Fix API diff tool crash when no attribute exclusion files are specified

src/Compatibility/ApiDiff/Microsoft.DotNet.ApiDiff.Tool/Microsoft.DotNet.ApiDiff.Tool.csproj

@@ -12,11 +12,7 @@
     <ExcludeFromSourceOnlyBuild>true</ExcludeFromSourceOnlyBuild>
   </PropertyGroup>
 
-  <ItemGroup>
-    <None Update="AttributesToExclude.txt">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
-  </ItemGroup>
+
 
   <ItemGroup>
     <ProjectReference Include="..\..\Microsoft.DotNet.ApiSymbolExtensions\Microsoft.DotNet.ApiSymbolExtensions.csproj" />

src/Compatibility/ApiDiff/Microsoft.DotNet.ApiDiff.Tool/Program.cs

@@ -14,7 +14,6 @@ namespace Microsoft.DotNet.ApiDiff.Tool;
 /// </summary>
 public static class Program
 {
-    private static readonly string AttributesToExcludeDefaultFileName = "AttributesToExclude.txt";
 
     public static async Task Main(string[] args)
     {
@@ -87,10 +86,10 @@ public static async Task Main(string[] args)
 
         Option<FileInfo[]?> optionFilesWithAttributesToExclude = new("--attributesToExclude", "-eattrs")
         {
-            Description = $"An optional array of filepaths, each containing a list of attributes to exclude from the diff. Each file should contain one API full name per line. You can either modify the default file '{AttributesToExcludeDefaultFileName}' to add your own attributes, or include additional files using this command line option.",
+            Description = "An optional array of filepaths, each containing a list of attributes to exclude from the diff. Each file should contain one docID per line in the format 'T:Namespace.TypeName'. If not specified, a default set of common attributes will be excluded automatically. Specifying this option replaces the defaults with the attributes listed in the provided files.",
             Arity = ArgumentArity.ZeroOrMore,
             Required = false,
-            DefaultValueFactory = _ => [new FileInfo(AttributesToExcludeDefaultFileName)]
+            DefaultValueFactory = _ => null
         };
 
         Option<FileInfo[]?> optionFilesWithApisToExclude = new("--apisToExclude", "-eapis")

src/Compatibility/ApiDiff/Microsoft.DotNet.ApiDiff/FileOutputDiffGenerator.cs

@@ -1,10 +1,10 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the
 
+using System.Diagnostics;
 using Microsoft.CodeAnalysis;
-using Microsoft.DotNet.ApiSymbolExtensions.Logging;
 using Microsoft.DotNet.ApiSymbolExtensions;
-using System.Diagnostics;
+using Microsoft.DotNet.ApiSymbolExtensions.Logging;
 
 namespace Microsoft.DotNet.ApiDiff;
 
@@ -75,7 +75,7 @@ internal FileOutputDiffGenerator(ILog log,
         _afterFriendlyName = afterFriendlyName;
         _tableOfContentsTitle = tableOfContentsTitle;
         _assembliesToExclude = CollectListsFromFiles(filesWithAssembliesToExclude);
-        _attributesToExclude = filesWithAttributesToExclude != null ? CollectListsFromFiles(filesWithAttributesToExclude) : [];
+        _attributesToExclude = CollectAttributesFromFilesOrDefaults(filesWithAttributesToExclude);
         _apisToExclude = CollectListsFromFiles(filesWithApisToExclude);
         _addPartialModifier = addPartialModifier;
         _writeToDisk = writeToDisk;
@@ -191,4 +191,40 @@ private static string[] CollectListsFromFiles(FileInfo[]? filesWithLists)
 
         return [.. list.Order()];
     }
+
+    private static string[] CollectAttributesFromFilesOrDefaults(FileInfo[]? filesWithLists)
+    {
+        // If no files are specified, use default attributes
+        if (filesWithLists == null || filesWithLists.Length == 0)
+        {
+            return [
+                "T:System.AttributeUsageAttribute",
+                "T:System.ComponentModel.EditorBrowsableAttribute",
+                "T:System.Diagnostics.CodeAnalysis.RequiresDynamicCodeAttribute",
+                "T:System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute",
+                "T:System.Windows.Markup.ContentWrapperAttribute",
+                "T:System.Windows.TemplatePartAttribute"
+            ];
+        }
+
+        List<string> list = [];
+
+        foreach (FileInfo file in filesWithLists)
+        {
+            // Only read files that exist, skip missing files silently
+            if (file.Exists)
+            {
+                foreach (string line in File.ReadLines(file.FullName))
+                {
+                    if (!list.Contains(line))
+                    {
+                        // Prevent duplicates.
+                        list.Add(line);
+                    }
+                }
+            }
+        }
+
+        return [.. list.Order()];
+    }
 }

src/Compatibility/ApiDiff/Microsoft.DotNet.ApiDiff/MemoryOutputDiffGenerator.cs

@@ -71,7 +71,7 @@ internal MemoryOutputDiffGenerator(
         _afterAssemblySymbols = new ConcurrentDictionary<string, IAssemblySymbol>(afterAssemblySymbols);
         _addPartialModifier = addPartialModifier;
         _diagnosticOptions = diagnosticOptions ?? DiffGeneratorFactory.DefaultDiagnosticOptions;
-        _attributeSymbolFilter = SymbolFilterFactory.GetFilterFromList(attributesToExclude ?? [], includeExplicitInterfaceImplementationSymbols: true);
+        _attributeSymbolFilter = SymbolFilterFactory.GetFilterFromList(GetAttributesToExcludeOrDefaults(attributesToExclude), includeExplicitInterfaceImplementationSymbols: true);
         _symbolFilter = SymbolFilterFactory.GetFilterFromList(apisToExclude ?? [], includeExplicitInterfaceImplementationSymbols: true);
         _twoSpacesTrivia = SyntaxFactory.TriviaList(SyntaxFactory.Space, SyntaxFactory.Space);
         _missingCloseBrace = SyntaxFactory.MissingToken(SyntaxKind.CloseBraceToken);
@@ -760,6 +760,24 @@ private string GetDocId(SyntaxNode node, SemanticModel model)
         return sb.Length == 0 ? null : sb.ToString();
     }
 
+    private static string[] GetAttributesToExcludeOrDefaults(string[]? attributesToExclude)
+    {
+        // If no attributes are specified, use default attributes
+        if (attributesToExclude == null)
+        {
+            return [
+                "T:System.AttributeUsageAttribute",
+                "T:System.ComponentModel.EditorBrowsableAttribute",
+                "T:System.Diagnostics.CodeAnalysis.RequiresDynamicCodeAttribute",
+                "T:System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute",
+                "T:System.Windows.Markup.ContentWrapperAttribute",
+                "T:System.Windows.TemplatePartAttribute"
+            ];
+        }
+
+        return attributesToExclude;
+    }
+
     private class ChildrenNodesComparer : IComparer<KeyValuePair<string, MemberDeclarationSyntax>>
     {
         public int Compare(KeyValuePair<string, MemberDeclarationSyntax> first, KeyValuePair<string, MemberDeclarationSyntax> second)

test/Microsoft.DotNet.ApiDiff.Tests/Diff.Attribute.Tests.cs

@@ -734,15 +734,16 @@ public class MyClass
     [Fact]
     public Task SuppressAllDefaultAttributesUsedByTool()
     {
-        // The attributes that should get hidden in this test must all be part of
-        // the AttributesToExclude.txt file that the ApiDiff tool uses by default.
-
-        FileInfo file = new FileInfo("AttributesToExclude.txt");
-        if (!file.Exists)
-        {
-            throw new FileNotFoundException($"{file.FullName} file not found.");
-        }
-        string[] attributesToExclude = File.ReadAllLines(file.FullName);
+        // Test that the default attributes defined in FileOutputDiffGenerator are properly excluded.
+        // These are the same attributes that are excluded when no -eattrs parameter is specified.
+        string[] attributesToExclude = [
+            "T:System.AttributeUsageAttribute",
+            "T:System.ComponentModel.EditorBrowsableAttribute",
+            "T:System.Diagnostics.CodeAnalysis.RequiresDynamicCodeAttribute",
+            "T:System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute",
+            "T:System.Windows.Markup.ContentWrapperAttribute",
+            "T:System.Windows.TemplatePartAttribute"
+        ];
 
         return RunTestAsync(
                 beforeCode: """
@@ -787,6 +788,56 @@ public class MyClass
                 attributesToExclude: attributesToExclude);
     }
 
+    [Fact]
+    public Task DefaultBehaviorExcludesDefaultAttributes()
+    {
+        // Test that when no attributesToExclude is specified (null), 
+        // the tool automatically excludes the default set of attributes.
+        // This simulates the behavior when -eattrs is not specified on the command line.
+
+        return RunTestAsync(
+                beforeCode: """
+                namespace MyNamespace
+                {
+                    public class MyClass
+                    {
+                    }
+                }
+                """,
+                afterCode: """
+                using System;
+                namespace MyNamespace
+                {
+                    [System.AttributeUsage(System.AttributeTargets.All)]
+                    public class MyAttributeAttribute : System.Attribute
+                    {
+                        public MyAttributeAttribute() { }
+                    }
+                    [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
+                    [System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Text")]
+                    [MyAttribute]
+                    [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Text")]
+                    public class MyClass
+                    {
+                    }
+                }
+                """,
+                expectedCode: """
+                  namespace MyNamespace
+                  {
+                +     [MyNamespace.MyAttributeAttribute]
+                      public class MyClass
+                      {
+                      }
+                +     public class MyAttributeAttribute : System.Attribute
+                +     {
+                +         public MyAttributeAttribute();
+                +     }
+                  }
+                """,
+                attributesToExclude: null); // null simulates default behavior
+    }
+
     [Fact]
     public Task SuppressNone() => RunTestAsync(
                 beforeCode: """

test/Microsoft.DotNet.ApiDiff.Tests/Microsoft.DotNet.ApiDiff.Tests.csproj

@@ -14,11 +14,6 @@
     <Compile Include="..\Microsoft.DotNet.GenAPI.Tests\TestAssemblyLoaderFactory.cs" />
     <Compile Include="..\Microsoft.DotNet.ApiSymbolExtensions.Tests\SymbolFactory.cs" />
     <Compile Include="..\Microsoft.DotNet.ApiSymbolExtensions.Tests\TempDirectory.cs" />
-    <None
-      Include="$(RepoRoot)src\Compatibility\ApiDiff\Microsoft.DotNet.ApiDiff.Tool\AttributesToExclude.txt"
-      Link="AttributesToExclude.txt">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
   </ItemGroup>
 
   <ItemGroup>

test/TestAssets/TestProjects/ProjectWithEsProjReference/obj\Debug/\package.g.props

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+  <PropertyGroup>
+    <PackageJsonName Condition="$(PackageJsonName) == ''">lib</PackageJsonName>
+    <PackageJsonVersion Condition="$(PackageJsonVersion) == ''">1.0.0</PackageJsonVersion>
+    <PackageJsonDescription Condition="$(PackageJsonDescription) == ''">A test project to verify .NET SDK compatibility for workload restore and non-Managed projects</PackageJsonDescription>
+    <PackageJsonMain Condition="$(PackageJsonMain) == ''">index.js</PackageJsonMain>
+    <PackageJsonScriptsTest Condition="$(PackageJsonScriptsTest) == ''">echo "Error: no test specified" &amp;&amp; exit 1</PackageJsonScriptsTest>
+    <PackageJsonAuthor Condition="$(PackageJsonAuthor) == ''"></PackageJsonAuthor>
+    <PackageJsonLicense Condition="$(PackageJsonLicense) == ''">MIT</PackageJsonLicense>
+  </PropertyGroup>
+</Project>