Add control flow analysis.

ICSharpCode.Decompiler/CecilExtensions.cs

@@ -0,0 +1,185 @@
+// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
+// 
+// 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;
+using System.IO;
+using System.Linq;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler
+{
+	/// <summary>
+	/// Cecil helper methods.
+	/// </summary>
+	public static class CecilExtensions
+	{
+		#region GetPushDelta / GetPopDelta
+		public static int GetPushDelta(this Instruction instruction)
+		{
+			OpCode code = instruction.OpCode;
+			switch (code.StackBehaviourPush) {
+				case StackBehaviour.Push0:
+					return 0;
+
+				case StackBehaviour.Push1:
+				case StackBehaviour.Pushi:
+				case StackBehaviour.Pushi8:
+				case StackBehaviour.Pushr4:
+				case StackBehaviour.Pushr8:
+				case StackBehaviour.Pushref:
+					return 1;
+
+				case StackBehaviour.Push1_push1:
+					return 2;
+
+				case StackBehaviour.Varpush:
+					if (code.FlowControl != FlowControl.Call)
+						break;
+
+					IMethodSignature method = (IMethodSignature) instruction.Operand;
+					return IsVoid (method.ReturnType) ? 0 : 1;
+			}
+
+			throw new NotSupportedException ();
+		}
+		
+		public static int GetPopDelta(this Instruction instruction, MethodDefinition current, int currentStackSize)
+		{
+			OpCode code = instruction.OpCode;
+			switch (code.StackBehaviourPop) {
+				case StackBehaviour.Pop0:
+					return 0;
+				case StackBehaviour.Popi:
+				case StackBehaviour.Popref:
+				case StackBehaviour.Pop1:
+					return 1;
+
+				case StackBehaviour.Pop1_pop1:
+				case StackBehaviour.Popi_pop1:
+				case StackBehaviour.Popi_popi:
+				case StackBehaviour.Popi_popi8:
+				case StackBehaviour.Popi_popr4:
+				case StackBehaviour.Popi_popr8:
+				case StackBehaviour.Popref_pop1:
+				case StackBehaviour.Popref_popi:
+					return 2;
+
+				case StackBehaviour.Popi_popi_popi:
+				case StackBehaviour.Popref_popi_popi:
+				case StackBehaviour.Popref_popi_popi8:
+				case StackBehaviour.Popref_popi_popr4:
+				case StackBehaviour.Popref_popi_popr8:
+				case StackBehaviour.Popref_popi_popref:
+					return 3;
+
+				case StackBehaviour.PopAll:
+					return currentStackSize;
+
+				case StackBehaviour.Varpop:
+					if (code == OpCodes.Ret)
+						return IsVoid (current.ReturnType) ? 0 : 1;
+
+					if (code.FlowControl != FlowControl.Call)
+						break;
+
+					IMethodSignature method = (IMethodSignature) instruction.Operand;
+					int count = method.HasParameters ? method.Parameters.Count : 0;
+					if (method.HasThis && code != OpCodes.Newobj)
+						++count;
+
+					return count;
+			}
+
+			throw new NotSupportedException ();
+		}
+		
+		public static bool IsVoid(this TypeReference type)
+		{
+			return type.FullName == "System.Void" && !(type is TypeSpecification);
+		}
+		
+		public static bool IsValueTypeOrVoid(this TypeReference type)
+		{
+			while (type is OptionalModifierType || type is RequiredModifierType)
+				type = ((TypeSpecification)type).ElementType;
+			if (type is ArrayType)
+				return false;
+			return type.IsValueType || type.IsVoid();
+		}
+		#endregion
+		
+		public static void WriteTo(this Instruction instruction, TextWriter writer)
+		{
+			writer.Write(OffsetToString(instruction.Offset));
+			writer.Write(": ");
+			writer.Write(instruction.OpCode.Name);
+			if(null != instruction.Operand) {
+				writer.Write(' ');
+				writer.Write(OperandToString(instruction.Operand));
+			}
+		}
+		
+		public static void WriteTo(this ExceptionHandler exceptionHandler, TextWriter writer)
+		{
+			writer.Write("Try IL_{0:x4}-IL_{1:x4} ", exceptionHandler.TryStart.Offset, exceptionHandler.TryEnd.Offset);
+			writer.Write(exceptionHandler.HandlerType.ToString());
+			if (exceptionHandler.FilterStart != null) {
+				writer.Write(" IL_{0:x4}-IL_{1:x4} handler ", exceptionHandler.FilterStart.Offset, exceptionHandler.FilterEnd.Offset);
+			}
+			writer.Write(" IL_{0:x4}-IL_{1:x4} ", exceptionHandler.HandlerStart.Offset, exceptionHandler.HandlerEnd.Offset);
+		}
+		
+		public static string OffsetToString(int offset)
+		{
+			return string.Format("IL_{0:x4}", offset);
+		}
+		
+		public static string OperandToString(object operand)
+		{
+			if(null == operand) throw new ArgumentNullException("operand");
+			
+			Instruction targetInstruction = operand as Instruction;
+			if(null != targetInstruction) {
+				return OffsetToString(targetInstruction.Offset);
+			}
+			
+			Instruction [] targetInstructions = operand as Instruction [];
+			if(null != targetInstructions) {
+				return string.Join(", ", targetInstructions.Select(i => OffsetToString(i.Offset)));
+			}
+			
+			VariableReference variableRef = operand as VariableReference;
+			if(null != variableRef) {
+				return variableRef.Index.ToString();
+			}
+			
+			MethodReference methodRef = operand as MethodReference;
+			if(null != methodRef) {
+				return methodRef.ToString();
+			}
+			
+			string s = operand as string;
+			if(null != s) {
+				return "\"" + s + "\"";
+			}
+			
+			return operand.ToString();
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/ControlFlowEdge.cs

@@ -0,0 +1,56 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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.Decompiler.FlowAnalysis
+{
+	public enum JumpType
+	{
+		Normal,
+		JumpToExceptionHandler,
+		LeaveTry,
+		MutualProtection
+	}
+	
+	public sealed class ControlFlowEdge
+	{
+		public readonly ControlFlowNode Source;
+		public readonly ControlFlowNode Target;
+		public readonly JumpType Type;
+		
+		public ControlFlowEdge(ControlFlowNode source, ControlFlowNode target, JumpType type)
+		{
+			this.Source = source;
+			this.Target = target;
+			this.Type = type;
+		}
+		
+		public override string ToString()
+		{
+			switch (Type) {
+				case JumpType.Normal:
+					return "#" + Target.BlockIndex;
+				case JumpType.JumpToExceptionHandler:
+					return "e:#" + Target.BlockIndex;
+				default:
+					return Type.ToString() + ":#" + Target.BlockIndex;
+			}
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/ControlFlowGraph.cs

@@ -0,0 +1,180 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	/// <summary>
+	/// Contains the control flow graph.
+	/// </summary>
+	public sealed class ControlFlowGraph
+	{
+		readonly ReadOnlyCollection<ControlFlowNode> nodes;
+		
+		public ControlFlowNode EntryPoint {
+			get { return nodes[0]; }
+		}
+		
+		public ControlFlowNode RegularExit {
+			get { return nodes[1]; }
+		}
+		
+		public ControlFlowNode ExceptionalExit {
+			get { return nodes[2]; }
+		}
+		
+		public ReadOnlyCollection<ControlFlowNode> Nodes {
+			get { return nodes; }
+		}
+		
+		internal ControlFlowGraph(ControlFlowNode[] nodes)
+		{
+			this.nodes = new ReadOnlyCollection<ControlFlowNode>(nodes);
+			Debug.Assert(EntryPoint.NodeType == ControlFlowNodeType.EntryPoint);
+			Debug.Assert(RegularExit.NodeType == ControlFlowNodeType.RegularExit);
+			Debug.Assert(ExceptionalExit.NodeType == ControlFlowNodeType.ExceptionalExit);
+		}
+		
+		#if DEBUG
+		public GraphVizGraph ExportGraph()
+		{
+			GraphVizGraph graph = new GraphVizGraph();
+			foreach (ControlFlowNode node in nodes) {
+				graph.AddNode(new GraphVizNode(node.BlockIndex) { label = node.ToString(), shape = "box" });
+			}
+			foreach (ControlFlowNode node in nodes) {
+				foreach (ControlFlowEdge edge in node.Outgoing) {
+					GraphVizEdge e = new GraphVizEdge(edge.Source.BlockIndex, edge.Target.BlockIndex);
+					switch (edge.Type) {
+						case JumpType.Normal:
+							break;
+						case JumpType.LeaveTry:
+							e.color = "red";
+							break;
+						default:
+							e.color = "gray";
+							//e.constraint = false;
+							break;
+					}
+					graph.AddEdge(e);
+				}
+				if (node.ImmediateDominator != null) {
+					graph.AddEdge(new GraphVizEdge(node.ImmediateDominator.BlockIndex, node.BlockIndex) { color = "green", constraint = false });
+				}
+			}
+			return graph;
+		}
+		#endif
+		
+		internal void ResetVisited()
+		{
+			foreach (ControlFlowNode node in nodes) {
+				node.Visited = false;
+			}
+		}
+		
+		public void ComputeDominance()
+		{
+			// A Simple, Fast Dominance Algorithm
+			// Keith D. Cooper, Timothy J. Harvey and Ken Kennedy
+			
+			EntryPoint.ImmediateDominator = EntryPoint;
+			bool changed = true;
+			while (changed) {
+				changed = false;
+				ResetVisited();
+				
+				// for all nodes b except the entry point
+				EntryPoint.TraversePreOrder(
+					b => b.Successors,
+					b => {
+						if (b != EntryPoint) {
+							ControlFlowNode newIdom = b.Predecessors.First(block => block.Visited);
+							// for all other predecessors p of b
+							foreach (ControlFlowNode p in b.Predecessors) {
+								if (p != b && p.ImmediateDominator != null) {
+									newIdom = FindCommonDominator(p, newIdom);
+								}
+							}
+							if (b.ImmediateDominator != newIdom) {
+								b.ImmediateDominator = newIdom;
+								changed = true;
+							}
+						}
+					});
+			}
+			EntryPoint.ImmediateDominator = null;
+			foreach (ControlFlowNode node in nodes) {
+				if (node.ImmediateDominator != null)
+					node.ImmediateDominator.DominatorTreeChildren.Add(node);
+			}
+		}
+		
+		static ControlFlowNode FindCommonDominator(ControlFlowNode b1, ControlFlowNode b2)
+		{
+			// Here we could use the postorder numbers to get rid of the hashset, see "A Simple, Fast Dominance Algorithm"
+			HashSet<ControlFlowNode> path1 = new HashSet<ControlFlowNode>();
+			while (b1 != null && path1.Add(b1))
+				b1 = b1.ImmediateDominator;
+			while (b2 != null) {
+				if (path1.Contains(b2))
+					return b2;
+				else
+					b2 = b2.ImmediateDominator;
+			}
+			throw new Exception("No common dominator found!");
+		}
+		
+		public void ComputeDominanceFrontier()
+		{
+			ResetVisited();
+			
+			EntryPoint.TraversePostOrder(
+				b => b.DominatorTreeChildren,
+				n => {
+					//logger.WriteLine("Calculating dominance frontier for " + n.Name);
+					n.DominanceFrontier = new HashSet<ControlFlowNode>();
+					// DF_local computation
+					foreach (ControlFlowNode succ in n.Successors) {
+						if (succ.ImmediateDominator != n) {
+							//logger.WriteLine("  local: " + succ.Name);
+							n.DominanceFrontier.Add(succ);
+						}
+					}
+					// DF_up computation
+					foreach (ControlFlowNode child in n.DominatorTreeChildren) {
+						foreach (ControlFlowNode p in child.DominanceFrontier) {
+							if (p.ImmediateDominator != n) {
+								//logger.WriteLine("  DF_up: " + p.Name + " (child=" + child.Name);
+								n.DominanceFrontier.Add(p);
+							}
+						}
+					}
+				});
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/ControlFlowGraphBuilder.cs

@@ -0,0 +1,388 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	public sealed class ControlFlowGraphBuilder
+	{
+		public static ControlFlowGraph Build(MethodBody methodBody)
+		{
+			return new ControlFlowGraphBuilder(methodBody).Build();
+		}
+		
+		MethodBody methodBody;
+		int[] offsets; // array index = instruction index; value = IL offset
+		bool[] hasIncomingJumps; // array index = instruction index
+		List<ControlFlowNode> nodes = new List<ControlFlowNode>();
+		ControlFlowNode entryPoint;
+		ControlFlowNode regularExit ;
+		ControlFlowNode exceptionalExit;
+		//Stack<> activeExceptionHandlers = new Stack<ExceptionHandler>();
+		
+		private ControlFlowGraphBuilder(MethodBody methodBody)
+		{
+			this.methodBody = methodBody;
+			offsets = methodBody.Instructions.Select(i => i.Offset).ToArray();
+			hasIncomingJumps = new bool[methodBody.Instructions.Count];
+			
+			entryPoint = new ControlFlowNode(0, ControlFlowNodeType.EntryPoint);
+			nodes.Add(entryPoint);
+			regularExit = new ControlFlowNode(1, ControlFlowNodeType.RegularExit);
+			nodes.Add(regularExit);
+			exceptionalExit = new ControlFlowNode(2, ControlFlowNodeType.ExceptionalExit);
+			nodes.Add(exceptionalExit);
+			Debug.Assert(nodes.Count == 3);
+		}
+		
+		int GetInstructionIndex(Instruction inst)
+		{
+			int index = Array.BinarySearch(offsets, inst.Offset);
+			Debug.Assert(index >= 0);
+			return index;
+		}
+		
+		public ControlFlowGraph Build()
+		{
+			CalculateHasIncomingJumps();
+			CreateNodes();
+			CreateRegularControlFlow();
+			CreateExceptionalControlFlow();
+			CopyFinallyBlocksIntoLeaveEdges();
+			return new ControlFlowGraph(nodes.ToArray());
+		}
+		
+		void CalculateHasIncomingJumps()
+		{
+			foreach (Instruction inst in methodBody.Instructions) {
+				if (inst.OpCode.OperandType == OperandType.InlineBrTarget) {
+					hasIncomingJumps[GetInstructionIndex((Instruction)inst.Operand)] = true;
+				} else if (inst.OpCode.OperandType == OperandType.InlineSwitch) {
+					foreach (Instruction i in (Instruction[])inst.Operand)
+						hasIncomingJumps[GetInstructionIndex(i)] = true;
+				}
+			}
+			foreach (ExceptionHandler eh in methodBody.ExceptionHandlers) {
+				if (eh.FilterStart != null) {
+					hasIncomingJumps[GetInstructionIndex(eh.FilterStart)] = true;
+				}
+				hasIncomingJumps[GetInstructionIndex(eh.HandlerStart)] = true;
+			}
+		}
+		
+		void CreateNodes()
+		{
+			for (int i = 0; i < methodBody.Instructions.Count; i++) {
+				Instruction blockStart = methodBody.Instructions[i];
+				// try and see how big we can make that block:
+				for (; i + 1 < methodBody.Instructions.Count; i++) {
+					Instruction inst = methodBody.Instructions[i];
+					if (IsBranch(inst.OpCode) || CanThrowException(inst.OpCode))
+						break;
+					if (hasIncomingJumps[i + 1])
+						break;
+				}
+				
+				nodes.Add(new ControlFlowNode(nodes.Count, blockStart, methodBody.Instructions[i]));
+			}
+			foreach (ExceptionHandler handler in methodBody.ExceptionHandlers) {
+				if (handler.HandlerType == ExceptionHandlerType.Filter)
+					throw new NotSupportedException();
+				ControlFlowNode endFinallyOrFaultNode = null;
+				if (handler.HandlerType == ExceptionHandlerType.Finally || handler.HandlerType == ExceptionHandlerType.Fault) {
+					endFinallyOrFaultNode = new ControlFlowNode(nodes.Count, ControlFlowNodeType.EndFinallyOrFault);
+					nodes.Add(endFinallyOrFaultNode);
+				}
+				nodes.Add(new ControlFlowNode(nodes.Count, handler, endFinallyOrFaultNode));
+			}
+		}
+		
+		void CreateRegularControlFlow()
+		{
+			CreateEdge(entryPoint, methodBody.Instructions[0], JumpType.Normal);
+			foreach (ControlFlowNode node in nodes) {
+				if (node.End != null) {
+					// create normal edges from one instruction to the next
+					if (!IsUnconditionalBranch(node.End.OpCode))
+						CreateEdge(node, node.End.Next, JumpType.Normal);
+					
+					// create edges for branch instructions
+					if (node.End.OpCode.OperandType == OperandType.InlineBrTarget) {
+						if (node.End.OpCode == OpCodes.Leave) {
+							var handlerBlock = FindInnermostHandlerBlock(node.End.Offset);
+							if (handlerBlock.NodeType == ControlFlowNodeType.FinallyOrFaultHandler)
+								CreateEdge(node, (Instruction)node.End.Operand, JumpType.LeaveTry);
+							else
+								CreateEdge(node, (Instruction)node.End.Operand, JumpType.Normal);
+						} else {
+							CreateEdge(node, (Instruction)node.End.Operand, JumpType.Normal);
+						}
+					} else if (node.End.OpCode.OperandType == OperandType.InlineSwitch) {
+						foreach (Instruction i in (Instruction[])node.End.Operand)
+							CreateEdge(node, i, JumpType.Normal);
+					}
+					
+					// create edges for return instructions
+					if (node.End.OpCode.FlowControl == FlowControl.Return) {
+						switch (node.End.OpCode.Code) {
+							case Code.Ret:
+								CreateEdge(node, regularExit, JumpType.Normal);
+								break;
+							case Code.Endfinally:
+								ControlFlowNode handlerBlock = FindInnermostHandlerBlock(node.End.Offset);
+								if (handlerBlock.EndFinallyOrFaultNode == null)
+									throw new InvalidProgramException("Found endfinally in block " + handlerBlock);
+								CreateEdge(node, handlerBlock.EndFinallyOrFaultNode, JumpType.Normal);
+								break;
+							default:
+								throw new NotSupportedException(node.End.OpCode.ToString());
+						}
+					}
+				}
+			}
+		}
+		
+		void CreateExceptionalControlFlow()
+		{
+			foreach (ControlFlowNode node in nodes) {
+				if (node.End != null && CanThrowException(node.End.OpCode)) {
+					CreateEdge(node, FindInnermostExceptionHandler(node.End.Offset), JumpType.JumpToExceptionHandler);
+				}
+				if (node.ExceptionHandler != null) {
+					if (node.EndFinallyOrFaultNode != null) {
+						// For Fault and Finally blocks, create edge from "EndFinally" to next exception handler.
+						// This represents the exception bubbling up after finally block was executed.
+						CreateEdge(node.EndFinallyOrFaultNode, FindInnermostExceptionHandler(node.ExceptionHandler.HandlerEnd.Offset), JumpType.JumpToExceptionHandler);
+					} else {
+						// For Catch blocks, create edge from "CatchHandler" block (at beginning) to next exception handler.
+						// This represents the exception bubbling up because it did not match the type of the catch block.
+						CreateEdge(node, FindInnermostExceptionHandler(node.ExceptionHandler.HandlerStart.Offset), JumpType.JumpToExceptionHandler);
+					}
+					CreateEdge(node, node.ExceptionHandler.HandlerStart, JumpType.Normal);
+				}
+			}
+			
+			// now create edges between catch handlers that mutually protect
+			for (int i = 0; i < methodBody.ExceptionHandlers.Count; i++) {
+				ExceptionHandler first = methodBody.ExceptionHandlers[i];
+				if (first.HandlerType == ExceptionHandlerType.Catch) {
+					for (int j = i + 1; j < methodBody.ExceptionHandlers.Count; j++) {
+						ExceptionHandler second = methodBody.ExceptionHandlers[j];
+						if (second.HandlerType == ExceptionHandlerType.Catch && second.TryStart == first.TryStart && second.TryEnd == first.TryEnd) {
+							CreateEdge(nodes.Single(n => n.ExceptionHandler == first), nodes.Single(n => n.ExceptionHandler == second), JumpType.MutualProtection);
+						}
+					}
+				}
+			}
+		}
+		
+		ControlFlowNode FindInnermostExceptionHandler(int instructionOffsetInTryBlock)
+		{
+			foreach (ExceptionHandler h in methodBody.ExceptionHandlers) {
+				if (h.TryStart.Offset <= instructionOffsetInTryBlock && instructionOffsetInTryBlock < h.TryEnd.Offset) {
+					return nodes.Single(n => n.ExceptionHandler == h && n.CopyFrom == null);
+				}
+			}
+			return exceptionalExit;
+		}
+		
+		ControlFlowNode FindInnermostHandlerBlock(int instructionOffset)
+		{
+			foreach (ExceptionHandler h in methodBody.ExceptionHandlers) {
+				if (h.TryStart.Offset <= instructionOffset && instructionOffset < h.TryEnd.Offset
+				    || h.HandlerStart.Offset <= instructionOffset && instructionOffset < h.HandlerEnd.Offset)
+				{
+					return nodes.Single(n => n.ExceptionHandler == h && n.CopyFrom == null);
+				}
+			}
+			return exceptionalExit;
+		}
+		
+		void CopyFinallyBlocksIntoLeaveEdges()
+		{
+			// We need to process try-finally blocks inside-out.
+			// We'll do that by going through all instructions in reverse order
+			for (int i = nodes.Count - 1; i >= 0; i--) {
+				ControlFlowNode node = nodes[i];
+				if (node.End != null && node.Outgoing.Count == 1 && node.Outgoing[0].Type == JumpType.LeaveTry) {
+					Debug.Assert(node.End.OpCode == OpCodes.Leave);
+					
+					ControlFlowNode target = node.Outgoing[0].Target;
+					// remove the edge
+					target.Incoming.Remove(node.Outgoing[0]);
+					node.Outgoing.Clear();
+					
+					ControlFlowNode handler = FindInnermostExceptionHandler(node.End.Offset);
+					Debug.Assert(handler.NodeType == ControlFlowNodeType.FinallyOrFaultHandler);
+					
+					ControlFlowNode copy = CopyFinallySubGraph(handler, handler.EndFinallyOrFaultNode, target);
+					CreateEdge(node, copy, JumpType.Normal);
+				}
+			}
+		}
+		
+		/// <summary>
+		/// Creates a copy of all nodes pointing to 'end' and replaces those references with references to 'newEnd'.
+		/// Nodes pointing to the copied node are copied recursively to update those references, too.
+		/// This recursion stops at 'start'. The modified version of start is returned.
+		/// </summary>
+		ControlFlowNode CopyFinallySubGraph(ControlFlowNode start, ControlFlowNode end, ControlFlowNode newEnd)
+		{
+			return new CopyFinallySubGraphLogic(this, start, end, newEnd).CopyFinallySubGraph();
+		}
+		
+		class CopyFinallySubGraphLogic
+		{
+			readonly ControlFlowGraphBuilder builder;
+			readonly Dictionary<ControlFlowNode, ControlFlowNode> oldToNew = new Dictionary<ControlFlowNode, ControlFlowNode>();
+			readonly ControlFlowNode start;
+			readonly ControlFlowNode end;
+			readonly ControlFlowNode newEnd;
+			
+			public CopyFinallySubGraphLogic(ControlFlowGraphBuilder builder, ControlFlowNode start, ControlFlowNode end, ControlFlowNode newEnd)
+			{
+				this.builder = builder;
+				this.start = start;
+				this.end = end;
+				this.newEnd = newEnd;
+			}
+			
+			internal ControlFlowNode CopyFinallySubGraph()
+			{
+				foreach (ControlFlowNode n in end.Predecessors) {
+					CollectNodes(n);
+				}
+				foreach (var pair in oldToNew)
+					ReconstructEdges(pair.Key, pair.Value);
+				return GetNew(start);
+			}
+			
+			void CollectNodes(ControlFlowNode node)
+			{
+				if (node == end || node == newEnd)
+					throw new InvalidOperationException("unexpected cycle involving finally construct");
+				if (!oldToNew.ContainsKey(node)) {
+					int newBlockIndex = builder.nodes.Count;
+					ControlFlowNode copy;
+					switch (node.NodeType) {
+						case ControlFlowNodeType.Normal:
+							copy = new ControlFlowNode(newBlockIndex, node.Start, node.End);
+							break;
+						case ControlFlowNodeType.FinallyOrFaultHandler:
+							copy = new ControlFlowNode(newBlockIndex, node.ExceptionHandler, node.EndFinallyOrFaultNode);
+							break;
+						default:
+							// other nodes shouldn't occur when copying finally blocks
+							throw new NotSupportedException(node.NodeType.ToString());
+					}
+					copy.CopyFrom = node;
+					builder.nodes.Add(copy);
+					oldToNew.Add(node, copy);
+					
+					if (node != start) {
+						foreach (ControlFlowNode n in node.Predecessors) {
+							CollectNodes(n);
+						}
+					}
+				}
+			}
+			
+			void ReconstructEdges(ControlFlowNode oldNode, ControlFlowNode newNode)
+			{
+				foreach (ControlFlowEdge oldEdge in oldNode.Outgoing) {
+					builder.CreateEdge(newNode, GetNew(oldEdge.Target), oldEdge.Type);
+				}
+			}
+			
+			ControlFlowNode GetNew(ControlFlowNode oldNode)
+			{
+				if (oldNode == end)
+					return newEnd;
+				ControlFlowNode newNode;
+				if (oldToNew.TryGetValue(oldNode, out newNode))
+					return newNode;
+				return oldNode;
+			}
+		}
+		
+		#region CreateEdge methods
+		void CreateEdge(ControlFlowNode fromNode, Instruction toInstruction, JumpType type)
+		{
+			CreateEdge(fromNode, nodes.Single(n => n.Start == toInstruction), type);
+		}
+		
+		void CreateEdge(ControlFlowNode fromNode, ControlFlowNode toNode, JumpType type)
+		{
+			ControlFlowEdge edge = new ControlFlowEdge(fromNode, toNode, type);
+			fromNode.Outgoing.Add(edge);
+			toNode.Incoming.Add(edge);
+		}
+		#endregion
+		
+		#region OpCode info
+		static bool CanThrowException(OpCode opcode)
+		{
+			if (opcode.OpCodeType == OpCodeType.Prefix)
+				return false;
+			return OpCodeInfo.Get(opcode).CanThrow;
+		}
+		
+		static bool IsBranch(OpCode opcode)
+		{
+			if (opcode.OpCodeType == OpCodeType.Prefix)
+				return false;
+			switch (opcode.FlowControl) {
+				case FlowControl.Cond_Branch:
+				case FlowControl.Branch:
+				case FlowControl.Throw:
+				case FlowControl.Return:
+					return true;
+				case FlowControl.Next:
+				case FlowControl.Call:
+					return false;
+				default:
+					throw new NotSupportedException(opcode.FlowControl.ToString());
+			}
+		}
+		
+		static bool IsUnconditionalBranch(OpCode opcode)
+		{
+			if (opcode.OpCodeType == OpCodeType.Prefix)
+				return false;
+			switch (opcode.FlowControl) {
+				case FlowControl.Branch:
+				case FlowControl.Throw:
+				case FlowControl.Return:
+					return true;
+				case FlowControl.Next:
+				case FlowControl.Call:
+				case FlowControl.Cond_Branch:
+					return false;
+				default:
+					throw new NotSupportedException(opcode.FlowControl.ToString());
+			}
+		}
+		#endregion
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/ControlFlowNode.cs

@@ -0,0 +1,184 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	public enum ControlFlowNodeType
+	{
+		Normal,
+		EntryPoint,
+		RegularExit,
+		ExceptionalExit,
+		CatchHandler,
+		FinallyOrFaultHandler,
+		EndFinallyOrFault
+	}
+	
+	public sealed class ControlFlowNode
+	{
+		public readonly int BlockIndex;
+		public readonly ControlFlowNodeType NodeType;
+		public readonly ControlFlowNode EndFinallyOrFaultNode;
+		
+		/// <summary>
+		/// Visited flag that's used in various algorithms.
+		/// </summary>
+		internal bool Visited;
+		
+		/// <summary>
+		/// Signalizes that this node is a copy of another node.
+		/// </summary>
+		public ControlFlowNode CopyFrom { get; internal set; }
+		
+		/// <summary>
+		/// Gets the immediate dominator.
+		/// </summary>
+		public ControlFlowNode ImmediateDominator { get; internal set; }
+		
+		public readonly List<ControlFlowNode> DominatorTreeChildren = new List<ControlFlowNode>();
+		
+		public HashSet<ControlFlowNode> DominanceFrontier;
+		
+		/// <summary>
+		/// Start of code block represented by this node.  Only set for nodetype == Normal.
+		/// </summary>
+		public readonly Instruction Start;
+		
+		/// <summary>
+		/// End of the code block represented by this node. Only set for nodetype == Normal.
+		/// </summary>
+		public readonly Instruction End;
+		
+		/// <summary>
+		/// Gets the exception handler associated with this node. Only set for nodetype == ExceptionHandler.
+		/// </summary>
+		public readonly ExceptionHandler ExceptionHandler;
+		
+		public readonly List<ControlFlowEdge> Incoming = new List<ControlFlowEdge>();
+		public readonly List<ControlFlowEdge> Outgoing = new List<ControlFlowEdge>();
+		
+		internal ControlFlowNode(int blockIndex, ControlFlowNodeType nodeType)
+		{
+			this.BlockIndex = blockIndex;
+			this.NodeType = nodeType;
+		}
+		
+		internal ControlFlowNode(int blockIndex, Instruction start, Instruction end)
+		{
+			if (start == null)
+				throw new ArgumentNullException("start");
+			if (end == null)
+				throw new ArgumentNullException("end");
+			this.BlockIndex = blockIndex;
+			this.NodeType = ControlFlowNodeType.Normal;
+			this.Start = start;
+			this.End = end;
+		}
+		
+		internal ControlFlowNode(int blockIndex, ExceptionHandler exceptionHandler, ControlFlowNode endFinallyOrFaultNode)
+		{
+			this.BlockIndex = blockIndex;
+			this.NodeType = endFinallyOrFaultNode != null ? ControlFlowNodeType.FinallyOrFaultHandler : ControlFlowNodeType.CatchHandler;
+			this.ExceptionHandler = exceptionHandler;
+			this.EndFinallyOrFaultNode = endFinallyOrFaultNode;
+			Debug.Assert((exceptionHandler.HandlerType == ExceptionHandlerType.Finally || exceptionHandler.HandlerType == ExceptionHandlerType.Fault) == (endFinallyOrFaultNode != null));
+		}
+		
+		public IEnumerable<ControlFlowNode> Predecessors {
+			get {
+				return Incoming.Select(e => e.Source);
+			}
+		}
+		
+		public IEnumerable<ControlFlowNode> Successors {
+			get {
+				return Outgoing.Select(e => e.Target);
+			}
+		}
+		
+		public IEnumerable<Instruction> Instructions {
+			get {
+				Instruction inst = Start;
+				if (inst != null) {
+					yield return inst;
+					while (inst != End) {
+						inst = inst.Next;
+						yield return inst;
+					}
+				}
+			}
+		}
+		
+		public void TraversePreOrder(Func<ControlFlowNode, IEnumerable<ControlFlowNode>> children, Action<ControlFlowNode> visitAction)
+		{
+			if (Visited)
+				return;
+			Visited = true;
+			visitAction(this);
+			foreach (ControlFlowNode t in children(this))
+				t.TraversePreOrder(children, visitAction);
+		}
+		
+		public void TraversePostOrder(Func<ControlFlowNode, IEnumerable<ControlFlowNode>> children, Action<ControlFlowNode> visitAction)
+		{
+			if (Visited)
+				return;
+			Visited = true;
+			foreach (ControlFlowNode t in children(this))
+				t.TraversePostOrder(children, visitAction);
+			visitAction(this);
+		}
+		
+		public override string ToString()
+		{
+			StringWriter writer = new StringWriter();
+			switch (NodeType) {
+				case ControlFlowNodeType.Normal:
+					int endOffset = End.Next != null ? End.Next.Offset : End.Offset + End.GetSize();
+					writer.Write("Block #{0}: IL_{1:x4} to IL_{2:x4}", BlockIndex, Start.Offset, endOffset);
+					break;
+				case ControlFlowNodeType.CatchHandler:
+				case ControlFlowNodeType.FinallyOrFaultHandler:
+					writer.Write("Block #{0}: {1}: ", BlockIndex, NodeType);
+					ExceptionHandler.WriteTo(writer);
+					break;
+				default:
+					writer.Write("Block #{0}: {1}", BlockIndex, NodeType);
+					break;
+			}
+//			if (ImmediateDominator != null) {
+//				writer.WriteLine();
+//				writer.Write("ImmediateDominator: #{0}", ImmediateDominator.BlockIndex);
+//			}
+			foreach (Instruction inst in this.Instructions) {
+				writer.WriteLine();
+				inst.WriteTo(writer);
+			}
+			return writer.ToString();
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/OpCodeInfo.cs

@@ -0,0 +1,240 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <author name="Daniel Grunwald"/>
+//     <version>$Revision: 776 $</version>
+// </file>
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler
+{
+	/// <summary>
+	/// Additional info about opcodes.
+	/// </summary>
+	sealed class OpCodeInfo
+	{
+		static readonly OpCodeInfo[] knownOpCodes = {
+			#region Base Instructions
+			new OpCodeInfo(OpCodes.Add)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Add_Ovf)    { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Add_Ovf_Un) { CanThrow = true  },
+			new OpCodeInfo(OpCodes.And)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Arglist)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Beq)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Bge)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Bge_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Bgt)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Bgt_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ble)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ble_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Blt)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Blt_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Bne_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Br)         { CanThrow = false },
+			new OpCodeInfo(OpCodes.Break)      { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Brfalse)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Brtrue)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Call)       { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Calli)      { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Ceq)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Cgt)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Cgt_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ckfinite)   { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Clt)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Clt_Un)     { CanThrow = false },
+			// conv.<to type>
+			new OpCodeInfo(OpCodes.Conv_I1)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_I2)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_I4)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_I8)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_R4)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_R8)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_U1)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_U2)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_U4)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_U8)    { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_I)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_U)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Conv_R_Un)  { CanThrow = false },
+			// conv.ovf.<to type>
+			new OpCodeInfo(OpCodes.Conv_Ovf_I1) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_I2) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_I4) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_I8) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_U1) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_U2) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_U4) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_U8) { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_I)  { CanThrow = true},
+			new OpCodeInfo(OpCodes.Conv_Ovf_U)  { CanThrow = true},
+			// conv.ovf.<to type>.un
+			new OpCodeInfo(OpCodes.Conv_Ovf_I1_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_I2_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_I4_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_I8_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_U1_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_U2_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_U4_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_U8_Un) { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_I_Un)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Conv_Ovf_U_Un)  { CanThrow = true },
+			
+			//new OpCodeInfo(OpCodes.Cpblk)      { CanThrow = true }, - no idea whether this might cause trouble for the type system, C# shouldn't use it so I'll disable it
+			new OpCodeInfo(OpCodes.Div)        { CanThrow = true },
+			new OpCodeInfo(OpCodes.Div_Un)     { CanThrow = true },
+			new OpCodeInfo(OpCodes.Dup)        { CanThrow = true, IsMoveInstruction = true },
+			new OpCodeInfo(OpCodes.Endfilter)  { CanThrow = false },
+			new OpCodeInfo(OpCodes.Endfinally) { CanThrow = false },
+			//new OpCodeInfo(OpCodes.Initblk)    { CanThrow = true }, - no idea whether this might cause trouble for the type system, C# shouldn't use it so I'll disable it
+			//new OpCodeInfo(OpCodes.Jmp)        { CanThrow = true } - We don't support non-local control transfers.
+			new OpCodeInfo(OpCodes.Ldarg)  { CanThrow = false, IsMoveInstruction = true },
+			new OpCodeInfo(OpCodes.Ldarga) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldc_I4) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldc_I8) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldc_R4) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldc_R8) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldftn)  { CanThrow = false },
+			// ldind.<type>
+			new OpCodeInfo(OpCodes.Ldind_I1)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_I2)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_I4)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_I8)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_U1)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_U2)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_U4)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_R4)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_R8)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_I)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Ldind_Ref) { CanThrow = true },
+			// the ldloc exceptions described in the spec can only occur on methods without .localsinit - but csc always sets that flag
+			new OpCodeInfo(OpCodes.Ldloc)      { CanThrow = false, IsMoveInstruction = true },
+			new OpCodeInfo(OpCodes.Ldloca)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldnull)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Leave)      { CanThrow = false },
+			new OpCodeInfo(OpCodes.Localloc)   { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Mul)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Mul_Ovf)    { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Mul_Ovf_Un) { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Neg)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Nop)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Not)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Or)         { CanThrow = false },
+			new OpCodeInfo(OpCodes.Pop)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Rem)        { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Rem_Un)     { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Ret)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Shl)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Shr)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Shr_Un)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Starg)      { CanThrow = false, IsMoveInstruction = true },
+			new OpCodeInfo(OpCodes.Stind_I1)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_I2)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_I4)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_I8)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_R4)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_R8)   { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_I)    { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stind_Ref)  { CanThrow = true },
+			new OpCodeInfo(OpCodes.Stloc)      { CanThrow = false, IsMoveInstruction = true },
+			new OpCodeInfo(OpCodes.Sub)        { CanThrow = false },
+			new OpCodeInfo(OpCodes.Sub_Ovf)    { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Sub_Ovf_Un) { CanThrow = true  },
+			new OpCodeInfo(OpCodes.Switch)     { CanThrow = false },
+			new OpCodeInfo(OpCodes.Xor)        { CanThrow = false },
+			#endregion
+			#region Object model instructions
+			// CanThrow is true by default - most OO instructions can throw, so we don't specify CanThrow all of the time
+			new OpCodeInfo(OpCodes.Box),
+			new OpCodeInfo(OpCodes.Callvirt),
+			new OpCodeInfo(OpCodes.Castclass), // (output type not Input0 as type arguments may change)
+			new OpCodeInfo(OpCodes.Cpobj),
+			new OpCodeInfo(OpCodes.Initobj) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Isinst)  { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldelem_Any),
+			// ldelem.<type>
+			new OpCodeInfo(OpCodes.Ldelem_I) ,
+			new OpCodeInfo(OpCodes.Ldelem_I1),
+			new OpCodeInfo(OpCodes.Ldelem_I2),
+			new OpCodeInfo(OpCodes.Ldelem_I4),
+			new OpCodeInfo(OpCodes.Ldelem_I8),
+			new OpCodeInfo(OpCodes.Ldelem_R4),
+			new OpCodeInfo(OpCodes.Ldelem_R8),
+			new OpCodeInfo(OpCodes.Ldelem_Ref),
+			new OpCodeInfo(OpCodes.Ldelem_U1),
+			new OpCodeInfo(OpCodes.Ldelem_U2),
+			new OpCodeInfo(OpCodes.Ldelem_U4),
+			new OpCodeInfo(OpCodes.Ldelema)  ,
+			new OpCodeInfo(OpCodes.Ldfld) ,
+			new OpCodeInfo(OpCodes.Ldflda),
+			new OpCodeInfo(OpCodes.Ldlen) ,
+			new OpCodeInfo(OpCodes.Ldobj) ,
+			new OpCodeInfo(OpCodes.Ldsfld),
+			new OpCodeInfo(OpCodes.Ldsflda),
+			new OpCodeInfo(OpCodes.Ldstr) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldtoken) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Ldvirtftn),
+			//new OpCodeInfo(OpCodes.Mkrefany), don't enable this without checking what it is
+			new OpCodeInfo(OpCodes.Newarr),
+			new OpCodeInfo(OpCodes.Newobj),
+			//new OpCodeInfo(OpCodes.Mkrefany), don't enable this without checking what it is
+			//new OpCodeInfo(OpCodes.Refanyval), don't enable this without checking what it is
+			new OpCodeInfo(OpCodes.Rethrow),
+			new OpCodeInfo(OpCodes.Sizeof) { CanThrow = false },
+			new OpCodeInfo(OpCodes.Stelem_Any),
+			new OpCodeInfo(OpCodes.Stelem_I1),
+			new OpCodeInfo(OpCodes.Stelem_I2),
+			new OpCodeInfo(OpCodes.Stelem_I4),
+			new OpCodeInfo(OpCodes.Stelem_I8),
+			new OpCodeInfo(OpCodes.Stelem_R4),
+			new OpCodeInfo(OpCodes.Stelem_R8),
+			new OpCodeInfo(OpCodes.Stelem_Ref),
+			new OpCodeInfo(OpCodes.Stfld),
+			new OpCodeInfo(OpCodes.Stobj),
+			new OpCodeInfo(OpCodes.Stsfld),
+			new OpCodeInfo(OpCodes.Throw),
+			new OpCodeInfo(OpCodes.Unbox),
+			new OpCodeInfo(OpCodes.Unbox_Any),
+			#endregion
+		};
+		static readonly Dictionary<Code, OpCodeInfo> knownOpCodeDict = knownOpCodes.ToDictionary(info => info.OpCode.Code);
+		
+		public static OpCodeInfo Get(OpCode opCode)
+		{
+			return Get(opCode.Code);
+		}
+		
+		public static OpCodeInfo Get(Code code)
+		{
+			OpCodeInfo info;
+			if (knownOpCodeDict.TryGetValue(code, out info))
+				return info;
+			else
+				throw new NotSupportedException(code.ToString());
+		}
+		
+		OpCode opcode;
+		
+		private OpCodeInfo(OpCode opcode)
+		{
+			this.opcode = opcode;
+			this.CanThrow = true;
+		}
+		
+		public OpCode OpCode { get { return opcode; } }
+		
+		/// <summary>
+		/// 'Move' kind of instructions have one input (may be stack or local variable) and copy that value to all outputs (again stack or local variable).
+		/// </summary>
+		public bool IsMoveInstruction { get; private set; }
+		
+		/// <summary>
+		/// Specifies whether this opcode is capable of throwing exceptions.
+		/// </summary>
+		public bool CanThrow { get; private set; }
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SimplifyByRefCalls.cs

@@ -0,0 +1,169 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	sealed class SimplifyByRefCalls
+	{
+		public static bool MakeByRefCallsSimple(SsaForm ssaForm)
+		{
+			SimplifyByRefCalls instance = new SimplifyByRefCalls(ssaForm);
+			foreach (SsaBlock block in ssaForm.Blocks) {
+				for (int i = 0; i < block.Instructions.Count; i++) {
+					SsaInstruction inst = block.Instructions[i];
+					if (inst.Instruction != null) {
+						switch (inst.Instruction.OpCode.Code) {
+							case Code.Call:
+							case Code.Callvirt:
+								instance.MakeByRefCallSimple(block, ref i, (IMethodSignature)inst.Instruction.Operand);
+								break;
+							case Code.Initobj:
+								instance.MakeInitObjCallSimple(block, ref i);
+								break;
+							case Code.Ldfld:
+								instance.MakeLoadFieldCallSimple(block, ref i);
+								break;
+						}
+					}
+				}
+			}
+			instance.RemoveRedundantInstructions();
+			if (instance.couldSimplifySomething)
+				ssaForm.ComputeVariableUsage();
+			return instance.couldSimplifySomething;
+		}
+		
+		readonly SsaForm ssaForm;
+		
+		bool couldSimplifySomething;
+		
+		// the list of ldloca instructions we will remove
+		readonly List<SsaInstruction> redundantLoadAddressInstructions = new List<SsaInstruction>();
+		
+		private SimplifyByRefCalls(SsaForm ssaForm)
+		{
+			this.ssaForm = ssaForm;
+		}
+		
+		void MakeByRefCallSimple(SsaBlock block, ref int instructionIndexInBlock, IMethodSignature targetMethod)
+		{
+			SsaInstruction inst = block.Instructions[instructionIndexInBlock];
+			for (int i = 0; i < inst.Operands.Length; i++) {
+				SsaVariable operand = inst.Operands[i];
+				if (operand.IsSingleAssignment && operand.Usage.Count == 1 && IsLoadAddress(operand.Definition)) {
+					// address is used for this method call only
+					
+					Instruction loadAddressInstruction = operand.Definition.Instruction;
+					
+					// find target parameter type:
+					bool isOut;
+					if (i == 0 && targetMethod.HasThis) {
+						isOut = false;
+					} else {
+						ParameterDefinition parameter = targetMethod.Parameters[i - (targetMethod.HasThis ? 1 : 0)];
+						isOut = parameter.IsOut;
+					}
+					
+					SsaVariable addressTakenOf = GetVariableFromLoadAddressInstruction(loadAddressInstruction);
+					
+					// insert "Prepare" instruction on front
+					SpecialOpCode loadOpCode = isOut ? SpecialOpCode.PrepareByOutCall : SpecialOpCode.PrepareByRefCall;
+					block.Instructions.Insert(instructionIndexInBlock++, new SsaInstruction(
+						block, null, operand, new SsaVariable[] { addressTakenOf }, specialOpCode: loadOpCode));
+					
+					// insert "WriteAfterByRefOrOutCall" instruction after call
+					block.Instructions.Insert(instructionIndexInBlock + 1, new SsaInstruction(
+						block, null, addressTakenOf, new SsaVariable[] { operand }, specialOpCode: SpecialOpCode.WriteAfterByRefOrOutCall));
+					
+					couldSimplifySomething = true;
+					
+					// remove the loadAddressInstruction later
+					// (later because it might be defined in the current block and we don't want instructionIndex to become invalid)
+					redundantLoadAddressInstructions.Add(operand.Definition);
+				}
+			}
+		}
+
+		SsaVariable GetVariableFromLoadAddressInstruction(Instruction loadAddressInstruction)
+		{
+			if (loadAddressInstruction.OpCode == OpCodes.Ldloca) {
+				return ssaForm.GetOriginalVariable((VariableReference)loadAddressInstruction.Operand);
+			} else {
+				Debug.Assert(loadAddressInstruction.OpCode == OpCodes.Ldarga);
+				return ssaForm.GetOriginalVariable((ParameterReference)loadAddressInstruction.Operand);
+			}
+		}
+		
+		static bool IsLoadAddress(SsaInstruction inst)
+		{
+			return inst.Instruction != null && (inst.Instruction.OpCode == OpCodes.Ldloca || inst.Instruction.OpCode == OpCodes.Ldarga);
+		}
+		
+		void MakeInitObjCallSimple(SsaBlock block, ref int instructionIndexInBlock)
+		{
+			SsaInstruction inst = block.Instructions[instructionIndexInBlock];
+			Debug.Assert(inst.Operands.Length == 1);
+			SsaVariable operand = inst.Operands[0];
+			if (operand.IsSingleAssignment && operand.Usage.Count == 1 && IsLoadAddress(operand.Definition)) {
+				// replace instruction with special "InitObj" instruction
+				block.Instructions[instructionIndexInBlock] = new SsaInstruction(
+					inst.ParentBlock, null, GetVariableFromLoadAddressInstruction(operand.Definition.Instruction), null,
+					specialOpCode: SpecialOpCode.InitObj,
+					typeOperand: (TypeReference)inst.Instruction.Operand);
+				
+				couldSimplifySomething = true;
+				
+				// remove the loadAddressInstruction later
+				redundantLoadAddressInstructions.Add(operand.Definition);
+			}
+		}
+		
+		void MakeLoadFieldCallSimple(SsaBlock block, ref int instructionIndexInBlock)
+		{
+			SsaInstruction inst = block.Instructions[instructionIndexInBlock];
+			Debug.Assert(inst.Operands.Length == 1);
+			SsaVariable operand = inst.Operands[0];
+			if (operand.IsSingleAssignment && operand.Usage.Count == 1 && IsLoadAddress(operand.Definition)) {
+				// insert special "PrepareForFieldAccess" instruction in front
+				block.Instructions.Insert(instructionIndexInBlock++, new SsaInstruction(
+					inst.ParentBlock, null, operand, 
+					new SsaVariable[] { GetVariableFromLoadAddressInstruction(operand.Definition.Instruction) },
+					specialOpCode: SpecialOpCode.PrepareForFieldAccess));
+				
+				couldSimplifySomething = true;
+				
+				// remove the loadAddressInstruction later
+				redundantLoadAddressInstructions.Add(operand.Definition);
+			}
+		}
+		
+		void RemoveRedundantInstructions()
+		{
+			foreach (SsaInstruction inst in redundantLoadAddressInstructions) {
+				inst.ParentBlock.Instructions.Remove(inst);
+			}
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SsaBlock.cs

@@ -0,0 +1,50 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.IO;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	public sealed class SsaBlock
+	{
+		public readonly List<SsaBlock> Successors = new List<SsaBlock>();
+		public readonly List<SsaBlock> Predecessors = new List<SsaBlock>();
+		public readonly ControlFlowNodeType NodeType;
+		public readonly List<SsaInstruction> Instructions = new List<SsaInstruction>();
+		public readonly int BlockIndex;
+		
+		internal SsaBlock(ControlFlowNode node)
+		{
+			this.NodeType = node.NodeType;
+			this.BlockIndex = node.BlockIndex;
+		}
+		
+		public override string ToString()
+		{
+			StringWriter writer = new StringWriter();
+			writer.Write("Block #{0} ({1})", BlockIndex, NodeType);
+			foreach (SsaInstruction inst in Instructions) {
+				writer.WriteLine();
+				inst.WriteTo(writer);
+			}
+			return writer.ToString();
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SsaForm.cs

@@ -0,0 +1,158 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Linq;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	public sealed class SsaForm
+	{
+		readonly SsaVariable[] parameters;
+		readonly SsaVariable[] locals;
+		public readonly ReadOnlyCollection<SsaVariable> OriginalVariables;
+		public readonly ReadOnlyCollection<SsaBlock> Blocks;
+		readonly bool methodHasThis;
+		
+		public SsaBlock EntryPoint {
+			get { return this.Blocks[0]; }
+		}
+		
+		public SsaBlock RegularExit {
+			get { return this.Blocks[1]; }
+		}
+		
+		public SsaBlock ExceptionalExit {
+			get { return this.Blocks[2]; }
+		}
+		
+		internal SsaForm(SsaBlock[] blocks, SsaVariable[] parameters, SsaVariable[] locals, SsaVariable[] stackLocations, bool methodHasThis)
+		{
+			this.parameters = parameters;
+			this.locals = locals;
+			this.Blocks = new ReadOnlyCollection<SsaBlock>(blocks);
+			this.OriginalVariables = new ReadOnlyCollection<SsaVariable>(parameters.Concat(locals).Concat(stackLocations).ToList());
+			this.methodHasThis = methodHasThis;
+			
+			Debug.Assert(EntryPoint.NodeType == ControlFlowNodeType.EntryPoint);
+			Debug.Assert(RegularExit.NodeType == ControlFlowNodeType.RegularExit);
+			Debug.Assert(ExceptionalExit.NodeType == ControlFlowNodeType.ExceptionalExit);
+			for (int i = 0; i < this.OriginalVariables.Count; i++) {
+				this.OriginalVariables[i].OriginalVariableIndex = i;
+			}
+		}
+		
+		public GraphVizGraph ExportBlockGraph(Func<SsaBlock, string> labelProvider = null)
+		{
+			if (labelProvider == null)
+				labelProvider = b => b.ToString();
+			GraphVizGraph graph = new GraphVizGraph();
+			foreach (SsaBlock block in this.Blocks) {
+				graph.AddNode(new GraphVizNode(block.BlockIndex) { label = labelProvider(block), shape = "box" });
+			}
+			foreach (SsaBlock block in this.Blocks) {
+				foreach (SsaBlock s in block.Successors) {
+					graph.AddEdge(new GraphVizEdge(block.BlockIndex, s.BlockIndex));
+				}
+			}
+			return graph;
+		}
+		
+		public GraphVizGraph ExportVariableGraph(Func<SsaVariable, string> labelProvider = null)
+		{
+			if (labelProvider == null)
+				labelProvider = v => v.ToString();
+			GraphVizGraph graph = new GraphVizGraph();
+			foreach (SsaVariable v in this.AllVariables) {
+				graph.AddNode(new GraphVizNode(v.Name) { label = labelProvider(v) });
+			}
+			int instructionIndex = 0;
+			foreach (SsaBlock block in this.Blocks) {
+				foreach (SsaInstruction inst in block.Instructions) {
+					if (inst.Operands.Length == 0 && inst.Target == null)
+						continue;
+					string id = "instruction" + (++instructionIndex);
+					graph.AddNode(new GraphVizNode(id) { label = inst.ToString(), shape = "box" });
+					foreach (SsaVariable op in inst.Operands)
+						graph.AddEdge(new GraphVizEdge(op.Name, id));
+					if (inst.Target != null)
+						graph.AddEdge(new GraphVizEdge(id, inst.Target.Name));
+				}
+			}
+			return graph;
+		}
+		
+		public SsaVariable GetOriginalVariable(ParameterReference parameter)
+		{
+			if (methodHasThis)
+				return parameters[parameter.Index + 1];
+			else
+				return parameters[parameter.Index];
+		}
+		
+		public SsaVariable GetOriginalVariable(VariableReference variable)
+		{
+			return locals[variable.Index];
+		}
+		
+		#region ComputeVariableUsage
+		public void ComputeVariableUsage()
+		{
+			// clear data from previous runs
+			foreach (SsaBlock block in this.Blocks) {
+				foreach (SsaInstruction inst in block.Instructions) {
+					foreach (SsaVariable v in inst.Operands) {
+						if (v.Usage != null)
+							v.Usage.Clear();
+					}
+					if (inst.Target != null && inst.Target.Usage != null)
+						inst.Target.Usage.Clear();
+				}
+			}
+			foreach (SsaBlock block in this.Blocks) {
+				foreach (SsaInstruction inst in block.Instructions) {
+					foreach (SsaVariable v in inst.Operands) {
+						if (v.Usage == null)
+							v.Usage = new List<SsaInstruction>();
+						v.Usage.Add(inst);
+					}
+					if (inst.Target != null && inst.Target.Usage == null)
+						inst.Target.Usage = new List<SsaInstruction>();
+				}
+			}
+		}
+		#endregion
+		
+		public IEnumerable<SsaVariable> AllVariables {
+			get {
+				return (
+					from block in this.Blocks
+					from instruction in block.Instructions
+					where instruction.Target != null
+					select instruction.Target
+				).Distinct();
+			}
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SsaFormBuilder.cs

@@ -0,0 +1,254 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	/// <summary>
+	/// Constructs "SsaForm" graph for a CFG.
+	/// This class transforms the method from stack-based IL to a register-based IL language.
+	/// Then it calls into TransformToSsa to convert the resulting graph to static single assignment form.
+	/// </summary>
+	public sealed class SsaFormBuilder
+	{
+		public static SsaForm Build(MethodDefinition method)
+		{
+			if (method == null)
+				throw new ArgumentNullException("method");
+			var cfg = ControlFlowGraphBuilder.Build(method.Body);
+			cfg.ComputeDominance();
+			cfg.ComputeDominanceFrontier();
+			var ssa = BuildRegisterIL(method, cfg);
+			TransformToSsa.Transform(cfg, ssa);
+			return ssa;
+		}
+		
+		public static SsaForm BuildRegisterIL(MethodDefinition method, ControlFlowGraph cfg)
+		{
+			if (method == null)
+				throw new ArgumentNullException("method");
+			if (cfg == null)
+				throw new ArgumentNullException("cfg");
+			return new SsaFormBuilder(method, cfg).Build();
+		}
+		
+		readonly MethodDefinition method;
+		readonly ControlFlowGraph cfg;
+		
+		readonly SsaBlock[] blocks; // array index = block index
+		readonly int[] stackSizeAtBlockStart; // array index = block index
+		
+		readonly SsaVariable[] parameters; // array index = parameter number
+		readonly SsaVariable[] locals; // array index = local number
+		readonly SsaVariable[] stackLocations; // array index = position on the IL evaluation stack
+		SsaForm ssaForm;
+		
+		private SsaFormBuilder(MethodDefinition method, ControlFlowGraph cfg)
+		{
+			this.method = method;
+			this.cfg = cfg;
+			
+			this.blocks = new SsaBlock[cfg.Nodes.Count];
+			this.stackSizeAtBlockStart = new int[cfg.Nodes.Count];
+			for (int i = 0; i < stackSizeAtBlockStart.Length; i++) {
+				stackSizeAtBlockStart[i] = -1;
+			}
+			stackSizeAtBlockStart[cfg.EntryPoint.BlockIndex] = 0;
+			
+			this.parameters = new SsaVariable[method.Parameters.Count + (method.HasThis ? 1 : 0)];
+			if (method.HasThis)
+				parameters[0] = new SsaVariable(method.Body.ThisParameter);
+			for (int i = 0; i < method.Parameters.Count; i++)
+				parameters[i + (method.HasThis ? 1 : 0)] = new SsaVariable(method.Parameters[i]);
+			
+			this.locals = new SsaVariable[method.Body.Variables.Count];
+			for (int i = 0; i < locals.Length; i++)
+				locals[i] = new SsaVariable(method.Body.Variables[i]);
+			
+			this.stackLocations = new SsaVariable[method.Body.MaxStackSize];
+			for (int i = 0; i < stackLocations.Length; i++) {
+				stackLocations[i] = new SsaVariable(i);
+			}
+		}
+		
+		internal SsaForm Build()
+		{
+			CreateGraphStructure();
+			this.ssaForm = new SsaForm(blocks, parameters, locals, stackLocations, method.HasThis);
+			CreateInstructions(cfg.EntryPoint.BlockIndex);
+			CreateSpecialInstructions();
+			return ssaForm;
+		}
+		
+		void CreateGraphStructure()
+		{
+			for (int i = 0; i < blocks.Length; i++) {
+				blocks[i] = new SsaBlock(cfg.Nodes[i]);
+			}
+			for (int i = 0; i < blocks.Length; i++) {
+				foreach (ControlFlowNode node in cfg.Nodes[i].Successors) {
+					blocks[i].Successors.Add(blocks[node.BlockIndex]);
+					blocks[node.BlockIndex].Predecessors.Add(blocks[i]);
+				}
+			}
+		}
+		
+		void CreateInstructions(int blockIndex)
+		{
+			ControlFlowNode cfgNode = cfg.Nodes[blockIndex];
+			SsaBlock block = blocks[blockIndex];
+			
+			int stackSize = stackSizeAtBlockStart[blockIndex];
+			Debug.Assert(stackSize >= 0);
+			
+			List<Instruction> prefixes = new List<Instruction>();
+			foreach (Instruction inst in cfgNode.Instructions) {
+				if (inst.OpCode.OpCodeType == OpCodeType.Prefix) {
+					prefixes.Add(inst);
+					continue;
+				}
+				
+				int popCount = inst.GetPopDelta(method, stackSize);
+				stackSize -= popCount;
+				if (stackSize < 0)
+					throw new InvalidProgramException("IL stack underflow");
+				
+				int pushCount = inst.GetPushDelta();
+				if (stackSize + pushCount > stackLocations.Length)
+					throw new InvalidProgramException("IL stack overflow");
+				
+				SsaVariable target;
+				SsaVariable[] operands;
+				DetermineOperands(stackSize, inst, popCount, pushCount, out target, out operands);
+				
+				Instruction[] prefixArray = prefixes.Count > 0 ? prefixes.ToArray() : null;
+				prefixes.Clear();
+				
+				// ignore NOP instructions
+				if (!(inst.OpCode == OpCodes.Nop || inst.OpCode == OpCodes.Pop)) {
+					block.Instructions.Add(new SsaInstruction(block, inst, target, operands, prefixArray));
+				}
+				stackSize += pushCount;
+			}
+			
+			foreach (ControlFlowEdge edge in cfgNode.Outgoing) {
+				int newStackSize;
+				switch (edge.Type) {
+					case JumpType.Normal:
+						newStackSize = stackSize;
+						break;
+					case JumpType.MutualProtection:
+					case JumpType.JumpToExceptionHandler:
+						switch (edge.Target.NodeType) {
+							case ControlFlowNodeType.FinallyOrFaultHandler:
+								newStackSize = 0;
+								break;
+							case ControlFlowNodeType.ExceptionalExit:
+							case ControlFlowNodeType.CatchHandler:
+								newStackSize = 1;
+								break;
+							default:
+								throw new NotSupportedException("unsupported target node type: " + edge.Target.NodeType);
+						}
+						break;
+					default:
+						throw new NotSupportedException("unsupported jump type: " + edge.Type);
+				}
+				
+				int nextStackSize = stackSizeAtBlockStart[edge.Target.BlockIndex];
+				if (nextStackSize == -1) {
+					stackSizeAtBlockStart[edge.Target.BlockIndex] = newStackSize;
+					CreateInstructions(edge.Target.BlockIndex);
+				} else if (nextStackSize != newStackSize) {
+					throw new InvalidProgramException("Stack size doesn't match");
+				}
+			}
+		}
+
+		void DetermineOperands(int stackSize, Instruction inst, int popCount, int pushCount, out SsaVariable target, out SsaVariable[] operands)
+		{
+			switch (inst.OpCode.Code) {
+				case Code.Ldarg:
+					operands = new SsaVariable[] { ssaForm.GetOriginalVariable((ParameterReference)inst.Operand) };
+					target = stackLocations[stackSize];
+					break;
+				case Code.Starg:
+					operands = new SsaVariable[] { stackLocations[stackSize] };
+					target = ssaForm.GetOriginalVariable((ParameterReference)inst.Operand);
+					break;
+				case Code.Ldloc:
+					operands = new SsaVariable[] { ssaForm.GetOriginalVariable((VariableReference)inst.Operand) };
+					target = stackLocations[stackSize];
+					break;
+				case Code.Stloc:
+					operands = new SsaVariable[] { stackLocations[stackSize] };
+					target = ssaForm.GetOriginalVariable((VariableReference)inst.Operand);
+					break;
+				case Code.Dup:
+					operands = new SsaVariable[] { stackLocations[stackSize] };
+					target = stackLocations[stackSize + 1];
+					break;
+				default:
+					operands = new SsaVariable[popCount];
+					for (int i = 0; i < popCount; i++) {
+						operands[i] = stackLocations[stackSize + i];
+					}
+
+					switch (pushCount) {
+						case 0:
+							target = null;
+							break;
+						case 1:
+							target = stackLocations[stackSize];
+							break;
+						default:
+							throw new NotSupportedException("unsupported pushCount=" + pushCount);
+					}
+					break;
+			}
+		}
+		
+		void CreateSpecialInstructions()
+		{
+			// Everything needs an initial write for the SSA transformation to work correctly.
+			foreach (SsaVariable v in parameters) {
+				ssaForm.EntryPoint.Instructions.Add(new SsaInstruction(ssaForm.EntryPoint, null, v, null, specialOpCode: SpecialOpCode.Parameter));
+			}
+			foreach (SsaVariable v in locals) {
+				ssaForm.EntryPoint.Instructions.Add(new SsaInstruction(ssaForm.EntryPoint, null, v, null, specialOpCode: SpecialOpCode.Uninitialized));
+			}
+			foreach (SsaVariable v in stackLocations) {
+				ssaForm.EntryPoint.Instructions.Add(new SsaInstruction(ssaForm.EntryPoint, null, v, null, specialOpCode: SpecialOpCode.Uninitialized));
+			}
+			foreach (SsaBlock b in blocks) {
+				if (b.NodeType == ControlFlowNodeType.CatchHandler) {
+					b.Instructions.Add(new SsaInstruction(b, null, stackLocations[0], null,
+					                                      specialOpCode: SpecialOpCode.Exception,
+					                                      typeOperand: cfg.Nodes[b.BlockIndex].ExceptionHandler.CatchType));
+				}
+			}
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SsaInstruction.cs

@@ -0,0 +1,190 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Diagnostics;
+using System.IO;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	public enum SpecialOpCode
+	{
+		/// <summary>
+		/// No special op code: SsaInstruction has a normal IL instruction
+		/// </summary>
+		None,
+		/// <summary>
+		/// Φ function: chooses the appropriate variable based on which CFG edge was used to enter this block
+		/// </summary>
+		Phi,
+		/// <summary>
+		/// Variable is read from before passing it by ref.
+		/// This instruction constructs a managed reference to the variable.
+		/// </summary>
+		PrepareByRefCall,
+		/// <summary>
+		/// This instruction constructs a managed reference to the variable.
+		/// The variable is not really read from.
+		/// </summary>
+		PrepareByOutCall,
+		/// <summary>
+		/// This instruction constructs a managed reference to the variable.
+		/// The reference is used for a field access on a value type.
+		/// </summary>
+		PrepareForFieldAccess,
+		/// <summary>
+		/// Variable is written to after passing it by ref or out.
+		/// </summary>
+		WriteAfterByRefOrOutCall,
+		/// <summary>
+		/// Variable is not initialized.
+		/// </summary>
+		Uninitialized,
+		/// <summary>
+		/// Value is passed in as parameter
+		/// </summary>
+		Parameter,
+		/// <summary>
+		/// Value is a caught exception.
+		/// TypeOperand is set to the exception type.
+		/// </summary>
+		Exception,
+		/// <summary>
+		/// Initialize a value type. Unlike the real initobj instruction, this one does not take an address
+		/// but assigns to the target variable.
+		/// TypeOperand is set to the type being created.
+		/// </summary>
+		InitObj
+	}
+	
+	public sealed class SsaInstruction
+	{
+		public readonly SsaBlock ParentBlock;
+		public readonly SpecialOpCode SpecialOpCode;
+		
+		/// <summary>
+		/// The original IL instruction.
+		/// May be null for "invented" instructions (SpecialOpCode != None).
+		/// </summary>
+		public readonly Instruction Instruction;
+		
+		/// <summary>
+		/// Prefixes in front of the IL instruction.
+		/// </summary>
+		public readonly Instruction[] Prefixes;
+		
+		/// <summary>
+		/// Gets the type operand. This is used only in combination with some special opcodes.
+		/// </summary>
+		public readonly TypeReference TypeOperand;
+		
+		public SsaVariable Target;
+		public SsaVariable[] Operands;
+		
+		static readonly SsaVariable[] emptyVariableArray = {};
+		static readonly Instruction[] emptyInstructionArray = {};
+		
+		public SsaInstruction(SsaBlock parentBlock, Instruction instruction, SsaVariable target, SsaVariable[] operands,
+		                      Instruction[] prefixes = null, SpecialOpCode specialOpCode = SpecialOpCode.None,
+		                      TypeReference typeOperand = null)
+		{
+			this.ParentBlock = parentBlock;
+			this.Instruction = instruction;
+			this.Prefixes = prefixes ?? emptyInstructionArray;
+			this.Target = target;
+			this.Operands = operands ?? emptyVariableArray;
+			this.SpecialOpCode = specialOpCode;
+			this.TypeOperand = typeOperand;
+			Debug.Assert((typeOperand != null) == (specialOpCode == SpecialOpCode.Exception || specialOpCode == SpecialOpCode.InitObj));
+		}
+		
+		/// <summary>
+		/// Gets whether this instruction is a simple assignment from one variable to another.
+		/// </summary>
+		public bool IsMoveInstruction {
+			get {
+				return Target != null && Operands.Length == 1 && Instruction != null && OpCodeInfo.Get(Instruction.OpCode).IsMoveInstruction;
+			}
+		}
+		
+		public void ReplaceVariableInOperands(SsaVariable oldVar, SsaVariable newVar)
+		{
+			for (int i = 0; i < this.Operands.Length; i++) {
+				if (this.Operands[i] == oldVar)
+					this.Operands[i] = newVar;
+			}
+		}
+		
+		public override string ToString()
+		{
+			StringWriter w = new StringWriter();
+			WriteTo(w);
+			return w.ToString();
+		}
+		
+		public void WriteTo(TextWriter writer)
+		{
+			foreach (Instruction prefix in this.Prefixes) {
+				prefix.WriteTo(writer);
+				writer.WriteLine();
+			}
+			if (Instruction != null && Instruction.Offset >= 0) {
+				writer.Write(CecilExtensions.OffsetToString(Instruction.Offset));
+				writer.Write(": ");
+			}
+			if (Target != null) {
+				writer.Write(Target.ToString());
+				writer.Write(" = ");
+			}
+			if (IsMoveInstruction) {
+				writer.Write(Operands[0].ToString());
+				if (Instruction != null) {
+					writer.Write(" (" + Instruction.OpCode.Name + ")");
+				}
+			} else {
+				if (Instruction == null) {
+					writer.Write(SpecialOpCode.ToString());
+				} else {
+					writer.Write(Instruction.OpCode.Name);
+					if(null != Instruction.Operand) {
+						writer.Write(' ');
+						writer.Write(CecilExtensions.OperandToString(Instruction.Operand));
+						writer.Write(' ');
+					}
+				}
+				if (TypeOperand != null) {
+					writer.Write(' ');
+					writer.Write(TypeOperand.ToString());
+					writer.Write(' ');
+				}
+				if (Operands.Length > 0) {
+					writer.Write('(');
+					for (int i = 0; i < Operands.Length; i++) {
+						if (i > 0)
+							writer.Write(", ");
+						writer.Write(Operands[i].ToString());
+					}
+					writer.Write(')');
+				}
+			}
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SsaOptimization.cs

@@ -0,0 +1,135 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	static class SsaOptimization
+	{
+		public static void Optimize(SsaForm ssaForm)
+		{
+			DirectlyStoreToVariables(ssaForm);
+			SimpleCopyPropagation(ssaForm);
+			RemoveDeadAssignments(ssaForm);
+		}
+		
+		/// <summary>
+		/// When any instructions stores its result in a stack location that's used only once in a 'stloc' or 'starg' instruction,
+		/// we optimize this to directly store in the target location.
+		/// As optimization this is redundant (does the same as copy propagation), but it'll make us keep the variables named
+		/// after locals instead of keeping the temps as using only the simple copy propagation would do.
+		/// </summary>
+		public static void DirectlyStoreToVariables(SsaForm ssaForm)
+		{
+			foreach (SsaBlock block in ssaForm.Blocks) {
+				block.Instructions.RemoveAll(
+					inst => {
+						if (inst.Instruction != null && (inst.Instruction.OpCode == OpCodes.Stloc || inst.Instruction.OpCode == OpCodes.Starg)) {
+							SsaVariable target = inst.Target;
+							SsaVariable temp = inst.Operands[0];
+							if (target.IsSingleAssignment && temp.IsSingleAssignment && temp.Usage.Count == 1 && temp.IsStackLocation) {
+								temp.Definition.Target = target;
+								return true;
+							}
+						}
+						return false;
+					});
+			}
+			ssaForm.ComputeVariableUsage(); // update usage after we modified stuff
+		}
+		
+		public static void SimpleCopyPropagation(SsaForm ssaForm, bool onlyForStackLocations = true)
+		{
+			foreach (SsaBlock block in ssaForm.Blocks) {
+				foreach (SsaInstruction inst in block.Instructions) {
+					if (inst.IsMoveInstruction && inst.Target.IsSingleAssignment && inst.Operands[0].IsSingleAssignment) {
+						if (inst.Target.IsStackLocation || !onlyForStackLocations) {
+							// replace all uses of 'target' with 'operands[0]'.
+							foreach (SsaInstruction useInstruction in inst.Target.Usage) {
+								useInstruction.ReplaceVariableInOperands(inst.Target, inst.Operands[0]);
+							}
+						}
+					}
+				}
+			}
+			ssaForm.ComputeVariableUsage(); // update usage after we modified stuff
+		}
+		
+		public static void RemoveDeadAssignments(SsaForm ssaForm)
+		{
+			HashSet<SsaVariable> liveVariables = new HashSet<SsaVariable>();
+			// find variables that are used directly
+			foreach (SsaBlock block in ssaForm.Blocks) {
+				foreach (SsaInstruction inst in block.Instructions) {
+					if (!CanRemoveAsDeadCode(inst)) {
+						if (inst.Target != null)
+							liveVariables.Add(inst.Target);
+						foreach (SsaVariable op in inst.Operands) {
+							liveVariables.Add(op);
+						}
+					}
+				}
+			}
+			Queue<SsaVariable> queue = new Queue<SsaVariable>(liveVariables);
+			// find variables that are used indirectly
+			while (queue.Count > 0) {
+				SsaVariable v = queue.Dequeue();
+				if (v.IsSingleAssignment) {
+					foreach (SsaVariable op in v.Definition.Operands) {
+						if (liveVariables.Add(op))
+							queue.Enqueue(op);
+					}
+				}
+			}
+			// remove assignments to all unused variables
+			foreach (SsaBlock block in ssaForm.Blocks) {
+				block.Instructions.RemoveAll(
+					inst => {
+						if (inst.Target != null && !liveVariables.Contains(inst.Target)) {
+							Debug.Assert(inst.Target.IsSingleAssignment);
+							return true;
+						}
+						return false;
+					});
+			}
+			ssaForm.ComputeVariableUsage(); // update usage after we modified stuff
+		}
+		
+		static bool CanRemoveAsDeadCode(SsaInstruction inst)
+		{
+			if (inst.Target != null && !inst.Target.IsSingleAssignment)
+				return false;
+			switch (inst.SpecialOpCode) {
+				case SpecialOpCode.Phi:
+				case SpecialOpCode.Exception:
+				case SpecialOpCode.Parameter:
+				case SpecialOpCode.Uninitialized:
+					return true;
+				case SpecialOpCode.None:
+					return inst.IsMoveInstruction;
+				default:
+					return false;
+			}
+		}
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/SsaVariable.cs

@@ -0,0 +1,85 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	public sealed class SsaVariable
+	{
+		public int OriginalVariableIndex;
+		public readonly string Name;
+		public readonly bool IsStackLocation;
+		
+		public readonly ParameterDefinition Parameter;
+		public readonly VariableDefinition Variable;
+		
+		public SsaVariable(ParameterDefinition p)
+		{
+			this.Name = string.IsNullOrEmpty(p.Name) ? "param" + p.Index : p.Name;
+			this.Parameter = p;
+		}
+		
+		public SsaVariable(VariableDefinition v)
+		{
+			this.Name = string.IsNullOrEmpty(v.Name) ? "V_" + v.Index : v.Name;
+			this.Variable = v;
+		}
+		
+		public SsaVariable(int stackLocation)
+		{
+			this.Name = "stack" + stackLocation;
+			this.IsStackLocation = true;
+		}
+		
+		public SsaVariable(SsaVariable original, string newName)
+		{
+			this.Name = newName;
+			this.IsStackLocation = original.IsStackLocation;
+			this.OriginalVariableIndex = original.OriginalVariableIndex;
+			this.Parameter = original.Parameter;
+			this.Variable = original.Variable;
+		}
+		
+		public override string ToString()
+		{
+			return Name;
+		}
+		
+		/// <summary>
+		/// Gets whether this variable has only a single assignment.
+		/// This field is initialized in TransformToSsa step.
+		/// </summary>
+		public bool IsSingleAssignment;
+		
+		/// <summary>
+		/// Gets the instruction defining the variable.
+		/// This field is initialized in TransformToSsa step. It is only set for variables with a single assignment.
+		/// </summary>
+		public SsaInstruction Definition;
+		
+		/// <summary>
+		/// Gets the places where a variable is used.
+		/// If a single instruction reads a variable 2 times (e.g. adding to itself), then it must be included 2 times in this list!
+		/// </summary>
+		public List<SsaInstruction> Usage;
+	}
+}

ICSharpCode.Decompiler/FlowAnalysis/TransformToSsa.cs

@@ -0,0 +1,254 @@
+// Copyright (c) 2010 Daniel Grunwald
+// 
+// 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;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Linq;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace ICSharpCode.Decompiler.FlowAnalysis
+{
+	/// <summary>
+	/// Convers a method to static single assignment form.
+	/// </summary>
+	sealed class TransformToSsa
+	{
+		public static void Transform(ControlFlowGraph cfg, SsaForm ssa, bool optimize = true)
+		{
+			TransformToSsa transform = new TransformToSsa(cfg, ssa);
+			transform.ConvertVariablesToSsa();
+			SsaOptimization.RemoveDeadAssignments(ssa); // required so that 'MakeByRefCallsSimple' can detect more cases
+			if (SimplifyByRefCalls.MakeByRefCallsSimple(ssa)) {
+				transform.ConvertVariablesToSsa();
+			}
+			if (optimize)
+				SsaOptimization.Optimize(ssa);
+		}
+		
+		readonly ControlFlowGraph cfg;
+		readonly SsaForm ssaForm;
+		readonly List<SsaInstruction>[] writeToOriginalVariables; // array index -> SsaVariable OriginalVariableIndex
+		readonly bool[] addressTaken; // array index -> SsaVariable OriginalVariableIndex; value = whether ldloca instruction was used with variable
+		
+		private TransformToSsa(ControlFlowGraph cfg, SsaForm ssaForm)
+		{
+			this.cfg = cfg;
+			this.ssaForm = ssaForm;
+			this.writeToOriginalVariables = new List<SsaInstruction>[ssaForm.OriginalVariables.Count];
+			this.addressTaken = new bool[ssaForm.OriginalVariables.Count];
+		}
+		
+		#region CollectInformationAboutOriginalVariableUse
+		void CollectInformationAboutOriginalVariableUse()
+		{
+			Debug.Assert(addressTaken.Length == writeToOriginalVariables.Length);
+			for (int i = 0; i < writeToOriginalVariables.Length; i++) {
+				Debug.Assert(ssaForm.OriginalVariables[i].OriginalVariableIndex == i);
+				
+				addressTaken[i] = false;
+				// writeToOriginalVariables is only used when placing phi functions
+				// we don't need to do that anymore for variables that are already in SSA form
+				if (ssaForm.OriginalVariables[i].IsSingleAssignment)
+					writeToOriginalVariables[i] = null;
+				else
+					writeToOriginalVariables[i] = new List<SsaInstruction>();
+			}
+			foreach (SsaBlock block in ssaForm.Blocks) {
+				foreach (SsaInstruction inst in block.Instructions) {
+					if (inst.Target != null ) {
+						var list = writeToOriginalVariables[inst.Target.OriginalVariableIndex];
+						if (list != null)
+							list.Add(inst);
+					}
+					if (inst.Instruction != null) {
+						if (inst.Instruction.OpCode == OpCodes.Ldloca) {
+							addressTaken[ssaForm.GetOriginalVariable((VariableDefinition)inst.Instruction.Operand).OriginalVariableIndex] = true;
+						} else if (inst.Instruction.OpCode == OpCodes.Ldarga) {
+							addressTaken[ssaForm.GetOriginalVariable((ParameterDefinition)inst.Instruction.Operand).OriginalVariableIndex] = true;
+						}
+					}
+				}
+			}
+		}
+		#endregion
+		
+		#region ConvertToSsa
+		void ConvertVariablesToSsa()
+		{
+			CollectInformationAboutOriginalVariableUse();
+			bool[] processVariable = new bool[ssaForm.OriginalVariables.Count];
+			foreach (SsaVariable variable in ssaForm.OriginalVariables) {
+				if (!variable.IsSingleAssignment && !addressTaken[variable.OriginalVariableIndex]) {
+					PlacePhiFunctions(variable);
+					processVariable[variable.OriginalVariableIndex] = true;
+				}
+			}
+			RenameVariables(processVariable);
+			foreach (SsaVariable variable in ssaForm.OriginalVariables) {
+				if (!addressTaken[variable.OriginalVariableIndex]) {
+					Debug.Assert(variable.IsSingleAssignment && variable.Definition != null);
+				}
+			}
+			ssaForm.ComputeVariableUsage();
+		}
+		#endregion
+		
+		#region PlacePhiFunctions
+		void PlacePhiFunctions(SsaVariable variable)
+		{
+			cfg.ResetVisited();
+			HashSet<SsaBlock> blocksWithPhi = new HashSet<SsaBlock>();
+			Queue<ControlFlowNode> worklist = new Queue<ControlFlowNode>();
+			foreach (SsaInstruction writeInstruction in writeToOriginalVariables[variable.OriginalVariableIndex]) {
+				ControlFlowNode cfgNode = cfg.Nodes[writeInstruction.ParentBlock.BlockIndex];
+				if (!cfgNode.Visited) {
+					cfgNode.Visited = true;
+					worklist.Enqueue(cfgNode);
+				}
+			}
+			while (worklist.Count > 0) {
+				ControlFlowNode cfgNode = worklist.Dequeue();
+				foreach (ControlFlowNode dfNode in cfgNode.DominanceFrontier) {
+					// we don't need phi functions in the exit node
+					if (dfNode.NodeType == ControlFlowNodeType.RegularExit || dfNode.NodeType == ControlFlowNodeType.ExceptionalExit)
+						continue;
+					SsaBlock y = ssaForm.Blocks[dfNode.BlockIndex];
+					if (blocksWithPhi.Add(y)) {
+						// add a phi instruction in y
+						SsaVariable[] operands = Enumerable.Repeat(variable, dfNode.Incoming.Count).ToArray();
+						y.Instructions.Insert(0, new SsaInstruction(y, null, variable, operands, specialOpCode: SpecialOpCode.Phi));
+						if (!dfNode.Visited) {
+							dfNode.Visited = true;
+							worklist.Enqueue(dfNode);
+						}
+					}
+				}
+			}
+		}
+		#endregion
+		
+		#region RenameVariable
+		int tempVariableCounter = 1;
+		
+		void RenameVariables(bool[] processVariable)
+		{
+			VariableRenamer r = new VariableRenamer(this, processVariable);
+			r.Visit(ssaForm.EntryPoint);
+		}
+		
+		sealed class VariableRenamer
+		{
+			readonly TransformToSsa transform;
+			readonly ReadOnlyCollection<SsaVariable> inputVariables;
+			internal readonly Stack<SsaVariable>[] versionStacks;
+			int[] versionCounters; // specifies for each input variable the next version number
+			
+			// processVariable = specifies for each input variable whether we should rename it
+			public VariableRenamer(TransformToSsa transform, bool[] processVariable)
+			{
+				this.transform = transform;
+				this.inputVariables = transform.ssaForm.OriginalVariables;
+				Debug.Assert(inputVariables.Count == processVariable.Length);
+				this.versionCounters = new int[inputVariables.Count];
+				this.versionStacks = new Stack<SsaVariable>[inputVariables.Count];
+				for (int i = 0; i < versionStacks.Length; i++) {
+					if (processVariable[i]) {
+						Debug.Assert(inputVariables[i].IsSingleAssignment == false);
+						// only create version stacks for the variables that we need to process and that weren't already processed earlier
+						versionStacks[i] = new Stack<SsaVariable>();
+						versionStacks[i].Push(inputVariables[i]);
+					}
+				}
+			}
+			
+			SsaVariable MakeNewVersion(int variableIndex)
+			{
+				int versionCounter = ++versionCounters[variableIndex];
+				SsaVariable x = inputVariables[variableIndex];
+				if (versionCounter == 1) {
+					return x;
+				} else {
+					if (x.IsStackLocation) {
+						return new SsaVariable(x, "temp" + (transform.tempVariableCounter++));
+					} else {
+						return new SsaVariable(x, x.Name + "_" + versionCounter);
+					}
+				}
+			}
+			
+			internal void Visit(SsaBlock block)
+			{
+				// duplicate top of all stacks
+				foreach (var stack in versionStacks) {
+					if (stack != null)
+						stack.Push(stack.Peek());
+				}
+				
+				foreach (SsaInstruction s in block.Instructions) {
+					// replace all uses of variables being processed with their current version.
+					if (s.SpecialOpCode != SpecialOpCode.Phi) {
+						for (int i = 0; i < s.Operands.Length; i++) {
+							var stack = versionStacks[s.Operands[i].OriginalVariableIndex];
+							if (stack != null)
+								s.Operands[i] = stack.Peek();
+						}
+					}
+					// if we're writing to a variable we should process:
+					if (s.Target != null) {
+						int targetIndex = s.Target.OriginalVariableIndex;
+						if (versionStacks[targetIndex] != null) {
+							s.Target = MakeNewVersion(targetIndex);
+							s.Target.IsSingleAssignment = true;
+							s.Target.Definition = s;
+							
+							// we already pushed our entry for this SsaBlock at the beginning (where we duplicated all stacks),
+							// so now replace the top element
+							versionStacks[targetIndex].Pop();
+							versionStacks[targetIndex].Push(s.Target);
+						}
+					}
+				}
+				
+				foreach (SsaBlock succ in block.Successors) {
+					int j = succ.Predecessors.IndexOf(block);
+					Debug.Assert(j >= 0);
+					foreach (SsaInstruction f in succ.Instructions) {
+						if (f.SpecialOpCode == SpecialOpCode.Phi) {
+							var stack = versionStacks[f.Target.OriginalVariableIndex];
+							if (stack != null) {
+								f.Operands[j] = stack.Peek();
+							}
+						}
+					}
+				}
+				foreach (ControlFlowNode child in transform.cfg.Nodes[block.BlockIndex].DominatorTreeChildren)
+					Visit(transform.ssaForm.Blocks[child.BlockIndex]);
+				// restore stacks:
+				foreach (var stack in versionStacks) {
+					if (stack != null)
+						stack.Pop();
+				}
+			}
+		}
+		#endregion
+	}
+}

ICSharpCode.Decompiler/GraphVizGraph.cs

@@ -0,0 +1,196 @@
+// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
+// 
+// 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;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Text.RegularExpressions;
+
+namespace ICSharpCode.Decompiler
+{
+	/// <summary>
+	/// GraphViz graph.
+	/// </summary>
+	public sealed class GraphVizGraph
+	{
+		List<GraphVizNode> nodes = new List<GraphVizNode>();
+		List<GraphVizEdge> edges = new List<GraphVizEdge>();
+		
+		public string rankdir;
+		
+		public void AddEdge(GraphVizEdge edge)
+		{
+			edges.Add(edge);
+		}
+		
+		public void AddNode(GraphVizNode node)
+		{
+			nodes.Add(node);
+		}
+		
+		public void Save(string fileName)
+		{
+			using (StreamWriter writer = new StreamWriter(fileName))
+				Save(writer);
+		}
+		
+		static string Escape(string text)
+		{
+			if (Regex.IsMatch(text, @"^[\w\d]+$")) {
+				return text;
+			} else {
+				return "\"" + text.Replace("\\", "\\\\").Replace("\r", "").Replace("\n", "\\n").Replace("\"", "\\\"") + "\"";
+			}
+		}
+		
+		static void WriteGraphAttribute(TextWriter writer, string name, string value)
+		{
+			if (value != null)
+				writer.WriteLine("{0}={1};", name, Escape(value));
+		}
+		
+		internal static void WriteAttribute(TextWriter writer, string name, double? value, ref bool isFirst)
+		{
+			if (value != null) {
+				WriteAttribute(writer, name, value.Value.ToString(CultureInfo.InvariantCulture), ref isFirst);
+			}
+		}
+		
+		internal static void WriteAttribute(TextWriter writer, string name, bool? value, ref bool isFirst)
+		{
+			if (value != null) {
+				WriteAttribute(writer, name, value.Value ? "true" : "false", ref isFirst);
+			}
+		}
+		
+		internal static void WriteAttribute(TextWriter writer, string name, string value, ref bool isFirst)
+		{
+			if (value != null) {
+				if (isFirst)
+					isFirst = false;
+				else
+					writer.Write(',');
+				writer.Write("{0}={1}", name, Escape(value));
+			}
+		}
+		
+		public void Save(TextWriter writer)
+		{
+			writer.WriteLine("digraph G {");
+			WriteGraphAttribute(writer, "rankdir", rankdir);
+			foreach (GraphVizNode node in nodes) {
+				node.Save(writer);
+			}
+			foreach (GraphVizEdge edge in edges) {
+				edge.Save(writer);
+			}
+			writer.WriteLine("}");
+		}
+	}
+	
+	public sealed class GraphVizEdge
+	{
+		public readonly string Source, Target;
+		
+		/// <summary>edge stroke color</summary>
+		public string color;
+		/// <summary>use edge to affect node ranking</summary>
+		public bool? constraint;
+		
+		public string label;
+		
+		public string style;
+		
+		/// <summary>point size of label</summary>
+		public int? fontsize;
+		
+		public GraphVizEdge(string source, string target)
+		{
+			if (source == null)
+				throw new ArgumentNullException("source");
+			if (target == null)
+				throw new ArgumentNullException("target");
+			this.Source = source;
+			this.Target = target;
+		}
+		
+		public GraphVizEdge(int source, int target)
+		{
+			this.Source = source.ToString(CultureInfo.InvariantCulture);
+			this.Target = target.ToString(CultureInfo.InvariantCulture);
+		}
+		
+		public void Save(TextWriter writer)
+		{
+			writer.Write("{0} -> {1} [", Source, Target);
+			bool isFirst = true;
+			GraphVizGraph.WriteAttribute(writer, "label", label, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "style", style, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "fontsize", fontsize, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "color", color, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "constraint", constraint, ref isFirst);
+			writer.WriteLine("];");
+		}
+	}
+	
+	public sealed class GraphVizNode
+	{
+		public readonly string ID;
+		public string label;
+		
+		public string labelloc;
+		
+		/// <summary>point size of label</summary>
+		public int? fontsize;
+		
+		/// <summary>minimum height in inches</summary>
+		public double? height;
+		
+		/// <summary>space around label</summary>
+		public string margin;
+		
+		/// <summary>node shape</summary>
+		public string shape;
+		
+		public GraphVizNode(string id)
+		{
+			if (id == null)
+				throw new ArgumentNullException("id");
+			this.ID = id;
+		}
+		
+		public GraphVizNode(int id)
+		{
+			this.ID = id.ToString(CultureInfo.InvariantCulture);
+		}
+		
+		public void Save(TextWriter writer)
+		{
+			writer.Write(ID);
+			writer.Write(" [");
+			bool isFirst = true;
+			GraphVizGraph.WriteAttribute(writer, "label", label, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "labelloc", labelloc, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "fontsize", fontsize, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "margin", margin, ref isFirst);
+			GraphVizGraph.WriteAttribute(writer, "shape", shape, ref isFirst);
+			writer.WriteLine("];");
+		}
+	}
+}

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+  <PropertyGroup>
+    <ProjectGuid>{984CC812-9470-4A13-AFF9-CC44068D666C}</ProjectGuid>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">x86</Platform>
+    <OutputType>Library</OutputType>
+    <RootNamespace>ICSharpCode.Decompiler</RootNamespace>
+    <AssemblyName>ICSharpCode.Decompiler</AssemblyName>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkProfile>Client</TargetFrameworkProfile>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Platform)' == 'x86' ">
+    <PlatformTarget>x86</PlatformTarget>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+    <OutputPath>bin\Debug\</OutputPath>
+    <DebugSymbols>True</DebugSymbols>
+    <DebugType>Full</DebugType>
+    <Optimize>False</Optimize>
+    <CheckForOverflowUnderflow>True</CheckForOverflowUnderflow>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+    <OutputPath>bin\Release\</OutputPath>
+    <DebugSymbols>False</DebugSymbols>
+    <DebugType>None</DebugType>
+    <Optimize>True</Optimize>
+    <CheckForOverflowUnderflow>False</CheckForOverflowUnderflow>
+    <DefineConstants>TRACE</DefineConstants>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core">
+      <RequiredTargetFramework>3.5</RequiredTargetFramework>
+    </Reference>
+    <Reference Include="System.Xml" />
+    <Reference Include="System.Xml.Linq">
+      <RequiredTargetFramework>3.5</RequiredTargetFramework>
+    </Reference>
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="CecilExtensions.cs" />
+    <Compile Include="FlowAnalysis\ControlFlowEdge.cs" />
+    <Compile Include="FlowAnalysis\ControlFlowGraph.cs" />
+    <Compile Include="FlowAnalysis\ControlFlowGraphBuilder.cs" />
+    <Compile Include="FlowAnalysis\ControlFlowNode.cs" />
+    <Compile Include="FlowAnalysis\OpCodeInfo.cs" />
+    <Compile Include="FlowAnalysis\SimplifyByRefCalls.cs" />
+    <Compile Include="FlowAnalysis\SsaBlock.cs" />
+    <Compile Include="FlowAnalysis\SsaForm.cs" />
+    <Compile Include="FlowAnalysis\SsaFormBuilder.cs" />
+    <Compile Include="FlowAnalysis\SsaInstruction.cs" />
+    <Compile Include="FlowAnalysis\SsaOptimization.cs" />
+    <Compile Include="FlowAnalysis\SsaVariable.cs" />
+    <Compile Include="FlowAnalysis\TransformToSsa.cs" />
+    <Compile Include="GraphVizGraph.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Mono.Cecil\Mono.Cecil.csproj">
+      <Project>{D68133BD-1E63-496E-9EDE-4FBDBF77B486}</Project>
+      <Name>Mono.Cecil</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <Folder Include="FlowAnalysis" />
+  </ItemGroup>
+  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.Targets" />
+</Project>

ICSharpCode.Decompiler/Properties/AssemblyInfo.cs

@@ -0,0 +1,31 @@
+#region Using directives
+
+using System;
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+#endregion
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ICSharpCode.Decompiler")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ICSharpCode.Decompiler")]
+[assembly: AssemblyCopyright("Copyright 2011")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// This sets the default COM visibility of types in the assembly to invisible.
+// If you need to expose a type to COM, use [ComVisible(true)] on that type.
+[assembly: ComVisible(false)]
+
+// The assembly version has following format :
+//
+// Major.Minor.Build.Revision
+//
+// You can specify all the values or you can use the default the Revision and 
+// Build Numbers by using the '*' as shown below:
+[assembly: AssemblyVersion("1.0.*")]

ILSpy.sln

@@ -10,6 +10,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Mono.Cecil", "Mono.Cecil\Mo
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ICSharpCode.AvalonEdit", "AvalonEdit\ICSharpCode.AvalonEdit\ICSharpCode.AvalonEdit.csproj", "{6C55B776-26D4-4DB3-A6AB-87E783B2F3D1}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ICSharpCode.Decompiler", "ICSharpCode.Decompiler\ICSharpCode.Decompiler.csproj", "{984CC812-9470-4A13-AFF9-CC44068D666C}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|x86 = Debug|x86
@@ -46,5 +48,13 @@ Global
 		{6C55B776-26D4-4DB3-A6AB-87E783B2F3D1}.Release|x86.ActiveCfg = Release|Any CPU
 		{6C55B776-26D4-4DB3-A6AB-87E783B2F3D1}.Release|Any CPU.Build.0 = Release|Any CPU
 		{6C55B776-26D4-4DB3-A6AB-87E783B2F3D1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Debug|x86.Build.0 = Debug|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Debug|x86.ActiveCfg = Debug|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Debug|Any CPU.Build.0 = Debug|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Debug|Any CPU.ActiveCfg = Debug|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Release|x86.Build.0 = Release|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Release|x86.ActiveCfg = Release|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Release|Any CPU.Build.0 = Release|x86
+		{984CC812-9470-4A13-AFF9-CC44068D666C}.Release|Any CPU.ActiveCfg = Release|x86
 	EndGlobalSection
 EndGlobal

ILSpy/Disassembler/DisassemblerHelpers.cs

@@ -1,20 +1,31 @@
-// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
-// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
+// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
+// 
+// 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;
+using ICSharpCode.Decompiler;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
 namespace ICSharpCode.ILSpy.Disassembler
 {
-	static class CecilExtensions
+	static class DisassemblerHelpers
 	{
 		#region Debug output(ToString helpers)
-		public static string OffsetToString(int offset)
-		{
-			return string.Format("IL_{0:x4}", offset);
-		}
-		
 		public static void WriteTo(this ExceptionHandler exceptionHandler, ITextOutput writer)
 		{
 			writer.Write("Try IL_{0:x4}-IL_{1:x4} ", exceptionHandler.TryStart.Offset, exceptionHandler.TryEnd.Offset);
@@ -27,7 +38,7 @@ namespace ICSharpCode.ILSpy.Disassembler
 		
 		public static void WriteTo(this Instruction instruction, ITextOutput writer)
 		{
-			writer.Write(OffsetToString(instruction.Offset));
+			writer.Write(CecilExtensions.OffsetToString(instruction.Offset));
 			writer.Write(": ");
 			writer.Write(instruction.OpCode.Name);
 			if(null != instruction.Operand) {
@@ -36,50 +47,12 @@ namespace ICSharpCode.ILSpy.Disassembler
 			}
 		}
 		
-		public static void WriteOperand(ITextOutput writer, object operand)
-		{
-			if(null == operand) throw new ArgumentNullException("operand");
-			
-			Instruction targetInstruction = operand as Instruction;
-			if(null != targetInstruction) {
-				writer.Write(OffsetToString(targetInstruction.Offset));
-				return;
-			}
-			
-			Instruction [] targetInstructions = operand as Instruction [];
-			if(null != targetInstructions) {
-				WriteLabelList(writer, targetInstructions);
-				return;
-			}
-			
-			VariableReference variableRef = operand as VariableReference;
-			if(null != variableRef) {
-				writer.Write(variableRef.Index.ToString());
-				return;
-			}
-			
-			MethodReference methodRef = operand as MethodReference;
-			if(null != methodRef) {
-				WriteMethodReference(writer, methodRef);
-				return;
-			}
-			
-			string s = operand as string;
-			if(null != s) {
-				writer.Write("\"" + s + "\"");
-				return;
-			}
-			
-			s = ToInvariantCultureString(operand);
-			writer.Write(s);
-		}
-		
 		static void WriteLabelList(ITextOutput writer, Instruction[] instructions)
 		{
 			writer.Write("(");
 			for(int i = 0; i < instructions.Length; i++) {
 				if(i != 0) writer.Write(", ");
-				writer.Write(OffsetToString(instructions [i].Offset));
+				writer.Write(CecilExtensions.OffsetToString(instructions [i].Offset));
 			}
 			writer.Write(")");
 		}
@@ -122,100 +95,43 @@ namespace ICSharpCode.ILSpy.Disassembler
 			}
 			return typeName;
 		}
-		#endregion
 		
-		#region GetPushDelta / GetPopDelta
-		public static int GetPushDelta(this Instruction instruction)
+		public static void WriteOperand(ITextOutput writer, object operand)
 		{
-			OpCode code = instruction.OpCode;
-			switch (code.StackBehaviourPush) {
-				case StackBehaviour.Push0:
-					return 0;
-
-				case StackBehaviour.Push1:
-				case StackBehaviour.Pushi:
-				case StackBehaviour.Pushi8:
-				case StackBehaviour.Pushr4:
-				case StackBehaviour.Pushr8:
-				case StackBehaviour.Pushref:
-					return 1;
-
-				case StackBehaviour.Push1_push1:
-					return 2;
-
-				case StackBehaviour.Varpush:
-					if (code.FlowControl != FlowControl.Call)
-						break;
-
-					IMethodSignature method = (IMethodSignature) instruction.Operand;
-					return IsVoid (method.ReturnType) ? 0 : 1;
+			if(null == operand) throw new ArgumentNullException("operand");
+			
+			Instruction targetInstruction = operand as Instruction;
+			if(null != targetInstruction) {
+				writer.Write(CecilExtensions.OffsetToString(targetInstruction.Offset));
+				return;
 			}
-
-			throw new NotSupportedException ();
-		}
-		
-		public static int GetPopDelta(this Instruction instruction, MethodDefinition current, int currentStackSize)
-		{
-			OpCode code = instruction.OpCode;
-			switch (code.StackBehaviourPop) {
-				case StackBehaviour.Pop0:
-					return 0;
-				case StackBehaviour.Popi:
-				case StackBehaviour.Popref:
-				case StackBehaviour.Pop1:
-					return 1;
-
-				case StackBehaviour.Pop1_pop1:
-				case StackBehaviour.Popi_pop1:
-				case StackBehaviour.Popi_popi:
-				case StackBehaviour.Popi_popi8:
-				case StackBehaviour.Popi_popr4:
-				case StackBehaviour.Popi_popr8:
-				case StackBehaviour.Popref_pop1:
-				case StackBehaviour.Popref_popi:
-					return 2;
-
-				case StackBehaviour.Popi_popi_popi:
-				case StackBehaviour.Popref_popi_popi:
-				case StackBehaviour.Popref_popi_popi8:
-				case StackBehaviour.Popref_popi_popr4:
-				case StackBehaviour.Popref_popi_popr8:
-				case StackBehaviour.Popref_popi_popref:
-					return 3;
-
-				case StackBehaviour.PopAll:
-					return currentStackSize;
-
-				case StackBehaviour.Varpop:
-					if (code == OpCodes.Ret)
-						return IsVoid (current.ReturnType) ? 0 : 1;
-
-					if (code.FlowControl != FlowControl.Call)
-						break;
-
-					IMethodSignature method = (IMethodSignature) instruction.Operand;
-					int count = method.HasParameters ? method.Parameters.Count : 0;
-					if (method.HasThis && code != OpCodes.Newobj)
-						++count;
-
-					return count;
+			
+			Instruction [] targetInstructions = operand as Instruction [];
+			if(null != targetInstructions) {
+				WriteLabelList(writer, targetInstructions);
+				return;
 			}
-
-			throw new NotSupportedException ();
-		}
-		
-		public static bool IsVoid(this TypeReference type)
-		{
-			return type.FullName == "System.Void" && !(type is TypeSpecification);
-		}
-		
-		public static bool IsValueTypeOrVoid(this TypeReference type)
-		{
-			while (type is OptionalModifierType || type is RequiredModifierType)
-				type = ((TypeSpecification)type).ElementType;
-			if (type is ArrayType)
-				return false;
-			return type.IsValueType || type.IsVoid();
+			
+			VariableReference variableRef = operand as VariableReference;
+			if(null != variableRef) {
+				writer.Write(variableRef.Index.ToString());
+				return;
+			}
+			
+			MethodReference methodRef = operand as MethodReference;
+			if(null != methodRef) {
+				WriteMethodReference(writer, methodRef);
+				return;
+			}
+			
+			string s = operand as string;
+			if(null != s) {
+				writer.Write("\"" + s + "\"");
+				return;
+			}
+			
+			s = ToInvariantCultureString(operand);
+			writer.Write(s);
 		}
 		#endregion
 		

ILSpy/ILSpy.csproj

@@ -75,7 +75,7 @@
     <Compile Include="BaseTypesTreeNode.cs" />
     <Compile Include="CueBannerService.cs" />
     <Compile Include="Decompiler\CSharpLanguage.cs" />
-    <Compile Include="Disassembler\CecilExtensions.cs" />
+    <Compile Include="Disassembler\DisassemblerHelpers.cs" />
     <Compile Include="Disassembler\ILLanguage.cs" />
     <Compile Include="EventTreeNode.cs" />
     <Compile Include="ExtensionMethods.cs" />
@@ -149,6 +149,10 @@
     <Folder Include="themes" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\ICSharpCode.Decompiler\ICSharpCode.Decompiler.csproj">
+      <Project>{984CC812-9470-4A13-AFF9-CC44068D666C}</Project>
+      <Name>ICSharpCode.Decompiler</Name>
+    </ProjectReference>
     <ProjectReference Include="..\Mono.Cecil\Mono.Cecil.csproj">
       <Project>{D68133BD-1E63-496E-9EDE-4FBDBF77B486}</Project>
       <Name>Mono.Cecil</Name>

ILSpy/MainWindow.xaml

@@ -44,6 +44,7 @@
 			</MenuItem>
 		</Menu>
 		<ToolBar
+			Name="toolBar"
 			DockPanel.Dock="Top">
 			<ToolBar.Resources>
 				<!-- Make images transparent if menu command is disabled -->

ILSpy/MainWindow.xaml.cs

@@ -24,9 +24,11 @@ using System.Reflection;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Input;
-
+using ICSharpCode.Decompiler;
+using ICSharpCode.Decompiler.FlowAnalysis;
 using ICSharpCode.TreeView;
 using Microsoft.Win32;
+using Mono.Cecil.Rocks;
 
 namespace ICSharpCode.ILSpy
 {
@@ -87,7 +89,47 @@ namespace ICSharpCode.ILSpy
 			for (int i = 1; i < args.Length; i++) {
 				assemblyList.OpenAssembly(args[i]);
 			}
+			
+			#if DEBUG
+			toolBar.Items.Add(new Separator());
+			Button cfg = new Button() { Content = "CFG" };
+			cfg.Click += new RoutedEventHandler(cfg_Click);
+			toolBar.Items.Add(cfg);
+			Button ssa = new Button() { Content = "SSA" };
+			ssa.Click += new RoutedEventHandler(ssa_Click);
+			toolBar.Items.Add(ssa);
+			#endif
+		}
+		
+		#region Debugging CFG
+		#if DEBUG
+		void cfg_Click(object sender, RoutedEventArgs e)
+		{
+			MethodTreeNode node = treeView.SelectedItem as MethodTreeNode;
+			if (node != null && node.MethodDefinition.HasBody) {
+				node.MethodDefinition.Body.SimplifyMacros();
+				ShowGraph(node.MethodDefinition.Name + "-cfg", ControlFlowGraphBuilder.Build(node.MethodDefinition.Body).ExportGraph());
+			}
+		}
+		
+		void ssa_Click(object sender, RoutedEventArgs e)
+		{
+			MethodTreeNode node = treeView.SelectedItem as MethodTreeNode;
+			if (node != null && node.MethodDefinition.HasBody) {
+				node.MethodDefinition.Body.SimplifyMacros();
+				ShowGraph(node.MethodDefinition.Name + "-cfg", SsaFormBuilder.Build(node.MethodDefinition).ExportBlockGraph());
+			}
+		}
+		
+		void ShowGraph(string name, GraphVizGraph graph)
+		{
+			string fileName = Path.Combine(Path.GetTempPath(), name);
+			graph.Save(fileName + ".gv");
+			Process.Start("dot", "\"" + fileName + ".gv\" -Tpng -o \"" + fileName + ".png\"").WaitForExit();
+			Process.Start(fileName + ".png");
 		}
+		#endif
+		#endregion
 		
 		void OpenCommandExecuted(object sender, ExecutedRoutedEventArgs e)
 		{

ILSpy/MethodTreeNode.cs

@@ -30,6 +30,10 @@ namespace ICSharpCode.ILSpy
 	{
 		MethodDefinition method;
 		
+		public MethodDefinition MethodDefinition {
+			get { return method; }
+		}
+		
 		public MethodTreeNode(MethodDefinition method)
 		{
 			if (method == null)