Preserve static type info for return value of ctor

src/coreclr/tools/Common/Compiler/Dataflow/MethodProxy.cs

@@ -66,6 +66,8 @@ internal partial ImmutableArray<GenericParameterProxy> GetGenericParameters()
             return builder.ToImmutableArray();
         }
 
+        internal partial bool IsConstructor() => Method.IsConstructor;
+
         internal partial bool IsStatic() => Method.Signature.IsStatic;
 
         internal partial bool HasImplicitThis() => !Method.Signature.IsStatic;

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/Dataflow/MethodReturnValue.cs

@@ -18,7 +18,7 @@ internal partial record MethodReturnValue
     {
         public MethodReturnValue(MethodDesc method, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
         {
-            StaticType = method.Signature.ReturnType;
+            StaticType = method.IsConstructor ? method.OwningType : method.Signature.ReturnType;
             Method = method;
             DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
         }

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/Dataflow/ReflectionMethodBodyScanner.cs

@@ -656,12 +656,6 @@ public static bool HandleCall(
                         if (Intrinsics.GetIntrinsicIdForMethod(callingMethodDefinition) == IntrinsicId.RuntimeReflectionExtensions_GetMethodInfo)
                             break;
 
-                        if (param.IsEmpty())
-                        {
-                            // The static value is unknown and the below `foreach` won't execute
-                            reflectionMarker.Dependencies.Add(reflectionMarker.Factory.ReflectedDelegate(null), "Delegate.Method access on unknown delegate type");
-                        }
-
                         foreach (var valueNode in param.AsEnumerable())
                         {
                             TypeDesc? staticType = (valueNode as IValueWithStaticType)?.StaticType?.Type;

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/MethodProxy.cs

@@ -46,6 +46,8 @@ internal partial ImmutableArray<GenericParameterProxy> GetGenericParameters ()
 			return builder.ToImmutableArray ();
 		}
 
+		internal partial bool IsConstructor () => Method.IsConstructor ();
+
 		internal partial bool IsStatic () => Method.IsStatic;
 
 		internal partial bool HasImplicitThis () => Method.HasImplicitThis ();

src/tools/illink/src/ILLink.Shared/TrimAnalysis/HandleCallAction.cs

@@ -1167,7 +1167,7 @@ GenericParameterValue genericParam
 
 			// For now, if the intrinsic doesn't set a return value, fall back on the annotations.
 			// Note that this will be DynamicallyAccessedMembers.None for the intrinsics which don't return types.
-			returnValue ??= calledMethod.ReturnsVoid () ? MultiValueLattice.Top : annotatedMethodReturnValue;
+			returnValue ??= (calledMethod.ReturnsVoid () && !calledMethod.IsConstructor ()) ? MultiValueLattice.Top : annotatedMethodReturnValue;
 
 			if (MethodIsTypeConstructor (calledMethod))
 				returnValue = UnknownValue.Instance;

src/tools/illink/src/ILLink.Shared/TypeSystemProxy/MethodProxy.cs

@@ -56,6 +56,7 @@ internal bool HasParameterOfType (ParameterIndex parameterIndex, string fullType
 		internal partial bool HasGenericParameters ();
 		internal partial bool HasGenericParametersCount (int genericParameterCount);
 		internal partial ImmutableArray<GenericParameterProxy> GetGenericParameters ();
+		internal partial bool IsConstructor ();
 		internal partial bool IsStatic ();
 		internal partial bool HasImplicitThis ();
 		internal partial bool ReturnsVoid ();

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

@@ -683,7 +683,7 @@ internal partial bool MethodRequiresDataFlowAnalysis (MethodProxy method)
 			=> RequiresDataFlowAnalysis (method.Method);
 
 		internal partial MethodReturnValue GetMethodReturnValue (MethodProxy method, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
-			=> new MethodReturnValue (method.Method.ReturnType.ResolveToTypeDefinition (_context), method.Method, dynamicallyAccessedMemberTypes);
+			=> MethodReturnValue.Create (method.Method, dynamicallyAccessedMemberTypes, _context);
 
 		internal partial MethodReturnValue GetMethodReturnValue (MethodProxy method)
 			=> GetMethodReturnValue (method, GetReturnParameterAnnotation (method.Method));

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

@@ -59,6 +59,8 @@ internal partial ImmutableArray<GenericParameterProxy> GetGenericParameters ()
 			return builder.ToImmutableArray ();
 		}
 
+		internal partial bool IsConstructor () => Method.IsConstructor;
+
 		internal partial bool IsStatic () => Method.IsStatic;
 
 		internal partial bool HasImplicitThis () => Method.HasImplicitThis ();

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

@@ -5,6 +5,7 @@
 using System.Diagnostics.CodeAnalysis;
 using ILLink.Shared.DataFlow;
 using Mono.Cecil;
+using Mono.Linker;
 using Mono.Linker.Dataflow;
 using TypeDefinition = Mono.Cecil.TypeDefinition;
 
@@ -16,7 +17,13 @@ namespace ILLink.Shared.TrimAnalysis
 	/// </summary>
 	internal partial record MethodReturnValue
 	{
-		public MethodReturnValue (TypeDefinition? staticType, MethodDefinition method, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
+		public static MethodReturnValue Create (MethodDefinition method, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes, LinkContext context)
+		{
+			var staticType = method.IsConstructor ? method.DeclaringType : method.ReturnType.ResolveToTypeDefinition (context);
+			return new MethodReturnValue (staticType, method, dynamicallyAccessedMemberTypes);
+		}
+
+		private MethodReturnValue (TypeDefinition? staticType, MethodDefinition method, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
 		{
 			StaticType = staticType == null ? null : new (staticType);
 			Method = method;

src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/generated/ILLink.RoslynAnalyzer.Tests.Generator/ILLink.RoslynAnalyzer.Tests.TestCaseGenerator/DataFlowTests.g.cs

@@ -19,12 +19,6 @@ public Task GenericParameterDataFlowMarking ()
 			return RunTest (allowMissingWarnings: true);
 		}
 
-		[Fact]
-		public Task MakeGenericDataflowIntrinsics ()
-		{
-			return RunTest (allowMissingWarnings: true);
-		}
-
 		[Fact]
 		public Task MethodByRefParameterDataFlow ()
 		{

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

@@ -164,6 +164,9 @@ class TestType
 			}
 
 			[Kept]
+			// MyReflectOverType is not intrinsically understood by the analysis, so
+			// it doesn't satisfy the PublicFields | NonPublicFields requirement.
+			[ExpectedWarning ("IL2075")]
 			public static void Test ()
 			{
 				new MyReflectOverType (typeof (TestType)).GetFields (BindingFlags.Instance | BindingFlags.Public);

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

@@ -88,6 +88,10 @@ static void AssignToThis ()
 			s.AssignToThisCaptured ();
 		}
 
+		// Analyzer warns that 'this' doesn't satisfy annotations on GetMethod,
+		// even though those annotations are invalid.
+		// https://github.com/dotnet/runtime/issues/101211
+		[ExpectedWarning ("IL2075", ProducedBy = Tool.Analyzer)]
 		static void TestAnnotationOnNonTypeMethod ()
 		{
 			var t = new NonTypeType ();