Expression.Call can act as MakeGenericMethod so make it perform same validation (#1930)

Also improved validation done by MakeGenericMethod to avoid warning if no type arguments are passed in.
Added tests.

1 files changed, 19 insertions, 0 deletions

diff --git a/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs b/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs
index 7872462f7..08bb958cd 100644
--- a/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs
+++ b/test/Mono.Linker.Tests.Cases/DataFlow/GenericParameterDataFlow.cs
@@ -882,12 +882,14 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 			{
 				TestNullMethod ();
 				TestUnknownInput (null);
+				TestUnknownMethodButNoTypeArguments (null);
 				TestWithNoArguments ();
 
 				TestWithRequirements ();
 				TestWithRequirementsFromParam (null);
 				TestWithRequirementsFromGenericParam<TestType> ();
 				TestWithRequirementsViaRuntimeMethod ();
+				TestWithRequirementsButNoTypeArguments ();
 
 				TestWithNoRequirements ();
 				TestWithNoRequirementsFromParam (null);
@@ -914,6 +916,14 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 				mi.MakeGenericMethod (typeof (TestType));
 			}
 
+			[UnrecognizedReflectionAccessPattern (typeof (MethodInfo), nameof (MethodInfo.MakeGenericMethod), new Type[] { typeof (Type[]) },
+				messageCode: "IL2060")]
+			static void TestUnknownMethodButNoTypeArguments (MethodInfo mi)
+			{
+				// Thechnically linker could figure this out, but it's not worth the complexity - such call will always fail at runtime.
+				mi.MakeGenericMethod (Type.EmptyTypes);
+			}
+
 			[RecognizedReflectionAccessPattern]
 			static void TestWithNoArguments ()
 			{
@@ -957,6 +967,15 @@ namespace Mono.Linker.Tests.Cases.DataFlow
 					.MakeGenericMethod (typeof (TestType));
 			}
 
+			[UnrecognizedReflectionAccessPattern (typeof (MethodInfo), nameof (MethodInfo.MakeGenericMethod), new Type[] { typeof (Type[]) },
+				messageCode: "IL2060")]
+			static void TestWithRequirementsButNoTypeArguments ()
+			{
+				// Linker could figure out that this is not a problem, but it's not worth the complexity, since this will always throw at runtime
+				typeof (MakeGenericMethod).GetMethod (nameof (GenericWithRequirements), BindingFlags.Static)
+					.MakeGenericMethod (Type.EmptyTypes);
+			}
+
 			public static void GenericWithRequirements<[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicFields)] T> ()
 			{
 			}