Qt: Make -g flag work in Qt build

CHANGES

@@ -56,6 +56,7 @@ Misc:
  - VFS: VFile.sync now updates modified time
  - GBA: Add overrides for DBZ: Legacy of Goku II and Ueki no Housoku
  - Util: Fix intermittent build failure on OS X
+ - Qt: Make -g flag work in Qt build
 
 0.4.0: (2016-02-02)
 Features:

doc/mgba-qt.6

@@ -11,7 +11,7 @@
 .Nd Game Boy Advance emulator
 .Sh SYNOPSIS
 .Nm mgba-qt
-.Op Fl 123456f
+.Op Fl 123456fg
 .Op Fl b Ar biosfile
 .Op Fl l Ar loglevel
 .Op Fl p Ar patchfile
@@ -42,6 +42,11 @@ will use the BIOS specified in the configuration file,
 or a high\(hylevel emulated BIOS if none is specified.
 .It Fl f
 Start the emulator full\(hyscreen.
+.It Fl g
+Start a
+.Xr gdb 1
+session.
+By default the session starts on port 2345.
 .It Fl l Ar loglevel
 Log messages during emulation.
 .Ar loglevel

src/platform/qt/Window.cpp

@@ -182,6 +182,15 @@ void Window::argumentsPassed(mArguments* args) {
 	if (args->fname) {
 		m_controller->loadGame(args->fname);
 	}
+
+#ifdef USE_GDB_STUB
+	if (args->debuggerType == DEBUGGER_GDB) {
+		if (!m_gdbController) {
+			m_gdbController = new GDBController(m_controller, this);
+			m_gdbController->listen();
+		}
+	}
+#endif
 }
 
 void Window::resizeFrame(const QSize& size) {