Fix handling of special intrinsics in analyzer (#2756)

Some intrinsics require generic instantiation handling. Currently the shared code doesn't have the abitlity to do this, so we leave it as a special case and analyzer/linker have special code to handle it.
In the analyzer this code was missing from the diagnsotic reporting part and thus the intrinsic was handled as a normal method call - which caused problems with TypeDelegator.

Added tests for TypeDelegator which cover these issues.

3 files changed, 29 insertions, 13 deletions

diff --git a/test/ILLink.RoslynAnalyzer.Tests/ReflectionTests.cs b/test/ILLink.RoslynAnalyzer.Tests/ReflectionTests.cs
index 605a37e47..b0f719ac8 100644
--- a/test/ILLink.RoslynAnalyzer.Tests/ReflectionTests.cs
+++ b/test/ILLink.RoslynAnalyzer.Tests/ReflectionTests.cs
@@ -169,6 +169,12 @@ namespace ILLink.RoslynAnalyzer.Tests
 		}
 
 		[Fact]
+		public Task TypeDelegator ()
+		{
+			return RunTest ();
+		}
+
+		[Fact]
 		public Task TypeHierarchyReflectionWarnings ()
 		{
 			// https://github.com/dotnet/linker/issues/2578
diff --git a/test/ILLink.RoslynAnalyzer.Tests/generated/ILLink.RoslynAnalyzer.Tests.Generator/ILLink.RoslynAnalyzer.Tests.TestCaseGenerator/ReflectionTests.g.cs b/test/ILLink.RoslynAnalyzer.Tests/generated/ILLink.RoslynAnalyzer.Tests.Generator/ILLink.RoslynAnalyzer.Tests.TestCaseGenerator/ReflectionTests.g.cs
index 353ac8968..08642e90e 100644
--- a/test/ILLink.RoslynAnalyzer.Tests/generated/ILLink.RoslynAnalyzer.Tests.Generator/ILLink.RoslynAnalyzer.Tests.TestCaseGenerator/ReflectionTests.g.cs
+++ b/test/ILLink.RoslynAnalyzer.Tests/generated/ILLink.RoslynAnalyzer.Tests.Generator/ILLink.RoslynAnalyzer.Tests.TestCaseGenerator/ReflectionTests.g.cs
@@ -62,12 +62,6 @@ namespace ILLink.RoslynAnalyzer.Tests
 		}
 
 		[Fact]
-		public Task TypeDelegator ()
-		{
-			return RunTest (allowMissingWarnings: true);
-		}
-
-		[Fact]
 		public Task TypeHierarchyLibraryModeSuppressions ()
 		{
 			return RunTest (allowMissingWarnings: true);
diff --git a/test/Mono.Linker.Tests.Cases/Reflection/TypeDelegator.cs b/test/Mono.Linker.Tests.Cases/Reflection/TypeDelegator.cs
index fb7f61b04..4f5d0542c 100644
--- a/test/Mono.Linker.Tests.Cases/Reflection/TypeDelegator.cs
+++ b/test/Mono.Linker.Tests.Cases/Reflection/TypeDelegator.cs
@@ -7,9 +7,11 @@ using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using System.Text;
 using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Helpers;
 
 namespace Mono.Linker.Tests.Cases.Reflection
 {
+	[ExpectedNoWarnings]
 	public class TypeDelegator
 	{
 		public static void Main ()
@@ -17,6 +19,8 @@ namespace Mono.Linker.Tests.Cases.Reflection
 			TestTypeUsedWithDelegator ();
 			TestNullValue ();
 			TestNoValue ();
+			TestDataFlowPropagation ();
+			TestDataFlowOfUnannotated ();
 		}
 
 		[Kept]
@@ -38,7 +42,7 @@ namespace Mono.Linker.Tests.Cases.Reflection
 		static void TestNullValue ()
 		{
 			var typeDelegator = new System.Reflection.TypeDelegator (null);
-			RequireAll (typeDelegator);
+			typeDelegator.RequiresAll ();
 		}
 
 		[Kept]
@@ -47,15 +51,27 @@ namespace Mono.Linker.Tests.Cases.Reflection
 			Type t = null;
 			Type noValue = Type.GetTypeFromHandle (t.TypeHandle);
 			var typeDelegator = new System.Reflection.TypeDelegator (noValue);
-			RequireAll (typeDelegator);
+			typeDelegator.RequiresAll ();
 		}
 
 		[Kept]
-		public static void RequireAll (
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicFields))]
+		static void TestDataFlowPropagation (
 			[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
-			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.All)]
-			System.Reflection.TypeDelegator t
-		)
-		{ }
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)]
+			Type typeWithPublicMethods = null)
+		{
+			var typeDelegator = new System.Reflection.TypeDelegator (typeWithPublicMethods);
+			typeDelegator.RequiresPublicMethods (); // Should not warn
+			typeDelegator.RequiresPublicFields (); // Should warn
+		}
+
+		[Kept]
+		[ExpectedWarning ("IL2067", nameof (DataFlowTypeExtensions.RequiresPublicMethods))]
+		static void TestDataFlowOfUnannotated (Type unknownType = null)
+		{
+			var typeDelegator = new System.Reflection.TypeDelegator (unknownType);
+			unknownType.RequiresPublicMethods ();
+		}
 	}
 }