Merge remote-tracking branch 'origin/5.12' into 5.13

Change-Id: Iec860bb703f983b7438e67c695b9c454e72b3e0f

17 files changed, 167 insertions, 71 deletions

diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp
index b2093101fa..ece97077c1 100644
--- a/src/corelib/global/qlogging.cpp
+++ b/src/corelib/global/qlogging.cpp
@@ -57,6 +57,7 @@
 #include "private/qloggingregistry_p.h"
 #include "private/qcoreapplication_p.h"
 #include "private/qsimd_p.h"
+#include <qtcore_tracepoints_p.h>
 #endif
 #ifdef Q_OS_WIN
 #include <qt_windows.h>
@@ -1811,6 +1812,8 @@ static void ungrabMessageHandler() { }
 static void qt_message_print(QtMsgType msgType, const QMessageLogContext &context, const QString &message)
 {
 #ifndef QT_BOOTSTRAPPED
+    Q_TRACE(qt_message_print, msgType, context.category, context.function, context.file, context.line, message);
+
     // qDebug, qWarning, ... macros do not check whether category is enabled
     if (isDefaultCategory(context.category)) {
         if (QLoggingCategory *defaultCategory = QLoggingCategory::defaultCategory()) {
diff --git a/src/corelib/global/qtrace_p.h b/src/corelib/global/qtrace_p.h
index 3d04a7311d..20f2beac98 100644
--- a/src/corelib/global/qtrace_p.h
+++ b/src/corelib/global/qtrace_p.h
@@ -52,11 +52,18 @@
 //
 
 /*
- * The Qt tracepoints API consists of only three macros:
+ * The Qt tracepoints API consists of only five macros:
  *
  *     - Q_TRACE(tracepoint, args...)
  *       Fires 'tracepoint' if it is enabled.
  *
+ *     - Q_TRACE_EXIT(tracepoint, args...)
+ *       Fires 'tracepoint' if it is enabled when the current scope exists.
+ *
+ *     - Q_TRACE_SCOPE(tracepoint, args...)
+ *       Wrapper around Q_TRACE/_EXIT to trace entry and exit. First it traces
+ *       `${tracepoint}_entry` and then `${tracepoint}_exit` on scope exit.
+ *
  *     - Q_UNCONDITIONAL_TRACE(tracepoint, args...)
  *       Fires 'tracepoint' unconditionally: no check is performed to query
  *       whether 'tracepoint' is enabled.
@@ -110,15 +117,23 @@
  */
 
 #include <QtCore/qglobal.h>
+#include <QtCore/qscopeguard.h>
 
 QT_BEGIN_NAMESPACE
 
 #if defined(Q_TRACEPOINT) && !defined(QT_BOOTSTRAPPED)
 #  define Q_TRACE(x, ...) QtPrivate::trace_ ## x(__VA_ARGS__)
+#  define Q_TRACE_EXIT(x, ...) \
+    const auto qTraceExit_ ## x ## __COUNTER__ = qScopeGuard([&]() { Q_TRACE(x, __VA_ARGS__); });
+#  define Q_TRACE_SCOPE(x, ...) \
+    Q_TRACE(x ## _entry, __VA_ARGS__); \
+    Q_TRACE_EXIT(x ## _exit, __VA_ARGS__);
 #  define Q_UNCONDITIONAL_TRACE(x, ...) QtPrivate::do_trace_ ## x(__VA_ARGS__)
 #  define Q_TRACE_ENABLED(x) QtPrivate::trace_ ## x ## _enabled()
 #else
 #  define Q_TRACE(x, ...)
+#  define Q_TRACE_EXIT(x, ...)
+#  define Q_TRACE_SCOPE(x, ...)
 #  define Q_UNCONDITIONAL_TRACE(x, ...)
 #  define Q_TRACE_ENABLED(x) false
 #endif // defined(Q_TRACEPOINT) && !defined(QT_BOOTSTRAPPED)
diff --git a/src/corelib/io/qstandardpaths_win.cpp b/src/corelib/io/qstandardpaths_win.cpp
index 1809861fc6..c2c3b2702b 100644
--- a/src/corelib/io/qstandardpaths_win.cpp
+++ b/src/corelib/io/qstandardpaths_win.cpp
@@ -86,15 +86,6 @@ static void appendOrganizationAndApp(QString &path) // Courtesy qstandardpaths_u
 #endif
 }
 
-static inline QString displayName(QStandardPaths::StandardLocation type)
-{
-#ifndef QT_BOOTSTRAPPED
-    return QStandardPaths::displayName(type);
-#else
-    return QString::number(type);
-#endif
-}
-
 static inline void appendTestMode(QString &path)
 {
     if (QStandardPaths::isTestModeEnabled())
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 2250f91dc3..30994d3056 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -778,7 +778,7 @@ QCoreApplication::QCoreApplication(int &argc, char **argv
 
 void QCoreApplicationPrivate::init()
 {
-    Q_TRACE(QCoreApplicationPrivate_init_entry);
+    Q_TRACE_SCOPE(QCoreApplicationPrivate_init);
 
 #if defined(Q_OS_MACOS)
     QMacAutoReleasePool pool;
@@ -883,8 +883,6 @@ void QCoreApplicationPrivate::init()
 #ifndef QT_NO_QOBJECT
     is_app_running = true; // No longer starting up.
 #endif
-
-    Q_TRACE(QCoreApplicationPrivate_init_exit);
 }
 
 /*!
@@ -1199,7 +1197,7 @@ bool QCoreApplicationPrivate::notify_helper(QObject *receiver, QEvent * event)
 {
     // Note: when adjusting the tracepoints in here
     // consider adjusting QApplicationPrivate::notify_helper too.
-    Q_TRACE(QCoreApplication_notify_entry, receiver, event, event->type());
+    Q_TRACE_SCOPE(QCoreApplication_notify, receiver, event, event->type());
 
     // send to all application event filters (only does anything in the main thread)
     if (QCoreApplication::self
@@ -1498,7 +1496,7 @@ bool QCoreApplication::sendSpontaneousEvent(QObject *receiver, QEvent *event)
 */
 void QCoreApplication::postEvent(QObject *receiver, QEvent *event, int priority)
 {
-    Q_TRACE(QCoreApplication_postEvent_entry, receiver, event, event->type());
+    Q_TRACE_SCOPE(QCoreApplication_postEvent, receiver, event, event->type());
 
     if (receiver == 0) {
         qWarning("QCoreApplication::postEvent: Unexpected null receiver");
diff --git a/src/corelib/qtcore.tracepoints b/src/corelib/qtcore.tracepoints
index 33734a4274..3a70136741 100644
--- a/src/corelib/qtcore.tracepoints
+++ b/src/corelib/qtcore.tracepoints
@@ -1,3 +1,9 @@
+{
+QT_BEGIN_NAMESPACE
+class QEvent;
+QT_END_NAMESPACE
+}
+
 QCoreApplicationPrivate_init_entry()
 QCoreApplicationPrivate_init_exit()
 
@@ -10,6 +16,7 @@ QEvent_ctor(QEvent *event, int type)
 QEvent_dtor(QEvent *event, int type)
 
 QCoreApplication_postEvent_entry(QObject *receiver, QEvent *event, int type)
+QCoreApplication_postEvent_exit(QObject *receiver, QEvent *event, int type)
 QCoreApplication_postEvent_event_compressed(QObject *receiver, QEvent *event)
 QCoreApplication_postEvent_event_posted(QObject *receiver, QEvent *event, int type)
 
@@ -17,6 +24,7 @@ QCoreApplication_sendEvent(QObject *receiver, QEvent *event, int type)
 QCoreApplication_sendSpontaneousEvent(QObject *receiver, QEvent *event, int type)
 
 QCoreApplication_notify_entry(QObject *receiver, QEvent *event, int type)
+QCoreApplication_notify_exit(QObject *receiver, QEvent *event, int type)
 QCoreApplication_notify_event_filtered(QObject *receiver, QEvent *event, int type)
 QCoreApplication_notify_before_delivery(QObject *receiver, QEvent *event, int type)
 QCoreApplication_notify_after_delivery(QObject *receiver, QEvent *event, int type, bool consumed)
@@ -32,3 +40,5 @@ QMetaObject_activate_begin_slot_functor(void *slotObject)
 QMetaObject_activate_end_slot_functor(void *slotObject)
 QMetaObject_activate_begin_declarative_signal(QObject *sender, int signalIndex)
 QMetaObject_activate_end_declarative_signal(QObject *sender, int signalIndex)
+
+qt_message_print(int type, const char *category, const char *function, const char *file, int line, const QString &message)
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 9d6e0cbdd8..a123aa8e75 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -501,7 +501,11 @@ bool qt_is_ascii(const char *&ptr, const char *end) Q_DECL_NOTHROW
     while (ptr + 4 <= end) {
         quint32 data = qFromUnaligned<quint32>(ptr);
         if (data &= 0x80808080U) {
+#if Q_BYTE_ORDER == Q_BIG_ENDIAN
+            uint idx = qCountLeadingZeroBits(data);
+#else
             uint idx = qCountTrailingZeroBits(data);
+#endif
             ptr += idx / 8;
             return false;
         }
diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp
index 140196004b..1c269213e2 100644
--- a/src/gui/image/qpnghandler.cpp
+++ b/src/gui/image/qpnghandler.cpp
@@ -231,8 +231,8 @@ void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scal
     if (screen_gamma != 0.0 && file_gamma != 0.0)
         png_set_gamma(png_ptr, 1.0f / screen_gamma, file_gamma);
 
-    png_uint_32 width;
-    png_uint_32 height;
+    png_uint_32 width = 0;
+    png_uint_32 height = 0;
     int bit_depth = 0;
     int color_type = 0;
     png_bytep trans_alpha = 0;
@@ -240,7 +240,7 @@ void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scal
     int num_trans;
     png_colorp palette = 0;
     int num_palette;
-    int interlace_method;
+    int interlace_method = PNG_INTERLACE_LAST;
     png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_method, 0, 0);
     png_set_interlace_handling(png_ptr);
 
@@ -689,7 +689,7 @@ bool QPngHandlerPrivate::readPngImage(QImage *outImage)
 QImage::Format QPngHandlerPrivate::readImageFormat()
 {
         QImage::Format format = QImage::Format_Invalid;
-        png_uint_32 width, height;
+        png_uint_32 width = 0, height = 0;
         int bit_depth = 0, color_type = 0;
         png_colorp palette;
         int num_palette;
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 4e0c45d8ae..3a93b09941 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1425,7 +1425,7 @@ void QGuiApplicationPrivate::eventDispatcherReady()
 
 void QGuiApplicationPrivate::init()
 {
-    Q_TRACE(QGuiApplicationPrivate_init_entry);
+    Q_TRACE_SCOPE(QGuiApplicationPrivate_init);
 
 #if defined(Q_OS_MACOS)
     QMacAutoReleasePool pool;
@@ -1589,8 +1589,6 @@ void QGuiApplicationPrivate::init()
     if (!QGuiApplicationPrivate::displayName)
         QObject::connect(q, &QGuiApplication::applicationNameChanged,
                          q, &QGuiApplication::applicationDisplayNameChanged);
-
-    Q_TRACE(QGuiApplicationPrivate_init_exit);
 }
 
 extern void qt_cleanupFontDatabase();
@@ -1834,7 +1832,7 @@ bool QGuiApplicationPrivate::processNativeEvent(QWindow *window, const QByteArra
 
 void QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent *e)
 {
-    Q_TRACE(QGuiApplicationPrivate_processWindowSystemEvent_entry, e->type);
+    Q_TRACE_SCOPE(QGuiApplicationPrivate_processWindowSystemEvent, e->type);
 
     switch(e->type) {
     case QWindowSystemInterfacePrivate::Mouse:
@@ -1944,8 +1942,6 @@ void QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePriv
         qWarning() << "Unknown user input event type:" << e->type;
         break;
     }
-
-    Q_TRACE(QGuiApplicationPrivate_processWindowSystemEvent_exit, e->type);
 }
 
 /*! \internal
diff --git a/src/gui/painting/qbrush.cpp b/src/gui/painting/qbrush.cpp
index ed575abf54..f56be55325 100644
--- a/src/gui/painting/qbrush.cpp
+++ b/src/gui/painting/qbrush.cpp
@@ -1378,10 +1378,8 @@ QGradient::QGradient(Preset preset)
         }();
 
         const QJsonValue presetData = jsonPresets[preset - 1];
-        if (!presetData.isObject()) {
-            qWarning("QGradient: Undefined preset %i", preset);
+        if (!presetData.isObject())
             return;
-        }
 
         m_type = LinearGradient;
         setCoordinateMode(ObjectMode);
diff --git a/src/gui/qtgui.tracepoints b/src/gui/qtgui.tracepoints
index aed6c35c03..0a96a589b1 100644
--- a/src/gui/qtgui.tracepoints
+++ b/src/gui/qtgui.tracepoints
@@ -1,3 +1,9 @@
+{
+QT_BEGIN_NAMESPACE
+class QImageReader;
+QT_END_NAMESPACE
+}
+
 QGuiApplicationPrivate_init_entry()
 QGuiApplicationPrivate_init_exit()
 
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index 1b17759b5f..ba441a1921 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -569,12 +569,10 @@ public:
 
     bool isFileSystem() const  { return (m_attributes & SFGAO_FILESYSTEM) != 0; }
     bool isDir() const         { return (m_attributes & SFGAO_FOLDER) != 0; }
-    // Copy using IFileOperation
-    bool canCopy() const       { return (m_attributes & SFGAO_CANCOPY) != 0; }
     // Supports IStream
     bool canStream() const     { return (m_attributes & SFGAO_STREAM) != 0; }
 
-    bool copyData(QIODevice *out);
+    bool copyData(QIODevice *out, QString *errorMessage);
 
     static IShellItems itemsFromItemArray(IShellItemArray *items);
 
@@ -666,14 +664,19 @@ QWindowsShellItem::IShellItems QWindowsShellItem::itemsFromItemArray(IShellItemA
     return result;
 }
 
-bool QWindowsShellItem::copyData(QIODevice *out)
+bool QWindowsShellItem::copyData(QIODevice *out, QString *errorMessage)
 {
-    if (!canCopy() || !canStream())
+    if (!canStream()) {
+        *errorMessage = QLatin1String("Item not streamable");
         return false;
+    }
     IStream *istream = nullptr;
     HRESULT hr = m_item->BindToHandler(nullptr, BHID_Stream, IID_PPV_ARGS(&istream));
-    if (FAILED(hr))
+    if (FAILED(hr)) {
+        *errorMessage = QLatin1String("BindToHandler() failed: ")
+                        + QLatin1String(QWindowsContext::comErrorString(hr));
         return false;
+    }
     enum : ULONG { bufSize = 102400 };
     char buffer[bufSize];
     ULONG bytesRead;
@@ -686,7 +689,12 @@ bool QWindowsShellItem::copyData(QIODevice *out)
             break;
     }
     istream->Release();
-    return hr == S_OK || hr == S_FALSE;
+    if (hr != S_OK && hr != S_FALSE) {
+        *errorMessage = QLatin1String("Read() failed: ")
+                        + QLatin1String(QWindowsContext::comErrorString(hr));
+        return false;
+    }
+    return true;
 }
 
 // Helper for "Libraries": collections of folders appearing from Windows 7
@@ -735,8 +743,6 @@ void QWindowsShellItem::format(QDebug &d) const
         d << " [dir]";
     if (canStream())
         d << " [stream]";
-    if (canCopy())
-        d << " [copyable]";
     d << ", normalDisplay=\"" << normalDisplay()
         << "\", desktopAbsoluteParsing=\"" << desktopAbsoluteParsing()
         << "\", urlString=\"" << urlString() << "\", fileSysPath=\"" << fileSysPath() << '"';
@@ -1395,21 +1401,50 @@ static void cleanupTemporaryItemCopies()
         QFile::remove(file);
 }
 
-static QString createTemporaryItemCopy(QWindowsShellItem &qItem)
+// Determine temporary file pattern from a shell item's display
+// name. This can be a URL.
+
+static bool validFileNameCharacter(QChar c)
 {
-    if (!qItem.canCopy() || !qItem.canStream())
+    return c.isLetterOrNumber() || c == QLatin1Char('_') || c == QLatin1Char('-');
+}
+
+QString tempFilePattern(QString name)
+{
+    const int lastSlash = qMax(name.lastIndexOf(QLatin1Char('/')),
+                               name.lastIndexOf(QLatin1Char('\\')));
+    if (lastSlash != -1)
+        name.remove(0, lastSlash + 1);
+
+    int lastDot = name.lastIndexOf(QLatin1Char('.'));
+    if (lastDot < 0)
+        lastDot = name.size();
+    name.insert(lastDot, QStringLiteral("_XXXXXX"));
+
+    for (int i = lastDot - 1; i >= 0; --i) {
+        if (!validFileNameCharacter(name.at(i)))
+            name[i] = QLatin1Char('_');
+    }
+
+    name.prepend(QDir::tempPath() + QLatin1Char('/'));
+    return name;
+}
+
+static QString createTemporaryItemCopy(QWindowsShellItem &qItem, QString *errorMessage)
+{
+    if (!qItem.canStream()) {
+        *errorMessage = QLatin1String("Item not streamable");
         return QString();
-    QString pattern = qItem.normalDisplay();
-    const int lastDot = pattern.lastIndexOf(QLatin1Char('.'));
-    const QString placeHolder = QStringLiteral("_XXXXXX");
-    if (lastDot >= 0)
-        pattern.insert(lastDot, placeHolder);
-    else
-        pattern.append(placeHolder);
-
-    QTemporaryFile targetFile(QDir::tempPath() + QLatin1Char('/') + pattern);
+    }
+
+    QTemporaryFile targetFile(tempFilePattern(qItem.normalDisplay()));
     targetFile.setAutoRemove(false);
-    if (!targetFile.open() || !qItem.copyData(&targetFile))
+    if (!targetFile.open())  {
+        *errorMessage = QLatin1String("Cannot create temporary file: ")
+                        + targetFile.errorString();
+        return QString();
+    }
+    if (!qItem.copyData(&targetFile, errorMessage))
         return QString();
     const QString result = targetFile.fileName();
     if (temporaryItemCopies()->isEmpty())
@@ -1427,11 +1462,14 @@ QList<QUrl> QWindowsNativeOpenFileDialog::dialogResult() const
             QWindowsShellItem qItem(item);
             const QString path = qItem.path();
             if (path.isEmpty() && !qItem.isDir()) {
-                const QString temporaryCopy = createTemporaryItemCopy(qItem);
-                if (temporaryCopy.isEmpty())
-                    qWarning() << "Unable to create a local copy of" << qItem;
-                else
+                QString errorMessage;
+                const QString temporaryCopy = createTemporaryItemCopy(qItem, &errorMessage);
+                if (temporaryCopy.isEmpty()) {
+                    qWarning().noquote() << "Unable to create a local copy of" << qItem
+                        << ": " << errorMessage;
+                } else {
                     result.append(QUrl::fromLocalFile(temporaryCopy));
+                }
             } else {
                 result.append(qItem.url());
             }
diff --git a/src/tools/tracegen/etw.cpp b/src/tools/tracegen/etw.cpp
index 8c065f93c9..e839137915 100644
--- a/src/tools/tracegen/etw.cpp
+++ b/src/tools/tracegen/etw.cpp
@@ -110,19 +110,21 @@ static QString createGuid(const QUuid &uuid)
     return guid;
 }
 
-static void writePrologue(QTextStream &stream, const QString &fileName, const QString &providerName)
+static void writePrologue(QTextStream &stream, const QString &fileName, const Provider &provider)
 {
-    QUuid uuid = QUuid::createUuidV5(QUuid(), providerName.toLocal8Bit());
+    QUuid uuid = QUuid::createUuidV5(QUuid(), provider.name.toLocal8Bit());
 
-    const QString provider = providerVar(providerName);
+    const QString providerV = providerVar(provider.name);
     const QString guard = includeGuard(fileName);
     const QString guid = createGuid(uuid);
     const QString guidString = uuid.toString();
 
     stream << "#ifndef " << guard << "\n"
            << "#define " << guard << "\n"
+           << "\n"
            << "#include <windows.h>\n"
-           << "#include <TraceLoggingProvider.h>\n";
+           << "#include <TraceLoggingProvider.h>\n"
+           << "\n";
 
     /* TraceLogging API macros cannot deal with UTF8
      * source files, so we work around it like this
@@ -132,30 +134,33 @@ static void writePrologue(QTextStream &stream, const QString &fileName, const QS
               "#define _TlgPragmaUtf8Begin\n"
               "#define _TlgPragmaUtf8End\n";
 
+    stream << "\n";
     stream << qtHeaders();
-
     stream << "\n";
 
+    if (!provider.prefixText.isEmpty())
+        stream << provider.prefixText.join(QLatin1Char('\n')) << "\n\n";
+
     stream << "#ifdef TRACEPOINT_DEFINE\n"
            << "/* " << guidString << " */\n"
-           << "TRACELOGGING_DEFINE_PROVIDER(" << provider << ", \""
-           << providerName <<"\", " << guid << ");\n\n";
+           << "TRACELOGGING_DEFINE_PROVIDER(" << providerV << ", \""
+           << provider.name <<"\", " << guid << ");\n\n";
 
     stream << "static inline void registerProvider()\n"
            << "{\n"
-           << "    TraceLoggingRegister(" << provider << ");\n"
+           << "    TraceLoggingRegister(" << providerV << ");\n"
            << "}\n\n";
 
     stream << "static inline void unregisterProvider()\n"
            << "{\n"
-           << "    TraceLoggingUnregister(" << provider << ");\n"
+           << "    TraceLoggingUnregister(" << providerV << ");\n"
            << "}\n";
 
     stream << "Q_CONSTRUCTOR_FUNCTION(registerProvider)\n"
            << "Q_DESTRUCTOR_FUNCTION(unregisterProvider)\n\n";
 
     stream << "#else\n"
-           << "TRACELOGGING_DECLARE_PROVIDER(" << provider << ");\n"
+           << "TRACELOGGING_DECLARE_PROVIDER(" << providerV << ");\n"
            << "#endif // TRACEPOINT_DEFINE\n\n";
 }
 
@@ -224,7 +229,7 @@ void writeEtw(QFile &file, const Provider &provider)
 
     const QString fileName = QFileInfo(file.fileName()).fileName();
 
-    writePrologue(stream, fileName, provider.name);
+    writePrologue(stream, fileName, provider);
     writeTracepoints(stream, provider);
     writeEpilogue(stream, fileName);
 }
diff --git a/src/tools/tracegen/lttng.cpp b/src/tools/tracegen/lttng.cpp
index 5d41bf5f1f..f0fbca9e16 100644
--- a/src/tools/tracegen/lttng.cpp
+++ b/src/tools/tracegen/lttng.cpp
@@ -104,16 +104,21 @@ static void writeCtfMacro(QTextStream &stream, const Tracepoint::Field &field)
     }
 }
 
-static void writePrologue(QTextStream &stream, const QString &fileName, const QString &providerName)
+static void writePrologue(QTextStream &stream, const QString &fileName, const Provider &provider)
 {
+    const QString guard = includeGuard(fileName);
+
     stream << "#undef TRACEPOINT_PROVIDER\n";
-    stream << "#define TRACEPOINT_PROVIDER " << providerName << "\n\n";
+    stream << "#define TRACEPOINT_PROVIDER " << provider.name << "\n";
+    stream << "\n";
 
+    // include prefix text or qt headers only once
+    stream << "#if !defined(" << guard << ")\n";
     stream << qtHeaders();
-
-    const QString guard = includeGuard(fileName);
-
     stream << "\n";
+    if (!provider.prefixText.isEmpty())
+        stream << provider.prefixText.join(QLatin1Char('\n')) << "\n\n";
+    stream << "#endif\n\n";
 
     /* the first guard is the usual one, the second is required
      * by LTTNG to force the re-evaluation of TRACEPOINT_* macros
@@ -213,7 +218,7 @@ void writeLttng(QFile &file, const Provider &provider)
 
     const QString fileName = QFileInfo(file.fileName()).fileName();
 
-    writePrologue(stream, fileName, provider.name);
+    writePrologue(stream, fileName, provider);
     writeTracepoints(stream, provider);
     writeEpilogue(stream, fileName);
 }
diff --git a/src/tools/tracegen/provider.cpp b/src/tools/tracegen/provider.cpp
index a6523a2e3d..39633efe5d 100644
--- a/src/tools/tracegen/provider.cpp
+++ b/src/tools/tracegen/provider.cpp
@@ -275,9 +275,21 @@ Provider parseProvider(const QString &filename)
     Provider provider;
     provider.name = QFileInfo(filename).baseName();
 
+    bool parsingPrefixText = false;
     for (int lineNumber = 1; !s.atEnd(); ++lineNumber) {
         QString line = s.readLine().trimmed();
 
+        if (line == QLatin1String("{")) {
+            parsingPrefixText = true;
+            continue;
+        } else if (parsingPrefixText && line == QLatin1String("}")) {
+            parsingPrefixText = false;
+            continue;
+        } else if (parsingPrefixText) {
+            provider.prefixText.append(line);
+            continue;
+        }
+
         if (line.isEmpty() || line.startsWith(QLatin1Char('#')))
             continue;
 
@@ -296,7 +308,14 @@ Provider parseProvider(const QString &filename)
         }
     }
 
+    if (parsingPrefixText) {
+        panic("Syntax error while processing '%s': "
+              "no closing brace found for prefix text block",
+              qPrintable(filename));
+    }
+
 #ifdef TRACEGEN_DEBUG
+    qDebug() << provider.prefixText;
     for (auto i = provider.tracepoints.constBegin(); i != provider.tracepoints.constEnd(); ++i)
         dumpTracepoint(*i);
 #endif
diff --git a/src/tools/tracegen/provider.h b/src/tools/tracegen/provider.h
index 9771e62f4d..9be0c33d89 100644
--- a/src/tools/tracegen/provider.h
+++ b/src/tools/tracegen/provider.h
@@ -86,6 +86,7 @@ struct Provider
 {
     QString name;
     QVector<Tracepoint> tracepoints;
+    QStringList prefixText;
 };
 
 Provider parseProvider(const QString &filename);
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index 7c44bfe39d..0ab9ed6ec2 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -3700,7 +3700,7 @@ bool QApplicationPrivate::notify_helper(QObject *receiver, QEvent * e)
     // to the ones in QCoreApplicationPrivate::notify_helper; the reason for their
     // duplication is because tracepoint symbols are not exported by QtCore.
     // If you adjust the tracepoints here, consider adjusting QCoreApplicationPrivate too.
-    Q_TRACE(QApplication_notify_entry, receiver, e, e->type());
+    Q_TRACE_SCOPE(QApplication_notify, receiver, e, e->type());
 
     // send to all application event filters
     if (threadRequiresCoreApplication()
diff --git a/src/widgets/qtwidgets.tracepoints b/src/widgets/qtwidgets.tracepoints
index 01a1383670..9c40cdb3e7 100644
--- a/src/widgets/qtwidgets.tracepoints
+++ b/src/widgets/qtwidgets.tracepoints
@@ -1,4 +1,11 @@
+{
+QT_BEGIN_NAMESPACE
+class QEvent;
+QT_END_NAMESPACE
+}
+
 QApplication_notify_entry(QObject *receiver, QEvent *event, int type)
+QApplication_notify_exit(QObject *receiver, QEvent *event, int type)
 QApplication_notify_event_filtered(QObject *receiver, QEvent *event, int type)
 QApplication_notify_before_delivery(QObject *receiver, QEvent *event, int type)
 QApplication_notify_after_delivery(QObject *receiver, QEvent *event, int type, bool consumed)