Completely rewritten the Node tree structure. It became increasingly difficult to maintain the node links (Predecessors, Successors) consistent during transformations. So rather then keeping them consistent I have implemented an algorithm that can calculate the Predecessors or Successors for any given node. There are a few caches on the way so that the calculation does not calculate everything again every time. Affected caches are automatically flushed when a tree structure changes. This is implemented using 'collection with events'.

Decompiler.csproj

@@ -45,8 +45,11 @@
     <Compile Include="src\ByteCode.Type.cs" />
     <Compile Include="src\ByteCodeCollection.cs" />
     <Compile Include="src\CilStack.cs" />
+    <Compile Include="src\ControlFlow\Node-Optimize.cs" />
+    <Compile Include="src\ControlFlow\Node-Transforms.cs" />
+    <Compile Include="src\ControlFlow\NodeCollection.cs" />
     <Compile Include="src\ControlFlow\Nodes.cs" />
-    <Compile Include="src\ControlFlow\Node.cs" />
+    <Compile Include="src\ControlFlow\Node-Structure.cs" />
     <Compile Include="src\MainForm.cs" />
     <Compile Include="src\MainForm.Designer.cs" />
     <Compile Include="src\Options.cs" />

src/AstMetodBodyBuilder.cs

@@ -65,7 +65,7 @@ namespace Decompiler
 		IEnumerable<Ast.INode> TransformNode(Node node)
 		{
 			if (Options.NodeComments) {
-				yield return MakeComment("// " + node.ToString());
+				yield return MakeComment("// " + node.Description);
 			}
 			
 			yield return new Ast.LabelStatement(node.Label);

src/ControlFlow/Node-Optimize.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Decompiler.ControlFlow
+{
+	public abstract partial class Node
+	{
+		public void Optimize()
+		{
+			OptimizeLoops();
+		}
+		
+		public void OptimizeLoops()
+		{
+		Reset:
+			foreach(Node child in this.Childs) {
+				if (child.Predecessors.Count == 1) {
+					if (Options.ReduceGraph <= 0) return;
+					Node predecessor = child.Predecessors[0];
+					Node mergedNode;
+					if (child.Successors.Contains(predecessor)) {
+						mergedNode = MergeChilds<Loop>(predecessor, child);
+					} else {
+						mergedNode = MergeChilds<AcyclicGraph>(predecessor, child);
+					}
+					mergedNode.FalttenAcyclicChilds();
+					goto Reset;
+				}
+			}
+			// If the result is single acyclic node, eliminate it
+			if (this.Childs.Count == 1 && this.HeadChild is AcyclicGraph) {
+				if (Options.ReduceGraph-- <= 0) return;
+				Node headChild = this.HeadChild;
+				this.Childs.Remove(this.HeadChild);
+				headChild.Childs.MoveTo(this);
+			}
+		}
+		
+		NodeCollection GetReachableNodes()
+		{
+			NodeCollection accumulator = new NodeCollection();
+			AddReachableNode(accumulator, this);
+			return accumulator;
+		}
+		
+		static void AddReachableNode(NodeCollection accumulator, Node node)
+		{
+			if (!accumulator.Contains(node)) {
+				accumulator.Add(node);
+				foreach(Node successor in node.Successors) {
+					AddReachableNode(accumulator, successor);
+				}
+			}
+		}
+		
+		public void OptimizeIf()
+		{
+			Node conditionNode = this.HeadChild;
+			// Find conditionNode (the start)
+			while(true) {
+				if (conditionNode is BasicBlock && conditionNode.Successors.Count == 2) {
+					break; // Found
+				} else if (conditionNode.Successors.Count == 1) {
+					conditionNode = conditionNode.Successors[0];
+					continue; // Next
+				} else {
+					return;
+				}
+			}
+		}
+	}
+}

src/ControlFlow/Node-Structure.cs

@@ -0,0 +1,227 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Decompiler.ControlFlow
+{
+	public abstract partial class Node
+	{
+		public static int NextNodeID = 1;
+		
+		int id;
+		Node parent;
+		NodeCollection childs = new NodeCollection();
+		
+		// Structural and linking cache
+		NodeCollection basicBlocks_cache = null;
+		NodeCollection predecessors_cache = null;
+		NodeCollection successors_cache = null;
+		
+		public int ID {
+			get { return id; }
+		}
+		
+		public Node Parent {
+			get { return parent; }
+		}
+		
+		public Node HeadChild {
+			get {
+				if (this.Childs.Count > 0) {
+					return this.Childs[0];
+				} else {
+					return null;
+				}
+			}
+		}
+		
+		public NodeCollection Childs {
+			get {
+				return childs;
+			}
+		}
+		
+		/// <summary> All basic blocks within the scope of this node (inclusive) </summary>
+		public NodeCollection BasicBlocks {
+			get {
+				if (basicBlocks_cache == null) {
+					NodeCollection basicBlocks = new NodeCollection();
+					
+					if (this is BasicBlock) {
+						basicBlocks.Add(this);
+					}
+					foreach(Node child in this.Childs) {
+						basicBlocks.AddRange(child.BasicBlocks);
+					}
+					
+					basicBlocks_cache = basicBlocks;
+				}
+				return basicBlocks_cache;
+			}
+		}
+		
+		NodeCollection FloatUpToNeighbours(IEnumerable<BasicBlock> basickBlocks)
+		{
+			NodeCollection neighbours = new NodeCollection();
+			if (this.Parent != null) {
+				foreach(BasicBlock basicBlock in basickBlocks) {
+					// Find neighbour coresponding to the target
+					Node targetNode = basicBlock;
+					while(targetNode != null && targetNode.Parent != this.Parent) {
+						targetNode = targetNode.Parent;
+					}
+					// The target is outside the scope of the parent node
+					if (targetNode == null) continue;
+					// This child is a loop
+					if (targetNode == this) continue;
+					// We found a target in our scope
+					neighbours.Add(targetNode);
+				}
+			}
+			return neighbours;
+		}
+		
+		public NodeCollection Predecessors {
+			get {
+				if (predecessors_cache == null) {
+					List<BasicBlock> basicBlockPredecessors = new List<BasicBlock>();
+					foreach(BasicBlock basicBlock in this.BasicBlocks) {
+						foreach(BasicBlock basicBlockPredecessor in basicBlock.BasicBlockPredecessors) {
+							basicBlockPredecessors.Add(basicBlockPredecessor);
+						}
+					}
+					
+					predecessors_cache = FloatUpToNeighbours(basicBlockPredecessors);
+				}
+				return predecessors_cache;
+			}
+		}
+		
+		public NodeCollection Successors {
+			get {
+				if (successors_cache == null) {
+					List<BasicBlock> basicBlockSuccessors = new List<BasicBlock>();
+					foreach(BasicBlock basicBlock in this.BasicBlocks) {
+						foreach(BasicBlock basicBlockSuccessor in basicBlock.BasicBlockSuccessors) {
+							basicBlockSuccessors.Add(basicBlockSuccessor);
+						}
+					}
+					
+					successors_cache = FloatUpToNeighbours(basicBlockSuccessors);
+				}
+				return successors_cache;
+			}
+		}
+		
+		int Index {
+			get {
+				if (this.Parent == null) throw new Exception("Does not have a parent");
+				return this.Parent.Childs.IndexOf(this);
+			}
+		}
+		
+		public Node NextNode {
+			get {
+				int index = this.Index + 1;
+				if (0 <= index && index < this.Parent.Childs.Count) {
+					return this.Parent.Childs[index];
+				} else {
+					return null;
+				}
+			}
+		}
+		
+		public string Label {
+			get {
+				return this.GetType().Name + "_" + ID;
+			}
+		}
+		
+		public string Description {
+			get {
+				return ToString();
+			}
+		}
+		
+		protected Node()
+		{
+			this.id = NextNodeID++;
+			this.Childs.Added += delegate(object sender, NodeEventArgs e) {
+				if (e.Node.Parent != null) {
+					throw new Exception("Node is already assigned to other parent");
+				}
+				e.Node.parent = this;
+				NotifyChildsChanged();
+			};
+			this.Childs.Removed += delegate(object sender, NodeEventArgs e) {
+				e.Node.parent = null;
+				NotifyChildsChanged();
+			};
+		}
+		
+		void NotifyChildsChanged()
+		{
+			this.basicBlocks_cache = null;
+			foreach(Node child in this.Childs) {
+				child.predecessors_cache = null;
+				child.successors_cache = null;
+			}
+			if (this.Parent != null) {
+				this.Parent.NotifyChildsChanged();
+			}
+		}
+		
+		public override string ToString()
+		{
+			System.Text.StringBuilder sb = new System.Text.StringBuilder();
+			sb.Append(this.GetType().Name);
+			sb.Append(" ");
+			sb.Append(ID);
+			sb.Append(" ");
+			
+			sb.Append("(");
+			
+			if (this.Predecessors.Count > 0) {
+				sb.Append("Predecessors:");
+				bool isFirst = true;
+				foreach(Node predecessor in this.Predecessors) {
+					if (isFirst) {
+						isFirst = false;
+					} else {
+						sb.Append(",");
+					}
+					sb.Append(predecessor.ID);
+				}
+				sb.Append(" ");
+			}
+			
+			if (this.Successors.Count > 0) {
+				sb.Append("Successors:");
+				bool isFirst = true;
+				foreach(Node successor in this.Successors) {
+					if (isFirst) {
+						isFirst = false;
+					} else {
+						sb.Append(",");
+					}
+					sb.Append(successor.ID);
+				}
+				sb.Append(" ");
+			}
+			
+			if (this.Parent != null) {
+				sb.Append("Parent:");
+				sb.Append(this.Parent.ID);
+				sb.Append(" ");
+			}
+			
+			if (sb[sb.Length - 1] == '(') {
+				sb.Length -= 1;
+			} else if (sb[sb.Length - 1] == ' ') {
+				sb.Length -= 1;
+				sb.Append(")");
+			}
+			return sb.ToString();
+		}
+	}
+}

src/ControlFlow/Node-Transforms.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Decompiler.ControlFlow
+{
+	public abstract partial class Node
+	{
+		public void Remove()
+		{
+			if (this.Parent != null) {
+				this.Parent.Childs.Remove(this);
+			}
+		}
+		
+		public void MoveTo(Node newNode)
+		{
+			MoveTo(newNode, newNode.Childs.Count);
+		}
+		
+		public void MoveTo(Node newNode, int index)
+		{
+			this.Remove();
+			newNode.Childs.Insert(index, this);
+		}
+		
+		Node MergeChilds<T>(params Node[] nodes) where T: Node, new()
+		{
+			foreach(Node node in nodes) {
+				if (node == null) throw new ArgumentNullException("nodes");
+				if (node.Parent != this) throw new ArgumentException("The node is not my child");
+			}
+			if (nodes.Length == 0) throw new ArgumentException("At least one node must be specified");
+			
+			Node mergedNode = new T();
+			
+			// Add the merged node
+			if (Options.ReduceGraph-- <= 0) return mergedNode;
+			int headIndex = this.Childs.IndexOf(nodes[0]);
+			this.Childs.Insert(headIndex, mergedNode);
+			
+			foreach(Node node in nodes) {
+				if (Options.ReduceGraph-- <= 0) return mergedNode;
+				node.MoveTo(mergedNode);
+			}
+			
+			return mergedNode;
+		}
+		
+		public void FalttenAcyclicChilds()
+		{
+		Reset:
+			foreach(Node child in this.Childs) {
+				if (child is AcyclicGraph) {
+					if (Options.ReduceGraph-- <= 0) return;
+					child.Childs.MoveTo(this, child.Index);
+					child.Remove();
+					goto Reset;
+				}
+			}
+		}
+	}
+}

src/ControlFlow/Node.cs

@@ -1,366 +0,0 @@
-using System;
-using System.Collections;
-using System.Collections.Generic;
-
-namespace Decompiler.ControlFlow
-{
-	public class NodeCollection: System.Collections.ObjectModel.Collection<Node>
-	{
-		public void AddRange(IEnumerable<Node> items)
-		{
-			foreach(Node item in items) {
-				this.Add(item);
-			}
-		}
-		
-		public void RemoveRange(IEnumerable<Node> items)
-		{
-			foreach(Node item in items) {
-				this.Remove(item);
-			}
-		}
-		
-		public static NodeCollection Intersection(NodeCollection collectionA, NodeCollection collectionB)
-		{
-			NodeCollection result = new NodeCollection();
-			foreach(Node a in collectionA) {
-				if (collectionB.Contains(a)) {
-					result.Add(a);
-				}
-			}
-			return result;
-		}
-		
-		protected override void InsertItem(int index, Node item)
-		{
-			if (!this.Contains(item)) {
-				base.InsertItem(index, item);
-			}
-		}
-		
-		public bool ContainsRecursive(Node node)
-		{
-			if (this.Contains(node)) {
-				return true;
-			}
-			foreach(Node item in this.Items) {
-				if (item.Childs.ContainsRecursive(node)) {
-					return true;
-				}
-			}
-			return false;
-		}
-		
-		public Node FindContainer(Node node)
-		{
-			foreach(Node item in this.Items) {
-				if (item == node || item.Childs.ContainsRecursive(node)) {
-					return item;
-				}
-			}
-			return null;
-		}
-	}
-	
-	public abstract class Node
-	{
-		public static int NextNodeID = 1;
-		
-		int id;
-		Node parent;
-		Node headChild;
-		NodeCollection childs = new NodeCollection();
-		NodeCollection predecessors = new NodeCollection();
-		NodeCollection successors = new NodeCollection();
-		
-		public int ID {
-			get { return id; }
-		}
-		
-		public Node Parent {
-			get { return parent; }
-			set { parent = value; }
-		}
-		
-		public Node HeadChild {
-			get { return headChild; }
-			protected set { headChild = value; }
-		}
-		
-		public NodeCollection Childs {
-			get { return childs; }
-		}
-		
-		public NodeCollection Predecessors {
-			get { return predecessors; }
-		}
-		
-		public NodeCollection Successors {
-			get { return successors; }
-		}
-		
-		public Node NextNode {
-			get {
-				if (this.Parent == null) throw new Exception("Does not have a parent");
-				int myIndex = this.Parent.Childs.IndexOf(this);
-				int index = myIndex + 1;
-				if (0 <= index && index < this.Parent.Childs.Count) {
-					return this.Parent.Childs[index];
-				} else {
-					return null;
-				}
-			}
-		}
-		
-		public string Label {
-			get {
-				return this.GetType().Name + "_" + ID;
-			}
-		}
-		
-		public Node(Node parent)
-		{
-			this.parent = parent;
-			this.id = NextNodeID++;
-		}
-		
-		NodeCollection GetReachableNodes()
-		{
-			NodeCollection accumulator = new NodeCollection();
-			AddReachableNode(accumulator, this);
-			return accumulator;
-		}
-		
-		static void AddReachableNode(NodeCollection accumulator, Node node)
-		{
-			if (!accumulator.Contains(node)) {
-				accumulator.Add(node);
-				foreach(Node successor in node.Successors) {
-					AddReachableNode(successor, accumulator);
-				}
-			}
-		}
-		
-		void GetBasicBlockSuccessors(NodeCollection accumulator)
-		{
-			BasicBlock me = this as BasicBlock;
-			if (me != null) {
-				if (me.FallThroughBasicBlock != null) {
-					accumulator.Add(me.FallThroughBasicBlock);
-				}
-				if (me.BranchBasicBlock != null) {
-					accumulator.Add(me.BranchBasicBlock);
-				}
-			} else {
-				foreach(Node child in this.Childs) {
-					child.GetBasicBlockSuccessors(accumulator);
-				}
-			}
-		}
-		
-		public void RebuildNodeLinks()
-		{
-			foreach(Node child in this.Childs) {
-				NodeCollection successorBasicBlocks = new NodeCollection();
-				child.GetBasicBlockSuccessors(successorBasicBlocks);
-				NodeCollection successorNodes = new NodeCollection();
-				foreach(Node successorBasicBlock in successorBasicBlocks) {
-					Node container = this.Childs.FindContainer(successorBasicBlock);
-					if (container != null) {
-						successorNodes.Add(container);
-					}
-				}
-				// Remove self link
-				if (successorNodes.Contains(child)) {
-					successorNodes.Remove(child);
-				}
-				foreach(Node target in successorNodes) {
-					child.Successors.Add(target);
-					target.Predecessors.Add(child);
-				}
-			}
-		}
-		
-		public void Optimize()
-		{
-			for(int i = 0; i < this.Childs.Count;) {
-				Node child = childs[i];
-				if (child.Predecessors.Count == 1) {
-					if (Options.ReduceGraph-- <= 0) return;
-					MergeChilds(child.Predecessors[0], child);
-					i = 0; // Restart
-				} else {
-					i++; // Next
-				}
-			}
-			// If it result is single acyclic node, eliminate it
-			if (this.Childs.Count == 1 && this.Childs[0] is AcyclicGraph) {
-				this.headChild = this.Childs[0].HeadChild;
-				this.childs = this.Childs[0].Childs;
-				this.UpdateParentOfChilds();
-			}
-			OptimizeIf();
-		}
-		
-		public void OptimizeIf()
-		{
-			Node conditionNode = this.HeadChild;
-			// Find conditionNode (the start)
-			while(true) {
-				if (conditionNode is BasicBlock && conditionNode.Successors.Count == 2) {
-					break; // Found
-				} else if (conditionNode.Successors == 1) {
-					conditionNode = conditionNode.Successors[0];
-					continue; // Next
-				} else {
-					return;
-				}
-			}
-		}
-		
-		void UpdateParentOfChilds()
-		{
-			foreach(Node child in this.Childs) {
-				child.Parent = this;
-			}
-		}
-		
-		static void MergeChilds(Node head, Node tail)
-		{
-			if (head == null) throw new ArgumentNullException("head");
-			if (tail == null) throw new ArgumentNullException("tail");
-			if (head.Parent != tail.Parent) throw new ArgumentException("different parents");
-			
-			Node container = head.Parent;
-			Node mergedNode;
-			// Get type
-			if (tail.Successors.Contains(head)) {
-				mergedNode = new Loop(container);
-			} else {
-				mergedNode = new AcyclicGraph(container);
-			}
-			
-			// Add head
-			if (head is BasicBlock) {
-				mergedNode.HeadChild = head;
-				mergedNode.Childs.Add(head);
-			} else if (head is AcyclicGraph) {
-				mergedNode.HeadChild = ((AcyclicGraph)head).HeadChild;
-				mergedNode.Childs.AddRange(((AcyclicGraph)head).Childs);
-			} else if (head is Loop) {
-				mergedNode.HeadChild = head;
-				mergedNode.Childs.Add(head);
-			} else {
-				throw new Exception("Invalid head type");
-			}
-			
-			// Add tail
-			if (tail is BasicBlock) {
-				mergedNode.Childs.Add(tail);
-			} else if (tail is AcyclicGraph) {
-				mergedNode.Childs.AddRange(((AcyclicGraph)tail).Childs);
-			} else if (tail is Loop) {
-				mergedNode.Childs.Add(tail);
-			} else {
-				throw new Exception("Invalid tail type");
-			}
-			
-			mergedNode.UpdateParentOfChilds();
-			
-			// Remove links between the head and tail
-			if (head.Successors.Contains(tail)) {
-				head.Successors.Remove(tail);
-				tail.Predecessors.Remove(head);
-			}
-			if (tail.Successors.Contains(head)) {
-				tail.Successors.Remove(head);
-				head.Predecessors.Remove(tail);
-			}
-			
-			Relink(head, mergedNode);
-			Relink(tail, mergedNode);
-			
-			mergedNode.RebuildNodeLinks();
-			
-			// Remove the old nodes and add the merged node - replace head with the merged node
-			container.Childs.Remove(tail);
-			int headIndex = container.Childs.IndexOf(head);
-			container.Childs.Remove(head);
-			container.Childs.Insert(headIndex, mergedNode);
-		}
-		
-		static void Relink(Node node, Node target)
-		{
-			// Relink all neighbours to the target node
-			foreach(Node predecessor in node.Predecessors) {
-				predecessor.Successors.Remove(node);
-				predecessor.Successors.Add(target);
-			}
-			foreach(Node successor in node.Successors) {
-				successor.Predecessors.Remove(node);
-				successor.Predecessors.Add(target);
-			}
-			
-			// Move our pointers to the target node
-			target.Predecessors.AddRange(node.Predecessors);
-			target.Successors.AddRange(node.Successors);
-			node.Predecessors.Clear();
-			node.Successors.Clear();
-		}
-		
-		public override string ToString()
-		{
-			System.Text.StringBuilder sb = new System.Text.StringBuilder();
-			sb.Append(this.GetType().Name);
-			sb.Append(" ");
-			sb.Append(ID);
-			sb.Append(" ");
-			
-			sb.Append("(");
-			
-			if (this.Predecessors.Count > 0) {
-				sb.Append("Predecessors:");
-				bool isFirst = true;
-				foreach(Node predecessor in this.Predecessors) {
-					if (isFirst) {
-						isFirst = false;
-					} else {
-						sb.Append(",");
-					}
-					sb.Append(predecessor.ID);
-				}
-				sb.Append(" ");
-			}
-			
-			if (this.Successors.Count > 0) {
-				sb.Append("Successors:");
-				bool isFirst = true;
-				foreach(Node successor in this.Successors) {
-					if (isFirst) {
-						isFirst = false;
-					} else {
-						sb.Append(",");
-					}
-					sb.Append(successor.ID);
-				}
-				sb.Append(" ");
-			}
-			
-			if (this.Parent != null) {
-				sb.Append("Parent:");
-				sb.Append(this.Parent.ID);
-			}
-			sb.Append(" ");
-			
-			if (this.HeadChild != null) {
-				sb.Append("Head:");
-				sb.Append(this.HeadChild.ID);
-			}
-			sb.Append(" ");
-			
-			sb.Length = sb.Length - 1;
-			sb.Append(")");
-			return sb.ToString();
-		}
-	}
-}

src/ControlFlow/NodeCollection.cs

@@ -0,0 +1,113 @@
+using System;
+using System.Collections.Generic;
+
+namespace Decompiler.ControlFlow
+{
+	public class NodeEventArgs: EventArgs
+	{
+		Node node;
+		
+		public Node Node {
+			get { return node; }
+		}
+		
+		public NodeEventArgs(Node node)
+		{
+			this.node = node;
+		}
+	}
+	
+	public class NodeCollection: System.Collections.ObjectModel.Collection<Node>
+	{
+		public event EventHandler<NodeEventArgs> Added;
+		public event EventHandler<NodeEventArgs> Removed;
+		
+		protected virtual void OnAdded(Node node)
+		{
+			if (Added != null) {
+				Added(this, new NodeEventArgs(node));
+			}
+		}
+		
+		protected virtual void OnRemoved(Node node)
+		{
+			if (Removed != null) {
+				Removed(this, new NodeEventArgs(node));
+			}
+		}
+		
+		protected override void ClearItems()
+		{
+			while(this.Count > 0) {
+				this.RemoveAt(this.Count - 1);
+			}
+		}
+		
+		protected override void InsertItem(int index, Node item)
+		{
+			if (!this.Contains(item)) {
+				base.InsertItem(index, item);
+			}
+			OnAdded(item);
+		}
+		
+		protected override void RemoveItem(int index)
+		{
+			Node node = this[index];
+			base.RemoveItem(index);
+			OnRemoved(node);
+		}
+		
+		protected override void SetItem(int index, Node item)
+		{
+			this.RemoveAt(index);
+			this.Insert(index, item);
+		}
+		
+		
+		public void AddRange(IEnumerable<Node> items)
+		{
+			foreach(Node item in items) {
+				this.Add(item);
+			}
+		}
+		
+		public void RemoveRange(IEnumerable<Node> items)
+		{
+			foreach(Node item in items) {
+				this.Remove(item);
+			}
+		}
+		
+		public void MoveTo(Node newNode)
+		{
+			while(this.Count > 0) {
+				this[0].MoveTo(newNode);
+			}
+		}
+		
+		public void MoveTo(Node newNode, int index)
+		{
+			while(this.Count > 0) {
+				this[0].MoveTo(newNode, index);
+				index++;
+			}
+		}
+		
+		public static NodeCollection Intersection(NodeCollection collectionA, NodeCollection collectionB)
+		{
+			NodeCollection result = new NodeCollection();
+			foreach(Node a in collectionA) {
+				if (collectionB.Contains(a)) {
+					result.Add(a);
+				}
+			}
+			return result;
+		}
+		
+		public override string ToString()
+		{
+			return string.Format("{0} Count = {1}", typeof(NodeCollection).Name, this.Count);
+		}
+	}
+}

src/ControlFlow/Nodes.cs

@@ -7,7 +7,13 @@ namespace Decompiler.ControlFlow
 {
 	public class MethodBodyGraph: Node
 	{
-		public MethodBodyGraph(StackExpressionCollection exprs): base(null)
+		BasicBlock methodEntry;
+		
+		public BasicBlock MethodEntry {
+			get { return methodEntry; }
+		}
+		
+		public MethodBodyGraph(StackExpressionCollection exprs)
 		{
 			if (exprs.Count == 0) throw new ArgumentException("Count == 0", "exprs");
 			
@@ -18,7 +24,7 @@ namespace Decompiler.ControlFlow
 				//  - last expression was branch
 				//  - this expression is branch target
 				if (i == 0 || exprs[i - 1].BranchTarget != null || exprs[i].BranchesHere.Count > 0){
-					basicBlock = new BasicBlock(this);
+					basicBlock = new BasicBlock();
 					this.Childs.Add(basicBlock);
 				}
 				basicBlock.Body.Add(exprs[i]);
@@ -37,6 +43,7 @@ namespace Decompiler.ControlFlow
 				if (exprs[i].LastByteCode.OpCode.Code == Code.Br) continue;
 				
 				node.FallThroughBasicBlock = target;
+				target.BasicBlockPredecessors.Add(node);
 			}
 			
 			// Add branch links to BasicBlocks
@@ -46,33 +53,26 @@ namespace Decompiler.ControlFlow
 					BasicBlock target = exprs[i].BranchTarget.BasicBlock;
 					
 					node.BranchBasicBlock = target;
+					target.BasicBlockPredecessors.Add(node);
 				}
 			}
 			
-			// Link all nodes
-			RebuildNodeLinks();
-			
-			this.HeadChild = this.Childs[0];
+			this.methodEntry = (BasicBlock)this.HeadChild;
 		}
 	}
 	
 	public class AcyclicGraph: Node
 	{
-		public AcyclicGraph(Node parent): base(parent){
-			
-		}
 	}
 	
 	public class Loop: Node
 	{
-		public Loop(Node parent): base(parent){
-			
-		}
 	}
 	
 	public class BasicBlock: Node
 	{
 		List<StackExpression> body = new List<StackExpression>();
+		List<BasicBlock> basicBlockPredecessors = new List<BasicBlock>();
 		BasicBlock fallThroughBasicBlock;
 		BasicBlock branchBasicBlock;
 		
@@ -80,6 +80,10 @@ namespace Decompiler.ControlFlow
 			get { return body; }
 		}
 		
+		public List<BasicBlock> BasicBlockPredecessors {
+			get { return basicBlockPredecessors; }
+		}
+		
 		public BasicBlock FallThroughBasicBlock {
 			get { return fallThroughBasicBlock; }
 			set { fallThroughBasicBlock = value; }
@@ -90,8 +94,15 @@ namespace Decompiler.ControlFlow
 			set { branchBasicBlock = value; }
 		}
 		
-		public BasicBlock(Node parent): base(parent)
-		{
+		public IEnumerable<BasicBlock> BasicBlockSuccessors {
+			get {
+				if (this.FallThroughBasicBlock != null) {
+					yield return this.FallThroughBasicBlock;
+				}
+				if (this.BranchBasicBlock != null) {
+					yield return this.BranchBasicBlock;
+				}
+			}
 		}
 	}
 }