Correctly handle assembly qualified names in generic parameters (dotn…

…et/linker#1546)

We always assumed that the generic parameters would come from the same assembly as the generic type itself.
Adds a new test to validate the scenario.


Commit migrated from dotnet/linker@82ae21e

src/tools/illink/src/linker/Linker.Dataflow/ReflectionMethodBodyScanner.cs

@@ -1336,7 +1336,7 @@ void ProcessCreateInstanceByName (ref ReflectionPatternContext reflectionContext
 								continue;
 							}
 
-							var resolvedType = (TypeNameResolver.ResolveTypeName (resolvedAssembly, typeNameStringValue.Contents))?.Resolve ();
+							var resolvedType = (_context.TypeNameResolver.ResolveTypeName (resolvedAssembly, typeNameStringValue.Contents))?.Resolve ();
 							if (resolvedType == null) {
 								// It's not wrong to have a reference to non-existing type - the code may well expect to get an exception in this case
 								// Note that we did find the assembly, so it's not a linker config problem, it's either intentional, or wrong versions of assemblies

src/tools/illink/src/linker/Linker.Steps/LinkAttributesStep.cs

@@ -172,7 +172,7 @@ bool GetAttributeType (XPathNodeIterator iterator, string attributeFullName, out
 					return false;
 				}
 
-				attributeType = TypeNameResolver.ResolveTypeName (assembly, attributeFullName)?.Resolve ();
+				attributeType = Context.TypeNameResolver.ResolveTypeName (assembly, attributeFullName)?.Resolve ();
 			}
 
 			if (attributeType == null) {

src/tools/illink/src/linker/Linker.Steps/MarkStep.cs

@@ -748,7 +748,7 @@ protected virtual void MarkUserDependency (MemberReference context, CustomAttrib
 
 			TypeDefinition td;
 			if (args.Count >= 2 && args[1].Value is string typeName) {
-				td = TypeNameResolver.ResolveTypeName (assembly ?? context.Module.Assembly, typeName)?.Resolve ();
+				td = _context.TypeNameResolver.ResolveTypeName (assembly ?? context.Module.Assembly, typeName)?.Resolve ();
 				if (td == null) {
 					_context.LogWarning (
 						$"Could not resolve dependency type '{typeName}' specified in a `PreserveDependency` attribute", 2004, context.Resolve ());
@@ -1562,10 +1562,10 @@ TypeDefinition GetDebuggerAttributeTargetType (CustomAttribute ca, AssemblyDefin
 					TypeName typeName = TypeParser.ParseTypeName (targetTypeName);
 					if (typeName is AssemblyQualifiedTypeName assemblyQualifiedTypeName) {
 						AssemblyDefinition assembly = _context.GetLoadedAssembly (assemblyQualifiedTypeName.AssemblyName.Name);
-						return TypeNameResolver.ResolveTypeName (assembly, targetTypeName)?.Resolve ();
+						return _context.TypeNameResolver.ResolveTypeName (assembly, targetTypeName)?.Resolve ();
 					}
 
-					return TypeNameResolver.ResolveTypeName (asm, targetTypeName)?.Resolve ();
+					return _context.TypeNameResolver.ResolveTypeName (asm, targetTypeName)?.Resolve ();
 				}
 			}
 

src/tools/illink/src/linker/Linker/TypeNameResolver.cs

@@ -28,8 +28,7 @@ public TypeReference ResolveTypeName (string typeNameString)
 			}
 
 			if (parsedTypeName is AssemblyQualifiedTypeName assemblyQualifiedTypeName) {
-				AssemblyDefinition assembly = _context.GetLoadedAssembly (assemblyQualifiedTypeName.AssemblyName.Name);
-				return ResolveTypeName (assembly, assemblyQualifiedTypeName.TypeName);
+				return ResolveTypeName (null, assemblyQualifiedTypeName);
 			}
 
 			foreach (var assemblyDefiniton in _context.GetAssemblies ()) {
@@ -41,19 +40,23 @@ public TypeReference ResolveTypeName (string typeNameString)
 			return null;
 		}
 
-		public static TypeReference ResolveTypeName (AssemblyDefinition assembly, string typeNameString)
+		public TypeReference ResolveTypeName (AssemblyDefinition assembly, string typeNameString)
 		{
 			return ResolveTypeName (assembly, TypeParser.ParseTypeName (typeNameString));
 		}
 
-		static TypeReference ResolveTypeName (AssemblyDefinition assembly, TypeName typeName)
+		TypeReference ResolveTypeName (AssemblyDefinition assembly, TypeName typeName)
 		{
+			if (typeName is AssemblyQualifiedTypeName assemblyQualifiedTypeName) {
+				// In this case we ignore the assembly parameter since the type name has assembly in it
+				var assemblyFromName = _context.GetLoadedAssembly (assemblyQualifiedTypeName.AssemblyName.Name);
+				return ResolveTypeName (assemblyFromName, assemblyQualifiedTypeName.TypeName);
+			}
+
 			if (assembly == null || typeName == null)
 				return null;
 
-			if (typeName is AssemblyQualifiedTypeName assemblyQualifiedTypeName) {
-				return ResolveTypeName (assembly, assemblyQualifiedTypeName.TypeName);
-			} else if (typeName is ConstructedGenericTypeName constructedGenericTypeName) {
+			if (typeName is ConstructedGenericTypeName constructedGenericTypeName) {
 				var genericTypeRef = ResolveTypeName (assembly, constructedGenericTypeName.GenericType);
 				if (genericTypeRef == null)
 					return null;

src/tools/illink/test/Mono.Linker.Tests.Cases/DataFlow/ApplyTypeAnnotations.cs

@@ -17,6 +17,10 @@ public static void Main ()
 			TestFromTypeOf ();
 			TestFromTypeGetTypeOverConstant ();
 			TestFromStringContantWithAnnotation ();
+			TestFromStringConstantWithGeneric ();
+			TestFromStringConstantWithGenericAndAssemblyQualified ();
+			TestFromStringConstantWithGenericAndAssemblyQualifiedInvalidAssembly ();
+			TestFromStringConstantWithGenericAndAssemblyQualifiedNonExistingAssembly ();
 		}
 
 		[Kept]
@@ -123,5 +127,65 @@ private static void RequireCombinationOnString (
 			string typeName)
 		{
 		}
+
+		// Issue: https://github.com/mono/linker/issues/1537
+		//[Kept]
+		//[KeptMember (".ctor()")]
+		class FromStringConstantWithGenericInner
+		{
+		}
+
+		[Kept]
+		[KeptMember (".ctor()")]
+		class FromStringConstantWithGeneric<T>
+		{
+			[Kept]
+			public T GetValue () { return default (T); }
+		}
+
+		[Kept]
+		static void TestFromStringConstantWithGeneric ()
+		{
+			RequireCombinationOnString ("Mono.Linker.Tests.Cases.DataFlow.ApplyTypeAnnotations+FromStringConstantWithGeneric`1[[Mono.Linker.Tests.Cases.DataFlow.ApplyTypeAnnotations+FromStringConstantWithGenericInner]]");
+		}
+
+		[Kept]
+		[KeptMember (".ctor()")]
+		class FromStringConstantWithGenericAndAssemblyQualified<T>
+		{
+			[Kept]
+			public T GetValue () { return default (T); }
+		}
+
+		[Kept]
+		// This is a workaround for the inability to lazy load assemblies. The type name resolver will not load new assemblies
+		// and since the KeptAttribute is otherwise not referenced by the test anywhere (the test-validation attributes are removed before processing normally)
+		// it would not resolve from name - since its assembly is not loaded.
+		// Adding DynamicDependency solves this problem as it is basically the only attribute which has the ability to load new assemblies.
+		[DynamicDependency (DynamicallyAccessedMemberTypes.None, typeof (KeptAttribute))]
+		static void TestFromStringConstantWithGenericAndAssemblyQualified ()
+		{
+			RequireCombinationOnString ("Mono.Linker.Tests.Cases.DataFlow.ApplyTypeAnnotations+FromStringConstantWithGenericAndAssemblyQualified`1[[Mono.Linker.Tests.Cases.Expectations.Assertions.KeptAttribute,Mono.Linker.Tests.Cases.Expectations]]");
+		}
+
+		class InvalidAssemblyNameType
+		{
+		}
+
+		[Kept]
+		static void TestFromStringConstantWithGenericAndAssemblyQualifiedInvalidAssembly ()
+		{
+			RequireCombinationOnString ("Mono.Linker.Tests.Cases.DataFlow.ApplyTypeAnnotations+InvalidAssemblyNameType,Invalid/Assembly/Name");
+		}
+
+		class NonExistingAssemblyType
+		{
+		}
+
+		[Kept]
+		static void TestFromStringConstantWithGenericAndAssemblyQualifiedNonExistingAssembly ()
+		{
+			RequireCombinationOnString ("Mono.Linker.Tests.Cases.DataFlow.ApplyTypeAnnotations+InvalidAssemblyNameType,NonExistingAssembly");
+		}
 	}
 }