Fix tuple types.

ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs

@@ -279,7 +279,7 @@ namespace ICSharpCode.Decompiler.Tests
 			RunForLibrary(cscOptions: cscOptions);
 		}
 
-		[Test, Ignore("tuple type support not yet implemented for SRM")]
+		[Test]
 		public void TupleTests([ValueSource("roslynOnlyOptions")] CSharpCompilerOptions cscOptions)
 		{
 			RunForLibrary(cscOptions: cscOptions);

ICSharpCode.Decompiler/CSharp/RequiredNamespaceCollector.cs

@@ -118,6 +118,11 @@ namespace ICSharpCode.Decompiler.CSharp
 				case PointerType pointerType:
 					CollectNamespacesForTypeReference(pointerType.ElementType, namespaces);
 					break;
+				case TupleType tupleType:
+					foreach (var elementType in tupleType.ElementTypes) {
+						CollectNamespacesForTypeReference(elementType, namespaces);
+					}
+					break;
 				default:
 					namespaces.Add(type.Namespace);
 					break;

ICSharpCode.Decompiler/TypeSystem/ApplyAttributeTypeVisitor.cs

@@ -40,7 +40,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	/// <summary>
 	/// Introduces 'dynamic' and tuple types based on attribute values.
 	/// </summary>
-    class ApplyAttributeTypeVisitor : TypeVisitor
+	sealed class ApplyAttributeTypeVisitor : TypeVisitor
 	{
 		public static IType ApplyAttributesToType(
 			IType inputType,

ICSharpCode.Decompiler/TypeSystem/DecompilerTypeSystem.cs

@@ -145,6 +145,18 @@ namespace ICSharpCode.Decompiler.TypeSystem
 				typeAttributeOptions 
 			);
 		}
+
+		IType ResolveDeclaringType(SRM.EntityHandle declaringTypeReference)
+		{
+			// resolve without substituting dynamic/tuple types
+			return MetadataTypeReference.Resolve(
+				declaringTypeReference,
+				moduleDefinition.Metadata,
+				context,
+				typeAttributes: null,
+				attributeOptions: TypeAttributeOptions.None
+			);
+		}
 		#endregion
 		
 		public SRM.MethodSignature<IType> DecodeMethodSignature(SRM.StandaloneSignatureHandle handle)
@@ -186,7 +198,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 						case SRM.HandleKind.FieldDefinition:
 							var fieldDefHandle = (SRM.FieldDefinitionHandle)fieldReference;
 							var fieldDef = metadata.GetFieldDefinition(fieldDefHandle);
-							declaringType = ResolveAsType(fieldDef.GetDeclaringType());
+							declaringType = ResolveDeclaringType(fieldDef.GetDeclaringType());
 							returnType = new FieldTypeReference(fieldDefHandle, metadata, typeAttributeOptions);
 							var declaringTypeDefinition = declaringType.GetDefinition();
 							if (declaringTypeDefinition == null)
@@ -199,7 +211,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 						case SRM.HandleKind.MemberReference:
 							var memberRef = metadata.GetMemberReference((SRM.MemberReferenceHandle)fieldReference);
 							Debug.Assert(memberRef.GetKind() == SRM.MemberReferenceKind.Field);
-							declaringType = ResolveAsType(memberRef.Parent);
+							declaringType = ResolveDeclaringType(memberRef.Parent);
 							field = FindNonGenericField(metadata, memberRef, declaringType);
 							break;
 						default:
@@ -318,7 +330,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			switch (methodReference.Kind) {
 				case SRM.HandleKind.MethodDefinition:
 					var methodDef = metadata.GetMethodDefinition((SRM.MethodDefinitionHandle)methodReference);
-					declaringType = ResolveAsType(methodDef.GetDeclaringType());
+					declaringType = ResolveDeclaringType(methodDef.GetDeclaringType());
 					declaringTypeDefinition = declaringType.GetDefinition();
 					if (declaringTypeDefinition == null) {
 						return CreateFakeMethod(declaringType, metadata.GetString(methodDef.Name), methodDef.DecodeSignature(TypeReferenceSignatureDecoder.Instance, default));
@@ -343,7 +355,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 							FindNonGenericMethod(metadata, memberRef.Parent, out declaringType);
 							break;
 						default:
-							declaringType = ResolveAsType(memberRef.Parent);
+							declaringType = ResolveDeclaringType(memberRef.Parent);
 							break;
 					}
 					declaringTypeDefinition = declaringType.GetDefinition();
@@ -480,7 +492,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		{
 			var propertyDefinition = metadata.GetPropertyDefinition(handle);
 			var declaringType = metadata.GetMethodDefinition(propertyDefinition.GetAccessors().GetAny()).GetDeclaringType();
-			ITypeDefinition typeDef = ResolveAsType(declaringType).GetDefinition();
+			ITypeDefinition typeDef = ResolveDeclaringType(declaringType).GetDefinition();
 			if (typeDef == null)
 				return null;
 			foreach (IProperty property in typeDef.Properties) {
@@ -518,7 +530,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		{
 			var eventDefinition = metadata.GetEventDefinition(handle);
 			var declaringType = metadata.GetMethodDefinition(eventDefinition.GetAccessors().GetAny()).GetDeclaringType();
-			ITypeDefinition typeDef = ResolveAsType(declaringType).GetDefinition();
+			ITypeDefinition typeDef = ResolveDeclaringType(declaringType).GetDefinition();
 			if (typeDef == null)
 				return null;
 			var returnType = ResolveAsType(eventDefinition.Type);

ICSharpCode.Decompiler/TypeSystem/MetadataLoader.cs

@@ -674,17 +674,38 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			foreach (var handle in attributes) {
 				var attribute = currentMetadata.GetCustomAttribute(handle);
 				var typeHandle = attribute.GetAttributeType(currentMetadata);
-				switch (typeHandle.GetFullTypeName(currentMetadata).ReflectionName) {
+				if (IgnoreAttribute(typeHandle.GetFullTypeName(currentMetadata))) {
-					case "System.Runtime.CompilerServices.DynamicAttribute":
+					continue;
-					case "System.Runtime.CompilerServices.ExtensionAttribute":
-					case "System.Runtime.CompilerServices.DecimalConstantAttribute":
-					case "System.ParamArrayAttribute":
-						continue;
 				}
 				targetCollection.Add(ReadAttribute(handle));
 			}
 		}
 
+		bool IgnoreAttribute(FullTypeName typeName)
+		{
+			if (typeName.IsNested || typeName.TopLevelTypeName.TypeParameterCount != 0)
+				return false;
+			switch (typeName.TopLevelTypeName.Namespace) {
+				case "System.Runtime.CompilerServices":
+					switch (typeName.Name) {
+						case "DynamicAttribute":
+							return UseDynamicType;
+						case "TupleElementNamesAttribute":
+							return UseTupleTypes;
+						case "ExtensionAttribute":
+							return true; // TODO: shouldn't we disable extension methods in C# 2.0 mode?
+						case "DecimalConstantAttribute":
+							return true;
+						default:
+							return false;
+					}
+				case "System":
+					return typeName.Name == "ParamArrayAttribute";
+				default:
+					return false;
+			}
+		}
+
 		public IUnresolvedAttribute ReadAttribute(CustomAttributeHandle handle)
 		{
 			var attribute = currentMetadata.GetCustomAttribute(handle);

ICSharpCode.Decompiler/TypeSystem/TypeProvider.cs

@@ -28,7 +28,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	/// <summary>
 	/// Allows decoding signatures using decompiler types.
 	/// </summary>
-	class TypeProvider : SRM.ISignatureTypeProvider<IType, ITypeResolveContext>, SRM.ICustomAttributeTypeProvider<IType>
+	sealed class TypeProvider : SRM.ISignatureTypeProvider<IType, ITypeResolveContext>, SRM.ICustomAttributeTypeProvider<IType>
 	{
 		readonly IAssembly assembly;
 		readonly ICompilation compilation;