Add support for VB.NET automatic events

ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj

@@ -110,6 +110,8 @@
     <Compile Include="Output\InsertParenthesesVisitorTests.cs" />
     <Compile Include="ProjectDecompiler\TargetFrameworkTests.cs" />
     <Compile Include="TestAssemblyResolver.cs" />
+    <None Include="TestCases\VBPretty\VBAutomaticEvents.vb" />
+    <Compile Include="TestCases\VBPretty\VBAutomaticEvents.cs" />
     <Compile Include="TypeSystem\ReflectionHelperTests.cs" />
     <None Include="TestCases\Pretty\MetadataAttributes.cs" />
     <None Include="TestCases\Correctness\ComInterop.cs" />

ICSharpCode.Decompiler.Tests/TestCases/VBPretty/VBAutomaticEvents.cs

@@ -0,0 +1,14 @@
+public class VBAutomaticEvents
+{
+	public delegate void EventWithParameterEventHandler(int EventNumber);
+	public delegate void EventWithoutParameterEventHandler();
+
+	public event EventWithParameterEventHandler EventWithParameter;
+	public event EventWithoutParameterEventHandler EventWithoutParameter;
+
+	public void RaiseEvents()
+	{
+		EventWithParameter?.Invoke(1);
+		EventWithoutParameter?.Invoke();
+	}
+}

ICSharpCode.Decompiler.Tests/TestCases/VBPretty/VBAutomaticEvents.vb

@@ -0,0 +1,9 @@
+Public Class VBAutomaticEvents
+	Event EventWithParameter(ByVal EventNumber As Integer)
+	Event EventWithoutParameter()
+
+	Sub RaiseEvents()
+		RaiseEvent EventWithParameter(1)
+		RaiseEvent EventWithoutParameter()
+	End Sub
+End Class

ICSharpCode.Decompiler.Tests/VBPrettyTestRunner.cs

@@ -1,4 +1,4 @@
-// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
 // 
 // Permission is hereby granted, free of charge, to any person obtaining a copy of this
 // software and associated documentation files (the "Software"), to deal in the Software
@@ -125,6 +125,12 @@ namespace ICSharpCode.Decompiler.Tests
 			await Run(options: options | CompilerOptions.Library);
 		}
 
+		[Test]
+		public async Task VBAutomaticEvents([ValueSource(nameof(defaultOptions))] CompilerOptions options)
+		{
+			await Run(options: options | CompilerOptions.Library);
+		}
+
 		async Task Run([CallerMemberName] string testName = null, CompilerOptions options = CompilerOptions.UseDebug, DecompilerSettings settings = null)
 		{
 			var vbFile = Path.Combine(TestCasePath, testName + ".vb");

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Daniel Grunwald
+// Copyright (c) 2014 Daniel Grunwald
 // 
 // Permission is hereby granted, free of charge, to any person obtaining a copy of this
 // software and associated documentation files (the "Software"), to deal in the Software
@@ -367,8 +367,16 @@ namespace ICSharpCode.Decompiler.CSharp
 							return true;
 					}
 					// event-fields are not [CompilerGenerated]
-					if (settings.AutomaticEvents && metadata.GetTypeDefinition(field.GetDeclaringType()).GetEvents().Any(ev => metadata.GetEventDefinition(ev).Name == field.Name))
-						return true;
+					if (settings.AutomaticEvents)
+					{
+						foreach (var ev in metadata.GetTypeDefinition(field.GetDeclaringType()).GetEvents())
+						{
+							var eventName = metadata.GetString(metadata.GetEventDefinition(ev).Name);
+							var fieldName = metadata.GetString(field.Name);
+							if (IsEventBackingFieldName(fieldName, eventName, out _))
+								return true;
+						}
+					}
 					if (settings.ArrayInitializers && metadata.GetString(metadata.GetTypeDefinition(field.GetDeclaringType()).Name).StartsWith("<PrivateImplementationDetails>", StringComparison.Ordinal))
 					{
 						// only hide fields starting with '__StaticArrayInit'
@@ -412,6 +420,20 @@ namespace ICSharpCode.Decompiler.CSharp
 			return false;
 		}
 
+		internal static bool IsEventBackingFieldName(string fieldName, string eventName, out int suffixLength)
+		{
+			suffixLength = 0;
+			if (fieldName == eventName)
+				return true;
+			var vbSuffixLength = "Event".Length;
+			if (fieldName.Length == eventName.Length + vbSuffixLength && fieldName.StartsWith(eventName, StringComparison.Ordinal) && fieldName.EndsWith("Event", StringComparison.Ordinal))
+			{
+				suffixLength = vbSuffixLength;
+				return true;
+			}
+			return false;
+		}
+
 		static bool IsAnonymousMethodCacheField(SRM.FieldDefinition field, MetadataReader metadata)
 		{
 			var name = metadata.GetString(field.Name);

ICSharpCode.Decompiler/CSharp/Transforms/PatternStatementTransform.cs

@@ -1,4 +1,4 @@
-// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
+// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
 // 
 // Permission is hereby granted, free of charge, to any person obtaining a copy of this
 // software and associated documentation files (the "Software"), to deal in the Software
@@ -763,12 +763,17 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			var field = mrr?.Member as IField;
 			if (field == null)
 				return null;
-			var @event = field.DeclaringType.GetEvents(ev => ev.Name == field.Name, GetMemberOptions.IgnoreInheritedMembers).SingleOrDefault();
-			if (@event != null && currentMethod.AccessorOwner != @event)
+			foreach (var ev in field.DeclaringType.GetEvents(null, GetMemberOptions.IgnoreInheritedMembers))
 			{
-				parent.RemoveAnnotations<MemberResolveResult>();
-				parent.AddAnnotation(new MemberResolveResult(mrr.TargetResult, @event));
-				return identifier;
+				if (CSharpDecompiler.IsEventBackingFieldName(field.Name, ev.Name, out int suffixLength) &&
+					currentMethod.AccessorOwner != ev)
+				{
+					parent.RemoveAnnotations<MemberResolveResult>();
+					parent.AddAnnotation(new MemberResolveResult(mrr.TargetResult, ev));
+					if (suffixLength != 0)
+						identifier.Name = identifier.Name.Substring(0, identifier.Name.Length - suffixLength);
+					return identifier;
+				}
 			}
 			return null;
 		}
@@ -911,11 +916,11 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			switch (fieldExpression)
 			{
 				case IdentifierExpression identifier:
-					if (identifier.Identifier != ev.Name)
+					if (!CSharpDecompiler.IsEventBackingFieldName(identifier.Identifier, ev.Name, out _))
 						return false;
 					break;
 				case MemberReferenceExpression memberRef:
-					if (memberRef.MemberName != ev.Name)
+					if (!CSharpDecompiler.IsEventBackingFieldName(memberRef.MemberName, ev.Name, out _))
 						return false;
 					break;
 				default:
@@ -1013,7 +1018,7 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			ed.CopyAnnotationsFrom(ev);
 
 			var fieldDecl = ev.Parent?.Children.OfType<FieldDeclaration>()
-				.FirstOrDefault(fd => fd.Variables.Single().Name == ev.Name);
+				.FirstOrDefault(fd => CSharpDecompiler.IsEventBackingFieldName(fd.Variables.Single().Name, ev.Name, out _));
 			if (fieldDecl != null)
 			{
 				fieldDecl.Remove();