Resurrect Ast based "goto removal" - we will use that until it is converted to ILAst based one.

ICSharpCode.Decompiler/Ast/AstBuilder.cs

@@ -19,11 +19,11 @@ namespace Decompiler
 		{
 			for (int i = 0; i < 4; i++) {
 				if (Options.ReduceAstJumps) {
-					//astCompileUnit.AcceptVisitor(new Transforms.Ast.RemoveGotos(), null);
+					astCompileUnit.AcceptVisitor(new Transforms.Ast.RemoveGotos(), null);
-					//astCompileUnit.AcceptVisitor(new Transforms.Ast.RemoveDeadLabels(), null);
+					astCompileUnit.AcceptVisitor(new Transforms.Ast.RemoveDeadLabels(), null);
 				}
 				if (Options.ReduceAstLoops) {
-					//astCompileUnit.AcceptVisitor(new Transforms.Ast.RestoreLoop(), null);
+					astCompileUnit.AcceptVisitor(new Transforms.Ast.RestoreLoop(), null);
 				}
 				if (Options.ReduceAstOther) {
 					astCompileUnit.AcceptVisitor(new Transforms.Ast.RemoveEmptyElseBody(), null);

ICSharpCode.Decompiler/Ast/Transforms/RemoveDeadLabels.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections.Generic;
+using ICSharpCode.NRefactory.CSharp;
+
+namespace Decompiler.Transforms.Ast
+{
+	public class RemoveDeadLabels : DepthFirstAstVisitor<object, object>
+	{
+		List<string> usedLabels = new List<string>();
+		bool collectingUsedLabels;
+		
+		public override object VisitConstructorDeclaration(ConstructorDeclaration constructorDeclaration, object data)
+		{
+			collectingUsedLabels = true;
+			base.VisitConstructorDeclaration(constructorDeclaration, data);
+			collectingUsedLabels = false;
+			base.VisitConstructorDeclaration(constructorDeclaration, data);
+			return null;
+		}
+		
+		public override object VisitMethodDeclaration(MethodDeclaration methodDeclaration, object data)
+		{
+			collectingUsedLabels = true;
+			base.VisitMethodDeclaration(methodDeclaration, data);
+			collectingUsedLabels = false;
+			base.VisitMethodDeclaration(methodDeclaration, data);
+			return null;
+		}
+		
+		public override object VisitAccessor(Accessor accessor, object data)
+		{
+			collectingUsedLabels = true;
+			base.VisitAccessor(accessor, data);
+			collectingUsedLabels = false;
+			return base.VisitAccessor(accessor, data);
+		}
+		
+		public override object VisitGotoStatement(GotoStatement gotoStatement, object data)
+		{
+			if (collectingUsedLabels) {
+				usedLabels.Add(gotoStatement.Label);
+			}
+			return null;
+		}
+		
+		public override object VisitLabelStatement(LabelStatement labelStatement, object data)
+		{
+			if (!collectingUsedLabels) {
+				if (!usedLabels.Contains(labelStatement.Label)) {
+					labelStatement.Remove();
+				}
+			}
+			return null;
+		}
+	}
+}

ICSharpCode.Decompiler/Ast/Transforms/RemoveGotos.cs

@@ -1,16 +1,15 @@
 using System;
 using System.Collections.Generic;
-
+using System.Linq;
 using ICSharpCode.NRefactory.CSharp;
 
 namespace Decompiler.Transforms.Ast
 {
-	/*
 	public class RemoveGotos: DepthFirstAstVisitor<object, object>
 	{
-		Stack<Statement> enteredLoops = new Stack<Statement>();
+		Stack<ForStatement> enteredLoops = new Stack<ForStatement>();
 		
-		Statement CurrentLoop {
+		ForStatement CurrentLoop {
 			get {
 				if (enteredLoops.Count > 0) {
 					return enteredLoops.Peek();
@@ -28,27 +27,20 @@ namespace Decompiler.Transforms.Ast
 			return null;
 		}
 		
-		public override object VisitWhileStatement(WhileStatement whileStatement, object data)
+//		public override object VisitWhileStatement(WhileStatement whileStatement, object data)
-		{
+//		{
-			enteredLoops.Push(whileStatement);
+//			enteredLoops.Push(whileStatement);
-			base.VisitWhileStatement(whileStatement, data);
+//			base.VisitWhileStatement(whileStatement, data);
-			enteredLoops.Pop();
+//			enteredLoops.Pop();
-			return null;
+//			return null;
-		}
+//		}
 		
 		public override object VisitBlockStatement(BlockStatement blockStatement, object data)
 		{
 			base.VisitBlockStatement(blockStatement, data);
 			
 			// Remove redundant jump at the end of block
-			INode lastStmt = blockStatement.Children.Last;
+			AstNode lastStmt = blockStatement.Children.LastOrDefault();
-			// End of while loop
-			if (lastStmt is ContinueStatement && 
-			    blockStatement.Parent is DoLoopStatement)
-			{
-				lastStmt.Remove();
-				return null;
-			}
 			// End of for loop
 			if (lastStmt is ContinueStatement && 
 			    blockStatement.Parent is ForStatement)
@@ -74,7 +66,7 @@ namespace Decompiler.Transforms.Ast
 		{
 			if (statement == null) throw new ArgumentNullException();
 			
-			Statement next = (Statement)statement.Next();
+			Statement next = (Statement)statement.NextSibling;
 			
 			if (next != null) {
 				return EnterBlockStatement(next);
@@ -104,12 +96,12 @@ namespace Decompiler.Transforms.Ast
 			// Iterator; Condition; Body
 			if (statement is ForStatement) {
 				ForStatement forLoop = statement as ForStatement;
-				if (forLoop.Iterator.Count > 0) {
+				if (forLoop.Iterators.Any()) {
-					return forLoop.Iterator[0];
+					return forLoop.Iterators.First();
 				} else if (!forLoop.Condition.IsNull) {
 					return forLoop.Condition;
 				} else {
-					return EnterBlockStatement((Statement)forLoop.EmbeddedStatement.Children.First);
+					return EnterBlockStatement((Statement)forLoop.EmbeddedStatement.FirstChild);
 				}
 			}
 			
@@ -124,14 +116,12 @@ namespace Decompiler.Transforms.Ast
 			// For loop starts as follows: Initializers; Condition; Body
 			if (statement is ForStatement) {
 				ForStatement forLoop = statement as ForStatement;
-				if (forLoop.Initializers.Count > 0) {
+				if (forLoop.Initializers.Any()) {
-					return forLoop.Initializers[0];
+				    	return forLoop.Initializers.First();
 				} else if (!forLoop.Condition.IsNull) {
 					return forLoop.Condition;
-				} else if (forLoop.EmbeddedStatement is BlockStatement &&
+				} else if (forLoop.EmbeddedStatement.Children.FirstOrDefault() is Statement) {
-					       forLoop.EmbeddedStatement.Children.Count > 0) {
+					return EnterBlockStatement((Statement)forLoop.EmbeddedStatement.FirstChild);  // Simplify again
-					statement = (Statement)forLoop.EmbeddedStatement.Children.First;
-					return EnterBlockStatement(statement);  // Simplify again
 				}
 			}
 			
@@ -141,11 +131,11 @@ namespace Decompiler.Transforms.Ast
 		public override object VisitGotoStatement(GotoStatement gotoStatement, object data)
 		{
 			// Remove redundant goto which goes to a label that imideately follows
-			INode fallthoughTarget = GetNextStatement(gotoStatement);
+			AstNode fallthoughTarget = GetNextStatement(gotoStatement);
 			while(true) {
 				if (fallthoughTarget is LabelStatement) {
 				    if ((fallthoughTarget as LabelStatement).Label == gotoStatement.Label) {
-						RemoveCurrentNode();
+						gotoStatement.Remove();
 						return null;
 					} else {
 						fallthoughTarget = GetNextStatement((LabelStatement)fallthoughTarget);
@@ -158,10 +148,10 @@ namespace Decompiler.Transforms.Ast
 			// Replace goto with 'break'
 			// Break statement moves right outside the looop
 			if (CurrentLoop != null) {
-				INode breakTarget = GetNextStatement(CurrentLoop);
+				AstNode breakTarget = GetNextStatement(CurrentLoop);
 				if ((breakTarget is LabelStatement) &&
 				    (breakTarget as LabelStatement).Label == gotoStatement.Label) {
-					ReplaceCurrentNode(new BreakStatement());
+					gotoStatement.ReplaceWith(new BreakStatement());
 					return null;
 				}
 			}
@@ -170,24 +160,24 @@ namespace Decompiler.Transforms.Ast
 			// Continue statement which moves at the very end of loop
 			if (CurrentLoop != null &&
 			    (CurrentLoop.EmbeddedStatement is BlockStatement) &&
-			    ((CurrentLoop.EmbeddedStatement as BlockStatement).Children.Last as LabelStatement) != null &&
+			    ((CurrentLoop.EmbeddedStatement as BlockStatement).LastChild as LabelStatement) != null &&
-			    ((CurrentLoop.EmbeddedStatement as BlockStatement).Children.Last as LabelStatement).Label == gotoStatement.Label) {
+			    ((CurrentLoop.EmbeddedStatement as BlockStatement).LastChild as LabelStatement).Label == gotoStatement.Label) {
-				ReplaceCurrentNode(new ContinueStatement());
+				gotoStatement.ReplaceWith(new ContinueStatement());
 				return null;
 			}
 			
 			// Replace goto with 'continue'
 			// Continue statement which moves at the very start of for loop
 			if (CurrentLoop != null) {
-				INode continueTarget = ExitBlockStatement(CurrentLoop); // The start of the loop
+				AstNode continueTarget = ExitBlockStatement(CurrentLoop); // The start of the loop
 				if ((continueTarget is LabelStatement) &&
 				    (continueTarget as LabelStatement).Label == gotoStatement.Label) {
-					ReplaceCurrentNode(new ContinueStatement());
+					gotoStatement.ReplaceWith(new ContinueStatement());
 					return null;
 				}
 			}
 			
 			return null;
 		}
-	}*/
+	}
 }

ICSharpCode.Decompiler/Ast/Transforms/RestoreLoop.cs

@@ -1,10 +1,9 @@
-using System;
+using System;
-
+using System.Linq;
-using ICSharpCode.NRefactory.CSharp;
+using ICSharpCode.NRefactory.CSharp;
 
 namespace Decompiler.Transforms.Ast
 {
-	/*
 	public class RestoreLoop: DepthFirstAstVisitor<object, object>
 	{
 		public override object VisitForStatement(ForStatement forStatement, object data)
@@ -12,25 +11,25 @@ namespace Decompiler.Transforms.Ast
 			base.VisitForStatement(forStatement, data);
 			
 			// Restore loop initializer
-			if (forStatement.Initializers.Count == 0) {
+			if (!forStatement.Initializers.Any()) {
-				LocalVariableDeclaration varDeclr = forStatement.Previous() as LocalVariableDeclaration;
+				VariableDeclarationStatement varDeclr = forStatement.PrevSibling as VariableDeclarationStatement;
 				if (varDeclr != null) {
 					varDeclr.ReplaceWith(Statement.Null);
-					forStatement.Initializers.Add(varDeclr);
+					forStatement.Initializers = new Statement[] { varDeclr };
 				}
 			}
 			
 			// Restore loop condition
 			if (forStatement.Condition.IsNull &&
-				forStatement.EmbeddedStatement.Children.Count >= 3)
+			    forStatement.EmbeddedStatement.Children.Count() >= 3)
 			{
-				IfElseStatement  condition = forStatement.EmbeddedStatement.Children[0] as IfElseStatement;
+				IfElseStatement  condition = forStatement.EmbeddedStatement.Children.First() as IfElseStatement;
-				BreakStatement   breakStmt = forStatement.EmbeddedStatement.Children[1] as BreakStatement;
+				BreakStatement   breakStmt = forStatement.EmbeddedStatement.Children.Skip(1).First() as BreakStatement;
-				LabelStatement   label     = forStatement.EmbeddedStatement.Children[2] as LabelStatement;
+				LabelStatement   label     = forStatement.EmbeddedStatement.Children.Skip(2).First() as LabelStatement;
 				if (condition != null && breakStmt != null && label != null &&
-				    condition.TrueStatement.Count == 1)
+				    condition.TrueStatement.Children.Count() == 1)
 				{
-					GotoStatement gotoStmt = condition.TrueStatement[0] as GotoStatement;
+					GotoStatement gotoStmt = condition.TrueStatement.FirstChild as GotoStatement;
 					if (gotoStmt != null && gotoStmt.Label == label.Label) {
 						condition.Remove();
 						breakStmt.Remove();
@@ -41,34 +40,34 @@ namespace Decompiler.Transforms.Ast
 			
 			// Restore loop condition (version 2)
 			if (forStatement.Condition.IsNull) {
-				IfElseStatement condition = forStatement.EmbeddedStatement.Children.First as IfElseStatement;
+				IfElseStatement condition = forStatement.EmbeddedStatement.FirstChild as IfElseStatement;
 				if (condition != null &&
-				    condition.TrueStatement.Count == 1 &&
+				    condition.TrueStatement.Children.Any() &&
-				    condition.TrueStatement[0] is BlockStatement &&
+				    condition.TrueStatement.FirstChild is BlockStatement &&
-				    condition.TrueStatement[0].Children.Count == 1 &&
+				    condition.TrueStatement.Children.Count() == 1 &&
-				    condition.TrueStatement[0].Children.First is BreakStatement &&
+				    condition.TrueStatement.FirstChild.FirstChild is BreakStatement &&
-				    condition.FalseStatement.Count == 1 &&
+				    condition.FalseStatement.Children.Any() &&
-				    condition.FalseStatement[0] is BlockStatement &&
+				    condition.FalseStatement.FirstChild is BlockStatement &&
-				    condition.FalseStatement[0].Children.Count == 0)
+				    condition.FalseStatement.Children.Count() == 0)
 				{
 					condition.Remove();
-					forStatement.Condition = new UnaryOperatorExpression(condition.Condition, UnaryOperatorType.Not);
+					forStatement.Condition = new UnaryOperatorExpression() { Expression = condition.Condition, Operator = UnaryOperatorType.Not };
 				}
 			}
 			
 			// Restore loop iterator
-			if (forStatement.EmbeddedStatement.Children.Count > 0 &&
+			if (forStatement.EmbeddedStatement.Children.Any() &&
-			    forStatement.Iterator.Count == 0)
+			    !forStatement.Iterators.Any())
 			{
-				ExpressionStatement lastStmt = forStatement.EmbeddedStatement.Children.Last as ExpressionStatement;
+				ExpressionStatement lastStmt = forStatement.EmbeddedStatement.LastChild as ExpressionStatement;
 				if (lastStmt != null &&
 				    (lastStmt.Expression is AssignmentExpression || lastStmt.Expression is UnaryOperatorExpression)) {
 					lastStmt.Remove();
-					forStatement.Iterator.Add(lastStmt);
+					forStatement.Iterators = new Statement[] { lastStmt };
 				}
 			}
 			
 			return null;
 		}
-	}*/
+	}
 }

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -57,6 +57,7 @@
     <Compile Include="Ast\Transforms\ConvertConstructorCallIntoInitializer.cs" />
     <Compile Include="Ast\Transforms\ReplaceMethodCallsWithOperators.cs" />
     <Compile Include="Ast\Transforms\PushNegation.cs" />
+    <Compile Include="Ast\Transforms\RemoveDeadLabels.cs" />
     <Compile Include="Ast\Transforms\RemoveEmptyElseBody.cs" />
     <Compile Include="Ast\Transforms\RemoveGotos.cs" />
     <Compile Include="Ast\Transforms\RestoreLoop.cs" />