EnC: Mark deleted members with an attribute

eng/Directory.Packages.props

@@ -255,7 +255,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.VisualBasic.CodeRefactoring.Testing.XUnit" Version="$(MicrosoftCodeAnalysisTestingVersion)" />
     <PackageVersion Include="Microsoft.DiaSymReader.Converter" Version="1.1.0-beta2-22302-02" />
     <PackageVersion Include="Microsoft.DiaSymReader.Converter.Xml" Version="1.1.0-beta2-22302-02" />
-    <PackageVersion Include="Microsoft.Metadata.Visualizer" Version="1.0.0-beta3.21075.2" />
+    <PackageVersion Include="Microsoft.Metadata.Visualizer" Version="2.0.0-beta1.25425.3" />
     <PackageVersion Include="Microsoft.ILVerification" Version="9.0.7" />
     <PackageVersion Include="Microsoft.NETCore.Platforms" Version="5.0.0" />
     <PackageVersion Include="Microsoft.VisualStudio.Cache" Version="17.3.26-alpha" />

src/Compilers/CSharp/Portable/Compiler/MethodCompiler.cs

@@ -186,7 +186,7 @@ public static void CompileMethodBodies(
                 // Deleted definitions must be emitted before PrivateImplementationDetails are frozen since
                 // it may add new members to it. All changes to PrivateImplementationDetails are additions,
                 // so we don't need to create deleted method defs for those.
-                moduleBeingBuiltOpt.CreateDeletedMethodDefinitions(diagnostics.DiagnosticBag);
+                moduleBeingBuiltOpt.CreateDeletedMemberDefinitions(diagnostics.DiagnosticBag);
 
                 // all threads that were adding methods must be finished now, we can freeze the class:
                 var privateImplClass = moduleBeingBuiltOpt.FreezePrivateImplementationDetails();

src/Compilers/CSharp/Portable/Emitter/Model/PEModuleBuilder.cs

@@ -111,12 +111,12 @@ internal sealed override string ModuleName
         {
             get { return _metadataName; }
         }
-
-        internal sealed override Cci.ICustomAttribute SynthesizeAttribute(WellKnownMember attributeConstructor)
+#nullable enable
+        internal sealed override Cci.ICustomAttribute? SynthesizeAttribute(WellKnownMember attributeConstructor)
         {
             return Compilation.TrySynthesizeAttribute(attributeConstructor);
         }
-
+#nullable disable
         public sealed override IEnumerable<Cci.ICustomAttribute> GetSourceAssemblyAttributes(bool isRefAssembly)
         {
             return SourceModule.ContainingSourceAssembly

src/Compilers/CSharp/Portable/Symbols/EventSymbol.cs

@@ -7,14 +7,15 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Microsoft.CodeAnalysis.Symbols;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp.Symbols
 {
     /// <summary>
     /// Represents an event.
     /// </summary>
-    internal abstract partial class EventSymbol : Symbol
+    internal abstract partial class EventSymbol : Symbol, IEventSymbolInternal
     {
         // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
         // Changes to the public interface of this class should remain synchronized with the VB version.

src/Compilers/CSharp/Test/Emit2/Emit/EditAndContinue/EditAndContinueClosureTests.cs

@@ -4965,6 +4965,7 @@ .maxstack  1
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -5071,6 +5072,7 @@ public void F(int x)
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -5218,6 +5220,7 @@ .maxstack  1
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -5582,6 +5585,7 @@ class B(Func<int> f);
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class B(Func<int> f);
@@ -5681,6 +5685,7 @@ public void Capture_TopLevelArgs()
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     <N:0>
                     using System;
@@ -5808,6 +5813,7 @@ .maxstack  1
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -5945,6 +5951,7 @@ .maxstack  1
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -6048,6 +6055,7 @@ public void F()
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C(int x)
@@ -6157,6 +6165,7 @@ public void F()
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C(int x)
@@ -6691,6 +6700,7 @@ public void F()
                             """);
                     })
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -7022,6 +7032,7 @@ .maxstack  1
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -7431,6 +7442,7 @@ void F()
                             """);
                     })
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
 
@@ -7631,6 +7643,7 @@ .maxstack  1
                             """);
                     })
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
 
@@ -7779,6 +7792,7 @@ void F()
                             """);
                     })
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
 
@@ -7973,6 +7987,7 @@ .maxstack  2
                             """);
                     })
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
 
@@ -8101,6 +8116,7 @@ void F()
                             "C.<>c__DisplayClass1_1: {z, CS$<>8__locals1, <F>b__1}");
                     })
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
 
@@ -8532,6 +8548,7 @@ .maxstack  2
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -8738,6 +8755,7 @@ .maxstack  2
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -8907,6 +8925,7 @@ .maxstack  2
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -9115,6 +9134,7 @@ .maxstack  2
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -9364,6 +9384,7 @@ .maxstack  1
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -9584,6 +9605,7 @@ public void F()
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -9720,6 +9742,7 @@ public void F()
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C
@@ -9947,6 +9970,7 @@ public void F()
                     })
 
                 .AddGeneration(
+                    // 1
                     source: """
                     using System;
                     class C

src/Compilers/CSharp/Test/Emit2/Emit/EditAndContinue/EditAndContinueTestBase.cs

@@ -29,6 +29,14 @@ namespace Microsoft.CodeAnalysis.CSharp.EditAndContinue.UnitTests
 
     public abstract class EditAndContinueTestBase : EmitMetadataTestBase
     {
+        public static readonly string MetadataUpdateDeletedAttributeSource = """
+            namespace System.Runtime.CompilerServices
+            {
+                [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = false)]
+                public sealed class MetadataUpdateDeletedAttribute : Attribute; 
+            }
+            """;
+
         // PDB reader can only be accessed from a single thread, so avoid concurrent compilation:
         internal static readonly CSharpCompilationOptions ComSafeDebugDll = TestOptions.DebugDll.WithConcurrentBuild(false);