Merge pull request #827 from microsoft/fix751

Bring back Vtbl for IUnknown and IDispatch
microsoft · Dec 9, 2022 · 7ff965b · 7ff965b
2 parents 187018b + b038ed7
commit 7ff965b
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Showing 2 changed files with 15 additions and 7 deletions.
diff --git a/src/Microsoft.Windows.CsWin32/Generator.Com.cs b/src/Microsoft.Windows.CsWin32/Generator.Com.cs
@@ -447,15 +447,15 @@ void AddCcwThunk(params StatementSyntax[] thunkInvokeAndReturn)
             members.Add(propertyOrMethod);
         }
 
+        // We expose the vtbl struct to support CCWs.
+        IdentifierNameSyntax vtblStructName = IdentifierName("Vtbl");
+        StructDeclarationSyntax? vtblStruct = StructDeclaration(Identifier("Vtbl")).WithTrailingTrivia(Space)
+            .AddMembers(vtblMembers.ToArray())
+            .AddModifiers(TokenWithSpace(this.Visibility));
+        members.Add(vtblStruct);
+
         if (ccwThisParameter is not null)
         {
-            // We expose the vtbl struct to support CCWs
-            IdentifierNameSyntax vtblStructName = IdentifierName("Vtbl");
-            StructDeclarationSyntax? vtblStruct = StructDeclaration(Identifier("Vtbl")).WithTrailingTrivia(Space)
-                .AddMembers(vtblMembers.ToArray())
-                .AddModifiers(TokenWithSpace(this.Visibility));
-            members.Add(vtblStruct);
-
             // internal static void PopulateVTable(Vtbl* vtable)
             MethodDeclarationSyntax populateVtblMethodDecl = MethodDeclaration(PredefinedType(Token(SyntaxKind.VoidKeyword)), Identifier("PopulateVTable"))
                 .AddModifiers(Token(this.Visibility), Token(SyntaxKind.StaticKeyword))

diff --git a/test/GenerationSandbox.Unmarshalled.Tests/GeneratedForm.cs b/test/GenerationSandbox.Unmarshalled.Tests/GeneratedForm.cs
@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 #pragma warning disable CA1812 // dead code
+#pragma warning disable CS0168 // Variable is declared but never used
 
 using Windows.Win32;
 using Windows.Win32.Foundation;
@@ -26,4 +27,11 @@ private static unsafe void COMStructsPreserveSig()
         hr = o.get_MachineName(out SysFreeStringSafeHandle sh);
         o.MachineName = bstr;
     }
+
+    private static unsafe void IUnknownGetsVtbl()
+    {
+        // WinForms needs the v-table to be declared for these base interfaces.
+        IUnknown.Vtbl v;
+        IDispatch.Vtbl v2;
+    }
 }