Debugger: correctness fixes and cleanup

* Remove m_current_choice, it's not correct to rely on thread name entry. In extreme corner cases a newly thread can be created, old destroyed with the same entry name. (reoccuring LV2 SPU/PPU ID)
* Remove m_no_thread_selected, can be easily replaced with std::weak_ptr expired() function and is more accurate this way.
* In HandleBreakpointRequest: only remove breakpoint on valid PPU thread and not any thread! also fix potential nullptr deref if thread has recently been destroyed.

rpcs3/rpcs3qt/breakpoint_list.cpp

@@ -86,18 +86,21 @@ void breakpoint_list::AddBreakpoint(u32 pc)
 */
 void breakpoint_list::HandleBreakpointRequest(u32 loc)
 {
+	const auto cpu = this->cpu.lock();
+
+	if (!cpu || cpu->id_type() != 1 || !vm::check_addr(loc, vm::page_allocated | vm::page_executable))
+	{
+		// TODO: SPU breakpoints
+		return;
+	}
+
 	if (m_breakpoint_handler->HasBreakpoint(loc))
 	{
 		RemoveBreakpoint(loc);
 	}
 	else
 	{
-		const auto cpu = this->cpu.lock();
-
-		if (cpu->id_type() == 1 && vm::check_addr(loc, vm::page_allocated | vm::page_executable))
-		{
-			AddBreakpoint(loc);
-		}
+		AddBreakpoint(loc);
 	}
 }
 

rpcs3/rpcs3qt/debugger_frame.cpp

@@ -226,7 +226,7 @@ void debugger_frame::keyPressEvent(QKeyEvent* event)
 	const auto cpu = this->cpu.lock();
 	int i = m_debugger_list->currentRow();
 
-	if (!isActiveWindow() || !cpu || m_no_thread_selected)
+	if (!isActiveWindow() || !cpu)
 	{
 		return;
 	}
@@ -356,8 +356,6 @@ void debugger_frame::UpdateUI()
 {
 	UpdateUnitList();
 
-	if (m_no_thread_selected) return;
-
 	const auto cpu = this->cpu.lock();
 
 	if (!cpu)
@@ -449,18 +447,22 @@ void debugger_frame::UpdateUnitList()
 
 void debugger_frame::OnSelectUnit()
 {
-	if (m_choice_units->count() < 1 || m_current_choice == m_choice_units->currentText()) return;
+	if (m_choice_units->count() < 1) return;
 
-	m_current_choice = m_choice_units->currentText();
-	m_no_thread_selected = m_current_choice == NoThreadString;
-	m_debugger_list->m_no_thread_selected = m_no_thread_selected;
+	const auto weak = m_choice_units->currentData().value<std::weak_ptr<cpu_thread>>();
+
+	if (!weak.owner_before(cpu) && !cpu.owner_before(weak))
+	{
+		// They match, nothing to do.
+		return;
+	}
 
 	m_disasm.reset();
 	cpu.reset();
 
-	if (!m_no_thread_selected)
+	if (!weak.expired())
 	{
-		if (const auto cpu0 = m_choice_units->currentData().value<std::weak_ptr<cpu_thread>>().lock())
+		if (const auto cpu0 = weak.lock())
 		{
 			if (cpu0->id_type() == 1)
 			{
@@ -481,7 +483,7 @@ void debugger_frame::OnSelectUnit()
 		}
 	}
 
-	EnableButtons(!m_no_thread_selected);
+	EnableButtons(true);
 
 	m_debugger_list->UpdateCPUData(this->cpu, m_disasm);
 	m_breakpoint_list->UpdateCPUData(this->cpu, m_disasm);
@@ -698,7 +700,7 @@ void debugger_frame::EnableUpdateTimer(bool enable)
 
 void debugger_frame::EnableButtons(bool enable)
 {
-	if (m_no_thread_selected) enable = false;
+	if (cpu.expired()) enable = false;
 
 	m_go_to_addr->setEnabled(enable);
 	m_go_to_pc->setEnabled(enable);

rpcs3/rpcs3qt/debugger_frame.h

@@ -36,7 +36,6 @@ class debugger_frame : public custom_dock_widget
 	QPushButton* m_btn_step_over;
 	QPushButton* m_btn_run;
 	QComboBox* m_choice_units;
-	QString m_current_choice;
 	QTimer* m_update;
 	QSplitter* m_splitter;
 
@@ -45,7 +44,6 @@ class debugger_frame : public custom_dock_widget
 	u32 m_last_pc = -1;
 	std::vector<char> m_last_query_state;
 	u32 m_last_step_over_breakpoint = -1;
-	bool m_no_thread_selected = true;
 
 	std::shared_ptr<CPUDisAsm> m_disasm;
 	std::weak_ptr<cpu_thread> cpu;

rpcs3/rpcs3qt/debugger_list.cpp

@@ -149,7 +149,7 @@ void debugger_list::keyPressEvent(QKeyEvent* event)
 
 void debugger_list::mouseDoubleClickEvent(QMouseEvent* event)
 {
-	if (event->button() == Qt::LeftButton && !Emu.IsStopped() && !m_no_thread_selected)
+	if (event->button() == Qt::LeftButton)
 	{
 		int i = currentRow();
 		if (i < 0) return;

rpcs3/rpcs3qt/debugger_list.h

@@ -16,7 +16,6 @@ class debugger_list : public QListWidget
 public:
 	u32 m_pc = 0;
 	u32 m_item_count = 30;
-	bool m_no_thread_selected;
 	QColor m_color_bp;
 	QColor m_color_pc;
 	QColor m_text_color_bp;