Change entry point for WinRT apps to WinMain

Using wmain causes the problem that the linker seems to create some code
around it, which calls ExitProcess. That function however is forbidden by
the Windows Store Certification process and hence you cannot publish an
application currently. This does not apply to Windows Phone, which links
in such a way that this problem does not occur there.

With WinMain as the entry point this does not happen and also is the
default entry point. Testing locally shows that certification goes fine.
Since it does not pass the full command line string, the C-runtime method
__getmainargs is used instead. This also gives access to any environment
strings which may be passed.

Note that MSDN states that this function should only be used for desktop
applications. For XAML/C++ scenarios there is no entry function at all,
but rather the App object gets instantiated in the default template. But
this only works for XAML itself and not for plain C++ applications,
probably some other entry wrapper is created on the fly here.

Done-with: Andrew Knight <andrew.knight@digia.com>
Change-Id: I8a118eddf6cfeddeca7d676267e979af17123e02
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>

mkspecs/common/winrt_winphone/qmake.conf

@@ -79,7 +79,7 @@ QMAKE_LIBS_NETWORK      =
 QMAKE_LIBS_OPENGL_ES2   = libEGL.lib libGLESv2.lib
 QMAKE_LIBS_OPENGL_ES2_DEBUG = libEGLd.lib libGLESv2d.lib
 
-QMAKE_LIBS_QT_ENTRY     = -lqtmain /ENTRY:wmainCRTStartup
+QMAKE_LIBS_QT_ENTRY     = -lqtmain
 
 QMAKE_IDL               = midl
 QMAKE_LIB               = lib /NOLOGO

src/winmain/qtmain_winrt.cpp

@@ -44,11 +44,22 @@
   linking to the Qt DLL.
 
   When a Windows application starts, the WinMain function is
-  invoked. WinMain creates the WinRT application which in turn
+  invoked. This WinMain creates the WinRT application
-  calls the main entry point.
+  container, which in turn calls the application's main()
+  entry point within the newly created GUI thread.
 */
 
-extern "C" int main(int, char **);
+#include <new.h>
+
+typedef struct
+{
+    int newmode;
+} _startupinfo;
+
+extern "C" {
+    int __getmainargs(int *argc, char ***argv, char ***env, int expandWildcards, _startupinfo *info);
+    int main(int, char **);
+}
 
 #include <qbytearray.h>
 #include <qstring.h>
@@ -69,19 +80,17 @@ typedef ITypedEventHandler<Core::CoreApplicationView *, Activation::IActivatedEv
 class AppContainer : public Microsoft::WRL::RuntimeClass<Core::IFrameworkView>
 {
 public:
-    AppContainer(int argc, wchar_t **argv) : m_argc(argc), m_debugWait(false)
+    AppContainer(int argc, char *argv[]) : m_argc(argc), m_debugWait(false)
     {
         m_argv.reserve(argc);
-        for (int i = 0; i < argc; ++i) {
+        for (int i = 0; i < argc; ++i)
-            QByteArray arg = QString::fromWCharArray(argv[i]).toLocal8Bit();
+            m_argv.append(argv[i]);
-            m_argv.append(qstrdup(arg.constData()));
-        }
     }
 
     ~AppContainer()
     {
-        foreach (const char *arg, m_argv)
+        for (int i = m_argc; i < m_argv.size(); ++i)
-            delete[] arg;
+            delete[] m_argv[i];
     }
 
     // IFrameworkView Methods
@@ -136,19 +145,32 @@ private:
 class AppViewSource : public Microsoft::WRL::RuntimeClass<Core::IFrameworkViewSource>
 {
 public:
-    AppViewSource(int argc, wchar_t *argv[]) : argc(argc), argv(argv) { }
+    AppViewSource(int argc, char **argv) : m_argc(argc), m_argv(argv) { }
     HRESULT __stdcall CreateView(Core::IFrameworkView **frameworkView)
     {
-        return (*frameworkView = Make<AppContainer>(argc, argv).Detach()) ? S_OK : E_OUTOFMEMORY;
+        return (*frameworkView = Make<AppContainer>(m_argc, m_argv).Detach()) ? S_OK : E_OUTOFMEMORY;
     }
 private:
-    int argc;
+    int m_argc;
-    wchar_t **argv;
+    char **m_argv;
 };
 
 // Main entry point for Appx containers
-int wmain(int argc, wchar_t *argv[])
+int WinMain()
 {
+    int argc = 0;
+    char **argv, **env;
+    _startupinfo info = { _query_new_mode() };
+    if (int init = __getmainargs(&argc, &argv, &env, false, &info))
+        return init;
+
+    for (int i = 0; env && env[i]; ++i) {
+        QByteArray var(env[i]);
+        int split = var.indexOf('=');
+        if (split > 0)
+            qputenv(var.mid(0, split), var.mid(split + 1));
+    }
+
     if (FAILED(RoInitialize(RO_INIT_MULTITHREADED)))
         return 1;
 

src/winmain/winmain.pro

@@ -17,7 +17,6 @@ win32-msvc*:QMAKE_CXXFLAGS_DEBUG *= -Z7
 win32-g++*: DEFINES += QT_NEEDS_QMAIN
 
 winrt {
-    QMAKE_LFLAGS += /ENTRY:wmainCRTStartup
     SOURCES = qtmain_winrt.cpp
 } else {
     SOURCES = qtmain_win.cpp