Removed empty expression / fixed potential bug where unary operator

expression may be null.

ICSharpCode.NRefactory.CSharp/Ast/DepthFirstAstVisitor.cs

@@ -614,11 +614,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			VisitChildren (namedExpression);
 		}
 
-		public virtual void VisitEmptyExpression (EmptyExpression emptyExpression)
-		{
-			VisitChildren (emptyExpression);
-		}
-		
 		public virtual void VisitPatternPlaceholder(AstNode placeholder, PatternMatching.Pattern pattern)
 		{
 			VisitChildren (placeholder);
@@ -1212,11 +1207,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			return VisitChildren (namedExpression);
 		}
 		
-		public virtual T VisitEmptyExpression (EmptyExpression emptyExpression)
-		{
-			return VisitChildren (emptyExpression);
-		}
-		
 		public virtual T VisitPatternPlaceholder(AstNode placeholder, PatternMatching.Pattern pattern)
 		{
 			return VisitChildren (placeholder);
@@ -1810,11 +1800,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			return VisitChildren (namedExpression, data);
 		}
 		
-		public virtual S VisitEmptyExpression (EmptyExpression emptyExpression, T data)
-		{
-			return VisitChildren (emptyExpression, data);
-		}
-		
 		public virtual S VisitPatternPlaceholder(AstNode placeholder, PatternMatching.Pattern pattern, T data)
 		{
 			return VisitChildren (placeholder, data);

ICSharpCode.NRefactory.CSharp/Ast/Expressions/EmptyExpression.cs

@@ -1,79 +0,0 @@
-// 
-// EmptyExpression.cs
-//  
-// Author:
-//       Mike Krüger <mkrueger@novell.com>
-// 
-// Copyright (c) 2011 Novell, Inc (http://www.novell.com)
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-using System;
-
-namespace ICSharpCode.NRefactory.CSharp
-{
-	/// <summary>
-	/// Type&lt;[EMPTY]&gt;
-	/// </summary>
-	public class EmptyExpression : Expression
-	{
-		TextLocation location;
-
-		public override TextLocation StartLocation {
-			get {
-				return location;
-			}
-		}
-		
-		public override TextLocation EndLocation {
-			get {
-				return location;
-			}
-		}
-
-		public EmptyExpression ()
-		{
-		}
-
-		public EmptyExpression (TextLocation location)
-		{
-			this.location = location;
-		}
-		
-		public override void AcceptVisitor (IAstVisitor visitor)
-		{
-			visitor.VisitEmptyExpression (this);
-		}
-			
-		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
-		{
-			return visitor.VisitEmptyExpression (this);
-		}
-		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
-		{
-			return visitor.VisitEmptyExpression (this, data);
-		}
-
-		protected internal override bool DoMatch (AstNode other, PatternMatching.Match match)
-		{
-			var o = other as EmptyExpression;
-			return o != null;
-		}
-	}
-}

ICSharpCode.NRefactory.CSharp/Ast/Expressions/ErrorExpression.cs

@@ -43,6 +43,11 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 
+		public string Error {
+			get;
+			private set;
+		}
+
 		public ErrorExpression ()
 		{
 		}
@@ -52,6 +57,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.location = location;
 		}
 
+		public ErrorExpression (string error)
+		{
+			this.Error = error;
+		}
+
+		public ErrorExpression (string error, TextLocation location)
+		{
+			this.location = location;
+			this.Error = error;
+		}
+
 		public override void AcceptVisitor (IAstVisitor visitor)
 		{
 			// nothing

ICSharpCode.NRefactory.CSharp/Ast/Expressions/UnaryOperatorExpression.cs

@@ -63,8 +63,9 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (GetOperatorRole (Operator)); }
 		}
 
+		static Expression NoUnaryExpressionError = new ErrorExpression ("No unary expression");
 		public Expression Expression {
-			get { return GetChildByRole (Roles.Expression); }
+			get { return GetChildByRole (Roles.Expression) ?? NoUnaryExpressionError; }
 			set { SetChildByRole (Roles.Expression, value); }
 		}
 		

ICSharpCode.NRefactory.CSharp/Ast/IAstVisitor.cs

@@ -59,7 +59,6 @@ namespace ICSharpCode.NRefactory.CSharp
 		void VisitTypeReferenceExpression(TypeReferenceExpression typeReferenceExpression);
 		void VisitUnaryOperatorExpression(UnaryOperatorExpression unaryOperatorExpression);
 		void VisitUncheckedExpression(UncheckedExpression uncheckedExpression);
-		void VisitEmptyExpression (EmptyExpression emptyExpression);
 
 		void VisitQueryExpression(QueryExpression queryExpression);
 		void VisitQueryContinuationClause(QueryContinuationClause queryContinuationClause);
@@ -190,7 +189,6 @@ namespace ICSharpCode.NRefactory.CSharp
 		S VisitTypeReferenceExpression(TypeReferenceExpression typeReferenceExpression);
 		S VisitUnaryOperatorExpression(UnaryOperatorExpression unaryOperatorExpression);
 		S VisitUncheckedExpression(UncheckedExpression uncheckedExpression);
-		S VisitEmptyExpression (EmptyExpression emptyExpression);
 
 		S VisitQueryExpression(QueryExpression queryExpression);
 		S VisitQueryContinuationClause(QueryContinuationClause queryContinuationClause);
@@ -321,7 +319,6 @@ namespace ICSharpCode.NRefactory.CSharp
 		S VisitTypeReferenceExpression(TypeReferenceExpression typeReferenceExpression, T data);
 		S VisitUnaryOperatorExpression(UnaryOperatorExpression unaryOperatorExpression, T data);
 		S VisitUncheckedExpression(UncheckedExpression uncheckedExpression, T data);
-		S VisitEmptyExpression (EmptyExpression emptyExpression, T data);
 
 		S VisitQueryExpression(QueryExpression queryExpression, T data);
 		S VisitQueryContinuationClause(QueryContinuationClause queryContinuationClause, T data);

ICSharpCode.NRefactory.CSharp/Ast/ObservableAstVisitor.cs

@@ -842,13 +842,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			Visit(EnterNamedExpression, LeaveNamedExpression, namedExpression);
 		}
 		
-		public event Action<EmptyExpression> EnterEmptyExpression, LeaveEmptyExpression;
-		
-		void IAstVisitor.VisitEmptyExpression(EmptyExpression emptyExpression)
-		{
-			Visit(EnterEmptyExpression, LeaveEmptyExpression, emptyExpression);
-		}
-		
 		void IAstVisitor.VisitPatternPlaceholder(AstNode placeholder, PatternMatching.Pattern pattern)
 		{
 		}

ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj

@@ -119,7 +119,6 @@
     <Compile Include="Ast\Expressions\ConditionalExpression.cs" />
     <Compile Include="Ast\Expressions\DefaultValueExpression.cs" />
     <Compile Include="Ast\Expressions\DirectionExpression.cs" />
-    <Compile Include="Ast\Expressions\EmptyExpression.cs" />
     <Compile Include="Ast\Expressions\Expression.cs" />
     <Compile Include="Ast\Expressions\IdentifierExpression.cs" />
     <Compile Include="Ast\Expressions\IndexerExpression.cs" />

ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpOutputVisitor.cs

@@ -989,12 +989,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			EndNode(pointerReferenceExpression);
 		}
 		
-		public void VisitEmptyExpression(EmptyExpression emptyExpression)
-		{
-			StartNode(emptyExpression);
-			EndNode(emptyExpression);
-		}
-
 		#region VisitPrimitiveExpression
 		public void VisitPrimitiveExpression(PrimitiveExpression primitiveExpression)
 		{

ICSharpCode.NRefactory.CSharp/OutputVisitor/CodeDomConvertVisitor.cs

@@ -591,11 +591,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			return MakeSnippetExpression(uncheckedExpression);
 		}
 		
-		CodeObject IAstVisitor<CodeObject>.VisitEmptyExpression(EmptyExpression emptyExpression)
-		{
-			return null;
-		}
-		
 		CodeObject IAstVisitor<CodeObject>.VisitQueryExpression(QueryExpression queryExpression)
 		{
 			return MakeSnippetExpression(queryExpression);

ICSharpCode.NRefactory.CSharp/Parser/CSharpParser.cs

@@ -1466,11 +1466,6 @@ namespace ICSharpCode.NRefactory.CSharp
 				return result;
 			}
 			
-			public override object Visit (Mono.CSharp.EmptyExpression emptyExpression)
-			{
-				return new ICSharpCode.NRefactory.CSharp.EmptyExpression (Convert (emptyExpression.Location));
-			}
-			
 			public override object Visit (Mono.CSharp.ErrorExpression emptyExpression)
 			{
 				return new ICSharpCode.NRefactory.CSharp.ErrorExpression (Convert (emptyExpression.Location));
@@ -1478,7 +1473,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			
 			public override object Visit (EmptyExpressionStatement emptyExpressionStatement)
 			{
-				return new EmptyExpression (Convert (emptyExpressionStatement.Location));
+				// Should never happen.
+				throw new NotSupportedException();
 			}
 			
 			public override object Visit (If ifStatement)

ICSharpCode.NRefactory.CSharp/Refactoring/TypeSystemAstBuilder.cs

@@ -436,7 +436,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			} else if (rr.IsCompileTimeConstant) {
 				return ConvertConstantValue(rr.Type, rr.ConstantValue);
 			} else {
-				return new EmptyExpression();
+				return new ErrorExpression();
 			}
 		}
 		

ICSharpCode.NRefactory.CSharp/Refactoring/VariableReferenceGraph.cs

@@ -362,10 +362,6 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			{
 			}
 
-			public override void VisitEmptyExpression (EmptyExpression emptyExpression)
-			{
-			}
-
 			#endregion
 
 			public override void VisitAssignmentExpression (AssignmentExpression assignmentExpression)

ICSharpCode.NRefactory.CSharp/Resolver/ResolveVisitor.cs

@@ -1434,11 +1434,6 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			}
 		}
 		
-		ResolveResult IAstVisitor<ResolveResult>.VisitEmptyExpression(EmptyExpression emptyExpression)
-		{
-			return errorResult;
-		}
-		
 		ResolveResult IAstVisitor<ResolveResult>.VisitIndexerExpression(IndexerExpression indexerExpression)
 		{
 			if (resolverEnabled || NeedsResolvingDueToNamedArguments(indexerExpression)) {