qmlprofiler tool: In attach mode, finish when connection drops

We won't have a process that terminates in this case and we don't want
to wait forever.

Task-number: QTBUG-66159
Change-Id: I5d0bbe2f8bc9c7cbc8732272ccca779d5f9bcc7d
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

tools/qmlprofiler/qmlprofilerapplication.cpp

@@ -91,6 +91,8 @@ QmlProfilerApplication::QmlProfilerApplication(int &argc, char **argv) :
 
     connect(&m_connection, &QQmlDebugConnection::connected,
             this, &QmlProfilerApplication::connected);
+    connect(&m_connection, &QQmlDebugConnection::disconnected,
+            this, &QmlProfilerApplication::disconnected);
 
     connect(&m_qmlProfilerClient, &QmlProfilerClient::enabledChanged,
             this, &QmlProfilerApplication::traceClientEnabledChanged);
@@ -512,6 +514,22 @@ void QmlProfilerApplication::connected()
            .arg(endpoint).arg(m_recording ? tr("on") : tr("off")));
 }
 
+void QmlProfilerApplication::disconnected()
+{
+    if (m_runMode == AttachMode) {
+        int exitCode = 0;
+        if (m_recording) {
+            logError("Connection dropped while recording, last trace is damaged!");
+            exitCode = 2;
+        }
+
+        if (!m_interactive )
+            exit(exitCode);
+        else
+            m_qmlProfilerClient.clearPendingData();
+    }
+}
+
 void QmlProfilerApplication::processHasOutput()
 {
     Q_ASSERT(m_process);

tools/qmlprofiler/qmlprofilerapplication.h

@@ -69,6 +69,7 @@ private:
     void run();
     void tryToConnect();
     void connected();
+    void disconnected();
     void processHasOutput();
     void processFinished();