Add tracepoint to qt_message_print

This allows us to deduce a lot about what a Qt application is doing,
since the debug output usually contains a lot of information.

Change-Id: I28a18afd151a1640a44ba8c7c9cd87d5d66c99b0
Reviewed-by: Christoph Sterz <christoph.sterz@kdab.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

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()) {

src/corelib/qtcore.tracepoints

@@ -38,3 +38,5 @@ 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)