Add trim/aot analyzer warnings for transitive references (#118180)

sbomer · web-flow · commit e911894ae86e · 2025-08-04T11:27:24.000-07:00
Adds new analyzer warnings for references to assemblies not marked as
trim or aot compatible.

The new warnings are opt-in under the following settings:

- `&lt;VerifyReferenceTrimCompatibility&gt;true&lt;/VerifyReferenceTrimCompatibility&gt;`
- `&lt;VerifyReferenceAotCompatibility&gt;true&lt;/VerifyReferenceAotCompatibility&gt;`

The analyzer uses AssemblyMetadataAttribute in the referenced
assemblies to detect whether they are marked as trim/aot
compatible. To mark a project as trim/aot compatible, it should be
built with the usual recommended property settings:

- `&lt;IsTrimmable&gt;true&lt;/IsTrimmable&gt;`
  adds `[assembly: AssemblyMetadata("IsTrimmable", "True")]`
- `&lt;IsAotCompatible&gt;true&lt;/IsAotCompatible&gt;`
  adds `[assembly: AssemblyMetadata("IsAotCompatible", "True")`
diff --git a/eng/pipelines/runtime-linker-tests.yml b/eng/pipelines/runtime-linker-tests.yml
@@ -82,7 +82,11 @@ extends:
               or(
                 eq(stageDependencies.EvaluatePaths.evaluate_paths.outputs['SetPathVars_tools_illink.containsChange'], true),
                 eq(variables['isRollingBuild'], true))
-            buildArgs: -s tools.illinktests -test -c $(_BuildConfig)
+            # Build libs.sfx subset first so that Roslyn analyzer tests can use live ref pack
+            buildArgs: -s libs.sfx -c $(_BuildConfig)
+            postBuildSteps:
+            - script: $(Build.SourcesDirectory)$(dir)build$(scriptExt) -ci -arch ${{ parameters.archType }} $(_osParameter) -s tools.illinktests -test -c $(_BuildConfig) $(crossArg) $(_officialBuildParameter)
+              displayName: Run ILLink Tests
 
       #
       # Build Release config vertical for Windows, Linux, and OSX
diff --git a/src/libraries/System.Runtime.InteropServices.JavaScript/Directory.Build.props b/src/libraries/System.Runtime.InteropServices.JavaScript/Directory.Build.props
@@ -3,6 +3,5 @@
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
     <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <IsAotCompatible>false</IsAotCompatible>
   </PropertyGroup>
 </Project>
diff --git a/src/tools/illink/src/ILLink.RoslynAnalyzer/MSBuildPropertyOptionNames.cs b/src/tools/illink/src/ILLink.RoslynAnalyzer/MSBuildPropertyOptionNames.cs
@@ -9,5 +9,7 @@ public static class MSBuildPropertyOptionNames
         public const string IncludeAllContentForSelfExtract = nameof(IncludeAllContentForSelfExtract);
         public const string EnableTrimAnalyzer = nameof(EnableTrimAnalyzer);
         public const string EnableAotAnalyzer = nameof(EnableAotAnalyzer);
+        public const string VerifyReferenceAotCompatibility = nameof(VerifyReferenceAotCompatibility);
+        public const string VerifyReferenceTrimCompatibility = nameof(VerifyReferenceTrimCompatibility);
     }
 }
diff --git a/src/tools/illink/src/ILLink.RoslynAnalyzer/RequiresAnalyzerBase.cs b/src/tools/illink/src/ILLink.RoslynAnalyzer/RequiresAnalyzerBase.cs
@@ -36,6 +36,7 @@ public abstract class RequiresAnalyzerBase : DiagnosticAnalyzer
 
         private protected virtual ImmutableArray<(Action<SyntaxNodeAnalysisContext> Action, SyntaxKind[] SyntaxKind)> ExtraSyntaxNodeActions { get; } = ImmutableArray<(Action<SyntaxNodeAnalysisContext> Action, SyntaxKind[] SyntaxKind)>.Empty;
         private protected virtual ImmutableArray<(Action<SymbolAnalysisContext> Action, SymbolKind[] SymbolKind)> ExtraSymbolActions { get; } = ImmutableArray<(Action<SymbolAnalysisContext> Action, SymbolKind[] SymbolKind)>.Empty;
+        private protected virtual ImmutableArray<Action<CompilationAnalysisContext>> ExtraCompilationActions { get; } = ImmutableArray<Action<CompilationAnalysisContext>>.Empty;
 
         public override void Initialize(AnalysisContext context)
         {
@@ -165,6 +166,9 @@ void CheckMatchingAttributesInInterfaces(
                     }
                 }
             });
+
+            foreach (var extraCompilationAction in ExtraCompilationActions)
+                context.RegisterCompilationAction(extraCompilationAction);
         }
 
         internal void CheckAndCreateRequiresDiagnostic(
@@ -386,5 +390,38 @@ ImmutableArray<MultiValue> arguments
         {
             return false;
         }
+
+        protected void CheckReferencedAssemblies(
+            CompilationAnalysisContext context,
+            string msbuildPropertyName,
+            string assemblyMetadataName,
+            DiagnosticDescriptor diagnosticDescriptor)
+        {
+            var options = context.Options;
+            if (!IsAnalyzerEnabled(options))
+                return;
+
+            if (!options.IsMSBuildPropertyValueTrue(msbuildPropertyName))
+                return;
+
+            foreach (var reference in context.Compilation.References)
+            {
+                var refAssembly = context.Compilation.GetAssemblyOrModuleSymbol(reference) as IAssemblySymbol;
+                if (refAssembly is null)
+                    continue;
+
+                var assemblyMetadata = refAssembly.GetAttributes().FirstOrDefault(attr =>
+                    attr.AttributeClass?.Name == "AssemblyMetadataAttribute" &&
+                    attr.ConstructorArguments.Length == 2 &&
+                    attr.ConstructorArguments[0].Value?.ToString() == assemblyMetadataName &&
+                    string.Equals(attr.ConstructorArguments[1].Value?.ToString(), "True", StringComparison.OrdinalIgnoreCase));
+
+                if (assemblyMetadata is null)
+                {
+                    var diag = Diagnostic.Create(diagnosticDescriptor, Location.None, refAssembly.Name);
+                    context.ReportDiagnostic(diag);
+                }
+            }
+        }
     }
 }
diff --git a/src/tools/illink/src/ILLink.RoslynAnalyzer/RequiresDynamicCodeAnalyzer.cs b/src/tools/illink/src/ILLink.RoslynAnalyzer/RequiresDynamicCodeAnalyzer.cs
@@ -23,9 +23,10 @@ public sealed class RequiresDynamicCodeAnalyzer : RequiresAnalyzerBase
         private static readonly DiagnosticDescriptor s_requiresDynamicCodeOnEntryPoint = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.RequiresDynamicCodeOnEntryPoint);
         private static readonly DiagnosticDescriptor s_requiresDynamicCodeRule = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.RequiresDynamicCode);
         private static readonly DiagnosticDescriptor s_requiresDynamicCodeAttributeMismatch = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.RequiresDynamicCodeAttributeMismatch);
+        private static readonly DiagnosticDescriptor s_referenceNotMarkedIsAotCompatibleRule = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.ReferenceNotMarkedIsAotCompatible);
 
         public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics =>
-            ImmutableArray.Create(s_requiresDynamicCodeRule, s_requiresDynamicCodeAttributeMismatch, s_requiresDynamicCodeOnStaticCtor, s_requiresDynamicCodeOnEntryPoint);
+            ImmutableArray.Create(s_requiresDynamicCodeRule, s_requiresDynamicCodeAttributeMismatch, s_requiresDynamicCodeOnStaticCtor, s_requiresDynamicCodeOnEntryPoint, s_referenceNotMarkedIsAotCompatibleRule);
 
         private protected override string RequiresAttributeName => RequiresDynamicCodeAttribute;
 
@@ -163,6 +164,16 @@ private protected override bool IsRequiresCheck(IPropertySymbol propertySymbol,
             return SymbolEqualityComparer.Default.Equals(propertySymbol, isDynamicCodeSupportedProperty);
         }
 
+        private protected override ImmutableArray<Action<CompilationAnalysisContext>> ExtraCompilationActions =>
+            ImmutableArray.Create<Action<CompilationAnalysisContext>>((context) =>
+            {
+                CheckReferencedAssemblies(
+                    context,
+                    MSBuildPropertyOptionNames.VerifyReferenceAotCompatibility,
+                    "IsAotCompatible",
+                    s_referenceNotMarkedIsAotCompatibleRule);
+            });
+
         protected override bool VerifyAttributeArguments(AttributeData attribute) =>
             attribute.ConstructorArguments.Length >= 1 && attribute.ConstructorArguments is [{ Type.SpecialType: SpecialType.System_String }, ..];
 
diff --git a/src/tools/illink/src/ILLink.RoslynAnalyzer/RequiresUnreferencedCodeAnalyzer.cs b/src/tools/illink/src/ILLink.RoslynAnalyzer/RequiresUnreferencedCodeAnalyzer.cs
@@ -25,8 +25,10 @@ public sealed class RequiresUnreferencedCodeAnalyzer : RequiresAnalyzerBase
         private static readonly DiagnosticDescriptor s_requiresUnreferencedCodeOnStaticCtor = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.RequiresUnreferencedCodeOnStaticConstructor);
         private static readonly DiagnosticDescriptor s_requiresUnreferencedCodeOnEntryPoint = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.RequiresUnreferencedCodeOnEntryPoint);
 
+        private static readonly DiagnosticDescriptor s_referenceNotMarkedIsTrimmableRule = DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.ReferenceNotMarkedIsTrimmable);
+
         public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics =>
-            ImmutableArray.Create(s_makeGenericMethodRule, s_makeGenericTypeRule, s_requiresUnreferencedCodeRule, s_requiresUnreferencedCodeAttributeMismatch, s_requiresUnreferencedCodeOnStaticCtor, s_requiresUnreferencedCodeOnEntryPoint);
+            ImmutableArray.Create(s_makeGenericMethodRule, s_makeGenericTypeRule, s_requiresUnreferencedCodeRule, s_requiresUnreferencedCodeAttributeMismatch, s_requiresUnreferencedCodeOnStaticCtor, s_requiresUnreferencedCodeOnEntryPoint, s_referenceNotMarkedIsTrimmableRule);
 
         private protected override string RequiresAttributeName => RequiresUnreferencedCodeAttribute;
 
@@ -76,6 +78,16 @@ protected override bool CreateSpecialIncompatibleMembersDiagnostic(
             return false;
         }
 
+        private protected override ImmutableArray<Action<CompilationAnalysisContext>> ExtraCompilationActions =>
+            ImmutableArray.Create<Action<CompilationAnalysisContext>>((context) =>
+            {
+                CheckReferencedAssemblies(
+                    context,
+                    MSBuildPropertyOptionNames.VerifyReferenceTrimCompatibility,
+                    "IsTrimmable",
+                    s_referenceNotMarkedIsTrimmableRule);
+            });
+
         protected override bool VerifyAttributeArguments(AttributeData attribute) =>
             RequiresUnreferencedCodeUtils.VerifyRequiresUnreferencedCodeAttributeArguments(attribute);
 
diff --git a/src/tools/illink/src/ILLink.RoslynAnalyzer/build/Microsoft.NET.ILLink.Analyzers.props b/src/tools/illink/src/ILLink.RoslynAnalyzer/build/Microsoft.NET.ILLink.Analyzers.props
@@ -1,8 +1,10 @@
 <Project>
   <ItemGroup>
-    <CompilerVisibleProperty Include="EnableAotAnalyzer"/>
-    <CompilerVisibleProperty Include="EnableSingleFileAnalyzer"/>
-    <CompilerVisibleProperty Include="EnableTrimAnalyzer"/>
-    <CompilerVisibleProperty Include="IncludeAllContentForSelfExtract"/>
+    <CompilerVisibleProperty Include="EnableAotAnalyzer" />
+    <CompilerVisibleProperty Include="EnableSingleFileAnalyzer" />
+    <CompilerVisibleProperty Include="EnableTrimAnalyzer" />
+    <CompilerVisibleProperty Include="IncludeAllContentForSelfExtract" />
+    <CompilerVisibleProperty Include="VerifyReferenceTrimCompatibility" />
+    <CompilerVisibleProperty Include="VerifyReferenceAotCompatibility" />
   </ItemGroup>
 </Project>
diff --git a/src/tools/illink/src/ILLink.Shared/DiagnosticId.cs b/src/tools/illink/src/ILLink.Shared/DiagnosticId.cs
@@ -189,6 +189,7 @@ public enum DiagnosticId
         TypeNameIsNotAssemblyQualified = 2122,
         RequiresUnreferencedCodeOnEntryPoint = 2123,
         TypeMapGroupTypeCannotBeStaticallyDetermined = 2124,
+        ReferenceNotMarkedIsTrimmable = 2125,
         _EndTrimAnalysisWarningsSentinel,
 
         // Single-file diagnostic ids.
@@ -208,6 +209,7 @@ public enum DiagnosticId
         CorrectnessOfAbstractDelegatesCannotBeGuaranteed = 3055,
         RequiresDynamicCodeOnStaticConstructor = 3056,
         RequiresDynamicCodeOnEntryPoint = 3057,
+        ReferenceNotMarkedIsAotCompatible = 3058,
         _EndAotAnalysisWarningsSentinel,
 
         // Feature guard diagnostic ids.
diff --git a/src/tools/illink/src/ILLink.Shared/SharedStrings.resx b/src/tools/illink/src/ILLink.Shared/SharedStrings.resx
@@ -1239,4 +1239,16 @@
   <data name="TypeNameIsNotAssemblyQualifiedTitle" xml:space="preserve">
     <value>Type name is not assembly qualified.</value>
   </data>
+  <data name="ReferenceNotMarkedIsTrimmableTitle" xml:space="preserve">
+    <value>Referenced assembly is not marked as trimmable.</value>
+  </data>
+  <data name="ReferenceNotMarkedIsTrimmableMessage" xml:space="preserve">
+    <value>Referenced assembly '{0}' is not built with `<IsTrimmable>true</IsTrimmable>` and may not be compatible with trimming.</value>
+  </data>
+  <data name="ReferenceNotMarkedIsAotCompatibleTitle" xml:space="preserve">
+    <value>Referenced assembly is not marked as AOT-compatible.</value>
+  </data>
+  <data name="ReferenceNotMarkedIsAotCompatibleMessage" xml:space="preserve">
+    <value>Referenced assembly '{0}' is not built with `<IsAotCompatible>true</IsAotCompatible>` and may not be compatible with AOT.</value>
+  </data>
 </root>
diff --git a/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ILLink.RoslynAnalyzer.Tests.csproj b/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ILLink.RoslynAnalyzer.Tests.csproj
@@ -37,16 +37,12 @@
   <!-- The analyzer tests require the reference assemblies that are compiled against.
        Copy them to the output/publish directory so that tests still work on a different
        machine (i.e. when testing with Helix). -->
-  <Target Name="CopyReferenceAssembliesToOutputDir"
-          DependsOnTargets="FindReferenceAssembliesForReferences"
-          BeforeTargets="AssignTargetPaths;GetCopyToPublishDirectoryItems">
-    <ItemGroup>
-      <None Include="@(ReferencePathWithRefAssemblies->WithMetadataValue('FrameworkReferenceName', 'Microsoft.NETCore.App'))"
-            CopyToOutputDirectory="PreserveNewest"
-            CopyToPublishDirectory="PreserveNewest"
-            Link="live-ref-pack\%(RecursiveDir)%(Filename)%(Extension)"
-            Visible="false" />
-    </ItemGroup>
-  </Target>
+  <ItemGroup>
+    <None Include="$(MicrosoftNetCoreAppRefPackRefDir)**/*.dll"
+          CopyToOutputDirectory="PreserveNewest"
+          CopyToPublishDirectory="PreserveNewest"
+          LinkBase="live-ref-pack/"
+          Visible="false" />
+  </ItemGroup>
 
 </Project>
diff --git a/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ReferenceAotCompatibilityTests.cs b/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ReferenceAotCompatibilityTests.cs
@@ -0,0 +1,76 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Threading.Tasks;
+using ILLink.Shared;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Testing;
+using Xunit;
+using System.IO;
+using VerifyCS = ILLink.RoslynAnalyzer.Tests.CSharpCodeFixVerifier<
+    ILLink.RoslynAnalyzer.RequiresDynamicCodeAnalyzer,
+    ILLink.CodeFix.RequiresDynamicCodeCodeFixProvider>;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using ILLink.CodeFix;
+
+namespace ILLink.RoslynAnalyzer.Tests
+{
+    public class ReferenceAotCompatibilityTests
+    {
+        [Fact]
+        public async Task EmitsWarningForReferenceWithoutIsAotCompatible_WhenPropertyEnabled()
+        {
+            var referencedSource = "public class ReferencedClass { }";
+            var testSource = "public class MainClass { ReferencedClass c; }";
+
+            var test = ReferenceCompatibilityTestUtils.CreateTestWithReference<RequiresDynamicCodeAnalyzer, RequiresDynamicCodeCodeFixProvider>(
+                testSource, referencedSource);
+            test.TestState.AnalyzerConfigFiles.Add(("/.editorconfig", Microsoft.CodeAnalysis.Text.SourceText.From($"""
+                is_global = true
+                build_property.{ILLink.RoslynAnalyzer.MSBuildPropertyOptionNames.EnableAotAnalyzer} = true
+                build_property.VerifyReferenceAotCompatibility = true
+                """)));
+            test.ExpectedDiagnostics.Add(VerifyCS.Diagnostic(DiagnosticId.ReferenceNotMarkedIsAotCompatible).WithArguments("ReferencedAssembly"));
+            await test.RunAsync();
+        }
+
+        [Fact]
+        public async Task DoesNotEmitWarning_WhenVerifyReferenceAotCompatibilityDisabled()
+        {
+            var referencedSource = "public class ReferencedClass { }";
+            var testSource = "public class MainClass { ReferencedClass c; }";
+
+            var test = ReferenceCompatibilityTestUtils.CreateTestWithReference<RequiresDynamicCodeAnalyzer, RequiresDynamicCodeCodeFixProvider>(
+                testSource, referencedSource);
+            test.TestState.AnalyzerConfigFiles.Add(("/.editorconfig", Microsoft.CodeAnalysis.Text.SourceText.From($"""
+                is_global = true
+                build_property.{ILLink.RoslynAnalyzer.MSBuildPropertyOptionNames.EnableAotAnalyzer} = true
+                build_property.VerifyReferenceAotCompatibility = false
+                """)));
+            await test.RunAsync();
+        }
+
+        [Fact]
+        public async Task DoesNotEmitWarning_WhenReferenceMarkedIsAotCompatible()
+        {
+            var referencedSource = """
+                [assembly: System.Reflection.AssemblyMetadata("IsAotCompatible", "True")]
+                public class ReferencedClass { }
+                """;
+            var testSource = "public class MainClass { ReferencedClass c; }";
+
+            var test = ReferenceCompatibilityTestUtils.CreateTestWithReference<RequiresDynamicCodeAnalyzer, RequiresDynamicCodeCodeFixProvider>(
+                testSource, referencedSource);
+            test.TestState.AnalyzerConfigFiles.Add(("/.editorconfig", Microsoft.CodeAnalysis.Text.SourceText.From($"""
+                is_global = true
+                build_property.{ILLink.RoslynAnalyzer.MSBuildPropertyOptionNames.EnableAotAnalyzer} = true
+                build_property.VerifyReferenceAotCompatibility = true
+                """)));
+            await test.RunAsync();
+        }
+    }
+}
diff --git a/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ReferenceCompatibilityTestUtils.cs b/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ReferenceCompatibilityTestUtils.cs
@@ -0,0 +1,55 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Threading.Tasks;
+using ILLink.Shared;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Testing;
+using Xunit;
+using System.IO;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace ILLink.RoslynAnalyzer.Tests
+{
+    public class ReferenceCompatibilityTestUtils
+    {
+        public static CSharpCodeFixVerifier<TAnalyzer, TCodeFix>.Test CreateTestWithReference<TAnalyzer, TCodeFix>(string mainSource, string referenceSource)
+            where TAnalyzer : DiagnosticAnalyzer, new()
+            where TCodeFix : Microsoft.CodeAnalysis.CodeFixes.CodeFixProvider, new()
+        {
+            var referencedMetadata = CreateReferencedMetadata(referenceSource);
+            var test = new CSharpCodeFixVerifier<TAnalyzer, TCodeFix>.Test
+            {
+                TestCode = mainSource
+            };
+            test.SolutionTransforms.Add((solution, projectId) =>
+            {
+                var project = solution.GetProject(projectId);
+                if (project is null)
+                    return solution;
+                project = project.AddMetadataReference(referencedMetadata);
+                return project.Solution;
+            });
+            return test;
+
+            static MetadataReference CreateReferencedMetadata(string referencedSource)
+            {
+                var refs = SourceGenerators.Tests.LiveReferencePack.GetMetadataReferences();
+                var referencedCompilation = CSharpCompilation.Create(
+                    "ReferencedAssembly",
+                    new[] { SyntaxFactory.ParseSyntaxTree(referencedSource) },
+                    refs,
+                    new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
+                var referencedImage = new MemoryStream();
+                referencedCompilation.Emit(referencedImage);
+                referencedImage.Position = 0;
+                return MetadataReference.CreateFromStream(referencedImage);
+            }
+        }
+    }
+}
diff --git a/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ReferenceTrimCompatibilityTests.cs b/src/tools/illink/test/ILLink.RoslynAnalyzer.Tests/ReferenceTrimCompatibilityTests.cs

Original file line number	Diff line number	Diff line change
`@@ -9,5 +9,7 @@ public static class MSBuildPropertyOptionNames`
`9`	`9`	`public const string IncludeAllContentForSelfExtract = nameof(IncludeAllContentForSelfExtract);`
`10`	`10`	`public const string EnableTrimAnalyzer = nameof(EnableTrimAnalyzer);`
`11`	`11`	`public const string EnableAotAnalyzer = nameof(EnableAotAnalyzer);`
	`12`	`+ public const string VerifyReferenceAotCompatibility = nameof(VerifyReferenceAotCompatibility);`
	`13`	`+ public const string VerifyReferenceTrimCompatibility = nameof(VerifyReferenceTrimCompatibility);`
`12`	`14`	`}`
`13`	`15`	`}`