Qml Debugger: Enable debugging qml+cpp standalone applications

A new debugger engine, QmlCppEngine, is introduced, which wraps gdb
and qml engines into one. Alternatively, if using Windows, Cdb is used
instead of Gdb.

Most of the debugger ui switcher is now rewritten, and it is tailored
for the QML and CPP layout case, the only one supported anyway.

Reviewed-by: hjk

src/plugins/debugger/qml/qmlengine.cpp

@@ -105,6 +105,8 @@ QmlEngine::QmlEngine(const DebuggerStartParameters &startParameters)
     , m_ping(0)
     , m_adapter(new QmlAdapter(this))
     , m_addedAdapterToObjectPool(false)
+    , m_attachToRunningExternalApp(false)
+    , m_hasShutdown(false)
 {
     setObjectName(QLatin1String("QmlEngine"));
 }
@@ -113,6 +115,16 @@ QmlEngine::~QmlEngine()
 {
 }
 
+void QmlEngine::setAttachToRunningExternalApp(bool value)
+{
+    m_attachToRunningExternalApp = value;
+}
+
+void QmlEngine::pauseConnection()
+{
+    m_adapter->pauseConnection();
+}
+
 void QmlEngine::setupInferior()
 {
     QTC_ASSERT(state() == InferiorSetupRequested, qDebug() << state());
@@ -154,26 +166,71 @@ void QmlEngine::runEngine()
 {
     QTC_ASSERT(state() == EngineRunRequested, qDebug() << state());
 
-    // ### TODO for non-qmlproject apps, start in a different way
-    m_applicationLauncher.start(ProjectExplorer::ApplicationLauncher::Gui,
-                                startParameters().executable,
-                                startParameters().processArgs);
+    if (!m_attachToRunningExternalApp) {
+        m_applicationLauncher.start(ProjectExplorer::ApplicationLauncher::Gui,
+                                    startParameters().executable,
+                                    startParameters().processArgs);
+    }
 
     m_adapter->beginConnection();
     plugin()->showMessage(tr("QML Debugger connecting..."), StatusBar);
+}
 
-    // FIXME: refactor the UI
-    Debugger::DebuggerUISwitcher::instance()->setActiveLanguage("QML");
+void QmlEngine::shutdownInferiorAsSlave()
+{
+    resetLocation();
+
+    // This can be issued in almost any state. We assume, though,
+    // that at this point of time the inferior is not running anymore,
+    // even if stop notification were not issued or got lost.
+    if (state() == InferiorRunOk) {
+        setState(InferiorStopRequested);
+        setState(InferiorStopOk);
+    }
+    setState(InferiorShutdownRequested);
+    setState(InferiorShutdownOk);
+}
+
+void QmlEngine::shutdownEngineAsSlave()
+{
+    if (m_hasShutdown)
+        return;
+
+    disconnect(m_adapter, SIGNAL(connectionStartupFailed()), this, SLOT(connectionStartupFailed()));
+    m_adapter->closeConnection();
+
+    if (m_addedAdapterToObjectPool) {
+        ExtensionSystem::PluginManager *pluginManager = ExtensionSystem::PluginManager::instance();
+        pluginManager->removeObject(m_adapter);
+    }
+
+    if (m_attachToRunningExternalApp) {
+        setState(EngineShutdownRequested, true);
+        setState(EngineShutdownOk, true);
+        setState(DebuggerFinished, true);
+    } else {
+        if (m_applicationLauncher.isRunning()) {
+            // should only happen if engine is ill
+            disconnect(&m_applicationLauncher, SIGNAL(processExited(int)), this, SLOT(disconnected()));
+            m_applicationLauncher.stop();
+        }
+    }
+    m_hasShutdown = true;
 }
 
 void QmlEngine::shutdownInferior()
 {
+    // don't do normal shutdown if running as slave engine
+    if (m_attachToRunningExternalApp)
+        return;
+
     QTC_ASSERT(state() == InferiorShutdownRequested, qDebug() << state());
     if (!m_applicationLauncher.isRunning()) {
         showMessage(tr("Trying to stop while process is no longer running."), LogError);
     } else {
         disconnect(&m_applicationLauncher, SIGNAL(processExited(int)), this, SLOT(disconnected()));
-        m_applicationLauncher.stop();
+        if (!m_attachToRunningExternalApp)
+            m_applicationLauncher.stop();
     }
     notifyInferiorShutdownOk();
 }
@@ -182,16 +239,7 @@ void QmlEngine::shutdownEngine()
 {
     QTC_ASSERT(state() == EngineShutdownRequested, qDebug() << state());
 
-    if (m_addedAdapterToObjectPool) {
-        ExtensionSystem::PluginManager *pluginManager = ExtensionSystem::PluginManager::instance();
-        pluginManager->removeObject(m_adapter);
-    }
-
-    if (m_applicationLauncher.isRunning()) {
-        // should only happen if engine is ill
-        disconnect(&m_applicationLauncher, SIGNAL(processExited(int)), this, SLOT(disconnected()));
-        m_applicationLauncher.stop();
-    }
+    shutdownEngineAsSlave();
 
     notifyEngineShutdownOk();
 }
@@ -468,7 +516,9 @@ void QmlEngine::messageReceived(const QByteArray &message)
 
     showMessage(_("RECEIVED RESPONSE: ") + quoteUnprintableLatin1(message));
     if (command == "STOPPED") {
-        notifyInferiorSpontaneousStop();
+        if (state() == InferiorRunOk) {
+            notifyInferiorSpontaneousStop();
+        }
 
         QList<QPair<QString, QPair<QString, qint32> > > backtrace;
         QList<WatchData> watches;
@@ -516,14 +566,9 @@ void QmlEngine::messageReceived(const QByteArray &message)
         else
             watchHandler()->endCycle();
 
-        // Ensure we got the right ui right now.
-        Debugger::DebuggerUISwitcher *uiSwitcher
-            = Debugger::DebuggerUISwitcher::instance();
-        uiSwitcher->setActiveLanguage("C++");
-
-        bool becauseOfexception;
-        stream >> becauseOfexception;
-        if (becauseOfexception) {
+        bool becauseOfException;
+        stream >> becauseOfException;
+        if (becauseOfException) {
             QString error;
             stream >> error;