Don't show [AsyncStateMachine] attribute.

ICSharpCode.Decompiler/Ast/AstBuilder.cs

@@ -1348,6 +1348,7 @@ namespace ICSharpCode.Decompiler.Ast
 		
 		static void ConvertCustomAttributes(AstNode attributedNode, ICustomAttributeProvider customAttributeProvider, string attributeTarget = null)
 		{
+			EntityDeclaration entityDecl = attributedNode as EntityDeclaration;
 			if (customAttributeProvider.HasCustomAttributes) {
 				var attributes = new List<ICSharpCode.NRefactory.CSharp.Attribute>();
 				foreach (var customAttribute in customAttributeProvider.CustomAttributes.OrderBy(a => a.AttributeType.FullName)) {
@@ -1359,12 +1360,15 @@ namespace ICSharpCode.Decompiler.Ast
 						// don't show the ParamArrayAttribute (it's converted to the 'params' modifier)
 						continue;
 					}
+					// if the method is async, remove [DebuggerStepThrough] and [Async
+					if (entityDecl != null && entityDecl.HasModifier(Modifiers.Async)) {
 						if (customAttribute.AttributeType.Name == "DebuggerStepThroughAttribute" && customAttribute.AttributeType.Namespace == "System.Diagnostics") {
-						// don't show the attribute if the method is async
-						EntityDeclaration entityDecl = attributedNode as EntityDeclaration;
-						if (entityDecl != null && entityDecl.HasModifier(Modifiers.Async))
 							continue;
 						}
+						if (customAttribute.AttributeType.Name == "AsyncStateMachineAttribute" && customAttribute.AttributeType.Namespace == "System.Runtime.CompilerServices") {
+							continue;
+						}
+					}
 					
 					var attribute = new ICSharpCode.NRefactory.CSharp.Attribute();
 					attribute.AddAnnotation(customAttribute);

ICSharpCode.Decompiler/Tests/PropertiesAndEvents.cs

@@ -24,7 +24,7 @@ public class PropertiesAndEvents
 	public event EventHandler AutomaticEvent;
 	
 	[field: NonSerialized]
-	public event EventHandler AutomaticEventWithInitializer = delegate
+	public event EventHandler AutomaticEventWithInitializer = delegate(object sender, EventArgs e)
 	{
 	};
 	

ILSpy.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 11.00
 # Visual Studio 2010
-# SharpDevelop 4.2.0.8657-Beta 2
+# SharpDevelop 4.3.0.8807-alpha
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "doc", "doc", "{F45DB999-7E72-4000-B5AD-3A7B485A0896}"
 	ProjectSection(SolutionItems) = postProject
 		doc\Command Line.txt = doc\Command Line.txt
@@ -171,6 +171,14 @@ Global
 		{53DCA265-3C3C-42F9-B647-F72BA678122B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{53DCA265-3C3C-42F9-B647-F72BA678122B}.Release|x86.Build.0 = Release|Any CPU
 		{53DCA265-3C3C-42F9-B647-F72BA678122B}.Release|x86.ActiveCfg = Release|Any CPU
+		{1D18D788-F7EE-4585-A23B-34DC8EC63CB8}.Debug|x86.Build.0 = Debug|Any CPU
+		{1D18D788-F7EE-4585-A23B-34DC8EC63CB8}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{1D18D788-F7EE-4585-A23B-34DC8EC63CB8}.Release|x86.Build.0 = Release|Any CPU
+		{1D18D788-F7EE-4585-A23B-34DC8EC63CB8}.Release|x86.ActiveCfg = Release|Any CPU
+		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A}.Debug|x86.Build.0 = Debug|Any CPU
+		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A}.Release|x86.Build.0 = Release|Any CPU
+		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A}.Release|x86.ActiveCfg = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE