1 files changed, 81 insertions, 0 deletions
diff --git a/main/src/addins/CSharpBinding/Util/SemanticMap.cs b/main/src/addins/CSharpBinding/Util/SemanticMap.cs
new file mode 100644
index 0000000000..ee69eb9fe6
--- /dev/null
+++ b/main/src/addins/CSharpBinding/Util/SemanticMap.cs
@@ -0,0 +1,81 @@
+// 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.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Text;
+
+namespace ICSharpCode.NRefactory6.CSharp
+{
+	partial class SemanticMap
+	{
+		private readonly Dictionary<SyntaxNode, SymbolInfo> _expressionToInfoMap =
+			new Dictionary<SyntaxNode, SymbolInfo>();
+
+		private readonly Dictionary<SyntaxToken, SymbolInfo> _tokenToInfoMap =
+			new Dictionary<SyntaxToken, SymbolInfo>();
+
+		private SemanticMap()
+		{
+		}
+
+		internal static SemanticMap From(SemanticModel semanticModel, SyntaxNode node, CancellationToken cancellationToken)
+		{
+			var map = new SemanticMap();
+			var walker = new Walker(semanticModel, map, cancellationToken);
+			walker.Visit(node);
+			return map;
+		}
+
+		public IEnumerable<ISymbol> AllReferencedSymbols
+		{
+			get
+			{
+				return _expressionToInfoMap.Values.Concat(_tokenToInfoMap.Values).Select(info => info.Symbol).Distinct();
+			}
+		}
+
+		private class Walker : SyntaxWalker
+		{
+			private readonly SemanticModel _semanticModel;
+			private readonly SemanticMap _map;
+			private readonly CancellationToken _cancellationToken;
+
+			public Walker(SemanticModel semanticModel, SemanticMap map, CancellationToken cancellationToken) :
+			base(SyntaxWalkerDepth.Token)
+			{
+				_semanticModel = semanticModel;
+				_map = map;
+				_cancellationToken = cancellationToken;
+			}
+
+			public override void Visit(SyntaxNode node)
+			{
+				var info = _semanticModel.GetSymbolInfo(node);
+				if (!IsNone(info))
+				{
+					_map._expressionToInfoMap.Add(node, info);
+				}
+
+				base.Visit(node);
+			}
+
+			protected override void VisitToken(SyntaxToken token)
+			{
+				var info = _semanticModel.GetSymbolInfo(token, _cancellationToken);
+				if (!IsNone(info))
+				{
+					_map._tokenToInfoMap.Add(token, info);
+				}
+
+				base.VisitToken(token);
+			}
+
+			private bool IsNone(SymbolInfo info)
+			{
+				return info.Symbol == null && info.CandidateSymbols.Length == 0;
+			}
+		}
+	}
+}