Support for LTTNG and ETW tracing

This commit introduces minimal support for instrumentation within Qt.
Currently, only LTTNG/Linux and ETW/Windows are supported.

Change-Id: I59b48cf83acf5532a998bb493e6379e9177e14c8
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

4 files changed, 31 insertions, 0 deletions

diff --git a/src/gui/gui.pro b/src/gui/gui.pro
index f8cec00b82..759d6f3cbf 100644
--- a/src/gui/gui.pro
+++ b/src/gui/gui.pro
@@ -95,3 +95,6 @@ qtConfig(angle) {
 qtConfig(egl): CMAKE_EGL_INCDIRS = $$cmakePortablePaths($$QMAKE_INCDIR_EGL)
 
 QMAKE_DYNAMIC_LIST_FILE = $$PWD/QtGui.dynlist
+
+TRACEPOINT_PROVIDER = $$PWD/qtgui.tracepoints
+CONFIG += qt_tracepoints
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 3d85f47f34..70b4869442 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -111,6 +111,8 @@
 #  include <QtCore/QLibraryInfo>
 #endif // Q_OS_WIN
 
+#include <qtgui_tracepoints_p.h>
+
 #include <ctype.h>
 
 QT_BEGIN_NAMESPACE
@@ -1360,6 +1362,8 @@ void QGuiApplicationPrivate::eventDispatcherReady()
 
 void QGuiApplicationPrivate::init()
 {
+    Q_TRACE(qguiapplicationprivate_init_entry);
+
 #if defined(Q_OS_MACOS)
     QMacAutoReleasePool pool;
 #endif
@@ -1522,6 +1526,8 @@ void QGuiApplicationPrivate::init()
     if (!QGuiApplicationPrivate::displayName)
         QObject::connect(q, &QGuiApplication::applicationNameChanged,
                          q, &QGuiApplication::applicationDisplayNameChanged);
+
+    Q_TRACE(qguiapplicationprivate_init_exit);
 }
 
 extern void qt_cleanupFontDatabase();
@@ -1756,6 +1762,8 @@ bool QGuiApplicationPrivate::processNativeEvent(QWindow *window, const QByteArra
 
 void QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent *e)
 {
+    Q_TRACE(qguiapplicationprivate_processwsevents_entry, e->type);
+
     switch(e->type) {
     case QWindowSystemInterfacePrivate::Mouse:
         QGuiApplicationPrivate::processMouseEvent(static_cast<QWindowSystemInterfacePrivate::MouseEvent *>(e));
@@ -1864,6 +1872,8 @@ void QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePriv
         qWarning() << "Unknown user input event type:" << e->type;
         break;
     }
+
+    Q_TRACE(qguiapplicationprivate_processwsevents_exit, e->type);
 }
 
 /*! \internal
diff --git a/src/gui/qtgui.tracepoints b/src/gui/qtgui.tracepoints
new file mode 100644
index 0000000000..aa8a8ede57
--- /dev/null
+++ b/src/gui/qtgui.tracepoints
@@ -0,0 +1,8 @@
+qfontdatabase_addapplicationfont(const QString &filename)
+qfontdatabase_load(const QString &family, int pointSize)
+qfontdatabase_loadengine(const QString &family, int pointSize)
+qfontdatabaseprivate_addappfont(const QString &fileName)
+qguiapplicationprivate_init_entry()
+qguiapplicationprivate_init_exit()
+qguiapplicationprivate_processwsevents_entry(int type)
+qguiapplicationprivate_processwsevents_exit(int type)
diff --git a/src/gui/text/qfontdatabase.cpp b/src/gui/text/qfontdatabase.cpp
index 4be2197c68..404a722e29 100644
--- a/src/gui/text/qfontdatabase.cpp
+++ b/src/gui/text/qfontdatabase.cpp
@@ -74,6 +74,7 @@
 #  define FM_DEBUG if (false) qDebug
 #endif
 
+#include <qtgui_tracepoints_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -1009,6 +1010,8 @@ QFontEngine *loadEngine(int script, const QFontDef &request,
     QFontEngine *engine = loadSingleEngine(script, request, family, foundry, style, size);
 
     if (engine && !(request.styleStrategy & QFont::NoFontMerging) && !engine->symbol) {
+        Q_TRACE(qfontdatabase_loadengine, request.family, request.pointSize);
+
         QPlatformFontDatabase *pfdb = QGuiApplicationPrivate::platformIntegration()->fontDatabase();
         QFontEngineMulti *pfMultiEngine = pfdb->fontEngineMulti(engine, QChar::Script(script));
         if (!request.fallBackFamilies.isEmpty()) {
@@ -2439,6 +2442,8 @@ int QFontDatabasePrivate::addAppFont(const QByteArray &fontData, const QString &
     font.data = fontData;
     font.fileName = fileName;
 
+    Q_TRACE(qfontdatabaseprivate_addappfont, fileName);
+
     int i;
     for (i = 0; i < applicationFonts.count(); ++i)
         if (applicationFonts.at(i).families.isEmpty())
@@ -2494,6 +2499,9 @@ int QFontDatabase::addApplicationFont(const QString &fileName)
         QFile f(fileName);
         if (!f.open(QIODevice::ReadOnly))
             return -1;
+
+        Q_TRACE(qfontdatabase_addapplicationfont, fileName);
+
         data = f.readAll();
     }
     QMutexLocker locker(fontDatabaseMutex());
@@ -2792,6 +2800,8 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
 
     QFontEngine *fe = nullptr;
 
+    Q_TRACE(qfontdatabase_load, req.family, req.pointSize);
+
     req.fallBackFamilies = fallBackFamilies;
     if (!req.fallBackFamilies.isEmpty())
         req.family = req.fallBackFamilies.takeFirst();