Strip inaccessible attributes when generating event handlers

src/VisualStudio/CSharp/Impl/EventHookup/EventHookupCommandHandler_TabKeyCommand.cs

@@ -265,17 +265,18 @@ private void GenerateAndAddEventHandler(ITextView textView, ITextBuffer subjectB
             }
 
             var syntaxFactory = semanticDocument.Document.GetLanguageService<SyntaxGenerator>();
+            var delegateInvokeMethod = delegateType.DelegateInvokeMethod.RemoveInaccessibleAttributesAndAttributesOfTypes(semanticDocument.SemanticModel.Compilation.Assembly);
 
             return CodeGenerationSymbolFactory.CreateMethodSymbol(
                 attributes: default,
                 accessibility: Accessibility.Private,
                 modifiers: new DeclarationModifiers(isStatic: eventHookupExpression.IsInStaticContext()),
-                returnType: delegateType.DelegateInvokeMethod.ReturnType,
-                refKind: delegateType.DelegateInvokeMethod.RefKind,
+                returnType: delegateInvokeMethod.ReturnType,
+                refKind: delegateInvokeMethod.RefKind,
                 explicitInterfaceImplementations: default,
                 name: eventHandlerMethodName,
                 typeParameters: default,
-                parameters: delegateType.DelegateInvokeMethod.Parameters,
+                parameters: delegateInvokeMethod.Parameters,
                 statements: ImmutableArray.Create(
                     CodeGenerationHelpers.GenerateThrowStatement(syntaxFactory, semanticDocument, "System.NotImplementedException", cancellationToken)));
         }

src/VisualStudio/CSharp/Test/EventHookup/EventHookupCommandHandlerTests.cs

@@ -2,6 +2,7 @@
 
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using System.Xml.Linq;
 using Microsoft.CodeAnalysis.CodeStyle;
 using Microsoft.CodeAnalysis.Options;
 using Microsoft.CodeAnalysis.Test.Utilities;
@@ -905,6 +906,59 @@ private void C_MyEvent()
             testState.AssertCodeIs(expectedCode);
         }
 
+        [WpfFact, Trait(Traits.Feature, Traits.Features.EventHookup)]
+        public async Task EventHookupRemovesInaccessibleAttributes()
+        {
+            var workspaceXml = @"
+<Workspace>
+    <Project Language=""C#"" AssemblyName=""A"" CommonReferences=""true"">
+        <Document>
+using System;
+
+public static class C
+{
+    public static event DelegateType E;
+
+    public delegate void DelegateType([ShouldBeRemovedInternalAttribute] object o);
+}
+
+internal class ShouldBeRemovedInternalAttribute : Attribute { }
+        </Document>
+    </Project>
+    <Project Language=""C#"" CommonReferences=""true"">
+        <ProjectReference>A</ProjectReference>
+        <Document>
+class D
+{
+    void M()
+    {
+        C.E +$$
+    }
+}</Document>
+    </Project>
+</Workspace>";
+
+            using var testState = new EventHookupTestState(XElement.Parse(workspaceXml), options: null);
+            testState.SendTypeChar('=');
+            testState.SendTab();
+            await testState.WaitForAsynchronousOperationsAsync();
+
+            var expectedCode = @"
+class D
+{
+    void M()
+    {
+        C.E += C_E;
+    }
+
+    private void C_E(object o)
+    {
+        throw new System.NotImplementedException();
+    }
+}";
+            testState.AssertCodeIs(expectedCode);
+        }
+
         [WpfFact, Trait(Traits.Feature, Traits.Features.EventHookup)]
         public async Task EventHookupWithQualifiedMethodAccessAndNotificationOptionSilent()
         {