[DAM analyzer] Respect EnableTrimAnalyzer property (#2602)

2 files changed, 56 insertions, 20 deletions

diff --git a/src/ILLink.RoslynAnalyzer/DynamicallyAccessedMembersAnalyzer.cs b/src/ILLink.RoslynAnalyzer/DynamicallyAccessedMembersAnalyzer.cs
index 653ff4f8d..518e855b2 100644
--- a/src/ILLink.RoslynAnalyzer/DynamicallyAccessedMembersAnalyzer.cs
+++ b/src/ILLink.RoslynAnalyzer/DynamicallyAccessedMembersAnalyzer.cs
@@ -57,31 +57,36 @@ namespace ILLink.RoslynAnalyzer
 			if (!System.Diagnostics.Debugger.IsAttached)
 				context.EnableConcurrentExecution ();
 			context.ConfigureGeneratedCodeAnalysis (GeneratedCodeAnalysisFlags.ReportDiagnostics);
-			context.RegisterOperationBlockAction (context => {
-				if (context.OwningSymbol.IsInRequiresUnreferencedCodeAttributeScope ())
+			context.RegisterCompilationStartAction (context => {
+				if (!context.Options.IsMSBuildPropertyValueTrue (MSBuildPropertyOptionNames.EnableTrimAnalyzer, context.Compilation))
 					return;
 
-				foreach (var operationBlock in context.OperationBlocks) {
-					ControlFlowGraph cfg = context.GetControlFlowGraph (operationBlock);
-					TrimDataFlowAnalysis trimDataFlowAnalysis = new (context, cfg);
+				context.RegisterOperationBlockAction (context => {
+					if (context.OwningSymbol.IsInRequiresUnreferencedCodeAttributeScope ())
+						return;
 
-					foreach (var diagnostic in trimDataFlowAnalysis.ComputeTrimAnalysisPatterns ().CollectDiagnostics ()) {
-						context.ReportDiagnostic (diagnostic);
+					foreach (var operationBlock in context.OperationBlocks) {
+						ControlFlowGraph cfg = context.GetControlFlowGraph (operationBlock);
+						TrimDataFlowAnalysis trimDataFlowAnalysis = new (context, cfg);
+
+						foreach (var diagnostic in trimDataFlowAnalysis.ComputeTrimAnalysisPatterns ().CollectDiagnostics ()) {
+							context.ReportDiagnostic (diagnostic);
+						}
 					}
-				}
+				});
+				context.RegisterSyntaxNodeAction (context => {
+					ProcessGenericParameters (context);
+				}, SyntaxKind.GenericName);
+				context.RegisterSymbolAction (context => {
+					VerifyMemberOnlyApplyToTypesOrStrings (context, context.Symbol);
+				}, SymbolKind.Method);
+				context.RegisterSymbolAction (context => {
+					VerifyMemberOnlyApplyToTypesOrStrings (context, context.Symbol);
+				}, SymbolKind.Property);
+				context.RegisterSymbolAction (context => {
+					VerifyMemberOnlyApplyToTypesOrStrings (context, context.Symbol);
+				}, SymbolKind.Field);
 			});
-			context.RegisterSyntaxNodeAction (context => {
-				ProcessGenericParameters (context);
-			}, SyntaxKind.GenericName);
-			context.RegisterSymbolAction (context => {
-				VerifyMemberOnlyApplyToTypesOrStrings (context, context.Symbol);
-			}, SymbolKind.Method);
-			context.RegisterSymbolAction (context => {
-				VerifyMemberOnlyApplyToTypesOrStrings (context, context.Symbol);
-			}, SymbolKind.Property);
-			context.RegisterSymbolAction (context => {
-				VerifyMemberOnlyApplyToTypesOrStrings (context, context.Symbol);
-			}, SymbolKind.Field);
 		}
 
 		static void ProcessGenericParameters (SyntaxNodeAnalysisContext context)
diff --git a/test/ILLink.RoslynAnalyzer.Tests/DynamicallyAccessedMembersAnalyzerTests.cs b/test/ILLink.RoslynAnalyzer.Tests/DynamicallyAccessedMembersAnalyzerTests.cs
index 24f0f1d3e..d24ad8aa7 100644
--- a/test/ILLink.RoslynAnalyzer.Tests/DynamicallyAccessedMembersAnalyzerTests.cs
+++ b/test/ILLink.RoslynAnalyzer.Tests/DynamicallyAccessedMembersAnalyzerTests.cs
@@ -20,6 +20,37 @@ namespace ILLink.RoslynAnalyzer.Tests
 				expected: expected);
 		}
 
+		[Fact]
+		public Task NoWarningsIfAnalyzerIsNotEnabled ()
+		{
+			var TargetParameterWithAnnotations = @"
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+public class Foo
+{
+}
+
+class C
+{
+	public static void Main()
+	{
+		M(typeof(Foo));
+	}
+
+	private static void NeedsPublicMethodsOnParameter(
+		[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicMethods)] Type parameter)
+	{
+	}
+
+	private static void M(Type type)
+	{
+		NeedsPublicMethodsOnParameter(type);
+	}
+}";
+			return VerifyCS.VerifyAnalyzerAsync (TargetParameterWithAnnotations);
+		}
+
 		#region SourceParameter
 		[Fact]
 		public Task SourceParameterDoesNotMatchTargetParameterAnnotations ()