Pass in the fallback generator to BoundGenerators

src/libraries/System.Runtime.InteropServices.JavaScript/gen/JSImportGenerator/JSExportCodeGenerator.cs

@@ -34,7 +34,7 @@ public JSExportCodeGenerator(
             NativeToManagedStubCodeContext innerContext = new NativeToManagedStubCodeContext(targetFramework, targetFrameworkVersion, ReturnIdentifier, ReturnIdentifier);
             _context = new JSExportCodeContext(attributeData, innerContext);
 
-            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context);
+            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context, new EmptyJSGenerator());
             foreach (var failure in _marshallers.GeneratorBindingFailures)
             {
                 marshallingNotSupportedCallback(failure.Info, failure.Exception);

src/libraries/System.Runtime.InteropServices.JavaScript/gen/JSImportGenerator/JSImportCodeGenerator.cs

@@ -40,7 +40,7 @@ public JSImportCodeGenerator(
             _signatureContext = signatureContext;
             ManagedToNativeStubCodeContext innerContext = new ManagedToNativeStubCodeContext(targetFramework, targetFrameworkVersion, ReturnIdentifier, ReturnIdentifier);
             _context = new JSImportCodeContext(attributeData, innerContext);
-            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context);
+            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context, new EmptyJSGenerator());
 
             foreach (var failure in _marshallers.GeneratorBindingFailures)
             {

src/libraries/System.Runtime.InteropServices/gen/ComInterfaceGenerator/ManagedToNativeVTableMethodGenerator.cs

@@ -75,7 +75,7 @@ public ManagedToNativeVTableMethodGenerator(
             }
 
             _context = new ManagedToNativeStubCodeContext(targetFramework, targetFrameworkVersion, ReturnIdentifier, ReturnIdentifier);
-            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context);
+            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context, new Forwarder());
 
             foreach (var failure in _marshallers.GeneratorBindingFailures)
             {

src/libraries/System.Runtime.InteropServices/gen/ComInterfaceGenerator/UnmanagedToManagedStubGenerator.cs

@@ -30,7 +30,7 @@ public UnmanagedToManagedStubGenerator(
             IMarshallingGeneratorFactory generatorFactory)
         {
             _context = new NativeToManagedStubCodeContext(targetFramework, targetFrameworkVersion, ReturnIdentifier, ReturnIdentifier);
-            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context);
+            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context, new Forwarder());
 
             foreach (var failure in _marshallers.GeneratorBindingFailures)
             {

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/Analyzers/ConvertToLibraryImportAnalyzer.cs

@@ -112,7 +112,7 @@ private static void AnalyzeSymbol(SymbolAnalysisContext context, INamedTypeSymbo
                     return forwarder;
                 }
                 return generatorFactoryKey.GeneratorFactory.Create(info, stubCodeContext);
-            }), stubCodeContext);
+            }), stubCodeContext, forwarder);
 
             mayRequireAdditionalWork |= generators.GeneratorBindingFailures.Length > 0;
 

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/PInvokeStubCodeGenerator.cs

@@ -68,7 +68,7 @@ public PInvokeStubCodeGenerator(
             }
 
             _context = new ManagedToNativeStubCodeContext(targetFramework, targetFrameworkVersion, ReturnIdentifier, ReturnIdentifier);
-            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context);
+            _marshallers = new BoundGenerators(argTypes, generatorFactory, _context, new Forwarder());
 
             foreach (var failure in _marshallers.GeneratorBindingFailures)
             {

src/libraries/System.Runtime.InteropServices/gen/Microsoft.Interop.SourceGeneration/BoundGenerators.cs

@@ -18,9 +18,7 @@ namespace Microsoft.Interop
 
     public class BoundGenerators
     {
-        private static readonly Forwarder FallbackGenerator = new();
-
-        public BoundGenerators(ImmutableArray<TypePositionInfo> elementTypeInfo, IMarshallingGeneratorFactory generatorFactory, StubCodeContext context)
+        public BoundGenerators(ImmutableArray<TypePositionInfo> elementTypeInfo, IMarshallingGeneratorFactory generatorFactory, StubCodeContext context, IMarshallingGenerator fallbackGenerator)
         {
             ImmutableArray<BoundGenerator>.Builder allMarshallers = ImmutableArray.CreateBuilder<BoundGenerator>();
             ImmutableArray<BoundGenerator>.Builder nativeParamMarshallers = ImmutableArray.CreateBuilder<BoundGenerator>();
@@ -29,9 +27,9 @@ public BoundGenerators(ImmutableArray<TypePositionInfo> elementTypeInfo, IMarsha
             bool foundNativeRetMarshaller = false;
             bool foundManagedRetMarshaller = false;
             TypePositionInfo? managedExceptionInfo = null;
-            NativeReturnMarshaller = new(new TypePositionInfo(SpecialTypeInfo.Void, NoMarshallingInfo.Instance), FallbackGenerator);
-            ManagedReturnMarshaller = new(new TypePositionInfo(SpecialTypeInfo.Void, NoMarshallingInfo.Instance), FallbackGenerator);
-            ManagedExceptionMarshaller = new(new TypePositionInfo(SpecialTypeInfo.Void, NoMarshallingInfo.Instance), FallbackGenerator);
+            NativeReturnMarshaller = new(new TypePositionInfo(SpecialTypeInfo.Void, NoMarshallingInfo.Instance), fallbackGenerator);
+            ManagedReturnMarshaller = new(new TypePositionInfo(SpecialTypeInfo.Void, NoMarshallingInfo.Instance), fallbackGenerator);
+            ManagedExceptionMarshaller = new(new TypePositionInfo(SpecialTypeInfo.Void, NoMarshallingInfo.Instance), fallbackGenerator);
 
             foreach (TypePositionInfo argType in elementTypeInfo)
             {
@@ -158,7 +156,7 @@ IMarshallingGenerator CreateGenerator(TypePositionInfo p, IMarshallingGeneratorF
                 catch (MarshallingNotSupportedException e)
                 {
                     bindingFailures.Add((p, e));
-                    return FallbackGenerator;
+                    return fallbackGenerator;
                 }
             }
         }