ProjectExplorer: Run RunControl::{start,stop} always asynchronously

This introduces a mini-state-"machine" to handle RunControl states
Intialized->[Starting->Running->Stopping->Stopped->]*->Finished.

Needing time between trying to start and getting feedback is nowadays
the normal setup for all remote targets as well as for most local tools.
Making that the default for all runs simplifies the code and provides an
opportunity to (a) fix some currently wrong reports of "stopped
immediately" and (b) to remove target-specific (WinRT) or tool-specific
(Valgrind, GammaRay) state members doing essentially the same.

Change-Id: I7f52fee41144188ee8389e922fdc265f8c0a6459
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/projectexplorer/runconfiguration.cpp

@@ -535,7 +535,7 @@ public:
     // A handle to the actual application process.
     Utils::ProcessHandle applicationProcessHandle;
 
-    bool isRunning = false;
+    RunControl::State state = RunControl::State::Initialized;
 
 #ifdef Q_OS_OSX
     // This is used to bring apps in the foreground on Mac
@@ -575,6 +575,18 @@ RunControl::~RunControl()
     delete d;
 }
 
+void RunControl::initiateStart()
+{
+    setState(State::Starting);
+    QTimer::singleShot(0, this, &RunControl::start);
+}
+
+void RunControl::initiateStop()
+{
+    setState(State::Stopping);
+    QTimer::singleShot(0, this, &RunControl::stop);
+}
+
 Utils::OutputFormatter *RunControl::outputFormatter() const
 {
     return d->outputFormatter;
@@ -696,7 +708,7 @@ bool RunControl::promptToStop(bool *optionalPrompt) const
 
 bool RunControl::isRunning() const
 {
-    return d->isRunning;
+    return d->state == State::Running;
 }
 
 /*!
@@ -735,6 +747,33 @@ bool RunControl::showPromptToStopDialog(const QString &title,
     return close;
 }
 
+static bool isAllowedTransition(RunControl::State from, RunControl::State to)
+{
+    switch (from) {
+    case RunControl::State::Initialized:
+        return to == RunControl::State::Starting;
+    case RunControl::State::Starting:
+        return to == RunControl::State::Running;
+    case RunControl::State::Running:
+        return to == RunControl::State::Stopping
+            || to == RunControl::State::Stopped;
+    case RunControl::State::Stopping:
+        return to == RunControl::State::Stopped;
+    case RunControl::State::Stopped:
+        return false;
+    }
+    qDebug() << "UNKNOWN DEBUGGER STATE:" << from;
+    return false;
+}
+
+void RunControl::setState(RunControl::State state)
+{
+    if (!isAllowedTransition(d->state, state)) {
+        qDebug() << "Invalid run state transition from " << d->state << " to " << state;
+    }
+    d->state = state;
+}
+
 /*!
     Brings the application determined by this RunControl's \c applicationProcessHandle
     to the foreground.
@@ -752,13 +791,18 @@ void RunControl::bringApplicationToForeground()
 
 void RunControl::reportApplicationStart()
 {
-    d->isRunning = true;
+    setState(State::Running);
     emit started(QPrivateSignal());
 }
 
 void RunControl::reportApplicationStop()
 {
-    d->isRunning = false;
+    if (d->state == State::Stopped) {
+        // FIXME: Currently various tool implementations call reportApplicationStop()
+        // multiple times. Fix it there and then add a soft assert here.
+        return;
+    }
+    setState(State::Stopped);
     QTC_CHECK(d->applicationProcessHandle.isValid());
     setApplicationProcessHandle(Utils::ProcessHandle());
     emit finished(QPrivateSignal());
@@ -896,14 +940,9 @@ void SimpleRunControl::start()
     }
 }
 
-RunControl::StopResult SimpleRunControl::stop()
+void SimpleRunControl::stop()
 {
     d->m_launcher.stop();
-
-    if (isSynchronousLauncher(this))
-        return StoppedSynchronously;
-    else
-        return AsynchronousStop;
 }
 
 void SimpleRunControl::onProcessStarted()