Support for trimming and AOT

src/NServiceBus.Core.Analyzer.Tests.Roslyn5/Handlers/AddHandlerInterceptorSuppressorTests.cs

@@ -42,6 +42,40 @@ public class SampleCommand : ICommand { }
         Assert.That(diagnostics, Does.Not.Contain("IL2026"));
     }
 
+    [Test]
+    public void SuppressesIL3050ForAddHandler()
+    {
+        var source = """
+                     using System.Threading.Tasks;
+                     using NServiceBus;
+
+                     public class Test
+                     {
+                         public void Configure(EndpointConfiguration cfg)
+                         {
+                             cfg.AddHandler<SampleHandler>();
+                         }
+                     }
+
+                     public class SampleHandler : IHandleMessages<SampleCommand>
+                     {
+                         public Task Handle(SampleCommand cmd, IMessageHandlerContext context) => Task.CompletedTask;
+                     }
+
+                     public class SampleCommand : ICommand { }
+                     """;
+
+        var result = SourceGeneratorTest.ForIncrementalGenerator<AddHandlerInterceptor>()
+            .WithSource(source, "test.cs")
+            .WithAnalyzer<MockTrimmingAnalyzer>()
+            .WithSuppressor<AddHandlerInterceptorSuppressor>()
+            .Run();
+
+        var diagnostics = result.GetCompilationOutput();
+
+        Assert.That(diagnostics, Does.Not.Contain("IL3050"));
+    }
+
     [Test]
     public void DoesNotSuppressIL2026ForNonAddHandlerCalls()
     {
@@ -74,4 +108,37 @@ public void SomeOtherMethod() { }
 
         Assert.That(diagnostics, Does.Contain("IL2026"));
     }
+
+    [Test]
+    public void DoesNotSuppressIL3050ForNonAddHandlerCalls()
+    {
+        var source = """
+                     using System.Diagnostics.CodeAnalysis;
+                     using NServiceBus;
+
+                     public class Test
+                     {
+                         public void Configure(EndpointConfiguration cfg)
+                         {
+                             // This call should still produce IL3050 since it's not intercepted
+                             SomeOtherMethod();
+                         }
+
+                         [RequiresDynamicCode("Test method")]
+                         public void SomeOtherMethod() { }
+                     }
+                     """;
+
+        var result = SourceGeneratorTest.ForIncrementalGenerator<AddHandlerInterceptor>()
+            .WithSource(source, "test.cs")
+            .WithAnalyzer<MockTrimmingAnalyzer>()
+            .WithSuppressor<AddHandlerInterceptorSuppressor>()
+            .SuppressDiagnosticErrors()
+            .SuppressCompilationErrors()
+            .Run();
+
+        var diagnostics = result.GetCompilationOutput();
+
+        Assert.That(diagnostics, Does.Contain("IL3050"));
+    }
 }

src/NServiceBus.Core.Analyzer.Tests.Roslyn5/Helpers/MockTrimmingAnalyzer.cs

@@ -6,7 +6,7 @@ namespace NServiceBus.Core.Analyzer.Tests.Helpers;
 using Microsoft.CodeAnalysis.Diagnostics;
 
 // Currently, this mock analyzer does not support all trimming-related warnings.
-// It only supports IL2026 for method invocations for now.
+// It only supports IL2026 and IL3050 for method invocations for now.
 #pragma warning disable RS1001 // Yes we don't want it to be found
 class MockTrimmingAnalyzer : DiagnosticAnalyzer
 #pragma warning restore RS1001
@@ -21,7 +21,17 @@ class MockTrimmingAnalyzer : DiagnosticAnalyzer
         defaultSeverity: DiagnosticSeverity.Warning,
         isEnabledByDefault: true);
 
-    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [IL2026Descriptor];
+    static readonly DiagnosticDescriptor IL3050Descriptor = new(
+#pragma warning disable RS2008
+        id: "IL3050",
+#pragma warning restore RS2008
+        title: "Using member with RequiresDynamicCodeAttribute",
+        messageFormat: "Using member '{0}' which has 'RequiresDynamicCodeAttribute'",
+        category: "AOT",
+        defaultSeverity: DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [IL2026Descriptor, IL3050Descriptor];
 
     public override void Initialize(AnalysisContext context)
     {
@@ -36,13 +46,16 @@ public override void Initialize(AnalysisContext context)
             }
 
             var method = invocation.TargetMethod;
-            if (!method.GetAttributes().Any(attr => attr.AttributeClass?.Name == "RequiresUnreferencedCodeAttribute"))
+            var attributes = method.GetAttributes();
+            if (attributes.Any(attr => attr.AttributeClass?.Name == "RequiresUnreferencedCodeAttribute"))
             {
-                return;
+                operationContext.ReportDiagnostic(Diagnostic.Create(IL2026Descriptor, invocation.Syntax.GetLocation(), method.Name));
             }
 
-            var diagnostic = Diagnostic.Create(IL2026Descriptor, invocation.Syntax.GetLocation(), method.Name);
-            operationContext.ReportDiagnostic(diagnostic);
+            if (attributes.Any(attr => attr.AttributeClass?.Name == "RequiresDynamicCodeAttribute"))
+            {
+                operationContext.ReportDiagnostic(Diagnostic.Create(IL3050Descriptor, invocation.Syntax.GetLocation(), method.Name));
+            }
         }, OperationKind.Invocation);
     }
 }

src/NServiceBus.Core.Analyzer.Tests.Roslyn5/Sagas/AddSagaInterceptorSuppressorTests.cs

@@ -57,6 +57,55 @@ public class SampleCommand : ICommand
         Assert.That(diagnostics, Does.Not.Contain("IL2026"));
     }
 
+    [Test]
+    public void SuppressesIL3050ForAddSaga()
+    {
+        var source = """
+                     using System.Threading.Tasks;
+                     using NServiceBus;
+
+                     public class Test
+                     {
+                         public void Configure(EndpointConfiguration cfg)
+                         {
+                             cfg.AddSaga<SampleSaga>();
+                         }
+                     }
+
+                     public class SampleSaga : Saga<SampleSagaData>,
+                         IAmStartedByMessages<SampleCommand>
+                     {
+                         protected override void ConfigureHowToFindSaga(SagaPropertyMapper<SampleSagaData> mapper)
+                         {
+                             mapper.MapSaga(saga => saga.CorrelationId)
+                                 .ToMessage<SampleCommand>(msg => msg.CorrelationId);
+                         }
+
+                         public Task Handle(SampleCommand cmd, IMessageHandlerContext context) => Task.CompletedTask;
+                     }
+
+                     public class SampleSagaData : ContainSagaData
+                     {
+                         public string CorrelationId { get; set; }
+                     }
+
+                     public class SampleCommand : ICommand
+                     {
+                         public string CorrelationId { get; set; }
+                     }
+                     """;
+
+        var result = SourceGeneratorTest.ForIncrementalGenerator<AddSagaInterceptor>()
+            .WithSource(source, "test.cs")
+            .WithAnalyzer<MockTrimmingAnalyzer>()
+            .WithSuppressor<AddSagaInterceptorSuppressor>()
+            .Run();
+
+        var diagnostics = result.GetCompilationOutput();
+
+        Assert.That(diagnostics, Does.Not.Contain("IL3050"));
+    }
+
     [Test]
     public void SuppressesIL2026ForFinderOnlySaga()
     {
@@ -111,6 +160,60 @@ public class StartSagaMessage : IMessage;
         Assert.That(diagnostics, Does.Not.Contain("IL2026"));
     }
 
+    [Test]
+    public void SuppressesIL3050ForFinderOnlySaga()
+    {
+        var source = """
+                     using System.Threading;
+                     using System.Threading.Tasks;
+                     using NServiceBus;
+                     using NServiceBus.Persistence;
+                     using NServiceBus.Extensibility;
+                     using NServiceBus.Sagas;
+
+                     public class Test
+                     {
+                         public void Configure(EndpointConfiguration cfg)
+                         {
+                             cfg.AddSaga<FinderOnlySaga>();
+                         }
+                     }
+
+                     public class FinderOnlySaga : Saga<FinderOnlySagaData>,
+                         IAmStartedByMessages<StartSagaMessage>
+                     {
+                         protected override void ConfigureHowToFindSaga(SagaPropertyMapper<FinderOnlySagaData> mapper)
+                         {
+                             mapper.ConfigureFinderMapping<StartSagaMessage, FinderOnlyFinder>();
+                         }
+
+                         public Task Handle(StartSagaMessage message, IMessageHandlerContext context) => Task.CompletedTask;
+                     }
+
+                     public class FinderOnlySagaData : ContainSagaData
+                     {
+                         public string Property { get; set; }
+                     }
+
+                     public class FinderOnlyFinder : ISagaFinder<FinderOnlySagaData, StartSagaMessage>
+                     {
+                         public Task<FinderOnlySagaData> FindBy(StartSagaMessage message, ISynchronizedStorageSession storageSession, IReadOnlyContextBag context, CancellationToken cancellationToken = default) => Task.FromResult(default(FinderOnlySagaData));
+                     }
+
+                     public class StartSagaMessage : IMessage;
+                     """;
+
+        var result = SourceGeneratorTest.ForIncrementalGenerator<AddSagaInterceptor>()
+            .WithSource(source, "test.cs")
+            .WithAnalyzer<MockTrimmingAnalyzer>()
+            .WithSuppressor<AddSagaInterceptorSuppressor>()
+            .Run();
+
+        var diagnostics = result.GetCompilationOutput();
+
+        Assert.That(diagnostics, Does.Not.Contain("IL3050"));
+    }
+
     [Test]
     public void DoesNotSuppressIL2026ForNonAddSagaCalls()
     {
@@ -143,4 +246,37 @@ public void SomeOtherMethod() { }
 
         Assert.That(diagnostics, Does.Contain("IL2026"));
     }
+
+    [Test]
+    public void DoesNotSuppressIL3050ForNonAddSagaCalls()
+    {
+        var source = """
+                     using System.Diagnostics.CodeAnalysis;
+                     using NServiceBus;
+
+                     public class Test
+                     {
+                         public void Configure(EndpointConfiguration cfg)
+                         {
+                             // This call should still produce IL3050 since it's not intercepted
+                             SomeOtherMethod();
+                         }
+
+                         [RequiresDynamicCode("Test method")]
+                         public void SomeOtherMethod() { }
+                     }
+                     """;
+
+        var result = SourceGeneratorTest.ForIncrementalGenerator<AddSagaInterceptor>()
+            .WithSource(source, "test.cs")
+            .WithAnalyzer<MockTrimmingAnalyzer>()
+            .WithSuppressor<AddSagaInterceptorSuppressor>()
+            .SuppressDiagnosticErrors()
+            .SuppressCompilationErrors()
+            .Run();
+
+        var diagnostics = result.GetCompilationOutput();
+
+        Assert.That(diagnostics, Does.Contain("IL3050"));
+    }
 }

src/NServiceBus.Core.Analyzer/Handlers/AddHandlerInterceptor.Suppressor.cs

@@ -9,16 +9,23 @@
 [DiagnosticAnalyzer(LanguageNames.CSharp)]
 public sealed class AddHandlerInterceptorSuppressor : DiagnosticSuppressor
 {
+    const string Justification = "The AddHandler method has been intercepted by a statically generated variant.";
+
     static readonly SuppressionDescriptor SuppressRUCDiagnostic = new(
         SupressionIds.AddHandlerInterceptorSuppression,
         suppressedDiagnosticId: "IL2026",
-        justification: "The AddHandler method has been intercepted by a statically generated variant.");
+        justification: Justification);
+
+    static readonly SuppressionDescriptor SuppressRDCDiagnostic = new(
+        SupressionIds.AddHandlerInterceptorAotSuppression,
+        suppressedDiagnosticId: "IL3050",
+        justification: Justification);
 
     public override void ReportSuppressions(SuppressionAnalysisContext context)
     {
         foreach (var diagnostic in context.ReportedDiagnostics)
         {
-            if (diagnostic.Id != SuppressRUCDiagnostic.SuppressedDiagnosticId)
+            if (diagnostic.Id != SuppressRUCDiagnostic.SuppressedDiagnosticId && diagnostic.Id != SuppressRDCDiagnostic.SuppressedDiagnosticId)
             {
                 continue;
             }
@@ -47,10 +54,11 @@ public override void ReportSuppressions(SuppressionAnalysisContext context)
             var operation = semanticModel.GetOperation(node, context.CancellationToken);
             if (operation is IInvocationOperation { TargetMethod: { } methodSymbol } && AddHandlerInterceptor.Parser.IsAddHandlerMethod(methodSymbol))
             {
-                context.ReportSuppression(Suppression.Create(SuppressRUCDiagnostic, diagnostic));
+                var targetSuppression = diagnostic.Id == SuppressRUCDiagnostic.SuppressedDiagnosticId ? SuppressRUCDiagnostic : SuppressRDCDiagnostic;
+                context.ReportSuppression(Suppression.Create(targetSuppression, diagnostic));
             }
         }
     }
 
-    public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => [SuppressRUCDiagnostic];
+    public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => [SuppressRUCDiagnostic, SuppressRDCDiagnostic];
 }

src/NServiceBus.Core.Analyzer/Sagas/AddSagaInterceptor.Suppressor.cs

@@ -10,16 +10,23 @@
 [DiagnosticAnalyzer(LanguageNames.CSharp)]
 public sealed class AddSagaInterceptorSuppressor : DiagnosticSuppressor
 {
+    const string Justification = "The AddSaga method has been intercepted by a statically generated variant.";
+
     static readonly SuppressionDescriptor SuppressRUCDiagnostic = new(
         SupressionIds.AddSagaInterceptorSuppression,
         suppressedDiagnosticId: "IL2026",
-        justification: "The AddSaga method has been intercepted by a statically generated variant.");
+        justification: Justification);
+
+    static readonly SuppressionDescriptor SuppressRDCDiagnostic = new(
+        SupressionIds.AddSagaInterceptorAotSuppression,
+        suppressedDiagnosticId: "IL3050",
+        justification: Justification);
 
     public override void ReportSuppressions(SuppressionAnalysisContext context)
     {
         foreach (var diagnostic in context.ReportedDiagnostics)
         {
-            if (diagnostic.Id != SuppressRUCDiagnostic.SuppressedDiagnosticId)
+            if (diagnostic.Id != SuppressRUCDiagnostic.SuppressedDiagnosticId && diagnostic.Id != SuppressRDCDiagnostic.SuppressedDiagnosticId)
             {
                 continue;
             }
@@ -53,17 +60,18 @@ public override void ReportSuppressions(SuppressionAnalysisContext context)
 
             // Only suppress when an interceptor can actually be emitted for this call site. A saga that cannot be
             // parsed (no Saga<TSagaData> base, abstract, or otherwise unsupported) keeps the RequiresUnreferencedCode
-            // fallback warning.
+            // and RequiresDynamicCode fallback warnings.
             if (methodSymbol.TypeArguments[0] is not INamedTypeSymbol sagaType ||
                 !HandlerKnownTypes.TryGet(context.Compilation, out var knownTypes) ||
                 Sagas.Parser.Parse(semanticModel, sagaType, knownTypes, context.CancellationToken) is null)
             {
                 continue;
             }
 
-            context.ReportSuppression(Suppression.Create(SuppressRUCDiagnostic, diagnostic));
+            var targetSuppression = diagnostic.Id == SuppressRUCDiagnostic.SuppressedDiagnosticId ? SuppressRUCDiagnostic : SuppressRDCDiagnostic;
+            context.ReportSuppression(Suppression.Create(targetSuppression, diagnostic));
         }
     }
 
-    public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => [SuppressRUCDiagnostic];
+    public override ImmutableArray<SuppressionDescriptor> SupportedSuppressions => [SuppressRUCDiagnostic, SuppressRDCDiagnostic];
 }

src/NServiceBus.Core.Analyzer/SupressionIds.cs

@@ -5,4 +5,6 @@ public static class SupressionIds
     public const string AddHandlerInterceptorSuppression = "NSBS0001";
     public const string AddSagaInterceptorSuppression = "NSBS0002";
     public const string AddMessageTypeInterceptorSuppression = "NSBS0003";
+    public const string AddHandlerInterceptorAotSuppression = "NSBS0004";
+    public const string AddSagaInterceptorAotSuppression = "NSBS0005";
 }