Interop interfaces are all pass-by-ref for IID param

src/Tests/TestComponentCSharp/Class.cpp

@@ -1480,6 +1480,25 @@ namespace winrt::TestComponentCSharp::implementation
         return winrt::make<service_provider>();
     }
 
+    struct __declspec(uuid("15651B9F-6C6B-4CC0-944C-C7D7B0F36F81")) IComInterop : ::IUnknown
+    {
+        virtual HRESULT __stdcall GetForWindow(HWND window, guid riid, int64_t* value) noexcept = 0;
+    };
+
+    WF::IInspectable Class::ComInterop()
+    {
+        struct com_interop : winrt::implements<com_interop, WF::IInspectable, IComInterop>
+        {
+            HRESULT __stdcall GetForWindow(HWND window, guid riid, int64_t* value) noexcept override
+            {
+                *value = riid == winrt::guid_of<IComInterop>() ? (int64_t)window : 0;
+                return 0;
+            }
+        };
+
+        return winrt::make<com_interop>();
+    }
+
     // INotifyDataErrorInfo
     bool Class::HasErrors()
     {

src/Tests/TestComponentCSharp/Class.h

@@ -367,6 +367,7 @@ namespace winrt::TestComponentCSharp::implementation
 
         static IProperties1 NativeProperties1();
         static Windows::Foundation::IInspectable ServiceProvider();
+        static winrt::Windows::Foundation::IInspectable ComInterop();
 
         // IStringable
         hstring ToString();

src/Tests/TestComponentCSharp/TestComponentCSharp.idl

@@ -386,6 +386,7 @@ namespace TestComponentCSharp
         // Interface projections
         static IProperties1 NativeProperties1{ get; };
         static Object ServiceProvider{ get; };
+        static Object ComInterop{ get; };
 
         // INotifyDataErrorInfo
         void RaiseDataErrorChanged();

src/Tests/UnitTest/ComInteropTests.cs

@@ -13,13 +13,43 @@
 using Windows.UI.Input.Spatial;
 using Windows.UI.ViewManagement;
 using Xunit;
+using WinRT;
+using TestComponentCSharp;
 
 namespace UnitTest
 {
+    [ComImport]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    [Guid("15651B9F-6C6B-4CC0-944C-C7D7B0F36F81")]
+    internal interface IComInterop
+    {
+        Int64 GetForWindow(IntPtr hwnd, Guid iid);
+    }
+
     // Note: Many of the COM interop APIs cannot be easily tested without significant test setup.
     // These cases either expect a runtime exception, or are compile-time only (skipped to validate types).
     public class ComInteropTests
     {
+        [Fact]
+        public void TestHWND()
+        {
+            var comInterop = Class.ComInterop.As<IComInterop>();
+            if (System.Environment.Is64BitProcess)
+            {
+                var hwnd = new IntPtr(0x0123456789ABCDEF);
+                var value = comInterop.GetForWindow(hwnd, typeof(IComInterop).GUID);
+                var hwndValue = hwnd.ToInt64();
+                Assert.Equal(hwndValue, value);
+            }
+            else 
+            {
+                var hwnd = new IntPtr(0x01234567);
+                var value = comInterop.GetForWindow(hwnd, typeof(IComInterop).GUID);
+                var hwndValue = hwnd.ToInt32();
+                Assert.Equal(hwndValue, value);
+            }
+        }
+
         [Fact]
         public void TestAccountsSettingsPane()
         {

src/build.cmd

@@ -137,7 +137,11 @@ if "%cswinrt_build_only%"=="true" goto :eof
 :unittest
 rem Build/Run xUnit tests, generating xml output report for Azure Devops reporting, via XunitXml.TestLogger NuGet
 echo Running cswinrt unit tests for %cswinrt_platform% %cswinrt_configuration%
-set dotnet_exe="%DOTNET_ROOT%\dotnet.exe"
+if %cswinrt_platform%==x86 (
+  set dotnet_exe="%DOTNET_ROOT(86)%\dotnet.exe"
+) else (
+  set dotnet_exe="%DOTNET_ROOT%\dotnet.exe"
+)
 if not exist %dotnet_exe% (
   if %cswinrt_platform%==x86 (
     set dotnet_exe="%ProgramFiles(x86)%\dotnet\dotnet.exe"

src/cswinrt/WinRT.Interop.idl

@@ -24,13 +24,13 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
         Object ShowManageAccountsForWindowAsync(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
         Object ShowAddAccountForWindowAsync(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -41,7 +41,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND hwnd,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -52,7 +52,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -63,7 +63,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
 
         void ShowPlayToUIForWindow(
             HWND appWindow);
@@ -77,11 +77,11 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
 
         Object ShowPrintUIForWindowAsync(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -92,7 +92,7 @@ namespace WinRT.Interop
     {
         Object CreateForWindow(
             HWND hwnd,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -102,7 +102,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND hwnd,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -112,7 +112,7 @@ namespace WinRT.Interop
     {
         Object CreateForWindow(
             HWND hwnd,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -124,7 +124,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND window,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -135,7 +135,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND appWindow,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -146,7 +146,7 @@ namespace WinRT.Interop
     {
         Object GetForWindow(
             HWND hwnd,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -158,7 +158,7 @@ namespace WinRT.Interop
         Object RequestVerificationForWindowAsync(
             HWND appWindow,
             String message,
-            GUID riid);
+            ref const GUID riid);
     }
 #endif
 
@@ -170,13 +170,13 @@ namespace WinRT.Interop
         Object RequestTokenForWindowAsync(
             HWND appWindow,
             Windows.Security.Authentication.Web.Core.WebTokenRequest request, 
-            GUID riid); // __uuidof(IAsyncOperation<WebTokenRequestResult*>)    
+            ref const GUID riid); // __uuidof(IAsyncOperation<WebTokenRequestResult*>)    
 
         Object RequestTokenWithWebAccountForWindowAsync(
             HWND appWindow,
             Windows.Security.Authentication.Web.Core.WebTokenRequest request,
             Windows.Security.Credentials.WebAccount webAccount,
-            GUID riid); // __uuidof(IAsyncOperation<WebTokenRequestResult*>)
+            ref const GUID riid); // __uuidof(IAsyncOperation<WebTokenRequestResult*>)
     }
 #endif
 }