citra_qt: Better debug widget lifetime

src/citra_qt/debugger/graphics/graphics.cpp

@@ -19,7 +19,7 @@ int GPUCommandStreamItemModel::rowCount([[maybe_unused]] const QModelIndex& pare
 }
 
 QVariant GPUCommandStreamItemModel::data(const QModelIndex& index, int role) const {
-    if (!index.isValid())
+    if (!index.isValid() || !GetDebugger())
         return QVariant();
 
     int command_index = index.row();
@@ -74,16 +74,26 @@ GPUCommandStreamWidget::GPUCommandStreamWidget(Core::System& system_, QWidget* p
     setWidget(command_list);
 }
 
+void GPUCommandStreamWidget::Register() {
+    auto& debugger = system.GPU().Debugger();
+    debugger.RegisterObserver(&model);
+}
+
+void GPUCommandStreamWidget::Unregister() {
+    auto& debugger = system.GPU().Debugger();
+    debugger.UnregisterObserver(&model);
+}
+
 void GPUCommandStreamWidget::showEvent(QShowEvent* event) {
     if (system.IsPoweredOn()) {
-        system.GPU().Debugger().RegisterObserver(&model);
+        Register();
     }
     QDockWidget::showEvent(event);
 }
 
 void GPUCommandStreamWidget::hideEvent(QHideEvent* event) {
     if (system.IsPoweredOn()) {
-        system.GPU().Debugger().UnregisterObserver(&model);
+        Unregister();
     }
     QDockWidget::hideEvent(event);
 }

src/citra_qt/debugger/graphics/graphics.h

@@ -41,6 +41,9 @@ class GPUCommandStreamWidget : public QDockWidget {
 public:
     GPUCommandStreamWidget(Core::System& system, QWidget* parent = nullptr);
 
+    void Register();
+    void Unregister();
+
 protected:
     void showEvent(QShowEvent* event) override;
     void hideEvent(QHideEvent* event) override;

src/citra_qt/main.cpp

@@ -1237,6 +1237,11 @@ void GMainWindow::BootGame(const QString& filename) {
         video_dumping_path.clear();
     }
 
+    // Register debug widgets
+    if (graphicsWidget->isVisible()) {
+        graphicsWidget->Register();
+    }
+
     // Create and start the emulation thread
     emu_thread = std::make_unique<EmuThread>(system, *render_window);
     emit EmulationStarting(emu_thread.get());
@@ -1315,6 +1320,11 @@ void GMainWindow::ShutdownGame() {
     // TODO(bunnei): This function is not thread safe, but it's being used as if it were
     Pica::g_debug_context->ClearBreakpoints();
 
+    // Unregister debug widgets
+    if (graphicsWidget->isVisible()) {
+        graphicsWidget->Unregister();
+    }
+
     // Frame advancing must be cancelled in order to release the emu thread from waiting
     system.frame_limiter.SetFrameAdvancing(false);
 

src/core/memory.cpp

@@ -346,7 +346,7 @@ std::shared_ptr<PageTable> MemorySystem::GetCurrentPageTable() const {
 }
 
 void RasterizerFlushVirtualRegion(VAddr start, u32 size, FlushMode mode) {
-    VAddr end = start + size;
+    const VAddr end = start + size;
 
     auto CheckRegion = [&](VAddr region_start, VAddr region_end, PAddr paddr_region_start) {
         if (start >= region_end || end <= region_start) {