Fix warning suppressions on types for type hierarchy (#2148)v6.0.100-preview.6.21365.1

* Fix warning suppressions on types for type hierarchy

* Add non-library mode tests

3 files changed, 222 insertions, 2 deletions

diff --git a/src/linker/Linker.Steps/MarkStep.cs b/src/linker/Linker.Steps/MarkStep.cs
index 7bb060381..c9d46760f 100644
--- a/src/linker/Linker.Steps/MarkStep.cs
+++ b/src/linker/Linker.Steps/MarkStep.cs
@@ -1756,14 +1756,16 @@ namespace Mono.Linker.Steps
 
 			MarkType (type.BaseType, new DependencyInfo (DependencyKind.BaseType, type));
 
+			MarkCustomAttributes (type, new DependencyInfo (DependencyKind.CustomAttribute, type));
+
 			// The DynamicallyAccessedMembers hiearchy processing must be done after the base type was marked
-			// (to avoid inconsistencies in the cache), but before anything else as work done below
+			// (to avoid inconsistencies in the cache), and after marking custom attributes (in case the attributes have
+			// warning suppressions for the type hierarchy marking) but before anything else as work done below
 			// might need the results of the processing here.
 			_dynamicallyAccessedMembersTypeHierarchy.ProcessMarkedTypeForDynamicallyAccessedMembersHierarchy (type);
 
 			if (type.DeclaringType != null)
 				MarkType (type.DeclaringType, new DependencyInfo (DependencyKind.DeclaringType, type));
-			MarkCustomAttributes (type, new DependencyInfo (DependencyKind.CustomAttribute, type));
 			MarkSecurityDeclarations (type, new DependencyInfo (DependencyKind.CustomAttribute, type));
 
 			if (type.IsMulticastDelegate ()) {
diff --git a/test/Mono.Linker.Tests.Cases/Reflection/TypeHierarchyLibraryModeSuppressions.cs b/test/Mono.Linker.Tests.Cases/Reflection/TypeHierarchyLibraryModeSuppressions.cs
new file mode 100644
index 000000000..6d81d5b07
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/Reflection/TypeHierarchyLibraryModeSuppressions.cs
@@ -0,0 +1,51 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Text;
+using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Helpers;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
+
+namespace Mono.Linker.Tests.Cases.Reflection
+{
+	[SetupLinkerArgument ("-a", "test.exe", "library")]
+	[ExpectedNoWarnings]
+	[KeptMember (".ctor()")]
+	public class TypeHierarchyLibraryModeSuppressions
+	{
+		public static void Main ()
+		{
+			var t1 = typeof (Unsuppressed);
+			var t2 = typeof (Suppressed);
+		}
+
+		[Kept]
+		[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
+		[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)]
+		[ExpectedWarning ("IL2026", nameof (Unsuppressed))]
+		class Unsuppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on Unsuppressed--")]
+			public void RUCMethod () { }
+		}
+
+		[Kept]
+		[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
+		[KeptAttributeAttribute (typeof (UnconditionalSuppressMessageAttribute))]
+		[UnconditionalSuppressMessage ("TrimAnalysis", "IL2026")]
+		[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)]
+		class Suppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on Suppressed--")]
+			public void RUCMethod () { }
+		}
+	}
+}
diff --git a/test/Mono.Linker.Tests.Cases/Reflection/TypeHierarchySuppressions.cs b/test/Mono.Linker.Tests.Cases/Reflection/TypeHierarchySuppressions.cs
new file mode 100644
index 000000000..67c9e4efc
--- /dev/null
+++ b/test/Mono.Linker.Tests.Cases/Reflection/TypeHierarchySuppressions.cs
@@ -0,0 +1,167 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Text;
+using Mono.Linker.Tests.Cases.Expectations.Assertions;
+using Mono.Linker.Tests.Cases.Expectations.Helpers;
+using Mono.Linker.Tests.Cases.Expectations.Metadata;
+
+namespace Mono.Linker.Tests.Cases.Reflection
+{
+	[ExpectedNoWarnings]
+	public class TypeHierarchySuppressions
+	{
+		// https://github.com/mono/linker/issues/2136
+		// Warnings should originate from the types (or rather their members, with the
+		// proposed behavior), and the type suppressions should silence the relevant
+		// warnings.
+
+		// Should originate from types instead
+		[ExpectedWarning ("IL2026", "--RUC on Unsuppressed--")]
+		[ExpectedWarning ("IL2026", "--RUC on DerivedFromUnsuppressed1--")]
+
+		// Should be suppressed by type-level suppression
+		[ExpectedWarning ("IL2026", "--RUC on Suppressed--")]
+		[ExpectedWarning ("IL2026", "--RUC on SuppressedOnDerived1--")]
+		[ExpectedWarning ("IL2026", "--RUC on DerivedFromSuppressed1--")]
+		public static void Main ()
+		{
+			RequireMethods (unsuppressed.GetType ());
+			RequireMethods (suppressed.GetType ());
+
+			var t = typeof (DerivedFromSuppressed1);
+			var t2 = typeof (DerivedFromUnsuppressed1);
+			var t3 = typeof (SuppressedOnDerived1);
+
+			UseDerivedTypes ();
+		}
+
+		// Referencing these types in a separate method ensures that they get
+		// marked after applying annotations on the base type.
+		[Kept]
+		static void UseDerivedTypes ()
+		{
+			var t = typeof (DerivedFromUnsuppressed2);
+			var t2 = typeof (DerivedFromSuppressed2);
+			var t3 = typeof (SuppressedOnDerived2);
+		}
+
+		[Kept]
+		static Unsuppressed unsuppressed;
+
+		[Kept]
+		static Suppressed suppressed;
+
+		[Kept]
+		static void RequireMethods (
+			[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
+			[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)]
+			Type type)
+		{ }
+
+		[Kept]
+		[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
+		[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)]
+		// https://github.com/mono/linker/issues/2136
+		// [ExpectedWarning ("IL2026", "--RUC on Unsuppressed--")]
+		class Unsuppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on Unsuppressed--")]
+			public void RUCMethod () { }
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (Unsuppressed))]
+		// https://github.com/mono/linker/issues/2136
+		// [ExpectedWarning ("IL2026", "--RUC on DerivedFromUnsuppressed1--")]
+		class DerivedFromUnsuppressed1 : Unsuppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on DerivedFromUnsuppressed1--")]
+			public void DerivedRUCMethod () { }
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (Unsuppressed))]
+		[ExpectedWarning ("IL2026", "--RUC on DerivedFromUnsuppressed2")]
+		// https://github.com/mono/linker/issues/2136
+		// Should originate from the base type instead
+		[ExpectedWarning ("IL2026", "--RUC on Unsuppressed--")]
+		class DerivedFromUnsuppressed2 : Unsuppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on DerivedFromUnsuppressed2--")]
+			public void DerivedRUCMethod () { }
+		}
+
+		[Kept]
+		[KeptAttributeAttribute (typeof (DynamicallyAccessedMembersAttribute))]
+		[KeptAttributeAttribute (typeof (UnconditionalSuppressMessageAttribute))]
+		[UnconditionalSuppressMessage ("TrimAnalysis", "IL2026")]
+		[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicMethods)]
+		class Suppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on Suppressed--")]
+			public void RUCMethod () { }
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (Suppressed))]
+		// https://github.com/mono/linker/issues/2136
+		// [ExpectedWarning ("IL2026", "--RUC on DerivedFromSuppressed1--")]
+		class DerivedFromSuppressed1 : Suppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on DerivedFromSuppressed1--")]
+			public void RUCDerivedMethod () { }
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (Suppressed))]
+		[ExpectedWarning ("IL2026", "--RUC on DerivedFromSuppressed2--")]
+		// https://github.com/mono/linker/issues/2136
+		[ExpectedWarning ("IL2026", "--RUC on Suppressed--")]
+		class DerivedFromSuppressed2 : Suppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on DerivedFromSuppressed2--")]
+			public void RUCDerivedMethod () { }
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (Unsuppressed))]
+		[KeptAttributeAttribute (typeof (UnconditionalSuppressMessageAttribute))]
+		[UnconditionalSuppressMessage ("TrimAnalysis", "IL2026")]
+		class SuppressedOnDerived1 : Unsuppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on SuppressedOnDerived1--")]
+			public void DerivedRUCMethod () { }
+		}
+
+		[Kept]
+		[KeptBaseType (typeof (Unsuppressed))]
+		[KeptAttributeAttribute (typeof (UnconditionalSuppressMessageAttribute))]
+		[UnconditionalSuppressMessage ("TrimAnalysis", "IL2026")]
+		class SuppressedOnDerived2 : Unsuppressed
+		{
+			[Kept]
+			[KeptAttributeAttribute (typeof (RequiresUnreferencedCodeAttribute))]
+			[RequiresUnreferencedCode ("--RUC on SuppressedOnDerived2--")]
+			public void DerivedRUCMethod () { }
+		}
+	}
+}