Add new Xml Type parser (dotnet#82145)

Use new type parser for xml processing
Add tests in nativeAOT
Port XML testing changes from NativeAOT to illink
Port logic to distinguish who needs to Kept an element in illink

src/coreclr/tools/Common/Compiler/ProcessLinkerXmlBase.cs

@@ -212,11 +212,7 @@ protected virtual void ProcessTypes(ModuleDesc assembly, XPathNavigator nav, boo
 
                 // TODO: Process exported types
 
-                // TODO: Semantics differ and xml format is cecil specific, therefore they are discrepancies on things like nested types
-                // for now just hack replacing / for + to support basic resolving of nested types
-                // https://github.com/dotnet/runtime/issues/73083
-                fullname = fullname.Replace("/", "+");
-                TypeDesc type = CustomAttributeTypeNameParser.GetTypeByCustomAttributeTypeName(assembly, fullname, throwIfNotFound: false);
+                TypeDesc? type = CecilCompatibleTypeParser.GetType(assembly, fullname);
 
                 if (type == null)
                 {
@@ -753,4 +749,56 @@ public bool TryConvertValue(string value, TypeDesc type, out object? result)
 #endif
         }
     }
+
+    public class CecilCompatibleTypeParser
+    {
+        public static TypeDesc? GetType(ModuleDesc assembly, string fullName)
+        {
+            Debug.Assert(!string.IsNullOrEmpty(fullName));
+            var position = fullName.IndexOf('/');
+            if (position > 0)
+                return GetNestedType(assembly, fullName);
+            string @namespace, name;
+            SplitFullName(fullName, out @namespace, out name);
+
+            return assembly.GetType(@namespace, name, throwIfNotFound: false);
+        }
+
+        private static MetadataType? GetNestedType(ModuleDesc assembly, string fullName)
+        {
+            var names = fullName.Split('/');
+            var type = GetType(assembly, names[0]);
+
+            if (type == null)
+                return null;
+
+            MetadataType typeReference = (MetadataType)type;
+            for (int i = 1; i < names.Length; i++)
+            {
+                var nested_type = typeReference.GetNestedType(names[i]);
+                if (nested_type == null)
+                    return null;
+
+                typeReference = nested_type;
+            }
+
+            return typeReference;
+        }
+
+        public static void SplitFullName(string fullName, out string @namespace, out string name)
+        {
+            var last_dot = fullName.LastIndexOf('.');
+
+            if (last_dot == -1)
+            {
+                @namespace = string.Empty;
+                name = fullName;
+            }
+            else
+            {
+                @namespace = fullName.Substring(0, last_dot);
+                name = fullName.Substring(last_dot + 1);
+            }
+        }
+    }
 }

src/coreclr/tools/aot/Mono.Linker.Tests.Cases/LinkXml/LinkXmlErrorCases.cs

@@ -17,6 +17,10 @@ namespace Mono.Linker.Tests.Cases.LinkXml
 	[ExpectedWarning ("IL2017", "NonExistentProperty", "TypeWithNoProperties", FileName = "LinkXmlErrorCases.xml", SourceLine = 21, SourceColumn = 8)]
 	[ExpectedWarning ("IL2018", "SetOnlyProperty", "TypeWithProperties", FileName = "LinkXmlErrorCases.xml", SourceLine = 25, SourceColumn = 8)]
 	[ExpectedWarning ("IL2019", "GetOnlyProperty", "TypeWithProperties", FileName = "LinkXmlErrorCases.xml", SourceLine = 26, SourceColumn = 8)]
+	[ExpectedWarning ("IL2025", "Method", FileName = "LinkXmlErrorCases.xml", SourceLine = 39, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	[ExpectedWarning ("IL2025", "Event", FileName = "LinkXmlErrorCases.xml", SourceLine = 40, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	[ExpectedWarning ("IL2025", "Field", FileName = "LinkXmlErrorCases.xml", SourceLine = 41, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	[ExpectedWarning ("IL2025", "Property", FileName = "LinkXmlErrorCases.xml", SourceLine = 42, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
 	// NativeAOT doesn't support wildcard * and will skip usages of it, including if they would warn
 	// https://github.com/dotnet/runtime/issues/80466
 	[ExpectedWarning ("IL2100", FileName = "LinkXmlErrorCases.xml", SourceLine = 50, SourceColumn = 4, ProducedBy = ProducedBy.Trimmer)]

src/coreclr/tools/aot/Mono.Linker.Tests.Cases/LinkXml/UnusedTypePreservedByLinkXmlIsKept.cs

@@ -16,4 +16,20 @@ public static void Main ()
 	class UnusedTypePreservedByLinkXmlIsKeptUnusedType
 	{
 	}
-}
+
+	[Kept]
+	public class UnusedGenericTypePreservedByLinkXmlIsKept<T>
+	{
+		[Kept]
+		public class UnusedNestedTypePreservedByLinkXmlIsKept { }
+
+		[Kept]
+		public class UnusedNestedGenericTypePreservedByLinkXmlIsKept<U, V>
+		{
+			[Kept]
+			public class UnusedNestedNestedGenericTypePreservedByLinkXmlIsKept<W> { }
+		}
+
+		public class UnusedNestedTypeNotPreserved { }
+	}
+}

src/coreclr/tools/aot/Mono.Linker.Tests.Cases/LinkXml/UnusedTypePreservedByLinkXmlIsKept.xml

@@ -1,5 +1,9 @@
 <linker>
   <assembly fullname="test, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null">
     <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedTypePreservedByLinkXmlIsKeptUnusedType" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1" preserve="none" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1/UnusedNestedTypePreservedByLinkXmlIsKept" preserve="none" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1/UnusedNestedGenericTypePreservedByLinkXmlIsKept`2" preserve="none" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1/UnusedNestedGenericTypePreservedByLinkXmlIsKept`2/UnusedNestedNestedGenericTypePreservedByLinkXmlIsKept`1" preserve="none" />
   </assembly>
 </linker>

src/tools/illink/test/Mono.Linker.Tests.Cases.Expectations/Assertions/KeptAttribute.cs

@@ -8,5 +8,11 @@ namespace Mono.Linker.Tests.Cases.Expectations.Assertions
 	[AttributeUsage (AttributeTargets.All, Inherited = false)]
 	public class KeptAttribute : BaseExpectedLinkedBehaviorAttribute
 	{
+		/// <summary>
+		/// By default the target should be kept by all platforms
+		/// This property can override that by setting only the platforms
+		/// which are expected to keep the target.
+		/// </summary>
+		public ProducedBy By { get; set; } = ProducedBy.TrimmerAnalyzerAndNativeAot;
 	}
-}
+}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/LinkXmlErrorCases.cs

@@ -17,12 +17,13 @@ namespace Mono.Linker.Tests.Cases.LinkXml
 	[ExpectedWarning ("IL2017", "NonExistentProperty", "TypeWithNoProperties", FileName = "LinkXmlErrorCases.xml", SourceLine = 21, SourceColumn = 8)]
 	[ExpectedWarning ("IL2018", "SetOnlyProperty", "TypeWithProperties", FileName = "LinkXmlErrorCases.xml", SourceLine = 25, SourceColumn = 8)]
 	[ExpectedWarning ("IL2019", "GetOnlyProperty", "TypeWithProperties", FileName = "LinkXmlErrorCases.xml", SourceLine = 26, SourceColumn = 8)]
-
-	[ExpectedWarning ("IL2025", "Method", FileName = "LinkXmlErrorCases.xml", SourceLine = 39, SourceColumn = 8)]
-	[ExpectedWarning ("IL2025", "Event", FileName = "LinkXmlErrorCases.xml", SourceLine = 40, SourceColumn = 8)]
-	[ExpectedWarning ("IL2025", "Field", FileName = "LinkXmlErrorCases.xml", SourceLine = 41, SourceColumn = 8)]
-	[ExpectedWarning ("IL2025", "Property", FileName = "LinkXmlErrorCases.xml", SourceLine = 42, SourceColumn = 8)]
-	[ExpectedWarning ("IL2100", FileName = "LinkXmlErrorCases.xml", SourceLine = 50, SourceColumn = 4)]
+	[ExpectedWarning ("IL2025", "Method", FileName = "LinkXmlErrorCases.xml", SourceLine = 39, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	[ExpectedWarning ("IL2025", "Event", FileName = "LinkXmlErrorCases.xml", SourceLine = 40, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	[ExpectedWarning ("IL2025", "Field", FileName = "LinkXmlErrorCases.xml", SourceLine = 41, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	[ExpectedWarning ("IL2025", "Property", FileName = "LinkXmlErrorCases.xml", SourceLine = 42, SourceColumn = 8, ProducedBy = ProducedBy.Trimmer)]
+	// NativeAOT doesn't support wildcard * and will skip usages of it, including if they would warn
+	// https://github.com/dotnet/runtime/issues/80466
+	[ExpectedWarning ("IL2100", FileName = "LinkXmlErrorCases.xml", SourceLine = 50, SourceColumn = 4, ProducedBy = ProducedBy.Trimmer)]
 	class LinkXmlErrorCases
 	{
 		public static void Main ()
@@ -76,4 +77,4 @@ public void Method () { }
 			public int Property { [Kept] get; [Kept] set; }
 		}
 	}
-}
+}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/TypeWithPreserveFieldsHasBackingFieldsOfPropertiesRemoved.cs

@@ -40,6 +40,7 @@ class Unused : IFoo<int>, IFoo<string>, IFoo<Cat>, IFoo2<int>, IFoo3<int, string
 			int IFoo<IFoo<int>>.Bar { get; set; }
 		}
 
+		[Kept (By = ProducedBy.NativeAot)]
 		interface IDog
 		{
 			string Name { get; set; }
@@ -52,16 +53,19 @@ interface IFoo<T>
 			int Bar { get; set; }
 		}
 
+		[Kept (By = ProducedBy.NativeAot)]
 		interface IFoo2<T>
 		{
 			int Bar2 { get; set; }
 		}
 
+		[Kept (By = ProducedBy.NativeAot)]
 		interface IFoo3<T, K, J>
 		{
 			int Bar3 { get; set; }
 		}
 
+		[Kept (By = ProducedBy.NativeAot)]
 		class Cat
 		{
 		}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UnusedInterfaceTypeOnTypeWithPreserveNothingIsRemoved.cs

@@ -10,6 +10,7 @@ public static void Main ()
 		{
 		}
 
+		[Kept (By = ProducedBy.NativeAot)]
 		interface IFoo
 		{
 		}
@@ -19,4 +20,4 @@ class Bar : IFoo
 		{
 		}
 	}
-}
+}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UnusedMethodPreservedByLinkXmlIsKept.cs

@@ -38,10 +38,12 @@ private void NotPreservedMethod ()
 			{
 			}
 
-			[Kept]
+			// NativeAOT fails to translate Cecil generic methods
+			// https://github.com/dotnet/runtime/issues/80462
+			[Kept (By = ProducedBy.Trimmer)]
 			private void PreservedMethod5<T> (T arg)
 			{
 			}
 		}
 	}
-}
+}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UnusedNonRequiredTypeIsRemoved.cs

@@ -1,3 +1,4 @@
+using Mono.Linker.Tests.Cases.Expectations.Assertions;
 using Mono.Linker.Tests.Cases.Expectations.Metadata;
 
 namespace Mono.Linker.Tests.Cases.LinkXml
@@ -9,8 +10,12 @@ public static void Main ()
 		{
 		}
 
+		// NativeAOT should generate conditional dependencies for the required tag
+		// https://github.com/dotnet/runtime/issues/80464
+		[Kept (By = ProducedBy.NativeAot)]
+		[KeptMember (".ctor()", By = ProducedBy.NativeAot)]
 		class Unused
 		{
 		}
 	}
-}
+}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UnusedNonRequiredTypeIsRemoved.xml

@@ -1,5 +1,5 @@
 <linker>
-	<assembly fullname="test, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null">
+    <assembly fullname="test, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null">
         <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedNonRequiredTypeIsRemoved/Unused" preserve="all" required="0"/>
     </assembly>
-</linker>
+</linker>

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UnusedTypePreservedByLinkXmlIsKept.cs

@@ -16,4 +16,20 @@ public static void Main ()
 	class UnusedTypePreservedByLinkXmlIsKeptUnusedType
 	{
 	}
-}
+
+	[Kept]
+	public class UnusedGenericTypePreservedByLinkXmlIsKept<T>
+	{
+		[Kept]
+		public class UnusedNestedTypePreservedByLinkXmlIsKept { }
+
+		[Kept]
+		public class UnusedNestedGenericTypePreservedByLinkXmlIsKept<U, V>
+		{
+			[Kept]
+			public class UnusedNestedNestedGenericTypePreservedByLinkXmlIsKept<W> { }
+		}
+
+		public class UnusedNestedTypeNotPreserved { }
+	}
+}

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UnusedTypePreservedByLinkXmlIsKept.xml

@@ -1,5 +1,9 @@
 <linker>
   <assembly fullname="test, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null">
     <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedTypePreservedByLinkXmlIsKeptUnusedType" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1" preserve="none" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1/UnusedNestedTypePreservedByLinkXmlIsKept" preserve="none" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1/UnusedNestedGenericTypePreservedByLinkXmlIsKept`2" preserve="none" />
+    <type fullname="Mono.Linker.Tests.Cases.LinkXml.UnusedGenericTypePreservedByLinkXmlIsKept`1/UnusedNestedGenericTypePreservedByLinkXmlIsKept`2/UnusedNestedNestedGenericTypePreservedByLinkXmlIsKept`1" preserve="none" />
   </assembly>
 </linker>

src/tools/illink/test/Mono.Linker.Tests.Cases/LinkXml/UsedNonRequiredTypeIsKeptWithSingleMethod.cs

@@ -32,19 +32,27 @@ public SecondLevel (int arg)
 			}
 		}
 
+		// NativeAOT should generate conditional dependencies for the tag required
+		// https://github.com/dotnet/runtime/issues/80464
+		[Kept (By = ProducedBy.NativeAot)]
 		class ReallyUnused
 		{
+			[Kept (By = ProducedBy.NativeAot)]
 			private void PreservedMethod ()
 			{
 				new SecondLevelUnused (2);
 			}
 		}
 
+		// NativeAOT should generate conditional dependencies for the tag required
+		// https://github.com/dotnet/runtime/issues/80464
+		[Kept (By = ProducedBy.NativeAot)]
 		class SecondLevelUnused
 		{
+			[Kept (By = ProducedBy.NativeAot)]
 			public SecondLevelUnused (int arg)
 			{
 			}
 		}
 	}
-}
+}

src/tools/illink/test/Mono.Linker.Tests/TestCasesRunner/AssemblyChecker.cs

@@ -115,9 +115,9 @@ protected virtual void VerifyTypeDefinition (TypeDefinition original, TypeDefini
 			// - It contains at least one member which has [Kept] attribute (not recursive)
 			//
 			bool expectedKept =
-				original.HasAttributeDerivedFrom (nameof (KeptAttribute)) ||
+				HasActiveKeptDerivedAttribute (original) ||
 				(linked != null && linkedModule.Assembly.EntryPoint?.DeclaringType == linked) ||
-				original.AllMembers ().Any (l => l.HasAttribute (nameof (KeptAttribute)));
+				original.AllMembers ().Any (HasActiveKeptDerivedAttribute);
 
 			if (!expectedKept) {
 				if (linked != null)
@@ -1061,14 +1061,54 @@ protected virtual bool ShouldMethodBeKept (MethodDefinition method)
 
 		protected virtual bool ShouldBeKept<T> (T member, string signature = null) where T : MemberReference, ICustomAttributeProvider
 		{
-			if (member.HasAttribute (nameof (KeptAttribute)) || member.HasAttribute (nameof (KeptByAttribute)))
+			if (HasActiveKeptAttribute (member) || member.HasAttribute (nameof (KeptByAttribute)))
 				return true;
 
 			ICustomAttributeProvider cap = (ICustomAttributeProvider) member.DeclaringType;
 			if (cap == null)
 				return false;
 
-			return GetCustomAttributeCtorValues<string> (cap, nameof (KeptMemberAttribute)).Any (a => a == (signature ?? member.Name));
+			return GetActiveKeptAttributes (cap, nameof (KeptMemberAttribute)).Any (ca => {
+				if (ca.Constructor.Parameters.Count != 1 ||
+					ca.ConstructorArguments[0].Value is not string a)
+					return false;
+
+				return a == (signature ?? member.Name);
+			});
+		}
+
+		private static IEnumerable<CustomAttribute> GetActiveKeptAttributes (ICustomAttributeProvider provider, string attributeName)
+		{
+			return provider.CustomAttributes.Where(ca => {
+				if (ca.AttributeType.Name != attributeName) {
+					return false;
+				}
+
+				object keptBy = ca.GetPropertyValue (nameof (KeptAttribute.By));
+				return keptBy is null ? true : ((ProducedBy) keptBy).HasFlag (ProducedBy.Trimmer);
+			});
+ 		}
+
+		private static bool HasActiveKeptAttribute (ICustomAttributeProvider provider)
+		{
+			return GetActiveKeptAttributes (provider, nameof (KeptAttribute)).Any ();
+		}
+
+		private static IEnumerable<CustomAttribute> GetActiveKeptDerivedAttributes (ICustomAttributeProvider provider)
+		{
+			return provider.CustomAttributes.Where (ca => {
+				if (!ca.AttributeType.Resolve ().DerivesFrom (nameof (KeptAttribute))) {
+					return false;
+				}
+
+				object keptBy = ca.GetPropertyValue (nameof (KeptAttribute.By));
+				return keptBy is null ? true : ((ProducedBy) keptBy).HasFlag (ProducedBy.Trimmer);
+			});
+		}
+
+		private static bool HasActiveKeptDerivedAttribute (ICustomAttributeProvider provider)
+		{
+			return GetActiveKeptDerivedAttributes (provider).Any ();
 		}
 
 		protected static uint GetExpectedPseudoAttributeValue (ICustomAttributeProvider provider, uint sourceValue)