Simplify code now that we natively support reading/writing locations in a SymbolKey.

src/Workspaces/Core/Portable/SymbolKey/SymbolKey.AnonymousSymbolKey.cs → src/Workspaces/Core/Portable/SymbolKey/SymbolKey.AnonymousFunctionOrDelegateSymbolKey.cs

-using System.Diagnostics;
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Diagnostics;
 using System.Linq;
-using System.Threading;
 using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.Shared.Utilities;
-using Microsoft.CodeAnalysis.Text;
-using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis
 {
     internal partial struct SymbolKey
     {
+        /// <summary>
+        /// Anonymous functions and anonymous-delegates (the special VB synthesized delegate types),
+        /// only come into existence when someone has explicitly written a lambda in their source 
+        /// code. So to appropriately round-trip this symbol we store the location that the lambda
+        /// was at so that we can find the symbol again when we resolve the key.
+        /// </summary>
         private static class AnonymousFunctionOrDelegateSymbolKey
         {
-            private enum LocalSymbolType
-            {
-                AnonymousFunction,
-                AnonymousDelegate,
-            }
-
             public static void Create(ISymbol symbol, SymbolKeyWriter visitor)
             {
-                // var reference = symbol.DeclaringSyntaxReferences.FirstOrDefault();
-                //var filePath = reference?.SyntaxTree.FilePath ?? "";
-                //var textSpan = reference?.Span ?? new TextSpan();
-                Debug.Assert(symbol.IsAnonymousDelegateType() ||
-                    symbol.IsAnonymousFunction());
-                var type = symbol.IsAnonymousDelegateType()
-                    ? LocalSymbolType.AnonymousDelegate
-                    : LocalSymbolType.AnonymousFunction;
-
-                var location = symbol.Locations.FirstOrDefault();
-                var filePath = location?.SourceTree.FilePath ?? "";
-                var textSpan = location?.SourceSpan ?? new TextSpan();
+                Debug.Assert(symbol.IsAnonymousDelegateType() || symbol.IsAnonymousFunction());
 
-                visitor.WriteInteger((int)type);
-                visitor.WriteString(filePath);
-                visitor.WriteInteger(textSpan.Start);
-                visitor.WriteInteger(textSpan.Length);
+                visitor.WriteBoolean(symbol.IsAnonymousDelegateType());
+                visitor.WriteLocation(symbol.Locations.FirstOrDefault());
             }
 
             public static SymbolKeyResolution Resolve(SymbolKeyReader reader)
             {
-                var type = (LocalSymbolType)reader.ReadInteger();
-                var filePath = reader.ReadString();
-                var start = reader.ReadInteger();
-                var length = reader.ReadInteger();
+                var isAnonymousDelegateType = reader.ReadBoolean();
+                var location = reader.ReadLocation();
 
-                var syntaxTree = reader.GetSyntaxTree(filePath);
+                var syntaxTree = location.SourceTree;
                 if (syntaxTree != null)
                 {
                     var semanticModel = reader.Compilation.GetSemanticModel(syntaxTree);
                     var root = syntaxTree.GetRoot(reader.CancellationToken);
-                    var node = root.FindNode(new TextSpan(start, length), getInnermostNodeForTie: true);
+                    var node = root.FindNode(location.SourceSpan, getInnermostNodeForTie: true);
 
                     var symbol = semanticModel.GetSymbolInfo(node, reader.CancellationToken)
                                               .GetAnySymbol();
 
-                    if (type == LocalSymbolType.AnonymousDelegate)
+                    if (isAnonymousDelegateType)
                     {
                         var anonymousDelegate = (symbol as IMethodSymbol).AssociatedAnonymousDelegate;
                         symbol = anonymousDelegate;

src/Workspaces/Core/Portable/Workspaces.csproj

@@ -484,7 +484,7 @@
     <Compile Include="SolutionCrawler\PredefinedInvocationReasons.cs" />
     <Compile Include="FindSymbols\StreamingProgressCollector.cs" />
     <Compile Include="FindSymbols\SymbolFinder.ServerCallback.cs" />
-    <Compile Include="SymbolKey\SymbolKey.AnonymousSymbolKey.cs" />
+    <Compile Include="SymbolKey\SymbolKey.AnonymousFunctionOrDelegateSymbolKey.cs" />
     <Compile Include="SymbolKey\SymbolKey.AnonymousTypeSymbolKey.cs" />
     <Compile Include="SymbolKey\SymbolKey.ComparisonOptions.cs" />
     <Compile Include="SymbolKey\SymbolKey.SymbolKeyComparer.cs" />