C#: Refactor and regenerate stubs

Author: hvitved

csharp/extractor/Semmle.Extraction.CSharp.StubGenerator/RelevantSymbol.cs

@@ -0,0 +1,33 @@
+using System.Linq;
+
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+
+using Semmle.Util;
+
+namespace Semmle.Extraction.CSharp.StubGenerator;
+
+internal class RelevantSymbol
+{
+    private readonly IAssemblySymbol assembly;
+    private readonly MemoizedFunc<INamedTypeSymbol, bool> isRelevantNamedType;
+    private readonly MemoizedFunc<INamespaceSymbol, bool> isRelevantNamespace;
+
+    public RelevantSymbol(IAssemblySymbol assembly)
+    {
+        this.assembly = assembly;
+
+        isRelevantNamedType = new(symbol =>
+            StubVisitor.IsRelevantBaseType(symbol) &&
+            SymbolEqualityComparer.Default.Equals(symbol.ContainingAssembly, assembly));
+
+        isRelevantNamespace = new(symbol =>
+            symbol.GetTypeMembers().Any(IsRelevantNamedType) ||
+            symbol.GetNamespaceMembers().Any(IsRelevantNamespace));
+    }
+
+    public bool IsRelevantNamedType(INamedTypeSymbol symbol) => isRelevantNamedType.Invoke(symbol);
+
+    public bool IsRelevantNamespace(INamespaceSymbol symbol) => isRelevantNamespace.Invoke(symbol);
+}
+

csharp/extractor/Semmle.Extraction.CSharp.StubGenerator/StubGenerator.cs

@@ -1,12 +1,13 @@
-using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
+
 using Semmle.Util;
 using Semmle.Util.Logging;
 
@@ -56,20 +57,18 @@ private static void StubReference(ILogger logger, CSharpCompilation compilation,
         if (compilation.GetAssemblyOrModuleSymbol(reference) is not IAssemblySymbol assembly)
             return;
 
-        Func<StreamWriter> makeWriter = () =>
-        {
-            var fileStream = new FileStream(FileUtils.NestPaths(logger, outputPath, path.Replace(".dll", ".cs")), FileMode.Create, FileAccess.Write);
-            var writer = new StreamWriter(fileStream, new UTF8Encoding(false));
-            return writer;
-        };
-
-        using var visitor = new StubVisitor(assembly, makeWriter);
+        var relevantSymbol = new RelevantSymbol(assembly);
 
-        if (!assembly.Modules.Any(m => visitor.IsRelevantNamespace(m.GlobalNamespace)))
+        if (!assembly.Modules.Any(m => relevantSymbol.IsRelevantNamespace(m.GlobalNamespace)))
             return;
 
-        visitor.StubWriter.WriteLine("// This file contains auto-generated code.");
-        visitor.StubWriter.WriteLine($"// Generated from `{assembly.Identity}`.");
+        using var fileStream = new FileStream(FileUtils.NestPaths(logger, outputPath, path.Replace(".dll", ".cs")), FileMode.Create, FileAccess.Write);
+        using var writer = new StreamWriter(fileStream, new UTF8Encoding(false));
+
+        var visitor = new StubVisitor(writer, relevantSymbol);
+
+        writer.WriteLine("// This file contains auto-generated code.");
+        writer.WriteLine($"// Generated from `{assembly.Identity}`.");
 
         visitor.StubAttributes(assembly.GetAttributes(), "assembly: ");