Debugger: Fix object leakage on shutdown and heap-use-after-free.

Task-number: QTCREATORBUG-15938
Change-Id: I437756705c33730398a129651fabe34c92334656
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/debugger/debuggermainwindow.cpp

@@ -81,9 +81,22 @@ DebuggerMainWindow::~DebuggerMainWindow()
 {
     // as we have to setParent(0) on dock widget that are not selected,
     // we keep track of all and make sure we don't leak any
-    foreach (const DockPtr &ptr, m_dockWidgets) {
+    foreach (const Perspective &perspective, m_perspectiveForPerspectiveId) {
-        if (ptr)
+        foreach (const Perspective::Operation &operation, perspective.operations()) {
-            delete ptr.data();
+            if (operation.widget) {
+                // There are two possible states: Either addDockForWidget(widget) has
+                // been on operation.widget (e.g. when the perspective gets activated)
+                // for the first time, or not. In the first case we delete only the
+                // widget, in the second case its parent, which is the dock.
+                if (QWidget *parent = operation.widget->parentWidget()) {
+                    QTC_CHECK(qobject_cast<QDockWidget *>(parent));
+                    delete parent;
+                } else {
+                    // These are from perspectives that never
+                    delete operation.widget;
+                }
+            }
+        }
     }
 }
 
@@ -119,11 +132,6 @@ QDockWidget *DebuggerMainWindow::dockWidget(const QByteArray &dockId) const
     return m_dockForDockId.value(dockId);
 }
 
-QWidget *DebuggerMainWindow::modeWindow()
-{
-    return m_modeWindow;
-}
-
 void DebuggerMainWindow::resetCurrentPerspective()
 {
     loadPerspectiveHelper(m_currentPerspectiveId, false);
@@ -140,7 +148,7 @@ void DebuggerMainWindow::restorePerspective(const QByteArray &perspectiveId)
         m_perspectiveChooser->setCurrentIndex(index);
 }
 
-void DebuggerMainWindow::finalizeSetup(Core::IMode *mode, QWidget *central)
+void DebuggerMainWindow::finalizeSetup()
 {
     auto viewButton = new QToolButton;
     viewButton->setText(tr("Views"));
@@ -195,7 +203,10 @@ void DebuggerMainWindow::finalizeSetup(Core::IMode *mode, QWidget *central)
     m_toolbarDock = dock;
 
     addDockWidget(Qt::BottomDockWidgetArea, dock);
+}
 
+QWidget *createModeWindow(Core::IMode *mode, DebuggerMainWindow *mainWindow, QWidget *central)
+{
     if (!central)
         central = new EditorManagerPlaceHolder(mode);
 
@@ -225,7 +236,7 @@ void DebuggerMainWindow::finalizeSetup(Core::IMode *mode, QWidget *central)
 
     // Right-side window with editor, output etc.
     auto mainWindowSplitter = new MiniSplitter;
-    mainWindowSplitter->addWidget(this);
+    mainWindowSplitter->addWidget(mainWindow);
     mainWindowSplitter->addWidget(new OutputPanePlaceHolder(mode, mainWindowSplitter));
     auto outputPane = new OutputPanePlaceHolder(mode, mainWindowSplitter);
     outputPane->setObjectName(QLatin1String("DebuggerOutputPanePlaceHolder"));
@@ -242,9 +253,9 @@ void DebuggerMainWindow::finalizeSetup(Core::IMode *mode, QWidget *central)
     splitter->setStretchFactor(0, 0);
     splitter->setStretchFactor(1, 1);
     splitter->setObjectName(QLatin1String("DebugModeWidget"));
-    setCentralWidget(centralEditorWidget);
+    mainWindow->setCentralWidget(centralEditorWidget);
 
-    m_modeWindow  = splitter;
+    return splitter;
 }
 
 void DebuggerMainWindow::loadPerspectiveHelper(const QByteArray &perspectiveId, bool fromStoredSettings)
@@ -351,7 +362,6 @@ QDockWidget *DebuggerMainWindow::registerDockWidget(const QByteArray &dockId, QW
     QTC_ASSERT(!widget->objectName().isEmpty(), return 0);
     QDockWidget *dockWidget = addDockForWidget(widget);
     dockWidget->setParent(0);
-    m_dockWidgets.append(DebuggerMainWindow::DockPtr(dockWidget));
     m_dockForDockId[dockId] = dockWidget;
     return dockWidget;
 }

src/plugins/debugger/debuggermainwindow.h

@@ -61,7 +61,7 @@ public:
                   Qt::DockWidgetArea area = Qt::BottomDockWidgetArea);
 
         QByteArray dockId;
-        QWidget *widget = 0;
+        QPointer<QWidget> widget;
         QByteArray anchorDockId;
         OperationType operationType;
         bool visibleByDefault;
@@ -115,14 +115,12 @@ public:
     void resetCurrentPerspective();
     void restorePerspective(const QByteArray &perspectiveId);
 
-    void finalizeSetup(Core::IMode *mode, QWidget *central = 0);
+    void finalizeSetup();
 
     void showStatusMessage(const QString &message, int timeoutMS);
     QDockWidget *dockWidget(const QByteArray &dockId) const;
     QByteArray currentPerspective() const { return m_currentPerspectiveId; }
 
-    QWidget *modeWindow();
-
 private:
     QDockWidget *registerDockWidget(const QByteArray &dockId, QWidget *widget);
     void loadPerspectiveHelper(const QByteArray &perspectiveId, bool fromStoredSettings = true);
@@ -136,14 +134,10 @@ private:
     QHash<QByteArray, QDockWidget *> m_dockForDockId;
     QHash<QByteArray, QWidget *> m_toolbarForPerspectiveId;
     QHash<QByteArray, Perspective> m_perspectiveForPerspectiveId;
-
-    // list of dock widgets to prevent memory leak
-    typedef QPointer<QDockWidget> DockPtr;
-    QList<DockPtr> m_dockWidgets;
-
-    QWidget *m_modeWindow = 0;
 };
 
+QWidget *createModeWindow(Core::IMode *mode, DebuggerMainWindow *mainWindow, QWidget *central);
+
 } // Utils
 
 #endif // DEBUGGERMAINWINDOW_H

src/plugins/debugger/debuggerplugin.cpp

@@ -486,41 +486,27 @@ bool DummyEngine::hasCapability(unsigned cap) const
 class DebugModeContext : public IContext
 {
 public:
-    DebugModeContext(DebuggerMainWindow *mainWindow) : m_mainWindow(mainWindow)
+    DebugModeContext(QWidget *modeWindow)
     {
         setContext(Context(CC::C_EDITORMANAGER));
+        setWidget(modeWindow);
         ICore::addContextObject(this);
     }
-
-    QWidget *widget() const override { return m_mainWindow->modeWindow(); }
-
-    DebuggerMainWindow *m_mainWindow;
 };
 
 class DebugMode : public IMode
 {
 public:
-    DebugMode(DebuggerMainWindow *mainWindow) : m_mainWindow(mainWindow)
+    DebugMode()
     {
         setObjectName(QLatin1String("DebugMode"));
         setContext(Context(C_DEBUGMODE, CC::C_NAVIGATION_PANE));
         setDisplayName(DebuggerPlugin::tr("Debug"));
         setIcon(Utils::Icon::modeIcon(Icons::MODE_DEBUGGER_CLASSIC,
                                       Icons::MODE_DEBUGGER_FLAT, Icons::MODE_DEBUGGER_FLAT_ACTIVE));
-//        setIcon(Utils::Icon::modeIcon(Icons::MODE_ANALYZE_CLASSIC,
-//                                      Icons::MODE_ANALYZE_FLAT, Icons::MODE_ANALYZE_FLAT_ACTIVE));
         setPriority(85);
         setId(MODE_DEBUG);
     }
-
-    QWidget *widget() const override { return m_mainWindow->modeWindow(); }
-
-    ~DebugMode()
-    {
-//        delete m_widget;
-    }
-
-    DebuggerMainWindow *m_mainWindow;
 };
 
 ///////////////////////////////////////////////////////////////////////
@@ -924,7 +910,9 @@ public:
     void updateActiveLanguages();
 
 public:
-    DebuggerMainWindow *m_mainWindow = 0;
+    QPointer<DebuggerMainWindow> m_mainWindow;
+    QPointer<QWidget> m_modeWindow;
+    QPointer<DebugMode> m_mode;
 
     QHash<Id, ActionDescription> m_descriptions;
     ActionContainer *m_menu = 0;
@@ -1051,11 +1039,6 @@ DebuggerPluginPrivate::~DebuggerPluginPrivate()
 
     delete m_breakHandler;
     m_breakHandler = 0;
-
-//    delete m_debugMode;
-//    m_debugMode = 0;
-    delete m_mainWindow;
-    m_mainWindow = 0;
 }
 
 DebuggerEngine *DebuggerPluginPrivate::dummyEngine()
@@ -1748,13 +1731,16 @@ bool DebuggerPluginPrivate::initialize(const QStringList &arguments,
     connect(ProjectExplorerPlugin::instance(), &ProjectExplorerPlugin::settingsChanged,
         this, &DebuggerPluginPrivate::updateDebugWithoutDeployMenu);
 
+    m_mainWindow->finalizeSetup();
+
     // Debug mode setup
-    auto mode = new DebugMode(m_mainWindow);
+    m_mode = new DebugMode;
+    m_modeWindow = createModeWindow(m_mode, m_mainWindow, 0);
+    m_mode->setWidget(m_modeWindow);
 
     (void) new DebugModeContext(m_mainWindow);
-    m_mainWindow->finalizeSetup(mode);
 
-    m_plugin->addAutoReleasedObject(mode);
+    m_plugin->addObject(m_mode);
 
 
     connect(SessionManager::instance(), &SessionManager::startupProjectChanged,
@@ -3047,6 +3033,23 @@ void DebuggerPluginPrivate::aboutToShutdown()
     disconnect(SessionManager::instance(),
         SIGNAL(startupProjectChanged(ProjectExplorer::Project*)),
         this, 0);
+
+    m_mainWindow->saveCurrentPerspective();
+    delete m_mainWindow;
+    m_mainWindow = 0;
+
+    // removeObject leads to aboutToRemoveObject, which leads to
+    // ModeManager::aboutToRemove, which leads to the mode manager
+    // removing the mode's widget from the stackwidget
+    // (currently by index, but possibly the stackwidget resets the
+    // parent and stuff on the widget)
+    m_plugin->removeObject(m_mode);
+
+    delete m_modeWindow;
+    m_modeWindow = 0;
+
+    delete m_mode;
+    m_mode = 0;
 }
 
 void updateState(DebuggerEngine *engine)
@@ -3214,7 +3217,6 @@ IPlugin::ShutdownFlag DebuggerPlugin::aboutToShutdown()
 {
     removeObject(this);
     dd->aboutToShutdown();
-    dd->m_mainWindow->saveCurrentPerspective();
     return SynchronousShutdown;
 }
 

src/plugins/valgrind/callgrindtool.cpp

@@ -503,7 +503,6 @@ CallgrindTool::CallgrindTool(QObject *parent)
 CallgrindTool::~CallgrindTool()
 {
     qDeleteAll(m_textMarks);
-    doClear(false);
 }
 
 void CallgrindTool::slotGoToOverview()