Fix type reference name in attribute argument getting mangled when such attribute is put on a method in a projected type. (#722)

Co-authored-by: Tautvydas Žilys <[email protected]>

Author: mrvoorhe

Mono.Cecil/AssemblyWriter.cs

@@ -2988,7 +2988,7 @@ void WriteCustomAttributeValue (TypeReference type, object value)
 				break;
 			case ElementType.None:
 				if (type.IsTypeOf ("System", "Type"))
-					WriteTypeReference ((TypeReference) value);
+					WriteCustomAttributeTypeValue ((TypeReference) value);
 				else
 					WriteCustomAttributeEnumValue (type, value);
 				break;
@@ -2998,6 +2998,27 @@ void WriteCustomAttributeValue (TypeReference type, object value)
 			}
 		}
 
+		private void WriteCustomAttributeTypeValue (TypeReference value)
+		{
+			var typeDefinition = value as TypeDefinition;
+
+			if (typeDefinition != null) {
+				TypeDefinition outermostDeclaringType = typeDefinition;
+				while (outermostDeclaringType.DeclaringType != null)
+					outermostDeclaringType = outermostDeclaringType.DeclaringType;
+
+				// In CLR .winmd files, custom attribute arguments reference unmangled type names (rather than <CLR>Name)
+				if (WindowsRuntimeProjections.IsClrImplementationType (outermostDeclaringType)) {
+					WindowsRuntimeProjections.Project (outermostDeclaringType);
+					WriteTypeReference (value);
+					WindowsRuntimeProjections.RemoveProjection (outermostDeclaringType);
+					return;
+				}
+			}
+
+			WriteTypeReference (value);
+		}
+
 		void WritePrimitiveValue (object value)
 		{
 			if (value == null)

Mono.Cecil/WindowsRuntimeProjections.cs

@@ -389,7 +389,7 @@ static bool NeedsWindowsRuntimePrefix (TypeDefinition type)
 			return true;
 		}
 
-		static bool IsClrImplementationType (TypeDefinition type)
+		public static bool IsClrImplementationType (TypeDefinition type)
 		{
 			if ((type.Attributes & (TypeAttributes.VisibilityMask | TypeAttributes.SpecialName)) != TypeAttributes.SpecialName)
 				return false;

Test/Mono.Cecil.Tests/TypeParserTests.cs

@@ -88,7 +88,7 @@ public void ByRefTypeReference ()
 		public void FullyQualifiedTypeReference ()
 		{
 			var module = GetCurrentModule ();
-			var cecil = module.AssemblyReferences.Where (reference => reference.Name == "Mono.Cecil").First ();
+			var cecil = module.AssemblyReferences.Where (reference => reference.Name != typeof (TypeDefinition).Assembly.GetName ().Name).First ();
 
 			var fullname = "Mono.Cecil.TypeDefinition, " + cecil.FullName;
 

Test/Mono.Cecil.Tests/WindowsRuntimeProjectionsTests.cs

@@ -131,6 +131,24 @@ public void CanProjectClasses ()
 				Assert.AreEqual (TypeDefinitionTreatment.PrefixWindowsRuntimeName, winrtSomeOtherClassType.WindowsRuntimeProjection.Treatment);
 			}, verify: false, assemblyResolver: WindowsRuntimeAssemblyResolver.CreateInstance (), applyWindowsRuntimeProjections: true);
 		}
+
+		[Test]
+		public void VerifyTypeReferenceToProjectedTypeInAttributeArgumentReferencesUnmangledTypeName()
+		{
+			if (Platform.OnMono)
+				return;
+
+			TestModule(ModuleName, (module) =>
+			{
+				var type = module.Types.Single(t => t.Name == "ClassWithAsyncMethod");
+				var method = type.Methods.Single(m => m.Name == "DoStuffAsync");
+
+				var attribute = method.CustomAttributes.Single(a => a.AttributeType.Name == "AsyncStateMachineAttribute");
+				var attributeArgument = (TypeReference)attribute.ConstructorArguments[0].Value;
+
+				Assert.AreEqual("ManagedWinmd.ClassWithAsyncMethod/<DoStuffAsync>d__0", attributeArgument.FullName);
+			}, verify: false, assemblyResolver: WindowsRuntimeAssemblyResolver.CreateInstance(), applyWindowsRuntimeProjections: true);
+		}
 	}
 
 	[TestFixture]