Fix code review findings

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CIL/Analyser.cs

@@ -7,7 +7,7 @@ namespace Semmle.Extraction.CIL
 {
     public static class Analyser
     {
-        private static void ExtractCIL(NonStandaloneExtractor extractor, TrapWriter trapWriter, bool extractPdbs)
+        private static void ExtractCIL(TracingExtractor extractor, TrapWriter trapWriter, bool extractPdbs)
         {
             using var cilContext = new Context(extractor, trapWriter, extractor.OutputPath, extractPdbs);
             cilContext.Populate(new Assembly(cilContext));
@@ -33,7 +33,7 @@ public static void ExtractCIL(Layout layout, string assemblyPath, ILogger logger
             {
                 var canonicalPathCache = CanonicalPathCache.Create(logger, 1000);
                 var pathTransformer = new PathTransformer(canonicalPathCache);
-                var extractor = new NonStandaloneExtractor(assemblyPath, logger, pathTransformer);
+                var extractor = new TracingExtractor(assemblyPath, logger, pathTransformer);
                 var transformedAssemblyPath = pathTransformer.Transform(assemblyPath);
                 var project = layout.LookupProjectOrDefault(transformedAssemblyPath);
                 using var trapWriter = project.CreateTrapWriter(logger, transformedAssemblyPath.WithSuffix(".cil"), trapCompression, discardDuplicates: true);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Assembly.cs

@@ -17,7 +17,7 @@ private Assembly(Context cx, Microsoft.CodeAnalysis.Location? init)
             if (init == null)
             {
                 // This is the output assembly
-                assemblyPath = ((NonStandaloneExtractor)cx.Extractor).OutputPath;
+                assemblyPath = ((TracingExtractor)cx.Extractor).OutputPath;
                 assembly = cx.Compilation.Assembly;
             }
             else

csharp/extractor/Semmle.Extraction.CSharp/Entities/CachedEntity.cs

@@ -1,6 +1,6 @@
 namespace Semmle.Extraction.CSharp.Entities
 {
-    internal abstract class CachedEntity<T> : Extraction.CachedEntity<T> where T : class
+    internal abstract class CachedEntity<T> : Extraction.CachedEntity<T> where T : notnull
     {
         public override Context Context => (Context)base.Context;
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/CommentLine.cs

@@ -4,10 +4,10 @@
 
 namespace Semmle.Extraction.CSharp.Entities
 {
-    internal class CommentLine : CachedEntity<Tuple<Microsoft.CodeAnalysis.Location, string>>
+    internal class CommentLine : CachedEntity<(Microsoft.CodeAnalysis.Location, string)>
     {
         private CommentLine(Context cx, Microsoft.CodeAnalysis.Location loc, CommentLineType type, string text, string raw)
-            : base(cx, new Tuple<Microsoft.CodeAnalysis.Location, string>(loc, text))
+            : base(cx, (loc, text))
         {
             Type = type;
             RawText = raw;

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

@@ -86,7 +86,7 @@ public static ExitCode Run(string[] args)
             var canonicalPathCache = CanonicalPathCache.Create(logger, 1000);
             var pathTransformer = new PathTransformer(canonicalPathCache);
 
-            using var analyser = new NonStandaloneAnalyser(new LogProgressMonitor(logger), logger, options.AssemblySensitiveTrap, pathTransformer);
+            using var analyser = new TracingAnalyser(new LogProgressMonitor(logger), logger, options.AssemblySensitiveTrap, pathTransformer);
 
             try
             {
@@ -120,7 +120,7 @@ public static ExitCode Run(string[] args)
                     return ExitCode.Ok;
                 }
 
-                return AnalyseNonStandalone(analyser, compilerArguments, options, canonicalPathCache, stopwatch);
+                return AnalyseTracing(analyser, compilerArguments, options, canonicalPathCache, stopwatch);
             }
             catch (Exception ex)  // lgtm[cs/catch-of-all-exceptions]
             {
@@ -291,7 +291,7 @@ private static ExitCode Analyse(Stopwatch stopwatch, Analyser analyser, CommonOp
             {
                 analyser.Logger.Log(Severity.Error, "  No source files");
                 ++analyser.CompilationErrors;
-                if (analyser is NonStandaloneAnalyser)
+                if (analyser is TracingAnalyser)
                 {
                     return ExitCode.Failed;
                 }
@@ -369,8 +369,8 @@ private static void AnalyseStandalone(
                 });
         }
 
-        private static ExitCode AnalyseNonStandalone(
-            NonStandaloneAnalyser analyser,
+        private static ExitCode AnalyseTracing(
+            TracingAnalyser analyser,
             CSharpCommandLineArguments compilerArguments,
             Options options,
             CanonicalPathCache canonicalPathCache,

csharp/extractor/Semmle.Extraction.CSharp/Extractor/NonStandaloneAnalyser.cs renamed to csharp/extractor/Semmle.Extraction.CSharp/Extractor/TracingAnalyser.cs

@@ -10,14 +10,14 @@
 
 namespace Semmle.Extraction.CSharp
 {
-    public class NonStandaloneAnalyser : Analyser, IDisposable
+    public class TracingAnalyser : Analyser, IDisposable
     {
         private Entities.Compilation? compilationEntity;
         private IDisposable? compilationTrapFile;
 
         private bool init;
 
-        public NonStandaloneAnalyser(IProgressMonitor pm, ILogger logger, bool addAssemblyTrapPrefix, PathTransformer pathTransformer)
+        public TracingAnalyser(IProgressMonitor pm, ILogger logger, bool addAssemblyTrapPrefix, PathTransformer pathTransformer)
             : base(pm, logger, addAssemblyTrapPrefix, pathTransformer)
         {
         }
@@ -49,7 +49,7 @@ public void EndInitialize(
             this.layout = new Layout();
             this.options = options;
             this.compilation = compilation;
-            this.extractor = new NonStandaloneExtractor(GetOutputName(compilation, commandLineArguments), Logger, PathTransformer);
+            this.extractor = new TracingExtractor(GetOutputName(compilation, commandLineArguments), Logger, PathTransformer);
             LogDiagnostics();
 
             SetReferencePaths();
@@ -199,7 +199,7 @@ private void DoAnalyseCompilation()
         {
             try
             {
-                var assemblyPath = ((NonStandaloneExtractor?)extractor).OutputPath;
+                var assemblyPath = ((TracingExtractor?)extractor).OutputPath;
                 var transformedAssemblyPath = PathTransformer.Transform(assemblyPath);
                 var assembly = compilation.Assembly;
                 var projectLayout = layout.LookupProjectOrDefault(transformedAssemblyPath);

csharp/extractor/Semmle.Extraction/Entities/Base/CachedEntity`1.cs

@@ -28,7 +28,7 @@ protected CachedEntity(Context context) : base(context)
     /// An abstract symbol, which encapsulates a data type (such as a C# symbol).
     /// </summary>
     /// <typeparam name="TSymbol">The type of the symbol.</typeparam>
-    public abstract class CachedEntity<TSymbol> : CachedEntity where TSymbol : class
+    public abstract class CachedEntity<TSymbol> : CachedEntity where TSymbol : notnull
     {
         public TSymbol Symbol { get; }
 

csharp/extractor/Semmle.Extraction/Extractor/NonStandaloneExtractor.cs renamed to csharp/extractor/Semmle.Extraction/Extractor/TracingExtractor.cs

@@ -2,7 +2,7 @@
 
 namespace Semmle.Extraction
 {
-    public class NonStandaloneExtractor : Extractor
+    public class TracingExtractor : Extractor
     {
         public override bool Standalone => false;
 
@@ -14,7 +14,7 @@ public class NonStandaloneExtractor : Extractor
         /// <param name="outputPath">The name of the output DLL/EXE, or null if not specified (standalone extraction).</param>
         /// <param name="logger">The object used for logging.</param>
         /// <param name="pathTransformer">The object used for path transformations.</param>
-        public NonStandaloneExtractor(string outputPath, ILogger logger, PathTransformer pathTransformer) : base(logger, pathTransformer)
+        public TracingExtractor(string outputPath, ILogger logger, PathTransformer pathTransformer) : base(logger, pathTransformer)
         {
             OutputPath = outputPath;
         }