Don't cache attributes in the type system.

ICSharpCode.Decompiler.Tests/TypeSystem/TypeSystemLoaderTests.cs

@@ -106,7 +106,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(method.IsVirtual);
 			Assert.IsFalse(method.IsStatic);
 			Assert.AreEqual(0, method.Parameters.Count);
-			Assert.AreEqual(0, method.Attributes.Count);
+			Assert.AreEqual(0, method.GetAttributes().Count());
 			Assert.IsTrue(method.HasBody);
 			Assert.IsNull(method.AccessorOwner);
 		}
@@ -117,7 +117,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			ITypeDefinition testClass = GetTypeDefinition(typeof(DynamicTest));
 			Assert.AreEqual(SpecialType.Dynamic, testClass.Fields.Single(f => f.Name == "DynamicField").ReturnType);
 			Assert.AreEqual(SpecialType.Dynamic, testClass.Properties.Single().ReturnType);
-			Assert.AreEqual(0, testClass.Properties.Single().Attributes.Count);
+			Assert.AreEqual(0, testClass.Properties.Single().GetAttributes().Count());
 		}
 
 		[Test]
@@ -153,7 +153,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		{
 			ITypeDefinition testClass = GetTypeDefinition(typeof(DynamicTest));
 			IMethod m1 = testClass.Methods.Single(me => me.Name == "DynamicGenerics1");
-			Assert.AreEqual(0, m1.Parameters[0].Attributes.Count);
+			Assert.AreEqual(0, m1.Parameters[0].GetAttributes().Count());
 		}
 
 		[Test]
@@ -550,7 +550,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		[Test]
 		public void SerializableAttribute()
 		{
-			IAttribute attr = GetTypeDefinition(typeof(NonCustomAttributes)).Attributes.Single();
+			IAttribute attr = GetTypeDefinition(typeof(NonCustomAttributes)).GetAttributes().Single();
 			Assert.AreEqual("System.SerializableAttribute", attr.AttributeType.FullName);
 		}
 
@@ -558,13 +558,13 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void NonSerializedAttribute()
 		{
 			IField field = GetTypeDefinition(typeof(NonCustomAttributes)).Fields.Single(f => f.Name == "NonSerializedField");
-			Assert.AreEqual("System.NonSerializedAttribute", field.Attributes.Single().AttributeType.FullName);
+			Assert.AreEqual("System.NonSerializedAttribute", field.GetAttributes().Single().AttributeType.FullName);
 		}
 
 		[Test]
 		public void ExplicitStructLayoutAttribute()
 		{
-			IAttribute attr = GetTypeDefinition(typeof(ExplicitFieldLayoutStruct)).Attributes.Single();
+			IAttribute attr = GetTypeDefinition(typeof(ExplicitFieldLayoutStruct)).GetAttributes().Single();
 			Assert.AreEqual("System.Runtime.InteropServices.StructLayoutAttribute", attr.AttributeType.FullName);
 			var arg1 = attr.FixedArguments.Single();
 			Assert.AreEqual("System.Runtime.InteropServices.LayoutKind", arg1.Type.FullName);
@@ -585,14 +585,14 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void FieldOffsetAttribute()
 		{
 			IField field = GetTypeDefinition(typeof(ExplicitFieldLayoutStruct)).Fields.Single(f => f.Name == "Field0");
-			Assert.AreEqual("System.Runtime.InteropServices.FieldOffsetAttribute", field.Attributes.Single().AttributeType.FullName);
+			Assert.AreEqual("System.Runtime.InteropServices.FieldOffsetAttribute", field.GetAttributes().Single().AttributeType.FullName);
-			var arg = field.Attributes.Single().FixedArguments.Single();
+			var arg = field.GetAttributes().Single().FixedArguments.Single();
 			Assert.AreEqual("System.Int32", arg.Type.FullName);
 			Assert.AreEqual(0, arg.Value);
 
 			field = GetTypeDefinition(typeof(ExplicitFieldLayoutStruct)).Fields.Single(f => f.Name == "Field100");
-			Assert.AreEqual("System.Runtime.InteropServices.FieldOffsetAttribute", field.Attributes.Single().AttributeType.FullName);
+			Assert.AreEqual("System.Runtime.InteropServices.FieldOffsetAttribute", field.GetAttributes().Single().AttributeType.FullName);
-			arg = field.Attributes.Single().FixedArguments.Single();
+			arg = field.GetAttributes().Single().FixedArguments.Single();
 			Assert.AreEqual("System.Int32", arg.Type.FullName);
 			Assert.AreEqual(100, arg.Value);
 		}
@@ -601,7 +601,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void DllImportAttribute()
 		{
 			IMethod method = GetTypeDefinition(typeof(NonCustomAttributes)).Methods.Single(m => m.Name == "DllMethod");
-			IAttribute dllImport = method.Attributes.Single();
+			IAttribute dllImport = method.GetAttributes().Single();
 			Assert.AreEqual("System.Runtime.InteropServices.DllImportAttribute", dllImport.AttributeType.FullName);
 			Assert.AreEqual("unmanaged.dll", dllImport.FixedArguments[0].Value);
 			Assert.AreEqual((int)CharSet.Unicode, dllImport.NamedArguments.Single().Value);
@@ -613,16 +613,17 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			IParameter p = GetTypeDefinition(typeof(NonCustomAttributes)).Methods.Single(m => m.Name == "DllMethod").Parameters.Single();
 			Assert.IsTrue(p.IsRef);
 			Assert.IsFalse(p.IsOut);
-			Assert.AreEqual(2, p.Attributes.Count);
+			var attr = p.GetAttributes().ToList();
-			Assert.AreEqual("System.Runtime.InteropServices.InAttribute", p.Attributes[0].AttributeType.FullName);
+			Assert.AreEqual(2, attr.Count);
-			Assert.AreEqual("System.Runtime.InteropServices.OutAttribute", p.Attributes[1].AttributeType.FullName);
+			Assert.AreEqual("System.Runtime.InteropServices.InAttribute", attr[0].AttributeType.FullName);
+			Assert.AreEqual("System.Runtime.InteropServices.OutAttribute", attr[1].AttributeType.FullName);
 		}
 
 		[Test]
 		public void MarshalAsAttributeOnMethod()
 		{
 			IMethod method = GetTypeDefinition(typeof(NonCustomAttributes)).Methods.Single(m => m.Name == "DllMethod");
-			IAttribute marshalAs = method.ReturnTypeAttributes.Single();
+			IAttribute marshalAs = method.GetReturnTypeAttributes().Single();
 			Assert.AreEqual((int)UnmanagedType.Bool, marshalAs.FixedArguments.Single().Value);
 		}
 
@@ -633,7 +634,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(p.IsOptional);
 			Assert.IsFalse(p.IsRef);
 			Assert.IsTrue(p.IsOut);
-			Assert.AreEqual(0, p.Attributes.Count);
+			Assert.AreEqual(0, p.GetAttributes().Count());
 			Assert.IsTrue(p.Type.Kind == TypeKind.ByReference);
 		}
 
@@ -645,7 +646,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(p.IsRef);
 			Assert.IsFalse(p.IsOut);
 			Assert.IsTrue(p.IsParams);
-			Assert.AreEqual(0, p.Attributes.Count);
+			Assert.AreEqual(0, p.GetAttributes().Count());
 			Assert.IsTrue(p.Type.Kind == TypeKind.Array);
 		}
 
@@ -657,7 +658,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(p.IsRef);
 			Assert.IsFalse(p.IsOut);
 			Assert.IsFalse(p.IsParams);
-			Assert.AreEqual(0, p.Attributes.Count);
+			Assert.AreEqual(0, p.GetAttributes().Count());
 			Assert.AreEqual(4, p.ConstantValue);
 		}
 
@@ -670,7 +671,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(p.IsOut);
 			Assert.IsFalse(p.IsParams);
 			// explicit optional parameter appears in type system if it's read from C#, but not when read from IL
-			//Assert.AreEqual(1, p.Attributes.Count);
+			//Assert.AreEqual(1, p.GetAttributes().Count());
 		}
 
 		[Test]
@@ -681,7 +682,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(p.IsRef);
 			Assert.IsFalse(p.IsOut);
 			Assert.IsFalse(p.IsParams);
-			Assert.AreEqual(0, p.Attributes.Count);
+			Assert.AreEqual(0, p.GetAttributes().Count());
 			Assert.AreEqual((int)StringComparison.OrdinalIgnoreCase, p.ConstantValue);
 		}
 
@@ -693,7 +694,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			Assert.IsFalse(p.IsRef);
 			Assert.IsFalse(p.IsOut);
 			Assert.IsFalse(p.IsParams);
-			Assert.AreEqual(0, p.Attributes.Count);
+			Assert.AreEqual(0, p.GetAttributes().Count());
 			Assert.IsNull(p.ConstantValue);
 		}
 
@@ -781,7 +782,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		{
 			ITypeDefinition type = GetTypeDefinition(typeof(IAssemblyEnum));
 			// [ComImport]
-			Assert.AreEqual(1, type.Attributes.Count(a => a.AttributeType.FullName == typeof(ComImportAttribute).FullName));
+			Assert.AreEqual(1, type.GetAttributes().Count(a => a.AttributeType.FullName == typeof(ComImportAttribute).FullName));
 
 			IMethod m = type.Methods.Single();
 			Assert.AreEqual("GetNextAssembly", m.Name);
@@ -892,7 +893,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		CustomAttributeTypedArgument<IType> GetParamsAttributeArgument(int index)
 		{
 			ITypeDefinition type = GetTypeDefinition(typeof(ParamsAttribute));
-			var arr = (AttributeArray)type.Attributes.Single().FixedArguments.Single().Value;
+			var arr = (AttributeArray)type.GetAttributes().Single().FixedArguments.Single().Value;
 			Assert.AreEqual(5, arr.Length);
 			return arr[index];
 		}
@@ -942,7 +943,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		{
 			ITypeDefinition type = GetTypeDefinition(typeof(ParamsAttribute));
 			IProperty prop = type.Properties.Single(p => p.Name == "Property");
-			var attr = prop.Attributes.Single();
+			var attr = prop.GetAttributes().Single();
 			Assert.AreEqual(type, attr.AttributeType);
 
 			var elements = (AttributeArray)attr.FixedArguments.Single().Value;
@@ -959,15 +960,15 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		{
 			ITypeDefinition type = GetTypeDefinition(typeof(ParamsAttribute));
 			IProperty prop = type.Properties.Single(p => p.Name == "Property");
-			Assert.AreEqual(0, prop.Getter.Attributes.Count);
+			Assert.AreEqual(0, prop.Getter.GetAttributes().Count());
-			Assert.AreEqual(1, prop.Getter.ReturnTypeAttributes.Count);
+			Assert.AreEqual(1, prop.Getter.GetReturnTypeAttributes().Count());
 		}
 
 		[Test]
 		public void DoubleAttribute_ImplicitNumericConversion()
 		{
 			ITypeDefinition type = GetTypeDefinition(typeof(DoubleAttribute));
-			var arg = type.Attributes.Single().FixedArguments.Single();
+			var arg = type.GetAttributes().Single().FixedArguments.Single();
 			Assert.AreEqual("System.Double", arg.Type.ReflectionName);
 			Assert.AreEqual(1.0, arg.Value);
 		}
@@ -1397,7 +1398,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			var f = type.GetFields().Single(x => x.Name == name);
 			Assert.IsTrue(f.IsConst);
 			Assert.AreEqual(expected, f.ConstantValue);
-			Assert.AreEqual(0, f.Attributes.Count);
+			Assert.AreEqual(0, f.GetAttributes().Count());
 		}
 
 		[Test]
@@ -1518,33 +1519,33 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 			var type = GetTypeDefinition(typeof(ClassWithAttributesUsingNestedMembers));
 			var inner = type.GetNestedTypes().Single(t => t.Name == "Inner");
 			var myAttribute = type.GetNestedTypes().Single(t => t.Name == "MyAttribute");
-			var typeTypeTestAttr = type.Attributes.Single(a => a.AttributeType.Name == "TypeTestAttribute");
+			var typeTypeTestAttr = type.GetAttributes().Single(a => a.AttributeType.Name == "TypeTestAttribute");
 			Assert.AreEqual(42, typeTypeTestAttr.FixedArguments[0].Value);
 			Assert.AreEqual(inner, typeTypeTestAttr.FixedArguments[1].Value);
-			var typeMyAttr = type.Attributes.Single(a => a.AttributeType.Name == "MyAttribute");
+			var typeMyAttr = type.GetAttributes().Single(a => a.AttributeType.Name == "MyAttribute");
 			Assert.AreEqual(myAttribute, typeMyAttr.AttributeType);
 
 			var prop = type.GetProperties().Single(p => p.Name == "P");
-			var propTypeTestAttr = prop.Attributes.Single(a => a.AttributeType.Name == "TypeTestAttribute");
+			var propTypeTestAttr = prop.GetAttributes().Single(a => a.AttributeType.Name == "TypeTestAttribute");
 			Assert.AreEqual(42, propTypeTestAttr.FixedArguments[0].Value);
 			Assert.AreEqual(inner, propTypeTestAttr.FixedArguments[1].Value);
-			var propMyAttr = prop.Attributes.Single(a => a.AttributeType.Name == "MyAttribute");
+			var propMyAttr = prop.GetAttributes().Single(a => a.AttributeType.Name == "MyAttribute");
 			Assert.AreEqual(myAttribute, propMyAttr.AttributeType);
 
 			var attributedInner = (ITypeDefinition)type.GetNestedTypes().Single(t => t.Name == "AttributedInner");
-			var innerTypeTestAttr = attributedInner.Attributes.Single(a => a.AttributeType.Name == "TypeTestAttribute");
+			var innerTypeTestAttr = attributedInner.GetAttributes().Single(a => a.AttributeType.Name == "TypeTestAttribute");
 			Assert.AreEqual(42, innerTypeTestAttr.FixedArguments[0].Value);
 			Assert.AreEqual(inner, innerTypeTestAttr.FixedArguments[1].Value);
-			var innerMyAttr = attributedInner.Attributes.Single(a => a.AttributeType.Name == "MyAttribute");
+			var innerMyAttr = attributedInner.GetAttributes().Single(a => a.AttributeType.Name == "MyAttribute");
 			Assert.AreEqual(myAttribute, innerMyAttr.AttributeType);
 
 			var attributedInner2 = (ITypeDefinition)type.GetNestedTypes().Single(t => t.Name == "AttributedInner2");
 			var inner2 = attributedInner2.GetNestedTypes().Single(t => t.Name == "Inner");
 			var myAttribute2 = attributedInner2.GetNestedTypes().Single(t => t.Name == "MyAttribute");
-			var inner2TypeTestAttr = attributedInner2.Attributes.Single(a => a.AttributeType.Name == "TypeTestAttribute");
+			var inner2TypeTestAttr = attributedInner2.GetAttributes().Single(a => a.AttributeType.Name == "TypeTestAttribute");
 			Assert.AreEqual(43, inner2TypeTestAttr.FixedArguments[0].Value);
 			Assert.AreEqual(inner2, inner2TypeTestAttr.FixedArguments[1].Value);
-			var inner2MyAttr = attributedInner2.Attributes.Single(a => a.AttributeType.Name == "MyAttribute");
+			var inner2MyAttr = attributedInner2.GetAttributes().Single(a => a.AttributeType.Name == "MyAttribute");
 			Assert.AreEqual(myAttribute2, inner2MyAttr.AttributeType);
 		}
 
@@ -1552,7 +1553,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void ClassWithAttributeOnTypeParameter()
 		{
 			var tp = GetTypeDefinition(typeof(ClassWithAttributeOnTypeParameter<>)).TypeParameters.Single();
-			var attr = tp.Attributes.Single();
+			var attr = tp.GetAttributes().Single();
 			Assert.AreEqual("DoubleAttribute", attr.AttributeType.Name);
 		}
 
@@ -1658,7 +1659,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void Void_SerializableAttribute()
 		{
 			ITypeDefinition c = compilation.FindType(typeof(void)).GetDefinition();
-			var attr = c.Attributes.Single(a => a.AttributeType.FullName == "System.SerializableAttribute");
+			var attr = c.GetAttributes().Single(a => a.AttributeType.FullName == "System.SerializableAttribute");
 			Assert.AreEqual(0, attr.Constructor.Parameters.Count);
 			Assert.AreEqual(0, attr.FixedArguments.Length);
 			Assert.AreEqual(0, attr.NamedArguments.Length);
@@ -1668,7 +1669,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void Void_StructLayoutAttribute()
 		{
 			ITypeDefinition c = compilation.FindType(typeof(void)).GetDefinition();
-			var attr = c.Attributes.Single(a => a.AttributeType.FullName == "System.Runtime.InteropServices.StructLayoutAttribute");
+			var attr = c.GetAttributes().Single(a => a.AttributeType.FullName == "System.Runtime.InteropServices.StructLayoutAttribute");
 			Assert.AreEqual(1, attr.Constructor.Parameters.Count);
 			Assert.AreEqual(1, attr.FixedArguments.Length);
 			Assert.AreEqual(0, attr.FixedArguments[0].Value);
@@ -1681,7 +1682,7 @@ namespace ICSharpCode.Decompiler.Tests.TypeSystem
 		public void Void_ComVisibleAttribute()
 		{
 			ITypeDefinition c = compilation.FindType(typeof(void)).GetDefinition();
-			var attr = c.Attributes.Single(a => a.AttributeType.FullName == "System.Runtime.InteropServices.ComVisibleAttribute");
+			var attr = c.GetAttributes().Single(a => a.AttributeType.FullName == "System.Runtime.InteropServices.ComVisibleAttribute");
 			Assert.AreEqual(1, attr.Constructor.Parameters.Count);
 			Assert.AreEqual(1, attr.FixedArguments.Length);
 			Assert.AreEqual(true, attr.FixedArguments[0].Value);

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -794,7 +794,7 @@ namespace ICSharpCode.Decompiler.CSharp
 
 		EnumValueDisplayMode DetectBestEnumValueDisplayMode(ITypeDefinition typeDef, PEFile module)
 		{
-			if (typeDef.GetAttribute(KnownAttribute.Flags) != null)
+			if (typeDef.HasAttribute(KnownAttribute.Flags, inherit: false))
 				return EnumValueDisplayMode.All;
 			bool first = true;
 			long firstValue = 0, previousValue = 0;
@@ -997,7 +997,7 @@ namespace ICSharpCode.Decompiler.CSharp
 		void AddDefinesForConditionalAttributes(ILFunction function, DecompileRun decompileRun, ITypeResolveContext decompilationContext)
 		{
 			foreach (var call in function.Descendants.OfType<CallInstruction>()) {
-				var attr = call.Method.GetAttribute(KnownAttribute.Conditional);
+				var attr = call.Method.GetAttribute(KnownAttribute.Conditional, inherit: true);
 				var symbolName = attr?.FixedArguments.FirstOrDefault().Value as string;
 				if (symbolName == null || !decompileRun.DefinedSymbols.Add(symbolName))
 					continue;
@@ -1014,12 +1014,12 @@ namespace ICSharpCode.Decompiler.CSharp
 				long initValue = (long)CSharpPrimitiveCast.Cast(TypeCode.Int64, field.ConstantValue, false);
 				enumDec.Initializer = typeSystemAstBuilder.ConvertConstantValue(decompilationContext.CurrentTypeDefinition.EnumUnderlyingType, field.ConstantValue);
 				if (enumDec.Initializer is PrimitiveExpression primitive
-					&& (decompilationContext.CurrentTypeDefinition.Attributes.Any(a => a.AttributeType.FullName == "System.FlagsAttribute")
+					&& (decompilationContext.CurrentTypeDefinition.HasAttribute(KnownAttribute.Flags)
 						|| (initValue > 9 && ((initValue & (initValue - 1)) == 0 || (initValue & (initValue + 1)) == 0))))
 				{
 					primitive.SetValue(initValue, $"0x{initValue:X}");
 				}
-				enumDec.Attributes.AddRange(field.Attributes.Select(a => new AttributeSection(typeSystemAstBuilder.ConvertAttribute(a))));
+				enumDec.Attributes.AddRange(field.GetAttributes().Select(a => new AttributeSection(typeSystemAstBuilder.ConvertAttribute(a))));
 				enumDec.AddAnnotation(new MemberResolveResult(null, field));
 				return enumDec;
 			}

ICSharpCode.Decompiler/CSharp/RequiredNamespaceCollector.cs

@@ -40,10 +40,10 @@ namespace ICSharpCode.Decompiler.CSharp
 			switch (entity) {
 				case ITypeDefinition td:
 					namespaces.Add(td.Namespace);
-					HandleAttributes(td.Attributes, namespaces);
+					HandleAttributes(td.GetAttributes(), namespaces);
 
 					foreach (var typeParam in td.TypeParameters) {
-						HandleAttributes(typeParam.Attributes, namespaces);
+						HandleAttributes(typeParam.GetAttributes(), namespaces);
 					}
 
 					foreach (var baseType in td.DirectBaseTypes) {
@@ -71,19 +71,19 @@ namespace ICSharpCode.Decompiler.CSharp
 					}
 					break;
 				case IField field:
-					HandleAttributes(field.Attributes, namespaces);
+					HandleAttributes(field.GetAttributes(), namespaces);
 					CollectNamespacesForTypeReference(field.ReturnType, namespaces);
 					break;
 				case IMethod method:
-					HandleAttributes(method.Attributes, namespaces);
+					HandleAttributes(method.GetAttributes(), namespaces);
-					HandleAttributes(method.ReturnTypeAttributes, namespaces);
+					HandleAttributes(method.GetReturnTypeAttributes(), namespaces);
 					CollectNamespacesForTypeReference(method.ReturnType, namespaces);
 					foreach (var param in method.Parameters) {
-						HandleAttributes(param.Attributes, namespaces);
+						HandleAttributes(param.GetAttributes(), namespaces);
 						CollectNamespacesForTypeReference(param.Type, namespaces);
 					}
 					foreach (var typeParam in method.TypeParameters) {
-						HandleAttributes(typeParam.Attributes, namespaces);
+						HandleAttributes(typeParam.GetAttributes(), namespaces);
 					}
 					if (!method.MetadataToken.IsNil && method.HasBody) {
 						var reader = typeSystem.ModuleDefinition.Reader;
@@ -93,12 +93,12 @@ namespace ICSharpCode.Decompiler.CSharp
 					}
 					break;
 				case IProperty property:
-					HandleAttributes(property.Attributes, namespaces);
+					HandleAttributes(property.GetAttributes(), namespaces);
 					CollectNamespaces(property.Getter, typeSystem, namespaces);
 					CollectNamespaces(property.Setter, typeSystem, namespaces);
 					break;
 				case IEvent @event:
-					HandleAttributes(@event.Attributes, namespaces);
+					HandleAttributes(@event.GetAttributes(), namespaces);
 					CollectNamespaces(@event.AddAccessor, typeSystem, namespaces);
 					CollectNamespaces(@event.RemoveAccessor, typeSystem, namespaces);
 					break;

ICSharpCode.Decompiler/CSharp/Resolver/CSharpOperators.cs

@@ -150,8 +150,9 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 				get { return SymbolKind.Operator; }
 			}
 			
-			IReadOnlyList<IAttribute> IEntity.Attributes {
+			IEnumerable<IAttribute> IEntity.GetAttributes()
-				get { return EmptyList<IAttribute>.Instance; }
+			{
+				return EmptyList<IAttribute>.Instance;
 			}
 			
 			Accessibility IEntity.Accessibility {

ICSharpCode.Decompiler/CSharp/Resolver/CSharpResolver.cs

@@ -1741,7 +1741,7 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 		void CheckForEnumerableInterface(ResolveResult expression, out IType collectionType, out IType enumeratorType, out IType elementType, out ResolveResult getEnumeratorInvocation)
 		{
 			bool? isGeneric;
-			elementType = GetElementTypeFromIEnumerable(expression.Type, compilation, false, out isGeneric);
+			elementType = expression.Type.GetElementTypeFromIEnumerable(compilation, false, out isGeneric);
 			if (isGeneric == true) {
 				ITypeDefinition enumerableOfT = compilation.FindType(KnownTypeCode.IEnumerableOfT).GetDefinition();
 				if (enumerableOfT != null)
@@ -1765,33 +1765,6 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 			getEnumeratorInvocation = ResolveMemberAccess(getEnumeratorInvocation, "GetEnumerator", EmptyList<IType>.Instance, NameLookupMode.InvocationTarget);
 			getEnumeratorInvocation = ResolveInvocation(getEnumeratorInvocation, new ResolveResult[0]);
 		}
-
-		static IType GetElementTypeFromIEnumerable(IType collectionType, ICompilation compilation, bool allowIEnumerator, out bool? isGeneric)
-		{
-			bool foundNonGenericIEnumerable = false;
-			foreach (IType baseType in collectionType.GetAllBaseTypes()) {
-				ITypeDefinition baseTypeDef = baseType.GetDefinition();
-				if (baseTypeDef != null) {
-					KnownTypeCode typeCode = baseTypeDef.KnownTypeCode;
-					if (typeCode == KnownTypeCode.IEnumerableOfT || (allowIEnumerator && typeCode == KnownTypeCode.IEnumeratorOfT)) {
-						ParameterizedType pt = baseType as ParameterizedType;
-						if (pt != null) {
-							isGeneric = true;
-							return pt.GetTypeArgument(0);
-						}
-					}
-					if (typeCode == KnownTypeCode.IEnumerable || (allowIEnumerator && typeCode == KnownTypeCode.IEnumerator))
-						foundNonGenericIEnumerable = true;
-				}
-			}
-			// System.Collections.IEnumerable found in type hierarchy -> Object is element type.
-			if (foundNonGenericIEnumerable) {
-				isGeneric = false;
-				return compilation.FindType(KnownTypeCode.Object);
-			}
-			isGeneric = null;
-			return SpecialType.UnknownType;
-		}
 		#endregion
 
 		#region GetExtensionMethods

ICSharpCode.Decompiler/CSharp/Resolver/ReducedExtensionMethod.cs

@@ -136,12 +136,6 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 
 		#region IMethod implementation
 
-		public IReadOnlyList<IAttribute> ReturnTypeAttributes {
-			get {
-				return baseMethod.ReturnTypeAttributes;
-			}
-		}
-
 		public IReadOnlyList<ITypeParameter> TypeParameters {
 			get {
 				return baseMethod.TypeParameters;
@@ -243,11 +237,8 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 			}
 		}
 
-		public IReadOnlyList<IAttribute> Attributes {
+		IEnumerable<IAttribute> IEntity.GetAttributes() => baseMethod.GetAttributes();
-			get {
+		IEnumerable<IAttribute> IMethod.GetReturnTypeAttributes() => baseMethod.GetReturnTypeAttributes();
-				return baseMethod.Attributes;
-			}
-		}
 
 		public bool IsStatic {
 			get {

ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs

@@ -455,7 +455,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public Attribute ConvertAttribute(IAttribute attribute)
 		{
 			Attribute attr = new Attribute();
-			attr.Type = ConvertType(attribute.AttributeType);
+			attr.Type = ConvertAttributeType(attribute.AttributeType);
 			SimpleType st = attr.Type as SimpleType;
 			MemberType mt = attr.Type as MemberType;
 			if (st != null && st.Identifier.EndsWith("Attribute", StringComparison.Ordinal)) {
@@ -482,6 +482,18 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			}
 			return attr;
 		}
+
+		private IEnumerable<AttributeSection> ConvertAttributes(IEnumerable<IAttribute> attibutes)
+		{
+			return attibutes.Select(a => new AttributeSection(ConvertAttribute(a)));
+		}
+
+		private IEnumerable<AttributeSection> ConvertAttributes(IEnumerable<IAttribute> attibutes, string target)
+		{
+			return attibutes.Select(a => new AttributeSection(ConvertAttribute(a)) {
+				AttributeTarget = target
+			});
+		}
 		#endregion
 
 		#region Convert Attribute Type
@@ -495,6 +507,28 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			if (type.Name.Length > 9 && type.Name.EndsWith("Attribute", StringComparison.Ordinal)) {
 				shortName = type.Name.Remove(type.Name.Length - 9);
 			}
+			if (AlwaysUseShortTypeNames) {
+				switch (astType) {
+					case SimpleType st:
+						st.Identifier = shortName;
+						break;
+					case MemberType mt:
+						mt.MemberName = shortName;
+						break;
+				}
+			} else if (resolver != null) {
+				ApplyShortAttributeNameIfPossible(type, astType, shortName);
+			}
+
+			if (AddTypeReferenceAnnotations)
+				astType.AddAnnotation(type);
+			if (AddResolveResultAnnotations)
+				astType.AddAnnotation(new TypeResolveResult(type));
+			return astType;
+		}
+
+		private void ApplyShortAttributeNameIfPossible(IType type, AstType astType, string shortName)
+		{
 			switch (astType) {
 				case SimpleType st:
 					ResolveResult shortRR = null;
@@ -529,12 +563,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 					}
 					break;
 			}
-
-			if (AddTypeReferenceAnnotations)
-				astType.AddAnnotation(type);
-			if (AddResolveResultAnnotations)
-				astType.AddAnnotation(new TypeResolveResult(type));
-			return astType;
 		}
 
 		private bool IsAttributeType(IType type)
@@ -792,8 +820,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 
 		bool IsFlagsEnum(ITypeDefinition type)
 		{
-			IType flagsAttributeType = type.Compilation.FindType(typeof(System.FlagsAttribute));
+			return type.HasAttribute(KnownAttribute.Flags, inherit: false);
-			return type.GetAttribute(flagsAttributeType) != null;
 		}
 		
 		Expression ConvertEnumValue(IType type, long val)
@@ -880,7 +907,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 				decl.ParameterModifier = ParameterModifier.Params;
 			}
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (parameter.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(parameter.GetAttributes()));
 			}
 			if (parameter.Type.Kind == TypeKind.ByReference) {
 				// avoid 'out ref'
@@ -997,7 +1024,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			decl.ClassType = classType;
 			decl.Modifiers = modifiers;
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (typeDefinition.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(typeDefinition.GetAttributes()));
 			}
 			if (AddResolveResultAnnotations) {
 				decl.AddAnnotation(new TypeResolveResult(typeDefinition));
@@ -1034,7 +1061,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			}
 			return decl;
 		}
-		
+
 		DelegateDeclaration ConvertDelegate(IMethod invokeMethod, Modifiers modifiers)
 		{
 			ITypeDefinition d = invokeMethod.DeclaringTypeDefinition;
@@ -1042,10 +1069,8 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			DelegateDeclaration decl = new DelegateDeclaration();
 			decl.Modifiers = modifiers & ~Modifiers.Sealed;
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (d.Attributes.Select (a => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(d.GetAttributes()));
-				decl.Attributes.AddRange (invokeMethod.ReturnTypeAttributes.Select ((a) => new AttributeSection (ConvertAttribute (a)) {
+				decl.Attributes.AddRange(ConvertAttributes(invokeMethod.GetReturnTypeAttributes(), "return"));
-					AttributeTarget = "return"
-				}));
 			}
 			if (AddResolveResultAnnotations) {
 				decl.AddAnnotation(new TypeResolveResult(d));
@@ -1091,7 +1116,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 				decl.Modifiers = m;
 			}
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (field.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(field.GetAttributes()));
 			}
 			if (AddResolveResultAnnotations) {
 				decl.AddAnnotation(new MemberResolveResult(null, field));
@@ -1115,7 +1140,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			}
 		}
 		
-		Accessor ConvertAccessor(IMethod accessor, Accessibility ownerAccessibility, bool addParamterAttribute)
+		Accessor ConvertAccessor(IMethod accessor, Accessibility ownerAccessibility, bool addParameterAttribute)
 		{
 			if (accessor == null)
 				return Accessor.Null;
@@ -1123,14 +1148,10 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			if (this.ShowAccessibility && accessor.Accessibility != ownerAccessibility)
 				decl.Modifiers = ModifierFromAccessibility(accessor.Accessibility);
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (accessor.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(accessor.GetAttributes()));
-				decl.Attributes.AddRange (accessor.ReturnTypeAttributes.Select ((a) => new AttributeSection (ConvertAttribute (a)) {
+				decl.Attributes.AddRange(ConvertAttributes(accessor.GetReturnTypeAttributes(), "return"));
-					AttributeTarget = "return"
+				if (addParameterAttribute && accessor.Parameters.Count > 0) {
-				}));
+					decl.Attributes.AddRange(ConvertAttributes(accessor.Parameters.Last().GetAttributes(), "param"));
-				if (addParamterAttribute && accessor.Parameters.Count > 0) {
-					decl.Attributes.AddRange (accessor.Parameters.Last ().Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a)) {
-						AttributeTarget = "param"
-					}));
 				}
 			}
 			if (AddResolveResultAnnotations) {
@@ -1145,7 +1166,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			PropertyDeclaration decl = new PropertyDeclaration();
 			decl.Modifiers = GetMemberModifiers(property);
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (property.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(property.GetAttributes()));
 			}
 			if (AddResolveResultAnnotations) {
 				decl.AddAnnotation(new MemberResolveResult(null, property));
@@ -1163,7 +1184,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			IndexerDeclaration decl = new IndexerDeclaration();
 			decl.Modifiers = GetMemberModifiers(indexer);
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (indexer.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(indexer.GetAttributes()));
 			}
 			if (AddResolveResultAnnotations) {
 				decl.AddAnnotation(new MemberResolveResult(null, indexer));
@@ -1184,7 +1205,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 				CustomEventDeclaration decl = new CustomEventDeclaration();
 				decl.Modifiers = GetMemberModifiers(ev);
 				if (ShowAttributes) {
-					decl.Attributes.AddRange (ev.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+					decl.Attributes.AddRange(ConvertAttributes(ev.GetAttributes()));
 				}
 				if (AddResolveResultAnnotations) {
 					decl.AddAnnotation(new MemberResolveResult(null, ev));
@@ -1199,7 +1220,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 				EventDeclaration decl = new EventDeclaration();
 				decl.Modifiers = GetMemberModifiers(ev);
 				if (ShowAttributes) {
-					decl.Attributes.AddRange (ev.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+					decl.Attributes.AddRange(ConvertAttributes(ev.GetAttributes()));
 				}
 				if (AddResolveResultAnnotations) {
 					decl.AddAnnotation(new MemberResolveResult(null, ev));
@@ -1215,10 +1236,8 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			MethodDeclaration decl = new MethodDeclaration();
 			decl.Modifiers = GetMemberModifiers(method);
 			if (ShowAttributes) {
-				decl.Attributes.AddRange (method.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(method.GetAttributes()));
-				decl.Attributes.AddRange (method.ReturnTypeAttributes.Select ((a) => new AttributeSection (ConvertAttribute (a)) {
+				decl.Attributes.AddRange(ConvertAttributes(method.GetReturnTypeAttributes(), "return"));
-					AttributeTarget = "return"
-				}));
 			}
 			if (AddResolveResultAnnotations) {
 				decl.AddAnnotation(new MemberResolveResult(null, method));
@@ -1275,7 +1294,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			ConstructorDeclaration decl = new ConstructorDeclaration();
 			decl.Modifiers = GetMemberModifiers(ctor);
 			if (ShowAttributes)
-				decl.Attributes.AddRange (ctor.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(ctor.GetAttributes()));
 			if (ctor.DeclaringTypeDefinition != null)
 				decl.Name = ctor.DeclaringTypeDefinition.Name;
 			foreach (IParameter p in ctor.Parameters) {
@@ -1369,7 +1388,7 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			decl.Variance = tp.Variance;
 			decl.Name = tp.Name;
 			if (ShowAttributes)
-				decl.Attributes.AddRange (tp.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
+				decl.Attributes.AddRange(ConvertAttributes(tp.GetAttributes()));
 			return decl;
 		}
 		

ICSharpCode.Decompiler/CSharp/Transforms/PatternStatementTransform.cs

@@ -507,17 +507,17 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 				propertyDeclaration.Getter.Body = null;
 				propertyDeclaration.Setter.Body = null;
 
-			// Add C# 7.3 attributes on backing field:
+				// Add C# 7.3 attributes on backing field:
-			var attributes = field.Attributes
+				var attributes = field.GetAttributes()
-				.Where(a => !attributeTypesToRemoveFromAutoProperties.Any(t => t == a.AttributeType.FullName))
+					.Where(a => !attributeTypesToRemoveFromAutoProperties.Contains(a.AttributeType.FullName))
-				.Select(context.TypeSystemAstBuilder.ConvertAttribute).ToArray();
+					.Select(context.TypeSystemAstBuilder.ConvertAttribute).ToArray();
-			if (attributes.Length > 0) {
+				if (attributes.Length > 0) {
-				var section = new AttributeSection {
+					var section = new AttributeSection {
-					AttributeTarget = "field"
+						AttributeTarget = "field"
-				};
+					};
-				section.Attributes.AddRange(attributes);
+					section.Attributes.AddRange(attributes);
-				propertyDeclaration.Attributes.Add(section);
+					propertyDeclaration.Attributes.Add(section);
-			}
+				}
 			}
 			// Since the property instance is not changed, we can continue in the visitor as usual, so return null
 			return null;
@@ -788,8 +788,8 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 				IField field = eventDef.DeclaringType.GetFields(f => f.Name == ev.Name, GetMemberOptions.IgnoreInheritedMembers).SingleOrDefault();
 				if (field != null) {
 					ed.AddAnnotation(field);
-					var attributes = field.Attributes
+					var attributes = field.GetAttributes()
-							.Where(a => !attributeTypesToRemoveFromAutoEvents.Any(t => t == a.AttributeType.FullName))
+							.Where(a => !attributeTypesToRemoveFromAutoEvents.Contains(a.AttributeType.FullName))
 							.Select(context.TypeSystemAstBuilder.ConvertAttribute).ToArray();
 					if (attributes.Length > 0) {
 						var section = new AttributeSection {

ICSharpCode.Decompiler/NRExtensions.cs

@@ -44,10 +44,7 @@ namespace ICSharpCode.Decompiler
 		public static bool IsCompilerGenerated(this IEntity entity)
 		{
 			if (entity != null) {
-				foreach (IAttribute a in entity.Attributes) {
+				return entity.HasAttribute(KnownAttribute.CompilerGenerated);
-					if (a.AttributeType.FullName == "System.Runtime.CompilerServices.CompilerGeneratedAttribute")
-						return true;
-				}
 			}
 			return false;
 		}

ICSharpCode.Decompiler/TypeSystem/ComHelper.cs

@@ -33,7 +33,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		{
 			return typeDefinition != null
 				&& typeDefinition.Kind == TypeKind.Interface
-				&& typeDefinition.GetAttributes(KnownAttribute.ComImport, inherit: false) != null;
+				&& typeDefinition.HasAttribute(KnownAttribute.ComImport, inherit: false);
 		}
 		
 		/// <summary>

ICSharpCode.Decompiler/TypeSystem/IEntity.cs

@@ -123,8 +123,9 @@ namespace ICSharpCode.Decompiler.TypeSystem
 
 		/// <summary>
 		/// Gets the attributes on this entity.
+		/// Does not include inherited attributes.
 		/// </summary>
-		IReadOnlyList<IAttribute> Attributes { get; }
+		IEnumerable<IAttribute> GetAttributes();
 
 		/// <summary>
 		/// Gets the accessibility of this entity.

ICSharpCode.Decompiler/TypeSystem/IMethod.cs

@@ -79,7 +79,10 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		/// <summary>
 		/// Gets the attributes associated with the return type. (e.g. [return: MarshalAs(...)])
 		/// </summary>
-		IReadOnlyList<IAttribute> ReturnTypeAttributes { get; }
+		/// <remarks>
+		/// Does not include inherited attributes.
+		/// </remarks>
+		IEnumerable<IAttribute> GetReturnTypeAttributes();
 
 		/// <summary>
 		/// Gets the type parameters of this method; or an empty list if the method is not generic.

ICSharpCode.Decompiler/TypeSystem/IParameter.cs

@@ -63,9 +63,9 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	public interface IParameter : IVariable
 	{
 		/// <summary>
-		/// Gets the list of attributes.
+		/// Gets the attributes on this parameter.
 		/// </summary>
-		IReadOnlyList<IAttribute> Attributes { get; }
+		IEnumerable<IAttribute> GetAttributes();
 		
 		/// <summary>
 		/// Gets whether this parameter is a C# 'ref' parameter.

ICSharpCode.Decompiler/TypeSystem/ITypeParameter.cs

@@ -82,9 +82,9 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		new string Name { get; }
 
 		/// <summary>
-		/// Gets the list of attributes declared on this type parameter.
+		/// Gets the attributes declared on this type parameter.
 		/// </summary>
-		IReadOnlyList<IAttribute> Attributes { get; }
+		IEnumerable<IAttribute> GetAttributes();
 		
 		/// <summary>
 		/// Gets the variance of this type parameter.

ICSharpCode.Decompiler/TypeSystem/Implementation/AbstractResolvedEntity.cs

@@ -59,6 +59,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		}
 		
 		public IReadOnlyList<IAttribute> Attributes { get; protected set; }
+		IEnumerable<IAttribute> IEntity.GetAttributes() => Attributes;
 
 		public bool IsStatic { get { return unresolved.IsStatic; } }
 		public bool IsAbstract { get { return unresolved.IsAbstract; } }

ICSharpCode.Decompiler/TypeSystem/Implementation/AbstractResolvedTypeParameter.cs

@@ -71,8 +71,8 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public int Index {
 			get { return index; }
 		}
-		
+
-		public abstract IReadOnlyList<IAttribute> Attributes { get; }
+		public abstract IEnumerable<IAttribute> GetAttributes();
 		
 		public VarianceModifier Variance {
 			get { return variance; }

ICSharpCode.Decompiler/TypeSystem/Implementation/DefaultParameter.cs

@@ -72,9 +72,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 			get { return owner; }
 		}
 		
-		public IReadOnlyList<IAttribute> Attributes {
+		public IEnumerable<IAttribute> GetAttributes() => attributes;
-			get { return attributes; }
-		}
 		
 		public bool IsRef {
 			get { return isRef; }

ICSharpCode.Decompiler/TypeSystem/Implementation/DefaultResolvedMethod.cs

@@ -170,6 +170,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		
 		public IReadOnlyList<IParameter> Parameters { get; private set; }
 		public IReadOnlyList<IAttribute> ReturnTypeAttributes { get; private set; }
+		IEnumerable<IAttribute> IMethod.GetReturnTypeAttributes() => ReturnTypeAttributes;
 		public IReadOnlyList<ITypeParameter> TypeParameters { get; private set; }
 
 		public IReadOnlyList<IType> TypeArguments {

ICSharpCode.Decompiler/TypeSystem/Implementation/DefaultResolvedTypeDefinition.cs

@@ -105,7 +105,9 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 				return LazyInit.GetOrSet(ref this.attributes, result);
 			}
 		}
-		
+
+		public IEnumerable<IAttribute> GetAttributes() => Attributes;
+
 		public System.Reflection.Metadata.EntityHandle MetadataToken => parts[0].MetadataToken;
 
 		public SymbolKind SymbolKind {

ICSharpCode.Decompiler/TypeSystem/Implementation/DefaultResolvedTypeParameter.cs

@@ -61,7 +61,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 			this.attributes = attributes ?? EmptyList<IAttribute>.Instance;
 		}
 
-		public override IReadOnlyList<IAttribute> Attributes => attributes;
+		public override IEnumerable<IAttribute> GetAttributes() => attributes;
 
 		public override bool HasValueTypeConstraint => hasValueTypeConstraint;
 		public override bool HasReferenceTypeConstraint => hasReferenceTypeConstraint;

ICSharpCode.Decompiler/TypeSystem/Implementation/DefaultUnresolvedParameter.cs

@@ -229,6 +229,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 			public IType Type { get; internal set; }
 			public string Name { get; internal set; }
 			public IReadOnlyList<IAttribute> Attributes { get; internal set; }
+			public IEnumerable<IAttribute> GetAttributes() => Attributes;
 			public bool IsRef { get; internal set; }
 			public bool IsOut { get; internal set; }
 			public bool IsParams { get; internal set; }

ICSharpCode.Decompiler/TypeSystem/Implementation/DummyTypeParameter.cs

@@ -141,9 +141,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 			get { return index; }
 		}
 		
-		IReadOnlyList<IAttribute> ITypeParameter.Attributes {
+		IEnumerable<IAttribute> ITypeParameter.GetAttributes() =>EmptyList<IAttribute>.Instance;
-			get { return EmptyList<IAttribute>.Instance; }
-		}
 		
 		SymbolKind ITypeParameter.OwnerType {
 			get { return ownerType; }

ICSharpCode.Decompiler/TypeSystem/Implementation/FakeMember.cs

@@ -58,7 +58,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 
 		IAssembly IEntity.ParentAssembly => DeclaringType?.GetDefinition()?.ParentAssembly;
 
-		IReadOnlyList<IAttribute> IEntity.Attributes => EmptyList<IAttribute>.Instance;
+		IEnumerable<IAttribute> IEntity.GetAttributes() => EmptyList<IAttribute>.Instance;
 
 		public Accessibility Accessibility { get; set; } = Accessibility.Public;
 
@@ -130,7 +130,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 
 		public override SymbolKind SymbolKind => symbolKind;
 		
-		IReadOnlyList<IAttribute> IMethod.ReturnTypeAttributes => EmptyList<IAttribute>.Instance;
+		IEnumerable<IAttribute> IMethod.GetReturnTypeAttributes() => EmptyList<IAttribute>.Instance;
 
 		public IReadOnlyList<ITypeParameter> TypeParameters { get; set; } = EmptyList<ITypeParameter>.Instance;
 

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataEvent.cs

@@ -38,7 +38,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		readonly string name;
 
 		// lazy-loaded:
-		IAttribute[] customAttributes;
 		IType returnType;
 
 		internal MetadataEvent(MetadataAssembly assembly, EventDefinitionHandle handle)
@@ -103,16 +102,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		TypeParameterSubstitution IMember.Substitution => TypeParameterSubstitution.Identity;
 
 		#region Attributes
-		public IReadOnlyList<IAttribute> Attributes {
+		public IEnumerable<IAttribute> GetAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
-		IAttribute[] DecodeAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 			var metadata = assembly.metadata;

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataField.cs

@@ -43,7 +43,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		IType type;
 		bool isVolatile; // initialized together with this.type
 		byte decimalConstant; // 0=no, 1=yes, 2=unknown
-		IAttribute[] customAttributes;
 
 		internal MetadataField(MetadataAssembly assembly, FieldDefinitionHandle handle)
 		{
@@ -127,17 +126,8 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public IType DeclaringType => DeclaringTypeDefinition;
 		public IAssembly ParentAssembly => assembly;
 		public ICompilation Compilation => assembly.Compilation;
-
+		
-		public IReadOnlyList<IAttribute> Attributes {
+		public IEnumerable<IAttribute> GetAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
-		IAttribute[] DecodeAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 			var metadata = assembly.metadata;

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataMethod.cs

@@ -45,8 +45,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		// lazy-loaded fields:
 		ITypeDefinition declaringType;
 		string name;
-		IAttribute[] customAttributes;
-		IAttribute[] returnTypeAttributes;
 		IParameter[] parameters;
 		IType returnType;
 
@@ -232,15 +230,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public ICompilation Compilation => assembly.Compilation;
 
 		#region Attributes
-		public IReadOnlyList<IAttribute> Attributes {
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
 		IType FindInteropType(string name)
 		{
 			return assembly.Compilation.FindType(new TopLevelTypeName(
@@ -248,7 +237,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 			));
 		}
 
-		IAttribute[] DecodeAttributes()
+		public IEnumerable<IAttribute> GetAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 
@@ -365,16 +354,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		#endregion
 
 		#region Return type attributes
-		public IReadOnlyList<IAttribute> ReturnTypeAttributes {
+		public IEnumerable<IAttribute> GetReturnTypeAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.returnTypeAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.returnTypeAttributes, DecodeReturnTypeAttributes());
-			}
-		}
-
-		private IAttribute[] DecodeReturnTypeAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 			var metadata = assembly.metadata;

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataParameter.cs

@@ -37,7 +37,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 
 		// lazy-loaded:
 		string name;
-		IAttribute[] customAttributes;
 
 		internal MetadataParameter(MetadataAssembly assembly, IParameterizedMember owner, IType type, ParameterHandle handle)
 		{
@@ -53,16 +52,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public EntityHandle MetadataToken => handle;
 
 		#region Attributes
-		public IReadOnlyList<IAttribute> Attributes {
+		public IEnumerable<IAttribute> GetAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
-		IAttribute[] DecodeAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 			var metadata = assembly.metadata;

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataProperty.cs

@@ -42,7 +42,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		readonly SymbolKind symbolKind;
 
 		// lazy-loaded:
-		IAttribute[] customAttributes;
 		volatile Accessibility cachedAccessiblity = InvalidAccessibility;
 		IParameter[] parameters;
 		IType returnType;
@@ -144,16 +143,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		TypeParameterSubstitution IMember.Substitution => TypeParameterSubstitution.Identity;
 
 		#region Attributes
-		public IReadOnlyList<IAttribute> Attributes {
+		public IEnumerable<IAttribute> GetAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
-		IAttribute[] DecodeAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 			var metadata = assembly.metadata;

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeDefinition.cs

@@ -51,7 +51,6 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public bool HasExtensionMethods { get; }
 
 		// lazy-loaded:
-		IAttribute[] customAttributes;
 		IMember[] members;
 		IField[] fields;
 		IProperty[] properties;
@@ -284,16 +283,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public IAssembly ParentAssembly => assembly;
 
 		#region Type Attributes
-		public IReadOnlyList<IAttribute> Attributes {
+		public IEnumerable<IAttribute> GetAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
-		IAttribute[] DecodeAttributes()
 		{
 			var b = new AttributeListBuilder(assembly);
 			var metadata = assembly.metadata;

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataTypeParameter.cs

@@ -98,16 +98,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 
 		public GenericParameterHandle MetadataToken => handle;
 
-		public override IReadOnlyList<IAttribute> Attributes {
+		public override IEnumerable<IAttribute> GetAttributes()
-			get {
-				var attr = LazyInit.VolatileRead(ref this.customAttributes);
-				if (attr != null)
-					return attr;
-				return LazyInit.GetOrSet(ref this.customAttributes, DecodeAttributes());
-			}
-		}
-
-		IAttribute[] DecodeAttributes()
 		{
 			var metadata = assembly.metadata;
 			var gp = metadata.GetGenericParameter(handle);

ICSharpCode.Decompiler/TypeSystem/Implementation/SpecializedMember.cs

@@ -150,10 +150,8 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public ITypeDefinition DeclaringTypeDefinition {
 			get { return baseMember.DeclaringTypeDefinition; }
 		}
-		
+
-		public IReadOnlyList<IAttribute> Attributes {
+		IEnumerable<IAttribute> IEntity.GetAttributes() => baseMember.GetAttributes();
-			get { return baseMember.Attributes; }
-		}
 		
 		public IEnumerable<IMember> ExplicitlyImplementedInterfaceMembers {
 			get {

ICSharpCode.Decompiler/TypeSystem/Implementation/SpecializedMethod.cs

@@ -92,10 +92,8 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 		public IReadOnlyList<IType> TypeArguments {
 			get { return this.Substitution.MethodTypeArguments ?? EmptyList<IType>.Instance; }
 		}
-		
+
-		public IReadOnlyList<IAttribute> ReturnTypeAttributes {
+		public IEnumerable<IAttribute> GetReturnTypeAttributes() => methodDefinition.GetReturnTypeAttributes();
-			get { return methodDefinition.ReturnTypeAttributes; }
-		}
 		
 		public IReadOnlyList<ITypeParameter> TypeParameters {
 			get {
@@ -230,7 +228,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 				this.baseTp = baseTp;
 			}
 
-			public override IReadOnlyList<IAttribute> Attributes => baseTp.Attributes;
+			public override IEnumerable<IAttribute> GetAttributes() => baseTp.GetAttributes();
 
 			public override int GetHashCode()
 			{

ICSharpCode.Decompiler/TypeSystem/Implementation/SpecializedParameter.cs

@@ -35,7 +35,7 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 			this.newOwner = newOwner;
 		}
 
-		IReadOnlyList<IAttribute> IParameter.Attributes => baseParameter.Attributes;
+		IEnumerable<IAttribute> IParameter.GetAttributes() => baseParameter.GetAttributes();
 		bool IParameter.IsRef => baseParameter.IsRef;
 		bool IParameter.IsOut => baseParameter.IsOut;
 		bool IParameter.IsParams => baseParameter.IsParams;

ICSharpCode.Decompiler/TypeSystem/InheritanceHelper.cs

@@ -29,7 +29,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	{
 		// TODO: maybe these should be extension methods?
 		// or even part of the interface itself? (would allow for easy caching)
-		
+
 		#region GetBaseMember
 		/// <summary>
 		/// Gets the base member that has the same signature.
@@ -58,16 +58,16 @@ namespace ICSharpCode.Decompiler.TypeSystem
 					yield return member;
 				}*/
 			}
-			
+
 			// Remove generic specialization
 			var substitution = member.Substitution;
 			member = member.MemberDefinition;
-			
+
 			if (member.DeclaringTypeDefinition == null) {
 				// For global methods, return empty list. (prevent SharpDevelop UDC crash 4524)
 				yield break;
 			}
-			
+
 			IEnumerable<IType> allBaseTypes;
 			if (includeImplementedInterfaces) {
 				allBaseTypes = member.DeclaringTypeDefinition.GetAllBaseTypes();
@@ -93,7 +93,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			}
 		}
 		#endregion
-		
+
 		#region GetDerivedMember
 		/// <summary>
 		/// Finds the member declared in 'derivedType' that has the same signature (could override) 'baseMember'.
@@ -104,10 +104,10 @@ namespace ICSharpCode.Decompiler.TypeSystem
 				throw new ArgumentNullException("baseMember");
 			if (derivedType == null)
 				throw new ArgumentNullException("derivedType");
-			
+
 			if (baseMember.Compilation != derivedType.Compilation)
 				throw new ArgumentException("baseMember and derivedType must be from the same compilation");
-			
+
 			baseMember = baseMember.MemberDefinition;
 			bool includeInterfaces = baseMember.DeclaringTypeDefinition.Kind == TypeKind.Interface;
 			IMethod method = baseMember as IMethod;
@@ -147,5 +147,34 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			return null;
 		}
 		#endregion
+
+		#region Attributes
+		internal static IEnumerable<IAttribute> GetAttributes(ITypeDefinition typeDef)
+		{
+			foreach (var baseType in typeDef.GetNonInterfaceBaseTypes().Reverse()) {
+				ITypeDefinition baseTypeDef = baseType.GetDefinition();
+				if (baseTypeDef == null)
+					continue;
+				foreach (var attr in baseTypeDef.GetAttributes()) {
+					yield return attr;
+				}
+			}
+		}
+
+		internal static IEnumerable<IAttribute> GetAttributes(IMember member)
+		{
+			HashSet<IMember> visitedMembers = new HashSet<IMember>();
+			do {
+				member = member.MemberDefinition; // it's sufficient to look at the definitions
+				if (!visitedMembers.Add(member)) {
+					// abort if we seem to be in an infinite loop (cyclic inheritance)
+					break;
+				}
+				foreach (var attr in member.GetAttributes()) {
+					yield return attr;
+				}
+			} while (member.IsOverride && (member = InheritanceHelper.GetBaseMember(member)) != null);
+		}
+		#endregion
 	}
 }

ICSharpCode.Decompiler/TypeSystem/TypeSystemExtensions.cs

@@ -420,181 +420,70 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			return null;
 		}
 		#endregion
-
-		#region ITypeReference.Resolve(ICompilation)
-
-		/// <summary>
-		/// Resolves a type reference in the compilation's main type resolve context.
-		/// Some type references require a more specific type resolve context and will not resolve using this method.
-		/// </summary>
-		/// <returns>
-		/// Returns the resolved type.
-		/// In case of an error, returns <see cref="SpecialType.UnknownType"/>.
-		/// Never returns null.
-		/// </returns>
-		public static IType Resolve (this ITypeReference reference, ICompilation compilation)
-		{
-			if (reference == null)
-				throw new ArgumentNullException ("reference");
-			if (compilation == null)
-				throw new ArgumentNullException ("compilation");
-			return reference.Resolve (compilation.TypeResolveContext);
-		}
-		#endregion
 		
-		#region ITypeDefinition.GetAttribute
+		#region IEntity.GetAttribute
 		/// <summary>
-		/// Gets the attribute of the specified attribute type (or derived attribute types).
+		/// Gets whether the entity has an attribute of the specified attribute type (or derived attribute types).
 		/// </summary>
 		/// <param name="entity">The entity on which the attributes are declared.</param>
 		/// <param name="attributeType">The attribute type to look for.</param>
 		/// <param name="inherit">
-		/// Specifies whether attributes inherited from base classes and base members (if the given <paramref name="entity"/> in an <c>override</c>)
+		/// Specifies whether attributes inherited from base classes and base members
-		/// should be returned. The default is <c>true</c>.
+		/// (if the given <paramref name="entity"/> in an <c>override</c>)
+		/// should be returned.
 		/// </param>
-		/// <returns>
+		public static bool HasAttribute(this IEntity entity, KnownAttribute attrType, bool inherit=false)
-		/// Returns the attribute that was found; or <c>null</c> if none was found.
-		/// If inherit is true, an from the entity itself will be returned if possible;
-		/// and the base entity will only be searched if none exists.
-		/// </returns>
-		public static IAttribute GetAttribute(this IEntity entity, IType attributeType, bool inherit = true)
 		{
-			return GetAttributes(entity, attributeType, inherit).FirstOrDefault();
+			return GetAttribute(entity, attrType, inherit) != null;
 		}
-		
+
-		/// <summary>
-		/// Gets the attributes of the specified attribute type (or derived attribute types).
-		/// </summary>
-		/// <param name="entity">The entity on which the attributes are declared.</param>
-		/// <param name="attributeType">The attribute type to look for.</param>
-		/// <param name="inherit">
-		/// Specifies whether attributes inherited from base classes and base members (if the given <paramref name="entity"/> in an <c>override</c>)
-		/// should be returned. The default is <c>true</c>.
-		/// </param>
-		/// <returns>
-		/// Returns the list of attributes that were found.
-		/// If inherit is true, attributes from the entity itself are returned first; followed by attributes inherited from the base entity.
-		/// </returns>
-		public static IEnumerable<IAttribute> GetAttributes(this IEntity entity, IType attributeType, bool inherit = true)
-		{
-			if (entity == null)
-				throw new ArgumentNullException("entity");
-			if (attributeType == null)
-				throw new ArgumentNullException("attributeType");
-			return GetAttributes(entity, attributeType.Equals, inherit);
-		}
-		
 		/// <summary>
 		/// Gets the attribute of the specified attribute type (or derived attribute types).
 		/// </summary>
 		/// <param name="entity">The entity on which the attributes are declared.</param>
 		/// <param name="attributeType">The attribute type to look for.</param>
 		/// <param name="inherit">
-		/// Specifies whether attributes inherited from base classes and base members (if the given <paramref name="entity"/> in an <c>override</c>)
+		/// Specifies whether attributes inherited from base classes and base members
-		/// should be returned. The default is <c>true</c>.
+		/// (if the given <paramref name="entity"/> in an <c>override</c>)
+		/// should be returned.
 		/// </param>
 		/// <returns>
 		/// Returns the attribute that was found; or <c>null</c> if none was found.
 		/// If inherit is true, an from the entity itself will be returned if possible;
 		/// and the base entity will only be searched if none exists.
 		/// </returns>
-		public static IAttribute GetAttribute(this IEntity entity, KnownAttribute attributeType, bool inherit = true)
+		public static IAttribute GetAttribute(this IEntity entity, KnownAttribute attributeType, bool inherit=false)
-		{
-			return GetAttributes(entity, attributeType, inherit).FirstOrDefault();
-		}
-		
-		/// <summary>
-		/// Gets the attributes of the specified attribute type (or derived attribute types).
-		/// </summary>
-		/// <param name="entity">The entity on which the attributes are declared.</param>
-		/// <param name="attributeType">The attribute type to look for.</param>
-		/// <param name="inherit">
-		/// Specifies whether attributes inherited from base classes and base members (if the given <paramref name="entity"/> in an <c>override</c>)
-		/// should be returned. The default is <c>true</c>.
-		/// </param>
-		/// <returns>
-		/// Returns the list of attributes that were found.
-		/// If inherit is true, attributes from the entity itself are returned first; followed by attributes inherited from the base entity.
-		/// </returns>
-		public static IEnumerable<IAttribute> GetAttributes(this IEntity entity, KnownAttribute attributeType, bool inherit = true)
 		{
-			if (entity == null)
+			return GetAttributes(entity, inherit).FirstOrDefault(a => a.AttributeType.IsKnownType(attributeType));
-				throw new ArgumentNullException("entity");
-			return GetAttributes(entity, attrType => {
-			                     	ITypeDefinition typeDef = attrType.GetDefinition();
-			                     	return typeDef != null && typeDef.FullTypeName == attributeType.GetTypeName();
-			                     }, inherit);
 		}
 
 		/// <summary>
-		/// Gets the attribute of the specified attribute type (or derived attribute types).
+		/// Gets the attributes on the entity.
 		/// </summary>
 		/// <param name="entity">The entity on which the attributes are declared.</param>
 		/// <param name="inherit">
-		/// Specifies whether attributes inherited from base classes and base members (if the given <paramref name="entity"/> in an <c>override</c>)
+		/// Specifies whether attributes inherited from base classes and base members
-		/// should be returned. The default is <c>true</c>.
+		/// (if the given <paramref name="entity"/> in an <c>override</c>)
+		/// should be returned.
 		/// </param>
 		/// <returns>
-		/// Returns the attribute that was found; or <c>null</c> if none was found.
+		/// Returns the list of attributes that were found.
-		/// If inherit is true, an from the entity itself will be returned if possible;
+		/// If inherit is true, attributes from the entity itself are returned first;
-		/// and the base entity will only be searched if none exists.
+		/// followed by attributes inherited from the base entity.
 		/// </returns>
-		public static IEnumerable<IAttribute> GetAttributes(this IEntity entity, bool inherit = true)
+		public static IEnumerable<IAttribute> GetAttributes(this IEntity entity, bool inherit)
-		{
+		{
-			if (entity == null)
+			if (inherit) {
-				throw new ArgumentNullException ("entity");
+				if (entity is ITypeDefinition td) {
-			return GetAttributes(entity, a => true, inherit);
+					return InheritanceHelper.GetAttributes(td);
-		}
+				} else if (entity is IMember m) {
-		
+					return InheritanceHelper.GetAttributes(m);
-		static IEnumerable<IAttribute> GetAttributes(IEntity entity, Predicate<IType> attributeTypePredicate, bool inherit)
+				} else {
-		{
+					throw new NotSupportedException("Unknown entity type");
-			if (!inherit) {
-				foreach (var attr in entity.Attributes) {
-					if (attributeTypePredicate(attr.AttributeType))
-						yield return attr;
 				}
-				yield break;
+			} else {
+				return entity.GetAttributes();
 			}
-			ITypeDefinition typeDef = entity as ITypeDefinition;
-			if (typeDef != null) {
-				foreach (var baseType in typeDef.GetNonInterfaceBaseTypes().Reverse()) {
-					ITypeDefinition baseTypeDef = baseType.GetDefinition();
-					if (baseTypeDef == null)
-						continue;
-					foreach (var attr in baseTypeDef.Attributes) {
-						if (attributeTypePredicate(attr.AttributeType))
-							yield return attr;
-					}
-				}
-				yield break;
-			}
-			IMember member = entity as IMember;
-			if (member != null) {
-				HashSet<IMember> visitedMembers = new HashSet<IMember>();
-				do {
-					member = member.MemberDefinition; // it's sufficient to look at the definitions
-					if (!visitedMembers.Add(member)) {
-						// abort if we seem to be in an infinite loop (cyclic inheritance)
-						break;
-					}
-					foreach (var attr in member.Attributes) {
-						if (attributeTypePredicate(attr.AttributeType))
-							yield return attr;
-					}
-				} while (member.IsOverride && (member = InheritanceHelper.GetBaseMember(member)) != null);
-				yield break;
-			}
-			throw new NotSupportedException("Unknown entity type");
-		}
-		#endregion
-
-		#region IsCompilerGenerated
-		public static bool IsCompilerGenereated(this IEntity entity)
-		{
-			if (entity == null)
-				throw new ArgumentNullException(nameof(entity));
-
-			return entity.GetAttribute(KnownAttribute.CompilerGenerated) != null;
 		}
 		#endregion
 

ICSharpCode.Decompiler/TypeSystem/VarArgInstanceMethod.cs

@@ -109,10 +109,9 @@ namespace ICSharpCode.Decompiler.TypeSystem
 				baseMethod.Specialize(substitution),
 				parameters.Skip(baseMethod.Parameters.Count - 1).Select(p => p.Type.AcceptVisitor(substitution)).ToList());
 		}
-		
+
-		public IReadOnlyList<IAttribute> ReturnTypeAttributes {
+		IEnumerable<IAttribute> IEntity.GetAttributes() => baseMethod.GetAttributes();
-			get { return baseMethod.ReturnTypeAttributes; }
+		IEnumerable<IAttribute> IMethod.GetReturnTypeAttributes() => baseMethod.GetReturnTypeAttributes();
-		}
 
 		public IReadOnlyList<ITypeParameter> TypeParameters {
 			get { return baseMethod.TypeParameters; }
@@ -225,10 +224,6 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			get { return baseMethod.ParentAssembly; }
 		}
 
-		public IReadOnlyList<IAttribute> Attributes {
-			get { return baseMethod.Attributes; }
-		}
-
 		public bool IsStatic {
 			get { return baseMethod.IsStatic; }
 		}