WinRT winmain: enable debugger waiting

WinRT applications are not invoked directly, so a debugger may attach too
late to be useful. While the application can be launched with a debugging
server, attaching directly to the running process is simpler and less
resource-intensive. For this reason, it is useful for applications to
wait for the direct debugger to attach. If the existing -qdebug parameter
is passed to the application, wait idly until the debugger attaches.

Change-Id: I7b4957beb9728ab6311b459e4d809dc5f4767780
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/winmain/qtmain_winrt.cpp b/src/winmain/qtmain_winrt.cpp
index d0f138269f..c0542ff242 100644
--- a/src/winmain/qtmain_winrt.cpp
+++ b/src/winmain/qtmain_winrt.cpp
@@ -69,7 +69,7 @@ typedef ITypedEventHandler<Core::CoreApplicationView *, Activation::IActivatedEv
 class AppContainer : public Microsoft::WRL::RuntimeClass<Core::IFrameworkView>
 {
 public:
-    AppContainer(int argc, wchar_t **argv) : m_argc(argc)
+    AppContainer(int argc, wchar_t **argv) : m_argc(argc), m_debugWait(false)
     {
         m_argv.reserve(argc);
         for (int i = 0; i < argc; ++i) {
@@ -95,6 +95,11 @@ public:
     HRESULT __stdcall Load(HSTRING) { return S_OK; }
     HRESULT __stdcall Run()
     {
+        // Wait for debugger before continuing
+        if (m_debugWait) {
+            while (!IsDebuggerPresent())
+                WaitForSingleObjectEx(GetCurrentThread(), 1, true);
+        }
         return main(m_argv.count(), m_argv.data());
     }
     HRESULT __stdcall Uninitialize() { return S_OK; }
@@ -113,6 +118,8 @@ private:
             foreach (const QByteArray &arg, QString::fromWCharArray(
                          WindowsGetStringRawBuffer(arguments, nullptr)).toLocal8Bit().split(' ')) {
                 m_argv.append(qstrdup(arg.constData()));
+                if (arg == "-qdebug")
+                    m_debugWait = true;
             }
         }
         return S_OK;
@@ -120,6 +127,7 @@ private:
 
     int m_argc;
     QVector<char *> m_argv;
+    bool m_debugWait;
     EventRegistrationToken m_activationToken;
 };