Support class target in RUC/RDC code fixers (#107956)

This adds support to the RequiresUnreferencedCode and
RequiresDynamicCode code fixer for adding new annotations at
the class level. This helps while annotating libraries where static field
initializers had trim/aot warnings.

---------

Co-authored-by: Jackson Schuster <[email protected]>

Author: 2 people

src/tools/illink/src/ILLink.CodeFix/BaseAttributeCodeFixProvider.cs

@@ -86,7 +86,8 @@ protected enum AttributeableParentTargets
 			Property = 0x0002,
 			Field = 0x0004,
 			Event = 0x0008,
-			All = MethodOrConstructor | Property | Field | Event
+			Class = 0x0010,
+			All = MethodOrConstructor | Property | Field | Event | Class
 		}
 
 		private static CSharpSyntaxNode? FindAttributableParent (SyntaxNode node, AttributeableParentTargets targets)
@@ -97,11 +98,23 @@ protected enum AttributeableParentTargets
 				case LambdaExpressionSyntax:
 					return null;
 
-				case LocalFunctionStatementSyntax or BaseMethodDeclarationSyntax or AccessorDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.MethodOrConstructor):
 				case PropertyDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.Property):
-				case FieldDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.Field):
 				case EventDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.Event):
 					return (CSharpSyntaxNode) parentNode;
+				case PropertyDeclarationSyntax:
+				case EventDeclarationSyntax:
+					// If the attribute can be placed on a method but not directly on a property/event, we don't want to keep walking up
+					// the syntax tree to annotate the class. Instead the correct thing to do is to add accessor methods and annotate those.
+					// The code fixer doesn't support doing this automatically, so return null to indicate that the attribute can't be added.
+					if (targets.HasFlag (AttributeableParentTargets.MethodOrConstructor))
+						return null;
+
+					parentNode = parentNode.Parent;
+					break;
+				case LocalFunctionStatementSyntax or BaseMethodDeclarationSyntax or AccessorDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.MethodOrConstructor):
+				case FieldDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.Field):
+				case ClassDeclarationSyntax when targets.HasFlag (AttributeableParentTargets.Class):
+					return (CSharpSyntaxNode) parentNode;
 
 				default:
 					parentNode = parentNode.Parent;

src/tools/illink/src/ILLink.CodeFix/RequiresDynamicCodeCodeFixProvider.cs

@@ -25,7 +25,7 @@ public class RequiresDynamicCodeCodeFixProvider : BaseAttributeCodeFixProvider
 
 		private protected override string FullyQualifiedAttributeName => RequiresDynamicCodeAnalyzer.FullyQualifiedRequiresDynamicCodeAttribute;
 
-		private protected override AttributeableParentTargets AttributableParentTargets => AttributeableParentTargets.MethodOrConstructor;
+		private protected override AttributeableParentTargets AttributableParentTargets => AttributeableParentTargets.MethodOrConstructor | AttributeableParentTargets.Class;
 
 		public sealed override Task RegisterCodeFixesAsync (CodeFixContext context) => BaseRegisterCodeFixesAsync (context);
 

src/tools/illink/src/ILLink.CodeFix/RequiresUnreferencedCodeCodeFixProvider.cs

@@ -25,7 +25,7 @@ public sealed class RequiresUnreferencedCodeCodeFixProvider : BaseAttributeCodeF
 
 		private protected override string FullyQualifiedAttributeName => RequiresUnreferencedCodeAnalyzer.FullyQualifiedRequiresUnreferencedCodeAttribute;
 
-		private protected override AttributeableParentTargets AttributableParentTargets => AttributeableParentTargets.MethodOrConstructor;
+		private protected override AttributeableParentTargets AttributableParentTargets => AttributeableParentTargets.MethodOrConstructor | AttributeableParentTargets.Class;
 
 		public sealed override Task RegisterCodeFixesAsync (CodeFixContext context) => BaseRegisterCodeFixesAsync (context);
 

src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/RequiresDynamicCodeAnalyzerTests.cs

@@ -348,6 +348,46 @@ private int M2 {
 			return VerifyRequiresDynamicCodeCodeFix (src, fix, diag, Array.Empty<DiagnosticResult> ());
 		}
 
+		[Fact]
+		public Task FixInClass ()
+		{
+			var src = $$"""
+			using System;
+			using System.Diagnostics.CodeAnalysis;
+
+			public class C
+			{
+				[RequiresDynamicCodeAttribute("message")]
+				static int M1() => 0;
+
+				static int Field = M1();
+			}
+			""";
+
+			var fix = $$"""
+			using System;
+			using System.Diagnostics.CodeAnalysis;
+
+			[RequiresDynamicCode()]
+			public class C
+			{
+				[RequiresDynamicCodeAttribute("message")]
+				static int M1() => 0;
+
+				static int Field = M1();
+			}
+			""";
+			return VerifyRequiresDynamicCodeCodeFix (src, fix,
+				baselineExpected: new[] {
+					// /0/Test0.cs(9,21,9,25): warning IL2026: Using member 'C.M1()' which has 'RequiresDynamicCodeAttribute' can break functionality when trimming application code. message.
+					VerifyCS.Diagnostic(DiagnosticId.RequiresDynamicCode).WithSpan(9, 21, 9, 25).WithArguments("C.M1()", " message.", ""),
+				},
+				fixedExpected: new[] {
+					// /0/Test0.cs(4,2): error CS7036: There is no argument given that corresponds to the required parameter 'message' of 'RequiresDynamicCodeAttribute.RequiresDynamicCodeAttribute(string)'
+					DiagnosticResult.CompilerError("CS7036").WithSpan(4, 2, 4, 23).WithArguments("message", "System.Diagnostics.CodeAnalysis.RequiresDynamicCodeAttribute.RequiresDynamicCodeAttribute(string)"),
+					});
+		}
+
 		[Fact]
 		public Task MakeGenericTypeWithAllKnownTypes ()
 		{

src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/RequiresUnreferencedCodeAnalyzerTests.cs

@@ -371,6 +371,46 @@ private int M2 {
 			return VerifyRequiresUnreferencedCodeCodeFix (src, fix, diag, Array.Empty<DiagnosticResult> ());
 		}
 
+		[Fact]
+		public Task FixInClass ()
+		{
+			var src = $$"""
+			using System;
+			using System.Diagnostics.CodeAnalysis;
+
+			public class C
+			{
+				[RequiresUnreferencedCodeAttribute("message")]
+				static int M1() => 0;
+
+				static int Field = M1();
+			}
+			""";
+
+			var fix = $$"""
+			using System;
+			using System.Diagnostics.CodeAnalysis;
+
+			[RequiresUnreferencedCode()]
+			public class C
+			{
+				[RequiresUnreferencedCodeAttribute("message")]
+				static int M1() => 0;
+
+				static int Field = M1();
+			}
+			""";
+			return VerifyRequiresUnreferencedCodeCodeFix (src, fix,
+				baselineExpected: new[] {
+					// /0/Test0.cs(9,21): warning IL2026: Using member 'C.M1()' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. message.
+					VerifyCS.Diagnostic(DiagnosticId.RequiresUnreferencedCode).WithSpan(9, 21, 9, 25).WithArguments("C.M1()", " message.", "")
+				},
+				fixedExpected: new[] {
+					// /0/Test0.cs(4,2): error CS7036: There is no argument given that corresponds to the required parameter 'message' of 'RequiresUnreferencedCodeAttribute.RequiresUnreferencedCodeAttribute(string)'
+					DiagnosticResult.CompilerError("CS7036").WithSpan(4, 2, 4, 28).WithArguments("message", "System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute.RequiresUnreferencedCodeAttribute(string)"),
+					});
+		}
+
 		[Fact]
 		public Task TestMakeGenericMethodUsage ()
 		{