A new debugger.

Lots of bugs/rough edges/etc - issues will be filed.
Old-style debugging still works (just use --emit_source_annotations to get
the helpful movs back and --break_on_instruction will still fire).

src/xenia/app/emulator_window.cc

@@ -9,6 +9,7 @@
 
 #include "xenia/app/emulator_window.h"
 
+#include "third_party/elemental-forms/src/el/elements.h"
 #include "xenia/base/clock.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/platform.h"
@@ -105,6 +106,10 @@ bool EmulatorWindow::Initialize() {
         }
       } break;
 
+      case 0x13: {  // VK_PAUSE
+        CpuBreakIntoDebugger();
+      } break;
+
       case 0x70: {  // VK_F1
         ShowHelpWebsite();
       } break;
@@ -147,6 +152,12 @@ bool EmulatorWindow::Initialize() {
                                         L"&Pause/Resume Profiler", L"`",
                                         []() { Profiler::TogglePause(); }));
   }
+  cpu_menu->AddChild(MenuItem::Create(MenuItem::Type::kSeparator));
+  {
+    cpu_menu->AddChild(MenuItem::Create(
+        MenuItem::Type::kString, L"&Break and Show Debugger", L"Pause/Break",
+        std::bind(&EmulatorWindow::CpuBreakIntoDebugger, this)));
+  }
   main_menu->AddChild(std::move(cpu_menu));
 
   // GPU menu.
@@ -207,6 +218,25 @@ void EmulatorWindow::CpuTimeScalarSetDouble() {
   UpdateTitle();
 }
 
+void EmulatorWindow::CpuBreakIntoDebugger() {
+  auto debugger = emulator()->debugger();
+  if (!debugger) {
+    auto message_form = new el::MessageForm(window_->root_element(),
+                                            TBIDC("debug_error_window"));
+    message_form->Show("Xenia Debugger",
+                       "Xenia must be launched with the --debug flag in order "
+                       "to enable debugging.");
+    return;
+  }
+  if (debugger->execution_state() == debug::ExecutionState::kRunning) {
+    // Currently running, so interrupt (and show the debugger).
+    debugger->Pause();
+  } else {
+    // Not running, so just bring the debugger into focus.
+    debugger->Show();
+  }
+}
+
 void EmulatorWindow::GpuTraceFrame() {
   emulator()->graphics_system()->RequestFrameTrace();
 }

src/xenia/app/emulator_window.h

@@ -43,6 +43,7 @@ class EmulatorWindow {
   void CpuTimeScalarReset();
   void CpuTimeScalarSetHalf();
   void CpuTimeScalarSetDouble();
+  void CpuBreakIntoDebugger();
   void GpuTraceFrame();
   void GpuClearCaches();
   void ToggleFullscreen();

src/xenia/app/premake5.lua

@@ -10,6 +10,7 @@ project("xenia-app")
   links({
     "elemental-forms",
     "gflags",
+    "imgui",
     "xenia-apu",
     "xenia-apu-nop",
     "xenia-base",
@@ -17,6 +18,7 @@ project("xenia-app")
     "xenia-cpu",
     "xenia-cpu-backend-x64",
     "xenia-debug",
+    "xenia-debug-ui",
     "xenia-gpu",
     "xenia-gpu-gl4",
     "xenia-hid-nop",

src/xenia/app/xenia_main.cc

@@ -12,6 +12,7 @@
 #include "xenia/app/emulator_window.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/main.h"
+#include "xenia/debug/ui/debug_window.h"
 #include "xenia/emulator.h"
 #include "xenia/profiling.h"
 #include "xenia/ui/file_picker.h"
@@ -39,6 +40,27 @@ int xenia_main(const std::vector<std::wstring>& args) {
     return 1;
   }
 
+  // Set a debug handler.
+  // This will respond to debugging requests so we can open the debug UI.
+  std::unique_ptr<xe::debug::ui::DebugWindow> debug_window;
+  if (emulator->debugger()) {
+    emulator->debugger()->set_debug_listener_request_handler([&](
+        xe::debug::Debugger* debugger) {
+      if (debug_window) {
+        return debug_window.get();
+      }
+      emulator_window->loop()->PostSynchronous([&]() {
+        debug_window = xe::debug::ui::DebugWindow::Create(
+            emulator.get(), emulator_window->loop());
+        debug_window->window()->on_closed.AddListener([&](xe::ui::UIEvent* e) {
+          emulator->debugger()->set_debug_listener(nullptr);
+          emulator_window->loop()->Post([&]() { debug_window.reset(); });
+        });
+      });
+      return debug_window.get();
+    });
+  }
+
   // Grab path from the flag or unnamed argument.
   std::wstring path;
   if (!FLAGS_target.empty() || args.size() >= 2) {
@@ -91,6 +113,7 @@ int xenia_main(const std::vector<std::wstring>& args) {
     emulator->display_window()->loop()->AwaitQuit();
   }
 
+  debug_window.reset();
   emulator.reset();
   emulator_window.reset();