, prev, false);
                 return iterator(z);
             }
-            if (next->left == Q_NULLPTR) {
+            if (next->left == nullptr) {
                 Node *z = d->createNode(akey, avalue, next, true);
                 return iterator(z);
             }
-            Q_ASSERT(false); // We should have prev->right == Q_NULLPTR or next->left == Q_NULLPTR.
+            Q_ASSERT(false); // We should have prev->right == nullptr or next->left == nullptr.
             return this->insert(akey, avalue);
         }
     }
@@ -801,7 +801,7 @@ Q_INLINE_TEMPLATE typename QMap<Key, T>::iterator QMap<Key, T>::insertMulti(cons
     Node* y = d->end();
     Node* x = static_cast<Node *>(d->root());
     bool left = true;
-    while (x != Q_NULLPTR) {
+    while (x != nullptr) {
         left = !qMapLessThanKey(x->key, akey);
         y = x;
         x = left ? x->leftNode() : x->rightNode();
@@ -848,15 +848,15 @@ typename QMap<Key, T>::iterator QMap<Key, T>::insertMulti(const_iterator pos, co
                 return this->insertMulti(akey, avalue); // ignore hint
 
             // Hint is ok - do insert
-            if (prev->right == Q_NULLPTR) {
+            if (prev->right == nullptr) {
                 Node *z = d->createNode(akey, avalue, prev, false);
                 return iterator(z);
             }
-            if (next->left == Q_NULLPTR) {
+            if (next->left == nullptr) {
                 Node *z = d->createNode(akey, avalue, next, true);
                 return iterator(z);
             }
-            Q_ASSERT(false); // We should have prev->right == Q_NULLPTR or next->left == Q_NULLPTR.
+            Q_ASSERT(false); // We should have prev->right == nullptr or next->left == nullptr.
             return this->insertMulti(akey, avalue);
         }
     }
@@ -1102,7 +1102,7 @@ Q_OUTOFLINE_TEMPLATE QList<T> QMap<Key, T>::values(const Key &akey) const
 template <class Key, class T>
 Q_INLINE_TEMPLATE typename QMap<Key, T>::const_iterator QMap<Key, T>::lowerBound(const Key &akey) const
 {
-    Node *lb = d->root() ? d->root()->lowerBound(akey) : Q_NULLPTR;
+    Node *lb = d->root() ? d->root()->lowerBound(akey) : nullptr;
     if (!lb)
         lb = d->end();
     return const_iterator(lb);
@@ -1112,7 +1112,7 @@ template <class Key, class T>
 Q_INLINE_TEMPLATE typename QMap<Key, T>::iterator QMap<Key, T>::lowerBound(const Key &akey)
 {
     detach();
-    Node *lb = d->root() ? d->root()->lowerBound(akey) : Q_NULLPTR;
+    Node *lb = d->root() ? d->root()->lowerBound(akey) : nullptr;
     if (!lb)
         lb = d->end();
     return iterator(lb);
@@ -1122,7 +1122,7 @@ template <class Key, class T>
 Q_INLINE_TEMPLATE typename QMap<Key, T>::const_iterator
 QMap<Key, T>::upperBound(const Key &akey) const
 {
-    Node *ub = d->root() ? d->root()->upperBound(akey) : Q_NULLPTR;
+    Node *ub = d->root() ? d->root()->upperBound(akey) : nullptr;
     if (!ub)
         ub = d->end();
     return const_iterator(ub);
@@ -1132,7 +1132,7 @@ template <class Key, class T>
 Q_INLINE_TEMPLATE typename QMap<Key, T>::iterator QMap<Key, T>::upperBound(const Key &akey)
 {
     detach();
-    Node *ub = d->root() ? d->root()->upperBound(akey) : Q_NULLPTR;
+    Node *ub = d->root() ? d->root()->upperBound(akey) : nullptr;
     if (!ub)
         ub = d->end();
     return iterator(ub);
diff --git a/src/corelib/tools/qringbuffer_p.h b/src/corelib/tools/qringbuffer_p.h
index 558a456515..1f3f2d3fb0 100644
--- a/src/corelib/tools/qringbuffer_p.h
+++ b/src/corelib/tools/qringbuffer_p.h
@@ -80,7 +80,7 @@ public:
     }
 
     inline const char *readPointer() const {
-        return bufferSize == 0 ? Q_NULLPTR : (buffers.first().constData() + head);
+        return bufferSize == 0 ? nullptr : (buffers.first().constData() + head);
     }
 
     Q_CORE_EXPORT const char *readPointerAtPosition(qint64 pos, qint64 &length) const;
diff --git a/src/corelib/tools/qscopedpointer.h b/src/corelib/tools/qscopedpointer.h
index eeed3afd83..2a4083466b 100644
--- a/src/corelib/tools/qscopedpointer.h
+++ b/src/corelib/tools/qscopedpointer.h
@@ -97,7 +97,7 @@ class QScopedPointer
 {
     typedef T *QScopedPointer:: *RestrictedBool;
 public:
-    explicit QScopedPointer(T *p = Q_NULLPTR) Q_DECL_NOTHROW : d(p)
+    explicit QScopedPointer(T *p = nullptr) Q_DECL_NOTHROW : d(p)
     {
     }
 
@@ -126,12 +126,12 @@ public:
 #if defined(Q_QDOC)
     inline operator bool() const
     {
-        return isNull() ? Q_NULLPTR : &QScopedPointer::d;
+        return isNull() ? nullptr : &QScopedPointer::d;
     }
 #else
     operator RestrictedBool() const Q_DECL_NOTHROW
     {
-        return isNull() ? Q_NULLPTR : &QScopedPointer::d;
+        return isNull() ? nullptr : &QScopedPointer::d;
     }
 #endif
 
@@ -150,7 +150,7 @@ public:
         return !d;
     }
 
-    void reset(T *other = Q_NULLPTR) Q_DECL_NOEXCEPT_EXPR(noexcept(Cleanup::cleanup(std::declval<T *>())))
+    void reset(T *other = nullptr) Q_DECL_NOEXCEPT_EXPR(noexcept(Cleanup::cleanup(std::declval<T *>())))
     {
         if (d == other)
             return;
@@ -162,7 +162,7 @@ public:
     T *take() Q_DECL_NOTHROW
     {
         T *oldD = d;
-        d = Q_NULLPTR;
+        d = nullptr;
         return oldD;
     }
 
@@ -226,7 +226,7 @@ class QScopedArrayPointer : public QScopedPointer<T, Cleanup>
     template <typename Ptr>
     using if_same_type = typename std::enable_if<std::is_same<typename std::remove_cv<T>::type, Ptr>::value, bool>::type;
 public:
-    inline QScopedArrayPointer() : QScopedPointer<T, Cleanup>(Q_NULLPTR) {}
+    inline QScopedArrayPointer() : QScopedPointer<T, Cleanup>(nullptr) {}
 
     template <typename D, if_same_type<D> = true>
     explicit QScopedArrayPointer(D *p)
diff --git a/src/corelib/tools/qshareddata.h b/src/corelib/tools/qshareddata.h
index 13b0032605..dbf0907a0f 100644
--- a/src/corelib/tools/qshareddata.h
+++ b/src/corelib/tools/qshareddata.h
@@ -85,7 +85,7 @@ public:
     inline bool operator==(const QSharedDataPointer<T> &other) const { return d == other.d; }
     inline bool operator!=(const QSharedDataPointer<T> &other) const { return d != other.d; }
 
-    inline QSharedDataPointer() { d = Q_NULLPTR; }
+    inline QSharedDataPointer() { d = nullptr; }
     inline ~QSharedDataPointer() { if (d && !d->ref.deref()) delete d; }
 
     explicit QSharedDataPointer(T *data) Q_DECL_NOTHROW;
@@ -113,7 +113,7 @@ public:
         return *this;
     }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QSharedDataPointer(QSharedDataPointer &&o) Q_DECL_NOTHROW : d(o.d) { o.d = Q_NULLPTR; }
+    QSharedDataPointer(QSharedDataPointer &&o) Q_DECL_NOTHROW : d(o.d) { o.d = nullptr; }
     inline QSharedDataPointer<T> &operator=(QSharedDataPointer<T> &&other) Q_DECL_NOTHROW
     { qSwap(d, other.d); return *this; }
 #endif
@@ -151,17 +151,17 @@ public:
         if(d && !d->ref.deref())
             delete d;
 
-        d = Q_NULLPTR;
+        d = nullptr;
     }
 
-    inline operator bool () const { return d != Q_NULLPTR; }
+    inline operator bool () const { return d != nullptr; }
 
     inline bool operator==(const QExplicitlySharedDataPointer<T> &other) const { return d == other.d; }
     inline bool operator!=(const QExplicitlySharedDataPointer<T> &other) const { return d != other.d; }
     inline bool operator==(const T *ptr) const { return d == ptr; }
     inline bool operator!=(const T *ptr) const { return d != ptr; }
 
-    inline QExplicitlySharedDataPointer() { d = Q_NULLPTR; }
+    inline QExplicitlySharedDataPointer() { d = nullptr; }
     inline ~QExplicitlySharedDataPointer() { if (d && !d->ref.deref()) delete d; }
 
     explicit QExplicitlySharedDataPointer(T *data) Q_DECL_NOTHROW;
@@ -202,7 +202,7 @@ public:
         return *this;
     }
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) Q_DECL_NOTHROW : d(o.d) { o.d = Q_NULLPTR; }
+    inline QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) Q_DECL_NOTHROW : d(o.d) { o.d = nullptr; }
     inline QExplicitlySharedDataPointer<T> &operator=(QExplicitlySharedDataPointer<T> &&other) Q_DECL_NOTHROW
     { qSwap(d, other.d); return *this; }
 #endif
diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index 9e1a5c7c62..736049b722 100644
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -305,7 +305,7 @@ public:
     T *data() const Q_DECL_NOTHROW { return value; }
     T *get() const Q_DECL_NOTHROW { return value; }
     bool isNull() const Q_DECL_NOTHROW { return !data(); }
-    operator RestrictedBool() const Q_DECL_NOTHROW { return isNull() ? Q_NULLPTR : &QSharedPointer::value; }
+    operator RestrictedBool() const Q_DECL_NOTHROW { return isNull() ? nullptr : &QSharedPointer::value; }
     bool operator !() const Q_DECL_NOTHROW { return isNull(); }
     T &operator*() const { return *data(); }
     T *operator->() const Q_DECL_NOTHROW { return data(); }
@@ -338,8 +338,8 @@ public:
     QSharedPointer(QSharedPointer &&other) Q_DECL_NOTHROW
         : value(other.value), d(other.d)
     {
-        other.d = Q_NULLPTR;
-        other.value = Q_NULLPTR;
+        other.d = nullptr;
+        other.value = nullptr;
     }
     QSharedPointer &operator=(QSharedPointer &&other) Q_DECL_NOTHROW
     {
@@ -352,8 +352,8 @@ public:
     QSharedPointer(QSharedPointer<X> &&other) Q_DECL_NOTHROW
         : value(other.value), d(other.d)
     {
-        other.d = Q_NULLPTR;
-        other.value = Q_NULLPTR;
+        other.d = nullptr;
+        other.value = nullptr;
     }
 
     template <class X>
@@ -379,7 +379,7 @@ public:
     }
 
     template <class X>
-    inline QSharedPointer(const QWeakPointer<X> &other) : value(Q_NULLPTR), d(Q_NULLPTR)
+    inline QSharedPointer(const QWeakPointer<X> &other) : value(nullptr), d(nullptr)
     { *this = other; }
 
     template <class X>
@@ -477,7 +477,7 @@ private:
     inline void internalConstruct(X *ptr, Deleter deleter)
     {
         if (!ptr) {
-            d = Q_NULLPTR;
+            d = nullptr;
             return;
         }
 
@@ -528,14 +528,14 @@ public:
                 o->weakref.ref();
             } else {
                 o->checkQObjectShared(actual);
-                o = Q_NULLPTR;
+                o = nullptr;
             }
         }
 
         qSwap(d, o);
         qSwap(this->value, actual);
         if (!d || d->strongref.load() == 0)
-            this->value = Q_NULLPTR;
+            this->value = nullptr;
 
         // dereference saved data
         deref(o);
@@ -560,19 +560,19 @@ public:
     typedef const value_type &const_reference;
     typedef qptrdiff difference_type;
 
-    bool isNull() const Q_DECL_NOTHROW { return d == Q_NULLPTR || d->strongref.load() == 0 || value == Q_NULLPTR; }
-    operator RestrictedBool() const Q_DECL_NOTHROW { return isNull() ? Q_NULLPTR : &QWeakPointer::value; }
+    bool isNull() const Q_DECL_NOTHROW { return d == nullptr || d->strongref.load() == 0 || value == nullptr; }
+    operator RestrictedBool() const Q_DECL_NOTHROW { return isNull() ? nullptr : &QWeakPointer::value; }
     bool operator !() const Q_DECL_NOTHROW { return isNull(); }
-    T *data() const Q_DECL_NOTHROW { return d == Q_NULLPTR || d->strongref.load() == 0 ? Q_NULLPTR : value; }
+    T *data() const Q_DECL_NOTHROW { return d == nullptr || d->strongref.load() == 0 ? nullptr : value; }
 
-    inline QWeakPointer() Q_DECL_NOTHROW : d(Q_NULLPTR), value(Q_NULLPTR) { }
+    inline QWeakPointer() Q_DECL_NOTHROW : d(nullptr), value(nullptr) { }
     inline ~QWeakPointer() { if (d && !d->weakref.deref()) delete d; }
 
 #ifndef QT_NO_QOBJECT
     // special constructor that is enabled only if X derives from QObject
 #if QT_DEPRECATED_SINCE(5, 0)
     template <class X>
-    QT_DEPRECATED inline QWeakPointer(X *ptr) : d(ptr ? Data::getAndRef(ptr) : Q_NULLPTR), value(ptr)
+    QT_DEPRECATED inline QWeakPointer(X *ptr) : d(ptr ? Data::getAndRef(ptr) : nullptr), value(ptr)
     { }
 #endif
 #endif
@@ -589,8 +589,8 @@ public:
     QWeakPointer(QWeakPointer &&other) Q_DECL_NOTHROW
         : d(other.d), value(other.value)
     {
-        other.d = Q_NULLPTR;
-        other.value = Q_NULLPTR;
+        other.d = nullptr;
+        other.value = nullptr;
     }
     QWeakPointer &operator=(QWeakPointer &&other) Q_DECL_NOTHROW
     { QWeakPointer moved(std::move(other)); swap(moved); return *this; }
@@ -617,7 +617,7 @@ public:
     }
 
     template <class X>
-    inline QWeakPointer(const QWeakPointer<X> &o) : d(Q_NULLPTR), value(Q_NULLPTR)
+    inline QWeakPointer(const QWeakPointer<X> &o) : d(nullptr), value(nullptr)
     { *this = o; }
 
     template <class X>
@@ -638,7 +638,7 @@ public:
     { return !(*this == o); }
 
     template <class X>
-    inline QWeakPointer(const QSharedPointer<X> &o) : d(Q_NULLPTR), value(Q_NULLPTR)
+    inline QWeakPointer(const QSharedPointer<X> &o) : d(nullptr), value(nullptr)
     { *this = o; }
 
     template <class X>
@@ -682,7 +682,7 @@ public:
 
 #ifndef QT_NO_QOBJECT
     template <class X>
-    inline QWeakPointer(X *ptr, bool) : d(ptr ? Data::getAndRef(ptr) : Q_NULLPTR), value(ptr)
+    inline QWeakPointer(X *ptr, bool) : d(ptr ? Data::getAndRef(ptr) : nullptr), value(ptr)
     { }
 #endif
 
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 3826d7531a..ea157a23d0 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -4007,7 +4007,7 @@ int QString::count(const QRegExp& rx) const
 */
 int QString::indexOf(const QRegularExpression& re, int from) const
 {
-    return indexOf(re, from, Q_NULLPTR);
+    return indexOf(re, from, nullptr);
 }
 
 /*!
@@ -4058,7 +4058,7 @@ int QString::indexOf(const QRegularExpression &re, int from, QRegularExpressionM
 */
 int QString::lastIndexOf(const QRegularExpression &re, int from) const
 {
-    return lastIndexOf(re, from, Q_NULLPTR);
+    return lastIndexOf(re, from, nullptr);
 }
 
 /*!
@@ -4110,7 +4110,7 @@ int QString::lastIndexOf(const QRegularExpression &re, int from, QRegularExpress
 */
 bool QString::contains(const QRegularExpression &re) const
 {
-    return contains(re, Q_NULLPTR);
+    return contains(re, nullptr);
 }
 
 /*!
diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index 16472ff6b9..1eca773c3e 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -91,7 +91,7 @@ template <typename T> class QVector;
 class QLatin1String
 {
 public:
-    Q_DECL_CONSTEXPR inline QLatin1String() Q_DECL_NOTHROW : m_size(0), m_data(Q_NULLPTR) {}
+    Q_DECL_CONSTEXPR inline QLatin1String() Q_DECL_NOTHROW : m_size(0), m_data(nullptr) {}
     Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s) Q_DECL_NOTHROW : m_size(s ? int(strlen(s)) : 0), m_data(s) {}
     Q_DECL_CONSTEXPR explicit QLatin1String(const char *f, const char *l)
         : QLatin1String(f, int(l - f)) {}
@@ -624,16 +624,16 @@ public:
     static int localeAwareCompare(const QString& s1, const QStringRef& s2);
 
     // ### Qt6: make inline except for the long long versions
-    short  toShort(bool *ok=Q_NULLPTR, int base=10) const;
-    ushort toUShort(bool *ok=Q_NULLPTR, int base=10) const;
-    int toInt(bool *ok=Q_NULLPTR, int base=10) const;
-    uint toUInt(bool *ok=Q_NULLPTR, int base=10) const;
-    long toLong(bool *ok=Q_NULLPTR, int base=10) const;
-    ulong toULong(bool *ok=Q_NULLPTR, int base=10) const;
-    qlonglong toLongLong(bool *ok=Q_NULLPTR, int base=10) const;
-    qulonglong toULongLong(bool *ok=Q_NULLPTR, int base=10) const;
-    float toFloat(bool *ok=Q_NULLPTR) const;
-    double toDouble(bool *ok=Q_NULLPTR) const;
+    short  toShort(bool *ok=nullptr, int base=10) const;
+    ushort toUShort(bool *ok=nullptr, int base=10) const;
+    int toInt(bool *ok=nullptr, int base=10) const;
+    uint toUInt(bool *ok=nullptr, int base=10) const;
+    long toLong(bool *ok=nullptr, int base=10) const;
+    ulong toULong(bool *ok=nullptr, int base=10) const;
+    qlonglong toLongLong(bool *ok=nullptr, int base=10) const;
+    qulonglong toULongLong(bool *ok=nullptr, int base=10) const;
+    float toFloat(bool *ok=nullptr) const;
+    double toDouble(bool *ok=nullptr) const;
 
     QString &setNum(short, int base=10);
     QString &setNum(ushort, int base=10);
@@ -1417,7 +1417,7 @@ public:
     typedef QString::const_reference const_reference;
 
     // ### Qt 6: make this constructor constexpr, after the destructor is made trivial
-    inline QStringRef() : m_string(Q_NULLPTR), m_position(0), m_size(0) {}
+    inline QStringRef() : m_string(nullptr), m_position(0), m_size(0) {}
     inline QStringRef(const QString *string, int position, int size);
     inline QStringRef(const QString *string);
 
@@ -1533,10 +1533,10 @@ public:
     Q_REQUIRED_RESULT QByteArray toLocal8Bit() const;
     Q_REQUIRED_RESULT QVector<uint> toUcs4() const;
 
-    inline void clear() { m_string = Q_NULLPTR; m_position = m_size = 0; }
+    inline void clear() { m_string = nullptr; m_position = m_size = 0; }
     QString toString() const;
     inline bool isEmpty() const { return m_size == 0; }
-    inline bool isNull() const { return m_string == Q_NULLPTR || m_string->isNull(); }
+    inline bool isNull() const { return m_string == nullptr || m_string->isNull(); }
 
     QStringRef appendTo(QString *string) const;
 
@@ -1576,16 +1576,16 @@ public:
     static int localeAwareCompare(const QStringRef &s1, const QStringRef &s2);
 
     Q_REQUIRED_RESULT QStringRef trimmed() const;
-    short  toShort(bool *ok = Q_NULLPTR, int base = 10) const;
-    ushort toUShort(bool *ok = Q_NULLPTR, int base = 10) const;
-    int toInt(bool *ok = Q_NULLPTR, int base = 10) const;
-    uint toUInt(bool *ok = Q_NULLPTR, int base = 10) const;
-    long toLong(bool *ok = Q_NULLPTR, int base = 10) const;
-    ulong toULong(bool *ok = Q_NULLPTR, int base = 10) const;
-    qlonglong toLongLong(bool *ok = Q_NULLPTR, int base = 10) const;
-    qulonglong toULongLong(bool *ok = Q_NULLPTR, int base = 10) const;
-    float toFloat(bool *ok = Q_NULLPTR) const;
-    double toDouble(bool *ok = Q_NULLPTR) const;
+    short  toShort(bool *ok = nullptr, int base = 10) const;
+    ushort toUShort(bool *ok = nullptr, int base = 10) const;
+    int toInt(bool *ok = nullptr, int base = 10) const;
+    uint toUInt(bool *ok = nullptr, int base = 10) const;
+    long toLong(bool *ok = nullptr, int base = 10) const;
+    ulong toULong(bool *ok = nullptr, int base = 10) const;
+    qlonglong toLongLong(bool *ok = nullptr, int base = 10) const;
+    qulonglong toULongLong(bool *ok = nullptr, int base = 10) const;
+    float toFloat(bool *ok = nullptr) const;
+    double toDouble(bool *ok = nullptr) const;
 };
 Q_DECLARE_TYPEINFO(QStringRef, Q_PRIMITIVE_TYPE);
 
diff --git a/src/corelib/tools/qtextboundaryfinder.h b/src/corelib/tools/qtextboundaryfinder.h
index d021df3f2c..b1e5008f54 100644
--- a/src/corelib/tools/qtextboundaryfinder.h
+++ b/src/corelib/tools/qtextboundaryfinder.h
@@ -74,7 +74,7 @@ public:
     Q_DECLARE_FLAGS( BoundaryReasons, BoundaryReason )
 
     QTextBoundaryFinder(BoundaryType type, const QString &string);
-    QTextBoundaryFinder(BoundaryType type, const QChar *chars, int length, unsigned char *buffer = Q_NULLPTR, int bufferSize = 0);
+    QTextBoundaryFinder(BoundaryType type, const QChar *chars, int length, unsigned char *buffer = nullptr, int bufferSize = 0);
 
     inline bool isValid() const { return d; }
 
diff --git a/src/corelib/tools/qtimeline.h b/src/corelib/tools/qtimeline.h
index 4cba49e185..d9982bdb58 100644
--- a/src/corelib/tools/qtimeline.h
+++ b/src/corelib/tools/qtimeline.h
@@ -76,7 +76,7 @@ public:
         CosineCurve
     };
 
-    explicit QTimeLine(int duration = 1000, QObject *parent = Q_NULLPTR);
+    explicit QTimeLine(int duration = 1000, QObject *parent = nullptr);
     virtual ~QTimeLine();
 
     State state() const;
diff --git a/src/corelib/tools/qversionnumber.h b/src/corelib/tools/qversionnumber.h
index 3836bc2119..1bfb4aab39 100644
--- a/src/corelib/tools/qversionnumber.h
+++ b/src/corelib/tools/qversionnumber.h
@@ -281,7 +281,7 @@ public:
 
     Q_REQUIRED_RESULT Q_CORE_EXPORT QString toString() const;
 #if QT_STRINGVIEW_LEVEL < 2
-    Q_REQUIRED_RESULT Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(const QString &string, int *suffixIndex = Q_NULLPTR);
+    Q_REQUIRED_RESULT Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(const QString &string, int *suffixIndex = nullptr);
 #endif
     Q_REQUIRED_RESULT Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QLatin1String string, int *suffixIndex = nullptr);
     Q_REQUIRED_RESULT Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QStringView string, int *suffixIndex = nullptr);
diff --git a/src/corelib/xml/qxmlstream.h b/src/corelib/xml/qxmlstream.h
index bf6ddefcdd..2350d12dd6 100644
--- a/src/corelib/xml/qxmlstream.h
+++ b/src/corelib/xml/qxmlstream.h
@@ -120,7 +120,7 @@ public:
           reserved(other.reserved),
           m_isDefault(other.m_isDefault)
     {
-        other.reserved = Q_NULLPTR;
+        other.reserved = nullptr;
     }
     QXmlStreamAttribute &operator=(QXmlStreamAttribute &&other) Q_DECL_NOTHROW // = default;
     {
diff --git a/src/dbus/qdbusabstractinterface.cpp b/src/dbus/qdbusabstractinterface.cpp
index 2239f48a7d..50a0483231 100644
--- a/src/dbus/qdbusabstractinterface.cpp
+++ b/src/dbus/qdbusabstractinterface.cpp
@@ -70,7 +70,7 @@ class DisconnectRelayEvent : public QMetaCallEvent
 {
 public:
     DisconnectRelayEvent(QObject *sender, const QMetaMethod &m)
-        : QMetaCallEvent(0, 0, Q_NULLPTR, sender, m.methodIndex())
+        : QMetaCallEvent(0, 0, nullptr, sender, m.methodIndex())
     {}
 
     void placeMetaCall(QObject *object) override
diff --git a/src/dbus/qdbusargument.h b/src/dbus/qdbusargument.h
index 5342a79227..a6d4e9cd25 100644
--- a/src/dbus/qdbusargument.h
+++ b/src/dbus/qdbusargument.h
@@ -77,7 +77,7 @@ public:
     QDBusArgument();
     QDBusArgument(const QDBusArgument &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QDBusArgument(QDBusArgument &&other) Q_DECL_NOTHROW : d(other.d) { other.d = Q_NULLPTR; }
+    QDBusArgument(QDBusArgument &&other) Q_DECL_NOTHROW : d(other.d) { other.d = nullptr; }
     QDBusArgument &operator=(QDBusArgument &&other) Q_DECL_NOTHROW { swap(other); return *this; }
 #endif
     QDBusArgument &operator=(const QDBusArgument &other);
@@ -160,7 +160,7 @@ QT_BEGIN_NAMESPACE
 
 template<typename T> inline T qdbus_cast(const QDBusArgument &arg
 #ifndef Q_QDOC
-, T * = Q_NULLPTR
+, T * = nullptr
 #endif
     )
 {
@@ -171,7 +171,7 @@ template<typename T> inline T qdbus_cast(const QDBusArgument &arg
 
 template<typename T> inline T qdbus_cast(const QVariant &v
 #ifndef Q_QDOC
-, T * = Q_NULLPTR
+, T * = nullptr
 #endif
     )
 {
diff --git a/src/dbus/qdbusconnection.cpp b/src/dbus/qdbusconnection.cpp
index 75c1e92f96..c95f195aca 100644
--- a/src/dbus/qdbusconnection.cpp
+++ b/src/dbus/qdbusconnection.cpp
@@ -147,7 +147,7 @@ QDBusConnectionManager::QDBusConnectionManager()
     // prevent the library from being unloaded on Windows. See comments in the function.
     preventDllUnload();
 #endif
-    defaultBuses[0] = defaultBuses[1] = Q_NULLPTR;
+    defaultBuses[0] = defaultBuses[1] = nullptr;
     start();
 }
 
@@ -186,13 +186,13 @@ void QDBusConnectionManager::run()
             delete d;
         } else {
             d->closeConnection();
-            d->moveToThread(Q_NULLPTR);     // allow it to be deleted in another thread
+            d->moveToThread(nullptr);     // allow it to be deleted in another thread
         }
     }
     connectionHash.clear();
 
     // allow deletion from any thread without warning
-    moveToThread(Q_NULLPTR);
+    moveToThread(nullptr);
 }
 
 QDBusConnectionPrivate *QDBusConnectionManager::connectToBus(QDBusConnection::BusType type, const QString &name,
@@ -1175,7 +1175,7 @@ bool QDBusConnection::unregisterService(const QString &serviceName)
 QDBusConnection QDBusConnection::sessionBus()
 {
     if (_q_manager.isDestroyed())
-        return QDBusConnection(Q_NULLPTR);
+        return QDBusConnection(nullptr);
     return QDBusConnection(_q_manager()->busConnection(SessionBus));
 }
 
@@ -1189,7 +1189,7 @@ QDBusConnection QDBusConnection::sessionBus()
 QDBusConnection QDBusConnection::systemBus()
 {
     if (_q_manager.isDestroyed())
-        return QDBusConnection(Q_NULLPTR);
+        return QDBusConnection(nullptr);
     return QDBusConnection(_q_manager()->busConnection(SystemBus));
 }
 
diff --git a/src/dbus/qdbusconnection.h b/src/dbus/qdbusconnection.h
index ba28938b60..0352978989 100644
--- a/src/dbus/qdbusconnection.h
+++ b/src/dbus/qdbusconnection.h
@@ -130,7 +130,7 @@ public:
     explicit QDBusConnection(const QString &name);
     QDBusConnection(const QDBusConnection &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QDBusConnection(QDBusConnection &&other) Q_DECL_NOTHROW : d(other.d) { other.d = Q_NULLPTR; }
+    QDBusConnection(QDBusConnection &&other) Q_DECL_NOTHROW : d(other.d) { other.d = nullptr; }
     QDBusConnection &operator=(QDBusConnection &&other) Q_DECL_NOTHROW { swap(other); return *this; }
 #endif
     QDBusConnection &operator=(const QDBusConnection &other);
diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp
index 16cd021d0d..c74c63fdc6 100644
--- a/src/dbus/qdbusintegrator.cpp
+++ b/src/dbus/qdbusintegrator.cpp
@@ -1078,7 +1078,7 @@ QDBusConnectionPrivate::~QDBusConnectionPrivate()
         Q_ASSERT(ref.load() == 0);
         QObject *obj = (QObject *)busService;
         if (obj) {
-            disconnect(obj, Q_NULLPTR, this, Q_NULLPTR);
+            disconnect(obj, nullptr, this, nullptr);
             delete obj;
         }
         if (connection)
@@ -1950,7 +1950,7 @@ bool QDBusConnectionPrivate::send(const QDBusMessage& message)
 
     q_dbus_message_set_no_reply(msg, true); // the reply would not be delivered to anything
     qDBusDebug() << this << "sending message (no reply):" << message;
-    emit messageNeedsSending(Q_NULLPTR, msg);
+    emit messageNeedsSending(nullptr, msg);
     return true;
 }
 
@@ -2166,7 +2166,7 @@ void QDBusConnectionPrivate::sendInternal(QDBusPendingCallPrivate *pcall, void *
     checkThread();
     QDBusDispatchLocker locker(SendMessageAction, this);
 
-    if (isNoReply && q_dbus_connection_send(connection, msg, Q_NULLPTR)) {
+    if (isNoReply && q_dbus_connection_send(connection, msg, nullptr)) {
         // success
     } else if (!isNoReply && q_dbus_connection_send_with_reply(connection, msg, &pending, timeout)) {
         if (pending) {
@@ -2509,7 +2509,7 @@ QString QDBusConnectionPrivate::getNameOwnerNoCache(const QString &serviceName)
     QDBusMessagePrivate::setParametersValidated(msg, true);
     msg << serviceName;
 
-    QDBusPendingCallPrivate *pcall = sendWithReplyAsync(msg, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR);
+    QDBusPendingCallPrivate *pcall = sendWithReplyAsync(msg, nullptr, nullptr, nullptr);
     if (thread() == QThread::currentThread()) {
         // this function may be called in our own thread and
         // QDBusPendingCallPrivate::waitForFinished() would deadlock there
diff --git a/src/dbus/qdbusintegrator_p.h b/src/dbus/qdbusintegrator_p.h
index 6026508a5c..3cd029a933 100644
--- a/src/dbus/qdbusintegrator_p.h
+++ b/src/dbus/qdbusintegrator_p.h
@@ -148,7 +148,7 @@ public:
     typedef void (*Hook)(const QDBusMessage&);
     QDBusSpyCallEvent(QDBusConnectionPrivate *cp, const QDBusConnection &c, const QDBusMessage &msg,
                       const Hook *hooks, int count)
-        : QMetaCallEvent(0, 0, Q_NULLPTR, cp, 0), conn(c), msg(msg), hooks(hooks), hookCount(count)
+        : QMetaCallEvent(0, 0, nullptr, cp, 0), conn(c), msg(msg), hooks(hooks), hookCount(count)
     {}
     ~QDBusSpyCallEvent();
     void placeMetaCall(QObject *) override;
diff --git a/src/dbus/qdbusinterface.h b/src/dbus/qdbusinterface.h
index 5d73cf8bc3..c147d07d50 100644
--- a/src/dbus/qdbusinterface.h
+++ b/src/dbus/qdbusinterface.h
@@ -59,7 +59,7 @@ private:
 public:
     QDBusInterface(const QString &service, const QString &path, const QString &interface = QString(),
                    const QDBusConnection &connection = QDBusConnection::sessionBus(),
-                   QObject *parent = Q_NULLPTR);
+                   QObject *parent = nullptr);
     ~QDBusInterface();
 
     virtual const QMetaObject *metaObject() const override;
diff --git a/src/dbus/qdbuspendingcall.h b/src/dbus/qdbuspendingcall.h
index 1e4c6ebfd2..ec8ba6c541 100644
--- a/src/dbus/qdbuspendingcall.h
+++ b/src/dbus/qdbuspendingcall.h
@@ -100,7 +100,7 @@ class Q_DBUS_EXPORT QDBusPendingCallWatcher: public QObject, public QDBusPending
 {
     Q_OBJECT
 public:
-    explicit QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject *parent = Q_NULLPTR);
+    explicit QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject *parent = nullptr);
     ~QDBusPendingCallWatcher();
 
 #ifdef Q_QDOC
@@ -110,7 +110,7 @@ public:
     void waitForFinished();     // non-virtual override
 
 Q_SIGNALS:
-    void finished(QDBusPendingCallWatcher *self = Q_NULLPTR);
+    void finished(QDBusPendingCallWatcher *self = nullptr);
 
 private:
     Q_DECLARE_PRIVATE(QDBusPendingCallWatcher)
diff --git a/src/dbus/qdbusreply.h b/src/dbus/qdbusreply.h
index 227615024a..869687ac85 100644
--- a/src/dbus/qdbusreply.h
+++ b/src/dbus/qdbusreply.h
@@ -130,7 +130,7 @@ private:
 template<> inline QDBusReply<QVariant>&
 QDBusReply<QVariant>::operator=(const QDBusMessage &reply)
 {
-    void *null = Q_NULLPTR;
+    void *null = nullptr;
     QVariant data(qMetaTypeId<QDBusVariant>(), null);
     qDBusReplyFill(reply, m_error, data);
     m_data = qvariant_cast<QDBusVariant>(data).variant();
diff --git a/src/dbus/qdbusserver.cpp b/src/dbus/qdbusserver.cpp
index ce55297abb..a2dfb86164 100644
--- a/src/dbus/qdbusserver.cpp
+++ b/src/dbus/qdbusserver.cpp
@@ -116,7 +116,7 @@ QDBusServer::~QDBusServer()
             QDBusConnectionManager::instance()->removeConnection(name);
         d->serverConnectionNames.clear();
     }
-    d->serverObject = Q_NULLPTR;
+    d->serverObject = nullptr;
     d->ref.store(0);
     d->deleteLater();
 }
diff --git a/src/dbus/qdbusserver.h b/src/dbus/qdbusserver.h
index ac4dfcb67f..668b8705b1 100644
--- a/src/dbus/qdbusserver.h
+++ b/src/dbus/qdbusserver.h
@@ -57,8 +57,8 @@ class Q_DBUS_EXPORT QDBusServer: public QObject
 {
     Q_OBJECT
 public:
-    explicit QDBusServer(const QString &address, QObject *parent = Q_NULLPTR);
-    explicit QDBusServer(QObject *parent = Q_NULLPTR);
+    explicit QDBusServer(const QString &address, QObject *parent = nullptr);
+    explicit QDBusServer(QObject *parent = nullptr);
     virtual ~QDBusServer();
 
     bool isConnected() const;
diff --git a/src/dbus/qdbusservicewatcher.h b/src/dbus/qdbusservicewatcher.h
index 77573beb5d..2c45c85cb9 100644
--- a/src/dbus/qdbusservicewatcher.h
+++ b/src/dbus/qdbusservicewatcher.h
@@ -64,9 +64,9 @@ public:
     Q_DECLARE_FLAGS(WatchMode, WatchModeFlag)
     Q_FLAG(WatchMode)
 
-    explicit QDBusServiceWatcher(QObject *parent = Q_NULLPTR);
+    explicit QDBusServiceWatcher(QObject *parent = nullptr);
     QDBusServiceWatcher(const QString &service, const QDBusConnection &connection,
-                        WatchMode watchMode = WatchForOwnerChange, QObject *parent = Q_NULLPTR);
+                        WatchMode watchMode = WatchForOwnerChange, QObject *parent = nullptr);
     ~QDBusServiceWatcher();
 
     QStringList watchedServices() const;
diff --git a/src/dbus/qdbusvirtualobject.h b/src/dbus/qdbusvirtualobject.h
index 1a96d900b4..b69e21b378 100644
--- a/src/dbus/qdbusvirtualobject.h
+++ b/src/dbus/qdbusvirtualobject.h
@@ -56,7 +56,7 @@ class Q_DBUS_EXPORT QDBusVirtualObject : public QObject
 {
     Q_OBJECT
 public:
-    explicit QDBusVirtualObject(QObject *parent = Q_NULLPTR);
+    explicit QDBusVirtualObject(QObject *parent = nullptr);
     virtual ~QDBusVirtualObject();
 
     virtual QString introspect(const QString &path) const = 0;
diff --git a/src/gui/accessible/qaccessible.h b/src/gui/accessible/qaccessible.h
index 27756d764d..1309f17efd 100644
--- a/src/gui/accessible/qaccessible.h
+++ b/src/gui/accessible/qaccessible.h
@@ -511,7 +511,7 @@ public:
     virtual void virtual_hook(int id, void *data);
 
     virtual void *interface_cast(QAccessible::InterfaceType)
-    { return Q_NULLPTR; }
+    { return nullptr; }
 
 protected:
     friend class QAccessibleCache;
@@ -682,7 +682,7 @@ public:
     }
 
     inline QAccessibleEvent(QAccessibleInterface *iface, QAccessible::Event typ)
-        : m_type(typ), m_object(Q_NULLPTR)
+        : m_type(typ), m_object(nullptr)
     {
         Q_ASSERT(iface);
         Q_ASSERT(m_type != QAccessible::ValueChanged);
diff --git a/src/gui/accessible/qaccessiblebridge.h b/src/gui/accessible/qaccessiblebridge.h
index 7429716e65..168889135b 100644
--- a/src/gui/accessible/qaccessiblebridge.h
+++ b/src/gui/accessible/qaccessiblebridge.h
@@ -66,7 +66,7 @@ class Q_GUI_EXPORT QAccessibleBridgePlugin : public QObject
 {
     Q_OBJECT
 public:
-    explicit QAccessibleBridgePlugin(QObject *parent = Q_NULLPTR);
+    explicit QAccessibleBridgePlugin(QObject *parent = nullptr);
     ~QAccessibleBridgePlugin();
 
     virtual QAccessibleBridge *create(const QString &key) = 0;
diff --git a/src/gui/accessible/qaccessiblecache.cpp b/src/gui/accessible/qaccessiblecache.cpp
index 097634c0a3..f4242036ce 100644
--- a/src/gui/accessible/qaccessiblecache.cpp
+++ b/src/gui/accessible/qaccessiblecache.cpp
@@ -54,7 +54,7 @@ static QAccessibleCache *accessibleCache = nullptr;
 static void cleanupAccessibleCache()
 {
     delete accessibleCache;
-    accessibleCache = Q_NULLPTR;
+    accessibleCache = nullptr;
 }
 
 QAccessibleCache *QAccessibleCache::instance()
diff --git a/src/gui/accessible/qaccessibleplugin.h b/src/gui/accessible/qaccessibleplugin.h
index 09d4c542d3..68e6a839d8 100644
--- a/src/gui/accessible/qaccessibleplugin.h
+++ b/src/gui/accessible/qaccessibleplugin.h
@@ -60,7 +60,7 @@ class Q_GUI_EXPORT QAccessiblePlugin : public QObject
 {
     Q_OBJECT
 public:
-    explicit QAccessiblePlugin(QObject *parent = Q_NULLPTR);
+    explicit QAccessiblePlugin(QObject *parent = nullptr);
     ~QAccessiblePlugin();
 
     virtual QAccessibleInterface *create(const QString &key, QObject *object) = 0;
diff --git a/src/gui/image/qbitmap.h b/src/gui/image/qbitmap.h
index def59b3f89..6a8c8b3457 100644
--- a/src/gui/image/qbitmap.h
+++ b/src/gui/image/qbitmap.h
@@ -55,7 +55,7 @@ public:
     QBitmap(const QPixmap &);
     QBitmap(int w, int h);
     explicit QBitmap(const QSize &);
-    explicit QBitmap(const QString &fileName, const char *format = Q_NULLPTR);
+    explicit QBitmap(const QString &fileName, const char *format = nullptr);
     // ### Qt 6: don't inherit QPixmap
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     QBitmap(const QBitmap &other) : QPixmap(other) {}
diff --git a/src/gui/image/qicon.h b/src/gui/image/qicon.h
index 40d3e92af9..4832455c9f 100644
--- a/src/gui/image/qicon.h
+++ b/src/gui/image/qicon.h
@@ -63,7 +63,7 @@ public:
 #ifdef Q_COMPILER_RVALUE_REFS
     QIcon(QIcon &&other) Q_DECL_NOEXCEPT
         : d(other.d)
-    { other.d = Q_NULLPTR; }
+    { other.d = nullptr; }
 #endif
     explicit QIcon(const QString &fileName); // file or resource name
     explicit QIcon(QIconEngine *engine);
@@ -147,7 +147,7 @@ Q_GUI_EXPORT QDebug operator<<(QDebug dbg, const QIcon &);
 #endif
 
 Q_GUI_EXPORT QString qt_findAtNxFile(const QString &baseFileName, qreal targetDevicePixelRatio,
-                                     qreal *sourceDevicePixelRatio = Q_NULLPTR);
+                                     qreal *sourceDevicePixelRatio = nullptr);
 
 QT_END_NAMESPACE
 
diff --git a/src/gui/image/qiconengineplugin.h b/src/gui/image/qiconengineplugin.h
index 7a01d3731c..f2a1c0107a 100644
--- a/src/gui/image/qiconengineplugin.h
+++ b/src/gui/image/qiconengineplugin.h
@@ -55,7 +55,7 @@ class Q_GUI_EXPORT QIconEnginePlugin : public QObject
 {
     Q_OBJECT
 public:
-    QIconEnginePlugin(QObject *parent = Q_NULLPTR);
+    QIconEnginePlugin(QObject *parent = nullptr);
     ~QIconEnginePlugin();
 
     virtual QIconEngine *create(const QString &filename = QString()) = 0;
diff --git a/src/gui/image/qimage.h b/src/gui/image/qimage.h
index dd1751427c..11ad9b7510 100644
--- a/src/gui/image/qimage.h
+++ b/src/gui/image/qimage.h
@@ -136,20 +136,20 @@ public:
     QImage() Q_DECL_NOEXCEPT;
     QImage(const QSize &size, Format format);
     QImage(int width, int height, Format format);
-    QImage(uchar *data, int width, int height, Format format, QImageCleanupFunction cleanupFunction = Q_NULLPTR, void *cleanupInfo = Q_NULLPTR);
-    QImage(const uchar *data, int width, int height, Format format, QImageCleanupFunction cleanupFunction = Q_NULLPTR, void *cleanupInfo = Q_NULLPTR);
-    QImage(uchar *data, int width, int height, int bytesPerLine, Format format, QImageCleanupFunction cleanupFunction = Q_NULLPTR, void *cleanupInfo = Q_NULLPTR);
-    QImage(const uchar *data, int width, int height, int bytesPerLine, Format format, QImageCleanupFunction cleanupFunction = Q_NULLPTR, void *cleanupInfo = Q_NULLPTR);
+    QImage(uchar *data, int width, int height, Format format, QImageCleanupFunction cleanupFunction = nullptr, void *cleanupInfo = nullptr);
+    QImage(const uchar *data, int width, int height, Format format, QImageCleanupFunction cleanupFunction = nullptr, void *cleanupInfo = nullptr);
+    QImage(uchar *data, int width, int height, int bytesPerLine, Format format, QImageCleanupFunction cleanupFunction = nullptr, void *cleanupInfo = nullptr);
+    QImage(const uchar *data, int width, int height, int bytesPerLine, Format format, QImageCleanupFunction cleanupFunction = nullptr, void *cleanupInfo = nullptr);
 
 #ifndef QT_NO_IMAGEFORMAT_XPM
     explicit QImage(const char * const xpm[]);
 #endif
-    explicit QImage(const QString &fileName, const char *format = Q_NULLPTR);
+    explicit QImage(const QString &fileName, const char *format = nullptr);
 
     QImage(const QImage &);
 #ifdef Q_COMPILER_RVALUE_REFS
     inline QImage(QImage &&other) Q_DECL_NOEXCEPT
-        : QPaintDevice(), d(Q_NULLPTR)
+        : QPaintDevice(), d(nullptr)
     { qSwap(d, other.d); }
 #endif
     ~QImage();
@@ -294,16 +294,16 @@ public:
 
 
     bool load(QIODevice *device, const char* format);
-    bool load(const QString &fileName, const char *format = Q_NULLPTR);
-    bool loadFromData(const uchar *buf, int len, const char *format = Q_NULLPTR);
-    inline bool loadFromData(const QByteArray &data, const char *aformat = Q_NULLPTR)
+    bool load(const QString &fileName, const char *format = nullptr);
+    bool loadFromData(const uchar *buf, int len, const char *format = nullptr);
+    inline bool loadFromData(const QByteArray &data, const char *aformat = nullptr)
         { return loadFromData(reinterpret_cast<const uchar *>(data.constData()), data.size(), aformat); }
 
-    bool save(const QString &fileName, const char *format = Q_NULLPTR, int quality = -1) const;
-    bool save(QIODevice *device, const char *format = Q_NULLPTR, int quality = -1) const;
+    bool save(const QString &fileName, const char *format = nullptr, int quality = -1) const;
+    bool save(QIODevice *device, const char *format = nullptr, int quality = -1) const;
 
-    static QImage fromData(const uchar *data, int size, const char *format = Q_NULLPTR);
-    inline static QImage fromData(const QByteArray &data, const char *format = Q_NULLPTR)
+    static QImage fromData(const uchar *data, int size, const char *format = nullptr);
+    inline static QImage fromData(const QByteArray &data, const char *format = nullptr)
         { return fromData(reinterpret_cast<const uchar *>(data.constData()), data.size(), format); }
 
 #if QT_DEPRECATED_SINCE(5, 0)
@@ -335,7 +335,7 @@ public:
 #endif
 
 #if QT_DEPRECATED_SINCE(5, 0)
-    QT_DEPRECATED inline QString text(const char *key, const char *lang = Q_NULLPTR) const;
+    QT_DEPRECATED inline QString text(const char *key, const char *lang = nullptr) const;
     QT_DEPRECATED inline QList<QImageTextKeyLang> textList() const;
     QT_DEPRECATED inline QStringList textLanguages() const;
     QT_DEPRECATED inline QString text(const QImageTextKeyLang&) const;
diff --git a/src/gui/image/qimageiohandler.h b/src/gui/image/qimageiohandler.h
index baf9853259..35984dd6a5 100644
--- a/src/gui/image/qimageiohandler.h
+++ b/src/gui/image/qimageiohandler.h
@@ -140,7 +140,7 @@ class Q_GUI_EXPORT QImageIOPlugin : public QObject
 {
     Q_OBJECT
 public:
-    explicit QImageIOPlugin(QObject *parent = Q_NULLPTR);
+    explicit QImageIOPlugin(QObject *parent = nullptr);
     virtual ~QImageIOPlugin();
 
     enum Capability {
diff --git a/src/gui/image/qmovie.h b/src/gui/image/qmovie.h
index ca559d491b..e13c528894 100644
--- a/src/gui/image/qmovie.h
+++ b/src/gui/image/qmovie.h
@@ -79,9 +79,9 @@ public:
     };
     Q_ENUM(CacheMode)
 
-    explicit QMovie(QObject *parent = Q_NULLPTR);
-    explicit QMovie(QIODevice *device, const QByteArray &format = QByteArray(), QObject *parent = Q_NULLPTR);
-    explicit QMovie(const QString &fileName, const QByteArray &format = QByteArray(), QObject *parent = Q_NULLPTR);
+    explicit QMovie(QObject *parent = nullptr);
+    explicit QMovie(QIODevice *device, const QByteArray &format = QByteArray(), QObject *parent = nullptr);
+    explicit QMovie(const QString &fileName, const QByteArray &format = QByteArray(), QObject *parent = nullptr);
     ~QMovie();
 
     static QList<QByteArray> supportedFormats();
diff --git a/src/gui/image/qpicture.h b/src/gui/image/qpicture.h
index 303806809d..ec7b4bd7e3 100644
--- a/src/gui/image/qpicture.h
+++ b/src/gui/image/qpicture.h
@@ -69,10 +69,10 @@ public:
 
     bool play(QPainter *p);
 
-    bool load(QIODevice *dev, const char *format = Q_NULLPTR);
-    bool load(const QString &fileName, const char *format = Q_NULLPTR);
-    bool save(QIODevice *dev, const char *format = Q_NULLPTR);
-    bool save(const QString &fileName, const char *format = Q_NULLPTR);
+    bool load(QIODevice *dev, const char *format = nullptr);
+    bool load(const QString &fileName, const char *format = nullptr);
+    bool save(QIODevice *dev, const char *format = nullptr);
+    bool save(const QString &fileName, const char *format = nullptr);
 
     QRect boundingRect() const;
     void setBoundingRect(const QRect &r);
diff --git a/src/gui/image/qpictureformatplugin.h b/src/gui/image/qpictureformatplugin.h
index 32195687c7..3f59c04d79 100644
--- a/src/gui/image/qpictureformatplugin.h
+++ b/src/gui/image/qpictureformatplugin.h
@@ -60,7 +60,7 @@ class Q_GUI_EXPORT QPictureFormatPlugin : public QObject
 {
     Q_OBJECT
 public:
-    explicit QPictureFormatPlugin(QObject *parent = Q_NULLPTR);
+    explicit QPictureFormatPlugin(QObject *parent = nullptr);
     ~QPictureFormatPlugin();
 
     virtual bool loadPicture(const QString &format, const QString &filename, QPicture *pic);
diff --git a/src/gui/image/qpixmap.h b/src/gui/image/qpixmap.h
index 822773d3c7..55cca7a766 100644
--- a/src/gui/image/qpixmap.h
+++ b/src/gui/image/qpixmap.h
@@ -65,7 +65,7 @@ public:
     explicit QPixmap(QPlatformPixmap *data);
     QPixmap(int w, int h);
     explicit QPixmap(const QSize &);
-    QPixmap(const QString& fileName, const char *format = Q_NULLPTR, Qt::ImageConversionFlags flags = Qt::AutoColor);
+    QPixmap(const QString& fileName, const char *format = nullptr, Qt::ImageConversionFlags flags = Qt::AutoColor);
 #ifndef QT_NO_IMAGEFORMAT_XPM
     explicit QPixmap(const char * const xpm[]);
 #endif
@@ -138,19 +138,19 @@ public:
     }
 #endif
 
-    bool load(const QString& fileName, const char *format = Q_NULLPTR, Qt::ImageConversionFlags flags = Qt::AutoColor);
-    bool loadFromData(const uchar *buf, uint len, const char* format = Q_NULLPTR, Qt::ImageConversionFlags flags = Qt::AutoColor);
-    inline bool loadFromData(const QByteArray &data, const char* format = Q_NULLPTR, Qt::ImageConversionFlags flags = Qt::AutoColor);
-    bool save(const QString& fileName, const char* format = Q_NULLPTR, int quality = -1) const;
-    bool save(QIODevice* device, const char* format = Q_NULLPTR, int quality = -1) const;
+    bool load(const QString& fileName, const char *format = nullptr, Qt::ImageConversionFlags flags = Qt::AutoColor);
+    bool loadFromData(const uchar *buf, uint len, const char* format = nullptr, Qt::ImageConversionFlags flags = Qt::AutoColor);
+    inline bool loadFromData(const QByteArray &data, const char* format = nullptr, Qt::ImageConversionFlags flags = Qt::AutoColor);
+    bool save(const QString& fileName, const char* format = nullptr, int quality = -1) const;
+    bool save(QIODevice* device, const char* format = nullptr, int quality = -1) const;
 
     bool convertFromImage(const QImage &img, Qt::ImageConversionFlags flags = Qt::AutoColor);
 
     inline QPixmap copy(int x, int y, int width, int height) const;
     QPixmap copy(const QRect &rect = QRect()) const;
 
-    inline void scroll(int dx, int dy, int x, int y, int width, int height, QRegion *exposed = Q_NULLPTR);
-    void scroll(int dx, int dy, const QRect &rect, QRegion *exposed = Q_NULLPTR);
+    inline void scroll(int dx, int dy, int x, int y, int width, int height, QRegion *exposed = nullptr);
+    void scroll(int dx, int dy, const QRect &rect, QRegion *exposed = nullptr);
 
 #if QT_DEPRECATED_SINCE(5, 0)
     QT_DEPRECATED inline int serialNumber() const { return cacheKey() >> 32; }
diff --git a/src/gui/image/qpixmapcache.h b/src/gui/image/qpixmapcache.h
index 856b82f559..ea10ab1b76 100644
--- a/src/gui/image/qpixmapcache.h
+++ b/src/gui/image/qpixmapcache.h
@@ -56,7 +56,7 @@ public:
         Key();
         Key(const Key &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-        Key(Key &&other) Q_DECL_NOTHROW : d(other.d) { other.d = Q_NULLPTR; }
+        Key(Key &&other) Q_DECL_NOTHROW : d(other.d) { other.d = nullptr; }
         Key &operator =(Key &&other) Q_DECL_NOTHROW { swap(other); return *this; }
 #endif
         ~Key();
diff --git a/src/gui/itemmodels/qstandarditemmodel.h b/src/gui/itemmodels/qstandarditemmodel.h
index 547df92891..c54e7b27d9 100644
--- a/src/gui/itemmodels/qstandarditemmodel.h
+++ b/src/gui/itemmodels/qstandarditemmodel.h
@@ -327,8 +327,8 @@ class Q_GUI_EXPORT QStandardItemModel : public QAbstractItemModel
     Q_PROPERTY(int sortRole READ sortRole WRITE setSortRole)
 
 public:
-    explicit QStandardItemModel(QObject *parent = Q_NULLPTR);
-    QStandardItemModel(int rows, int columns, QObject *parent = Q_NULLPTR);
+    explicit QStandardItemModel(QObject *parent = nullptr);
+    QStandardItemModel(int rows, int columns, QObject *parent = nullptr);
     ~QStandardItemModel();
 
     void setItemRoleNames(const QHash<int,QByteArray> &roleNames);
@@ -422,7 +422,7 @@ Q_SIGNALS:
     void itemChanged(QStandardItem *item);
 
 protected:
-    QStandardItemModel(QStandardItemModelPrivate &dd, QObject *parent = Q_NULLPTR);
+    QStandardItemModel(QStandardItemModelPrivate &dd, QObject *parent = nullptr);
 
 private:
     friend class QStandardItemPrivate;
diff --git a/src/gui/kernel/qcursor.h b/src/gui/kernel/qcursor.h
index ccce3d84ef..d62ee7a053 100644
--- a/src/gui/kernel/qcursor.h
+++ b/src/gui/kernel/qcursor.h
@@ -87,7 +87,7 @@ public:
     ~QCursor();
     QCursor &operator=(const QCursor &cursor);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QCursor(QCursor &&other) Q_DECL_NOTHROW : d(other.d) { other.d = Q_NULLPTR; }
+    QCursor(QCursor &&other) Q_DECL_NOTHROW : d(other.d) { other.d = nullptr; }
     inline QCursor &operator=(QCursor &&other) Q_DECL_NOTHROW
     { swap(other); return *this; }
 #endif
diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index b8f86acd75..c4afde8afd 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -717,7 +717,7 @@ class Q_GUI_EXPORT QActionEvent : public QEvent
 {
     QAction *act, *bef;
 public:
-    QActionEvent(int type, QAction *action, QAction *before = Q_NULLPTR);
+    QActionEvent(int type, QAction *action, QAction *before = nullptr);
     ~QActionEvent();
 
     inline QAction *action() const { return act; }
@@ -845,7 +845,7 @@ public:
         TouchPoint(const TouchPoint &other);
 #ifdef Q_COMPILER_RVALUE_REFS
         TouchPoint(TouchPoint &&other) Q_DECL_NOEXCEPT
-            : d(Q_NULLPTR)
+            : d(nullptr)
         { qSwap(d, other.d); }
         TouchPoint &operator=(TouchPoint &&other) Q_DECL_NOEXCEPT
         { qSwap(d, other.d); return *this; }
@@ -933,7 +933,7 @@ public:
 #endif
 
     explicit QTouchEvent(QEvent::Type eventType,
-                         QTouchDevice *device = Q_NULLPTR,
+                         QTouchDevice *device = nullptr,
                          Qt::KeyboardModifiers modifiers = Qt::NoModifier,
                          Qt::TouchPointStates touchPointStates = Qt::TouchPointStates(),
                          const QList<QTouchEvent::TouchPoint> &touchPoints = QList<QTouchEvent::TouchPoint>());
diff --git a/src/gui/kernel/qgenericplugin.h b/src/gui/kernel/qgenericplugin.h
index e8aa2e6f32..69b4f29854 100644
--- a/src/gui/kernel/qgenericplugin.h
+++ b/src/gui/kernel/qgenericplugin.h
@@ -52,7 +52,7 @@ class Q_GUI_EXPORT QGenericPlugin : public QObject
 {
     Q_OBJECT
 public:
-    explicit QGenericPlugin(QObject *parent = Q_NULLPTR);
+    explicit QGenericPlugin(QObject *parent = nullptr);
     ~QGenericPlugin();
 
     virtual QObject* create(const QString& name, const QString &spec) = 0;
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index a29ddbe44e..88d04f978e 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -190,7 +190,7 @@ QWindow *QGuiApplicationPrivate::focus_window = 0;
 
 static QBasicMutex applicationFontMutex;
 QFont *QGuiApplicationPrivate::app_font = 0;
-QStyleHints *QGuiApplicationPrivate::styleHints = Q_NULLPTR;
+QStyleHints *QGuiApplicationPrivate::styleHints = nullptr;
 bool QGuiApplicationPrivate::obey_desktop_settings = true;
 
 QInputDeviceManager *QGuiApplicationPrivate::m_inputDeviceManager = 0;
@@ -748,7 +748,7 @@ QString QGuiApplication::desktopFileName()
 */
 QWindow *QGuiApplication::modalWindow()
 {
-    CHECK_QAPP_INSTANCE(Q_NULLPTR)
+    CHECK_QAPP_INSTANCE(nullptr)
     if (QGuiApplicationPrivate::self->modalWindowList.isEmpty())
         return 0;
     return QGuiApplicationPrivate::self->modalWindowList.first();
@@ -1053,7 +1053,7 @@ QWindow *QGuiApplication::topLevelAt(const QPoint &pos)
     const QList<QScreen *> screens = QGuiApplication::screens();
     if (!screens.isEmpty()) {
         const QList<QScreen *> primaryScreens = screens.first()->virtualSiblings();
-        QScreen *windowScreen = Q_NULLPTR;
+        QScreen *windowScreen = nullptr;
 
         // Find the window on the primary virtual desktop first
         for (QScreen *screen : primaryScreens) {
@@ -1081,7 +1081,7 @@ QWindow *QGuiApplication::topLevelAt(const QPoint &pos)
             return windowScreen->handle()->topLevelAt(devicePosition);
         }
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 /*!
@@ -1526,7 +1526,7 @@ QGuiApplicationPrivate::~QGuiApplicationPrivate()
     cleanupThreadData();
 
     delete QGuiApplicationPrivate::styleHints;
-    QGuiApplicationPrivate::styleHints = Q_NULLPTR;
+    QGuiApplicationPrivate::styleHints = nullptr;
     delete inputMethod;
 
     qt_cleanupFontDatabase();
@@ -1649,10 +1649,10 @@ QFunctionPointer QGuiApplication::platformFunction(const QByteArray &function)
     QPlatformIntegration *pi = QGuiApplicationPrivate::platformIntegration();
     if (!pi) {
         qWarning("QGuiApplication::platformFunction(): Must construct a QGuiApplication before accessing a platform function");
-        return Q_NULLPTR;
+        return nullptr;
     }
 
-    return pi->nativeInterface() ? pi->nativeInterface()->platformFunction(function) : Q_NULLPTR;
+    return pi->nativeInterface() ? pi->nativeInterface()->platformFunction(function) : nullptr;
 }
 
 /*!
@@ -2348,7 +2348,7 @@ void QGuiApplicationPrivate::processTabletEvent(QWindowSystemInterfacePrivate::T
             localValid = false;
         }
         if (type == QEvent::TabletRelease)
-            pointData.target = Q_NULLPTR;
+            pointData.target = nullptr;
         if (!window)
             return;
     }
@@ -3505,7 +3505,7 @@ Qt::LayoutDirection QGuiApplication::layoutDirection()
 #ifndef QT_NO_CURSOR
 QCursor *QGuiApplication::overrideCursor()
 {
-    CHECK_QAPP_INSTANCE(Q_NULLPTR)
+    CHECK_QAPP_INSTANCE(nullptr)
     return qGuiApp->d_func()->cursor_list.isEmpty() ? 0 : &qGuiApp->d_func()->cursor_list.first();
 }
 
@@ -3705,7 +3705,7 @@ bool QGuiApplication::desktopSettingsAware()
   */
 QInputMethod *QGuiApplication::inputMethod()
 {
-    CHECK_QAPP_INSTANCE(Q_NULLPTR)
+    CHECK_QAPP_INSTANCE(nullptr)
     if (!qGuiApp->d_func()->inputMethod)
         qGuiApp->d_func()->inputMethod = new QInputMethod();
     return qGuiApp->d_func()->inputMethod;
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index ee5c5f8cde..b7b847785c 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -213,7 +213,7 @@ public:
     static bool highDpiScalingUpdated;
 
     struct TabletPointData {
-        TabletPointData(qint64 devId = 0) : deviceId(devId), state(Qt::NoButton), target(Q_NULLPTR) {}
+        TabletPointData(qint64 devId = 0) : deviceId(devId), state(Qt::NoButton), target(nullptr) {}
         qint64 deviceId;
         Qt::MouseButtons state;
         QWindow *target;
diff --git a/src/gui/kernel/qoffscreensurface.h b/src/gui/kernel/qoffscreensurface.h
index c3f4656850..9d4839cb25 100644
--- a/src/gui/kernel/qoffscreensurface.h
+++ b/src/gui/kernel/qoffscreensurface.h
@@ -59,7 +59,7 @@ class Q_GUI_EXPORT QOffscreenSurface : public QObject, public QSurface
 public:
     // ### Qt 6: merge overloads
     explicit QOffscreenSurface(QScreen *screen, QObject *parent);
-    explicit QOffscreenSurface(QScreen *screen = Q_NULLPTR);
+    explicit QOffscreenSurface(QScreen *screen = nullptr);
     virtual ~QOffscreenSurface();
 
     SurfaceType surfaceType() const override;
diff --git a/src/gui/kernel/qopenglcontext.h b/src/gui/kernel/qopenglcontext.h
index 07153db84e..9cfaa52f17 100644
--- a/src/gui/kernel/qopenglcontext.h
+++ b/src/gui/kernel/qopenglcontext.h
@@ -151,7 +151,7 @@ class Q_GUI_EXPORT QOpenGLContext : public QObject
     Q_OBJECT
     Q_DECLARE_PRIVATE(QOpenGLContext)
 public:
-    explicit QOpenGLContext(QObject *parent = Q_NULLPTR);
+    explicit QOpenGLContext(QObject *parent = nullptr);
     ~QOpenGLContext();
 
     void setFormat(const QSurfaceFormat &format);
diff --git a/src/gui/kernel/qopenglcontext_p.h b/src/gui/kernel/qopenglcontext_p.h
index eeb1a83283..c5239af69e 100644
--- a/src/gui/kernel/qopenglcontext_p.h
+++ b/src/gui/kernel/qopenglcontext_p.h
@@ -213,7 +213,7 @@ public:
         , workaround_missingPrecisionQualifiers(false)
         , active_engine(0)
         , qgl_current_fbo_invalid(false)
-        , qgl_current_fbo(Q_NULLPTR)
+        , qgl_current_fbo(nullptr)
         , defaultFboRedirect(0)
     {
         requestedFormat = QSurfaceFormat::defaultFormat();
@@ -266,7 +266,7 @@ public:
 
     static QOpenGLContextPrivate *get(QOpenGLContext *context)
     {
-        return context ? context->d_func() : Q_NULLPTR;
+        return context ? context->d_func() : nullptr;
     }
 
 #if !defined(QT_NO_DEBUG)
diff --git a/src/gui/kernel/qopenglwindow.cpp b/src/gui/kernel/qopenglwindow.cpp
index f82430005b..cf3d712421 100644
--- a/src/gui/kernel/qopenglwindow.cpp
+++ b/src/gui/kernel/qopenglwindow.cpp
@@ -344,7 +344,7 @@ void QOpenGLWindowPaintDevice::ensureActiveTarget()
   \sa QOpenGLWindow::UpdateBehavior
  */
 QOpenGLWindow::QOpenGLWindow(QOpenGLWindow::UpdateBehavior updateBehavior, QWindow *parent)
-    : QPaintDeviceWindow(*(new QOpenGLWindowPrivate(Q_NULLPTR, updateBehavior)), parent)
+    : QPaintDeviceWindow(*(new QOpenGLWindowPrivate(nullptr, updateBehavior)), parent)
 {
     setSurfaceType(QSurface::OpenGLSurface);
 }
diff --git a/src/gui/kernel/qopenglwindow.h b/src/gui/kernel/qopenglwindow.h
index 85b380249b..7b3bf004a3 100644
--- a/src/gui/kernel/qopenglwindow.h
+++ b/src/gui/kernel/qopenglwindow.h
@@ -64,8 +64,8 @@ public:
         PartialUpdateBlend
     };
 
-    explicit QOpenGLWindow(UpdateBehavior updateBehavior = NoPartialUpdate, QWindow *parent = Q_NULLPTR);
-    explicit QOpenGLWindow(QOpenGLContext *shareContext, UpdateBehavior updateBehavior = NoPartialUpdate, QWindow *parent = Q_NULLPTR);
+    explicit QOpenGLWindow(UpdateBehavior updateBehavior = NoPartialUpdate, QWindow *parent = nullptr);
+    explicit QOpenGLWindow(QOpenGLContext *shareContext, UpdateBehavior updateBehavior = NoPartialUpdate, QWindow *parent = nullptr);
     ~QOpenGLWindow();
 
     UpdateBehavior updateBehavior() const;
diff --git a/src/gui/kernel/qpalette.h b/src/gui/kernel/qpalette.h
index d04fb1f0c5..71f3d0c3b8 100644
--- a/src/gui/kernel/qpalette.h
+++ b/src/gui/kernel/qpalette.h
@@ -70,7 +70,7 @@ public:
 #ifdef Q_COMPILER_RVALUE_REFS
     QPalette(QPalette &&other) Q_DECL_NOTHROW
         : d(other.d), data(other.data)
-    { other.d = Q_NULLPTR; }
+    { other.d = nullptr; }
     inline QPalette &operator=(QPalette &&other) Q_DECL_NOEXCEPT
     {
         for_faster_swapping_dont_use = other.for_faster_swapping_dont_use;
diff --git a/src/gui/kernel/qplatformgraphicsbuffer.cpp b/src/gui/kernel/qplatformgraphicsbuffer.cpp
index d42231e958..cc01efd6db 100644
--- a/src/gui/kernel/qplatformgraphicsbuffer.cpp
+++ b/src/gui/kernel/qplatformgraphicsbuffer.cpp
@@ -217,7 +217,7 @@ void QPlatformGraphicsBuffer::unlock()
     the memory returned when not having a SWWriteAccess.
 */
 const uchar *QPlatformGraphicsBuffer::data() const
-{ return Q_NULLPTR; }
+{ return nullptr; }
 
 /*!
     Accessor for the bytes of the buffer. This function needs to be called on a
@@ -226,7 +226,7 @@ const uchar *QPlatformGraphicsBuffer::data() const
 */
 uchar *QPlatformGraphicsBuffer::data()
 {
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 /*!
diff --git a/src/gui/kernel/qplatformgraphicsbufferhelper.h b/src/gui/kernel/qplatformgraphicsbufferhelper.h
index 5b7daff65a..6307f54a3e 100644
--- a/src/gui/kernel/qplatformgraphicsbufferhelper.h
+++ b/src/gui/kernel/qplatformgraphicsbufferhelper.h
@@ -47,7 +47,7 @@ QT_BEGIN_NAMESPACE
 
 namespace QPlatformGraphicsBufferHelper {
     bool lockAndBindToTexture(QPlatformGraphicsBuffer *graphicsBuffer, bool *swizzleRandB, bool *premultipliedB, const QRect &rect = QRect());
-    bool bindSWToTexture(const QPlatformGraphicsBuffer *graphicsBuffer, bool *swizzleRandB = Q_NULLPTR, bool *premultipliedB = Q_NULLPTR, const QRect &rect = QRect());
+    bool bindSWToTexture(const QPlatformGraphicsBuffer *graphicsBuffer, bool *swizzleRandB = nullptr, bool *premultipliedB = nullptr, const QRect &rect = QRect());
 }
 
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformnativeinterface.cpp b/src/gui/kernel/qplatformnativeinterface.cpp
index 6614d45b12..b24541d3ec 100644
--- a/src/gui/kernel/qplatformnativeinterface.cpp
+++ b/src/gui/kernel/qplatformnativeinterface.cpp
@@ -92,7 +92,7 @@ void *QPlatformNativeInterface::nativeResourceForCursor(const QByteArray &resour
 {
     Q_UNUSED(resource);
     Q_UNUSED(cursor);
-    return Q_NULLPTR;
+    return nullptr;
 }
 #endif // !QT_NO_CURSOR
 
@@ -129,7 +129,7 @@ QPlatformNativeInterface::NativeResourceForBackingStoreFunction QPlatformNativeI
 QFunctionPointer QPlatformNativeInterface::platformFunction(const QByteArray &function) const
 {
     Q_UNUSED(function);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 /*!
diff --git a/src/gui/kernel/qplatformwindow.cpp b/src/gui/kernel/qplatformwindow.cpp
index ae39411729..2284290d6c 100644
--- a/src/gui/kernel/qplatformwindow.cpp
+++ b/src/gui/kernel/qplatformwindow.cpp
@@ -104,7 +104,7 @@ QPlatformWindow *QPlatformWindow::parent() const
 QPlatformScreen *QPlatformWindow::screen() const
 {
     QScreen *scr = window()->screen();
-    return scr ? scr->handle() : Q_NULLPTR;
+    return scr ? scr->handle() : nullptr;
 }
 
 /*!
diff --git a/src/gui/kernel/qrasterwindow.h b/src/gui/kernel/qrasterwindow.h
index 6dee03c3ad..9fe01c076b 100644
--- a/src/gui/kernel/qrasterwindow.h
+++ b/src/gui/kernel/qrasterwindow.h
@@ -53,7 +53,7 @@ class Q_GUI_EXPORT QRasterWindow : public QPaintDeviceWindow
     Q_DECLARE_PRIVATE(QRasterWindow)
 
 public:
-    explicit QRasterWindow(QWindow *parent = Q_NULLPTR);
+    explicit QRasterWindow(QWindow *parent = nullptr);
     ~QRasterWindow();
 
 protected:
diff --git a/src/gui/kernel/qsimpledrag.cpp b/src/gui/kernel/qsimpledrag.cpp
index 481971f21a..1fba649354 100644
--- a/src/gui/kernel/qsimpledrag.cpp
+++ b/src/gui/kernel/qsimpledrag.cpp
@@ -97,7 +97,7 @@ QBasicDrag::QBasicDrag() :
     m_restoreCursor(false), m_eventLoop(0),
     m_executed_drop_action(Qt::IgnoreAction), m_can_drop(false),
     m_drag(0), m_drag_icon_window(0), m_useCompositing(true),
-    m_screen(Q_NULLPTR)
+    m_screen(nullptr)
 {
 }
 
diff --git a/src/gui/kernel/qwindow.h b/src/gui/kernel/qwindow.h
index be8f10529d..cbb0c6a51c 100644
--- a/src/gui/kernel/qwindow.h
+++ b/src/gui/kernel/qwindow.h
@@ -141,7 +141,7 @@ public:
     };
     Q_ENUM(AncestorMode)
 
-    explicit QWindow(QScreen *screen = Q_NULLPTR);
+    explicit QWindow(QScreen *screen = nullptr);
     explicit QWindow(QWindow *parent);
     virtual ~QWindow();
 
@@ -380,12 +380,12 @@ private:
 #ifndef Q_QDOC
 template <> inline QWindow *qobject_cast<QWindow*>(QObject *o)
 {
-    if (!o || !o->isWindowType()) return Q_NULLPTR;
+    if (!o || !o->isWindowType()) return nullptr;
     return static_cast<QWindow*>(o);
 }
 template <> inline const QWindow *qobject_cast<const QWindow*>(const QObject *o)
 {
-    if (!o || !o->isWindowType()) return Q_NULLPTR;
+    if (!o || !o->isWindowType()) return nullptr;
     return static_cast<const QWindow*>(o);
 }
 #endif // !Q_QDOC
diff --git a/src/gui/kernel/qwindowsysteminterface.h b/src/gui/kernel/qwindowsysteminterface.h
index 7ea7b072f0..566abe37a9 100644
--- a/src/gui/kernel/qwindowsysteminterface.h
+++ b/src/gui/kernel/qwindowsysteminterface.h
@@ -166,7 +166,7 @@ public:
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
     static void handleExposeEvent(QWindow *window, const QRegion &region);
 
-    static void handleCloseEvent(QWindow *window, bool *accepted = Q_NULLPTR);
+    static void handleCloseEvent(QWindow *window, bool *accepted = nullptr);
 
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
     static void handleEnterEvent(QWindow *window, const QPointF &local = QPointF(), const QPointF& global = QPointF());
diff --git a/src/gui/kernel/qwindowsysteminterface_p.h b/src/gui/kernel/qwindowsysteminterface_p.h
index ef993501f8..060aaa4db7 100644
--- a/src/gui/kernel/qwindowsysteminterface_p.h
+++ b/src/gui/kernel/qwindowsysteminterface_p.h
@@ -512,7 +512,7 @@ public:
 
     static QList<QTouchEvent::TouchPoint>
         fromNativeTouchPoints(const QList<QWindowSystemInterface::TouchPoint> &points,
-                              const QWindow *window, quint8 deviceId, QEvent::Type *type = Q_NULLPTR);
+                              const QWindow *window, quint8 deviceId, QEvent::Type *type = nullptr);
     static QList<QWindowSystemInterface::TouchPoint>
         toNativeTouchPoints(const QList<QTouchEvent::TouchPoint>& pointList,
                             const QWindow *window);
diff --git a/src/gui/math3d/qmatrix4x4.h b/src/gui/math3d/qmatrix4x4.h
index 4db96d07c0..054deffd73 100644
--- a/src/gui/math3d/qmatrix4x4.h
+++ b/src/gui/math3d/qmatrix4x4.h
@@ -93,7 +93,7 @@ public:
     inline void fill(float value);
 
     double determinant() const;
-    QMatrix4x4 inverted(bool *invertible = Q_NULLPTR) const;
+    QMatrix4x4 inverted(bool *invertible = nullptr) const;
     QMatrix4x4 transposed() const;
     QMatrix3x3 normalMatrix() const;
 
diff --git a/src/gui/opengl/qopengl.cpp b/src/gui/opengl/qopengl.cpp
index 7e663d48bb..3a476978e7 100644
--- a/src/gui/opengl/qopengl.cpp
+++ b/src/gui/opengl/qopengl.cpp
@@ -143,7 +143,7 @@ typedef QJsonArray::ConstIterator JsonArrayConstIt;
 static inline bool contains(const QJsonArray &haystack, unsigned needle)
 {
     for (JsonArrayConstIt it = haystack.constBegin(), cend = haystack.constEnd(); it != cend; ++it) {
-        if (needle == it->toString().toUInt(Q_NULLPTR, /* base */ 0))
+        if (needle == it->toString().toUInt(nullptr, /* base */ 0))
             return true;
     }
     return false;
@@ -331,7 +331,7 @@ static bool matches(const QJsonObject &object,
 
     const QJsonValue vendorV = object.value(QLatin1String("vendor_id"));
     if (vendorV.isString()) {
-        if (gpu.vendorId != vendorV.toString().toUInt(Q_NULLPTR, /* base */ 0))
+        if (gpu.vendorId != vendorV.toString().toUInt(nullptr, /* base */ 0))
             return false;
     } else {
         if (object.contains(QLatin1String("gl_vendor"))) {
diff --git a/src/gui/opengl/qopenglbuffer.h b/src/gui/opengl/qopenglbuffer.h
index f2dfec3bb4..a810783731 100644
--- a/src/gui/opengl/qopenglbuffer.h
+++ b/src/gui/opengl/qopenglbuffer.h
@@ -124,7 +124,7 @@ public:
     void write(int offset, const void *data, int count);
 
     void allocate(const void *data, int count);
-    inline void allocate(int count) { allocate(Q_NULLPTR, count); }
+    inline void allocate(int count) { allocate(nullptr, count); }
 
     void *map(QOpenGLBuffer::Access access);
     void *mapRange(int offset, int count, QOpenGLBuffer::RangeAccessFlags access);
diff --git a/src/gui/opengl/qopengldebug.h b/src/gui/opengl/qopengldebug.h
index 6b10c36291..556ec175e1 100644
--- a/src/gui/opengl/qopengldebug.h
+++ b/src/gui/opengl/qopengldebug.h
@@ -167,7 +167,7 @@ public:
     };
     Q_ENUM(LoggingMode)
 
-    explicit QOpenGLDebugLogger(QObject *parent = Q_NULLPTR);
+    explicit QOpenGLDebugLogger(QObject *parent = nullptr);
     ~QOpenGLDebugLogger();
 
     bool initialize();
diff --git a/src/gui/opengl/qopenglextrafunctions.h b/src/gui/opengl/qopenglextrafunctions.h
index 81716fb8d3..a68e269065 100644
--- a/src/gui/opengl/qopenglextrafunctions.h
+++ b/src/gui/opengl/qopenglextrafunctions.h
@@ -511,7 +511,7 @@ public:
     void glTexStorage3DMultisample(GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height, GLsizei depth, GLboolean fixedsamplelocations);
 
 private:
-    static bool isInitialized(const QOpenGLExtraFunctionsPrivate *d) { return d != Q_NULLPTR; }
+    static bool isInitialized(const QOpenGLExtraFunctionsPrivate *d) { return d != nullptr; }
 };
 
 
diff --git a/src/gui/opengl/qopenglframebufferobject.cpp b/src/gui/opengl/qopenglframebufferobject.cpp
index b56bcd0866..628475a90a 100644
--- a/src/gui/opengl/qopenglframebufferobject.cpp
+++ b/src/gui/opengl/qopenglframebufferobject.cpp
@@ -953,7 +953,7 @@ QOpenGLFramebufferObject::~QOpenGLFramebufferObject()
     QOpenGLContextPrivate *contextPrv = QOpenGLContextPrivate::get(QOpenGLContext::currentContext());
     if (contextPrv && contextPrv->qgl_current_fbo == this) {
         contextPrv->qgl_current_fbo_invalid = true;
-        contextPrv->qgl_current_fbo = Q_NULLPTR;
+        contextPrv->qgl_current_fbo = nullptr;
     }
 }
 
@@ -1116,7 +1116,7 @@ bool QOpenGLFramebufferObject::release()
 
         QOpenGLContextPrivate *contextPrv = QOpenGLContextPrivate::get(current);
         contextPrv->qgl_current_fbo_invalid = true;
-        contextPrv->qgl_current_fbo = Q_NULLPTR;
+        contextPrv->qgl_current_fbo = nullptr;
     }
 
     return true;
@@ -1472,7 +1472,7 @@ bool QOpenGLFramebufferObject::bindDefault()
     if (ctx) {
         ctx->functions()->glBindFramebuffer(GL_FRAMEBUFFER, ctx->defaultFramebufferObject());
         QOpenGLContextPrivate::get(ctx)->qgl_current_fbo_invalid = true;
-        QOpenGLContextPrivate::get(ctx)->qgl_current_fbo = Q_NULLPTR;
+        QOpenGLContextPrivate::get(ctx)->qgl_current_fbo = nullptr;
     }
 #ifdef QT_DEBUG
     else
diff --git a/src/gui/opengl/qopenglfunctions.h b/src/gui/opengl/qopenglfunctions.h
index 0a5de2c9af..273ceaddc0 100644
--- a/src/gui/opengl/qopenglfunctions.h
+++ b/src/gui/opengl/qopenglfunctions.h
@@ -413,7 +413,7 @@ public:
 
 protected:
     QOpenGLFunctionsPrivate *d_ptr;
-    static bool isInitialized(const QOpenGLFunctionsPrivate *d) { return d != Q_NULLPTR; }
+    static bool isInitialized(const QOpenGLFunctionsPrivate *d) { return d != nullptr; }
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QOpenGLFunctions::OpenGLFeatures)
diff --git a/src/gui/opengl/qopenglfunctions_2_0.cpp b/src/gui/opengl/qopenglfunctions_2_0.cpp
index c175b13c5b..212723aa00 100644
--- a/src/gui/opengl/qopenglfunctions_2_0.cpp
+++ b/src/gui/opengl/qopenglfunctions_2_0.cpp
@@ -79,7 +79,7 @@ QOpenGLFunctions_2_0::QOpenGLFunctions_2_0()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
 {
 }
 
diff --git a/src/gui/opengl/qopenglfunctions_2_1.cpp b/src/gui/opengl/qopenglfunctions_2_1.cpp
index 4e77efd121..b8b255014c 100644
--- a/src/gui/opengl/qopenglfunctions_2_1.cpp
+++ b/src/gui/opengl/qopenglfunctions_2_1.cpp
@@ -80,7 +80,7 @@ QOpenGLFunctions_2_1::QOpenGLFunctions_2_1()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
 {
 }
 
diff --git a/src/gui/opengl/qopenglfunctions_3_0.cpp b/src/gui/opengl/qopenglfunctions_3_0.cpp
index 09e3ad09ef..4972c03b1e 100644
--- a/src/gui/opengl/qopenglfunctions_3_0.cpp
+++ b/src/gui/opengl/qopenglfunctions_3_0.cpp
@@ -81,8 +81,8 @@ QOpenGLFunctions_3_0::QOpenGLFunctions_3_0()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
- , m_reserved_3_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
+ , m_reserved_3_0_Deprecated(nullptr)
 {
 }
 
diff --git a/src/gui/opengl/qopenglfunctions_3_2_compatibility.cpp b/src/gui/opengl/qopenglfunctions_3_2_compatibility.cpp
index b90a123bfe..709f65edf8 100644
--- a/src/gui/opengl/qopenglfunctions_3_2_compatibility.cpp
+++ b/src/gui/opengl/qopenglfunctions_3_2_compatibility.cpp
@@ -83,8 +83,8 @@ QOpenGLFunctions_3_2_Compatibility::QOpenGLFunctions_3_2_Compatibility()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
- , m_reserved_3_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
+ , m_reserved_3_0_Deprecated(nullptr)
 {
 }
 
diff --git a/src/gui/opengl/qopenglfunctions_3_3_compatibility.cpp b/src/gui/opengl/qopenglfunctions_3_3_compatibility.cpp
index c585f0fc7c..b034391c86 100644
--- a/src/gui/opengl/qopenglfunctions_3_3_compatibility.cpp
+++ b/src/gui/opengl/qopenglfunctions_3_3_compatibility.cpp
@@ -84,7 +84,7 @@ QOpenGLFunctions_3_3_Compatibility::QOpenGLFunctions_3_3_Compatibility()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
  , d_3_3_Deprecated(0)
 {
 }
diff --git a/src/gui/opengl/qopenglfunctions_4_0_compatibility.cpp b/src/gui/opengl/qopenglfunctions_4_0_compatibility.cpp
index b5c423ef0c..4fe4526efc 100644
--- a/src/gui/opengl/qopenglfunctions_4_0_compatibility.cpp
+++ b/src/gui/opengl/qopenglfunctions_4_0_compatibility.cpp
@@ -85,7 +85,7 @@ QOpenGLFunctions_4_0_Compatibility::QOpenGLFunctions_4_0_Compatibility()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
  , d_3_3_Deprecated(0)
 {
 }
diff --git a/src/gui/opengl/qopenglfunctions_4_1_compatibility.cpp b/src/gui/opengl/qopenglfunctions_4_1_compatibility.cpp
index 72c60c74b7..41ecb4672a 100644
--- a/src/gui/opengl/qopenglfunctions_4_1_compatibility.cpp
+++ b/src/gui/opengl/qopenglfunctions_4_1_compatibility.cpp
@@ -86,7 +86,7 @@ QOpenGLFunctions_4_1_Compatibility::QOpenGLFunctions_4_1_Compatibility()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
  , d_3_3_Deprecated(0)
 {
 }
diff --git a/src/gui/opengl/qopenglfunctions_4_2_compatibility.cpp b/src/gui/opengl/qopenglfunctions_4_2_compatibility.cpp
index 8398ef0948..fcc049c67b 100644
--- a/src/gui/opengl/qopenglfunctions_4_2_compatibility.cpp
+++ b/src/gui/opengl/qopenglfunctions_4_2_compatibility.cpp
@@ -87,7 +87,7 @@ QOpenGLFunctions_4_2_Compatibility::QOpenGLFunctions_4_2_Compatibility()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
  , d_3_3_Deprecated(0)
 {
 }
diff --git a/src/gui/opengl/qopenglfunctions_4_3_compatibility.cpp b/src/gui/opengl/qopenglfunctions_4_3_compatibility.cpp
index 19e67c6331..131ebc810f 100644
--- a/src/gui/opengl/qopenglfunctions_4_3_compatibility.cpp
+++ b/src/gui/opengl/qopenglfunctions_4_3_compatibility.cpp
@@ -88,7 +88,7 @@ QOpenGLFunctions_4_3_Compatibility::QOpenGLFunctions_4_3_Compatibility()
  , d_1_2_Deprecated(0)
  , d_1_3_Deprecated(0)
  , d_1_4_Deprecated(0)
- , m_reserved_2_0_Deprecated(Q_NULLPTR)
+ , m_reserved_2_0_Deprecated(nullptr)
  , d_3_3_Deprecated(0)
 {
 }
diff --git a/src/gui/opengl/qopenglshaderprogram.h b/src/gui/opengl/qopenglshaderprogram.h
index fd4d82ecf9..84eb8d6956 100644
--- a/src/gui/opengl/qopenglshaderprogram.h
+++ b/src/gui/opengl/qopenglshaderprogram.h
@@ -79,7 +79,7 @@ public:
     };
     Q_DECLARE_FLAGS(ShaderType, ShaderTypeBit)
 
-    explicit QOpenGLShader(QOpenGLShader::ShaderType type, QObject *parent = Q_NULLPTR);
+    explicit QOpenGLShader(QOpenGLShader::ShaderType type, QObject *parent = nullptr);
     virtual ~QOpenGLShader();
 
     QOpenGLShader::ShaderType shaderType() const;
@@ -96,7 +96,7 @@ public:
 
     GLuint shaderId() const;
 
-    static bool hasOpenGLShaders(ShaderType type, QOpenGLContext *context = Q_NULLPTR);
+    static bool hasOpenGLShaders(ShaderType type, QOpenGLContext *context = nullptr);
 
 private:
     friend class QOpenGLShaderProgram;
@@ -114,7 +114,7 @@ class Q_GUI_EXPORT QOpenGLShaderProgram : public QObject
 {
     Q_OBJECT
 public:
-    explicit QOpenGLShaderProgram(QObject *parent = Q_NULLPTR);
+    explicit QOpenGLShaderProgram(QObject *parent = nullptr);
     virtual ~QOpenGLShaderProgram();
 
     bool addShader(QOpenGLShader *shader);
@@ -306,7 +306,7 @@ public:
     void setUniformValueArray(const char *name, const QMatrix4x3 *values, int count);
     void setUniformValueArray(const char *name, const QMatrix4x4 *values, int count);
 
-    static bool hasOpenGLShaderPrograms(QOpenGLContext *context = Q_NULLPTR);
+    static bool hasOpenGLShaderPrograms(QOpenGLContext *context = nullptr);
 
 private Q_SLOTS:
     void shaderDestroyed();
diff --git a/src/gui/opengl/qopengltexture.h b/src/gui/opengl/qopengltexture.h
index 12d9b91603..c0c5283374 100644
--- a/src/gui/opengl/qopengltexture.h
+++ b/src/gui/opengl/qopengltexture.h
@@ -459,60 +459,60 @@ public:
 #if QT_DEPRECATED_SINCE(5, 3)
     QT_DEPRECATED void setData(int mipLevel, int layer, CubeMapFace cubeFace,
                                PixelFormat sourceFormat, PixelType sourceType,
-                               void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                               void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     QT_DEPRECATED void setData(int mipLevel, int layer,
                                PixelFormat sourceFormat, PixelType sourceType,
-                               void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                               void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     QT_DEPRECATED void setData(int mipLevel,
                                PixelFormat sourceFormat, PixelType sourceType,
-                               void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                               void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     QT_DEPRECATED void setData(PixelFormat sourceFormat, PixelType sourceType,
-                               void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                               void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
 #endif // QT_DEPRECATED_SINCE(5, 3)
 
     void setData(int mipLevel, int layer, CubeMapFace cubeFace,
                  PixelFormat sourceFormat, PixelType sourceType,
-                 const void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                 const void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     void setData(int mipLevel, int layer, int layerCount, CubeMapFace cubeFace,
                  PixelFormat sourceFormat, PixelType sourceType,
-                 const void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                 const void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     void setData(int mipLevel, int layer,
                  PixelFormat sourceFormat, PixelType sourceType,
-                 const void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                 const void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     void setData(int mipLevel,
                  PixelFormat sourceFormat, PixelType sourceType,
-                 const void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                 const void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
     void setData(PixelFormat sourceFormat, PixelType sourceType,
-                 const void *data, const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                 const void *data, const QOpenGLPixelTransferOptions * const options = nullptr);
 
     // Compressed data upload
     // ### Qt 6: remove the non-const void * overloads
 #if QT_DEPRECATED_SINCE(5, 3)
     QT_DEPRECATED void setCompressedData(int mipLevel, int layer, CubeMapFace cubeFace,
                                          int dataSize, void *data,
-                                         const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                                         const QOpenGLPixelTransferOptions * const options = nullptr);
     QT_DEPRECATED void setCompressedData(int mipLevel, int layer,
                                          int dataSize, void *data,
-                                         const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                                         const QOpenGLPixelTransferOptions * const options = nullptr);
     QT_DEPRECATED void setCompressedData(int mipLevel, int dataSize, void *data,
-                                         const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                                         const QOpenGLPixelTransferOptions * const options = nullptr);
     QT_DEPRECATED void setCompressedData(int dataSize, void *data,
-                                         const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                                         const QOpenGLPixelTransferOptions * const options = nullptr);
 #endif // QT_DEPRECATED_SINCE(5, 3)
 
     void setCompressedData(int mipLevel, int layer, CubeMapFace cubeFace,
                            int dataSize, const void *data,
-                           const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                           const QOpenGLPixelTransferOptions * const options = nullptr);
     void setCompressedData(int mipLevel, int layer, int layerCount, CubeMapFace cubeFace,
                            int dataSize, const void *data,
-                           const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                           const QOpenGLPixelTransferOptions * const options = nullptr);
     void setCompressedData(int mipLevel, int layer,
                            int dataSize, const void *data,
-                           const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                           const QOpenGLPixelTransferOptions * const options = nullptr);
     void setCompressedData(int mipLevel, int dataSize, const void *data,
-                           const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                           const QOpenGLPixelTransferOptions * const options = nullptr);
     void setCompressedData(int dataSize, const void *data,
-                           const QOpenGLPixelTransferOptions * const options = Q_NULLPTR);
+                           const QOpenGLPixelTransferOptions * const options = nullptr);
 
     // Helpful overloads for setData
     void setData(const QImage& image, MipMapGeneration genMipMaps = GenerateMipMaps);
diff --git a/src/gui/opengl/qopengltimerquery.h b/src/gui/opengl/qopengltimerquery.h
index 7b9ab850e2..27da74a3fb 100644
--- a/src/gui/opengl/qopengltimerquery.h
+++ b/src/gui/opengl/qopengltimerquery.h
@@ -56,7 +56,7 @@ class Q_GUI_EXPORT QOpenGLTimerQuery : public QObject
     Q_OBJECT
 
 public:
-    explicit QOpenGLTimerQuery(QObject *parent = Q_NULLPTR);
+    explicit QOpenGLTimerQuery(QObject *parent = nullptr);
     ~QOpenGLTimerQuery();
 
     bool create();
@@ -84,7 +84,7 @@ class Q_GUI_EXPORT QOpenGLTimeMonitor : public QObject
     Q_OBJECT
 
 public:
-    explicit QOpenGLTimeMonitor(QObject *parent = Q_NULLPTR);
+    explicit QOpenGLTimeMonitor(QObject *parent = nullptr);
     ~QOpenGLTimeMonitor();
 
     void setSampleCount(int sampleCount);
diff --git a/src/gui/opengl/qopenglversionfunctions.h b/src/gui/opengl/qopenglversionfunctions.h
index 63209cf392..3af1ed0466 100644
--- a/src/gui/opengl/qopenglversionfunctions.h
+++ b/src/gui/opengl/qopenglversionfunctions.h
@@ -193,7 +193,7 @@ class QAbstractOpenGLFunctionsPrivate
 {
 public:
     QAbstractOpenGLFunctionsPrivate()
-        : owningContext(Q_NULLPTR),
+        : owningContext(nullptr),
           initialized(false)
     {}
 
diff --git a/src/gui/opengl/qopenglvertexarrayobject.h b/src/gui/opengl/qopenglvertexarrayobject.h
index a8153ea40b..b81ae6a2a9 100644
--- a/src/gui/opengl/qopenglvertexarrayobject.h
+++ b/src/gui/opengl/qopenglvertexarrayobject.h
@@ -56,7 +56,7 @@ class Q_GUI_EXPORT QOpenGLVertexArrayObject : public QObject
     Q_OBJECT
 
 public:
-    explicit QOpenGLVertexArrayObject(QObject* parent = Q_NULLPTR);
+    explicit QOpenGLVertexArrayObject(QObject* parent = nullptr);
     ~QOpenGLVertexArrayObject();
 
     bool create();
diff --git a/src/gui/opengl/qopenglvertexarrayobject_p.h b/src/gui/opengl/qopenglvertexarrayobject_p.h
index 937921765b..fd3a6f0f89 100644
--- a/src/gui/opengl/qopenglvertexarrayobject_p.h
+++ b/src/gui/opengl/qopenglvertexarrayobject_p.h
@@ -70,10 +70,10 @@ class QOpenGLVertexArrayObjectHelper
 
 public:
     explicit inline QOpenGLVertexArrayObjectHelper(QOpenGLContext *context)
-        : GenVertexArrays(Q_NULLPTR)
-        , DeleteVertexArrays(Q_NULLPTR)
-        , BindVertexArray(Q_NULLPTR)
-        , IsVertexArray(Q_NULLPTR)
+        : GenVertexArrays(nullptr)
+        , DeleteVertexArrays(nullptr)
+        , BindVertexArray(nullptr)
+        , IsVertexArray(nullptr)
     {
         qtInitializeVertexArrayObjectHelper(this, context);
     }
diff --git a/src/gui/painting/qcolor.h b/src/gui/painting/qcolor.h
index 0c5ebcbda9..f7a9e9db59 100644
--- a/src/gui/painting/qcolor.h
+++ b/src/gui/painting/qcolor.h
@@ -129,10 +129,10 @@ public:
     void setGreenF(qreal green);
     void setBlueF(qreal blue);
 
-    void getRgb(int *r, int *g, int *b, int *a = Q_NULLPTR) const;
+    void getRgb(int *r, int *g, int *b, int *a = nullptr) const;
     void setRgb(int r, int g, int b, int a = 255);
 
-    void getRgbF(qreal *r, qreal *g, qreal *b, qreal *a = Q_NULLPTR) const;
+    void getRgbF(qreal *r, qreal *g, qreal *b, qreal *a = nullptr) const;
     void setRgbF(qreal r, qreal g, qreal b, qreal a = 1.0);
 
     QRgba64 rgba64() const Q_DECL_NOTHROW;
@@ -156,10 +156,10 @@ public:
     qreal hsvSaturationF() const Q_DECL_NOTHROW;
     qreal valueF() const Q_DECL_NOTHROW;
 
-    void getHsv(int *h, int *s, int *v, int *a = Q_NULLPTR) const;
+    void getHsv(int *h, int *s, int *v, int *a = nullptr) const;
     void setHsv(int h, int s, int v, int a = 255);
 
-    void getHsvF(qreal *h, qreal *s, qreal *v, qreal *a = Q_NULLPTR) const;
+    void getHsvF(qreal *h, qreal *s, qreal *v, qreal *a = nullptr) const;
     void setHsvF(qreal h, qreal s, qreal v, qreal a = 1.0);
 
     int cyan() const Q_DECL_NOTHROW;
@@ -172,10 +172,10 @@ public:
     qreal yellowF() const Q_DECL_NOTHROW;
     qreal blackF() const Q_DECL_NOTHROW;
 
-    void getCmyk(int *c, int *m, int *y, int *k, int *a = Q_NULLPTR);
+    void getCmyk(int *c, int *m, int *y, int *k, int *a = nullptr);
     void setCmyk(int c, int m, int y, int k, int a = 255);
 
-    void getCmykF(qreal *c, qreal *m, qreal *y, qreal *k, qreal *a = Q_NULLPTR);
+    void getCmykF(qreal *c, qreal *m, qreal *y, qreal *k, qreal *a = nullptr);
     void setCmykF(qreal c, qreal m, qreal y, qreal k, qreal a = 1.0);
 
     int hslHue() const Q_DECL_NOTHROW; // 0 <= hue < 360
@@ -186,10 +186,10 @@ public:
     qreal hslSaturationF() const Q_DECL_NOTHROW;
     qreal lightnessF() const Q_DECL_NOTHROW;
 
-    void getHsl(int *h, int *s, int *l, int *a = Q_NULLPTR) const;
+    void getHsl(int *h, int *s, int *l, int *a = nullptr) const;
     void setHsl(int h, int s, int l, int a = 255);
 
-    void getHslF(qreal *h, qreal *s, qreal *l, qreal *a = Q_NULLPTR) const;
+    void getHslF(qreal *h, qreal *s, qreal *l, qreal *a = nullptr) const;
     void setHslF(qreal h, qreal s, qreal l, qreal a = 1.0);
 
     QColor toRgb() const Q_DECL_NOTHROW;
diff --git a/src/gui/painting/qmatrix.h b/src/gui/painting/qmatrix.h
index 15e0ab5be1..74ecef767e 100644
--- a/src/gui/painting/qmatrix.h
+++ b/src/gui/painting/qmatrix.h
@@ -108,7 +108,7 @@ public:
     bool isInvertible() const { return !qFuzzyIsNull(_m11*_m22 - _m12*_m21); }
     qreal determinant() const { return _m11*_m22 - _m12*_m21; }
 
-    Q_REQUIRED_RESULT QMatrix inverted(bool *invertible = Q_NULLPTR) const;
+    Q_REQUIRED_RESULT QMatrix inverted(bool *invertible = nullptr) const;
 
     bool operator==(const QMatrix &) const;
     bool operator!=(const QMatrix &) const;
diff --git a/src/gui/painting/qpainter.h b/src/gui/painting/qpainter.h
index 64d15d5296..12a9c720a8 100644
--- a/src/gui/painting/qpainter.h
+++ b/src/gui/painting/qpainter.h
@@ -416,9 +416,9 @@ public:
 
     void drawText(const QPointF &p, const QString &str, int tf, int justificationPadding);
 
-    void drawText(const QRectF &r, int flags, const QString &text, QRectF *br = Q_NULLPTR);
-    void drawText(const QRect &r, int flags, const QString &text, QRect *br = Q_NULLPTR);
-    inline void drawText(int x, int y, int w, int h, int flags, const QString &text, QRect *br = Q_NULLPTR);
+    void drawText(const QRectF &r, int flags, const QString &text, QRectF *br = nullptr);
+    void drawText(const QRect &r, int flags, const QString &text, QRect *br = nullptr);
+    inline void drawText(int x, int y, int w, int h, int flags, const QString &text, QRect *br = nullptr);
 
     void drawText(const QRectF &r, const QString &text, const QTextOption &o = QTextOption());
 
@@ -461,7 +461,7 @@ public:
 
     static void setRedirected(const QPaintDevice *device, QPaintDevice *replacement,
                               const QPoint& offset = QPoint());
-    static QPaintDevice *redirected(const QPaintDevice *device, QPoint *offset = Q_NULLPTR);
+    static QPaintDevice *redirected(const QPaintDevice *device, QPoint *offset = nullptr);
     static void restoreRedirected(const QPaintDevice *device);
 
     void beginNativePainting();
diff --git a/src/gui/painting/qpen.h b/src/gui/painting/qpen.h
index d8d99ba800..03abfb3d7d 100644
--- a/src/gui/painting/qpen.h
+++ b/src/gui/painting/qpen.h
@@ -72,7 +72,7 @@ public:
     QPen &operator=(const QPen &pen) Q_DECL_NOTHROW;
 #ifdef Q_COMPILER_RVALUE_REFS
     QPen(QPen &&other) Q_DECL_NOTHROW
-        : d(other.d) { other.d = Q_NULLPTR; }
+        : d(other.d) { other.d = nullptr; }
     QPen &operator=(QPen &&other) Q_DECL_NOTHROW
     { qSwap(d, other.d); return *this; }
 #endif
diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp
index 6cb115afba..4d1c4932c8 100644
--- a/src/gui/painting/qplatformbackingstore.cpp
+++ b/src/gui/painting/qplatformbackingstore.cpp
@@ -690,7 +690,7 @@ void QPlatformBackingStore::endPaint()
 */
 QPlatformGraphicsBuffer *QPlatformBackingStore::graphicsBuffer() const
 {
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 /*!
diff --git a/src/gui/painting/qregion.cpp b/src/gui/painting/qregion.cpp
index ba8defbfe3..1b8aae16e1 100644
--- a/src/gui/painting/qregion.cpp
+++ b/src/gui/painting/qregion.cpp
@@ -3620,7 +3620,7 @@ static void PtsToRegion(int numFullPtBlocks, int iCurPtBlock,
                 }
 
                 if (rowSize) {
-                    QPoint *next = i ? &pts[2] : (numFullPtBlocks && iCurPtBlock ? CurPtBlock->next->pts : Q_NULLPTR);
+                    QPoint *next = i ? &pts[2] : (numFullPtBlocks && iCurPtBlock ? CurPtBlock->next->pts : nullptr);
 
                     if (!next || next->y() != pts[0].y()) {
                         flushRow(row.data(), pts[0].y(), rowSize, reg, &lastRow, &extendTo, &needsExtend);
diff --git a/src/gui/painting/qtransform.cpp b/src/gui/painting/qtransform.cpp
index 7f06915444..7a53c44bc4 100644
--- a/src/gui/painting/qtransform.cpp
+++ b/src/gui/painting/qtransform.cpp
@@ -265,7 +265,7 @@ QTransform::QTransform()
     , m_13(0), m_23(0), m_33(1)
     , m_type(TxNone)
     , m_dirty(TxNone)
-    , d(Q_NULLPTR)
+    , d(nullptr)
 {
 }
 
@@ -284,7 +284,7 @@ QTransform::QTransform(qreal h11, qreal h12, qreal h13,
     , m_13(h13), m_23(h23), m_33(h33)
     , m_type(TxNone)
     , m_dirty(TxProject)
-    , d(Q_NULLPTR)
+    , d(nullptr)
 {
 }
 
@@ -301,7 +301,7 @@ QTransform::QTransform(qreal h11, qreal h12, qreal h21,
     , m_13(0), m_23(0), m_33(1)
     , m_type(TxNone)
     , m_dirty(TxShear)
-    , d(Q_NULLPTR)
+    , d(nullptr)
 {
 }
 
@@ -317,7 +317,7 @@ QTransform::QTransform(const QMatrix &mtx)
       m_13(0), m_23(0), m_33(1)
     , m_type(TxNone)
     , m_dirty(TxShear)
-    , d(Q_NULLPTR)
+    , d(nullptr)
 {
 }
 
diff --git a/src/gui/painting/qtransform.h b/src/gui/painting/qtransform.h
index 06ae611861..79835b36e2 100644
--- a/src/gui/painting/qtransform.h
+++ b/src/gui/painting/qtransform.h
@@ -116,7 +116,7 @@ public:
                    qreal m21, qreal m22, qreal m23,
                    qreal m31, qreal m32, qreal m33);
 
-    Q_REQUIRED_RESULT QTransform inverted(bool *invertible = Q_NULLPTR) const;
+    Q_REQUIRED_RESULT QTransform inverted(bool *invertible = nullptr) const;
     Q_REQUIRED_RESULT QTransform adjoint() const;
     Q_REQUIRED_RESULT QTransform transposed() const;
 
@@ -173,7 +173,7 @@ private:
         , m_13(h13), m_23(h23), m_33(h33)
         , m_type(TxNone)
         , m_dirty(TxProject)
-        , d(Q_NULLPTR)
+        , d(nullptr)
     {
     }
     inline QTransform(bool)
@@ -181,7 +181,7 @@ private:
         , m_13(0), m_23(0), m_33(1)
         , m_type(TxNone)
         , m_dirty(TxNone)
-        , d(Q_NULLPTR)
+        , d(nullptr)
     {
     }
     inline TransformationType inline_type() const;
diff --git a/src/gui/text/qabstracttextdocumentlayout.h b/src/gui/text/qabstracttextdocumentlayout.h
index 438ad6e70b..8fea27f772 100644
--- a/src/gui/text/qabstracttextdocumentlayout.h
+++ b/src/gui/text/qabstracttextdocumentlayout.h
@@ -100,7 +100,7 @@ public:
     QTextDocument *document() const;
 
     void registerHandler(int objectType, QObject *component);
-    void unregisterHandler(int objectType, QObject *component = Q_NULLPTR);
+    void unregisterHandler(int objectType, QObject *component = nullptr);
     QTextObjectInterface *handlerForObject(int objectType) const;
 
 Q_SIGNALS:
diff --git a/src/gui/text/qfont.cpp b/src/gui/text/qfont.cpp
index f0a5053196..0c72ac3019 100644
--- a/src/gui/text/qfont.cpp
+++ b/src/gui/text/qfont.cpp
@@ -2837,7 +2837,7 @@ QFontEngine *QFontCache::findEngine(const Key &key)
                          end = engineCache.end();
     if (it == end) return 0;
 
-    Q_ASSERT(it.value().data != Q_NULLPTR);
+    Q_ASSERT(it.value().data != nullptr);
     Q_ASSERT(key.multi == (it.value().data->type() == QFontEngine::Multi));
 
     // found... update the hitcount and timestamp
@@ -2860,7 +2860,7 @@ void QFontCache::updateHitCountAndTimeStamp(Engine &value)
 
 void QFontCache::insertEngine(const Key &key, QFontEngine *engine, bool insertMulti)
 {
-    Q_ASSERT(engine != Q_NULLPTR);
+    Q_ASSERT(engine != nullptr);
     Q_ASSERT(key.multi == (engine->type() == QFontEngine::Multi));
 
 #ifdef QFONTCACHE_DEBUG
diff --git a/src/gui/text/qfontdatabase.cpp b/src/gui/text/qfontdatabase.cpp
index 2cc071d67b..288352b370 100644
--- a/src/gui/text/qfontdatabase.cpp
+++ b/src/gui/text/qfontdatabase.cpp
@@ -2775,7 +2775,7 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
     if (d->engineData->engines[script])
         return;
 
-    QFontEngine *fe = Q_NULLPTR;
+    QFontEngine *fe = nullptr;
 
     req.fallBackFamilies = fallBackFamilies;
     if (!req.fallBackFamilies.isEmpty())
diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
index e4f9b8b9d4..5be8745b15 100644
--- a/src/gui/text/qfontengine.cpp
+++ b/src/gui/text/qfontengine.cpp
@@ -1080,7 +1080,7 @@ QFontEngineGlyphCache *QFontEngine::glyphCache(const void *context, GlyphFormat
 {
     const QHash<const void*, GlyphCaches>::const_iterator caches = m_glyphCaches.constFind(context);
     if (caches == m_glyphCaches.cend())
-        return Q_NULLPTR;
+        return nullptr;
 
     for (GlyphCaches::const_iterator it = caches->begin(), end = caches->end(); it != end; ++it) {
         QFontEngineGlyphCache *cache = it->cache.data();
@@ -1088,7 +1088,7 @@ QFontEngineGlyphCache *QFontEngine::glyphCache(const void *context, GlyphFormat
             return cache;
     }
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 static inline QFixed kerning(int left, int right, const QFontEngine::KernPair *pairs, int numPairs)
@@ -1234,7 +1234,7 @@ int QFontEngine::glyphCount() const
 
 Qt::HANDLE QFontEngine::handle() const
 {
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 const uchar *QFontEngine::getCMap(const uchar *table, uint tableSize, bool *isSymbolFont, int *cmapSize)
diff --git a/src/gui/text/qfontmetrics.h b/src/gui/text/qfontmetrics.h
index 3eac309092..25e708be29 100644
--- a/src/gui/text/qfontmetrics.h
+++ b/src/gui/text/qfontmetrics.h
@@ -101,11 +101,11 @@ public:
     QRect boundingRect(QChar) const;
 
     QRect boundingRect(const QString &text) const;
-    QRect boundingRect(const QRect &r, int flags, const QString &text, int tabstops = 0, int *tabarray = Q_NULLPTR) const;
+    QRect boundingRect(const QRect &r, int flags, const QString &text, int tabstops = 0, int *tabarray = nullptr) const;
     inline QRect boundingRect(int x, int y, int w, int h, int flags, const QString &text,
-                              int tabstops = 0, int *tabarray = Q_NULLPTR) const
+                              int tabstops = 0, int *tabarray = nullptr) const
         { return boundingRect(QRect(x, y, w, h), flags, text, tabstops, tabarray); }
-    QSize size(int flags, const QString& str, int tabstops = 0, int *tabarray = Q_NULLPTR) const;
+    QSize size(int flags, const QString& str, int tabstops = 0, int *tabarray = nullptr) const;
 
     QRect tightBoundingRect(const QString &text) const;
 
@@ -170,8 +170,8 @@ public:
 
     QRectF boundingRect(const QString &string) const;
     QRectF boundingRect(QChar) const;
-    QRectF boundingRect(const QRectF &r, int flags, const QString& string, int tabstops = 0, int *tabarray = Q_NULLPTR) const;
-    QSizeF size(int flags, const QString& str, int tabstops = 0, int *tabarray = Q_NULLPTR) const;
+    QRectF boundingRect(const QRectF &r, int flags, const QString& string, int tabstops = 0, int *tabarray = nullptr) const;
+    QSizeF size(int flags, const QString& str, int tabstops = 0, int *tabarray = nullptr) const;
 
     QRectF tightBoundingRect(const QString &text) const;
 
diff --git a/src/gui/text/qtextdocument.h b/src/gui/text/qtextdocument.h
index c2761a39b9..41c578fc1b 100644
--- a/src/gui/text/qtextdocument.h
+++ b/src/gui/text/qtextdocument.h
@@ -116,11 +116,11 @@ class Q_GUI_EXPORT QTextDocument : public QObject
     Q_PROPERTY(QUrl baseUrl READ baseUrl WRITE setBaseUrl NOTIFY baseUrlChanged)
 
 public:
-    explicit QTextDocument(QObject *parent = Q_NULLPTR);
-    explicit QTextDocument(const QString &text, QObject *parent = Q_NULLPTR);
+    explicit QTextDocument(QObject *parent = nullptr);
+    explicit QTextDocument(const QString &text, QObject *parent = nullptr);
     ~QTextDocument();
 
-    QTextDocument *clone(QObject *parent = Q_NULLPTR) const;
+    QTextDocument *clone(QObject *parent = nullptr) const;
 
     bool isEmpty() const;
     virtual void clear();
diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index faddb3552d..71f02376ac 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -1242,7 +1242,7 @@ int QTextEngine::shapeTextWithHarfbuzzNG(const QScriptItem &si,
                 { HB_TAG('h','l','i','g'), !dontLigate, 0, uint(-1) } };
             const int num_features = dontLigate ? 5 : 1;
 
-            const char *const *shaper_list = Q_NULLPTR;
+            const char *const *shaper_list = nullptr;
 #if defined(Q_OS_DARWIN)
             // What's behind QFontEngine::FaceData::user_data isn't compatible between different font engines
             // - specifically functions in hb-coretext.cc would run into undefined behavior with data
@@ -1252,7 +1252,7 @@ int QTextEngine::shapeTextWithHarfbuzzNG(const QScriptItem &si,
                     "graphite2",
                     "ot",
                     "fallback",
-                    Q_NULLPTR
+                    nullptr
                 };
                 shaper_list = s_shaper_list_without_coretext;
             }
diff --git a/src/gui/text/qtextlayout.h b/src/gui/text/qtextlayout.h
index 980a099b05..67bc75a6b8 100644
--- a/src/gui/text/qtextlayout.h
+++ b/src/gui/text/qtextlayout.h
@@ -69,7 +69,7 @@ class Q_GUI_EXPORT QTextInlineObject
 {
 public:
     QTextInlineObject(int i, QTextEngine *e) : itm(i), eng(e) {}
-    inline QTextInlineObject() : itm(0), eng(Q_NULLPTR) {}
+    inline QTextInlineObject() : itm(0), eng(nullptr) {}
     inline bool isValid() const { return eng; }
 
     QRectF rect() const;
@@ -107,7 +107,7 @@ public:
     // does itemization
     QTextLayout();
     QTextLayout(const QString& text);
-    QTextLayout(const QString& text, const QFont &font, QPaintDevice *paintdevice = Q_NULLPTR);
+    QTextLayout(const QString& text, const QFont &font, QPaintDevice *paintdevice = nullptr);
     QTextLayout(const QTextBlock &b);
     ~QTextLayout();
 
@@ -210,7 +210,7 @@ Q_DECLARE_TYPEINFO(QTextLayout::FormatRange, Q_RELOCATABLE_TYPE);
 class Q_GUI_EXPORT QTextLine
 {
 public:
-    inline QTextLine() : index(0), eng(Q_NULLPTR) {}
+    inline QTextLine() : index(0), eng(nullptr) {}
     inline bool isValid() const { return eng; }
 
     QRectF rect() const;
@@ -255,7 +255,7 @@ public:
 
     int lineNumber() const { return index; }
 
-    void draw(QPainter *p, const QPointF &point, const QTextLayout::FormatRange *selection = Q_NULLPTR) const;
+    void draw(QPainter *p, const QPointF &point, const QTextLayout::FormatRange *selection = nullptr) const;
 
 #if !defined(QT_NO_RAWFONT)
     QList<QGlyphRun> glyphRuns(int from = -1, int length = -1) const;
diff --git a/src/gui/text/qtextobject.h b/src/gui/text/qtextobject.h
index a5030de112..7e4efa28f8 100644
--- a/src/gui/text/qtextobject.h
+++ b/src/gui/text/qtextobject.h
@@ -203,7 +203,7 @@ class Q_GUI_EXPORT QTextBlock
     friend class QSyntaxHighlighter;
 public:
     inline QTextBlock(QTextDocumentPrivate *priv, int b) : p(priv), n(b) {}
-    inline QTextBlock() : p(Q_NULLPTR), n(0) {}
+    inline QTextBlock() : p(nullptr), n(0) {}
     inline QTextBlock(const QTextBlock &o) : p(o.p), n(o.n) {}
     inline QTextBlock &operator=(const QTextBlock &o) { p = o.p; n = o.n; return *this; }
 
@@ -260,7 +260,7 @@ public:
         friend class QTextBlock;
         iterator(const QTextDocumentPrivate *priv, int begin, int end, int f) : p(priv), b(begin), e(end), n(f) {}
     public:
-        iterator() : p(Q_NULLPTR), b(0), e(0), n(0) {}
+        iterator() : p(nullptr), b(0), e(0), n(0) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
         iterator(const iterator &o) : p(o.p), b(o.b), e(o.e), n(o.n) {}
 #endif
@@ -304,7 +304,7 @@ class Q_GUI_EXPORT QTextFragment
 {
 public:
     inline QTextFragment(const QTextDocumentPrivate *priv, int f, int fe) : p(priv), n(f), ne(fe) {}
-    inline QTextFragment() : p(Q_NULLPTR), n(0), ne(0) {}
+    inline QTextFragment() : p(nullptr), n(0), ne(0) {}
     inline QTextFragment(const QTextFragment &o) : p(o.p), n(o.n), ne(o.ne) {}
     inline QTextFragment &operator=(const QTextFragment &o) { p = o.p; n = o.n; ne = o.ne; return *this; }
 
diff --git a/src/gui/text/qtexttable.h b/src/gui/text/qtexttable.h
index ee8e974396..156b091b05 100644
--- a/src/gui/text/qtexttable.h
+++ b/src/gui/text/qtexttable.h
@@ -54,7 +54,7 @@ class QTextTablePrivate;
 class Q_GUI_EXPORT QTextTableCell
 {
 public:
-    QTextTableCell() : table(Q_NULLPTR) {}
+    QTextTableCell() : table(nullptr) {}
     ~QTextTableCell() {}
     QTextTableCell(const QTextTableCell &o) : table(o.table), fragment(o.fragment) {}
     QTextTableCell &operator=(const QTextTableCell &o)
@@ -69,7 +69,7 @@ public:
     int rowSpan() const;
     int columnSpan() const;
 
-    inline bool isValid() const { return table != Q_NULLPTR; }
+    inline bool isValid() const { return table != nullptr; }
 
     QTextCursor firstCursorPosition() const;
     QTextCursor lastCursorPosition() const;
diff --git a/src/gui/util/qvalidator.h b/src/gui/util/qvalidator.h
index a30f5bfa83..ad23092537 100644
--- a/src/gui/util/qvalidator.h
+++ b/src/gui/util/qvalidator.h
@@ -59,7 +59,7 @@ class Q_GUI_EXPORT QValidator : public QObject
 {
     Q_OBJECT
 public:
-    explicit QValidator(QObject * parent = Q_NULLPTR);
+    explicit QValidator(QObject * parent = nullptr);
     ~QValidator();
 
     enum State {
@@ -93,8 +93,8 @@ class Q_GUI_EXPORT QIntValidator : public QValidator
     Q_PROPERTY(int top READ top WRITE setTop NOTIFY topChanged)
 
 public:
-    explicit QIntValidator(QObject * parent = Q_NULLPTR);
-    QIntValidator(int bottom, int top, QObject *parent = Q_NULLPTR);
+    explicit QIntValidator(QObject * parent = nullptr);
+    QIntValidator(int bottom, int top, QObject *parent = nullptr);
     ~QIntValidator();
 
     QValidator::State validate(QString &, int &) const override;
@@ -130,8 +130,8 @@ class Q_GUI_EXPORT QDoubleValidator : public QValidator
     Q_PROPERTY(Notation notation READ notation WRITE setNotation NOTIFY notationChanged)
 
 public:
-    explicit QDoubleValidator(QObject * parent = Q_NULLPTR);
-    QDoubleValidator(double bottom, double top, int decimals, QObject *parent = Q_NULLPTR);
+    explicit QDoubleValidator(QObject * parent = nullptr);
+    QDoubleValidator(double bottom, double top, int decimals, QObject *parent = nullptr);
     ~QDoubleValidator();
 
     enum Notation {
@@ -174,8 +174,8 @@ class Q_GUI_EXPORT QRegExpValidator : public QValidator
     Q_PROPERTY(QRegExp regExp READ regExp WRITE setRegExp NOTIFY regExpChanged)
 
 public:
-    explicit QRegExpValidator(QObject *parent = Q_NULLPTR);
-    explicit QRegExpValidator(const QRegExp& rx, QObject *parent = Q_NULLPTR);
+    explicit QRegExpValidator(QObject *parent = nullptr);
+    explicit QRegExpValidator(const QRegExp& rx, QObject *parent = nullptr);
     ~QRegExpValidator();
 
     virtual QValidator::State validate(QString& input, int& pos) const override;
@@ -204,8 +204,8 @@ class Q_GUI_EXPORT QRegularExpressionValidator : public QValidator
     Q_PROPERTY(QRegularExpression regularExpression READ regularExpression WRITE setRegularExpression NOTIFY regularExpressionChanged)
 
 public:
-    explicit QRegularExpressionValidator(QObject *parent = Q_NULLPTR);
-    explicit QRegularExpressionValidator(const QRegularExpression &re, QObject *parent = Q_NULLPTR);
+    explicit QRegularExpressionValidator(QObject *parent = nullptr);
+    explicit QRegularExpressionValidator(const QRegularExpression &re, QObject *parent = nullptr);
     ~QRegularExpressionValidator();
 
     virtual QValidator::State validate(QString &input, int &pos) const override;
diff --git a/src/network/access/qabstractnetworkcache.h b/src/network/access/qabstractnetworkcache.h
index 33b0bc4ce3..678bae2d6e 100644
--- a/src/network/access/qabstractnetworkcache.h
+++ b/src/network/access/qabstractnetworkcache.h
@@ -131,7 +131,7 @@ public Q_SLOTS:
     virtual void clear() = 0;
 
 protected:
-    explicit QAbstractNetworkCache(QObject *parent = Q_NULLPTR);
+    explicit QAbstractNetworkCache(QObject *parent = nullptr);
     QAbstractNetworkCache(QAbstractNetworkCachePrivate &dd, QObject *parent);
 
 private:
diff --git a/src/network/access/qhttpmultipart.h b/src/network/access/qhttpmultipart.h
index 6d4531b099..9e95e82a77 100644
--- a/src/network/access/qhttpmultipart.h
+++ b/src/network/access/qhttpmultipart.h
@@ -98,8 +98,8 @@ public:
         AlternativeType
     };
 
-    explicit QHttpMultiPart(QObject *parent = Q_NULLPTR);
-    explicit QHttpMultiPart(ContentType contentType, QObject *parent = Q_NULLPTR);
+    explicit QHttpMultiPart(QObject *parent = nullptr);
+    explicit QHttpMultiPart(ContentType contentType, QObject *parent = nullptr);
     ~QHttpMultiPart();
 
     void append(const QHttpPart &httpPart);
diff --git a/src/network/access/qhttpnetworkconnection.cpp b/src/network/access/qhttpnetworkconnection.cpp
index 107d22f14d..09e5e1c1ef 100644
--- a/src/network/access/qhttpnetworkconnection.cpp
+++ b/src/network/access/qhttpnetworkconnection.cpp
@@ -123,7 +123,7 @@ QHttpNetworkConnectionPrivate::~QHttpNetworkConnectionPrivate()
 {
     for (int i = 0; i < channelCount; ++i) {
         if (channels[i].socket) {
-            QObject::disconnect(channels[i].socket, Q_NULLPTR, &channels[i], Q_NULLPTR);
+            QObject::disconnect(channels[i].socket, nullptr, &channels[i], nullptr);
             channels[i].socket->close();
             delete channels[i].socket;
         }
diff --git a/src/network/access/qnetworkaccessmanager.h b/src/network/access/qnetworkaccessmanager.h
index 4806ec0475..9cbf8a48d5 100644
--- a/src/network/access/qnetworkaccessmanager.h
+++ b/src/network/access/qnetworkaccessmanager.h
@@ -100,7 +100,7 @@ public:
     Q_ENUM(NetworkAccessibility)
 #endif
 
-    explicit QNetworkAccessManager(QObject *parent = Q_NULLPTR);
+    explicit QNetworkAccessManager(QObject *parent = nullptr);
     ~QNetworkAccessManager();
 
     // ### Qt 6: turn into virtual
@@ -139,7 +139,7 @@ public:
     QNetworkReply *put(const QNetworkRequest &request, const QByteArray &data);
     QNetworkReply *put(const QNetworkRequest &request, QHttpMultiPart *multiPart);
     QNetworkReply *deleteResource(const QNetworkRequest &request);
-    QNetworkReply *sendCustomRequest(const QNetworkRequest &request, const QByteArray &verb, QIODevice *data = Q_NULLPTR);
+    QNetworkReply *sendCustomRequest(const QNetworkRequest &request, const QByteArray &verb, QIODevice *data = nullptr);
     QNetworkReply *sendCustomRequest(const QNetworkRequest &request, const QByteArray &verb, const QByteArray &data);
     QNetworkReply *sendCustomRequest(const QNetworkRequest &request, const QByteArray &verb, QHttpMultiPart *multiPart);
 
@@ -181,7 +181,7 @@ Q_SIGNALS:
 
 protected:
     virtual QNetworkReply *createRequest(Operation op, const QNetworkRequest &request,
-                                         QIODevice *outgoingData = Q_NULLPTR);
+                                         QIODevice *outgoingData = nullptr);
 
 protected Q_SLOTS:
     QStringList supportedSchemesImplementation() const;
diff --git a/src/network/access/qnetworkcookiejar.h b/src/network/access/qnetworkcookiejar.h
index f9c1549e20..c3b2200443 100644
--- a/src/network/access/qnetworkcookiejar.h
+++ b/src/network/access/qnetworkcookiejar.h
@@ -54,7 +54,7 @@ class Q_NETWORK_EXPORT QNetworkCookieJar: public QObject
 {
     Q_OBJECT
 public:
-    explicit QNetworkCookieJar(QObject *parent = Q_NULLPTR);
+    explicit QNetworkCookieJar(QObject *parent = nullptr);
     virtual ~QNetworkCookieJar();
 
     virtual QList<QNetworkCookie> cookiesForUrl(const QUrl &url) const;
diff --git a/src/network/access/qnetworkdiskcache.h b/src/network/access/qnetworkdiskcache.h
index 4f1bbe44e7..ffdfd0fd1b 100644
--- a/src/network/access/qnetworkdiskcache.h
+++ b/src/network/access/qnetworkdiskcache.h
@@ -54,7 +54,7 @@ class Q_NETWORK_EXPORT QNetworkDiskCache : public QAbstractNetworkCache
     Q_OBJECT
 
 public:
-    explicit QNetworkDiskCache(QObject *parent = Q_NULLPTR);
+    explicit QNetworkDiskCache(QObject *parent = nullptr);
     ~QNetworkDiskCache();
 
     QString cacheDirectory() const;
diff --git a/src/network/access/qnetworkreply.h b/src/network/access/qnetworkreply.h
index 0912294a10..63c2752caf 100644
--- a/src/network/access/qnetworkreply.h
+++ b/src/network/access/qnetworkreply.h
@@ -169,7 +169,7 @@ Q_SIGNALS:
     void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
 
 protected:
-    explicit QNetworkReply(QObject *parent = Q_NULLPTR);
+    explicit QNetworkReply(QObject *parent = nullptr);
     QNetworkReply(QNetworkReplyPrivate &dd, QObject *parent);
     virtual qint64 writeData(const char *data, qint64 len) override;
 
diff --git a/src/network/bearer/qnetworkconfigmanager.h b/src/network/bearer/qnetworkconfigmanager.h
index da248bc7d0..e8866999c7 100644
--- a/src/network/bearer/qnetworkconfigmanager.h
+++ b/src/network/bearer/qnetworkconfigmanager.h
@@ -66,7 +66,7 @@ public:
 
     Q_DECLARE_FLAGS(Capabilities, Capability)
 
-    explicit QNetworkConfigurationManager(QObject *parent = Q_NULLPTR);
+    explicit QNetworkConfigurationManager(QObject *parent = nullptr);
     virtual ~QNetworkConfigurationManager();
 
     QNetworkConfigurationManager::Capabilities capabilities() const;
diff --git a/src/network/bearer/qnetworksession.h b/src/network/bearer/qnetworksession.h
index c7e27145a2..1b5ae9098b 100644
--- a/src/network/bearer/qnetworksession.h
+++ b/src/network/bearer/qnetworksession.h
@@ -87,7 +87,7 @@ public:
 
     Q_DECLARE_FLAGS(UsagePolicies, UsagePolicy)
 
-    explicit QNetworkSession(const QNetworkConfiguration &connConfig, QObject *parent = Q_NULLPTR);
+    explicit QNetworkSession(const QNetworkConfiguration &connConfig, QObject *parent = nullptr);
     virtual ~QNetworkSession();
 
     bool isOpen() const;
diff --git a/src/network/kernel/qdnslookup.h b/src/network/kernel/qdnslookup.h
index ead5e650f5..cd424b0cb9 100644
--- a/src/network/kernel/qdnslookup.h
+++ b/src/network/kernel/qdnslookup.h
@@ -218,9 +218,9 @@ public:
     };
     Q_ENUM(Type)
 
-    explicit QDnsLookup(QObject *parent = Q_NULLPTR);
-    QDnsLookup(Type type, const QString &name, QObject *parent = Q_NULLPTR);
-    QDnsLookup(Type type, const QString &name, const QHostAddress &nameserver, QObject *parent = Q_NULLPTR);
+    explicit QDnsLookup(QObject *parent = nullptr);
+    QDnsLookup(Type type, const QString &name, QObject *parent = nullptr);
+    QDnsLookup(Type type, const QString &name, const QHostAddress &nameserver, QObject *parent = nullptr);
     ~QDnsLookup();
 
     Error error() const;
diff --git a/src/network/kernel/qhostaddress.cpp b/src/network/kernel/qhostaddress.cpp
index 1b7061d050..7d8de71421 100644
--- a/src/network/kernel/qhostaddress.cpp
+++ b/src/network/kernel/qhostaddress.cpp
@@ -740,7 +740,7 @@ void QHostAddress::setAddress(const struct sockaddr *sockaddr)
 */
 quint32 QHostAddress::toIPv4Address() const
 {
-    return toIPv4Address(Q_NULLPTR);
+    return toIPv4Address(nullptr);
 }
 
 /*!
diff --git a/src/network/kernel/qnetworkdatagram.h b/src/network/kernel/qnetworkdatagram.h
index fa994d6170..c7605d67ba 100644
--- a/src/network/kernel/qnetworkdatagram.h
+++ b/src/network/kernel/qnetworkdatagram.h
@@ -63,7 +63,7 @@ public:
 
     QNetworkDatagram(QNetworkDatagram &&other) Q_DECL_NOTHROW
         : d(other.d)
-    { other.d = Q_NULLPTR; }
+    { other.d = nullptr; }
     QNetworkDatagram &operator=(QNetworkDatagram &&other) Q_DECL_NOTHROW
     { swap(other); return *this; }
 
diff --git a/src/network/socket/qabstractsocket.h b/src/network/socket/qabstractsocket.h
index ce4d2a74c6..710eac6c3e 100644
--- a/src/network/socket/qabstractsocket.h
+++ b/src/network/socket/qabstractsocket.h
@@ -221,7 +221,7 @@ protected:
     void setPeerAddress(const QHostAddress &address);
     void setPeerName(const QString &name);
 
-    QAbstractSocket(SocketType socketType, QAbstractSocketPrivate &dd, QObject *parent = Q_NULLPTR);
+    QAbstractSocket(SocketType socketType, QAbstractSocketPrivate &dd, QObject *parent = nullptr);
 
 private:
     Q_DECLARE_PRIVATE(QAbstractSocket)
diff --git a/src/network/socket/qlocalserver.h b/src/network/socket/qlocalserver.h
index 454ac30c9b..211aa94d85 100644
--- a/src/network/socket/qlocalserver.h
+++ b/src/network/socket/qlocalserver.h
@@ -71,7 +71,7 @@ public:
     Q_DECLARE_FLAGS(SocketOptions, SocketOption)
     Q_FLAG(SocketOptions)
 
-    explicit QLocalServer(QObject *parent = Q_NULLPTR);
+    explicit QLocalServer(QObject *parent = nullptr);
     ~QLocalServer();
 
     void close();
@@ -87,7 +87,7 @@ public:
     static bool removeServer(const QString &name);
     QAbstractSocket::SocketError serverError() const;
     void setMaxPendingConnections(int numConnections);
-    bool waitForNewConnection(int msec = 0, bool *timedOut = Q_NULLPTR);
+    bool waitForNewConnection(int msec = 0, bool *timedOut = nullptr);
 
     void setSocketOptions(SocketOptions options);
     SocketOptions socketOptions() const;
diff --git a/src/network/socket/qlocalsocket.h b/src/network/socket/qlocalsocket.h
index bea87236b8..1876a6ac0d 100644
--- a/src/network/socket/qlocalsocket.h
+++ b/src/network/socket/qlocalsocket.h
@@ -79,7 +79,7 @@ public:
         ClosingState = QAbstractSocket::ClosingState
     };
 
-    QLocalSocket(QObject *parent = Q_NULLPTR);
+    QLocalSocket(QObject *parent = nullptr);
     ~QLocalSocket();
 
     void connectToServer(OpenMode openMode = ReadWrite);
diff --git a/src/network/socket/qnativesocketengine_winrt.cpp b/src/network/socket/qnativesocketengine_winrt.cpp
index b7d7042923..0baf5c9e21 100644
--- a/src/network/socket/qnativesocketengine_winrt.cpp
+++ b/src/network/socket/qnativesocketengine_winrt.cpp
@@ -1340,7 +1340,7 @@ QNativeSocketEnginePrivate::QNativeSocketEnginePrivate()
     , closingDown(false)
     , socketDescriptor(-1)
     , worker(new SocketEngineWorker(this))
-    , sslSocket(Q_NULLPTR)
+    , sslSocket(nullptr)
     , connectionToken( { -1 } )
 {
 }
diff --git a/src/network/socket/qtcpserver.h b/src/network/socket/qtcpserver.h
index 192cbce54c..37df12919f 100644
--- a/src/network/socket/qtcpserver.h
+++ b/src/network/socket/qtcpserver.h
@@ -58,7 +58,7 @@ class Q_NETWORK_EXPORT QTcpServer : public QObject
 {
     Q_OBJECT
 public:
-    explicit QTcpServer(QObject *parent = Q_NULLPTR);
+    explicit QTcpServer(QObject *parent = nullptr);
     virtual ~QTcpServer();
 
     bool listen(const QHostAddress &address = QHostAddress::Any, quint16 port = 0);
@@ -75,7 +75,7 @@ public:
     qintptr socketDescriptor() const;
     bool setSocketDescriptor(qintptr socketDescriptor);
 
-    bool waitForNewConnection(int msec = 0, bool *timedOut = Q_NULLPTR);
+    bool waitForNewConnection(int msec = 0, bool *timedOut = nullptr);
     virtual bool hasPendingConnections() const;
     virtual QTcpSocket *nextPendingConnection();
 
@@ -95,7 +95,7 @@ protected:
     void addPendingConnection(QTcpSocket* socket);
 
     QTcpServer(QAbstractSocket::SocketType socketType, QTcpServerPrivate &dd,
-               QObject *parent = Q_NULLPTR);
+               QObject *parent = nullptr);
 
 Q_SIGNALS:
     void newConnection();
diff --git a/src/network/socket/qtcpsocket.h b/src/network/socket/qtcpsocket.h
index 3c3e3b69fd..b2c8bcc884 100644
--- a/src/network/socket/qtcpsocket.h
+++ b/src/network/socket/qtcpsocket.h
@@ -53,13 +53,13 @@ class Q_NETWORK_EXPORT QTcpSocket : public QAbstractSocket
 {
     Q_OBJECT
 public:
-    explicit QTcpSocket(QObject *parent = Q_NULLPTR);
+    explicit QTcpSocket(QObject *parent = nullptr);
     virtual ~QTcpSocket();
 
 protected:
-    QTcpSocket(QTcpSocketPrivate &dd, QObject *parent = Q_NULLPTR);
+    QTcpSocket(QTcpSocketPrivate &dd, QObject *parent = nullptr);
     QTcpSocket(QAbstractSocket::SocketType socketType, QTcpSocketPrivate &dd,
-               QObject *parent = Q_NULLPTR);
+               QObject *parent = nullptr);
 
 private:
     Q_DISABLE_COPY(QTcpSocket)
diff --git a/src/network/socket/qudpsocket.h b/src/network/socket/qudpsocket.h
index 6ef10e2edb..ce4429d1cd 100644
--- a/src/network/socket/qudpsocket.h
+++ b/src/network/socket/qudpsocket.h
@@ -57,7 +57,7 @@ class Q_NETWORK_EXPORT QUdpSocket : public QAbstractSocket
 {
     Q_OBJECT
 public:
-    explicit QUdpSocket(QObject *parent = Q_NULLPTR);
+    explicit QUdpSocket(QObject *parent = nullptr);
     virtual ~QUdpSocket();
 
 #ifndef QT_NO_NETWORKINTERFACE
@@ -75,7 +75,7 @@ public:
     bool hasPendingDatagrams() const;
     qint64 pendingDatagramSize() const;
     QNetworkDatagram receiveDatagram(qint64 maxSize = -1);
-    qint64 readDatagram(char *data, qint64 maxlen, QHostAddress *host = Q_NULLPTR, quint16 *port = Q_NULLPTR);
+    qint64 readDatagram(char *data, qint64 maxlen, QHostAddress *host = nullptr, quint16 *port = nullptr);
 
     qint64 writeDatagram(const QNetworkDatagram &datagram);
     qint64 writeDatagram(const char *data, qint64 len, const QHostAddress &host, quint16 port);
diff --git a/src/network/ssl/qsslcertificate.h b/src/network/ssl/qsslcertificate.h
index 8b051a5c88..6cd66fd20f 100644
--- a/src/network/ssl/qsslcertificate.h
+++ b/src/network/ssl/qsslcertificate.h
@@ -154,7 +154,7 @@ public:
 
     static bool importPkcs12(QIODevice *device,
                              QSslKey *key, QSslCertificate *cert,
-                             QList<QSslCertificate> *caCertificates = Q_NULLPTR,
+                             QList<QSslCertificate> *caCertificates = nullptr,
                              const QByteArray &passPhrase=QByteArray());
 
     Qt::HANDLE handle() const;
diff --git a/src/network/ssl/qssldiffiehellmanparameters_openssl.cpp b/src/network/ssl/qssldiffiehellmanparameters_openssl.cpp
index 5ebad822f1..00e9be91d8 100644
--- a/src/network/ssl/qssldiffiehellmanparameters_openssl.cpp
+++ b/src/network/ssl/qssldiffiehellmanparameters_openssl.cpp
@@ -161,12 +161,12 @@ void QSslDiffieHellmanParametersPrivate::decodePem(const QByteArray &pem)
         return;
     }
 
-    DH *dh = Q_NULLPTR;
+    DH *dh = nullptr;
     q_PEM_read_bio_DHparams(bio, &dh, 0, 0);
 
     if (dh) {
         if (isSafeDH(dh)) {
-            char *buf = Q_NULLPTR;
+            char *buf = nullptr;
             int len = q_i2d_DHparams(dh, reinterpret_cast<unsigned char **>(&buf));
             if (len > 0)
                 derData = QByteArray(buf, len);
diff --git a/src/network/ssl/qsslsocket.h b/src/network/ssl/qsslsocket.h
index 43b60e4f39..d76361029c 100644
--- a/src/network/ssl/qsslsocket.h
+++ b/src/network/ssl/qsslsocket.h
@@ -79,7 +79,7 @@ public:
         AutoVerifyPeer
     };
 
-    explicit QSslSocket(QObject *parent = Q_NULLPTR);
+    explicit QSslSocket(QObject *parent = nullptr);
     ~QSslSocket();
     void resume() override; // to continue after proxy authentication required, SSL errors etc.
 
diff --git a/src/network/ssl/qsslsocket_mac.cpp b/src/network/ssl/qsslsocket_mac.cpp
index 68c8ccff89..a8d09feb31 100644
--- a/src/network/ssl/qsslsocket_mac.cpp
+++ b/src/network/ssl/qsslsocket_mac.cpp
@@ -167,7 +167,7 @@ static SSLContextRef qt_createSecureTransportContext(QSslSocket::SslMode mode)
     const bool isServer = mode == QSslSocket::SslServerMode;
     const SSLProtocolSide side = isServer ? kSSLServerSide : kSSLClientSide;
     // We never use kSSLDatagramType, so it's kSSLStreamType unconditionally.
-    SSLContextRef context = SSLCreateContext(Q_NULLPTR, side, kSSLStreamType);
+    SSLContextRef context = SSLCreateContext(nullptr, side, kSSLStreamType);
     if (!context)
         qCWarning(lcSsl) << "SSLCreateContext failed";
     return context;
@@ -356,7 +356,7 @@ void QSslSocketPrivate::resetDefaultEllipticCurves()
 }
 
 QSslSocketBackendPrivate::QSslSocketBackendPrivate()
-    : context(Q_NULLPTR)
+    : context(nullptr)
 {
 }
 
@@ -885,7 +885,7 @@ bool QSslSocketBackendPrivate::initSslContext()
 
 void QSslSocketBackendPrivate::destroySslContext()
 {
-    context.reset(Q_NULLPTR);
+    context.reset(nullptr);
 }
 
 static QByteArray _q_makePkcs12(const QList<QSslCertificate> &certs, const QSslKey &key, const QString &passPhrase);
diff --git a/src/network/ssl/qsslsocket_winrt.cpp b/src/network/ssl/qsslsocket_winrt.cpp
index ca65f8a015..6c5a09962b 100644
--- a/src/network/ssl/qsslsocket_winrt.cpp
+++ b/src/network/ssl/qsslsocket_winrt.cpp
@@ -518,7 +518,7 @@ HRESULT QSslSocketBackendPrivate::onSslUpgrade(IAsyncAction *action, AsyncStatus
     QList<QSslCertificate> peerCertificateChain;
     if (certificate) {
         ComPtr<IAsyncOperation<CertificateChain *>> op;
-        hr = certificate->BuildChainAsync(Q_NULLPTR, &op);
+        hr = certificate->BuildChainAsync(nullptr, &op);
         Q_ASSERT_SUCCEEDED(hr);
         ComPtr<ICertificateChain> certificateChain;
         hr = QWinRTFunctions::await(op, certificateChain.GetAddressOf());
diff --git a/src/opengl/qgl.h b/src/opengl/qgl.h
index 8bafdb1031..902a2a2104 100644
--- a/src/opengl/qgl.h
+++ b/src/opengl/qgl.h
@@ -250,7 +250,7 @@ public:
     QGLContext(const QGLFormat& format);
     virtual ~QGLContext();
 
-    virtual bool create(const QGLContext* shareContext = Q_NULLPTR);
+    virtual bool create(const QGLContext* shareContext = nullptr);
     bool isValid() const;
     bool isSharing() const;
     void reset();
@@ -318,7 +318,7 @@ public:
     QOpenGLContext *contextHandle() const;
 
 protected:
-    virtual bool chooseContext(const QGLContext* shareContext = Q_NULLPTR);
+    virtual bool chooseContext(const QGLContext* shareContext = nullptr);
 
     bool deviceIsPixmap() const;
     bool windowCreated() const;
@@ -371,12 +371,12 @@ class Q_OPENGL_EXPORT QGLWidget : public QWidget
     Q_OBJECT
     Q_DECLARE_PRIVATE(QGLWidget)
 public:
-    explicit QGLWidget(QWidget* parent=Q_NULLPTR,
-                       const QGLWidget* shareWidget = Q_NULLPTR, Qt::WindowFlags f=Qt::WindowFlags());
-    explicit QGLWidget(QGLContext *context, QWidget* parent=Q_NULLPTR,
-                       const QGLWidget* shareWidget = Q_NULLPTR, Qt::WindowFlags f=Qt::WindowFlags());
-    explicit QGLWidget(const QGLFormat& format, QWidget* parent=Q_NULLPTR,
-                       const QGLWidget* shareWidget = Q_NULLPTR, Qt::WindowFlags f=Qt::WindowFlags());
+    explicit QGLWidget(QWidget* parent=nullptr,
+                       const QGLWidget* shareWidget = nullptr, Qt::WindowFlags f=Qt::WindowFlags());
+    explicit QGLWidget(QGLContext *context, QWidget* parent=nullptr,
+                       const QGLWidget* shareWidget = nullptr, Qt::WindowFlags f=Qt::WindowFlags());
+    explicit QGLWidget(const QGLFormat& format, QWidget* parent=nullptr,
+                       const QGLWidget* shareWidget = nullptr, Qt::WindowFlags f=Qt::WindowFlags());
     ~QGLWidget();
 
     void qglColor(const QColor& c) const;
@@ -395,7 +395,7 @@ public:
     void setFormat(const QGLFormat& format);
 
     QGLContext* context() const;
-    void setContext(QGLContext* context, const QGLContext* shareContext = Q_NULLPTR,
+    void setContext(QGLContext* context, const QGLContext* shareContext = nullptr,
                     bool deleteOldContext = true);
 
     QPixmap renderPixmap(int w = 0, int h = 0, bool useContext = false);
@@ -457,8 +457,8 @@ protected:
 
     QGLWidget(QGLWidgetPrivate &dd,
               const QGLFormat &format = QGLFormat(),
-              QWidget *parent = Q_NULLPTR,
-              const QGLWidget* shareWidget = Q_NULLPTR,
+              QWidget *parent = nullptr,
+              const QGLWidget* shareWidget = nullptr,
               Qt::WindowFlags f = Qt::WindowFlags());
 private:
     Q_DISABLE_COPY(QGLWidget)
diff --git a/src/opengl/qglbuffer.h b/src/opengl/qglbuffer.h
index 454036a938..daf5227c66 100644
--- a/src/opengl/qglbuffer.h
+++ b/src/opengl/qglbuffer.h
@@ -109,7 +109,7 @@ public:
     void write(int offset, const void *data, int count);
 
     void allocate(const void *data, int count);
-    inline void allocate(int count) { allocate(Q_NULLPTR, count); }
+    inline void allocate(int count) { allocate(nullptr, count); }
 
     void *map(QGLBuffer::Access access);
     bool unmap();
diff --git a/src/opengl/qglcolormap.h b/src/opengl/qglcolormap.h
index 199ed82534..772e327e34 100644
--- a/src/opengl/qglcolormap.h
+++ b/src/opengl/qglcolormap.h
@@ -69,7 +69,7 @@ public:
     int    findNearest(QRgb color) const;
 
 protected:
-    Qt::HANDLE handle() { return d ? d->cmapHandle : Q_NULLPTR; }
+    Qt::HANDLE handle() { return d ? d->cmapHandle : nullptr; }
     void setHandle(Qt::HANDLE ahandle) { d->cmapHandle = ahandle; }
 
 private:
diff --git a/src/opengl/qglfunctions.h b/src/opengl/qglfunctions.h
index 211212125e..d8c5249a1a 100644
--- a/src/opengl/qglfunctions.h
+++ b/src/opengl/qglfunctions.h
@@ -76,7 +76,7 @@ public:
     QGLFunctions::OpenGLFeatures openGLFeatures() const;
     bool hasOpenGLFeature(QGLFunctions::OpenGLFeature feature) const;
 
-    void initializeGLFunctions(const QGLContext *context = Q_NULLPTR);
+    void initializeGLFunctions(const QGLContext *context = nullptr);
 
     void glActiveTexture(GLenum texture);
     void glAttachShader(GLuint program, GLuint shader);
@@ -178,14 +178,14 @@ public:
 
 private:
     QGLFunctionsPrivate *d_ptr;
-    static bool isInitialized(const QGLFunctionsPrivate *d) { return d != Q_NULLPTR; }
+    static bool isInitialized(const QGLFunctionsPrivate *d) { return d != nullptr; }
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QGLFunctions::OpenGLFeatures)
 
 struct QGLFunctionsPrivate
 {
-    QGLFunctionsPrivate(const QGLContext *context = Q_NULLPTR);
+    QGLFunctionsPrivate(const QGLContext *context = nullptr);
     QOpenGLFunctions *funcs;
 };
 
diff --git a/src/opengl/qglpixelbuffer.h b/src/opengl/qglpixelbuffer.h
index 9735f51e4f..f5d7929c35 100644
--- a/src/opengl/qglpixelbuffer.h
+++ b/src/opengl/qglpixelbuffer.h
@@ -53,9 +53,9 @@ class Q_OPENGL_EXPORT QGLPixelBuffer : public QPaintDevice
     Q_DECLARE_PRIVATE(QGLPixelBuffer)
 public:
     QGLPixelBuffer(const QSize &size, const QGLFormat &format = QGLFormat::defaultFormat(),
-                   QGLWidget *shareWidget = Q_NULLPTR);
+                   QGLWidget *shareWidget = nullptr);
     QGLPixelBuffer(int width, int height, const QGLFormat &format = QGLFormat::defaultFormat(),
-                   QGLWidget *shareWidget = Q_NULLPTR);
+                   QGLWidget *shareWidget = nullptr);
     virtual ~QGLPixelBuffer();
 
     bool isValid() const;
diff --git a/src/opengl/qglshaderprogram.h b/src/opengl/qglshaderprogram.h
index f95017d09c..3ce88197d2 100644
--- a/src/opengl/qglshaderprogram.h
+++ b/src/opengl/qglshaderprogram.h
@@ -64,8 +64,8 @@ public:
     };
     Q_DECLARE_FLAGS(ShaderType, ShaderTypeBit)
 
-    explicit QGLShader(QGLShader::ShaderType type, QObject *parent = Q_NULLPTR);
-    QGLShader(QGLShader::ShaderType type, const QGLContext *context, QObject *parent = Q_NULLPTR);
+    explicit QGLShader(QGLShader::ShaderType type, QObject *parent = nullptr);
+    QGLShader(QGLShader::ShaderType type, const QGLContext *context, QObject *parent = nullptr);
     virtual ~QGLShader();
 
     QGLShader::ShaderType shaderType() const;
@@ -82,7 +82,7 @@ public:
 
     GLuint shaderId() const;
 
-    static bool hasOpenGLShaders(ShaderType type, const QGLContext *context = Q_NULLPTR);
+    static bool hasOpenGLShaders(ShaderType type, const QGLContext *context = nullptr);
 
 private:
     friend class QGLShaderProgram;
@@ -100,8 +100,8 @@ class Q_OPENGL_EXPORT QGLShaderProgram : public QObject
 {
     Q_OBJECT
 public:
-    explicit QGLShaderProgram(QObject *parent = Q_NULLPTR);
-    explicit QGLShaderProgram(const QGLContext *context, QObject *parent = Q_NULLPTR);
+    explicit QGLShaderProgram(QObject *parent = nullptr);
+    explicit QGLShaderProgram(const QGLContext *context, QObject *parent = nullptr);
     virtual ~QGLShaderProgram();
 
     bool addShader(QGLShader *shader);
@@ -286,7 +286,7 @@ public:
     void setUniformValueArray(const char *name, const QMatrix4x3 *values, int count);
     void setUniformValueArray(const char *name, const QMatrix4x4 *values, int count);
 
-    static bool hasOpenGLShaderPrograms(const QGLContext *context = Q_NULLPTR);
+    static bool hasOpenGLShaderPrograms(const QGLContext *context = nullptr);
 
 private Q_SLOTS:
     void shaderDestroyed();
diff --git a/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp b/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp
index 969a9c17e0..733d6dc531 100644
--- a/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp
+++ b/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp
@@ -428,7 +428,7 @@ static void populateFromPattern(FcPattern *pattern)
     if (res == FcResultMatch) {
         bool hasLang = false;
 #if FC_VERSION >= 20297
-        FcChar8 *cap = Q_NULLPTR;
+        FcChar8 *cap = nullptr;
         FcResult capRes = FcResultNoMatch;
 #endif
         for (int j = 1; j < QFontDatabase::WritingSystemsCount; ++j) {
@@ -438,7 +438,7 @@ static void populateFromPattern(FcPattern *pattern)
                 if (langRes != FcLangDifferentLang) {
 #if FC_VERSION >= 20297
                     if (*capabilityForWritingSystem[j] && requiresOpenType(j)) {
-                        if (cap == Q_NULLPTR)
+                        if (cap == nullptr)
                             capRes = FcPatternGetString(pattern, FC_CAPABILITY, 0, &cap);
                         if (capRes == FcResultMatch && strstr(reinterpret_cast<const char *>(cap), capabilityForWritingSystem[j]) == 0)
                             continue;
diff --git a/src/platformsupport/fontdatabases/freetype/qfontengine_ft.cpp b/src/platformsupport/fontdatabases/freetype/qfontengine_ft.cpp
index 64a0ef6fe8..cf0314fa47 100644
--- a/src/platformsupport/fontdatabases/freetype/qfontengine_ft.cpp
+++ b/src/platformsupport/fontdatabases/freetype/qfontengine_ft.cpp
@@ -1542,7 +1542,7 @@ QFontEngineFT::QGlyphSet *QFontEngineFT::loadGlyphSet(const QTransform &matrix)
 
     // FT_Set_Transform only supports scalable fonts
     if (!FT_IS_SCALABLE(freetype->face))
-        return matrix.type() <= QTransform::TxTranslate ? &defaultGlyphSet : Q_NULLPTR;
+        return matrix.type() <= QTransform::TxTranslate ? &defaultGlyphSet : nullptr;
 
     FT_Matrix m = QTransformToFTMatrix(matrix);
 
@@ -1961,7 +1961,7 @@ glyph_metrics_t QFontEngineFT::alphaMapBoundingBox(glyph_t glyph, QFixed subPixe
 
 static inline QImage alphaMapFromGlyphData(QFontEngineFT::Glyph *glyph, QFontEngine::GlyphFormat glyphFormat)
 {
-    if (glyph == Q_NULLPTR || glyph->height == 0 || glyph->width == 0)
+    if (glyph == nullptr || glyph->height == 0 || glyph->width == 0)
         return QImage();
 
     QImage::Format format = QImage::Format_Invalid;
@@ -2009,14 +2009,14 @@ QImage *QFontEngineFT::lockedAlphaMapForGlyph(glyph_t glyphIndex, QFixed subPixe
 
     currentlyLockedAlphaMap = alphaMapFromGlyphData(glyph, neededFormat);
 
-    const bool glyphHasGeometry = glyph != Q_NULLPTR && glyph->height != 0 && glyph->width != 0;
+    const bool glyphHasGeometry = glyph != nullptr && glyph->height != 0 && glyph->width != 0;
     if (!cacheEnabled && glyph != &emptyGlyph) {
         currentlyLockedAlphaMap = currentlyLockedAlphaMap.copy();
         delete glyph;
     }
 
     if (!glyphHasGeometry)
-        return Q_NULLPTR;
+        return nullptr;
 
     if (currentlyLockedAlphaMap.isNull())
         return QFontEngine::lockedAlphaMapForGlyph(glyphIndex, subPixelPosition, neededFormat, t, offset);
@@ -2114,7 +2114,7 @@ QImage QFontEngineFT::alphaRGBMapForGlyph(glyph_t g, QFixed subPixelPosition, co
 QImage QFontEngineFT::bitmapForGlyph(glyph_t g, QFixed subPixelPosition, const QTransform &t)
 {
     Glyph *glyph = loadGlyphFor(g, subPixelPosition, defaultFormat, t);
-    if (glyph == Q_NULLPTR)
+    if (glyph == nullptr)
         return QImage();
 
     QImage img;
diff --git a/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase.cpp b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase.cpp
index d3e4daa341..1f976be066 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase.cpp
+++ b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase.cpp
@@ -77,19 +77,19 @@ typedef HRESULT (WINAPI *DWriteCreateFactoryType)(DWRITE_FACTORY_TYPE, const IID
 static inline DWriteCreateFactoryType resolveDWriteCreateFactory()
 {
     if (QSysInfo::windowsVersion() < QSysInfo::WV_VISTA)
-        return Q_NULLPTR;
+        return nullptr;
     QSystemLibrary library(QStringLiteral("dwrite"));
     QFunctionPointer result = library.resolve("DWriteCreateFactory");
     if (Q_UNLIKELY(!result)) {
         qWarning("Unable to load dwrite.dll");
-        return Q_NULLPTR;
+        return nullptr;
     }
     return reinterpret_cast<DWriteCreateFactoryType>(result);
 }
 
 static void createDirectWriteFactory(IDWriteFactory **factory)
 {
-    *factory = Q_NULLPTR;
+    *factory = nullptr;
 
     static const DWriteCreateFactoryType dWriteCreateFactory = resolveDWriteCreateFactory();
     if (!dWriteCreateFactory)
@@ -539,7 +539,7 @@ namespace {
     class CustomFontFileLoader
     {
     public:
-        CustomFontFileLoader() : m_directWriteFontFileLoader(Q_NULLPTR)
+        CustomFontFileLoader() : m_directWriteFontFileLoader(nullptr)
         {
             createDirectWriteFactory(&m_directWriteFactory);
 
@@ -1128,7 +1128,7 @@ static int QT_WIN_CALLBACK storeFont(const LOGFONT *logFont, const TEXTMETRIC *t
     // NEWTEXTMETRICEX (passed for TT fonts) is a NEWTEXTMETRIC, which according
     // to the documentation is identical to a TEXTMETRIC except for the last four
     // members, which we don't use anyway
-    const FONTSIGNATURE *signature = Q_NULLPTR;
+    const FONTSIGNATURE *signature = nullptr;
     if (type & TRUETYPE_FONTTYPE)
         signature = &reinterpret_cast<const NEWTEXTMETRICEX *>(textmetric)->ntmFontSig;
     addFontToDatabase(familyName, styleName, *logFont, textmetric, signature, type);
@@ -1909,7 +1909,7 @@ QFontEngine *QWindowsFontDatabase::createEngine(const QFontDef &request, const Q
             } else {
                 bool isColorFont = false;
 #if defined(QT_USE_DIRECTWRITE2)
-                IDWriteFontFace2 *directWriteFontFace2 = Q_NULLPTR;
+                IDWriteFontFace2 *directWriteFontFace2 = nullptr;
                 if (SUCCEEDED(directWriteFontFace->QueryInterface(__uuidof(IDWriteFontFace2),
                                                                   reinterpret_cast<void **>(&directWriteFontFace2)))) {
                     if (directWriteFontFace2->IsColorFont())
diff --git a/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_ft.cpp b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_ft.cpp
index 3f03b30f10..78477de38a 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_ft.cpp
+++ b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_ft.cpp
@@ -144,7 +144,7 @@ static FontKeys &fontKeys()
     return result;
 }
 
-static const FontKey *findFontKey(const QString &name, int *indexIn = Q_NULLPTR)
+static const FontKey *findFontKey(const QString &name, int *indexIn = nullptr)
 {
      const FontKeys &keys = fontKeys();
      for (auto it = keys.constBegin(), cend = keys.constEnd(); it != cend; ++it) {
@@ -157,7 +157,7 @@ static const FontKey *findFontKey(const QString &name, int *indexIn = Q_NULLPTR)
      }
      if (indexIn)
          *indexIn = -1;
-     return Q_NULLPTR;
+     return nullptr;
 }
 
 static bool addFontToDatabase(QString familyName,
@@ -310,7 +310,7 @@ static int QT_WIN_CALLBACK storeFont(const LOGFONT *logFont, const TEXTMETRIC *t
     // NEWTEXTMETRICEX (passed for TT fonts) is a NEWTEXTMETRIC, which according
     // to the documentation is identical to a TEXTMETRIC except for the last four
     // members, which we don't use anyway
-    const FONTSIGNATURE *signature = Q_NULLPTR;
+    const FONTSIGNATURE *signature = nullptr;
     if (type & TRUETYPE_FONTTYPE)
         signature = &reinterpret_cast<const NEWTEXTMETRICEX *>(textmetric)->ntmFontSig;
     addFontToDatabase(faceName, styleName, fullName, *logFont, textmetric, signature, type);
diff --git a/src/platformsupport/fontdatabases/windows/qwindowsfontenginedirectwrite.cpp b/src/platformsupport/fontdatabases/windows/qwindowsfontenginedirectwrite.cpp
index f07e711048..0e017c3b77 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsfontenginedirectwrite.cpp
+++ b/src/platformsupport/fontdatabases/windows/qwindowsfontenginedirectwrite.cpp
@@ -282,7 +282,7 @@ static UUID uuidIdWriteLocalFontFileLoader()
 
 QString QWindowsFontEngineDirectWrite::filenameFromFontFile(IDWriteFontFile *fontFile)
 {
-    IDWriteFontFileLoader *loader = Q_NULLPTR;
+    IDWriteFontFileLoader *loader = nullptr;
 
     HRESULT hr = fontFile->GetLoader(&loader);
     if (FAILED(hr)) {
@@ -290,11 +290,11 @@ QString QWindowsFontEngineDirectWrite::filenameFromFontFile(IDWriteFontFile *fon
         return QString();
     }
 
-    QIdWriteLocalFontFileLoader *localLoader = Q_NULLPTR;
+    QIdWriteLocalFontFileLoader *localLoader = nullptr;
     hr = loader->QueryInterface(uuidIdWriteLocalFontFileLoader(),
                                 reinterpret_cast<void **>(&localLoader));
 
-    const void *fontFileReferenceKey = Q_NULLPTR;
+    const void *fontFileReferenceKey = nullptr;
     UINT32 fontFileReferenceKeySize = 0;
     if (SUCCEEDED(hr)) {
         hr = fontFile->GetReferenceKey(&fontFileReferenceKey,
@@ -326,10 +326,10 @@ QString QWindowsFontEngineDirectWrite::filenameFromFontFile(IDWriteFontFile *fon
             ret = QString::fromWCharArray(filePath.data());
     }
 
-    if (localLoader != Q_NULLPTR)
+    if (localLoader != nullptr)
         localLoader->Release();
 
-    if (loader != Q_NULLPTR)
+    if (loader != nullptr)
         loader->Release();
     return ret;
 }
@@ -349,7 +349,7 @@ void QWindowsFontEngineDirectWrite::collectMetrics()
     m_lineGap = DESIGN_TO_LOGICAL(metrics.lineGap);
     m_underlinePosition = DESIGN_TO_LOGICAL(metrics.underlinePosition);
 
-    IDWriteFontFile *fontFile = Q_NULLPTR;
+    IDWriteFontFile *fontFile = nullptr;
     UINT32 numberOfFiles = 1;
     if (SUCCEEDED(m_directWriteFontFace->GetFiles(&numberOfFiles, &fontFile))) {
         m_faceId.filename = QFile::encodeName(filenameFromFontFile(fontFile));
@@ -713,7 +713,7 @@ QImage QWindowsFontEngineDirectWrite::imageForGlyph(glyph_t t,
 #if defined(QT_USE_DIRECTWRITE2)
         HRESULT hr = DWRITE_E_NOCOLOR;
         IDWriteColorGlyphRunEnumerator *enumerator = 0;
-        IDWriteFactory2 *factory2 = Q_NULLPTR;
+        IDWriteFactory2 *factory2 = nullptr;
         if (glyphFormat == QFontEngine::Format_ARGB
                 && SUCCEEDED(m_fontEngineData->directWriteFactory->QueryInterface(__uuidof(IDWriteFactory2),
                                                                                   reinterpret_cast<void **>(&factory2)))) {
diff --git a/src/platformsupport/fontdatabases/windows/qwindowsnativeimage.cpp b/src/platformsupport/fontdatabases/windows/qwindowsnativeimage.cpp
index f8fcff952a..67a6619b91 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsnativeimage.cpp
+++ b/src/platformsupport/fontdatabases/windows/qwindowsnativeimage.cpp
@@ -98,7 +98,7 @@ static inline HBITMAP createDIB(HDC hdc, int width, int height,
         bmi.blueMask = 0;
     }
 
-    uchar *bits = Q_NULLPTR;
+    uchar *bits = nullptr;
     HBITMAP bitmap = CreateDIBSection(hdc, reinterpret_cast<BITMAPINFO *>(&bmi),
                                       DIB_RGB_COLORS, reinterpret_cast<void **>(&bits), 0, 0);
     if (Q_UNLIKELY(!bitmap || !bits))
diff --git a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp
index 5c87cb7c9c..d6c7173d3c 100644
--- a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp
+++ b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp
@@ -71,7 +71,7 @@ void QFdContainer::reset() Q_DECL_NOTHROW
 }
 
 QEvdevKeyboardHandler::QEvdevKeyboardHandler(const QString &device, QFdContainer &fd, bool disableZap, bool enableCompose, const QString &keymapFile)
-    : m_device(device), m_fd(fd.release()), m_notify(Q_NULLPTR),
+    : m_device(device), m_fd(fd.release()), m_notify(nullptr),
       m_modifiers(0), m_composing(0), m_dead_unicode(0xffff),
       m_no_zap(disableZap), m_do_compose(enableCompose),
       m_keymap(0), m_keymap_size(0), m_keycompose(0), m_keycompose_size(0)
@@ -172,7 +172,7 @@ void QEvdevKeyboardHandler::readKeycode()
                 // by the above error over and over again.
                 if (errno == ENODEV) {
                     delete m_notify;
-                    m_notify = Q_NULLPTR;
+                    m_notify = nullptr;
                     m_fd.reset();
                 }
                 return;
diff --git a/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp b/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp
index 562e7e2821..bcc5a21669 100644
--- a/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp
+++ b/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp
@@ -209,7 +209,7 @@ void QEvdevMouseHandler::readMouseData()
                 // by the above error over and over again.
                 if (errno == ENODEV) {
                     delete m_notify;
-                    m_notify = Q_NULLPTR;
+                    m_notify = nullptr;
                     qt_safe_close(m_fd);
                     m_fd = -1;
                 }
diff --git a/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp b/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp
index 8cce403b31..15e00cea82 100644
--- a/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp
+++ b/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp
@@ -190,9 +190,9 @@ static inline bool testBit(long bit, const long *array)
 #endif
 
 QEvdevTouchScreenHandler::QEvdevTouchScreenHandler(const QString &device, const QString &spec, QObject *parent)
-    : QObject(parent), m_notify(Q_NULLPTR), m_fd(-1), d(Q_NULLPTR), m_device(Q_NULLPTR)
+    : QObject(parent), m_notify(nullptr), m_fd(-1), d(nullptr), m_device(nullptr)
 #if QT_CONFIG(mtdev)
-      , m_mtdev(Q_NULLPTR)
+      , m_mtdev(nullptr)
 #endif
 {
     setObjectName(QLatin1String("Evdev Touch Handler"));
@@ -425,7 +425,7 @@ err:
             qErrnoWarning(errno, "evdevtouch: Could not read from input device");
             if (errno == ENODEV) { // device got disconnected -> stop reading
                 delete m_notify;
-                m_notify = Q_NULLPTR;
+                m_notify = nullptr;
 
                 QT_CLOSE(m_fd);
                 m_fd = -1;
@@ -464,7 +464,7 @@ void QEvdevTouchScreenHandler::unregisterTouchDevice()
         delete m_device;
     }
 
-    m_device = Q_NULLPTR;
+    m_device = nullptr;
 }
 
 void QEvdevTouchScreenData::addTouchPoint(const Contact &contact, Qt::TouchPointStates *combinedStates)
@@ -779,13 +779,13 @@ void QEvdevTouchScreenData::reportPoints()
     if (m_filtered)
         emit q->touchPointsUpdated();
     else
-        QWindowSystemInterface::handleTouchEvent(Q_NULLPTR, q->touchDevice(), m_touchPoints);
+        QWindowSystemInterface::handleTouchEvent(nullptr, q->touchDevice(), m_touchPoints);
 }
 
 QEvdevTouchScreenHandlerThread::QEvdevTouchScreenHandlerThread(const QString &device, const QString &spec, QObject *parent)
-    : QDaemonThread(parent), m_device(device), m_spec(spec), m_handler(Q_NULLPTR), m_touchDeviceRegistered(false)
+    : QDaemonThread(parent), m_device(device), m_spec(spec), m_handler(nullptr), m_touchDeviceRegistered(false)
     , m_touchUpdatePending(false)
-    , m_filterWindow(Q_NULLPTR)
+    , m_filterWindow(nullptr)
     , m_touchRate(-1)
 {
     start();
@@ -810,7 +810,7 @@ void QEvdevTouchScreenHandlerThread::run()
     exec();
 
     delete m_handler;
-    m_handler = Q_NULLPTR;
+    m_handler = nullptr;
 }
 
 bool QEvdevTouchScreenHandlerThread::isTouchDeviceRegistered() const
@@ -951,7 +951,7 @@ void QEvdevTouchScreenHandlerThread::filterAndSendTouchPoints()
 
     m_filteredPoints = filteredPoints;
 
-    QWindowSystemInterface::handleTouchEvent(Q_NULLPTR,
+    QWindowSystemInterface::handleTouchEvent(nullptr,
                                              m_handler->touchDevice(),
                                              points);
 }
diff --git a/src/platformsupport/input/evdevtouch/qevdevtouchhandler_p.h b/src/platformsupport/input/evdevtouch/qevdevtouchhandler_p.h
index b93744815c..04e22e1b5e 100644
--- a/src/platformsupport/input/evdevtouch/qevdevtouchhandler_p.h
+++ b/src/platformsupport/input/evdevtouch/qevdevtouchhandler_p.h
@@ -75,7 +75,7 @@ class QEvdevTouchScreenHandler : public QObject
     Q_OBJECT
 
 public:
-    explicit QEvdevTouchScreenHandler(const QString &device, const QString &spec = QString(), QObject *parent = Q_NULLPTR);
+    explicit QEvdevTouchScreenHandler(const QString &device, const QString &spec = QString(), QObject *parent = nullptr);
     ~QEvdevTouchScreenHandler();
 
     QTouchDevice *touchDevice() const;
@@ -108,7 +108,7 @@ class QEvdevTouchScreenHandlerThread : public QDaemonThread
 {
     Q_OBJECT
 public:
-    explicit QEvdevTouchScreenHandlerThread(const QString &device, const QString &spec, QObject *parent = Q_NULLPTR);
+    explicit QEvdevTouchScreenHandlerThread(const QString &device, const QString &spec, QObject *parent = nullptr);
     ~QEvdevTouchScreenHandlerThread();
     void run() override;
 
diff --git a/src/platformsupport/input/libinput/qlibinputhandler.cpp b/src/platformsupport/input/libinput/qlibinputhandler.cpp
index 961eb3539f..4775eb0724 100644
--- a/src/platformsupport/input/libinput/qlibinputhandler.cpp
+++ b/src/platformsupport/input/libinput/qlibinputhandler.cpp
@@ -94,7 +94,7 @@ QLibInputHandler::QLibInputHandler(const QString &key, const QString &spec)
     if (Q_UNLIKELY(!m_udev))
         qFatal("Failed to get udev context for libinput");
 
-    m_li = libinput_udev_create_context(&liInterface, Q_NULLPTR, m_udev);
+    m_li = libinput_udev_create_context(&liInterface, nullptr, m_udev);
     if (Q_UNLIKELY(!m_li))
         qFatal("Failed to get libinput context");
 
@@ -137,7 +137,7 @@ void QLibInputHandler::onReadyRead()
     }
 
     libinput_event *ev;
-    while ((ev = libinput_get_event(m_li)) != Q_NULLPTR) {
+    while ((ev = libinput_get_event(m_li)) != nullptr) {
         processEvent(ev);
         libinput_event_destroy(ev);
     }
diff --git a/src/platformsupport/input/libinput/qlibinputkeyboard.cpp b/src/platformsupport/input/libinput/qlibinputkeyboard.cpp
index f14a2e8f04..21f7fde7c8 100644
--- a/src/platformsupport/input/libinput/qlibinputkeyboard.cpp
+++ b/src/platformsupport/input/libinput/qlibinputkeyboard.cpp
@@ -143,7 +143,7 @@ QLibInputKeyboard::QLibInputKeyboard()
         qWarning("Failed to create xkb context");
         return;
     }
-    m_keymap = xkb_keymap_new_from_names(m_ctx, Q_NULLPTR, XKB_KEYMAP_COMPILE_NO_FLAGS);
+    m_keymap = xkb_keymap_new_from_names(m_ctx, nullptr, XKB_KEYMAP_COMPILE_NO_FLAGS);
     if (!m_keymap) {
         qWarning("Failed to compile keymap");
         return;
@@ -211,7 +211,7 @@ void QLibInputKeyboard::processKey(libinput_event_keyboard *e)
 
     xkb_state_update_key(m_state, k, pressed ? XKB_KEY_DOWN : XKB_KEY_UP);
 
-    QWindowSystemInterface::handleExtendedKeyEvent(Q_NULLPTR,
+    QWindowSystemInterface::handleExtendedKeyEvent(nullptr,
                                                    pressed ? QEvent::KeyPress : QEvent::KeyRelease,
                                                    qtkey, mods, k, sym, mods, text);
 
@@ -237,7 +237,7 @@ void QLibInputKeyboard::processKey(libinput_event_keyboard *e)
 #ifndef QT_NO_XKBCOMMON_EVDEV
 void QLibInputKeyboard::handleRepeat()
 {
-    QWindowSystemInterface::handleExtendedKeyEvent(Q_NULLPTR, QEvent::KeyPress,
+    QWindowSystemInterface::handleExtendedKeyEvent(nullptr, QEvent::KeyPress,
                                                    m_repeatData.qtkey, m_repeatData.mods,
                                                    m_repeatData.nativeScanCode, m_repeatData.virtualKey, m_repeatData.nativeMods,
                                                    m_repeatData.unicodeText, true, m_repeatData.repeatCount);
diff --git a/src/platformsupport/input/libinput/qlibinputpointer.cpp b/src/platformsupport/input/libinput/qlibinputpointer.cpp
index bdeac8db7e..b20cc4c095 100644
--- a/src/platformsupport/input/libinput/qlibinputpointer.cpp
+++ b/src/platformsupport/input/libinput/qlibinputpointer.cpp
@@ -78,7 +78,7 @@ void QLibInputPointer::processButton(libinput_event_pointer *e)
 
     m_buttons.setFlag(button, pressed);
 
-    QWindowSystemInterface::handleMouseEvent(Q_NULLPTR, m_pos, m_pos, m_buttons, QGuiApplication::keyboardModifiers());
+    QWindowSystemInterface::handleMouseEvent(nullptr, m_pos, m_pos, m_buttons, QGuiApplication::keyboardModifiers());
 }
 
 void QLibInputPointer::processMotion(libinput_event_pointer *e)
@@ -91,7 +91,7 @@ void QLibInputPointer::processMotion(libinput_event_pointer *e)
     m_pos.setX(qBound(g.left(), qRound(m_pos.x() + dx), g.right()));
     m_pos.setY(qBound(g.top(), qRound(m_pos.y() + dy), g.bottom()));
 
-    QWindowSystemInterface::handleMouseEvent(Q_NULLPTR, m_pos, m_pos, m_buttons, QGuiApplication::keyboardModifiers());
+    QWindowSystemInterface::handleMouseEvent(nullptr, m_pos, m_pos, m_buttons, QGuiApplication::keyboardModifiers());
 }
 
 void QLibInputPointer::processAxis(libinput_event_pointer *e)
@@ -100,15 +100,15 @@ void QLibInputPointer::processAxis(libinput_event_pointer *e)
     const double v = libinput_event_pointer_get_axis_value(e) * 120;
     const Qt::Orientation ori = libinput_event_pointer_get_axis(e) == LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL
         ? Qt::Vertical : Qt::Horizontal;
-    QWindowSystemInterface::handleWheelEvent(Q_NULLPTR, m_pos, m_pos, qRound(-v), ori, QGuiApplication::keyboardModifiers());
+    QWindowSystemInterface::handleWheelEvent(nullptr, m_pos, m_pos, qRound(-v), ori, QGuiApplication::keyboardModifiers());
 #else
     if (libinput_event_pointer_has_axis(e, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL)) {
         const double v = libinput_event_pointer_get_axis_value(e, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL) * 120;
-        QWindowSystemInterface::handleWheelEvent(Q_NULLPTR, m_pos, m_pos, qRound(-v), Qt::Vertical, QGuiApplication::keyboardModifiers());
+        QWindowSystemInterface::handleWheelEvent(nullptr, m_pos, m_pos, qRound(-v), Qt::Vertical, QGuiApplication::keyboardModifiers());
     }
     if (libinput_event_pointer_has_axis(e, LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL)) {
         const double v = libinput_event_pointer_get_axis_value(e, LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL) * 120;
-        QWindowSystemInterface::handleWheelEvent(Q_NULLPTR, m_pos, m_pos, qRound(-v), Qt::Horizontal, QGuiApplication::keyboardModifiers());
+        QWindowSystemInterface::handleWheelEvent(nullptr, m_pos, m_pos, qRound(-v), Qt::Horizontal, QGuiApplication::keyboardModifiers());
     }
 #endif
 }
diff --git a/src/platformsupport/input/libinput/qlibinputtouch.cpp b/src/platformsupport/input/libinput/qlibinputtouch.cpp
index 42925a18e1..a65bc91c39 100644
--- a/src/platformsupport/input/libinput/qlibinputtouch.cpp
+++ b/src/platformsupport/input/libinput/qlibinputtouch.cpp
@@ -53,7 +53,7 @@ QWindowSystemInterface::TouchPoint *QLibInputTouch::DeviceState::point(int32_t s
         if (m_points.at(i).id == id)
             return &m_points[i];
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QLibInputTouch::DeviceState *QLibInputTouch::deviceState(libinput_event_touch *e)
@@ -150,7 +150,7 @@ void QLibInputTouch::processTouchCancel(libinput_event_touch *e)
 {
     DeviceState *state = deviceState(e);
     if (state->m_touchDevice)
-        QWindowSystemInterface::handleTouchCancelEvent(Q_NULLPTR, state->m_touchDevice, QGuiApplication::keyboardModifiers());
+        QWindowSystemInterface::handleTouchCancelEvent(nullptr, state->m_touchDevice, QGuiApplication::keyboardModifiers());
     else
         qWarning("TouchCancel without registered device");
 }
@@ -165,7 +165,7 @@ void QLibInputTouch::processTouchFrame(libinput_event_touch *e)
     if (state->m_points.isEmpty())
         return;
 
-    QWindowSystemInterface::handleTouchEvent(Q_NULLPTR, state->m_touchDevice, state->m_points,
+    QWindowSystemInterface::handleTouchEvent(nullptr, state->m_touchDevice, state->m_points,
                                              QGuiApplication::keyboardModifiers());
 
     for (int i = 0; i < state->m_points.count(); ++i) {
diff --git a/src/platformsupport/kmsconvenience/qkmsdevice.cpp b/src/platformsupport/kmsconvenience/qkmsdevice.cpp
index 48ad984bf5..f001f3219d 100644
--- a/src/platformsupport/kmsconvenience/qkmsdevice.cpp
+++ b/src/platformsupport/kmsconvenience/qkmsdevice.cpp
@@ -170,7 +170,7 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
     const int crtc = crtcForConnector(resources, connector);
     if (crtc < 0) {
         qWarning() << "No usable crtc/encoder pair for connector" << connectorName;
-        return Q_NULLPTR;
+        return nullptr;
     }
 
     OutputConfiguration configuration;
@@ -217,14 +217,14 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
 
     if (configuration == OutputConfigOff) {
         qCDebug(qLcKmsDebug) << "Turning off output" << connectorName;
-        drmModeSetCrtc(m_dri_fd, crtc_id, 0, 0, 0, 0, 0, Q_NULLPTR);
-        return Q_NULLPTR;
+        drmModeSetCrtc(m_dri_fd, crtc_id, 0, 0, 0, 0, 0, nullptr);
+        return nullptr;
     }
 
     // Skip disconnected output
     if (configuration == OutputConfigPreferred && connector->connection == DRM_MODE_DISCONNECTED) {
         qCDebug(qLcKmsDebug) << "Skipping disconnected output" << connectorName;
-        return Q_NULLPTR;
+        return nullptr;
     }
 
     // Get the current mode on the current crtc
@@ -235,7 +235,7 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
         drmModeFreeEncoder(encoder);
 
         if (!crtc)
-            return Q_NULLPTR;
+            return nullptr;
 
         if (crtc->mode_valid)
             crtc_mode = crtc->mode;
@@ -305,7 +305,7 @@ QPlatformScreen *QKmsDevice::createScreenForConnector(drmModeResPtr resources,
 
     if (selected_mode < 0) {
         qWarning() << "No modes available for output" << connectorName;
-        return Q_NULLPTR;
+        return nullptr;
     } else {
         int width = modes[selected_mode].hdisplay;
         int height = modes[selected_mode].vdisplay;
@@ -438,7 +438,7 @@ drmModePropertyPtr QKmsDevice::connectorProperty(drmModeConnectorPtr connector,
         drmModeFreeProperty(prop);
     }
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 drmModePropertyBlobPtr QKmsDevice::connectorPropertyBlob(drmModeConnectorPtr connector, const QByteArray &name)
diff --git a/src/platformsupport/platformcompositor/qopenglcompositorbackingstore.cpp b/src/platformsupport/platformcompositor/qopenglcompositorbackingstore.cpp
index b24491b187..5b5ed2c9b7 100644
--- a/src/platformsupport/platformcompositor/qopenglcompositorbackingstore.cpp
+++ b/src/platformsupport/platformcompositor/qopenglcompositorbackingstore.cpp
@@ -196,7 +196,7 @@ void QOpenGLCompositorBackingStore::flush(QWindow *window, const QRegion &region
     dstCtx->makeCurrent(dstWin);
     updateTexture();
     m_textures->clear();
-    m_textures->appendTexture(Q_NULLPTR, m_bsTexture, window->geometry());
+    m_textures->appendTexture(nullptr, m_bsTexture, window->geometry());
 
     compositor->update();
 }
@@ -234,7 +234,7 @@ void QOpenGLCompositorBackingStore::composeAndFlush(QWindow *window, const QRegi
                                   textures->clipRect(i), textures->flags(i));
 
     updateTexture();
-    m_textures->appendTexture(Q_NULLPTR, m_bsTexture, window->geometry());
+    m_textures->appendTexture(nullptr, m_bsTexture, window->geometry());
 
     textures->lock(true);
     m_lockedWidgetTextures = textures;
@@ -281,7 +281,7 @@ void QOpenGLCompositorBackingStore::resize(const QSize &size, const QRegion &sta
     if (m_bsTexture) {
         glDeleteTextures(1, &m_bsTexture);
         m_bsTexture = 0;
-        m_bsTextureContext = Q_NULLPTR;
+        m_bsTextureContext = nullptr;
     }
 }
 
diff --git a/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuadaptor.cpp b/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuadaptor.cpp
index 354b9c3a2e..eabb4b4122 100644
--- a/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuadaptor.cpp
+++ b/src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuadaptor.cpp
@@ -122,7 +122,7 @@ void QDBusMenuAdaptor::Event(int id, const QString &eventId, const QDBusVariant
         emit item->hovered();
     if (eventId == QLatin1String("closed")) {
         // There is no explicit AboutToHide method, so map closed event to aboutToHide method
-        const QDBusPlatformMenu *menu = Q_NULLPTR;
+        const QDBusPlatformMenu *menu = nullptr;
         if (item)
             menu = static_cast<const QDBusPlatformMenu *>(item->menu());
         else if (id == 0)
diff --git a/src/platformsupport/themes/genericunix/dbusmenu/qdbusplatformmenu.cpp b/src/platformsupport/themes/genericunix/dbusmenu/qdbusplatformmenu.cpp
index 51c690d43a..fc1b37f2f2 100644
--- a/src/platformsupport/themes/genericunix/dbusmenu/qdbusplatformmenu.cpp
+++ b/src/platformsupport/themes/genericunix/dbusmenu/qdbusplatformmenu.cpp
@@ -68,7 +68,7 @@ QDBusPlatformMenuItem::~QDBusPlatformMenuItem()
 {
     menuItemsByID.remove(m_dbusID);
     if (m_subMenu)
-        static_cast<QDBusPlatformMenu *>(m_subMenu)->setContainingMenuItem(Q_NULLPTR);
+        static_cast<QDBusPlatformMenu *>(m_subMenu)->setContainingMenuItem(nullptr);
 }
 
 void QDBusPlatformMenuItem::setText(const QString &text)
@@ -88,7 +88,7 @@ void QDBusPlatformMenuItem::setIcon(const QIcon &icon)
 void QDBusPlatformMenuItem::setMenu(QPlatformMenu *menu)
 {
     if (m_subMenu)
-        static_cast<QDBusPlatformMenu *>(m_subMenu)->setContainingMenuItem(Q_NULLPTR);
+        static_cast<QDBusPlatformMenu *>(m_subMenu)->setContainingMenuItem(nullptr);
     m_subMenu = menu;
     if (menu)
         static_cast<QDBusPlatformMenu *>(menu)->setContainingMenuItem(this);
@@ -147,7 +147,7 @@ QDBusPlatformMenuItem *QDBusPlatformMenuItem::byId(int id)
     // a default-constructed nullptr value into menuItemsByID
     if (menuItemsByID.contains(id))
         return menuItemsByID[id];
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QList<const QDBusPlatformMenuItem *> QDBusPlatformMenuItem::byIds(const QList<int> &ids)
@@ -165,14 +165,14 @@ QDBusPlatformMenu::QDBusPlatformMenu()
     : m_isEnabled(true)
     , m_isVisible(true)
     , m_revision(1)
-    , m_containingMenuItem(Q_NULLPTR)
+    , m_containingMenuItem(nullptr)
 {
 }
 
 QDBusPlatformMenu::~QDBusPlatformMenu()
 {
     if (m_containingMenuItem)
-        m_containingMenuItem->setMenu(Q_NULLPTR);
+        m_containingMenuItem->setMenu(nullptr);
 }
 
 void QDBusPlatformMenu::insertMenuItem(QPlatformMenuItem *menuItem, QPlatformMenuItem *before)
diff --git a/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp b/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp
index 9baf94726d..8480c15fb7 100644
--- a/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp
+++ b/src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp
@@ -102,17 +102,17 @@ static int instanceCount = 0;
 */
 
 QDBusTrayIcon::QDBusTrayIcon()
-    : m_dbusConnection(Q_NULLPTR)
+    : m_dbusConnection(nullptr)
     , m_adaptor(new QStatusNotifierItemAdaptor(this))
-    , m_menuAdaptor(Q_NULLPTR)
-    , m_menu(Q_NULLPTR)
-    , m_notifier(Q_NULLPTR)
+    , m_menuAdaptor(nullptr)
+    , m_menu(nullptr)
+    , m_notifier(nullptr)
     , m_instanceId(KDEItemFormat.arg(QCoreApplication::applicationPid()).arg(++instanceCount))
     , m_category(QStringLiteral("ApplicationStatus"))
     , m_defaultStatus(QStringLiteral("Active")) // be visible all the time.  QSystemTrayIcon has no API to control this.
     , m_status(m_defaultStatus)
-    , m_tempIcon(Q_NULLPTR)
-    , m_tempAttentionIcon(Q_NULLPTR)
+    , m_tempIcon(nullptr)
+    , m_tempAttentionIcon(nullptr)
     , m_registered(false)
 {
     qCDebug(qLcTray);
@@ -149,9 +149,9 @@ void QDBusTrayIcon::cleanup()
     if (m_registered)
         dBusConnection()->unregisterTrayIcon(this);
     delete m_dbusConnection;
-    m_dbusConnection = Q_NULLPTR;
+    m_dbusConnection = nullptr;
     delete m_notifier;
-    m_notifier = Q_NULLPTR;
+    m_notifier = nullptr;
     m_registered = false;
 }
 
@@ -203,7 +203,7 @@ QTemporaryFile *QDBusTrayIcon::tempIcon(const QIcon &icon)
         necessity_checked = true;
     }
     if (!necessary)
-        return Q_NULLPTR;
+        return nullptr;
     qreal dpr = qGuiApp->devicePixelRatio();
     QTemporaryFile *ret = new QTemporaryFile(TempFileTemplate, this);
     ret->open();
diff --git a/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp b/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
index be0fac4b55..eeb03eb958 100644
--- a/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
+++ b/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
@@ -197,7 +197,7 @@ QPlatformSystemTrayIcon *QGenericUnixTheme::createPlatformSystemTrayIcon() const
 {
     if (isDBusTrayAvailable())
         return new QDBusTrayIcon();
-    return Q_NULLPTR;
+    return nullptr;
 }
 #endif
 
@@ -672,7 +672,7 @@ QPlatformSystemTrayIcon *QKdeTheme::createPlatformSystemTrayIcon() const
 {
     if (isDBusTrayAvailable())
         return new QDBusTrayIcon();
-    return Q_NULLPTR;
+    return nullptr;
 }
 #endif
 
@@ -691,7 +691,7 @@ const char *QGnomeTheme::name = "gnome";
 class QGnomeThemePrivate : public QPlatformThemePrivate
 {
 public:
-    QGnomeThemePrivate() : systemFont(Q_NULLPTR), fixedFont(Q_NULLPTR) {}
+    QGnomeThemePrivate() : systemFont(nullptr), fixedFont(nullptr) {}
     ~QGnomeThemePrivate() { delete systemFont; delete fixedFont; }
 
     void configureFonts(const QString &gtkFontName) const
@@ -791,7 +791,7 @@ QPlatformSystemTrayIcon *QGnomeTheme::createPlatformSystemTrayIcon() const
 {
     if (isDBusTrayAvailable())
         return new QDBusTrayIcon();
-    return Q_NULLPTR;
+    return nullptr;
 }
 #endif
 
@@ -829,7 +829,7 @@ QPlatformTheme *QGenericUnixTheme::createUnixTheme(const QString &name)
 #endif
     if (name == QLatin1String(QGnomeTheme::name))
         return new QGnomeTheme;
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QStringList QGenericUnixTheme::themeNames()
diff --git a/src/plugins/platforms/cocoa/qcocoacursor.mm b/src/plugins/platforms/cocoa/qcocoacursor.mm
index 99a136d384..14daf62878 100644
--- a/src/plugins/platforms/cocoa/qcocoacursor.mm
+++ b/src/plugins/platforms/cocoa/qcocoacursor.mm
@@ -86,7 +86,7 @@ void QCocoaCursor::setPos(const QPoint &position)
 
 NSCursor *QCocoaCursor::convertCursor(QCursor *cursor)
 {
-    if (cursor == Q_NULLPTR)
+    if (cursor == nullptr)
         return 0;
 
     const Qt::CursorShape newShape = cursor->shape();
diff --git a/src/plugins/platforms/cocoa/qcocoamenubar.mm b/src/plugins/platforms/cocoa/qcocoamenubar.mm
index 70fcb40774..edefe7bd9a 100644
--- a/src/plugins/platforms/cocoa/qcocoamenubar.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenubar.mm
@@ -450,7 +450,7 @@ NSMenuItem *QCocoaMenuBar::itemForRole(QPlatformMenuItem::MenuRole r)
         foreach (QCocoaMenuItem *i, m->items())
             if (i->effectiveRole() == r)
                 return i->nsItem();
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoanativeinterface.mm b/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
index 8943cb6cd5..1422aebd65 100644
--- a/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
+++ b/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
@@ -233,7 +233,7 @@ QFunctionPointer QCocoaNativeInterface::platformFunction(const QByteArray &funct
     if (function == QCocoaWindowFunctions::bottomLeftClippedByNSWindowOffsetIdentifier())
         return QFunctionPointer(QCocoaWindowFunctions::BottomLeftClippedByNSWindowOffset(QCocoaWindow::bottomLeftClippedByNSWindowOffsetStatic));
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void QCocoaNativeInterface::addToMimeList(void *macPasteboardMime)
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.mm b/src/plugins/platforms/cocoa/qcocoatheme.mm
index 04dce802f3..2094f29770 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.mm
+++ b/src/plugins/platforms/cocoa/qcocoatheme.mm
@@ -97,7 +97,7 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QCocoaThemeNotificationReceiver);
 {
     Q_UNUSED(notification);
     mPrivate->reset();
-    QWindowSystemInterface::handleThemeChange(Q_NULLPTR);
+    QWindowSystemInterface::handleThemeChange(nullptr);
 }
 @end
 
@@ -126,7 +126,7 @@ QCocoaTheme::~QCocoaTheme()
 void QCocoaTheme::reset()
 {
     delete m_systemPalette;
-    m_systemPalette = Q_NULLPTR;
+    m_systemPalette = nullptr;
     qDeleteAll(m_palettes);
     m_palettes.clear();
 }
@@ -274,7 +274,7 @@ QPixmap QCocoaTheme::standardPixmap(StandardPixmap sp, const QSizeF &size) const
     }
     if (iconType != 0) {
         QPixmap pixmap;
-        IconRef icon = Q_NULLPTR;
+        IconRef icon = nullptr;
         GetIconRef(kOnSystemDisk, kSystemIconsCreator, iconType, &icon);
 
         if (icon) {
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2ddevicecontext.cpp b/src/plugins/platforms/direct2d/qwindowsdirect2ddevicecontext.cpp
index 643ae877d0..d578a58982 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2ddevicecontext.cpp
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2ddevicecontext.cpp
@@ -161,7 +161,7 @@ void QWindowsDirect2DDeviceContextSuspender::resume()
 {
     if (m_dc) {
         m_dc->resume();
-        m_dc = Q_NULLPTR;
+        m_dc = nullptr;
     }
 }
 
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dintegration.cpp b/src/plugins/platforms/direct2d/qwindowsdirect2dintegration.cpp
index ea51135583..97e3a25b86 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dintegration.cpp
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dintegration.cpp
@@ -203,7 +203,7 @@ QWindowsDirect2DIntegration *QWindowsDirect2DIntegration::create(const QStringLi
                     caption.toStdWString().c_str(),
                     MB_OK | MB_ICONERROR);
 
-        return Q_NULLPTR;
+        return nullptr;
     }
 
     QWindowsDirect2DIntegration *integration = new QWindowsDirect2DIntegration(paramList);
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
index 164429ba30..95fbd37247 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
@@ -804,7 +804,7 @@ public:
         const bool alias = !q->antiAliasingEnabled();
 
         QVectorPath::CacheEntry *cacheEntry = path.isCacheable() ? path.lookupCacheData(q)
-                                                                 : Q_NULLPTR;
+                                                                 : nullptr;
 
         if (cacheEntry) {
             D2DVectorPathCache *e = static_cast<D2DVectorPathCache *>(cacheEntry->data);
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dwindow.cpp b/src/plugins/platforms/direct2d/qwindowsdirect2dwindow.cpp
index 21294cfb15..f81182e0b1 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dwindow.cpp
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dwindow.cpp
@@ -209,7 +209,7 @@ void QWindowsDirect2DWindow::resizeSwapChain(const QSize &size)
 {
     m_pixmap.reset();
     m_bitmap.reset();
-    m_deviceContext->SetTarget(Q_NULLPTR);
+    m_deviceContext->SetTarget(nullptr);
     m_needsFullFlush = true;
 
     if (!m_swapChain)
@@ -241,7 +241,7 @@ QSharedPointer<QWindowsDirect2DBitmap> QWindowsDirect2DWindow::copyBackBuffer()
         dpiX,                       // FLOAT dpiX;
         dpiY,                       // FLOAT dpiY;
         D2D1_BITMAP_OPTIONS_TARGET, // D2D1_BITMAP_OPTIONS bitmapOptions;
-        Q_NULLPTR                   // _Field_size_opt_(1) ID2D1ColorContext *colorContext;
+        nullptr                   // _Field_size_opt_(1) ID2D1ColorContext *colorContext;
     };
     ComPtr<ID2D1Bitmap1> copy;
     HRESULT hr = m_deviceContext.Get()->CreateBitmap(size, NULL, 0, properties, &copy);
@@ -257,7 +257,7 @@ QSharedPointer<QWindowsDirect2DBitmap> QWindowsDirect2DWindow::copyBackBuffer()
         return null_result;
     }
 
-    return QSharedPointer<QWindowsDirect2DBitmap>(new QWindowsDirect2DBitmap(copy.Get(), Q_NULLPTR));
+    return QSharedPointer<QWindowsDirect2DBitmap>(new QWindowsDirect2DBitmap(copy.Get(), nullptr));
 }
 
 void QWindowsDirect2DWindow::setupBitmap()
diff --git a/src/plugins/platforms/eglfs/api/qeglfsdeviceintegration.cpp b/src/plugins/platforms/eglfs/api/qeglfsdeviceintegration.cpp
index 7c279a6b77..0fc4cc54e0 100644
--- a/src/plugins/platforms/eglfs/api/qeglfsdeviceintegration.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfsdeviceintegration.cpp
@@ -103,7 +103,7 @@ QStringList QEglFSDeviceIntegrationFactory::keys(const QString &pluginPath)
 
 QEglFSDeviceIntegration *QEglFSDeviceIntegrationFactory::create(const QString &key, const QString &pluginPath)
 {
-    QEglFSDeviceIntegration *integration = Q_NULLPTR;
+    QEglFSDeviceIntegration *integration = nullptr;
 #if QT_CONFIG(library)
     if (!pluginPath.isEmpty()) {
         QCoreApplication::addLibraryPath(pluginPath);
@@ -365,7 +365,7 @@ void *QEglFSDeviceIntegration::nativeResourceForIntegration(const QByteArray &na
 
 void *QEglFSDeviceIntegration::wlDisplay() const
 {
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 EGLConfig QEglFSDeviceIntegration::chooseConfig(EGLDisplay display, const QSurfaceFormat &format)
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp
index 800118362d..9bd7fee1fb 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp
@@ -68,7 +68,7 @@ Q_DECLARE_LOGGING_CATEGORY(qLcEglfsKmsDebug)
 QEglFSKmsGbmCursor::QEglFSKmsGbmCursor(QEglFSKmsGbmScreen *screen)
     : m_screen(screen)
     , m_cursorSize(64, 64) // 64x64 is the old standard size, we now try to query the real size below
-    , m_bo(Q_NULLPTR)
+    , m_bo(nullptr)
     , m_cursorImage(0, 0, 0, 0, 0, 0)
     , m_state(CursorPendingVisible)
 {
@@ -118,7 +118,7 @@ QEglFSKmsGbmCursor::~QEglFSKmsGbmCursor()
 
     if (m_bo) {
         gbm_bo_destroy(m_bo);
-        m_bo = Q_NULLPTR;
+        m_bo = nullptr;
     }
 }
 
@@ -132,7 +132,7 @@ void QEglFSKmsGbmCursor::updateMouseStatus()
     m_state = visible ? CursorPendingVisible : CursorPendingHidden;
 
 #ifndef QT_NO_CURSOR
-    changeCursor(Q_NULLPTR, m_screen->topLevelAt(pos()));
+    changeCursor(nullptr, m_screen->topLevelAt(pos()));
 #endif
 }
 
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
index e2dd8cf9ad..20127ae7f7 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
@@ -55,15 +55,15 @@ Q_DECLARE_LOGGING_CATEGORY(qLcEglfsKmsDebug)
 
 QEglFSKmsGbmDevice::QEglFSKmsGbmDevice(QKmsScreenConfig *screenConfig, const QString &path)
     : QEglFSKmsDevice(screenConfig, path)
-    , m_gbm_device(Q_NULLPTR)
-    , m_globalCursor(Q_NULLPTR)
+    , m_gbm_device(nullptr)
+    , m_globalCursor(nullptr)
 {
 }
 
 bool QEglFSKmsGbmDevice::open()
 {
     Q_ASSERT(fd() == -1);
-    Q_ASSERT(m_gbm_device == Q_NULLPTR);
+    Q_ASSERT(m_gbm_device == nullptr);
 
     int fd = qt_safe_open(devicePath().toLocal8Bit().constData(), O_RDWR | O_CLOEXEC);
     if (fd == -1) {
@@ -92,7 +92,7 @@ void QEglFSKmsGbmDevice::close()
 
     if (m_gbm_device) {
         gbm_device_destroy(m_gbm_device);
-        m_gbm_device = Q_NULLPTR;
+        m_gbm_device = nullptr;
     }
 
     if (fd() != -1) {
@@ -123,7 +123,7 @@ void QEglFSKmsGbmDevice::destroyGlobalCursor()
     if (m_globalCursor) {
         qCDebug(qLcEglfsKmsDebug, "Destroying global GBM mouse cursor");
         delete m_globalCursor;
-        m_globalCursor = Q_NULLPTR;
+        m_globalCursor = nullptr;
     }
 }
 
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
index 73342327cc..4742143121 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
@@ -102,7 +102,7 @@ QEglFSKmsGbmScreen::FrameBuffer *QEglFSKmsGbmScreen::framebufferForBufferObject(
 
     if (ret) {
         qWarning("Failed to create KMS FB!");
-        return Q_NULLPTR;
+        return nullptr;
     }
 
     gbm_bo_set_user_data(bo, fb.data(), bufferDestroyedHandler);
@@ -111,12 +111,12 @@ QEglFSKmsGbmScreen::FrameBuffer *QEglFSKmsGbmScreen::framebufferForBufferObject(
 
 QEglFSKmsGbmScreen::QEglFSKmsGbmScreen(QKmsDevice *device, const QKmsOutput &output, bool headless)
     : QEglFSKmsScreen(device, output, headless)
-    , m_gbm_surface(Q_NULLPTR)
-    , m_gbm_bo_current(Q_NULLPTR)
-    , m_gbm_bo_next(Q_NULLPTR)
+    , m_gbm_surface(nullptr)
+    , m_gbm_bo_current(nullptr)
+    , m_gbm_bo_next(nullptr)
     , m_flipPending(false)
-    , m_cursor(Q_NULLPTR)
-    , m_cloneSource(Q_NULLPTR)
+    , m_cursor(nullptr)
+    , m_cloneSource(nullptr)
 {
 }
 
@@ -283,7 +283,7 @@ void QEglFSKmsGbmScreen::flip()
         qErrnoWarning("Could not queue DRM page flip on screen %s", qPrintable(name()));
         m_flipPending = false;
         gbm_surface_release_buffer(m_gbm_surface, m_gbm_bo_next);
-        m_gbm_bo_next = Q_NULLPTR;
+        m_gbm_bo_next = nullptr;
         return;
     }
 
@@ -354,7 +354,7 @@ void QEglFSKmsGbmScreen::updateFlipStatus()
                                    m_gbm_bo_current);
 
     m_gbm_bo_current = m_gbm_bo_next;
-    m_gbm_bo_next = Q_NULLPTR;
+    m_gbm_bo_next = nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp
index cca413ff2d..8c8e6260f1 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp
@@ -58,7 +58,7 @@ bool QEglFSKmsEglDevice::open()
 {
     Q_ASSERT(fd() == -1);
 
-    int fd = drmOpen(devicePath().toLocal8Bit().constData(), Q_NULLPTR);
+    int fd = drmOpen(devicePath().toLocal8Bit().constData(), nullptr);
     if (Q_UNLIKELY(fd < 0))
         qFatal("Could not open DRM (NV) device");
 
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
index c04a5e1724..a67457a6a5 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
@@ -51,7 +51,7 @@ QT_BEGIN_NAMESPACE
 
 QEglFSKmsEglDeviceIntegration::QEglFSKmsEglDeviceIntegration()
     : m_egl_device(EGL_NO_DEVICE_EXT)
-    , m_funcs(Q_NULLPTR)
+    , m_funcs(nullptr)
 {
     qCDebug(qLcEglfsKmsDebug, "New DRM/KMS on EGLDevice integration created");
 }
@@ -75,7 +75,7 @@ EGLDisplay QEglFSKmsEglDeviceIntegration::createDisplay(EGLNativeDisplayType nat
     EGLDisplay display;
 
     if (m_funcs->has_egl_platform_device) {
-        display = m_funcs->get_platform_display(EGL_PLATFORM_DEVICE_EXT, nativeDisplay, Q_NULLPTR);
+        display = m_funcs->get_platform_display(EGL_PLATFORM_DEVICE_EXT, nativeDisplay, nullptr);
     } else {
         qWarning("EGL_EXT_platform_device not available, falling back to legacy path!");
         display = eglGetDisplay(nativeDisplay);
@@ -162,7 +162,7 @@ void QEglFSKmsEglDeviceWindow::resetSurface()
         qCDebug(qLcEglfsKmsDebug, "Could not query number of EGLStream FIFO frames");
     }
 
-    if (!m_integration->m_funcs->get_output_layers(display, Q_NULLPTR, Q_NULLPTR, 0, &count) || count == 0) {
+    if (!m_integration->m_funcs->get_output_layers(display, nullptr, nullptr, 0, &count) || count == 0) {
         qWarning("No output layers found");
         return;
     }
@@ -172,7 +172,7 @@ void QEglFSKmsEglDeviceWindow::resetSurface()
     QVector<EGLOutputLayerEXT> layers;
     layers.resize(count);
     EGLint actualCount;
-    if (!m_integration->m_funcs->get_output_layers(display, Q_NULLPTR, layers.data(), count, &actualCount)) {
+    if (!m_integration->m_funcs->get_output_layers(display, nullptr, layers.data(), count, &actualCount)) {
         qWarning("Failed to get layers");
         return;
     }
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp
index 455a94d0d3..975b1947bf 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp
@@ -55,7 +55,7 @@ QT_BEGIN_NAMESPACE
 Q_LOGGING_CATEGORY(qLcEglfsKmsDebug, "qt.qpa.eglfs.kms")
 
 QEglFSKmsIntegration::QEglFSKmsIntegration()
-    : m_device(Q_NULLPTR),
+    : m_device(nullptr),
       m_screenConfig(new QKmsScreenConfig)
 {
 }
@@ -78,7 +78,7 @@ void QEglFSKmsIntegration::platformDestroy()
     qCDebug(qLcEglfsKmsDebug, "platformDestroy: Closing DRM device");
     m_device->close();
     delete m_device;
-    m_device = Q_NULLPTR;
+    m_device = nullptr;
 }
 
 EGLNativeDisplayType QEglFSKmsIntegration::platformDisplay() const
diff --git a/src/plugins/platforms/haiku/main.cpp b/src/plugins/platforms/haiku/main.cpp
index 02168d0165..841891970d 100644
--- a/src/plugins/platforms/haiku/main.cpp
+++ b/src/plugins/platforms/haiku/main.cpp
@@ -47,7 +47,7 @@ QPlatformIntegration *QHaikuIntegrationPlugin::create(const QString& system, con
     if (!system.compare(QLatin1String("haiku"), Qt::CaseInsensitive))
         return new QHaikuIntegration(paramList);
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/haiku/qhaikubuffer.cpp b/src/plugins/platforms/haiku/qhaikubuffer.cpp
index c6f6ffe6bc..f25ddef86b 100644
--- a/src/plugins/platforms/haiku/qhaikubuffer.cpp
+++ b/src/plugins/platforms/haiku/qhaikubuffer.cpp
@@ -45,7 +45,7 @@
 QT_BEGIN_NAMESPACE
 
 QHaikuBuffer::QHaikuBuffer()
-    : m_buffer(Q_NULLPTR)
+    : m_buffer(nullptr)
 {
 }
 
@@ -63,12 +63,12 @@ BBitmap* QHaikuBuffer::nativeBuffer() const
 
 const QImage *QHaikuBuffer::image() const
 {
-    return (m_buffer != Q_NULLPTR) ? &m_image : Q_NULLPTR;
+    return (m_buffer != nullptr) ? &m_image : nullptr;
 }
 
 QImage *QHaikuBuffer::image()
 {
-    return (m_buffer != Q_NULLPTR) ? &m_image : Q_NULLPTR;
+    return (m_buffer != nullptr) ? &m_image : nullptr;
 }
 
 QRect QHaikuBuffer::rect() const
diff --git a/src/plugins/platforms/haiku/qhaikuclipboard.cpp b/src/plugins/platforms/haiku/qhaikuclipboard.cpp
index 774da4432a..20519e21d0 100644
--- a/src/plugins/platforms/haiku/qhaikuclipboard.cpp
+++ b/src/plugins/platforms/haiku/qhaikuclipboard.cpp
@@ -47,8 +47,8 @@
 #include <Clipboard.h>
 
 QHaikuClipboard::QHaikuClipboard()
-    : m_systemMimeData(Q_NULLPTR)
-    , m_userMimeData(Q_NULLPTR)
+    : m_systemMimeData(nullptr)
+    , m_userMimeData(nullptr)
 {
     if (be_clipboard)
         be_clipboard->StartWatching(BMessenger(this));
@@ -81,12 +81,12 @@ QMimeData *QHaikuClipboard::mimeData(QClipboard::Mode mode)
 
     const BMessage *clipboard = be_clipboard->Data();
     if (clipboard) {
-        char *name = Q_NULLPTR;
+        char *name = nullptr;
         uint32 type = 0;
         int32 count = 0;
 
         for (int i = 0; clipboard->GetInfo(B_MIME_TYPE, i, &name, &type, &count) == B_OK; i++) {
-            const void *data = Q_NULLPTR;
+            const void *data = nullptr;
             int32 dataLen = 0;
 
             const status_t status = clipboard->FindData(name, B_MIME_TYPE, &data, &dataLen);
@@ -162,7 +162,7 @@ void QHaikuClipboard::MessageReceived(BMessage* message)
 {
     if (message->what == B_CLIPBOARD_CHANGED) {
         delete m_userMimeData;
-        m_userMimeData = Q_NULLPTR;
+        m_userMimeData = nullptr;
 
         emitChanged(QClipboard::Clipboard);
     }
diff --git a/src/plugins/platforms/haiku/qhaikuintegration.cpp b/src/plugins/platforms/haiku/qhaikuintegration.cpp
index d46d77ff18..8bd2171794 100644
--- a/src/plugins/platforms/haiku/qhaikuintegration.cpp
+++ b/src/plugins/platforms/haiku/qhaikuintegration.cpp
@@ -87,13 +87,13 @@ QHaikuIntegration::QHaikuIntegration(const QStringList &parameters)
 QHaikuIntegration::~QHaikuIntegration()
 {
     destroyScreen(m_screen);
-    m_screen = Q_NULLPTR;
+    m_screen = nullptr;
 
     delete m_services;
-    m_services = Q_NULLPTR;
+    m_services = nullptr;
 
     delete m_clipboard;
-    m_clipboard = Q_NULLPTR;
+    m_clipboard = nullptr;
 
     be_app->LockLooper();
     be_app->Quit();
diff --git a/src/plugins/platforms/haiku/qhaikurasterbackingstore.cpp b/src/plugins/platforms/haiku/qhaikurasterbackingstore.cpp
index ee53f693cd..613ae471cb 100644
--- a/src/plugins/platforms/haiku/qhaikurasterbackingstore.cpp
+++ b/src/plugins/platforms/haiku/qhaikurasterbackingstore.cpp
@@ -47,14 +47,14 @@ QT_BEGIN_NAMESPACE
 
 QHaikuRasterBackingStore::QHaikuRasterBackingStore(QWindow *window)
     : QPlatformBackingStore(window)
-    , m_bitmap(Q_NULLPTR)
+    , m_bitmap(nullptr)
 {
 }
 
 QHaikuRasterBackingStore::~QHaikuRasterBackingStore()
 {
     delete m_bitmap;
-    m_bitmap = Q_NULLPTR;
+    m_bitmap = nullptr;
 }
 
 QPaintDevice *QHaikuRasterBackingStore::paintDevice()
@@ -62,7 +62,7 @@ QPaintDevice *QHaikuRasterBackingStore::paintDevice()
     if (!m_bufferSize.isEmpty() && m_bitmap)
         return m_buffer.image();
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void QHaikuRasterBackingStore::flush(QWindow *window, const QRegion &region, const QPoint &offset)
diff --git a/src/plugins/platforms/haiku/qhaikurasterwindow.cpp b/src/plugins/platforms/haiku/qhaikurasterwindow.cpp
index 9834b7cbc7..7e57e67bab 100644
--- a/src/plugins/platforms/haiku/qhaikurasterwindow.cpp
+++ b/src/plugins/platforms/haiku/qhaikurasterwindow.cpp
@@ -211,7 +211,7 @@ void HaikuViewProxy::handleKeyEvent(QEvent::Type type, BMessage *message)
 {
     int32 key = 0;
     uint32 code = 0;
-    const char *bytes = Q_NULLPTR;
+    const char *bytes = nullptr;
     QString text;
 
     if (message) {
@@ -265,7 +265,7 @@ QHaikuRasterWindow::~QHaikuRasterWindow()
     m_window->UnlockLooper();
 
     delete m_view;
-    m_view = Q_NULLPTR;
+    m_view = nullptr;
 }
 
 BView* QHaikuRasterWindow::nativeViewHandle() const
diff --git a/src/plugins/platforms/haiku/qhaikurasterwindow.h b/src/plugins/platforms/haiku/qhaikurasterwindow.h
index fd821be763..24b13aa122 100644
--- a/src/plugins/platforms/haiku/qhaikurasterwindow.h
+++ b/src/plugins/platforms/haiku/qhaikurasterwindow.h
@@ -51,7 +51,7 @@ class HaikuViewProxy : public QObject, public BView
     Q_OBJECT
 
 public:
-    explicit HaikuViewProxy(BWindow *window, QObject *parent = Q_NULLPTR);
+    explicit HaikuViewProxy(BWindow *window, QObject *parent = nullptr);
 
     void MessageReceived(BMessage *message) override;
     void Draw(BRect updateRect) override;
diff --git a/src/plugins/platforms/haiku/qhaikuscreen.cpp b/src/plugins/platforms/haiku/qhaikuscreen.cpp
index 54951a0af5..2c8abba8aa 100644
--- a/src/plugins/platforms/haiku/qhaikuscreen.cpp
+++ b/src/plugins/platforms/haiku/qhaikuscreen.cpp
@@ -58,10 +58,10 @@ QHaikuScreen::QHaikuScreen()
 QHaikuScreen::~QHaikuScreen()
 {
     delete m_cursor;
-    m_cursor = Q_NULLPTR;
+    m_cursor = nullptr;
 
     delete m_screen;
-    m_screen = Q_NULLPTR;
+    m_screen = nullptr;
 }
 
 QPixmap QHaikuScreen::grabWindow(WId winId, int x, int y, int width, int height) const
@@ -69,8 +69,8 @@ QPixmap QHaikuScreen::grabWindow(WId winId, int x, int y, int width, int height)
     if (width == 0 || height == 0)
         return QPixmap();
 
-    BScreen screen(Q_NULLPTR);
-    BBitmap *bitmap = Q_NULLPTR;
+    BScreen screen(nullptr);
+    BBitmap *bitmap = nullptr;
     screen.GetBitmap(&bitmap);
 
     const BRect frame = (winId ? ((BWindow*)winId)->Frame() : screen.Frame());
diff --git a/src/plugins/platforms/haiku/qhaikuwindow.cpp b/src/plugins/platforms/haiku/qhaikuwindow.cpp
index 4bea7f7ff6..f8fdf3f92d 100644
--- a/src/plugins/platforms/haiku/qhaikuwindow.cpp
+++ b/src/plugins/platforms/haiku/qhaikuwindow.cpp
@@ -118,12 +118,12 @@ void HaikuWindowProxy::zoomByQt()
 
 QHaikuWindow::QHaikuWindow(QWindow *window)
     : QPlatformWindow(window)
-    , m_window(Q_NULLPTR)
+    , m_window(nullptr)
     , m_windowState(Qt::WindowNoState)
 {
     const QRect rect = initialGeometry(window, window->geometry(), DefaultWindowWidth, DefaultWindowHeight);
 
-    HaikuWindowProxy *haikuWindow = new HaikuWindowProxy(window, rect, Q_NULLPTR);
+    HaikuWindowProxy *haikuWindow = new HaikuWindowProxy(window, rect, nullptr);
     connect(haikuWindow, SIGNAL(moved(QPoint)), SLOT(haikuWindowMoved(QPoint)));
     connect(haikuWindow, SIGNAL(resized(QSize,bool)), SLOT(haikuWindowResized(QSize,bool)));
     connect(haikuWindow, SIGNAL(windowActivated(bool)), SLOT(haikuWindowActivated(bool)));
@@ -145,7 +145,7 @@ QHaikuWindow::~QHaikuWindow()
     m_window->LockLooper();
     m_window->Quit();
 
-    m_window = Q_NULLPTR;
+    m_window = nullptr;
 }
 
 void QHaikuWindow::setGeometry(const QRect &rect)
@@ -330,7 +330,7 @@ void QHaikuWindow::haikuWindowResized(const QSize &size, bool zoomInProgress)
 
 void QHaikuWindow::haikuWindowActivated(bool activated)
 {
-    QWindowSystemInterface::handleWindowActivated(activated ? window() : Q_NULLPTR);
+    QWindowSystemInterface::handleWindowActivated(activated ? window() : nullptr);
 }
 
 void QHaikuWindow::haikuWindowMinimized(bool minimize)
diff --git a/src/plugins/platforms/haiku/qhaikuwindow.h b/src/plugins/platforms/haiku/qhaikuwindow.h
index efa47939a7..bb57742087 100644
--- a/src/plugins/platforms/haiku/qhaikuwindow.h
+++ b/src/plugins/platforms/haiku/qhaikuwindow.h
@@ -51,7 +51,7 @@ class HaikuWindowProxy : public QObject, public BWindow
     Q_OBJECT
 
 public:
-    explicit HaikuWindowProxy(QWindow *window, const QRect &rect, QObject *parent = Q_NULLPTR);
+    explicit HaikuWindowProxy(QWindow *window, const QRect &rect, QObject *parent = nullptr);
 
     void FrameMoved(BPoint pos) override;
     void FrameResized(float width, float height) override;
diff --git a/src/plugins/platforms/ios/qiosfiledialog.mm b/src/plugins/platforms/ios/qiosfiledialog.mm
index c5722d33f8..5987bc1540 100644
--- a/src/plugins/platforms/ios/qiosfiledialog.mm
+++ b/src/plugins/platforms/ios/qiosfiledialog.mm
@@ -48,7 +48,7 @@
 #include "qiosoptionalplugininterface.h"
 
 QIOSFileDialog::QIOSFileDialog()
-    : m_viewController(Q_NULLPTR)
+    : m_viewController(nullptr)
 {
 }
 
@@ -112,7 +112,7 @@ void QIOSFileDialog::hide()
 
     [m_viewController dismissViewControllerAnimated:YES completion:nil];
     [m_viewController release];
-    m_viewController = Q_NULLPTR;
+    m_viewController = nullptr;
     m_eventLoop.exit();
 }
 
diff --git a/src/plugins/platforms/ios/qiosmessagedialog.mm b/src/plugins/platforms/ios/qiosmessagedialog.mm
index 4f0c667861..58b2b36b49 100644
--- a/src/plugins/platforms/ios/qiosmessagedialog.mm
+++ b/src/plugins/platforms/ios/qiosmessagedialog.mm
@@ -49,7 +49,7 @@
 #include "qiosmessagedialog.h"
 
 QIOSMessageDialog::QIOSMessageDialog()
-    : m_alertController(Q_NULLPTR)
+    : m_alertController(nullptr)
 {
 }
 
@@ -138,5 +138,5 @@ void QIOSMessageDialog::hide()
     m_eventLoop.exit();
     [m_alertController dismissViewControllerAnimated:YES completion:nil];
     [m_alertController release];
-    m_alertController = Q_NULLPTR;
+    m_alertController = nullptr;
 }
diff --git a/src/plugins/platforms/ios/qiosoptionalplugininterface.h b/src/plugins/platforms/ios/qiosoptionalplugininterface.h
index 3f74e41c83..660c74e856 100644
--- a/src/plugins/platforms/ios/qiosoptionalplugininterface.h
+++ b/src/plugins/platforms/ios/qiosoptionalplugininterface.h
@@ -55,7 +55,7 @@ class QIosOptionalPluginInterface
 public:
     virtual ~QIosOptionalPluginInterface() {}
     virtual void initPlugin() const {};
-    virtual UIViewController* createImagePickerController(QIOSFileDialog *) const { return Q_NULLPTR; };
+    virtual UIViewController* createImagePickerController(QIOSFileDialog *) const { return nullptr; };
 };
 
 Q_DECLARE_INTERFACE(QIosOptionalPluginInterface, QIosOptionalPluginInterface_iid)
diff --git a/src/plugins/platforms/ios/qiostextinputoverlay.mm b/src/plugins/platforms/ios/qiostextinputoverlay.mm
index 9b97ce17bb..034c1bba08 100644
--- a/src/plugins/platforms/ios/qiostextinputoverlay.mm
+++ b/src/plugins/platforms/ios/qiostextinputoverlay.mm
@@ -617,7 +617,7 @@ static void executeBlockWithoutAnimation(Block block)
 - (QIOSLoupeLayer *)createLoupeLayer
 {
     Q_UNREACHABLE();
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 - (void)updateFocalPoint:(QPointF)touchPoint
@@ -993,12 +993,12 @@ static void executeBlockWithoutAnimation(Block block)
 
 QT_BEGIN_NAMESPACE
 
-QIOSEditMenu *QIOSTextInputOverlay::s_editMenu = Q_NULLPTR;
+QIOSEditMenu *QIOSTextInputOverlay::s_editMenu = nullptr;
 
 QIOSTextInputOverlay::QIOSTextInputOverlay()
-    : m_cursorRecognizer(Q_NULLPTR)
-    , m_selectionRecognizer(Q_NULLPTR)
-    , m_openMenuOnTapRecognizer(Q_NULLPTR)
+    : m_cursorRecognizer(nullptr)
+    , m_selectionRecognizer(nullptr)
+    , m_openMenuOnTapRecognizer(nullptr)
 {
     connect(qApp, &QGuiApplication::focusObjectChanged, this, &QIOSTextInputOverlay::updateFocusObject);
 }
@@ -1021,10 +1021,10 @@ void QIOSTextInputOverlay::updateFocusObject()
         [m_selectionRecognizer release];
         [m_openMenuOnTapRecognizer release];
         [s_editMenu release];
-        m_cursorRecognizer = Q_NULLPTR;
-        m_selectionRecognizer = Q_NULLPTR;
-        m_openMenuOnTapRecognizer = Q_NULLPTR;
-        s_editMenu = Q_NULLPTR;
+        m_cursorRecognizer = nullptr;
+        m_selectionRecognizer = nullptr;
+        m_openMenuOnTapRecognizer = nullptr;
+        s_editMenu = nullptr;
     }
 
     if (platformInputContext()->inputMethodAccepted()) {
diff --git a/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp b/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp
index ba1a4c27a8..5d31af53d5 100644
--- a/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp
+++ b/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp
@@ -156,7 +156,7 @@ QAbstractEventDispatcher *QMinimalEglIntegration::createEventDispatcher() const
 #elif defined(Q_OS_WIN)
     return new QWindowsGuiEventDispatcher;
 #else
-    return Q_NULLPTR;
+    return nullptr;
 #endif
 }
 
diff --git a/src/plugins/platforms/windows/accessible/iaccessible2.cpp b/src/plugins/platforms/windows/accessible/iaccessible2.cpp
index 9239facb0c..3e60f45dd7 100644
--- a/src/plugins/platforms/windows/accessible/iaccessible2.cpp
+++ b/src/plugins/platforms/windows/accessible/iaccessible2.cpp
@@ -925,7 +925,7 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_selectedColumns(long **sele
         const QList<int> selectedIndices = tableIface->selectedColumns();
         const int count = selectedIndices.count();
         *nColumns = count;
-        *selectedColumns = Q_NULLPTR;
+        *selectedColumns = nullptr;
         if (count) {
             *selectedColumns = coTaskMemAllocArray<long>(count);
             std::copy(selectedIndices.constBegin(), selectedIndices.constEnd(),
@@ -948,7 +948,7 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_selectedRows(long **selecte
         const QList<int> selectedIndices = tableIface->selectedRows();
         const int count = selectedIndices.count();
         *nRows = count;
-        *selectedRows = Q_NULLPTR;
+        *selectedRows = nullptr;
         if (count) {
             *selectedRows = coTaskMemAllocArray<long>(count);
             std::copy(selectedIndices.constBegin(), selectedIndices.constEnd(),
@@ -1617,7 +1617,7 @@ HRESULT QWindowsIA2Accessible::wrapListOfCells(const QList<QAccessibleInterface*
     const int count = inputCells.count();
     // Server allocates array
     *nCellCount = count;
-    *outputAccessibles = Q_NULLPTR;
+    *outputAccessibles = nullptr;
     if (count) {
         *outputAccessibles = coTaskMemAllocArray<IUnknown *>(count);
         std::transform(inputCells.constBegin(), inputCells.constEnd(),
diff --git a/src/plugins/platforms/windows/qwindowsbackingstore.cpp b/src/plugins/platforms/windows/qwindowsbackingstore.cpp
index 49c7144221..80872c3ea3 100644
--- a/src/plugins/platforms/windows/qwindowsbackingstore.cpp
+++ b/src/plugins/platforms/windows/qwindowsbackingstore.cpp
@@ -93,7 +93,7 @@ void QWindowsBackingStore::flush(QWindow *window, const QRegion &region,
         // Windows with alpha: Use blend function to update.
         QRect r = QHighDpi::toNativePixels(window->frameGeometry(), window);
         QPoint frameOffset(QHighDpi::toNativePixels(QPoint(window->frameMargins().left(), window->frameMargins().top()),
-                                                    static_cast<const QWindow *>(Q_NULLPTR)));
+                                                    static_cast<const QWindow *>(nullptr)));
         QRect dirtyRect = br.translated(offset + frameOffset);
 
         SIZE size = {r.width(), r.height()};
diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 6d4b7922db..2848bb4a4e 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -754,7 +754,7 @@ HWND QWindowsContext::createDummyWindow(const QString &classNameIn,
 // present in the MSVCRT.DLL found on Windows XP (QTBUG-35617).
 static inline QString errorMessageFromComError(const _com_error &comError)
 {
-     TCHAR *message = Q_NULLPTR;
+     TCHAR *message = nullptr;
      FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
                    NULL, DWORD(comError.Error()), MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
                    message, 0, NULL);
diff --git a/src/plugins/platforms/windows/qwindowscursor.cpp b/src/plugins/platforms/windows/qwindowscursor.cpp
index e7ba08b719..a325b9d1d7 100644
--- a/src/plugins/platforms/windows/qwindowscursor.cpp
+++ b/src/plugins/platforms/windows/qwindowscursor.cpp
@@ -184,7 +184,7 @@ static HCURSOR createBitmapCursor(const QCursor &cursor, qreal scaleFactor = 1)
     return createBitmapCursor(bbits, mbits, cursor.hotSpot(), invb, invm);
 }
 
-static QSize systemCursorSize(const QPlatformScreen *screen = Q_NULLPTR)
+static QSize systemCursorSize(const QPlatformScreen *screen = nullptr)
 {
     const QSize primaryScreenCursorSize(GetSystemMetrics(SM_CXCURSOR), GetSystemMetrics(SM_CYCURSOR));
     if (screen) {
diff --git a/src/plugins/platforms/windows/qwindowscursor.h b/src/plugins/platforms/windows/qwindowscursor.h
index 9aa9523ac8..8af56e4e0c 100644
--- a/src/plugins/platforms/windows/qwindowscursor.h
+++ b/src/plugins/platforms/windows/qwindowscursor.h
@@ -70,7 +70,7 @@ class CursorHandle
 {
     Q_DISABLE_COPY(CursorHandle)
 public:
-    explicit CursorHandle(HCURSOR hcursor = Q_NULLPTR) : m_hcursor(hcursor) {}
+    explicit CursorHandle(HCURSOR hcursor = nullptr) : m_hcursor(hcursor) {}
     ~CursorHandle()
     {
         if (m_hcursor)
@@ -113,9 +113,9 @@ public:
 
     static HCURSOR createPixmapCursor(QPixmap pixmap, const QPoint &hotSpot, qreal scaleFactor = 1);
     static HCURSOR createPixmapCursor(const PixmapCursor &pc, qreal scaleFactor = 1) { return createPixmapCursor(pc.pixmap, pc.hotSpot, scaleFactor); }
-    static PixmapCursor customCursor(Qt::CursorShape cursorShape, const QPlatformScreen *screen = Q_NULLPTR);
+    static PixmapCursor customCursor(Qt::CursorShape cursorShape, const QPlatformScreen *screen = nullptr);
 
-    static HCURSOR createCursorFromShape(Qt::CursorShape cursorShape, const QPlatformScreen *screen = Q_NULLPTR);
+    static HCURSOR createCursorFromShape(Qt::CursorShape cursorShape, const QPlatformScreen *screen = nullptr);
     static QPoint mousePosition();
     static CursorState cursorState();
 
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index c4aeb15bd1..5501601c1a 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -711,7 +711,7 @@ QString QWindowsShellItem::libraryItemDefaultSaveFolder(IShellItem *item)
 {
     QString result;
     if (IShellLibrary *library = sHLoadLibraryFromItem(item, STGM_READ | STGM_SHARE_DENY_WRITE)) {
-        IShellItem *item = Q_NULLPTR;
+        IShellItem *item = nullptr;
         if (SUCCEEDED(library->GetDefaultSaveFolder(DSFT_DETECT, IID_IShellItem, reinterpret_cast<void **>(&item)))) {
             result = QDir::cleanPath(QWindowsShellItem::displayName(item, SIGDN_FILESYSPATH));
             item->Release();
@@ -893,7 +893,7 @@ void QWindowsNativeFileDialogBase::setWindowTitle(const QString &title)
 IShellItem *QWindowsNativeFileDialogBase::shellItem(const QUrl &url)
 {
     if (url.isLocalFile()) {
-        IShellItem *result = Q_NULLPTR;
+        IShellItem *result = nullptr;
         const QString native = QDir::toNativeSeparators(url.toLocalFile());
         const HRESULT hr =
                 SHCreateItemFromParsingName(reinterpret_cast<const wchar_t *>(native.utf16()),
@@ -901,30 +901,30 @@ IShellItem *QWindowsNativeFileDialogBase::shellItem(const QUrl &url)
                                             reinterpret_cast<void **>(&result));
         if (FAILED(hr)) {
             qErrnoWarning("%s: SHCreateItemFromParsingName(%s)) failed", __FUNCTION__, qPrintable(url.toString()));
-            return Q_NULLPTR;
+            return nullptr;
         }
         return result;
     } else if (url.scheme() == QLatin1String("clsid")) {
         // Support for virtual folders via GUID
         // (see https://msdn.microsoft.com/en-us/library/windows/desktop/dd378457(v=vs.85).aspx)
         // specified as "clsid:<GUID>" (without '{', '}').
-        IShellItem *result = Q_NULLPTR;
+        IShellItem *result = nullptr;
         const auto uuid = QUuid::fromString(url.path());
         if (uuid.isNull()) {
             qWarning() << __FUNCTION__ << ": Invalid CLSID: " << url.path();
-            return Q_NULLPTR;
+            return nullptr;
         }
         PIDLIST_ABSOLUTE idList;
         HRESULT hr = SHGetKnownFolderIDList(uuid, 0, 0, &idList);
         if (FAILED(hr)) {
             qErrnoWarning("%s: SHGetKnownFolderIDList(%s)) failed", __FUNCTION__, qPrintable(url.toString()));
-            return Q_NULLPTR;
+            return nullptr;
         }
         hr = SHCreateItemFromIDList(idList, IID_IShellItem, reinterpret_cast<void **>(&result));
         CoTaskMemFree(idList);
         if (FAILED(hr)) {
             qErrnoWarning("%s: SHCreateItemFromIDList(%s)) failed", __FUNCTION__, qPrintable(url.toString()));
-            return Q_NULLPTR;
+            return nullptr;
         }
         return result;
     } else {
diff --git a/src/plugins/platforms/windows/qwindowseglcontext.h b/src/plugins/platforms/windows/qwindowseglcontext.h
index 47878a7169..3e5f2c81d5 100644
--- a/src/plugins/platforms/windows/qwindowseglcontext.h
+++ b/src/plugins/platforms/windows/qwindowseglcontext.h
@@ -95,7 +95,7 @@ struct QWindowsLibGLESv2
 #if !defined(QT_STATIC) || defined(QT_OPENGL_DYNAMIC)
     void *moduleHandle() const { return m_lib; }
 #else
-    void *moduleHandle() const { return Q_NULLPTR; }
+    void *moduleHandle() const { return nullptr; }
 #endif
 
     const GLubyte * (APIENTRY * glGetString)(GLenum name);
diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index f9bac3920b..f0be761690 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -252,7 +252,7 @@ QWindowsIntegrationPrivate::~QWindowsIntegrationPrivate()
         delete m_fontDatabase;
 }
 
-QWindowsIntegration *QWindowsIntegration::m_instance = Q_NULLPTR;
+QWindowsIntegration *QWindowsIntegration::m_instance = nullptr;
 
 QWindowsIntegration::QWindowsIntegration(const QStringList &paramList) :
     d(new QWindowsIntegrationPrivate(paramList))
@@ -266,7 +266,7 @@ QWindowsIntegration::QWindowsIntegration(const QStringList &paramList) :
 
 QWindowsIntegration::~QWindowsIntegration()
 {
-    m_instance = Q_NULLPTR;
+    m_instance = nullptr;
 }
 
 void QWindowsIntegration::initialize()
@@ -336,7 +336,7 @@ QPlatformWindow *QWindowsIntegration::createPlatformWindow(QWindow *window) cons
         << " handle=" << obtained.hwnd << ' ' << obtained.flags << '\n';
 
     if (Q_UNLIKELY(!obtained.hwnd))
-        return Q_NULLPTR;
+        return nullptr;
 
     QWindowsWindow *result = createPlatformWindowHelper(window, obtained);
     Q_ASSERT(result);
@@ -356,7 +356,7 @@ QPlatformWindow *QWindowsIntegration::createForeignWindow(QWindow *window, WId n
     }
     QWindowsForeignWindow *result = new QWindowsForeignWindow(window, hwnd);
     const QRect obtainedGeometry = result->geometry();
-    QScreen *screen = Q_NULLPTR;
+    QScreen *screen = nullptr;
     if (const QPlatformScreen *pScreen = result->screenForGeometry(obtainedGeometry))
         screen = pScreen->screen();
     if (screen && screen != window->screen())
@@ -402,7 +402,7 @@ QWindowsStaticOpenGLContext *QWindowsStaticOpenGLContext::doCreate()
         qCWarning(lcQpaGl, "Software OpenGL failed. Falling back to system OpenGL.");
         if (QWindowsOpenGLTester::supportedRenderers() & QWindowsOpenGLTester::DesktopGl)
             return QOpenGLStaticContext::create();
-        return Q_NULLPTR;
+        return nullptr;
     default:
         break;
     }
diff --git a/src/plugins/platforms/windows/qwindowsnativeinterface.cpp b/src/plugins/platforms/windows/qwindowsnativeinterface.cpp
index dc8e97c886..324b00144e 100644
--- a/src/plugins/platforms/windows/qwindowsnativeinterface.cpp
+++ b/src/plugins/platforms/windows/qwindowsnativeinterface.cpp
@@ -134,7 +134,7 @@ void *QWindowsNativeInterface::nativeResourceForCursor(const QByteArray &resourc
                 return static_cast<const QWindowsCursor *>(pCursor)->hCursor(cursor);
         }
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 #endif // !QT_NO_CURSOR
 
@@ -280,7 +280,7 @@ QFunctionPointer QWindowsNativeInterface::platformFunction(const QByteArray &fun
         return QFunctionPointer(QWindowsWindow::setHasBorderInFullScreenStatic);
     else if (function == QWindowsWindowFunctions::isTabletModeIdentifier())
         return QFunctionPointer(QWindowsNativeInterface::isTabletMode);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QVariant QWindowsNativeInterface::gpu() const
diff --git a/src/plugins/platforms/windows/qwindowsscreen.cpp b/src/plugins/platforms/windows/qwindowsscreen.cpp
index 3a4793efcd..01b5e6510a 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.cpp
+++ b/src/plugins/platforms/windows/qwindowsscreen.cpp
@@ -563,7 +563,7 @@ const QWindowsScreen *QWindowsScreenManager::screenAtDp(const QPoint &p) const
         if (scr->geometry().contains(p))
             return scr;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 3f417fde27..06ca162ea5 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -857,7 +857,7 @@ QWindowsBaseWindow *QWindowsBaseWindow::baseWindowOf(const QWindow *w)
         if (QPlatformWindow *pw = w->handle())
             return static_cast<QWindowsBaseWindow *>(pw);
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 HWND QWindowsBaseWindow::handleOf(const QWindow *w)
diff --git a/src/plugins/platforms/winrt/qwinrtclipboard.cpp b/src/plugins/platforms/winrt/qwinrtclipboard.cpp
index 117cb515df..05c34b82f8 100644
--- a/src/plugins/platforms/winrt/qwinrtclipboard.cpp
+++ b/src/plugins/platforms/winrt/qwinrtclipboard.cpp
@@ -59,7 +59,7 @@ typedef IEventHandler<IInspectable *> ContentChangedHandler;
 QT_BEGIN_NAMESPACE
 
 QWinRTClipboard::QWinRTClipboard()
-    : m_mimeData(Q_NULLPTR)
+    : m_mimeData(nullptr)
 {
     QEventDispatcherWinRT::runOnXamlThread([this]() {
         HRESULT hr;
diff --git a/src/plugins/platforms/winrt/qwinrtcursor.cpp b/src/plugins/platforms/winrt/qwinrtcursor.cpp
index 28a5f73e6e..3c918df935 100644
--- a/src/plugins/platforms/winrt/qwinrtcursor.cpp
+++ b/src/plugins/platforms/winrt/qwinrtcursor.cpp
@@ -89,7 +89,7 @@ void QWinRTCursor::changeCursor(QCursor *windowCursor, QWindow *window)
     switch (windowCursor ? windowCursor->shape() : Qt::ArrowCursor) {
     case Qt::BlankCursor:
         hr = QEventDispatcherWinRT::runOnXamlThread([coreWindow]() {
-            coreWindow->put_PointerCursor(Q_NULLPTR);
+            coreWindow->put_PointerCursor(nullptr);
             return S_OK;
         });
         RETURN_VOID_IF_FAILED("Failed to set blank native cursor");
diff --git a/src/plugins/platforms/winrt/qwinrtdrag.cpp b/src/plugins/platforms/winrt/qwinrtdrag.cpp
index 43c406e1fb..0c918230b3 100644
--- a/src/plugins/platforms/winrt/qwinrtdrag.cpp
+++ b/src/plugins/platforms/winrt/qwinrtdrag.cpp
@@ -104,7 +104,7 @@ class DragThreadTransferData : public QObject
 public slots:
     void handleDrag();
 public:
-    explicit DragThreadTransferData(QObject *parent = Q_NULLPTR);
+    explicit DragThreadTransferData(QObject *parent = nullptr);
     QWindow *window;
     QWinRTInternalMimeData *mime;
     QPoint point;
diff --git a/src/plugins/platforms/winrt/qwinrtfiledialoghelper.cpp b/src/plugins/platforms/winrt/qwinrtfiledialoghelper.cpp
index 62eacba89b..3c90334c8c 100644
--- a/src/plugins/platforms/winrt/qwinrtfiledialoghelper.cpp
+++ b/src/plugins/platforms/winrt/qwinrtfiledialoghelper.cpp
@@ -83,7 +83,7 @@ public:
     }
     HRESULT __stdcall GetView(IVectorView<HSTRING> **view)
     {
-        *view = Q_NULLPTR;
+        *view = nullptr;
         return E_NOTIMPL;
     }
     HRESULT __stdcall IndexOf(HSTRING value, quint32 *index, boolean *found)
diff --git a/src/plugins/platforms/winrt/qwinrtfileengine.cpp b/src/plugins/platforms/winrt/qwinrtfileengine.cpp
index f037c516b5..76efdf6cc8 100644
--- a/src/plugins/platforms/winrt/qwinrtfileengine.cpp
+++ b/src/plugins/platforms/winrt/qwinrtfileengine.cpp
@@ -144,7 +144,7 @@ QAbstractFileEngine *QWinRTFileEngineHandler::create(const QString &fileName) co
     if (file != d->files.end())
         return new QWinRTFileEngine(fileName, file.value().Get());
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 static HRESULT getDestinationFolder(const QString &fileName, const QString &newFileName,
diff --git a/src/plugins/platforms/winrt/qwinrtscreen.cpp b/src/plugins/platforms/winrt/qwinrtscreen.cpp
index c370c2ec50..7b9502f9ab 100644
--- a/src/plugins/platforms/winrt/qwinrtscreen.cpp
+++ b/src/plugins/platforms/winrt/qwinrtscreen.cpp
@@ -497,7 +497,7 @@ QWinRTScreen::QWinRTScreen()
     Q_D(QWinRTScreen);
     qCDebug(lcQpaWindows) << __FUNCTION__;
     d->orientation = Qt::PrimaryOrientation;
-    d->touchDevice = Q_NULLPTR;
+    d->touchDevice = nullptr;
 
     HRESULT hr;
     ComPtr<Xaml::IWindowStatics> windowStatics;
@@ -540,7 +540,7 @@ QWinRTScreen::QWinRTScreen()
     Q_ASSERT_SUCCEEDED(hr);
     d->nativeOrientation = static_cast<Qt::ScreenOrientation>(static_cast<int>(qtOrientationsFromNative(displayOrientation)));
     // Set initial pixel density
-    onDpiChanged(Q_NULLPTR, Q_NULLPTR);
+    onDpiChanged(nullptr, nullptr);
     d->orientation = d->nativeOrientation;
 
     ComPtr<IApplicationViewStatics2> applicationViewStatics;
@@ -764,7 +764,7 @@ void QWinRTScreen::initialize()
     Q_ASSERT_SUCCEEDED(hr);
     hr = d->displayInformation->add_DpiChanged(Callback<DisplayInformationHandler>(this, &QWinRTScreen::onDpiChanged).Get(), &d->displayTokens[&IDisplayInformation::remove_DpiChanged]);
     Q_ASSERT_SUCCEEDED(hr);
-    onOrientationChanged(Q_NULLPTR, Q_NULLPTR);
+    onOrientationChanged(nullptr, nullptr);
     onVisibilityChanged(nullptr, nullptr);
 
     hr = d->redirect->add_PointerRoutedReleased(Callback<RedirectHandler>(this, &QWinRTScreen::onRedirectReleased).Get(), &d->redirectTokens[&ICorePointerRedirector::remove_PointerRoutedReleased]);
@@ -864,7 +864,7 @@ void QWinRTScreen::removeWindow(QWindow *window)
 
     const Qt::WindowType type = window->type();
     if (wasTopWindow && type != Qt::Popup && type != Qt::ToolTip && type != Qt::Tool)
-        QWindowSystemInterface::handleWindowActivated(Q_NULLPTR, Qt::OtherFocusReason);
+        QWindowSystemInterface::handleWindowActivated(nullptr, Qt::OtherFocusReason);
     handleExpose();
     QWindowSystemInterface::flushWindowSystemEvents(QEventLoop::ExcludeUserInputEvents);
 #ifndef QT_NO_DRAGANDDROP
diff --git a/src/plugins/platforms/xcb/gl_integrations/qxcbglintegration.h b/src/plugins/platforms/xcb/gl_integrations/qxcbglintegration.h
index 926e5e22df..07e983a499 100644
--- a/src/plugins/platforms/xcb/gl_integrations/qxcbglintegration.h
+++ b/src/plugins/platforms/xcb/gl_integrations/qxcbglintegration.h
@@ -69,7 +69,7 @@ public:
 #endif
     virtual QPlatformOffscreenSurface *createPlatformOffscreenSurface(QOffscreenSurface *surface) const = 0;
 
-    virtual QXcbNativeInterfaceHandler *nativeInterfaceHandler() const  { return Q_NULLPTR; }
+    virtual QXcbNativeInterfaceHandler *nativeInterfaceHandler() const  { return nullptr; }
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/xcb/gl_integrations/qxcbnativeinterfacehandler.cpp b/src/plugins/platforms/xcb/gl_integrations/qxcbnativeinterfacehandler.cpp
index ac992b859d..e18656c6ec 100644
--- a/src/plugins/platforms/xcb/gl_integrations/qxcbnativeinterfacehandler.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/qxcbnativeinterfacehandler.cpp
@@ -56,37 +56,37 @@ QXcbNativeInterfaceHandler::~QXcbNativeInterfaceHandler()
 QPlatformNativeInterface::NativeResourceForIntegrationFunction QXcbNativeInterfaceHandler::nativeResourceFunctionForIntegration(const QByteArray &resource) const
 {
     Q_UNUSED(resource);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForContextFunction QXcbNativeInterfaceHandler::nativeResourceFunctionForContext(const QByteArray &resource) const
 {
     Q_UNUSED(resource);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForScreenFunction QXcbNativeInterfaceHandler::nativeResourceFunctionForScreen(const QByteArray &resource) const
 {
     Q_UNUSED(resource);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForWindowFunction QXcbNativeInterfaceHandler::nativeResourceFunctionForWindow(const QByteArray &resource) const
 {
     Q_UNUSED(resource);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForBackingStoreFunction QXcbNativeInterfaceHandler::nativeResourceFunctionForBackingStore(const QByteArray &resource) const
 {
     Q_UNUSED(resource);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QFunctionPointer QXcbNativeInterfaceHandler::platformFunction(const QByteArray &function) const
 {
     Q_UNUSED(function);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglintegration.cpp
index 7aa1d631df..fe18bc24db 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglintegration.cpp
@@ -49,7 +49,7 @@
 QT_BEGIN_NAMESPACE
 
 QXcbEglIntegration::QXcbEglIntegration()
-    : m_connection(Q_NULLPTR)
+    : m_connection(nullptr)
     , m_egl_display(EGL_NO_DISPLAY)
 {
     qCDebug(lcQpaGl) << "Xcb EGL gl-integration created";
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglnativeinterfacehandler.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglnativeinterfacehandler.cpp
index 30f5e3a00d..c0e3f820fe 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglnativeinterfacehandler.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglnativeinterfacehandler.cpp
@@ -77,7 +77,7 @@ QPlatformNativeInterface::NativeResourceForIntegrationFunction QXcbEglNativeInte
     default:
         break;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForContextFunction QXcbEglNativeInterfaceHandler::nativeResourceFunctionForContext(const QByteArray &resource) const
@@ -90,7 +90,7 @@ QPlatformNativeInterface::NativeResourceForContextFunction QXcbEglNativeInterfac
     default:
         break;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForWindowFunction QXcbEglNativeInterfaceHandler::nativeResourceFunctionForWindow(const QByteArray &resource) const
@@ -101,7 +101,7 @@ QPlatformNativeInterface::NativeResourceForWindowFunction QXcbEglNativeInterface
     default:
         break;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbEglNativeInterfaceHandler::eglDisplay()
@@ -114,11 +114,11 @@ void *QXcbEglNativeInterfaceHandler::eglDisplay()
 void *QXcbEglNativeInterfaceHandler::eglDisplayForWindow(QWindow *window)
 {
     Q_ASSERT(window);
-    if (window->supportsOpenGL() && window->handle() == Q_NULLPTR)
+    if (window->supportsOpenGL() && window->handle() == nullptr)
         return eglDisplay();
     else if (window->supportsOpenGL())
         return static_cast<QXcbEglWindow *>(window->handle())->glIntegration()->eglDisplay();
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbEglNativeInterfaceHandler::eglContextForContext(QOpenGLContext *context)
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp
index 9c3fd26d49..65beac227c 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp
@@ -49,7 +49,7 @@ QT_BEGIN_NAMESPACE
 QXcbEglWindow::QXcbEglWindow(QWindow *window, QXcbEglIntegration *glIntegration)
     : QXcbWindow(window)
     , m_glIntegration(glIntegration)
-    , m_config(Q_NULLPTR)
+    , m_config(nullptr)
     , m_surface(EGL_NO_SURFACE)
 {
 }
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
index 3bc8590d36..56a737e882 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
@@ -321,7 +321,7 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share)
         if (!m_context && m_shareContext) {
             // re-try without a shared glx context
             m_shareContext = 0;
-            m_context = glXCreateContext(m_display, visualInfo, Q_NULLPTR, true);
+            m_context = glXCreateContext(m_display, visualInfo, nullptr, true);
         }
 
         // Create a temporary window so that we can make the new context current
@@ -470,7 +470,7 @@ static QXcbScreen *screenForPlatformSurface(QPlatformSurface *surface)
     } else if (surfaceClass == QSurface::Offscreen) {
         return static_cast<QXcbScreen *>(static_cast<QGLXPbuffer *>(surface)->screen());
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QVariant QGLXContext::nativeHandle() const
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
index 377066df61..13f03f8bf3 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
@@ -87,7 +87,7 @@ QT_BEGIN_NAMESPACE
 #endif
 
 QXcbGlxIntegration::QXcbGlxIntegration()
-    : m_connection(Q_NULLPTR)
+    : m_connection(nullptr)
     , m_glx_first_event(0)
 {
     qCDebug(lcQpaGl) << "Xcb GLX gl-integration created";
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxnativeinterfacehandler.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxnativeinterfacehandler.cpp
index 638fdd46b5..e9bb4460ff 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxnativeinterfacehandler.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxnativeinterfacehandler.cpp
@@ -72,7 +72,7 @@ QPlatformNativeInterface::NativeResourceForContextFunction QXcbGlxNativeInterfac
     default:
         break;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbGlxNativeInterfaceHandler::glxContextForContext(QOpenGLContext *context)
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxwindow.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxwindow.cpp
index 145a11a5e3..d682ea87fb 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxwindow.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxwindow.cpp
@@ -58,7 +58,7 @@ const xcb_visualtype_t *QXcbGlxWindow::createVisual()
 {
     QXcbScreen *scr = xcbScreen();
     if (!scr)
-        return Q_NULLPTR;
+        return nullptr;
 
     qDebug(lcQpaGl) << "Requested format before FBConfig/Visual selection:" << m_format;
 
@@ -74,7 +74,7 @@ const xcb_visualtype_t *QXcbGlxWindow::createVisual()
     XVisualInfo *visualInfo = qglx_findVisualInfo(dpy, scr->screenNumber(), &m_format, GLX_WINDOW_BIT, flags);
     if (!visualInfo) {
         qWarning() << "No XVisualInfo for format" << m_format;
-        return Q_NULLPTR;
+        return nullptr;
     }
     const xcb_visualtype_t *xcb_visualtype = scr->visualForId(visualInfo->visualid);
     XFree(visualInfo);
diff --git a/src/plugins/platforms/xcb/nativepainting/qbackingstore_x11.cpp b/src/plugins/platforms/xcb/nativepainting/qbackingstore_x11.cpp
index 2dd2cdd9e3..cb2bbafee1 100644
--- a/src/plugins/platforms/xcb/nativepainting/qbackingstore_x11.cpp
+++ b/src/plugins/platforms/xcb/nativepainting/qbackingstore_x11.cpp
@@ -115,7 +115,7 @@ void QXcbNativeBackingStore::flush(QWindow *window, const QRegion &region, const
     else
 #endif
     {
-        GC gc = XCreateGC(display(), wid, 0, Q_NULLPTR);
+        GC gc = XCreateGC(display(), wid, 0, nullptr);
 
         if (clipRects.size() != 1)
             XSetClipRectangles(display(), gc, 0, 0, clipRects.data(), clipRects.size(), YXBanded);
@@ -155,7 +155,7 @@ void QXcbNativeBackingStore::resize(const QSize &size, const QRegion &staticCont
         QRect br = staticContents.boundingRect().intersected(QRect(QPoint(0, 0), size));
 
         if (!br.isEmpty()) {
-            GC gc = XCreateGC(display(), to, 0, Q_NULLPTR);
+            GC gc = XCreateGC(display(), to, 0, nullptr);
             XCopyArea(display(), from, to, gc, br.x(), br.y(), br.width(), br.height(), br.x(), br.y());
             XFreeGC(display(), gc);
         }
@@ -172,7 +172,7 @@ bool QXcbNativeBackingStore::scroll(const QRegion &area, int dx, int dy)
     QRect rect = area.boundingRect();
     Pixmap pix = qt_x11PixmapHandle(m_pixmap);
 
-    GC gc = XCreateGC(display(), pix, 0, Q_NULLPTR);
+    GC gc = XCreateGC(display(), pix, 0, nullptr);
     XCopyArea(display(), pix, pix, gc,
               rect.x(), rect.y(), rect.width(), rect.height(),
               rect.x()+dx, rect.y()+dy);
diff --git a/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h b/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h
index 098ccaf1d9..79e607c6f8 100644
--- a/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h
+++ b/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h
@@ -123,7 +123,7 @@ inline QX11PlatformPixmap *qt_x11Pixmap(const QPixmap &pixmap)
 {
     return (pixmap.handle() && pixmap.handle()->classId() == QPlatformPixmap::X11Class)
             ? static_cast<QX11PlatformPixmap *>(pixmap.handle())
-            : Q_NULLPTR;
+            : nullptr;
 }
 
 inline Picture qt_x11PictureHandle(const QPixmap &pixmap)
diff --git a/src/plugins/platforms/xcb/nativepainting/qxcbnativepainting.cpp b/src/plugins/platforms/xcb/nativepainting/qxcbnativepainting.cpp
index ccb421d868..7731f6c806 100644
--- a/src/plugins/platforms/xcb/nativepainting/qxcbnativepainting.cpp
+++ b/src/plugins/platforms/xcb/nativepainting/qxcbnativepainting.cpp
@@ -38,7 +38,7 @@
 
 QT_BEGIN_NAMESPACE
 
-QXcbX11Data *qt_x11Data = Q_NULLPTR;
+QXcbX11Data *qt_x11Data = nullptr;
 
 void qt_xcb_native_x11_info_init(QXcbConnection *conn)
 {
@@ -122,7 +122,7 @@ class QXcbX11InfoData : public QSharedData, public QX11InfoData
 {};
 
 QXcbX11Info::QXcbX11Info()
-    : d(Q_NULLPTR)
+    : d(nullptr)
 {}
 
 QXcbX11Info::~QXcbX11Info()
diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.cpp b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
index 17927af3e3..0369ef4d9f 100644
--- a/src/plugins/platforms/xcb/qxcbbackingstore.cpp
+++ b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
@@ -145,7 +145,7 @@ private:
 
 QXcbShmImage::QXcbShmImage(QXcbScreen *screen, const QSize &size, uint depth, QImage::Format format)
     : QXcbObject(screen->connection())
-    , m_graphics_buffer(Q_NULLPTR)
+    , m_graphics_buffer(nullptr)
     , m_gc(0)
     , m_gc_drawable(0)
     , m_xcb_pixmap(0)
@@ -265,7 +265,7 @@ void QXcbShmImage::destroy()
     if (m_gc)
         xcb_free_gc(xcb_connection(), m_gc);
     delete m_graphics_buffer;
-    m_graphics_buffer = Q_NULLPTR;
+    m_graphics_buffer = nullptr;
 
     if (m_xcb_pixmap) {
         xcb_free_pixmap(xcb_connection(), m_xcb_pixmap);
@@ -565,7 +565,7 @@ QImage QXcbBackingStore::toImage() const
 
 QPlatformGraphicsBuffer *QXcbBackingStore::graphicsBuffer() const
 {
-    return m_image ? m_image->graphicsBuffer() : Q_NULLPTR;
+    return m_image ? m_image->graphicsBuffer() : nullptr;
 }
 
 void QXcbBackingStore::flush(QWindow *window, const QRegion &region, const QPoint &offset)
diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 536c709dbe..d53a961b85 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -369,7 +369,7 @@ void QXcbConnection::destroyScreen(QXcbScreen *screen)
         // If there are no other screens on the same virtual desktop,
         // then transform the physical screen into a fake screen.
         const QString nameWas = screen->name();
-        screen->setOutput(XCB_NONE, Q_NULLPTR);
+        screen->setOutput(XCB_NONE, nullptr);
         qCDebug(lcQpaScreen) << "transformed" << nameWas << "to fake" << screen;
     } else {
         // There is more than one screen on the same virtual desktop, remove the screen
@@ -395,7 +395,7 @@ void QXcbConnection::initializeScreens()
 {
     xcb_screen_iterator_t it = xcb_setup_roots_iterator(m_setup);
     int xcbScreenNumber = 0;    // screen number in the xcb sense
-    QXcbScreen *primaryScreen = Q_NULLPTR;
+    QXcbScreen *primaryScreen = nullptr;
     while (it.rem) {
         // Each "screen" in xcb terminology is a virtual desktop,
         // potentially a collection of separate juxtaposed monitors.
@@ -415,7 +415,7 @@ void QXcbConnection::initializeScreens()
                 qWarning("failed to get the current screen resources");
             } else {
                 xcb_timestamp_t timestamp = 0;
-                xcb_randr_output_t *outputs = Q_NULLPTR;
+                xcb_randr_output_t *outputs = nullptr;
                 int outputCount = xcb_randr_get_screen_resources_current_outputs_length(resources_current.get());
                 if (outputCount) {
                     timestamp = resources_current->config_timestamp;
@@ -487,7 +487,7 @@ void QXcbConnection::initializeScreens()
                 while (it.rem) {
                     xcb_xinerama_screen_info_t *screen_info = it.data;
                     QXcbScreen *screen = new QXcbScreen(this, virtualDesktop,
-                                                        XCB_NONE, Q_NULLPTR,
+                                                        XCB_NONE, nullptr,
                                                         screen_info, it.index);
                     siblings << screen;
                     m_screens << screen;
@@ -498,7 +498,7 @@ void QXcbConnection::initializeScreens()
         if (siblings.isEmpty()) {
             // If there are no XRandR outputs or XRandR extension is missing,
             // then create a fake/legacy screen.
-            QXcbScreen *screen = new QXcbScreen(this, virtualDesktop, XCB_NONE, Q_NULLPTR);
+            QXcbScreen *screen = new QXcbScreen(this, virtualDesktop, XCB_NONE, nullptr);
             qCDebug(lcQpaScreen) << "created fake screen" << screen;
             m_screens << screen;
             if (m_primaryScreenNumber == xcbScreenNumber) {
@@ -631,7 +631,7 @@ QXcbConnection::QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGra
             if (m_glIntegration && !m_glIntegration->initialize(this)) {
                 qCDebug(lcQpaGl) << "Failed to initialize xcb gl-integration" << glIntegrationNames.at(i);
                 delete m_glIntegration;
-                m_glIntegration = Q_NULLPTR;
+                m_glIntegration = nullptr;
             }
         }
         if (!m_glIntegration)
@@ -689,7 +689,7 @@ QXcbScreen *QXcbConnection::primaryScreen() const
         return m_screens.first();
     }
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void QXcbConnection::addWindowEventListener(xcb_window_t id, QXcbWindowEventListener *eventListener)
@@ -1413,7 +1413,7 @@ void QXcbConnection::setFocusWindow(QWindow *w)
 void QXcbConnection::setMouseGrabber(QXcbWindow *w)
 {
     m_mouseGrabber = w;
-    m_mousePressWindow = Q_NULLPTR;
+    m_mousePressWindow = nullptr;
 }
 void QXcbConnection::setMousePressWindow(QXcbWindow *w)
 {
diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index 58e99ef3de..d97c532b67 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -1333,7 +1333,7 @@ QXcbConnection::TabletData *QXcbConnection::tabletDataForDevice(int id)
         if (m_tabletData.at(i).deviceId == id)
             return &m_tabletData[i];
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 #endif // QT_CONFIG(tabletevent)
diff --git a/src/plugins/platforms/xcb/qxcbcursor.cpp b/src/plugins/platforms/xcb/qxcbcursor.cpp
index da63360333..bfa3eccdf8 100644
--- a/src/plugins/platforms/xcb/qxcbcursor.cpp
+++ b/src/plugins/platforms/xcb/qxcbcursor.cpp
@@ -660,7 +660,7 @@ QPoint QXcbCursor::pos() const
 
 void QXcbCursor::setPos(const QPoint &pos)
 {
-    QXcbVirtualDesktop *virtualDesktop = Q_NULLPTR;
+    QXcbVirtualDesktop *virtualDesktop = nullptr;
     queryPointer(connection(), &virtualDesktop, 0);
     xcb_warp_pointer(xcb_connection(), XCB_NONE, virtualDesktop->root(), 0, 0, 0, 0, pos.x(), pos.y());
     xcb_flush(xcb_connection());
diff --git a/src/plugins/platforms/xcb/qxcbdrag.cpp b/src/plugins/platforms/xcb/qxcbdrag.cpp
index d4521de8e0..18f5ff4f0d 100644
--- a/src/plugins/platforms/xcb/qxcbdrag.cpp
+++ b/src/plugins/platforms/xcb/qxcbdrag.cpp
@@ -208,7 +208,7 @@ void QXcbDrag::startDrag()
     setScreen(current_virtual_desktop->screens().constFirst()->screen());
     initiatorWindow = QGuiApplicationPrivate::currentMouseWindow;
     QBasicDrag::startDrag();
-    if (connection()->mouseGrabber() == Q_NULLPTR)
+    if (connection()->mouseGrabber() == nullptr)
         shapedPixmapWindow()->setMouseGrabEnabled(true);
 }
 
@@ -308,7 +308,7 @@ void QXcbDrag::move(const QPoint &globalPos)
     if (source_sameanswer.contains(globalPos) && source_sameanswer.isValid())
         return;
 
-    QXcbVirtualDesktop *virtualDesktop = Q_NULLPTR;
+    QXcbVirtualDesktop *virtualDesktop = nullptr;
     QPoint cursorPos;
     QXcbCursor::queryPointer(connection(), &virtualDesktop, &cursorPos);
     QXcbScreen *screen = virtualDesktop->screenAt(cursorPos);
@@ -317,7 +317,7 @@ void QXcbDrag::move(const QPoint &globalPos)
     if (virtualDesktop != current_virtual_desktop) {
         setUseCompositing(virtualDesktop->compositingActive());
         recreateShapedPixmapWindow(static_cast<QPlatformScreen*>(screen)->screen(), deviceIndependentPos);
-        if (connection()->mouseGrabber() == Q_NULLPTR)
+        if (connection()->mouseGrabber() == nullptr)
             shapedPixmapWindow()->setMouseGrabEnabled(true);
 
         current_virtual_desktop = virtualDesktop;
diff --git a/src/plugins/platforms/xcb/qxcbintegration.cpp b/src/plugins/platforms/xcb/qxcbintegration.cpp
index 72d31060db..6afa7bc934 100644
--- a/src/plugins/platforms/xcb/qxcbintegration.cpp
+++ b/src/plugins/platforms/xcb/qxcbintegration.cpp
@@ -121,7 +121,7 @@ static bool runningUnderDebugger()
 #endif
 }
 
-QXcbIntegration *QXcbIntegration::m_instance = Q_NULLPTR;
+QXcbIntegration *QXcbIntegration::m_instance = nullptr;
 
 QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char **argv)
     : m_services(new QGenericUnixServices)
@@ -222,7 +222,7 @@ QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char
 QXcbIntegration::~QXcbIntegration()
 {
     qDeleteAll(m_connections);
-    m_instance = Q_NULLPTR;
+    m_instance = nullptr;
 }
 
 QPlatformPixmap *QXcbIntegration::createPlatformPixmap(QPlatformPixmap::PixelType type) const
@@ -274,7 +274,7 @@ QPlatformOpenGLContext *QXcbIntegration::createPlatformOpenGLContext(QOpenGLCont
     QXcbGlIntegration *glIntegration = screen->connection()->glIntegration();
     if (!glIntegration) {
         qWarning("QXcbIntegration: Cannot create platform OpenGL context, neither GLX nor EGL are enabled");
-        return Q_NULLPTR;
+        return nullptr;
     }
     return glIntegration->createPlatformOpenGLContext(context);
 }
@@ -296,7 +296,7 @@ QPlatformOffscreenSurface *QXcbIntegration::createPlatformOffscreenSurface(QOffs
     QXcbGlIntegration *glIntegration = screen->connection()->glIntegration();
     if (!glIntegration) {
         qWarning("QXcbIntegration: Cannot create platform offscreen surface, neither GLX nor EGL are enabled");
-        return Q_NULLPTR;
+        return nullptr;
     }
     return glIntegration->createPlatformOffscreenSurface(surface);
 }
diff --git a/src/plugins/platforms/xcb/qxcbnativeinterface.cpp b/src/plugins/platforms/xcb/qxcbnativeinterface.cpp
index caa9499c45..d989761297 100644
--- a/src/plugins/platforms/xcb/qxcbnativeinterface.cpp
+++ b/src/plugins/platforms/xcb/qxcbnativeinterface.cpp
@@ -101,7 +101,7 @@ QXcbNativeInterface::QXcbNativeInterface() :
 static inline QXcbSystemTrayTracker *systemTrayTracker(const QScreen *s)
 {
     if (!s)
-        return Q_NULLPTR;
+        return nullptr;
 
     return static_cast<const QXcbScreen *>(s->handle())->connection()->systemTrayTracker();
 }
@@ -194,7 +194,7 @@ void *QXcbNativeInterface::nativeResourceForScreen(const QByteArray &resourceStr
 {
     if (!screen) {
         qWarning("nativeResourceForScreen: null screen");
-        return Q_NULLPTR;
+        return nullptr;
     }
 
     QByteArray lowerCaseResource = resourceString.toLower();
@@ -236,7 +236,7 @@ void *QXcbNativeInterface::nativeResourceForScreen(const QByteArray &resourceStr
         break;
     case CompositingEnabled:
         if (QXcbVirtualDesktop *vd = xcbScreen->virtualDesktop())
-            result = vd->compositingActive() ? this : Q_NULLPTR;
+            result = vd->compositingActive() ? this : nullptr;
         break;
     default:
         break;
@@ -294,7 +294,7 @@ void *QXcbNativeInterface::nativeResourceForCursor(const QByteArray &resource, c
             }
         }
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 #endif // !QT_NO_CURSOR
 
@@ -323,7 +323,7 @@ QPlatformNativeInterface::NativeResourceForContextFunction QXcbNativeInterface::
     QPlatformNativeInterface::NativeResourceForContextFunction func = handlerNativeResourceFunctionForContext(lowerCaseResource);
     if (func)
         return func;
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForScreenFunction QXcbNativeInterface::nativeResourceFunctionForScreen(const QByteArray &resource)
@@ -390,13 +390,13 @@ QFunctionPointer QXcbNativeInterface::platformFunction(const QByteArray &functio
     if (function == QXcbScreenFunctions::virtualDesktopNumberIdentifier())
         return QFunctionPointer(QXcbScreenFunctions::VirtualDesktopNumber(QXcbScreen::virtualDesktopNumberStatic));
 
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::appTime(const QXcbScreen *screen)
 {
     if (!screen)
-        return Q_NULLPTR;
+        return nullptr;
 
     return reinterpret_cast<void *>(quintptr(screen->connection()->time()));
 }
@@ -404,7 +404,7 @@ void *QXcbNativeInterface::appTime(const QXcbScreen *screen)
 void *QXcbNativeInterface::appUserTime(const QXcbScreen *screen)
 {
     if (!screen)
-        return Q_NULLPTR;
+        return nullptr;
 
     return reinterpret_cast<void *>(quintptr(screen->connection()->netWmUserTime()));
 }
@@ -412,7 +412,7 @@ void *QXcbNativeInterface::appUserTime(const QXcbScreen *screen)
 void *QXcbNativeInterface::getTimestamp(const QXcbScreen *screen)
 {
     if (!screen)
-        return Q_NULLPTR;
+        return nullptr;
 
     return reinterpret_cast<void *>(quintptr(screen->connection()->getTimestamp()));
 }
@@ -452,7 +452,7 @@ void *QXcbNativeInterface::display()
     if (defaultConnection)
         return defaultConnection->xlib_display();
 #endif
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::connection()
@@ -525,10 +525,10 @@ QXcbScreen *QXcbNativeInterface::qPlatformScreenForWindow(QWindow *window)
     QXcbScreen *screen;
     if (window) {
         QScreen *qs = window->screen();
-        screen = static_cast<QXcbScreen *>(qs ? qs->handle() : Q_NULLPTR);
+        screen = static_cast<QXcbScreen *>(qs ? qs->handle() : nullptr);
     } else {
         QScreen *qs = QGuiApplication::primaryScreen();
-        screen = static_cast<QXcbScreen *>(qs ? qs->handle() : Q_NULLPTR);
+        screen = static_cast<QXcbScreen *>(qs ? qs->handle() : nullptr);
     }
     return screen;
 }
@@ -537,23 +537,23 @@ void *QXcbNativeInterface::displayForWindow(QWindow *window)
 {
 #if QT_CONFIG(xcb_xlib)
     QXcbScreen *screen = qPlatformScreenForWindow(window);
-    return screen ? screen->connection()->xlib_display() : Q_NULLPTR;
+    return screen ? screen->connection()->xlib_display() : nullptr;
 #else
     Q_UNUSED(window);
-    return Q_NULLPTR;
+    return nullptr;
 #endif
 }
 
 void *QXcbNativeInterface::connectionForWindow(QWindow *window)
 {
     QXcbScreen *screen = qPlatformScreenForWindow(window);
-    return screen ? screen->xcb_connection() : Q_NULLPTR;
+    return screen ? screen->xcb_connection() : nullptr;
 }
 
 void *QXcbNativeInterface::screenForWindow(QWindow *window)
 {
     QXcbScreen *screen = qPlatformScreenForWindow(window);
-    return screen ? screen->screen() : Q_NULLPTR;
+    return screen ? screen->screen() : nullptr;
 }
 
 void QXcbNativeInterface::addHandler(QXcbNativeInterfaceHandler *handler)
@@ -575,7 +575,7 @@ QPlatformNativeInterface::NativeResourceForIntegrationFunction QXcbNativeInterfa
         if (result)
             return result;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForContextFunction QXcbNativeInterface::handlerNativeResourceFunctionForContext(const QByteArray &resource) const
@@ -586,7 +586,7 @@ QPlatformNativeInterface::NativeResourceForContextFunction QXcbNativeInterface::
         if (result)
             return result;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForScreenFunction QXcbNativeInterface::handlerNativeResourceFunctionForScreen(const QByteArray &resource) const
@@ -597,7 +597,7 @@ QPlatformNativeInterface::NativeResourceForScreenFunction QXcbNativeInterface::h
         if (result)
             return result;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForWindowFunction QXcbNativeInterface::handlerNativeResourceFunctionForWindow(const QByteArray &resource) const
@@ -608,7 +608,7 @@ QPlatformNativeInterface::NativeResourceForWindowFunction QXcbNativeInterface::h
         if (result)
             return result;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForBackingStoreFunction QXcbNativeInterface::handlerNativeResourceFunctionForBackingStore(const QByteArray &resource) const
@@ -619,7 +619,7 @@ QPlatformNativeInterface::NativeResourceForBackingStoreFunction QXcbNativeInterf
         if (result)
             return result;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QFunctionPointer QXcbNativeInterface::handlerPlatformFunction(const QByteArray &function) const
@@ -630,7 +630,7 @@ QFunctionPointer QXcbNativeInterface::handlerPlatformFunction(const QByteArray &
         if (func)
             return func;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::handlerNativeResourceForIntegration(const QByteArray &resource) const
@@ -638,7 +638,7 @@ void *QXcbNativeInterface::handlerNativeResourceForIntegration(const QByteArray
     NativeResourceForIntegrationFunction func = handlerNativeResourceFunctionForIntegration(resource);
     if (func)
         return func();
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::handlerNativeResourceForContext(const QByteArray &resource, QOpenGLContext *context) const
@@ -646,7 +646,7 @@ void *QXcbNativeInterface::handlerNativeResourceForContext(const QByteArray &res
     NativeResourceForContextFunction func = handlerNativeResourceFunctionForContext(resource);
     if (func)
         return func(context);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::handlerNativeResourceForScreen(const QByteArray &resource, QScreen *screen) const
@@ -654,7 +654,7 @@ void *QXcbNativeInterface::handlerNativeResourceForScreen(const QByteArray &reso
     NativeResourceForScreenFunction func = handlerNativeResourceFunctionForScreen(resource);
     if (func)
         return func(screen);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::handlerNativeResourceForWindow(const QByteArray &resource, QWindow *window) const
@@ -662,7 +662,7 @@ void *QXcbNativeInterface::handlerNativeResourceForWindow(const QByteArray &reso
     NativeResourceForWindowFunction func = handlerNativeResourceFunctionForWindow(resource);
     if (func)
         return func(window);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::handlerNativeResourceForBackingStore(const QByteArray &resource, QBackingStore *backingStore) const
@@ -670,7 +670,7 @@ void *QXcbNativeInterface::handlerNativeResourceForBackingStore(const QByteArray
     NativeResourceForBackingStoreFunction func = handlerNativeResourceFunctionForBackingStore(resource);
     if (func)
         return func(backingStore);
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/xcb/qxcbscreen.cpp b/src/plugins/platforms/xcb/qxcbscreen.cpp
index ec0f9ba561..45a0f19d98 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.cpp
+++ b/src/plugins/platforms/xcb/qxcbscreen.cpp
@@ -140,7 +140,7 @@ QXcbScreen *QXcbVirtualDesktop::screenAt(const QPoint &pos) const
         if (screen->virtualDesktop() == this && screen->geometry().contains(pos))
             return screen;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 void QXcbVirtualDesktop::addScreen(QPlatformScreen *s)
diff --git a/src/plugins/platforms/xcb/qxcbscreen.h b/src/plugins/platforms/xcb/qxcbscreen.h
index 842738b622..4a9b1bd209 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.h
+++ b/src/plugins/platforms/xcb/qxcbscreen.h
@@ -140,7 +140,7 @@ class Q_XCB_EXPORT QXcbScreen : public QXcbObject, public QPlatformScreen
 public:
     QXcbScreen(QXcbConnection *connection, QXcbVirtualDesktop *virtualDesktop,
                xcb_randr_output_t outputId, xcb_randr_get_output_info_reply_t *outputInfo,
-               const xcb_xinerama_screen_info_t *xineramaScreenInfo = Q_NULLPTR, int xineramaScreenIdx = -1);
+               const xcb_xinerama_screen_info_t *xineramaScreenInfo = nullptr, int xineramaScreenIdx = -1);
     ~QXcbScreen();
 
     QString getOutputName(xcb_randr_get_output_info_reply_t *outputInfo);
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index affc2a0dd6..a97b951935 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -287,7 +287,7 @@ static inline XTextProperty* qstringToXTP(Display *dpy, const QString& s)
     if (!mapper || errCode < 0) {
         mapper = QTextCodec::codecForName("latin1");
         if (!mapper || !mapper->canEncode(s))
-            return Q_NULLPTR;
+            return nullptr;
 #endif
         static QByteArray qcs;
         qcs = s.toLatin1();
@@ -322,7 +322,7 @@ static QWindow *childWindowAt(QWindow *win, const QPoint &p)
             && win->geometry().contains(win->parent()->mapFromGlobal(p))) {
         return win;
     }
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 static const char *wm_window_type_property_id = "_q_xcb_wm_window_type";
@@ -418,7 +418,7 @@ void QXcbWindow::create()
 
     resolveFormat(platformScreen->surfaceFormatFor(window()->requestedFormat()));
 
-    const xcb_visualtype_t *visual = Q_NULLPTR;
+    const xcb_visualtype_t *visual = nullptr;
 
     if (connection()->hasDefaultVisualId()) {
         visual = platformScreen->visualForId(connection()->defaultVisualId());
@@ -641,7 +641,7 @@ void QXcbWindow::destroy()
     if (connection()->focusWindow() == this)
         doFocusOut();
     if (connection()->mouseGrabber() == this)
-        connection()->setMouseGrabber(Q_NULLPTR);
+        connection()->setMouseGrabber(nullptr);
 
     if (m_syncCounter && m_usingSyncProtocol)
         xcb_sync_destroy_counter(xcb_connection(), m_syncCounter);
@@ -877,12 +877,12 @@ void QXcbWindow::hide()
     xcb_flush(xcb_connection());
 
     if (connection()->mouseGrabber() == this)
-        connection()->setMouseGrabber(Q_NULLPTR);
+        connection()->setMouseGrabber(nullptr);
     if (QPlatformWindow *w = connection()->mousePressWindow()) {
         // Unset mousePressWindow when it (or one of its parents) is unmapped
         while (w) {
             if (w == this) {
-                connection()->setMousePressWindow(Q_NULLPTR);
+                connection()->setMousePressWindow(nullptr);
                 break;
             }
             w = w->parent();
@@ -900,7 +900,7 @@ void QXcbWindow::hide()
 
         // Find the top level window at cursor position.
         // Don't use QGuiApplication::topLevelAt(): search only the virtual siblings of this window's screen
-        QWindow *enterWindow = Q_NULLPTR;
+        QWindow *enterWindow = nullptr;
         const auto screens = xcbScreen()->virtualSiblings();
         for (QPlatformScreen *screen : screens) {
             if (screen->geometry().contains(cursorPos)) {
@@ -2227,7 +2227,7 @@ void QXcbWindow::handleButtonReleaseEvent(int event_x, int event_y, int root_x,
     }
 
     if (connection()->buttonState() == Qt::NoButton)
-        connection()->setMousePressWindow(Q_NULLPTR);
+        connection()->setMousePressWindow(nullptr);
 
     handleMouseEvent(timestamp, local, global, modifiers, source);
 }
@@ -2252,7 +2252,7 @@ static inline bool doCheckUnGrabAncestor(QXcbConnection *conn)
     return true;
 }
 
-static bool ignoreLeaveEvent(quint8 mode, quint8 detail, QXcbConnection *conn = Q_NULLPTR)
+static bool ignoreLeaveEvent(quint8 mode, quint8 detail, QXcbConnection *conn = nullptr)
 {
     return ((doCheckUnGrabAncestor(conn)
              && mode == XCB_NOTIFY_MODE_GRAB && detail == XCB_NOTIFY_DETAIL_ANCESTOR)
@@ -2261,7 +2261,7 @@ static bool ignoreLeaveEvent(quint8 mode, quint8 detail, QXcbConnection *conn =
             || detail == XCB_NOTIFY_DETAIL_NONLINEAR_VIRTUAL);
 }
 
-static bool ignoreEnterEvent(quint8 mode, quint8 detail, QXcbConnection *conn = Q_NULLPTR)
+static bool ignoreEnterEvent(quint8 mode, quint8 detail, QXcbConnection *conn = nullptr)
 {
     return ((doCheckUnGrabAncestor(conn)
              && mode == XCB_NOTIFY_MODE_UNGRAB && detail == XCB_NOTIFY_DETAIL_ANCESTOR)
@@ -2338,11 +2338,11 @@ void QXcbWindow::handleMotionNotifyEvent(int event_x, int event_y, int root_x, i
     // "mousePressWindow" can be NULL i.e. if a window will be grabbed or unmapped, so set it again here.
     // Unset "mousePressWindow" when mouse button isn't pressed - in some cases the release event won't arrive.
     const bool isMouseButtonPressed = (connection()->buttonState() != Qt::NoButton);
-    const bool hasMousePressWindow = (connection()->mousePressWindow() != Q_NULLPTR);
+    const bool hasMousePressWindow = (connection()->mousePressWindow() != nullptr);
     if (isMouseButtonPressed && !hasMousePressWindow)
         connection()->setMousePressWindow(this);
     else if (hasMousePressWindow && !isMouseButtonPressed)
-        connection()->setMousePressWindow(Q_NULLPTR);
+        connection()->setMousePressWindow(nullptr);
 
     handleMouseEvent(timestamp, local, global, modifiers, source);
 }
@@ -2524,7 +2524,7 @@ void QXcbWindow::handlePropertyNotifyEvent(const xcb_property_notify_event_t *ev
             m_lastWindowStateEvent = newState;
             m_windowState = newState;
             if ((m_windowState & Qt::WindowMinimized) && connection()->mouseGrabber() == this)
-                connection()->setMouseGrabber(Q_NULLPTR);
+                connection()->setMouseGrabber(nullptr);
         }
         return;
     } else if (event->atom == atom(QXcbAtom::_NET_FRAME_EXTENTS)) {
@@ -2592,7 +2592,7 @@ bool QXcbWindow::setKeyboardGrabEnabled(bool grab)
 bool QXcbWindow::setMouseGrabEnabled(bool grab)
 {
     if (!grab && connection()->mouseGrabber() == this)
-        connection()->setMouseGrabber(Q_NULLPTR);
+        connection()->setMouseGrabber(nullptr);
 
 #if QT_CONFIG(xinput2)
     if (connection()->hasXInput2() && !connection()->xi2MouseEventsDisabled()) {
diff --git a/src/plugins/printsupport/windows/qwindowsprintdevice.cpp b/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
index 1cb14514ee..b1589c0738 100644
--- a/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
+++ b/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
@@ -87,13 +87,13 @@ static LPDEVMODE getDevmode(HANDLE hPrinter, const QString &printerId)
     // Allocate the required DEVMODE buffer
     LONG dmSize = DocumentProperties(NULL, hPrinter, printerIdUtf16, NULL, NULL, 0);
     if (dmSize <= 0)
-        return Q_NULLPTR;
+        return nullptr;
     LPDEVMODE pDevMode = reinterpret_cast<LPDEVMODE>(malloc(dmSize));
      // Get the default DevMode
     LONG result = DocumentProperties(NULL, hPrinter, printerIdUtf16, pDevMode, NULL, DM_OUT_BUFFER);
     if (result != IDOK) {
         free(pDevMode);
-        pDevMode = Q_NULLPTR;
+        pDevMode = nullptr;
     }
     return pDevMode;
 }
diff --git a/src/printsupport/dialogs/qabstractprintdialog.h b/src/printsupport/dialogs/qabstractprintdialog.h
index eb4dc3eb99..3cc89890fc 100644
--- a/src/printsupport/dialogs/qabstractprintdialog.h
+++ b/src/printsupport/dialogs/qabstractprintdialog.h
@@ -81,7 +81,7 @@ public:
     Q_DECLARE_FLAGS(PrintDialogOptions, PrintDialogOption)
     Q_FLAG(PrintDialogOptions)
 
-    explicit QAbstractPrintDialog(QPrinter *printer, QWidget *parent = Q_NULLPTR);
+    explicit QAbstractPrintDialog(QPrinter *printer, QWidget *parent = nullptr);
     ~QAbstractPrintDialog();
 
     int exec() override = 0;
@@ -108,7 +108,7 @@ public:
     QPrinter *printer() const;
 
 protected:
-    QAbstractPrintDialog(QAbstractPrintDialogPrivate &ptr, QPrinter *printer, QWidget *parent = Q_NULLPTR);
+    QAbstractPrintDialog(QAbstractPrintDialogPrivate &ptr, QPrinter *printer, QWidget *parent = nullptr);
 
 private:
     Q_DISABLE_COPY(QAbstractPrintDialog)
diff --git a/src/printsupport/dialogs/qpagesetupdialog.h b/src/printsupport/dialogs/qpagesetupdialog.h
index 61edcc3370..a7aaa03134 100644
--- a/src/printsupport/dialogs/qpagesetupdialog.h
+++ b/src/printsupport/dialogs/qpagesetupdialog.h
@@ -57,8 +57,8 @@ class Q_PRINTSUPPORT_EXPORT QPageSetupDialog : public QDialog
     Q_DECLARE_PRIVATE(QPageSetupDialog)
 
 public:
-    explicit QPageSetupDialog(QPrinter *printer, QWidget *parent = Q_NULLPTR);
-    explicit QPageSetupDialog(QWidget *parent = Q_NULLPTR);
+    explicit QPageSetupDialog(QPrinter *printer, QWidget *parent = nullptr);
+    explicit QPageSetupDialog(QWidget *parent = nullptr);
     ~QPageSetupDialog();
 
 #if defined(Q_OS_MAC) || defined(Q_OS_WIN)
diff --git a/src/printsupport/dialogs/qprintdialog.h b/src/printsupport/dialogs/qprintdialog.h
index 20ef1c7fed..bbb12202f0 100644
--- a/src/printsupport/dialogs/qprintdialog.h
+++ b/src/printsupport/dialogs/qprintdialog.h
@@ -59,8 +59,8 @@ class Q_PRINTSUPPORT_EXPORT QPrintDialog : public QAbstractPrintDialog
     Q_PROPERTY(PrintDialogOptions options READ options WRITE setOptions)
 
 public:
-    explicit QPrintDialog(QPrinter *printer, QWidget *parent = Q_NULLPTR);
-    explicit QPrintDialog(QWidget *parent = Q_NULLPTR);
+    explicit QPrintDialog(QPrinter *printer, QWidget *parent = nullptr);
+    explicit QPrintDialog(QWidget *parent = nullptr);
     ~QPrintDialog();
 
     int exec() override;
diff --git a/src/printsupport/dialogs/qprintpreviewdialog.h b/src/printsupport/dialogs/qprintpreviewdialog.h
index 6f9de92050..53fede7e83 100644
--- a/src/printsupport/dialogs/qprintpreviewdialog.h
+++ b/src/printsupport/dialogs/qprintpreviewdialog.h
@@ -58,8 +58,8 @@ class Q_PRINTSUPPORT_EXPORT QPrintPreviewDialog : public QDialog
     Q_DECLARE_PRIVATE(QPrintPreviewDialog)
 
 public:
-    explicit QPrintPreviewDialog(QWidget *parent = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
-    explicit QPrintPreviewDialog(QPrinter *printer, QWidget *parent = Q_NULLPTR,
+    explicit QPrintPreviewDialog(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
+    explicit QPrintPreviewDialog(QPrinter *printer, QWidget *parent = nullptr,
                                  Qt::WindowFlags flags = Qt::WindowFlags());
     ~QPrintPreviewDialog();
 
diff --git a/src/printsupport/widgets/qprintpreviewwidget.h b/src/printsupport/widgets/qprintpreviewwidget.h
index d6b5929d52..f11d686602 100644
--- a/src/printsupport/widgets/qprintpreviewwidget.h
+++ b/src/printsupport/widgets/qprintpreviewwidget.h
@@ -69,9 +69,9 @@ public:
         FitInView
     };
 
-    explicit QPrintPreviewWidget(QPrinter *printer, QWidget *parent = Q_NULLPTR,
+    explicit QPrintPreviewWidget(QPrinter *printer, QWidget *parent = nullptr,
                                  Qt::WindowFlags flags = Qt::WindowFlags());
-    explicit QPrintPreviewWidget(QWidget *parent = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
+    explicit QPrintPreviewWidget(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
     ~QPrintPreviewWidget();
 
     qreal zoomFactor() const;
diff --git a/src/sql/kernel/qsqldriver.h b/src/sql/kernel/qsqldriver.h
index 1296bd5d51..1e03be48d3 100644
--- a/src/sql/kernel/qsqldriver.h
+++ b/src/sql/kernel/qsqldriver.h
@@ -89,7 +89,7 @@ public:
         DB2
     };
 
-    explicit QSqlDriver(QObject *parent = Q_NULLPTR);
+    explicit QSqlDriver(QObject *parent = nullptr);
     ~QSqlDriver();
     virtual bool isOpen() const;
     bool isOpenError() const;
@@ -139,7 +139,7 @@ Q_SIGNALS:
     void notification(const QString &name, QSqlDriver::NotificationSource source, const QVariant &payload);
 
 protected:
-    QSqlDriver(QSqlDriverPrivate &dd, QObject *parent = Q_NULLPTR);
+    QSqlDriver(QSqlDriverPrivate &dd, QObject *parent = nullptr);
     virtual void setOpen(bool o);
     virtual void setOpenError(bool e);
     virtual void setLastError(const QSqlError& e);
diff --git a/src/sql/kernel/qsqldriverplugin.h b/src/sql/kernel/qsqldriverplugin.h
index c0f4c00943..001368a291 100644
--- a/src/sql/kernel/qsqldriverplugin.h
+++ b/src/sql/kernel/qsqldriverplugin.h
@@ -55,7 +55,7 @@ class Q_SQL_EXPORT QSqlDriverPlugin : public QObject
 {
     Q_OBJECT
 public:
-    explicit QSqlDriverPlugin(QObject *parent = Q_NULLPTR);
+    explicit QSqlDriverPlugin(QObject *parent = nullptr);
     ~QSqlDriverPlugin();
 
     virtual QSqlDriver *create(const QString &key) = 0;
diff --git a/src/sql/models/qsqlrelationaltablemodel.h b/src/sql/models/qsqlrelationaltablemodel.h
index 5175b8f0dd..90b7a6481f 100644
--- a/src/sql/models/qsqlrelationaltablemodel.h
+++ b/src/sql/models/qsqlrelationaltablemodel.h
@@ -88,7 +88,7 @@ public:
         LeftJoin
     };
 
-    explicit QSqlRelationalTableModel(QObject *parent = Q_NULLPTR,
+    explicit QSqlRelationalTableModel(QObject *parent = nullptr,
                                       QSqlDatabase db = QSqlDatabase());
     virtual ~QSqlRelationalTableModel();
 
diff --git a/src/sql/models/qsqltablemodel.h b/src/sql/models/qsqltablemodel.h
index bf5835129b..77b0517c74 100644
--- a/src/sql/models/qsqltablemodel.h
+++ b/src/sql/models/qsqltablemodel.h
@@ -60,7 +60,7 @@ class Q_SQL_EXPORT QSqlTableModel: public QSqlQueryModel
 public:
     enum EditStrategy {OnFieldChange, OnRowChange, OnManualSubmit};
 
-    explicit QSqlTableModel(QObject *parent = Q_NULLPTR, QSqlDatabase db = QSqlDatabase());
+    explicit QSqlTableModel(QObject *parent = nullptr, QSqlDatabase db = QSqlDatabase());
     virtual ~QSqlTableModel();
 
     virtual void setTable(const QString &tableName);
@@ -122,7 +122,7 @@ Q_SIGNALS:
     void beforeDelete(int row);
 
 protected:
-    QSqlTableModel(QSqlTableModelPrivate &dd, QObject *parent = Q_NULLPTR, QSqlDatabase db = QSqlDatabase());
+    QSqlTableModel(QSqlTableModelPrivate &dd, QObject *parent = nullptr, QSqlDatabase db = QSqlDatabase());
 
     virtual bool updateRowInTable(int row, const QSqlRecord &values);
     virtual bool insertRowIntoTable(const QSqlRecord &values);
diff --git a/src/testlib/qsignalspy.h b/src/testlib/qsignalspy.h
index f05dd95565..d9a0f4496b 100644
--- a/src/testlib/qsignalspy.h
+++ b/src/testlib/qsignalspy.h
@@ -88,7 +88,7 @@ public:
         }
 
         if (!QMetaObject::connect(obj, sigIndex, this, memberOffset,
-                    Qt::DirectConnection, Q_NULLPTR)) {
+                    Qt::DirectConnection, nullptr)) {
             qWarning("QSignalSpy: QMetaObject::connect returned false. Unable to connect.");
             return;
         }
diff --git a/src/testlib/qtest.h b/src/testlib/qtest.h
index ca045120d5..a5df27e3b9 100644
--- a/src/testlib/qtest.h
+++ b/src/testlib/qtest.h
@@ -263,7 +263,7 @@ inline bool qCompare(QList<T> const &t1, QList<T> const &t2, const char *actual,
             delete [] val2;
         }
     }
-    return compare_helper(isOk, msg, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+    return compare_helper(isOk, msg, nullptr, nullptr, actual, expected, file, line);
 }
 
 template <>
diff --git a/src/testlib/qtest_gui.h b/src/testlib/qtest_gui.h
index 4e9ce0d0f6..f56aa60949 100644
--- a/src/testlib/qtest_gui.h
+++ b/src/testlib/qtest_gui.h
@@ -164,24 +164,24 @@ inline bool qCompare(QImage const &t1, QImage const &t2,
         qsnprintf(msg, 1024, "Compared QImages differ.\n"
                   "   Actual   (%s).isNull(): %d\n"
                   "   Expected (%s).isNull(): %d", actual, t1Null, expected, t2Null);
-        return compare_helper(false, msg, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(false, msg, nullptr, nullptr, actual, expected, file, line);
     }
     if (t1Null && t2Null)
-        return compare_helper(true, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(true, nullptr, nullptr, nullptr, actual, expected, file, line);
     if (t1.width() != t2.width() || t1.height() != t2.height()) {
         qsnprintf(msg, 1024, "Compared QImages differ in size.\n"
                   "   Actual   (%s): %dx%d\n"
                   "   Expected (%s): %dx%d",
                   actual, t1.width(), t1.height(),
                   expected, t2.width(), t2.height());
-        return compare_helper(false, msg, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(false, msg, nullptr, nullptr, actual, expected, file, line);
     }
     if (t1.format() != t2.format()) {
         qsnprintf(msg, 1024, "Compared QImages differ in format.\n"
                   "   Actual   (%s): %d\n"
                   "   Expected (%s): %d",
                   actual, t1.format(), expected, t2.format());
-        return compare_helper(false, msg, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(false, msg, nullptr, nullptr, actual, expected, file, line);
     }
     return compare_helper(t1 == t2, "Compared values are not the same",
                           toString(t1), toString(t2), actual, expected, file, line);
@@ -198,17 +198,17 @@ inline bool qCompare(QPixmap const &t1, QPixmap const &t2, const char *actual, c
         qsnprintf(msg, 1024, "Compared QPixmaps differ.\n"
                   "   Actual   (%s).isNull(): %d\n"
                   "   Expected (%s).isNull(): %d", actual, t1Null, expected, t2Null);
-        return compare_helper(false, msg, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(false, msg, nullptr, nullptr, actual, expected, file, line);
     }
     if (t1Null && t2Null)
-        return compare_helper(true, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(true, nullptr, nullptr, nullptr, actual, expected, file, line);
     if (t1.width() != t2.width() || t1.height() != t2.height()) {
         qsnprintf(msg, 1024, "Compared QPixmaps differ in size.\n"
                   "   Actual   (%s): %dx%d\n"
                   "   Expected (%s): %dx%d",
                   actual, t1.width(), t1.height(),
                   expected, t2.width(), t2.height());
-        return compare_helper(false, msg, Q_NULLPTR, Q_NULLPTR, actual, expected, file, line);
+        return compare_helper(false, msg, nullptr, nullptr, actual, expected, file, line);
     }
     return qCompare(t1.toImage(), t2.toImage(), actual, expected, file, line);
 }
diff --git a/src/testlib/qtestaccessible.h b/src/testlib/qtestaccessible.h
index 464f87fb5c..0470d15ed7 100644
--- a/src/testlib/qtestaccessible.h
+++ b/src/testlib/qtestaccessible.h
@@ -132,7 +132,7 @@ public:
     static void cleanup()
     {
         delete instance();
-        instance() = Q_NULLPTR;
+        instance() = nullptr;
     }
     static void clearEvents() { eventList().clear(); }
     static EventList events() { return eventList(); }
@@ -167,8 +167,8 @@ private:
 
     ~QTestAccessibility()
     {
-        QAccessible::installUpdateHandler(Q_NULLPTR);
-        QAccessible::installRootObjectHandler(Q_NULLPTR);
+        QAccessible::installUpdateHandler(nullptr);
+        QAccessible::installRootObjectHandler(nullptr);
     }
 
     static void rootObjectHandler(QObject *object)
@@ -273,7 +273,7 @@ private:
 
     static QTestAccessibility *&instance()
     {
-        static QTestAccessibility *ta = Q_NULLPTR;
+        static QTestAccessibility *ta = nullptr;
         return ta;
     }
 
diff --git a/src/testlib/qtestcase.cpp b/src/testlib/qtestcase.cpp
index fd68bbe461..7e7f016bf6 100644
--- a/src/testlib/qtestcase.cpp
+++ b/src/testlib/qtestcase.cpp
@@ -1387,7 +1387,7 @@ void TestMethods::invokeTests(QObject *testObject) const
 
         if (!QTestResult::skipCurrentTest() && !previousFailed) {
             for (int i = 0, count = int(m_methods.size()); i < count; ++i) {
-                const char *data = Q_NULLPTR;
+                const char *data = nullptr;
                 if (i < QTest::testTags.size() && !QTest::testTags.at(i).isEmpty())
                     data = qstrdup(QTest::testTags.at(i).toLatin1().constData());
                 const bool ok = invokeTest(i, data, watchDog.data());
@@ -1532,7 +1532,7 @@ class DebugSymbolResolver
     Q_DISABLE_COPY(DebugSymbolResolver)
 public:
     struct Symbol {
-        Symbol() : name(Q_NULLPTR), address(0) {}
+        Symbol() : name(nullptr), address(0) {}
 
         const char *name; // Must be freed by caller.
         DWORD64 address;
@@ -1580,11 +1580,11 @@ void DebugSymbolResolver::cleanup()
     if (m_dbgHelpLib)
         FreeLibrary(m_dbgHelpLib);
     m_dbgHelpLib = 0;
-    m_symFromAddr = Q_NULLPTR;
+    m_symFromAddr = nullptr;
 }
 
 DebugSymbolResolver::DebugSymbolResolver(HANDLE process)
-    : m_process(process), m_dbgHelpLib(0), m_symFromAddr(Q_NULLPTR)
+    : m_process(process), m_dbgHelpLib(0), m_symFromAddr(nullptr)
 {
     bool success = false;
     m_dbgHelpLib = LoadLibraryW(L"dbghelp.dll");
diff --git a/src/testlib/qtestcase.h b/src/testlib/qtestcase.h
index b738043cb7..20e6f022b4 100644
--- a/src/testlib/qtestcase.h
+++ b/src/testlib/qtestcase.h
@@ -248,7 +248,7 @@ namespace QTest
     template <typename T> // Fallback
     inline typename std::enable_if<!QtPrivate::IsQEnumHelper<T>::Value, char*>::type toString(const T &)
     {
-        return Q_NULLPTR;
+        return nullptr;
     }
 
     } // namespace Internal
@@ -271,14 +271,14 @@ namespace QTest
     Q_TESTLIB_EXPORT char *toString(const char *);
     Q_TESTLIB_EXPORT char *toString(const void *);
 
-    Q_TESTLIB_EXPORT void qInit(QObject *testObject, int argc = 0, char **argv = Q_NULLPTR);
+    Q_TESTLIB_EXPORT void qInit(QObject *testObject, int argc = 0, char **argv = nullptr);
     Q_TESTLIB_EXPORT int qRun();
     Q_TESTLIB_EXPORT void qCleanup();
 
-    Q_TESTLIB_EXPORT int qExec(QObject *testObject, int argc = 0, char **argv = Q_NULLPTR);
+    Q_TESTLIB_EXPORT int qExec(QObject *testObject, int argc = 0, char **argv = nullptr);
     Q_TESTLIB_EXPORT int qExec(QObject *testObject, const QStringList &arguments);
 
-    Q_TESTLIB_EXPORT void setMainSourcePath(const char *file, const char *builddir = Q_NULLPTR);
+    Q_TESTLIB_EXPORT void setMainSourcePath(const char *file, const char *builddir = nullptr);
 
     Q_TESTLIB_EXPORT bool qVerify(bool statement, const char *statementStr, const char *description,
                                  const char *file, int line);
@@ -286,7 +286,7 @@ namespace QTest
     Q_TESTLIB_EXPORT void qSkip(const char *message, const char *file, int line);
     Q_TESTLIB_EXPORT bool qExpectFail(const char *dataIndex, const char *comment, TestFailMode mode,
                            const char *file, int line);
-    Q_TESTLIB_EXPORT void qWarn(const char *message, const char *file = Q_NULLPTR, int line = 0);
+    Q_TESTLIB_EXPORT void qWarn(const char *message, const char *file = nullptr, int line = 0);
     Q_TESTLIB_EXPORT void ignoreMessage(QtMsgType type, const char *message);
 #ifndef QT_NO_REGULAREXPRESSION
     Q_TESTLIB_EXPORT void ignoreMessage(QtMsgType type, const QRegularExpression &messagePattern);
@@ -295,8 +295,8 @@ namespace QTest
 #if QT_CONFIG(temporaryfile)
     Q_TESTLIB_EXPORT QSharedPointer<QTemporaryDir> qExtractTestData(const QString &dirName);
 #endif
-    Q_TESTLIB_EXPORT QString qFindTestData(const char* basepath, const char* file = Q_NULLPTR, int line = 0, const char* builddir = Q_NULLPTR);
-    Q_TESTLIB_EXPORT QString qFindTestData(const QString& basepath, const char* file = Q_NULLPTR, int line = 0, const char* builddir = Q_NULLPTR);
+    Q_TESTLIB_EXPORT QString qFindTestData(const char* basepath, const char* file = nullptr, int line = 0, const char* builddir = nullptr);
+    Q_TESTLIB_EXPORT QString qFindTestData(const QString& basepath, const char* file = nullptr, int line = 0, const char* builddir = nullptr);
 
     Q_TESTLIB_EXPORT void *qData(const char *tagName, int typeId);
     Q_TESTLIB_EXPORT void *qGlobalData(const char *tagName, int typeId);
diff --git a/src/testlib/qtesteventloop.h b/src/testlib/qtesteventloop.h
index bcf4a4be2d..81c0b9126c 100644
--- a/src/testlib/qtesteventloop.h
+++ b/src/testlib/qtesteventloop.h
@@ -56,8 +56,8 @@ class Q_TESTLIB_EXPORT QTestEventLoop : public QObject
     Q_OBJECT
 
 public:
-    inline QTestEventLoop(QObject *aParent = Q_NULLPTR)
-        : QObject(aParent), inLoop(false), _timeout(false), timerId(-1), loop(Q_NULLPTR) {}
+    inline QTestEventLoop(QObject *aParent = nullptr)
+        : QObject(aParent), inLoop(false), _timeout(false), timerId(-1), loop(nullptr) {}
 
     inline void enterLoopMSecs(int ms);
     inline void enterLoop(int secs) { enterLoopMSecs(secs * 1000); }
@@ -103,7 +103,7 @@ inline void QTestEventLoop::enterLoopMSecs(int ms)
 
     loop = &l;
     l.exec();
-    loop = Q_NULLPTR;
+    loop = nullptr;
 }
 
 inline void QTestEventLoop::exitLoop()
diff --git a/src/testlib/qtestsystem.h b/src/testlib/qtestsystem.h
index f38a156936..dc6e481bb2 100644
--- a/src/testlib/qtestsystem.h
+++ b/src/testlib/qtestsystem.h
@@ -62,7 +62,7 @@ namespace QTest
         int remaining = ms;
         do {
             QCoreApplication::processEvents(QEventLoop::AllEvents, remaining);
-            QCoreApplication::sendPostedEvents(Q_NULLPTR, QEvent::DeferredDelete);
+            QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
             remaining = timer.remainingTime();
             if (remaining <= 0)
                 break;
@@ -78,7 +78,7 @@ namespace QTest
         int remaining = timeout;
         while (!window->isActive() && remaining > 0) {
             QCoreApplication::processEvents(QEventLoop::AllEvents, remaining);
-            QCoreApplication::sendPostedEvents(Q_NULLPTR, QEvent::DeferredDelete);
+            QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
             QTest::qSleep(10);
             remaining = timer.remainingTime();
         }
@@ -105,7 +105,7 @@ namespace QTest
         int remaining = timeout;
         while (!window->isExposed() && remaining > 0) {
             QCoreApplication::processEvents(QEventLoop::AllEvents, remaining);
-            QCoreApplication::sendPostedEvents(Q_NULLPTR, QEvent::DeferredDelete);
+            QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
             QTest::qSleep(10);
             remaining = timer.remainingTime();
         }
diff --git a/src/testlib/qtesttable.cpp b/src/testlib/qtesttable.cpp
index 1afe2f7af5..953495a18a 100644
--- a/src/testlib/qtesttable.cpp
+++ b/src/testlib/qtesttable.cpp
@@ -58,7 +58,7 @@ public:
     }
 
     struct Element {
-        Element() : name(Q_NULLPTR), type(0) {}
+        Element() : name(nullptr), type(0) {}
         Element(const char *n, int t) : name(n), type(t) {}
 
         const char *name;
@@ -130,12 +130,12 @@ int QTestTable::elementTypeId(int index) const
 
 const char *QTestTable::dataTag(int index) const
 {
-    return size_t(index) < d->elementList.size() ? d->elementList[index].name : Q_NULLPTR;
+    return size_t(index) < d->elementList.size() ? d->elementList[index].name : nullptr;
 }
 
 QTestData *QTestTable::testData(int index) const
 {
-    return size_t(index) < d->dataList.size() ? d->dataList[index] : Q_NULLPTR;
+    return size_t(index) < d->dataList.size() ? d->dataList[index] : nullptr;
 }
 
 class NamePredicate : public std::unary_function<QTestTablePrivate::Element, bool>
diff --git a/src/testlib/qtesttouch.h b/src/testlib/qtesttouch.h
index bda185bfee..bdb6d5b629 100644
--- a/src/testlib/qtesttouch.h
+++ b/src/testlib/qtesttouch.h
@@ -75,21 +75,21 @@ namespace QTest
             if (commitWhenDestroyed)
                 commit();
         }
-        QTouchEventSequence& press(int touchId, const QPoint &pt, QWindow *window = Q_NULLPTR)
+        QTouchEventSequence& press(int touchId, const QPoint &pt, QWindow *window = nullptr)
         {
             QTouchEvent::TouchPoint &p = point(touchId);
             p.setScreenPos(mapToScreen(window, pt));
             p.setState(Qt::TouchPointPressed);
             return *this;
         }
-        QTouchEventSequence& move(int touchId, const QPoint &pt, QWindow *window = Q_NULLPTR)
+        QTouchEventSequence& move(int touchId, const QPoint &pt, QWindow *window = nullptr)
         {
             QTouchEvent::TouchPoint &p = point(touchId);
             p.setScreenPos(mapToScreen(window, pt));
             p.setState(Qt::TouchPointMoved);
             return *this;
         }
-        QTouchEventSequence& release(int touchId, const QPoint &pt, QWindow *window = Q_NULLPTR)
+        QTouchEventSequence& release(int touchId, const QPoint &pt, QWindow *window = nullptr)
         {
             QTouchEvent::TouchPoint &p = point(touchId);
             p.setScreenPos(mapToScreen(window, pt));
@@ -104,21 +104,21 @@ namespace QTest
         }
 
 #ifdef QT_WIDGETS_LIB
-        QTouchEventSequence& press(int touchId, const QPoint &pt, QWidget *widget = Q_NULLPTR)
+        QTouchEventSequence& press(int touchId, const QPoint &pt, QWidget *widget = nullptr)
         {
             QTouchEvent::TouchPoint &p = point(touchId);
             p.setScreenPos(mapToScreen(widget, pt));
             p.setState(Qt::TouchPointPressed);
             return *this;
         }
-        QTouchEventSequence& move(int touchId, const QPoint &pt, QWidget *widget = Q_NULLPTR)
+        QTouchEventSequence& move(int touchId, const QPoint &pt, QWidget *widget = nullptr)
         {
             QTouchEvent::TouchPoint &p = point(touchId);
             p.setScreenPos(mapToScreen(widget, pt));
             p.setState(Qt::TouchPointMoved);
             return *this;
         }
-        QTouchEventSequence& release(int touchId, const QPoint &pt, QWidget *widget = Q_NULLPTR)
+        QTouchEventSequence& release(int touchId, const QPoint &pt, QWidget *widget = nullptr)
         {
             QTouchEvent::TouchPoint &p = point(touchId);
             p.setScreenPos(mapToScreen(widget, pt));
@@ -151,14 +151,14 @@ namespace QTest
 private:
 #ifdef QT_WIDGETS_LIB
         QTouchEventSequence(QWidget *widget, QTouchDevice *aDevice, bool autoCommit)
-            : targetWidget(widget), targetWindow(Q_NULLPTR), device(aDevice), commitWhenDestroyed(autoCommit)
+            : targetWidget(widget), targetWindow(nullptr), device(aDevice), commitWhenDestroyed(autoCommit)
         {
         }
 #endif
         QTouchEventSequence(QWindow *window, QTouchDevice *aDevice, bool autoCommit)
             :
 #ifdef QT_WIDGETS_LIB
-              targetWidget(Q_NULLPTR),
+              targetWidget(nullptr),
 #endif
               targetWindow(window), device(aDevice), commitWhenDestroyed(autoCommit)
         {
diff --git a/src/widgets/accessible/itemviews_p.h b/src/widgets/accessible/itemviews_p.h
index 61d0387f9c..683ae9c948 100644
--- a/src/widgets/accessible/itemviews_p.h
+++ b/src/widgets/accessible/itemviews_p.h
@@ -180,13 +180,13 @@ public:
     QAccessibleTableCell(QAbstractItemView *view, const QModelIndex &m_index, QAccessible::Role role);
 
     void *interface_cast(QAccessible::InterfaceType t) override;
-    QObject *object() const override { return Q_NULLPTR; }
+    QObject *object() const override { return nullptr; }
     QAccessible::Role role() const override;
     QAccessible::State state() const override;
     QRect rect() const override;
     bool isValid() const override;
 
-    QAccessibleInterface *childAt(int, int) const override { return Q_NULLPTR; }
+    QAccessibleInterface *childAt(int, int) const override { return nullptr; }
     int childCount() const override { return 0; }
     int indexOfChild(const QAccessibleInterface *) const override { return -1; }
 
@@ -234,13 +234,13 @@ public:
     // For header cells, pass the header view in addition
     QAccessibleTableHeaderCell(QAbstractItemView *view, int index, Qt::Orientation orientation);
 
-    QObject *object() const override { return Q_NULLPTR; }
+    QObject *object() const override { return nullptr; }
     QAccessible::Role role() const override;
     QAccessible::State state() const override;
     QRect rect() const override;
     bool isValid() const override;
 
-    QAccessibleInterface *childAt(int, int) const override { return Q_NULLPTR; }
+    QAccessibleInterface *childAt(int, int) const override { return nullptr; }
     int childCount() const override { return 0; }
     int indexOfChild(const QAccessibleInterface *) const override { return -1; }
 
@@ -273,13 +273,13 @@ public:
         :view(view_)
     {}
 
-    QObject *object() const override { return Q_NULLPTR; }
+    QObject *object() const override { return nullptr; }
     QAccessible::Role role() const override { return QAccessible::Pane; }
     QAccessible::State state() const override { return QAccessible::State(); }
     QRect rect() const override { return QRect(); }
     bool isValid() const override { return true; }
 
-    QAccessibleInterface *childAt(int, int) const override { return Q_NULLPTR; }
+    QAccessibleInterface *childAt(int, int) const override { return nullptr; }
     int childCount() const override { return 0; }
     int indexOfChild(const QAccessibleInterface *) const override { return -1; }
 
@@ -290,7 +290,7 @@ public:
         return QAccessible::queryAccessibleInterface(view);
     }
     QAccessibleInterface *child(int) const override {
-        return Q_NULLPTR;
+        return nullptr;
     }
 
 private:
diff --git a/src/widgets/accessible/qaccessiblemenu.cpp b/src/widgets/accessible/qaccessiblemenu.cpp
index ae50bbaef0..2391f74c2f 100644
--- a/src/widgets/accessible/qaccessiblemenu.cpp
+++ b/src/widgets/accessible/qaccessiblemenu.cpp
@@ -238,7 +238,7 @@ QObject *QAccessibleMenuItem::object() const
 /*! \reimp */
 QWindow *QAccessibleMenuItem::window() const
 {
-    QWindow *result = Q_NULLPTR;
+    QWindow *result = nullptr;
     if (!m_owner.isNull()) {
         result = m_owner->windowHandle();
         if (!result) {
diff --git a/src/widgets/accessible/rangecontrols.cpp b/src/widgets/accessible/rangecontrols.cpp
index c890c50938..4aa948ed33 100644
--- a/src/widgets/accessible/rangecontrols.cpp
+++ b/src/widgets/accessible/rangecontrols.cpp
@@ -64,7 +64,7 @@ QT_BEGIN_NAMESPACE
 
 #ifndef QT_NO_SPINBOX
 QAccessibleAbstractSpinBox::QAccessibleAbstractSpinBox(QWidget *w)
-: QAccessibleWidget(w, QAccessible::SpinBox), lineEdit(Q_NULLPTR)
+: QAccessibleWidget(w, QAccessible::SpinBox), lineEdit(nullptr)
 {
     Q_ASSERT(abstractSpinBox());
 }
diff --git a/src/widgets/dialogs/qcolordialog.h b/src/widgets/dialogs/qcolordialog.h
index daad20710c..6451ff9bde 100644
--- a/src/widgets/dialogs/qcolordialog.h
+++ b/src/widgets/dialogs/qcolordialog.h
@@ -68,8 +68,8 @@ public:
 
     Q_DECLARE_FLAGS(ColorDialogOptions, ColorDialogOption)
 
-    explicit QColorDialog(QWidget *parent = Q_NULLPTR);
-    explicit QColorDialog(const QColor &initial, QWidget *parent = Q_NULLPTR);
+    explicit QColorDialog(QWidget *parent = nullptr);
+    explicit QColorDialog(const QColor &initial, QWidget *parent = nullptr);
     ~QColorDialog();
 
     void setCurrentColor(const QColor &color);
@@ -88,12 +88,12 @@ public:
     void setVisible(bool visible) override;
 
     static QColor getColor(const QColor &initial = Qt::white,
-                           QWidget *parent = Q_NULLPTR,
+                           QWidget *parent = nullptr,
                            const QString &title = QString(),
                            ColorDialogOptions options = ColorDialogOptions());
 
     // obsolete
-    static QRgb getRgba(QRgb rgba = 0xffffffff, bool *ok = Q_NULLPTR, QWidget *parent = Q_NULLPTR);
+    static QRgb getRgba(QRgb rgba = 0xffffffff, bool *ok = nullptr, QWidget *parent = nullptr);
 
     static int customCount();
     static QColor customColor(int index);
diff --git a/src/widgets/dialogs/qdialog.h b/src/widgets/dialogs/qdialog.h
index 72250172d3..7f267dd939 100644
--- a/src/widgets/dialogs/qdialog.h
+++ b/src/widgets/dialogs/qdialog.h
@@ -60,7 +60,7 @@ class Q_WIDGETS_EXPORT QDialog : public QWidget
     Q_PROPERTY(bool modal READ isModal WRITE setModal)
 
 public:
-    explicit QDialog(QWidget *parent = Q_NULLPTR, Qt::WindowFlags f = Qt::WindowFlags());
+    explicit QDialog(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags());
     ~QDialog();
 
     enum DialogCode { Rejected, Accepted };
diff --git a/src/widgets/dialogs/qdialog_p.h b/src/widgets/dialogs/qdialog_p.h
index 9ee89863f6..c4677918a4 100644
--- a/src/widgets/dialogs/qdialog_p.h
+++ b/src/widgets/dialogs/qdialog_p.h
@@ -143,7 +143,7 @@ public:
     T *operator->() const Q_DECL_NOTHROW { return get(); }
     T *get() const Q_DECL_NOTHROW { return o; }
     T &operator*() const { return *get(); }
-    operator RestrictedBool() const Q_DECL_NOTHROW { return o ? &internal::func : Q_NULLPTR; }
+    operator RestrictedBool() const Q_DECL_NOTHROW { return o ? &internal::func : nullptr; }
     bool operator!() const Q_DECL_NOTHROW { return !o; }
 private:
     Q_DISABLE_COPY(QAutoPointer);
diff --git a/src/widgets/dialogs/qerrormessage.h b/src/widgets/dialogs/qerrormessage.h
index 8b350eefee..220694e54e 100644
--- a/src/widgets/dialogs/qerrormessage.h
+++ b/src/widgets/dialogs/qerrormessage.h
@@ -55,7 +55,7 @@ class Q_WIDGETS_EXPORT QErrorMessage: public QDialog
     Q_OBJECT
     Q_DECLARE_PRIVATE(QErrorMessage)
 public:
-    explicit QErrorMessage(QWidget* parent = Q_NULLPTR);
+    explicit QErrorMessage(QWidget* parent = nullptr);
     ~QErrorMessage();
 
     static QErrorMessage * qtHandler();
diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index 97afce1734..28cc7f8884 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -1992,7 +1992,7 @@ QFileIconProvider *QFileDialog::iconProvider() const
 {
     Q_D(const QFileDialog);
     if (!d->model)
-        return Q_NULLPTR;
+        return nullptr;
     return d->model->iconProvider();
 }
 
@@ -3619,7 +3619,7 @@ void QFileDialogPrivate::_q_enterDirectory(const QModelIndex &index)
         }
     } else {
         // Do not accept when shift-clicking to multi-select a file in environments with single-click-activation (KDE)
-        if (!q->style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, Q_NULLPTR, qFileDialogUi->treeView)
+        if (!q->style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, nullptr, qFileDialogUi->treeView)
             || q->fileMode() != QFileDialog::ExistingFiles || !(QGuiApplication::keyboardModifiers() & Qt::CTRL)) {
             q->accept();
         }
diff --git a/src/widgets/dialogs/qfiledialog.h b/src/widgets/dialogs/qfiledialog.h
index 9f331101d1..1cbd690f24 100644
--- a/src/widgets/dialogs/qfiledialog.h
+++ b/src/widgets/dialogs/qfiledialog.h
@@ -98,7 +98,7 @@ public:
     Q_FLAG(Options)
 
     QFileDialog(QWidget *parent, Qt::WindowFlags f);
-    explicit QFileDialog(QWidget *parent = Q_NULLPTR,
+    explicit QFileDialog(QWidget *parent = nullptr,
                          const QString &caption = QString(),
                          const QString &directory = QString(),
                          const QString &filter = QString());
@@ -207,59 +207,59 @@ Q_SIGNALS:
 
 public:
 
-    static QString getOpenFileName(QWidget *parent = Q_NULLPTR,
+    static QString getOpenFileName(QWidget *parent = nullptr,
                                    const QString &caption = QString(),
                                    const QString &dir = QString(),
                                    const QString &filter = QString(),
-                                   QString *selectedFilter = Q_NULLPTR,
+                                   QString *selectedFilter = nullptr,
                                    Options options = Options());
 
-    static QUrl getOpenFileUrl(QWidget *parent = Q_NULLPTR,
+    static QUrl getOpenFileUrl(QWidget *parent = nullptr,
                                const QString &caption = QString(),
                                const QUrl &dir = QUrl(),
                                const QString &filter = QString(),
-                               QString *selectedFilter = Q_NULLPTR,
+                               QString *selectedFilter = nullptr,
                                Options options = Options(),
                                const QStringList &supportedSchemes = QStringList());
 
-    static QString getSaveFileName(QWidget *parent = Q_NULLPTR,
+    static QString getSaveFileName(QWidget *parent = nullptr,
                                    const QString &caption = QString(),
                                    const QString &dir = QString(),
                                    const QString &filter = QString(),
-                                   QString *selectedFilter = Q_NULLPTR,
+                                   QString *selectedFilter = nullptr,
                                    Options options = Options());
 
-    static QUrl getSaveFileUrl(QWidget *parent = Q_NULLPTR,
+    static QUrl getSaveFileUrl(QWidget *parent = nullptr,
                                const QString &caption = QString(),
                                const QUrl &dir = QUrl(),
                                const QString &filter = QString(),
-                               QString *selectedFilter = Q_NULLPTR,
+                               QString *selectedFilter = nullptr,
                                Options options = Options(),
                                const QStringList &supportedSchemes = QStringList());
 
-    static QString getExistingDirectory(QWidget *parent = Q_NULLPTR,
+    static QString getExistingDirectory(QWidget *parent = nullptr,
                                         const QString &caption = QString(),
                                         const QString &dir = QString(),
                                         Options options = ShowDirsOnly);
 
-    static QUrl getExistingDirectoryUrl(QWidget *parent = Q_NULLPTR,
+    static QUrl getExistingDirectoryUrl(QWidget *parent = nullptr,
                                         const QString &caption = QString(),
                                         const QUrl &dir = QUrl(),
                                         Options options = ShowDirsOnly,
                                         const QStringList &supportedSchemes = QStringList());
 
-    static QStringList getOpenFileNames(QWidget *parent = Q_NULLPTR,
+    static QStringList getOpenFileNames(QWidget *parent = nullptr,
                                         const QString &caption = QString(),
                                         const QString &dir = QString(),
                                         const QString &filter = QString(),
-                                        QString *selectedFilter = Q_NULLPTR,
+                                        QString *selectedFilter = nullptr,
                                         Options options = Options());
 
-    static QList<QUrl> getOpenFileUrls(QWidget *parent = Q_NULLPTR,
+    static QList<QUrl> getOpenFileUrls(QWidget *parent = nullptr,
                                        const QString &caption = QString(),
                                        const QUrl &dir = QUrl(),
                                        const QString &filter = QString(),
-                                       QString *selectedFilter = Q_NULLPTR,
+                                       QString *selectedFilter = nullptr,
                                        Options options = Options(),
                                        const QStringList &supportedSchemes = QStringList());
 
diff --git a/src/widgets/dialogs/qfilesystemmodel.h b/src/widgets/dialogs/qfilesystemmodel.h
index 5862006e60..c2c8b8818e 100644
--- a/src/widgets/dialogs/qfilesystemmodel.h
+++ b/src/widgets/dialogs/qfilesystemmodel.h
@@ -75,7 +75,7 @@ public:
         FilePermissions = Qt::UserRole + 3
     };
 
-    explicit QFileSystemModel(QObject *parent = Q_NULLPTR);
+    explicit QFileSystemModel(QObject *parent = nullptr);
     ~QFileSystemModel();
 
     QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
@@ -144,7 +144,7 @@ public:
     bool remove(const QModelIndex &index);
 
 protected:
-    QFileSystemModel(QFileSystemModelPrivate &, QObject *parent = Q_NULLPTR);
+    QFileSystemModel(QFileSystemModelPrivate &, QObject *parent = nullptr);
     void timerEvent(QTimerEvent *event) override;
     bool event(QEvent *event) override;
 
diff --git a/src/widgets/dialogs/qfontdialog.h b/src/widgets/dialogs/qfontdialog.h
index c5a20340e1..ae1320e779 100644
--- a/src/widgets/dialogs/qfontdialog.h
+++ b/src/widgets/dialogs/qfontdialog.h
@@ -72,8 +72,8 @@ public:
 
     Q_DECLARE_FLAGS(FontDialogOptions, FontDialogOption)
 
-    explicit QFontDialog(QWidget *parent = Q_NULLPTR);
-    explicit QFontDialog(const QFont &initial, QWidget *parent = Q_NULLPTR);
+    explicit QFontDialog(QWidget *parent = nullptr);
+    explicit QFontDialog(const QFont &initial, QWidget *parent = nullptr);
     ~QFontDialog();
 
     void setCurrentFont(const QFont &font);
@@ -91,8 +91,8 @@ public:
 
     void setVisible(bool visible) override;
 
-    static QFont getFont(bool *ok, QWidget *parent = Q_NULLPTR);
-    static QFont getFont(bool *ok, const QFont &initial, QWidget *parent = Q_NULLPTR, const QString &title = QString(),
+    static QFont getFont(bool *ok, QWidget *parent = nullptr);
+    static QFont getFont(bool *ok, const QFont &initial, QWidget *parent = nullptr, const QString &title = QString(),
                          FontDialogOptions options = FontDialogOptions());
 
 Q_SIGNALS:
diff --git a/src/widgets/dialogs/qinputdialog.cpp b/src/widgets/dialogs/qinputdialog.cpp
index 757b53e5ad..43a51c334c 100644
--- a/src/widgets/dialogs/qinputdialog.cpp
+++ b/src/widgets/dialogs/qinputdialog.cpp
@@ -74,7 +74,7 @@ static const char *candidateSignal(int which)
     case NumCandidateSignals:       ; // fall through
     };
     Q_UNREACHABLE();
-    return Q_NULLPTR;
+    return nullptr;
 }
 
 static const char *signalForMember(const char *member)
diff --git a/src/widgets/dialogs/qinputdialog.h b/src/widgets/dialogs/qinputdialog.h
index 5c97a425b7..c3a5e59d53 100644
--- a/src/widgets/dialogs/qinputdialog.h
+++ b/src/widgets/dialogs/qinputdialog.h
@@ -91,7 +91,7 @@ public:
         DoubleInput
     };
 
-    QInputDialog(QWidget *parent = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
+    QInputDialog(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
     ~QInputDialog();
 
     void setInputMode(InputMode mode);
@@ -161,24 +161,24 @@ public:
 
     static QString getText(QWidget *parent, const QString &title, const QString &label,
                            QLineEdit::EchoMode echo = QLineEdit::Normal,
-                           const QString &text = QString(), bool *ok = Q_NULLPTR,
+                           const QString &text = QString(), bool *ok = nullptr,
                            Qt::WindowFlags flags = Qt::WindowFlags(),
                            Qt::InputMethodHints inputMethodHints = Qt::ImhNone);
     static QString getMultiLineText(QWidget *parent, const QString &title, const QString &label,
-                                    const QString &text = QString(), bool *ok = Q_NULLPTR,
+                                    const QString &text = QString(), bool *ok = nullptr,
                                     Qt::WindowFlags flags = Qt::WindowFlags(),
                                     Qt::InputMethodHints inputMethodHints = Qt::ImhNone);
     static QString getItem(QWidget *parent, const QString &title, const QString &label,
                            const QStringList &items, int current = 0, bool editable = true,
-                           bool *ok = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags(),
+                           bool *ok = nullptr, Qt::WindowFlags flags = Qt::WindowFlags(),
                            Qt::InputMethodHints inputMethodHints = Qt::ImhNone);
 
     static int getInt(QWidget *parent, const QString &title, const QString &label, int value = 0,
                       int minValue = -2147483647, int maxValue = 2147483647,
-                      int step = 1, bool *ok = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
+                      int step = 1, bool *ok = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
     static double getDouble(QWidget *parent, const QString &title, const QString &label, double value = 0,
                             double minValue = -2147483647, double maxValue = 2147483647,
-                            int decimals = 1, bool *ok = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
+                            int decimals = 1, bool *ok = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
     // ### Qt 6: merge overloads
     static double getDouble(QWidget *parent, const QString &title, const QString &label, double value,
                             double minValue, double maxValue, int decimals, bool *ok, Qt::WindowFlags flags,
@@ -187,7 +187,7 @@ public:
 #if QT_DEPRECATED_SINCE(5, 0)
     QT_DEPRECATED static inline int getInteger(QWidget *parent, const QString &title, const QString &label, int value = 0,
                           int minValue = -2147483647, int maxValue = 2147483647,
-                          int step = 1, bool *ok = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags())
+                          int step = 1, bool *ok = nullptr, Qt::WindowFlags flags = Qt::WindowFlags())
     {
         return getInt(parent, title, label, value, minValue, maxValue, step, ok, flags);
     }
diff --git a/src/widgets/dialogs/qmessagebox.cpp b/src/widgets/dialogs/qmessagebox.cpp
index 4debdc114b..3fe6a7ea7d 100644
--- a/src/widgets/dialogs/qmessagebox.cpp
+++ b/src/widgets/dialogs/qmessagebox.cpp
@@ -2604,7 +2604,7 @@ QPixmap QMessageBoxPrivate::standardIcon(QMessageBox::Icon icon, QMessageBox *mb
         break;
     }
     if (!tmpIcon.isNull()) {
-        QWindow *window = Q_NULLPTR;
+        QWindow *window = nullptr;
         if (mb) {
             window = mb->windowHandle();
             if (!window) {
diff --git a/src/widgets/dialogs/qmessagebox.h b/src/widgets/dialogs/qmessagebox.h
index 56f156c616..c2ce1ab333 100644
--- a/src/widgets/dialogs/qmessagebox.h
+++ b/src/widgets/dialogs/qmessagebox.h
@@ -132,9 +132,9 @@ public:
     Q_DECLARE_FLAGS(StandardButtons, StandardButton)
     Q_FLAG(StandardButtons)
 
-    explicit QMessageBox(QWidget *parent = Q_NULLPTR);
+    explicit QMessageBox(QWidget *parent = nullptr);
     QMessageBox(Icon icon, const QString &title, const QString &text,
-                StandardButtons buttons = NoButton, QWidget *parent = Q_NULLPTR,
+                StandardButtons buttons = NoButton, QWidget *parent = nullptr,
                 Qt::WindowFlags flags = Qt::Dialog | Qt::MSWindowsFixedSizeDialogHint);
     ~QMessageBox();
 
@@ -201,7 +201,7 @@ public:
 
     QMessageBox(const QString &title, const QString &text, Icon icon,
                   int button0, int button1, int button2,
-                  QWidget *parent = Q_NULLPTR,
+                  QWidget *parent = nullptr,
                   Qt::WindowFlags f = Qt::Dialog | Qt::MSWindowsFixedSizeDialogHint);
 
     static int information(QWidget *parent, const QString &title,
diff --git a/src/widgets/dialogs/qprogressdialog.h b/src/widgets/dialogs/qprogressdialog.h
index f6dcfdb2e9..74adb6bd84 100644
--- a/src/widgets/dialogs/qprogressdialog.h
+++ b/src/widgets/dialogs/qprogressdialog.h
@@ -68,9 +68,9 @@ class Q_WIDGETS_EXPORT QProgressDialog : public QDialog
     Q_PROPERTY(QString labelText READ labelText WRITE setLabelText)
 
 public:
-    explicit QProgressDialog(QWidget *parent = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
+    explicit QProgressDialog(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
     QProgressDialog(const QString &labelText, const QString &cancelButtonText,
-                    int minimum, int maximum, QWidget *parent = Q_NULLPTR,
+                    int minimum, int maximum, QWidget *parent = nullptr,
                     Qt::WindowFlags flags = Qt::WindowFlags());
     ~QProgressDialog();
 
diff --git a/src/widgets/dialogs/qwizard.h b/src/widgets/dialogs/qwizard.h
index 1850d9e967..0dd837b197 100644
--- a/src/widgets/dialogs/qwizard.h
+++ b/src/widgets/dialogs/qwizard.h
@@ -120,7 +120,7 @@ public:
     Q_DECLARE_FLAGS(WizardOptions, WizardOption)
     Q_FLAG(WizardOptions)
 
-    explicit QWizard(QWidget *parent = Q_NULLPTR, Qt::WindowFlags flags = Qt::WindowFlags());
+    explicit QWizard(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
     ~QWizard();
 
     int addPage(QWizardPage *page);
@@ -215,7 +215,7 @@ class Q_WIDGETS_EXPORT QWizardPage : public QWidget
     Q_PROPERTY(QString subTitle READ subTitle WRITE setSubTitle)
 
 public:
-    explicit QWizardPage(QWidget *parent = Q_NULLPTR);
+    explicit QWizardPage(QWidget *parent = nullptr);
     ~QWizardPage();
 
     void setTitle(const QString &title);
@@ -243,8 +243,8 @@ Q_SIGNALS:
 protected:
     void setField(const QString &name, const QVariant &value);
     QVariant field(const QString &name) const;
-    void registerField(const QString &name, QWidget *widget, const char *property = Q_NULLPTR,
-                       const char *changedSignal = Q_NULLPTR);
+    void registerField(const QString &name, QWidget *widget, const char *property = nullptr,
+                       const char *changedSignal = nullptr);
     QWizard *wizard() const;
 
 private:
diff --git a/src/widgets/effects/qgraphicseffect.h b/src/widgets/effects/qgraphicseffect.h
index ec5cf886a6..f7c0769778 100644
--- a/src/widgets/effects/qgraphicseffect.h
+++ b/src/widgets/effects/qgraphicseffect.h
@@ -79,7 +79,7 @@ public:
         PadToEffectiveBoundingRect
     };
 
-    QGraphicsEffect(QObject *parent = Q_NULLPTR);
+    QGraphicsEffect(QObject *parent = nullptr);
     virtual ~QGraphicsEffect();
 
     virtual QRectF boundingRectFor(const QRectF &sourceRect) const;
@@ -95,7 +95,7 @@ Q_SIGNALS:
     void enabledChanged(bool enabled);
 
 protected:
-    QGraphicsEffect(QGraphicsEffectPrivate &d, QObject *parent = Q_NULLPTR);
+    QGraphicsEffect(QGraphicsEffectPrivate &d, QObject *parent = nullptr);
     virtual void draw(QPainter *painter) = 0;
     virtual void sourceChanged(ChangeFlags flags);
     void updateBoundingRect();
@@ -104,7 +104,7 @@ protected:
     QRectF sourceBoundingRect(Qt::CoordinateSystem system = Qt::LogicalCoordinates) const;
     void drawSource(QPainter *painter);
     QPixmap sourcePixmap(Qt::CoordinateSystem system = Qt::LogicalCoordinates,
-                         QPoint *offset = Q_NULLPTR,
+                         QPoint *offset = nullptr,
                          PixmapPadMode mode = PadToEffectiveBoundingRect) const;
 
 private:
@@ -129,7 +129,7 @@ class Q_WIDGETS_EXPORT QGraphicsColorizeEffect: public QGraphicsEffect
     Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged)
     Q_PROPERTY(qreal strength READ strength WRITE setStrength NOTIFY strengthChanged)
 public:
-    QGraphicsColorizeEffect(QObject *parent = Q_NULLPTR);
+    QGraphicsColorizeEffect(QObject *parent = nullptr);
     ~QGraphicsColorizeEffect();
 
     QColor color() const;
@@ -167,7 +167,7 @@ public:
     Q_DECLARE_FLAGS(BlurHints, BlurHint)
     Q_FLAG(BlurHints)
 
-    QGraphicsBlurEffect(QObject *parent = Q_NULLPTR);
+    QGraphicsBlurEffect(QObject *parent = nullptr);
     ~QGraphicsBlurEffect();
 
     QRectF boundingRectFor(const QRectF &rect) const override;
@@ -202,7 +202,7 @@ class Q_WIDGETS_EXPORT QGraphicsDropShadowEffect: public QGraphicsEffect
     Q_PROPERTY(qreal blurRadius READ blurRadius WRITE setBlurRadius NOTIFY blurRadiusChanged)
     Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged)
 public:
-    QGraphicsDropShadowEffect(QObject *parent = Q_NULLPTR);
+    QGraphicsDropShadowEffect(QObject *parent = nullptr);
     ~QGraphicsDropShadowEffect();
 
     QRectF boundingRectFor(const QRectF &rect) const override;
@@ -255,7 +255,7 @@ class Q_WIDGETS_EXPORT QGraphicsOpacityEffect: public QGraphicsEffect
     Q_PROPERTY(qreal opacity READ opacity WRITE setOpacity NOTIFY opacityChanged)
     Q_PROPERTY(QBrush opacityMask READ opacityMask WRITE setOpacityMask NOTIFY opacityMaskChanged)
 public:
-    QGraphicsOpacityEffect(QObject *parent = Q_NULLPTR);
+    QGraphicsOpacityEffect(QObject *parent = nullptr);
     ~QGraphicsOpacityEffect();
 
     qreal opacity() const;
diff --git a/src/widgets/graphicsview/qgraphicsanchorlayout.h b/src/widgets/graphicsview/qgraphicsanchorlayout.h
index 34c6e12c16..e392be1568 100644
--- a/src/widgets/graphicsview/qgraphicsanchorlayout.h
+++ b/src/widgets/graphicsview/qgraphicsanchorlayout.h
@@ -76,7 +76,7 @@ private:
 class Q_WIDGETS_EXPORT QGraphicsAnchorLayout : public QGraphicsLayout
 {
 public:
-    QGraphicsAnchorLayout(QGraphicsLayoutItem *parent = Q_NULLPTR);
+    QGraphicsAnchorLayout(QGraphicsLayoutItem *parent = nullptr);
     virtual ~QGraphicsAnchorLayout();
 
     QGraphicsAnchor *addAnchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
diff --git a/src/widgets/graphicsview/qgraphicsgridlayout.h b/src/widgets/graphicsview/qgraphicsgridlayout.h
index c20a931617..4c0a1b4527 100644
--- a/src/widgets/graphicsview/qgraphicsgridlayout.h
+++ b/src/widgets/graphicsview/qgraphicsgridlayout.h
@@ -53,7 +53,7 @@ class QGraphicsGridLayoutPrivate;
 class Q_WIDGETS_EXPORT QGraphicsGridLayout : public QGraphicsLayout
 {
 public:
-    QGraphicsGridLayout(QGraphicsLayoutItem *parent = Q_NULLPTR);
+    QGraphicsGridLayout(QGraphicsLayoutItem *parent = nullptr);
     virtual ~QGraphicsGridLayout();
 
     void addItem(QGraphicsLayoutItem *item, int row, int column, int rowSpan, int columnSpan,
diff --git a/src/widgets/graphicsview/qgraphicsitem.h b/src/widgets/graphicsview/qgraphicsitem.h
index c291f94c78..47ef5ba80e 100644
--- a/src/widgets/graphicsview/qgraphicsitem.h
+++ b/src/widgets/graphicsview/qgraphicsitem.h
@@ -158,7 +158,7 @@ public:
         SceneModal
     };
 
-    explicit QGraphicsItem(QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsItem(QGraphicsItem *parent = nullptr);
     virtual ~QGraphicsItem();
 
     QGraphicsScene *scene() const;
@@ -194,7 +194,7 @@ public:
 
     PanelModality panelModality() const;
     void setPanelModality(PanelModality panelModality);
-    bool isBlockedByModalPanel(QGraphicsItem **blockingPanel = Q_NULLPTR) const;
+    bool isBlockedByModalPanel(QGraphicsItem **blockingPanel = nullptr) const;
 
 #ifndef QT_NO_TOOLTIP
     QString toolTip() const;
@@ -290,7 +290,7 @@ public:
     QTransform transform() const;
     QTransform sceneTransform() const;
     QTransform deviceTransform(const QTransform &viewportTransform) const;
-    QTransform itemTransform(const QGraphicsItem *other, bool *ok = Q_NULLPTR) const;
+    QTransform itemTransform(const QGraphicsItem *other, bool *ok = nullptr) const;
     void setTransform(const QTransform &matrix, bool combine = false);
     void resetTransform();
 #if QT_DEPRECATED_SINCE(5, 0)
@@ -341,7 +341,7 @@ public:
     void setBoundingRegionGranularity(qreal granularity);
 
     // Drawing
-    virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) = 0;
+    virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) = 0;
     void update(const QRectF &rect = QRectF());
     inline void update(qreal x, qreal y, qreal width, qreal height);
     void scroll(qreal dx, qreal dy, const QRectF &rect = QRectF());
@@ -558,7 +558,7 @@ class Q_WIDGETS_EXPORT QGraphicsObject : public QObject, public QGraphicsItem
     Q_CLASSINFO("DefaultProperty", "children")
     Q_INTERFACES(QGraphicsItem)
 public:
-    explicit QGraphicsObject(QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsObject(QGraphicsItem *parent = nullptr);
     ~QGraphicsObject();
 
     using QObject::children;
@@ -600,7 +600,7 @@ class QAbstractGraphicsShapeItemPrivate;
 class Q_WIDGETS_EXPORT QAbstractGraphicsShapeItem : public QGraphicsItem
 {
 public:
-    explicit QAbstractGraphicsShapeItem(QGraphicsItem *parent = Q_NULLPTR);
+    explicit QAbstractGraphicsShapeItem(QGraphicsItem *parent = nullptr);
     ~QAbstractGraphicsShapeItem();
 
     QPen pen() const;
@@ -625,8 +625,8 @@ class QGraphicsPathItemPrivate;
 class Q_WIDGETS_EXPORT QGraphicsPathItem : public QAbstractGraphicsShapeItem
 {
 public:
-    explicit QGraphicsPathItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsPathItem(const QPainterPath &path, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsPathItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsPathItem(const QPainterPath &path, QGraphicsItem *parent = nullptr);
     ~QGraphicsPathItem();
 
     QPainterPath path() const;
@@ -636,7 +636,7 @@ public:
     QPainterPath shape() const override;
     bool contains(const QPointF &point) const override;
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
     bool isObscuredBy(const QGraphicsItem *item) const override;
     QPainterPath opaqueArea() const override;
@@ -658,9 +658,9 @@ class QGraphicsRectItemPrivate;
 class Q_WIDGETS_EXPORT QGraphicsRectItem : public QAbstractGraphicsShapeItem
 {
 public:
-    explicit QGraphicsRectItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsRectItem(const QRectF &rect, QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsRectItem(qreal x, qreal y, qreal w, qreal h, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsRectItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsRectItem(const QRectF &rect, QGraphicsItem *parent = nullptr);
+    explicit QGraphicsRectItem(qreal x, qreal y, qreal w, qreal h, QGraphicsItem *parent = nullptr);
     ~QGraphicsRectItem();
 
     QRectF rect() const;
@@ -671,7 +671,7 @@ public:
     QPainterPath shape() const override;
     bool contains(const QPointF &point) const override;
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
     bool isObscuredBy(const QGraphicsItem *item) const override;
     QPainterPath opaqueArea() const override;
@@ -696,9 +696,9 @@ class QGraphicsEllipseItemPrivate;
 class Q_WIDGETS_EXPORT QGraphicsEllipseItem : public QAbstractGraphicsShapeItem
 {
 public:
-    explicit QGraphicsEllipseItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsEllipseItem(const QRectF &rect, QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsEllipseItem(qreal x, qreal y, qreal w, qreal h, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsEllipseItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsEllipseItem(const QRectF &rect, QGraphicsItem *parent = nullptr);
+    explicit QGraphicsEllipseItem(qreal x, qreal y, qreal w, qreal h, QGraphicsItem *parent = nullptr);
     ~QGraphicsEllipseItem();
 
     QRectF rect() const;
@@ -715,7 +715,7 @@ public:
     QPainterPath shape() const override;
     bool contains(const QPointF &point) const override;
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
     bool isObscuredBy(const QGraphicsItem *item) const override;
     QPainterPath opaqueArea() const override;
@@ -740,9 +740,9 @@ class QGraphicsPolygonItemPrivate;
 class Q_WIDGETS_EXPORT QGraphicsPolygonItem : public QAbstractGraphicsShapeItem
 {
 public:
-    explicit QGraphicsPolygonItem(QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsPolygonItem(QGraphicsItem *parent = nullptr);
     explicit QGraphicsPolygonItem(const QPolygonF &polygon,
-                                  QGraphicsItem *parent = Q_NULLPTR);
+                                  QGraphicsItem *parent = nullptr);
     ~QGraphicsPolygonItem();
 
     QPolygonF polygon() const;
@@ -755,7 +755,7 @@ public:
     QPainterPath shape() const override;
     bool contains(const QPointF &point) const override;
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
     bool isObscuredBy(const QGraphicsItem *item) const override;
     QPainterPath opaqueArea() const override;
@@ -777,9 +777,9 @@ class QGraphicsLineItemPrivate;
 class Q_WIDGETS_EXPORT QGraphicsLineItem : public QGraphicsItem
 {
 public:
-    explicit QGraphicsLineItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsLineItem(const QLineF &line, QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsLineItem(qreal x1, qreal y1, qreal x2, qreal y2, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsLineItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsLineItem(const QLineF &line, QGraphicsItem *parent = nullptr);
+    explicit QGraphicsLineItem(qreal x1, qreal y1, qreal x2, qreal y2, QGraphicsItem *parent = nullptr);
     ~QGraphicsLineItem();
 
     QPen pen() const;
@@ -794,7 +794,7 @@ public:
     QPainterPath shape() const override;
     bool contains(const QPointF &point) const override;
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
     bool isObscuredBy(const QGraphicsItem *item) const override;
     QPainterPath opaqueArea() const override;
@@ -822,8 +822,8 @@ public:
         HeuristicMaskShape
     };
 
-    explicit QGraphicsPixmapItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsPixmapItem(const QPixmap &pixmap, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsPixmapItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsPixmapItem(const QPixmap &pixmap, QGraphicsItem *parent = nullptr);
     ~QGraphicsPixmapItem();
 
     QPixmap pixmap() const;
@@ -874,8 +874,8 @@ class Q_WIDGETS_EXPORT QGraphicsTextItem : public QGraphicsObject
     QDOC_PROPERTY(QTextCursor textCursor READ textCursor WRITE setTextCursor)
 
 public:
-    explicit QGraphicsTextItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsTextItem(const QString &text, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsTextItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsTextItem(const QString &text, QGraphicsItem *parent = nullptr);
     ~QGraphicsTextItem();
 
     QString toHtml() const;
@@ -965,8 +965,8 @@ class QGraphicsSimpleTextItemPrivate;
 class Q_WIDGETS_EXPORT QGraphicsSimpleTextItem : public QAbstractGraphicsShapeItem
 {
 public:
-    explicit QGraphicsSimpleTextItem(QGraphicsItem *parent = Q_NULLPTR);
-    explicit QGraphicsSimpleTextItem(const QString &text, QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsSimpleTextItem(QGraphicsItem *parent = nullptr);
+    explicit QGraphicsSimpleTextItem(const QString &text, QGraphicsItem *parent = nullptr);
     ~QGraphicsSimpleTextItem();
 
     void setText(const QString &text);
@@ -1001,14 +1001,14 @@ class QGraphicsItemGroupPrivate;
 class Q_WIDGETS_EXPORT QGraphicsItemGroup : public QGraphicsItem
 {
 public:
-    explicit QGraphicsItemGroup(QGraphicsItem *parent = Q_NULLPTR);
+    explicit QGraphicsItemGroup(QGraphicsItem *parent = nullptr);
     ~QGraphicsItemGroup();
 
     void addToGroup(QGraphicsItem *item);
     void removeFromGroup(QGraphicsItem *item);
 
     QRectF boundingRect() const override;
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
     bool isObscuredBy(const QGraphicsItem *item) const override;
     QPainterPath opaqueArea() const override;
diff --git a/src/widgets/graphicsview/qgraphicsitemanimation.h b/src/widgets/graphicsview/qgraphicsitemanimation.h
index a819acc880..7417d7729c 100644
--- a/src/widgets/graphicsview/qgraphicsitemanimation.h
+++ b/src/widgets/graphicsview/qgraphicsitemanimation.h
@@ -58,7 +58,7 @@ class Q_WIDGETS_EXPORT QGraphicsItemAnimation : public QObject
 {
     Q_OBJECT
 public:
-    QGraphicsItemAnimation(QObject *parent = Q_NULLPTR);
+    QGraphicsItemAnimation(QObject *parent = nullptr);
     virtual ~QGraphicsItemAnimation();
 
     QGraphicsItem *item() const;
diff --git a/src/widgets/graphicsview/qgraphicslayout.h b/src/widgets/graphicsview/qgraphicslayout.h
index 60c9a35037..28b335ceaa 100644
--- a/src/widgets/graphicsview/qgraphicslayout.h
+++ b/src/widgets/graphicsview/qgraphicslayout.h
@@ -54,7 +54,7 @@ class QGraphicsWidget;
 class Q_WIDGETS_EXPORT QGraphicsLayout : public QGraphicsLayoutItem
 {
 public:
-    QGraphicsLayout(QGraphicsLayoutItem *parent = Q_NULLPTR);
+    QGraphicsLayout(QGraphicsLayoutItem *parent = nullptr);
     ~QGraphicsLayout();
 
     void setContentsMargins(qreal left, qreal top, qreal right, qreal bottom);
diff --git a/src/widgets/graphicsview/qgraphicslayoutitem.h b/src/widgets/graphicsview/qgraphicslayoutitem.h
index 10c7870412..44f430034b 100644
--- a/src/widgets/graphicsview/qgraphicslayoutitem.h
+++ b/src/widgets/graphicsview/qgraphicslayoutitem.h
@@ -54,7 +54,7 @@ class QGraphicsItem;
 class Q_WIDGETS_EXPORT QGraphicsLayoutItem
 {
 public:
-    QGraphicsLayoutItem(QGraphicsLayoutItem *parent = Q_NULLPTR, bool isLayout = false);
+    QGraphicsLayoutItem(QGraphicsLayoutItem *parent = nullptr, bool isLayout = false);
     virtual ~QGraphicsLayoutItem();
 
     void setSizePolicy(const QSizePolicy &policy);
diff --git a/src/widgets/graphicsview/qgraphicslinearlayout.h b/src/widgets/graphicsview/qgraphicslinearlayout.h
index a46ec660e7..d27191adb3 100644
--- a/src/widgets/graphicsview/qgraphicslinearlayout.h
+++ b/src/widgets/graphicsview/qgraphicslinearlayout.h
@@ -53,8 +53,8 @@ class QGraphicsLinearLayoutPrivate;
 class Q_WIDGETS_EXPORT QGraphicsLinearLayout : public QGraphicsLayout
 {
 public:
-    QGraphicsLinearLayout(QGraphicsLayoutItem *parent = Q_NULLPTR);
-    QGraphicsLinearLayout(Qt::Orientation orientation, QGraphicsLayoutItem *parent = Q_NULLPTR);
+    QGraphicsLinearLayout(QGraphicsLayoutItem *parent = nullptr);
+    QGraphicsLinearLayout(Qt::Orientation orientation, QGraphicsLayoutItem *parent = nullptr);
     virtual ~QGraphicsLinearLayout();
 
     void setOrientation(Qt::Orientation orientation);
diff --git a/src/widgets/graphicsview/qgraphicsproxywidget.h b/src/widgets/graphicsview/qgraphicsproxywidget.h
index bb06ac3c16..76fdf8aeba 100644
--- a/src/widgets/graphicsview/qgraphicsproxywidget.h
+++ b/src/widgets/graphicsview/qgraphicsproxywidget.h
@@ -53,7 +53,7 @@ class Q_WIDGETS_EXPORT QGraphicsProxyWidget : public QGraphicsWidget
 {
     Q_OBJECT
 public:
-    QGraphicsProxyWidget(QGraphicsItem *parent = Q_NULLPTR, Qt::WindowFlags wFlags = Qt::WindowFlags());
+    QGraphicsProxyWidget(QGraphicsItem *parent = nullptr, Qt::WindowFlags wFlags = Qt::WindowFlags());
     ~QGraphicsProxyWidget();
 
     void setWidget(QWidget *widget);
diff --git a/src/widgets/graphicsview/qgraphicsscene.h b/src/widgets/graphicsview/qgraphicsscene.h
index 071f83aeb6..5ecd2baab8 100644
--- a/src/widgets/graphicsview/qgraphicsscene.h
+++ b/src/widgets/graphicsview/qgraphicsscene.h
@@ -121,9 +121,9 @@ public:
     };
     Q_DECLARE_FLAGS(SceneLayers, SceneLayer)
 
-    QGraphicsScene(QObject *parent = Q_NULLPTR);
-    QGraphicsScene(const QRectF &sceneRect, QObject *parent = Q_NULLPTR);
-    QGraphicsScene(qreal x, qreal y, qreal width, qreal height, QObject *parent = Q_NULLPTR);
+    QGraphicsScene(QObject *parent = nullptr);
+    QGraphicsScene(const QRectF &sceneRect, QObject *parent = nullptr);
+    QGraphicsScene(qreal x, qreal y, qreal width, qreal height, QObject *parent = nullptr);
     virtual ~QGraphicsScene();
 
     QRectF sceneRect() const;
@@ -159,7 +159,7 @@ public:
 #if QT_DEPRECATED_SINCE(5, 0)
     QT_DEPRECATED inline QGraphicsItem *itemAt(const QPointF &position) const {
         QList<QGraphicsItem *> itemsAtPoint = items(position);
-        return itemsAtPoint.isEmpty() ? Q_NULLPTR : itemsAtPoint.first();
+        return itemsAtPoint.isEmpty() ? nullptr : itemsAtPoint.first();
     }
 #endif
     QGraphicsItem *itemAt(const QPointF &pos, const QTransform &deviceTransform) const;
@@ -173,7 +173,7 @@ public:
 #if QT_DEPRECATED_SINCE(5, 0)
     QT_DEPRECATED inline QGraphicsItem *itemAt(qreal x, qreal y) const {
         QList<QGraphicsItem *> itemsAtPoint = items(QPointF(x, y));
-        return itemsAtPoint.isEmpty() ? Q_NULLPTR : itemsAtPoint.first();
+        return itemsAtPoint.isEmpty() ? nullptr : itemsAtPoint.first();
     }
 #endif
     inline QGraphicsItem *itemAt(qreal x, qreal y, const QTransform &deviceTransform) const
@@ -285,7 +285,7 @@ protected:
     virtual void drawItems(QPainter *painter, int numItems,
                            QGraphicsItem *items[],
                            const QStyleOptionGraphicsItem options[],
-                           QWidget *widget = Q_NULLPTR);
+                           QWidget *widget = nullptr);
 
 protected Q_SLOTS:
     // ### Qt 6: make unconditional
diff --git a/src/widgets/graphicsview/qgraphicstransform.h b/src/widgets/graphicsview/qgraphicstransform.h
index 4c0535f419..b8455781c5 100644
--- a/src/widgets/graphicsview/qgraphicstransform.h
+++ b/src/widgets/graphicsview/qgraphicstransform.h
@@ -57,7 +57,7 @@ class Q_WIDGETS_EXPORT QGraphicsTransform : public QObject
 {
     Q_OBJECT
 public:
-    QGraphicsTransform(QObject *parent = Q_NULLPTR);
+    QGraphicsTransform(QObject *parent = nullptr);
     ~QGraphicsTransform();
 
     virtual void applyTo(QMatrix4x4 *matrix) const = 0;
@@ -85,7 +85,7 @@ class Q_WIDGETS_EXPORT QGraphicsScale : public QGraphicsTransform
     Q_PROPERTY(qreal yScale READ yScale WRITE setYScale NOTIFY yScaleChanged)
     Q_PROPERTY(qreal zScale READ zScale WRITE setZScale NOTIFY zScaleChanged)
 public:
-    QGraphicsScale(QObject *parent = Q_NULLPTR);
+    QGraphicsScale(QObject *parent = nullptr);
     ~QGraphicsScale();
 
     QVector3D origin() const;
@@ -123,7 +123,7 @@ class Q_WIDGETS_EXPORT QGraphicsRotation : public QGraphicsTransform
     Q_PROPERTY(qreal angle READ angle WRITE setAngle NOTIFY angleChanged)
     Q_PROPERTY(QVector3D axis READ axis WRITE setAxis NOTIFY axisChanged)
 public:
-    QGraphicsRotation(QObject *parent = Q_NULLPTR);
+    QGraphicsRotation(QObject *parent = nullptr);
     ~QGraphicsRotation();
 
     QVector3D origin() const;
diff --git a/src/widgets/graphicsview/qgraphicsview.h b/src/widgets/graphicsview/qgraphicsview.h
index 20273ad068..e02fba69c9 100644
--- a/src/widgets/graphicsview/qgraphicsview.h
+++ b/src/widgets/graphicsview/qgraphicsview.h
@@ -114,8 +114,8 @@ public:
     };
     Q_DECLARE_FLAGS(OptimizationFlags, OptimizationFlag)
 
-    QGraphicsView(QWidget *parent = Q_NULLPTR);
-    QGraphicsView(QGraphicsScene *scene, QWidget *parent = Q_NULLPTR);
+    QGraphicsView(QWidget *parent = nullptr);
+    QGraphicsView(QGraphicsScene *scene, QWidget *parent = nullptr);
     ~QGraphicsView();
 
     QSize sizeHint() const override;
@@ -236,7 +236,7 @@ protected Q_SLOTS:
     void setupViewport(QWidget *widget) override;
 
 protected:
-    QGraphicsView(QGraphicsViewPrivate &, QWidget *parent = Q_NULLPTR);
+    QGraphicsView(QGraphicsViewPrivate &, QWidget *parent = nullptr);
     bool event(QEvent *event) override;
     bool viewportEvent(QEvent *event) override;
 
diff --git a/src/widgets/graphicsview/qgraphicswidget.cpp b/src/widgets/graphicsview/qgraphicswidget.cpp
index c658e40a9e..4108dd803a 100644
--- a/src/widgets/graphicsview/qgraphicswidget.cpp
+++ b/src/widgets/graphicsview/qgraphicswidget.cpp
@@ -276,7 +276,7 @@ QGraphicsWidget::~QGraphicsWidget()
     // Unset the parent here, when we're still a QGraphicsWidget.
     // It is otherwise done in ~QGraphicsItem() where we'd be
     // calling QGraphicsWidget members on an ex-QGraphicsWidget object
-    setParentItem(Q_NULLPTR);
+    setParentItem(nullptr);
 }
 
 /*!
diff --git a/src/widgets/graphicsview/qgraphicswidget.h b/src/widgets/graphicsview/qgraphicswidget.h
index f71e2f8149..481fb55db3 100644
--- a/src/widgets/graphicsview/qgraphicswidget.h
+++ b/src/widgets/graphicsview/qgraphicswidget.h
@@ -80,7 +80,7 @@ class Q_WIDGETS_EXPORT QGraphicsWidget : public QGraphicsObject, public QGraphic
     Q_PROPERTY(bool autoFillBackground READ autoFillBackground WRITE setAutoFillBackground)
     Q_PROPERTY(QGraphicsLayout* layout READ layout WRITE setLayout NOTIFY layoutChanged)
 public:
-    QGraphicsWidget(QGraphicsItem *parent = Q_NULLPTR, Qt::WindowFlags wFlags = Qt::WindowFlags());
+    QGraphicsWidget(QGraphicsItem *parent = nullptr, Qt::WindowFlags wFlags = Qt::WindowFlags());
     ~QGraphicsWidget();
     QGraphicsLayout *layout() const;
     void setLayout(QGraphicsLayout *layout);
@@ -163,8 +163,8 @@ public:
     };
     int type() const override;
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR) override;
-    virtual void paintWindowFrame(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = Q_NULLPTR);
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
+    virtual void paintWindowFrame(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr);
     QRectF boundingRect() const override;
     QPainterPath shape() const override;
 
diff --git a/src/widgets/itemviews/qabstractitemdelegate.h b/src/widgets/itemviews/qabstractitemdelegate.h
index 9b6bde1c87..575728e806 100644
--- a/src/widgets/itemviews/qabstractitemdelegate.h
+++ b/src/widgets/itemviews/qabstractitemdelegate.h
@@ -69,7 +69,7 @@ public:
         RevertModelCache
     };
 
-    explicit QAbstractItemDelegate(QObject *parent = Q_NULLPTR);
+    explicit QAbstractItemDelegate(QObject *parent = nullptr);
     virtual ~QAbstractItemDelegate();
 
     // painting
@@ -119,7 +119,7 @@ Q_SIGNALS:
     void sizeHintChanged(const QModelIndex &);
 
 protected:
-    QAbstractItemDelegate(QObjectPrivate &, QObject *parent = Q_NULLPTR);
+    QAbstractItemDelegate(QObjectPrivate &, QObject *parent = nullptr);
 private:
     Q_DECLARE_PRIVATE(QAbstractItemDelegate)
     Q_DISABLE_COPY(QAbstractItemDelegate)
diff --git a/src/widgets/itemviews/qabstractitemview.h b/src/widgets/itemviews/qabstractitemview.h
index 676b6cb21e..96745a84ea 100644
--- a/src/widgets/itemviews/qabstractitemview.h
+++ b/src/widgets/itemviews/qabstractitemview.h
@@ -124,7 +124,7 @@ public:
     };
     Q_ENUM(ScrollMode)
 
-    explicit QAbstractItemView(QWidget *parent = Q_NULLPTR);
+    explicit QAbstractItemView(QWidget *parent = nullptr);
     ~QAbstractItemView();
 
     virtual void setModel(QAbstractItemModel *model);
@@ -270,7 +270,7 @@ Q_SIGNALS:
     void iconSizeChanged(const QSize &size);
 
 protected:
-    QAbstractItemView(QAbstractItemViewPrivate &, QWidget *parent = Q_NULLPTR);
+    QAbstractItemView(QAbstractItemViewPrivate &, QWidget *parent = nullptr);
 
     void setHorizontalStepsPerItem(int steps);
     int horizontalStepsPerItem() const;
@@ -295,7 +295,7 @@ protected:
     virtual bool edit(const QModelIndex &index, EditTrigger trigger, QEvent *event);
 
     virtual QItemSelectionModel::SelectionFlags selectionCommand(const QModelIndex &index,
-                                                                 const QEvent *event = Q_NULLPTR) const;
+                                                                 const QEvent *event = nullptr) const;
 
 #ifndef QT_NO_DRAGANDDROP
     virtual void startDrag(Qt::DropActions supportedActions);
diff --git a/src/widgets/itemviews/qcolumnview.h b/src/widgets/itemviews/qcolumnview.h
index 4f34406b21..5c62f9c9af 100644
--- a/src/widgets/itemviews/qcolumnview.h
+++ b/src/widgets/itemviews/qcolumnview.h
@@ -58,7 +58,7 @@ Q_SIGNALS:
     void updatePreviewWidget(const QModelIndex &index);
 
 public:
-    explicit QColumnView(QWidget *parent = Q_NULLPTR);
+    explicit QColumnView(QWidget *parent = nullptr);
     ~QColumnView();
 
     // QAbstractItemView overloads
@@ -82,7 +82,7 @@ public:
     QList<int> columnWidths() const;
 
 protected:
-    QColumnView(QColumnViewPrivate &dd, QWidget *parent = Q_NULLPTR);
+    QColumnView(QColumnViewPrivate &dd, QWidget *parent = nullptr);
 
     // QAbstractItemView overloads
     bool isIndexHidden(const QModelIndex &index) const override;
diff --git a/src/widgets/itemviews/qdatawidgetmapper.h b/src/widgets/itemviews/qdatawidgetmapper.h
index 7d4d61378a..2d75b63a5e 100644
--- a/src/widgets/itemviews/qdatawidgetmapper.h
+++ b/src/widgets/itemviews/qdatawidgetmapper.h
@@ -61,7 +61,7 @@ class Q_WIDGETS_EXPORT QDataWidgetMapper: public QObject
     Q_PROPERTY(SubmitPolicy submitPolicy READ submitPolicy WRITE setSubmitPolicy)
 
 public:
-    explicit QDataWidgetMapper(QObject *parent = Q_NULLPTR);
+    explicit QDataWidgetMapper(QObject *parent = nullptr);
     ~QDataWidgetMapper();
 
     void setModel(QAbstractItemModel *model);
diff --git a/src/widgets/itemviews/qdirmodel.h b/src/widgets/itemviews/qdirmodel.h
index 30486c2e67..ab91bbd763 100644
--- a/src/widgets/itemviews/qdirmodel.h
+++ b/src/widgets/itemviews/qdirmodel.h
@@ -66,8 +66,8 @@ public:
     };
 
     QDirModel(const QStringList &nameFilters, QDir::Filters filters,
-              QDir::SortFlags sort, QObject *parent = Q_NULLPTR);
-    explicit QDirModel(QObject *parent = Q_NULLPTR);
+              QDir::SortFlags sort, QObject *parent = nullptr);
+    explicit QDirModel(QObject *parent = nullptr);
     ~QDirModel();
 
     QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
@@ -133,7 +133,7 @@ public Q_SLOTS:
     void refresh(const QModelIndex &parent = QModelIndex());
 
 protected:
-    QDirModel(QDirModelPrivate &, QObject *parent = Q_NULLPTR);
+    QDirModel(QDirModelPrivate &, QObject *parent = nullptr);
     friend class QFileDialogPrivate;
 
 private:
diff --git a/src/widgets/itemviews/qheaderview.h b/src/widgets/itemviews/qheaderview.h
index 91217a69a3..b6554c0730 100644
--- a/src/widgets/itemviews/qheaderview.h
+++ b/src/widgets/itemviews/qheaderview.h
@@ -74,7 +74,7 @@ public:
     };
     Q_ENUM(ResizeMode)
 
-    explicit QHeaderView(Qt::Orientation orientation, QWidget *parent = Q_NULLPTR);
+    explicit QHeaderView(Qt::Orientation orientation, QWidget *parent = nullptr);
     virtual ~QHeaderView();
 
     void setModel(QAbstractItemModel *model) override;
@@ -208,7 +208,7 @@ protected Q_SLOTS:
     void sectionsAboutToBeRemoved(const QModelIndex &parent, int logicalFirst, int logicalLast);
 
 protected:
-    QHeaderView(QHeaderViewPrivate &dd, Qt::Orientation orientation, QWidget *parent = Q_NULLPTR);
+    QHeaderView(QHeaderViewPrivate &dd, Qt::Orientation orientation, QWidget *parent = nullptr);
     void initialize();
 
     void initializeSections();
diff --git a/src/widgets/itemviews/qitemdelegate.h b/src/widgets/itemviews/qitemdelegate.h
index d15e15b5e4..539dec4374 100644
--- a/src/widgets/itemviews/qitemdelegate.h
+++ b/src/widgets/itemviews/qitemdelegate.h
@@ -59,7 +59,7 @@ class Q_WIDGETS_EXPORT QItemDelegate : public QAbstractItemDelegate
     Q_PROPERTY(bool clipping READ hasClipping WRITE setClipping)
 
 public:
-    explicit QItemDelegate(QObject *parent = Q_NULLPTR);
+    explicit QItemDelegate(QObject *parent = nullptr);
     ~QItemDelegate();
 
     bool hasClipping() const;
diff --git a/src/widgets/itemviews/qlistview.h b/src/widgets/itemviews/qlistview.h
index 1a59b7b54a..2da510facf 100644
--- a/src/widgets/itemviews/qlistview.h
+++ b/src/widgets/itemviews/qlistview.h
@@ -78,7 +78,7 @@ public:
     enum ViewMode { ListMode, IconMode };
     Q_ENUM(ViewMode)
 
-    explicit QListView(QWidget *parent = Q_NULLPTR);
+    explicit QListView(QWidget *parent = nullptr);
     ~QListView();
 
     void setMovement(Movement movement);
@@ -137,7 +137,7 @@ Q_SIGNALS:
     void indexesMoved(const QModelIndexList &indexes);
 
 protected:
-    QListView(QListViewPrivate &, QWidget *parent = Q_NULLPTR);
+    QListView(QListViewPrivate &, QWidget *parent = nullptr);
 
     bool event(QEvent *e) override;
 
diff --git a/src/widgets/itemviews/qlistwidget.h b/src/widgets/itemviews/qlistwidget.h
index 4fa542c8b8..3caa5ce6f2 100644
--- a/src/widgets/itemviews/qlistwidget.h
+++ b/src/widgets/itemviews/qlistwidget.h
@@ -61,10 +61,10 @@ class Q_WIDGETS_EXPORT QListWidgetItem
     friend class QListWidget;
 public:
     enum ItemType { Type = 0, UserType = 1000 };
-    explicit QListWidgetItem(QListWidget *view = Q_NULLPTR, int type = Type);
-    explicit QListWidgetItem(const QString &text, QListWidget *view = Q_NULLPTR, int type = Type);
+    explicit QListWidgetItem(QListWidget *view = nullptr, int type = Type);
+    explicit QListWidgetItem(const QString &text, QListWidget *view = nullptr, int type = Type);
     explicit QListWidgetItem(const QIcon &icon, const QString &text,
-                             QListWidget *view = Q_NULLPTR, int type = Type);
+                             QListWidget *view = nullptr, int type = Type);
     QListWidgetItem(const QListWidgetItem &other);
     virtual ~QListWidgetItem();
 
@@ -204,7 +204,7 @@ class Q_WIDGETS_EXPORT QListWidget : public QListView
     friend class QListWidgetItem;
     friend class QListModel;
 public:
-    explicit QListWidget(QWidget *parent = Q_NULLPTR);
+    explicit QListWidget(QWidget *parent = nullptr);
     ~QListWidget();
 
     void setSelectionModel(QItemSelectionModel *selectionModel) override;
@@ -322,7 +322,7 @@ private:
 };
 
 inline void QListWidget::removeItemWidget(QListWidgetItem *aItem)
-{ setItemWidget(aItem, Q_NULLPTR); }
+{ setItemWidget(aItem, nullptr); }
 
 inline void QListWidget::addItem(QListWidgetItem *aitem)
 { insertItem(count(), aitem); }
diff --git a/src/widgets/itemviews/qstyleditemdelegate.h b/src/widgets/itemviews/qstyleditemdelegate.h
index 7fd07b8a59..2df2450f07 100644
--- a/src/widgets/itemviews/qstyleditemdelegate.h
+++ b/src/widgets/itemviews/qstyleditemdelegate.h
@@ -58,7 +58,7 @@ class Q_WIDGETS_EXPORT QStyledItemDelegate : public QAbstractItemDelegate
     Q_OBJECT
 
 public:
-    explicit QStyledItemDelegate(QObject *parent = Q_NULLPTR);
+    explicit QStyledItemDelegate(QObject *parent = nullptr);
     ~QStyledItemDelegate();
 
     // painting
diff --git a/src/widgets/itemviews/qtableview.h b/src/