Disable array support for the COM variant wrapper classes when built-in COM is disabled.

eng/testing/linker/project.csproj.template

@@ -19,6 +19,10 @@
     <_ExtraTrimmerArgs>{ExtraTrimmerArgs} $(_ExtraTrimmerArgs)</_ExtraTrimmerArgs>
   </PropertyGroup>
 
+  <ItemGroup>
+    {RuntimeHostConfigurationOptions}
+  </ItemGroup>
+
   <ItemGroup>
     {AdditionalProjectReferences}
   </ItemGroup>

eng/testing/linker/trimmingTests.targets

@@ -68,6 +68,15 @@
       <_additionalProjectSourceFiles Include="%(TestConsoleApps.AdditionalSourceFiles)" />
     </ItemGroup>
 
+    <ItemGroup>
+      <_switchesAsItems Include="%(TestConsoleApps.DisabledFeatureSwitches)" Value="false" />
+      <_switchesAsItems Include="%(TestConsoleApps.EnabledFeatureSwitches)" Value="true" />
+    </ItemGroup>
+
+    <PropertyGroup>
+      <_runtimeHostConfigurationOptionsString>@(_switchesAsItems->'&lt;RuntimeHostConfigurationOption Include=&quot;%(Identity)&quot; Value=&quot;%(Value)&quot; Trim=&quot;true&quot; /&gt;', '%0a    ')</_runtimeHostConfigurationOptionsString>
+    </PropertyGroup>
+
     <MakeDir Directories="$(_projectDir)" />
     <WriteLinesToFile File="$(_projectFile)"
                       Lines="$([System.IO.File]::ReadAllText('$(ProjectTemplate)')
@@ -79,6 +88,7 @@
                                                  .Replace('{UseMonoRuntime}','$(UseMonoRuntime)')
                                                  .Replace('{MicrosoftNETILLinkTasksVersion}', '$(MicrosoftNETILLinkTasksVersion)')
                                                  .Replace('{ExtraTrimmerArgs}', '%(TestConsoleApps.ExtraTrimmerArgs)')
+                                                 .Replace('{RuntimeHostConfigurationOptions}', '$(_runtimeHostConfigurationOptionsString)')
                                                  .Replace('{AdditionalProjectReferences}', '$(_additionalProjectReferencesString)')
                                                  .Replace('{RepositoryEngineeringDir}', '$(RepositoryEngineeringDir)')
                                                  .Replace('{MonoAOTCompilerDir}', '$(MonoAOTCompilerDir)')

src/coreclr/vm/mlinfo.cpp

@@ -3863,7 +3863,7 @@ void ArrayMarshalInfo::InitElementInfo(CorNativeType arrayNativeType, MarshalInf
             }
         }
 #ifdef FEATURE_COMINTEROP
-        else if (m_thElement == TypeHandle(CoreLibBinder::GetClass(CLASS__ERROR_WRAPPER)))
+        else if (g_pConfig->IsBuiltInCOMSupported() && m_thElement == TypeHandle(CoreLibBinder::GetClass(CLASS__ERROR_WRAPPER)))
         {
             m_vtElement = VT_ERROR;
         }

src/coreclr/vm/olevariant.cpp

@@ -329,20 +329,24 @@ VARTYPE OleVariant::GetVarTypeForTypeHandle(TypeHandle type)
 #endif
 
 #ifdef FEATURE_COMINTEROP
-    if (CoreLibBinder::IsClass(pMT, CLASS__DISPATCH_WRAPPER))
-        return VT_DISPATCH;
-    if (CoreLibBinder::IsClass(pMT, CLASS__UNKNOWN_WRAPPER))
-        return VT_UNKNOWN;
-    if (CoreLibBinder::IsClass(pMT, CLASS__ERROR_WRAPPER))
-        return VT_ERROR;
-    if (CoreLibBinder::IsClass(pMT, CLASS__CURRENCY_WRAPPER))
-        return VT_CY;
-    if (CoreLibBinder::IsClass(pMT, CLASS__BSTR_WRAPPER))
-        return VT_BSTR;
+    // The wrapper types are only available when built-in COM is supported.
+    if (g_pConfig->IsBuiltInCOMSupported())
+    {
+        if (CoreLibBinder::IsClass(pMT, CLASS__DISPATCH_WRAPPER))
+            return VT_DISPATCH;
+        if (CoreLibBinder::IsClass(pMT, CLASS__UNKNOWN_WRAPPER))
+            return VT_UNKNOWN;
+        if (CoreLibBinder::IsClass(pMT, CLASS__ERROR_WRAPPER))
+            return VT_ERROR;
+        if (CoreLibBinder::IsClass(pMT, CLASS__CURRENCY_WRAPPER))
+            return VT_CY;
+        if (CoreLibBinder::IsClass(pMT, CLASS__BSTR_WRAPPER))
+            return VT_BSTR;
 
-    // VariantWrappers cannot be stored in VARIANT's.
-    if (CoreLibBinder::IsClass(pMT, CLASS__VARIANT_WRAPPER))
-        COMPlusThrow(kArgumentException, IDS_EE_COM_UNSUPPORTED_SIG);
+        // VariantWrappers cannot be stored in VARIANT's.
+        if (CoreLibBinder::IsClass(pMT, CLASS__VARIANT_WRAPPER))
+            COMPlusThrow(kArgumentException, IDS_EE_COM_UNSUPPORTED_SIG);
+    }
 #endif // FEATURE_COMINTEROP
 
     if (pMT->IsEnum())
@@ -4847,7 +4851,7 @@ void OleVariant::TransposeArrayData(BYTE *pDestData, BYTE *pSrcData, SIZE_T dwNu
     }
 }
 
-BOOL OleVariant::IsArrayOfWrappers(BASEARRAYREF *pArray, BOOL *pbOfInterfaceWrappers)
+BOOL OleVariant::IsArrayOfWrappers(_In_ BASEARRAYREF *pArray, _Out_opt_ BOOL *pbOfInterfaceWrappers)
 {
     CONTRACTL
     {
@@ -4857,27 +4861,40 @@ BOOL OleVariant::IsArrayOfWrappers(BASEARRAYREF *pArray, BOOL *pbOfInterfaceWrap
     }
     CONTRACTL_END;
 
+    if (!g_pConfig->IsBuiltInCOMSupported())
+    {
+        return FALSE;
+    }
+
     TypeHandle hndElemType = (*pArray)->GetArrayElementTypeHandle();
 
     if (!hndElemType.IsTypeDesc())
     {
         if (hndElemType == TypeHandle(CoreLibBinder::GetClass(CLASS__DISPATCH_WRAPPER)) ||
             hndElemType == TypeHandle(CoreLibBinder::GetClass(CLASS__UNKNOWN_WRAPPER)))
         {
-            *pbOfInterfaceWrappers = TRUE;
+            if (pbOfInterfaceWrappers)
+            {
+                *pbOfInterfaceWrappers = TRUE;
+            }
             return TRUE;
         }
 
         if (hndElemType == TypeHandle(CoreLibBinder::GetClass(CLASS__ERROR_WRAPPER)) ||
             hndElemType == TypeHandle(CoreLibBinder::GetClass(CLASS__CURRENCY_WRAPPER)) ||
             hndElemType == TypeHandle(CoreLibBinder::GetClass(CLASS__BSTR_WRAPPER)))
         {
-            *pbOfInterfaceWrappers = FALSE;
+            if (pbOfInterfaceWrappers)
+            {
+                *pbOfInterfaceWrappers = FALSE;
+            }
             return TRUE;
         }
     }
 
-    *pbOfInterfaceWrappers = FALSE;
+    if (pbOfInterfaceWrappers)
+        *pbOfInterfaceWrappers = FALSE;
+
     return FALSE;
 }
 
@@ -4889,6 +4906,7 @@ BASEARRAYREF OleVariant::ExtractWrappedObjectsFromArray(BASEARRAYREF *pArray)
         GC_TRIGGERS;
         MODE_COOPERATIVE;
         PRECONDITION(CheckPointer(pArray));
+        PRECONDITION(IsArrayOfWrappers(pArray, NULL));
     }
     CONTRACTL_END;
 
@@ -5022,6 +5040,7 @@ TypeHandle OleVariant::GetWrappedArrayElementType(BASEARRAYREF *pArray)
         GC_TRIGGERS;
         MODE_COOPERATIVE;
         PRECONDITION(CheckPointer(pArray));
+        PRECONDITION(IsArrayOfWrappers(pArray, NULL));
     }
     CONTRACTL_END;
 
@@ -5067,8 +5086,7 @@ TypeHandle OleVariant::GetArrayElementTypeWrapperAware(BASEARRAYREF *pArray)
     }
     CONTRACTL_END;
 
-    BOOL bArrayOfInterfaceWrappers;
-    if (IsArrayOfWrappers(pArray, &bArrayOfInterfaceWrappers))
+    if (IsArrayOfWrappers(pArray, nullptr))
     {
         return GetWrappedArrayElementType(pArray);
     }

src/libraries/System.Runtime/tests/TrimmingTests/System.Runtime.TrimmingTests.proj

@@ -35,6 +35,9 @@
       as this test will ensure exceptions are using Resource keys -->
       <ExtraTrimmerArgs>--feature System.Resources.UseSystemResourceKeys true</ExtraTrimmerArgs>
     </TestConsoleAppSourceFiles>
+    <TestConsoleAppSourceFiles Include="TypeBuilderComDisabled.cs">
+      <DisabledFeatureSwitches>System.Runtime.InteropServices.BuiltInComInterop.IsSupported</DisabledFeatureSwitches>
+    </TestConsoleAppSourceFiles>
   </ItemGroup>
 
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets))" />

src/libraries/System.Runtime/tests/TrimmingTests/TypeBuilderComDisabled.cs

@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Reflection;
+using System.Reflection.Emit;
+
+AssemblyBuilder assembly = AssemblyBuilder.DefineDynamicAssembly(new AssemblyName("GeneratedAssembly"), AssemblyBuilderAccess.Run);
+ModuleBuilder module = assembly.DefineDynamicModule("GeneratedModule");
+
+string typeName = "GeneratedType";
+TypeBuilder genericType = module.DefineType(typeName);
+genericType.DefineField("_int", typeof(int), FieldAttributes.Private);
+genericType.DefineProperty("Prop", PropertyAttributes.None, typeof(string), null);
+
+Type generatedType = genericType.CreateType();
+if (generatedType.Name != typeName)
+{
+    Console.WriteLine($"Unexpected name for generated type. Expected: {typeName}, Actual: {generatedType.Name}");
+    return -1;
+}
+
+object obj = Activator.CreateInstance(generatedType);
+string objAsString = obj.ToString();
+if (objAsString != typeName)
+{
+    Console.WriteLine($"Unexpected result of ToString() for instance of generated type. Expected: {typeName}, Actual: {objAsString}");
+    return -2;
+}
+
+return 100;