Passing null to args for Activator.CreateInstance means no args (#2111)

The core already recognized empty array as no args, but null means the same thing.

This change also:
* Fixes a bug when PublicConstructors was required but only PublicParameterlessConstructors were provided the warning message would not say what the requirement was.
* Simplifies some of the code
* Better matching for UnrecognizedReflectionAccessPattern and warnings in tests
* Added tests

3 files changed, 163 insertions, 47 deletions

diff --git a/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs b/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs
index 3889225a2..09de0a015 100644
--- a/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs
+++ b/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs
@@ -264,6 +264,8 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 		[UnrecognizedReflectionAccessPattern (typeof (GenericBaseTypeWithRequirements<>), "T", messageCode: "IL2091")]
 		class DerivedTypeWithOpenGenericOnBase<T> : GenericBaseTypeWithRequirements<T>
 		{
+			[UnrecognizedReflectionAccessPattern (typeof (GenericBaseTypeWithRequirements<>), "T", messageCode: "IL2091")]
+			public DerivedTypeWithOpenGenericOnBase () { }
 		}
 
 		[RecognizedReflectionAccessPattern]
@@ -363,11 +365,12 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 				[RecognizedReflectionAccessPattern]
 				set;
 			}
+
 			public TypeRequiresPublicMethods<TOuter> PublicMethodsProperty {
 				[UnrecognizedReflectionAccessPattern (typeof (TypeRequiresPublicMethods<>), "T", messageCode: "IL2091")]
-				get;
+				get => null;
 				[UnrecognizedReflectionAccessPattern (typeof (TypeRequiresPublicMethods<>), "T", messageCode: "IL2091")]
-				set;
+				set { }
 			}
 
 			[RecognizedReflectionAccessPattern]
@@ -424,6 +427,8 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 		class PartialyInstantiatedMethods<[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicFields)] TOuter>
 			: BaseForPartialInstantiation<TestType, TOuter>
 		{
+			[UnrecognizedReflectionAccessPattern (typeof (BaseForPartialInstantiation<,>), "TMethods", messageCode: "IL2091")]
+			public PartialyInstantiatedMethods () { }
 		}
 
 		[RecognizedReflectionAccessPattern]
diff --git a/test/Mono.Linker.Tests.Cases/DataFlow/MemberTypesRelationships.cs b/test/Mono.Linker.Tests.Cases/DataFlow/MemberTypesRelationships.cs
index a16ffd9ef..5d3805aef 100644
--- a/test/Mono.Linker.Tests.Cases/DataFlow/MemberTypesRelationships.cs
+++ b/test/Mono.Linker.Tests.Cases/DataFlow/MemberTypesRelationships.cs
@@ -34,12 +34,13 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			TestNonPublicEvents (typeof (TestType));
 			TestInterfaces (typeof (TestType));
 			TestAll (typeof (TestType));
+			TestMultiple (typeof (TestType));
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicMethods))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicParameterlessConstructor (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)] Type type)
 		{
@@ -51,9 +52,10 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicMethods))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicConstructors (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicConstructors)] Type type)
 		{
@@ -65,10 +67,10 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicParameterlessConstructor))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicParameterlessConstructor), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicMethods))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestNonPublicConstructors (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicConstructors)] Type type)
 		{
@@ -80,9 +82,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicMethods))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicMethods), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicMethods))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors), "y '" + nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicConstructors) + "' i")]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicMethods (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)] Type type)
 		{
@@ -93,9 +95,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicMethods))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestNonPublicMethods (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicMethods)] Type type)
 		{
@@ -106,9 +108,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicFields))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicFields), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicFields))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicFields (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicFields)] Type type)
 		{
@@ -119,9 +121,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicFields))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicConstructors), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicConstructors))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestNonPublicFields (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicFields)] Type type)
 		{
@@ -132,9 +134,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicNestedTypes))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresInterfaces))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicNestedTypes), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicNestedTypes))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresInterfaces), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.Interfaces))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicNestedTypes (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicNestedTypes)] Type type)
 		{
@@ -145,9 +147,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicNestedTypes))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresInterfaces))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicNestedTypes), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicNestedTypes))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresInterfaces), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.Interfaces))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestNonPublicNestedTypes (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicNestedTypes)] Type type)
 		{
@@ -158,9 +160,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicProperties))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicProperties), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicProperties))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicFields))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicProperties (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicProperties)] Type type)
 		{
@@ -171,9 +173,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicProperties))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicFields))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicProperties), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicProperties))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicFields), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicFields))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestNonPublicProperties (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicProperties)] Type type)
 		{
@@ -184,9 +186,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicEvents))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicEvents), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicEvents))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicFields))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestPublicEvents (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicEvents)] Type type)
 		{
@@ -197,9 +199,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicEvents))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicFields))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicEvents), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicEvents))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicFields), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicFields))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestNonPublicEvents (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicEvents)] Type type)
 		{
@@ -210,9 +212,9 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresAll (); // Warns
 		}
 
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicNestedTypes))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicNestedTypes))]
-		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicNestedTypes), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.PublicNestedTypes))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresNonPublicNestedTypes), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicNestedTypes))]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresAll), nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.All))]
 		static void TestInterfaces (
 			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.Interfaces)] Type type)
 		{
@@ -244,6 +246,31 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			type.RequiresInterfaces ();
 		}
 
+		static void RequiresMultiplePrivates (
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.NonPublicMethods | DynamicallyAccessedMemberTypes.NonPublicFields)] Type type)
+		{
+		}
+
+		static void RequiresSomePublic (
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.Interfaces | DynamicallyAccessedMemberTypes.PublicParameterlessConstructor | DynamicallyAccessedMemberTypes.NonPublicNestedTypes | DynamicallyAccessedMemberTypes.PublicMethods)] Type type)
+		{
+		}
+
+		[ExpectedWarning ("IL2067",
+			nameof (RequiresMultiplePrivates),
+			nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicMethods),
+			nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicFields))]
+		[ExpectedWarning ("IL2067",
+			nameof (RequiresSomePublic),
+			nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.Interfaces),
+			nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicNestedTypes))]
+		static void TestMultiple (
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods | DynamicallyAccessedMemberTypes.PublicFields | DynamicallyAccessedMemberTypes.PublicConstructors)] Type type)
+		{
+			RequiresMultiplePrivates (type);
+			RequiresSomePublic (type);
+		}
+
 		class TestType { }
 	}
 }
diff --git a/test/Mono.Linker.Tests.Cases/Reflection/ActivatorCreateInstance.cs b/test/Mono.Linker.Tests.Cases/Reflection/ActivatorCreateInstance.cs
index 8f1cfae07..bd21af5bc 100644
--- a/test/Mono.Linker.Tests.Cases/Reflection/ActivatorCreateInstance.cs
+++ b/test/Mono.Linker.Tests.Cases/Reflection/ActivatorCreateInstance.cs
@@ -16,7 +16,7 @@ namespace Mono.Linker.Tests.Cases.Reflection
 			Activator.CreateInstance (typeof (Test1));
 			Activator.CreateInstance (typeof (Test2), true);
 			Activator.CreateInstance (typeof (Test3), BindingFlags.NonPublic | BindingFlags.Instance, null, null, null);
-			Activator.CreateInstance (typeof (Test4), GetBindingFlags (), null, null, null);
+			Activator.CreateInstance (typeof (Test4), GetBindingFlags (), null, GetArgs (), null);
 			Activator.CreateInstance (typeof (Test5), new object[] { 1, "ss" });
 
 			var p = new ActivatorCreateInstance ();
@@ -51,6 +51,12 @@ namespace Mono.Linker.Tests.Cases.Reflection
 			TestCreateInstanceOfTWithNoConstraint<TestCreateInstanceOfTWithNoConstraintType> ();
 
 			TestCreateInstanceOfTWithDataflow<TestCreateInstanceOfTWithDataflowType> ();
+
+			TestNullArgsOnKnownType ();
+			TestNullArgsOnAnnotatedType (typeof (TestType));
+			TestNullArgsNonPublicOnly (typeof (TestType));
+
+			CreateInstanceWithGetTypeFromHierarchy.Test ();
 		}
 
 		[Kept]
@@ -292,6 +298,12 @@ namespace Mono.Linker.Tests.Cases.Reflection
 		}
 
 		[Kept]
+		private static object[] GetArgs ()
+		{
+			return null;
+		}
+
+		[Kept]
 		private static void WithAssemblyName ()
 		{
 			Activator.CreateInstance ("test", "Mono.Linker.Tests.Cases.Reflection.ActivatorCreateInstance+WithAssemblyNameParameterless1");
@@ -485,5 +497,77 @@ namespace Mono.Linker.Tests.Cases.Reflection
 		{
 			Activator.CreateInstance<T> ();
 		}
+
+		[Kept]
+		class TestNullArgsType
+		{
+			[Kept]
+			public TestNullArgsType () { }
+
+			public TestNullArgsType (int i) { }
+		}
+
+		[Kept]
+		[RecognizedReflectionAccessPattern]
+		private static void TestNullArgsOnKnownType ()
+		{
+			Activator.CreateInstance (typeof (TestNullArgsType), null);
+		}
+
+		[Kept]
+		[RecognizedReflectionAccessPattern]
+		private static void TestNullArgsOnAnnotatedType (
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor),
+			KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))] Type type)
+		{
+			Activator.CreateInstance (type, BindingFlags.Public | BindingFlags.Instance, null, null, CultureInfo.InvariantCulture);
+		}
+
+		[Kept]
+		[ExpectedWarning ("IL2067", nameof (DynamicallyAccessedMemberTypes) + "." + nameof (DynamicallyAccessedMemberTypes.NonPublicConstructors))]
+		private static void TestNullArgsNonPublicOnly (
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor),
+			KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))] Type type)
+		{
+			Activator.CreateInstance (type, BindingFlags.NonPublic | BindingFlags.Instance, null, null, CultureInfo.InvariantCulture);
+		}
+
+		[Kept]
+		class CreateInstanceWithGetTypeFromHierarchy
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
+			[KeptMember (".ctor()")]
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)]
+			class AnnotatedBase
+			{
+				[Kept]
+				[ExpectedNoWarnings]
+				public void TestCreateInstance ()
+				{
+					Activator.CreateInstance (GetType (), BindingFlags.Public | BindingFlags.Instance, null, null, CultureInfo.InvariantCulture, null);
+				}
+			}
+
+			[Kept]
+			[KeptBaseType (typeof (AnnotatedBase))]
+			[KeptMember (".ctor()")]
+			class Derived : AnnotatedBase
+			{
+				[Kept]
+				public static void KeepIt () { }
+			}
+
+			[Kept]
+			public static void Test ()
+			{
+				Derived.KeepIt ();
+				(new AnnotatedBase ()).TestCreateInstance ();
+			}
+		}
+
+		[Kept]
+		[KeptMember (".ctor()")]
+		class TestType { }
 	}
 }